Microorganisms

Environ Health Perspect, 1991 Jun, 93, 175 - 9
Nonmutagenic mechanisms in carcinogenesis: role of protein kinase C in signal transduction and growth control; Weinstein IB; There is accumulating evidence that the multistage carcinogenic process is associated with the progressive acquisition of mutations in cellular proto-oncogenes and in growth-suppressor genes . At the same time, several types of evidence indicate that nongenotoxic agents and epigenetic events also play an important role in the evolution of tumors . One of the most intensively studied nongenotoxic agents is the phorbol ester tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and related compounds . Since TPA appears to exert its biologic effects through protein kinase C (PKC), a key enzyme in signal transduction, we have studied this enzyme in considerable detail . Our strategy has been to perturb signal transduction by developing cell lines that overexpress the beta 1 isoform of PKC . Such derivatives of rat fibroblasts display alterations in morphology and growth factors, altered expression of c-myc, ornithine decarboxylase, and phorbin, and increased susceptibility to transformation by certain oncogenes, H-ras, myc, and fos . These findings provide direct genetic evidence that PKC plays a critical role in growth control and the action of certain growth factors, tumor promoters, and oncogenes . In related studies, we have characterized the beta 1 isoform that is overproduced in the above cell systems in terms of its biochemical, kinetic, and immunologic properties . The enzyme has several properties characteristic of native PKCs . A surprising finding is that c-H-ras-transformed derivatives of the cells that overexpress PKC beta 1 display a several-fold increase in the expression of the endogenous alpha 1 isoform of PKC and a decrease in the expression of the endogenous epsilon isoform.(ABSTRACT TRUNCATED AT 250 WORDS)

Arch Pharm (Weinheim), 1991 Jun, 324(6), 349 - 51
Reaction of isatin with thiocarbohydrazide: a correction; Badawy MA et al.; Heterocycles containing the indole ring system include some novel pharmacologically active compounds . Isatin and its N-acetylisatin are extremely versatile intermediates in the construction of a variety of heterocyclic systems when reacted with thiosemicarbazide derivatives . Literature survey revealed various interesting reactions of thiocarbohydrazide with cyclic ketones, cyclic 1,2-diketones and isatin.

J Med Assoc Thai, 1991 Jun, 74(6), 322 - 6
Histochemical stainings, biological cultures and therapeutic responses of granulomatous lymphadenitis in Ramathibodi Hospital-prospective study of 57 cases; Sirikulchayanonta V et al.; The study was designed to delineate the etiology of granulomatous lymphadenitis which is one of the most common lesions encountered in our routine surgical pathology practice . Fifty-seven lymph nodes diagnosed histopathologically as granulomatous lymphadenitis were cultured and stained by special histochemical stains for tuberculosis, fungus, anaerobic and aerobic bacteria . M.tuberculosis was isolated in 60-70 per cent of lesions . The remaining 30-40 per cent of the lesions failed to demonstrate any infectious agent but most of the available follow-up cases showed satisfactory response to antituberculous drugs . Ziehl-Neelsen's stain showed very low sensitivity but excellent specificity and is still recommended for use to differentiate from other infectious agents in the areas where infectious agents are prevalent.

J Hosp Infect, 1991 Jun, 18 Suppl A, 481 - 9
Legionella in hospitals: a review; Hart CA et al.; Although epidemics of nosocomial Legionnaires' disease attract great attention, up to 30% of sporadic cases of hospital-acquired pneumonia are caused by legionellae . Legionellae are ubiquitous contaminants of potable water and can achieve high numbers in the hot-water systems of large buildings such as hospitals . They are present in the mains water supply in small numbers but are amplified considerably in the hospital's hot-water system . This is encouraged by water temperatures below 50 degrees C, areas of stagnation and sludge formation, the presence of amoebae and other bacteria and the materials used in the piping . Formation of aerosols from contaminated water is a major mode of spread of legionellae, but there is evidence to suggest that aspiration is also a mode of entry . Safe levels of legionellae in cooling towers have been defined, but not for hot-water systems . A combination of culture and antigen detection by immunofluorescence offer the best method for enumerating legionellae in environmental samples . Control involves a mixture of physical (heat, UV irradiation, sanitation) and chemical (hypochlorite, ozone) methods combined with good plumbing practice (e.g . arrangement of pumps and calorifiers, elimination of dead-legs) . Adequate control can be costly and requires considerable attention to detail.

J Hosp Infect, 1991 Jun, 18 Suppl A, 308 - 16
Predictors for bacteraemia; Gransden WR; In a study of 4104 episodes of septicaemia seen at St Thomas's Hospital between 1969 and 1989, predictors for the condition, other than age and hospital service, were difficult to identify, mainly as a result of the limited data available on the denominator groups . The collection of a small number of simple and readily assessed items of information on all patients with septicaemia did, however, allow the identification of some associations between certain groups of patients and particular species of bacteria and foci of infection . Until there is a substantially larger amount of accurate, complete and computerized data on all hospital patients, further recognition of predictors for bacteraemia will prove difficult to develop.

J Hosp Infect, 1991 Jun, 18 Suppl A, 136 - 40
Viral transmission and fibreoptic endoscopy; Hanson PJ et al.; Fibreoptic endoscopes have been responsible for outbreaks of infection with bacteria although viral transmission has been reported only once . The emergence of human immunodeficiency virus (HIV) has prompted a review of infection control practices in endoscopy units because of the theoretical possibility that HIV might be transmitted at endoscopy . Recent studies have shown that bronchoscopes and gastroscopes used on AIDS patients become contaminated with HIV genetic material although cleaning equipment in detergent removes all traces of the virus . Thorough precleaning has been shown to eliminate even high titres of HIV from endoscopes and 2% alkaline glutaraldehyde has been found to inactivate the virus rapidly even if the virus is dried in serum to a surface . These findings support the British Society of Gastroenterology recommendations for the cleaning and disinfection of endoscopic equipment and demonstrate that a uniform policy of infection control is practicable in endoscopy units.

J Hosp Infect, 1991 Jun, 18 Suppl B, 35 - 40
Handwashing in Finland; Ojajarvi J; To prevent skin problems we have recommended in Finland that hospital personnel should avoid soap or other detergents for handwashing and instead use alcoholic preparations containing emollients such as 2% glycerol . Alcohol with emollient disinfection is used frequently in hospitals and it causes fewer complaints of skin dryness than washing with soap . However, there are still members of staff who have hand skin problems . Our studies conducted during winter have shown that when these persons used emulsion for hand cleansing, instead of washing with soap, skin deterioration was much less, allowing alcoholic disinfection of the hands whenever necessary, without impairment of the disinfecting effect of alcohol.

J Hosp Infect, 1991 Jun, 18(2), 93 - 107
The relative importance of routes and sources of wound contamination during general surgery . I . Non-airborne; Whyte W et al.; A study was undertaken to determine the relative importance of some sources, routes of transmission, and measures to prevent bacteria entering the wound during biliary tract surgery . When bacteria were growing in the bile they accounted for the majority (greater than 99%) of the bacteria found in the wound . However, when the bile was sterile the skin bacteria at the incision site were found to make a substantial contribution to the wound flora . The difference in the total wound contamination between a patient who had practically no skin bacteria and one who had an average amount was in the region of 17-fold . No transfer of skin bacteria from the surgical team through perforated gloves or by direct contact from the surface of operating gowns was demonstrated . Ten of the patients studied had septic wounds . Five of these were infected by bacteria from the bile.

Eur J Clin Microbiol Infect Dis, 1991 Jun, 10(6), 491 - 6
Fiberoptic bronchoscopic diagnosis of pulmonary disease in 151 HIV-infected patients with pneumonitis; Jimenez ML et al.; In a prospective study the efficacy of fiberoptic bronchoscopy was evaluated in the diagnosis of infections with opportunistic pathogens, Kaposi's sarcoma and nonspecific interstitial pneumonitis in 171 episodes of pneumonitis in 151 HIV-infected patients . Samples were collected by suction through the inner aspiration channel of the bronchoscope (n = 164), telescoping plugged catheter (n = 117) and transbronchial lung biopsy (n = 82) . A high incidence of infections with pyogenic bacteria (12%), Legionella spp . (5 %) and Mycobacterium tuberculosis were diagnosed (9%) . Bronchoalveolar lavage demonstrated a high diagnostic rate in bacterial pneumonia (significance level greater than 10(5) cfu/ml) and a low degree (10%) of contamination (less than 1% squamous epithelial cells) . Bronchoalveolar lavage was more effective than the telescoping plugged catheter in yielding a significant number of colonies in patients with bacterial pneumonia previously treated with antibiotics . Nondiagnosed pneumonitis was more frequent in intravenous drug abusers than in homosexual men (p less than 0.001).

Trends Biochem Sci, 1991 Jun, 16(6), 225 - 9
Cytolytic pore-forming proteins and peptides: is there a common structural motif?
Ojcius DM, Young JD.
Pore-forming proteins or peptides (PFP) have now been isolated from a wide array of species ranging from humans to bacteria . A great number of these toxins lyse cells through a 'barrel-stave' mechanism, in which monomers of the toxin bind to and insert into the target membrane and then aggregate like barrel staves surrounding a central, water-filled pore . An evaluation of the secondary structures suggest that common secondary structures may be employed by most of these toxic PFP.

Science, 1991 May 31, 252(5010), 1296 - 300
Identification of the DNA binding site for NGFI-B by genetic selection in yeast; Wilson TE et al.; An in vivo selection system for isolating targets of DNA binding proteins in yeast was developed and used to identify the DNA binding site for the NGFI-B protein, a member of the steroid-thyroid hormone receptor superfamily . The feasibility of the technique was verified by selecting DNA fragments that contained binding sites for GCN4, a well-characterized yeast transcriptional activator . The DNA binding domain of NGFI-B, expressed as part of a LexA-NGFI-B-GAL4 chimeric activator, was then used to isolate a rat genomic DNA fragment that contained an NGFI-B binding site . The NGFI-B response element (NBRE) is similar to but functionally distinct from elements recognized by the estrogen and thyroid hormone receptors and the hormone receptor-like proteins COUP-TF, CF1, and H-2RIIBP . Cotransfection experiments in mammalian cells demonstrated that NGFI-B can activate transcription from the NBRE with or without its putative ligand binding domain.

Biochim Biophys Acta, 1991 May 23, 1058(1), 67 - 70
Biological electron transfer: progress and future directions; Cusanovich MA et al.; The rich diversity among bacterial cytochromes has played a key role in the development of our understanding of biological electron transfer . Although studies to date have allowed the elucidation of the contributions of driving force, electrostatics interactions and surface topology to electron transfer kinetics in collision-dependent reactions, much remains to be learned . Little is known about intramolecular and intracomplex electron transfer . Several factors controlling intramolecular and intracomplex electron transfer can be defined . These include driving force, the distance between redox centers, the relative orientation of prosthetic groups, the nature of the intervening media and the molecular dynamics within the electron transfer complex . However, at the present time, we have only a limited understanding of the contribution of these factors to electron transfer kinetics in biologically relevant systems . Nevertheless, a wide range of techniques are now available which should soon provide the information necessary to describe in molecular terms the mechanism of intramolecular and intracomplex electron transfer . Principal among these new approaches are site-directed mutagenesis and NMR spectroscopy.

Rev Prat, 1991 May 21, 41(15), 1341 - 4
{Immune defenses of newborn infants}; Sterkers G; Host defenses to bacterial infection are deficient in the neonate . This deficiency contributes to severe systemic infections in newborns . Phagocytosis of bacteria is decreased due to deficient activity of phagocytic cells and opsonines . Immunoglobulin secretion depending on B and helper T cell activities is strongly depressed due to immaturity of both populations . Therefore, maternal immunoglobulins of IgG type which cross placenta since 32 weeks of gestation play an important role in newborn defenses to bacteria even if this protection is incomplete.

Science, 1991 May 17, 252(5008), 965 - 9
Similarity of human mitochondrial transcription factor 1 to high mobility group proteins; Parisi MA et al.; Human mitochondrial transcription factor 1 (mtTF1) has been sequenced and is a nucleus-encoded DNA binding protein of 204 amino acids (24,400 daltons) . Expression of human mtTF1 in bacteria yields a protein with correct physical properties and the ability to activate mitochondrial DNA promoters . Analysis of the protein's sequence reveals no similarities to any other DNA binding proteins except for the existence of two domains that are characteristic of high mobility group (HMG) proteins . Human mtTF1 is most closely related to a DNA binding HMG-box region in hUBF, a human protein known to be important for transcription by RNA polymerase I.

Clin Chim Acta, 1991 May 15, 198(3), 183 - 93
An enzyme-linked lectin assay for sialidase; Lambre CR et al.; A procedure for the detection of low activities of sialidase (= neuraminidase) is described . Natural substrates for sialidase (human erythrocytes, fetuin or gangliosides) were coated onto the wells of microplates and incubated at 37 degrees C with the enzyme . Sialidase-induced desialylation of these natural substrates unmasks saccharides that are specifically recognized by the peanut agglutinin lectin (PNA) . The use of a peroxidase-conjugated PNA (Po-PNA) allowed the binding of the lectin to the desialylated substrate to be quantified . The amount of bound Po-PNA correlated directly with the amount of sialic acid released from the substrate, and therefore with the sialidase activity . With this method, it was possible to detect sialidase activity associated with bacteria, myxoviruses and cells from higher organisms . This method may have important clinical implications as the use of ELISA allows automation and concurrent analysis of numerous samples.

J Immunol, 1991 May 15, 146(10), 3380 - 5
Multiple Amb a I allergens demonstrate specific reactivity with IgE and T cells from ragweed-allergic patients; Bond JF et al.; The relationship between the structure and abundance of an inhaled protein and its potential for causing an allergic response is unknown . This study analyzes Amb a I, a family of related proteins formerly known as Ag E, that comprise the major allergens of short ragweed (Ambrosia artemisiifolia) . T cells isolated from ragweed allergic patients were shown to proliferate in response to purified Amb a I.1 protein from pollen in in vitro secondary cultures, demonstrating the presence of T cell stimulatory epitopes in Amb a I.1 . Three recombinant forms of Amb a I (Amb a I.1, Amb a I.2, and Amb a I.3) obtained as cDNA derived from pollen mRNA were expressed in bacteria . All three recombinant forms were shown to be specifically recognized by pooled ragweed-allergic human IgE on immunoblots, confirming these gene products are important allergens . An examination of immunoblots probed with sera derived from allergic patients revealed a variation in IgE binding specificity . A minority of patients' IgE exclusively reacted with recombinant Amb a I.1, whereas most patients' IgE reacted with Amb a I.1 as well as Amb a I.2 and Amb a I.3 proteins . A detailed examination of the reactivity of T cells derived from 12 allergic patients to these recombinant Amb a I forms revealed that these allergens are all capable of stimulating T cell proliferation in in vitro assays . It is concluded that the allergic response to ragweed pollen in most allergic patients is composed of a reaction to multiple related Amb a I proteins at both the B and T cell levels.

Rev Infect Dis, 1991 May-Jun, 13 Suppl 6, S509 - 17
Pathogenesis of pneumococcal pneumonia; Johnston RB Jr; Pneumococcal pneumonia poses a serious threat to children in developing countries and remains an important disease in the industrialized world . Capsular polysaccharide is the only bacterial factor proven to contribute to pathogenesis . However, the mechanisms responsible for the hypoxemia, toxemia, crisis, and death associated with this common infection are poorly understood . Toxins secreted by the bacteria, byproducts of bacterial breakdown (e.g., pneumolysin or teichoic acid), or constituents of the intense inflammatory response in the lung might play a role in these phenomena . Malnourished children presumably carry less metabolic reserve with which they can resist the exceptional stresses of pneumococcal disease, and underlying parasitic infestation or other chronic infections, through release of potent mediators such as tumor necrosis factor or platelet-activating factor, might prime the mechanisms of host defense for a more fulminant and systemic response to infection . Vaccines that can protect infants are badly needed, and a better understanding must be gained of the mechanisms by which this pathogen continues to cause such devastating disease in the world's children and elderly.

Biochemistry, 1991 May 7, 30(18), 4559 - 64
Laser flash photolysis study of intermolecular and intramolecular electron transfer in trimethylamine dehydrogenase; Hazzard JT et al.; Laser flash photolysis has been used to investigate the kinetics of reduction of trimethylamine dehydrogenase by substoichiometric amounts of 5-deazariboflavin semiquinone, and the subsequent intramolecular electron transfer from the FMN cofactor to the Fe4S4 center . The initial reduction event followed second-order kinetics (k = 1.0 x 10(8) M-1 s-1 at pH 7.0 and 6.4 x 10(7) M-1 s-1 at pH 8.5) and resulted in the formation of the neutral FMN semiquinone and the reduced iron-sulfur cluster (in a ratio of approximately 1:3) . Following this, a slower, protein concentration independent (and thus intramolecular) electron transfer was observed corresponding to FMN semiquinone oxidation and iron-sulfur cluster reduction (k = 62 s-1 at pH 7.0 and 30 s-1 at pH 8.5) . The addition of the inhibitor tetramethylammonium chloride to the reaction mixture had no effect on these kinetic properties, suggesting that this compound exerts its effect on the reduced form of the enzyme . Treatment of the enzyme with phenylhydrazine, which introduces a phenyl group at the 4a-position of the FMN cofactor, decreased both the rate constant for reduction of the protein and the extent of FMN semiquinone production, while increasing the amount of iron-sulfur center reduction, consistent with the results obtained with the native enzyme . Experiments in which the kinetics of reduction of the enzyme were determined during various stages of partial reduction were also consistent with these results, and further indicated that the FMN semiquinone form of the enzyme is more reactive toward the deazariboflavin reductant than is the oxidized FMN.(ABSTRACT TRUNCATED AT 250 WORDS)

FEBS Lett, 1991 May 6, 282(2), 385 - 7
Identification of glycolipid receptors for Helicobacter pylori by TLC-immunostaining; Saitoh T et al.; Helicobacter pylori has been identified as a causative agent in active chronic gastritis . The receptor for this bacteria, however, is not known . It is likely that the receptor molecules may be glycosphingolipids as shown in the cases of other bacteria . We explored this possibility by a thin-layer chromatography (TLC)-immunostaining method . Among glycosphingolipids extracted from human gastric mucosa, intact Helicobacter pylori specifically bound to I3SO3-GalCer and II3NeuAc-LacCer, whereas no specific binding to neutral glycosphingolipids, which share the same ceramide moiety with I3SO3-GalCer or II3NeuAc-LacCer, was demonstrated . Sonicated bacteria could still bind to II3NeuAc-LacCer with comparable affinity . In contrast, the binding of bacteria to I3SO3-GalCer was greatly diminished upon sonication . These results suggest that each of the oligosaccharide moieties of II3NeuAc-LacCer and I3SO3-GalCer may be specifically recognized by different ligand molecules of Helicobacter pylori.

Pol Tyg Lek, 1991 May 27-Jun 3, 46(22-23), 422 - 3
{Clinical evaluation of broncho-vaxom efficiency}; Moniuszko T et al.; Broncho-vaxom was administered to 40 patients with recurrent respiratory infections, allergic-infectious bronchial asthma and chronic bronchitis . Broncho-vaxom was administered in the dose of one capsule for the first month, and 1 capsule for 10 days in the third, fourth, and fifth month . A favourable clinical effect has been achieved in over 50% of the treated patients manifested by the decrease in the number and severity of respiratory infections and reductions in antibiotics use . These results confirm clinical efficiency of this vaccine.

J Periodontol, 1991 May, 62(5), 293 - 9
Periodontal findings in adult twins; Michalowicz BS et al.; Gingivitis and periodontitis are among the most common diseases known to man . Although bacterial plaque is generally accepted as the primary etiologic agent, little information is available concerning the influence that host genetic factors have on these diseases . The purpose of the present study was to examine the relative contribution of environmental and host genetic factors to clinical measures of periodontal disease through the study of both reared-together twins and monozygous twins reared apart . Probing depth, clinical attachment loss, gingivitis, and plaque were assessed from the Ramfjord teeth in 110 pairs of adult twins (mean age 40.3 years), including 63 monozygous and 33 dizygous twin pairs reared together and 14 monozygous twin pairs reared apart . Bootstrap sampling was used to estimate and provide confidence limits of between-pair and within-pair variances, intraclass correlations and heritability . Based on ratios of within-pair variances or heritability estimates, a significant (P less than 0.05) genetic component was identified for gingivitis, probing depth, attachment loss and plaque . Heritability estimates indicated that between 38% to 82% of the population variance for these periodontal measures of disease may be attributed to genetic factors . While there is general agreement that bacteria are important in the pathogenesis of the periodontal diseases, future etiologic studies should consider the role of host genetic influences.

Br J Surg, 1991 May, 78(5), 568 - 71
Effects of relief of biliary obstruction on mononuclear phagocyte system function and cell mediated immunity; Megison SM et al.; Obstructive jaundice causes depression of immune system function but it is unclear at present how rapidly immune function recovers after relief of biliary obstruction . To address this issue, we studied 218 Sprague-Dawley rats with common bile duct obstruction . Mononuclear phagocyte function, cell mediated immune function, portal-systemic shunt fraction, liver function tests, and liver histology were evaluated in normal (sham) rats, obstructed rats, and at weekly intervals after relief of biliary obstruction . Hepatic uptake of radiolabelled bacteria was 82 per cent in sham rats and 66 per cent in rats 21 days after CBD obstruction (P less than 0.05) . Phagocytic activity returned to normal within 7 days after choledochoduodenostomy . Cell mediated immunity, measured by skin graft rejection, was significantly prolonged in the obstructed group (P less than 0.05) but had returned to normal 7 days after biliary diversion . Return of hepatocellular function, as measured by liver function tests, paralleled recovery of immune function . This study demonstrates prompt recovery of the immune system after internal biliary drainage for obstructive jaundice . This finding is in contrast to previous studies that demonstrated persistent immune suppression months after biliary diversion . These data may have implications concerning the usefulness of internal biliary drainage before surgery in patients with obstructive jaundice.

Oral Surg Oral Med Oral Pathol, 1991 May, 71(5), 603 - 11
Clinical, radiographic, and histologic study of endodontic treatment failures; Lin LM et al.; One hundred fifty cases of endodontic treatment failures were studied clinically, radiographically, and histologically . Fifty-seven percent of the teeth were asymptomatic . Pain alone and/or associated with swelling was present in 21% of the teeth . There was no correlation between the size of periradicular rarefaction and the occurrence or severity of clinical signs and/or symptoms . Stainable bacteria were demonstrated in 69% of the teeth and were present mostly in the canal . The severity of periradicular inflammation was related to presence of stainable bacteria in the canal . Swelling and pain or a draining sinus tract was often associated with stainable bacteria inside the canal . The development of a radicular cyst associated with an endodontically treated tooth that has failed is not necessarily the cause of endodontic treatment failure.

Hepatology, 1991 May, 13(5), 929 - 35
Ascitic fluid pH and lactate: insensitive and nonspecific tests in detecting ascitic fluid infection; Runyon BA et al.; Ascitic fluid pH and lactate concentration have been proposed as useful tests for the detection of ascitic fluid infection . However, past studies involved small numbers of infected patients, and all did not use optimal culture techniques . This large study was performed using highly sensitive culture methods and sought (a) to compare the sensitivity, specificity and accuracy of pH and lactate to that of the ascitic fluid neutrophil count and (b) to determine whether evaluation of ascitic fluid pH or lactate (or arterial-ascitic fluid pH or lactate gradient) would result in improved decision-making regarding empirical treatment of suspected ascitic fluid infection . Analysis of 206 ascitic fluid specimens obtained in 175 patients, including 101 infected specimens, revealed that ascitic fluid (or arterial-ascitic fluid) pH and lactate were less than 50% sensitive in detecting bacterial peritonitis and that these tests did not improve clinical decision-making about empirical treatment of suspected ascitic fluid infection . Although statistically significant differences in ascitic fluid pH were detected between infected samples and control samples, these differences did not appear to be clinically helpful . The ascitic fluid pH was 0% sensitive in detecting the presence of bacteria in the absence of neutrophils (i.e., no such specimens had a pH lower than 7.35) . Ascitic fluid pH correlated well with neutrophil count and appears to be, at least in part, an indirect measure of the presence of neutrophils in ascitic fluid . Measurement of pH or lactate (or arterial-ascitic fluid gradients) is not helpful in the clinical management of infected ascitic fluid.

