Emerg Infect Dis, 1995 Jan-Mar, 1(1), 7 - 15 Factors in the emergence of infectious diseases; Morse SS; "Emerging" infectious diseases can be defined as infections that have newly appeared in a population or have existed but are rapidly increasing in incidence or geographic range . Among recent examples are HIV/AIDS, hantavirus pulmonary syndrome, Lyme disease, and hemolytic uremic syndrome (a foodborne infection caused by certain strains of Escherichia coli) . Specific factors precipitating disease emergence can be identified in virtually all cases . These include ecological, environmental, or demographic factors that place people at increased contact with a previously unfamiliar microbe or its natural host or promote dissemination . These factors are increasing in prevalence; this increase, together with the ongoing evolution of viral and microbial variants and selection for drug resistance, suggests that infections will continue to emerge and probably increase and emphasizes the urgent need for effective surveillance and control . Dr . David Satcher's article and this overview inaugurate Perspectives, a regular section in this journal intended to present and develop unifying concepts and strategies for considering emerging infections and their underlying factors . The editors welcome, as contributions to the Perspectives section, overviews, syntheses, and case studies that shed light on how and why infections emerge, and how they may be anticipated and prevented. Fundam Clin Pharmacol, 1995, 9(6), 554 - 61 Comparison between acute hypoxia-induced and mechanically-induced pulmonary artery hypertension on the hemodynamics, myocardial contractility and regional blood flow in dogs; Girard C et al.; Two groups of eight anesthetized dogs with pulmonary artery hypertension (PAH) were compared . PAH was induced by submitting one group (HP) to hypoxia (FiO2 range: 6-10%) and the other group (ME) to microemboli through glass microbead injection into the pulmonary circulation . Hypoxia-induced PAH was moderate (PAP: +65%; PVR: +152%) contrasting with marked PAH after microbead injection (PAP: +190%; PVR: +389%) . For similar effects on left ventricular contractility (LV dP/dt max and segmental myocardial shortening), heart rate and systemic vascular resistance, left ventricular end-diastolic pressure showed significant differences between the two groups (HP group: +75%, ME group: -9%), and so did left ventricular end-diastolic length (HP: +9%, ME: -11%) . Thus, contrary to the injection of microbeads, hypoxia did not give rise to any pulmonary barrier, and consequently the changes in cardiac output (HP: +19%, ME: -15%) and hepatic blood flow (HP: +383%, ME: -77%) were significantly different . Hypoxia, and not microbead injection, was responsible for systemic hypertension (MAP: +34% and -4%, respectively) . The microbead model resulted in a significantly higher PVR/SVR ratio compared to the hypoxic model (HP: 0.14, ME: 0.41) . Hypoxia increased left and right myocardial blood flows whereas microbead injection affected only right ventricular blood flow, leading to significantly different RV/LV endocardial perfusion ratios (HP: +10%, ME: +98%) . We conclude that microbead-induced PAH is more appropriate than hypoxia-induced PAH for hemodynamic and pharmacological studies. J Cardiovasc Pharmacol, 1995, 25 Suppl 2, S20 - 2 Cytokines, phagocytes, and pentoxifylline; Mandell GL; Phagocytic cells, such as polymorphonuclear neutrophils, monocytes, and macrophages, are essential for defense against infection caused by a variety of microorganisms . The mechanisms used by these cells to destroy microbes comprise a potent oxidative armamentarium including superoxide, hydrogen peroxide, and hypochlorous acid . In addition, granule contents such as proteolytic enzymes, lysozyme, lactoferrin, and myeloperoxidase are released into the phagosome to destroy ingested microorganisms . Inflammatory cytokines, such as tumor necrosis factor (TNF), interleukin-1 (IL-1), and IL-6, enhance the phagocytic and microbicidal activity of the cells and increase their stickiness . It has been demonstrated in a variety of animal and clinical studies that activated phagocytes can damage the host they are designed to protect, using the mechanisms described above . Alkylxanthines, including pentoxifylline, are potent inhibitors of this inflammatory damage by two major actions: (a) reduction of the production of inflammatory cytokines (especially TNF) by phagocytes stimulated with a variety of microbial products (e.g., endotoxin); and (b) reversal of the effect of these cytokines on phagocytes . Thus, pentoxifylline counteracts the following effects of inflammatory cytokines on phagocytes: increased adherence, shape change resulting in larger size and rigidity, increased oxidative burst, priming for an enhanced oxidative burst, increased degranulation, and decreased chemotactic movement . In addition, these activities synergize with the normal anti-inflammatory mediator adenosine . Alkylxanthines have the potential to be effective therapy for conditions in which inflammatory cytokines and phagocytes cause damage, including the sepsis syndrome, ARDS, AIDS, and arthritis. Crit Rev Oral Biol Med, 1995, 6(4), 343 - 67 Does variability in salivary protein concentrations influence oral microbial ecology and oral health? Rudney JD. Salivary protein interactions with oral microbes in vitro include aggregation, adherence, cell-killing, inhibition of metabolism, and nutrition . Such interactions might be expected to influence oral ecology . However, inconsistent results have been obtained from in vivo tests of the hypothesis that quantitative variation in salivary protein concentrations will affect oral disease prevalence . Results may have been influenced by choices made during study design, including saliva source, stimulation status, control for flow rate, and assay methods . Salivary protein concentrations also may be subject to circadian variation . Values for saliva collected at the same time of day tend to remain consistent within subjects, but events such as stress, inflammation, infection, menstruation, or pregnancy may induce short-term changes . Long-term factors such as aging, systemic disease, or medication likewise may influence salivary protein concentrations . Such sources of variation may increase the sample size needed to find statistically significant differences . Clinical studies also must consider factors such as human population variation, strain and species differences in protein-microbe interactions, protein polymorphism, and synergistic or antagonistic interaction between proteins . Salivary proteins may form heterotypic complexes with unique effects, and different proteins may exert redundant effects . Patterns of protein-microbe interaction also may differ between oral sites . Future clinical studies must take those factors into account . Promising approaches might involve meta-analysis or multi-center studies, retrospective and prospective longitudinal designs, short-term measurement of salivary protein effects, and consideration of individual variation in multiple protein effects such as aggregation, adherence, and cell-killing. Annu Rev Microbiol, 1995, 49, 399 - 426 Cellulose degradation in anaerobic environments; Leschine SB; In anaerobic environments rich in decaying plant material, the decomposition of cellulose is brought about by complex communities of interacting microorganisms . Because the substrate, cellulose, is insoluble, bacterial and fungal degradation occurs exocellularly, either in association with the outer cell envelope layer or extracellularly . Products of cellulose hydrolysis are available as carbon and energy sources for other microbes that inhabit environments in which cellulose is biodegraded, and this availability forms the basis of many microbial interactions that occur in these environments . This review discusses interactions among members of cellulose-decomposing microbial communities in various environments . It considers cellulose decomposing communities in soils, sediments, and aquatic environments, as well as those that degrade cellulose in association with animals . These microbial communities contribute significantly to the cycling of carbon on a global scale. Rev Chir Orthop Reparatrice Appar Mot, 1995, 81(6), 505 - 13 {Uncemented knee prosthesis . Results apropos of 58 cases with a minimum of 5-year follow-up}; Gacon G et al.; PURPOSE OF THE STUDY: The aim of this study was to evaluate, after at least 5 year's follow-up, the results of 64 PCA (TM) cementless total knee prostheses . MATERIAL: From 1984 to 1988, 13 male and 45 female patients (a total of 64 prostheses including 6 bilateral) received PCA Primary prostheses . Both femoral and tibial components were implanted without cement . Mean age of patients was 68.9 years (range: 35-81); mean patient height was 164.41 cm and mean weight 76.74 Kg . The most frequent pathology was gonarthrosis: 43 cases of medial gonarthrosis and 15 of lateral gonarthrosis . There were 4 cases of rheumatoid arthritis and two post-traumatic degenerative arthritis . 52 knees were free of any previous surgical procedure . Of the 64 prostheses and the 58 patients: 6 died and 2 were lost to follow-up; 56 knees were reviewed . The longest follow-up is 9 years for an average of 6.8 years . METHODS: Prosthetic review included clinical evaluation (Hungerford score based on 100 points, ISK rate based on 200 points) and complete radiological evaluation enabling the postoperative position of the implants to be examined . Radiolucencies were examined according to Ewald . X-ray study of polyethylene wear was performed based on the distance between the prosthetic condyle to the height of the metal tibial plateau . All patients were operated on by the same surgeon using the same procedure, and the same postoperative outcome . RESULTS: There were no local postoperative complications or any early reoperations . PHlebitis occurred in 12 per cent of cases . With the exception of 8 patients who were reoperated due to mechanical complications, the Hungerford score raised from 37.5 preoperatively to 88.3 postoperatively . The results of 43 of the 48 patients were rated good or excellent . The 200 point score rating gave 91 per cent of good and excellent results for knee examination, and 69 per cent of good and excellent results for knee function . Mean flexion angle was 107.8 degrees mean pain scored 45/50 . Radiologically 75 per cent of operated patients had postoperative varus or valgus in the range 0-5 degrees as against 24 per cent preoperatively . The study of edge defects revealed the absence of any radiological abnormality on the femoral lateral projection in 85 per cent of cases, and the absence of abnormality on the tibial anteroposterior and lateral projections in more than 60 per cent of cases . X-ray study of polyethylene wear was conducted on 49 cases: polyethylene wear was observed radiologically in 1 of 4 cases . There was no correlation between polyethylene wear and polyethylene thickness, postoperative axes, body weight or clinical results . 8 patients had to be reoperated due to mechanical complications: 2 because of a tilting tibial plateau (due to a technical fault), 4 because of polyethylene wear and 2 because of patellar loosening (uncemented metal-back patellar implant) . DISCUSSION: The implantation of femoral and tibial components of cementless PCA Primary fitted seems very satisfactory . With longer follow-up, we noted no tibial or femoral osteolysis signs such as those described by Engh, Peters or Berry in the USA . Stability of mid term radiographical results was commonly observed throughout our study . Only 5 very slight lateral displacements were noted: 3 cases of secondary LCP insufficiency with tibial posterior subluxation; in 2 cases the cause was R.A . CONCLUSION: The implantation of uncemented PCA Primary prosthesis caused non complications with respect to the femur . Regarding the tibia, only two reoperations were required because of tibial fixation failure due to a technical fault . The use of a hybrid prosthesis is not required . The microbeads used in PCA are effective but current availability of other materials promoting better bone growth (such as hydroxyapatite, titanium mesh) allows safe implantation of uncemented prostheses . PCA Primary polyethylene wear seems to develop steadily . This is why it should be replaced by the less Reprod Nutr Dev, 1995, 35(5), 517 - 35 Reassessing the manipulation of protein synthesis by rumen microbes; Broudiscou L et al.; Protein synthesis by rumen microbes plays an important role in ruminant nutrition . Microbial proteins that are not recycled flow out of the rumen and account for more than 50% of the total proteins entering the intestines . Determination of microbial nitrogen in digesta is based on the isolation of a representative sample of rumen microbes and on the use of specific markers (purine bases, RNA, 15N incorporation) . This review discusses the reliability of microbial markers and examines current methods for assessing differences in turnover rate and microbial composition among liquid and particulate compartments . Four groups of factors acting on microbial synthesis, which are also adaptable to farm conditions, are considered: I) modification of protozoal population; II) modification of liquid and solid phase kinetics in the rumen; III) balance in the components of the diet; and IV) probiotics . The effects of these factors are discussed, considering their feasibility and their usefulness for the host. Reprod Nutr Dev, 1995, 35(1), 45 - 70 Development of a mechanistic model for rumen digestion validated using the duodenal flux of amino acids; Lescoat P et al.; A mechanistic model describing rumen digestion is presented . The model consists of 22 compartments for classical nutrients, microbes associated with either solids or fluid, and 8 amino-acid compartments . An empirical approach for volatile fatty acids production is used . Sensitivity and behavioural analysis on several parameters demonstrated the need to improve knowledge concerning certain factors . Model results on general criteria are in good agreement with observed data . Validation on 49 experimental lysine and methionine duodenal fluxes were satisfactory . A