Bacteria

J Anim Sci, 1992 Oct, 70(10), 3055 - 65
Effect of long- or short-term feeding of alpha-tocopheryl acetate to Holstein and crossbred beef steers on performance, carcass characteristics, and beef color stability; Arnold RN et al.; Three experiments were conducted to examine the effects of vitamin E supplementation on feedlot cattle . Vitamin E supplementation did not affect feedlot performance or carcass characteristics of cattle fed a high-concentrate diet (P greater than .1) . The major finding was the effectiveness of vitamin E in extending the color stability of displayed beef (P less than .01) . Color stability during display of longissimus lumborum steaks from cattle supplemented with 300 IU/d for 266 d, 1,140 IU/d for 67 d, or 1,200 IU/d for 38 d was extended by 2.5 to 4.8 d . Gluteus medius steaks had an extended color display life of 1.6 to 3.8 d . The accumulation of lipid oxidation products, but not aerobic microbes, associated with displayed longissimus lumborum was suppressed for muscle from vitamin E-supplemented steers . Taste panelists detected no difference among longissimus lumborum steaks from control and vitamin E-supplemented steers but found (P less than .01) steaks aged for 21 d to be more tender than steaks aged for 7 d . Supplementing cattle with vitamin E should reduce economic losses associated with discolored beef during retail display.

CLAO J, 1992 Oct, 18(4), 240 - 4
Microbial contamination of hydrophilic contact lenses . Part II: Quantitation of microbes after patient handling and after aseptic removal from the eye; Mowrey-McKee MF et al.; We cultured Soflens (polymacon) contact lenses to determine the number of microorganisms present after patient handling and the number present after patient handling and 5 hours of lens wear . Twenty adapted contact lens patients were each dispensed two pairs of new sterile Soflens contact lenses . Both pairs of lenses were handled by the patients during a single experimental session . Prior to handling lenses, patients were instructed to wash their hands with soap and water, rinse with tap water, and dry with a paper towel . One pair (handled-only) was cultured immediately after handling . The second pair (handled-and-worn) was placed on the eyes by the patient, removed aseptically following 5 hours of wear, and then cultured . All 40 handled-only lenses had viable microorganisms associated with them (mean: 653 colony forming units (CFU) per lens) . Bacteria were isolated on all of these lenses and fungi were detected on six . The mean bacterial count for the handled-and-worn lenses was 30 CFU/lens; fewer than half exhibited handled-and-worn lenses was 30 CFU/lens; fewer than half exhibited bacteria and no fungi were isolated . These data suggest that patient handling is a highly significant source of microbial contamination of hydrophilic contact lenses . Also, the number of microorganisms on lenses is significantly reduced (P < 0.0001) after the lens has been worn on the eye.

J Periodontol, 1992 Oct, 63(10), 821 - 4
Efficacy of preprocedural rinsing with an antiseptic in reducing viable bacteria in dental aerosols; Fine DH et al.; This double-blind, controlled, cross-over, clinical study evaluated the effect of preprocedural rinsing with an antiseptic mouthrinse on the level of recoverable viable bacteria in an aerosol generated during a typical dental procedure . Eighteen subjects participated . Following 24 hours of abstention from all oral hygiene procedures, subjects received a 10-minute ultrasonic scaling of a randomly selected one-half of their mouth which served as the unrinsed control . They were then randomly assigned either antiseptic mouthwash or a control rinse and rinsed with 20 ml for 30 seconds, after which the remaining half mouth (experimental side) was scaled ultrasonically for 10 minutes . During each 10-minute scaling period aerosolized bacteria were collected on a sterile filter using a modified vacuum air-sampling device . Microbes captured on the sterile filter were quantitated by overlaying the filters onto trypticase soy agar, incubating the filters aerobically at 37 degrees C for 24 to 72 hours, and counting the resulting colony forming units (CFU) . Preliminary experiments had confirmed that neither the collection method nor residual antiseptic mouthwash in the aerosol adversely affected the number of viable bacteria recovered from the filter . Rinsing with the antiseptic mouthwash produced a 94.1% reduction in recoverable CFUs compared to the non-rinsed control, while the control rinse produced a 33.9% reduction . The difference between the mouthwash and control was statistically significant (P < .001) . This study indicates that preprocedural rinsing with an antiseptic mouthwash can significantly reduce the microbial content of aerosols generated during ultrasonic scaling and may have potential in-office use as part of an infection control regimen.

Eur J Immunol, 1992 Oct, 22(10), 2555 - 63
Genetics of nonspecific immunity: I . Bidirectional selective breeding of lines of mice endowed with maximal or minimal inflammatory responsiveness; Ibanez OM et al.; The genetic regulation of acute inflammatory reaction (AIR) was studied by the method of bidirectional selective breeding, used to produce a line of mice giving the maximal and a line of mice giving the minimal inflammatory reaction (AIR max and AIR min, respectively) . The AIR was triggered by subcutaneous injection of a neutral substrate (suspension of polyacrylamide microbeads), and measured by the leukocyte and serum protein accumulation in the exudate . The two parameters are positively correlated and present a normal frequency distribution . The highly genetically heterogeneous foundation population was produced by the equipoised intercrossing of eight inbred strains of mice, and selective breeding carried out by assortative matings of extreme phenotypes . The response to selection in 11 consecutive generations was highly asymmetrical: a marked AIR increase in the AIR max and no change in the AIR min line occurred . The mean value of realized heritability in the AIR max line was 0.26 and 0.18 for cell and protein concentrations, respectively . The response to selection must have resulted from the interaction of seven to nine independent gene loci endowed with additive effects . The lack of response to selection of the AIR min line is discussed . The large inter-line difference opens new possibilities for studying the biochemistry and molecular genetics of inflammation, and also for investigating the beneficial or detrimental effect of inflammatory responses.

J Cell Sci, 1992 Sep, 103 ( Pt 1), 39 - 51
Examination of transcellular membrane protein polarity of bovine aortic endothelial cells in vitro using the cationic colloidal silica microbead membrane-isolation procedure; Stolz DB et al.; In this report we describe a rapid, high-yield protocol for the isolation of apical (AP) and basolateral (BL) plasma membrane domains from monolayers of bovine aortic endothelial cells (BAECs) grown on tissue culture dishes as well as microcarrier beads . Using a modified cationic colloidal silica microbead membrane-isolation procedure, which deposits a uniform silica-polyacrylate pellicle over the entire AP membrane surface, a 4- to 9.6-fold relative enrichment of AP membrane and a 3.55- to 3.67-fold relative enrichment of BL membrane was obtained when the isolated domains were examined for silica and Na+/K(+)-ATPase, respectively . Immunoblotting of the isolated membrane domains displayed the presence of angiotensin-converting enzyme (ACE) exclusively in the AP domain and collagen receptors (CRs) highly enriched in the BL membrane domain when monolayers were grown on a gelatin substratum.

J Dent Hyg, 1992 Sep, 66(7), 314 - 8
Aerosol generation by two ultrasonic scalers and one sonic scaler . A comparative study; Gross KB et al.; The purposes of this study were to compare the amount of aerosols generated from ultrasonic and sonic scalers and to measure the potential depth of respiratory tract penetration . Forty subjects were randomly assigned to receive instrumentation with the magnetostrictive, piezoelectric, or air turbine scaler . The Anderson Air Sampler collected total baseline airborne microbes for 20 minutes prior to treatment and for 20 minutes during instrumentation . This cascade impactor system measures the degree of microbial penetration in a simulated respiratory system . Blood agar plates from the sampler were incubated for 24 hours at 37 degrees C . Colony forming units per cubic foot of air (CFUs/cu . ft.) were enumerated by one blind examiner using a Lab Line Colony Counter . Data for total microbial CFUs/cu.ft . and CFUs/cu.ft . by sampler level were analyzed on the log-transformed data using ANCOVA . Baseline values of airborne bacteria served as the covariate . Results showed no significant difference in mean combined total CFUs/cu.ft . for the magnetostrictive, piezoelectric, or air turbine sonic scalers . The magnetostrictive scaler generated the lowest CFUs/cu.ft . at the deepest level of penetration; however, no significant difference in level of penetration was found among the three scalers.

Mol Plant Microbe Interact, 1992 Sep-Oct, 5(5), 397 - 404
Resistance to tobacco mosaic virus induced by the 54-kDa gene sequence requires expression of the 54-kDa protein; Carr JP et al.; Tobacco plants transformed with the sequence encoding the 54-kDa putative replicase protein of tobacco mosaic virus were resistant to systemic virus disease (D . B . Golemboski, G . P . Lomonossoff, and M . Zaitlin, Proc . Natl . Acad . Sci . USA 87:6311-6315, 1990) . Resistance was due to a marked suppression of virus replication at the site of inoculation (J . P . Carr and M . Zaitlin, Mol . Plant-Microbe Interact . 4:579-585, 1991) . Although RNA transcripts encoding the 54-kDa protein were present in resistant plants, the 54-kDa protein itself was not observed in vivo . We wished to assess the relative importance of the 54-kDa protein versus its RNA in mediating resistance . Further attempts to detect the 54-kDa protein in plant tissues were unsuccessful; therefore, an indirect approach was taken using a protoplast-based transient gene expression system . Electroporation of protoplasts with plasmids capable of expressing the wild-type 54-kDa protein gene sequence or a mutant lacking the first AUG initiation codon of the 54-kDa open reading frame and encoding a slightly truncated protein reduced virus replication in protoplasts . In contrast, a frameshift mutant that was capable of directing synthesis of a protein only 20% the size of the 54-kDa protein, did not produce resistance in protoplasts . These results show that expression of the 54-kDa protein gene sequence at the RNA level alone is insufficient for resistance, and they implicate the 54-kDa protein itself in mediating this resistance phenomenon.

Curr Opin Immunol, 1992 Aug, 4(4), 442 - 8
Old microbes with new faces: molecular biology and the design of new vaccines; Connell N et al.; Rational approaches to the design of live attenuated bacterial and viral recombinant vaccine strains are leading to the manipulation of old vaccines and the generation of new ones . The two basic problems to be solved are attenuation of pathogenic strains, and the stable expression of foreign antigens.

FEBS Lett, 1992 Aug 10, 308(1), 94 - 6
A novel role for calcite in calcium homeostasis; Anderson S et al.; Calcium carbonate (CaCO3) minerals are known to be deposited in a wide array of different organisms, ranging from microbes to vertebrates {(1989) On Biomineralization, Oxford University Press, New York} . Calcite, aragonite and vaterite are the major crystalline structural polymorphs of CaCO3 associated with living systems, and participate in a variety of biological functions {(1989) Biomineralization: Chemical and Biochemical Perspectives, VCH Publishers, Weinham, Germany; (1991) Advances in Inorganic Chemistry 36, 137-200} . Here we report on the ability of a soil bacterium to synthesize calcite in a calcium-stressed environment . The elaboration of this exocellular crystalline residue enables the organism to regulate its calcium content . The attainment of calcium homeostasis via the exocellular deposition of bacterial calcite with unique crystal habits is a novel biological phenomenon.

Inflammation, 1992 Aug, 16(4), 383 - 92
Stimulus-dependent actin polymerization in bovine neutrophils; Bochsler PN et al.; Polymorphonuclear leukocytes (PMNs) are responsible for much of the first wave of leukocyte-mediated host defense against microbial pathogens . In order to migrate through the endothelium of vessel walls, undergo chemotaxis, and phagocytize microbes, PMNs must modulate their cytoskeletal elements and undergo change of cellular shape . We have used fluorescence flow cytometric analysis and cellular microscopic observations to demonstrate actin polymerization in bovine PMNs and to examine the kinetics of PMN actin polymerization utilizing different PMN stimuli . In addition, we compared temporal relationships between cellular shape and actin polymerization . Actin polymerization occurred rapidly, and the kinetics of actin polymerization were similar for each of the three PMN agonists used, ZAS (10%), PAF (10(-6) M), and rhC5a (10(-7) M) . Actin polymerization was near-maximal by 10 sec poststimulation (95.4% of maximal F-actin content attained by 10 sec poststimulation with ZAS stimulation), and reached peak values by 30 sec . The maximal increase in F-actin content of agonist-stimulated cells as compared to resting cells was 2.8-fold with ZAS; 2.3-fold with PAF; and 2.3-fold with rhC5a . PMN shape change (pseudopodia, membrane ruffles) was not as rapid, with only 22.4% of cells attaining visible membrane deformation by 10 sec and requiring 120 sec to reach peak shape-change values . After attaining peak values, the two events also differed . Whereas the percent of shape-changed PMNs remained plateaued up to 5 min poststimulation, the F-actin content gradually decreased after 30 sec, approaching F-actin values of unstimulated PMNs.

J Acoust Soc Am, 1992 Aug, 92(2 Pt 1), 688 - 700
Inferring articulation and recognizing gestures from acoustics with a neural network trained on x-ray microbeam data; Papcun G et al.; This paper describes a method for inferring articulatory parameters from acoustics with a neural network trained on paired acoustic and articulatory data . An x-ray microbeam recorded the vertical movements of the lower lip, tongue tip, and tongue dorsum of three speakers saying the English stop consonants in repeated Ce syllables . A neural network was then trained to map from simultaneously recorded acoustic data to the articulatory data . To evaluate learning, acoustics from the training set were passed through the neural network . To evaluate generalization, acoustics from speakers or consonants excluded from the training set were passed through the network . The articulatory trajectories thus inferred were a good fit to the actual movements in both the learning and generalization conditions, as judged by root-mean-square error and correlation . Inferred trajectories were also matched to templates of lower lip, tongue tip, and tongue dorsum release gestures extracted from the original data . This technique correctly recognized from 94.4% to 98.9% of all gestures in the learning and cross-speaker generalization conditions, and 75% of gestures underlying consonants excluded from the training set . In addition, greater regularity was observed for movements of articulators that were critical in the formation of each consonant.

J Am Vet Med Assoc, 1992 Aug 1, 201(3), 478 - 82
Clinical and laboratory findings associated with actual or suspected azoospermia in dogs: 18 cases (1979-1990); Olson PN et al.; Eighteen dogs were evaluated for azoospermia, 8 of which had sired pups . On the basis of history, physical examination, and various laboratory evaluations, the cause and site of azoospermia varied . Two dogs that had never sired pups had likely been azoospermic from puberty (congenital azoospermia) . Two dogs were azoospermic as a result of tumors (Sertoli cell tumor and malignant astrocytoma of the pituitary gland) . Deposits of IgG were observed in testicular biopsy samples, which suggested an auto-immune cause for azoospermia in 5 dogs . One of the 5 dogs with IgG deposits in testicular tissues also had evidence of immune-mediated thyroiditis . Culturing of microbes in the semen was not helpful in determining potential causes of azoospermia, and results did not correlate with organisms isolated from testicular biopsy samples or with the finding of inflammation in biopsy samples . Because 6 dogs had relatives with histories of reproductive dysfunction, inbreeding also must be considered when evaluating dogs for azoospermia.

J Cell Biol, 1992 Aug, 118(4), 865 - 75
Tubulin protofilaments and kinesin-dependent motility; Kamimura S et al.; Microtubules are built of tubulin subunits assembled into hollow cylinders which consist of parallel protofilaments . Thus, motor molecules interacting with a microtubule could do so either with one or several tubulin subunits . This makes it difficult to determine the structural requirements for the interaction . One way to approach the problem is to alter the surface lattice . This can be done in several ways . Proto-filaments can be exposed on their inside (C-tubules or "sheets"), they can be made antiparallel (zinc sheets), or they can be rolled up (duplex tubules) . We have exploited this polymorphism to study how the motor protein kinesin attached to a glass surface interacts and moves the various tubulin assemblies . Microtubules glide over the surface along straight paths and with uniform velocities . In the case of C-tubules, approximately 40% glide similarly to microtubules, but a major fraction do not glide at all . This indicates (a) that a full cylindrical closure is not necessary for movement, and (b) that the inside surface of microtubules does not support gliding . With zinc sheets, up to 70% of the polymers move, but the movement is discontinuous, has a reduced speed, and follows along a curved path . Since zinc sheets have protofilaments alternating in orientation and polarity, this result suggests that in principle a single protofilament can produce movement, even when its neighbors cannot . Duplex microtubules do not move because they are covered with protofilaments coiled inside out, thus preventing the interaction with kinesin . The data can be explained by assuming that the outside of one protofilament represents the minimal track for kinesin, but smooth gliding requires several parallel protofilaments . Finally, we followed the motion of kinesin-coated microbeads on sea-urchin sperm flagella, from the flagellar outer doublet microtubules to the singlet microtubule tips extending from the A-tubules . No change in behavior was detected during the transition . This indicates that even if these microtubules differ in surface lattice, this does not affect the motility.

Voen Med Zh, 1992 Aug, (8), 20 - 3
{A comparative study of charcoal sorbents for local wound treatment}; Adamian AA et al.; The laboratory and medico-biological findings made it possible to choose the most suitable carbonaceous sorbents for local management of wounds, basing on the fact that every carbonaceous material has strictly selected capacity for protein and microbe sorption, and also can be the carrier of the water-miscible drugs . The "Dnieper-MN" carbonaceous fabric and "Aktilen" fibrous sorbent have the best features for sorption . It is possible to use these materials for the construction of bandages to treat wounds and burns which have little exudation . "Karpema" and "AUTM-2" sorbents, which are characterized by the low degree of activation, can be used for the manufacturing of surgical pads . "Karpema" being strong and having a less fiber structure, has a good electrical conductivity and, thus, can be used as medical electrodes.

Gesundheitswesen, 1992 Aug, 54(8), 420 - 2
{Sanitation measures in evidence of Legionella}; Bosenberg H et al.; Appearance of Legionella disease generally is underrated . Conclusions as to disease frequency from Legionella antibody investigations are not reliable . The number of microbes necessary to produce illness depends from individual preliminary conditions . In special areas of the hospital the rate of diseases caused by Legionella can be reduced by protection . In bathing areas generally the hitherto existing regulations of the Federal Health Authority are sufficient: Continual warm water temperature increases from 60 degrees C, chlorination if necessary, regular stepwise controls . Insufficient results are produced by intermittent temperature increases . Filters that are impermeable for microbes appear uneconomical for bathing areas.

Biotechniques, 1992 Aug, 13(2), 276 - 81
Analysis of mixed human/microbial DNA samples: a validation study of two PCR AMP-FLP typing methods; Lienert K et al.; The reliability of the PCR technique used to type two human variable number tandem repeats, that is, 3' to apolipoprotein B gene and locus D17S30, was examined using DNA samples of mixed human and microbial origin . Mixtures of human and microbial DNA were amplified, choosing microbes found commonly in the vagina . Total inhibition of human amplification and/or "drop-out" of the larger amplification fragment length polymorphism allele was observed at both loci in the presence of DNA from some vaginal micro-flora.

Biochim Biophys Acta, 1992 Jul 31, 1122(2), 143 - 6
Lipases from different sources vary widely in dependence of catalytic activity on water activity; Valivety RH et al.; We have measured the rates of esterification in hexane catalysed by suspended immobilised lipases (triacylglycerol acylhydrolase, EC 3.1.1.3), with pre-equilibration to known thermodynamic water activity (a(w)) . There were important differences between the enzymes from five different microbes in their retention of activity at low a(w) . That from Rhizomucor miehei showed over 40% maximal activity at an a(w) of 0.12, and that from Rhizopus niveus was also fairly active at low a(w) . Lipases from other sources required higher a(w) values to show good activity, increasing in the sequence Humicola sp., Candida rugosa and Pseudomonas cepacia . The behaviour was generally similar to two very different support materials, anion-exchange resin and macroporous polypropylene . Comparison of the sequences of the homologous enzymes from Rh . miehei, Rh . niveus and Humicola sp . suggests that changes in charged residues in the 'hinge and lid' region of the structure may be significant in low a(w) tolerance.

Experientia, 1992 Jul 15, 48(7), 640 - 3
The cellular immune response to heat shock proteins; Kaufmann SH; T lymphocytes, which are central to almost every immune response, frequently recognize microbial hsp60 . Such cells could provide an early defense mechanism against pathogenic microbes . However, T cells also recognize epitopes of hsp60 shared by microbe and host . Not only conventional alpha/beta T cells respond to hsp60; gamma/delta T cells do so, as well . In fact, certain gamma/delta T cells seem to have a particular preference for this molecule . Recognition of stressed host cells expressing hsp60 could facilitate the scavenger function of the T cell system . On the other hand, such recognition could be involved in autoimmune disease.

Lab Anim, 1992 Jul, 26(3), 206 - 10
The effects of intracage ventilation on microenvironmental conditions in filter-top cages; Lipman NS et al.; Filter-top cages, while effective in reducing cross contamination by particulate material including microbes, can also cause accumulation of the waste gases carbon dioxide and ammonia as well as increased intracage relative humidity . A prototype system which provided each cage with 23 air changes per hour through a nozzle inserted in the filter lid was evaluated . The ventilated cageing system was effective in reducing intracage carbon dioxide, ammonia and relative humidity levels . Mean weekly carbon dioxide levels were 2900 ppm lower, ammonia levels 240 ppm lower and intracage relative humidity levels 8% lower in the ventilated cages than in unventilated controls.

J Biomed Mater Res, 1992 Jul, 26(7), 967 - 77
Agarose for a bioartificial pancreas; Iwata H et al.; Islets were encapsulated into 5% concentration agarose microbeads . The effect of microencapsulation on islet allograft survivals was determined using a streptozotocin-induced diabetic (STZ) mouse and a nonobese diabetic (NOD) mouse as recipients . All five STZ BALB/c mice receiving microencapsulated islets (C57BL/6) maintained normoglycemia indefinitely . When NOD mice were used as recipients of the bioartificial pancreas, four of five grafts (islets from C3H/He) functioned for more than 80 d . Two of five NOD mice maintained normoglycemia until animals were sacrificed at 102 and 192 postoperative d . Microbeads made of commercially available agarose can effectively prolong alloislets functioning in the STZ-diabetic mouse and even in the NOD mouse (animal model of human type I diabetes) without the use of any immunosuppressive drug.

ASAIO J, 1992 Jul-Sep, 38(3), M386 - 9
Inflammatory reaction induced by agarose implants reduced by adding adrenal cells to the polymer; Cadic-Amadeuf CM et al.; Microencapsulation of adrenal cells is proposed for reducing the non-specific inflammatory reaction observed around polymer implants . This hypothesis was tested by comparing both host cellular reaction and the surrounding graft cell populations that appeared when either agarose embedded cells or empty agarose beads were implanted . The authors' results showed that the fibrotic material that surrounded the implanted empty agarose microbeads was not as severe when adrenal cells were present . Similarly, the T lymphocyte population surrounding the graft was considerably reduced, along with the percentage of CD4 and CD8 positive cell subpopulations . The activation macrophage marker IaD disappeared . The authors' results support the hypothesis that embedded adrenal cells may be a suitable solution for reducing early inflammatory events due to microcapsule implantation.

Environ Health Perspect, 1992 Jul, 97, 171 - 5
Activity testing of alveolar macrophages and changes in surfactant phospholipids after irradiation in bronchoalveolar lavage: experimental and clinical data; Steinberg F et al.; This study presents results of bronchoalveolar lavage (BAL) after irradiation to the lungs in mice as well as clinical data . The number of BAL cells, mainly macrophages, lymphocytes, and granulocytes, changed in a time-dependent manner . The phagocytic activity of the macrophages measured as the phagocytosis of microbeads and measured as the esterase activity also showed a strong time-dependent increase during the acute phase up to 21 days after irradiation . The contents of surfactant phospholipids (SF) and sphingomyelin (SPH; as a parameter for cell death) were quantified by HPLC . Both were significantly changed between day 2 and 21 after irradiation . Three BALs of a patient with idiopathic interstitial pneumonitis, who had received an allogenic bone marrow graft after total body irradiation with 10 Gy, showed similar effects in the cellular and surfactant parameters . These data indicate that there are positive interactions between the number of different BAL cells, macrophage activity, and SF and SPH content in the preclinical model of the mouse as well as in the clinical situation after lung irradiation.

Mikrobiol Zh, 1992 Jul-Aug, 54(4), 3 - 7
{The interaction of the causative agent of melioidosis with the host's alveolar macrophages}; Popov SF et al.; Studies were carried out on guinea pigs and albino rats, intranasally infected with P . pseudomallei C-141 . The cells of bronchovesicular exudate were obtained from animals 1, 4 and 24 hours after infection . Electron microscopy was applied to study the process of interaction of the agent and alveolar macrophages . Bacteria were shown to form a capsule which permitted avoiding phagocytosis, when entering the host respiratory system . Microbes that failed to form a capsule were absorbed by macrophages and enclosed in a phagosome . Then some bacteria were destroyed by the lysosomal enzymes, the other synthesized a capsule, which protected them against the effect of phagolysosome content . There were also such microbes which escaped from a phagosome prior to fusion with lysosomes and parasitized in phagocytic cytoplasma forming a capsule there . By the end of the first 24 hours of observation the intact encapsulated microbe species were found to prevail in the host cells.

Ann Acad Med Singapore, 1992 Jul, 21(4), 571 - 5
Human ampullary co-cultures for blastocyst transfer in assisted reproduction; Bongso TA et al.; Although the assisted reproductive techniques (ART) have contributed significantly over the last decade in alleviating subfertility in the childless couple, the implantation and take-home baby rates have been stubbornly low . A major cause for such low success rates has been the reduced viability of replaced embryos perhaps induced by the suboptimal in vitro conditions used in ART laboratories . One approach to improving embryo viability is to provide the growing embryo with a simulated in vivo environment by replicating the conditions existing in the human fallopian tube in vitro . This requires either the maintenance of an intact fallopian tube in vitro or establishment and maintenance of tubal epithelial cell-lines which could be used as feeder layers for early embryonic growth . The concomitant growth of cells with embryos in vitro has been referred to as co-culture . This paper discusses the in vitro behaviour of human tubal epithelial cells, the fertilisation and growth of embryos in ampullary co-culture, the specificity of co-cultures, the mechanism of action of co-cultures and the methods of screening the human ampullary co-culture system for microbes . The pregnancy and implantation results on 50 patients enrolled for a co-culture clinical trial are presented and the future use of this system discussed.

Biochem J, 1992 Jun 15, 284 ( Pt 3), 781 - 8
Cytochrome b-245 is a flavocytochrome containing FAD and the NADPH-binding site of the microbicidal oxidase of phagocytes; Segal AW et al.; The NADPH oxidase of phagocytic cells is important for the efficient killing and digestion of ingested microbes . A very unusual low-potential cytochrome b (b-245) is the only redox molecule to have been identified in this system . The FAD-containing flavoprotein that binds NADPH and transfers electrons to the cytochrome has eluded identification for three decades . We show here that the haem/FAD ratio in the membranes does not change significantly on activation of this oxidase, indicating that the FAD is present in the membranes from the outset and not recruited from the cytosol . The FAD content of membranes from cells of patients with X-linked chronic granulomatous disease (CGD) lacking the cytochrome b was roughly one-quarter of that in normal subjects and in autosomal recessive CGD patients lacking the cytosolic protein p47-phox . Similar low amounts of FAD were present in uninduced promyelocytic (HL60) cells, suggesting that the low amount of FAD in cells from X-CGD patients was probably unrelated to this oxidase system . Cytochrome b-245 appears to bind both the haem and FAD, in a molar ratio of 2:1 . The e.p.r . signal of the purified cytochrome was weak and had an asymmetric g(z) peak at g = 3.31 . The purified cytochrome could be partially reflavinated (about 20%) in the presence of lipid . Amino acid sequence homology was detected between the beta-subunit of this cytochrome b and the ferredoxin-NADP+ reductase (FNR) family of reductases in the putative NADPH- and FAD-binding sites . 32P-labelled 2-azido-NADP was used as a photoaffinity label for the NADPH-binding site . Labelling that was competed off with NADP was observed in the region of the beta-subunit of the cytochrome . No labelling was seen in this region in X-CGD in three subjects in whom this cytochrome was missing and in a third in whom it was present but bore a Pro-His transposition in the putative NADPH-binding site . These studies indicate that cytochrome b-245 is a flavocytochrome, the first described in higher eukaryotic cells, bearing the complete electron-transporting apparatus of the NADPH oxidase.

Nature, 1992 Jun 11, 357(6378), 515 - 8
Novel form of growth cone motility involving site-directed actin filament assembly; Forscher P et al.; Regulation of cytoskeletal structure and motility by extracellular signals is essential for all directed forms of cell movement and underlies the developmental process of axonal guidance in neuronal growth cones . Interaction with polycationic microbeads can trigger morphogenic changes in neurons and muscle cells normally associated with formation of pre- and postsynaptic specializations . Furthermore, when various types of microscopic particles are applied to the lamellar surface of a neuronal growth cone or motile cell they often exhibit retrograde movement at rates of 1-6 microns min-1 (refs 3-6) . There is strong evidence that this form of particle movement results from translocation of membrane proteins associated with cortical F-actin networks, not from bulk retrograde lipid flow and may be a mechanism behind processes such as cell locomotion, growth cone migration and capping of cell-surface antigens . Here we report a new form of motility stimulated by polycationic bead interactions with the growth-cone membrane surface . Bead binding rapidly induces intracellular actin filament assembly, coincident with a production of force sufficient to drive bead movements . These extracellular bead movements resemble intracellular movements of bacterial parasites known to redirect host cell F-actin assembly for propulsion . Our results suggest that site-directed actin filament assembly may be a widespread cellular mechanism for generating force at membrane-cytoskeletal interfaces.

Am J Physiol, 1992 Jun, 262(6 Pt 1), L708 - 12
Release of reactive oxygen species by guinea pig tracheal epithelial cells in vitro; Kinnula VL et al.; Regulatory and stimulatory mechanisms of H2O2 release from guinea pig tracheal epithelial cells were investigated . Cells in primary culture maintained in a previously described air-liquid interface system released H2O2 to the extracellular space only from the apical side of the cells . The rate of release was 0.044 +/- 0.003 nmol.min-1.mg protein-1 . H2O2 release could be stimulated significantly during a 30-min incubation period with phorbol myristate acetate (PMA) and platelet-activating factor (PAF) . A stimulatory effect of PAF was achieved at concentrations greater than 100 nM and with PMA at concentrations greater than 10 ng (16 nM) . When protein kinase C was inactivated with staurosporine, the responses to both PAF and PMA were abolished, whereas the cyclooxygenase inhibitor, indomethacin, did not affect H2O2 generation . When guinea pig tracheal epithelial cells were exposed to sublethal concentrations of extracellular H2O2 (30 microM), H2O2 was detoxified from both apical and basal sides, H2O2 removal being significantly more rapid from the apical side of the cells . These results suggest that tracheal epithelial cells can be stimulated to generate reactive oxygen species into the airway lumen and that this occurs in response to inflammatory mediators that act through protein kinase C . Luminal H2O2 release may have developed as a defense mechanism against microbes, and, similarly, luminal detoxification of H2O2 could represent an important mechanism of modulation of airway inflammation in response to oxidant stress.

Fertil Steril, 1992 Jun, 57(6), 1225 - 9
Cyclic variation of major histocompatibility complex class II antigen expression in the human fallopian tube epithelium; Edelstam GA et al.; OBJECTIVE: To systematically investigate the expression of major histocompatibility complex (MHC) class II antigens (human leukocyte antigens, HLA-DR, -DP, and -DQ) on columnar epithelium in the fallopian tube during the menstrual cycle . STUDY DESIGN: Biopsies were collected from the fallopian tube during laparotomy sterilization and immunoperoxidase staining was performed . SETTINGS: Departments of Gynecology and Obstetrics and Clinical Immunology and Transfusion Medicine, Uppsala University, Uppsala, Sweden . PATIENTS: Twenty healthy fertile women undergoing sterilization at different times of the menstrual cycle . INTERVENTIONS: None . MAIN OUTCOME MEASURES: The staining of the columnar epithelium was judged on a 4-graded scale according to the distribution of class II antigens . RESULTS: A widespread preovulatory HLA-DR expression was observed almost completely lining the columnar epithelial cells including the luminal surface, whereas postovulatory the HLA-DR expression was withdrawn from the surface . The HLA-DP and -DQ antigens varied in a similar way, although not as pronounced . CONCLUSIONS: The MHC class II antigen variation in the fallopian tube epithelium seen in this study may indicate a hormonal regulation that could reflect variable need for local immunocompetence during the menstrual cycle: a preovulatory need for immunoreactivity against invading microbes and postovulatory an optimal survival of the foreign preimplantation embryo.

J Oral Maxillofac Surg, 1992 May, 50(5), 477 - 82; discussion 482-3
Autologous facial fat transplantation: improved graft maintenance by microbead bioactivation; Eppley BL et al.; An alternative approach to the management of free fat transplantation resorption was evaluated in a rat facial model . Fat grafts obtained from the inguinal region were transferred to subcutaneous lateral facial sites in 20 animals . The grafts were mixed with either basic fibroblast growth factor (bFGF) alone or dextran beads that had been pretreated with bFGF . The grafts were then compared by weight and histology at 1 and 6 months postoperatively . Although graft weights were nearly comparable at 1 month, substantial differences were seen at 6 months, with the bead-containing grafts exhibiting near complete weight maintenance and better overall graft form . Histologically, the bead-containing grafts had extensive intercellular collagen formation and a heterogeneity of adipocyte cell sizes, particularly after 1 month . These findings suggest that the addition of cell-specific bioactive peptides that affect either the preadipocyte cell line and/or the fibroblastic components of the recipient site improve postoperative fat graft weight maintenance . Delivery of the biochemical agent appears to require a carrier system to exert its effects.

J Can Dent Assoc, 1992 May, 58(5), 377 - 8, 382-6
Concerns regarding infection control recommendations for dental practice; Hardie J; It goes without saying that the members of any professional group are more likely to modify their behavior if they are provided with logical, rational reasons to enact the suggested change . In the mid 1980s, health care providers, including dental personnel, were advised to adopt universal precautions and to alter their infection control habits with minimal justification, apart from the general unease and paranoia surrounding AIDS . Therefore, it is understandable that some practitioners would react with scepticism to the idea that their traditional infection control techniques were less than adequate, while others would overwhelmingly embrace the new recommendations in the misguided belief that personal, patient, staff and family safety would be enhanced . This predictable confusion is epitomized by the dentist who "sterilizes" extraction forceps by immersing them in alcohol for 10 minutes, versus the dentist who wears gloves, mask and disposable gown to conduct a recall examination . And if dentists are perplexed, it is clear that their staffs are equally, if not more confused, since they are exposed to the exaggerated claims and counter claims of sales agents . The microbes encountered in dental practise, apart from the hepatitis B virus, pose no significant risk to dental personnel or their patients, and the danger of hepatitis B transmission is reduced most effectively by vaccination . In reality, the genesis of dentistry's current emphasis on infection control resides entirely with HIV disease . But there is no credible clinical evidence to suggest that HIV infection is transmitted via dental treatment . Indeed, it may be theorized that for such a transmission to occur, the blood stream of the susceptible recipient would have to be invaded directly by a pathogenic inoculum of the virus--an unlikely event in the normal practise of dentistry . Under such circumstances, infection control practises should ignore the danger of HIV transmission, but concentrate on: Sterilization of all surgical and invasive instruments to protect patients from potential cross-infection . All dental staff receiving hepatitis B vaccinations . Dental staff wearing gloves, especially while performing intraoral procedures with blood release, and handling used instruments, to protect them from direct contact with potential pathogens . Working in a clean environment, in which blood spills and splatters are removed mainly for esthetic reasons . Such measures reflect the actual potential for disease transmission, as it exists in dentistry . They are justified and economical, and will be implemented by concerned but knowledgeable dental staff.