Proc Natl Acad Sci U S A, 1991 May 1, 88(9), 3715 - 9
c-rel activates but v-rel suppresses transcription from kappa B sites; Inoue J et al.; We show that the product of the protooncogene c-rel is a constituent of an NF-kappa B-like complex that binds to the kappa B site originally identified in the enhancer of immunoglobulin kappa light chain gene . c-rel protein synthesized in bacteria binds to the kappa B site in a sequence-specific manner . The rel-kappa B complex can be disrupted by incubation with anti-rel antibodies . The rel protein can form oligomers . The c-rel protein can activate transcription from promoters containing kappa B sites; v-rel, on the other hand, suppresses the transcription of genes linked to kappa B sites . Thus, v-rel may interfere with the normal transcriptional machinery of the cell by acting as a dominant negative mutant.

J Exp Med, 1991 May 1, 173(5), 1143 - 9
Integrin-mediated localization of Bordetella pertussis within macrophages: role in pulmonary colonization; Saukkonen K et al.; The adherence of Bordetella pertussis to human respiratory cilia is critical to the pathogenesis of whooping cough but the significance of bacterial attachment to macrophages has not been determined . Adherence to cilia and macrophages is mediated by two large, nonfimbrial bacterial proteins, filamentous hemagglutinin (FHA), and pertussis toxin (PT) . PT and FHA both recognize carbohydrates on cilia and macrophages; FHA also contains an Arg-Gly-Asp (RGD) sequence which promotes bacterial association with the macrophage integrin complement receptor 3 (CR3) . We determined that virulent B . pertussis enter and survive in mammalian macrophages in vitro and that CR3 is important for this uptake process . We then determined the relative contribution of CR3 versus carbohydrate-dependent interactions to in vivo pulmonary colonization using a rabbit model . B . pertussis colonized the lung as two approximately equal populations, one extracellular population attached to ciliary and macrophage surface glycoconjugates and another population within pulmonary macrophages . Loss of the CR3 interaction, either by mutation of FHA or treatment with antibody to CR3, disrupted accumulation of viable intracellular bacteria but did not prevent lung pathology . In contrast, elimination of carbohydrate-bound bacteria, either by a competitive receptor analogue or an anti-receptor antibody, was sufficient to prevent pulmonary edema . We propose that CR3-dependent localization of B . pertussis within macrophages promotes persistence of bacteria in the lung without pulmonary injury . On the other hand, the presence of extracellular bacteria adherent to cilia and macrophages in carbohydrate-dependent interactions is associated with pulmonary pathology.

Infect Immun, 1991 May, 59(5), 1790 - 4
Prophylaxis or treatment of experimental brucellosis with interleukin-1; Zhan YF et al.; Intravenously injected recombinant human interleukin-1 alpha (IL-1 alpha) given to mice 4 h before infection with Brucella abortus 19 depressed the growth of bacteria in the spleen and liver . However, the same dose (10(5) U) or a 10-fold higher dose was not able to decrease numbers of bacteria when given to chronically infected mice . IL-1 injected into normal mice induced a dramatic increase 2 h later in colony-stimulating activity in serum, measured by bone marrow proliferation, and in colony-stimulating factor 1, measured by radioimmunoassay . Colony-stimulating factor levels declined but remained higher than normal for at least 12 h . The early peak stimulation was not observed in chronically infected mice, but the more prolonged elevation was . As a result of IL-1 treatment, the number of colony-forming cells, especially in the spleen, was increased in normal and acutely or chronically infected mice . Myeloperoxidase staining of newly formed monocytes and polymorphonuclear cells in the spleen revealed an increase in the number of these cells in normal and acutely infected mice as a result of IL-1 treatment, but there was no increase in the already high numbers in chronically infected mice . The relationship between these observations and the basis of chronic infection are discussed.

Mol Microbiol, 1991 May, 5(5), 1235 - 9
Light and oxygen effects share a common regulatory DNA sequence in Rhodobacter capsulatus; Klug G et al.; External factors regulate the formation of pigment protein complexes in facultatively photosynthetic bacteria . The puf operon of Rhodobacter capsulatus encodes the pigment binding proteins of the reaction centre and light-harvesting I complex . Here we demonstrate that a single base-pair exchange within a sequence of dyad symmetry upstream of the puf promoter affects both the oxygen regulation and the light regulation of the formation of reaction-centre and light-harvesting I complexes in Rhodobacter capsulatus . Our results imply that effects of oxygen or light ultimately act on the same regulatory DNA sequence, although it is still unknown how these environmental signals are sensed and transmitted to a transcriptional regulator.

Vopr Med Khim, 1991 May-Jun, 37(3), 14 - 7
{The effect of Legionella pneumophila metalloproteinase on certain human blood proteins . Cleavage of anti(1)-antitrypsin and acid-stable serine proteinase inhibitors}; Gul'nik SV et al.; Antitryptic activity of human blood serum was decreased after incubation with metalloproteinase from Legionella pneumophila . The enzymatic activity depends on the time of incubation as well as on the ratio between the enzyme content and blood serum total protein . Cross immunoelectrophoresis, involving monospecific rabbit antiserum towards the alpha 1-antitrypsin, demonstrated highly effective hydrolysis of alpha 1-antitrypsin by the metalloproteinase . As shown by polyacrylamide gel electrophoresis the metalloproteinase hydrolyzed acid stable inhibitor of serine proteinases into fragments with distinct loss of the inhibitor activity . Thermolysine hydrolyzed similarly the proteins studied but at a lower rate . The metalloproteinase from L . pneumophila appears to be mainly responsible for production of utilizable components from protein substrates involved in vital activity of the bacteria . It may not be excluded that the enzyme is able to impair some host protective mechanisms.

Prev Assist Dent, 1991 May-Jun, 17(3), 19 - 22
{Fluoride prophylaxis a distant reality again?}; Rini MS et al.; The fluorine-prophylaxis is the caries only real therapeutic protection . The fluorine modifies calcificated tissues composition and property (hydroxyapatite----fluorapatite) and it acts on the plaque bacteria metabolism . The fluorine intoxication is very rare . But interviewed parents are disinterested, fear full and bad-informed . Unfortunately the fluorine-prophylaxis and the periodic controls are a distant reality for Italy.

Plasmid, 1991 May, 25(3), 163 - 76
Genetic and physical mapping of the Rhodobacter sphaeroides photosynthetic gene cluster from R-prime pWS2; Wu YQ et al.; Plasmid pWS2 is an R68.45 chimera originally isolated as an R-prime which complemented the Rhodobacter sphaeroides bch-420 allele . Our experiments have shown that pWS2 is also able to complement a wide range of R . sphaeroides pigment and photosynthetic mutants employing nitrosoquanidine, transposon or insertion-generated mutations effecting puhA, puc, puf, cycA, bch, and crt genes . A combination of orthogonal-field-alternation gel electrophoresis, transverse alternating field gel electrophoresis, and conventional electrophoresis have been used to estimate the size of pWS2 at congruent to 168.3 +/- 3.5 kb . A restriction map of the congruent to 109 kb of R . sphaeroides insert DNA was generated by partial and complete restriction endonuclease digestion coupled with Southern hybridization analysis using either gene-specific or junction fragment probes . Genes encoding bacteriochlorophyll (Bchl)-binding proteins (pufBALMX, pucBA, and puhA), cytochrome c2 (cycA), and enzymes involved in Bchl (bch) and carotenoid (crt) biosynthesis have been shown to reside within a contiguous 53-kb region of the R . sphaeroides DNA present on pWS2 . The puf operon lies at one end of the 53-kb segment, while the genes puhA, cycA, and pucBA, the latter two of which are located within congruent to 12.0 kb of each other, define the other end of this 53-kb region . The genetic and physical mapping data provided in this paper are discussed in terms of the similarities and differences in the organization of the photosynthetic gene cluster between R . sphaeroides and other photosynthetic bacteria as well as highlighting the use of pWS2 in studies of photosynthetic gene structure and function.

Exp Clin Endocrinol, 1991 May, 97(2-3), 127 - 32
The relevance of genetic susceptibility in Graves' disease and immune thyroiditis; Schleusener H et al.; It has been known for a long time that there is an increased incidence of Graves' disease and immune thyroiditis in certain families . Genetic research of this disease has shown that it is most probably transmitted in a multifactorial way, i.e . that environmental as well as genetic factors play a role in the genesis of the diseases . This hypothesis is supported by the fact that the rate of concordance is maximally 50% in identical twins . The following model of threshold values is conceivable for the formal genetics of Graves' disease and immune thyroiditis: the diseases break out whenever the sum of environmental (viruses, bacteria, iodine excess, hormones, stress) and genetic (MHC and non MHC-restricted) factors is higher than a given threshold . One of the major genes influencing the genesis of the diseases seems to be HLA-DR3 (or a closely linked gene in strong linkage disequilibrium) . If this gene is present, fewer environmental factors are possibly needed.

Biofizika, 1991 May-Jun, 36(3), 489 - 98
{Sensitivity and functional characteristics of modern chemoluminescence meters}; Zhuravlev AI et al.; The paper describes the following quantum phenomenon discovered by B . N . Tarusov, A . I . Zhuravlev and A . I . Polivoda in 1961: spontaneous endogenous biochemiluminescence of animal tissues and cells in the spectral range of 320-1100 nm . It initiated studies of the role of electron-excited states and quanta in metabolism, i.e . it started the development of quantum biology of animal organisms . Intensity of this ultra-weak luminescence is determined and its classification is presented according to sensitivity towards fixation ability: a) ultra-weak 10-10(2) quanta/sec (spontaneous luminescence of blood plasma and serum, mitochondria suspension at 37 degrees C); b) ultra-weak 10(2)-10(3) quanta/sec (spontaneous luminescence of lipids and urea at 37 degrees C); weak 10(5)-10(6) quanta/sec (luminol-dependent luminescence of the blood immunocompetent cells, initiated by peroxides and luminescence catalysts in serum, plasma, lipids, suspension of organelles; d) 10(6) quanta/sec and higher (fixed by the eye or photoelement luminescence of glow worms, bacteria or ATP-triggered luciferin-luciferase reactions).

New Biol, 1991 May, 3(5), 455 - 64
Serum response factor affects preinitiation complex formation by TFIID in vitro; Zhu H et al.; Serum response factor (SRF), a transcription factor that binds to the serum response element (SRE) of the c-fos proto-oncogene, activates transcription of an SRE-containing reporter plasmid in vitro . We describe here preincubation experiments which indicate that SRF activates transcription by facilitating the formation of active preinitiation complexes . Full activation by SRF occurred if SRF was preincubated with the general transcription factors . However, if the general transcription factors were preincubated and SRF was added subsequently, only poor activation of transcription was observed . This suggests that SRF must be present during preinitiation complex formation and that this complex is refractory to activation if SRF is absent during its formation . We have fractionated the general transcription factors and found that only a highly purified fraction containing the TATA-binding factor TFIID (and other unidentified components) must be present during preincubation for maximal transcriptional induction by SRF . This supports a model in which SRF activates transcription by affecting the conformation of TFIID bound to the promoter . Also of interest was the finding that recombinant human TFIID expressed in bacteria cannot mediate SRF-activated transcription, although it does support basal transcription . These results suggest that SRF may affect TFIID via a cofactor or coactivator.

Immunology, 1991 May, 73(1), 109 - 13
Activation of mouse peritoneal macrophages by maintenance in serum-free medium; Walker L et al.; Normal mouse peritoneal macrophages maintained in a serum-free medium for 48-72 h and then stimulated with phorbol myristate acetate, zymosan or bacteria, released large amounts of hydrogen peroxide . Opsonized zymosan and bacteria stimulated greater release than their unopsonized counterparts . Enhanced peroxide production was not a consequence of increased uptake of particles . Addition of serum to the serum-free medium abolished activation . The addition of interferon-gamma to the serum-free medium enhanced the effect of the serum-free treatment of macrophages from C3H/HeJ mice but abolished the effect of serum free treatment of macrophages from CFLP mice . The results are discussed in terms of negative regulation of receptor-oxidase linkage by serum.

J Med Primatol, 1991 May, 20(3), 104 - 9
Use of a grooming and foraging substrate to reduce cage stereotypies in macaques; Lam K et al.; We examined the effects of a synthetic fleece pad on cage stereotypies in individually housed cynomolgus monkeys . Animals which received the fleece alone engaged in grooming which was associated with an increase in time spent resting . Monkeys given fleece pads sprinkled with morsels of food did not groom the fleece, but rather foraged for long periods (up to 27 min/h) . Stereotyped behaviours were reduced by up to 73% by use of the fleece pad both alone and with foraging crumbles.

Pediatr Dent, 1991 May-Jun, 13(3), 136 - 41
Comparison of ultrasonic and mechanical cleaning of primary root canals using a novel radiometric method; Seow WK; Although ultrasound is employed increasingly as an adjunct to biomechanical preparation in clinical endodontics for adult teeth, there have been no previous investigation of this technique for primary teeth . This investigation studied the efficacy of ultrasonication compared with mechanical cleaning in primary root canals using a novel radiometric method . The results indicated that in multiple-rooted teeth, ultrasonication with an endosonic file for 3 min was able to remove 81.1% of inoculated bacteria, compared with only 65.2% using conventional filing . A combination of mechanical filing followed by ultrasonication produced the best results, with greater than 95% bacteria removed . The results show that ultrasonication may be useful for primary teeth endodontics.

Arch Androl, 1991 May-Jun, 26(3), 173 - 83
Semen parameters in men with and without proven chronic prostatitis; Weidner W et al.; In patients with complaints of chronic prostatitis, analysis of prostatic secretions for leukocytes and the use of the four-specimen technique allow a distinct classification of chronic bacterial (CBP), nonbacterial prostatitis (NBP), and prostatodynia (Pd) . In this study, 32 men with CBP, 102 men with NBP, 142 men with Pd, and 42 volunteers, classified as mentioned above, underwent a two-fold ejaculate analysis using WHO criteria . Sperm count, progressive motility, range of abnormal spermatozoa, increased numbers of common bacteria, and peroxidase-positive leukocytes were analyzed . Additionally, antibody-coated bacteria (ACB), numbers of ureaplasmas in semen, and urethral colonization by chlamydia were investigated . Mean values of sperm density, motility, and morphology revealed no differences between the groups . Significant bacteriospermia (greater than or equal to 10(3) bacterial/ml) was evident in only 47% of the CBP group versus 6.8% (NBP), 16% (Pd), and 4.2% (controls) . ACB was positive in 31 of 32 men with CBP versus 3 of 102 with NBP, 9 of 142 with Pd, and none of the controls . Increased numbers of leukocytes were evident in CBP and NBP patients compared to the controls (p less than or equal to 0.001) but were also present in patients of the NBP and Pd groups with chlamydial infections.

AIDS, 1991 May, 5(5), 527 - 33
Cellular profiles in bronchoalveolar lavage fluid of HIV-infected patients with pulmonary symptoms: relation to diagnosis and prognosis; Jensen BN et al.; Bronchoalveolar lavage (BAL) cell differentials and T-lymphocyte subpopulations were analysed in 95 HIV-infected patients with pulmonary symptoms to determine whether the type of cellular inflammatory response could be useful in diagnosis or as a prognostic marker . Patients with Pneumocystis carinii pneumonia (PCP) had more BAL fluid lymphocytes, mainly comprising CD8+ cells, and patients with bacterial infection had more neutrophils than other patients . Neither of these changes were mirrored in peripheral blood . Seven patients who died after their acute episode of PCP had significantly higher BAL fluid neutrophils than 53 patients with PCP who survived (P = 0.002) . There seems to be correlation between BAL fluid neutrophilia, PCP and concomitant bacterial infection since four out of seven patients with a fatal outcome had coinfection with bacteria, whereas only one patient with PCP and bacterial coinfection survived (P = 0.0007).

Klin Med (Mosk), 1991 May, 69(5), 71 - 3
{Tick-borne encephalitis associated with other infections}; Meierova RA; Possibility of mixed infection arising in encounter of agents from different families (virus-virus, virus-bacteria, virus-protozoa) was demonstrated on 103 cases of chronic tick-borne encephalitis (TBE) association with other acute and chronic infection . The addition of influenza, tuberculosis, pyogenic infection in most cases entails a relapse of TBE or promotes a primary-progressive course of the disease . TBE association with rheumatic fever relieves pain symptoms . It is emphasized that mixed infections used to bring suppression of immune reactivity thus necessitating serological and virological monitoring of the disease run.

Acta Anaesthesiol Scand, 1991 May, 35(4), 315 - 9
Long-term use of central venous catheters in paediatric oncology treatment; Sellden H et al.; During a 26-month period, 158 central venous catheters were inserted in 114 children (median age: 4.5 years) with malignant diseases . Polyurethane catheters were used, inserted either using a cut-down procedure or percutaneously in the external or internal jugular vein . All catheters were tunnelled from the point of insertion to the midpoint of the manubrium or upper sternum . The catheter tip reached the superior caval vein or the right atrium in 94% of the cases . The catheters were used for all infusions, including total parenteral nutrition, and for blood sampling . The median catheter duration was 104 days (range 5-835 days) . Sixty-eight (43%) of the catheters were removed as they were no longer needed, and 31 (20%) were removed due to local infection or septicaemia . During a total of 23,486 catheter days (64.4 years), 110 episodes of septicaemia occurred . This represents one episode per 214 catheter days . In 43 of the 110 episodes of septicaemia, blood cultures showed growth of bacteria of the kind usually found in the gastrointestinal and respiratory tracts . All septicaemias were treated with intravenous broad-spectrum antibiotics and in 21 cases the catheters were removed due to septicaemia . Thirty-four (22%) catheters were removed accidentally . There were two cases of subclavian vein thrombosis.

World J Surg, 1991 May-Jun, 15(3), 383 - 7; discussion 387-8
Postoperative wound infections and surgical face masks: a controlled study; Tunevall TG; It has never been shown that wearing surgical face masks decreases postoperative wound infections . On the contrary, a 50% decrease has been reported after omitting face masks . The present study was designed to reveal any 30% or greater difference in general surgery wound infection rates by using face masks or not . During 115 weeks, a total of 3,088 patients were included in the study . Weeks were denoted as "masked" or "unmasked" according to a random list . After 1,537 operations performed with face masks, 73 (4.7%) wound infections were recorded and, after 1,551 operations performed without face masks, 55 (3.5%) infections occurred . This difference was not statistically significant (p greater than 0.05) and the bacterial species cultured from the wound infections did not differ in any way, which would have supported the fact tha the numerical difference was a statistically "missed" difference . These results indicated that the use of face masks might be reconsidered . Masks may be used to protect the operating team from drops of infected blood and from airborne infections, but have not been proven to protect the patient operated by a healthy operating team.

World J Surg, 1991 May-Jun, 15(3), 372 - 6; discussion 376-7
Pyogenic liver abscess: multivariate analysis of risk factors; Lee KT et al.; Seventy-three patients with pyogenic liver abscess during the year 1978-1988 were studied in the Kaohsiung Medical College Hospital . The overall mortality rate was 19.2% in this study . By using univariate analysis, it was revealed that clinical jaundice, pleural effusion, bilobar abscess, profound hypoalbuminemia (less than 2.5 g/dl), hyperbilirubinemia (less than 2 mg/dl), elevated level of serum AST (greater than 100 IU/L), alkaline phosphatase (greater than 150 IU/L), and marked leukocytosis (greater than 20,000 mm3) were associated with a higher mortality rate . Multivariate stepwise logistic regression analysis detected only 3 factors of marked leukocytosis (greater than 20,000 mm3), profound hypoalbuminemia (less than 2.5 g/dl), and presence of pleural effusion with independent significance in predicting mortality . Meanwhile, it was also revealed that the laboratory data could not predict a risk factor to mortality unless they became markedly abnormal.

Proc Soc Exp Biol Med, 1991 May, 197(1), 19 - 26
Physiologic importance of pyrroloquinoline quinone; Smidt CR et al.; Pyrroloquinoline quinone (PQQ, methoxatin) is a dissociable cofactor for a number of bacterial dehydrogenases . The compound is unusual because of its ability to catalyze redox cycling reactions at a high rate of efficiency and it has the potential of catalyzing various carbonyl amine reactions as well . In methylotrophic bacteria, PQQ is derived from the condensation of L-tyrosine with L-glutamic acid . Whether or not PQQ serves as a cofactor in higher plants and animals remains controversial . Nevertheless, a strong case may be made that PQQ and related quinoids have nutritional and pharmacologic importance . In highly purified, chemically defined diets, PQQ stimulates animal growth . Furthermore, PQQ deprivation appears to impair connective tissue maturation, particularly when initiated in utero and throughout perinatal development.

Math Biosci, 1991 May, 104(2), 203 - 45
Global stability in a synthrophic chain model; Elkhader AS; A mathematical model formulated by G . Powell in 1986 is considered . This model describes a synthrophic chain of species Xi, 1 less than or equal to i less than or equal to n, in a continuous chemostat culture . Species Xi utilizes substrate Si and forms a product Si + 1 . Substrate Si + 1 inhibits the growth of Xi and constitutes a growth-limiting substrate of Xi + 1 . For this model, the conditions for coexistence of all species are improved, and the local stability results are extended to global stability . Some interesting cases are discussed.

Ann Ital Chir, 1991 May-Jun, 62(3), 261 - 3; discussion 264
{Complicated jejunoileal diverticulosis . A clinical case report}; Rogati L et al.; The diverticulosis of jejunum ileum is an uncommon pathology, that is often revealed just from the complications which it presents . The clinical case reported by the Authors describes a woman who reached to admission for a serious condition of shock secondary to a jejunum bleeding diverticulosis and who underwent an intestinal resection . The patient was discharged home on IX p.o . day . From the review of literature results that the incidence of the diverticulosis of jejunum ileum consists of 0.1%-0.11% of all the gastrointestinal's diverticula and the predominance is for the female, especially in the middle age . The diverticulosis of jejunum ileum can be congenital or acquired; the first one came to the antimesenteric side of the intestines, the second one to the mesenteric side of the same . The diverticulosis is generally asymptomatic, but often produces many complications as the intestinal occlusion, secondary to a bridle, a volvulus, an invagination, also if the peritonitis caused by a diverticulosis's perforation represents the most frequent complication of them . Others rarest complications are the massive haemorrhage of diverticula, the stagnant loop syndrome, the malabsorption's syndrome due to lack of B12 vitamin and growth of bacteria within them, the diverticulitis caused by infection . The therapy of all complicated cases of jejunum ileum diverticula is necessarily the surgery only and exactly the intestinal resection.

Acta Pathol Jpn, 1991 May, 41(5), 363 - 8
Monocytoid B lymphocytes and epithelioid cell clusters in abscess-forming granulomatous lymphadenitis . With special reference to cat scratch disease; Kojima M et al.; In order to clarify the appearance of monocytoid B lymphocytes (MBLs) in abscess-forming granulomatous lymphadenitis (AGL) and the relation between AGL and cat-scratch disease (CSD), 48 cases of AGL were studied histologically . MBLs were present in about 50% of AGL cases . Warthin-Starry (WS) silver stain-positive bacteria, which are the causative agent of CSD, were present in 52.4% of AGL cases with MBLs and 59.2% of AGL cases without MBLs . The appearance of MBLs in AGL was not related to various clinical features, including disease interval from initial lymphadenopathy to lymph node biopsy . Histologically, epithelioid cell clusters appeared in about 70% of MBL-positive AGL cases, but were not observed in MBL-negative AGL . Therefore, a close interaction between MBLs and epithelioid cells in AGL is suggested, and we emphasize that the histological features of some AGL cases resemble those of toxoplasmic lymphadenitis.

J Trauma, 1991 May, 31(5), 589 - 98; discussion 599-600
Microcirculatory flow changes after initial resuscitation of hemorrhagic shock with 7.5% hypertonic saline/6% dextran 70; Behrman SW et al.; In rabbits, laser Doppler flow probes were placed in the jejunum and on the renal cortex . Pulsed Doppler probes were implanted on the abdominal aorta and superior mesenteric and femoral arteries for measuring blood flow velocity . Cardiac output was measured by thermal dilution . Either 30% or 40% of the calculated blood volume was withdrawn through a carotid catheter . After 30 or 60 minutes, an initial bolus of either lactated Ringer's (LR, 16 ml/kg) or 7.5% hypertonic saline/6% dextran 70 (HSD; 4 ml/kg) IV was followed by unlimited IV LR (administered as rapidly as possible) to restore systemic arterial blood pressure to the prehemorrhage levels . With HSD, arterial pressure corrected more rapidly (p less than 0.05), and the initial hemodilution was greater (p less than 0.05), but there were no differences by two hours . With HSD, cardiac output (90%-100% vs . 130%-160% of control; p less than 0.05), plasma Na+ (139-140 mM vs . 146-148 mM; p less than 0.05) and plasma osmolarity (292-295 mOsm vs . 308-310 mOsm; p less than 0.05) were all significantly higher than the values with LR, but there was no effect on blood flow velocities through the infrarenal aorta, femoral artery, or superior mesenteric artery . Renal cortical perfusion (56% vs . 97% of control; p less than 0.05) and jejunal mucosal perfusion (83% vs . 162% of control; p less than 0.05) were significantly higher with HSD . HSD had no detectable effect on bacterial translocation at 24 hours . Thus: 1) HSD restores blood flow more rapidly to the gut mucosal and kidney microcirculations than initial resuscitation with LR; 2) the mechanism could be associated with a transient hemodilution and persistent increases in plasma Na and osmolarity, which reduce hemorrhage-induced cell swelling and blood viscosity changes; and 3) laser Doppler analysis could aid in the diagnosis of reperfusion injury after shock.