comparison between observed and predicted values of LysDi and Metdi on several feedstuffs showed good results . This model is a first step in the building of a rumen model suitable for research and application. Scand J Rheumatol, 1995, 24(1), 44 - 7 Synovial fluid culture and blood culture in acute arthritis . A multi-case report of 90 patients; Kortekangas P et al.; The use of blood culture methods for culture of synovial fluid (SF) has been suggested to increase the yield of microbes from SF of patients with septic arthritis . We report on a study of 94 SF cultures of 90 adult patients with acute effusions of the knee joint . Three different culture methods were used: conventional agar plate culture, culture with lysis and centrifugation (Isolator) and broth enrichment (BACTEC 6A and 7A) . Blood was cultured simultaneously from 76 patients . In the patients with clinical septic arthritis, the SF cultures were positive by all the methods in 8 patients and negative by all the methods in 19 patients . The contamination rate of the SF cultures was 3/215 in the patients without clinical septic arthritis . We conclude that reliable evidence of septic arthritis is emerged from a SF culture by a single method, and that the choice of culture method is less critical . In addition, we discuss the role of blood cultures in the diagnosis of acute arthritides. J Acoust Soc Am, 1995 Jan, 97(1), 491 - 504 The supraglottal articulation of prominence in English: linguistic stress as localized hyperarticulation; de Jong KJ; The results of an articulatory investigation of the supraglottal correlates of linguistic prominence in English, and a proposal of a unified description of linguistic stress are reported . Three models of stress are evaluated: that prominence expands jaw movement, that stress expands an abstract articulatory scale involving the opening and closing of the vocal tract, and that stress involves a localized shift toward hyperarticulate speech . A corpus of x-ray microbeam records of sensible speech is studied, within which the stress pattern is controlled and is checked by means of an intonational analysis . Jaw movement data yield similar results to earlier studies, but kinematic differences interpreted with reference to a gestural theory suggest that different subjects use different articulatory strategies to articulate stress contrasts . In addition, the jaw, lip, and tongue interact in the articulation of stress in subject dependent ways . Thus the articulation of stress should be formulated in terms of abstract articulatory goals, rather than in terms of individual articulator positioning . Finally, the data show that stress affects the articulation of nonsonority distinctions such as backness in vowels and point of articulation in consonants . A hyperarticulation model of stress is discussed in terms of these results. Artif Cells Blood Substit Immobil Biotechnol, 1995, 23(2), 143 - 51 In vitro slow release profile of endothelial cell growth factor immobilized within calcium alginate microbeads; Ko C et al.; Although a variety of angiogenic growth factors have been isolated, its appropriate in vivo delivery remains problematic due to nonspecific, uncontrolled delivery by conventional methods . We have investigated calcium alginate microbeads as a vehicle for the controlled slow-release of endothelial cell growth factor (ECGF) . Three different microbead compositions, dependent on ECGF amount and alginate percentage were studied . Microbeads were incubated in a 1.5% calcium chloride solution and release of ECGF into solution was measured spectrophotometrically at specific timepoints . Our results show release rate and amount released after the first 2 hours are dependent on initial quick delivery of ECGF in the first 2 hours after which a sustained controlled release occurred for 4-5 days . Beyond this point, release at a slower rate was noted for at least approximately 2 weeks . Calcium alginate microbeads demonstrated a controlled and predictable rate of release and that the amount of ECGF delivered can be varied by varying the initial concentration of ECGF in the microbeads . Based on these observations we conclude that calcium alginate microbeads are a convenient and practical vehicle for sustained ECGF delivery. Vestn Ross Akad Med Nauk, 1995, (2), 57 - 61 {Molecular and catalytic properties of bacterial glutamin-(asparagin-)ase}; Lebedeva ZI et al.; The review summarizes and analyzes experimental evidence for the properties of glutamine(asparagine)ase from Pseudomonas aurantiaca-548 . The enzyme is a tetramer having a molecular weight of 148 kD and consisting of 4 identical subunits having a molecular weight of 37 kD . For glutaminase activity, the optimum pH is in the range of 6.0-8.0, asparaginase activity increases as pH rises . The enzyme is maximally stable at pH 6.8-8.0 . The Michaelis constants are 5.3 +/- 0.7 x 10(-6) M for L-glutamine and 5.7 +/- 0.1 x 10(-6) M for asparagine . The reaction products L-aspartate and L-glutamate are competitive inhibitors anazaserine and 6-diase-5-oxo-1-norleucine are classic inhibitors of glutamine(asparagine)ase . The review also presents data on the conditions for culturing Ps . aurantiaca, on the procedures for isolating glutamine(asparagine)ase from biomass of this microbe, on substrate specificity . The results of searching for regulators of catalytic activity, as well as agents enhancing the resistance of enzymes to heat exposures are considered in the paper . Whether the properties of glutamine(asparagine)ase are in conformity with the criteria for primary choice of promising antitumor agents is discussed. J Eukaryot Microbiol, 1995 Jan-Feb, 42(1), 1 - 7 The large, free-living amoebae: wonderful cells for biological studies; Jeon KW; The large, free-living amoebae have been widely used as model cells for studying a variety of biological phenomena, including cell motility, nucleocytoplasmic interactions, membrane function, and symbiosis . Results of studies by our group on amoebae as moving cells, as material for micrurgical manipulations, and as hosts for intracellular symbionts are summarized here . In particular, our recent studies of the amoeba as a microcosm, in which spontaneously infecting foreign microbes have become integrated as necessary cell components, are described in some detail . These processes have involved an initial microbial infection, mutual adaptation by the host and symbionts, and development of obligatory symbiosis . Evidence is presented to show that symbiont-derived macromolecules are involved in the protection of symbionts from digestion, the symbionts have acquired regulatory elements on their chromosomal genes to enhance production of beneficial gene products, and symbionts apparently utilize host-derived macromolecules to their benefit . These studies involved morphological observations both at light and electron microscopic levels, physiological and genetic studies, production and use of poly- and monoclonal antibodies, and molecular-biological approaches including gene cloning and sequencing . It is shown that amoebae are uniquely suited as model cells with which to study these phenomena. J Periodontal Res, 1995 Jan, 30(1), 51 - 7 Identification and possible function of cathepsin G in gingival crevicular fluid from chronic adult periodontitis patients and from experimental gingivitis subjects; Kunimatsu K et al.; The levels of cathepsin G in gingival crevicular fluid (GCF) from chronic adult periodontitis patients and experimental gingivitis subjects were determined both by activity measurement using N-benzoyl-(DL)-phenylalanine-2-naphthyl ester as a substrate and by enzyme immunoassay using anti-human cathepsin G IgG . The activity level of cathepsin G in GCF of both periodontitis and experimental gingivitis has no significant correlation with all measured clinical parameters . Western immunoblotting using antibodies specific for cathepsin G or alpha 1-proteinase inhibitor revealed that the difficulty in demonstrating the association of its activity with the severity of these diseases was due largely to formation of the enzyme-inhibitor complexes . By contrast, statistically significant positive correlation was found between cathepsin G content in GCF of periodontitis, which was determined by enzyme immunoassay, and such clinical parameters as the GCF volume, the gingival index and probing depth . The increased cathepsin G content with increasing severity of periodontal inflammation was markedly diminished by the initial treatment . Although no significant activity was detectable in GCF of experimental gingivitis, a rapid increase of the immunoreactive cathepsin G was found in GCF at 3-5 d after refraining from oral hygiene measures, which rapidly decreased by 10 d . The progressively increased cathepsin G between 10th and 21st d rapidly decreased by cleaning of the teeth . The results indicate that cathepsin G is involved in the host's defensive mechanism against the invasion of etiologic microbes and/or the development of either periodontitis or gingivitis. Nat Toxins, 1995, 3(2), 65 - 74 Interactions between bacteria and harmful algae: a review; Doucette GJ; The ways in which bacteria interact with eukaryotic, unicellular algae are extremely diverse . Such relationships vary widely according to a number of criteria, including spatial and temporal scales, the degree of specificity, and if the relationship can be characterized as beneficial or detrimental to any of the organisms involved . These criteria can be applied to our assessment of how microbes interact with those species involved in the formation of harmful algal blooms (HABs) . The aim of this paper is to assess the current state of our knowledge of bacterial/HAB interactions as they pertain to the influence of bacteria on HAB population dynamics, the role of bacteria in the production of toxins normally attributed to the algae, and the suggestion that HABs may act as vectors for pathogenic bacteria . Given that viruses are now considered to play a potentially important role in structuring phytoplankton communities, the possible effects of viruses on the population dynamics of harmful algal species are also addressed. Agents Actions Suppl, 1995, 46, 1 - 9 Eosinophil chemoattractants generated in vivo; Williams TJ et al.; The eosinophil is the predominant inflammatory cell which accumulates in the asthmatic lung . There is considerable circumstantial evidence linking these cells to lung dysfunction, but the precise cause and effect relationship is controversial . The defensive role of the eosinophil appears to be concerned largely with eliminating helminth parasites which do not normally present a constant threat . Thus, unlike the neutrophil whose defensive role against microbes is essential, the eosinophil presents a target for therapeutic intervention which is potentially applicable to long-term treatment . Several approaches to suppressing eosinophil accumulation are possible, based on the multiple steps involved in their appearance and activation in the lung (for review see {1}) . One approach is to block the receptor(s) to the important endogenous eosinophil chemoattractants generated in the asthmatic lung, offering the potential for selective leukocyte-type suppression . A first step in this pursuit is the identification of such chemoattractants . This article describes recent attempts in this direction, with the long-term goal of producing chemoattractant receptor antagonists. Antonie Van Leeuwenhoek, 1995, 67(4), 315 - 24 Molecular evolution in bacteria; Trevors JT; Recent advances in microbiology and molecular biology have a unifying influence on our understanding of genetic diversity/similarity and evolutionary relationships in microorganisms . This article attempts to unify information from diverse areas such as microbiology, molecular biology, microbial physiology, clay crystal genes, metals-microbe-clay interactions and bacterial DNA restriction-modification systems (R-M) as they may apply to molecular evolution of bacteria . The possibility is discussed that the first informational molecules may have been catalytic RNA (micro-assembler) not DNA (now the master copy) and these first micro-assemblers may have been precursors of ribosomes. Gene, 1994 Dec 2, 150(1), 51 - 6 Escherichia coli genome targeting, I . Cre-lox-mediated in vitro generation of ori- plasmids and their in vivo chromosomal integration and retrieval; Hasan N et al.; We have constructed a plasmid system designed for the insertion of cloned DNA (e.g., genes, gene fusions, regulatory elements, etc.) into the Escherichia coli genome . Its principal feature is the presence of two tandem lox sites on the plasmids, which upon Cre-mediated in vitro recombination resolve the plasmids into ori- and ori+ DNA circles . The non-replicating ori- circles contain the lambda attP site, several unique restriction sites for cloning, a NotI site and KmR, a kanamycin-resistance-encoding gene . The ori+ circles carry the origin of DNA replication (ori) together with several cleavage sites not present in the ori- circles, including the rare site for the very efficient I-SceI enzyme, that are used to inactivate the ori+ circles and any unresolved plasmid DNA . We have used this system to insert cloned DNA into the host genome at (i) the attB site, by Int-mediated integration and (ii) at any predetermined sequence, as mediated by the Rec system(s) of the host . The genomes of the resulting transformants were analyzed by NotI digestion of the chromosomal DNA, embedded in agarose microbeads, followed by pulsed-field gel electrophoresis . A system for the retrieval of DNA fragments inserted at the attB site was also developed. Vet Microbiol, 1994 Dec, 42(4), 317 - 26 Use of bovine myeloperoxidase as an indicator of mastitis in dairy cattle; Cooray R; Bovine myeloperoxidase (MPO) is a heme protein consisting of both large and small polypeptide subunits . In mammals the role of MPO in defending against microbes is well documented . To evaluate the potential of using MPO in the diagnosis of udder infections in dairy cattle we developed a specific enzyme immunoassay for bovine MPO in milk . Antibodies against bovine MPO were produced using the purified enzyme . The ELISA utilizes two specific antibodies: one that is anti-MPO monoclonal and one that is anti-MPO polyclonal . For a total of 141 milk samples the correlation coefficient between the somatic cell count and MPO concentrations determined using the ELISA was 0.91 . The ELISA showed good precision and accuracy in measuring MPO in milk, with a total variation of ca . 