J Antibiot (Tokyo), 1991 Mar, 44(3), 366 - 70 L-669,262, a potent HMG-CoA reductase inhibitor; Joshua H et al.; The microbial transformation of simvastatin (MK-733) by Nocardia autotrophica subspecies amethystina yielded iso-simvastatin-6-one as a minor component . This transformation product is a dienone and is one of the more potent inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase found to date. Arch Pathol Lab Med, 1991 Mar, 115(3), 299 - 305 The role of the clinical microbiology laboratory in transplantation; Walker RC; The clinical microbiology laboratory plays a central role in any transplantation program . Pretransplantation microbiologic testing often determines prophylactic treatment, donor selection, and blood product use . With suspected infection, rapid microbiologic tests permit prompt therapy but are challenged by an ever-changing diversity of potential pathogens and limited specimen size . Antigen detection and the polymerase chain reaction with nucleic acid hybridization are newer methods that promise earlier detection of such serious infections as disseminated aspergillosis and primary cytomegalovirus and may reveal new microbial causes of various posttransplantation syndromes. J Dent Res, 1991 Mar, 70(3), 182 - 6 Acid profile in carious dentin; Hojo S et al.; Organic acids in carious dentin from 69 permanent teeth were analyzed by gas chromatography . Lactate, acetate, propionate, and butyrate were detected in most samples, and limited amounts of isobutyrate, valerate, isovalerate, caproate, and isocaproate were occasionally detected . Lactate, acetate, and propionate were major acids and altogether accounted for about 90% of total acid in most samples of carious dentin . However, the proportion of these three acids varied among the samples . Some samples contained over 85% lactate, while others contained mainly acetate and propionate . A high percentage of acetate was usually accompanied by an appreciable amount of propionate . All seven samples in carious dentin under fillings or restorations had little lactate, but a high percentage of acetate plus propionate . The differences in acid profiles of carious dentin may reflect differences in the microbial ecology of carious dentin, and a stage of progress of dentin caries or a type of dentin caries. Appl Environ Microbiol, 1991 Mar, 57(3), 744 - 50 Hydrolysis of carbaryl by a Pseudomonas sp . and construction of a microbial consortium that completely metabolizes carbaryl; Chapalamadugu S et al.; Two Pseudomonas spp . (isolates 50552 and 50581) isolated from soil degraded 1-naphthol and carbaryl, an N-methylcarbamate pesticide, respectively . They utilized these compounds as a sole source of carbon . 1-Naphthol was completely metabolized to CO2 by the isolate 50552, while the carbaryl was first hydrolyzed to 1-naphthol and then converted into a brown-colored compound by the isolate 50581 . The colored metabolite was not degraded, but 1-naphthol produced by the isolate 50581 during the exponential phase of growth was metabolized by the isolate 50552 . The two isolates were used to construct a bacterial consortium which completely catabolized carbaryl to CO2 . No metabolite was detected in the cell cultures of the consortium . The isolate 50581 harbored a 50-kb plasmid pCD1, while no plasmid was detected in the isolate 50552 . The isolated bacteria individually or as a consortium may be used for detoxification of certain industrial and agricultural wastes. Am J Obstet Gynecol, 1991 Mar, 164(3), 859 - 62 Meconium-stained amniotic fluid: a risk factor for microbial invasion of the amniotic cavity; Romero R et al.; The purpose of this study was to determine whether meconium-stained amniotic fluid is a marker for microbial invasion of the amniotic cavity . Amniocentesis was performed on 707 patients presenting with preterm labor and intact membranes . Meconium-stained amniotic fluid was present in 4.2% (30/707) of patients with preterm labor . The prevalence of positive amniotic fluid cultures was significantly higher in women with meconium-stained amniotic fluid than in women with clear fluid (33% {10/30} vs 11% {75/677}; p = 0.001; odds ratio = 4.01; 95% confidence interval = 1.6 to 9.4) . Patients with meconium-stained amniotic fluid were also more likely to have failed tocolysis and delivered a preterm neonate more frequently than patients with clear fluid (83% {25/30} vs 38% (258/677); p = 0.0001; odds ratio = 8.1; 95% confidence interval = 2.9 to 24.4) . We conclude that meconium-stained amniotic fluid is a risk factor for microbial invasion of the amniotic cavity and preterm delivery in women with preterm labor and intact membranes. Vopr Med Khim, 1991 Mar-Apr, 37(2), 69 - 72 {Determination of nitrate reductase activity in mixed saliva}; Vavilova TP et al.; A procedure is developed for estimation of nitrate reductase activity in saliva . Effects of pH, temperature and nature of electron donor on the enzymatic activity were studied . The maximal enzymatic activity was found at pH 6.5-7.0; heating and freezing of saliva led to loss of the enzymatic activity . Salivary nitrate reductases are of microbial origin and belong to "terminal" type of nitrate reductases . The enzyme activity varied in the interval 0.8-17.3 mmole/min per I L saliva and did not depend on human sex. J Dairy Sci, 1991 Mar, 74(3), 871 - 81 Ruminal digestion and microbial utilization of diets varying in type of carbohydrate and protein; Stokes SR et al.; Three ruminally and duodenally cannulated, lactating Holstein cows were used in a 3 x 3 Latin square experiment to study the effects of differing levels of nonstructural carbohydrate and degradable intake protein on ruminal digestibility and microbial protein production . Three diets were formulated to contain 1) 38 and 13.2%, 2) 31 and 11.8%, and 3) 24 and 9% nonstructural carbohydrate and degradable intake protein as percentages of the DM, respectively . Dry matter intakes were similar for all diets (21.9, 21.1, and 18.3 kg/d for diets 1, 2, and 3, respectively) . Likewise, microbial efficiency, as estimated from purine analysis, was unaffected by diet and averaged 24 g of microbial N/kg of OM digested for all treatments . Ruminal digestion of OM averaged 66.6, 65.1, and 55.7% for diets 1, 2, and 3, respectively, resulting in lower microbial N flow per day for diet 3 (317, 333, and 202 g, respectively) . Digestion of nonstructural carbohydrate and CP followed similar trends as did OM digestion, whereas NDF digestion remained similar across all diets . These results indicate that nonstructural carbohydrate greater than 24% and ruminally degradable protein greater than 9% of DM will enhance microbial protein flow from the rumen. J Cardiovasc Pharmacol, 1991 Mar, 17(3), 508 - 18 Characteristics of the vasorelaxing action of (3E)-4-ethyl-2-hydroximino-5-nitro-3-hexamide FK409, a new vasodilator isolated from microbial sources, in isolated rabbit arteries; Shibata S et al.; We examined the vasoinhibitory effect of (3E)-4-ethyl-2-hydroximino-5-nitro-3-hexamide FK409, a new vasodilator, on contractile responses in isolated rabbit arteries . FK409 (10(-8)-10(-5) M) inhibited contractile responses to norepinephrine (NE), histamine (His), and 5-hydroxytryptamine (5-HT) in rabbit aorta . The pattern of inhibition by FK409 was not competitive . The inhibitory effect of FK409 on the 5-HT response was much greater than that of nitroglycerin (NG) . A high concentration of FK409 (10(-5) M) was necessary to inhibit the response to KCl (10-70 mM) . The effect of combined treatment with FK409 (10(-5) M) and a subthreshold concentration of nifedipine (10(-9) M) on the KCl response was much greater than a single treatment with either agent . In addition, 3 x 10(-6) M D600, but not FK409 (10(-6) or 10(-5) M), inhibited the increase in the rate of 45Ca influx stimulated by a 40-mM KCl substituted solution . In a Ca2(+)-free medium containing EGTA and nifedipine, FK409 (10(-9)-10(-5) M) inhibited phasic responses to NE, His, and 5-HT, and subsequent sustained responses owing to addition of Ca2+ . The response to caffeine in rabbit iliac arteries incubated in Ca2(+)-free medium was also inhibited by FK409 (10(-6) and 10(-5) M) . In rabbit aorta precontracted with NE (10(-5) M) and partially inhibited by prior exposure to NG (10(-5) M), the relaxing effect of FK409 was slightly attenuated . Pretreatment of tissues with FK409 (10(-6) M) inhibited the relaxing action of NG much more than prior NG inhibited the relaxing action of FK409 . Methylene blue (10(-5) M), but not hemoglobin (10(-6) M), inhibited the relaxing action of FK409, whereas M&B 22,948 (3 x 10(-4) M) potentiated it . FK409 caused a relaxation of precontracted aorta without endothelium that was inhibited by methylene blue . In rabbit aorta precontracted with NE, FK409 (10(-6) M) increased cyclic GMP but not cyclic AMP content . FK409 (10(-5) M) had no effect on the NE-mediated increase in tissue inositol monophosphate (IP) . These results suggest that FK409 inhibits the responses attributed to both intracellular Ca2+ release and Ca2+ influx through receptor-operated channels . The inhibitory effect of FK409 on both the KCl contractile response and KCl-stimulated 45Ca influx appears to be different from that of nifedipine or D600 . Furthermore, the inhibitory action of FK409 may be partially mediated by cyclic GMP. J Clin Immunol, 1991 Mar, 11(2), 55 - 64 Allergic manifestations of human immunodeficiency virus (HIV) infection; Carr A et al.; Drug allergy is the most common and significant allergic manifestation of HIV3 infection . Initially described in patients treated with SMX-TMP for PCP, allergy is now known to involve a multitude of drugs . The pathogenesis of, and risk factors for, allergy in HIV infection are poorly understood, although there is evidence suggesting that allergy is more common with advancing immunodeficiency . HIV-negative subjects with sulfonamide allergy may have drug-specific antibodies and drug metabolite-induced lymphocyte cytotoxicity, abnormalities that could partly explain the allergic mechanisms and which may have future diagnostic potential; these abnormalities have not been described in HIV-infected subjects . Therapy includes avoidance, suppressive agents such as corticosteroids, and desensitization, although the appropriate role for each is not entirely clear . Serum IgE levels have been shown to rise with progressive disease; those patients with higher levels may have a worse prognosis . The mechanisms of this rise are multifactorial, probably a combination of altered T-lymphocyte regulation of IgE synthesis and of production of specific IgE directed against microbial antigens. J Dent Res, 1991 Mar, 70(3), 226 - 32 Draft results of a workshop to develop guidelines for studies involving microbial incidence or populations in the oral cavity; Krichevsky MI; The following five outlines are the results to date of the Workshop held in Rockville, Maryland, in January, 1990 . The topics considered in these outlines are: (1) validation of immunological and/or nucleic acid identification probes, (2) cross-calibration of methods and/or laboratories for multi-laboratory cooperative studies, (3) choosing methods for identifying or describing microbial populations appropriate to the scientific question asked, (4) microbial ecology methods (e.g., population dynamics) for the oral cavity studies, and (5) epidemiological methods (e.g., incidence, risk factor analysis) for oral microbial studies . Each topic was considered by two independent groups of participants and later rationalized into one . These outlines are meant to be working outlines for evolution of a set of guidelines to advise on designing studies with microbial incidence and/or population components . We are publishing this preliminary version to elicit comment and criticism from people who did not attend the Workshop . (Attendance at the Workshop was necessarily limited by both space and funds) . Some of the topic outlines have been condensed to save Journal space . The full document is available on request . The next stage will be an open forum to gather and discuss further amplification of the "Guidelines", planned for April 17, 1991, Acapulco, Mexico, in conjunction with the IADR/AADR Meeting . Written comments and requests for further information should be sent to the Workshop organizer (MIK) at the above address.(ABSTRACT TRUNCATED AT 250 WORDS) Agents Actions, 1991 Mar, 32(3-4), 188 - 93 Modulation of cellular processes by H7, a non-selective inhibitor of protein kinases; Nixon JS et al.; H7 has been described as a potent inhibitor of protein kinase C (PKC) and has been widely used to investigate the regulatory role of this enzyme in intact cell systems . In this comparative study between H7 and the microbial alkaloid, staurosporine, we found that the former inhibited rat brain PKC and cAMP dependent protein kinase with IC50 values of 18 and 16 microM respectively whereas the latter was a much more potent inhibitor of both kinases with IC50 values of 9.5 nM and 42 nM respectively . H7, at concentrations up to 100 microM, failed to block cellular events induced by phorbol esters, agents which specifically stimulate PKC, yet was a potent inhibitor of IL-2 induced T cell proliferation with an IC50 value of 19 microM . In contrast, staurosporine was a potent inhibitor of both phorbol ester induced p47 phosphorylation in platelet (I50 value = 540 nM) and also CD3 and CD4 down-regulation in T cells (I50 values 200 nM and 50 nM respectively) . Staurosporine was also a potent inhibitor of IL-2 induced T cell proliferation I50 value = 9 nM) . These results provide a strong argument against the use of H7 to probe for PKC involvement in cellular processes. Eur J Biochem, 1991 Feb 14, 195(3), 849 - 56 Investigations on microbial sulfur respiration . Isolation, purification, and characterization of cellular components from Spirillum 5175; Zophel A et al.; The sulfur-reducing bacterium Spirillum 5175 was investigated with regard to membrane constituents that might be part of the sulfur oxidoreductase which converts elemental sulfur to hydrogen sulfide . Regardless of the electron acceptor used for cultivation of the bacteria, i.e . elemental sulfur, fumarate, or nitrate (Sp . 