J Pharm Pharmacol, 1991 May, 43(5), 353 - 5
Relative anti-inflammatory effect of oral dexamethasone-beta-D-glucoside and dexamethasone in experimental inflammatory bowel disease in guinea-pigs; Friend DR et al.; The relative anti-inflammatory effect of dexamethasone and a prodrug, dexamethasone-beta-D-glucoside, has been assessed in guinea-pigs with experimentally-induced inflammatory bowel disease (IBD) . The glucoside prodrug is designed to reach the large intestine following oral administration . The active agent is liberated when the prodrug is hydrolysed by glycosidases of colonic bacteria . Guinea-pigs were administered degraded carrageenan in their drinking water to produce experimental IBD . Starting on day 15, dexamethasone (1.3 mumol kg-1) or dexamethasone-beta-D-glucoside (1.3 or 0.65 mumol kg-1) was administered by gastric intubation once daily for 5 days . Relative to control animals, the drug and prodrug treatments significantly (P less than 0.05) reduced the total number of caecal ulcers . While there was no difference statistically between the drug and prodrug treatments, the data suggest that a lower dose of dexamethasone, administered as its glucoside prodrug, could reduce side-effects without reduced efficacy . These results support the hypothesis that localized delivery of dexamethasone to the large bowel can improve pharmacotherapy of IBD by reducing the side-effects associated with corticosteroids.

Rev Infect Dis, 1991 May-Jun, 13 Suppl 6, S562 - 70
Viral vaccines for the prevention of childhood pneumonia in developing nations: priorities and prospects; Steinhoff MC; In concert with bacteria, respiratory viruses play a major role in the high rates of acute lower respiratory infection (ALRI) experienced in developing nations . Respiratory syncytial virus, parainfluenza and influenza viruses, and the adenoviruses are the predominant viral causes of ALRI in both developed and developing regions . In this review, the epidemiologic data from developing nations for these viral infections are summarized and the current status of viral vaccines for prevention of ALRI are described . Among the questions to be addressed before these vaccines are used in developing nations are (1) the age-specific rates of infection and disease, (2) the effect of high-dose early exposure to these viruses, and (3) the effect of malnutrition on the immunogenicity of the vaccines . Prospective family studies and other community-based approaches will be required in the acquisition of these data.

Kokyu To Junkan, 1991 May, 39(5), 481 - 5
{Effect of roxithromycin on ciliary motility of rabbit tracheal epithelium in culture}; Tamaoki J et al.; Mucociliary transport plays an important role in the lung defense mechanism by clearing inhaled particles and bacteria from the respiratory tract . In the present study, we tried to determine whether roxithromycin (RXM), a new semisynthetic macrolide, can affect airway mucociliary functions and, if so, what the mechanism of its action is . To do so we measured ciliary beat frequency (CBF) of rabbit cultured tracheal epithelium by a photoelectric method . Addition of RXM (10(-4) M) to a Rose chamber containing epithelial cells caused a rapid increase in CBF from 12.1 +/- 0.6 to 16.2 +/- 0.8 Hz (mean +/- SE, p less than 0.001) within 5 min . This effect was dose-dependent, the maximal increase from the baseline CBF and EC50 being 34.6 +/- 5.0% and 3 x 10(-6)M, respectively . The increase in CBF produced by RXM (3 x 10(-6)M) was not influenced by pretreatment of cells with the beta-adrenergic blocker propranolol, the lipoxygenase inhibitor AA-861, or the Ca(2+)-channel blocker verapamil, but it was partially reduced by the cyclooxygenase inhibitor indomethacin (p less than 0.05) . Intracellular cyclic AMP levels were increased by 10(-4)M RXM from 42.3 +/- 8.7 to 72.7 +/- 7.0 pmoles/mg protein (p less than 0.05) . These results indicate that RXM stimulates ciliary motility; an effect that may be attributed at least in part to the synthesis of cyclooxygenase products and cyclic AMP, and suggest that this macrolide could be useful in treating patients with impaired mucociliary transport in the airway.

Trends Biotechnol, 1991 May, 9(5), 169 - 75
Human and mouse monoclonal antibodies by repertoire cloning; Burton DR; Antibody repertoires, the wide range of antibody molecules produced by animals, can now be established in bacteria by cloning and expression of antibody genes . Beginning with immunized animals, antigen can be used to select, from the repertoire, clones which secrete specific monoclonal antibody . In the future, immunization may become unnecessary . The method may provide a general route, which has so far eluded biotechnologists, to human monoclonal antibodies.

Pharm Weekbl Sci, 1991 Apr 26, 13(2), 70 - 3
Distribution of naturally occurring quinones; Thomson RH; Angiosperms, fungi (including lichens), and bacteria are the main sources of natural quinones . Small numbers are present in algae, ferns, conifers, sponges, echinoderms, other marine animals, and arthropods . In angiosperms quinones have some chemotaxonomic value at the genus and family level but more surveys are required.

J Immunol Methods, 1991 Apr 25, 138(2), 191 - 9
Fetal intestinal transplant model for mucosal immune responses; Kantak AG et al.; A rat fetal intestinal transplant model was developed for long-term study of intestinal immune responses . For the model, fetal small intestine is transplanted into the dorsal subcutaneous tissue of syngeneic adults and allowed to mature, providing an accessible site, isolated from the intestinal stream . We previously demonstrated normal histologic maturation of the transplant . Specific antibody-producing cells appeared in the lamina propria of both transplant and native in situ intestine following intraluminal immunization of the transplant with cholera toxin, and conversely, in transplants after immunization of in situ intestine . An enterointestinal lymphocyte migratory pathway (originating in intestine and migrating to another region of the intestine) was thus demonstrated unequivocally . We found a bacterial flora in the transplant, and showed normal villus morphology in scanning electron microscopy . Less than 200 pg, i.e., a 10(-7) fraction, of 2 mg macromolecular lipopolysaccharide placed in the transplant lumen was absorbed per plasma lipopolysaccharide half-life . Immunization of the transplant with cholera toxin resulted in specific IgA and IgG antibody in the transplant lumen and in bile, and specific IgG, but not IgA, antibody in serum . A second dose of antigen gave an anamnestic rise in intra-transplant antibody . Intestinal immune tolerance was also demonstrated: sheep red blood cells (SRBC) administered into the transplant for 7 days suppressed splenic IgM plaque forming responses to subsequent intraperitoneal challenge with SRBC . These studies further demonstrate that the fetal intestinal transplant behaves immunologically like native intestine, and therefore provides a useful model for investigation of the intestinal immune system.

J Immunol, 1991 Apr 15, 146(8), 2678 - 86
Epitopes of the p70 and p80 (Ku) lupus autoantigens; Reeves WH et al.; High titer autoantibodies to the Ku Ag, a DNA-protein complex containing 70- and approximately 80-kDa protein subunits (p70 and p80, respectively), are found in sera of certain patients with systemic lupus erythematosus and related disorders . Autoepitopes of the Ku Ag were identified and partially characterized by expressing fragments of the p70 and p80 cDNA as fusion proteins in bacteria . Systemic lupus erythematosus sera reacted on immunoblots with at least three epitopes of p70 (amino acids 560-609, 506-535, and 115-467), and three epitopes of p80 (amino acids 682-732, 558-681, and 1-374) . These six antigenic regions had distinct amino acid sequences, and were also immunologically distinct, as determined by using immunoaffinity-purified auto-antibodies to particular epitopes . Detailed mapping of the strongly antigenic region near the C terminus of p70 revealed a complex conformational or discontinuous epitope, the antigenicity of which was abolished by deleting either amino acids 560-571 or 601-609 . The C terminus of p80 may also contain a discontinuous or conformational epitope(s) . Although only some sera reacted with p70 or p80 on immunoblots, all sera that immunoprecipitated the native Ku complex reacted with native Ku by ELISA, and inhibited the binding of mAb directed at epitopes of native Ku . Taken together, these studies indicate that anti-Ku autoantibodies target a diversity of independent epitopes located on p70, p80, and the intact Ku complex, and that a significant portion of the autoantibodies in most patients' sera is directed against conformational/discontinuous epitopes.

Allerg Immunol (Paris), 1991 Apr, 23(4), 145 - 52
{Determination of the anti-infective action of an immunomodulator . Biostim as an example}; Ounis I; In order to evaluate the antiinfectious action of an immunomodulator, either in vitro or in vivo, in both animal and man, we have to answer three questions: What the targets are? Which models best allow the study of the mode of action? Which method should be used to evaluate clinical improvement? The targets of RU 41740 (Biostim), a purified Immunomodulator of biological origin, are the pool of immunocompetent cells with an enhancement of two major mediators: IL1 and CSF . As there are numerous interactions between antiinfectious, antiinflammatory, antiallergic responses and mediators pleiotropism, no reliable predictions exist . Moreover concerning the "in vivo" activity experimentally induced infections represent a preferential pharmacologic model in order to study the antiinfectious activity of an immunomodulating compound . Under such conditions, RU 41740 testing administered either orally, intraperitoneally or by aerosol is effective, whatever the responsible infectious agents are: extra or intracellular development bacteria, virus or yeasts . In regard to the differences of the local defenses (pulmonary and cutaneous), the targeted organ has to be identified during the mode of action studies . RU 41740 enhances alveolar macrophage metabolic functions in the respiratory tract . From a pharmacoclinical point of view, this stimulation of immune components has been investigated under different doses and treatment schedule of RU 41740 with a double blind versus placebo studies . The targeted pathology involves the risk of infections and immune deficiency . In chronic bronchitis infections often occur and are responsible for acute respiratory failures and this contributes to the obstructive syndrome . The clinical efficiency on prophylaxis must be evaluated by double blind versus placebo, randomized studies with a long follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Mol Reprod Dev, 1991 Apr, 28(4), 346 - 50
Ultrastructural study of the mature egg of the marine sponge Stelletta grubii (Porifera Demospongiae); Sciscioli M et al.; Stelletta grubii is an oviparous demosponge, which, during its reproductive period from summer to autumn, has small eggs (80-90 microns) dispersed uniformly in the mesohyl . The nucleolated nucleus is surrounded by dictyosomes containing small vesicles, which contribute to form reserve material . Vesicles, numerous food vacuoles, and groups of mitochondria are observed in the granular cytoplasm . Electron-dense yolk inclusions and lipids are found peripherally . The cortical portion of the egg cytoplasm possesses vacuoles with fibrillar contents . The egg forms pseudopodia, which could permit the capture of numerous bacteria present in the surrounding mesohyl . A thick layer of collagen fibrils, including lophocytes, separates the egg from the surrounding sponge mesohyl . Ultrastructural analysis has demonstrated the presence both of cellular components capable of autosynthetic activity (nutrient vesicles) and of phagocytosis mechanisms (pseudopod capture of bacteria) for the storage of nutrients by the egg.

Comput Appl Biosci, 1991 Apr, 7(2), 189 - 93
Software for the development and evaluation of probabilistic identification matrices; Bryant TN; A number of programs are described for the development and evaluation of probabilistic identification matrices for use with computer-assisted identification . The program BEST reads an initial matrix of per cent probabilities for all the binary characters examined during a cluster analysis and determines the most useful set of tests for distinguishing taxa in the matrix . Program RESORT creates from the initial matrix an identification matrix in which the order of the tests may be different or the number of tests reduced . A printed version of a matrix can be produced by MATPRINT, which creates tables giving the per cent probability of a positive test result and the test results presented as '-', 'v' and '+' depending on a user-specified threshold . Program IDSC evaluates an identification matrix by calculating the best identification score for each taxon in the matrix using the expected result for each test . The programs were written in FORTRAN 77 and can be run on any micro-computer using the PC/MS-DOS operating system.

Theor Popul Biol, 1991 Apr, 39(2), 201 - 39
Optimal growth schedule of pathogens within a host: switching between lytic and latent cycles; Sasaki A et al.; We have studied the optimal growth schedule of a pathogen, which maximizes the total number of transmissions from an infected host to other individuals until host death or recovery . It is assumed that both transmission rate f(N) and host mortality increase with the number of pathogens, N . The model predicts that the optimal growth schedule of pathogens strongly depends on the curvature of f(N): If f(N) increases faster than linearly with N, the pathogens should always reproduce at the maximum speed . By contrast, if f(N) saturates with N, the optimal schedule is composed of (1) a brief initial stage of infection, in which the pathogens proliferate at the maximum speed (productive cycle), (2) followed by the long latent period with the "stationary infection level," N* (latent cycle), (3) which may end when the pathogens start rapid proliferation triggered either by the host's senescence ("programmed break") or by the sudden rise in the host's mortality ("incidental break") . The latter may be caused by the double infection of another strain . We also examine the Nash equilibrium schedule of pathogen growth in the presence of multiple infections.

Gene, 1991 Apr, 100, 231 - 5
Cloning and characterization of the Saccharopolyspora erythraea fdxA gene encoding ferredoxin; Donadio S et al.; The Saccharopolyspora erythraea gene (fdxA) corresponding to a previously purified ferredoxin {Shafiee and Hutchinson, J . Bacteriol., 170 (1988) 1548-1553} was cloned using an oligodeoxyribonucleotide probe based on the N-terminal sequence of the ferredoxin . The nucleotide sequence of a 1.3-kb segment encompassing fdxA indicates that the corresponding protein, SeFdI, is 105 amino acids long, and very similar to other 7Fe ferredoxins . A partial open reading frame closely linked to fdxA was also detected . Disruption of fdxA was attempted by replacing the wild-type allele with an in vitro mutated copy . The failure to construct an fdxA mutant strain suggests that fdxA lies in an essential region of the S . erythraea chromosome.

Anal Chem, 1991 Apr 1, 63(7), 658 - 65
Pulsed field gel electrophoresis; Gardiner K; The development of pulsed field gel electrophoresis has increased by 2 orders of magnitude the size of DNA molecules that can be routinely fractionated and analyzed . This increase is of major importance to molecular biology because it simplifies many previously laborious investigations and makes possible many new ones . Its range of application spans all organisms, from bacteria and viruses to mammals.

Scand J Dent Res, 1991 Apr, 99(2), 117 - 29
Phagocytosis and virulence of different strains of Porphyromonas gingivalis; Sundqvist G et al.; In this study 17 strains of Porphyromonas gingivalis, both reference and clinical isolates, were investigated for their in vitro interaction with human polymorphonuclear leukocytes, hydrophobicity, density, and virulence in a mouse model . The results of the phagocytosis, hydrophobicity, and density experiments showed that P . gingivalis strains could be divided into two distinct groups . One group of strains were readily attached and phagocytosed when exposed to the leukocytes . These bacteria were hydrophobic and had a higher buoyant density than the other group, which were poorly phagocytosed, had a low buoyant density, and were hydrophilic . This latter group also exhibited an extracellular meshwork resembling a glycocalyx when examined by electron microscopy . There were also significant differences between strains in the mouse pathogenicity model . Two strains caused an invasive, spreading infection compared with the other 15 strains which produced small, localized abscesses . There was no clear correlation between the results of the phagocytosis assay and the virulence of the bacteria when injected subcutaneously in mice . Resistance to phagocytosis may be important for survival of these bacteria, but it does not in itself imply the ability to cause damage to the host.

J Dent, 1991 Apr, 19(2), 71 - 9
Materials techniques for lining composite resin restorations: a critical approach; Brannstrom M et al.; Composite resin restoration of posterior teeth necessitates a reassessment of cavity insulation and dentine conditioning . The primary function of cavity insulation under composite resin restorations is to prevent the formation of a bacterial, fluid-filled gap nearest the cavity walls . Gap formation can contribute not only to sensitivity to cold but also to pulpal complications and secondary caries . Unfortunately, none of the currently available systems for cavity insulation fulfil this basic requirement . The evidence suggests, however, that the most effective insulator is a very thin liner which does not pool in retention grooves and which can cover the entire cervical wall as well as the remaining cavity walls, except for etched enamel . Such a liner should not bond to composite resin and thus be detached from the dentine during polymerization contraction of the composite . Nor should it be leached away by the oral fluids . In order to preserve the liner, the air-filled contraction gap which forms between liner and composite should be impregnated with resin immediately after the major setting contraction of the composite . In this context the use of retention grooves in Class II and Class V cavities is recommended, to minimize the effect of thermal and occlusal stress . Combined with etched enamel walls, well-placed retention grooves can reduce the risk of gap formation and creep due to mechanical stress and the deformation potential of the tooth structure and the filling . The smear layer can disappear entirely and be replaced by fluid and bacteria . It should therefore be removed, but the smear plugs blocking the apertures of the dentinal tubules should be left undisturbed and reinforced by impregnation with fluoride.(ABSTRACT TRUNCATED AT 250 WORDS)

J Egypt Soc Parasitol, 1991 Apr, 21(1), 15 - 22
Fresh-water amoebae from four aquatic sites in Egypt; Mansour NS et al.; Water samples from four aquatic sites in Egypt were examined for the presence of free-living amoebae . Amoebae were isolated and cultured on 1.5% non-nutrient agar with bacteria . They were studied morphologically and tested for production of flagellated forms, encystment, excystment, nuclear division, temperature tolerance and pathogenicity in young mice (8 - 10 gm) . Didascalus thorntoni and Naegleria gruberi were dominant in all surface waters . Naegleria fowleri, Acanthamoeba glebae, A . culbertsoni and A . rhysodes were found in Lower Egypt, while Vahlkampfia avara and V . thornata were found in Upper Egypt . All species tolerated incubation temperatures of up to 36 degrees C except for A . rhysodes which degenerated at 34 degrees C . A . culbertsoni tolerated 38 degrees C but died at 40 degrees C . Amoebae were detected histologically in a necrotic brain tissue from only one mouse which was inoculated with A . culbertsoni.

Arch Dis Child, 1991 Apr, 66(4), 495 - 500
Energy content of stools in normal healthy controls and patients with cystic fibrosis; Murphy JL et al.; Stool energy losses and the sources of energy within the stool were determined in 20 healthy controls and 20 patients with cystic fibrosis while on their habitual pancreatic enzyme replacement treatment . Stool energy losses were equivalent to 3.5% of gross energy intake in healthy children (range 1.3-5.8%) . Despite a comparable gross energy intake, stool energy losses were three times greater in patients with cystic fibrosis than controls averaging 10.6% of gross energy intake (range 4.9-19.7%) . Stool lipid could account for only 29% and 41% of the energy within the stool in controls and patients with cystic fibrosis respectively and was poorly related to stool energy . Approximately 30% of the energy within the stool could be attributable to colonic bacteria in both the healthy children and patients with cystic fibrosis . These results suggest that stool energy losses in healthy children are relatively modest but that even when patients with cystic fibrosis are symptomatically well controlled on pancreatic enzyme replacement, raised stool energy losses may continue to contribute towards an energy deficit sufficient to limit growth in cystic fibrosis . As the energy content per gram wet weight remains relatively constant (8 kJ/g), stool energy losses may be estimated from simple measurements of stool wet weight.

Epidemiol Infect, 1991 Apr, 106(2), 221 - 9
ABO blood group, secretor status and detection of Helicobacter pylori among patients with gastric or duodenal ulcers; Mentis A et al.; Patients (454) referred for gastroscopy to the General Hospital of Athens were examined to determine (1) if non-secretors were over-represented among patients with ulcers and (2) if there was an association with ABO blood group or secretor status and carriage of Helicobacter pylori . Compared with the local population, among patients with either gastric ulcer (51) or duodenal ulcer (96) there was a significant increase in the proportion of those who were blood group O (P less than 0.025); however, there were no significant differences in the proportions of non-secretors . H . pylori was identified in 62% of the 454 patients: 59.5% of those without evidence of ulcers; 62.5% of those with gastric ulcer; 88% of those with duodenal ulcer (P less than 0.0005) . These bacteria were cultured more often and in higher numbers from patients with duodenal ulcer (P less than 0.025) . There was no association between ABO blood group and prevalence of H . pylori . The prevalence of H . pylori among non-secretors with gastric ulcer (12.5%) was significantly lower than that for non-secretors with duodenal ulcer (100%) (P less than 0.0005) . This was not observed for secretors.

Eur J Immunol, 1991 Apr, 21(4), 1039 - 46
The genes for a mouse hematopoietic differentiation marker called the heat-stable antigen; Wenger RH et al.; We have isolated a murine cDNA by virtue of its expression in pre-B cell lines but not in plasmacytomas . In mouse, mRNA is detected by Northern blot analysis exclusively in hematopoietic tissues with the exception of brain . When expressed in bacteria, the encoded protein is specifically recognized by several antibodies against the murine hematopoietic differentiation marker called heat-stable antigen (HSA) . In contrast to previous speculations, these results suggest that the antigenic determinant recognized by anti-HSA antibodies is proteinaceous . The cDNA sequence is essentially identical to a mouse HSA cDNA recently published (Kay et al., J . Immunol . 1990 . 145: 1952) . Three HSA genes were isolated, one of which corresponds to the isolated cDNA . The other two appear to be intronless retroposons which, despite numerous sequence changes, maintain an open reading frame . One of these intronless genes could code for an alternative form of HSA with a transmembrane domain and a cytoplasmic tail not encoded by the intron-containing gene . This gene could be expressed, based on sequence comparisons of the three genes . However, using polymerase chain reaction amplification of first strand cDNA from various cell lines and adult mouse tissues, we could detect expression only of the intron-containing gene.

Ann Thorac Surg, 1991 Apr, 51(4), 593 - 8
Tricuspid valve repair for tricuspid valve endocarditis: tricuspid valve "recycling"; Allen MD et al.; Tricuspid valve endocarditis traditionally has been treated with either valve excision or valve replacement . To avoid implantation of foreign material in an infected field, we have applied the principles of mitral valve repair to 4 patients with tricuspid valve endocarditis . On preoperative echocardiography, all patients had 3 to 4+ tricuspid regurgitation, evidence of progressive right ventricular enlargement, and mobile vegetations . In each case, up to three quarters of the anterior leaflet was excised en bloc with infected chordae and papillary muscle heads . Surgical procedures included standard quadrangular resection, conversion to a bicuspid valve, and pericardial patch replacement of the anterior leaflet with mobilization of basal chordae to replace resected marginal chordae . On postoperative echocardiography, tricuspid regurgitation and right ventricular dimensions were reduced in 2 of 4 patients in spite of loss of leaflet tissue . All excised valve tissue demonstrated bacteria on Gram stain or culture . Nonetheless, all repaired valves were successfully sterilized without recurrent infections . Tricuspid valve repair can allow eradication of infection with potential for improving valve competency in complicated tricuspid valve endocarditis.

Am J Med, 1991 Apr, 90(4), 516 - 8
Prosthetic valve endocarditis due to Cardiobacterium hominis occurring after upper gastrointestinal endoscopy; Pritchard TM et al.; Bacterial endocarditis secondary to endoscopic procedures has been convincingly documented in only four cases . We describe a case of prosthetic valve endocarditis due to Cardiobacterium hominis that developed after upper gastrointestinal endoscopy . Because of this, we recommend subacute bacterial endocarditis prophylaxis in patients who have a prior history of endocarditis or valve replacement.

Proc Natl Acad Sci U S A, 1991 Apr 1, 88(7), 2678 - 82
Biosynthetic threonine deaminase gene of tomato: isolation, structure, and upregulation in floral organs; Samach A et al.; The gene encoding the plant biosynthetic threonine deaminase (Td; EC 4.2.1.16) has been cloned as a result of its unusual upregulation in tomato flowers . The Td gene of tomato encodes a polypeptide of 595 residues, the first 80 of which comprise a putative two-domain transit peptide cleaved at position 51 . Comparison of the amino acid sequence with the corresponding enzymes from yeast and bacteria reveals a near identity of the important catalytic regions and greater than 40% overall similarity . The Td gene is unique in the tomato genome and its coding region is interrupted by eight introns . Its expression is greater than 50-fold higher in sepals and greater than 500-fold higher in the rest of the flower than in leaves or roots . Its overexpression, however, is strictly confined to the parenchymal cells of the floral organs . In young tomato leaves, the chloroplast-bound enzyme is found almost exclusively in the subepidermal spongy mesophyll cells.