10% . The recoveries of known amounts of MPO from milk were satisfactory . Thus the stability of the enzyme in milk was judged to be good . Microorganisms were isolated in ca . 85% of the milk samples with elevated concentrations of MPO . Microorganisms were not isolated from more than 90% of non mastitic milk samples with low somatic cell counts where MPO was not detectable using ELISA . The results clearly show that the quantitative analysis of the amount of MPO in mastitic milk can be used to detect intramammary infections in dairy cattle. Clin Chem, 1994 Dec, 40(12), 2282 - 7 Urea and lactate determined in 1-microL whole-blood samples with a miniaturized thermal biosensor; Xie B et al.; A miniaturized flow-injected thermal biosensor was developed for the determination of urea and L-lactate in undiluted blood in 1-microL samples . The sensor employed a small enzyme column constructed of stainless steel tubing and microbead thermistors . Urease and lactate oxidase/catalase were separately immobilized onto controlled-pore glass beads, which, in turn, were charged into the enzyme column . With a flow rate of 70 microL/min, linear analytical ranges from 0.2 to at least 50 mmol/L and 0.2 to 14 mmol/L were obtained for urea and lactate, respectively . The relative standard deviations (CVs) for measurements of analyte in buffer were 0.91% for urea and 1.84% for lactate . For urea in whole blood, the CV for 50 determinations was 4.1% . Contrived samples containing various concentrations of urea and L-lactate in whole blood were determined with this sensor and with a spectrophotometric method . Comparisons of the results gave correlation coefficients of 0.989 and 0.984 for 30 blood urea and 30 blood lactate assays in concentrations ranging from 4 to 20.9 mmol/L and from 1.7 to 12.7 mmol/L, respectively. Scand J Gastroenterol, 1994 Dec, 29(12), 1117 - 21 Phospholipids prevent enteric bacterial translocation in the early stage of experimental acute liver failure in the rat; Wang XD et al.; BACKGROUND: Bacterial infections and bacteremia in acute liver failure may at least partly be attributed to translocation of enteric bacteria . Attempts to prevent or treat such infections by the use of antibiotics may instead result in overgrowth of surviving microbes . METHODS: In the present study, normal saline (1.5 ml/100 g body weight), phosphatidylcholine (1.5 ml/100 g body weight), and phosphatidylinositol (1.5 ml/100 g body weight) were orally administered by means of a gastric tube both 12 h and 30 min before operation . Effects of enteric administration of phospholipids on the prevention of enteric bacterial translocation, intestinal and mucosal mass, and enterocyte protein contents in acute liver failure induced by subtotal liver resection in the rat were evaluated . RESULTS: The incidence of bacterial translocation increased significantly 2 and 4 h after 90% hepatectomy as compared with sham-operated animals . Enteric administration of phospholipids, however, significantly reduced the incidence of bacterial translocation after 90% hepatectomy . Phospholipid treatment prevented the postoperative decrease in intestinal mucosal mass and enterocyte protein content . CONCLUSIONS: Enteral administration of phospholipids thus seems to protect against translocation of enteric bacteria and prevent against a decrease in intestinal mucosal mass and enterocyte protein content after subtotal hepatectomy in the rat. Semin Respir Infect, 1994 Dec, 9(4), 256 - 60 Effect of critical illness on microbial translocation and gastrointestinal mucosa permeability; Fink MP; It has been hypothesized that the barrier function of the gastrointestinal tract is deranged in patients with trauma, sepsis, or other critical illnesses . Derangements in intestinal barrier function might lead to bloodstream invasion by gut-derived microbes and/or activation of inflammatory cells in the submucosa of the intestine or within the liver . Activated immune cells are capable of releasing a number of inflammatory mediators, including eicosanoids and cytokines, which have been implicated in the pathogenesis of the multiple organ dysfunction syndrome (MODS) . Thus, gut-barrier dysfunction might be primary factor leading to MODS in patients with critical illness . Two distinct forms of gut-barrier dysfunction have been described . The first, called translocation, appears to a transcellular process, whereby particulate antigens, including viable microbes, are transported across enterocytes into the submucosal compartment . The second is an increase in the paracellular permeability of the intestinal epithelium, which permits increased transmucosal absorption of water-soluble macromolecules . Pathological increases in both translocation and permeability occur in a number of animal models of critical illness . Moreover, a number of studies have documented that intestinal permeability is increased in humans with trauma, sepsis, burns, or other serious, acute medical problems . Nevertheless, convincing data to establish a causal link between gut-barrier dysfunction and organ failure in humans are lacking, and the importance of translocation and/or mucosal hyperpermeability on the development of MODS in patients remains to be elucidated. Semin Respir Infect, 1994 Dec, 9(4), 248 - 55 The effect of nutrition on gastrointestinal barrier function; Alverdy J; The tightly adherent monolayer of epithelial cells that line the luminal side of the intestine provides a dynamic and highly regulated barrier to the passive transport of macromolecules . The presence of both nutrients and microbes within the gastrointestinal lumen impose a dichotomous task to this epithelial barrier . Several lines of evidence suggest that conditions created in modern intensive care units (ICUs) dysregulate the discriminatory function of the epithelial barrier . Alterations in intestinal barrier function may result in permeation of autotoxic macromolecules of immense size and diversity that normally reside in the gut lumen . It is becoming increasingly recognized that artificial nutritional support of the critically ill patient may result in significant alterations in epithelial barrier function . The causes and consequences of diet-induced alterations in the gastrointestinal barrier will be discussed . Future strategies in the development of more physiological diets for the critically ill will likely involve the addition of neural, hormonal, and growth factors as stimulants for enhancement of barrier function. J Clin Microbiol, 1994 Dec, 32(12), 3082 - 4 Evaluation of new transport medium for detection of herpes simplex virus by culture and direct enzyme-linked immunosorbent assay; Ogburn JR et al.; The transport medium Multi-Microbe Media (M4) was evaluated prospectively by culture and direct enzyme-linked immunosorbent assay (ELISA) for detection of herpes simplex virus from 473 specimens . In addition, 377 specimens in Bartels Viral Transport Medium were evaluated . By using culture as a "gold standard," the ELISA sensitivity was approximately 85%, while the specificities exceeded 96% for both media. J Prosthodont, 1994 Dec, 3(4), 213 - 8 Development of a radiopaque, autopolymerizing dental acrylic resin; Mattie PA et al.; PURPOSE: Current prosthetic acrylic resins are radiolucent and cannot be imaged using standard radiographic techniques . If accidentally impacted or ingested, delays in localizing or removing the foreign body may be life-threatening . The purpose of this study was to evaluate the influence of an experimental radiopaque additive, triphenyl bismuth (TPB), on polymethyl methacrylate resins formulated for dental use . We also investigated methods to improve TPB-containing resin microbeads and optimize processing variables for specimen fabrication in autopolymerizing resin systems . MATERIALS AND METHODS: Selfcured samples of experimental resins were prepared containing 0% to 27% TPB and were tested according to American National Standards Institute/American Dental Association and International Organization for Standardization performance standards . A control group and two commercial provisional crown and bridge resins were used for comparison . RESULTS: The standard of radiopacity (> or = aluminum radiopacity) is met at TPB levels of > or = 14.5% . The control resin had a greater transverse deflection compared with the TPB-resin groups, but deflection was within standard limits for all resins . Polishability, color stability, and solubility were unaffected by TPB, whereas sorption decreased, although not significantly, at higher TPB levels . Translucency decreased at 27% TPB, and specimens containing 0% to 20% TPB were transparent . A tendency to entrain air bubbles, because of the hydrophobicity of TPB, resulted in increased susceptibility to brittle failure at the higher TPB levels . Solubility slightly exceeded American Dental Association standards for all TPB-resins and the control . All other performance standards were acceptable for resins containing 0% to 20% TPB . CONCLUSIONS: At concentrations that provide a diagnostic level of radiopacity, TPB does not significantly alter required performance and processing properties . Thus, TPB is capable of commercially acceptable performance as a radiopacifying additive for dental acrylics. Bioessays, 1994 Dec, 16(12), 919 - 23 The regulation of superoxide production by the NADPH oxidase of neutrophils and other mammalian cells; Jones OT; Superoxide is produced by a NADPH oxidase of phagocytic cells and contributes to their microbicidal activities . The oxidase is activated when receptors in the neutrophil plasma membrane bind to the target microbe . These receptors recognise antibodies and complement fragments which coat the target cell . The oxidase electron transport chain, located in the plasma membrane, comprises a low potential cytochrome b heterodimer (gp 91-phox and p22-phox) associated with FAD . It is non-functional until at least three proteins, p67-phox, p47-phox and p21rac (and possibly others), move from the cytosol to dock on the cytochrome b . The docking involves the interaction of SH3 domains on p47-phox or p67-phox with a proline-rich sequence on the small subunit of the cytochrome b . These SH3 domains may become exposed following phosphorylation of p47-phox by protein kinase C or, in model systems, by addition of arachidonic acid to reconstitution mixtures . Following the docking process the electron-transporting component is able to transfer electrons from NADPH to oxygen . This electrogenic event is charge-compensated by the opening of a proton channel . Components of the oxidase are expressed in non-phagocytes, where their function is uncertain but could be related to some signal function of superoxide. Dev Biol, 1994 Dec, 166(2), 363 - 79 Signal propagation and regulation in the mating pheromone response pathway of the yeast Saccharomyces cerevisiae; Bardwell L et al.; Extracellular signals can affect the rate of proliferation and the state of differentiation of eukaryotic cells . Signal transduction pathways have evolved to detect these signals at the plasma membrane, transmit them through the cytoplasm and into the nucleus, and thereby generate the appropriate changes in metabolism and transcription . Much attention has been focused recently on regulatory pathways of this sort that lead to activation of a family of protein kinases known as the mitogen- or messenger-activated, or extracellular signal-regulated protein kinases (MAPKs or ERKs) because this particular class of enzyme is highly conserved among eukaryotes, as is documented here and in the accompanying reviews in this issue . The mating pheromone response pathway in a unicellular microbe, the budding yeast Saccharomyces cerevisiae, is perhaps the best understood multicomponent signaling pathway known in any eukaryotic organism, especially at the genetic level . Furthermore, structural homologs and functional analogs of the components of the yeast pheromone response pathway are recapitulated in the signaling systems present in multicellular eukaryotes . This article emphasizes recent findings and common molecular themes for understanding the organization and regulation of MAPK-dependent signaling cascades that have emerged from biochemical and genetic analysis of the mating pheromone response pathway in yeast. Am J Physiol, 1994 Dec, 267(6 Pt 2), R1596 - 605 Comparison of acute phase responses induced in rabbits by lipopolysaccharide and double-stranded RNA; Kimura M et al.; Infection of injury results in several systemic and central reactions termed the acute phase response (APR) . Substantial evidence suggests that cytokines induced by microbes initiate the APR . We compared the APR induced in rabbits by a model bacterial stimulus, lipopolysaccharide (LPS), to that induced by a model viral stimulus, polyriboinosinic:polyribocytidylic acid (poly I:C) . The cytokine mRNA responses in a mouse macrophage cell line (RAW 264.7) to LPS or poly I:C were also determined . Rabbits were injected intravenously or intracerebroventricularly with different doses of LPS or poly I:C . Colonic temperatures (Tco) and blood samples were taken at the time of injection and at 3, 6, and 24 h after injection . Leukocyte numbers, serum antiviral activity, serum ceruloplasmin, and plasma fibrinogen were analyzed . Both intravenously injected LPS and poly I:C increased Tco, decreased leukocytes, and increased ceruloplasmin . Only LPS by the intravenous route increased fibrinogen, whereas only intravenously injected poly I:C induced antiviral activity . Intracerebroventricular injections of LPS and poly I:C also elicited dose-dependent febrile responses but did not change the hematologic APR significantly except for fibrinogen . The primary distinctions between LPS and poly I:C with respect to cytokine induction in the RAW 264.7 macrophage cell line were that LPS failed to induce interferon (IFN)-alpha, poly I:C induced interleukin (IL)-6 mRNA minimally and for a shorter time period than did LPS, and LPS induced IL-1 alpha and IFN-beta more rapidly than did poly I:C.