5175S,F,N), the qualitative pattern of cytochromes and Fe-S proteins did not change significantly, as documented by ultraviolet/visible and electron paramagnetic resonance spectroscopy of oxidized (as isolated) and reduced (dithionite) samples . With elemental sulfur the prominent cytochrome exhibited absorption maxima at 553, 522.5 and 426 nm in the reduced state . In fumarate-grown cells two prominent cytochromes were found with maxima at 561, 551, 530, 521 and 430 nm . Two b-type cytochromes with Em at -198 mV and -20 mV vs the standard hydrogen electrode were identified in the membrane fraction of Sp . 5175F . A yellow pigment was extracted and identified as a flexirubin-type pigment . Although present in large quantities, it seemed not to be involved in the reduction of elemental sulfur . Menaquinone, MK 6 (Mr 580) was the prominent quinone identified in Sp . 5175 . Characterization of a second quinone was not attempted because of its much lower concentration . The membrane constituents of Sp . 5175 were solubilized by a variety of detergents and detergent mixtures . A colorimetric procedure with photochemically reduced phenosafranin as the electron donor and cysteamine trisulfide (RS-S-SR, R = -CH2CH2NH2) as the electron acceptor was used to detect sulfur oxidoreductase activity . Three membrane proteins of Sp . 5175 were purified: (1) an {NiFe} hydrogenase, homogeneous by SDS/polyacrylamide gel electrophoresis, with electron paramagnetic resonance signals as isolated at gx,y,z = 2.01, 2.16, 2.33 (100 K), and a strong signal at g = 2.02 below 20 K; (2) a cytochrome b, Fe-S-dependent fumarate reductase, and (3) a protein apparently linked to the sulfur oxidoreductase activity . In contrast to fumarate reductase, no b-type cytochrome was present in the fractions exhibiting sulfur oxidoreductase activity . The presence of Fe-S centers was demonstrated by electron paramagnetic resonance spectroscopy at 10 K . It is not clear whether the c-type cytochrome in the same fractions is part of the sulfur-reducing apparatus of Sp . 5175. Am J Surg, 1991 Feb, 161(2), 279 - 83 Germfree animals and technics in surgical research; Cohn I Jr et al.; Germfree animals have been reared to a size, weight, and age permitting the performance of major surgical procedures and the pursuit of a variety of surgical research problems . Germfree dogs have been maintained in the isolator system through three generations, indicating that life, reproduction, and growth are all possible in the absence of microbial contamination . The value of the germfree approach to surgical problems has been utilized in studies of a variety of gastrointestinal problems, shock, cancer, immunology, burns, wound healing, and in direct patient application . Patients have been maintained in isolator environments for prevention of infection, for operative procedures, for treatment of extensive burns, and for management of immune-suppressed individuals . We conclude that germfree animals and germfree technics provide a valuable addition to the armamentarium of the surgeon in both research and clinical applications. J Theor Biol, 1991 Feb 7, 148(3), 305 - 29 A host-host-pathogen model with free-living infective stages, applicable to microbial pest control; Bowers RG et al.; A model has been investigated of the dynamics of the interaction between two hosts which are both attacked by a common pathogen, where the pathogen has free-living infective stages the population size of which must itself be modelled explicitly, and where the host species do not interact with one another except through their shared pathogen . If either host interacted with the pathogen alone, three broad classes of dynamics would be possible: host regulation, pathogen persistence and pathogen extinction . Here, all possible types of combinations of hosts are examined: regulation-regulation (both hosts would be regulated if they interacted with the pathogen alone), regulation-persistence, regulation-extinction, persistence-persistence persistence-extinction and extinction-extinction . A wide range of dynamics is generated, including a number of patterns quite unlike those found in the one-host pathogen case (e.g . persistence in one host, elimination of the other host) and behaviour contingent on initial densities in the system . For clarity and pertinence, attention is focused on the case where one host is a pest, the pathogen is a potential microbial control agent, and the other host is a non-target species which it is undesirable to harm . The model suggests, broadly, that non-targets are unlikely to be seriously threatened in such cases, and also that non-targets, far from undermining pest control, are quite likely to contribute to its efficacy. Hum Reprod, 1991 Feb, 6(2), 267 - 76 Relationship between local anti-sperm antibodies and sperm-mucus interaction in vitro and in vivo; Eggert-Kruse W et al.; Sperm-mucus interaction under in-vitro or in-vivo conditions can be affected by local anti-sperm antibodies (ASA) . In a prospective study, a mixed antiglobulin reaction (MAR) test, using immunoglobulin-coated red cells and spermatozoa, was used to detect the presence of IgG and/or IgA on the spermatozoal surface in 209 males of infertile partnerships . The results of direct MAR tests range from 0 to 100% and a significant correlation between MAR % IgG and MAR % IgA (r = 0.74) was found . MAR positive semen samples were significantly more frequent in the group of patients with an inadequate outcome of postcoital testing (PCT) . The sperm-mucus interaction in vitro, evaluated by means of the in-vitro sperm-cervical mucus penetration test (SCMPT) with cervical mucus (CM) of patients' partners, was particularly related to spermatozoal surface antibodies of the IgA class: MAR IgA positive ejaculates were seen in 13.9% of males with inadequate SCMPT versus 4.4% when SCMPT was adequate . The significant correlation between MAR IgA and the sperm penetration ability in vitro could also be proven when donors' CM was taken for the SCMPT, but not when a non-human material was used for in-vitro penetration testing . Microbial colonization of semen specimens did not interfere with the outcome of MAR testing . The pregnancy rate after 12 months was 23% (48/209) and was significantly lower when greater than 30% of spermatozoa were covered with surface ASA of the IgG or IgA class.(ABSTRACT TRUNCATED AT 250 WORDS) Behring Inst Mitt, 1991 Feb, (88), 161 - 9 T-cell reactivity to purified lipophosphoglycan from Leishmania major: a model for analysis of the cellular immune response to microbial carbohydrates; Moll H et al.; The major macromolecule on the surface of Leishmania major promastigotes is a lipophosphoglycan (LPG) . This glycoconjugate plays a key role in determining infectivity and survival of parasites in the mammalian host cell . In addition, L . major LPG is able to induce a host-protective immune response . In this article, we summarise the evidence for recognition of highly purified LPG by T cells and we discuss the potential mechanisms of T-cell stimulation by this non-protein antigen. J Anim Sci, 1991 Feb, 69(2), 836 - 42 Evaluation of a feed intake model for the grazing beef steer; Hyer JC et al.; Responses of a feed intake model for grazing beef cattle to changes in model parameters, forage composition, and supplementation programs with energy and protein were evaluated . Without supplements, the model systematically underpredicted intake of low-quality (low digestibility) forages and subsequent overprediction was observed for high-quality diets . In general, for a reference diet of Italian ryegrass, the model was relatively insensitive to microbial growth parameters, highly sensitive to the microbial carbohydrate composition constant, and moderately sensitive to the microbial N composition constant . Intake prediction was sensitive to changes in the microbial use rate constant for fiber but insensitive to those for protein and starch . Model predictions were highly sensitive to the amount of nondegradable fiber in each of the forages tested . Supplementation effects on forage intake were quantified by supplementing all forage diets with chemical components equivalent to that provided by 1 kg of corn grain or 1 kg of cottonseed meal . Supplementation of the forage diet with the concentrate source resulted in substitution ratios of forage to supplement intake consistent with in vivo results . As forage quality increased, substitution of concentrate for the forage increased . However, the model failed to predict the increased forage intake typically observed with protein supplementation, suggesting that it is insufficient for intake prediction in protein-limiting situations . Nevertheless, the model correctly predicted effects of energy supplementation and forage composition on forage intake, suggesting that different controls must regulate intake responses to supplemental protein. Am J Trop Med Hyg, 1991 Feb, 44(2), 176 - 82 Immunization and protection against malaria during murine pregnancy; Pavia CS et al.; Normal and immune mice were evaluated for their ability to resist infection to the rodent malaria parasite, Plasmodium yoelii, during pregnancy . Parasitemia levels were slightly higher and time-to-death shorter in the nonimmunized pregnant group infected with virulent parasites relative to virgin controls . Subinoculation experiments revealed that numerous virulent organisms were present in the placentas of unprotected gravida but were absent from the fetal livers of their conceptuses . It was also found that mice preimmunized with irradiated P . yoelii survived a usually lethal challenge infection during mid-gestation and delivered healthy newborns . Associated with this protection against transplacental spread of parasites was the additional key finding that placental macrophages were as effective as peritoneal exudate cells in phagocytosing parasite derived material in vitro . This murine malaria-pregnancy model should provide new insights on the various factors (virulence, immunogenicity) of microbial infections affecting the fetal-maternal relationship, as well as on the expression of immune effector mechanisms and immunoregulation, during the reproductive process. J Antibiot (Tokyo), 1991 Feb, 44(2), 232 - 40 Microbial conversion of milbemycins: hydroxylation of milbemycin A4 and related compounds by Cunninghamella echinulata ATCC 9244; Nakagawa K et al.; Many strains of zygomycetes and actinomycetes were found to convert milbemycin A4 (1a) to 13 beta-hydroxymilbemycin A4 (1b) . Among these strains, Cunninghamella echinulata ATCC 9244 had the most efficient 13 beta-hydroxylation ability on milbemycins . In the conversion of milbemycin A3 (2a), 29-hydroxymilbemycin A4 (4a), and 30-hydroxymilbemycin A4 (5a) with this strain, only 13 beta-hydroxylated products were obtained . On the other hand, starting from milbemycin A4 (1a) and 5-ketomilbemycin A4 5-oxime (6a), 13 beta,24- and 13 beta,30-dihydroxy derivatives were also isolated along with 13 beta-hydroxylated products . Similarly, conversion of milbemycin D (3a) and LL-F28249 alpha (8a) gave 13 beta- and 28-hydroxy derivatives (8b and 8c). Ophthalmology, 1991 Feb, 98(2), 146 - 9 Excimer laser ablative treatment of microbial keratitis; Gottsch JD et al.; The 193-nm excimer laser was used to ablate experimental septate fungal (Fusarium) and an atypical mycobacterial (Mycobacterium fortuitum) keratitis in an animal model . The infections were allowed to proceed for 24 and 72 hours . After incubation, ablation with a 193-nm excimer laser with 5.0-mm treatment zones was performed until all suppurative areas were treated . The corneas were excised, halved, homogenized, and plated . All cultures were negative in the 24-hour group . However, in those corneas in which the infections were allowed to proceed to 72 hours, post-treatment cultures were positive for both organisms . Histopathologic examination confirmed that 24-hour infections had been eradicated and that 72-hour infections had organisms present . Three of the eight eyes in the M . fortuitum group perforated during treatment, even though the treatment depth by computer preselection was only 150 microns . Excimer laser photoablation may be a useful technique to eradicate early, localized microbial infections . However, it is apparent that advanced infections with deep stromal involvement and suppuration cannot be eradicated using this technique . Because corneas may be perforated inadvertently during treatment, excimer laser treatment of infectious keratitis should be approached with caution and used for superficial and well circumscribed lesions. J Steroid Biochem Mol Biol, 1991 Feb, 38(2), 249 - 56 Microbial transformation of steroids--VII . Hydroxylation of progesterone by extracts of Phycomyces blakesleeanus; Smith KE et al.; Post mitochondrial supernatants (S-12 extracts) were prepared from Phycomyces blakesleeanus by grinding washed and frozen mycelial cakes in fine sand and extracting the paste produced with buffer containing Tris-HCl pH 7.8 (0.1 M), EDTA (0.01 M), dithiothreitol (5 mM) and glycerol (10% v/v) . The S-12 extracts, obtained in this way, reproducibly hydroxylated progesterone, producing 7 alpha- and 15 beta-hydroxyprogesterone the major products of whole-cell transformation . Cell-free progesterone hydroxylation was found to be approximately