Genes Dev, 1991 Apr, 5(4), 656 - 69
A thymus-specific member of the HMG protein family regulates the human T cell receptor C alpha enhancer; Waterman ML et al.; The human T cell-specific transcription factor TCF-1 alpha plays a key role in the tissue-specific activation of the T cell receptor (TCR) C alpha enhancer and binds to pyrimidine-rich elements (5'-PyCTTTG-3') present in a variety of other T cell-specific control regions . Using amino acid sequence information derived from the DNA affinity-purified protein, we have now isolated cDNA clones encoding TCF-1 alpha . The TCF-1 alpha cDNA contains a single 68-amino-acid domain that is homologous to a region conserved among high-mobility group (HMG) and nonhistone chromosomal proteins . Expression of full-length and mutant cDNA clones in bacteria reveal that the single HMG motif, which is predicted to contain two extended alpha-helical segments, is sufficient to direct the sequence-specific binding of TCF-1 alpha to DNA . Northern blot experiments demonstrate further that TCF-1 alpha mRNA is highly tissue specific, found primarily in the thymus or T cell lines . The immature CEM T cell line expresses relatively low levels of TCF-1 alpha mRNA, which are increased upon activation of these cells by phorbol esters . Interestingly, the cloned TCF-1 alpha protein is a potent transcriptional activator of the human TCR alpha enhancer in nonlymphoid cell lines, whereas the activity of the endogenous protein in T cell lines is strongly dependent on an additional T cell-specific protein that interacts with the core enhancer . TCF-1 alpha is currently unique among the newly emerging family of DNA-binding regulatory proteins that share the HMG motif in that it is a highly tissue-specific RNA polymerase II transcription factor.

FASEB J, 1991 Apr, 5(7), 2061 - 7
Short-term and long-term memory in single cells; Morimoto BH et al.; Many approaches have been used to study short- and long-term memory . Bacteria detect chemical gradients using a memory obtained by the combination of a fast excitation process and a slow adaptation process . This model system, which has the advantages of extensive genetic and biochemical information, shows no features of long-term memory . To study long-term memory, neural cell line systems have been developed that exhibit two phenomena associated with learning and memory, habituation and potentiation . The expression of these phenomena in clonal cell lines, devoid of synaptic connections, makes it possible to study the biochemical and molecular mechanisms that contribute to short-term and long-term memory.

Am Rev Respir Dis, 1991 Apr, 143(4 Pt 1), 738 - 43
Prospective study of nosocomial pneumonia and of patient and circuit colonization during mechanical ventilation with circuit changes every 48 hours versus no change; Dreyfuss D et al.; Circuits on mechanical ventilators with cascade humidifiers are routinely changed every day or every other day, although humidifying cascades have been considered unlikely to increase the risk of respiratory infection because they do not generate aerosols . Moreover, changing ventilator tubings every 24 rather than every 48 h increases the risk of ventilator-associated pneumonia . To study the effects of ventilator circuit changes on the rate of nosocomial pneumonia and on patient and circuit colonization, 73 consecutive patients requiring continuous mechanical ventilation for more than 48 h were randomly assigned to either ventilator circuit changes every 48 h (Group 1, n = 38) or no change (Group 2, n = 35) . Patients dying or being weaned before 96 h were not analyzed (Group 1 n = 3; Group 2 n = 7; leaving Group 1 n = 35 and Group 2 n = 28; p = 0.13) . Ventilator-associated pneumonia was defined as the occurrence during mechanical ventilation or within 48 h after weaning of a new and persistent infiltrate on chest X-ray, purulent tracheal secretions, and a positive culture of a protected brush specimen (greater than or equal to 10(3) cfu/ml) . Bacterial colonization was assessed every 48 h by quantitative cultures of pharyngeal swab, tracheal aspirate, humidifying cascade, and expiratory tubing trap . The two groups were similar in terms of age, indication for and duration of ventilation, and severity of illness.(ABSTRACT TRUNCATED AT 250 WORDS)

Arch Dermatol, 1991 Apr, 127(4), 493 - 6
Cutaneous cellulitis; Sachs MK; Cellulitis has long been postulated to be the result of antecedent bacterial invasion with subsequent bacterial proliferation . Nonetheless, the difficulty in isolating putative pathogens from cellulitic skin has served to cast doubt on this hypothesis . In this regard, the skin is provided with a unique set of lymphoid and reticular cells with the capacity to secrete lymphokines and cytokines . These substances rapidly reduce the number of viable bacteria from infection by enhancing the infiltration of skin by circulating macrophages and neutrophils . The warmth and erythema associated with cellulitis are most likely produced both by a small number of residual bacteria and by fragmented bacterial remnants, and amplified by the lymphokines that are secreted in response to antigenic challenge . Anti-inflammatory agents may play a significant role in enhancing the resolution of infection by reducing the production of soluble mediators by these intra-epidermal immunocompetent cells.

Mol Cell Biol, 1991 Apr, 11(4), 2169 - 79
Dissection of the bifunctional ARGRII protein involved in the regulation of arginine anabolic and catabolic pathways; Qui HF et al.; ARGRII is a regulatory protein which regulates the arginine anabolic and catabolic pathways in combination with ARGRI and ARGRIII . We have investigated, by deletion analysis and fusion to LexA protein, the different domains of ARGRII protein . In contrast to other yeast regulatory proteins, 92% of ARGRII is necessary for its anabolic repression function and 80% is necessary for its catabolic activator function . We can define three domains in this protein: a putative DNA-binding domain containing a zinc finger motif, a region more involved in the repression activity located around the RNase-like sequence, and a large activation domain.

Exp Cell Res, 1991 Apr, 193(2), 432 - 4
Cooperative ATP binding by cloned lamin C; Schwartz AM et al.; Cloned human lamin C was expressed in and purified from bacteria and used in ATP binding assays . Scatchard analysis revealed strong positive cooperative and noncooperative binding, with estimated apparent dissociation constants of 3 X 10(-6) and 2 X 10(-5) M, respectively . The binding is strongly pH dependent . ATP binding by lamins A/C (presumably as intermediate filaments) may provide a substantial storage depot for ATP at the peripheral lamina for use by a number of ATP-requiring nuclear scaffold enzymes.

Zentralbl Bakteriol, 1991 Apr, 275(1), 54 - 62
Isolation and characterization of temperature sensitive mutants of the F5 deletion mutant of mycobacteriophage D29; Seres S et al.; Seven thermosensitive mutants of the F5 deletion mutant of the mycobacteriophage D29 were described . The mutants were obtained using N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) mutagenesis, and were characterized using temperature shift assays, complementation and recombination tests, electron microscopy of infected host bacteria at non-permissive temperature, and serum blocking power . Mutants deficient in tail assembly, and mutants deficient in head and tail assembly were described . Mutants deficient in head assembly but capable of assembling tails were not isolated during this study . From the data, 3 provisional linkage map of the phage F5 was proposed.

DICP, 1991 Apr, 25(4), 359 - 60
Effect of I-Scrub on signs and symptoms of chronic blepharitis; Avisar R et al.; To assess the effect of I-Scrub (Spectra Pharmaceutical Services), a new detergent eyelid scrub, on the subjective symptoms and objective clinical signs of chronic blepharitis, 20 patients with this disease were treated for three weeks . None of them yielded positive cultures for virulent bacteria from the eyelids and conjunctiva . Most of the patients reported significant reduction in the subjective symptoms and in the severity of the clinical signs as well . No adverse effects were observed . The results of our study suggest that this product is of value as a detergent eyelid scrub in the treatment of chronic blepharitis.

Biochimie, 1991 Apr, 73(4), 411 - 21
Mechanism of specific LexA cleavage: autodigestion and the role of RecA coprotease; Little JW; Specific LexA cleavage can occur under two different conditions: RecA-mediated cleavage requires an activated form of RecA, while an intramolecular self-cleavage termed autodigestion proceeds spontaneously at high pH and does not involve RecA . The two cleavage reactions are closely related . We postulate that RecA stimulates autodigestion rather than acting as a typical protease, and it is proposed to term this activity 'RecA coprotease' to emphasize this indirect role . The mechanism of autodigestion is similar to that of a serine protease, and RecA appears to act by reducing the pKa of a critical lysine residue LexA . A new class of mutants, termed lexA (IndS), is described; these mutations increase the rate of LexA cleavage.

Zh Mikrobiol Epidemiol Immunobiol, 1991 Apr, (4), 63 - 6
{Brucellar antibody erythrocytic diagnostic agent made from monoclonal antibodies}; Karal'nik BV et al.; Two preparations based on monoclonal antibodies to bacteria of the genus Brucella have been obtained . From the monoclonal preparations and globulins isolated from them erythrocyte diagnostica have been obtained with the use of amidol . Experiments on the cross indication of brucellae and other bacteria by means of these diagnostica and a similar preparation obtained from polyclonal serum have shown very high specificity of erythrocyte immunoreagents prepared from monoclonal antibodies.

Mol Gen Genet, 1991 Apr, 226(1-2), 107 - 12
Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp . PCC6803 leads to the activation of the cryptic psbG2 gene; Steinmuller K et al.; The genes psbG1 and psbG2 in the cyanobacterium Synechocystis sp . PCC6803 are homologous . The psbG1 gene is located on the chromosome and is part of the ndhC--psbG1--ORF157 operon, while psbG2 is located on a plasmid and is not flanked by equivalent ndhC or ORF157 genes . Mutants in which psbG1 is deleted grow well under autotrophic conditions, while their growth is impeded in mixotrophic medium . These results argue against a functional role for psbG1 in photosynthesis, i.e . photosystem II, and are more compatible with a function in respiration . The psbG2 gene is not transcribed in wild-type cells, but in psbG1 mutants the insertion of DNA sequences in close proximity to the psbG2 reading frame has led to transcriptional activation of psbG2 . Thus, psbG2 represents an example of a cryptic gene, similar to those found in other bacteria.

J Bacteriol, 1991 Apr, 173(8), 2704 - 6
Acetate catabolism in the dissimilatory iron-reducing isolate GS-15; Champine JE et al.; Acetate-grown GS-15 whole-cell suspensions were disrupted with detergent and assayed for enzymes associated with acetate catabolism . Carbon monoxide dehydrogenase and formate dehydrogenase were not observed in GS-15 . Catabolic levels of acetokinase and phosphotransacetylase were observed . Enzyme activities of the citric acid cycle, i.e., isocitrate dehydrogenase, 2-oxoglutarate sythase, succinate dehydrogenase, fumarase, and malate dehydrogenase, were observed.

J Bacteriol, 1991 Apr, 173(8), 2576 - 80
Three-dimensional structure of the nickel-containing hydrogenase from Thiocapsa roseopersicina; Sherman MB et al.; The three-dimensional structure of the nickel-containing hydrogenase from Thiocapsa roseopersicina has been determined at a resolution of 2 nm in the plane and 4 nm in the vertical direction by electron microscopy and computerized image processing on microcrystals of the enzyme . The enzyme forms a large ring-shaped complex containing six each of the large (62-kDa) and small (26-kDa) subunits . The complex is very open, with six well-separated dumbbell-shaped masses surrounding a large cylindrical hole . Each dumbbell is interpreted as consisting of one large and one small subunit.

Infect Immun, 1991 Apr, 59(4), 1558 - 63
T-cell proliferative response to antigens secreted by Mycobacterium tuberculosis; Andersen P et al.; An infection model of human tuberculosis was established with C57BL/6J mice . The lymphocyte proliferative responses to antigens from Mycobacterium tuberculosis were investigated during the course of infection and compared with results obtained with a group of mice immunized with large amounts of killed bacteria . The two groups responded similarly to a number of mycobacterial antigens, but marked differences in responses against secreted antigens were found; only infected mice responded vigorously to these . The responding lymphocyte subpopulation was made up of L3T4+ T lymphocytes under restriction of the Ia molecule.

J Leukoc Biol, 1991 Apr, 49(4), 380 - 7
Tumor necrosis factor and granulocyte macrophage-colony stimulating factor stimulate human macrophages to restrict growth of virulent Mycobacterium avium and to kill avirulent M . avium: killing effector mechanism depends on the generation of reactive nitrogen intermediates; Denis M; An avirulent and a virulent strain of Mycobacterium avium were selected on the basis of their growth patterns in human monocyte-derived macrophages . The virulent 7497 M . avium grew progressively in untreated macrophages, whereas the avirulent LR/149 M . avium was killed to a moderate extent by untreated human macrophages (50% of the original infectious inoculum killed 7 days after infection) . We set out to investigate the possibility of modulating these growth patterns by cytokine treatment . Application of tumor necrosis factor (TNF) (100 U/ml) led to macrophages restricting significantly the growth of virulent M . avium 7497 (tenfold decrease at 7 days) . TNF was also effective at modulating positively the interaction between avirulent LR/149 M . avium and macrophages inasmuch as TNF-treated cells killed 99% of infecting mycobacteria at 7 days . Granulocyte macrophage-colony stimulating factor (GM-CSF) (100-10,000 U/ml) treatment led to macrophages being as mycobacteriostatic for virulent 7497 M . avium as TNF-alpha-treated cells (i.e., tenfold reduction in growth) . Treatment of macrophages with both GM-CSF and TNF-alpha was shown to have additive effects on bacteriostatic activity on M . avium . The mechanism of killing of avirulent M . avium by TNF-alpha was shown to be dependent on the generation of reactive nitrogen intermediates, as seen by inhibition of effector mechanisms by NG-monomethyl-arginine and arginase . Moreover, there was a correlation between NO2- generation and mycobactericidal activity of macrophages . Addition of superoxide dismutase reversed the killing of avirulent M . avium by untreated or TNF-treated macrophages . This abrogation was also apparent in chronic granulomatous disease (CGD) macrophages, which were inefficient at generating reactive oxygen intermediates . Moreover, macrophages from CGD patients killed avirulent M . avium as efficiently as cells from normal individuals . We conclude from these results that 1) GM-CSF and TNF-alpha, alone or in combination, increase effector functions of macrophages against virulent and avirulent strains of M . avium; 2) reactive nitrogen intermediates seem to be involved in this effector mechanism; and 3) superoxide dismutase protected M . avium against macrophage effector function, seemingly by protecting the bacteria against endogenous superoxide anion . The implications of these findings for host resistance to atypical mycobacteria are discussed.

Arch Biochem Biophys, 1991 Apr, 286(1), 257 - 63
Reconstitution of the Deinococcus radiodurans aposuperoxide dismutase; Juan JY et al.; Deinococcus radiodurans, a radiation-resistant aerobe, synthesized a 43,000 Mr dimeric superoxide dismutase . The holoenzyme, sp act 3300 U/mg, contained 1.5 g-atoms Mn, 0.6 g-atom Fe, and 0.1 g-atom Zn per mole dimer . Apoprotein, prepared by dialysis of the holoenzyme in denaturant plus chelator and then renatured in chelex-treated Tris chloride buffer, rapidly regained superoxide dismuting activity upon incubation in 1 mM MnCl2 . Reconstitution was dependent on Mn concentration and pH . The Mn-reconstituted protein, sp act 3560 U/mg, contained 1.7 g-atoms Mn per mole dimer . The holoenzyme and Mn-reconstituted apoprotein migrated with the same patterns in 10% acrylamide gels and focused to the same pattern upon isoelectric focusing . Fluorescence emission maxima of the holoenzyme, Mn-reconstituted apoprotein, and the renaturated apoprotein were 329 +/- 1 nm but differed from the denatured apoprotein (352 nm) . Apoprotein bound 1.7 g-atoms Zn and from 3-7 g-atoms Fe per mole dimer on incubation with 1 mM ZnSO4 and Fe(NH4)2(SO4)2, respectively . Although neither Zn nor Fe restored superoxide dismuting activity, the ferrous and the zinc salt inhibited reconstitution of the apoprotein with manganese . Metal addition to renatured aposuperoxide dismutase offers a novel approach to reconstitution of procaryote superoxide dismutases.

Minerva Stomatol, 1991 Apr, 40(4), 203 - 10
{The role of phagocytic cells in periodontal disease}; Matarasso S et al.; Having described the morphological and functional characteristics of phagocytic cells, the paper underlines that, in addition to the etiological responsibility of bacterial plaque, the main role in the onset and evolution of periodontitis is played by the host's response . Phagocytic response plays a fundamental role in the host's defence reaction and represents the first barrier to the penetration of bacteria into periodontal tissue . In addition to their defensive role, phagocytic cells may also be responsible for damage to periodontal tissue as a collateral effect of their phagocytic function, thus worsening the periodontal lesion.

Biochem Soc Trans, 1991 Apr, 19(2), 249 - 52
An overview of conventional and novel routes of protein secretion; Colman A; The purpose of this overview is to demonstrate the new complexities that have been revealed in secretory pathways . It is clear that in some areas (e.g . ATP-driven translocators), mechanisms have been conserved between bacteria and higher eukaryotic cells, while certain new processes involve modified secretory routes (e.g . antigen presentation) which will be restricted to eukaryotic cells . It is generally believed that in the evolution of living systems, the development of membrane-delimited compartments was crucial, and that insertion of proteins into membranes allowed more control of the passage of molecules through the membrane . It has been suggested that the first secretory proteins were in fact membrane bound, and extracellular proteolysis was responsible for the release of the first soluble secretory proteins . If so, it is interesting to note that the process still exists today and Pandiella {259-262} has described how the release of the growth factor transforming growth factor-alpha (TGF alpha) from mammalian cells is a case of regulated surface proteolysis . Finally, it is clear to see that as regards secretory pathways, we should keep an open mind as to which routes are utilized and which are not, and indeed, which routes exist and which do not . It appears that if two secretory organelles exist then some protein will be shown to move between them . Even the cytosol can provide a reservoir for secretory proteins or peptides . Perhaps in time S . S . Rothman will be thought of as the Nostradamus of protein secretion.

Can J Vet Res, 1991 Apr, 55(2), 121 - 7
A model for demonstrating the adhesion of Actinobacillus seminis to epithelial cells; Healey MC et al.; The objective of this study was to demonstrate that a field isolate of Actinobacillus seminis (As8C) will adhere to epithelial cells and that this adhesion can be inhibited by pretreating the bacteria with mouse serum containing polyclonal antibodies (PoAbs) prepared against this isolate . An indirect fluorescent antibody test, transmission electron microscopy, and phase-contrast microscopy confirmed the adhesion of As8C to an established culture of bovine kidney epithelial cells (BKECs) . In a bacterial adhesion assay, 40 As8C were estimated to adhere to each BKEC after 60 min . Using a bacterial inhibition assay, PoAbs diluted 10(-2) or 10(-3) inhibited the adhesion of As8C to BKECs by approximately 90% . Bacterial inhibition decreased to about 50% when the PoAbs were diluted to 10(-4) . There was less than 10% inhibition of adhesion of As8C to BKECs when higher dilutions of PoAbs were used . The inhibition of As8C adhesion to BKECs was less than 20% following pretreatment of BKECs with 10(-2) to 10(-5) dilutions of PoAbs . Moreover, pretreatment of As8C with a 10(-2) dilution of PoAbs did not appear to adversely affect bacterial growth on agar . It is likely that the PoAbs interrupted the adhesion of As8C to BKECs by sterically interfering with a bacterial adhesin-epithelial cell receptor interaction.

Zh Mikrobiol Epidemiol Immunobiol, 1991 Apr, (4), 53 - 6
{Immunoglobulin efficacy for intravenous administration in the therapy of newborn infants with a suppurative infection}; Feklisova LV et al.; The data on the results of clinico-immunological examination of 46 infants having purulent inflammatory infections in the first month of their life and treated with (a) immunoglobulin for intravenous injection, (b) with hyperimmune antistaphylococcal plasma and immunoglobulin for intravenous injection and (c) without the use of specific hyperimmune preparations are presented . The clinico-laboratory data thus obtained (the levels of serum immunoglobulins and the content of T-rosette-forming lymphocytes) are indicative of the expediency of including the intravenous injection of donor immunoglobulin into the complex therapy of newborn infants with severe and moderate forms of purulent inflammatory infections at an early period of the disease irrespective of its etiology.

Aust Dent J, 1991 Apr, 36(2), 120 - 5
The effect of cheese on dental caries: a review of the literature; Herod EL; The relationship between nutrition and dental health has been a topic of interest for many years . Recently, the cariostatic properties of cheese have been the subject of intensive research . Most of these studies suggest that the use of cheese as the final food in a meal will help to reduce caries . Several mechanisms by which cheese may reduce enamel demineralization have been proposed . Chewing cheese stimulates saliva flow . The alkaline nature of saliva buffers the acids formed in plaque . There is also an increased rate of sugar clearance due to the diluting action of cheese-stimulated saliva . Research has also suggested that chewing cheese may reduce the levels of cariogenic bacteria . This may be secondary to the reduced incidence of caries as conditions within a carious lesion tend to promote the growth of these organisms . The high calcium and phosphorus content seems to be another factor in the cariostatic mechanism of cheese . Both casein and whey protein seem to be involved in the reduction of enamel demineralization . Casein phosphopeptides may also be responsible for some anticariogenicity by concentrating calcium and phosphate in plaque . An overview of the effect of milk on dental caries is also presented in this review.

Trends Biochem Sci, 1991 Apr, 16(4), 145 - 9
Photosynthetic reaction centers: interfacing molecular genetics and optical spectroscopy; Youvan DC; In the elucidation of the mechanism by which certain photosynthetic bacteria convert light into chemical energy, genetics has become intertwined with biophysical techniques . While X-ray crystallography has yielded an atomic resolution structure of the photosynthetic reaction center (RC), optical spectroscopy remains the most important technique for screening mutants . Newly developed imaging devices and genetic techniques should enable biophysicists to characterize rapidly the spectra of extremely large numbers of RC and light harvesting (LH) antennae mutants . The intrinsic pigments of the RC and LH antennae act as spectroscopic reporters for assembly and function of these integral membrane proteins . To optimize this genetics/spectroscopy interface, new algorithms that relate the structure of the genetic code to the physico-chemical properties of the amino acids are being developed to design libraries of mutants.

Cell Growth Differ, 1991 Apr, 2(4), 179 - 86
A new growth-regulated complementary DNA with the sequence of a putative trans-activating factor; Ku DH et al.; A new complementary DNA (cDNA) clone has been isolated by differential screening of a cDNA library . The cognate RNA of this clone, called SC1, is growth regulated in human, mouse, and hamster cell lines . Its kinetics of growth regulation (time of increase in mRNA levels, sensitivity to cycloheximide, behavior in G1-specific temperature-sensitive mutants) classify the SC1 gene as a late growth-regulated gene, like the histone genes and the genes coding for the proteins of the DNA synthesis apparatus . By run-on assay, there is a modest increase in transcriptional rates after serum stimulation, which is not sufficient to explain the sharp increase in mRNA levels . The SC1 gene localizes to human chromosome 6p21-22 . In bacteria, the SC1 cDNA clone makes a protein of Mr 39,000, in agreement with the putative reading frame . The amino acid sequence derived from the cDNA sequence indicates a previously unknown gene with a domain strongly suggestive of a trans-activating domain . The SC1 gene can be considered as coding for a possible new trans-activating factor that could play an important role in the transcription of genes required for the later stages of cell cycle progression.

Ther Umsch, 1991 Apr, 48(4), 210 - 4
{Skin and hand disinfection}; Mathis U; In modern medicine, hygiene has become an issue of ever increasing importance . Disinfection of hands is crucial, since hands are the main vector of bacteria . Successful disinfection depends not only on the appropriate choice of an active agent, but equally so on proper techniques and skin care . The spectre and the time profile of activity as well as the skin-protecting properties of the chosen disinfectant must be known . Basic knowledge of disinfection is necessary for a rational interpretation of the information given in the glossy printed material of advertisement.

Microbiologica, 1991 Apr, 14(2), 153 - 6
A characterization study of a cell line (BS/BEK) from bovine embryo kidney; Ferrari M et al.; A cell line (BS/BEK) which was obtained from bovine embryo kidney tissue, when studied at its 140th passage level it showed the following properties: 1 . An epithelial-like morphology, possessing a heteroploid karyotype with a modal chromosome number ranging between 70 and 75 chromosomes . 2 . It failed to produce tumors in mice and in hamster . 3 . It was shown to be ready susceptible to the replication of several viral agents originated from a variety of animal species . 4 . It was not contaminated by mycoplasma or other bacterial spp.