(ABSTRACT TRUNCATED AT 250 WORDS) Environ Health Perspect, 1994 Dec, 102 Suppl 10, 201 - 8 Role of oxygen in phagocyte microbicidal action; Allen RC; Immune information in the form of inflammatory mediators directs phagocyte locomotion and increases expression of opsonin receptors such that contact with an opsonized microbe results in receptor ligation and activation of microbicidal metabolism . Carbohydrate dehydrogenation and O2 consumption feed reactions that effectively lower the spin quantum number (S) of O2 from 1 to 1/2 and finally to 0 . Oxidase-catalyzed univalent reduction of O2 (S = 1; triplet multiplicity) yields hydrodioxylic acid (HO2) and its conjugate base superoxide, O2- (S = 1/2; doublet multiplicity) . Acid or enzymatic disproportionation of superoxide yields H2O2 (S = 0; singlet multiplicity) . Haloperoxidase catalyzes H2O2-dependent oxidation of Cl- yielding HOCl (S = 0), and reaction of HOCl with H2O2 yields singlet molecular oxygen, 1O2 (S = 0; singlet multiplicity) . The Wigner spin conservation rule restricts direct reaction of S = 1 O2 with S = 0 organic molecules . Lowering the S of O2 overcomes this spin restriction and allows microbicidal combustion . High exergonicity dioxygenation reactions yield electronically excited carbonyl products that relax by photon emission, i.e., phagocyte luminescence . Addition of high quantum yield substrates susceptible to spin allowed dioxygenation, i.e., chemiluminigenic substrates, greatly increases detection sensitivity and defines the nature of the oxygenating agent . Measurement of luminescence allows high sensitivity, real-time, and substrate-specific differential analysis of phagocyte dioxygenating activities . Under assay conditions where immune mediator and opsonin exposure are controlled, luminescence analysis of the initial phase of opsonin-stimulated oxygenation activity allows functional assessment of the opsonin receptor expression per circulating phagocyte and can be used to gauge the in vivo state of immune activation. Can J Microbiol, 1994 Dec, 40(12), 993 - 9 Occurrence of legionellae in hot water distribution systems of Finnish apartment buildings; Zacheus OM et al.; The occurrence of legionellae in the hot water distribution systems of 67 buildings located in different parts of Finland was studied . Most of the buildings were apartment buildings . They had different hot water temperatures, and some received their cold potable water from surface water plants and some from ground water plants . Hot water samples were taken from taps, showers, and water mains just before and after the heat exchanger . Legionella pneumophila was isolated from 30% of the distribution systems . In the legionella-positive samples the legionella concentration varied from < 50 to 3.2 x 10(5) colony-forming units (cfu)/L (mean 2.7 x 10(3) cfu/L) . The highest concentration of legionellae was found in the shower water . Legionellae appeared more often and with higher concentrations in hot water systems using cold water processed in surface water plants than in hot water systems associated with ground water plants . A high organic matter content in surface waters might favor the occurrence of legionellae and also the growth of other heterotrophic microbes . Mean water temperature just after heating was slightly higher in the legionella-negative systems than in the legionella-positive systems (53.5 vs . 51.5 degrees C). J Cell Biol, 1994 Dec, 127(6 Pt 1), 1703 - 15 Interactions of the chondroitin sulfate proteoglycan phosphacan, the extracellular domain of a receptor-type protein tyrosine phosphatase, with neurons, glia, and neural cell adhesion molecules; Milev P et al.; Phosphacan is a chondroitin sulfate proteoglycan produced by glial cells in the central nervous system, and represents the extracellular domain of a receptor-type protein tyrosine phosphatase (RPTP zeta/beta) . We previously demonstrated that soluble phosphacan inhibited the aggregation of microbeads coated with N-CAM or Ng-CAM, and have now found that soluble 125I-phosphacan bound reversibly to these neural cell adhesion molecules, but not to a number of other cell surface and extracellular matrix proteins . The binding was saturable, and Scatchard plots indicated a single high affinity binding site with a Kd of approximately 0.1 nM . Binding was reduced by approximately 15% after chondroitinase treatment, and free chondroitin sulfate was only moderately inhibitory, indicating that the phosphacan core glycoprotein accounts for most of the binding activity . Immunocytochemical studies of embryonic rat spinal phosphacan, Ng-CAM, and N-CAM have overlapping distributions . When dissociated neurons were incubated on dishes coated with combinations of phosphacan and Ng-CAM, neuronal adhesion and neurite growth were inhibited . 125I-phosphacan bound to neurons, and the binding was inhibited by antibodies against Ng-CAM and N-CAM, suggesting that these CAMs are major receptors for phosphacan on neurons . C6 glioma cells, which express phosphacan, adhered to dishes coated with Ng-CAM, and low concentrations of phosphacan inhibited adhesion to Ng-CAM but not to laminin and fibronectin . Our studies suggest that by binding to neural cell adhesion molecules, and possibly also by competing for ligands of the transmembrane phosphatase, phosphacan may play a major role in modulating neuronal and glial adhesion, neurite growth, and signal transduction during the development of the central nervous system. Int J Food Microbiol, 1994 Nov, 23(3-4), 449 - 65 Modelling the destruction of Escherichia coli on the base of reaction kinetics; Reichart O; Assuming that the inactivation of microorganisms is due to a chemical reaction between a 'critical structure' of the cell and another reactant molecule, mathematical models of the reaction rates can be applied to the process . Considering the stoichiometric equation of the chemical reaction, the thermal death or disinfection of microbes can be described by an extension of the Eyring's model . The extended model is applicable not only to heat inactivation, but also to disinfection kinetics and to the effect of pH . Taking into account the effect of the water activity on heat destruction, the extended model has been modified empirically and fitted to experimental data on the heat destruction of Escherichia coli. Rev Med Brux, 1994 Nov-Dec, 15(6), 355 - 8 {Virology: diagnosis or screening?}; Thiry L; Andre Dachy is a sensitive clinician as well as a microbiologist who knows about hidden meanings of laboratory tests . Pediatrics was enriched by his dual interest in observation of the children and of the microbes which threaten them . As time went by, Dachy's interest for social medicine grew . Thus, it is justified to address him the present consideration on relevancy of virology diagnosis and modalities of screening. Prof Nurse, 1994 Nov, 10(2), 94 - 6 A time and money saver? Cost comparison of i.v . therapy with and without Pall 96 filters; Johnson S; 1 . Nurses should not be adverse to performing their own research projects to inform their clinical practice . 2 . Intravenous filters can reduce the risks involved in IV therapy from microbes, particulates or air, and reduce the incidence of phlebitis . 3 . Use of Pall 96 filters may be cost-effective in general medical wards, but this study was too small for general application. Dev Comp Immunol, 1994 Nov-Dec, 18(6), 455 - 66 Comparative analysis of phagocytosis of fungal cells by insect hemocytes versus horse neutrophils; Mazet I et al.; In this study, the phagocytic ability of Spodoptera exigua hemocytes was compared to horse neutrophils . In vitro assays showed that the insect granulocytes and horse neutrophils actively phagocytose FITC-labeled Paecilomyces farinosus blastospores opsonized with S . exigua hemolymph lectin or horse serum, respectively . Killing of fungal cells by the neutrophils and hemocytes was analyzed under in vitro conditions . Neutrophils reduced the growth of P . farinosus up to 65% whereas no fungicidal activity was observed with hemocyte monolayers . The production of oxygen metabolites by both phagocytic cells incubated with various elicitors (fungal cells, bacteria, phorbol myristate acetate) was examined using luminol-enhanced chemiluminescence . Phagocytosis of opsonized microbes by horse neutrophils resulted in marked increase of chemiluminescence activity whereas no chemiluminescence was detected in similarly challenged phagocytic insect hemocytes . Electron microscopy was used to examine phagocytic events and confirmed that insect phagocytes were unable to kill tested microbes. Int Endod J, 1994 Nov, 27(6), 330 - 3 Efficacy of sterilization of endodontic files after autoclaving in a synthetic sponge; Boyd KS et al.; A common way of sterilizing endodontic files for clinical use is to insert them into synthetic sponges . The files are sterilized in the sponge, and the sponge is then used on the patient tray for ease of file retrieval . The ability to sterilize the files in a sponge has been questioned . The purpose of the present investigation was to evaluate the sterility of files and spore strips following autoclaving in a sponge . Commercial spore strips and contaminated endodontic files were inserted into sponges, sealed in sterilization pouches and autoclaved . The spore strips and the files were removed from the sponge and cultured for growth of microorganisms . Results show that no microbes were cultured from spore strips or contaminated files after autoclaving them in the sponges sealed in autoclave pouches . These results indicate that the insertion of files into the sponges used in this study does not obstruct the autoclaving process. Appl Environ Microbiol, 1994 Oct, 60(10), 3640 - 6 Degradation of methyl bromide by methanotrophic bacteria in cell suspensions and soils; Oremland RS et al.; Cell suspensions of Methylococcus capsulatus mineralized methyl bromide (MeBr), as evidence by its removal from the gas phase, the quantitative recovery of Br- in the spent medium, and the production of 14CO2 from {14C}MeBr . Methyl fluoride fluoride (MeF) inhibited oxidation of methane as well as that of {14C}MeBr . The rate of MeBr consumption by cells varied inversely with the supply of methane, which suggested a competitive relationship between these two substrates . However, MeBr did not support growth of the methanotroph . In soils exposed to high levels (10,000 ppm) of MeBr, methane oxidation was completely inhibited . At this concentration, MeBr removal rates were equivalent in killed and live controls, which indicated a chemical rather than biological removal reaction . At lower concentration (1,000 ppm) of MeBr, methanotrophs were active and MeBr consumption rates were 10-fold higher in live controls than in killed controls . Soils exposed to trace levels (10 ppm) of MeBr demonstrated complete consumption within 5 h of incubation, while controls inhibited with MeF or incubated without O2 had 50% lower removal rates . Aerobic soils oxidized {14C}MeBr to 14CO2, and MeF inhibited oxidation by 72% . Field experiments demonstrated slightly lower MeBr removal rates in chambers containing MeF than in chambers lacking MeF . Collectively, these results show that soil methanotrophic bacteria, as well as other microbes, can degrade MeBr present in the environment. J Cell Sci, 1994 Oct, 107 ( Pt 10), 2861 - 73 Dinoflagellates have a eukaryotic nuclear matrix with lamin-like proteins and topoisomerase II; Minguez A et al.; Unicellular Dinoflagellates represent the only eukaryotic Phylum lacking histones and nucleosomes . To investigate whether Dinoflagellates do have a nuclear matrix that would modulate the supramolecular organization of their non-nucleosomal DNA and chromosomes, cells of the free-living unarmored Dinoflagellate Amphidinium carterae were encapsulated in agarose microbeads and submitted to sequential extraction with non-ionic detergents, nucleases and 2 M NaCl . Our results demonstrate that this species has a residual nuclear matrix similar to that of vertebrates and higher plants . The cytoskeleton-nuclear matrix complex of A . carterae shows a relatively intricate polypeptide pattern . Immunoblots with different antibodies reveal several intermediate filament types of proteins, one of which is immunologically related to vertebrate lamins, confirming that these proteins are ancestral members of the IF family, which is highly conserved in eukaryotes . A topoisomerase II homologue has also been identified in the nuclear matrix, suggesting that these structures could play a role in organizing the Dinoflagellate DNA in loop domains . Taken together our results demonstrate that the nuclear matrix is an early acquisition of the eukaryotic nucleus, independent of histones and nucleosomes in such a way that the mechanisms controlling the two levels of organization in eukaryotic chromatin would be molecularly and evolutionarily independent. Transfus Med Rev, 1994 Oct, 8(4), 253 - 66 Transfusion-related transmissible diseases: detection by polymerase chain reaction-amplified genes of the microbial agents; Vyas GN et al.; The detection of blood-borne microbes by PCR has broadly and rapidly progressed in the past 5 years as briefly described in this article . This progress has been largely because of the scientific developments made at Roche Molecular Systems by Sninsky et al through collaborations with academic and Government institutions . This unprecedented cooperation propels the continuing work at Roche Molecular Systems to bring the PCR technology into routine laboratory diagnosis . Whether the success of EIA in virtual elimination of hepatitis and retroviral infections can be matched by the cost-effectiveness of putative application of PCR in screening blood supply remains to be determined. J Biomed Mater Res, 1994 Oct, 28(10), 1201 - 7 Strategy for developing microbeads applicable to islet xenotransplantation into a spontaneous diabetic NOD mouse; Iwata H et al.; A bioartificial pancreas (BAP) created through the encapsulation of islets of Langerhans (islets) in a semipermeable membrane has been proposed as a promising approach to treating insulin-dependent diabetes patients . A nonobese diabetic (NOD) mouse, which shares many features of human insulin-dependent