linearly dependent on extract concentration, to require reduced NADP (partly replaceable by NADH), and to be dependent on progesterone (apparent Km calculated to be 4 mM) . K+ and Mg2+ were found not to be required . Maximum progesterone hydroxylation occurred after 2 h at pH 7.8 and at 24 degrees C . Using optimum conditions S-12 extracts were capable of hydroxylating between 5 and 15% of added progesterone (0.2 mM) . Hydroxylation was found to be partially inhibited by carbon monoxide (ca 40%) and almost completely inhibited by azoles, ketoconazole and diconazole . The NADPH and molecular oxygen requirements were replaceable by NaIO4 . These findings strongly suggest that hydroxylation was being catalyzed by cytochrome P-450 . This was confirmed by preparing progesterone-hydroxylating microsomes and Triton N-101-solubilized microsome extracts, and by obtaining a dithionite-reduced carbon monoxide-difference absorption spectrum peak at 455 nm in the solubilized microsome extracts. J Allergy Clin Immunol, 1991 Feb, 87(2), 581 - 5 Particle penetration into the automotive interior . I . Influence of vehicle speed and ventilatory mode; Muilenberg ML et al.; Penetration of particulate aeroallergens into the interiors of two, new, similar Chrysler Corporation passenger vehicles (having no evidence of intrinsic microbial contamination) was studied on a large circular test track during periods of high pollen and spore prevalence . Impactor collections were obtained at front and rear seat points and at the track center during periods with (1) windows and vents closed and air conditioning on, (2) windows closed, vents open, and no air conditioning, and (3) air conditioner off, front windows open, and vents closed . These conditions were examined sequentially during travel at 40, 50, 60, and 80 kph . Particle recoveries within the two, new, similar Chrysler Corporation passenger vehicles did not vary with the speed of travel, either overall or with regard to each of the three ventilatory modalities . In addition, collections at front and rear seat sampling points were comparable . Highest interior aeroallergen levels were recorded with WO, and yet, these levels averaged only half the concurrent outside concentrations at track center . Recoveries within the cars were well below recoveries obtained outside when windows were closed (both VO and AC modes) . These findings suggest window ventilation as an overriding factor determining particle ingress into moving vehicles . Efforts to delineate additional determinants of exposure by direct sampling are feasible and would appear essential in formulating realistic strategies of avoidance. Ned Tijdschr Tandheelkd, 1991 Feb, 98(2), 62 - 5 {Recommended protection against infection in the dental office}; Moorer WR; Identification of pathways of microbial contamination and assessment of corresponding infection risks in general dental practice, precede the recommendation of infection control activities . Ten practical and appropriate rules are suggested. Curr Opin Dent, 1991 Feb, 1(1), 17 - 28 Etiology of periodontal diseases; Caton JG et al.; Periodontal diseases are a series of complex, distinct, pathologic entities caused by the interaction of bacterial plaque and the host . This interaction results in destruction of the supporting alveolar bone and connective tissue . Although bacterial plaque has been implicated as the primary etiologic agent in most forms of periodontal disease, there are local and systemic factors which may modify both microbial and host components . Local factors may favor plaque accumulation and maturation, while systemic factors may modulate and decrease the host's protective response. J Pediatr Gastroenterol Nutr, 1991 Feb, 12(2), 195 - 203 Chronic diarrhea and malnutrition--histology of the small intestinal lesion; Sullivan PB et al.; The purpose of this study was to quantitate the jejunal lesion in Gambian children with chronic diarrhea-malnutrition syndrome . There were 40 subjects (20 male, 20 female) with a mean age of 19.7 months . All were severely malnourished, with marasmus in 30, marasmic kwashiorkor in 9, and kwashiorkor in 1 . Of subjects tested, 70% were anergic to intradermal challenge with either purified protein derivative or candidin . Jejunal biopsies, performed on every subject after admission to hospital, were studied by computerised image analysis and immunocytochemistry . A spectrum of mucosal changes that varied from "normal" to "flat" was seen . Mucosae with "normal" architecture revealed infiltration of villous epithelium by small lymphocytes, while crypt hypertrophy was invariably present . At the other extreme, the surface epithelium of flat mucosae was less severely infiltrated, although heavy lymphoid infiltrates persisted within crypt epithelium . Immunohistochemical studies revealed that most intraepithelial lymphocytes were of the CD8 + phenotype . Mucosal morphology did not relate to clinical, biochemical, or anthropometric data for each child . These findings are consistent with an intestinal reaction to some environmental antigen (dietary, microbial, or both) of the cell-mediated type . This interpretation is strengthened by the expression of major histocompatibility class 2D locus alloantigens on crypt epithelial cells in the absence of gut-reactive autoantibodies. Eur J Immunol, 1991 Feb, 21(2), 391 - 5 Growth of Mycobacterium avium in human monocytes: identification of cytokines which reduce and enhance intracellular microbial growth; Denis M; Human monocytes were isolated by standard procedures and their ability to harbor growth of two virulent strains of Mycobacterium avium, TMC724 and TMC7479, was assessed in the absence or presence of cytokines . Both strains of mycobacteria, especially the M . avium TMC7479, grew progressively in untreated human monocytes . Inclusion of certain macrophage-activating cytokines, such as interferon-gamma in the presence of indomethacin or 1.25(OH2)-vitamin D3 (calcitriol) led to significant reductions in bacterial growth at 7 days post-infection . Conversely, treatment of human monocytes with interleukin-(IL) 1, macrophage-colony stimulating factor or IL 3 led to an increased permissiveness of these cells for M . avium . Moreover, these cytokines were shown to increase dramatically extracellular M . avium growth in vitro in tissue culture medium . Further, inclusion of antibodies against IL 1 beta and IL 6 in untreated infected monocytes monolayers led to a reduced growth of M . avium, suggesting that infected monocytes produce factors which enhance their susceptibility to M . avium . Overall, my findings suggest that cytokines may play a bidirectional role in atypical mycobacterial infections, by either increasing or decreasing resistance of the monocyte. Jpn J Med Sci Biol, 1991 Feb, 44(1), 7 - 16 Evaluation of microbial metabolites for trypanocidal activity: significance of biochemical and biological parameters in the mouse model of trypanosomiasis; Kumar A et al.; Trypanosomiasis is a parasitic disease, prevailing in both humans and animals, caused by a single-cell parasite, Trypanosoma spp . Three microbial metabolites, namely antiamoebin, F-857 and 6-MFA, were evaluated for trypanocidal activity by using a mouse model of trypanosomiasis, which is caused by T . evansi . The significance of the biological and biochemical parameters with respect to physio-pathology of trypanosomiasis and their implications in the evaluation of new trypanocidal compounds were discussed. J Appl Bacteriol, 1991 Feb, 70(2), 144 - 55 Effect of ciliate protozoa on the activity of polysaccharide-degrading enzymes and fibre breakdown in the rumen ecosystem; Williams AG et al.; The effect of ciliate protozoa on the activity of polysaccharide-degrading enzymes in microbial populations from the digesta solids and liquor fractions of rumen contents was examined after the refaunation of ciliate-free sheep with an A-type rumen protozoal population . Although the culturable rumen bacterial population was reduced after refaunation the number of fibrolytic micro-organisms detected was higher; the xylanolytic bacterial population and numbers of fungal zoospores were increased after refaunation . The proportion of propionic acid was lower in the refaunated animals, whereas the concentration of ammonia and the acidic metabolites acetate, butyrate and valerate were all increased . The range of enzyme activities present in the digesta subpopulations were the same in defaunated and refaunated animals . The activities of the polysaccharide-degrading enzymes, however, were increased in the microbial populations associated with the digesta solids after refaunation, and at 16 h after feeding the activities were 4-8 times (beta-D-xylosidase 20 times) higher than the levels detected in the adherent population from defaunated sheep . The protozoa, either directly through their own enzymes or indirectly as a consequence of their effects on the population size and activity of the other fibrolytic micro-organisms present, have an important role in determining the level of activity of polysaccharide-degrading enzymes in the rumen ecosystem . Although the extent of ryegrass (Lolium perenne) hay digestion was similar after 24 h in the absence or presence of protozoa, the initial ruminal degradation was higher in refaunated sheep. Behring Inst Mitt, 1991 Feb, (88), 133 - 41 Cloning of microbial epitopes relevant for T- and B-cells; Miles MA et al.; This review summarises, and illustrates, the technology that is available for the molecular cloning and precise identification of T-cell and B-cell epitopes, particularly those of bacteria and parasites . Methods include: selective cloning following subtractive hybridization of nucleic acids; selective screening of expression libraries; analysis of subcloned "epitope libraries" or "deletion constructs"; scanning of multiple synthetic peptides, and computer enhanced prediction . The direct sequencing of polymerase chain reaction products allows the rapid analysis of epitope heterogeneity occurring among natural populations . Multiple epitopes can be assembled either by synthesis or by the expression of polymeric epitope-bearing peptides . Prospects for probing expression libraries with T-cells are bleak due to the complexities of antigen processing, presentation and T-cell recognition in vitro . Elucidation of the enzymic steps involved in processing, resolution of peptide/MHC II co-crystals, and pairing of a large number of known epitopes with their functional restriction elements will significantly improve the ability to predict T-cell epitopes. Sci Total Environ, 1991 Jan 15, 101(3), 263 - 8 Microbial dehalogenation of 4,4'-dichlorobiphenyl under anaerobic conditions; Mavoungou R et al.; Anaerobic cultures containing 4,4'-dichlorobiphenyl (4,4'CB) were inoculated with various environmental samples . The degradation of the substrate was followed by gas chromatographic analysis . Three of the cultures tested showed an ability to dehalogenate the substrate, as judged by the presence of 4-chlorobiphenyl and biphenyl in those media inoculated with them. Klin Khir, 1991, (3), 1 - 5 {Plastic surgery using skin and adipose tissue flaps in burns and their sequelae}; Povstianoi NE; The principles of cutaneous plasty in IV degree burns with uncovering, or primary death of the deep structures (tendons, bone, joints) are substantiated . The necessity and possibility to perform early plasty with fatty-cutaneous flaps irrespective of character of the inflammatory process and degree of microbial contamination of the wounds are proved; peculiarities of its different methods (use of interpolated and sliding flaps, Filatov's graft, "Italian plasty", dermotension, plasty with the pedicle graft, free transfer of the fatty-cutaneous flaps) are noted . On the basis of the experience with plasty of more than in 250 sufferers, the frequency of performing its separate types, effectiveness, results of social and vocational rehabilitation of the patients are presented. Kansenshogaku Zasshi, 1991 Jan, 65(1), 40 - 6 {Clinical significance of gastrointestinal decontamination under protected environment}; Nagao T et al.; Many infections are caused by the patient's own oro-intestinal microbial flora under a protected environment . Thirty-eight patients with acute leukemia and two patients with blast crisis of chronic myelocytic leukemia were treated under a protected environment with or without prophylactic antibiotics . Antibiotics used for decontamination were vancomycin (V), polymyxin B (P) and nystatin (N) . The number of patients in the VPN, PN and the no antibiotic group were 13, 13 and 14, respectively . While the intestinal microbial flora was almost completely eliminated in VPN group, the number of bacteria decreased slightly in PN group . The mean number of pharyngeal and anorectal bacterial species decreased most markedly in the VPN group, but there were no significant differences among the three groups . The number of febrile days was significantly lower in the VPN and PN group than the no antibiotics group with neutrophil counts of less than 100 microliters . The average number of episodes of infection per patient was lowest in VPN group and highest in the no antibiotic group . These data indicate that VPN administration is effective for eliminating intestinal bacterial flora and resultantly protecting endogenous infections. Rev Actual Odontoestomatol Esp, 1991 Jan-Feb, 51(400), 51 - 4 {Acute mediastinitis with fatal outcome secondary to odontogenic infection}; Infante Cossio P et al.; This article describes a patient who developed a deep neck and mediastinal infection that was initiated by a odontogenic infection . The history of the patient's illness and the surgical procedures are reviewed and the anatomic and microbial considerations