Mol Microbiol, 1991 Apr, 5(4), 927 - 32
Isolation and properties of the RepA1 protein of the IncFII replicon, RepFIC; Maas R et al.; The initiator protein RepA1 of the IncFII replicon RepFIC derived from the enterotoxin plasmid EntP307 has been cloned under the control of the lambda PL promoter . This has enabled us to overproduce this protein and study its properties . Here we show that RepA1 is a soluble basic protein with an experimentally determined molecular weight of 40,000 . Deletion analysis indicates that the overproduced protein originates from the open reading frame which we previously designated as coding for RepA1 . We have also shown that the replication function of the replicon RepFIC depends on the intact RepA1 coding frame.

Hepatogastroenterology, 1991 Apr, 38(2), 149 - 53
Mucin-producing cells and endocrine cells of gallbladder epithelium in patients with uncomplicated cholelithiasis; Carlei F et al.; In this study we have investigated various morphofunctional features of gallbladder mucosa in patients with uncomplicated cholelithiasis . The histological changes, endocrine cell types and their distribution, and mucin-producing cells were characterized by immunocytochemistry and mucin histochemistry; moreover, we attempted to correlate these findings to the number and size of gallbladder stones and the type of bacteria present in the bile . Our results indicate that, despite similar clinical parameters, a wide range of histological changes can occur in the gallbladder mucosa of these patients . Moreover, the presence of certain endocrine and mucin-producing cell types in so-called "pyloric metaplasia" led us to hypothesize that this finding may be a trivial event in the gallbladder epithelium.

Parasitology, 1991 Apr, 102 Pt 2, 193 - 9
Comparative study on Rickettsia-like organisms in the midgut epithelial cells of different Glossina species; Shaw MK et al.; The midgut epithelium of Glossina morsitans centralis, G . austeni, G . pallidipes, G . palpalis palpalis, G . p . gambiensis, G . fuscipes fuscipes, G . tachinoides and G . brevipalpis from ILRAD-bred colonies was examined, by electron microscopy, for the presence and distribution of Rickettsia-like organisms (RLOs) . RLOs were present in the midgut epithelial cells of all non-teneral tsetse . In G.m . centralis, G . pallidipes and, to a much lesser extent, G . brevipalpis, RLOs were numerous and were present in all the specimens examined . RLOs were present in fewer numbers in the epithelial cells of tenerals of these three tsetse species . In contrast, RLOs occurred in very much lower numbers within the midgut cells of nonteneral G . austeni, G . p . palpalis, G . p . gambiensis, G.f . fuscipes and G . tachinoides; were not seen in every specimen, and were rarely observed in the midgut cells of teneral testse . The RLOs were typical rod-shaped bacteria with an inner and outer membrane, which occurred free within the host cell cytoplasm and appeared to cause no obvious pathology . The micro-organisms divided by binary fission and at least two distinct morphological forms plus a range of intermediate forms were seen in the midgut cells . A comparison of the presence and numbers of RLOs within the midgut cells and the midgut infection rates of both Trypanosoma congolense and T . b . brucei, both between Glossina species and also within the same stock of tsetse, clearly indicates that the ability of trypanosomes to establish and develop to mature infections is unlikely to be correlated solely with the presence of RLOs within the tsetse midgut.

Mol Gen Genet, 1991 Apr, 226(1-2), 59 - 64
Disruption of the gene encoding the p34/31 polypeptides affects growth and development of Dictyostelium discoideum; Bain G et al.; We have used homologous recombination to disrupt the gene which codes for p34 and p31, two polypeptides related to a cAMP-binding protein (CABP1) in Dictyostelium discoideum . By screening a total of 80 independent transformants by Southern blotting, four mutants have been isolated . Two of these mutants were analyzed in detail . Our results indicate that, while a null allele has not been obtained, both mutants express drastically reduced levels of truncated p34 and p31 . Phenotypic analysis has demonstrated that both of them grow significantly more slowly than wild-type controls when bacteria are used as a food source . Interestingly, this growth defect is not seen when the cells are cultured axenically . In addition, the mutants possess an altered developmental profile . They complete development approximately 3 h later than wild-type controls . These results indicate that p34 and p31 play roles in both growth and development in this organism.

J Lab Clin Med, 1991 Apr, 117(4), 291 - 8
Increased phagocytic activity of polymorphonuclear leukocytes of chronic granulomatous disease as determined with flow cytometric assay; Hasui M et al.; Using flow cytometry, we compared the phagocytic activity of polymorphonuclear leukocytes (PMNs) from healthy donors with that of PMNs from 10 patients with chronic granulomatous disease (CGD), eight carriers of X-linked CGD, and one patient with myeloperoxidase deficiency . Ingestion of fluorescent bacteria by CGD and myeloperoxidase-deficient PMNs was significantly increased, that is, about 1.5 times that of normal controls . In CGD carriers, two PMN populations were found: one population consisted of PMNs with enhanced phagocytosis, and the other consisted of PMNs with normal phagocytic activity . With a two-dimensional analysis, we also demonstrated in CGD carriers that phagocytosis of the PMNs that failed to generate hydrogen peroxide was significantly elevated, as was phagocytosis of PMNs in patients with CGD, while on the other hand, the PMNs that normally produced hydrogen peroxide exhibited a normal phagocytic activity . When sodium azide, an inhibitor of myeloperoxidase and catalase, was added to control and carrier PMNs, phagocytic activity was significantly increased, p less than 0.01 in both, but not to the level seen with CGD PMNs . Phagocytosis of CGD and myeloperoxidase-deficient PMNs, however, remained unchanged by the azide treatment . On the basis of above findings, we speculate that phagocytosis of CGD PMNs is increased because the H2O2-myeloperoxidase-halide system, which may modulate phagocytic activity of PMNs, fails to operate.

J Bacteriol, 1991 Apr, 173(7), 2196 - 205
Nucleotide and derived amino acid sequences of the major porin of Comamonas acidovorans and comparison of porin primary structures; Gerbl-Rieger S et al.; The DNA sequence of the gene which codes for the major outer membrane porin (Omp32) of Comamonas acidovorans has been determined . The structural gene encodes a precursor consisting of 351 amino acid residues with a signal peptide of 19 amino acid residues . Comparisons with amino acid sequences of outer membrane proteins and porins from several other members of the class Proteobacteria and of the Chlamydia trachomatis porin and the Neurospora crassa mitochondrial porin revealed a motif of eight regions of local homology . The results of this analysis are discussed with regard to common structural features of porins.

G E N, 1991 Apr-Jun, 45(2), 111 - 3
{Incidence of Helicobacter pylori in Barrett esophagus}; Gelrud D et al.; In Barrett's esophagus the normal squamous epithelium of the mucosa is replaced by columnar epithelium . In this study, we evaluated the incidence of Helicobacter pylori in 28 patients with Barrett's esophagus . In 11 patients (39%) H . Pylori was present and all of them had the bacteria in the gastric antrum . From the 17 patients without H . pylori in the Barrett's mucosa, in 4 (22%) the bacteria was present in the gastric antrum . In conclusion, H . pylori infects the esophagus only when the esophageal mucosa is replaced by the columnar epithelium . The clinical significance of this finding is yet to be determined.

Endod Dent Traumatol, 1991 Apr, 7(2), 59 - 64
Glass ionomer cements and dental pulp; Mjor IA et al.; Only slight pulp reactions to glass ionomer cements occurred when inserted in Class V cavities of dog teeth . Most inflammatory reactions were due to bacteria at the tooth/filling interface . Special dentin reactions were noted in almost half the teeth, including hematoxyphilic bands in the dentin and a disturbance of the mineralization pattern of predentin . The clinical significance of these dentin reactions is not known.

Zhong Xi Yi Jie He Za Zhi, 1991 Apr, 11(4), 203 - 5, 195
{Clinical and experimental research on chronic bronchitis treated with ke chuan ping decoction}; Cheng CL; This paper presents the results of clinical observation and experimental research of ke chuan ping (KCP) in treating 31 cases of chronic bronchitis compared with that of traditional prescription qing jin hua tan decoction (QJHT) in other 31 patients with the same conditions randomized as control . The total effective rate of KCP group was 93.55% including 67.74% of basically cured and markedly effective cases . The total effective rate of QJHT group was 74.19% including 41.94% basically cured and markedly effective cases . There were significant differences between them (P less than 0.05) . According to laboratory observation KCP had the ability to dilute sputum viscosity, promote pulmonary ventilation function, decrease WBC and raise PO2 . Animal experimental research suggested that KCP had the effects on reducing sputum, relieving cough, modifying stridor and inhibiting bacteria . It was proved that KCP is a highly effective recipe for patients with chronic bronchitis . It was also shown that clearing away heat and dispersing phlegm therapy is an important measure for chronic bronchitis with Biao Zheng.

J Biomol Struct Dyn, 1991 Apr, 8(5), 1027 - 44
Predicting common foldings of homologous RNAs; Le SY et al.; A new approach is proposed for determining common RNA secondary structures within a set of homologous RNAs . The approach is a combination of phylogenetic and thermodynamic methods which is based on the prediction of optimal and suboptimal secondary structures, topological similarity searches and phylogenetic comparative analysis . The optimal and suboptimal RNA secondary structures are predicted by energy minimization . Structural comparison of the predicted RNA secondary structures is used to find conserved structures that are topologically similar in all these homologous RNAs . The validity of the conserved structural elements found is then checked by phylogenetic comparison of the sequences . This procedure is used to predict common structures of ribonuclease P (RNAase P) RNAs.

Plant Mol Biol, 1991 Apr, 16(4), 527 - 36
A gene coding for a basic pathogenesis-related (PR-like) protein from Zea mays . Molecular cloning and induction by a fungus (Fusarium moniliforme) in germinating maize seeds; Casacuberta JM et al.; Pathogenesis-related proteins (PRs) are plant proteins produced in leaves in response to infection by pathogens including viruses, viroids, fungi and bacteria . Information on the presence and/or expression of PRs in monocotyledonous plants is scare . Here we report the identification of cDNA and genomic clones coding for a basic form of a protein from germinating maize seeds having a high homology with the group of PR-1 from tobacco . A cDNA library enriched in aleurone-specific sequences was prepared from maize seeds two days after germination . One clone was found to contain an open reading frame encoding a protein homologous to PR proteins from tomato (p14) and tobacco (PR-1 group) . Sequence analysis of the corresponding genomic clone revealed that it was encoded by a single exon . Besides, DNA blot hybridization indicates that this PR-like protein is encoded by a single-copy gene in maize . The accumulation of its mRNA increases after rehydration of desiccated seeds . Furthermore, a relationship was found between its expression and infection by a natural pathogen of maize, the fungus Fusarium moniliforme . The possible role of this protein as a response mechanism following fungal infection in cereal seeds is discussed.

Surgery, 1991 Apr, 109(4), 507 - 14
Cytologic patterns in juice from human pancreatic transplants: correlation with histologic findings in the graft; Kubota K et al.; In 19 patients who had undergone pancreatic transplantation with temporary exteriorization of the pancreatic juice, graft tissue became available for histologic examination . In these patients the cytologic patterns in the pancreatic juice were compared with the histologic findings in the graft specimens . In five samples the diagnosis by cytologic studies was rejection . Acute rejection was confirmed in all the histologic specimens . In eight cytologic samples, graft pancreatitis was suspected because of the increased amounts of neutrophils, degenerating cells, epithelial cells, monocytes, and some macrophages, with or without necrotic tissue fragments . All eight histologic specimens showed findings characteristic of pancreatitis . In three cytologic samples, bacteria or fungi were observed . Histologic examination of these patients showed graft pancreatitis . In four patients the cytologic findings were normal . Graft histologic factors were normal in two instances . In one of these grafts there was graft pancreatitis, and in one graft chronic vascular rejection was seen . Our study shows that two different pathologic events occurring in the pancreatic graft (i.e., acute rejection and pancreatitis) are reflected by characteristic changes in pancreatic juice cytology.

Mol Cell Biol, 1991 Apr, 11(4), 1988 - 95
Control of protein phosphatase 2A by simian virus 40 small-t antigen; Yang SI et al.; Soluble, monomeric simian virus 40 (SV40) small-t antigen (small-t) was purified from bacteria and assayed for its ability to form complexes with protein phosphatase 2A (PP2A) and to modify its catalytic activity . Different forms of purified PP2A, composed of combinations of regulatory subunits (A and B) with a common catalytic subunit (C), were used . The forms used included free A and C subunits and AC and ABC complexes . Small-t associated with both the free A subunit and the AC form of PP2A, resulting in a shift in mobility during nondenaturing polyacrylamide gel electrophoresis . Small-t did not interact with the free C subunit or the ABC form . These data demonstrate that the primary interaction is between small-t and the A subunit and that the B subunit of PP2A blocks interaction of small-t with the AC form . The effect of small-t on phosphatase activity was determined by using several exogenous substrates, including myosin light chains phosphorylated by myosin light-chain kinase, myelin basic protein phosphorylated by microtubule-associated protein 2 kinase/ERK1, and histone H1 phosphorylated by protein kinase C . With the exception of histone H1, small-t inhibited the dephosphorylation of these substrates by the AC complex . With histone H1, a small stimulation of dephosphorylation by AC was observed . Small-t had no effect on the activities of free C or the ABC complex . A maximum of 50 to 75% inhibition was obtained, with half-maximal inhibition occurring at 10 to 20 nM small-t . The specific activity of the small-t/AC complex was similar to that of the ABC form of PP2A with myosin light chains or histone H1 as the substrate . These results suggested that small-t and the B subunit have similar qualitative and quantitative effects on PP2A enzyme activity . These data show that SV40 small-antigen binds to purified PP2A in vitro, through interaction with the A subunit, and that this interaction inhibits enzyme activity.

Int J Radiat Biol, 1991 Apr, 59(4), 963 - 71
Repair of potentially lethal damage by introduction of T4 DNA ligase in eucaryotic cells; Durante M et al.; The bacterial enzyme PvuII, which generates blunt-ended DNA double-strand breaks, and T4 DNA ligase, which seals adjacent DNA fragments in coupling to ATP cleavage, were introduced in mouse C3H10T1/2 fibroblasts using osmolytic shock of pinocytic vesicles . Cells were then assayed for their clonogenic ability . In agreement with previous studies by others, we find that the PvuII restriction endonuclease simulates ionizing radiation effects by causing a dose-dependent loss of reproductive capacity . Here we show that the concomitant treatment with DNA ligase considerably increases cell survival . Survival curves were shown to be dependent on the ligase enzyme dose and on ATP concentration in the hypertonic medium . We conclude that T4 DNA ligase is able to repair some of the potentially lethal damage produced by restriction endonucleases in eucaryotic cells.

Vestn Khir Im I I Grek, 1991 Apr, 146(4), 31 - 6
{The prevention and treatment of the deep phlegmons of "diabetic foot"}; Ivashkevich GA et al.; Based on clinical observations of pyo-necrotic lesions of the foot in patients with diabetic mellitus and on an analysis of their personal operations performed on these patients the authors support the tendency to local necrotomies . Two original operations are proposed: ablation of the great toe with a preliminary transection of the tendon of the long flexor and radical operation of the deep phlegmon of the foot with the dissection of plantar aponeurosis and short flexors of the toes . These methods allow the general amount of amputations and lethality to be decreased.

J Dairy Sci, 1991 Apr, 74(4), 1395 - 400
Yeast culture to improve intake, nutrient digestibility, and performance by dairy cattle during early lactation; Wohlt JE et al.; Twenty-four primiparous Holstein cows were fed corn silage:grain (1:1, DM basis) and hay (.9 kg/d) beginning 30 d prepartum and through wk 18 of lactation . Ten grams of Biomate Yeast Plus (5 X 10(9) cfu of Saccharomyces cerevisiae/g) were top-dressed on the a.m . allotment of corn silage:grain fed to 12 cows . Corn silage:grain was restricted during prepartum and thereafter fed for ad libitum intake . Cows fed supplemental yeast peaked earlier and had a higher milk yield compared with control cows (wk 7, 29.5 kg/d vs . wk 11, 28.7 kg/d) . Digestibilities of protein and cellulose were improved in cows fed supplemental yeast, contributing to a greater DMI during the first 6 wk of lactation and a higher average milk yield through wk 18 of lactation compared with control cows (27.2 vs . 26.0 kg/d).

HPB Surg, 1991 Apr, 3(4), 221 - 32; discussion 232-3
Infections following orthotopic liver transplantation; Arnow PM; The epidemiology of infections associated with orthotopic liver transplantation is summarized herein, and approaches to prophylaxis are outlined . Infection is a major complication following orthotopic liver transplantation, and more than half of transplant recipients develop at least one infection . The risk of infection is highest in the first month after transplantation, and the most common pathogens are bacteria and cytomegalovirus (CMV) . Bacterial infections usually occur in the first month, arise in the abdomen, and are caused by aerobes . The peak incidence of CMV infection is late in the first month and early in the second month after transplantation . CMV syndromes include fever and neutropenia, hepatitis, pneumonitis, gut ulceration, and disseminated infection . Other significant problems are Candida intraabdominal infection, Herpes simplex mucocutaneous infection or hepatitis, adenovirus hepatitis, and Pneumocystis carinii pneumonia . Prophylaxis of infection in liver transplant recipients has not been well-studied . Several different regimens of parenteral, oral absorbable, and/or oral non-absorbable antibiotics active against bacteria and yeast have been used at various centers, but no randomized controlled trials have been conducted . Selective bowel decontamination appears to be a promising approach to the prevention of bacterial and Candida infections, while oral acyclovir may be a relatively convenient and effective agent for CMV prophylaxis.

Nippon Jibiinkoka Gakkai Kaiho, 1991 Apr, 94(4), 506 - 15
{Influenza A virus-induced mucociliary dysfunction of tubotympanum}; Sugiura Y et al.; There is amount of epidemiologic, clinical and laboratory evidence to document that viral infection is involved in otitis media with effusion (OME) . However, few studies have demonstrated the direct influence of viruses on the tubotympanum . The purpose of this study is to establish the effect of influenza A virus invaded in the tubotympanum, in an attempt to elucidate the possible mechanism by which the virus contributes to the pathogenesis of OME . 80 guinea pigs with normal otoscopic findings were inoculated with 0.2ml suspension of influenza A (3.3 x 10(8)PFU/ml) into their tympanic cavities through their tympanic membranes . To serve as controls, the same number of guinea pigs were injected with 0.2ml of physiologic saline solution into their tympanic cavities . At 3, 7, 14, and 28 days postinoculation, they were used for examination of the mucociliary function . Middle ear effusions were observed only in the animals inoculated with the virus . Mucociliary dysfunction was observed only in the animals inoculated with the virus . The ciliary activity in the bulla was declined at any time examined . On the other hand, the ciliary activity in the eustachian tube and the tympanic orifice was slightly lowered between 7 and 14 days, but the level was not different from that of the control . However, the number of active ciliated cells (showing more than 500 beats/min) was significantly smaller than that of the control . The mucociliary clearance time of the tubotympanum was more prolonged than that of the control at 3, 7, and 14 days, and returned to the control level at 28 days . A variety of morphologic changes were observed in the tubotympanum treated with the virus . Major pathologies observed included a general inflammatory cell infiltration, vacuolation and other degeneration of ciliated cells, and vascular damage and increased vascular permeability . Regeneration of cilia or ciliated cells followed the degeneration, which included an increased number of basal cells and new formed centrioles . However, the viral infection had an influence on the epithelial cells with new centrioles . Our study has demonstrated that viral infection could evoke mucociliary dysfunction of the tubotympanum and create an increased susceptibility to bacteria . Therefore, viral infection could enhance bacterial infectious process in the tubotympanum . Through the failure viruses could contribute to the occurrence of OME.

Biochem Biophys Res Commun, 1991 Mar 29, 175(3), 1082 - 9
Chlamydia trachomatis and Chlamydia pneumoniae bind specifically to phosphatidylethanolamine in HeLa cells and to GalNAc beta 1-4Gal beta 1-4GLC sequences-found in asialo-GM1 and asial-GM2; Krivan HC et al.; To examine the possible role of lipids as adhesion receptors for infection, Chlamydia trachomatis and Chlamydia pneumoniae were labeled with 125I and layered on thin-layer chromatograms (tlc) of separated lipids isolated from target cells, and bound bacteria were detected by autoradiography . Elementary bodies from both species bound specifically and with high affinity to one lipid in HeLa 229 cells . Purification of this receptor by column chromatography on DEAE Sepharose followed by continuous preparative tlc, and structural analysis by 500-MHz 1H-NMR spectroscopy and fast atom bombardment mass spectrometry confirmed the HeLa cell chlamydial receptor to be phosphatidylethanolamine (PE) . The chlamydiae also bound strongly to purified asialo-GM1 and asialo-GM2, but not to other neutral or acidic lipids tested . The relative binding of chlamydiae to human PE and asialo-GM1 was modified in the presence divalent cations, suggesting that chlamydiae have two interrelated receptor binding sites.

Biochem Biophys Res Commun, 1991 Mar 29, 175(3), 963 - 70
Inhibition of gastric mucosal laminin receptor by Helicobacter pylori lipopolysaccharide; Slomiany BL et al.; Laminin receptor was isolated from gastric epithelial cell membrane by the procedure involving membrane solubilization with octylglucoside followed by affinity chromatography on laminin-coupled Sepharose . The receptor protein, eluted from the matrix with cation-free EDTA buffer, yielded on SDS-PAGE a single 67kDa band . After radioiodination, the protein was incorporated into liposomes which displayed specific affinity toward the laminin-coated surface . The binding of liposomal receptor to the laminin-coated surface was inhibited by lipopolysaccharide from H.pylori . The inhibitory effect was proportional to the concentration of lipopolysaccharide up to 50 micrograms/ml at which point a 96% decrease in the receptor binding occurred . It is suggested that a similar process may account for the loss of mucosal integrity in the pathogenesis of H . pylori associated gastric disease.

Nature, 1991 Mar 28, 350(6316), 359 - 62
A Tyr/Ser protein phosphatase encoded by vaccinia virus; Guan KL et al.; Protein tyrosine phosphorylation is associated with alterations in receptor activity, cellular proliferation and modulation of the cell cycle . Inappropriate tyrosine phosphorylation can lead to unrestrained cell growth and oncogenesis . Enzymes important in tyrosine dephosphorylation have also been described . Protein tyrosine phosphatases (PTPases) consist of two families . There is a receptor-like family of PTPases with an extracellular domain, transmembrane-spanning region and typically two repeated phosphatase domains . Proteins of the non-receptor-like family have a single catalytic phosphatase domain, show a substrate specificity for Tyr phosphate and will not hydrolyse Ser or Thr phosphate . Here we report that the vaccinia virus genome contains an open reading frame which shares amino-acid sequence identity with the PTPases . The purified protein encoded by the vaccinia virus H1 open reading frame expressed in bacteria hydrolyses substrates containing phosphotyrosine and phosphoserine . Mutagenesis of an essential Cys in the vaccinia phosphatase abolishes catalytic activity directed towards both substrates, suggesting that hydrolysis proceeds by a common mechanism . Understanding the function of the H1-encoded protein will help to define the role of the phosphatase in viral replication and pathogenesis.

Biochim Biophys Acta, 1991 Mar 26, 1088(3), 445 - 7
The primary structure of chicken ribosomal protein L5; Kenmochi N et al.; The nucleotide sequence of a cDNA for chicken ribosomal protein L5, which is considered to associate with 5S rRNA, was determined . The cDNA is 975 bp long . The deduced protein has 297 amino acids and has a molecular mass of 34,090 Da . A comparative analysis of the amino acid sequences of chicken L5 and its homologous proteins revealed an extremely conserved region which contains a cluster of basic amino acids.