diabetes mellitus, is an ideal model for evaluating the function of BAP . However, the functions of BAPs that have been developed have been limited in NOD mice . We propose novel microbeads that can realize long-term BAP function in NOD mice . The novel microbeads were composed of agarose and poly(styrene sulfonic acid) (PSSa) mixed gel . A polyion complex layer between PSSa and polycationic polybrene was formed on and just inside the microbead, and the microbead surfaces were further covered by polyanions to produce anionic surface charges . The islets in the novel microbeads were intraperitoneally implanted . Graft-functioning periods were dependent on both PSSa concentration and the kinds of polyanion . Islets in the microbeads composed of 5% agarose and 5% PSSa, which had an outermost surface covered by carboxymethyl cellulose, produced normoglycemic periods of more than 60 days in all five recipients . Control mice receiving either transplants of unenclosed islets or islets in agarose microbeads showed normoglycemic periods of less than 12 days . We believe that agarose/PSSa microbeads are promising for producing semipermeable membranes that enable xenotransplantation of islets in spontaneous diabetes mellitus. Pacing Clin Electrophysiol, 1994 Oct, 17(10), 1603 - 9 A closed-chest pig model of sustained ventricular tachycardia; Eldar M et al.; The goal of this study was to develop and explore a closed-chest animal model of sustained VT . Seven of 11 domestic pigs had successful induction of myocardial infarction by injection of agarose gel microbeads into the left anterior descending coronary artery through an inflated balloon angioplasty catheter . Four of the first five pigs died and seem to represent a "learning experience." During a 3- to 50-day follow-up period, each pig underwent 1-3 electrophysiological studies . Sustained, monomorphic VT was induced 1-4 times in 5 of the 7 pigs (a total of 19 episodes), was reproducible during the same study in all pigs, and could be repetitively induced during successive studies in some . Ventricular fibrillation was induced less frequently (nine episodes) and was successfully terminated by DC shock in eight episodes . We conclude that a closed-chest pig model of VT is feasible and is associated with a relatively high induction rate of sustained, monomorphic, and reproducible VT and a relatively low mortality rate. Immunobiology, 1994 Oct, 191(4-5), 402 - 12 Respiratory host defenses--surface immunity; Reynolds HY; The mucosal surface of the respiratory tract has an operable immune system, specially designed for producing immunoglobulins (antibodies); however, it has not been harnessed effectively yet to provide local, immunospecific protection against many microbes that enter . Respiratory host responses in humans have been used in this review where possible . New research approaches seem necessary to manipulate the physical and immunologic barriers in the respiratory tract and this may require different antigen preparations, better and more specific vehicles for delivery and selective enhancement of cytokines and interleukins in the mucosa . The immunologic tools are available and need to be explored more in the human model. Development, 1994 Oct, 120(10), 2869 - 77 Fate mapping of the silkworm, Bombyx mori, using localized UV irradiation of the egg at fertilization; Myohara M; Bombyx eggs at the fertilization stage (0-2 hours after oviposition) were irradiated with a scanning UV-laser microbeam (355 nm) over an area of about 1% of the total egg surface . In spite of absence of nuclei or cells at the irradiated sites, larvae from treated eggs showed localized cuticle defects in the integument . The location and frequency of the defects within the cuticular pattern correlated closely to the site of irradiation both in the anteroposterior and the dorsoventral direction . Based on the correlation, presumptive regions for each larval segment were located and a fate map of the Bombyx egg was established. FEMS Microbiol Rev, 1994 Oct, 15(2-3), 155 - 73 Bacterial phylogeny based on 16S and 23S rRNA sequence analysis; Ludwig W et al.; Molecular phylogeny increasingly supports the understanding of organismal relationships and provides the basis for the classification of microorganisms according to their natural affiliations . Comparative sequence analysis of ribosomal RNAs or the corresponding genes currently is the most widely used approach for the reconstruction of microbial phylogeny . The highly and less conserved primary and higher order structure elements of rRNAs document the history of microbial evolution and are informative for definite phylogenetic levels . An optimal alignment of the primary structures and a careful data selection are prerequisites for reliable phylogenetic conclusions . rRNA based phylogenetic trees can be reconstructed and the significance of their topologies evaluated by applying distance, maximum parsimony and maximum likelihood methods of phylogeny inference in comparison, and by fortuitous or directed resampling of the data set . Phylogenetic trees based on almost equivalent data sets of bacterial 23S and 16S rRNAs are in good agreement and their overall topologies are supported by alternative phylogenetic markers such as elongation factors and ATPase subunits . Besides their phylogenetic information content, the differently conserved primary structure regions of rRNAs provide target sites for specific hybridization probes which have been proven to be powerful tools for the identification of microbes on the basis of their phylogenetic relationships. J Cell Biol, 1994 Oct, 127(2), 537 - 46 Inhibition of anchorage-dependent cell spreading triggers apoptosis in cultured human endothelial cells; Re F et al.; When cultivated on substrates that prevent cell adhesion (the polymer polyhydroxyethylmethacrylate, bovine serum albumin, and Teflon), human endothelial cells (EC) rapidly lost viability with a half-life of approximately 10 h . Dying EC showed the morphological and biochemical characteristics of apoptosis . The apoptotic process of suspended EC was delayed by the protein synthesis inhibitor cycloheximide . To obtain information as to the mechanism involved in the apoptosis of suspended EC, we investigated whether adhesion to matrix proteins or integrin occupancy in EC retaining a round shape may affect EC suicide . EC bound to low coating concentration of either fibronectin or vitronectin, retaining a round shape and failing to organize actin microfilaments, underwent to rapid cell death; by contrast, cells on high substrate concentrations became flattened, showed actin microfilament organization, and retained viability . Addition of saturating amounts of soluble vitronectin to suspended round-shaped EC did not reduce the process of apoptosis . Finally, when suspended EC bound Gly-Arg-Gly-Asp-Ser-coated microbeads (approximately 10 microbeads/cell), yet retaining a round shape, the apoptotic process was not affected . Oncogene-transformed EC in suspension were less susceptible to cell death and apoptosis than normal EC . Overall, these data indicate that cell attachment to matrix or integrin binding per se is not sufficient for maintaining cell viability, and that cells need to undergo some minimal degree of shape change to survive . Modulation of interaction with the extracellular matrix can, therefore, be an important target for the control of angiogenesis. J Biotechnol, 1994 Sep 30, 37(2), 89 - 108 The search for novel microbial fine chemicals, agrochemicals and biopharmaceuticals; Vandamme EJ; An ever-increasing number of fine chemicals and enzymes is now produced based on microbial biotechnology . Microbial products generally display desired chirality, are biodegradable and are produced from renewable (agro)-substrates . Bioconversion reactions, based on the use of (immobilised) biocatalysts (cell or enzymes), yield interesting regio- and enantioselective molecules under mild reaction conditions, starting from racemic precursors . Furthermore these bioprocesses have a positive environmental impact . Ingenious screening procedures for novel microbial primary and secondary metabolites, bioactive peptides, proteins and enzymes reveal that only the tip of the iceberg has been explored . Examples of such novel microbial products pertain to enzymes, enzyme-inhibitors, biopolysaccharides, bio-plastics, bioactive peptides, bacteriocins, targeted toxins, alkaloids, steroids, immunomodulators, vaccines, antibiotics and lantibiotics, biopesticides, vitamins and related growth factors, amino acids and specialty sugars, polyols and organic acids, biomagnets, bioflavours and biopigments . Several trends are discussed which are now in vogue to detect novel useful compounds from microbes . Examples are given of those microbial metabolites and enzymes, which have attracted industrial interest. J Neurosci, 1994 Sep, 14(9), 5694 - 707 Afferents to the midline thalamus issue collaterals to the nucleus tractus solitarii: an anatomical basis for thalamic and visceral reflex integration; Otake K et al.; The goal of this study was to establish a structural basis for thalamic and visceral integration . We sought to define neural networks that convey visceral or integrated environmental stimuli to the diffuse thalamocortical relay system and that link periodic changes in forebrain and visceral reflex function . Our experiments were designed to determine whether afferents to the midline-intralaminar thalamic nuclei (MIT) issue collaterals to the general viscerosensory division of the nucleus tractus solitarii (NTS) . Experiments were performed on anesthetized male Sprague-Dawley rats . Two tracers, FluoroGold and rhodamine latex microbeads, were stereotaxically centered on the MIT and NTS, respectively, in each animal . Subsets of midline thalamic afferents were identified that issue collaterals to the solitary complex . In the cerebral cortex, dually labeled soma were detected in layer V of the insular and infralimbic areas . In the subcortical forebrain, the lateral septal nucleus, anterolateral area of the bed nuclei of stria terminalis, medial preoptic nucleus, medial and central amygdaloid nuclei, caudal lateral hypothalamic area, supramammillary nucleus, and parvicellular division of the paraventricular hypothalamic nucleus constitute other newly identified sources of collateral projection . In the midbrain and pons, collateral projection cells were observed in the periaqueductal gray, dorsal raphe nucleus, mesencephalic reticular formation, laterodorsal tegmental nucleus, lateral and medial parabrachial nuclei, and noradrenergic A5 area . In the lateral parabrachial nucleus, dually labeled neurons were detected in the dorsal-lateral division . In the medulla, collaterals are derived from cells in the rostral and caudal ventrolateral reticular formation and parapyramidal area . Dually labeled cells were also found in the cerebellar fastigial nucleus . Collaterals may coordinate changes in visceral reflex excitability and thalamocortical rhythms during phases of sleep-wake cycle and behavioral expression. Cytometry, 1994 Sep 1, 17(1), 75 - 83 Flow cytometric detection and quantitation of the epidermal growth factor receptor in comparison to Scatchard analysis in human bladder carcinoma cell lines; Brockhoff G et al.; The epidermal growth factor receptor (EGFR) is considered a tumor-related marker with potential diagnostic and prognostic value . In order to assess the sensitivity of flow cytometry to detect EGFR and to quantify receptors objectively, two human bladder carcinoma cell lines with different urothelial differentiation, RT4 and J82, were grown in vitro, and their membrane EGFR content was measured by flow cytometry . Exponential monolayers showed decrease of EGFR content after 20 min pulses with 10 ng/ml EGF in medium, as detected with the antibody EGFR1 in a double staining technique with propidium iodide for DNA evaluation . Further decrease of green fluorescence intensity was seen in cells constantly exposed to EGF . Absolute receptor numbers were determined by Scatchard analysis with radioactive EGF and resulted in relatively low receptor numbers for both cell lines (approximately 3-4 x 10(4) EGFR/cell), as well as one affinity class . These findings could be matched by absolute receptor quantification by flow cytometry, adding beads with defined antigenic sites (Quantum Simply Cellular, Microbead Corporation) to the cell suspension for staining . Our data suggest that flow cytometric EGFR detection and quantitation may be supplied to in vivo tumor samples and that measurements by multiparameter analysis may define subpopulations valuable for tumor diagnosis and judgment on tumor progression. Clin Obstet Gynecol, 1994 Sep, 37(3), 722 - 9 Microbiology relevant to recurrent miscarriage; Summers PR; The best evidence suggests that infection is an occasional cause of sporadic spontaneous abortion, and, consistent with statistical probability, recurrent miscarriage due to infection occurs with a frequency that is much lower . In the medical literature, the limited evidence linking infection and recurrent pregnancy loss in humans remains largely anecdotal and generally cannot be reproduced in prospective studies . This observation reflects the low frequency with which the necessary microbial and maternal factors combine to cause recurrent miscarriage . The patient's susceptibility to chronic infection must play a determining role in some of the reported cases . Susceptibility factors that allow severe chronic infection, such as immunocompromise, are rare in the general infertility population and may remain unrecognized in broad cumulative studies . Probable factors that play a role in the risk of abortion due to infection are the following: 1 . Primary exposure during early gestation 2 . The capability of the organism to cause placental infection 3 . The development of an infectious carrier state 4 . Immunocompromise caused by immunosuppressants, chemotherapy, corticosteroids, or acquired immune deficiency syndrome . Exposure to a microbe that can establish chronic infection that can spread to the placenta in an immunocompromised patient is probably the most obvious risk situation for habitual abortion . In routine medical practice, it is not necessary or efficient to screen universally for the unexpected, but it is necessary to be aware of the rare possibilities . Most patients with a history of recurrent miscarriage will not benefit from an extensive infection workup . All patients should first be categorized according to their own personal risk infection, as outlined in Table 2.