Br J Ind Med, 1992 May, 49(5), 332 - 6
Class specific antibodies in serodiagnosis of farmer's lung; Ojanen T; The aim of the present study was to determine which microbes and which immunoglobulin (Ig) classes should be included in tests to discriminate between patients with farmer's lung and reference persons . The sera of a group of farmer's lung patients and their spouses were measured for IgG, IgA, IgM, and IgE antibodies against a panel of farmer's lung microbes . The concentrations of IgG, IgA, and IgE antibodies were higher in patients compared with their spouses . The patients were generally positive for antibodies of several Ig classes whereas the spouses had only either IgG or IgA antibodies . A test comprising the determinations of IgG antibodies against T vulgaris and IgA antibodies against A fumigatus would correctly group 94% of the cases in the Finnish farming population . The selection of microbes for other environments needs to be determined locally.

Antibiot Khimioter, 1992 May, 37(5), 30 - 1
{Antibiotics of the aminoglycoside group (gentamicin, sisomicin and amikacin) in the prevention and treatment of experimental plague}; Shcherbaniuk AI et al.; Activity of aminoglycosides such as gentamicin, sisomicin and amikacin against plague microbe strains of natural origin was studied in vitro . It was also studied in prophylaxis and treatment of experimental plague infection in albino mice . The MAC of gentamicin and sisomicin for 50 strains of the plague microbe was 0.2-1.6 micrograms/ml . For the majority of the strains it was 0.4 micrograms/ml . The amikacin MICs were 0.4-3.2 and 0.8 micrograms/ml, respectively . High efficacy of gentamicin, sisomicin and amikacin was shown in prophylaxis and treatment of experimental plague infection in albino mice . The optimal doses of the antibiotics were determined . Under definite conditions such as the use of short-term regimens and higher intervals, advantages of sisomicin over gentamicin and amikacin in prophylaxis of experimental plague infection were observed.

J Immunol Methods, 1992 Apr 27, 149(1), 1 - 10
A critical evaluation of the magnetic cell sorter and its use in the positive and negative selection of CD45RO+ cells; Manyonda IT et al.; In this paper, we report on our year-long experience with the magnetic cell sorter (MACS), and present a critical evaluation of its pitfalls and benefits . Satisfactory separation of lymphocytes into subsets with preservation of function can be achieved, but there are several drawbacks: in comparison with Dynal beads, MACS results in a higher cell loss due to the increased number of separation steps and requires depletion of plastic-adherent cells as these will engulf microbeads and contaminate the enriched fraction, and is more expensive . The advantage of MACS over Dynal beads is that the microbeads are biodegradable and do not interfere with proliferation assays: both the depleted and enriched fractions of cells can therefore be used in culture immediately following separation . We used MACS for the positive and negative selection of CD45RO cells: the enriched fraction was of high purity (greater than 98%), but a depleted fraction of greater than 90% purity could not be obtained even after running the same sample over three separating columns . Dynabeads, on the other hand, achieved 98% pure CD45RO-depleted fractions after three separation runs.

CLAO J, 1992 Apr, 18(2), 87 - 91
Microbial contamination of hydrophilic contact lenses . Part I: Quantitation of microbes on patient worn-and-handled lenses; Mowrey-McKee MF et al.; We cultured Soflens (polymacon) contact lenses to determine the number of microorganisms present following normal patient wear and handling just prior to disinfection . Total protein deposited was determined for the companion lens from each patient . A random population of 109 adapted soft contact lens patients participated in the study . Some patients participated more than once, resulting in a total of 196 lenses being cultured and 195 lenses analyzed for total protein . The left lens was cultured immediately . The right lens was extracted at 70 degrees C in sodium hydroxide, and the total protein in the extract determined using a modified Lowry protein assay . The mean protein deposition per lens was 3.4 micrograms (median 2 micrograms per lens; range less than 1 to 78 micrograms/lens) . Microorganisms were cultured from 95% of the lenses . The mean bacterial count (in colony forming units per lens) was 2,482 (median: 123; range less than 3 to 150,000) . Fungal contamination was found on 11% of the lenses at very low levels (3-9 yeast/lens and 3-18 mold/lens) . Statistical analysis found no significant relationship between bacterial bioburden and any of the study parameters, including total protein, lens age, or subjective evaluation of lens cleanliness.

Mol Microbiol, 1992 Apr, 6(7), 825 - 31
The suicidal DNA repair methyltransferases of microbes; Samson L; Virtually every organism so far tested has been found to possess an extremely efficient DNA repair mechanism to ensure that certain alkylated oxygens do not accumulate in the genome . The repair is executed by DNA methyltransferases (MTases) which repair DNA O6-methylguanine (O6MeG), O4-methylthymine (O4MeT) and methylphosphotriesters (MePT) . The mechanism is rather extravagant because an entire protein molecule is expended for the repair of just one, or sometimes two, O-alkyl DNA adduct(s) . Cells profit from such an expensive transaction by earning protection against death and mutation by alkylating agents . This review considers the structure, function and biological roles of a number of well-characterized microbial DNA repair MTases.

J Cell Biol, 1992 Apr, 117(1), 105 - 20
Differential behavior of photoactivated microtubules in growing axons of mouse and frog neurons; Okabe S et al.; To characterize the behavior of axonal microtubules in vivo, we analyzed the movement of tubulin labeled with caged fluorescein after activation to be fluorescent by irradiation of 365-nm light . When mouse sensory neurons were microinjected with caged fluorescein-labeled tubulin and then a narrow region of the axon was illuminated with a 365-nm microbeam, photoactivated tubulin was stationary regardless of the position of photoactivation . We next introduced caged fluorescein-labeled tubulin into Xenopus embryos and nerve cells isolated from injected embryos were analyzed by photoactivation . In this case, movement of the photoactivated zone toward the axon tip was frequently observed . The photoactivated microtubule segments in the Xenopus axon moved out from their initial position without significant spreading, suggesting that fluorescent microtubules are not sliding as individual filaments, but rather translocating en bloc . Since these observations raised the possibility that the mechanism of nerve growth might differ between two types of neurons, we further characterized the movement of another component of the axon structure, the plasma membrane . Analysis of the position of polystyrene beads adhering to the neurites of Xenopus neurons revealed anterograde movement of the beads at the rate similar to the rate of microtubule movement . In contrast, no movement of the beads relative to the cell body was observed in mouse sensory neurons . These results suggest that the mode of translocation of cytoskeletal polymers and some components of the axon surface differ between two neuron types and that most microtubules are stationary within the axon of mammalian neurons where the surface-related motility of the axon is not observed.

Khirurgiia (Mosk), 1992 Apr, (4), 77 - 80
{The modelling of diffuse peritonitis}; Ashurmetov RI et al.; Peritonitis is still an urgent problem and its solution is determined to a great measure by purposeful studies in the field of pathogenesis and treatment . The creation of adequate models of peritonitis acquires particular significance . Eighty-four animals (dogs) were used to create the model . It is shown in the work that a standard model of generalized peritonitis can be produced by two injections of a polymicrobial suspension consisting of the most commonly encountered peritoneal microbes E . coli and B . fragilis . The suspension is injected into different levels of the abdominal cavity . With this method of administration of the polymicrobial suspension the model was reproduced in 90% of cases . Thus, the developed model resembles human peritonitis in the clinical picture and the laboratory and morphological values.

J Autoimmun, 1992 Apr, 5 Suppl A, 11 - 26
The forces driving autoimmune disease; Roitt IM et al.; There are two classes of autoimmune disease, organ-specific and non-organ specific or systemic . That cells producing autoantibodies are selected by antigen is strongly suggested by the presence of mutations and high affinity antibody . T-cells are pivotal in all forms of autoimmunity as evidenced by the therapeutic benefit of anti-T-cell monoclonals such as anti-CD4, and the frequent development of high affinity IgG autoantibodies . The production of anergic T-cells by the use of non-depleting anti-CD4 in the presence of antigen is discussed with particular reference to its potential for immunological intervention in autoimmune disease . It is possible to identify T-cell epitopes in organ-specific autoimmunity using pathogenic T-cell clones or hybridomas to identify the peptide sequences which are reactive . Antigen-specific therapy may ultimately be based on such peptide epitopes . The specificity of the T-cells in systemic autoimmunity is still obscure, but there is some evidence that reactivity with certain germ-line idiotypes can lead to the development of systemic autoimmunity . The possibility of stimulating B-cells specific for auto-antigens such as DNA becomes feasible if a complex of antibody and DNA is taken up by these specific B-cells and processed idiotype is presented to T-helpers specific for those idiotype epitopes . Evidence is presented that there may be pre-existing defects in the target organ in certain organ-specific disorders, and the evidence for a glycosylation defect in the IgG in patients with rheumatoid arthritis is explored . It is noted that the spouses of probands with rheumatoid arthritis is explored . It is noted that the spouses of probands with rheumatoid arthritis also tend to have this glycosylation defect and this raises the possibility of an effect due to an environmental factor, such as a microbial infection . Molecular mimicry of autoantigens by microbes can stimulate autoreactive cells by their cross-reactivity . It is emphasized that cross-reaction which gives rise to the priming of autoreactive T-cells could give rise to the establishment of a chronic autoimmune state . In animals with normal regulatory immune systems, such induced autoimmunity is ultimately corrected and it is only in animals where there are defects in regulation, that autoimmunity persists . Thus, there are many factors giving rise to autoimmunity, and the diseases are rightly regarded as multifactorial in origin.

Eur J Biochem, 1992 Mar 15, 204(3), 991 - 1001
Molecular cloning and regulatory analysis of the cuticle-degrading-protease structural gene from the entomopathogenic fungus Metarhizium anisopliae; St Leger RJ et al.; The proteinaceous insect cuticle is an effective barrier against most microbes, but entomopathogenic fungi can breach it using extracellular proteases . We report here the isolation and characterization of a cDNA clone of the cuticle-degrading protease (Pr1) of Metarhizium anisopliae . The cDNA sequence revealed that Pr1 is synthesized as a large precursor (40.3 kDa) containing a signal peptide, a propeptide and the mature protein predicted to have a molecular mass of 28.6 kDa . The primary structure of Pr1 has extensive similarity with enzymes of the subtilisin subclass of serine endopeptidases and the serine, histidine and aspartate components of the active site in subtilisins are preserved . Proteinase K demonstrated the closest sequence similarity to Pr1 (61%) but Pr1 was twofold more effective than proteinase K at degrading isolated cuticles of Manduca sexta and 33-fold more effective at degrading structural proteins bound to the cuticle by covalent bonds . We postulate that the additional positively charged residues on the surface of the Pr1 molecule, as determined using proteinase K, may facilitate electrostatic binding to cuticle proteins which is a prerequisite for activity . Northern-blot analysis of RNA and nuclear run-on assays demonstrated transcriptional control of the expression of Pr1 during nutrient deprivation and during the formation of infection structures . Southern-blot analysis demonstrated that genes with significant homologies to Metarhizium Pr1 were present in the entomopathogens Aspergillus flavus and Verticillium lecanii but not Zoophthora (= Erynia) radicans.

Scanning Microsc, 1992 Mar, 6(1), 167 - 74; discussion 174-5
Microbeam studies of the sensitivity of structures within living cells; Braby LA; Determining the biological effects of low doses of radiation with high linear energy transfer (LET) is complicated by the stochastic nature of charged-particle interactions . Populations of cells exposed to very low radiation doses contain a few cells which have been hit by a charged particle, while the majority of the cells receive no radiation damage . At somewhat higher doses, a few cells receive two or more events . Because the effects of damage produced by separate events can interact in the cell, we have had to make assumptions about the nature of these interactions in order to interpret the results of the experiments . Many of those assumptions can be tested if we can be sure of the number of charged-particle events which occur in individual cells, and correlate this number with the biological effect . We have developed a special irradiation facility at Pacific Northwest Laboratory (PNL) to control the actual number of charged particle tracks that pass through cell nuclei . The beam from a 2 MeV tandem accelerator is collimated to approximately 5 microns . Cells, grown in special dishes with 1.5 microns thick plastic bottoms, are positioned so that the desired portion of the cell aligns with the collimator . A shutter in the beam line is opened and closed after the desired number of particle tracks has been counted . This approach can be used to investigate the effects of the interaction between irradiated and unirradiated cells in an organized system, as well as to study the effects of spatial and temporal distribution of radiation damage within single cells.(ABSTRACT TRUNCATED AT 250 WORDS)

J Burn Care Rehabil, 1992 Mar-Apr, 13(2 Pt 2), 287 - 92
Natural resistance to infection: leukocyte functions; Benhaim P et al.; The nonspecific immune system has an extraordinarily important role in prevention of and response to wound infection . In the presence of injury or contamination, leukocytes adhere to local endothelial cells in response to complement signals through an integrin mechanism; they then migrate to the affected tissue site to locate, ingest, and kill microbes . Clinically, the major weaknesses in this system are impairment of cell recruitment and depression of microbial killing mechanisms; intracellular killing is the most problematic step in the process . Provided that leukocytes are able to migrate and ingest bacteria, nonoxidative killing proceeds in a normal fashion . Oxidative killing, however, can be profoundly impaired by poor blood perfusion and oxygenation . Low oxygen tension is a common clinical problem in surgical sites and wounds . There are a number of ways in which oxidative killing can be supported and facilitated in the clinical arena in a manner that is likely to enhance the effects of antibiotics in the treatment and prevention of infection.

Nippon Geka Hokan, 1992 Mar 1, 61(2), 190 - 8
Adenomyomatosis of the gallbladder: a clinical survey of 30 surgically treated patients; Kasahara Y et al.; Thirty patients with adenomyomatosis of the gallbladder (AMG) were operated on between January 1983 and June 1990 . They were made up 3.3% of patients who underwent cholecystectomy during the same interval . Of the 30 patients, ages ranged from 22 to 77 years (mean 52.3 years) and the male-to-female ratio was 8:7 . Among the macroscopic types, 10 cases of generalized, 12 of segmental (S) and 8 of fundal (F) were noted, and the size of the affected portion in type S (0.8 +/- 0.2 cm, mean +/- SD) was significantly thinner than in other two types (p less than 0.05) . Although the main symptom was abdominal pain, the majority of patients with type F had no complaints . Twenty patients (27%) were accompanied by gallstones including cholesterol stones in 60% of cases, and all six cases showing microbes in the bile had gallstones . Only six patients were diagnosed as AMG by preoperative imaging techniques . Other diagnoses comprised 15 of chronic cholecystitis and 3 of suspected gallbladder carcinoma . To identify the expanded Rokitansky-Aschoff sinuses, endoscopic retrograde cholangiography and/or ultrasonography of the abdomen were most useful . No preponderant coexistent lesion other than gallstones was noted . Levels of carcinoembryonic antigen in gallbladder bile in cases of AMG (2.5 +/- 1.5 ng/ml, mean +/- SD) were significantly lower than in gallbladder carcinoma (p less than 0.01) . All the patients were easily treated with cholecystectomy, and 24 patients who have been followed up after surgery are doing well.(ABSTRACT TRUNCATED AT 250 WORDS)

Parazitologiia, 1992 Mar-Apr, 26(2), 105 - 14
{The effect of the vole subspecies of the plague microbe on the viability of Callopsylla caspia fleas}; Vashchenok VS et al.; When infected with cultures of plague microbe reared at 28 C the experimental fleas showed no reliable differences in the mortality as compared to control ones . By contrast, the infection with agent cultures reared at 37 C as well as the infection on agonizing white mice caused a statistically reliable increase in the mortality in insects of both sexes . In the groups of fleas infected on white mice the most intensive mortality was observed during the first 24 hours after the infectious feeding that, apparently, is connected with the effect of toxins present in the blood of agonizing animals.

Biotechnology (N Y), 1992 Mar, 10(3), 301 - 4
DnaK-mediated alterations in human growth hormone protein inclusion bodies; Blum P et al.; Protein overproduction in microbes frequently results in protein misfolding and aggregation though the molecular basis for this process is unclear . The HSP70 chaperonin, DnaK, was identified as an important factor controlling heterologous protein aggregation in Escherichia coli . Co-overproduction of DnaK significantly reduced human growth hormone (HGH) protein inclusion body formation and the extent of HGH aggregation.

Biotechnology (N Y), 1992 Mar, 10(3), 286 - 91
Transformation of microbes, plants and animals by particle bombardment; Klein TM et al.; Over the past several years, particle bombardment has evolved into a useful tool for molecular biologists, allowing direct gene transfer to a broad range of cell and tissue types . Some of the important applications of the process include the production of transgenic crop species including maize and soybean and the introduction of DNA into plastids and mitochondria . Recent results have extended the range of gene transfer by particle bombardment to animal and bacterial cells . One noteworthy newer application is the direct insertion of genes into the organs of living animals . Here we discuss these advances and the instrument developments that contributed to them.

Br J Nutr, 1992 Mar, 67(2), 245 - 55
The effect of sucrose supplements on particle-associated carboxymethylcellulase (EC 3.2.1.4) and xylanase (EC 3.2.1.8) activities in cattle given grass-silage-based diet; Huhtanen P et al.; Carboxymethylcellulase (EC 3.2.1.4; CMCase) and xylanase (EC 3.2.1.8) activities were assayed in rumen fluid and from microbes closely associated either with rumen particulate material or with feed particles incubated in nylon bags in the rumen of cattle . The cattle were fitted with a permanent rumen cannula and a simple 'T'-piece duodenal cannula and were given four diets in a 4 x 4 Latin Square experiment . The basal diet (diet C) consisted of grass silage, barley and rapeseed meal (700, 240 and 60 g/kg total dry matter (DM)) given at the rate of 5.3 kg/d or supplemented with 1.0 kg sucrose/d given twice daily (diet S), twice daily with 0.25 kg sodium bicarbonate/d (diet B) or as a continuous intrarumen infusion (diet I) . Giving sucrose supplements decreased CMCase and xylanase activities extracted from microbes associated with rumen particulate material or feed particles incubated in nylon bags as compared with diet C . Supplementation of the sucrose diet with sodium bicarbonate resulted in higher CMCase and xylanase activities than other sucrose diets (S and I) . Particle-associated CMCase and xylanase activities were found to be very sensitive in detecting differences in the rumen environment and were related to changes in cell wall digestion . The activities were highly correlated with disappearance of DM and neutral-detergent fibre from nylon bags incubated in the rumen, rumen and total digestion of cell-wall carbohydrates and rumen pool size of cell-wall carbohydrates . It was concluded that the attachment of fibrinolytic enzymes is involved in the depression of fibre digestion . Particle-associated CMCase and xylanase activities were much higher when measured from rumen particulate material than from feed particles incubated in nylon bags.

J Bacteriol, 1992 Feb, 174(3), 1068 - 71
Extracellular polysaccharide is required for wild-type virulence of Pseudomonas solanacearum; Kao CC et al.; Several Pseudomonas solanacearum strains which produced no detectable extracellular polysaccharide (EPS) in planta had been reported to remain highly virulent when tested at high inoculum concentrations (P . Xu, M . Iwata, S . Leong, and L . Sequeira, J . Bacteriol . 172:3946-3951, 1990; P . Xu, S . Leong, and L . Sequeira, J . Bacteriol . 170:617-622, 1988) . Two of these mutants, KD700 and KD710, have now been molecularly and genetically mapped to the EPSI gene cluster described by Denny and Baek (Mol . Plant-Microbe Interact . 4:198-206, 1991) . When a range of inoculum concentrations was used, these two mutants and all other EPS-defective mutants tested were found to be reduced in virulence to eggplants and tobacco relative to the wild-type strain . Thus, EPS consistently is required for the wild-type level of virulence in P . solanacearum.

Curr Opin Immunol, 1992 Feb, 4(1), 3 - 7
Antibiotic peptides as mediators of innate immunity; Zasloff M; Antibiotic peptides are widely distributed in nature . Almost all function as membrane-active agents, disrupting target-cell permeability . Several exhibit a striking selectivity for single-celled microbes over metazoan cells, and as such are amongst the simplest components of the animal's defensive system, which distinguishes environmental microbes from 'self'.

Rheum Dis Clin North Am, 1992 Feb, 18(1), 37 - 48
Do bacterial antigens cause reactive arthritis?
Granfors K.
There are at least three common features among the microbes causing reactive arthritis: (1) they primarily cause infections on mucosal areas, (2) they are intracellularly living microorganisms, and (3) they have lipopolysaccharide as an essential structure of their outer membrane . It is obvious that during or after the acute infection microbial antigens are not properly eliminated, and they persist for long times in HLA-B27-positive persons developing ReA . Bacterial lipopolysaccharide has also been shown to enter the joints and is an important factor in the pathogenesis of ReA.

Am J Clin Pathol, 1992 Feb, 97(2), 202 - 8
A flow cytometric method to detect anti-pyruvate dehydrogenase antibody in primary biliary cirrhosis; Elkhalifa MY et al.; Primary biliary cirrhosis (PBC) is an autoimmune disease characterized by the presence of anti-mitochondrial antibodies specifically directed against the M2 group of mitochondrial antigens . Recently, the E-1, the E-2, and protein X components of pyruvate dehydrogenase enzyme complex have been identified as the major antigens within the M2 group of autoantigens . An immunoassay using pyruvate dehydrogenase enzyme complex as a specific antigen for the diagnosis of PBC was developed . Pyruvate dehydrogenase enzyme complex was attached to polystyrene microbeads, incubated with sera from PBC patients (n = 18), normal controls (n = 50), or patients with other autoimmune diseases (n = 26), followed by incubation with a second fluorescein isothiocyanate conjugated goat anti-human immunoglobulin and then analyzed by flow cytometry . High numbers of fluorescence channels (mean, 1,693 +/- 846) were obtained for all PBC sera except for two patients . Compared to the conventional anti-mitochondrial antibody assay, the assay had a sensitivity rate of 94% and a specificity rate of 100% . The reactive antibodies are predominantly of the immunoglobulin G3 subclass . Their levels could be correlated with the histopathologic stages of PBC . These results were corroborated by immunoblotting . Sera from patients with later stages of PBC strongly reacted with pyruvate dehydrogenase enzyme complex components, E1 alpha, and protein X.

Arch Surg, 1992 Feb, 127(2), 218 - 21
The Surgical Infection Society's policy on human immunodeficiency virus and hepatitis B and C infection . The Ad Hoc Committee on Acquired Immunodeficiency Syndrome and Hepatitis; Davis JM et al.; The Ad Hoc Committee on Acquired Immunodeficiency Syndrome and Hepatitis of The Surgical Infection Society has outlined its policy regarding three deadly blood-borne viral infections . The risk of transmission of these microbes, the role of preoperative testing, the problem of the human immunodeficiency virus-infected surgeon, and conduct in the operating room are discussed.

Khirurgiia (Mosk), 1992 Feb, (2), 94 - 101
{The use of the carbon dioxide laser in acute surgical infection of the soft tissues}; Kuleshov SE et al.; Clinico-laboratory studies were conducted in 46 patients with wound infection for the treatment of which carbon-dioxide laser was used, and in 78 patients who were operated on with a metal scalpel (control) . It is shown that "excision" and "evaporation" of tissues took 15-45 minutes . Repeated interventions were performed in 15% of cases due to bleeding from vessels measuring 1.0-1.5 mm in diameter . After surgical debridement with a scalpel the number of microbes reduced from 10(7)-10(9) to 10(3)-10(4) per g . After exposure to the laser beam this value was 10(1) but on day 3-4 it was 10(5)-10(6) . The extent of the zone of coagulation necrosis in the zone exposed to the laser beams measured up to 500 microns, and began diminishing only on day 7-9 of postoperation . Suppuration of the wounds in 56% of patients of the main group treated by operation was in conformity with the results of bacteriological and morphological studies . In the control group this index was 15.4% . It is concluded that the use of carbon-dioxide laser as a "light scalpel" with subsequent primary closure of the wound is inexpedient . Its use in preparing a wound for closure with secondary sutures has no advantages over radical surgical debridement.

J Clin Microbiol, 1992 Feb, 30(2), 377 - 80
Clinical and laboratory analyses of cytospin-prepared Gram stains for recovery and diagnosis of bacteria from sterile body fluids; Chapin-Robertson K et al.; The smear of a clinical specimen provides essential laboratory information that is used to make therapeutic decisions . For this study, smears were made by centrifugation in a Beckman Microfuge 11 (Beckman Instruments, Palo Alto, Calif.) and in parallel by using a Cytospin 2 apparatus (Shandon Inc., Pittsburgh, Pa.) . Of 350 consecutive body fluid specimens examined, 50 (14.0%) grew bacteria . Both methods were culture and smear positive for 24 (6.9%) specimens; 18 (5.1%) specimens were cytocentrifuge smear positive, culture positive, and high-speed centrifugation (HSC) negative; 3 (0.8%) were culture negative and positive by both smear methods; and 1 (0.2%) was HSC smear positive, culture positive, and cytocentrifuge negative . Seven (2.0%) specimens were culture positive and negative by both smear methods . Clinically, cytocentrifuge preparations showed greater sensitivity for culture-positive specimens and a closer correlation with the CFU per milliliter than HSC did, resulting in a greater ability to treat patients with specific therapies . In addition, analysts needed to examine only a 6-mm-diameter area on the slide, cells and microbes were somewhat larger and more regular in appearance, and smears stained more uniformly . Because of the increased clinical and laboratory utility of the cytocentrifuge, its use is recommended in clinical microbiology laboratories for all sterile body fluid specimens.

Biotechnology (N Y), 1992 Feb, 10(2), 157 - 62
Rational immunotherapy with interleukin 2; Kaplan G et al.; Interleukin 2 (IL-2), a T lymphocyte product released upon antigen stimulation, has been used for cancer therapy in high doses for more than five years . More recently, its potential as a stimulant of cell-mediated immunity in infectious diseases, particularly those caused by intracellular microbes, has become appreciated . Drawing on the extensive information available as to the structure, cellular and molecular effects of IL-2, this review focuses on its use in patients with lepromatous leprosy and AIDS in low, physiologic doses . The data indicate that IL-2 is effective in stimulating cell-mediated immunity without systemic toxicity.

Crit Care Clin, 1992 Jan, 8(1), 163 - 89
Inflammatory host responses in sepsis; Zimmerman JJ et al.; Although microbes and their associated toxins initiate sepsis, it is the subsequent host inflammatory response that defines most of what we characterize as clinical sepsis . This article considers the various cellular as well as humoral mediators involved in this response in addition to the complex networking that may result in both augmentation and modulation of the inflammatory response in sepsis.

Invest Ophthalmol Vis Sci, 1992 Jan, 33(1), 121 - 5
Analysis of glycoprotein deposits on disposable soft contact lenses; Tripathi PC et al.; By using gel electrophoresis, as well as Western blotting with specific antibodies or with the lectin concanavalin A, we characterized the types and amounts of proteins that are deposited on 58% ionic and 38% nonionic water-content disposable soft contact lenses (DSCLs) worn for 1 to 21 days by asymptomatic subjects with mild to moderate myopic refractive errors . The total amounts of protein eluted from the lenses ranged from 0.1 to 80 micrograms/lens . The amount of protein deposited on 58% water-content lenses was greater than that on 38% water-content DSCLs . We did not find a strict correlation between the amount of protein deposited and the duration of wear for either type of lens . The major polypeptide fractions detected had apparent molecular weights of 14, 17, 21, 30, and 60 kD . The fractions at 14 kD-bound antibodies specific for human lysozyme, and those at 17 kD corresponded to prealbumin . The 60 kD fraction included IgG heavy chains . The identity of the fractions at 21 kD and 30 kD is unknown . Because oligosaccharide side chains on the proteins attract microbes and facilitate their adherence, knowledge about the types of carbohydrate moieties in lens deposits can provide a rational approach to inhibiting or reversing microbial infection.

Tsitologiia, 1992, 34(2), 62 - 7
{The effect of the UV microirradiation of the centrosome on cell behavior . III . The ultrastructure of the centrosome after irradiation}; Uzbekov RE et al.; One of the spindle poles of mitotic PK cells was irradiated with UV microbeam in metaphase or in anaphase . Electron microscopy showed that immediately after irradiation the microtubules around the centrosome were maintained, and that the ultrastructure of both irradiated and nonirradiated poles was similar . After microirradiation of the centrosome in metaphase, the mitotic halo around this centrosome was retained, but in due time the number of microtubules was getting less compared to that around the nonirradiated centrosome . When daughter cells with irradiated centrosomes are passing into the interphase, their centrioles are not separated from each other, no primary cilia are formed, and no replication of centrioles occurs . In the interphase cells with irradiated centrosomes, satellites are formed on the active centriole, but centrosome-attached microtubules are practically absent.

Lasers Surg Med, 1992, 12(1), 51 - 62
Microbeam laser-injured neurons increase in vitro astrocytic gap junctional communication as measured by fluorescence recovery after laser photobleaching; Anders JJ et al.; An important aspect of the neuronal-astrocyte relationship is the interaction of reactive astrocytes with injured and/or dying neurons . Few studies have focused on the signaling of astrocytes by injured neurons or on the possibility that neurons can alter astrocytic gap junctional communication . The purpose of this study was to determine whether the presence of injured neurons could alter astrocytic gap junctional coupling by establishing an in vitro method of microbeam laser neuronal injury and coculturing these neurons with astrocytes . Neurons from two rat neuronal clonal cell lines were injured using a 20-W argon laser operating on the ultraviolet (UV) multiline (351-361 nm) directed through a X40 objective of an inverted microscope . After laser injury, the glass slide with the injured neurons was sandwiched with a slide on which primary rat astrocytes were grown . Although the neurons and astrocytes were bathed in the same medium, they were not in direct contact during the coculture period (24, 48, or 72 hr) . Astrocytic gap junctional dye coupling was examined using the fluorescence recovery after laser photobleaching (gap-FRAP) analysis technique . Astrocytes cocultured with the injured neurons for 24 to 48 hr did not show a significant difference in fluorescence recovery when compared to control values . After 72 hr of coculture, there was a significant increase in the gap junctional dye coupling . These results indicate that injured neurons influence in vitro astrocytic gap junctional conductance after 72 hr of coculture as measured by dye coupling.

Annu Rev Immunol, 1992, 10, 809 - 34
Complement deficiencies; Colten HR et al.; The complement system consists of about two dozen plasma and cell membrane proteins which function as cofactors in defense against pathogenic microbes and in the generation of many immunopathogenic disorders . The complexity of this system and its role in other biological functions has been appreciated within the last two decades . Recognition of genetic deficiencies of the complement proteins and their phenotypic expression has provided additional insights into the physiological role of the complement system . Complementary DNA (cDNA) clones for most of the complement components are now available, and the gene structures for many have been elucidated . Application of molecular biological methods to studies of the complement system and its deficiencies has permitted both the determination of primary structure and chromosomal localization of complement genes (Figure 1) and the capacity to elucidate the molecular basis of complement deficiency disorders.

Pharm Acta Helv, 1992, 67(1), 15 - 9
Bioconversion of tamoxifen by microbes; el-Sharkawy SH; Screening studies of tamoxifen (TAM) have shown that only one culture, Streptomyces rimosus ATCC 2234 was able to metabolize tamoxifen to 4-hydroxy tamoxifen (OHT) which was obtained in a 10% yield and chemically identified by 2 D nmr spectroscopy . A number of microorganisms were capable of biotransforming TAM to tamoxifen-N-oxide (TNO), and desmethyltamoxifen (DMT) . The chemical identity of the isolated metabolites was achieved using gas chromatography/mass spectrometry and different nmr spectroscopic techniques.

Appl Environ Microbiol, 1992 Jan, 58(1), 99 - 105
Comparative growth rates of various rumen bacteria in clarified rumen fluid from cows and sheep fed different diets; van Glyswyk NO et al.; Pure cultures of strains of different species of rumen bacteria were grown in filter-sterilized rumen fluid supplemented with glucose, bicarbonate, and reducing agent (cysteine and sulfide) . Growth rates were determined in a series of experiments . Strains of species most abundant in the rumen grew more rapidly than strains of less abundant bacteria . Ammonia, amino acids, and peptides increased growth rates to some extent, but the greatest stimulatory effect for less abundant bacteria was provided by other factors, present in yeast extract . Factors released from lysates of mixed rumen microbes stimulated growth, but their rate of release was slow . It was concluded that, besides energy and nitrogen sources, growth factors of an as-yet-undetermined nature probably play an important role in determining the predominance of different bacterial species in the rumen.

J Inherit Metab Dis, 1992, 15(4), 683 - 6
Biochemistry and molecular biology of chronic granulomatous disease; Segal AW; The NADPH oxidase of phagocytic cells is an electron transport chain in the wall of the endocytic vacuole that is activated upon engulfment of the microbe, and is important for its efficient killing and digestion . The oxidase consists of a heterodimeric cytochrome b in the membrane, which is the site of the haem and FAD groups, and two cystolic factors p47-phox and p67-phox that appear to activate the system . Absence of this oxidase as a result of defects in each of these specialized proteins causes the syndrome of chronic granulomatous disease (CGD), that is characterized by a profound predisposition to pyogenic infection.

Microbios, 1992, 70(282), 13 - 22
Aluminium, chromium and manganese detoxification mechanisms in Pseudomonas syringae: an X-ray fluorescence study; al-Aoukaty A et al.; Pseudomonas syringae cultured in a defined citrate medium supplemented with 1 mM aluminium, chromium and manganese, respectively, appeared to elicit disparate biochemical responses . At the stationary phase of growth aluminium was predominantly present as an insoluble residue . Although virtually none of this metallic element was detected in the supernatant, the bacterial cells appeared to contain some aluminium . Following the initial uptake of chromium the microbe secreted the metal in the supernatant . Only a small fraction of the chromium was localised in the bacterial cells; 91% manganese was biotransformed into an insoluble pellet . No citrate was detected in the exocellular fluid at cessation of cellular growth.