J Biol Chem, 1991 Mar 25, 266(9), 5854 - 9
The Neurospora crassa carotenoid biosynthetic gene (albino 3) reveals highly conserved regions among prenyltransferases; Carattoli A et al.; In the filamentous fungus Neurospora crassa the biosynthesis of carotenoids is regulated by blue light . Here we report the characterization of the albino-3 (al-3) gene of N . crassa, which encodes the carotenoid biosynthetic enzyme geranylgeranyl-pyrophosphate synthetase . This is the first geranylgeranyl-pyrophosphate synthetase gene isolated . Nucleotide sequence comparison of al-3 genomic and cDNA clones revealed that the al-3 gene is not interrupted by introns . Transcription of the al-3 gene has been examined in dark-grown and light-induced mycelia . The analysis revealed that the al-3 gene is not expressed in the dark and that its transcription is induced by blue light (Nelson, M . A., Morelli, G., Carattoli, A., Romano, N., and Macino, G . (1989) Mol . Cell . Biol . 9, 1271-1276) . The al-3 gene encodes a polypeptide of 428 amino acids . Comparison of the deduced amino acid sequence of al-3 with the sequences of prenyltransferases of other species, from bacteria to humans, showed three highly conserved homologous regions . These homologous regions may be involved in the formation of the catalytic site of the prenyltransferases.

Science, 1991 Mar 22, 251(5000), 1481 - 5
Crystal structure of defensin HNP-3, an amphiphilic dimer: mechanisms of membrane permeabilization; Hill CP et al.; Defensins (molecular weight 3500 to 4000) act in the mammalian immune response by permeabilizing the plasma membranes of a broad spectrum of target organisms, including bacteria, fungi, and enveloped viruses . The high-resolution crystal structure of defensin HNP-3 (1.9 angstrom resolution, R factor 0.19) reveals a dimeric beta sheet that has an architecture very different from other lytic peptides . The dimeric assembly suggests mechanisms by which defensins might bind to and permeabilize the lipid bilayer.

JAMA, 1991 Mar 20, 265(11), 1429 - 36
Biotechnology and the American agricultural industry . Council on Scientific Affairs, American Medical Association; Synthesis of 3'-deoxy-3'-fluorokanamycin A and 3' et al.; Institute of Bioorganic Chemistry, Kawasaki, Japan3'-Deoxy-3'-fluorokanamycin A (14) has been prepared by condensation of 6-azido-2,4-di-O-benzyl-3,6-dideoxy-3-fluoro-alpha-D-glucopyranlsyl++ + bromide (8) and 6-O-(2-O-acetyl-4,6-O-cyclohexylidene-3-deoxy- 3-tosylamino-alpha-D-glucopyranosyl)-2-deoxy-1,3-di-N-tosylstre ptamine (10) . Compound 8 was obtained from 3-deoxy-3-fluoro-1,2:5,6-di-O-isopropylidene-D-glucofuranose in seven steps . 3',4'-Dideoxy-3'-fluorokanamycin A (22) has been prepared from 12 through selective 4'-chlorodeoxygenation, a key reaction . Both 14 and 22 were more active than 3'-deoxykanamycin A against both sensitive and resistant bacteria.

Biochem Biophys Res Commun, 1991 Mar 15, 175(2), 430 - 6
The cAMP-dependent protein kinase phosphorylates the rap1 protein in vitro as well as in intact fibroblasts, but not the closely related rap2 protein; Lerosey I et al.; The products of rap genes (rap1A, rap1B and rap2) are small molecular weight GTP-binding proteins that share approximately 50% homology with ras-p21s . It had previously been shown that a rap1 protein (also named Krev-1 or smg p21) could be phosphorylated on serine residues by the cAMP-dependent protein kinase (PKA) in vitro as well as in intact platelets stimulated by prostaglandin E1 . We show here that the rap1A protein purified from recombinant bacteria is phosphorylated in vitro by the catalytic subunit of PKA and that the deletion of the 17 C-terminal amino acids leads to the loss of this phosphorylation . This suggests that the serine residue at position 180 constitutes the site of phosphorylation of the rap1A protein by PKA . The rap1 protein can also be phosphorylated by PKA in intact fibroblasts; this phenomenon is independent of their proliferative state . In contrast, protein kinase C (PKC) does not phosphorylate the rap1 proteins, neither in vitro nor in vivo . Finally, the 60% homologous rap2 protein is neither phosphorylated in vitro nor in vivo by PKA or PKC.

J Anim Sci, 1991 Mar, 69(3), 1300 - 11
Effects of urea and sodium bicarbonate supplementation of a high-fiber diet on nutrient digestion and ruminal characteristics of defaunated sheep; Hsu JT et al.; Five sheep (average BW 48 kg) with ruminal, duodenal, and ileal cannulas were fed 63% roughage: 37% concentrate diets (CP = 14.5%) in a 5 x 5 Latin square design to study effects of urea and sodium bicarbonate supplementation on nutrient digestion and ruminal characteristics of defaunated sheep . Diets were fed twice daily (DMI = 1,076 g/d) . Defaunation was accomplished with 25-ml doses of alkanate 3SL3/sheep daily for 3 d . Control sheep were faunated (Treatment 1) and fed soybean meal as the major N supplement . Remaining sheep were maintained defaunated and fed either the same diet as Treatment 1 (Treatment 2), Treatment 1 with urea replacing 30% of the soybean meal N (Treatment 3), or Treatment 1 with 2% sodium bicarbonate in the diet (Treatment 4) . Treatment 5 was a combination of Treatments 3 and 4 . Compared with the faunated control, defaunation decreased (P less than .05) total tract DM, OM, NDF, ADF, and CP digestibilities (71.5 vs 69.4, 73.8 vs 71.7, 64.6 vs 61.4, 58.7 vs 55.8, and 74.2 vs 70.6%, respectively) and average (2 to 12 h postfeeding) ruminal fluid ammonia (23.5 vs 13.7 mg/dl) and isobutyrate (.9 vs .7 mM) concentrations . However, defaunation increased (P less than .05) linoleic and linolenic acid flows (.58 vs .45 g C18:2/d; .17 vs .14 g C18:3/d) to and disappearance (.50 vs .39 g C18:2/d; .14 vs .11 g C18:3/d) from the small intestine . Urea supplementation increased (P less than .05) total tract DM (70.2 vs 68.6%) and OM (72.3 vs 71.0%) digestibilities of defaunated sheep but lowered (P less than .05) ruminal fluid isobutyrate concentration (.6 vs .8 mM) . Sodium bicarbonate supplementation increased (P less than .05) ruminal fluid pH (6.4 vs 6.2), isobutyrate concentration (.75 vs .60 mM), total tract ADF digestibility (57.6 vs 54.2%), and ruminal NDF (41.6 vs 28.5%), ADF (36.6 vs 22.8%), and CP (-5.5 vs -26.8%) digestibilities in defaunated sheep . Dietary supplementation of urea or sodium bicarbonate increased nutrient digestion by defaunated sheep.

Cell, 1991 Mar 8, 64(5), 903 - 14
The cdc25 protein controls tyrosine dephosphorylation of the cdc2 protein in a cell-free system; Kumagai A et al.; As a prerequisite for the activation of MPF, the cdc2 protein kinase must undergo tyrosine dephosphorylation . Genetic studies have demonstrated that the cdc25 protein activates the cdc2 protein kinase once DNA replication has been completed . We have produced the cdc25 protein in bacteria and shown that it activates MPF in Xenopus extracts . In extracts that normally cannot enter mitosis owing to inhibition of DNA synthesis, the addition of active cdc25 protein efficiently elicits the mitotic state by inducing premature dephosphorylation of tyrosine on the cdc2 protein . The cdc25-dependent activation reaction can be reconstituted in a partially purified system lacking ATP . These biochemical experiments demonstrate that the cdc25 protein actively drives tyrosine dephosphorylation of the cdc2 protein and offer the prospect for characterizing the individual factors that regulate the activation of MPF during the progression from S phase to mitosis.

Zentralbl Hyg Umweltmed, 1991 Mar, 191(2-3), 201 - 5
{Requirements for ambulatory operations from the point of view of hygienists}; Gundermann KO; Not least because of possible cost reduction ambulatory operations are being performed increasingly in hospitals and in accordingly equipped surgical practices . From the hygienic point of view infection control is just as important as with inpatients, i.e . requirement have to be the same in principle . This applies to constructional requirements, i.e . structure of operation areas including technical equipment and ventilation system, as well as to organizational requirements . On the other hand particularly operations in surgical practices have special features that have to be taken into account . One has to consider several factors like the lower probability of patients to be colonized by hospital specific bacteria, the as a rule relatively low number of operations and the small group of persons involved with operations, so that often staff discipline can be improved more easily than in big hospitals . Problems can arise with the supply of sterile goods, as facilities comparable to those of sterilization centers in hospitals are usually lacking . In these particular cases hygienically perfect solutions that consider all special features of a practice should be sought in cooperation with a hygienist.

Int J Legal Med, 1991 Mar, 104(2), 87 - 91
Immunocytochemical typing of ABO blood groups in vaginal swabs partly contaminated with semen; Scheithauer R et al.; ABH typing by immunocytochemical method has been carried out on 163 selected vaginal swabs . 127 cases (78%) were determined correctly, 11 cases (7%) incorrectly and 25 cases (15%) could not be classified . Often, not all of the vaginal cells showed the expected positive staining, which was not counted as a false result . The incorrect results were not dependent on the secretor status, but 37% of the non-secretor cases could not be classified immunocytochemically, as compared with 12% of the secretors . In a second series, 61 vaginal swabs, dried on microscope slides, have been covered with semen from an A1 B secretor . Absorption of heterologous antigens by the vaginal epithelia could be demonstrated only after extremely long incubation with semen and extremely long incubation with the anti-A or anti-B antibodies . From the 163 "native" swabs, 17 gave a positive reaction with the acid phosphatase test, but only one false ABH result . A possible influence of bacteria upon the results is discussed . We believe that in practice, no faults in immunocytochemical ABH typing have to be expected, due to absorption of heterologous antigens.

J Pharm Sci, 1991 Mar, 80(3), 293 - 5
Electrochemical reduction of arylethenylpyridinium salts: relation to structure and anthelmintic activity; Ames JR; Cyclic voltammetry data were obtained for a series of 1(1-)- and 1(2-arylethenyl)pyridinium salts . The 1(1-arylvinyl) salts exhibited more negative reduction potentials than their N-beta-styryl counterparts . Rationalizations of the reduction values are provided . Differences in reduction potentials within a series are discussed utilizing substituent constant effects . Correlations exist for the electrochemical data and anthelmintic activity.

Vestn Otorinolaringol, 1991 Mar-Apr, (2), 49 - 51
{Clinical features of nonclostridium anaerobic infection in the pathology of E.N.T . organs}; Mironov AIu et al.; The study of clinical features of nonclostridial anaerobic infection in 80 patients with purulent and inflammatory pathologies of ENT-organs (purulent sinusitis, purulent otitis media, paratonsillar abscesses) showed them to be as follows: prolonged, slow and often subclinical development of the disease; disseminated necrotic changes of tissues; disagreement between the level of clinical symptoms and destructive changes (prevalence of destructive changes over clinical symptoms); phenomenon of false anesthesia; existence of crumbs-like pus with a strong bad smell sometimes filled with air bubbles; limited bleeding from cut tissues.

J Am Soc Echocardiogr, 1991 Mar-Apr, 4(2), 97 - 104
Doppler echocardiography for rejection surveillance in the cardiac allograft recipient; Gibbons RS; Echocardiography is noninvasive, allows real-time visualization of the heart, and can be performed serially without harmful biologic effects . It is also relatively inexpensive compared with other diagnostic modalities used for cardiac transplant rejection surveillance, such as cardiac biopsy, computed tomography, and magnetic resonance imaging . It is free of the potential complications associated with cardiac biopsy, such as accidental disruption of cardiac valves or chordae tendineae, ventricular septal perforation, introduction of bacteria, and the difficulty of obtaining adequate sampling for effective diagnosis as a result of formation of scar tissue . Unlike biopsy, echocardiography does not cause the patient anxiety and discomfort or use many physician and instrument or laboratory resources . Because the results of echocardiography are available within minutes compared with the hours usually needed for biopsy results, it allows prompt decisions regarding patient clinical care and treatment . In our work to date, echocardiography has not replaced the cardiac biopsy in surveillance of rejection in the cardiac transplant patient, but rather has become a useful adjunct to it . When echocardiographic findings indicate changes characteristic of rejection, biopsies are performed earlier, leading to earlier diagnosis and treatment . Furthermore, when echocardiographic findings are stable and negative for rejection, the number of routine cardiac biopsies performed can be reduced . This article discusses the use of echocardiography in surveillance of the cardiac transplant patient and the ability of echocardiography to augment the biopsy and clinical regimens in assessing cardiac allograft rejection.

Gastroenterol Clin North Am, 1991 Mar, 20(1), 111 - 26
Pigment gallstone disease; Trotman BW; Black and brown pigment gallstones are morphologically, compositionally, and clinically distinct . Black stones form primarily in the gallbladder in sterile bile and are associated with advanced age, chronic hemolysis, alcoholism, cirrhosis, pancreatitis, and total parenteral nutrition . Brown stones form not only within the gallbladder but also within the intrahepatic and extrahepatic ducts; they are uniformly infected with enteric bacteria and are usually associated with ascending cholangitis . Brown stones are related to juxtapapillary duodenal diverticula and are the predominant type of de novo common bile duct stones . Cholecystectomy is usually curative in black pigment stone disease, whereas stones often recur after cholecystectomy for brown stone disease . The pathogenesis of black stones is probably related to nonbacterial, nonenzymatic hydrolysis of bilirubin conjugates . At the pH of bile, this results in two monohydrogenated bilirubin anions that precipitate with calcium ions . Bilirubin monoconjugates that are increased in several conditions, such as Gilbert's syndrome and chronic hemolysis, may play a pivotal role in black stone formation as a source of unconjugated monohydrogenated bilirubin and as a possible co-precipitant with calcium . The precipitation of calcium carbonate and phosphate is influenced by local gallbladder factors . Brown pigment stones are formed in bile infected with enteric bacteria that elaborate hydrolytic enzymes: beta-glucuronidase, phospholipase A, and conjugated bile acid hydrolase . The resulting anions of bilirubin and fatty acids form insoluble calcium salts . We used nb/nb mice with a chronic hemolytic anemia as a model of hemolysis-induced black stone disease . The presence of 40% bilirubin monoconjugates in mouse gallstones indicated the importance of this moiety in the pathogenesis of black stones . Other data obtained by marrow transplantation experiments in mice revealed the relative importance of genotype versus the hemolytic anemia on determinants such as biliary bile acid composition and mucin secretory glands in the mouse gallbladder neck . Additional physical chemical studies of the interaction of unconjugated bilirubin in model bile solutions will be helpful in further delineating the pathogenesis of both black and brown pigment gallstones.

J Med Microbiol, 1991 Mar, 34(3), 181 - 7
Influence of soluble haemagglutinins on adherence of Helicobacter pylori to HEp-2 cells; Armstrong JA et al.; In a study of six laboratory strains of Helicobacter pylori, two different modes of bacterial adherence to HEp-2 cells were found . Electronmicroscopy revealed that strains known to possess soluble haemagglutinin adhered intimately to the cell surfaces, with cupping of the plasma membrane and coalescence of glycocalyces at sites of attachment . Strains of H . pylori without soluble haemagglutinin also attached, but did not induce membrane cupping or show glycocalyx fusion . Light microscopy did not distinguish between these patterns of adherence . Bacterial attachment was unaffected by pre-treatment of HEp-2 cells with neuraminidase . Exposure of the bacteria to trypsin or to colloidal bismuth subcitrate (CBS) before being added to HEp-2 cells markedly impaired bacterial adherence . This effect of CBS may contribute to the known efficacy of bismuth therapy in patients with H . pylori-related gastritis.

J Med Microbiol, 1991 Mar, 34(3), 137 - 41
Peritonitis complicating continuous ambulatory peritoneal dialysis in Nottingham 1983-1988; Wilcox MH et al.; During the period 1983-1988 the incidence of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) in Nottingham fell from 2.0 to 1.2 episodes/patient/year . Cefuroxime, given intraperitoneally for 10 days, as recommended in published guidelines, failed to cure 35% of episodes of peritonitis, although only 7% of the pathogens responsible for these episodes were resistant in vitro . Cefuroxime is probably no longer appropriate as first line treatment of CAPD peritonitis.

Am Surg, 1991 Mar, 57(3), 139 - 41
Preperitoneal herniorrhaphy for the acutely incarcerated groin hernia; George SM Jr et al.; Elective preperitoneal or posterior repair for recurrent groin hernias and primary femoral hernias has been shown to be a technically advantageous approach . In addition to the ease of inguinal floor and femoral canal assessment, scar tissue from prior anterior herniorrhaphy can be avoided . The emergency management of the acutely incarcerated or strangulated hernia of the groin using this approach has not been addressed . During a 30-month period, all patients with a diagnosis of acute incarceration of a groin hernia (n = 28) were surgically managed using either the anterior approach (AA) (n = 14) or the preperitoneal approach (PA) (n = 14) . Two patients with strangulated intestine in the AA group required an additional midline incision for bowel evaluation and resection . Intestinal evaluation was easily accomplished through the same incision in four patients in the PA group . The preperitoneal approach also allowed proximal control of incarcerated or strangulated viscera, thus avoiding excessive manipulation of gangrenous or necrotic intestine, potential spillage of infected contents into the peritoneal cavity, and entry of bacteria, toxins, potassium, and the metabolic waste products of anaerobic metabolism into the systemic circulation during hernia reduction . There have been no recurrences in either group, and minor complications, such as wound infection and cellulitis, in the two groups are not statistically different.

Am J Obstet Gynecol, 1991 Mar, 164(3), 818 - 20
Amniotic fluid glucose and intraamniotic infection; Kirshon B et al.; Thirty-nine patients with either premature labor and/or preterm premature ruptured membranes underwent transabdominal amniocentesis to enable the following amniotic fluid analyses to be performed: culture and sensitivity, Gram's stain, and glucose determination . All nine patients with intraamniotic infection had amniotic fluid glucose values less than 10 mg/dl . Three patients with amniotic fluid glucose levels less than 10 mg/dl but without chorioamnionitis were delivered of infants within 72 hours of admission . The mean amniotic fluid glucose level of patients with intraamniotic infection (5 +/- 2.4 mg/dl) was significantly lower than in those without intraamniotic infection (39.8 +/- 18.42 mg/dl) . All patients with amniotic fluid glucose values less than 10 mg/dl had either bacteria and/or white blood cells on Gram's stain . Two patients without chorioamnionitis had white cells on Gram's stain and amniotic fluid glucose values greater than 10 mg/dl . It appears that amniotic fluid glucose is more sensitive and more specific than Gram's stain in the diagnosis of intraamniotic infection . All 12 patients with low amniotic fluid glucose values were delivered of infants within 72 hours as the result of either the presence of infection or the progression of labor.

Am J Clin Nutr, 1991 Mar, 53(3), 585 - 6
Rapid preparation of pyrogen-free 2H2(18)O for human-nutrition studies; Wong WW et al.; We describe a compact ultrafiltration system for the removal of pyrogens and bacteria from water labeled with the stable isotopes of deuterium and oxygen-18 . The ultrafiltration system is constructed from readily available commercial components and can achieve complete removal of pyrogens and bacteria from 1L contaminated water within 30 min . By use of our procedure, loss of the isotopically labeled water by retention in the filtration system was minimal . The purified water is suitable for both oral and intravenous administration to healthy human subjects participating in nutrition studies.

Urology, 1991 Mar, 37(3), 229 - 32
Bilateral emphysematous pyelonephritis; Lowe BA et al.; Emphysematous pyelonephritis is an uncommon and serious infection associated with gas-forming coliform bacteria . Bilateral involvement is rare with only 10 reported cases in the English literature . Prompt and aggressive management is required to salvage these patients . Preservation of renal function using broad-spectrum antibiotics and surgical drainage provide the greatest benefit to these patients . Three new cases are presented with a brief review of the results of management in the reported cases.

J Bacteriol, 1991 Mar, 173(6), 2141 - 5
Myxococcus xanthus protein C is a major spore surface protein; McCleary WR et al.; Fruiting body formation in Myxococcus xanthus involves the aggregation of cells to form mounds and the differentiation of rod-shaped cells into spherical myxospores . The surface of the myxospore is composed of several sodium dodecyl sulfate (SDS)-soluble proteins, the best characterized of which is protein S (Mr, 19,000) . We have identified a new major spore surface protein called protein C (Mr, 30,000) . Protein C is not present in extracts of vegetative cells but appears in extracts of developing cells by 6 h . Protein C, like protein S, is produced during starvation in liquid medium but is not made during glycerol-induced sporulation . Its synthesis is blocked in certain developmental mutants but not others . When examined by SDS-polyacrylamide gel electrophoresis, two forms of protein C are observed . Protein C is quantitatively released from spores by treatment with 0.1 N NaOH or by boiling in 1% SDS . It is slowly washed from the spore surface in water but is stabilized by the presence of magnesium . Protein C binds to the surface of spores depleted of protein C and protein S . Protein C is a useful new marker for development in M . xanthus because it is developmentally regulated, spore associated, abundant, and easily purified.

Odontostomatol Trop, 1991 Mar, 14(1), 13 - 5
{Aging and periodontal disease . Clinical study of gingival recession}; Ndiaye Senghor R et al.; Gingival mucus in an older patient is the site of the slowing-down of the cellular turnover, of a lessening of metabolic activity and of keratinisation . The resistance to mechanical attacks and bacteria lessens thus its potential for repair . Thus one notes a worsening state of parodontal complaints during old age . By means of a study carried out at the Clinique de Parodontie of the Institut d'Odonto-Stomatologie in Dakar, we propose to attempt to see if the presence of gingival retraction can be linked with parodontal senescence by means of observing 318 patients.

Diagn Microbiol Infect Dis, 1991 Mar-Apr, 14(2), 107 - 10
The detection of positive blood cultures by the BACTEC NR660 . The clinical importance of four-day versus seven-day testing; Evans MR et al.; A total of 471 positive blood cultures obtained over a 3-month period were identified and evaluated for day of positivity by the BACTEC NR660 . Of all positive blood cultures, 73% (344) were detected within the first 2 days, and 94% (441) were detected through day 4 . The proportion of positive cultures detected at day 5 was significantly lower than that at day 4 (p less than 0.01) . Patient chart review revealed that two of 30 isolates (0.4% of all positive isolates) identified on days 5-7 were considered clinically significant and would have been missed if cultures would not have been evaluated for seven days . Therefore, very limited additional patient benefit is derived after greater than 4 days of growth and detection by the BACTEC NR660.

Nucl Med Commun, 1991 Mar, 12(3), 175 - 87
Imaging of Pneumocystis carinii pneumonia with 111In-labelled non-specific polyclonal IgG: an experimental study in rats; Fishman JA et al.; The relative sensitivity of imaging with 67Ga-citrate (67Ga) and non-specific human polyclonal IgG radiolabelled with 111In (111In-IgG) for the detection of Pneumocystis carinii pneumonia (PCP) was determined in rats . Pneumocystis carinii pneumonia was induced by low protein diet and dexamethasone . The course of the disease was monitored by serial imaging with 111In-IgG and 67Ga . Diffuse accumulation of both radiopharmaceuticals was observed in the lungs of infected animals (infection was verified by histological examination of the lungs), however, accumulation of 111In-IgG was consistently higher . In rats with early PCP, 111In-IgG imaging revealed pulmonary accumulation in animals with normal chest radiographs and 67Ga scans . In animals successfully treated for PCP, decreased pulmonary accumulation of 111In-IgG coincided with histological improvements . Several animals developed superinfection with bacteria or fungi . These animals had striking focal accumulation of 111In-IgG, in addition to the pattern of generalized uptake . Gallium concentration in these animals did not show this focal accumulation . These observations suggest that 111In-IgG may be useful for detecting PCP and pulmonary abscesses in the immunocompromised host.

J Dent Hyg, 1991 Mar-Apr, 65(3), 146 - 50
Ovarian hormones and gingivitis; Zachariasen RD; PIP: Elevated plasma concentrations of the ovarian hormones--estrogen and progestins--during pregnancy, puberty, the menstrual cycle, and oral contraceptive (OC) use are associated with an increased incidence of gingival inflammation and exudate . Gingivitis is induced by the micro- organisms that compose subgingival plaque, particularly anaerobic organisms . The ovarian hormones both stimulate bacterial growth and promote the inflammatory process . In the presence of sex hormones, the metabolic breakdown of folate is increased, leading to a folate deficiency that enhances the inflammatory destruction of oral tissue . Gingivitis occurs in an estimated 60-75% of pregnancy women, but the numbers of gingivitis-producing bacteria decrease toward the end of pregnancy and the gingival tissues return to their previous state . In OC users, on the other hand, inflammation of the gingiva is chronic and may increase over time . If gingivitis is already present at the onset of pregnancy or OC use, the inflammation will become progressively more severe . Although these effects cannot be avoided, ovarian hormone- induced gingivitis can be substantially minimized of low plaque levels exist at the beginning of pregnancy or pill initiation .