(ABSTRACT TRUNCATED AT 250 WORDS) Mikrobiol Z, 1994 Sep-Oct, 56(5), 39 - 51 {The lectins of Mollicutes}; Skrypal' IH et al.; Lectine-carbohydrate interactions take the fundamental part in the intercellular relations as well as in microbes pathogenicity . Pathogenic Mollicutes are characterized by the firm adhesion to the cells of the affected organs of people, animals, insects and plants . Proteins which are localized on the external side of the mollicute membrane and interact with carbohydrate residues on the surface of mucous membranes of the damaged organs and vice versa take part in the adhesion . High degree of specificity of protein-carbohydrate interactions determines the pathogenic specializations to the cells of one or another organ of the host . Since proteins which take part in the mollicutes adhesion are rich in proline and hydrophobic fields it is not excluded that the adhesion processes are combined with hydrophobic interrelations between the cells of the pathogen and host . Substances from the cells of Mollicutes which completely correspond to the definition "lectin", i.e., are in a pure form, the carbohydrate-binding proteins specific to certain carbohydrate residues are not still isolated . Thus the mollicute lectines should be called lectine-like substances rather than lectines . Mollicutes form a lot of such substances and they may be separated into the extracellular (soluble) substances which are found outside the cell of the nutritious medium; intermediate (half-soluble) substances detected in the nutritious medium and in the state integrate into the microorganism membrane, and membrane-related (insoluble) substances which occur only in the state rigidly adhered to the membrane . Carbohydrate composition of lectine-like substances in different mollicutes is different which is the reflection of heterogenicity of the Mollicutes class representatives. J Biomed Mater Res, 1994 Sep, 28(9), 1003 - 11 Feasibility of agarose microbeads with xenogeneic islets as a bioartificial pancreas; Iwata H et al.; A bioartificial pancreas, that is, transplantation of islets of Langerhans (islets) which are enclosed in a semipermeable membrane, has been proposed as a treatment for type I diabetes . The islets are immuno-isolated from the host by the semipermeable membrane preventing rejection while maintaining control of glucose metabolism for an extended period . The purpose of the current research is to evaluate the feasibility of preparing agarose microbeads with xenogeneic hamster islets as a bioartificial pancreas in streptozotocin induced diabetic mice . In the recipients with a low level of anti-hamster antibodies, the combination of encapsulation of hamster islets in 5% agarose microbeads and in vitro culture of them prolonged xenograft survivals . Four of 6 recipients were still normoglycemic at 100 days after implantation . However, the same procedure was not effective in the recipients which were sensitized in advance by transplantation of free hamster islets and thus had high levels of anti-hamster antibodies . The average normoglycemic period was 32 days . Antibodies permeated through the microbeads and activated complement on the cell surfaces . The network of agarose microbeads was rendered dense by increasing the concentration of agarose to restrict the diffusion of antibodies . Graft survivals were prolonged with increasing concentrations of agarose . As an analysis using diffusion equations predicted, the survivals were inversely proportional to the diffusion coefficient of IgG in each agarose gel . Islet xenotransplantation was enabled by the combination of the microbeads with a concentration of agarose higher than 7.5% and in vitro culture even in recipients having a high level of preformed antibodies. Contemp Pediatr, 1994 Sep, 11(9), 72 - 6, 80, 82 passim Bacterial resistance in the '90s; Lieberman JM; The lesson of the antibiotic era is, the microbe always wins . Pediatricians need to understand why, to take the threat seriously, and to mobilize to fight back. Am J Physiol, 1994 Aug, 267(2 Pt 1), G151 - 65 Integrative immunophysiology in the intestinal mucosa; Perdue MH et al.; Over the past ten years, it has become evident that intestinal epithelial functions such as ion secretion are a host defense response to the presence of antigens, microbes, and other noxious substances in the gut lumen . Such responses are mediated by the activation of immune cells in the mucosa causing release of chemical mediators that act directly or indirectly on the epithelium . Frequently, immune cell products stimulate enteric nerves resulting in amplification . Thus immune cells and nerves form interactive units that can recognize various stimuli both specifically and nonspecifically and initiate mechanisms to eliminate offending material . Here, we review the current state of knowledge regarding immune regulation of epithelial physiology with particular emphasis on the ability of immune cells and their products (biogenic amines, cytokines, arachidonic acid metabolites, oxidants) to alter electrolyte transport . The mast cell will be highlighted in this scheme as this cell has been, and continues to be, the focus of extensive research efforts . However, recently it has become apparent that cells such as lymphocytes, macrophages, and polymorphonuclear leukocytes also play important roles in immunophysiology . The effect of immune cell activation on epithelial functions other than transport, such as permeability, proliferation, and antigen presentation, will be described where appropriate . Finally, we will present evidence that the enterocyte can express an "activated" phenotype and thus participate directly in mucosal immune responses. J Nutr, 1994 Aug, 124(8 Suppl), 1372S - 1376G Regulation of lipid metabolism in the rumen; Jenkins TC; Lipid added to animal diets can affect productive efficiency through a combination of caloric and regulatory effects . Any attempt to improve productive efficiency of ruminants by modifying the amount or composition of lipid added to the diet must take into account ruminal metabolism of lipids . The caloric value of lipid is changed little as it passes through the rumen, but the greater concern is the possible negative effect of lipid on the energy value of the basal diet . Limiting unsaturated fatty acids fed to ruminants to just a few percent of the diet to avoid digestive disturbances, combined with extensive hydrogenation by ruminal microbes, maintains only small quantities of unsaturated fatty acids in duodenal contents . However, in some studies, lipid added to ruminant diets has invoked metabolic changes that were not attributable to caloric effects . These metabolic changes suggest that the rumen does not maintain digesta flow with constant lipid composition in all circumstances . Variations in rumen outflow of biohydrogenation intermediates and microbial lipids are as great, or greater in some situations, than unsaturated fatty acids . Diet characteristics, such as amount of grain or unsaturated lipid, can substantially alter the nature of fatty acids absorbed from the duodenum and deposited in animal tissues. J Infect Dis, 1994 Aug, 170(2), 265 - 71 Dynamics of emergence; Krause RM; I have touched briefly here on the complex matrix of social, economic, political, and ecologic factors that have played a major role in the emergence of microbial diseases . But beyond these factors that contribute to the emergence of new infectious diseases, we must also recognize changes in microbial agents, human populations, insect vectors, and the ecologic relationships among them . Microbes and vectors swim in the evolutionary stream and they swim much faster than we do . Bacteria reproduce every 30 min; for them a millennium is compressed into a fortnight . Microbes were here, learning every trick for survival, 2 billion years before humans arrived, and it is likely that they will be here 2 billion years after we depart . Furthermore, science cannot halt the future occurrence of new microbes, which emerge from the evolutionary stream as a consequence of genetic events and selective pressures that favor the new over the old . It is nature's way . For all of these reasons, old and new infections will occur in the future as they have in the past . Surveillance efforts, both in the United States and other regions of the world, will be needed to blunt the emergence of such infections and to forestall epidemics and pandemics . But surveillance alone cannot detect the unexpected emergence of future microbes or prepare the defense against them . That will require a broadly based research effort to devise new methods of diagnosis, treatment, and prevention . We must swim with the microbes and study their survival and adaptation to new habitats.(ABSTRACT TRUNCATED AT 250 WORDS) Virology, 1994 Aug 1, 202(2), 530 - 9 Identification of novel herpes simplex virus replicative intermediates by field inversion gel electrophoresis: implications for viral DNA amplification strategies; Zhang X et al.; Many facets of herpes simplex virus (HSV) DNA replication are not understood and advances in our knowledge depend on accurate characterization of high-molecular-weight replicative intermediates . In the present work, we have used a refinement of field-inversion gel electrophoresis (FIGE) to analyze infected-cell DNA . Infected Vero cells were encapsulated and manipulated in agarose microbeads, allowing intact replicative intermediates to be recovered easily from the wells of FIGE gels after electrophoretic removal of 152-kb linear viral genomes . Digestion of replicative intermediates with SpeI, which cuts the viral genome once, generated two novel DNA fragments (186 and 118 kb), in addition to the expected unit-length fragment (152 kb) predicted to arise from head to tail concatemers generated by rolling-circle replication . The SpeI fragments are the products of previously unidentified concatemers containing a head to tail arrangement of different HSV isomers, with respect to the orientation of the long segment of the viral genome . Such concatemers were prominent at an early stage of DNA synthesis when replicating DNA appeared still to be in a circular configuration, raising the possibility that isomerization of the viral genome is intimately linked to the initial round of DNA replication . Moreover, high-molecular-weight replicative intermediates were flanked exclusively by the long segment of the viral genome, indicating a unique initiation/termination or cleavage/packaging mechanism during HSV DNA replication and viral maturation. Indian J Biochem Biophys, 1994 Aug, 31(4), 267 - 79 Role of alkali cations (K+ and Na+) in cyanobacterial nitrogen fixation and adaptation to salinity and osmotic stress; Apte SK et al.; Cyanobacteria occupy almost every possible ecological niche on earth, being tolerant to a large number of environmental stresses, including salinity and drought . Many of them also fix atmospheric nitrogen . They are responsible for a significant share of biosolar energy conversions on this planet and make substantial contributions to the carbon and nitrogen status of both oceans and soils . Sodium and potassium are two of the most prevalent cations on this planet . While K+ is an essential macronutrient in most life-forms, Na+ is strongly discriminated by means of highly selective alkali cation transport systems, favouring K+ over Na+ . Although a nutritional requirement for K+ has not been specifically investigated, rapid accumulation of K+ during salt/osmotic stress has been observed in several cyanobacteria . Genes and proteins constituting a membrane-bound, turgor- and osmo-inducible, Kdp-ATPase-like system in Anabaena strains that may help in their early K+ responses to salt/osmotic stress have been identified . An unusual, specific and absolute requirement for trace quantities of sodium has been documented in cyanobacteria . Work done in our laboratory, and elsewhere, has elucidated the mechanisms underlying such a unique requirement . It has long been believed that cyanobacteria scavenge and immobilise sodium . We have, however, shown that sodium exclusion brought about by curtailment of influx and active efflux of Na+ forms the basis of salt tolerance in these microbes and that the inherent salt tolerance can be modified by factors that modulate Na+ fluxes in cyanobacteria . Identification of genes affecting the cation relationships in nitrogen-fixing cyanobacteria is currently in progress. Physiol Meas, 1994 Aug, 15(3), 261 - 70 Design and evaluation of a fibre-optic sensor for limb blood flow measurements; Stenow EN et al.; A fibre-optic microbending sensor for clinical use in venous occlusion plethysmography (VOP) has been developed . The sensor utilizes the microbending principle to detect the volume expansion of a limb following venous occlusion . This principle is based on the loss of energy in an optical fibre that undergoes mechanical perturbations . A comparative study of 10 healthy subjects has been made between the new fibre-optic sensor and a mercury strain-gauge sensor . Each subject's limb blood flow was recorded 10 times . The two sensor types were positioned closely together on the same limb . The result of the study shows a high correlation (r = 0.949) verifying that the fibre-optic sensor's performance makes it a suitable alternative to the mercury strain-gauge sensor. Nippon Rinsho, 1994 Aug, 52(8), 1982 - 6 {Animal models for intractable vasculitis: significance of genetic background}; Ito MR et al.; Almost all of intractable vasculitis have been thought to develop mainly in immunological mechanisms, based on the data from several animal models previously established . Serum sickness models, microbe-induced models and others have contributed to supporting this idea . These models have furthermore indicated that vasculitis could be generated by exogenous factors in normal individuals, and that vasculitis might be explained in monism . However, recent studies in murine