Pharmacol Ther, 1992, 55(3), 201 - 77
AIDS acquired by drug consumption and other noncontagious risk factors; Duesberg PH; The hypothesis that human immunodeficiency virus (HIV) is a new, sexually transmitted virus that causes AIDS has been entirely unproductive in terms of public health benefits . Moreover, it fails to predict the epidemiology of AIDS, the annual AIDS risk and the very heterogeneous AIDS diseases of infected persons . The correct hypothesis must explain why: (1) AIDS includes 25 previously known diseases and two clinically and epidemiologically very different epidemics, one in America and Europe, the other in Africa; (2) almost all American (90%) and European (86%) AIDS patients are males over the age of 20, while African AIDS affects both sexes equally; (3) the annual AIDS risks of infected babies, intravenous drug users, homosexuals who use aphrodisiacs, hemophiliacs and Africans vary over 100-fold; (4) many AIDS patients have diseases that do not depend on immunodeficiency, such as Kaposi's sarcoma, lymphoma, dementia and wasting; (5) the AIDS diseases of Americans (97%) and Europeans (87%) are predetermined by prior health risks, including long-term consumption of illicit recreational drugs, the antiviral drug AZT and congenital deficiencies like hemophilia, and those of Africans are Africa-specific . Both negative and positive evidence shows that AIDS is not infectious: (1) the virus hypothesis fails all conventional criteria of causation; (2) over 100-fold different AIDS risks in different risk groups show that HIV is not sufficient for AIDS; (3) AIDS is only 'acquired,' if at all, years after HIV is neutralized by antibodies; (4) AIDS is new but HIV is a long-established, perinatally transmitted retrovirus; (5) alternative explanations disprove all assumptions and anecdotal cases cited in support of the virus hypothesis; (6) all AIDS-defining diseases occur in matched risk groups, at the same rate, in the absence of HIV; (7) there is no common, active microbe in all AIDS patients; (8) AIDS manifests in unpredictable and unrelated diseases; and (9) it does not spread randomly between the sexes in America and Europe . Based on numerous data documenting that drugs are necessary for HIV-positives and sufficient for HIV-negatives to develop AIDS diseases, it is proposed that all American/European AIDS diseases, that exceed their normal background, result from recreational and anti-HIV drugs . African AIDS is proposed to result from protein malnutrition, poor sanitation and subsequent parasitic infections . This hypothesis resolves all paradoxes of the virus-AIDS hypothesis . It is epidemiologically and experimentally testable and provides a rational basis for AIDS control.

Vox Sang, 1992, 63(4), 272 - 5
An enzyme-linked antiglobulin test to quantify nanogram quantities of IgG on polystyrene microspheres; Greenwalt TJ et al.; A method is described in which polystyrene latex beads are used for constructing standard curves to estimate the number of protein molecules on cell surfaces by an enzyme-liked immunoassay test (ELAT) . A series of immune globulin (IgG) dilutions in pH 9.8 carbonate buffer were coated on 3-microns microbeads by incubation overnight at 4 degrees C and subjected to ELAT . The r value of the curve derived from four assays was 0.9991 . This standard curve applied to previously recorded ELAT data resulted in estimating that normal RBC have 63 +/- 19 (SD) IgG molecules and that the lower level of sensitivity of the antiglobulin test is 155 IgG molecules per RBC . The method should be useful for more precise standardization of procedures for measuring proteins on cell surfaces.

Biomaterials, 1992, 13(13), 949 - 52
Chitosan beads and granules for oral sustained delivery of nifedipine: in vitro studies; Chandy T et al.; Nifedipine was embedded in a chitosan matrix to develop a prolonged-release form . The in vitro release profiles of nifedipine from chitosan beads and microgranules were monitored by UV spectrophotometer . The studies were performed in a rotating shaker (100 rev min-1) in 0.1 M HCl buffer (pH 2.0) or 0.1 M phosphate buffer (pH 7.4) . Comparison was made between drug-loaded microbeads and microgranules . The amount and percentage of drug release were much higher in HCl than in phosphate buffer, probably due to the salt formation of the matrix (chitosan hydrochloride) at acid pH . The release rate of nifedipine from chitosan matrix was slower for beads than granules . These findings suggest the possibility of modifying the formulations to obtain the desired controlled release of the drug in an oral sustained-delivery system.

Annu Rev Microbiol, 1992, 46, 219 - 52
Biodiversity as a source of innovation in biotechnology; Bull AT et al.; The object of this article is to draw attention to the significance of microbial diversity as a major resource for biotechnological products and processes . The topic is approached from two complementary standpoints . First, an attempt is made to assess the extent of biodiversity, particularly microbial diversity . In this context, the application of the modern techniques of molecular biology is enabling the detection of hitherto completely unknown groups of microbes and, also, is revealing the extent of genetic diversity within microbial taxa . The case is made for the establishment of sound microbial taxonomies both on the basis of satisfying fundamental scientific needs, and for designing effective isolation strategies . The impact of an ecological approach to search and discovery of novel organisms and properties also is emphasized and illustrated . Second, the question of screening a collection of appropriate microorganisms for the desired attributes is considered . The focus here is placed on modern intelligent or targeted screening, and on the power of molecular biology to extend the range of screening options . Discussions of microbial ecology or diversity only rarely touch upon questions of gene pool conservation . The point made here is that loss of biodiversity should be as ominous for microbiologists and biotechnologists as it is to conservationists . The article concludes with thoughts on some means of conserving microbial diversity.

Przegl Lek, 1992, 49(5), 141 - 4
{Chlamydia trachomatis infection of the urogenital system in our clinical experience}; Magott M et al.; The increased number of the genitourinary system infection caused by Chlamydia trachomatis (Ch . Tr.), increased number of patients with dysuria or sterile leukocyturia gave stimulus to studies of 615 patients from Department of Nephrology and District Outpatient Nephrological Care Unit with regard to infections with that microbes . Material for investigations derived from urethra . Diagnostic examinations were performed using the Mc Coy cell culture and the immunofluorescence method . The infection was noted in 176 patients (119 women and 57 men) that is in 28.6% of cases studied . The mean age of patients was 42.7 +/- 12 years . Clinical symptoms such as dysuria or frequency were typical for that kind of infection . The most frequent abnormality was leukocyturia or leukocyturia accompanied by erythrocyturia noted in 66% of patients . Isolated erythrocyturia was observed in 24.4% of cases . It has been stated that anamnesis or routine laboratory examinations were not able to the identification of infection . In face of poorly characteristics of clinical picture of infection the infection with Ch.Tr . could be the cause of unsuccessful therapy in patients with signs of genitourinary tract infections.

Dysphagia, 1992, 7(4), 226 - 33
Velar activity and timing of eustachian tube function in swallowing; Hamlet SL et al.; Velar motion for dry and liquid swallows was investigated . as well as velar activity in speech, based on X-ray microbeam pellet tracking data . Electromyographic recordings for tensor and levator veli palatini were obtained simultaneously . Velar pellet trajectories for swallowing were more complex than for speech, since there was a high-velocity anterior component in swallowing . For some swallows this anterior component was integrated with velar elevation (especially in liquid swallows), but in other cases initial velar elevation occurred considerably earlier (chiefly in dry swallows) . The burst of tensor and levator veli palatini activity characteristic of swallowing was associated with the anterior component of velar pellet motion, but not consistently with velar elevation per se . The conventional view on timing of tensor veli palatini contraction in a swallow, which governs Eustachian tube opening, is that this is associated with velar closure . The X-ray microbeam data suggest rather that Eustachian tube ventilation is more closely associated in time to the onset of pharyngeal peristalsis, which may or may not coincide with initial velar elevation.

Basic Life Sci, 1992, 59, 915 - 34
Condensed tannins in some forage legumes: their role in the prevention of ruminant pasture bloat; Lees GL; For the past 20 years, the focus in our laboratory has been on finding the causes of ruminant pasture bloat and eventually breeding a bloat-safe alfalfa (Medicago sativa L.); i.e., with bloat potential reduced to the economic threshold . In the mid-seventies, the mechanisms of bloat were explored and found to be more physical than chemical . Characteristic of all bloating legumes after ingestion was a very rapid initial rate of ingestion by rumen microbes . Through the study of bloating and non-bloating legumes, factors were elucidated in the plant that would slow this process . One of these factors was the presence of condensed tannins in the herbage . Some of the non-bloating legumes contained these secondary metabolites, but no condensed tannins were found in any of the bloating legumes . Therefore, species containing an appreciable amount of condensed tannins in their leaves and stems are considered to be non-bloating . Conventional breeding methods have not been successful in producing an alfalfa with condensed tannins in its herbage . New approaches using tissue culture techniques are being attempted, but genetic engineering has the greatest potential for success.

Eicosanoids, 1992, 5(1), 5 - 8
Comparison of bioanalytical determinations of Iloprost, a chemically stable PGI2 mimetic, by conventional radioimmunoassay (RIA) and scintillation proximity assay (SPA); Hildebrand M et al.; The scintillation proximity assay is a novel variant of classical radioimmunoassay . It can be performed as a single tube measurement because the separation of bound and unbound tracer fraction is avoided . In principle, microbeads are coated with anti-species antibodies that can couple with the respective antiserum used for RIA . By means of special cores, light emission takes place if labelled, antiserum-bound tracer is coupled to the anti-species antibody on the fluomicrosphere surface . In the present report, the novel assay was compared to a validated RIA for the bioanalysis of the PGI2 mimetic, Iloprost . Extraction recovery of Iloprost was approximately 90% at pH less than or equal to 4 . The detection limit of the novel assay was 2-4 pg/sample, corresponding to 10-20 pg/ml plasma (if 0.2 ml plasma was used) . Coefficients of variations were 9, 7 and 6% (within-day, n = 5) and 30, 11 and 10% (day-to-day, n = 10) at 50, 100 and 200 pg/ml . RIA and SPA levels of Iloprost measured in human plasma samples (n = 428) were similar . The SPA method exhibits both a similar specificity and detection limit to RIA and will be used for further analyses.

Mol Carcinog, 1992, 5(4), 301 - 10
Homologous and heterologous gap-junctional intercellular communication in v-raf-, v-myc-, and v-raf/v-myc-transduced rat liver epithelial cell lines; Kalimi GH et al.; We examined gap-junctional intercellular communication (GJIC) in a series of normal and v-raf-, v-myc-, and v-raf/v-myc-transduced rat liver epithelial (RLE) cell lines using the scrape loading-dye transfer and fluorescence-recovery-after-photobleaching (FRAP) assays . Whereas the normal RLE cell line, the control helper virus-transduced cell line, and the v-myc-transduced cell line all showed excellent GJIC, the v-raf-transduced cell lines displayed decreasing levels of GJIC associated with their increasing tumorigenicity . The v-raf/v-myc-transformed cell lines showed the lowest levels of GJIC and were also the most tumorigenic . Heterologous GJIC of these oncogene-transduced cell lines was also compared with that in the normal RLE cells . A modified FRAP assay, using fluorescent-microbead labelling to identify the oncogene-transduced cell from surrounding normal cells, was used to quantify the heterologous GJIC . The v-raf/v-myc-transformed RLE cells had no heterologous communication with the normal RLE cells, whereas v-raf- and v-myc-transduced cell lines maintained heterologous GJIC . Northern analysis showed that connexin 43 was the only gap-junction protein message expressed in these cell lines; connexin 32 and connexin 26 were not expressed . The levels of connexin 43 mRNA expression were relatively unchanged in all cell lines, suggesting that the reduction in GJIC was primarily at the posttranslational level . These findings suggest that reduction of homologous GJIC in v-raf- and v-raf/v-myc-transformed RLE cells is linked to their tumorigenic potential . Furthermore, the loss of heterologous GJIC, which we observed only in the v-raf/v-myc-transformed cells, might release such cells from the growth-regulating effects of surrounding normal cells, possibly contributing to their enhanced tumorigenic potential.

Res Immunol, 1992 Jan, 143(1), 71 - 8
Endotoxin-neutralizing capacity of soluble CD14; Schutt C et al.; Luminol-enhanced chemiluminescence was used to determine the effect of soluble CD14 (sCD14) on the endotoxin-inducible generation of reactive oxygen species in human monocytes . It was necessary to mediate lipopolysaccharide (LPS) monocyte-activating capability by serum factors (LPS-binding proteins) . sCD14 reduced LPS-inducible monocyte activation in a dose-dependent manner, even in the case of CD14- monocytes, obtained from a patient with paroxysmal nocturnal haemoglobinuria . These monocytes could be activated by opsonized LPS via other receptors . Using anti-mouse Ig-coated microbeads, it was demonstrated in FACS analysis that sCD14 mediates the binding of a mouse monoclonal anti-CD14 antibody (RoMo 1) to a complex of LPS/FITC (fluoroisothiocyanate) and a LPS-binding protein . The release of sCD14 from cultured monocytes was measured using LPS, TNF alpha (tumour necrosis factor), IL1, 4 and 6 (interleukin-1, -4 and -6) and IFN gamma (interferon-gamma) as stimulators . Addition of LPS and TNF alpha led to a dose-dependent increase in sCD14-levels in the culture supernatant, whereas IL1, IL6 and IFN gamma had no significant effect . IL4 dose-dependently depressed spontaneous sCD14 release . It is possible that elevated sCD14-serum levels in polytraumatized patients indicate a natural protective mechanism against excessive monocyte mediator production . Therefore, sCD14 may be a new therapeutic concept in endotoxic shock prevention.

J Appl Physiol, 1992 Jan, 72(1), 1 - 7
Tissue-specific regulation of inflammation; Colten HR; Proteins of the complement system are important effectors and modulators of inflammation . The complement cascade is triggered by microbes, tissue debris, and specific antibodies . Serum complement proteins are derived primarily from liver, but extrahepatic complement synthesis is important in homeostasis and in local host defenses . Tissue-specific regulation of expression of complement genes is governed by mechanisms similar to those that regulate other "acute phase reactants." That is, tissue injury or infection elicit changes in expression of these acute phase proteins, which, although variable in kinetics, magnitude, and direction, are a consequence of an elaborate system of cell-to-cell communication . This communication is mediated via a complex network of cytokines, including the interferons, interleukins, several growth factors, and sex hormones . The cell biological and molecular biological details of these mechanisms are now under active investigation . An understanding in molecular terms of the balance between proinflammatory and counterregulatory forces on complement gene expression should provide new insight into the functions of complement and the design of novel therapies for disorders of inflammation.

Biodegradation, 1992, 3(1), 3 - 18
Microbes and microbial enzymes for cyanide degradation; Raybuck SA; Cyanide is an important industrial chemical produced on a grand scale each year . Although extremely toxic to mammalian life, cyanide is a natural product generated by fungi and bacteria, and as a result microbial systems have evolved for the degradation of cyanide to less toxic compounds . The enzymes which utilize cyanide as a substrate can be categorized into the following reaction types: substitution/addition, hydrolysis, oxidation, and reduction . Each of these categories is reviewed with respect to the known biochemistry and feasibility for use in treatment of cyanide containing wastes.

APMIS Suppl, 1992, 27, 71 - 83
Microbial interaction with animal cell surface carbohydrates; Karlsson KA et al.; Microbes have selected primarily carbohydrates for attachment to host animal cells . Recent studies have revealed essential characteristics in the recognition of receptor carbohydrates . Of importance is the property of recognizing also sequences placed inside an oligosaccharide chain, which differs from most animal antibodies . This is the basis for series of isoreceptors with the minimum receptor sequence in common but with separate neighbouring groups . There are families of microbial ligands that show different preferences for members within one series of isoreceptors, indicating only slight differences in the complementary binding sites of the proteins . Such differences may explain shifts in the selectivity of separate host tissues for infection . A second characteristic is the low affinity interaction often found where simple receptor-containing saccharides are unable to inhibit attachment . Technical possibilities are rapidly developing for the design of synthetic receptor analogues to be used in the therapy of clinical infections . This is urgently needed in cases where no rational therapy exists today.

Monatsschr Kinderheilkd, 1992 Jan, 140(1), 6 - 18
{Encephalitis . Recent clinical, diagnostic and therapeutic aspects}; Hirt HR; The subjects of this paper are mainly the encephalitis of viral origin and in addition 3 types of non-viral encephalitis of practical importance . A review is given on the current diagnostic possibilities including; clinical criteria; examination of the cerebrospinal fluid; neuroradiology and; etiological investigation by means of direct identification of the microbes in the cerebrospinal fluid or by measuring intrathecally produced antibodies . After some general statements concerning treatment the specifically treatable encephalitis caused by Herpes simplex virus, Mycoplasma pneumoniae, Borrelia burgdorferi and Toxoplasma gondii are discussed in more detail.

Sci Prog, 1992, 76(300 Pt 2), 139 - 48
Designing microbes for release into the environment; Molin S; After 20 years in which gene technology has become an important part of modern biotechnology we have seen very beneficial applications of the new techniques in the pharmaceutical industry . We are now entering a second phase involving the deliberate release of genetically engineered organisms into the environment . This next step causes concern because of a low level of predictability of their possible effects . While the risk assessment of microbial release is far from easy, the strain designers also face problems concerning optimization of performance of the organisms . The two groups of actors in this new development--the risk assessors and the strain designers--need the same platform of understanding from the field of microbial ecology, and a number of specific areas which may now be approached by modern technology deserve particular attention . An increased understanding of the activities of microbes in the environment will also allow construction of more predictable, and therefore safer, strains . Biological containment and molecular microbial ecology are two sides of the same coin in the context of release of genetically engineered microorganisms.

Nat Toxins, 1992, 1(3), 197 - 208
Ecology of plant-herbivore communities: a fungal component?
Hammon KE, Faeth SH.
We consider how microorganisms may alter conventional theories of the organization of plant-herbivore communities . We focus on endophytic fungi and their role in mediating interactions among herbivores, their host plants, and natural enemies . We propose hypotheses about the role of microbes in plant-herbivore communities and suggest ways to test these hypotheses . An initial approach to the overwhelming complexity of interacting species is to view species as components of functional groups, be they micro- or macroscopic, that potentially affect the ecology and evolution of host plants.

Cell Transplant, 1992, 1(5), 349 - 54
Embedded adrenal cells graft reduced local and early nonspecific inflammatory phenomena which follow agarose beads implantation; Cadic C et al.; Microencapsulation of adrenal cells is proposed for reducing the nonspecific inflammatory reaction observed around polymer implants . This hypothesis was tested by comparing both host cellular reaction and the surrounding graft cell populations which appeared either when agarose embedded cells or when empty agarose beads were implanted . Our results showed that the fibrotic material that surrounded the implanted empty agarose microbeads was not as severe and important when adrenal cells were present . Similarly, T lymphocyte population surrounding the graft was considerably reduced together with the percentage of CD4 and CD8 positive cell subpopulations . The activation macrophage marker IaD disappeared . Our results support the hypothesis that embedded adrenal cells may be a suitable solution for reducing early inflammatory events due to microcapsules implantation.

Insect Mol Biol, 1992, 1(1), 25 - 36
Phylogeny of cytoplasmic incompatibility micro-organisms in the parasitoid wasp genus Nasonia (Hymenoptera: Pteromalidae) based on 16S ribosomal DNA sequences; Breeuwer JA et al.; Cytoplasmic incompatibility results in embryo mortality in diploids, or all male offspring in haplodiploids, when individuals carrying different cytoplasmic factors are crossed . Cytoplasmic factors have been identified as intracellular micro-organisms . Microbe-induced cytoplasmic incompatibility is found in many insect taxa and may play a role in reproductive isolation between populations . Such micro-organisms cause bidirectional incompatibility between species of the parasitoid wasp genus Nasonia . The phylogenetic relationship of cytoplasmic incompatibility microorganisms (CIM) of different Nasonia species was analysed using their 16S ribosomal DNA (rDNA) sequence . Two 16S rDNA operons were detected in the CIM of each Nasonia species . Sequence analysis indicates that the Nasonia CIM are closely related and belong to the alpha group of the Proteobacteria.

Zh Mikrobiol Epidemiol Immunobiol, 1992, (11-12), 5 - 7
{Phosphatase and penicillinase activities as stable traits for the differentiation of the racial classification of Francisella tularensis}; Pavlovich NV et al.; In the causative agent of tularemia new markers correlating with different subspecies of this microbe have been detected . Thus, F . tularensis strains belonging to the American and Central Asian subspecies are characterized by phosphatase activity, which makes it possible to use the phosphatase test for their differentiation from the strains of the holarctic variety . F . tularensis subsp . mediasiatica are incapable of producing beta-lactamase which differentiates them from the representatives of the varieties holarctica and tularensis . These newly discovered signs are stable and do not depend on the virulence of the cultures under study and on the conditions of the cultivation of F . tularensis.

Ciba Found Symp, 1992, 171, 184 - 94; discussion 195-8
Roles of secondary metabolites from microbes; Vining LC; The common feature of the seemingly diverse array of biological activities exhibited by microbial secondary metabolites is their survival value for the producing organism . The propensity to form these compounds is unevenly distributed in microbial taxa and seems more closely associated with existence in a competitive environment than with phylogeny . The characteristic multibranched elaboration of secondary biosynthetic pathways and the marked species specificity of the end products are consistent with their evolution by an 'inventive' mechanism . The species specificity suggests that distinctive terminal reactions may be of recent origin . However, comparisons of the nucleotide sequence of genes involved in the biosynthesis of phenazine and polyketide metabolites with related genes of primary pathways indicate that the secondary pathways have not evolved exclusively within the organisms in which they are now found . Sequence similarities with related primary pathway genes in phylogenetically distant organisms suggest that gene transfer has played an important part in the evolution of secondary metabolism . The diversity of products may reflect the many roles for which secondary metabolites have been selected after the genes for their biosynthesis have transferred to organisms with different physiologies and different environment challenges.

Arch Immunol Ther Exp (Warsz), 1992, 40(3-4), 183 - 90
Macrophage activating factors produced in the course of murine tularemia: effect on multiplication of microbes; Kovarova H et al.; Primary F . tularensis infection in mice induces the production of macrophage activating factors (MAFs) by spleen cells . The stimulation of macrophage cytolytic activity (MAF-c) and hydrogen peroxide production (MAF-H2O2) dominates between days 7 and 10 in the course of tularemia . Three various pools of active fractions (10-11, 14-15, 25-28) were fractionated by two-step chromatography . Typical for 10-11 and 14-15 is MAF-c activity whereas in 25-28 prevails MAF-H2O2 . Initial concentrated supernatant (day 7 of infection) and individual fractions have been used to raise antibodies KI (anti 10-11) and KII (anti 14-15) . Neutralization reactions with specific antibodies indicate the presence of tumor necrosis factor alpha (TNF alpha) in 14-15 (44% inhibitable), interferon gamma (IFN gamma) and interleukin 2 (IL 2) in 25-28 (65% and 30% neutralization, respectively) . Utilizing KI and KII, 99% and 90% inhibition of cytolytic activity is reached in 10-11 and 14-15, respectively, in spite of non-specific cross reaction . Western blot analysis of proteins in supernatant on day 7 detects, besides TNF alpha, further protein bands (13, 15.5, 52 and 72 kDa) that seem to be associated with macrophage activation . Significant protective effect against in vivo multiplication of tularemic microbes indicates a certain role of TNF alpha, however, cooperation of other molecules is worth to be taken into consideration.

Arch Tierernahr, 1992, 42(3-4), 197 - 211
{Comparison of methods for determining the prececal nutrient digestibility and amino acid absorption of swine with ileorectal anastomoses and ileocecal bridge cannulas}; Hennig U et al.; The apparent precaecal nutrient digestibility and amino acid (a.a.) absorption of 10 diets were estimated in pigs with end-to-side ileorectal anastomoses (IRA) as well as with ileocaecal re-entrant cannulae (IZB) . The digestibilities of organic matter and crude carbohydrates were significantly higher in IRA pigs than in IZB pigs in two resp . three diets only . There were no practical important differences for the digestibilities of crude protein and crude fat in all diets . Out of the 180 a.a . absorption comparisons only 20 (i.e . 11%) showed differences larger than 5%-units . The absorption rates of several a.a . were lower in IRA than in IZB pigs and of some other a.a . on the contrary . The methionine absorption of five legume diets and one barley + lysine diet were up to 15% resp . 4%-units lower in IRA pigs . Possibly this was due to the activity of microbes in the rectum in connection with a small intake level of protein bound methionine . In order to minimize such a falsification it is proposed to use the end-to-end anastomosis . The deviations in the apparent a.a . absorption between IRA and IZB pigs can be explained partly by differences in the quantity of precaecally excreted endogenous a.a . per 100 g DM intake.

Klin Wochenschr, 1991 Dec 15, 69(21-23), 975 - 80
The involvement of oxygen radicals in microbicidal mechanisms of leukocytes and macrophages; Roos D; Phagocytic leukocytes generate large amounts of reactive oxygen compounds during and after phagocytosis of micro-organisms . These compounds are essential for the killing of a wide variety of microbes . The enzyme responsible for this process is NADPH:O2 oxidoreductase (NADPH oxidase), which utilizes the reduction equivalents of NADPH to reduce atmospheric oxygen to superoxide (O2-.) . Subsequently, superoxide is converted by the leukocytes to other reactive compounds, such as hydrogen peroxide (H2O2), hypochlorous acid (HOCl) and N-chloramines (RNCl) . Each of these compounds has potent microbicidal properties . Under resting, non-phagocytizing conditions, phagocytes do not produce reactive oxygen compounds . However, within 15-30 sec after binding of micro-organisms to cell surface receptors, superoxide generation starts . This phenomenon is called the respiratory burst . This phenomenon is called the respiratory burst . The activation of the NADPH oxidase is caused by the assembly of components of this enzyme into an active complex . Under resting conditions, at least three components reside in the cytoplasm and at least two are located in the plasma membrane . Activation of the NADPH oxidase results in translocation of cytosolic components to the plasma membrane and formation of an active enzymatic complex in the plasma membrane.

Sci Rep Res Inst Tohoku Univ {Med}, 1991 Dec, 38(2-4), 83 - 9
beta-Lactamase activity in sputum and indirect pathogenicity; Watanabe A et al.; beta-Lactamase activity of sputum of 39 patients with respiratory infections and that of bacterial isolates from their sputum were determined by nitrocefin method . Forty-six microbial strains (16 different species) were recovered from 39 sputum samples . The beta-lactamase activity was negative only in nine of the 46 strains . beta-lactamase-positive strains were recovered from 35 of 39 sputum samples . Of these 35 sputum samples, the beta-lactamase activity was positive in 23 and negative in 12 . beta-lactamase-negative strains were recovered from 4 of 39 sputum samples, and the beta-lactamase activity was negative in all of these four sputum samples . Both beta-lactamase producing and non-producing strains were recovered in 5 of 6 sputum samples from which two to three microbes were isolated . The ratio of beta-lactamase-positive sputum sample was higher in patients who had received antibiotics than in those who had received no antibiotics . This difference was statistically significant (P < 0.025) . It is possible that non-causative beta-lactamase-positive organisms enhance the pathogenicity of causative organisms that are beta-lactamase-negative.

J Cell Sci, 1991 Dec, 100 ( Pt 4), 771 - 80
Assembly of actin-containing cortex occurs at distal regions of growing neurites in PC12 cells; Sanders MC et al.; Although actin filaments are known to be localized in the cortex of axons and in the growth cones of nerve cells, it is unclear how actin-containing structures are assembled during nerve growth . We have studied the formation of actin structures in growing neurites by microinjecting fluorescent phalloidin or actin into PC12 neuron-like cells to label endogenous actin filaments . Upon stimulation of neurite growth in cells microinjected with fluorescent phalloidin, little or no fluorescence was detected in nascent growth cones and adjacent neurites despite the presence of actin filaments in these regions, suggesting that actin filaments were primarily formed by de novo assembly rather than the transport and reorganization of pre-existing, phalloidin-labeled actin filaments . Time-lapse observations of the distribution of phalloidin-labeled actin filaments during neurite elongation confirmed that fluorescence associated with pre-existing neurite cortex spread out more slowly than the elongation of neurites . Furthermore, when a dark spot was photobleached with a laser microbeam along neurites of cells microinjected with either fluorescent phalloidin or actin, the spot showed no appreciable translocation during active neurite elongation . Taken together, these results suggest that de novo assembly of actin filaments plays a crucial role in the formation of growth cones and adjacent cortex in the distal region of neurites, but does not appear to require the anterograde or retrograde transport of cortical filaments, or the passive stretching of the proximal segment of the neurite cortex.

Biochem Int, 1991 Dec, 25(6), 1043 - 9
Identification of emodinanthrone oxygenase in fungus Aspergillus terreus; Fujii I et al.; Emodinanthrone oxygenase, which catalyzes the oxidation of emodinanthrone to emodin, has been identified in fungus, Aspergillus terreus . The fixation of an oxygen atom at the C-10 position of emodinanthrone from molecular oxygen catalyzed by the enzyme was proved by the 18O2 incubation experiment and analyses of the product emodin by mass spectrometry and nuclear magnetic resonance . The fact that the reaction did not require any foreign electron donor suggested the involvement of internal monooxygenase . Emodinanthrone oxygenase activities were found in other microbes which produce anthraquinone related metabolites.

Semin Respir Infect, 1991 Dec, 6(4), 194 - 203
Pathogenesis of respiratory infection in the disadvantaged; Bor DH et al.; People living in poverty suffer from an increased burden of illness . The increase in respiratory illnesses in poor populations spans a spectrum from immuno-preventive respiratory infections in refugee populations to tuberculosis among the inner-city homeless . Such populations suffer from greater exposures to disease-causing agents and from depressed host resistance to those microbes . This article discusses the latter cause . Studies are reviewed that show the associations between poverty and respiratory disease; between poverty and such factors as stress, poor nutrition, low birth weight, and co-infections; and those associations that help dissect the pathogenic pathways by which these factors impair host defenses against infection . In the end, such influences are aggregate, and the conditions of poverty and the growing inequality in resource distribution emerges worldwide as a major determinant of health.

EMBO J, 1991 Dec, 10(13), 4069 - 79
Molecular basis of Mycoplasma surface antigenic variation: a novel set of divergent genes undergo spontaneous mutation of periodic coding regions and 5' regulatory sequences; Yogev D et al.; Antigenic diversity is generated in the wall-less pathogen Mycoplasma hyorhinis by combinatorial expression and phase variation of multiple, size-variant membrane surface lipoproteins (Vlps) . The unusual structural basis for Vlp variation was revealed in a cluster of related but divergent vlp genes, vlpA, vlpB and vlpC, which occur as single chromosomal copies . These encode conserved N-terminal domains for membrane insertion and lipoprotein processing, but divergent external domains undergoing size variation by loss or gain of repetitive intragenic coding sequences while retaining a motif with distinctive charge distribution . Genetic analysis of phenotypically switched isogenic lineages representing ON or OFF expression states of Vlp products ruled out chromosomal rearrangement or frameshift mutations as mechanisms for Vlp phase variation . However, highly conserved vlp promoter regions contain a tract of contiguous A residues immediately upstream of the -10 box which is subject to frequent mutations altering its length in exact correspondence with the ON and OFF phase states of specific genes . This suggests a mechanism of transcriptional control regulating high frequency phase variation and random combinatorial expression of Vlps . The multiple levels of diversity embodied in the vlp gene cluster represents a novel adaptive capability particularly suited for this class of wall-less microbe.

J Dairy Sci, 1991 Dec, 74(12), 4273 - 83
Effects of protein, carbohydrate, and fat sources on bacterial colonization degradation of fiber in vitro; Firkins JL et al.; In trial 1, our objectives were to study effects of different substrates (cellulose, red clover, and orchardgrass) on bacterial colonization and degradation of fiber . To quantitate bacterial colonization, we used 15N as a marker . Use of 15N appeared to underestimate bacterial colonization of cellulose, but it was assumed that relative differences among treatments and across times were accurate . The 15N and carboxymethylcellulase activity techniques gave similar patterns for bacterial colonization with time on purified cellulose but not orchardgrass or red clover; this indicated a higher concentration of cellulolytic versus total bacteria colonizing cellulose . Relatively lower detachment from red clover or orchardgrass than cellulose with time may have been due to selection for different types of microbes that were attached more firmly or were less prone to lysis . In trial 2, replacing cellulose with 30% starch or different protein sources (12% CP) decreased NDF digestion of crystalline cellulose but increased adherent bacterial CP concentration (estimated using 15N) and carboxymethylcellulase activity . The addition of starch and preformed protein may have selected for adherent, noncellulolytic microbes and decreased cellulolysis . The addition of 10% unsaturated or saturated fat did not affect colonization or NDF digestion, perhaps because of the larger surface area of the cellulose dispersing fatty acids more than would occur with more typical substrates . The addition of starch probably increased carboxymethylcellulase activity more than when using purines or 15N . Experiments using pure cultures of bacteria or purified substrates are not necessarily related to those using mixed cultures or natural forages.

Proc R Soc Lond B Biol Sci, 1991 Nov 22, 246(1316), 97 - 105
The Leeuwenhoek Lecture, 1991 . The influence of the host on microbes that cause disease; Smith H; Microbial pathogenicity or virulence, the capacity to cause disease, depends on microbial gene products that promote infection and penetration of mucous membranes, multiplication in the tissues, interference with host defence and sickness . Formation of these virulence determinants by microbes is influenced by the environment of the host, which differs from that in laboratory cultures . Studies of microorganisms grown in vivo, and of the host's influence on the production of virulence determinants, are increasing . In most studies, however, the complex conditions in vivo are not dissected to show the influence of particular factors . In future we should define specific host factors that are responsible for producing identified virulence determinants . There are three studies which point the way . Iron limitation in vivo causes production of bacterial siderophores, outer membrane receptors and some toxins . Erythritol, a growth stimulant for brucellae, causes intense placentitis and hence abortion in cattle, sheep and pigs . Cytidine 5'-monophospho-N-acetyl neuraminic acid (CMP-NANA) sialylates a conserved component of gonococcal lipopolysaccharide (LPS), thereby rendering gonococci in patients resistant to complement-mediated killing by serum . Although the lecture uses bacteria for examples, the principle applies equally to studies of viral and fungal pathogenicity.

Clin Prev Dent, 1991 Nov-Dec, 13(6), 20 - 2
Study on adequacy of sterilization of air-water syringe tips; Merchant VA et al.; This study examined the adequacy of sterilization of air-water syringe (AWS) tips following contamination during routine dental care treatment procedures . Although the internal chambers of most AWS tips were determined to be contaminated following use, no residual microbes were detected following autoclave sterilization of the AWS tips used during patient treatment procedures . Therefore, AWS tips apparently are readily heat sterilizable by conventional methods following clinical usage.