Carcinogenesis, 1991 Mar, 12(3), 521 - 4
Activation of (+-)-trans-7,8-dihydroxy-7,8-dihydrobenzo{a}pyrene to diolepoxides by human polymorphonuclear leukocytes or myeloperoxidase; Mallet WG et al.; Previous studies have demonstrated that the interaction of (+-)-trans-7,8-dihydroxy-7,8-dihydrobenzo{a}pyrene {(+-)-B{a}P-7,8-diol} with 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated human polymorphonuclear leukocytes (PMNs) elicited genotoxic effects in bacteria and mammalian cells . Structure-activity studies with various polycyclic aromatic hydrocarbon derivatives suggest that a diolepoxide intermediate(s) was being formed from this chemical-cell interaction . In this study, we demonstrate by stereochemical analysis of tetraol products that primarily anti-diolepoxides are being formed from (+-)-B{a}P-7,8-diol by TPA-stimulated PMNs with an anti/syn ratio of 6 . Likewise, a myeloperoxidase (MPO)-H2O2 system generated primarily anti-diolepoxides of B{a}P-7,8-diol with an anti/syn ratio greater than 5 . Such ratios are indicative of the epoxidation of B{a}P-7,8-diol via a peroxyl radical or a ferryl oxygen transfer-mediated reaction . Addition of azide, an MPO inhibitor, resulted in decreased tetraols from B{a}P-7,8-diol by PMNs or the MPO system . These studies further support the concept that the activation of B{a}P-7,8-diol by PMNs could create a highly localized genotoxic environment which could impact on human health.

Mutat Res, 1991 Mar, 254(2), 119 - 23
UV mutation spectra in cell lines from patients with Cockayne's syndrome and ataxia telangiectasia, using the shuttle vector pZ189; Muriel WJ et al.; We have used the SV40-based shuttle vector pZ189 to determine ultraviolet mutation spectra in SV40-transformed cell lines from two patients with Cockayne's syndrome (CS) and ataxia telangiectasia (AT) . The shuttle vector was UV-irradiated, transfected into the cells and recovered two days later, after many rounds of replication had occurred . Plasmid DNA was used to transform indicator bacteria in which plasmids containing a mutation in the supF gene resulted in white colonies . Mutant plasmids were analysed both by agarose gels and by DNA sequencing . In contrast to published spectra for xeroderma pigmentosum cells, the types of mutation induced by UV mutation in the CS and AT cell lines were similar to each other and to published spectra for normal cell lines . There were however, some differences in the sequence distribution of the mutations.

FASEB J, 1991 Mar 1, 5(3), 295 - 300
Nucleotide chloramines and neutrophil-mediated cytotoxicity; Bernofsky C; Hypochlorite is a reactive oxidant formed as an end product of the respiratory burst in activated neutrophils . It is responsible for killing bacteria and has been implicated in neutrophil-mediated tissue injury associated with the inflammatory process . Although hypochlorite is a potent cytotoxic agent, the primary mechanism by which it exerts its effect is unclear . This review examines evidence that the primary event in hypochlorite cytotoxicity is the loss of adenine nucleotides from the target cell . This loss appears to be mediated by the formation of adenine nucleotide chloramines which are reactive intermediates with a free radical character and are capable of forming stable ligands with proteins and nucleic acids.

J Clin Invest, 1991 Mar, 87(3), 894 - 900
Soluble surface proteins from Helicobacter pylori activate monocytes/macrophages by lipopolysaccharide-independent mechanism; Mai UE et al.; The inflammatory lesions associated with Helicobacter pylori gastritis and duodenitis contain large numbers of mononuclear cells . The close proximity of H . pylori to gastric mucosa suggests that the organism interacts with mononuclear cells, thereby modulating the inflammatory response . To investigate the role of monocytes/macrophages in this response, we examined the effect of whole H . pylori bacteria, H . pylori surface proteins, and H . pylori lipopolysaccharide (LPS) on purified human monocytes . Whole H . pylori and the extracted LPS induced expression of the monocyte surface antigen HLA-DR and interleukin-2 receptors, production of the inflammatory cytokines interleukin 1 and tumor necrosis factor (peptide and messenger RNA), and secretion of the reactive oxygen intermediate superoxide anion . Since H . pylori in vivo does not invade mucosal tissue, we determined whether soluble constituents of the bacteria could activate monocytes . Soluble H . pylori surface proteins, which are enriched for urease and do not contain LPS, stimulated phenotypic, transcriptional, and functional changes consistent with highly activated monocytes . These findings indicate that H . pylori is capable of activating human monocytes by an LPS-independent as well as an LPS-dependent mechanism . H . pylori activation of resident lamina propria macrophages and monocytes trafficking through the mucosa, leading to the secretion of increased amounts of inflammatory cytokines and reactive oxygen intermediates, could play an important role in mediating the inflammatory response associated with H . pylori gastritis and duodenitis.

J Virol, 1991 Mar, 65(3), 1318 - 24
Memory and distribution of virus-specific cytotoxic T lymphocytes (CTLs) and CTL precursors after rotavirus infection; Offit PA et al.; The gastrointestinal tract is constantly exposed to a variety of potentially invasive bacteria, viruses, and parasites . The first line of defense against these pathogens is the intestinal mucosal surface, which consists of epithelial cells, intraepithelial lymphocytes (IELs), mucus, and secretory immunoglobulins . In addition, the intestine is a rich source of lymphocytes located within Peyer's patches and the lamina propria . Little is known about the function, memory, trafficking, or origin of intestinal T lymphocytes after intestinal infection . We studied the murine cytotoxic T-lymphocyte (CTL) response to the intestinal pathogen rotavirus (simian strain RRV) . Adult mice were inoculated orally or via the hind footpad with RRV; virus-specific cytotoxic activities in intestinal and nonintestinal lymphocyte populations were determined by 51Cr release assays . In addition, virus-specific CTL precursor (CTLp) frequencies were determined by limiting-dilution analysis . IELs containing rotavirus-specific cytotoxic activity were detected after oral but not footpad inoculation and expressed alpha/beta but not gamma/delta cell surface protein; virus-specific CTLs did not appear to arise from CTLp among IELs . In addition, the site at which RRV was presented to the immune system determined the site at which RRV-specific CTLp first appeared . Frequencies of rotavirus-specific CTLp detected in Peyer's patches were 25- to 30-fold greater after oral than after footpad inoculation . However, regardless of the route of inoculation, rotavirus-specific CTLp were distributed throughout the lymphoid system 21 days after infection . Implications of these findings for vaccine design are discussed.

Virology, 1991 Mar, 181(1), 172 - 9
The BI'LF4 trans-activator of Epstein-Barr virus is modulated by type and differentiation of the host cell; Marschall M et al.; We have analyzed the activity and regulated expression of a new Epstein-Barr virus (EBV) trans-activator (I'ta) encoded by left reading frame 4 (BI'LF4) of the BamHI I'fragment . The gene was detected in all genomes of established EBV strains and individual isolates, with the exception of B95-8, where the type-specific deletion of this open reading frame is tolerated in vitro . Specific trans-activation of two EBV promoters (early MS and I'ta promoter) could be shown in cotransfection assays . The I'ta product affected autoactivation but had no influence on heterologous target promoters . The I'ta promoter segment was shown to be costimulated in the process of host cell differentiation in the absence of other EBV gene products . Expression of the reading frame in bacteria identified a 48-kDa protein as a stable gene product . I'ta-specific antibodies were detected in sera from EBV-positive persons (nasopharyngeal carcinoma) . When expressed with suitable eucaryotic vectors, a nuclear protein could be immunostained in transfected cells . Our experiments suggest a cell type-specific requirement for I'ta in the lytic cycle of EBV at a determined differentiation stage of the host cell.

Mol Microbiol, 1991 Mar, 5(3), 515 - 20
Selenocysteine: the 21st amino acid; Bock A et al.; Great excitement was elicited in the field of selenium biochemistry in 1986 by the parallel discoveries that the genes encoding the selenoproteins glutathione peroxidase and bacterial formate dehydrogenase each contain an in-frame TGA codon within their coding sequence . We now know that this codon directs the incorporation of selenium, in the form of selenocysteine, into these proteins . Working with the bacterial system has led to a rapid increase in our knowledge of selenocysteine biosynthesis and to the exciting discovery that this system can now be regarded as an expansion of the genetic code . The prerequisites for such a definition are co-translational insertion into the polypeptide chain and the occurrence of a tRNA molecule which carries selenocysteine . Both of these criteria are fulfilled and, moreover, tRNASec even has its own special translation factor which delivers it to the translating ribosome . It is the aim of this article to review the events leading to the elucidation of selenocysteine as being the 21st amino acid.

J Periodontal Res, 1991 Mar, 26(2), 97 - 106
Isolation and characterization of a 180-kiloDalton salivary glycoprotein which mediates the attachment of Actinomyces naeslundii to human buccal epithelial cells; Babu JP et al.; The adherence of Actinomyces naeslundii to human buccal mucosa is mediated by specific interactions between the bacterial cell surface fimbriae and complementary beta-linked galactoside receptors on the epithelial cell surface . The buccal mucosa and the bacteria that colonize its surface are constantly bathed in saliva . Several salivary components are thought to play an important role in modulating adhesive interactions between oral bacteria and the buccal epithelium . We have observed that pretreatment of isolated buccal epithelial cells (BEC) with human parotid saliva increased the attachment of three different strains of A . naeslundii . By employing affinity chromatography, ion-exchange and high-pressure liquid chromatographic techniques we have isolated a 180 kDa A . naeslundii-binding salivary glycoprotein (An-SPG) . This salivary glycoprotein was capable of mediating separate but specific binding interactions with A . naeslundii and BEC . Pretreatment of BEC with increasing amounts of An-SGP resulted in a corresponding increase in the attachment of A . naeslundii . The adherence of A . naeslundii to An-SGP-coated BEC is sensitive to the same inhibitors previously shown to block adherence of A . naeslundii to uncoated BEC, namely lactose- and galactosyl-binding lectins . When a solubilized extract of freshly isolated and washed BEC was reacted on a Western blot with antibodies to An-SGP, a prominent 180 kDa immunoreactive band was detected . Furthermore, the immunoreactive component was demonstrated on the BEC surface when assayed by immunofluorescence using An-SGP-specific antibodies, suggesting that An-SGP or a protein structurally and immunologically identical to the isolated glycoprotein is present on BEC.

Clin Exp Allergy, 1991 Mar, 21(2), 161 - 6
IgE binding studies with large peptides expressed from Der p II cDNA constructs; Chua KY et al.; The major mite allergen Der p II shows marked resistance to denaturation and is expressed from cDNA in bacteria with almost all of its IgE binding activity . Despite these properties, the IgE binding activity appears to be dependent on maintaining the complete primary structure . Random fragment libraries of cDNA, able to code for up to 93 of the 129 amino acid residue protein, did not express IgE binding peptides . Large overlapping peptides 1-69, 69-129 and 42-117 expressed as the fusions from the glutathione transferase of pGEX vectors only had binding activity with IgE in 15 out of 57 sera, and this was typically weak . Sera from children with atopic dermatitis bound IgE in seven out of eight cases but this was also weak compared with their strong reactivity to intact recombinant Der p II . The inability of such large peptides to form IgE binding structures suggests that the antigenic determinants of Der p II are highly conformational and restricted.

Proc Natl Acad Sci U S A, 1991 Mar 1, 88(5), 1765 - 9
Endonucleolytic degradation of puf mRNA in Rhodobacter capsulatus is influenced by oxygen; Klug G; The formation of pigment-protein complexes in facultatively photosynthetic bacteria is regulated by the oxygen tension in the culture . It is shown that the degradation of some mRNA species encoding components of the photosynthetic apparatus is affected by oxygen . The puf mRNA segment, encoding the pigment-binding proteins of the reaction center, and the 0.5-kb puc mRNA species, encoding pigment-binding proteins of the light-harvesting LHII antenna complex of Rhodobacter capsulatus were degraded more rapidly under high oxygen tension than under low oxygen tension . Studies on strains having deletions or insertions in the puf operon indicate that rate-limiting endonucleolytic cleavage in the reaction center coding region of the polycistronic puf mRNA was influenced by growth conditions . However, other mRNA segments, for which exonucleolytic degradation was postulated to be rate-limiting, decayed with the same rate under either high or low oxygen tension . Likewise, the degradation of the puhA mRNA, the cycA mRNA, and the cytfbc mRNA was found to be independent of the oxygen tension in the culture . The data strongly suggest that specific mRNA sequences or structures are responsible for the observed oxygen effect on mRNA stability.

Eur J Biochem, 1991 Feb 26, 196(1), 247 - 54
Structure and expression of the attacin genes in Hyalophora cecropia; Sun SC et al.; To study the regulation of the immune genes in insects, we have cloned and sequenced the attacin gene locus of the giant silk moth Hyalophora cecropia . The locus contains one acidic and one basic attacin gene as well as two pseudogenes, which are remnants of basic attacin genes . A small insertion element was found within the locus . The two functional attacin genes are transcribed in opposite directions and have two introns inserted at homologous positions . A common sequence, GGGGATTCCT, is found at nucleotide position -48 in the acidic gene and at nucleotide position -58 in the basic gene . Interestingly, this decanucleotide is similar to the consensus of the NF-k B-binding site . Expression studies revealed that both attacins are strongly induced by phorbol 12-myristate 13-acetate, lipopolysaccharide and bacteria . However, only the acidic attacin gene showed a clear response to injury.

Nucleic Acids Res, 1991 Feb 25, 19(4), 861 - 6
Genomic fingerprints produced by PCR with consensus tRNA gene primers; Welsh J et al.; The polymerase chain reaction using only a single 'consensus' tRNA gene primer, or a pair of primers facing outward from tRNA genes, amplifies a set of DNA fragments in bacterial, plant and animal genomic DNAs . Presumably, these PCR fingerprints are mainly derived from the regions between closely linked tRNA genes . The pattern of the PCR products is determined by which genomes and which primer(s) are used . Genomic fingerprints are largely conserved within a species and, in bacteria, most products in the fingerprint are conserved between closely related species . Thus, PCR with tRNA gene consensus primers helps to identify species and genera.

FEBS Lett, 1991 Feb 25, 279(2), 210 - 5
Cloning and sequencing of Lol pI, the major allergenic protein of rye-grass pollen; Griffith IJ et al.; We have isolated a full length cDNA clone encoding the major glycoprotein allergen Lol pI . The clone was selected using a combination of immunological screening of a cDNA expression library and PCR amplification of Lol pI-specific transcripts . Lol pI expressed in bacteria as a fusion protein shows recognition by specific IgE antibodies present in sera of grass pollen-allergic subjects . Northern analysis has shown that the Lol pI transcripts are expressed only in pollen of rye-grass . Molecular cloning of Lol pI provides a molecular genetic approach to study the structure-function relationship of allergens.

Schweiz Med Wochenschr, 1991 Feb 23, 121(8), 245 - 54
{Gastritis associated with Gastrospirillum hominis--a zoonosis?}; Wegmann W et al.; We found spiral bacteria (non-Helicobacter pylori, SB) in gastric biopsies of 5 patients corresponding to an incidence of 0.3% . The bacteria were found on the surface of the gastric mucosa and in part tightly packed within the crypts . Contrary to Helicobacter pylori, most of them had no direct contact to the surface and crypt epithelium . They are distinctly coiled, 3.6-5.5 microns in length and on average 0.5 microns thick . Ultrastructural studies revealed sheathed flagella at each pole . In one case the bacteria displayed periplasmic fibrils in pairs as also described in cultures of SB from cats' stomachs . In all 5 cases there was histological evidence of inflammation of the gastric mucosa, i.e . one acute diffuse gastritis, one case of granulomatous and three of slight to medium grade chronic gastritis . Biopsies of 2 patients showed a positive urease reaction in the CLO test . Morphologically very similar SB occur as commensals in the stomachs of various animals, in particular dogs and cats . We investigated the stomachs of four dogs and four cats and found all to be infested with SB . The bacteria were found not only on the surface of the mucosa and in crypts, but within the glands of the corpus and antrum and often also within parietal (oxyntic) cells . Yet despite bacterial colonization there was no evidence of gastritis in dogs . However, all of the cats' stomachs showed slight to medium grade chronic gastritis . Cultivation of SB has not been successful so far, with the exception of cats' stomachs . Since the germs have been defined only morphologically, the question as to how close the relationship is among SB of various origins must for the time being remain unanswered . Furthermore, species-specific pathogenicity and the possibility of contagion from animal to man has not yet been clarified.

Eur J Biochem, 1991 Feb 14, 195(3), 807 - 22
Three-dimensional correlated NMR study of Megasphaera elsdenii flavodoxin in the oxidized state; Wijmenga SS et al.; The value of a three-dimensional (3D) non-selective total correlation/nuclear Overhauser enhancement spectroscopy (TOCSY-NOESY) spectrum for making sequential resonance assignments in proteins is demonstrated using the relatively large Megasphaera elsdenii flavodoxin (molecular mass 15 kDa) in the oxidized state . An easy and concise method for the analysis of 3D-NMR spectra and a strategy for the resonance assignment of 3D-NMR protein spectra is introduced . In this context, non-selective TOCSY-NOESY is compared with selective TOCSY-NOESY and non-selective NOESY-TOCSY . Sequential assignments in various secondary structure elements of flavodoxin are made using the method of analysis introduced . NOEs not previously identified in 2D-NMR spectra due to resonance overlap are found in the 3D Clean-TOCSY-NOESY spectrum . Also additional side-chain assignments could be made.

Nucleic Acids Res, 1991 Feb 11, 19(3), 631 - 6
Segments containing alternating purine and pyrimidine dinucleotides: patterns of polymorphism in humans and prevalence throughout phylogeny; Sarkar G et al.; Tandem dinucleotide repeats of GT or AC {(GT)n/(AC)n} where n greater than or equal to 14 are highly polymorphic and other simple repeats such as (CT)n/(AG)n and (A)n(T)n are also polymorphic . The uniformity of these sequences precludes a mechanistic differentiation between recombination or polymerase slippage . Since (GT)n/(AC)n or (CT)n/(AG)n segments of desired size were not available in our gene of interest, we analyzed a 187+ bp segment in the factor IX gene with multiple short dinucleotide repeats . This sequence contains a melody of short dinucleotide repeats which includes a 142+ bp segment of alternating purines and pyrimidines . Amplification of this sequence in 167 individuals of different ethnicity and direct sequencing of 106 individuals (23 kb of sequence) failed to reveal simple variation in the number of tandem dinucleotide repeats . However, polymorphism in the 142+ alternating purine and pyrimidine segment (RY)n was detected due to the insertion of two related repeat units of 24 bp (A) and 26 bp (B) . Two previously described alleles (AB, A2B2) and two novel presumptive recombinants were found (A2B, A3B2) for a total of four alleles . An analysis of (RY)n segments in GenBank revealed an extraordinary enrichment in the genome of mammals, invertebrates, and yeast and a marked reduction in bacteria . Rodent (RY)n were larger and substantially more frequent than those in primates . When a second (RY)n was examined in the exon 8 of human factor IX gene, it was polymorphic at short repeats of (GT)n/(AC)n (n = 3-6) in Western Europeans and Koreans . In addition, an (RY)n in the dystrophin gene had four polymorphic alleles involving AT and GT dinucleotides . Thus (RY)n segments appear to be abundant and highly polymorphic . The asymmetric patterns of polymorphism and the absence of simple dinucleotide variation in 23 kb of sequence are compatible with recombination or sister chromatid exchange, but not polymerase slippage . By inference, recombination should underlie the polymorphisms at (GT)n/(AC)n since they are a subset of (RY)n and they commonly occur in the context of longer (RY)n.

Schweiz Med Wochenschr, 1991 Feb 9, 121(6), 189 - 93
{The diagnosis of Lyme borreliosis . Apropos of a neurological case}; Peter O et al.; The clinical diagnosis of Lyme borreliosis is easily established in the initial phase of the illness . Erythema chronicum migrans is pathognomonic of this infection . However, during further complications (neurological, cardiac or articular) the diagnosis is chiefly based on laboratory results . The detection of specific antibodies to B . burgdorferi is one of the effective means of confirming the diagnosis . Culture or isolation of this bacteria is not routinely performed due to its very low yield . In this article a case of serologically proved neuro-borreliosis is described and the methods of diagnosis are discussed . Intrathecal synthesis of antibodies observed in the cerebrospinal fluid of this patient and the specificity of serologic tests confirmed by Western-blot provide the diagnosis . However, the absence of locally synthesized antibodies in the cerebrospinal fluid is not sufficient to rule out neuro-borreliosis.

Biochim Biophys Acta, 1991 Feb 8, 1056(3), 243 - 9
The structure of the dihaem cytochrome b of fumarate reductase in Wolinella succinogenes: circular dichroism and sequence analysis studies; Degli Esposti M et al.; The fumarate reductase from Wolinella succinogenes contains two haem groups with markedly different midpoint potentials (-20 mV and -200 mV) . The enzyme is made up of three subunits, the lipophilic one of which (cytochrome b) ligates the haems . Circular dichroism (CD) spectroscopy has been applied to the reductase in order to obtain information on the structure of the haems and of their environment . This approach is integrated with amino acid sequence comparison of the cytochrome b with other quinone-reacting membrane haemoproteins for predicting the axial ligands of the haems as well as their location relative to the membrane . The following results have been obtained: (1) the CD spectra in the Soret region show exciton coupling indicating haem-haem interaction, which is particularly evident in the reduced state and disappears upon denaturation of the enzyme; (2) The apoprotein of cytochrome b is predicted to consist of five hydrophobic helices (helices A-D and cd), four of which should span the membrane . Helices A, B, C and cd contain a histidine residue each which possibly forms one of the ligands of the haems . It is proposed that haem b (-20 mV) is ligated by H44 and H93, and haem b (-200 mV) by H143 and H182.

Int J Biol Macromol, 1991 Feb, 13(1), 45 - 9
Diagrammatic representation of the distribution of DNA bases and its applications; Zhang CT et al.; The frequencies of occurrence of the bases A, C, G and T (or U) in a DNA or mRNA sequence are denoted by a, c, g, t (or u), respectively . Since a + c + g + t = 1, the four real numbers are mapped into a point within a regular tetrahedron . The mapping points are then projected to some planes for further study . We have given several examples of application of this technique . As a by-product of an application we have found an empirical formula on the limit distribution of DNA bases for different kind of organisms, i.e . 1/4 less than or equal to a2 + c2 + g2 + t2 less than 1/3.

Br J Clin Pharmacol, 1991 Feb, 31(2), 204 - 6
A non-bronchoconstrictor, bacteriostatic preservative for nebuliser solutions; Summers QA et al.; We have studied the bacteriostatic and airways effects of the preservatives chlorocresol and chlorbutol, to assess if they may be safely used in nebuliser solutions . The bacteriostatic study was carried out according to standard techniques, and the preservatives were able to inhibit the growth of a range of bacteria and yeasts for a period of 28 days . The airways effects were studied in eight asthmatic subjects, who were challenged with either the preservatives or saline (as placebo) . Pulmonary function was followed as FEV1 for 60 min after inhalation, and there was no change in FEV1 following inhalation . We conclude that these preservatives may be used safely in nebuliser solutions.

Behring Inst Mitt, 1991 Feb, (88), 177 - 82
V beta selective elements: self and non-self; Janeway CA Jr et al.; Over the last four years, a number of potent T cell responses have been shown to be determined by that portion of the T cell receptor encoded in the V beta gene segment . Responses are essentially uninfluenced by junctional sequences in the beta-chain or by the nature of the alpha-chain . These responses also involve the class II MHC molecule expressed on a stimulating antigen presenting cell . The principle stimuli that have been studied are the polymorphic Mls loci in the mouse and a series of toxic proteins secreted by bacteria, now known as superantigens . Here, some aspects of stimulation by what we call V beta selective elements will be analyzed . The nature of stimulation by self V beta selective elements will be discussed and compared to that of non-self V beta selective elements . It will be shown that the similarities are extensive, including a preference for murine I-E molecules and a hierarchy in the effectiveness of murine I-A molecules in presenting V beta selective elements to certain T cell receptors.