lupus suggest that intractable vasculitis requires endogenous factors involving retroviruses and/or genetic background under the control of polygene system . In this review, although not comprehensive, significance of background genes in vasculitis will be focused. Mikrobiol Z, 1994 Jul-Sep, 56(4), 25 - 9 {The effect of a vaccinal strain of the plague microbe on C3-receptor expression on the surfaces of peritoneal and alveolar macrophages}; Vasil'eva GI et al.; The work is devoted to the effect of vaccine strain of the plague microbe on the expression of C3-receptors (C3R) in interaction with macrophages in vitro and in vivo . It is established that the activation of macrophages accompanied by the increase of C3R expression on the external surface of the membrane of both peritoneal and alveolar macrophages occurs in the process of formation of antiplague immunity . Maximum activity of C3R in the both populations of macrophages is observed on the 7th day after vaccination . Immunization of the plague microbe by the vaccine strain does not change the character of response of peritoneal and alveolar macrophages to their interaction with this microorganism in vitro: a decrease of C3R expression on the surface of the both populations of cells obtained from both intact and immunized animals is observed . Heterogeneity of the studied populations as to C3R expression both in the intact and immune organism is detected. Curr Opin Rheumatol, 1994 Jul, 6(4), 360 - 70 Etiopathogenesis of ankylosing spondylitis and reactive arthritis; Inman RD et al.; In ankylosing spondylitis and reactive arthritis, an interplay of microbe and major histocompatibility complex initiates a sequence of events resulting in chronic inflammation . With the use of molecular probes as direct evidence and immune response patterns as indirect evidence, a strong case has been made for a central role of local microbial antigen in reactive arthritis . Cofactors such as gender, persistent gut inflammation, and antibiotic treatment may contribute to this process . Studies of transgenic rats and of familial spondylitis implicate B27 itself as the critical host variable . The results of recent studies point to intimate B27-bacteria interrelationships . HLA-B27 and proteins from enteric bacteria are structurally related, in a manner that may affect T cell response to enteric pathogens . B27 also may directly affect host-microbe interactions by modulating the invasive potential of these bacteria into target cells . Studies are in progress to apply the predictions of these in vitro systems to the in vivo situations of these diseases . The insights of research in the spondyloarthropathies may find broad applications in the rheumatic diseases. Scand J Immunol, 1994 Jul, 40(1), 57 - 63 IFN-gamma inhibits internalization of soluble aminated beta-1,3-D-glucan by macrophages and thereby down-regulates the glucan induced release of TNF-alpha and IL-1 beta; Konopski Z et al.; We have previously shown that soluble animated beta-1,3-D-glucan (AG) and glucan-derivatized microbeads (GDM) bind to the specific beta-glucan receptor on mouse peritoneal macrophages . Phagocytosis of GDM by macrophages is mediated through the beta-glucan receptor . IFN-gamma which increases macrophage phagocytic capacity, also increased the phagocytosis of GDM . In the present study we show that IFN-gamma inhibits internalization of AG in macrophages in a dose- and time-dependent manner . The inhibitory effect of IFN-gamma was neutralized by treatment of the macrophages with cycloheximide . These results were confirmed by confocal laser scanning microscopy which showed that IFN-gamma treated cells incorporated less fluorescein-labelled AG than did untreated cells . IFN-gamma did not change the macrophage-binding capacity for AG showing that the inhibitory effect of IFN-gamma is not caused by decreased number of beta-glucan receptors on the cells . The stimulatory effect of AG on IL-1 beta and TNF-alpha release from macrophages was reduced by pretreatment of the cells with IFN-gamma . We conclude that the uptake of AG and GDM in macrophages, both mediated through the beta-glucan receptor, are differently regulated by IFN-gamma . The reduced internalization of AG after IFN-gamma treatment of macrophages, is probably responsible for the down-regulation of IL-1 and TNF-alpha secretion. Exp Cell Res, 1994 Jul, 213(1), 308 - 12 Directed movement of chromosome arms and fragments in mitotic newt lung cells using optical scissors and optical tweezers; Liang H et al.; A pulsed-laser microbeam at 532 nm wavelength (optical scissors) and a laser-induced optical trap at 1064 nm wavelength (optical tweezers) have been successively combined to dissect and manipulate chromosomes in live newt lung epithelial cells . These preliminary experimental results demonstrated that chromosome fragments dissected by laser microbeam surgery, regardless of their size, could be easily pulled or rotated by optical forces when positioned at the periphery of the mitotic spindle . In addition, chromosome arms which were not subjected to laser microsurgery also could be moved with the optical tweezers at the spindle periphery . In our previous study on rat kangaroo kidney cells (PTK2), this degree of facilty in manipulating chromosome movement was not possible, most likely due to the close proximity of the intermediate filament "cage" to the spindle . It is concluded herein that optical scissors and tweezers can be used in combination to study the interaction of chromosomes with the mitotic spindle in cells where the peripheral regions of the spindle are unobstructed by intermediate filaments . This can be performed on newt cells, where the diameter of the cage can be substantially larger than the diameter of the spindle. Am J Epidemiol, 1994 Jul 1, 140(1), 1 - 11 Invited commentary--"molecular epidemiology": new pathway or new travelling companion? McMichael AJ. The term "molecular epidemiology" is coming into general usage, but its implications are ambiguous . A simple definition is that it entails the inclusion in epidemiologic research of biologic measurements made at the molecular level--and is thus an extension of the increasing use of biologically based measures in epidemiologic research . "Molecular epidemiologic" measurements typically detect damaged or naturally variant molecular structures, or use immunologically based techniques to detect particular gene-product molecules . (In contrast, the measurement of biochemical concentration, such as of plasma estrogens, does not require information about molecular structure.) Molecular techniques can be used to measure exposure, early biologic response, or host characteristics that influence susceptibility . They may also elucidate mediating biologic events, and may enable differentiation of adverse health outcomes . Molecular biomarkers have been applied particularly in cancer epidemiology, to measure DNA damage, heritable genetic polymorphisms that influence susceptibility, and "cancer family" genes . Infectious disease epidemiologists use molecular measures of genetic strains of microbes, and they and cancer epidemiologists measure viral nucleic acids within host cells . The term "molecular epidemiology" may suggest the existence of a subdiscipline with substantive new research content . Molecular techniques, however, are directed principally at enhancing the measurement of exposure, effect, or susceptibility, and not at formulating new etiologic hypotheses . As techniques of refinement and elaboration, the integration of molecular measures into mainstream epidemiologic research can offer higher resolution answers in relation to disease causation. Immunol Lett, 1994 Jul, 41(2-3), 241 - 7 Inhibition of natural killer cell activity by dietary lipids; Yaqoob P et al.; Natural killer (NK) cells are a subset of cytotoxic lymphocytes found mainly in blood and the spleen . NK cells play a role in natural immunity to microbes, viruses and tumor cells and are involved in the rejection of grafts . The present study investigated the effects of diets containing oils rich in saturated fatty acids, mono-unsaturated fatty acids, n-6-poly-unsaturated fatty acids (PUFA) or n-3-PUFA on the NK cell activity and on the lymphokine-activated killer (LAK) cell activity of rat spleen lymphocytes . Weanling rats were fed for 10 weeks on a low-fat (LF) diet (approximately 2% fat by weight) or on 1 of 5 high-fat (HF) diets, which contained 20% (by weight) hydrogenated coconut oil (HCO), olive oil (OO), safflower oil (SO), evening primrose oil (EPO) or menhaden (fish) oil (MO) . Each of the HF diets suppressed the NK activity of freshly prepared spleen lymphocytes compared with the LF diet; cells from the MO-fed rats exhibited the lowest NK activity . Culture with IFN alpha for 3 h increased the NK activity of spleen lymphocytes from all animals, except those fed the OO diet; the increase in NK activity varied from 20% (LF) to 50% (MO) . Although feeding the OO, EPO or MO diets resulted in lower IFN alpha-stimulated NK activity than that obtained by feeding the LF diet, the only consistent significant difference was the lower activity of the cells from the OO-fed rats compared with those from the LF-fed rats.(ABSTRACT TRUNCATED AT 250 WORDS) J Cell Sci, 1994 Jul, 107 ( Pt 7), 1745 - 52 Sites in human nuclei where DNA damaged by ultraviolet light is repaired: visualization and localization relative to the nucleoskeleton; Jackson DA et al.; The repair of damage induced in DNA by ultraviolet light involves excision of the damage and then repair synthesis to fill the gap . We investigated the sites of repair synthesis using MRC-5 fibroblasts and HeLa cells in G1 phase . Cells were encapsulated in agarose microbeads to protect them during manipulation, irradiated, incubated to allow repair to initiate, and permeabilized with streptolysin O to allow entry of labelled triphosphates; {32P}dTTP was incorporated into acid-insoluble material in a dose-dependent manner . Incubation with biotin-16-dUTP allowed sites of incorporation to be indirectly immunolabeled using a FITC-conjugated antibody; sites were not diffusely spread throughout nuclei but concentrated in discrete foci . This is similar to sites of S phase activity that are attached to an underlying nucleoskeleton . After treatment with an endonuclease, most repaired DNA electroeluted from beads with chromatin fragments; this was unlike nascent DNA made during S phase and suggests that repaired DNA is not as closely associated with the skeleton . However, the procedure destroyed repair activity, so repaired DNA might be attached in vivo through a polymerase that was removed electrophoretically . Therefore this approach cannot be used to determine decisively whether repair sites are associated with a skeleton in vivo. Antimicrob Agents Chemother, 1994 Jul, 38(7), 1620 - 7 Localization of azithromycin in Toxoplasma gondii-infected cells; Schwab JC et al.; Agents effective against intracellular pathogens must enter infected cells, crossing vacuolar membranes surrounding the organisms and then penetrating into the microbe and localizing to the microbial target site . We have characterized these parameters for azithromycin entry into Toxoplasma gondii-infected Chinese hamster ovary cells and murine macrophage-like J774 cells . Azithromycin uptake into infected host cells was concentrative and was dependent upon proton gradients . Subcellular fractionation of azithromycin-loaded infected CHO cells demonstrated > 95% intracellular drug in host cell lysosomes and cytosol, with < 5% associated with the parasite . Uptake of azithromycin into the T . gondii vacuole increased if parasites were coated with antibody prior to internalization by murine J774 cells, conditions which result in the formation of acidified phagolysosomes . No redistribution or retention of azithromycin in the parasite was observed when drug efflux from antibiotic-loaded infected CHO cells was monitored . Azithromycin entry into extracellular T . gondii was concentrative, was temperature and pH dependent, and was not different when azithromycin-sensitive and -resistant parasites were compared . These results demonstrate that azithromycin concentrates primarily in acidified compartments in parasites and host cells . The high concentration of azithromycin within these compartments may not be biologically relevant to inhibition of intracellular parasite growth by this agent. Clin Exp Dermatol, 1994 Jul, 19(4), 327 - 9 Chronic verrucous varicella-zoster infection in a patient with AIDS; Vaughan Jones SA et al.; The expression of herpes varicella zoster virus in patients already infected with the human immunodeficiency virus (HIV) provides the perfect illustration of an opportunist microbe at work . There is an increased incidence of herpes zoster which may be more severe, recurrent or disseminated . Likewise, varicella may be more severe and recurrent . In both patterns of infection atypical lesions in the form of persistent ulcerative or verrucous lesions have been seen . An HIV-positive patient is described who developed verrucous lesions de novo, 4 months after her child had varicella. Biotechniques, 1994 Jul, 17(1), 82, 84, 86 - 7 Primers are decisive for sensitivity of PCR; He Q et al.; A sufficient sensitivity of PCR is a prerequisite for its use in the diagnosis of infectious diseases . We have used PCR for detecting gene elements of Borrelia burgdorferi, mycobacteria and Bordetella pertussis . With all these microbe groups, difficulties were encountered in achieving the demanded sensitivity with the primer pairs primarily selected . An extensive testing of various reaction parameters did not improve the sensitivity . Subsequently, we synthesized more primers derived from slightly different positions of the original target sequences . When the original and new primers were tested in possible combinations, some primer pairs reached 100-fold to 1000-fold higher sensitivity than the primary pairs . We conclude that in optimizing the sensitivity of PCR, more emphasis should be put on testing of several primer pairs than on the extensive screening of reaction parameters . Thus far, a trial-and-error approach has to be used, because there is no means to predict the sensitivity properties of a selected primer pair. Antibiot