of deep neck infections are discussed . Despite antibiotic therapy, cervicomediastinal drainage, tracheostomy and treatment for septic shock, the patient expired. Biosens Bioelectron, 1991, 6(2), 125 - 31 A microbial biosensor for trimethylamine using Pseudomonas aminovorans cells; Gamati S et al.; A biosensor system based on the difference in the oxygen uptake response of two microbial electrodes was developed to monitor trimethylamine (TMA) . The first electrode, constructed using Pseudomonas aminovorans grown on TMA, was sensitive to TMA, trimethylamine N-oxide (TMAO), dimethylamine (DMA) and monomethylamine (MMA) . The second electrode responding to TMAO, DMA and MMA was prepared using Ps . aminovorans grown on TMAO . The difference in oxygen uptake was linearly related to the TMA concentration in the range of 5-26 microM . The minimum detectable level was 2.6 microM and the relative standard deviation was determined to be 14% for 16 repeated analyses . When operated and stored at 30 degrees C, the response of the system was stable for only 2 days . However, when the biosensor system was operated at 30 degrees C but stored overnight at 4 degrees C, the system was stable up to 20 days . The biosensor system was applicable for the determination of TMA in fish tissue extracts and the results compared well with those determined by HPLC. Patol Fiziol Eksp Ter, 1991 Jan-Feb, (1), 32 - 4 {Enzymatic protective systems of saliva in inflammation of the periodontium}; Vavilova TP et al.; The activity of some glycosidases, trypsin-like proteinases, peroxidase, inhibitors of beta-glucuronidase and trypsin-like proteinases, as well as the amount of thiocyanates were studied in mixed saliva (MS), dental deposit (DD) and gums (G) of patients with inflammation of the periodontium . In periodontitis the activity of beta-glucuronidase increases fourfold and that of beta-galactosidase doubles in the G; the activity of beta-glucuronidase and its inhibitors increases, the activity of proteinases diminishes, and the antitryptic activity increases in MS, the activity of peroxidase and the amount of thiocyanates change in this case . Along with the peroxidase-H2O2-thiocyanates system, the inhibitors of beta-glucuronidase and trypsin-like proteinases possess properties of unspecific protection, preventing destruction of the periodontal tissues by glycosides and proteinases of microbial and animal origin. Biosens Bioelectron, 1991, 6(1), 15 - 20 Microbial sensor system for nondestructive evaluation of fish meat quality; Hoshi M et al.; A microbial sensor system consisting of the bacterium (Alteromonas putrefaciens) immobilized within membranes, a flow cell, an oxygen electrode, peristaltic pumps, a buffer tank, a thermostatically controlled bath and a recorder, was constructed for the nondestructive quality evaluation of bluefin tuna . The chemical compounds on fish meat surfaces which are the indicators of fish meat quality were rapidly determined by using the proposed sensor system . Fish meat quality was determined from the rate of current decrease of the sensor . Good correlations were obtained between fish meat quality and sensor response . One assay could be completed within one minute. Life Sci, 1991, 48(16), 1591 - 5 Inhibition of vitamin B12-dependent microbial growth by nitrous oxide; Alston TA; In methionine-free media, nitrous oxide inhibits the growth of an auxotrophic strain of Escherichia coli lacking a cobalamin-independent pathway for the de novo synthesis of methionine . Prototrophic E . coli is similarly inhibited by nitrous oxide if the cobalamin-independent pathway is selectively depressed by sulfanilamide . Nitrous oxide thus effectively inactivates cobalamin-dependent 5-methyltetrahydrofolate--homocysteine methyltransferase (methionine synthase, EC 2.1.1.13) in intact bacteria. Immunogenetics, 1991, 33(3), 178 - 83 Alteration of the T-cell receptor repertoire in A.CA mice expressing an Ead transgene; Ishikawa S et al.; In an effort to generate an A.CA mouse expressing Ed, the Ead gene has been introduced into A.CA mice which lack the major histocompatibility complex (MHC) class II E molecule . Flow cytometric analysis shows cell surface expression of the E alpha chain on lymphocytes and macrophages in the transgenic mice . Analysis of T-cell receptor (Tcr) genes deleted in some E-expressing mouse strains demonstrates that T cells expressing Tcrb-V5 are partially deleted in these transgenic mice while those expressing Tcrb-V8 and Tcrb-11 are not . In addition, the expressed E alpha d chain can promote Mycoplasma arthriditis mitogen (MAM)-induced T-cell proliferation . The expression of the E alpha chain, presumably as an A beta fE alpha d heterodimer, can alter the peripheral T-cell repertoire and T-cell reactivity to a microbial superantigen. Exp Cell Res, 1991 Jan, 192(1), 122 - 7 Highly synchronous culture of fibroblasts from G2 block caused by staurosporine, a potent inhibitor of protein kinases; Abe K et al.; The effect of staurosporine, a potent microbial inhibitor of protein kinases, on the cell cycle of cultured fibroblast cells was investigated . A low concentration of staurosporine (1-10 ng/ml) blocked the cell cycle of rat 3Y1 fibroblasts at the early G1 phase within 2 h after serum stimulation . On the other hand, a higher concentration of the drug (100 ng/ml) caused the specific G2 block . Both of these blocks were reversible . After release from the G2 block, highly synchronous transition to M phase was observed and both nuclear and cell divisions were completed within 180 min . This reversible G2 block showed a clear contrast to those by the other G2 arresters, trichostatin A and leptomycin B, which formed proliferative tetraploid cells after release by entering the cells into a new S phase without passage through M phase . The presence of trichostatin A or leptomycin B did not interfere with this synchronous progression through G2/M phases, suggesting that the arrest point of staurosporine was present in late G2 phase following those of trichostatin A and leptomycin B. Biomed Biochim Acta, 1991, 50(3), 225 - 32 {A thermostable alpha-amylase from Thermoactinomyces vulgaris: purification and characterization}; Heese O et al.; Alpha-amylase from Thermoactinomyces vulgaris (strain 94-2A) was purified by cellulose chromatography and gel-chromatography on Sephadex G-75 and subsequently characterised . The enzyme shows a single band in the polyacrylamide gel electrophoresis (PAGE) . The isoelectric point was determined to be pH 5.4, and the molecular mass was estimated as 53,000 Dalton by PAGE . The amino acid composition was determined; it shows characteristics of other microbial alpha-amylases . A comparison of the N-terminal sequence with that of other alpha-amylases shows a homology of 66.6% to Taka-amylase . The pH-optimum for the alpha-amylase activity is 4.8 to 6.0 and the temperature optimum 62.5 degrees C . The heat inactivation was investigated under different conditions (temperature, time, Ca2+, EDTA). J Postgrad Med, 1991 Jan, 37(1), 1 - 4 Formalin (0.25%) as topical anti-microbial agent in burns; Nair RG et al.; In a prospective controlled trial, 0.25% formalin spray was compared with 2% silver sulfadiazine cream as the local treatment of burns . Formation and separation of eschar, infection and death rates were recorded . In the group receiving formalin, rates of formation and separation of eschar were significantly more (P less than 0.001 and P less than 0.05 resp.) compared to other group . Infection rate and fatality due to infection were also reduced . Other advantages of formalin are ease of application and the low east. Crit Rev Microbiol, 1991, 18(2), 159 - 73 Basic and applied aspects of microbial adhesion at the hydrocarbon:water interface; Rosenberg M; Microbial hydrophobicity has been studied since 1924 . During the last decade, various techniques have become available for measuring hydrophobic surface properties of microbial cells . This has led to a surge in investigations suggesting a role for hydrophobicity in adhesion of bacteria to an array of surfaces (oral surfaces, mineral particles, fatty meat, epithelial cells, phagocytes, biomaterials), partitioning at interfaces, as well as gliding mobility . The present manuscript comprises a critical, chronological look at the origins of microbial hydrophobicity research, its development, origins, and applications . Emphasis is placed on microbial adhesion to hydrocarbons, a technique with which the author has the most experience and research interest. Toxicon, 1991, 29(7), 791 - 806 Plant and microbial toxic proteins as hemilectins: emphasis on canatoxin; Carlini CR et al.; Ribosome-inactivating plant toxic proteins and ADP-ribosylating microbial toxins share a common structural organization . These proteins present domains displaying different biological properties: a target cell membrane-binding component (B-subunit or haptomer) and an enzymatically active component (A-subunit or effectomer) . Interactions of these toxins with the target cells are mediated by the hemilectin-like haptomer, which recognizes and specifically binds to a given glycoderivative present at the cell surface . After binding the holoprotein is internalized via endocytosis . Inside the endocytic compartment the toxin is processed to release its effectomer moiety which catalytically modifies a cytoplasmic component, and this step accounts for its toxic effect . The structural relationships between toxic hemilectins and plant lectins are discussed, with emphasis on the example of canatoxin and concanavalin A, both present in the seeds of the jack bean Canavalia ensiformis . Contrary to other plant toxic proteins, which inhibit protein synthesis, canatoxin-induced toxicity includes central nervous system-mediated effects . In vivo as well as in vitro canatoxin acts as lipoxygenase-mediated secretagogue in several types of cells: blood platelets, mast cells, pancreatic islets and synaptosomes . Elucidation of structure vs biological activity relationships of canatoxin and other toxic proteins may provide data for their utilization as pharmacological tools and as therapeutic agents. Klin Khir, 1991, (1), 12 - 4 {Use of laser-enzyme therapy in preparing purulent wounds for early plastic closure}; Efendiev AI et al.; The results of treatment of 370 patients with purulent soft tissue diseases have shown that laseroenzymotherapy of the suppurating wounds contributed to their rapid cleaning, maintenance of microbial colonization at a stable low level, activation of reparative processes . This permitted to prepare a wound surface for closure at the nearest days after the operation. Adv Exp Med Biol, 1991, 289, 11 - 31 Wholesomeness and safety of irradiated foods; Swallow AJ; Irradiation with gamma-rays, X-rays or fast electrons can be used to change foodstuffs in beneficial ways or to destroy harmful organisms . Gamma rays do not induce radioactivity in foods, but X-rays and fast electrons can induce short lived radioactivity if sufficiently energetic . This imposes limitations on the energies which can be used, and a short wait between irradiation and consumption may be advisable . Irradiation produces chemical changes in foodstuffs, and some foods are unsuitable for irradiation . With appropriate foods, trials with animals and human volunteers generally show that the product is safe . Some loss in nutritional quality can take place, which could be significant for some individuals, but are unlikely to be important for those on a balanced diet . Irradiation does not eliminate all risk from microbial contamination . Foods to be irradiated should be good quality, and need to be kept under proper conditions after irradiation . Irradiated foods should be appropriately labelled . Tests for radiation would help to enforce necessary controls . If the process is properly carried out on appropriate foods, and all due precautions are taken, irradiated foods are wholesome and safe. Proc Finn Dent Soc, 1991, 87(2), 287 - 98 Analyses of periodontal glycosaminoglycans and proteoglycans . Regulation by microbial, chemical and inflammatory factors; Larjava H et al.; During the last two decades one of the main lines of research in the Department of Periodontology in Turku has related to connective tissue glycosaminoglycans and proteoglycans . A general outline of current knowledge about proteoglycans is presented, with a review of most published and unpublished results on periodontal glycosaminoglycans and proteoglycans obtained in our Department. Histochemistry, 1991, 95(5), 529 - 33 Paneth cell degranulation and lysozyme secretion during acute equine alimentary laminitis; Masty J et al.; The equine Paneth cell response to a shift in the microbial balance of the intestinal tract was studied by inducing an acute episode of alimentary laminitis in 6 mature ponies . The normal bacterial population of the gut was modified by administration of a carbohydrate-rich ration . During acute laminitis a dramatic degranulation of the Paneth cells occurred in the intestinal glands throughout the duodenum, jejunum, and ileum . Bacteriocidal lysozyme, which was immunohistochemically identified as a component of the Paneth cell secretory granule, was evident in the glandular lumina and in degranulated Paneth cells . These results indicate that lysozyme is secreted by the equine Paneth cell in an apparent attempt to regulate the changing microbial population induced by carbohydrate overload of the gut . From these observations, it is suggested that the Paneth cell plays a role in the mucosal defense system of the equine intestinal tract. Proteins, 1991, 9(4), 267 - 79 Thiol protease-like active site found in the enzyme dienelactone hydrolase: localization using biochemical, genetic, and structural tools; Pathak D et al.; The active site of dienelactone hydrolase (DLH), a microbial enzyme of the beta-ketoadipate pathway, has been conclusively located using a combination of crystallographic, biochemical, and genetic techniques . DLH hydrolyzes a dienelactone to maleylacetate and has esterase activity on p-nitrophenyl acetate and trans-cinnamoyl imidazole . The identification of Cys-123 as containing the essential thiol confirms the localization of the active site as suggested by the crystal structure of DLH, and disproves an earlier hypothesis regarding its location . Two mutant proteins have been engineered in which Cys-123 has been converted to a serine (C123S DLH) and an alanine (C123A DLH), respectively . C123S DLH (Km = 9900 +/- 2300 microM; Vmax = 4.4 +/- 0.8 mumol/min-mg) displays burst kinetics with p-nitrophenyl acetate and is 10% as active as DLH (Km = 170 +/- 7 microM; Vmax = 21.1 +/- 0.4 mumol/min-mg) . C123A DLH is inactive . The structures of DLH, C123S DLH, and C123A DLH have been refined at 1.8, 2.2, and 2.0 A, respectively . Comparison of the structures of these proteins demonstrates that the only differences between them are centered at residue 123 . The structures of the active sites of DLH, papain, and subtilisin are similar and are suggestive of the three enzymes having evolved convergently to similar active sites with similar enzymic mechanisms. Nahrung, 1991, 35(1), 61 - 9 {The characterization of microbial lipases . 