Rev Infect Dis, 1991 Nov-Dec, 13(6), 1139 - 50
Estrogens and infection; Styrt B et al.; The multiple effects of estrogens on infectious processes are only beginning to be understood . The existence of such effects is suggested by gender-related differences in the incidence and severity of some infections and by the association of certain infections with predictable hormonal changes . Current information indicates that estrogens may depress cell-mediated immunity, impair the activity of natural killer cells, and suppress some aspects of neutrophil function . Estrogens potentiate the production of systemic antibody, but local antibody responses may be impaired . Direct effects of estrogens on microorganisms have thus far been best studied in fungi; these hormones may either stimulate or suppress fungal virulence, depending on the species involved . Recent research also suggests responsiveness to estrogens in a wider variety of microorganisms . Studies in cell culture, animals, and humans indicate that pregnancy, estrogen supplementation, and menstrual stage can affect the acquisition and severity of certain bacterial, parasitic, and viral infections . This interaction depends on multiple attributes of both the microbe and the host in a given setting and thus may lead to disparate outcomes; however, there appears to be a predisposition to increased infectious morbidity in certain high-estrogen states . In view of the widespread use of estrogen supplementation, the clinical impact of estrogens on the incidence and outcome of infection needs to be better defined.

J Fla Med Assoc, 1991 Nov, 78(11), 763 - 5
Natural killer cells . Role in resistance to cancer and infection; Djeu JY; Specific immunity via antigen-recognizing T cells and B cells is crucial for complete host defense against infectious agents and cancer . However, the nonspecific arm of the host defense system plays an important role . NK cells, first described as an ever-present immunosurveillance mechanism against tumor development, are also important in early defense against microbes . With each type of microbe, NK cells use a different tactic to arm the host against the offending agent . To tackle intracellular viruses inaccessible to antibodies, they appear to lyse virus-infected fibroblasts and epithelial cells prior to maturation of the virions for dissemination in the host . Intracellular bacteria are dealt with in much the same manner, except that the targets are infected monocytes . Lastly, with organisms that cannot be directly killed, NK cells produce cytokines that can recruit and activate neutrophils . All accumulating evidence thus points to NK cells as a unique type of nonspecific lymphocytes that may be critical in either defense against microbes, particularly of the opportunistic nature, and in surveillance against certain types of tumors.

FASEB J, 1991 Nov, 5(14), 2934 - 44
Site-specific recombination in the immune system; Lieber MR; Site-specific DNA recombination has been identified in a wide variety of biological systems . In vertebrates, however, the only identified use of this genetic device is in the immune system . Here it plays a critical role in generating a diverse repertoire of surface receptors to intercept invading microbes and parasites . The mechanism and orchestration of this reaction are intriguing and are relevant to a broad array of related biological and biomedical issues.

Neuron, 1991 Nov, 7(5), 729 - 42
Chemosensory neurons with overlapping functions direct chemotaxis to multiple chemicals in C . elegans; Bargmann CI et al.; The functions of the 11 classes of exposed chemosensory neurons of C . elegans were tested by killing cells with a laser microbeam . One pair of neurons, the ASE neurons, is uniquely important for chemotaxis: killing the ASE neurons greatly reduced chemotaxis to cAMP, biotin, Cl-, and Na+ . Additional chemosensory function is distributed among several other cell types . Thus, 3 pairs of chemosensory neurons (ADF, ASG, and ASI) contribute to a residual response to cAMP, biotin, Cl-, and Na+ after ASE is killed . Chemotaxis to lysine similarly depends on the partly redundant functions of 4 pairs of chemosensory neurons (ASE, ASG, ASI, and ASK) . The combined activity of several neuron types that act in parallel might increase the fidelity of chemotaxis.

J Acoust Soc Am, 1991 Oct, 90(4 Pt 1), 1806 - 15
Phase relations of jaw and tongue tip movements in the production of VCV utterances; Nittrouer S; A previous study by Nittrouer et al . {J . Acoust . Soc . Am . 84, 1653-1661 (1988)} found that the spatiotemporal relations between jaw and upper lip movements for speech were affected not only by the segmental structure of the utterance, but by stress pattern and rate of production, as well . Specifically, the angle on the vowel-to-vowel jaw cycle phase plane at which the upper lip began moving toward closure for an intervocalic consonant varied systematically and discretely with changes in vowel-cycle duration . The development of the X-ray microbeam has permitted the observation of these effects for gestures involving articulators other than the lips and jaw . In the present study, the onset of tongue tip movement for an intervocalic consonant was represented as an angle on the jaw cycle phase plane for vowel-consonant-vowel utterances . Although the tongue tip exhibited greater variability in its movement onset than the upper lip had, the relative phasing of tongue tip movement onset was also found to vary with jaw vowel-cycle duration: Any manipulation that shortened the jaw vowel cycle also served to reduce the phase angle at which the tongue tip began movement . This relation was not found to be continuous in nature, but rather a main effect of phonetic and nonphonetic factors.

Dev Biol, 1991 Oct, 147(2), 464 - 79
Synaptic differentiation can be evoked by polymer microbeads that mimic localized pericellular proteolysis by removing proteins from adjacent surfaces; Anderson MJ et al.; Synaptic differentiation is normally "induced" by regulatory signals that are exchanged only at close contacts between neurites and their predetermined target cells . These signals can, however, be mimicked by contact of either cell with some kinds of polymer microbeads . To find what bead action is responsible for this mimicry, we compared the effects of active and inert microbeads on Xenopus muscle cells developing in culture and on glass-adsorbed films of laminin or fibronectin . Our results show that inductive bioactivity is a property of native polystyrene microbeads that (a) is not dependent merely on bead-muscle adhesion, (b) can be eliminated simply by exposing the beads to inert serum proteins, and (c) correlates closely with the ability of some beads to desorb proteins from adjacent surfaces . Quasi-synaptic differentiation of the muscle surface thus seems to be triggered by the focal removal of peripheral cell surface components, rather than by direct bead interactions with membrane receptors or ion channels or their gradual acquisition of endogenous regulatory substances . Since nerve-muscle interaction also causes an elimination of extracellular matrix proteins from the muscle surface, very early in synapse development, we consider the possibility that the extracellular degradation of peripheral surface components contributes to the transmission of inductive positional signals during synaptogenesis.

Pathology, 1991 Oct, 23(4), 344 - 5
The microbiology of peritonitis in continuous ambulatory peritoneal dialysis--experience in a provincial centre 1986-1989; Phua RT et al.; Laboratory procedures for isolating the causative microbe from infected effluent in continuous ambulatory peritoneal dialysis (CAPD) are still being refined . Our recovery rate from culturing centrifuged deposits of 10 mL of fluid averaged 55% for leukocytotic fluids from 1986 to 1989, a little lower than the published reports using blood culture methods . A combined use of spun deposit and blood culture broth should improve the yield without excessive cost in time and labor . Gram staining was worthwhile only for leukocytotic fluids.

Am J Vet Res, 1991 Oct, 52(10), 1723 - 30
Association of environmental air contaminants with disease and productivity in swine; Donham KJ; A cross-sectional epidemiologic study associating air quality with swine health was conducted on 28 swine farms in southern Sweden . Correlation of housing air environment to swine diseases and productivity (data collected over the preceding 12 months) were investigated . The most prevalent swine health problems detected at slaughter were pneumonia and pleuritis . In farrowing and nursery operations, the most prevalent problem was neonatal pig mortality . Several air contaminants (dust, ammonia carbon dioxide, and microbes) were found to be correlated with these swine health problems . Maximal safe concentrations of air contaminants were estimated on the basis of dose-response correlation to swine health or human health problems . Recommended maximal concentrations of contaminant were: dust, 2.4 mg/m3; ammonia, 7 ppm; endotoxin, 0.08 mg/m3; total microbes, 10(5) colony-forming units/m3; and carbon dioxide, 1,540 ppm . The overall quality of the ventilation system was correlated with lower concentration of ammonia, carbon dioxide, microorganisms, and endotoxin, but not with dust concentrations . High animal density was related to high ammonia and air microbe concentrations . Animal density measured as kilograms of swine per cubic meter (compared with kilograms of pig weight or swine per square meter) had the highest correlation to animal health and air contaminants.

J Microsc, 1991 Oct, 164 ( Pt 1), 53 - 60
Application of scanning electron microscopy (SEM) and microbead techniques to study the localization of p24 and p18 antigens of HIV-1 on the surface of HIV-1-infected H9-lymphocytes; Dennin RH et al.; Immunofluorescence staining techniques at present, when applied to follow the expression of HIV-1-specific antigens on infected cells, only give the information that the antigens detected are localized in the outer region of the membrane of the infected cell . We therefore set up a procedure using magnetic polystyrol particles coated with antibodies specific for the HIV-1 antigens under study, in combination with scanning electron microscopy . We were able to demonstrate that p24 and p18 structural antigens are clearly expressed on the surface of HIV-1-infected H9 lymphocytes . This means that there was no steric hindrance for structures of cell-like size specific for HIV-1 antigens to interact with their target antigens . Other antigens may be hidden in membrane structures and are therefore inaccessible, for example, to the beads used here, which were of a similar size to antigen-specific cells in vivo . The results of this model system must be seen with respect to the interaction of antigen-specific cell-mediated immunity with full antibody-dependent cellular cytotoxicity, or without cytotoxic T lymphocytes, the mediator function of antibodies.

J Cell Sci, 1991 Oct, 100 ( Pt 2), 279 - 88
Direct experimental evidence for the existence, structural basis and function of astral forces during anaphase B in vivo; Aist JR et al.; The existence, structural basis and function of astral forces that are active during anaphase B in the fungus, Nectria haematococca, were revealed by experiments performed on living cells . When one of the two asters of a mitotic apparatus was damaged, the entire mitotic apparatus migrated rapidly in the direction of the opposing astral forces, showing that the force that accelerated spindle pole body separation in earlier experiments is located in the asters . When a strong solution of the antimicrotubule drug, MBC, was applied at anaphase A, tubulin immunocytochemistry showed that both astral and spindle microtubules were destroyed completely in less than a minute . As a result, separation of the spindle pole bodies during anaphase B almost stopped . By contrast, disrupting only the spindle microtubules with a laser microbeam increased the rate of spindle pole body separation more than fourfold . Taken together, these two experiments show that the astral forces are microtubule-dependent . When only one of the two or three bundles of spindle microtubules was broken at very early anaphase B, most such diminished spindles elongated at a normal rate, whereas others elongated at an increased rate . This result suggests that only a critical mass or number of spindle microtubules needs be present for the rate of spindle elongation to be fully governed, and that astral forces can accelerate the elongation of a weakened or diminished spindle.

J Cell Sci, 1991 Oct, 100 ( Pt 2), 269 - 77
Electron-microscopic and immunochemical analysis of kinetochore microtubules after ultraviolet microbeam irradiation of kinetochores; Swedak JA et al.; We used an ultraviolet microbeam to irradiate kinetochores of chromosomes in crane-fly spermatocytes . We used one of two doses, low (0.106 erg microns-2) or high (0.301 erg microns-2), and then studied the microtubules in those spindles using electron microscopy or immunofluorescence microscopy . After irradiation with low doses microtubules are present as usual, with normal fluorescence and in normal numbers . After irradiation with high doses microtubules are no longer associated with the irradiated kinetochore . After irradiation with either dose, non-kinetochore microtubules are in smaller numbers in the irradiated half-spindle than in the non-irradiated half-spindle or in non-irradiated cells . Since irradiation with low doses alters interchromosomal 'signals', but microtubules remain attached to the kinetochore, we argue that low doses of ultraviolet light damage a signal-related function of kinetochores without altering the ability of the kinetochores to bind microtubules.

J Cell Sci, 1991 Oct, 100 ( Pt 2), 261 - 8
Kinetochore function can be altered by ultraviolet microbeam irradiation without loss of the associated birefringent spindle fibre; Swedak JA et al.; We have irradiated kinetochores of chromosomes in spermatocytes of crane flies (Nephrotoma abbreviata (Loew)) and Nephrotoma suturalis (Loew), while observing the cells using polarization microscopy . Irradiation of a kinetochore of one sex chromosome with 0.106 ergs microns-2, the minimum dose needed to stop movement, had no effect on the birefringence of the irradiated kinetochore's spindle fibre . Irradiation of the kinetochore of an autosomal half-bivalent in anaphase, with the same dose, had no effect on the birefringence of the irradiated kinetochore's spindle fibre, but nonetheless the anaphase movements of all six autosomal half-bivalents were stopped, temporarily, for up to 20 min . Irradiations of the kinetochores of an autosomal half-bivalent with higher doses (0.301 ergs microns-2) caused loss of birefringence of the irradiated kinetochore's spindle fibre, and the movements of all six autosomal half-bivalents were stopped permanently . We argue that the ultraviolet microbeam differentially affects two functions of the kinetochore: (1) a 'signalling' function, and (2) microtubule attachment, with the signalling function being altered at doses lower than that of microtubule attachment.

Appl Environ Microbiol, 1991 Oct, 57(10), 2981 - 5
Substrate interactions of benzene, toluene, and para-xylene during microbial degradation by pure cultures and mixed culture aquifer slurries; Alvarez PJ et al.; Benzene, toluene, and p-xylene (BTX) were degraded by indigenous mixed cultures in sandy aquifer material and by two pure cultures isolated from the same site . Although BTX compounds have a similar chemical structure, the fate of individual BTX compounds differed when the compounds were fed to each pure culture and mixed culture aquifer slurries . The identification of substrate interactions aided the understanding of this behavior . Beneficial substrate interactions included enhanced degradation of benzene and p-xylene by the presence of toluene in Pseudomonas sp . strain CFS-215 incubations, as well as benzene-dependent degradation of toluene and p-xylene by Arthrobacter sp . strain HCB . Detrimental substrate interactions included retardation in benzene and toluene degradation by the presence of p-xylene in both aquifer slurries and Pseudomonas incubations . The catabolic diversity of microbes in the environment precludes generalizations about the capacity of individual BTX compounds to enhance or inhibit the degradation of other BTX compounds.

Pflugers Arch, 1991 Oct, 419(3-4), 349 - 57
A simple method for monitoring changes in cell height using fluorescent microbeads and an Ussing-type chamber for the inverted microscope; Crowe WE et al.; In this study, we report two developments for studies of ion transport in cultured epithelial cells . First, a convenient method is presented for measuring apparent cell height using fluorescent microbeads as high-contrast landmarks of the apical and basal cell surfaces . The apparent cell height is then used as an indicator to monitor the time course of changes in cell volume in response to osmotic perturbations . Second, an Ussing-type chamber design for the inverted fluorescence microscope is presented, which allows determination of transepithelial electrical properties . Using these two methods, we obtained simultaneous measurements of cell height and transepithelial electrical parameters for cultured renal (A6) epithelium . Cell height was measured by alternately focusing the microscope between microbeads marking the apical and basal surfaces . The distance between these two surfaces was measured electrically from the voltage output of a potentiometer that was mechanically coupled to the fine-focusing knob of the microscope . Following decreases in the bathing solution osmolality, the cell height and transepithelial Na+ transport rate (measured as short-circuit current, ISC) increased . The increase in cell height preceded changes in ISC by several minutes, suggesting a lack of direct linkage between changes in cell volume and transepithelial Na+ transport . Both the fluorescent microbead cell height method and the Ussing-type chamber can be used in conjunction with patch-clamp techniques, intracellular microelectrode impalements, or fluorescent probes of intracellular composition . Therefore, this system may be advantageous for studies of epithelial cell volume and channel regulation.

Am J Cardiol, 1991 Sep 3, 68(7), 64B - 68B
Granulocyte function in coronary artery disease; de Servi S et al.; Granulocytes defend the body against invading microbes by producing a complex armamentarium of toxic substances, such as proteolytic enzymes, oxygen radicals and arachidonic acid metabolites . Under certain circumstances, however, such compounds may be released in the absence of phagocytosable particles, resulting in injury to normal cell and connective tissue degradation . Recent experimental studies have emphasized the potential role of granulocytes in the pathogenesis of myocardial ischemia . Clinical investigations have also shown alterations in neutrophil function in stable and unstable clinical manifestations of ischemic heart disease . "Priming" of granulocytes in stable forms of coronary disease may predispose to the subsequent development of acute coronary events, whereas activation of neutrophils may lead to alterations in vascular permeability and coronary flow regulation, leading to further myocardial and endothelial injury in acute myocardial infarction, unstable angina and coronary angioplasty.

Public Health Nurs, 1991 Sep, 8(3), 161 - 5
Baby's milk: a source of trust between mothers and nurses; Brodie B; The task of providing infants adequate amounts of nutritious milk, in spite of mothers' ability to produce breast milk, has never been easy . In America cow's milk became the food of choice when mothers ceased to breast-feed their infants . In the mid-1800s advances in bacteriology and chemistry led to a beginning understanding of the role of microbes in food and the development of commercial proprietary formulas . Many mothers discontinued breast-feeding at an early age and relied on these products for their children . With the growth of cities, dairy farms were pushed many miles from the consumers of milk . The distance the new uncooled milk had to be transported, especially during the hot summer months, increased the chances of milk-borne diseases infecting infants . To combat the high rates of infant gastroenteritis and death, welfare reformers and health professionals banded together to improve the milk supply through pasteurization, certification, and safe distribution; and to educate the public, especially mothers, on ways to feed and keep their infants healthy . Through their close contact with mothers in their homes, nurses taught these women how to prepare, store, and feed infants' milk . When their babies survived the summer, mothers developed a sense of trust in the nurse and the things she taught about ways to protect their infants and the entire family's health.

J Dairy Sci, 1991 Sep, 74(9), 3055 - 67
Effects of dietary fat and protein on fatty acid flow to the duodenum and in milk produced by dairy cows; Klusmeyer TH et al.; Four Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square with treatments in a 2 x 2 factorial arrangement . Treatments were 1) soybean meal, no fat; 2) fish meal, no fat; 3) soybean meal, fat; and 4) fish meal, fat . Cows were fed for ad libitum intake a diet of alfalfa haylage, corn silage, and concentrate (30:20:50) on a DM basis . Intake of gross energy (105 Mcal/d) was not altered by treatment comparisons . However, feeding fat decreased energy digested in the rumen (15 vs . 24%) and increased energy digested postruminally (55 vs . 43%) but resulted in similar amounts of energy (72 Mcal/d) digested in the total tract . The flow of C14:0, C16:0, C18:0, C18:1, C18:2, C18:3, and total fatty acids to the duodenum was increased by feeding fat . The average flow of C14:0, total C18, and total fatty acids to the duodenum was greater than their intake for all treatments, suggesting de novo synthesis of fatty acids by ruminal microbes . Biohydrogenation of unsaturated C18 was decreased 70, 67, 59, and 51% for treatments 1 to 4, respectively, by feeding fat and fish meal . Digestibility of total fatty acids entering the small intestine (78%) was not altered by treatment comparisons; however, feeding fat altered digestibility of individual fatty acids . The proportion of C16:0 and C18:1 was increased, and the proportion of C6:0, C8:0, C10:0, C12:0, and C14:0 was decreased in milk fat produced by cows fed fat.

J Clin Microbiol, 1991 Sep, 29(9), 1985 - 90
Detection of Pneumocystis carinii sequences by polymerase chain reaction: animal models and clinical application to noninvasive specimens; Kitada K et al.; Pneumocystis carinii is a eukaryotic microbe which causes fatal pneumonia in patients with AIDS . Oligonucleotide primers were used to amplify the 5S rDNA sequence of P . carinii by the polymerase chain reaction (PCR) in various clinical and animal samples . Of 35 independent lung specimens tested, PCR detected the P . carinii sequence in all 23 cases which were known to be P . carinii infected, i.e., 15 from mice, 1 from rat, 3 from human autopsy, and 4 from biopsy of AIDS patients by needle aspiration . The results were consistent with clinical and microscopic diagnosis . The detection was highly sensitive and specific . Direct sequencing of these amplified DNAs revealed homogeneity of 5S rDNA sequences of independent isolates from mice, rats, and humans . Preliminary trials manifested efficacy of the PCR method to detect P . carinii sequences in induced sputum or blood from AIDS patients, the latter case suggesting that P . carinii might enter peripheral blood via phagocytosis or direct intrusion . Development of less-invasive or noninvasive PCR diagnostic techniques to detect P . carinii infection would greatly facilitate therapeutic and prophylactic management of P . carinii pneumonia.

J Clin Lab Immunol, 1991 Sep, 36(1), 1 - 14
Three theories which explain the occurrence and inheritance of the autoimmune diseases; Adams DD; The immunity system uses random processes . In B lymphocytes these are antigen-driven somatic gene mutations which tighten antibody affinity for invading microbes to enable recovery from and prevention of infectious diseases . In T lymphocytes, randomized gene segment combinations continually provide new clones, needed to counter continually-changing microbial parasites . Because these B and T cell processes are random, they entail risk of producing forbidden (self-antigen-reactive) clones, a minority of which cause autoimmune diseases, as envisaged by Burnet in his forbidden clone theory . A corollary of the forbidden clone theory is the V gene theory, postulating that the specificities of the germline variable (V) genes coding for antigen receptors influence the risks of autoimmune diseases . The H gene theory, postulates that the main defense against autoimmune disease is mediated by the permanent, unbreakable tolerances imposed on the clonal repertoire by the histocompatibility (H) antigens, major, minor and H-Y . Recent work shows that the last two act as peptides which modify MHC antigens by occupying their Bjorkman grooves . The absolute absence of autoimmunity to histocompatibility, ABO and H-Y antigens shows that nascent clones with high affinity for these white cell antigens are continually eliminated . Application of molecular biological techniques has shown that H antigen tolerance impositions profoundly alter the clonal repertoire and hence the risks of development of the forbidden clones which cause the autoimmune diseases . Precise basic theory is crucially important for effective application of molecular biology and microbiology to the eminently achievable therapeutic and prophylactic conquest of the ubiquitous autoimmune diseases.

Proc Natl Acad Sci U S A, 1991 Aug 15, 88(16), 7160 - 4
A constant rate of spontaneous mutation in DNA-based microbes; Drake JW; In terms of evolution and fitness, the most significant spontaneous mutation rate is likely to be that for the entire genome (or its nonfrivolous fraction) . Information is now available to calculate this rate for several DNA-based haploid microbes, including bacteriophages with single- or double-stranded DNA, a bacterium, a yeast, and a filamentous fungus . Their genome sizes vary by approximately 6500-fold . Their average mutation rates per base pair vary by approximately 16,000-fold, whereas their mutation rates per genome vary by only approximately 2.5-fold, apparently randomly, around a mean value of 0.0033 per DNA replication . The average mutation rate per base pair is inversely proportional to genome size . Therefore, a nearly invariant microbial mutation rate appears to have evolved . Because this rate is uniform in such diverse organisms, it is likely to be determined by deep general forces, perhaps by a balance between the usually deleterious effects of mutation and the physiological costs of further reducing mutation rates.

Tierarztl Prax, 1991 Aug, 19(4), 381 - 5
{Postcoital uterine microbe colonization and endometritis in the mare}; Buchi S et al.; In the mare, natural breeding is associated with bacterial contamination of the reproductive tract . The purpose of this study was to examine postcoital bacterial contamination and the resulting inflammatory response of the uterus . Uterine swabs for bacteriological and cytological examination were obtained from 80 mares . Each mare was sampled once between 4 and 69 hours postbreeding . In mares which did not conceive, sampling was repeated at the following estrus . The findings were compared with those obtained prior to breeding and correlated with the breeding outcome . Bacteria were cultured from 72.5% of the postcoital swabs . There was a wide spectrum of organisms which included species known as potential causes of endometritis . Neutrophilic granulocytes were found in varying concentrations in 48.8% of cases . In 16.3% of mares both bacteriological and cytological examinations were negative . Mares with positive bacteriological and/or cytological results at the postcoital examination had better foaling rates compared to the remaining mares (p less than 0.05) . The postcoital findings did not correlate with those of the prebreeding examination, or with the interval between breeding and sampling, or with the different stallions.

J Otolaryngol, 1991 Aug, 20(4), 279 - 82
Infection of Waldeyer's ring: value of pernasal retropharyngeal swabs; Timon CI et al.; The value of pernasal retropharyngeal swabs in chronic adenoid and tonsillar disease was assessed in a prospective study involving 52 patients . Prior to adenoidectomy (34 patients) or adenotonsillectomy (17 patients), pernasal and tonsillar swabs were taken and the culture compared to the bacteriology profile obtained in the adenoid and tonsil tissue following surgery . The pernasal swab correctly identified 76% of pathogens isolated in the adenoid tissue . In addition, pernasal swabs forecast the presence of pathogens in 64% of core tonsil specimens, compared to an accuracy of 38% when superficial tonsil swabs were compared to the microbes in the deep tonsil . H . influenzae was the predominant organism isolated in all cultures . Our results clearly demonstrate that pernasal swabs give a representative picture of the adenoid bacterial content . Pernasal swabs are also superior to superficial tonsil swabs in indicating the deep tonsillar organisms.

Proc Natl Acad Sci U S A, 1991 Aug 1, 88(15), 6532 - 6
Molecular cloning and expression in photosynthetic bacteria of a soybean cDNA coding for phytoene desaturase, an enzyme of the carotenoid biosynthesis pathway; Bartley GE et al.; Carotenoids are orange, yellow, or red photo-protective pigments present in all plastids . The first carotenoid of the pathway is phytoene, a colorless compound that is converted into colored carotenoids through a series of desaturation reactions . Genes coding for carotenoid desaturases have been cloned from microbes but not from plants . We report the cloning of a cDNA for pds1, a soybean (Glycine max) gene that, based on a complementation assay using the photosynthetic bacterium Rhodobacter capsulatus, codes for an enzyme that catalyzes the two desaturation reactions that convert phytoene into zeta-carotene, a yellow carotenoid . The 2281-base-pair cDNA clone analyzed contains an open reading frame with the capacity to code for a 572-residue protein of predicted Mr 63,851 . Alignment of the deduced Pds1 peptide sequence with the sequences of fungal and bacterial carotenoid desaturases revealed conservation of several amino acid residues, including a dinucleotide-binding motif that could mediate binding to FAD . The Pds1 protein is synthesized in vitro as a precursor that, upon import into isolated chloroplasts, is processed to a smaller mature form . Hybridization of the pds1 cDNA to genomic blots indicated that this gene is a member of a low-copy-number gene family . One of these loci was genetically mapped using restriction fragment length polymorphisms between Glycine max and Glycine soja . We conclude that pds1 is a nuclear gene encoding a phytoene desaturase enzyme that, as its microbial counterparts, contains sequence motifs characteristic of flavoproteins.

Eur J Immunogenet, 1991 Aug, 18(4), 239 - 45
Phagocytosis of fluorescent latex microbeads by peritoneal macrophages in different strains of mice: a flow cytometric study; Abel G et al.; The phagocytosis of uniform fluorescent latex particles by resident and thioglycollate-elicited macrophages was analysed by flow cytometry . The percentage of phagocytosing macrophages and the number of internalized microspheres per cell was determined from cell size and fluorescence histograms . Results were corrected for the adherence of microbeads to the cells in the presence of sodium azide in the medium . Human C3b- or murine monoclonal IgG-coated microspheres were applied to assess receptor-mediated phagocytosis in different inbred strains of mice . Phagocytic activity of thioglycollate-elicited macrophages was consequently higher than that of resident macrophages . A decreasing gradient of C3b and Fc receptor-mediated phagocytosis was established in the following order: B10.BR, B10, C3H/Di and C3H.SW strains . Our results indicate that the phagocytic function of murine macrophages is under control of both the somatic (non-H-2) and H-2 genes.

Hum Reprod, 1991 Aug, 6(7), 1011 - 6
Micromanipulation of gametes using laser microbeams; Tadir Y et al.; Various microsurgical procedures at the cellular and subcellular levels using laser non-touch techniques are presented and reviewed . In these procedures, the beams of light, varying in their wavelength (range: 14 ns to continuous wave), were directed via microscopes towards the target area . Micromanipulation of human spermatozoa with a laser-generated optical trap enabled the assessment of possible effects on sperm motility and measurements of the relative force generated by each single spermatozoon . Furthermore, the optical trap also provides a new approach to the measurements of intracellular forces without physically touching the cell or its organelles, and inducing chromosome movement during cell division is also possible . Laser beams in a specific configuration are able to induce minimal superficial damage to the zona pellucida of oocytes from various species . This manipulation is aimed at increasing the fertilization rate following insemination with low-quality spermatozoa . Another intracellular application of the laser beams is the destruction of extra pronuclei in polyspermic fertilized human oocytes . These procedures require special equipment which is not commonly available . However, simpler devices may be developed if the advantages of this novel technology are demonstrated.

Antibiot Khimioter, 1991 Aug, 36(8), 35 - 7
{Chromosomal resistance of plague agent to quinolones}; Kasatkina IV et al.; The nature of increasing chromosomal resistance to quinolones was studied in a model of the plague microbe . Five virulent strains of the natural plague microbe (Y . pestis) were used in the experiment: 363 (1/1479), 231, 2385, 2442 and 2444 . The one-stage procedure for isolation of the mutants was applied . It was shown that the frequency of the one-stage mutants resistant to oxalinic acid, pefloxacin and ciprofloxacin amounted to 10(-9)-10(-11) and was 2 to 3 orders of magnitude lower than that of the mutants resistant to nalidixic acid . Two types of the plague microbe mutants resistant to the quinolones were detected: those resistant to the quinolones to the generations (Nalr-phenotype) and those resistant to the representatives of the 3rd generation quinolones (Nals-phenotype) . The quinolones were not efficient in the treatment of albino mice with experimental plague caused by the quinolone-resistant forms of the plague microbe.

Proc Natl Acad Sci U S A, 1991 Jul 1, 88(13), 5645 - 9
Induction of antibodies to the envelope protein of the human immunodeficiency virus by immunization with monoclonal anti-idiotypes; Zaghouani H et al.; Anti-idiotypes that possess the internal image of antigen can induce protective humoral immunity toward microbes . Herein we demonstrate antigen mimicry by monoclonal anti-idiotypes of a distinct epitope of the human immunodeficiency virus (HIV) envelope protein that is defined by a synthetic peptide . This peptide, corresponding to amino acid residues 503-535 (peptide 503-535) of HIV-1 IIIB gp160, induced antibodies in three mammalian species that interacted with HIV-1 gp120 and inhibited in vitro syncytium formation caused by HIV-1, IIIB and MN isolates . Three monoclonal anti-idiotypes were generated against rabbit anti-gp120 antibodies specific for peptide 503-535 . These anti-idiotypes recognize an interspecies cross-reactive idiotype expressed on mouse, chimpanzee, baboon, rabbit, and human anti-gp120 antibodies specific for peptide 503-535 . The interaction with the cross-reactive idiotype is inhibited by synthetic peptide and HIV-1 gp160 . Furthermore, rabbits immunized with the monoclonal anti-idiotypes produced antibodies that also bind HIV-1 gp120 and gp160 and recognized the epitope defined by peptide 503-535.

Antibiot Khimioter, 1991 Jul, 36(7), 35 - 7
{Immunoactive peptide obtained from the optical ganglia of squid}; Besednova NN et al.; The data on the effect of a peptide from the squid optic ganglia named gangliin on some parameters of animal natural resistance are presented . It was shown that the prophylactic use of the peptide in mice 24 hours before their contamination with the lethal dose of E . coli protected 40 to 60 per cent of the animals from death . Gangliin accelerated elimination of E . coli from the host and increased the absorptive and digestive activity of the macrophages and polymorphonuclear leukocytes . With the use of gangliin it was possible to correct the phagocytosis defects in infectious processes having the phagocytic protection mechanism . Moreover, gangliin was supposed to be efficient in control of long-term persistence of various microbes in the cells of the system of mononuclear phagocytes.

Br J Pharmacol, 1991 Jul, 103(3), 1691 - 6
Comparison of the haemodynamic effects of adenosine monophosphate with sodium nitroprusside in a canine model of acute global left ventricular dysfunction; Finegan BA et al.; 1 . The haemodynamic effects of adenosine 5'-monophosphate (AMP) and sodium nitroprusside (SNP) were compared in anaesthetized dogs following the induction of acute left ventricular (LV) dysfunction . 2 . LV dysfunction was induced by the intracoronary administration of glass microbeads until left ventricular end diastolic pressure (LVEDP) was increased from 5 to 15 mmHg . This was associated with a decrease in LV dP/dt and cardiac index (CI) of 30% and 27%, respectively, and an increase in systemic vascular resistance index (SVRI) of 37% . 3 . Graded doses of AMP (100 to 1000 micrograms kg-1 min-1) or SNP (1 to 10 micrograms kg-1 min-1) reduced SVRI and increased CI in a dose-related manner . Heart rate was not altered by either agent . At doses that caused similar reductions in SVRI, CI was increased more by AMP than by SNP . 4 . The mechanisms responsible for the greater elevation of CI by AMP relative to SNP may be related to its more selective arterial vasodilator activity . SNP reduced cardiac preload that limited the expected increase in CI . 5 . The haemodynamic profile of AMP suggests that it may be useful in the pharmacological management of acute cardiac failure, either when used alone or in combination with positive inotropic agents and/or selective venodilators.

Dtsch Tierarztl Wochenschr, 1991 Jul, 98(7), 257 - 61
{Emissions of dust and microbes from animal housing}; Hilliger HG; The content of airborne dust and germs in animal houses is described qualitatively and quantitatively . After having left the animal house by way of the exhaust air the microorganisms suffer a decay which is caused by dispersion and death-rate . The dispersion can be demonstrated by models . The boundary of the dispersion of germs and dust is about 200 m from source under normal conditions . Epidemiologic studies indicate that some virus particles can be transported over several miles by way of the air . Control of airborne dust and germ levels in animal houses is still poor.

Drug Des Deliv, 1991 Jul, 7(4), 251 - 7
Prolongation of drug release by covalent bonding of drugs to serum albumin microbeads; Sheu MT et al.; Reaction conditions for the covalent bonding of 5'-deoxy-5-fluorouridine to serum albumin microbeads by means of a water-soluble carbodiimide were studied . Optimum coupling of dFUR to the microbeads occurred when pure water was used as solvent . There was no significant difference in the bonding efficiency for microbeads prepared at different stirring speeds, and there was a limit to the amount of dFUR that could be bound with increasing reaction time . Yields were low possibly because of competing coupling reactions involving carbodiimide and other reactive groups in the protein . The release of dFUR from dFUR-bound microbeads was slow and biexponential . The fraction of dFUR bound in the interior of the microbeads increased with increasing reaction time.