Khimioter, 1994 Jul, 39(7), 20 - 3 {Beta-lactam antibiotics (ampicillin, cefotaxime) in prevention of experimental plague in albino mice, caused by non-fractioned strains of the pathogen}; Samokhodkina ED et al.; The prophylactic action of betalactam antibiotics such as ampicillin and cefotaxime in plague was studied on albino mice infected subcutaneously by Fra+ (Y . pestis 231) and Fra- (Y . pestis 231 Fra-, K-16) variants of the plague microbe . Ampicillin, a semisynthetic penicillin, was prophylactically less active in experimental plague infection induced by the fraction I defect forms of Y . pestis . Cefotaxime, a 3rd generation cephalosporin, was active in experimental plague induced by both the type and the fraction-free strains of Y . pestis. Sci Total Environ, 1994 Jun 6, 148(2-3), 157 - 66 Nickel enzymes in microbes; Hausinger RP; Four microbial enzymes are known to require nickel: hydrogenase, methyl coenzyme M reductase, carbon monoxide dehydrogenase, and urease . Recent biochemical and molecular biological experiments have provided clear evidence for the existence of multiple auxiliary genes that facilitate nickel incorporation into urease and hydrogenase . Similarly, accessory factors are also likely to be required for the other two enzymes . One of the urease-related genes (ureE) encodes a cytoplasmic protein that has been purified and shown to bind nickel reversibly . We propose that the UreE protein serves as a nickel donor to urease apoprotein . A second urease-related auxiliary gene (ureG) possesses a sequence motif that is found in ATP- and GTP-binding proteins . We have shown that nickel incorporation into urease requires energy and speculate that the UreG protein may serve as an energy transducer, coupling the energy of NTP hydrolysis to metallocenter incorporation . The UreG protein is related in sequence to HypB, a protein that has been proposed to function in nickel processing in hydrogenases . Hence, the mechanisms for metallocenter biosynthesis in these two dissimilar enzymes may have evolved from a common nickel incorporation system. J Neurosci, 1994 Jun, 14(6), 3437 - 48 Calcium wave fronts that cross gap junctions may signal neuronal death during development; Wolszon LR et al.; Embryonic anterior pagoda (AP) neurons in the leech interact with their segmental homologs in adjacent ganglia through transient axons that overlap during a critical period of development and then retract . However, when an AP neuron is ablated mechanically or by irradiation during this period, an adjacent homolog responds by reinitiating growth of its overlapped axon and thereby taking over vacated territory (Gao and Macagno, 1987b; Gao, 1989) . The death of an AP cell is therefore communicated to its homolog, but the mechanism underlying this signaling is presently unknown . Since it was recently found that AP homologs are electrically and dye coupled through their transient axons (Wolszon et al., 1994), we investigated the possibility that gap junctions may mediate the cell death signal that could occur between developing neurons . Among several candidate intercellular signals, we began by studying calcium dynamics in embryonic AP cells, in situ, since calcium is known to cross gap junctions and is implicated in cell death in many systems . We found that elements that usually increase {Ca2+}i in adult neurons, such as releasable internal stores or voltage-dependent calcium channels, were not present at the critical period . Instead, mechanisms that reduce free calcium, such as buffering and pumping, were the most robust . When a large, focal calcium rise was produced in an AP axon by making a lesion with a UV microbeam (leading to eventual death of these neurons), calcium did not rise quickly throughout the cell, but rather moved in a slow (0.05-0.25 micron/sec) wave front away from the lesion site, into other processes of the damaged cell . Furthermore, when a calcium wave front reached the growth cone of a transient axon, it crossed at the gap junctions into the coupled axon of the neighboring AP neuron, but went no further . Since it is known that an AP responds to a neighbor's death by reinitiating growth only in that axon that contacts the dying cell (Gao and Macagno, 1987b; Gao, 1989), these observations are consistent with calcium playing a role in the signaling of cell death to homologs that are coupled to a dying cell. Int Immunol, 1994 Jun, 6(6), 873 - 80 Spontaneous proliferation of Peyer's patch cells in vitro; Hooper DC et al.; Under normal circumstances most lymphoid cell populations do not exhibit strong proliferative reactions in culture unless provoked by antigen or mitogen . The autologous mixed lymphocyte reaction (AMLR) mediated by adult T cells is a relatively weak proliferative response that occurs in the absence of known heterologous stimuli . In this investigation we demonstrate that Peyer's patch (PP) cells possess an inherent capacity to commence dividing in vitro and to display an exceptionally vigorous AMLR . The magnitude and kinetics of this spontaneous proliferation resemble that of a secondary response to a strong mucosal immunogen such as reovirus type 1/Lang . Analysis of the cellular components of the PP cultures implicates CD4+CD8- T cells as the major responding population and dendritic cells (DC) as stimulators . Mixing experiments indicate that spleen contains a cell population which can stimulate PP T cells, albeit to a lesser extent than PP cells . Similarly, splenic T cells have a reduced but significant capacity to respond to PP DC, in comparison to PP T cells . These differences suggest the possibility that there may be a decreasing gradient of antigenicity between the gut and the spleen which is reflected in the spontaneous activity of PP versus splenic T cells in vitro . We propose that PP cells are in fact responding in vitro to heterologous antigens derived from food, enteric microbes and other environmental sources . This notion is supported by the observation that PP cells from antigen-minimized germ-free mice fail to proliferate spontaneously in culture. J Nihon Univ Sch Dent, 1994 Jun, 36(2), 135 - 8 Basic properties of an alginate impression material supplemented with chlorhexidine . I . Disinfectant effects on oral microbes; Tanaka H et al.; To examine the disinfectant effects on oral microbes of an alginate impression material supplemented with 1% chlorhexidine as the aseptic ingredient (Coe Hydrophilic Gel, CHG), several cell suspensions of oral microbes (3 Gram-positives, 2 Gram-negatives and 1 yeast) were exposed to the surface of cast CHG or that of a control impression material for 5 or 30 min . They were then transferred to the surfaces of agar plates . Colony formation was estimated after culture for several incubation periods . No growth of bacteria on the plates was observed when the suspensions had been exposed to CHG even for 5 min, whereas for the control material, all the bacteria formed colonies . The yeast showed colony formation irrespective of the kind of impression material and the duration of exposure . Thus, it appears that use of an impression material supplemented with 1% chlorhexidine such as CHG may protect clinical staff and dental technicians from possible bacterial infections associated with the impression procedures. Biophys J, 1994 Jun, 66(6), 2181 - 9 Control of cytoskeletal mechanics by extracellular matrix, cell shape, and mechanical tension; Wang N et al.; We have investigated how extracellular matrix (ECM) alters the mechanical properties of the cytoskeleton (CSK) . Mechanical stresses were applied to integrin receptors on the apical surfaces of adherent endothelial cells using RGD-coated ferromagnetic microbeads (5.5-microns diameter) in conjunction with a magnetic twisting device . Increasing the number of basal cell-ECM contacts by raising the fibronectin (FN) coating density from 10 to 500 ng/cm2 promoted cell spreading by fivefold and increased CSK stiffness, apparent viscosity, and permanent deformation all by more than twofold, as measured in response to maximal stress (40 dyne/cm2) . When the applied stress was increased from 7 to 40 dyne/cm2, the stiffness and apparent viscosity of the CSK increased in parallel, although cell shape, ECM contacts, nor permanent deformation was altered . Application of the same stresses over a lower number ECM contacts using smaller beads (1.4-microns diameter) resulted in decreased CSK stiffness and apparent viscosity, confirming that this technique probes into the depth of the CSK and not just the cortical membrane . When magnetic measurements were carried out using cells whose membranes were disrupted and ATP stores depleted using saponin, CSK stiffness and apparent viscosity were found to rise by approximately 20%, whereas permanent deformation decreased by more than half . Addition of ATP (250 microM) under conditions that promote CSK tension generation in membrane-permeabilized cells resulted in decreases in CSK stiffness and apparent viscosity that could be detected within 2 min after ATP addition, before any measurable change in cell size.(ABSTRACT TRUNCATED AT 250 WORDS) Vet Hum Toxicol, 1994 Jun, 36(3), 240 - 7 A review of the functional and evolutionary roles of the liver in the detoxification of poisonous plants, with special reference to pyrrolizidine alkaloids; Cheeke PR; Coevolutionary relationships between herbivores and poisonous plants are described . Hepatic detoxification reactions (Phase I and Phase II) are discussed in the context of susceptibility and resistance to poisonous plants . Animal species differences in susceptibility to poisonous plants are discussed, with a comparison of liver vs rumen microbe detoxification pathways . It is concluded, especially with regard to pyrrolizidine alkaloids, that species differences are due to differences in hepatic metabolism rather than to rumen microbes . Linkages between hepatic detoxification abilities and feeding behavior are proposed, as an evolutionary strategy allowing animals resistant to particular toxins to evolve feeding responses to exploit food resources containing toxins to which the animal is resistant. Genitourin Med, 1994 Jun, 70(3), 215 - 7 The history of venereology in Norway; Fyrand O et al.; Syphilis became a problem at the beginning of the eighteenth century when a virulent microbe was brought to Norway . This new disease was called "radesyken", a Nordic name for "the wicked disease" . "Rade" hospitals were built and this was the beginning of the Norwegian hospital system . Professor Caesar Boeck refused to use mercury in the treatment of syphilis; 2000 of his patients were included in the Oslo study of untreated syphilis . With the use of penicillin and other antibiotics, syphilis and gonorrhoea decreased . More frequent now are the viral diseases, herpes genitalis and condylomata acuminata . HIV is seldom found in the STD clinic in Oslo: only 5-6 HIV-positive persons per year; that is, about 0.09% of all new patients. J Neurol Sci, 1994 Jun, 124(1), 3 - 14 The Soriano Award Lecture . Emerging infections of the nervous system; Johnson RT; The epidemic of acquired immunodeficiency disease {AIDS} has focused interest on the origins of "new" infectious agents . Great plagues are well known from the distant past, but a number of novel diseases affecting the nervous system infections have emerged in recent years . The causes of such new disorders are diverse: whereas rapid mutations of microbes allow the evolution of truly novel agents, the appearance of new diseases is more often due to changes in human or vector populations or changes in societal mores that result in dissemination of preexistent microbes . Examples of recently emerging infections that involve the nervous system include the enterovirus 70 epidemics with poliomyelitis-like disease, the appearance of California virus encephalitis in the midwestern United States, the rapid spread of Lyme disease with its many neurological complications in the eastern United States, and the outbreak of bovine spongiform encephalopathy in the United Kingdom, in addition to the devastating epidemic of human immunodeficiency virus (HIV), which will cause nervous system disease in over half of those infected . As the world population increases and modern transportation brings us closer into a "global village" more new agents will emerge and more will be sustained . Knowledge of the molecular biology and ecology of the agents and awareness of how our actions can alter their behavior are our best defense. Antibiot Khimioter, 1994 Jun, 39(6), 13 - 4 {Effectiveness of new quinolones in experimental aerogenic plague infection of albino mice}; Shcherbaniuk AI et al.; It was shown that unlike nalidixic acid the 3rd generation quinolones i.e . the nitrogen-containing quinolones (LIB-71 and LIB-80) and the fluorine-containing quinolones (pefloxacin and ciprofloxacin) were highly efficient in the prophylaxis and treatment of experimental plague in albino mice infected via the plague microbe inhalation . By the ED50 the efficacy of pefloxacin was 25-30 times higher than that of nalidixic acid and 60-90 times higher than that of ciprofloxacin . The fluorine-containing quinolones proved to be more active than the nitrogen-containing ones. Hua Xi Yi Ke Da Xue Xue Bao, 1994 Jun, 25(2), 134 - 7 {Study on phagocytosis of human neutrophils in diabetics}; Yu Y et al.; Infection is one of the most common complications in diabetes mellitus (DM) . The neutrophil plays an important role in the anti-infection mechanism . A comparative study on phagocytosis of P . Aeruginosa by human neutrophils in diabetic patients and healthy volunteers was carried out by means of the monolayer of neutrophils and ultrastructural observation in electronic microscopy . The results showed that the rates of phagocytosis, index of phagocytosis and rates of microbe lysis in DM group were much lower than those in normal controls (P < 0.01) . The ultrastructure of neutrophils in diabetic patients became apparently abnormal during the process of neutrophil phagocytosis . The results demonstrated that the impairment in phagocytosis of neutrophils may be one of the causes of severe and repeated infection in diabetics. J Cell Sci, 1994 Jun, 107 ( Pt 6), 1485 - 97 Concentration of pp125 focal adhesion kinase (FAK) at the myot