2 . The determination of lipase specificity}; Bariszlovich M et al.; Types of lipase specificity are as follows: Positional specificity; fatty acid specificity; stereospecificity; substrate specificity (different rates of lipolysis of different glyceride classes . The acylglycerol used for determination of lipase specificity must be so structured, that specificities are not confused and unambiguous results are obtained . Different substrates and methods for detection of specificity are reviewed and advantages and disadvantages are discussed . Positional specificity can be determined with synthetic dialkylacylglycerols and 2,3-dioleoyl butanediol . Stereospecificity can be detected with enantiomeric dialkylacylglycerols or diacylalkylglycerols. Crit Rev Biotechnol, 1991, 11(1), 1 - 40 Biotransformation of halogenated compounds; Hardman DJ; As a result of natural production and contamination of the environment by xenobiotic compounds, halogenated substances are widely distributed in the biosphere . Concern arises as a result of the toxic, carcinogenic, and potential teratogenic nature of these substances . The biotransformations of such halogenated substances are reviewed, with particular emphasis on the biocatalytic cleavage of the carbon-halogen bonds . The physiology, biochemistry, and genetics of the biological system involved in the dehalogenation reactions are discussed for three groups of organohalogens: (1) the haloacids, (2) the haloaromatics, and (3) the haloalkanes . Finally, the biotechnological applications of these microbial transformations are discussed . This includes prospects for their future application in biosynthetic processes for the synthesis of halogenated intermediates or novel compounds and also the use of such systems for the detoxification and degradation of environmental pollutants. Biosystems, 1991, 24(4), 305 - 12 Oxygen toxicity and microbial evolution; Bilinski T; It is postulated that the role of oxygen toxicity in the evolution of life strongly depends on the origin of molecular oxygen, due to the strong redox buffering capacity of Precambrian waters containing large amounts of ferrous and manganese cations . The critical selective pressure could be observed only after aerobic photosynthesis had been developed, due to the high local concentration of oxygen in close vicinity of photosynthesizing cells . It is also postulated that early oxygen-evolving organisms excreted a substantial part of this element in the form of hydrogen peroxide . As a consequence of the high reactivity of this compound with ferrous and manganese cations, an important percentage of iron deposits were produced with H2O2 as a major oxidant after the development of aerobic photosynthesis . It is postulated that negatively charged extracellular polymers of simple pro- and eukaryotic organisms function as sacrificial targets of hydroxyl radicals and at the same time as extracellular equivalents of superoxide dismutases, in these two ways protecting cellular membranes against oxidative damage . The role of oxygen toxicity in developing aerobic mechanisms of iron uptake is also discussed. Zentralbl Bakteriol, 1991 Jan, 274(4), 481 - 9 Application of impediometry to rapid assessment of liquid culture media; Strassburger J et al.; The impedance method provides as unique opportunity to determine microbial activity and kinetics . Since the metabolic processes depend on the nature and quality of the culture medium, impediometry allows the assessment of liquid culture media . Impedance microbiology represents an approach to quantitative microbiology . We investigated the influence of pH, composition and variation of the amounts of industrially made dry media, overheating during the dissolving or sterilisation processes, and qualitative differences between batches of the same culture medium . Using glucose broth as an example, we showed that impediometry allows quantitative, microbial assessment of culture media . Inaccurate preparation of the culture medium could be detected quickly by the use of impediometry . The method is very simple to perform, requires no sample preparation, allows rapid assessment of liquid culture media, and interprets results automatically with the aid of a microcomputer. Biosystems, 1991, 25(1-2), 13 - 23 A model for diurnal patterns of carbon fixation in a Precambrian microbial mat based on a modern analog; Rothschild LJ; Microbial mat communities are one of the first and most prevalent biological communities known from the Precambrian fossil record . These fossil mat communities are found as laminated sedimentary rock structures called stromatolites . Using a modern microbial mat as an analog for Precambrian stromatolites, a study of carbon fixation during a diurnal cycle under ambient conditions was undertaken . The rate of carbon fixation depends primarily on the availability of light (consistent with photosynthetic carbon fixation) and inorganic carbon, and not nitrogen or phosphorus . Atmospheric PCO2 is thought to have decreased from 10 bars at 4 Ga (10(9) years before present) to approximately 10(-4) bars today, implying a change in the availability of inorganic carbon for carbon fixation . Experimental manipulation of levels of inorganic carbon to levels that may have been available to Precambrian mat communities resulted in increased levels of carbon fixation during daylight hours . Combining these data with models of daylength during the Precambrian, models are derived for diurnal patterns of photosynthetic carbon fixation in a Precambrian microbial mat community . The models suggest that, even in the face of shorter daylengths during the Precambrian, total daily carbon fixation has been declining over geological time, with most of the decrease having occurred during the Precambrian. Biotechnol Ther, 1991, 2(3-4), 231 - 9 Clinical applications of recombinant macrophage-colony stimulating factor (rhM-CSF); VandePol CJ et al.; rhM-CSF has diverse in vitro and in vivo hematologic and metabolic effects . Clinical trials with this new biopharmaceutical are now in progress and early results have confirmed preclinical findings . The major demonstrated effects of rhM-CSF include an increase in number and activation of monocytes and macrophages, the ability to enhance antibody-dependent cellular cytotoxicity, enhancement of macrophage microbial phagocytic and killing activity, cholesterol lowering, and platelet lowering . The range of potential indications for the use of rhM-CSF makes the further clinical development of this molecule both a challenge and an opportunity . Investigation of combination therapies with other cytokines or monoclonal antibodies will be an important aspect of future investigations. Khirurgiia (Sofiia), 1991, 44(6), 27 - 9 {The treatment of suppurative and atonic wounds with the CO2 laser and the helium-neon laser}; Poleganova IU et al.; The doctrine on wounds is the most important and current one in general surgery and reflects the level and development of medicine . Each surgeon should be well acquainted with all processes and stages of wound healing, because treatment of a suppurative wound requires keen knowledge and art . The basic principle of the local treatment of a septic wound is the thorough knowledge on the objective criteria underlying the course of the wound process and on the etiopathogenetic therapy . Laser therapy of wounds accomplishes adequate necrotomy, acts aseptically on the wound surfaces, inhibits the wound microbial flora and stimulates the regeneration processes . The authors record their experience in CO2 laser and helium-neon treatment of 120 patients with suppurative, atonic and decubital wounds over the period 1984-1990. Sci Prog, 1991, 75(298 Pt 3-4), 265 - 77 Molecular biology: new tools for studying microbial ecology; Morgan JA; The general aim of studies in microbial ecology is to determine the activities of particular groups of organisms in the natural environment . Current developments in molecular biology are providing methods that can be adopted for investigations in microbial ecology . Presently, molecular techniques are being used to determine population and community structures in samples . Following on from this, methods are needed to determine the activities of these organisms in their natural state . This review describes the application of molecular techniques to the study of micro-organisms in environmental samples. Folia Microbiol (Praha), 1991, 36(3), 311 - 3 Coordination of activities in the development of microbial culture databases; Bures R; The article deals with the problem of microbial culture data processing . In this field two tasks must be solved . First, data processing within collections themselves, and second, communicating the data to potential users. Acta Univ Palacki Olomuc Fac Med, 1991, 130, 311 - 22 An analysis of the health condition of personnel exposed to cytostatics at an oncology unit; Medkova J; Attention was paid in this study to the evaluation of the health condition of the hospital personnel exposed to cytostatics at a specialized oncology unit, Faculty Hospital in Olomouc . Questionnaires and interviews were used to examine 44 exposed personnel of the oncology unit and a control group of 32 partners of these workers who held no risk jobs . The questionnaires were focused on personal, family and occupational histories . The exposed female workers were asked for detailed information concerning fertility . The occupational history contained data on the conditions for handling cytostatics . The group of 44 exposed workers were aged from 19 to 63 years, the average age being 34.8 years . There were 38 female and 6 male workers in the group under study . The majority of the group were nurses (23) . The group further consisted of 7 physicians, 8 practical nurses, and 6 cleaners . Of importance to note is that the health nurses of the oncology unit were exposed to cytostatics for 8 or more hours daily . Almost half of the exposed health nurses belonged to the youngest age category (19 to 24 years) . In the health personnel under study, an increased incidence of respiratory diseases, blood diseases, allergies, dermatological affections and eczema, and renal diseases was found . The smokers at the oncology unit (52.3%) outnumbered the non-smokers . The health condition of the 32 persons of the control group was more favourable, increased morbidity due to acute respiratory diseases and diseases of blood components were not seen . The average age of the control group was 41.9 years . It follows from the results obtained that it is necessary to monitor continuously the health condition of personnel exposed to cytostatics, particularly of those working at specialized oncology units where they are exposed to cytostatics throughout their working day . At these workplaces, effects of other unfavourable factors, such as radiation and microbial agents, which may enhance the unfavourable effects of cytostatics, should not be neglected. Curr Top Microbiol Immunol, 1991, 173, 173 - 8 Analysis of primary T cell responses to intact and fractionated microbial pathogens; Pfeffer K et al.; Freshly isolated human T lymphocytes were tested for their response to mycobacteria, mycobacterial lysates, 2 dimensional (2D) PAGE separated mycobacterial lysates, leishmania and defined leishmanial antigen preparations . While gamma delta T cells proliferated vigorously in the presence of mycobacteria and mycobacteria derived lysates, a significant stimulation from 2 D gel separated lysates was not detected . In addition gamma delta T cells failed to respond towards leishmania or leishmanial components . In the alpha beta T cell compartment some donors, presumably according to their state of immunity against mycobacteria, responded to mycobacteria, mycobacterial lysates and 2 D gel separated mycobacterial lysates . Neither freshly isolated gamma delta T cells nor alpha beta T cells from naive donors did mount a significant immune response against leishmania. Biol Met, 1991, 4(1), 7 - 13 Iron and bacterial virulence--a brief overview; Griffiths E; Iron is now recognized as playing a vital role in infection . Not only does it restricted availability in tissue fluids present microbial pathogens with the problem of acquiring sufficient for multiplication in vivo, but it also constitutes a major environmental signal which co-ordinately regulates the expression of a number of virulence and metabolic genes . Progress in understanding the strategies used by pathogens for acquiring iron in vivo, and their responses to iron restriction, is providing a fresh insight into microbial pathogenicity. Biol Met, 1991, 4(1), 62 - 9 The design, synthesis and study of siderophore-antibiotic conjugates . Siderophore mediated drug transport; Miller MJ et al.; The use of conjugates of microbial iron chelators (siderophores) and antibiotics for illicit transport of antibiotics into cells is a potentially powerful method for the rational design of therapeutic agents . The structural complexity of most natural siderophores has impeded progress in this area . Described here are the design, syntheses and preliminary biological studies of several siderophore-beta-lactam antibiotic conjugates . Both hydroxamic-acid-based and catechol-based conjugates with and without amino acid spacers to carbacephalosporins were synthesized and demonstrated to be effective inhibitors of Escherichia coli X580 . Mutant selection was noted for each class of conjugates . Mutants selected from exposure of the E . coli to the hydroxamate conjugates were susceptible to the catechol conjugates and vice versa . Combinations of hydroxamate- and catechol-carbacephalosporin conjugates were most effective inhibitors of E . coli X580. Chin J Biotechnol, 1991, 7(4), 285 - 91 Interspecific hybridization of Streptomyces by electrofusion; Han L; Two auxotrophic mutants of S . rimosus and S . griseus were obtained through nitrosoguanidine treatment . The equal volume of two protoplast containing 10(9)/ml were mixed and put in the fusion chamber of Shimadzu somatic hybridizer-SSH-C11 . Fifteen seconds after protoplast pearl chains were formed through electrophoresis under high-frequency electric field (800 V/cm 1 MHz), it was turned into high DC pulse field (6 kV/cm) for 20 seconds immediately to make the protoplast to be fused . Colonies were raised on regeneration medium R3 . 