Dtsch Zahnarztl Z, 1991 Jul, 46(7), 485 - 7
{Water disinfection of dental treatment units using ozone}; Filippi A et al.; The disinfecting effect of ozonized water has been investigated . Under the precondition that the dental chair had been thoroughly sanitized, the system showed a good disinfecting effect . Finally, for reasons of practical medical treatment, the ozone concentration in air and, for reasons of hygiene in drinking water, the ozone concentrations in water were determined under various conditions . In addition, the influence of continuous-flow water heaters is discussed . The problem of continuous-flow water heaters regarding their effects on the colonisation of water by microbes proves not to be significant . The exposure of patients to disinfectants is discussed.

Fiziol Zh, 1991 Jul-Aug, 37(4), 92 - 7
{Immunologic response of divers working in the conditions of increased microbial contamination of water under pressure up to 5.1 MPa}; Semko VV et al.; The complex investigation of immune and nonspecific reactivity of 30 aquanauts was carried out during five experimental saturation divings up to 350-500 m accompanied by an increase of microbic contamination in water of the hyperbaric chamber . Peculiarities of humoral immune response and phagocyte functions were found to depend on the inflammatory disease of aquanauts . It is concluded that the situational transitory immune deficiency development under the influence of hyperbaric factors is possible and changes in the microbe spectrum are real.

Am J Respir Cell Mol Biol, 1991 Jul, 5(1), 27 - 33
Increased monocyte oxidase activity in cystic fibrosis heterozygotes and homozygotes; Regelmann WE et al.; Freshly isolated monocytes from cystic fibrosis (CF) heterozygotes and homozygotes had significantly increased oxygen uptake and superoxide formation after surface glycoprotein stimulation than did monocytes from age- and sex-matched controls . Lack of differences among the genotypes in inhibition by simple sugars of the concanavalin A-stimulated superoxide production and lack of differences in concanavalin A-binding surface proteins suggested that different regulation of the oxidase pathway produced the increased oxygen uptake and superoxide formation in CF patients and carriers . This regulatory role is consistent with the predicted structure of the CF gene product . The results support the hypothesis that the mononuclear phagocytes of CF heterozygotes have a significantly increased ability to kill intracellular microbes and may confer a selective advantage to the host.

J Immunol Methods, 1991 Jun 3, 139(2), 265 - 70
Determination of anti-IgA antibodies with a flow cytometer-based microbead immunoassay (MIA); Syrjala MT et al.; A flow cytometer-based microbead immunoassay (MIA) was employed to detect anti-IgA antibodies in patients with IgA deficiency . 3 microns latex particles were coated with purified IgA and serum anti-IgA antibodies of the IgG class were detected with FITC-conjugated anti-human IgG . Antibodies against three different IgA preparations were tested from 22 patients samples as well as 20 controls and compared with a conventional enzyme-linked immunosorbent assay (ELISA) and a passive hemagglutination assay (HA) . There was a very close correlation between the results obtained with the MIA and the ELISA assay and between MIA and the HA . Because of the low intra-assay variation and good linearity of the assay, the analysis of one single serum dilution was sufficient to determine the anti-IgA level of a patient and no titration series was required . We conclude that MIA is a satisfactory alternative method for routine anti-IgA antibody determinations . For laboratories already equipped with a flow cytometer the assay is cost effective.

J Speech Hear Res, 1991 Jun, 34(3), 453 - 9
The establishment of open articulatory postures by deaf and hearing talkers; Tye-Murray N; Previous researchers have proposed that prelingually deafened talkers do not displace the tongue body to establish vowel steady-state postures and displace the jaw excessively . The purpose of this investigation was to evaluate the opening gesture lingual displacement patterns of three deaf and two hearing adult talkers . Cinefluorography and x-ray microbeam data indicated that the deaf subjects displaced their tongue bodies during the opening gestures . However, their glossal movement trajectories were qualitatively dissimilar to those of the hearing subjects . Whereas the hearing subjects moved the tongue differently for different vowel contexts, the deaf subjects had similar trajectories for all contexts . The common trajectories suggest that some deaf talkers contract their tongue muscles such that the tongue body moves similarly for all vowels . The deaf subjects also appeared to have a less flexible tongue body during speech production than the hearing subjects . Means for quantifying and comparing the lingual behaviors of deaf and hearing talkers are considered.

Infect Control Hosp Epidemiol, 1991 Jun, 12(6), 368 - 72
Biological warfare and infection control; Nettleman MD; Though many agents have been proposed as potential biological weapons, the feasibility of biological warfare is largely a matter of conjecture . The unpredictable and indiscriminate devastation caused by natural epidemics during wartime should warn us of the dangers of employing microbes as weapons.

Arch Otolaryngol Head Neck Surg, 1991 Jun, 117(6), 653 - 6
Fine-needle aspiration in recurrent tonsillitis; Timon CI et al.; The incidence of tonsillitis that is unresponsive to penicillin therapy is leading to concern . This phenomenon has been linked to a change in the core tonsil bacteria, in particular beta-lactamase production . To date, the only way to identify the presence of these resistant microbes is at tonsillectomy . In this prospective study, we performed fine-needle tonsil aspiration in 34 patients (mean age, 7.6 years) before tonsillectomy . The bacteriologic nature of the aspirate was compared with that obtained from culturing the tonsillar surface (in situ) and core of the resected tonsils . The bacteriologic findings of the aspirate corresponded closely with those of the tonsil core (qualitative and quantitative comparison), while the superficial swab was of limited value in predicting the core bacteria . Based on this study, tonsil fine-needle aspiration may have a place in the treatment of recurrent tonsillitis.

Mol Gen Mikrobiol Virusol, 1991 Jun, (6), 9 - 13
{Comparison of the structural-functional properties of DNA-dependent RNA polymerase of the tularemia microbe and intestinal bacterial}; Pomerantsev AP et al.; The subunit compositions of RNA-polymerases from Escherichia coli and Francisella tularensis were compared . The activities of the enzymes on the corresponding chromosomal DNAs and their mixtures were defined.

Eur J Cell Biol, 1991 Jun, 55(1), 122 - 32
UV-microbeam irradiations of the mitotic spindle: spindle forces and structural analysis of lesions; Snyder JA et al.; Mitotic PtK1 spindles were UV irradiated (285 nm) during metaphase and anaphase between the chromosomes and the pole . The irradiation, a rectangle measuring 1.4 x 5 microns parallel to the metaphase plate, severed between 90 and 100% of spindle microtubules (MTs) in the irradiated region . Changes in organization of MTs in the irradiated region were analyzed by EM serial section analysis coupled with 3-D computer reconstruction . Metaphase cells irradiated 2 to 4 microns below the spindle pole (imaged by polarization optics) lost birefringence in the irradiated region . Peripheral spindle fibers, previously curved to focus on the pole, immediately splayed outwards when severed . We demonstrate via serial section analysis that following irradiation the lesion was devoid of MTs . Within 30 s to 1 min, recovery in live cells commenced as the severed spindle pole moved toward the metaphase plate closing the lesion . This movement was concomitant with the recovery of spindle birefringence and some of the severed fibers becoming refocused at the pole . Ultrastructurally we confirmed that this movement coincided with bridging of the lesion by MTs presumably growing from the pole . The non-irradiated half spindle also lost some birefringence and shortened until it resembled the recovered half spindle . Anaphase cells similarly irradiated did not show recovery of birefringence, and the pole remained disconnected from the remaining mitotic apparatus . Reconstructions of spindle structure confirmed that there were no MTs in the lesion which bridged the severed spindle pole with the remaining mitotic apparatus . These results suggest the existence of chromosome-to-pole spindle forces are dependent upon the existence of a MT continuum, and to a lesser extent to the loss of MT initiation capacity of the centrosome at the metaphase/anaphase transition.

Med Hypotheses, 1991 Jun, 35(2), 115 - 21
A novel hypothesis concerning the mechanisms of activation, and of control, of periodontal bone loss; Creamer HR; Chronic inflammatory periodontitis fulfills the classical definition of an infectious disease in that it is a disease of the host caused by the activities of one or more parasites . Typically, the etiology of an infectious disease has been defined as the specific microbe which incites the disease process, even though the quality and nature of host responses to the pathogen may underlie much of the pathology seen . This approach in the study of the etiology of chronic periodontitis has not resulted in the identification of a single 'periodontopathogen', but rather is leading to the realization that multiple sets of microbes may induce the same endpoint, albeit some possibly more efficiently than others . The premise of this paper is that a different view of the literature in the area, with the primary emphasis on the mechanisms of damage and resistance to periodontitis, reveals a probable commonality, rather than a plethora of diseases . The concept of a mechanism-based etiology, rather than of a microbe-based one, deserves consideration for this complex, host-parasite interaction . The novel hypothesis presented here is that the common virulence factor of chronic periodontitis is lipopolysaccharide (LPS), that the central damaging mediator is a cyclooxygenase product of arachidonic acid (probably prostaglandin E2), and that the critical resistance mechanism that limits disease activity is the effective, peripheral neutralization of LPS by emigrated polymorphonuclear neutrophils.

Biochemistry, 1991 May 21, 30(20), 5066 - 75
Real-time analysis of the assembly of ligand, receptor, and G protein by quantitative fluorescence flow cytometry; Fay SP et al.; We describe a general approach for the quantitative analysis of the interaction among fluorescent peptide ligands (L), receptors (R), and G proteins (G) using fluorescence flow cytometry . The scheme depends upon the use of commercially available fluorescent microbeads as standards to calibrate the concentration of fluorescent peptides in solution and the receptor number on cells in suspension . We have characterized a family of fluoresceinated formyl peptides and analyzed both steady-state and dynamic aspects of ligand formyl peptide-receptor interactions in digitonin-permeabilized human neutrophils . Detailed receptor-binding studies were performed with the pentapeptide N-formyl-Met-Leu-Phe-Phe-Lys-fluorescein . Equilibrium studies showed that GTP {S} caused a loss of binding affinity of approximately two orders of magnitude, from approximately 0.04 nM (LRG) to approximately 3 nM (LR), respectively . Kinetic studies revealed that this change in affinity was principally due to an increase in the dissociation rate constants from approximately 1 x 10(-3) s-1 (LRG) to approximately 1 x 10(-1) s-1 (LR) . In contrast, the association rate constants in the presence and absence of guanine nucleotide (approximately 3 x 10(7) s-1 M-1) were statistically indistinguishable and close to the diffusion limit . In the presence of guanine nucleotide (LR), the kinetic data were adequately fit by a single-step reversible-binding model . In the absence of guanine nucleotides, not all receptors have rapid access to G to form the LRG ternary complex . Mathematically, those R that have rapid access to G are either precoupled to R or the association of G with R is fast compared to the association of L with R . The physiological consequences of coupling heterogeneity are discussed.

Tidsskr Nor Laegeforen, 1991 May 20, 111(13), 1636 - 7
{Antibiotics and ecology in the Third World}; Midtvedt T; Infectious diseases are more common in developing than in developed countries, as in inapropriate use of antibiotics, and antibioticresistant microbes . Problems connected to misuse of antibiotics and resistance to these substances, and the ecological disturbances following use of such drugs, are of global importance . The author underlines the need for improvements.

Proc Natl Acad Sci U S A, 1991 May 15, 88(10), 4133 - 7
Structural and functional conservation of histidinol dehydrogenase between plants and microbes; Nagai A et al.; The partial amino acid sequence of histidinol dehydrogenase (L-histidinol:NAD+ oxidoreductase, EC 1.1.1.23) from cabbage was determined from peptide fragments of the purified protein . The relative positions of these peptides were deduced by aligning their sequences with the sequence of the HIS4C gene product of Saccharomyces cerevisiae . cDNA encoding histidinol dehydrogenase was then amplified from a library using a polymerase chain reaction primed with degenerate oligonucleotide pools of known position and orientation . By using this amplified fragment as a probe, an apparently full-length cDNA clone was isolated that is predicted to encode a proenzyme having a putative 31-amino acid chloroplast transit peptide and a mature molecular mass of 47.5 kDa . The predicted protein sequence was 51% identical to the yeast enzyme and 49% identical to the Escherichia coli enzyme . Expression of the cDNA clone in an E . coli his operon deletion strain rendered the mutant able to grow in the presence of histidinol.

Crit Care Med, 1991 May, 19(5), 627 - 41
Gastrointestinal mucosal injury in experimental models of shock, trauma, and sepsis; Fink MP; BACKGROUND AND METHODS: The mucosa of the GI tract serves as an important barrier limiting the systemic absorption of luminal microbes and microbial products . Two methods commonly used to assess the integrity of the GI mucosal barrier are assessment of the extent of microbial translocation and measurement of mucosal permeability to hydrophilic probes . RESULTS: Studies using these methods have provided convincing evidence that the barrier function of the intestinal mucosa is deranged in numerous animal models of shock, trauma, and sepsis . CONCLUSIONS: Although the mechanisms underlying mucosal injury under these circumstances remain incompletely understood, current evidence suggests that mucosal damage in shock, trauma, and sepsis is likely due to various combinations of intracellular hypoxia due to ischemia, tissue injury caused by reactive oxygen metabolites, the deleterious effects of various lipid mediators (e.g., platelet-activating factor) and/or cytokines (e.g., tumor necrosis factor), and deficient utilization or supply of key nutritional substrates (e.g., glutamine).

Infect Immun, 1991 May, 59(5), 1853 - 6
Interleukin-2 and granulocyte-macrophage colony-stimulating factor stimulate growth of a virulent strain of Escherichia coli; Denis M et al.; The effect of human recombinant interleukin-2 (IL-2) and human recombinant granulocyte-macrophage colony-stimulating factor on the growth of a virulent strain of Escherichia coli in tissue culture medium and in untreated, normal mouse serum was investigated . Both of these cytokines enhanced the growth of the microorganism two- to threefold in tissue culture medium with or without additional fetal calf serum and in untreated mouse serum . IL-4 did not have any effect on the growth of this microbe under the conditions tested . That the enhancement of growth seen with recombinant IL-2 was due to the active cytokine was shown by the following data: (i) addition of an antibody to IL-2 abrogated the growth-promoting effect; (ii) the excipient buffer, which contained everything except the active cytokine, was inactive in modifying bacterial growth; and (iii) heat-inactivated recombinant IL-2 did not promote enhanced microbial growth . The enhancement of growth with IL-2 was significant with concentrations as low as 1 U/ml . Growth of an avirulent strain of E . coli was not stimulated by IL-2 . Moreover, addition of IL-2 to growth virulent E . coli in tissue culture medium led to rapid removal of the cytokine from the medium . Collectively, these data suggest that cytokines may act as growth factors for some virulent bacteria.

J Toxicol Environ Health, 1991 May, 33(1), 81 - 91
Consumption of fish: benefits and perceived risk; Kimbrough RD; Fish, a useful source of protein, may be polluted by microbes, natural toxins, and/or synthetic chemicals . However, based on a review of the U.S . General Accounting Office, "There does not appear to be a compelling case to implement a mandatory comprehensive federal seafood inspection program." Although earlier studies showed higher body burdens of polychlorinated biphenyls (PCBs) in populations who consumed a lot of fish from polluted waterways, a recent study refutes these observations . No information is available in the United States on the levels of polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs) in anglers who consume a great deal of fish presumed to be contaminated by these chemicals.

CA Cancer J Clin, 1991 May-Jun, 41(3), A7 - 12
Unproven methods of cancer management . Livingston-Wheeler therapy.
{Allotransplantation of cultured fibroblasts on non-healing wounds after autodermatoplasty}
Sarkisov DS, Glushchenko EV, Gurukov ShR, Morozov SS, Tumanov VP, Berezhkov NV.

An allograft from man cultured fibroblasts has been received . Results of its transplantation on long not-healing donor wounds in 13 patients after autodermatoplastic operations have been studied . Expressed stimulating influence of cultured fibroblasts on donor wound epithelialization processes has been stated . In spite of allograft applications there has been no tearing away reactions . It has been connected with elimination of superficial cell antigens during cultivation . Microbe contamination of more than 10(2) is the contraindication for grafting.

J Cell Biochem, 1991 May, 46(1), 60 - 8
Novel immunomodulators with pronounced in vivo effects caused by stimulation of cytokine release; Rasmussen LT et al.; Beta-1,3-D-polyglucose derivatives protect mice against otherwise lethal bacterial infections . This protective effect has been considered to be mediated through mononuclear phagocytes . By using radioactive labelling, we localized the beta-1,3-D-polyglucose derivatized microbeads (GDM) during the period following injection . The GDM was recovered mainly in the milky spots of the omentum . In animals treated with GDM, the total white cell number was significantly increased in peritoneal fluid of mice before and after challenge with E . coli . Bacterial counts in peritoneal fluid of GDM treated animals declined to zero after 24 h . In untreated animals there was a slight increase in bacterial counts until the animals died after about 12 h . Mouse peritoneal macrophages stimulated with GDM released significant amounts of IL-1 and PGE2 . There was no significant release of TNF . Levels of IL-1 and PGE2 in peritoneal fluid increased significantly during the first 48 h after treatment with GDM . There was no increase of levels of TNF . After challenge with E . coli, the levels of IL-1, TNF, and PGE2 were significantly lower compared with control animals . In untreated animals the levels of IL-1 and TNF remained elevated until the animals died after about 12 h . These studies demonstrate that the raised levels of arachidonic acid metabolites after pretreatment with GDM or AG seems to inhibit the otherwise lethal elevation of IL-1 and TNF in body fluids which is seen in untreated animals.

Ann Neurol, 1991 May, 29(5), 492 - 7
Epidemiology of encephalitis in children: a 20-year survey; Koskiniemi M et al.; Four hundred five children from the Helsinki area who were 1 month to 16 years old were treated for acute encephalitis at the Children's Hospital, University of Helsinki, from January 1968 through December 1987 . Encephalitis occurred most commonly in children 1 to 1.9 years of age, among whom the incidence was 16.7 per 100,000 child-years . The incidence remained quite high until the age of 10 years, and then gradually declined to 1.0 per 100,000 child-years at the age of 15 years . Since 1983, when mumps, measles, and rubella vaccination eradicated the encephalitides associated with these microbes, the major associated agents have been varicella-zoster, Mycoplasma pneumoniae, and respiratory and enteroviruses . In infants younger than 1 year of age, the major agents were enteroviruses, herpes simplex virus, and the group of "others," whereas in older children, respiratory viruses and Mycoplasma pneumoniae, as well as varicella-zoster virus, dominated . In children aged 1 to 11 months, the causal agent could not be identified in one-half of all cases, whereas in children who were at least 10 years old, the etiology remained unknown in only one-fourth of cases . Male dominance was most evident in the 4- to 9-year age group . The difference in etiology between males and females was significant (p = 0.02); mumps and varicella were more common in boys, and adenovirus and Mycoplasma pneumoniae were more common in girls . The overall male-to-female ratio was 1.4:1 . Characteristic seasonal variation occurred in encephalitides associated with mumps, measles, and entero- and respiratory viruses.(ABSTRACT TRUNCATED AT 250 WORDS)

Biotechnology (N Y), 1991 May, 9(5), 468 - 71
A novel synthetic method for hybridoma cell encapsulation; Carmen Bano M et al.; We report here what we believe is the first example of the encapsulation of hybridoma cells within a synthetic polymer by a simple gelation with dissolved cations in water, and at room temperature . Two lines of hybridoma cells were encapsulated within calcium cross-linked polyphosphazene gel microbeads without affecting their viability or their capability to produce antibodies . Interaction of these gel beads with the positively-charged polyelectrolyte, poly(L-lysine), of 102-kD molecular weight, produced a semipermeable membrane that was capable of retaining the cell-secreted antibodies inside the beads . Cell density increased 3.5-fold within 13 days concomitant with a 6.4-fold increase in antibody production . These synthetic membranes have the potential to aid in protein recovery schemes.

Kansenshogaku Zasshi, 1991 Apr, 65(4), 365 - 73
{Role of transiently accumulated neutrophils in the lung of hamster in development of pneumonia due to Mycoplasma pneumoniae}; Yano T et al.; The importance of Mycoplasma pneumoniae as a pathogen of human infectious diseases, particularly of respiratory infections, has been well recognized . However, the details of the mechanism through which lung tissue damages are produced in mycoplasmal infection has not been fully understood . It has been pointed out that beside the direct invasive process certain immunological responses to the deposited microbes are crucial in development of mycoplasmal pneumonia . In the present study, we aimed at elucidating the role of neutrophils in producing pneumonia due to Mycoplasma pneumoniae in hamsters . For this purpose, hamsters were divided into two groups; the one not pretreated and infected with Mycoplasma pneumoniae and the other immunosuppressed by 60Co irradiation and infected . A serial determination of the numbers of mycoplasmal cells recovered from the treacheal tissue and bronchoalveolar lavage fluid (BALF) and analysis of cellular components in BALFs were carried out . The severity and the nature of pathological changes produced in the lungs were evaluated and scored on the basis of microscopic findings . As a result, it was found that the numbers of mycoplasmal cells recovered from both tracheal tissues and BALFs reached maximum on the seventh day of infection in both groups and decreased rapidly . There no apparent difference was found between the two groups in number of cells recovered . In the not-irradiated control groups, the percentage of polymorphonuclear leukocytes (PMNs) in BALF was very high on the seventh day and then they were replaced by lymphocytes by the 21st day of infection.(ABSTRACT TRUNCATED AT 250 WORDS)

J Acoust Soc Am, 1991 Apr, 89(4 Pt 1), 1782 - 91
The significance and measurement of head position during speech production experiments using the x-ray microbeam system; Westbury JR; Head position and orientation are important variables during experiments conducted on the University of Wisconsin x-ray microbeam system, a nationally shared imaging facility for speech production research . Normally, the head is not restrained during experiments, in order to maximize the naturalness of speech performance, even though free head movements may have an adverse effect on the accuracy of kinematic data that are obtained . The basis for this effect is explained, and techniques for dealing with temporal variations in head position are described . Results obtained from a novel method for three-dimensional measurement of head position, applied to data sets recorded from six normal adult speakers during otherwise typical x-ray microbeam experiments, are summarized to convey some sense of the measurement error that can arise from deviations from a required head position . These measurements suggested that among these speakers, errors attributable to improper positioning of the head, and/or inadvertent head movements within or between trials, never exceeded 5%.

Dent Clin North Am, 1991 Apr, 35(2), 339 - 55
Sterilization . Disciplined microbial control; Miller CH; The goal of instrument processing is to protect patients by preventing cross-contamination from instruments . The processing involves a series of sequential steps aimed at removing and killing microbes on contaminated instruments and maintaining those instruments in an aseptic state until they are reused . These steps must be conducted carefully to assure success and to reduce chances of disease spread or physical injury to those handling the contaminated instruments . Presoaking begins the cleaning process and facilitates terminal cleaning by ultrasonic or manual scrubbing . If instruments are not properly cleaned, subsequent sterilization may be jeopardized by insulation of blood- or saliva-coated microbes from the sterilizing agent . Items that would be destroyed by heat should be cleaned and sterilized in a properly prepared glutaraldehyde solution . Cleaned instruments must be packaged prior to heat sterilization to protect them from recontamination after sterilization and before reuse . Sterilization of cleaned, packaged instruments in steam, chemical vapor, or dry heat sterilizers must involve proper loading, processing, drying, and cooling . Routine use of spore tests and chemical indicators will provide quality assessment of packaging procedures and operation of the sterilizer, as well as assist in identifying processed packages during distribution . Using the results of sterilization monitoring to adjust procedures as a means of assuring sterilization provides quality assurance to the office staff and to the patients that the instruments have been properly processed . Carefully handling storage and distribution of the sterilized instrument packs or trays reduces the chances for recontamination until the instruments are reused . Instrument processing is a major part of the office infection control program . It must be performed in a controlled manner with proper monitoring to achieve the desired outcome of patient protection.

J Invest Dermatol, 1991 Apr, 96(4), 439 - 45
Immunoglobulins coat microorganisms of skin surface: a comparative immunohistochemical and ultrastructural study of cutaneous and oral microbial symbionts; Metze D et al.; Only recently have human sweat glands been demonstrated to secrete immunoglobulins (Ig), paralleling Ig secretion in mucosal epithelia . It is well established that Ig protect mucosal membranes against infections by binding to surface structures of microorganisms . In view of these findings immunohistochemical studies were performed to determine if microbes on the skin surface are coated by Ig as proposed for mucosal bacteria and fungi . Smear preparations from the skin and oral cavity rich in micro-organisms were subjected to immunoperoxidase staining using anti-secretory component (SC), -IgA, -IgM, -IgG antibodies . An immunogold labeling technique of microbial suspensions of sweat and saliva was adapted to correlate the results on an ultrastructural level . Negative controls included unsuccessful staining for IgA in preparations obtained from an IgA-deficient patient as well as nonreactivity of subcultured microorganisms for all Ig classes or SC . Smear preparations from both the oral cavity and skin surface exhibited labeling of bacterial or fungal elements with anti-IgA, -IgM, -IgG, and -SC antibodies . Skin bacteria revealed a lower number of reactive microbes as compared to saliva . Staining intensity for the different Ig classes exhibited intra- and interindividual variations . Immunoelectronmicroscopically, Ig and SC could be detected either directly along the cell wall of coccal, coryneform, and fungal elements or on floccular and fimbrial material adhering to the bacterial surface . It is concluded that secretory Ig of the skin cover surface structures of microorganisms and thus modify their adhesional and/or infectious properties, resembling humoral surface immunity on mucous membranes.

Clin Sci (Lond), 1991 Apr, 80(4), 281 - 4
Achlorhydria-induced hypergastrinaemia: the role of bacteria; Calam J et al.; 1 . Studies of Helicobacter pylori show that microbes can alter gastrin release . Lack of gastric acid (achlorhydria) causes hypergastrinaemia and allows bacteria to grow within the stomach . We speculated that the bacteria contribute to the rise in gastrin seen after acid inhibition, and tested the idea by comparing plasma gastrin levels during inhibition of acid secretion between germ-free and conventional rats . 2 . Matched germ-free and conventional rats (n = 8 per group) received either vehicle (saline) or one of two doses of the histamine-H2-receptor antagonist loxtidine for 1 week . Gastrin was measured in cardiac blood by a specific r.i.a . 3 . Plasma gastrin concentrations in germ-free and conventional rats were 59 +/- 11 pmol/l (mean +/- SEM) and 36 +/- 8 pmol/l, respectively, after vehicle, and 153 +/- 30 pmol/l and 181 +/- 27 pmol/l, respectively, after loxtidine at a dose of 10 mg day -1 kg -1, which partially inhibits acid secretion . Administration of loxtidine at a dose of 70 mg day -1 kg-1, which completely inhibits acid secretion, did not produce a significant extra rise in plasma gastrin concentration in germ-free rats (178 +/- 11 pmol/l), but further elevated plasma gastrin concentrations to 278 +/- 26 pmol/l in conventional rats (P less than 0.005 compared with germ-free rats) . 4 . Loxtidine produced a dose-dependent rise in the number of eosinophils in the gastric mucosa of conventional rats . 5 . We conclude that partial inhibition of gastric acid secretion increases gastrin release independently of bacteria, but that bacteria are involved in the further rise in gastrin which occurs on more profound inhibition of gastric acid secretion.

Proc Natl Acad Sci U S A, 1991 Mar 15, 88(6), 2259 - 63
Transcription is associated with Z-DNA formation in metabolically active permeabilized mammalian cell nuclei; Wittig B et al.; Mammalian cells have been encapsulated in agarose microbeads, and from these cells metabolically active permeabilized nuclei were prepared . Previously, we showed that biotin-labeled monoclonal antibodies against Z-DNA can be diffused into the nuclei and, over a specific concentration range, they will bind to Z-DNA within the nucleus in a concentration-independent manner . By using radiolabeled streptavidin, we showed that the amount of Z-DNA antibody bound is related to the torsional strain of the DNA in the nucleus . Relaxation of the DNA results in a decrease of Z-DNA formation, whereas increasing torsional strain through inhibiting topoisomerase I results in increased Z-DNA formation . Here we measure the influence of RNA transcription and DNA replication . Transcription is associated with a substantial increase in the binding of anti-Z-DNA antibodies, paralleling the increased level of RNA synthesized as the level of ribonucleoside triphosphate in the medium is increased . DNA replication yields smaller increases in the binding of Z-DNA antibodies . Stopping RNA transcription with inhibitors results in a large loss of Z-DNA antibody binding, whereas only a small decrease is associated with inhibition of DNA replication.

J Cell Sci, 1991 Mar, 98 ( Pt 3), 415 - 22
In ultraviolet microbeam irradiations, characteristics of the monochromator and lamp affect the spectral composition of the ultraviolet light and probably the biological results; Forer A; Biological conclusions recently published concerning ultraviolet (u.v.) microbeam irradiation of spindles are different from those we previously published . Several technical differences between the two sets of experiments were investigated . The spectral distributions in the light emitted from mercury-arc, xenon-mercury-arc, and xenon-arc lamps were measured, as were the spectral distributions after the light from these lamps passed through a monochromator that was set to various wavelengths and various half-band-widths . Both the source of the u.v . light and the half-band-width of the monochromator influence the spectral distribution of the light leaving the monochromator: depending on the conditions, the light leaving the monochromator is not necessarily of the same wavelength as that to which the monochromator is set . Differences in these aspects of the experiments could easily give rise to the different biological conclusions reached in the two sets of experiments.

Mol Microbiol, 1991 Mar, 5(3), 529 - 34
Physiological roles of the DnaK and GroE stress proteins: catalysts of protein folding or macromolecular sponges?
LaRossa RA, Van Dyk TK.
When organisms ranging from microbes to man are subjected to certain environmental stresses a characteristic 'heat shock' response is observed . In Escherichia coli this response is characterized by the induction of several proteins, three of which are the 70 kilodalton product of the dnaK gene, the 60 kilodalton product of the groEL (mopA) gene and the 15 kilodalton product of the groES (mopB) gene . In this review, utilizing enteric bacteria as model organisms, we focus on the role of these proteins within the context provided by well-established functions of other heat shock products . These facts serve as a starting point from which to speculate upon the in vivo role of these proteins during steady-state growth.

J Cell Biol, 1991 Mar, 112(5), 941 - 54
Poleward microtubule flux mitotic spindles assembled in vitro; Sawin KE et al.; In the preceding paper we described pathways of mitotic spindle assembly in cell-free extracts prepared from eggs of Xenopus laevis . Here we demonstrate the poleward flux of microtubules in spindles assembled in vitro, using a photoactivatable fluorescein covalently coupled to tubulin and multi-channel fluorescence videomicroscopy . After local photoactivation of fluorescence by UV microbeam, we observed poleward movement of fluorescein-marked microtubules at a rate of 3 microns/min, similar to rates of chromosome movement and spindle elongation during prometaphase and anaphase . This movement could be blocked by the addition of millimolar AMP-PNP but was not affected by concentrations of vanadate up to 150 microM, suggesting that poleward flux may be driven by a microtubule motor similar to kinesin . In contrast to previous results obtained in vivo (Mitchison, T . J . 1989 . J . Cell Biol . 109:637-652), poleward flux in vitro appears to occur independently of kinetochores or kinetochore microtubules, and therefore may be a general property of relatively stable microtubules within the spindle . We find that microtubules moving towards poles are dynamic structures, and we have estimated the average half-life of fluxing microtubules in vitro to be between approximately 75 and 100 s . We discuss these results with regard to the function of poleward flux in spindle movements in anaphase and prometaphase.

Hum Reprod, 1991 Mar, 6(3), 386 - 9
Comparison of the ability of two sperm preparation techniques to remove microbes; Karlstrom PO et al.; The ability of a new sperm preparation method--self migration in sodium hyaluronate (SH)--to remove microbes from samples was compared to that of the traditional method of centrifugation/swim up (CS) . Two 1-ml aliquots were taken from 20 semen samples used for inseminations, and prepared by each of the methods . Samples for culture were taken immediately before wash and at 2 and 24 h after . Microbes were found in all raw semen samples with a mean concentration of 47.8 x 10(3) colony forming units per ml (c.f.u./ml) . After preparation and 2 h incubation with and without penicillin, both CS and SH were found greatly to reduce the number of isolates . There were no differences between the ability of the two methods to reduce microbe concentration, although SH recovered more progressive motile spermatozoa than CS (P less than 0.05) . When penicillin preparation was omitted, both the CS and SH methods resulted in significantly more isolates after 24 h of incubation . This effect of penicillin preparation was also evident after only 2 h of incubation with CS, but not with SH . No clinical signs of infection were observed among women receiving treatment . We conclude that sperm preparation by self migration in sodium hyaluronate is a simple and safe method to remove microbes and to recover motile spermatozoa.

Antibiot Khimioter, 1991 Mar, 36(3), 34 - 7
{Some aspects of antibiotic resistance of oligotrophic bacteria}; Zlatkin IV et al.; Antibiotic resistance spectra of a large group of oligotrophic and eutrophic bacteria from the open soil and aquatic ecosystems were studied . It was shown that sometimes antibiotic resistance of the oligotrophs was of plasmid nature . A possible transfer of plasmid antibiotic resistance from oligotrophs to pathogenic eutrophic soil and aquatic bacteria in the natural ecosystems is discussed . It was demonstrated that there was no insurmountable transcription/translation barriers between oligotrophic and eutrophic bacteria though the two bacterial groups are taxonomically and evolutionally very distant . A hypothesis was proposed that oligotrophic bacteria are likely to be one of the possible pools of plasmid antibiotic resistance for pathogenic microbes . Plasmid-free strains of some oligotrophic bacteria were selected . With the method of antibioticograms, taxonomic patterns for oligotrophic bacteria of the central group were developed.

Scand J Immunol, 1991 Mar, 33(3), 297 - 306
Phagocytosis of beta-1,3-D-glucan-derivatized microbeads by mouse peritoneal macrophages involves three different receptors; Konopski Z et al.; Intraperitoneal injection of beta-1,3-D-glucan coupled to the surface of monodisperse methacrylate microbeads improves the resistance against bacterial infections in mice, while methacrylate microbeads alone do not . The effect of the glucan-derivatized microbeads (GDM) is considered to be mediated through peritoneal macrophages . We show that both GDM and the underivatized methacrylate microbeads (UDM) treated with normal serum were rapidly bound and phagocytized by mouse peritoneal macrophages in vitro . We found that both complement and fibronectin opsonized the beads and were responsible for the uptake . Treatment of microbeads with serum lacking fibronectin and complement activity still gave some uptake of GDM, but not uptake of UDM . The uptake of GDM was similar to the uptake of untreated GDM and was inhibited by pretreatment of macrophages with soluble beta-1,3-D-glucan . Our conclusion is that GDM and UDM intraperitoneally bind fibronectin and C3 through activation of the alternative pathway of complement . This leads to their phagocytosis by macrophages through fibronectin and complement receptors . GDM are also internalized via beta-glucan receptors . We present the hypothesis that the beta-glucan receptors on peritoneal macrophages account for the protective effect of GDM in intraperitoneal bacterial infections.