34971 colonies were selected and transferred to basic medium containing two antibiotics . Nine of them were prototrophic fusant with double resistance . They had good biological characteristics of parent strain, such as faster growth rate, higher productivity and stronger microbial activity . Bioautographic result showed that it can produce bioactive characteristics that their parents do not have. Chin J Biotechnol, 1991, 7(3), 221 - 8 The application of simplex method to the estimation of kinetic and energetic parameters of microbial growth; Fang B; Based on the mathematical models derived by the author for describing both batch and continuous microbial cultivation, the application of simplex method to the estimation of mu max, Ks, Ymaxx/s and ms is studied . The paper also presents the methods of determining objective function and initial value of simplex method and of introducing the whole process of estimation with single tank continuous culture of E . coli as an example. Folia Microbiol (Praha), 1991, 36(4), 375 - 82 Cell aggregates of Escherichia coli with benzylpenicillin amidase activity; Zeman R et al.; Intact cells Escherichia coli CCM 2843, exhibiting substantial benzylpenicillin amidase activity, were bound mutually with supporting waste microbial cells, native or treated, to obtain an inexpensive biocatalyst for the production of 6-aminopenicillanic acid (6-APA) . The bond was effected by glutaraldehyde (GA) and Sedipur CL-930 (PEI), without any carrier . The optimal concentration of GA was 2%, that of PEI 1% . The optimal biocatalyst was obtained by immobilization of productive cells with their fragments at a mass ratio of 4:1 . The cell aggregates were used for hydrolysis of potassium benzyl-penicillin at a concentration of 5% to 6-APA . After 25 repeated batch conversions the degree of conversion did not decrease; its average value was 96.4%. IARC Sci Publ, 1991, (115), 307 - 20 Risk assessment of ochratoxin A residues in food; Kuiper-Goodman T; Ochratoxin A is a mycotoxin that has been found to occur in foods of plant origin, in edible animal tissues and in human sera and tissues . The ability of ochratoxin A to move up the food chain is associated with its long half-life in certain edible animal species . In this presentation, approaches for the evaluation of the health risks due to the presence of ochratoxin A in food products are described . The major target for ochratoxin A toxicity in all mammalian species tested is the kidney, and endemic nephropathies affecting livestock as well as humans have been attributed to ochratoxin A . Ochratoxin A is also teratogenic, and in the fetus the major target is the developing central nervous system . Recent studies have provided 'clear evidence' for the carcinogenicity of ochratoxin A in two rodent species . It was found to be non-mutagenic in various microbial and mammalian gene mutation assays, but weak genotoxic activity to mammalian cells was noted . In addition, ochratoxin A was found to suppress immune function . On the basis of a carcinogenicity study with ochratoxin A in rats, reported from the National Toxicology Program in the USA, the estimated tolerable daily intake of ochratoxin A in humans ranges from 1.5 to 5.7 ng/kg bw per day, depending on the method of extrapolation used . The worst-case estimate for daily exposure to ochratoxin A from the consumption of pork-based food products and cereal foods for young Canadian children, the highest consumption group on a body weight basis, is probably less than 1.5 ng/kg body weight per day (mean of eaters) . In view of the toxic properties of ochratoxin A, it is recommended that exposure to this toxin be kept to a minimum. IARC Sci Publ, 1991, (115), 245 - 53 DNA adduct formation in mice treated with ochratoxin A; Pfohl-Leszkowicz A et al.; Several authors have reported the occurrence of renal and hepatic tumours in mice and rats exposed to ochratoxin A in long-term studies . The compound was not mutagenic, however, in various microbial and mammalian gene mutation assays, either with or without metabolic activation . Contradictory results were obtained for induction of unscheduled DNA synthesis and sister chromatid exchange . We showed previously that ochratoxin A causes DNA damage, manifested as single-strand breaks in mouse spleen cells and in vivo . These findings, which suggest that ochratoxin A is weakly genotoxic to mammalian cells, prompted us to search for DNA adducts using a modified 32P-postlabelling method, the sensitivity of which was improved by treatment with nuclease P1 . DNA was isolated from liver, kidney and spleen excised from mice 24, 48 and 72 h after oral treatment with ochratoxin A at 0.6, 1.2 and 2.5 mg/kg body weight . Several adducts were found in the DNA of the three organs, the levels varying greatly . After administration of 2.5 mg/kg body weight, 40 adducts per 10(9) nucleotides were found in kidney DNA and 7 adducts per 10(9) nucleotides in liver after 72 h . The levels of most of the adducts increased from 24 to 72 h, but those of others diminished after 24 or 48 h . Adducts were found in spleen only at 24 and 48 h . These results confirm the genotoxicity of ochratoxin A. J Basic Microbiol, 1991, 31(6), 453 - 77 Application of immobilized cells for biotransformations of steroids; Schmauder HP et al.; A survey is given of possible solutions and open-ended questions in the biotransformation of steroids (without side chain degradation of sterols) by using immobilized cells . The data of literature between 1975 and 1990 and results of preliminary experiments from the microbial, biochemical, biophysical, physiological, as well as the biotechnological point of view are summarized and discussed. Acta Microbiol Hung, 1991, 38(3-4), 293 - 304 Fluorogenic and chromogenic substrates--a promising tool in microbiology; Manafi M et al.; During the last few years the use of fluorogenic and chromogenic substrates for rapid and sensitive detection of bacteria has proved to be a powerful alternative to traditional methods . These sophisticated substrates might find widespread application in, for instance, the assay of clinically important enzymes, flow cytometry, and direct epifluorescent filter technique . Specific enzyme detection offers another approach to differential identification and characterization of viable bacteria from a sample . The use of some chromogenic and fluorogenic substrates specific for bacterial enzymes and their applications to microbial identification is reported . Particular emphasis is given to the examination of Escherichia coli and the description of the different techniques as used in routine analysis. Dtsch Z Mund Kiefer Gesichtschir, 1991 Jan-Feb, 15(1), 24 - 9 {Ultrastructural studies on obstructive palatal sialadenitis in denture wearers}; Fartasch M et al.; The ultrastructural phenomena of obstructive palatal sialadenitis were studied in 7 denture wearers versus 3 non-denture wearers as control . Apart from mucositis severe stagnation of salivary flow in the excretory ducts was observed in patients with dentures with short periods of service . In contrast to the control group there were mucous droplets after exocytosis of the acinus cells that remained intact even in the lumina of the distal excretory ducts . Desquamation of the duct and acinus cells results in a change in the organic components of the secretory mucus . The periductal infiltrate consisted mainly of plasma cells and lymphocytes, whereas neutrophils or macrophages were not observed . Ultrastructurally there was no evidence of an ascending microbial infection of the ducts . Probably, infections do not play an important role in the pathogenesis of obstructive palatal sialadenitis. J Clin Dent, 1991, 2(4), 83 - 6 The effect of a single episode of chlorhexidine irrigation on the gingival response to scaling and root planing; Tseng PW et al.; The adjunctive effects of subgingival chlorhexidine irrigation on gingival response following scaling and root planing were investigated . Changes in clinical parameters, and microbial composition of subgingival plaque as monitored by dark-field microscopy were assessed in 12 patients over a period of 12 weeks . Two test sites and two matched control sites with probing depth ranging from 4 mm to 7 mm were selected in each patient . Oral hygiene instruction and a single episode of scaling and root planing were carried out . In addition test sites were irrigated with one mL of 0.2% chlorhexidine solution by the operator, while control sites were either irrigated with an equal volume of physiological saline or not irrigated . There were significant improvements in the clinical parameters with little difference between test and control sites . Between the beginning and the end of the study there was a marked reduction in the proportion of spirochaetes with a concomitant increase in coccoid organisms with, again, only minor differences between the test and the control sites . It was concluded that subgingival irrigation with a single application of 0.2% chlorhexidine did not enhance gingival healing, or delay recolonization of pockets by certain micro-organisms (as monitored by dark-field microscopy), when scaling and root planing had been thoroughly carried out immediately prior to irrigation. C R Seances Soc Biol Fil, 1991, 185(5), 331 - 7 {Enzymatic release of mycobacteria in natural media}; Thorel MF et al.; Polysaccharases release mycobacteria from natural environment . The enzymatic activity works both on the microbial adherence polysaccharides and on the support surfaces (cellulose) . The release of mycobacteria from natural environment increases both the number of isolates and the number of species of mycobacteria. J Egypt Public Health Assoc, 1991, 66(1-2), 227 - 38 A study of the knowledge, attitude and practice (KAP) of a Saudi Arabian community towards the problem of brucellosis; Bilal NE et al.; The present study included 337 patients, presenting to Asir Central Hospital with fever of more than two weeks duration, or symptoms associated with brucellosis but without fever . Of the 337 subjects examined for knowledge about methods and means of transmission of brucellosis, 309 (92%) were ignorant while only 28 (8%) appeared to possess some knowledge as to the source, type of animal contact and presentation of illness . None of the 337 subjects was able to link the disease with a microbial infection . The most important common practices associated with brucellosis included raw milk consumption, close animal contact and the slaughtering and disposal of wastes . Illiteracy, ignorance and faulty behaviours emphasize the importance of health education of the community, to raise the KAP standard of the full spectrum of brucellosis in the community would be valuable in its prevention and control. Dev Biol Stand, 1991, 75, 193 - 204 Operator-induced contamination in cell culture systems; Hay RJ; Operator-induced biological contamination in cell cultures is a multifaceted problem involving the unexpected introduction of other animal cells, microbial and viral contaminants . Detailed studies on animal cell cross contaminations have been performed and published . The frequency of detection of problem cultures has been as high as 36% for one service performed in the USA, with interspecific cross contamination accounting for 25% and human intraspecific contamination representing 11% . Awareness of the potential of this problem plus the application of several characterizations are key factors for its control . For example, fluorescent antibody staining, isoenzyme analyses, cytogenetic evaluations and DNA fingerprinting using molecular probes are needed for quality assurance on master seed stocks . Detection of microbial contamination is relatively straightforward, but the prevalence of mycoplasmal infections in cell cultures used in general research is still a significant problem . Detection services report frequencies of infection varying from 10% upwards, depending upon the country and laboratory of origin . The utilization of prescreened reagents and antibiotic-free cultivation, plus the application of improved procedures, such as fluorescent dyes and molecular probes for detection, provide effective means of avoiding mycoplasma infection and facilitating control . For many viruses, the presence of mycoplasma reduces immunoreactivity, suppresses transcriptase and other enzyme activities, reverses viral neutralization etc . The introduction of viral contaminants into cell cultures is perhaps the most problematic, especially where no cytopathic effect is produced . Few cases are documented where technicians infected with specific viruses have introduced these unwittingly into cultures in their care . The potential exists, however, as reports have appeared documenting the considerable stability of rhinoviruses, respiratory syncytial virus, rotaviruses and others, in aerosols on workers' hands and safety hood surfaces . The infection of cell cultures via other contaminated cells or reagents such as sera is a related problem . In this regard, the infection of transplantable tumor cell lines with lymphocytic choriomeningitis virus from host animals led to an outbreak of the disease in medical center personnel . Similar infection of rat cell lines exposed to animals harboring hantaviruses has been reported . Technical staff in US government laboratories have been infected with human immunodeficiency virus produced in cultured cells . Such serious public health hazards warrant repeated emphasis . The use of multiple cell lines in a given laboratory, including cultures known to be virally infected, compounds the problems and necessitates application of preventive methods both to avoid cross-infections and to document freedom from contamination.(ABSTRACT TRUNCATED AT 250 WORDS) Eye, 1991, 5 ( Pt 5), 549 - 59 Microbial keratitis--the false negative; Ficker L et al.; The investigation of presumed microbial keratitis includes microscopy and culture of corneal specimens obtained by scraping the infiltrated cornea . Routine microscopy fails to identify the infecting organism in about 15% of cases . We discuss the problems presented by 20 such eyes which required further investigation . We present a diagnostic algorithm aimed at reducing the delay in identifying the pathogen and increasing the rate of positive culture . This is important since unusual pathogens may require treatment with drugs other than the 'first line' broad spectrum combination of an aminoglycoside and a cephalosporin . The algorithm allows sequential restaining and reculturing of specimens for more thorough investigation . In addition to the use of special stains and culture conditions, it presents indications for further corneal scrapes and biopsies . Uncontrolled infection resulted in five perforations and penetrating keratoplasty was indicated in 11 cases . The visual outcome for these patients was poor with fewer than 30% achieving 6/12 acuity . The delay in diagnosis increases morbidity and this should be significantly reduced by adopting the algorithm we propose. Rev Roum Virol, 1991 Jan-Jun, 42(1-2), 17 - 22 {New pathogenetic aspects of the relations between viral and microbial infections and peripheral vasculopathies}; Athanasiu P et al.; The immunofluorescence technique using antisera against some viruses and inframicrobes allowed the detection of pathogens in altered vascular tissues (arteritis and phlebitis-phlebectasia) . Pathomorphological aspects and some dehydrogenase activities in these patients were also investigated. Nahrung, 1991, 35(6), 581 - 90 Prediction of total body lipid from total body water in rats . Part 1 . Relations between directly measured major body components; Zahn L et al.; Aimed to the construction of a prediction equation for estimations of lipid content from animal water content body composition was determined by whole body analysis of male rats (1) given access, ad libitum, to a commercial standard diet (n = 144; ranging from 60 to 600 g in weight, and from the 4th to the 34th week of age), and (2) showing striking variations with regard to nutritional state, dietary history, enlarged fat deposition, genetic origin, intestinal microbial status, and advanced age (n = 75) . It was shown that a unique coefficient of water content in lipid-free body mass does not exist . The results of statistical analysis for the grouped values of percentage body dry matter (x) and percentage body lipid (y) indicate that the latter can be estimated accurately from body water content directly determined by the use of the quadratic regression equation y = -0.2864 x +0.01615 x2 with a standard deviation of the procedure Sy = +/- 1.40 . This prediction equation is valid for a wide developmental span even under highly different experimental states . Differences between the calculated body lipid contents vs . analytically determined values are smaller than by using a linear regression equation or coefficient(s) of hydration of lipid-free body mass. Fortschr Ophthalmol, 1991, 88(4), 363 - 7 {Keratoplasty in infancy and early childhood with special reference to the auto-rotation technique}; Meiser S et al.; Between January 1987 and August 1990, a total of 20 keratoplasties were performed in infants and children in the University Eye Hospital, Dusseldorf, accounting for 4% of all keratoplasties during this period . The indications included malformations of the anterior segment and central corneal opacities, mostly of herpetic or microbial etiology . The ages of the patients varied from 2 weeks to 6 years, and the cases were followed up for an average of 2 years . Five (25%) were treated with the autorotation technique . Visual acuity after surgery was satisfactory, although an irregular astigmatism was found in three cases and one child eventually had to have a contact lens fitted . In view of our encouraging results we recommend that ipsilateral rotational autokeratoplasties should be considered more often for suitable forms of central corneal opacyty, particularly for infants and children. Scand J Gastroenterol Suppl, 1991, 187, 39 - 46 Helicobacter pylori urease: properties and role in pathogenesis; Mobley HL et al.; Urease (urea amidohydrolase, EC 3.5.1.5) catalyzes the hydrolysis of urea to yield ammonia and carbon dioxide . Research on this enzyme has gained momentum since the discovery of Helicobacter pylori as a causative agent of human gastritis . The remarkably high urease activity of each organism has served as the basis of diagnostic tests for the presence of the organism in the urease biopsy test and urea breath test . Urease undoubtedly plays a central role in H . pylori pathogenesis . Hydrolysis of urea with generation of ammonia may enable survival of this acid-sensitive organism in the gastric mucosa . Ammonia generated by urea hydrolysis may also produce severe cytotoxic effects within gastric epithelium . The enzyme also elicits a strong immune response during acute infection, suggesting that this abundant antigen is readily available to the immune system . An increase in serum IgG titer is predictive of ongoing infection . Much progress has been made with regard to the molecular biology of urease . The high molecular weight protein (estimated by several investigators to be 300-520 kDa) has been purified, revealing two distinct subunits of 29.5 kDa and 66 kDa, a unique subunit structure as compared with other microbial ureases . However, amino acid sequences are nevertheless well conserved when compared with other bacterial ureases and that of the jack bean, Canavalia ensiformis . Furthermore, genes encoding urease of H . pylori have been cloned, sequenced, and amplified by the polymerase chain reaction. Proc Finn Dent Soc, 1991, 87(4), 607 - 19 Posteruptive changes in human dental fluorosis--a histological and ultrastructural study; Fejerskov O et al.; The aim of the present study was to describe the structural features characterizing the severe grades of human fluorotic enamel (TF scores 5-9) with particular emphasis on the posteruptive changes in severely fluorosed teeth . Dental fluorosis is a subsurface hypomineralized lesion deep to a well-mineralized outer enamel surface, which in severe cases breaks apart shortly after eruption . Early signs of posteruptive changes comprise small defects corresponding to the opening of striae of Retzius . The enamel pits which develop after eruption in more severe cases exhibit an increase in mineral content at their base which correspond to the exposed subsurface hypomineralized lesions . Likewise, the extensive removal of surface enamel in the most severe cases of human fluorosis results in a highly varying uptake of mineral into the exposed subsurface hypomineralized lesions . The uptake varies greatly within apparently similar degrees of hypomineralized lesions . In approximal abrasion facets, however, where the subsurface lesions are also exposed, no evidence of mineral uptake was found . At the ultrastructural level, the well-mineralized surface zone consists of large hexagonal enamel crystals separated by rather large intercrystalline spaces in which numerous irregular small crystals are observed . Moreover, the large crystals may exhibit central and peripheral dissolution . In addition, mineral appeared to be deposited into such defects as well as along the side of the crystals, often with the lattices being continuous from the original crystal into the apparently posteruptive formed crystal material . It is concluded that a substantial mineral uptake can take place in exposed porous hypomineralized fluorotic enamel after eruption, but is most likely to be associated with the presence of microbial deposits, the metabolic activity of which may play a keyrole in mineral exchange. Immunopharmacol Immunotoxicol, 1991, 13(4), 623 - 42 Correlation between modification of membrane phospholipids and some biological activity of lymphocytes, neutrophils and macrophages; Galdiero F et al.; Our study considered the possibility of modifying the functional response of human neutrophils, of mouse lymphocytes and macrophages treated with phospholipids having different polar groups, different isomerisms with saturated and unsaturated fatty acids from C12 to C20 carbon atoms . The results are as follows . a) Most of the phospholipids containing fatty acids from C12 to C20 cause inhibition of the blastogenic capacity of the polyclonal activators tested . b) The phospholipids tested cause a decrease in adherence of polymorphonuclear leukocytes with the exception of the phosphatidyl-choline containing saturated and unsaturated fatty acids . c) A decrease in polymorphonuclear leukocytes migrational capacity almost always occurs . d) The cells treated with L-phosphatidyl-ethanolamine having fatty acids from C14 to C17 show an increase in chemiluminescence; those treated with phosphatidyl-choline and L-phosphatidyl-glycerol show a decrease of the chemiluminescence; L-phosphatidic acid and L-phosphatidyl-ethanolamine having Microbial fatty acids (FAs) at C16 cause a decrease in the formation of phagolisosomes in the macrophages tested. Fortschr Ophthalmol, 1991, 88(5), 429 - 30 {Intraocular antibiotic administration for prevention of fibrin reaction after extracapsular cataract extraction? A randomized double-blind study}; Mittelviefhaus H; Postoperative fibrinoid reactions are regarded as a localized form of endophthalmitis caused by microbial contamination of the capsular bag during intraocular lens implantation . The incidence of early fibrinoid reactions within the first 6 postoperative days following extracapsular cataract extraction was examined after intraocular administration of antibiotics vs placebo . In a double-blind randomized trial, 2 mg cefamandol or a placebo was administered in a 0.4-ml volume at the end of the operation . A group of 28 patients received the antibiotic (mean age 74.6 years; 15 f, 13 m), while 33 patients received the placebo (mean age 72,1 years; 21 f, 12 m) . Fibrinoid reactions were observed in 8 out of 61 patients during the first 6 postoperative days . There was no significant difference between the antibiotic group and the placebo group (P = 0.31) . We were unable to reduce the incidence of fibrinoid reactions although we had selected a broad-spectrum cephalosporin for antibiotic treatment . The results give rise to the suspicion that most of the early postoperative fibrinoid reactions we observed were not caused by contamination with bacteria of low pathogenicity. Eye, 1991, 5 ( Pt 4), 425 - 31 The role of penetrating keratoplasty in the management of microbial keratitis; Kirkness CM et al.; Penetrating keratoplasty was performed as an emergency procedure in 52 eyes which had perforated from acute microbial keratitis and in a further 11 where perforation had not yet occurred . The results are compared with those of keratoplasty in 33 non-infected perforations and 20 eyes where there had been microbial keratitis which had responded to medical therapy leaving a scarred cornea . This latter group had both a better five year survival (90%) compared to all the others (51%), p less than 0.05, and achieved significantly better visual acuities, p less than 0.005. Ann Biomed Eng, 1991, 19(5), 529 - 45 Cellular engineering; Nerem RM; Cellular engineering applies the principles and methods of engineering to the problems of cell and molecular biology of both a basic and applied nature . As biomedical engineering has shifted from the organ and tissue level to the cellular and sub-cellular level, cellular engineering has emerged as a new area . A cornerstone of much of this activity is cell culture technology, i.e., the