Biochem J, 1991 Feb 15, 274 ( Pt 1), 121 - 32
Modification of host cell membrane lipid composition by the intra-erythrocytic human malaria parasite Plasmodium falciparum; Hsiao LL et al.; The phospholipid and fatty acid compositions of the host infected erythrocyte plasma membrane (IEPM) have been determined for erythrocytes infected with the human malaria parasite Plasmodium falciparum . IEPM were prepared by selective lysis of the host erythrocyte (but not of the parasite membranes) with 0.1% saponin, followed by differential centrifugation . The purity of the IEPM was determined by measuring the membrane-specific enzyme markers acetylcholinesterase, glutamate dehydrogenase and lactate dehydrogenase, and by immunoelectron microscopy using monoclonal antibodies specific for human erythrocyte glycophorin A (4E7) and for a 195 kDa parasite membrane glycoprotein (Pf6 3B10.1) . Both approaches demonstrated that the host erythrocyte plasma membrane preparation was free from contamination by parasite membranes . During intra-erythrocytic development of the parasite, the phospholipid composition of the erythrocyte membrane was strikingly altered . IEPM contained more phosphatidylcholine (38.7% versus 31.7%) and phosphatidylinositol (2.1% versus 0.8%) and less sphingomyelin (14.6% versus 28.0%) than normal uninfected erythrocytes . Similar alterations in phospholipid composition were determined for erythrocyte membranes of parasitized cells isolated by an alternative method utilizing polycationic polyacrylamide microbeads (Affigel 731) . The total fatty acid compositions of the major phospholipids in IEPM were determined by g.l.c . The percentage of polyunsaturated fatty acids in normal erythrocyte phospholipids (39.4%) was much higher than in phospholipids from purified parasites (23.3%) or IEPM (24.0%) . The unsaturation index of phospholipids in IEPM was considerably lower than in uninfected erythrocytes (107.5 versus 161.0) and was very similar to that in purified parasites (107.5 versus 98.5) . Large increases in palmitic acid (C16:0) (from 21.88% to 31.21%) and in oleic acid (C18:1) (from 14.64% to 24.60%), and major decreases in arachidonic acid (C20:4) (from 17.36% to 7.85%) and in docosahexaenoic acid (C22:6) (from 4.34% to 1.8%) occurred as a result of infection . The fatty acid profiles of individual phospholipid classes from IEPM resembled in many instances the fatty acid profiles of parasite phospholipids rather than those of uninfected erythrocytes . Analysis of IEPM from P . falciparum-infected erythrocytes (trophozoite stage) revealed that, during intra-erythrocytic maturation of the parasite, the host erythrocyte phospholipid composition was markedly refashioned . These alterations were not dependent on the method used to isolate the IEPM, with similar results obtained using either a saponin-lysis method or binding to Affigel beads . Since mature erythrocytes have negligible lipid synthesis and metabolism, these alterations must occur as a result of parasite-directed metabolism of erythrocyte lipids and/or trafficking of lipids between the parasite and erythrocyte membranes.

Hear Res, 1991 Feb, 51(2), 215 - 30
Application of a commercially-manufactured Doppler-shift laser velocimeter to the measurement of basilar-membrane vibration; Ruggero MA et al.; A commercially-available laser Doppler-shift velocimeter has been coupled to a compound microscope equipped with ultra-long-working-distance objectives for the purpose of measuring basilar membrane vibrations in the chinchilla . The animal preparation is nearly identical to that used in our laboratory for similar measurements using the Mossbauer technique . The vibrometer head is mounted on the third tube of the microscope's trinocular head and its laser beam is focused on high-refractive-index glass microbeads (10-30 microns) previously dropped, through the perilymph of scala tympani, on the basilar membrane . For equal sampling times, overall sensitivity of the laser velocimetry system is at least one order of magnitude greater than usually attained using the Mossbauer technique . However, the most important advantage of laser-velocimetry vis-a-vis the Mossbauer technique is its linearity, which permits undistorted recording of signals over a wide velocity range . Thus, for example, we have measured basilar-membrane responses to clicks whose waveforms have dynamic ranges exceeding 60 dB.

Hear Res, 1991 Feb, 51(2), 203 - 13
Laser Doppler velocimetry of basilar membrane vibration; Nuttall AL et al.; A method is described for the measurement of basilar membrane (BM) vibration velocimeter (LDV) . The instrumentation was coupled to a compound microscope which served to visualize reflective glass microbeads placed on the BM . The laser beam of the LDV was focused in the microscope object plane and positioned over the reflective bead . We show examples of frequency tuning curves and displacement input/output intensity functions obtained with the technique.

Cytotechnology, 1991 Feb, 5(2), 155 - 63
Methods for improving tissue culture of human tracheo-bronchial epithelium obtained at autopsy; Smith MW et al.; Human tracheo-bronchial epithelium obtained from autopsy, surgery, and organ donation will have areas of both viable and non-viable cells . It is important in the initial establishment of epithelial explant and cell cultures that injured, non-viable mucosal epithelium not be used for the cultures . Autopsy cases selected for culture should initially be chosen on the basis of a shorter post mortem interval and cause of death in order to increase the rate of successful culture . Staining the epithelium with the vital dye, trypan blue, in combination with phase contrast microscopy of the bronchial tissues will further identify those areas of the mucosa that are enriched for viable cells . The dead, non-viable areas are trypan blue positive, while the viable areas are clear and have foci of beating, motile cilia . Treatment of the mucosal tissue with mucolytic agents to remove cell debris, dead cells, and microbes trapped in the mucus material will further improve the chances for successful culture . Human tracheo-bronchial epithelium, although non-sterile and often injured at time zero for numerous reasons, can effectively be used in vitro pathophysiology studies.

Cytometry, 1991, 12(6), 525 - 36
Interlaboratory study of cellular fluorescence intensity measurements with fluorescein-labeled microbead standards; Vogt RF Jr et al.; To determine the precision of cellular fluorescence intensity (FI) measurements derived from labeled microbead standards, FI results were compared from 43 different flow cytometers in 34 laboratories . All laboratories analyzed prepared aliquots of fluoresceinated calf thymocyte nuclei (Fluorotrol), human lymphocytes stained with fluoresceinated anti-CD4 antibody, and fluoresceinated microbeads used as both internal and external standards . Measurements were conducted by most laboratories on the third and fourth days after sample preparation . Results for percent of events within the gates and the histograms returned by participants indicated that the samples had remained stable and that gated populations had been properly identified . All standard curves showed strong linearity, and the pooled results from all standards produced a best-fit curve that was in close agreement with the assigned values . Nonetheless, results for cellular FI were highly variable, with CVs of 20-34% . Agreement within lab/instrument was much better, with CVs ranging from 3.0 to 9.9% . The overall variability was not obviously attributable to differences in the types of cytometer, nor could it be explained by attributes of the standard curves or any other single variable examined . However, the application of a corrective factor based on FI results for Fluorotrol allowed a two-fold improvement in the precision of FI measurements on CD4-stained lymphocytes, with an overall CV of 11% . Uncharacterized differences in the operating conditions of flow cytometers can influence cellular FI measurements, but consistent results can be obtained if a stained cellular calibrator is analyzed in addition to the proper microbead standards.

Biomed Sci Instrum, 1991, 27, 283 - 9
Portable data acquisition cart for equine transportation stress study; Cain PW et al.; A remote data sampling cart has been designed and built for studying environmental factors that produce stress in horses during transportation . This dedicated sampling cart uses an XT-compatible mother board powered by a 12 V battery, with customized BIOS and ROM program . Sampling is performed using two digital and eight A/D (bipolar, differential) channels in burst mode at a frequency of 1 kHz . Digitized data are stored on magnetic tape for retrieval after the experiment . Configuration of sampling parameters is accomplished via a serial communications link to a host computer, and is stored in battery backed-up RAM, so that the cart can be self initializing . The digitized data consist of samples from transducers that measure 3-axis accelerations, air flow, sound intensity, environmental temperatures, and heart rates of two horses . Twenty four digital output lines control external sampling devices to collect gas samples for quantification and identification of airborne particles, noxious gas concentrations, and airborne microbes . The sampling cart has been used in an initial study of the effects of tethering position (head forward vs . head backward) on heart rates in horses being trailered, and in continuing studies designed to modify the transport environment to minimize stress imposed on animals during transit.

Crit Rev Microbiol, 1991, 17(6), 435 - 47
Biogenesis of bacterial cellulose; Cannon RE et al.; Cellulose is the most abundant biological polymer on Earth . It is found in wood and cotton, and forms the basic structural foundation of the cell wall of almost all eukaryotic plants . Bacteria are known to secrete cellulose as part of their metabolism of glucose and other sugars . The focus of this review is upon bacterial cellulose synthesis . We emphasize recent literature directed primarily upon Acetobacter xylinum, which has been most widely studied . Our review covers the following topics relating to cellulose synthesis: genetics, biochemistry, ultrastructure, growth conditions, and ecological considerations as they relate to the diversity of microbes capable of synthesizing this abundant, unique polymer--cellulose.

Immunol Today, 1991 Jan, 12(1), 4 - 6
Lymphocytes play the music but the macrophage calls the tune; Solbach W et al.; Researchers interested in immunological aspects of bacterial, fungal, protozoan and helminthic infection are too often kept apart by artificial subject boundaries . These barriers were temporarily breached by a recent workshop* in which the complex interplay between microbes and their mammalian hosts were examined from a global viewpoint . The role of T-cell subsets and their products came under close scrutiny but the most forceful image was that of the macrophage . As host for infective agents, as modulator of specific immune activity and as ultimate mediator of the host response, the macrophage plays a virtuoso's role in the host-parasite drama.

Biotechnology, 1991, 15, 57 - 73
Soil and groundwater transport of microorganisms; Berry DF et al.; Releases of GEMs into the environment are expected to increase in the next few years, with the most dramatic increases resulting from the application of pest-control agents in agriculture and forestry . Of major significance in assessing the environmental risk impact of GEMs is an understanding of their survival and transport in soil and subsurface environments . While information on the transport and survival of microorganisms through soil is available, it is neither abundant nor extensive in terms of microbial types tested or soils examined . Though the transport of microorganisms from an application site depends primarily upon passive mechanisms, broad generalizations pertaining to the transportability of a specific microorganism within a particular soil environment may not be possible . Indeed, to extrapolate from information about one microbe to another, or from one geographical location to another, may not be appropriate . What is clear, however, is that the broader the data base, the more powerful the argument for making reasoned judgement, and consequently the more satisfactory the results of the predictive process . Several inherent difficulties exist in studying the transport behavior of GEMs in soil and subsurface environments . Detection of low microbial numbers or of stressed microbial populations is exceedingly difficult with traditional technology . In an effort to improve detection sensitivity, many improved methods of monitoring GEMs in the soil and subsurface are currently under development (Chaudhry et al . 1989) . Beyond the difficulties of making accurate measurements of microorganisms to determine their spatial and temporal situation in the soil and subsurface environment, lies the need to ascertain the dynamic relationships between indigenous populations of microorganisms and how they may interact with a released GEM . Also, research strategies have not adequately addressed methods to predict the potential interactions between GEMs and natural microorganisms . These issues must be addressed if environmental risk assessment is to be valuable . There is clearly a need for focused research on the survival and transport of GEMs in these environments.

Cancer Res, 1991 Jan 1, 51(1), 255 - 60
Preclinical assessments of 90Y-labeled C110 anti-carcinoembryonic antigen immunotoxin: a therapeutic immunoconjugate for human colon cancer; Ito T et al.; We have synthesized 90Y-labeled immunotoxin (IT) containing ricin A chain and C110 anti-carcinoembryonic antigen monoclonal antibody (MAb) to produce a therapeutic immunoconjugate for human colon cancer . The C110 IT was labeled with 90Y via a benzylisothiocyanate derivative of diethylenetriaminepentaacetic acid . The efficiency of 90Y labeling was consistently 90 to 98%, with a specific activity of about 1 microCi/microgram . In in vitro stability studies, more than 80% of 90Y remained bound to the C110 IT for up to 5 days after incubation . The percentage of binding of 90Y-labeled C110 IT to carcinoembryonic antigen-coated microbeads was 86%, indicating good retention of the initial immunoreactivity of the C110 MAb . In in vitro protein synthesis inhibition assays, 90Y-labeled C110 IT was approximately 3.7-fold more toxic to the LS174T human colon carcinoma cell line than unmodified C110 IT and 1380-fold more toxic than 90Y-labeled C110 MAb . Biodistribution studies of 90Y-labeled C110 IT in LS174T tumor-bearing mice showed that, at 24 h following i.p . injection, high accumulation of radioactivity was seen in the i.p . tumor and liver and, thereafter, high accumulation in these tissues remained almost unchanged until up to 168 h, with percentage of injected dose/g ranging from 15 to 18% in the tumor and 10 to 15% in the liver . The radioactivity in the spleen and bone gradually increased with time and reached their highest levels (approximately 8% of injected dose/g) at 168 h . Estimation of absorbed radiation doses to the tissues showed that i.p . tumor would have received an approximately 1.5 to 7 times higher radiation dose than normal organs . In in vivo therapeutic trials, 90Y-labeled C110 IT provided survival prolongation of LS174T tumor-bearing mice superior to that with either unmodified C110 IT or 90Y-labeled C110 MAb (4 less than 0.01; Mann-Whitney U test) . These results indicate that 90Y-labeled C110 anti-carcinoembryonic antigen IT may be a potent therapeutic immunoconjugate for human colon cancer and that it may have direct relevance for i.p . treatment of peritoneal carcinomatosis from colon cancers.

Immunol Ser, 1991, 55, 285 - 313
Chronic infections and autoimmunity; Abu-Shakra M et al.; The studies summarized in this chapter indicate that chronic bacterial, viral, and parasitic infections can serve as a trigger factor of autoimmune reactivity according to various mechanisms . The relationship between microbes and autoimmunity could be manifested by the presence of autoantibodies, autoimmune complexes, or T cells with autoactivity . The presence of autoimmune phenomena in chronic infections could be related to polyclonal B-cell activation, molecular mimicry between microbial and host antigens, altered self, abnormal expression of immunoregulatory molecules, and the anti-idiotypic network . In most cases, the appearance of self-reactivity in the sera of patients with chronic infections is not associated with clinical manifestations . These findings suggest that autoimmune disease is the result of a combination of factors including immunologic, genetic, hormonal, and environmental . Infectious agents have a role in the breakdown of tolerance and the appearance of autoreactivity . However, only patients with the proper immunogenetic and hormonal background may develop clinical manifestations of autoimmune disease . In spite of the extensive knowledge that has accumulated, the specific relationship between infections and autoimmunity is still obscure . Clearly, additional studies are required to clarify the relevance of microbes to the pathogenesis of autoimmune diseases.

Pathobiology, 1991, 59(3), 162 - 5
Intracellular pathogens and professional phagocytes in reactive arthritis; Wuorela M et al.; Reactive arthritis is a postinfectious complication which develops after certain infections, mostly gastrointestinal or urogenital . Antigenic structures of the causative microbes, but no live organisms, have been demonstrated in inflamed joints . The host factors as well as the microbial antigens responsible for the initiation of the arthritic process are unknown . The pathogenesis of reactive arthritis is discussed here with special reference to the intracellular life of the causative microbes and to monocytes/macrophages, which may be involved in early events of the arthritic process as well as in maintenance of the autoimmune type of responses.

Ann Pharm Fr, 1991, 49(1), 1 - 17
{Current data on atmospheric pollutions}; Festy B et al.; Atmospheric pollutions (AP) are very important for human health and ecological equilibrium . They may be natural or anthropogenic and in this later case they can appear outdoor or indoor . Urban air pollution is the most known form of AP . Its main sources are industries, individual and collective heating and now mainly automobile traffic in most cities . Classical AP indicators are SO2, particles, NOx, CO and Pb measured in networks . Important factors of AP are amounts of pollutants emitted and local climatic and meteorological characteristics . Health effects of AP peaks and of AP background levels are not well known . But generally, mean AP levels of SO2 and particles decreased in the last years in most towns as the consequence of collective actions on the three main sources of AP and on fuels, emission and immission levels; but more is wanted about motor-cars . Progress are necessary for limitation of three major ecological risks: "acid-rain" (SO2 and NOx derivatives, ozone,...) which participates in lake and forest attacks; "green house" effects whose air CO2 concentration increase is the main responsible, and stratospheric ozone depletion mainly due to freons (CFC); the consequences of these two last phenomena are not well known but ecological and health risk exist . Besides, indoor air pollution (IAP) is very important because we live more than 20 h a day indoor . IAP may be occupational (a lot of chemical or biological agents) or not . In the later case air pollutants are very various: CO, NOx and particles from heating or cooking, formaldehyde from wood glue, plywood or urea-formol foams, radon and derivatives in some granitic countries, odd jobs products, cosmetics, aero-allergens of chemical or biological origins, microbes,.. . Environmental tobacco smoke (ETS) is also an important pollutant complex . Risks of IAP are real or potential: acute risk is obvious for CO, aero-allergens, formaldehyde, NOx,...); irritations are produced by ETS, formaldehyde, solvants,...; long term or potential risks are of concern for asbest, radon,.. . A complex and bad known pathology is described in a lot of modern buildings as the "Sick Building Syndrom" . Indoor air quality is very dependant of the quality of ventilation and possible air treatment . It may be considered in all urban epidemiological studies about air pollution.

Bull Soc Pathol Exot, 1991, 84(5 Pt 5), 563 - 71
{Risk factors for the development of diarrhea in children of 6-36 months carrying enteropathogenic microbes (apropos of 130 cases observed in Lomé-Togo)}; David M et al.; Diarrhoea, an important cause of infant morbidity and mortality is a priority problem in developing countries . The diarrhoea is most often of infectious origin . This is an evaluation of the parameters susceptible of influencing the carrying of enteropathogenic agents and the apparition of diarrhoea in children 6-36 months of age living in urban and peri-urban areas in the tropics . The study concerns 130 children divided between well nourished and malnourished . To the parameter "nutritional status" most often used in the different studies one finds in the literature, we chose to add a combination of others regrouped under the categories of "type of feeding" and "environmental factors" . In our socio-cultural context, these last two parameters are intimately linked to the mother who lives in symbiosis with her child at least until 36 months of age . At the end of the study we were able to put together the results of research on carriage of a large gamut of enteropathogenic agents (parasites, bacteria, viruses) with our chosen parameters . This allowed us observe all the interactions between these two variables, particularly relating to onset of diarrhoea . We were thus able to conclude that the factors characterizing "Food hygiene and environmental hygiene play the most important role whatever the nutritional status of child".

Tsitologiia, 1991, 33(10), 79 - 84
{The effect of centrosome UV microbeam irradiation on cell behavior . II . The radiation sequelae in the anaphase: the completion of division and the fate of the interphase cell}; Uzbekov RE et al.; Ultraviolet (280 nm) microbeam irradiation of the centrosome (spindle pole) in the early anaphase slows down and then stops chromosome movement towards the irradiated pole . This happens as a result of rapid (in 1-2 min) disorganization of the half-spindle . Chromosome movement towards the opposite pole continues normally . Irradiation of the centrosome also affects cystotomy--the residual body is formed later than in the normal cell . In some cases additional constrictions are formed or the cytoplasm starts blebbing . Immediately after division the microtubule network in two daughter cells (one of them with irradiated centrosome) is similar . Two hours later in the irradiated cell the amount of microtubules is often less than in the sister cell . Incubation with nocodazole (0.5-1.5 h, 0.15 microgram/ml) shows that in the irradiated cells microtubules radiating from the centrosome are practically absent . Irradiation of other regions of the cytoplasm does not cause any of the effects described above.

Biomater Artif Cells Immobilization Biotechnol, 1991, 19(4), 745 - 60
Biodegradable chitosan matrix for the controlled release of steroids; Chandy T et al.; Chitosan, a polysaccharide, having structural characteristics similar to glycosaminoglycans, seems to be nontoxic and bioabsorbable . This study highlights the use of chitosan matrix for controlled drug delivery systems . The steroid drugs, namely testosterone, progesterone and beta-oestradiol were mixed with chitosan and the films were prepared by evaporation technique . The in vitro release profile of these steroids from the film matrix was monitored, as a function of time, in phosphate buffered saline (PBS, pH 7.4) at 37 degree C using a U-V-spectrophotometer . The degradation, of these chitosan and drug loaded chitosan films, was also investigated by weight loss and tensile strength studies . The steroid release from chitosan films was compared with the release of these drugs from their microbeads . It appears, the films and the microbeads stayed intact during the dissolution study of 90 days and the possibility of using these systems in contraceptive applications and novel drug delivery systems are discussed.

Microbiol Immunol, 1991, 35(9), 717 - 27
Sensitive detection of viral antigens with a new method, "laser magnet immunoassay"; Mizutani H et al.; A new method, "laser magnet immunoassay" (LMIA), has been developed for sensitive detection of viral antigens . Target viruses captured on microbeads were made to react with antibodies labeled with magnetite particles . In a magnetic field, magnetically labeled antigens dispersed in water were attracted to and concentrated at one point on the surface, resulting in the lifting up of a small surface area . A laser beam which was incident on the point reflected, making an interference fringe . The intensity of the fringe indicates the amount of the magnetite conjugated with antigen . A very low concentration of antigens, such as 5 particles of influenza virus and 0.1 pg/ml of human immunodeficiency virus (HIV) p24 antigen in human serum, could be detected by this method . Application of this method to diagnoses of viral diseases in early stages is discussed.

Invasion Metastasis, 1991, 11(5), 261 - 72
Hemodynamic considerations in organ and tissue patterning of B16 melanoma systemic metastasis and colonization; Fogelquist S et al.; Several populations of the mouse B16 melanoma that are highly metastatic from subcutaneous transplants but differ in growth characteristics were compared with regard to systemic site patterning of visible metastasis, as well as colonization effected by intracardiac injection of tumor cells . In all cases, metastasis proceeded in two stages, initially to the lungs and secondarily from lung metastases to systemic sites . The relative ranking of systemic site involvement by secondary-stage metastasis was basically similar for all tumor cell populations; the overall hierarchy was: kidneys greater than brain greater than adrenals and ovaries greater than pancreas greater than mesentery . Colonization patterns resulting from intracardiac injection were also generally comparable but differed from metastasis patterning in that the kidneys and brain were poorly colonized while the bones were frequent sites of colonization . Enumeration of fluoresceinated tumor cells or microbeads trapped in various sites following intracardiac injection revealed a ranking of initial involvement that differed markedly from colony formation . These results indicate that the hemodynamics of blood flow is not a critical determinant of colonization patterning . Based on the colonizing behavior of microbead-bound tumor cells, the frequent metastatic involvement of the kidneys and brain appears to result from selective trapping of large multicell tumor emboli within arteries in those organs . The occurrence of metastasis in other systemic sites is, like colonization, not readily explained by hemodynamics.

Rev Environ Health, 1991, 9(3), 161 - 76
Non-target and environmental hazards of pesticides; Iyaniwura TT; When compared with pesticide pollution from other sources and pollution by other agents, the hazards of atmospheric pollution by pesticides appear relatively insignificant . The high persistency in the environment observed especially with the organochlorines suggests that there could be a gradual accumulation of residual pesticides in the atmosphere . Thus, in addition to the function of redistributing pesticides by air currents and aerial drifts, the atmosphere may become a major reservoir for drift prone finely divided particulate pesticides and highly volatile compounds . Indiscriminate aerial spraying should be avoided . A more selective approach should be adopted whereby forest areas are sprayed without contaminating streams, lakes and inland waters . Improvement in spraying devices are needed such that pesticides are more precisely delivered to target . Direct spraying of water bodies should be avoided as much as possible . Treatment of waste water for pesticide removal or neutralization prior to effluence from factories and disposal of effluence to legally designated sites in addition to chemical treatment of contaminated water are more ways of reducing water pollution . Pesticide residues in soil, in addition to eliminating or reducing parasitic microbes, are also toxic to the non-parasitic and ecologically useful soil microbial and vertebrate population . Pesticides may reduce certain microorganism populations while they stimulate the growth of others, especially the saphrophytic and spore forming types . Soil chemical properties may also be altered by accumulation of residual pesticides and their metabolites . These processes may disrupt the ecological balance in the soil microenvironment, first by simplifying the microbial population, and possibly by reducing soil fertility and its ability to support life . Non-target or residual pesticide toxicity would also disrupt the population of some of the valuable soil invertebrates like earthworms, predatory mites, centipedes and carabid beetles . Accumulation of pesticides in resistant or tolerant species may provoke episodes of toxicity to organisms higher in the food chain . The chlorinated hydrocarbons are likely to be most ecotoxic . Use of such pesticides ought to be restricted . Efforts to find alternatives to pesticides, especially research into biological control, should be intensified.

Rev Roum Virol, 1991 Jan-Jun, 42(1-2), 3 - 15
{The involvement of microbes in the etiology of respiratory diseases in infants 0 to 12 months old}; Abraham L et al.; A study was worked out on the etiopathogenic relations and a more exact evaluation of the incidence of some agents: viruses, chlamydiae, mycoplasmas and rickettsiae, in the respiratory diseases of 0- to 12-month-old children . Serological analysis and immunofluorescence examination of pharyngeal cells were done . Results showed that parainfluenzae and respiratory syncytial viruses, chlamydiae, rickettsiae and mycoplasmas had an important part in the outbreak and maintaining of severe respiratory diseases in the 0- to 12-month-old children population.

Int J Biochem, 1991, 23(10), 979 - 84
Two new extracellular serine proteases from Streptomyces fradiae; Sinha U et al.; 1 . Two new extracellular serine proteases have been purified to homogeneity from Streptomyces fradiae . 2 . On amino acid sequencing, striking homology is observed between the first enzyme and Streptomyces griseus Protease A, and the second enzyme and S . griseus trypsin . 3 . The sequence information shows for the first time that structurally and enzymatically related serine proteases are extracellularly expressed by different Streptomycetes . 4 . Differential keratinolytic substrate specificity among these two microbes are probable due to a difference in disulfide reduction capacity.

Cytometry, 1991, 12(6), 505 - 10
Laser induced cell fusion in combination with optical tweezers: the laser cell fusion trap; Steubing RW et al.; A single-beam gradient force optical trap was combined with a pulsed UV laser microbeam in order to perform laser induced cell fusion . This combination offers the possibility to selectively fuse two single cells without critical chemical or electrical treatment . The optical trap was created by directing a Nd:YAG laser, at a wavelength of 1.06 microns, into a microscope and focusing the laser beam with a high numerical aperture objective . The UV laser microbeam, produced by a nitrogen-pumped dye laser (366 nm), was collinear with the trapping beam . Once inside the trap, two cells could be fused with several pulses of the UV laser microbeam, attenuated to an energy of approximately 1 microJ/pulse in the object plane . This method of laser induced cell fusion should provide increased selectivity and efficiency in generating viable hybrid cells.

Proc Finn Dent Soc, 1991, 87(3), 343 - 50
Plaque accumulation on glass ionomer filling materials; Forss H et al.; It has been suggested that fluoride released by glass ionomers inhibits the growth of plaque . The aim of this study was to compare plaque accumulation on glass ionomers and composite . The materials tested were (1) freshly mixed glass ionomer (Ketac-Fil), (2) artificially aged glass ionomer (Ketac-Fil), (3) freshly mixed silver glass ionomer (Ketac-Silver) and (4) light-cured hybrid composite (Valux) . Ten volunteers wore an acrylic appliance for three periods of 18 hours, one for each glass ionomer . A glass ionomer disk was inserted on one randomly chosen side of the appliance and the composite disk on the other . The volunteers rinsed once an hour with a 15% sucrose solution . The amount of pellicle and plaque on the disk was estimated by analysing its protein content . During each cycle, more plaque accumulated on the glass ionomers than on the composite (fresh Ketac-Fil/Valux p less than 0.05, aged Ketac-Fil/Valux p less than 0.01, Ketac-Silver/Valux NS) . On examination using a scanning electron microscope the surfaces of the glass ionomers were found to be markedly more porous, and to contain more microbes, than the composite surface . The presence of silver in the silver glass ionomers may have affected the initial adherence of bacteria.

Phonetica, 1991, 48(1), 1 - 17
An articulatory study of consonant-induced vowel duration changes in English; de Jong K; The effects of voicing, manner, and number of consonants on the duration of previous vowels in English can be created in three ways: by planned expansion or contraction of the entire vowel, by changing the relative timing of consonant and vowel gestures, or by modifying the duration of the closing movement for the consonants . An X-ray microbeam data base of 2 speakers of American English reciting monosyllabic words, which differed in their final consonants and in their position in the accentual structure of the utterance, was studied to evaluate these three accounts . In this data base, vowel duration differences due to the voicing of the following consonants were amplified by the presence of accent . Also, many of the duration differences associated with the following consonants are localized in the later portion of the opening movement, suggesting that subjects often create vowel duration changes by initiating the consonant closing gesture at an earlier or later time relative to the opening gesture.

Annu Rev Microbiol, 1991, 45, 89 - 106
Techniques for selection of industrially important microorganisms; Steele DB et al.; The screening of microorganisms for the production of useful products continues to be an important aspect of biotechnology . Although advances in instrumentation, genetics, and microbial physiology are having an impact, screening programs are still primarily based on so-called classical techniques of enrichment and mutagenesis . One area that needs strengthening is the advancement of knowledge in microbial physiology . Recent surveys indicate that industry leaders see trained microbial physiologists as being the limiting factor in development of biotechnology in the coming decade . The largest impediment to development of new screening techniques is the ironic lack of programs specifically directed at developing new techniques . Too much emphasis is placed on using available techniques and relying on sheer labor and screening of vast numbers of organisms to produce novel products . In this respect, the Japanese are the exception and have proven that the establishment of new programs is worth the cost and effort . They are undoubtedly the world leaders in development of screening techniques and consequently the discovery of novel products . The isolation of microbes from novel and extreme environments holds tremendous promise in two areas . First, as Omura (46) and others (9, 48, 65) state, novel organisms will yield novel products . Second, such organisms serve as models for the understanding of structure and function that will facilitate the genetic manipulation of organisms and advance our ability to engineer novel enzymes . Hopefully such advances will enable genetic and protein engineering to have a greater impact on screening programs and techniques in the future . The earth holds a vast amount of varied and unique environments, from natural extremes such as high-altitude deserts and thermal springs, to manmade environments such as industrial-waste-treatment facilities, from which, with the appropriate methods and techniques, we may isolate and evaluate new potential products.

Acta Physiol Hung, 1991, 77(3-4), 279 - 91
Ceasing of epithelisation and deposit formation of unknown origin on the cornea; Szeghy G; The author presents a so far unknown pathological process interrupting permanently the regeneration of the superficially damaged cornea, and its consequences and therapy of the condition as well . The process occurs only in 5.6% of the injured individuals . The occurrence is in no correlation with the quality or extent of the damage . Also it is independent of the form and duration of therapy . The essence of the pathological changes is the slowing of corneal epithelisation within 2-4 days, followed by a complete cessation . After that a thin membrane-like layer develops simultaneously and evenly within 12 days on the area without epithelium, the surface of which is dull, transparent and whitish in colour . Within weeks or months an individually varying thickening of the membrane occurs, but the area does not grow . The surface becomes whitish-grey and is without any epithelium and with no adherence to tear . The deposits are closely and inseparably adherent to their base, their substance is rigid, being brittle only at the margins . The lesion is staining greenish-yellow with Na-fluorescein, and lively blue with toluidine blue . It is staining in small reddish-brown with rose bengal . In vivo the deposits are not measurably influenced by hyaluronidase, trypsin, alpha-chymotrypsin and papain . The microbes play no role in the process . Histological and electron-microscopical examinations suggest the corneal deposit are the product of the necrobiotic process occurring on the corneal surface during regeneration . The specific treatment consists of local application of corticoid-heparin . On the basis of the results of the examinations and literary data the author suggests that the corneal deposition and the similarly rare KCV (keratoconjunctivitis vernalis) plaque formation is the same specific process, i.e . the peculiar manifestation of the atopic state of the organism occurring independently of age.

Biotech Histochem, 1991, 1(1), 1 - 6
Phagocytosis of protein coated colloidal-gold-agarose-gelatin microbeads by cultured uterine glandular epithelial and stromal cells; Gao KX et al.; A procedure for fixing and immunostaining whole cells from primary cultures of ovine and bovine uterine gland fragments was used to identify keratin in intermediate filaments of epithelial cells to distinguish them from stromal cells . Colloidal gold encapsulated agarose-gelatin microbeads were coated with different proteins and used to investigate uptake by epithelial and stromal cells in culture . Microbeads were taken up by stromal cells and by epithelial cells on the outskirts of colonies . These cells formed ridges where they contacted and grew above stromal cells . Electron microscopy demonstrated that the microbeads had been internalized and appeared to be nontoxic . Individual cells could harbor more than 90 microbeads within their cytoplasm for at least seven to ten days with no apparent harm . Some cells with microbeads were seen to divide.

Zh Mikrobiol Epidemiol Immunobiol, 1991 Jan, (1), 49 - 51
{An experimental study of the safety of a chemical monovalent tableted cholera vaccine in enteral administration}; Nazarova LS et al.; The safety of experimental chemical cholera monovalent vaccine in tablets, produced by the institute "Microbe" (Saratov, USSR), has been studied . The study has shown that the vaccine, administered to adult rabbits and germ-free suckling rabbits by the enteral route, retains residual toxicity, mainly due to the presence of O-antigen . One or two administrations of 1-2 human doses of this preparation to adult rabbits induce minimal structural changes admissible from the viewpoint of safety . After immunization made in two administrations immunobiological transformation develops more rapidly and is more pronounced than after immunization in a single administration.

Cytometry, 1991, 12(6), 497 - 504
Application of laser optical tweezers in immunology and molecular genetics; Seeger S et al.; Optical tweezers, based on a compact diode pumped Nd:YAG laser providing 350 mW at 1,064 nm coupled into a Zeiss IM 35 microscope, were used to sort CD4+ T cells into a capillary for further mechanical handling and to establish contact between single human natural killer (NK) cells and human erythroleukemia cells (K562) as targets . After contact and a lag phase of a few tens of seconds, the target cell starts to change its morphology and membrane blebbing occurs . The kinetics of the attack of the NK cell on K562 cells is not straightforward but governed by temporal oscillations in the shape of the target cell (zeosis) . In a second application, the optical tweezers are combined with a UV laser microbeam based on a pulsed UV laser and with flow cytometry and sorting . With the pulsed laser, segments of sorted chromosome 1 of the chinese hamster karyotype (CHV 79) can be easily micro-dissected and subsequently collected using the optical tweezers . This allows preparation of a few hundred chromosome segments per day without mechanical contact and in an absolutely sterile way and thus may provide an interesting basic technique in any type of genome sequencing project.