ability to grow living cells in the artificial environment of a laboratory . Cellular engineering includes the role of engineering in both basic cell biology research and in the making of products which use living cells, e.g., tissue engineering and bioprocess engineering . The former involves the use of living cells in the development of biological substitutes for the restoration or replacement of function, and the latter the use of living cells to manufacture a biochemical product, e.g., through the use of recombinant DNA technology . In fact, as biomedical engineering has expanded to include the cellular level, and bioprocess engineering has shifted in interest from microbial organisms to include mammalian cells, there are intellectual issues in which an interest is shared by these two formerly separate areas of engineering activity . Cellular engineering thus transcends the field of biomedical engineering. Rev Roum Virol, 1991 Jan-Jun, 42(1-2), 53 - 8 {The incidence of viral and microbial antigens and the serum interferon titer in certain forms of rheumatism}; Petrescu A et al.; The presence of some viral and inframicrobial antigens in peripheral leukocytes was investigated by the indirect immunofluorescence technique in 120 patients with different forms of rheumatism and 50 clinically healthy controls . Mycoplasma pneumoniae and type 3 para-influenza virus were detected most frequently . The determination of serum interferon titer revealed a rise of this product in rheumatic patients. Biomed Pharmacother, 1991, 45(2-3), 81 - 6 Modulation of bone marrow cell functions in vitro by bestatin (ubenimex); Blazsek I et al.; Bestatin (ubenimex), the microbial leucil-aminopeptidase B inhibitor, has been shown previously to stimulate both interleukin-1 (IL-1) and IL-2 production and to enhance T-cell, as well as macrophage mediated immunoreaction when administered in vivo in mice . Here we show that although Bestatin has no direct growth stimulatory activity, it enhances the growth of GM-CFU populations in semisolide culture and stimulates the cell production in liquide organotypic Hematon cultures in synergy with recombinant human GM-CSF . In long term human bone marrow culture Bestatin accelerated the adipocytic differentiation among colony forming stroma cells (F-CFU) . Our data provide further evidences that Bestatin may interact with the hemopoietic cell renewal system at different levels of biological organisation. Ann Trop Paediatr, 1991, 11(1), 87 - 94 Lipoid pneumonia in children following aspiration of animal fat (ghee); Annobil SH et al.; Exogenous lipoid pneumonia induced by modified animal fat (ghee) in 10 children is described . The initial presentation was of an acute or chronic pneumonia which proved refractory to anti-microbial chemotherapy . The radiological presentation varied from mild perihilar consolidation to diffuse and extensive bilateral involvement, particularly of the posterior lung segments . A history of administration of ghee provided the initial clue to the diagnosis, which was confirmed by demonstration of fat by bronchoalveolar lavage or by open lung biopsy . Eight of the 10 patients improved with either steroid therapy alone or steroids with resection of the most involved lung segments . One patient, who had extensive superinfection with Mycobacterium fortuitum, died . Lipoid pneumonia should be considered in the differential diagnosis of 'non-resolving' pneumonias in communities where the cultural practice of infant feeding with ghee is prevalent . Public awareness through health education about the potential hazards of this practice to infants and children can contribute to reduce the incidence of the problem. Antibiot Khimioter, 1991 Jan, 36(1), 29 - 31 {Experimental study of protease C--proteolytic enzyme of microbial origin}; Dolgova GV et al.; The specific activity of protease C, a proteolytic enzyme isolated from Acremonium chrysogenum was studied under experimental conditions . Protease C was shown to lyse necrotic biological substrates (dry crusts of burn wounds) and blood clots . By the nature of the effect protease C was analogous to terrilytin and by the level of the effect it was superior in some experiments . Protease C was low toxic and had no mutagenic action. Biomed Biochim Acta, 1991, 50(4-6), 781 - 9 A novel membrane-bound serine esterase in human T4(+)-lymphocytes is a binding protein of envelope glycoprotein gp120 of HIV-1; Kido H et al.; A novel membrane-bound serine esterase, named tryptase TL2, which is immunologically reactive with the antibody inhibiting induction of syncytia by human immunodeficiency virus-1 (HIV-1) (HATTORI, T., KOITO, A., TAKATSUKI, K., KIDO, H., and KATUNUMA, N., 1989, FEBS Lett., 248, 48-52), has been purified from a human T4+ lymphocyte clone . The enzyme has a molecular mass of 198 +/- 15 kDa, and is composed of two subunits of 32 kDa and four subunits of 28 kDa . The enzyme was strongly inhibited by the envelope glycoprotein gp120 of HIV-1, by synthetic peptides of V3 domains of gp120 s with the sequence GPGR in their center, which correspond to the principal neutralizing epitopes of the gp120s of various HIV-1 strains, by Kunitz-type inhibitors with the sequence GPCR in their active site, such as trypstatin, H130, and {Arg15, Glu52} aprotinin and by the microbial inhibitors leupeptin and antipain . This enzyme was specifically bound to the inhibitor V3 domain of gp120 of HIV-1, and this binding was blocked by the inhibitors of tryptase TL2, with a central motif GPCR or GPGR sequence in their center, but not by leupeptin and antipain without the motif . These findings suggest that tryptase TL2 is important in target site recognition and binding of HIV-1 in co-operation with CD4 receptor in the initial process of HIV-1 infection. Virchows Arch B Cell Pathol Incl Mol Pathol, 1991, 60(6), 353 - 63 Handling of cationic antigens in the joint and induction of chronic allergic arthritis . In vivo studies in the rat; Gondolf KB et al.; The aims of the present study were to define, under in vivo conditions, factors governing antigen binding and persistence in the rat joint and to establish a chronic arthritis model by means of a natural polycation . The influence of size as well as charge on antigen handling was examined using a range of chemically cationized proteins and natural polycations . Arthritis was induced by intraarticular challenge in preimmunized rats . Immunofluorescence studies revealed that not only pI, which must exceed pH 8-9, but also molecular size was a decisive parameter: only antigens of more than 40 kD were able to persist for significant periods in joint structures . All existing models of antigen induced chronic arthritis in rodents utilize chemically cationized proteins . We extended this system to natural polycations by showing that lysozyme (pI 11.3; MW 14 kD) in tetrameric, charge conserved form (MW 56 kD) as a model-antigen was able to induce chronic arthritis in the rat . After intraarticular challenge of preimmunized animals the course of inflammation was assessed both by 99mTechnetium-pertechnetate (99mTc) scintigram and from the histology . In contrast to monomeric lysozyme, which evoked only a transient inflammatory response (less than two weeks), tetrameric lysozyme induced a chronic arthritis, which still persisted at day 90 . Our results show that the ability of cationic antigens to trigger chronic arthritis is vitally size dependent . This is also the first report of a natural polycation acting as an arthritogen, thus providing an experimental basis justifying the search for cationic microbial antigens in human post infectious reactive arthritis. Annu Rev Immunol, 1991, 9, 567 - 89 Autoimmunity to chaperonins in the pathogenesis of arthritis and diabetes; Cohen IR; The immunology of the 65 kd heat shock protein (hsp65) is paradoxical . Microbial and mammalian hsp65 molecules are 50% identical in amino acid sequence and immunologically cross-reactive, so microbial hsp65 looks like self; yet hsp65 is a dominant antigen in infection . Immunity to hsp65 can cause autoimmune diabetes in mice and may be related to autoimmune arthritis in rats and humans, so immunity to hsp65 should be forbidden; yet healthy persons manifest T-cell responses to self-hsp65 . The aim of this chapter is to explore the immunological dominance of hsp65 and its role in autoimmunity--benign and pernicious. Nahrung, 1991, 35(9), 921 - 48 {Lactose--a potential dietary fiber . The regulation of its microecologic effect in the intestinal tract . 4 . Dietary fiber action of lactose: evaluation with multivariate statistical analysis}; Zunft HJ et al.; The conditions and the intestinal processes responsible for the action of lactose as a potential dietary fibre are described . The beta-galactosidase activity in the rat caecum and colon is influenced by dietary factors: It declines with increasing lactose concentration and it rises with increasing protein and phosphate concentration in the diet . The enzyme activity correlates negatively with the content of lactose, and positively with the content of protein and phosphate in the chymus . The products of lactose hydrolysis are degraded by microbial glycolysis in caecum and colon . The glycolytic products are mainly absorbed and energetically utilized by the macroorganism . Phosphate stimulates the microbial metabolism and, therefore, accelerates the consumption of the energy substrate lactose . Mathematical optimization gives the necessary composition of the diet which causes an intended microecological effect . To minimize the chymus pH (5.1 in the colon ascendens; 4.6 in the colon descendens; 4.3 in the faeces) the lactose content of the diet has to be greater than or equal to 160 mumol/g, the protein content less than or equal to 10 mg/g, and the phosphate content less than or equal to 5.5 mumol/g . The minimal pH value depends to a greater extent on variations in the supply of protein and phosphorus with the diet whereas the response to changes in lactose concentration is less noticeable. Drugs Exp Clin Res, 1991, 17(4), 243 - 52 Topical treatment of burn wounds with chloroxidating solution and silver sulfadiazine: a comparative study; Mian EU et al.; The present paper reports the results of clinical and laboratory tests carried out on two homogeneous groups of ten burn patients subjected to local therapy, either with isotonic chloroxidating solution Amuchina* or with 1% silver sulfadiazine cream at the Burns Centre of the Pisa University Dermatological Clinic . The local systemic behaviour of the patients examined was evaluated for the containment of septic complications at the burn site . In the group subjected to treatment with chloroxidating solution, sepsis appeared to have a lower incidence in the evolution of dermatitis in the phase of escharolysis, in the formation of granulation tissue, and in the attachment of cutaneous grafts . The systemic involvement (temperature curve, etc.) appeared to be more marked for some patients treated with silver sulfadiazine in response to septic aggression of the burn wounds . On the basis of data referring to the development of the wound granulation and the temperature curve, as well as the microbial presence and the subjective tolerance of the medication, the comparison was favourable, making all necessary allowances, to topical treatment with electrolytic chloroxidating solution; other comparative data were at the limit of significance. Connect Tissue Res, 1991, 26(4), 247 - 57 Collagenolytic enzymes assayed by spectrophotometry with suspensions of reconstituted collagen fibrils; Bleeg HS; Collagenolytic enzymes were quantitated by a method based on spectrophotometry of suspended reconstituted collagen fibrils . To obtain optically stable suspensions it was necessary to perform a short sonication of the aggregated fibrils at 10 degrees C . When fibrils were cleaved with mammalian fibroblast collagenase at 35 degrees C the triple helical collagen fragments (TCA and TCB) would uncoil spontaneously and the decreasing turbidity was used as an estimate of enzyme activity . The method is a specific collagenase assay since a possible cleavage in the non-helical parts of the collagen molecule with contaminating proteinases is without effect on the turbidity of the suspension and the collagen substrate is not converted to gelatin at 35 degrees C . After 1 h of incubation 0.2 U (equivalent to 0.2 micrograms) of fibroblast collagenase could be detected . In purification procedures with microbial collagenases many fractions were tested by overnight incubations in disposable cuvettes . Sealing of cuvettes with square silicone stoppers allowed rotation of enzyme-substrate mixtures directly in the cuvettes . Only standard laboratory equipment is required for this assay, which is not dependent on radiolabeling or preparation of specific immunologic reagents. J Biol Chem, 1990 Dec 15, 265(35), 21979 - 85 A novel membrane-bound serine esterase in human T4+ lymphocytes immunologically reactive with antibody inhibiting syncytia induced by HIV-1 . Purification and characterization; Kido H et al.; A novel membrane-bound serine esterase, named tryptase TL2, which is immunologically reactive with the antibody inhibiting induction of syncytia by human immunodeficiency virus-1 (HIV-1) (Hattori, T., Koito, A., Takatsuki, K., Kido, H., and Kutunuma, N . (1989) FEBS Lett., 248, 48-52), has been purified from a human T4+ lymphocyte clone . The enzyme has a molecular mass of 198 +/- 15 kDa, as judged by gel-permeation liquid chromatography, and is composed of two subunits of 32 kDa and four subunits of 28 kDa, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Studies with model peptide substrates showed that the enzyme preferentially recognized L-arginine and cleaved Boc-Gln-Gly-Arg-4-methyl-coumary