Arthritis Rheum, 1991 Jan, 34(1), 6 - 14
Double-blind, placebo-controlled study of three-month treatment with lymecycline in reactive arthritis, with special reference to Chlamydia arthritis; Lauhio A et al.; We conducted a double-blind, placebo-controlled, randomized study of 3-month treatment with lymecycline, a form of tetracycline, in reactive arthritis (ReA) . Lymecycline therapy significantly decreased the duration of the illness in patients with Chlamydia trachomatis-triggered ReA, but not in other ReA patients . In 2 ReA patients, C trachomatis was found in the throat, an uncommon locale for this organism . Our results suggest that it is important to verify the triggering microbe and that it is beneficial to treat Chlamydia arthritis patients with a prolonged course of tetracycline.

J Biol Chem, 1990 Dec 15, 265(35), 21407 - 10
Iron (III) hydroxamate transport into Escherichia coli . Substrate binding to the periplasmic FhuD protein; Koster W et al.; Due to its extreme insolubility, Fe3+ is not transported as a monoatomic ion . In microbes, iron is bound to low molecular weight carriers, designated siderophores . For uptake into cells of Escherichia coli Fe3+ siderophores have to be translocated across two membranes . Transport across the outer membrane is receptor-dependent and energy-coupled; transport across the cytoplasmic membrane seems to follow a periplasmic binding protein-dependent transport mechanism . In support of this notion we demonstrate specific binding of the Fe3+ hydroxamate compounds ferrichrome, aerobactin, and coprogen, which are transported via the Fhu system, to the periplasmic FhuD protein, and no binding of the transport inactive ferrichrome A, ferric citrate, and iron sulfate . About 10(4) ferrichrome molecules were bound to the FhuD protein of cells which overproduced plasmid-encoded FhuD . Binding depended on transport across the outer membrane mediated by the FhuA receptor and the TonB protein . Binding to FhuD was supported by the exclusive resistance of FhuD to proteinase K in the presence of the transport active hydroxamates . The overproduced precursor form of the FhuD protein was not protected by the Fe3+ hydroxamates indicating a conformation different to the mature form . The FhuD protein apparently serves as a periplasmic carrier for Fe3+ hydroxamates with widely different structures.

J Arthroplasty, 1990 Dec, 5(4), 307 - 14
Uncemented press-fit total knee arthroplasty; Rackemann S et al.; Nineteen total knee arthroplasties in 16 patients were performed using a new prosthesis designed specifically for uncemented, press-fit fixation without any provision for tissue ingrowth . This design may be suited for use in patients with juvenile rheumatoid arthritis, postseptic knees, failed total knee arthroplasties with large bone stock deficiencies, and young, active, overweight individuals . Preservation of bone stock is possible because the fixation stems are nails rather than larger cement pegs, removal for revision is easier without cement, sequestration of microbes within cement cannot occur, and bone graft may be continually loaded with this type of prosthesis . Pain relief, discarding crutch support, operative blood loss, and corrective alignment were equivalent to results obtained with cemented arthroplasty . Seventeen of the 18 knees available for review (average follow-up period, 3 years, 7 months; range of follow-up period, 2 years, 10 months to 4 years, 11 months) were pain-free . Range of motion averaged -2 degrees of extension to 101 degrees of flexion . Ambulation was unrestricted and unsupported in the majority of patients . Radiographic evaluation showed the development of increased bone density under the tibial plateau as well as a sclerotic line at the ends of the femoral and tibial stems . This observation gives support to the theory that multiple microtrabecular fractures with healing form a new supportive "subchondral bone plate." There was one incidence of tibial subsidence . Prosthesis migration and loosening were not observed.

FEMS Microbiol Rev, 1990 Dec, 7(3-4), 309 - 13
Microbial H2/CO2 acetogenesis in animal guts: nature and nutritional significance; Breznak JA et al.; The intestinal tract of invertebrate and vertebrate animals, including man, is an anoxic habitat wherein microbial formation of acetate from H2 + CO2 is often a major H2-consuming reaction . This paper will discuss the magnitude and microbiology of H2/CO2 acetogenesis in animal guts, its impact on host animal nutrition, competition for H2 between anaerobic microbes, and the global significance of intestinal H2/CO2 acetogenesis.

Appl Environ Microbiol, 1990 Dec, 56(12), 3861 - 6
Flow cytometry sorting of viable bacteria and yeasts according to beta-galactosidase activity; Nir R et al.; We describe a novel method for quantitative measurement of beta-galactosidase (beta-gal) levels in bacteria and yeasts by using flow cytometry, a method which allows viable microbial cells to be sorted on the basis of the expressed activity and to be recultivated . The method is based on encapsulating single cells in agarose microbeads 20 to 30 microns in diameter and analyzing the beta-gal activity of the colonies that develop (containing several hundred cells) by using the fluorogenic substrate fluorescein-di-beta-D-galactopyranoside (FDG) . Three strains of Escherichia coli, containing different levels of beta-gal, served as a model system . A high degree of correlation was found between the average fluorescence measured per bead and the level of the enzyme in extracts of the respective strain . Although the use of FDG necessitates cell permeabilization, conditions were found under which a small part of each colony remained viable, yet most of the enzyme was exposed to the substrate . This allowed sorting of microcolonies and plating with close to 100% efficiency . The potential of the technique was demonstrated by selecting beta-gal-positive cells from an artificial mixture of beta-gal-positive and beta-gal-negative E . coli strains.

NIPH Ann, 1990 Dec, 13(2), 37 - 44
Detection of serum antibodies against Borrelia burgdorferi with some commercially available serological tests; Melby K et al.; Sixty-three sera were analysed for antibodies against Borrelia burgdorferi with an in-house indirect immunofluorescence assay . Thirty-nine sera were positive (titer greater than or equal to 256), seven borderline (titer 128) and 17 negative (titer less than or equal to 64) . These results were compared with results obtained with four different commercial assays for detection of such antibodies . Indirect immunofluorescence tests yielded most positive results . The flagellin ELISA test detected antibodies in patients with erythema chronicum migrans (ECM) more often than the other test systems . Sera from patients with acrodermatitis chronica atrophicans (ACA) were positive in all systems . The serological diagnosis of borreliosis is difficult and direct methods for detecting the presence of the microbe are highly needed.

Hepatogastroenterology, 1990 Dec, 37 Suppl 2, 97 - 9
Multiple myeloma associated with Budd-Chiari syndrome; Tsuji H et al.; A 51-year-old Japanese woman with Budd-Chiari syndrome, following dermatoplasty of the leg for burns, developed multiple myeloma and amyloidosis during the four-year observation period . In Budd-Chiari syndrome, polyclonal hypergammaglobulinemia is frequently seen as the result of intestinal antigenic stimulation through the portacaval shunt . Although monoclonal gammopathy is occasionally presented in chronic liver diseases, multiple myeloma has not been previously recognized as occurring in association with Budd-Chiari syndrome . This case demonstrates that, in Budd-Chiari syndrome, the development of multiple myeloma may be the result of chronic stimulation of the intestinal microbes.

Brain Res, 1990 Nov 5, 532(1-2), 317 - 22
Pontine cholinergic neurons simultaneously innervate two thalamic targets; Shiromani PJ et al.; Cholinergic neurons located in the lateral dorsal tegmental (LDT) and pedunculopontine tegmental (PPT) nuclei have been shown to principally innervate the thalamus . In order to determine whether some of these neurons might simultaneously project to two thalamic targets we made microinjections of rhodamine-conjugated microbeads into the central-lateral nucleus of the thalamus and fluorescein isothiocyanate (FITC)-conjugated microbeads into the dorso-lateral geniculate nucleus . We then determined whether both tracers were found in immunohistochemically identified cholinergic somata in the LDT and PPT nuclei . Results showed that some cholinergic and non-cholinergic neurons in the LDT and PPT nuclei projected to both thalamic sites . This finding extends our understanding of the projections of the LDT-PPT cholinergic neurons and further supports the role of these neurons in complex behaviors.

J Invertebr Pathol, 1990 Nov, 56(3), 337 - 46
Ultrastructural changes in salivary glands of tsetse, Glossina morsitans morsitans, infected with virus and rickettsia-like organisms; Kokwaro ED et al.; Electron microscope observations on enlarged hypertrophied salivary glands dissected from adult laboratory-reared male Glossina morsitans morsitans show a concurrent infection of the salivary gland tissue with rod-shaped virus particles and intracellular rickettsia-like organisms . The latter are found intracellular in the epithelium and in the gland lumen enclosed within lytic zones . The virus particles are found within the degenerating cytoplasm, nuclei, and lumen of the cell where they are especially numerous . Stratified epithelium and gland enlargement are a prominent feature of the infection . These observations suggest that biological associations between salivary gland tissue and diverse microbes may be more common than formerly recognized . The microbes appear to cause damage to salivary gland cells, causing hyperplasia which assumes pathologic proportions.

Parasite Immunol, 1990 Nov, 12(6), 559 - 67
Further studies on variable resistance of 129/J and C57BL/6 mice to infection with Schistosoma japonicum and Schistosoma mansoni; Mitchell GF et al.; Two mouse strains maintained in this laboratory (WEHI) are variably resistant to infection with Schistosoma japonicum and S . mansoni in that worms cannot be found in the liver and portal system in a high proportion (WEHI 129/J mice) or low proportion (C57BL/6 mice) some weeks after exposure to cercariae . Resistance can be as high as 100% in WEHI 129/J mice and is usually around 20% in C57BL/6 mice . The proportion of resistant mice closely parallels the proportion of mice that demonstrate a shunting of microbeads, injected into a mesenteric vein, from liver to lungs . This applies to F1 x WEHI 129/J backcross mice in which the data suggest oligogenic genetic effects although no evidence for a participation of MHC-linked genes in the phenomenon has emerged . 129/J mice derived from the Jackson Laboratory do not show a shunting of beads from the portal system to the lungs but their progeny bred at WEHI do . Germ-free WEHI 129/J mice resemble conventionally-maintained, SPF-derived WEHI 129/J mice in their variable resistance to schistosome infection . No satisfactory explantation for hepato-portal system peculiarities in WEHI 129/J and C57BL/6 mice can be advanced as yet and a possibility raised in this paper is a contribution from nutritional factors such as hypervitaminosis A superimposed on a genetic predisposition in these two related mouse strains.

Hum Reprod, 1990 Nov, 5(8), 893 - 900
Co-cultures: their relevance to assisted reproduction; Bongso A et al.; Assisted reproductive techniques have contributed significantly to alleviating subfertility in the childless couple . However, the take-home baby rates have been very low throughout the world . One of the contributory causes has been the reduced viability of replaced embryos brought about by suboptimal in vitro conditions . The culture of human embryos in the presence of passaged human tubal ampullary monolayers (co-cultures) is an attractive approach to improving the viability of embryos for assisted reproduction . Seventy per cent of blastocysts can be produced in human ampullary co-culture as compared to 33% in standard culture media . This paper discusses the various roles of human co-cultures in assisted reproduction and provides an opinion as to how the transfer of blastocysts produced via the co-culture system could enhance pregnancy rates . Particular emphasis is placed on human oviductal characteristics, the various co-culture systems, screening of co-cultures for microbes, freezing of ampullary cells, growth factors and embryonic blocks, specificity of co-cultures, sperm hyperactivation in co-culture and pregnancy rates . The first patient on a clinical trial who had four of her oocytes fertilized and grown in human ampullary co-culture and then replaced into her uterus became pregnant . The co-culture system may have tremendous potential in supporting human embryonic growth via embryotrophic factors.

Infection, 1990 Nov-Dec, 18(6), 383 - 5
Community-acquired pneumonia caused by Legionella dumoffii in a patient with hairy cell leukemia; Fang GD et al.; A case of community-acquired pneumonia caused by Legionella dumoffii in a patient with hairy cell leukemia is described . Diagnosis was confirmed by isolation by culture of sputum and broncho-alveolar lavage specimens, positive direct fluorescent antibody stains, and antibody seroconversion from 1:16 (acute) to 1:4096 (six months) . The blue white autofluorescence of the L . dumoffii colonies when viewed under ultraviolet light was particularly useful in preliminary identification . The patient recovered from his pneumonia after administration of erythromycin and rifampin . Legionella have been shown to multiply in monocytes and cell-mediated immunity appears to be the primary mechanism of host defense in man . Hairy cell leukemia is characterized by monocyte dysfunction and such patients have a predilection for infection by microbes that are controlled by cell-mediated defenses . We review other cases of community-acquired L . dumoffii pneumonia as well as other cases of Legionella infection in patients with hairy cell leukemia.

Brain Res, 1990 Oct 29, 531(1-2), 117 - 26
Dye-induced 'photo-degeneration' and 'photo-permeabilization' of mammalian neurons in vivo; Picaud S et al.; Dyes are known to induce neuronal 'photo-degeneration' and 'photo-permeabilization' in fly photoreceptor cells in vivo . In the present study, we attempted to generalize this photodynamic damage to vertebrate neurons, using the rat retina, a brain part which is optically accessible in vivo . After intravitreal injection of the photosensitizing dye Rose Bengal (RB), irradiation of the retina of a living rat with a T-shaped microbeam was found to induce striking 'optograms' which could be observed on the excised retina . The T-shaped pattern which was to be seen in the translucent retina under transmitted light was attributed to neuronal degeneration of the neurons irradiated in the presence of RB, as attested by classical degenerative features such as a cytoplasmic darkening or a drastic swelling . The T-shaped pattern could also be observed on adding the dye Lucifer yellow to the extracellular space of the retina either in vitro or in vivo, showing that the cells irradiated in the presence of RB became permeable . These structural reactions were observed in the cells in the inner nuclear layer (INL) and ganglion cell layer (GCL), in the processes in both plexiform layers, and in the ganglion cell axons crossing this area, whereas the photoreceptors in the outer retina appeared to be undamaged . From these reactions, due to photo-degeneration and photo-permeabilization, it was possible to identify the photodynamic damage to the nervous system histologically at the macroscopic, cellular and ultrastructural levels . In view of its accuracy and reproducibility, the photo-lesion technique holds great potential as a tool for investigating various nervous systems.

Biochemistry, 1990 Oct 16, 29(41), 9515 - 21
Slalom chromatography: size-dependent separation of DNA molecules by a hydrodynamic phenomenon; Hirabayashi J et al.; Slalom chromatography, a size-dependent DNA fractionation method based on a new principle {Hirabayashi, J., & Kasai, K . (1989) Anal . Biochem . 178, 336-341}, was systematically studied in detail . In this method, larger DNA fragments are eluted much later than smaller ones from columns packed with spherical microbeads . Elution of a series of DNA fragments was systematically examined by using columns packed with polymer-based packings of different diameter and different pore size for high-performance gel permeation chromatography . Packings of smaller diameter proved to be superior for resolving the smaller size range of DNA, while the reverse was the case for larger DNAs . Application of a faster flow rate led to larger retardation of every DNA fragment, while at the lowest flow rate applied (0.067 cm/min), all the fragments were eluted almost at the void volume . When the column temperature was lowered, retardation of DNA became larger . On the other hand, differences in the chemical nature and the pore size of packings, or in the hydrophobicity of the eluting solvent, had little effect on DNA retardation . Size-dependent fractionation of DNA was also achieved even on columns packed with nonporous packings having anionic groups (cation exchangers) . In conclusion, these results confirmed the previous conclusion that slalom chromatography is not based on an adsorption or equilibrium phenomenon but should be attributed to a hydrodynamic phenomenon.

Science, 1990 Oct 12, 250(4978), 271 - 3
Cleaving yeast and Escherichia coli genomes at a single site; Koob M et al.; The 15-megabase pair Saccharomyces cerevisiae and the 4.7-megabase pair Escherichia coli genomes were completely cleaved at a single predetermined site by means of the Achilles' heel cleavage (AC) procedure . The symmetric lac operator (lacOs) was introduced into the circular Escherichia coli genome and into one of the 16 yeast chromosomes . Intact chromosomes from the resulting strains were prepared in agarose microbeads and methylated with Hha I (5'-GCGC) methyltransferase (M.Hha I) in the presence of lac repressor (LacI) . All Hae II sites (5'-{sequence: see text}) with the exception of the one in lacOs, which was protected by LacI, were modified and thus no longer recognized by Hae II . After inactivation of M.Hha I and LacI, Hae II was used to completely cleave the chromosomes specifically at the inserted lacOs . These experiments demonstrate the feasibility of using the AC approach to efficiently extend the specificity of naturally occurring restriction enzymes and create new tools for the mapping and precise molecular dissection of multimegabase genomes.

J Anim Sci, 1990 Oct, 68(10), 3360 - 70
Quantity and characteristics of microorganisms associated with ruminal fluid or particles; Olubobokun JA et al.; An experiment was conducted to 1) determine quantity of microbial CP and DM associated with undigested feed particles, 2) quantify the amount of microorganisms removed from ruminally incubated forages and 3) compare forage disappearances (D) corrected for microbial contamination, using diaminopimelic acid (DAPA) ratios obtained from particle-associated or fluid-associated microorganisms . Samples of alfalfa hay, bermudagrass hay and orchardgrass hay placed in dacron bags were incubated via ruminal cannula for 6 and 12 h . Whole ruminal contents (WRC) were sampled at the time of bag removal and partitioned into fluid- and particle-associated microorganisms . Particle-associated microorganisms were further divided into loosely-associated (LA) and firmly associated (FA) microorganisms . Percentage microbial CP and DAPA, quantities of OM, CP (mg) and DAPA (micrograms), microbial contamination and microbial contribution to ruminal contents were not affected by time (P greater than .05) . The highest concentrations of CP and DAPA were found in fluid and LA, respectively (P less than .01) . The total amount (content) of OM, CP and DAPA were highest in FA and lowest in microbes in the fluid fraction . Firmly-associated microorganisms constituted 54.1% of the particle-associated population . Corrected DMD were higher (P less than .01) based on FA than on fluid and LA microbe compositions . Corrected CPD were similar (P greater than .10) between populations except at 6 h, when LA corrected CPD were lower . Theoretically, using FA microorganisms should give the most accurate correction for microbial contamination . However, results indicate that, although the three populations differed in composition, fluid and FA corrected CPD were similar . Corrections based on composition of any of these three populations will yield higher estimates of disappearance compared with uncorrected values.

Clin Biochem, 1990 Oct, 23(5), 433 - 6
Enzyme reagents from unusual sources; Wu TW; Although microbes are frequent sources of clinically useful enzymes, there are certain biocatalysts which appear to be enriched in, or more naturally available from nonmicrobes . This paper highlights several of these enzyme reagents, and illustrates their potential or actual clinical diagnostic uses . These reagents include: an enzyme extract containing both glucose oxidase and mutarotase activities from peppers; a bilirubin-degrading enzyme from orange peels; a gentisic acid metabolizing activity from onions; and enzymes from snails which catalyze the detoxification of cyanide by divergent mechanisms.

Calcif Tissue Int, 1990 Oct, 47(4), 237 - 42
Orientation of apatite and organic matrix in Lingula unguis shell; Iijima M et al.; The orientation relationship between apatite and organic matrix in shell of Lingula unguis (inarticulate brachiopod) was studied . The organic layers, mineralized layers, and decalcified mineralized layers were examined layer by layer using microbeam X-ray diffraction technique . Both organic layer and decalcified mineralized layer showed the diffraction pattern of beta-chitin . The degree of orientation of apatite showed correlation to that of beta-chitin: Well oriented diffraction patterns of apatite crystal and organic matrix were observed in the central part . In this part, the fiber axis of beta-chitin was parallel to the c-axis of apatite . A close relationship of unit cell dimension between apatite and chitin was indicated . These strongly suggest that the fibrous structure of organic matrix assists the orientation of apatite crystals in Lingula unguis shell.

Artif Organs, 1990 Oct, 14(5), 342 - 7
A large-scale magnetic separator for selective cell separations with paramagnetic microbeads; Hardwick RA et al.; An improved magnetic separator has been developed for use in large-scale cell separations . This separation method uses paramagnetic microbeads coated with antibodies that selectively bind to target cells . The magnetic separator attracts the microbead-target cell aggregates and holds these aggregates at its surface while the suspending fluid and nontarget cells flow past . The optimum separator design was determined to be two magnetic assemblies in series along with a peristaltic pump . The assemblies consist of neodymium-iron-boron magnet bars sandwiched between steel bars (magnetic pole pieces) . The size and pole spacing of the two magnetic assemblies are designed to be different, so that the first assembly, which captures greater than 99.99% of the microbeads, has good magnetic reach-out and a high magnetic holding force at its surface, while the second assembly has an even higher magnetic holding force at its surface . Studies show that the separator can remove 1 x 10(10) microbeads from a suspension of red blood cells processed at a flow rate of 9 ml/min, so that no microbeads are detected in the effluent.

Scand J Immunol, 1990 Oct, 32(4), 321 - 31
Dynamics of blood components and peritoneal fluid during treatment of murine E . coli sepsis with beta-1,3-D-polyglucose derivatives . I . Cells; Rasmussen LT et al.; Beta-1,3-D-polyglucose derivatives protect mice against otherwise lethal bacterial infections . This protective effect has previously been considered to be mediated through mononuclear phagocytes . We have now investigated the cellular composition in blood and peritoneal fluid after administration of the beta-1,3-D-polyglucose before and after challenge with Escherichia coli . In animals treated with beta-1,3-D-polyglucose derivatives, the total white cell number was significantly increased in both blood and peritoneal fluid before and after challenge with E . coli . The increased total cell number was mainly the result of raised levels of granulocytes . The effects of beta-1,3-D-polyglucose-derivatized microbeads (GDM) and soluble aminated beta-1,3-D-polyglucose (AG) were similar . Bacterial counts in peripheral blood in GDM- and AG-treated animals increased with 6 h after challenge and approached zero after 24 h . In untreated animals the bacterial counts increased gradually until the animals died after about 12 h . Bacterial counts in peritoneal fluid of GDM- and AG-treated animals declined to zero after 24 h . In untreated animals there was a slight increase in bacterial counts until the animals died after about 12 h . By using radioactive labelling, we localized the bacterial as well as the beta-1,3-D-polyglucose derivatives during the period following injection . Particle-bound beta-1,3-D-polyglucose was recovered mainly in the milky spots of the omentum . A conspicuous number of bacteria were also recovered in the milky spots . The soluble aminated beta-1,3-D-polyglucose was recovered mainly in the liver . However, on a weight basis, the greatest concentration of radioactivity was in the milky spots.

Immunology, 1990 Oct, 71(2), 230 - 5
The distribution of immunoreactive interferon-alpha in formalin-fixed paraffin-embedded normal human foetal and infant tissues; Khan NU et al.; Human foetal and infant tissues were studied to test the hypothesis that microbes have a role in switching on interferon-alpha (IFN-alpha) synthesis . Foetal tissues were essentially 'germ free', while the infants had been exposed to a normal microbial environment in life . IFN-alpha was first seen at 9 weeks gestation in macrophages in the liver and thereafter was seen in macrophages in most other organs . When infant lungs were compared with foetal lungs, a statistically significant increase in the number of macrophages and the percentage of these cells expressing IFN-alpha was noted in the infant lungs . No such change was observed in spleen, liver and thymus following birth . These findings suggest that there is a basal production of IFN-alpha by macrophages that is not dependent on microbial products, but that such products can enhance synthesis of this cytokine.

J Cell Biol, 1990 Oct, 111(4), 1505 - 18
UV microbeam irradiations of the mitotic spindle . II . Spindle fiber dynamics and force production; Spurck TP et al.; Metaphase and anaphase spindles in cultured newt and PtK1 cells were irradiated with a UV microbeam (285 nM), creating areas of reduced birefringence (ARBs) in 3 s that selectively either severed a few fibers or cut across the half spindle . In either case, the birefringence at the polewards edge of the ARB rapidly faded polewards, while it remained fairly constant at the other, kinetochore edge . Shorter astral fibers, however, remained present in the enlarged ARB; presumably these had not been cut by the irradiation . After this enlargement of the ARB, metaphase spindles recovered rapidly as the detached pole moved back towards the chromosomes, reestablishing spindle fibers as the ARB closed; this happened when the ARB cut a few fibers or across the entire half spindle . We never detected elongation of the cut kinetochore fibers . Rather, astral fibers growing from the pole appeared to bridge and then close the ARB, just before the movement of the pole toward the chromosomes . When a second irradiation was directed into the closing ARB, the polewards movement again stopped before it restarted . In all metaphase cells, once the pole had reestablished connection with the chromosomes, the unirradiated half spindle then also shortened to create a smaller symmetrical spindle capable of normal anaphase later . Anaphase cells did not recover this way; the severed pole remained detached but the chromosomes continued a modified form of movement, clumping into a telophase-like group . The results are discussed in terms of controls operating on spindle microtubule stability and mechanisms of mitotic force generation.

J Bacteriol, 1990 Oct, 172(10), 5677 - 85
Cloning of wild-type Pseudomonas solanacearum phcA, a gene that when mutated alters expression of multiple traits that contribute to virulence; Brumbley SM et al.; Pseudomonas solanacearum undergoes a spontaneous mutation that pleiotropically reduces extracellular polysaccharide (EPS) production, endoglucanase activity, and virulence and increases motility . We refer to the process that coordinately affects these traits as phenotype conversion (PC) and the resulting mutants as PC types . Previous research with the wild-type strain AW1 suggested that inactivation of a single locus could mimic phenotype conversion (T . P . Denny, F . W . Makini, and S . M . Brumbley, Mol . Plant-Microbe Interact . 1:215-223, 1988) . Additional Tn5 mutagenesis of AW1 generated three more mutants (AW1-81, AW1-82, and AW1-84) that were indistinguishable from the PC type and one slightly leaky mutant (AW1-87); all four had single insertions in the same 4.0-kilobase (kb) EcoRI fragment that were responsible for the PC-like phenotype . Another insertion mutant, AW1-83, which lacks an insertion in this 4.0-kb fragment, resembled the PC type except that it was reversibly induced to produce wild-type levels of EPS when cultured adjacent to AW1 . The wild-type region containing the gene that controls traits affected by phenotype conversion in AW1, designated phcA, was cloned on a 2.2-kb DNA fragment that restored all the phcA::Tn5 mutants and 11 independent spontaneous PC-type derivatives of AW1 to wild-type status . Homology with the phcA region was found in diverse wild-type strains of P . solanacearum, although restriction fragment length polymorphisms were seen . No major DNA alterations were observed in the phcA homologous region of PC types from strain AW1 or 82N . PC types from 7 of 11 conjugal strains of P . solanacearum were restored to EPS+ by phcA from AW1; however, only some PC types of strain K60 were restored, whereas others were not . We believe that a functional phcA gene is required to maintain the wild-type phenotype in P . solanacearum, and for most strains phenotype conversion results from a loss of phcA gene expression or the function of its gene product.

Scand J Immunol, 1990 Oct, 32(4), 333 - 40
Dynamics of blood components and peritoneal fluid during treatment of murine E . coli sepsis with beta-1,3-D-polyglucose derivatives . II . Interleukin 1, tumour necrosis factor, prostaglandin E2, and leukotriene B4; Rasmussen LT et al.; The influences of pretreatment with beta-1,3-D-polyglucose derivatives on levels of cytokines and arachidonic acid metabolites in body fluids in experimental peritonitis in mice are reported . Peritonitis was induced by an intraperitoneal injection of 10(8) live Escherichia coli . Pretreated animals survived the infection, untreated animals died about 12 h after inoculation with E . coli . Levels of IL-1 in plasma and peritoneal fluid, measured by cytotoxicity assay of the HT-2 cell line, increased significantly during the first 48 h after intraperitoneal treatment with beta-1,3-D-polyglucose-derivatized microbeads (GDM) or soluble, aminated beta-1,3-D-polyglucose (AG) . After subsequent challenge with E . coli, the levels of IL-1 were significantly lower than in untreated animals . There was no increase in levels of TNF after treatment with GDM or AG, measured by cytotoxicity assay of the WEHI clone 13 cell line . After challenge with E . coli, TNF in plasma and peritoneal fluid was significantly lower compared with untreated animals . Both PGE2 and LTB4, measured by radioimmunoassay kits, were increased in peritoneal fluid after treatment with GDM and AG . After challenge with E . coli, PGE2 and LTB4 in peritoneal fluid increased to about half the concentration of infected control animals . Intraperitoneal injection of indomethacin to pretreated animals resulted in increased levels of IL-1 and TNF and decreased levels of PGE2 following challenge with E . coli . The levels of IL-1 and TNF remained elevated until the animals died after about 12 h . These studies demonstrate that the raised levels of arachidonic acid metabolites after pretreatment with GDM or AG seem to inhibit the otherwise lethal elevation of IL-1 and TNF in body fluids which is seen in untreated animals.

Oral Surg Oral Med Oral Pathol, 1990 Oct, 70(4), 425 - 7
Invasive aspergillosis of the maxilla in an immunocompromised patient; Shannon MT et al.; Patients who are immunocompromised have a high susceptibility to infection, which can be fatal . Studies have shown that patients receiving chemotherapeutic and adjunctive medications have inhibited inflammatory response to microbes, particularly those increasing the potential for the development of invasive infection . Aspergillus is a fungus often found in the atmosphere . Colonization of Aspergillus in the upper respiratory tract is common . In the immunocompromised patient, Aspergillus flavus is found to be the most frequent fungus cultured in the maxillary sinus . Because of the depressed immunologic state of the patient, A . flavus can differentiate into hyphal forms producing toxins that destroy epithelial tissues . Penetration of Aspergillus into connective and vascular tissue produces thrombosis and ultimately necrosis of hard and soft tissue.

Hum Factors, 1990 Oct, 32(5), 527 - 36
Aging and performance of home tasks; Lawton MP; Household behaviors must be understood in terms of a hierarchy of behavioral competence within which complexity determines the location of behaviors that can be evaluated in terms of basic health and social-normative criteria . Older people's household behaviors as well as higher-order behaviors are schematized in terms of physical and instrumental activities of daily living (ADL) . Data on impairment rates for ADLs and time budget studies are cited to emphasize the importance of the home environment . Other behaviors that represent needs for autonomy, support, and proactivity are discussed, as are research needs, both for development of measures of microbehaviors and for the study of behaviors designed to achieve alternative routes to an instrumental goal whose preferred means of attainment has been disturbed by physical impairment.

Int J Cancer, 1990 Sep 15, 46(3), 533 - 8
Inflammation and anti-tumor resistance . V . Production of a cytostatic factor following cooperation of elicited polymorphonuclear leukocytes and macrophages; Hevin MB et al.; When Lewis tumor cells (3LL) included in a gel of polyacrylamide microbeads are injected into mice and recovered 1 day later, incorporation of 125I-UdR is strongly reduced . In contrast, no reduction is observed in irradiated mice . The cytostatic effect is non-existent in 6 hr-old granuloma (granulocytes 90%, macrophages 10%), but is maximal in 48 hr-old granuloma (granulocytes 50%, macrophages 50%) . When 6 hr-old granuloma cells (which are not cytostatic) are incubated with bone-marrow-derived macrophages (BMs) (which are slightly cytostatic), considerable cytostasis against 3LL is observed, such an effect being strongly reduced if the 2 cell populations are separated . This suggests that close contact of live polymorphs with macrophages is necessary for full expression of cytostasis . No increase in cytostasis of bone-marrow macrophages is observed when BMs are incubated with a cell-free extract of freeze-thawed 6-hr-old granuloma cells . Cell contact is not necessary between granuloma cells and 3LL since the cytostatic activity is found in the supernatant of incubated phagocytic cells . Cytostasis is also observed with B16, P815, J774 cells and normal mouse bone-marrow cells . An active cytostatic fraction has been purified from the supernatant of 48-hr-old granuloma cells following molecular filtration and HPLC . The cytostatic factor has a low molecular weight (400-500 daltons), is not a peptide and presents maximum absorption at 267 nm.

J Biol Chem, 1990 Sep 5, 265(25), 14907 - 10
Plasma membrane-stimulated vanadate-dependent NADH oxidation is not the primary mediator of vanadate toxicity in Saccharomyces cerevisiae; Minasi LA et al.; Interactions of oxyvanadium compounds with cellular metabolism have recently been demonstrated . Membrane-stimulated vanadate-dependent NADH oxidation has been hypothesized to involve the cellular accumulation of H2O2, which may cause the vanadate sensitivity of animals and microbes . This report shows that the vanadate-dependent NADH oxidation activity of the yeast plasma membrane requires oxygen and is present in vanadate-resistant mutants of Saccharomyces cerevisiae . In addition, the vanadate sensitivity of growth in S . cerevisiae is the same during aerobic and anaerobic growth . These results imply that neither plasma membrane-mediated vanadate-stimulated NADH oxidation, nor any other oxidative process, is the primary cause of vanadate sensitivity in yeast cells.

Appl Environ Microbiol, 1990 Sep, 56(9), 2870 - 5
Single-cell entrapment and microcolony development within uniform microspheres amenable to flow cytometry; Nir R et al.; A method is presented for encapsulating single microbial cells in small spheres suitable for analysis and sorting by flow cytometry . The entrapped cells are able to multiply and form colonies contained within their respective microspheres . The system is based on ejecting the cells suspended in a gellable liquid through an orifice vibrating at ultrasonic frequencies, thus shearing the cell-containing jet into uniform droplets . When low-melting-temperature agarose was used, the droplets could be gelled into solid spheres during flight by appropriately directed colling air streams . This gelling was accompanied by significant dehydration, resulting in a twofold decrease in bead diameter and a corresponding increase in agarose concentration . Nevertheless, the microbeads obtained were highly uniform and had diameters which could be precisely controlled in the range of 10 to 40 microns . A variety of bacterial and yeast species were entrapped in agarose beads by using this system . In all cases the cells were able to develop into microcolonies containing as many as several hundred cells . This system enables one to apply the powerful method of flow cytometry to the analysis and sorting of whole microbial colonies . Potential applications of this technology in various areas of microbiology are considered.

Mol Gen Mikrobiol Virusol, 1990 Sep, (9), 3 - 10
{What are toxins to microbes? (the role of toxins in bacterial ecology)}; Domaradskii IV; The author attempts to answer two questions: whether the toxins, in particular the toxins having their specificity connected with enzymatic activity, are needed for microbial cell physiology and their significance for bacteria that are not the obligate parasites for warm blooded animals . The analysis of literary data supposes the toxins to be essential cellular metabolites since many of them participate in energy acquiring . Besides that a number of toxins is shown to be relevant to microbial life and to affect the micropredators, especially the monocellular organisms feeding the microbes . In connection with the above mentioned, special attention is paid to extrachromosomal location of many toxins genes relating them to bacteriocins . The possibility is not excluded that in the future the new toxins might come to be found having the enzymatic activities.

J Anim Sci, 1990 Sep, 68(9), 2811 - 32
A review of the physiological significance of hypertonic body fluids on feed intake and ruminal function: salivation, motility and microbes; Carter RR et al.; Mechanisms exist in the ruminant to detect changes in osmolality and volume of plasma during feeding to maintain fluid and electrolyte homeostasis . Feed intake during a meal can be limited by the rise in osmolality of ruminal fluid, which is sensed in the wall of the rumino-reticulum . Ruminal microbes appear to be resilient to the short-term changes in ruminal fluid tonicity, but in vitro growth rates are inhibited when the tonicity of the culture medium is increased beyond physiological levels . Although mixing contractions of the rumen are not inhibited by the normal increases in tonicity of ruminal fluid, time to first rumination is increased . This aspect of motility requires further research . The tonicity of plasma increases toward the end of a large meal as a consequence primarily of absorption of VFA and Na+ from the rumen and fluid shifts into the gut . This hypertonicity is sensed centrally to inhibit parotid secretion by a reduction in the parasympathetic stimulation to the gland . Increases in animal production may result from future research directed toward developing ways of counteracting these negative effects of hypertonicity in body fluids on feed intake and ruminal function.

Hua Xi Yi Ke Da Xue Xue Bao, 1990 Sep, 21(3), 225 - 9
{Detection of the microquantity DNA of Leptospira interrogans by polymerase chain reaction}; Bao L et al.; Leptospirosis is a severe zoonosis in the world . The methods for detecting leptospira are not sensitive and specific so far . The problems in early diagnosis and epidemiological identification of Leptospirosis remain unsolved . Two recombinant DNA fragments of serogroup Icterohaemorrhagiae, Leptospira were selected by repeated molecular cloning and screening in this study firstly . One of them can hybridize with the DNA of various serogroups of Leptospira interrogans; the other can only hybridize with the DNA of serogroup Icterohaemorrhagiae . After the nucleotides sequence analysis, from these 2 recombinant DNA fragments, 2 pairs of polymerase chain reaction (PCR) oligonucleotide primers were synthesized, named primer B 1, 2 and primer B 3, 4 PCRs were carried out with these 2 primers for detecting the microquantity (0.1 ng) of various serovars, serogroup of leptospires . All the DNA of Leptospira interrogans can be amplified by primer B 1, 2, and only the DNA of serogroup icterohaemorrhagiae, Leptospira reacted specially with primer B 3, 4 . The DNA of non-pathogenetic Leptospira and some other microbes, however, had no amplification at all . This study is first reported at home and abroad . The results demonstrate that PCR is a very sensitive and specific technique of DNA amplification, which can be used as a powerful tool in the early diagnosis and epidemiological identification of leptospirosis.

Nucleic Acids Res, 1990 Aug 11, 18(15), 4385 - 93
Attachment of DNA to the nucleoskeleton of HeLa cells examined using physiological conditions; Jackson DA et al.; Although it is widely believed that eukaryotic DNA is looped by attachment to a nucleoskeleton, there is controversy about its composition and which sequences are attached to it . As most nuclear derivatives are isolated using unphysiological conditions, the criticism that attachments seen in vitro are generated artifactually has been difficult to rebut . Therefore we have re-investigated attachments of chromatin to the skeleton using physiological conditions . HeLa cells are encapsulated in agarose microbeads and lysed using Triton in a 'physiological' buffer . Then, most chromatin can be electroeluted after treatment with a restriction enzyme to leave some at the base of the loops still attached . Analysis of the size and amounts of these residual fragments indicates that the loops are 80-90kbp long . The residual fragments are stably attached, with about 1kbp of each fragment protected from nuclease attack . This is very much longer than a typical protein-binding site of 10-20bp.

J Neurosci, 1990 Aug, 10(8), 2502 - 12
Regenerated hair cells can originate from supporting cell progeny: evidence from phototoxicity and laser ablation experiments in the lateral line system; Balak KJ et al.; The mechanisms that lead to the production of sensory hair cells during regeneration have been investigated by using 2 different procedures to ablate preexisting hair cells in individual neuromast sensory epithelia of the lateral line in the tails of salamanders, then monitoring the responses of surviving cells . In one series of experiments, fluorescent excitation was used to cause the phototoxic death of hair cells that selectively take up the pyridinium dye DASPEI . In the other experiments, the ultraviolet output of a pulsed neodymium-YAG laser was focused to a microbeam through a quartz objective lens in epi-illumination mode and used to selectively kill individual unlabeled hair cells while the cells were simultaneously imaged by transmitted light DIC microscopy . Through observation of the treated neuromasts in vivo, these experiments demonstrated that mature sensory epithelia that have been completely depleted of hair cells can still generate new hair cells . Preexisting hair cells are not necessary for regeneration . Immediately after the ablations the only resident cells in the sensory epithelia were supporting cells . These cells were observed to divide at rates that were increased over control values, and eventually those cell divisions gave rise to progeny that differentiated as hair cells, replacing those that had been killed . Macrophages were active in these epithelia, and their phagocytic activity had a significant influence on the standing population of cells . The first new hair cells appeared 3-5 d after the treatments, and additional hair cells usually appeared every 1-2 d for at least 2 weeks . We conclude that the fate of the progeny produced by supporting cell divisions is plastic to a degree, in that these progeny can differentiate either as supporting cells or as hair cells in epithelia where hair cells are missing or depleted.

Immunol Lett, 1990 Aug, 25(1-3), 165 - 72
The spleen in malaria: the role of barrier cells; Weiss L; I believe that my laboratory has developed a construct of the spleen useful in understanding its range of normal and pathologic functions . The elements in the construct include recognition of an anatomically open vasculature with the interposition of reticular cell-reticular fiber filtration beds between terminal arterial vessels and proximal venules . The central function of the spleen, moreover--selective clearance of cells, microbes and other particles from the blood--depends upon these filtration beds . Such functions of the spleen as phagocytosis, immunologic reactivity, hematopoiesis, and blood cell storage derive from its clearance capacities . The reticular filtration beds offer but modest levels of basal clearance . The wide ranges of filtration that characterize the stressed spleen depend upon arming or augmenting the basic reticular filtration beds with responsive cells which can rapidly appear, and rapidly disappear . These include macrophages, salient phagocytic cells of rich repertoire, which have been accorded the major, even exclusive, role in splenic clearance . But other stromal cells participate in splenic clearance . I have identified a system of fibroblastic, contractile, granulated cells which fuse to form complex, branched syncytial sheets which, deployed as diverse barriers, augment the basic reticular filtration beds . Hence, I term these cells barrier cells . Barrier cells effectively interact with macrophages, reticular cells, other stromal and blood cells, contributing to the extraordinary range of splenic clearance capacities . Barrier cells may be elicited by a variety of infectious processes, damaged blood cells and hematopoietic factors . Interleukin-1-alpha evokes a strong barrier cell response, and may be the common denominator in splenic stress, stimulated by activated macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)

J Histochem Cytochem, 1990 Aug, 38(8), 1179 - 86
Elastase and cathepsin G of human monocytes: heterogeneity and subcellular localization to peroxidase-positive granules; Kargi HA et al.; We used antibodies to human leukocyte ("neutrophil") elastase and cathepsin G to localize the corresponding antigens in human neutrophils, monocytes, and alveolar macrophages by immunohistochemistry . Furthermore, we combined immunogold localization with enzyme histochemistry to localize proteinase antigens and endogenous peroxidase activity in the same sections . As expected, all neutrophils contained both elastase and cathepsin G, and the proteinases localized to granules with peroxidase activity . In contrast, marked heterogeneity in monocyte staining for elastase, cathepsin G, and endogenous peroxidase was found . Sixty percent or more were unstained, while the remainder varied greatly in staining intensity . The elastase and cathepsin G in monocytes were localized by immunoelectron microscopy, combined with histochemistry, to cytoplasmic granules which had peroxidase activity . Alveolar macrophages were unstained . Therefore, a subpopulation of peripheral blood monocytes contains leukocyte elastase and cathepsin G in a cell compartment from which these enzymes may potentially be released into the extracellular space . The occurrence of peroxidase and neutral proteinases in the same granules in monocytes could permit the H2O2-myeloperoxidase-halide system and the neutral proteinases to act in concert in such functions as microbe killing and extracellular proteolysis.

Hinyokika Kiyo, 1990 Aug, 36(8), 979 - 87
{Epidemiological and therapeutic study on urethritis of male and cervicitis from viewpoint of STD--a study using NY-198 . Sapporo Clinical Research Group for STD}; Kumamoto Y et al.; Urethritis in males and cervicitis in females, which were sexually transmitted diseases, were treated with NY-198, a new quinolone antibiotic, and its efficacy was studied . Seventeen male patients with gonorrheal urethritis were administered a single 300 mg dose of NY-198 . The efficacy rate on the 3rd day after administration was 100%, but it was 85.7% on the 7th day due to recurrence in 1 patient . The results of treatment of non-gonorrheal infections were as follow . In this treatment, NY-198 was administered in a daily dose of 600 mg in 3 divided doses for 14 consecutive days . In the treatment of chlamydial urethritis of males, the efficacy rate in 26 patients was 84.6% on the 7th day and 84.0% on the 14th day in 25 patients . In the treatment of chlamydial cervicitis, the efficacy rate was 100% on both the 7th (3/3) and 14th (6/6) days . In the treatment of non-gonorrheal and non-chlamydial cervicitis, the efficacy rate was 100% on the 7th day (1/1) and 50% (1/2) on 14th day . The efficacy rate in all 40 males with non-gonorrheal urethritis was 85.0% on the 7th day and 88.9% for 36 patients on the 14th day, while that in all 4 females with cervicitis was 100% on the 7th day and 87.5% on the 14th day . No side effects were seen in any of the patients . Overall, NY-198 had an efficacy rate of 80% in the treatment of chlamydial infections . NY-198 was found to be a useful drug which is efficacious in the treatment of all STD-related microbes such as gonococci and chlamydia.

J Immunol, 1990 Jul 15, 145(2), 697 - 701
High concentrations of bacterial lipopolysaccharide, but not microbial infection-induced inflammation, activate macrophage C3 receptors for phagocytosis; Griffin FM Jr et al.; Macrophage C3 receptors are normally immobilized in the plane of the cells' plasma membrane and are unable to promote phagocytosis even though they promote avid particle binding . We have previously identified a lymphokine that activates macrophage C3 receptors for phagocytosis both in vitro and in vivo, and others have found that certain types of nonimmunologically mediated inflammation are also able to activate mononuclear phagocyte C3 receptors . These findings raised the possibility that macrophage C3 receptor activation is a universal consequence of inflammation . We sought in the present experiments to determine whether or not inflammation induced by microbial infection in a nonimmune host resulted in activation of macrophage C3 receptors . We injected mice i.p . with either viable microorganisms, microbe-containing immune complexes, or bacterial LPS . Macrophages were harvested by peritoneal lavage 4 days later; nearly all lavage fluids grew the microorganism with which the mouse had been injected, indicating that an infection had been established . Monolayers of macrophages were established and their interaction with sheep E coated with C3 (EIgMC) was determined . All macrophages bound EIgMC, but only macrophages from mice injected with either very high concentrations of LPS or microbe-containing immune complexes ingested them . C3 receptors of macrophages that ingested EIgMC were mobile; others were not . Thus, inflammation induced by microbial infection does not commonly, if at all, activate macrophage C3 receptors; microbe-containing immune complexes and high concentrations of LPS do . The mechanism of receptor activation in each case is C3 receptor mobilization, which is probably mediated by a lymphokine.

J Biomed Mater Res, 1990 Jul, 24(7), 861 - 71
Study of the effect of the surface state on the cytocompatibility of a Co-Cr alloy using human osteoblasts and fibroblasts; Naji A et al.; Cobalt-chromium-based alloys are widely used in oral and orthopedic implantology . Although they are relatively well tolerated, biological complications could occur which sometimes are due to the insufficient biocompatibility of the alloy . This study shows the effects of an alloy (Co (base), 28% Cr, 5.5% Mo, 1% Ni, 0.95% Si, 0.7% Fe, 0.65% Mn, 0.25% C), on differentiated human cells derived from an oral implantation site, specifically alveolar bone osteoblasts and gingival fibroblasts . The cytocompatibility of the alloy is determined by the study of cell proliferation, determination of total cell protein and intracellular alkaline phosphatase contents, cytoskeleton, and cell morphology . The alloy is presented to the cells in four different surface states: rough cast, specular polished, microbead blasted, and RF sputtered . The results demonstrate that the same material has different effects on the basal and specific cellular functions, according to its surface state . For this alloy we can classify its cytocompatibility according to its surface state in such an order: Microbead blasted much greater than specular polished greater than RF sputtered greater than rough cast.

Am J Vet Res, 1990 Jul, 51(7), 1055 - 61
In vivo effects of chloramphenicol, tetracycline, and gentamicin on bovine neutrophil function and morphologic features; Paape MJ et al.; Antibiotics that have been shown in vitro to have a detrimental effect on bovine polymorphonuclear leukocytes (PMNL) were injected into the mammary gland . Chloramphenicol, tetracycline, gentamicin, or phosphate-buffered saline solution (PBSS) were administered to uninfected mammary quarters of four cows at recommended doses . Each cow received each of the 4 treatments . Total milk somatic cell count and N-acetyl-beta-D-glucosaminidase activity in milk in response to drug, changes in ultrastructure of PMNL, and effects on in vitro percentage phagocytosis, reduction of nitroblue tetrazolium, and chemiluminescence were studied . Chloramphenicol and tetracycline caused a significant (P less than 0.01) increase in somatic cell count, compared with baseline values . During the first 12 hours, no effect on NAGase activity was observed . All 3 antibiotics caused a significant (P less than 0.05) alteration of PMNL morphologic features . More abnormal PMNL (63%) were found in tetracycline-injected quarters . Gentamicin-injected quarters contained 33% abnormal PMNL, compared with only 5% for PBSS-injected quarters . A significant (P less than 0.01) decrease in percentage phagocytosis was observed for tetracycline and gentamicin . Tetracycline inhibited all chemiluminescence activity, whereas no effect was observed for the other 2 drugs . Nitroblue tetrazolium reduction was nonsignificantly (P greater than or equal to 0.05) decreased for the 3 drugs, compared with that for PBSS controls . On the basis of our findings, we concluded that some antibiotics may be inhibitory to phagocyte function and, thereby, impair host defense mechanisms against invading microbes.

Ther Umsch, 1990 Jul, 47(7), 606 - 11
{Infected prosthesis of large joints}; Bereiter H et al.; The problems related to infections of hip- and knee-prostheses are generally known . The aim of the operation- a mobile and painless joint is jeopardized . The best therapeutic measure has to be evaluated individually by a differentiated diagnostic procedure . The health condition of the patient, type and localization of the infection, bacteriology and resistance of the microbes as well as the biomechanical condition of the artificial hip joint and the trophic quality of bone and soft tissue play an important role . The different therapeutic concepts we can dispose of should take these factors into account, so that a successful healing may be expected in 80 to 90% of the cases.

EMBO J, 1990 Jul, 9(7), 2207 - 14
Active RNA polymerase I is fixed within the nucleus of HeLa cells; Dickinson P et al.; We have investigated whether active RNA polymerase I, the enzyme responsible for transcribing ribosomal RNA, is immobilized by attachment to a large subnuclear structure in HeLa cells . As unphysiological salt concentrations induce artifacts, we have used isotonic conditions throughout the preparative and analytic procedures . Cells are encapsulated in agarose microbeads and lysed in Triton and a 'physiological' buffer; then soluble proteins and RNA diffuse out through the agarose pores to leave encapsulated chromatin . This can be manipulated without aggregation but is accessible to molecular probes; it retains the replicational and transcriptional activities of the living cell . After treatment with a restriction endonuclease, most chromatin can be removed from beads by electrophoresis: then active ribosomal genes and polymerase I remain behind . Active ribosomal genes are very accessible to nuclease digestion whilst the rest are even more inaccessible than inactive globin genes . Our observations confirm the complex organization of rDNA within nucleoli and are compatible with transcription occurring at fixed sites . A model for transcription involving an attached polymerase is presented.

J Nat Prod, 1990 Jul-Aug, 53(4), 978 - 82
Novel marine sponge amino acids, 10 . Xestoaminols from Xestospongia sp; Jimenez C et al.; The study of the anthelminthic components from a Fiji sponge Xestospongia sp . has yielded new amino alcohols, xestoaminols A-C . Xestoaminol B, (2S*)-aminotetradeca-11, 13-dien-(3R*)-ol {2}, is isomeric to known Xestospongia products, (2S)-aminotetradeca-5,7-dien-(3R)-ol {6} and (2S)-aminotetradeca-5,7-dien-(3S)-ol {7}, recently reported by Gulavita and Scheuer . Xestoaminols A {1} and C {3} are, respectively, the dihydro and tetrahydro derivatives of xestoaminol B . A combined nmr and molecular mechanics study on the oxazolidinone of xestoaminol A provided the basis for the relative stereochemistry assigned at C-2 and C-3 in xestoaminol A . This compound was extremely active in assays testing for action against parasites, microbes, and reverse transcriptase.

Nature, 1990 Jun 21, 345(6277), 659 - 60
Duesberg, HIV and AIDS; Weiss RA et al.; Last century there was a sharp difference of opinion between those, such as Koch and Pasteur, who proposed that disease could be caused by invisible microbes, and others who held that epidemics are the result of evil vapours (mal'aria) . Arguments that AIDS does not have an infectious basis are as quaint as those of the miasmalists.

J Dairy Sci, 1990 Jun, 73(6), 1665 - 9
Uses of biotechnology and technology transfer to keep food safe; Hardy RW; The era of biology is composed of 1) the definition of molecular laws of biology, 2) the exponential expansion of the data base, and 3) the establishment of the first generation molecular and cellular tool kit; this era is driving the development and commercialization of biotechnological products and processes for agriculture and the food system . These products and processes should have a major impact in maintaining and improving food safety . Several meeting and organizational initiatives on biotechnology and food safety are summarized . Possible roles of biotechnology in areas of food safety involve microbial contaminants, nutritional quality, natural antimetabolites, allergens, toxicants, and synthetic chemical residues . Biotechnology will have an impact on all these areas through both improved ability to measure as well as to modify microbes, animals, and plants used as food . Diagnostics for microbial contaminants and biobased alternatives to synthetic chemicals are most advanced . However, all these biotechnological products and processes for food safety are in very early stages of development and commercialization.

Nature, 1990 May 3, 345(6270), 63 - 5
16S rRNA sequences reveal numerous uncultured microorganisms in a natural community; Ward DM et al.; Microbiologists have been constrained in their efforts to describe the compositions of natural microbial communities using traditional methods . Few microorganisms have sufficiently distinctive morphology to be recognized by microscopy . Culture-dependent methods are biased, as a microorganism can be cultivated only after its physiological niche is perceived and duplicated experimentally . It is therefore widely believed that fewer than 20% of the extant microorganisms have been discovered, and that culture methods are inadequate for studying microbial community composition . In view of the physiological and phylogenetic diversity among microorganisms, speculation that 80% or more of microbes remain undiscovered raises the question of how well we know the Earth's biota and its biochemical potential . We have performed a culture-independent analysis of the composition of a well-studied hot spring microbial community, using a common but distinctive cellular component, 16S ribosomal RNA . Our results confirm speculations about the diversity of uncultured microorganisms it contains.

Ann Allergy, 1990 May, 64(5), 455 - 8
Changes in the titers of IgG antibodies against farmer's lung antigens in the sera of healthy dairy farmers; Rautalahti M et al.; We investigated the effects of exposure to biologic dust on IgG antibody levels of farmers during the indoor feeding season for cattle . The reference group consisted of 90 healthy, nonsmoking teachers . At the beginning of the indoor feeding season, the mean titer of IgG antibodies to A . umbrosus for the farmers was significantly higher than that for the teachers (P less than .001) . During the indoor feeding season, the IgG antibody titer of A . umbrosus but not the titers of the other three studied microbes decreased for the farmers . For the teachers, titers of all four microbes decreased . The study confirmed earlier findings that, in Finland, exposure to A . umbrosus is related to cattle raising . The study also shows that during the indoor feeding season for cattle, the quality of hay and bedding materials is reflected in the serum antibody profile of even healthy dairy farmers.

Proc Natl Acad Sci U S A, 1990 May, 87(9), 3579 - 83
Fibronectin controls capillary endothelial cell growth by modulating cell shape; Ingber DE; An in vitro system has been developed to study the mechanism by which fibronectin (FN) regulates capillary endothelial cell growth in the presence of soluble angiogenic mitogens . Endothelial cells were cultured in chemically defined medium containing a constant, saturating amount of basic fibroblast growth factor . Formation of cell-FN contacts was then varied in a controlled fashion by three different techniques: (i) nonadhesive, bacteriological dishes were precoated with increasing densities of FN; (ii) soluble RGD peptides were used to progressively inhibit binding of cell-surface integrin receptors to adsorbed FN; and (iii) FN-coated surfaces were covered with increasingly thick layers of polyhydroxyethylmethacrylate (a nonadhesive polymer) to physically restrict cell access to FN binding sites . Endothelial cells became more extended and proliferated more rapidly as FN coating concentrations were raised from approximately 250 to approximately 10,000 FN molecules per micron 2 . Computerized morphometric analysis confirmed that cell shape (projected cell areas) was determined by the density of FN contacts and that DNA synthetic levels were tightly coupled to the extent of cell spreading, regardless of the method used to perturb cell adhesion . In contrast, neither soluble FN nor cell-surface binding of FN-coated microbeads (diameter, 4.5 microns) had any effect on growth when cells were grown in suspension and cell spreading was prohibited . These results suggest that FN controls capillary endothelial cell proliferation based on its ability to support tension-dependent alterations of cell shape--i.e., both by binding to cell-surface integrins and by resisting mechanical loads that are applied to these receptors.

Parazitologiia, 1990 May-Jun, 24(3), 186 - 92
{The epizootiological significance of flea accumulation in aggregations of the female long-tailed suslik in the Tuva plague focus}; Verzhutskii DB et al.; The formation of aggregations of related females is a peculiarity of the intrapopulational organization of long-tailed suslik that results in the accumulation of Citellophilus tesquorum, the main vector and keeper of the plague microbe in the Tuva plague nidus . The plague agent is adapted to the existence on the territory occupied by aggregations of females that manifests itself in the delay of the beginning and prolixity of block-formation periods in fleas . The transfer of the agent from one place to another takes place only at the high abundance of long-tailed suslik . When the number of the suslik is low the plague microbe circulates in the ranges of one or several neighbouring aggregations of females having no possibility for successful transfer to a new place.

J Acoust Soc Am, 1990 May, 87(5), 2207 - 17
A three-dimensional model of tongue movement based on ultrasound and x-ray microbeam data; Stone M; Point-tracking techniques provide timing information about structural movements of the tongue . Imaging techniques provide information about cross-sectional and pharyngeal tongue shape and movement . This study joined these techniques in a single subject . Five pellets on the tongue surface were tracked using x-ray microbeam, and the midsagittal and coronal planes of the tongue were imaged using real-time ultrasound . The speech materials were the consonants {s} and {l} and the vowels {i}, {a}, and {o} combined in VCVCe utterances . Analyses concentrated on the difference in tongue movements related to the two consonants . A model of tongue movement was developed, in which critical features of consonant shape and position dominated the tongue opening movement . In this model, the tongue is divided into subdivisions termed "functional segments" in both the sagittal and coronal planes . Movements of the functional segments created observable opening movement patterns.

Dent Cadmos, 1990 Apr 15, 58(6), 52 - 61
{Adhesiveness of microorganisms to some soft resins}; Provvisionato C et al.; Considering the fact that one of the main causes of the soft resins modification in prosthetic dentistry is the effect caused by a variety of microbe, experiments were carried out "in vitro" of microbe, experiments were carried out "in vitro" on three of the most commonly used resins with a modified method, based on the use of lymphoprep, it has been possible to study the capacity for adherence of bacteria and mycetes commonly found in the oral flora, over both the short and the long term . Results of this research underlined how ethylene and acetate based vinyl resins, probably for their physical and chemical characteristics, provide the best resistance to colonization by microbes, with special reference to mycetes . This is presumably an advantage for their use "in vivo" for a greater and improved conservation over the time, owing to this reduced interaction with microbe action.

Infect Immun, 1990 Apr, 58(4), 1038 - 42
Thermoregulation of protein synthesis in Borrelia burgdorferi; Cluss RG et al.; Borrelia burgdorferi, the etiological agent of Lyme disease, infects humans via the bite of a tick . The microbe survives in at least two vastly different environments: an arthropod vector and a warm-blooded host . We examined protein synthesis in B . burgdorferi B31 in response to sudden heat stress, which is similar to that which occurs during the transmission from vector to host . Proteins synthesized after shifts from 28 degrees C to higher temperatures and in pulse-chase experiments were labeled with 3H-labeled amino acids for 4 h and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography . The synthesis of four proteins we designated as heat stress proteins (HSPs) was increased by shifts to higher temperatures (HSP-1, 75 kilodaltons {kDa}; HSP-2, 42 kDa; HSP-3, 39 kDa; and HSP-4, 27 kDa); and the amount of one protein we designated as heat-labile protein 1 (29.5 kDa) was decreased at higher temperatures . At 37 to 40 degrees C, the major heat stress protein, HSP-1, represented 14 to 18% of the total cell protein compared with 1 to 2% of the total cell protein at 28 degrees C . HSP-1 was stable during a 4-h chase at either 40 or 28 degrees C . Demonstration of similar HSPs in low-passage, pathogenic strains of B . burgdorferi suggests that the heat stress response may be common among B . burgdorferi strains and may play a role in Lyme disease.

Hautarzt, 1990 Apr, 41(4), 196 - 203
{Activated granulocytes as producers of reactive oxygen species--their significance for inflammatory reaction}; Kapp A; The release of reactive oxygen species (ROS) by activated granulocytes is essential for the destruction of microbes and parasites in humans . Therefore, granulocytes play an important role in the pathogenesis of inflammatory reactions, particularly in inflammatory skin diseases . Besides their well-known toxic effects, ROS are capable of modulating a variety of different immune functions . The present review, therefore, focuses on the biological effects of ROS, on other producer cells of ROS besides granulocytes, on biochemical aspects of the production and interactions of ROS and on methods of detecting ROS production . Apart from well-known stimuli, which may be devoid of any physiological relevance or only induce a short-lived activation of granulocytes, cytokines are reported to induce a release of ROS . A possible modulatory effect of cytokines derived from immunocompetent and other cells on granulocyte activity could be of major importance for our understanding of the cellular interactions during inflammatory reactions, particularly in diseases characterized by granulocyte activation . The data presented allow a better understanding of the complex regulatory process of granulocyte activation in inflammatory skin diseases.

J Infect Dis, 1990 Apr, 161(4), 595 - 602
New molecular techniques for microbial epidemiology and the diagnosis of infectious diseases; Eisenstein BI; A major aim of clinical microbiologists over the last century has been to demonstrate the presence of pathogenic microorganisms in clinical or pathologic samples associated with infectious diseases . With the development of molecular genetics over the last two decades, new technologies have become available that allow more sensitive and specific determinations to be made in shorter periods . Two considerable benefits have accrued: Epidemiologists are now capable of judging clonality among various clinical isolates more powerfully, permitting added accuracy in the evaluation of the epidemic spread of microbes, and clinicians have gained enormous ability to diagnose previously difficult-to-detect pathogens.

Mikrobiol Zh, 1990 Mar-Apr, 52(2), 89 - 93
{The dynamics of antibody formation to a vaccinal strain of Francisella tularensis in different immunization regimens}; Cherepakhina IIa et al.; The use of different schemes of albino mice immunization either by living or by killed preparations of the vaccine strain of Francisella tularensis when obtaining monoclonal antibodies to the tularemia microbe made it possible to reveal definite regularities in the dynamics of antibody formation . The highest titres of antibodies in sera of animals-donors of splenocytes were obtained during the daily (for 3 days) intraperitoneal immunization of mice with living vaccine or with its thrice administration to the spleen thrice with the interval of 10 days . Revaccination against a background of high titres of antibodies decreased their quantity in blood serum of mice, while that against a background of low titres increased them.

Eur Respir J, 1990 Mar, 3(3), 257 - 60
Class-specific antibodies during follow up of patients with farmer's lung; Ojanen T et al.; Sequential serum samples of 13 patients with acute farmer's lung (FL) taken during a follow-up of 18-36 months, were tested for antibodies of immunoglobulin G (IgG), IgA, IgM and IgE classes against Thermoactinomyces vulgaris and Micropolyspora faeni, and compared with contemporary lung function parameters . In the acute phase, antibodies of several Ig classes were present, those of IgG and IgA being most common . At the end of the follow-up, the mean values of all antibody titres were lower than in the acute phase, and antibodies were now mostly of one or two Ig classes only . The reduction in antibody levels was most often detectable in IgG and IgA antibodies against T . vulgaris . Antibody titres correlated inversely with tested lung function parameters, especially IgA antibodies with pulmonary diffusing capacity . Our results show that a follow-up of levels of class-specific antibodies, especially of IgG and IgA gives valuable information on causative microbes and on temporal changes of the exposure.

Cancer Res, 1990 Mar 1, 50(5), 1421 - 5
L-arginine-dependent reactive nitrogen intermediates as mediators of tumor cell killing by activated macrophages; Keller R et al.; The capacities of lymphokines and of various microbes to induce in a pure population of bone marrow-derived mononuclear phagocytes tumoricidal activity and/or the production of L-arginine-dependent reactive nitrogen intermediates, measured by the release of nitrite, were comparatively assessed . These parameters were found to be closely correlated in a variety of experimental situations, i.e., enhanced by a surplus of L-arginine and abrogated by N-monomethyl-L-arginine, a selective inhibitor of L-arginine-dependent effector mechanisms . In other macrophage/tumor cell combinations, such correlation was less obvious or not at all detectable, suggesting that, in these models, L-arginine-dependent reactive nitrogen intermediates are not or not alone responsible for the mediation of tumoricidal activity by activated macrophages . Collectively, the present findings suggest that the mechanism of tumor cell killing by activated macrophages may differ, depending on the tumor cell type and the pathway of macrophage activation . Among the various effector mechanisms considered to be involved in tumor cell killing by activated macrophages, L-arginine-dependent reactive nitrogen intermediates appear to hold a major role.

Parazitologiia, 1990 Mar-Apr, 24(2), 151 - 4
{The efficiency of Rhadinopsylla rothschildi and R . dahurica fleas as vectors of the causative agent of plague in a Transbaikal natural focus}; Gan NV et al.; Experiments have shown that a block of proventriculus arises in 2.1 to 12.5% of infected fleas of R . rothschildi and in 7.2 to 10.5% of R . dahurica . These fleas transmit the plague agent to different animals (Brandt's vole, narrow-skulled vole, Dahurian suslik) . The plague microbe is preserved in the organism of infected insects till the end of the experiment, 74 and 24 days respectively . Therefore, the fleas can play a part in the maintenance of plague epizootics in the Transbaikal natural nidus.

Parazitologiia, 1990 Mar-Apr, 24(2), 106 - 12
{The ability of flea species on the common vole from mountainous Dagestan to transmit and preserve the causative agent of plague}; Degtiareva LV et al.; The infection ability and terms of preservation of plague microbe in fleas of common vole from Dagestan high-mountain plague focus (Frontopsylla causasica, Megabothris turbidus, Ctenophthalmus intermedius and Amphipsylla rossica) was studied experimentally . Block formation and transmission of the infection by F . caucasica and M . turbidus was observed . The transmission of plague microbe by Ct . intermedius fleas was first carried out . These species of fleas preserve the infection for a long time . Experiments with fleas of A . rossica yielded negative results.

J Appl Bacteriol, 1990 Mar, 68(3), 285 - 8
Lack of precision in commercial identification systems: correction using Bayesian analysis; Berger SA; Commercial microbial identification systems rank the relative likelihood of species identity on the basis of in vitro reactions only . Failure to consider the prevalence of individual taxa results in a spurious demotion of common species; and a tendency toward over reporting of rare microbes . The incorporation of Bayesian analysis into identification matrices can provide for a realistic ranking of bacterial species which fulfil given biocode schemes.

J Appl Physiol, 1990 Mar, 68(3), 1157 - 66
Fluorescence location of RVLM kainate microinjections that alter the control of breathing; Nattie EE et al.; Kainic acid (4.7 mM) applied to the rostral ventrolateral medulla (RVLM) surface decreases phrenic output, CO2 sensitivity, and blood pressure in chloralose-urethan-anesthetized, vagotomized, paralyzed, glomectomized, servoventilated cats . In this study using the same preparation, bilateral 50- to 100-nl kainate injections just below the RVLM surface better localized these responses topographically . The physiological responses to unilateral 10-nl kainate injections were then correlated with anatomic location determined by fluorescent microbeads (0.5 micron diam) . Many sites were associated with no effect, a few rostral and caudal sites with increased phrenic activity, and cluster of sites with decreased phrenic activity often to apnea, decreased CO2 sensitivity, and decreased responses to carotid sinus nerve stimulation . Blood pressure was unaffected . These sites, within 400 microns of the surface, were ventral to the facial nucleus, ventrolateral to the nucleus paragigantocellularis lateralis, caudal to the superior olive, and rostral to the retrofacial nucleus . They appeared to be within the recently described retrotrapezoid nucleus, which contains cells with respiratory-related activity and projections to the dorsal and ventral respiratory groups . Cells within this site appear able to provide tonic input to respiration and to affect peripheral and central chemoreception.

CA Cancer J Clin, 1990 Mar-Apr, 40(2), 103 - 8
Livingston-Wheeler therapy; The cell biology and pathogenic role of pulmonary intravascular macrophages; Department of Environmental Science and Physiology, Harvard School of Public Health, Boston, Massachusetts 02115Pulmonary intravascular macrophages (PIMs) are an extensive population of mature phagocytic cells adherent to the pulmonary capillary endothelium in selected species . They are not prevalent in lungs of commonly studied laboratory animals, such as rodents, and thus have only been recently appreciated . However, their potential role in host defense and acute lung injury has attracted interest, since a number of studies have demonstrated pulmonary localization of circulating particles, microbes, and endotoxin by PIMs . Those animal species, such as ruminants, that provide useful models of pathogen (or endotoxin)-induced acute lung injury demonstrate rapid pulmonary uptake of bacteria by PIMs . Inflammatory mediators released by activated PIMs may initiate the process and provoke accumulation of neutrophils and platelets . This review summarizes the morphological characteristics of PIMs and their species distribution . The role of these members of the mononuclear phagocyte system, both beneficial and potentially pathogenic, is reviewed . The question of whether PIMs have a role in acute lung injury in humans is also discussedPublication Types:

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