Med Hypotheses, 1991 Feb, 34(2), 186 - 9
Sudden infant death syndrome (SIDS): a time lag factor; Reid GM; A time lag factor of about five days has been identified in an increased incidence of SIDS in relation to a cold day . Sudden exposure to chilling appeared to trigger skeletal muscle weakness and renal failure about five days later in a man found to have only 25% of normal carnitine palmitoyl transferase (CPT) activity in biopsied skeletal muscle . White Muscle Disease is a muscular dystrophy in young ruminants which appears about five days after turnout to pasture in the weaned ruminant raised on a diet deficient in vitamin E and selenium (VESD) . Pasture has high levels of linoleic and linolenic acid (high PUFA diet) which are modified by developing rumen bacteria . Corbucci investigated the effects of circulatory shock (cardiogenic) on skeletal muscle mitochondrial activity in humans . Cytochrome oxidase activity fell markedly and, in particular, the capacity to oxidase palmitoyl carnitine was greatly reduced . He considered a consequence of this disorder was sequestration of carnitine as acyl carnitine which could not be recycled . Unusual acyl carnitines have been identified in six out of 13 SIDS victims in a USA group . In Finland, researchers identified a rise in SIDS incidence (mostly found in the prone position) after great and rapid temperature changes . Foster found a relationship between 1984 SIDS incidence and the incidence of goitre in World War I troops.

Vet Immunol Immunopathol, 1991 Feb, 27(4), 303 - 19
Bovine sire effects on daughters' in vitro blood neutrophil functions, lymphocyte blastogenesis, serum complement and conglutinin levels; Kehrli ME Jr et al.; Blood neutrophil functions, lymphocyte blastogenic responses, serum complement, and serum conglutinin activity of 98 lactating Holstein cows from two genetic lines were evaluated . The genetic lines were produced in a selection experiment that created and perpetuated genetic differences in milk production for up to seven generations . No significant differences between the two genetic lines of cows were found for neutrophil function, lymphocyte blastogenic responses, serum complement levels, or serum conglutinin levels . Significant differences between sire progeny groups within lines were found for unstimulated and mitogen-stimulated lymphocyte blastogenesis (P less than 0.0001), and almost all neutrophil functions (antibody independent neutrophil cytotoxicity, antibody dependent neutrophil cytotoxicity, ingestion of bacteria, iodination, chemiluminescence, chemokinesis, and chemotaxis (P less than or equal to 0.05)) . Sire progeny group differences (P less than or equal to 0.0001) within lines for serum complement and conglutinin activity were also found . Neutrophil chemiluminescence activity (positive relationship; P less than or equal to 0.001), concanavalin A-stimulated lymphocyte blastogenesis (positive relationship; P less than or equal to 0.004), and serum conglutinin activity levels (negative relationship; P less than or equal to 0.01) each had small but significant associations with the total milk somatic cell count . Cows seropositive for bovine leukosis virus had increased resting and mitogen-stimulated lymphocyte blastogenic activity and were associated with increased in vitro neutrophil random migration and production of superoxide anion . Estimates of genetic parameters of various immune cell functions, of serum complement and of conglutinin levels for daughters of 11 sires with 4-6 daughters in the data set were determined . In this report, genetic variation was demonstrated for nonspecific humoral and cellular immunity.

Vet Microbiol, 1991 Feb 1, 26(3), 291 - 9
Comparison of seroreactivity of rams with brucellosis in a complement fixation test, whole cell ELISA and by immunoblotting; Chin JC et al.; In rams with ovine brucellosis, a high degree of serological correlation exists between the complement fixation (CF) test which utilises antigen extracted from bacteria with hot saline, and the ELISA reactivity using methanol-fixed Brucella ovis as the assay reagent . Since the whole cell ELISA (CELISA) detects mainly antibodies against surface antigens of B . ovis, it was concluded that the similar findings of the two serological tests is due in part to the presence of membrane antigens in the CF test antigen following hot saline extraction of intact bacteria . Immunoblots with pooled sera representing different CF titres confirmed that the major immunoreactive antigens of B . ovis were located in four zones: alpha, beta, gamma 1 and 2 with corresponding apparent molecular masses of 55 and 60 kDa; 27 and 29 kDa; 18.5-20 kDa and 17-18 kDa, respectively . These zones of reactivity were consistently present in immunoblots when assayed against different B . ovis isolates even though Coomassie brilliant blue staining of SDS-PAGE gels revealed some differences in polypeptide banding patterns . However, these intensely-stained CBB bands located at 38 and 40 kDa which distinguished three of the seven B . ovis isolates were considerably less reactive in immunoblots compared to polypeptides that were located at positions equivalent to alpha, beta or gamma reactivities . Intensity of immunoblot reactivity against polypeptides located in the alpha, beta and gamma zones intensified with increasing CF titre . Sera with CF titres greater than 32 also tended to react against bands of higher apparent molecular masses located at 65, 70, 73, 78, 80 and 86 kDa.(ABSTRACT TRUNCATED AT 250 WORDS)

J Can Dent Assoc, 1991 Feb, 57(2), 127 - 9
Markers of periodontal disease susceptibility and activity--a review; Stark DE et al.; There appears to be sufficient evidence to indicate that traditional clinical parameters are unable to determine active disease sites in periodontitis and predict future periodontal breakdown . This paper attempts to review some of the recent research aimed at developing laboratory markers of disease susceptibility and activity . A wide variety of studies have involved specific plaque bacteria and their products, host cells and their products, and products of soft and hard tissue injury . Although research to date has been unsuccessful in providing the clinician with reliable diagnostic aids, the rapid progress being made towards refining sampling and analytic techniques gives cause for optimism . These markers may, in the near future, enable the dentist to target preventive measures for patients who are at a greater risk of losing their teeth to destructive periodontitis.

Vet Hum Toxicol, 1991 Feb, 33(1), 32 - 9
Hazards in confinement housing--gases and dusts in confined animal houses for swine, poultry, horses and humans; Pickrell J; Indoor atmospheres in swine or poultry confinement buildings, horse stalls or human dwellings contain gases, dusts and endotoxin in concentrations significantly in excess of those in outdoor environments . Although concentrations of such constituents differ appreciably between species, many of such differences may be related to differences in indoor mass loading and ventilation, or to the homogeneity of such ventilation . The high protein content of these indoor dust particles suggest they are of animal origin . Their ability to form bacterial colonies and to form or bind endotoxin suggest that the smallest and most respirable particles were manure particles containing enteric bacteria and endotoxin . Respiratory disease in swine, poultry and horses and in the workers who care for them may be caused by increased levels of carbon monoxide, ammonia, hydrogen sulfide, or indoor dust particles from feed and manure . The stagnant air of a well-insulated building causes the most active individual to attract these stagnant pockets, while the tendency of young animals to seek warmth may lead to the formation of additional pockets . Increased ventilation is an expensive solution to the problems associated with indoor air pollution . However, more thorough mixing of indoor air may reduce the effects of these clouds of pollutants.

Scand J Immunol, 1991 Feb, 33(2), 237 - 41
Gastric epithelial cells in Helicobacter pylori-associated gastritis express HLA-DR but not ICAM-1; Scheynius A et al.; Induced expression of the intercellular adhesion molecule 1 (ICAM-1) and of the major histocompatibility complex (MHC) class II antigens has been simultaneously observed on keratinocytes and epithelial cells in the thyroid and kidney, suggesting that ICAM-1 and HLA-DR expression might be under common regulation . We have previously found an association between the presence of Helicobacter pylori and an induced expression of class II antigens on gastric epithelial cells in gastric biopsy specimens from patients with gastritis . In this study we investigated whether ICAM-1 could also be expressed on the gastric epithelium . Thirty-one patients with clinical indications for upper gastrointestinal endoscopy were examined . In 23 patients gastritis was diagnosed endoscopically and histologically and H . pylori was cultured from biopsy specimens . In eight patients neither histological gastritis nor growth of the bacteria was observed . Immunoperoxidase staining demonstrated expression of HLA-DR but not ICAM-1 on the gastric epithelial cells in all patients with H . pylori-associated gastritis, indicating regulatory mechanisms different from those of other epithelial cells.

Pathol Biol (Paris), 1991 Feb, 39(2), 150 - 2
{Evaluation of a DNA probe test for the detection of Legionella SPP}; Pelloux I et al.; Seventeen suspension of Legionella pneumophila and ten of Legionella bozemanii in saline or bronchoalveolar lavage (BAL) fluid were tested using the Gen Probe technique . The detection threshold was found to be 10(3)-10(4) CFU/ml . Specificity and sensitivity were evaluated by using the probe on 8 suspensions of bacteria other than Legionella and by performing a comparative study of the probe test, direct immunofluorescence and culture with 103 specimens (BAL fluid in most instances) from 92 patients with possible legionellosis . Sensitivity was found to be acceptable (3 of the 4 culture-positive specimens were positive by the probe test) and specificity was 100% despite the fact that most (80/99) BAL specimens were not sterile and regardless of the cutoff level used to define positivity . The advantages of the DNA probe test, including rapidity, simplicity and objectivity, should be weighed against its disadvantage, i.e., only acceptable sensitivity and use of radioactivity.

Toxicology, 1991 Feb, 66(2), 187 - 95
Comparison of the critical concentration and critical volume hypotheses to model non-specific toxicity of individual compounds; Warne MS et al.; The critical concentration and critical volume hypotheses for non-specific toxicity require the molar concentration (CC) and volume fraction (VF) of toxicant in target tissue to be constant . Thus these factors should be independent of the octanol-water partition coefficient (Kow) for individual compounds . CC and VF values were calculated based on acute sub-lethal, acute and chronic lethal toxicity data, Kow and pure component molar volume (MV) data . When these values were plotted against log Kow, the slopes of the regression equations were significantly different to zero but were not significantly different from each other . The observed slight increase in CC and VF with increasing log Kow was attributed predominantly, to the use of Kow values which overestimate the target tissue-water partition coefficient (Kow) . An additional error associated with the volume fraction calculations was the use of the molar volume instead of partial molar volume . VF and CC values were calculated correcting for both these factors and regressed against log Kow . The resulting equation for VF had a gradient not significantly different from zero, while that for CC was, thus indicating the superiority of the critical volume hypothesis in modelling non-specific toxicity of individual compounds.

J Bioenerg Biomembr, 1991 Feb, 23(1), 83 - 104
Cell regulation by sphingosine and more complex sphingolipids; Merrill AH Jr; Sphingolipids have the potential to regulate cell behavior at essentially all levels of signal transduction . They serve as cell surface receptors for cytoskeletal proteins, immunoglobulins, and some bacteria; as modifiers of the properties of cell receptors for growth factors (and perhaps other agents); and as activators and inhibitors of protein kinases, ion transporters, and other proteins . Furthermore, the biological activity of these compounds resides not only in the more complex species (e.g., sphingomyelin, cerebrosides, gangliosides, and sulfatides), but also in their turnover products, such as the sphingosine backbone which inhibits protein kinase C and activates the EGF-receptor kinase, inter alia . Since sphingolipids change with cell growth, differentiation, and neoplastic transformation, they could be vital participants in the regulation of these processes.

Eur J Vasc Surg, 1991 Feb, 5(1), 83 - 6
In-situ replacement and extra-anatomic bypass for the treatment of infected abdominal aortic grafts; Jacobs MJ et al.; We reviewed the surgical results of 21 patients who had infected abdominal aortic grafts to determine the efficacy of in-situ graft replacement and extra-anatomic bypass in the management of these patients . Twelve patients had a primary perigraft infection, and nine had an infection secondary to an aortoenteric fistula (AEF) . Whereas the infected graft was replaced with a new aortic prosthesis in 18 patients, an axillobifemoral bypass operation followed graft excision in three patients . Twelve of the graft replacement patients (two AEF patients) had a low-grade infection, with negative perigraft and blood cultures . All 12 patients were alive at a mean follow-up of 8 years . Two had required above-knee amputation because of severe occlusive disease, and one had required an axillobifemoral bypass because of reinfection . The remaining six graft replacement patients (five AEF patients) had severe graft infections, with positive perigraft fluid and blood cultures in which one or more bacteria were present . Five died of sepsis within 1 month of operation . The remaining patient, who later required an axillobifemoral bypass because of reinfection, was alive at follow-up 4.3 years after operation . The three patients (two AEF patients) who had axillobifemoral bypasses had severe graft infections, with positive perigraft fluid and blood cultures . They survived the extra-anatomic bypass operation and were alive at a mean follow-up of 4.5 years . We conclude that patients who have a low-grade graft infection and negative blood and perigraft cultures can be treated safely by graft excision and in-situ replacement with a new prosthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

J Clin Microbiol, 1991 Feb, 29(2), 395 - 7
Comparison of isolates of Helicobacter pylori and Helicobacter mustelae; Morgan DR et al.; On the basis of analysis of protein profiles, isolates of Helicobacter pylori and Helicobacter mustelae were less than 40% similar . Cytotoxin produced by H . pylori was not detected in isolates of H . mustelae . Both bacterial species agglutinated human erythrocytes . These results substantiate a taxonomic difference between H . pylori and H . mustelae.

Am J Dent, 1991 Feb, 4(1), 5 - 9
Dentin permeability and restorative dentistry: a status report for the American Journal of Dentistry; Pashley DH et al.; Most dental materials permit of microleakage because oral fluids and bacteria commonly gain access to dentin surfaces . Dentin is permeable and allows the bidirectional movement of materials from the oral cavity, across dentin to the pulp and vice versa . The pupal irritation associated with microleakage is often dictated by the permeability of dentin . Thick dentin covered with a smear layer is a better barrier than thin dentin with the smear layer removed, while coronal dentin is more permeable than root dentin . Carious dentin is less permeable than normal dentin, but freshly cut dentin is more permeable than previously prepared dentin . This is partly due to the movement of large plasma proteins from the pulpal blood vessels into dentin . The pulpal circulation contributes to the health of the pulp by supplying nutrients and by removing toxic material that diffuses across dentin via the microcirculation . Thus, there is a delicate balance involving the rate bacterial products diffuse around microgaps between restorative materials and dentin, the rate these materials permeate across dentin and the rate they are removed during pulpal circulation.

Can J Surg, 1991 Feb, 34(1), 53 - 8
Etiology of prosthetic anastomotic false aneurysms: pathologic and structural evaluation in 26 cases; Downs AR et al.; To determine the etiology of anastomotic false aneurysms (AFAs), 26 textile graft specimens, removed because of AFA, were studied morphologically, histologically and by scanning electron microscopy . No cases of suture-related failures leading to AFA were found . Nine cases of frayed grafts were documented but were not the cause of AFA formation . In three cases, chemical degradation of the fibres, which may have been secondary to lipid infiltration, may have contributed to AFA formation . There were no cases of overt clinical infection, but the presence of bacteria was documented by scanning electron microscopy in 20 cases . The role of bacteria is not well defined, but they may be a factor in host arterial-wall degeneration as a cause for AFA formation.

J Gen Virol, 1991 Feb, 72 ( Pt 2), 461 - 4
Cloning and sequencing of the S RNA from a Bulgarian isolate of tomato spotted wilt virus; Maiss E et al.; Libraries of cloned cDNA were prepared from complete genomic RNA and isolated S RNA of the Bulgarian L3 isolate of tomato spotted wilt virus (TSWV-L3) . Northern blotting of TSWV genomic RNA detected clones specific for the L, M and S RNAs in the library from complete RNA . S RNA-specific clones selected from both libraries covered approximately 2.8 kb (about 95%) of the S RNA . Sequencing of these clones showed TSWV-L3 S RNA to be ambisense . It contains two open reading frames (ORFs); one of 1401 nucleotides located on the viral RNA encodes an Mr 52,400 (52K) protein, and the other of 774 nucleotides on the complementary strand encodes an Mr 28,900 (29K) protein . Expression of the 29K ORF in bacteria and immunological analysis of the fusion protein synthesized confirmed that the 29K protein is the N protein of TSWV-L3 . Comparison with the published sequence for the S RNA of a Brazilian TSWV isolate, CNPH1, revealed almost complete identity in the amino acid sequences for the 29K protein, but several clustered amino acid exchanges in the putative 52K protein . In addition, the separating non-translated intergenic region of the S RNA of the Bulgarian isolate is 81 nucleotides longer than that of CNPH1.

Obstet Gynecol, 1991 Feb, 77(2), 228 - 34
Low incidence of positive amnionic fluid cultures in preterm labor at 27-32 weeks in the absence of clinical evidence of chorioamnionitis; Harger JH et al.; In order to determine the utility of amniocentesis for detecting subclinical chorioamnionitis in asymptomatic afebrile women in preterm labor with intact membranes, we enrolled 47 women between 27-32 weeks' gestation in a prospective study . After enrollment, 38 women fulfilled all clinical and laboratory criteria for the study; nine women were excluded because they had a leukocyte count exceeding 15,000/microL . None of the 38 asymptomatic afebrile women had a positive culture from the amnionic fluid for bacteria, fungi, Mycoplasma hominis, Ureaplasma urealyticum, Chlamydia trachomatis, or any viruses . Sepsis was not proved in any of the 38 infants delivered to these patients . There was a clear relationship between histologic evidence of chorioamnionitis and failure of tocolytic therapy . Fetal lung profiles were mature in 29% of the amnionic fluid samples from 30-32 weeks' gestation, but in none of the amnionic fluid samples before 30 weeks . Amniocentesis does not seem useful to detect chorioamnionitis in asymptomatic afebrile women with preterm labor and intact membranes at 27-32 weeks' gestation, and should be reserved for those cases in which information about fetal lung maturity would be helpful.

Infect Immun, 1991 Feb, 59(2), 696 - 9
Effect of sulfide ions on complement factor C3; Granlund-Edstedt M et al.; In infected sites such as the gingival pockets of patients with periodontal disease, sulfide levels up to 1 mmol/liter may be reached . There is little information, however, on how sulfide may interact with the host defense . In a previous study (R . Claesson, M . Granlund-Edstedt, S . Persson, and J . Carlsson, Infect . Immun . 57:2776-2781, 1989), it was shown that polymorphonuclear leukocytes were able to kill bacteria in the presence of 1 mM sulfide . However, sulfide seemed to interfere with the opsonization of the bacteria . It has been claimed that sulfide may be toxic by splitting disulfide bonds of proteins . In the present study, serum was exposed to 2 mM sulfide under anaerobic conditions, and the capacity of sulfide to split disulfide bonds of 10 serum proteins involved in opsonization was evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunodetection of the proteins after blotting . Sulfide had a low capacity to split the disulfide bonds of most proteins . Sulfide had, however, a pronounced effect on the complement component C3 in the form of C3bi . Sulfide released the C-terminal region of the alpha chain from C3bi . When C3 opsonizes bacteria, it is this region of C3bi which binds to complement receptor 3 (CR3) of the polymorphonuclear leukocytes . If sulfide has the same effect on C3bi deposited on the bacterial surface as it has on C3bi in solution, it will annihilate the very important contribution of C3bi to opsonization.

Infect Immun, 1991 Feb, 59(2), 631 - 7
Monoclonal antibody characterization of a leukoagglutinin produced by Renibacterium salmoninarum; Wiens GD et al.; Renibacterium salmoninarum causes a chronic disease of salmonid fish known as bacterial kidney disease . High concentrations of bacterially produced extracellular protein (ECP) are present in plasma, kidney, and spleen tissue of naturally and experimentally infected fish . ECP agglutinated salmonid leukocytes in vitro at concentrations which correspond to levels found in highly infected fish . Association of biological activity with the structure of the major protein constituent of ECP, p57, was accomplished by monoclonal antibody (MAb) analysis . Location of the antigenic binding sites recognized by the MAbs was determined by two-dimensional electrophoresis and Western immunoblotting of the proteolytic breakdown fragments of p57 . Eight MAbs have been classified into three groups on the basis of their differential recognition of these proteolytic breakdown products . Group I MAbs bound a region proximal to the amino terminus of the protein . Two of these MAbs were also able to block leukoagglutinating activity . Group III MAbs bound to a region associated with the bacterial cell surface, while group II MAbs bound a region between group I and group III . These analyses have allowed the identification of potential structural and functional regions of p57.

Int J Hematol, 1991 Feb, 54(1), 79 - 84
Serum interleukin-1 and tumor necrosis factor activities in febrile children with acute leukemia; Ishii E et al.; In order to determine whether a relationship exists between levels of serum interleukin-1 (IL-1) and tumor necrosis factor (TNF) and the incidence of fever in malignant disease and infection, IL-1 and TNF levels in 60 children with acute leukemia, 18 children with bacterial infection, and 10 children with viral infection were compared with those of 20 healthy children . IL-1 levels greater than 100 pg/ml were seen in two febrile leukemic patients and six bacteria-infected patients, and the bacteria-infected group as a whole had IL-1 levels significantly higher than those of healthy children (p less than 0.05) . TNF levels greater than 50 pg/ml were noted in six febrile leukemic patients and two bacteria-infected patients (both of whom were complicated by septic shock) . No single group showed significantly higher levels when compared to healthy children . All patients showing high IL-1 or TNF levels had fevers at the time of diagnosis . These findings suggest that fever in bacterial infection is associated with the production of IL-1 but not TNF (except in cases of septic shock), whereas fever in acute leukemia may be associated with the production of either IL-1 or TNF . Monitoring patients with acute leukemia for IL-1 and TNF levels throughout the clinical course of disease may help clarify the causes of febrile episodes.

Mol Microbiol, 1991 Feb, 5(2), 335 - 42
Molecular analysis of the methane monooxygenase (MMO) gene cluster of Methylosinus trichosporium OB3b; Cardy DL et al.; The oxidation of methane to methanol in methanotrophic bacteria is catalysed by the enzyme methane monooxygenase (MM0) . This multicomponent enzyme catalyses a range of oxidations including that of aliphatic and aromatic compounds and therefore has potential for commercial exploitation . This study details the molecular characterization of the soluble MMO (sMMO) genes from the Type II methanotroph Methylosinus trichosporium OB3b . The structural genes encoding the alpha, beta and gamma subunits of sMMO protein A and the structural gene encoding component B have been isolated and sequenced . These genes have been expressed and their products identified using an in vitro system . A comparative analysis of sMMO predicted sequences of M . trichosporium OB3b and the taxonomically related M . capsulatus (Bath) is also presented.

Biochem Cell Biol, 1991 Feb-Mar, 69(2-3), 122 - 31
The puh structural gene coding for the H subunit of the Rhodospirillum rubrum photoreaction center; Berard J et al.; The Rhodospirillum rubrum structural gene puh, coding for the photoreaction center H polypeptide, and three other putative genes that surround puh were cloned and sequenced . The deduced 257 amino acid H polypeptide has a molecular weight of 27,909, in close agreement with polyacrylamide gel electrophoresis determination . Hydropathy plots predict a single hydrophobic alpha helix . The H polypeptide of Rhodospirillum rubrum shares only 23% of its residues with all three of the H polypeptides from Rhodopseudomonas viridis, Rhodobacter capsulatus, and Rhodobacter sphaeroides . Despite this apparent low degree of similarity, statistical analysis leaves no doubt about their close relatedness . Interspecies evolutionary distance, assessed by this analysis, confirms the closeness of the two Rhodobacter species, Rhodospirillum rubrum and Rhodopseudomonas viridis being approximately equidistant from them . Three regions of the H polypeptide are highly conserved in all four species . They correspond to known contact points of H with the complex of the other two (L and M) subunits on the cytoplasmic side of the membrane . A glutamic acid residue (H polypeptide residue 177), conserved in the other bacteria and suggested to be involved in the binding of secondary quinone QB, is replaced by serine in Rhodospirillum rubrum . The open reading frames G115, I2372, and I3087 are predicted to, respectively, encode polypeptides of 480, 224, and 155 residues coiled in 10, 2, and 1 transmembrane helices . Open reading frame G115 shares 56% identical residues with F1696, a sequence arranged in the genome of Rhodobacter capsulatus . The gene product of ORF I3087 is predicted to share highly similar sequences with nitrogenase reductase (encoded by nifH) of 11 different bacterial species and is suggested to have a regulatory function.

J Bacteriol, 1991 Feb, 173(4), 1414 - 9
Purification and characterization of NADP(+)-dependent 5,10-methylenetetrahydrofolate dehydrogenase from Peptostreptococcus productus marburg; Wohlfarth G et al.; The 5,10-methylenetetrahydrofolate dehydrogenase of heterotrophically grown Peptostreptococcus productus Marburg was purified to apparent homogeneity . The purified enzyme catalyzed the reversible oxidation of methylenetetrahydrofolate with NADP+ as the electron acceptor at a specific activity of 627 U/mg of protein . The Km values for methylenetetrahydrofolate and for NADP+ were 27 and 113 microM, respectively . The enzyme, which lacked 5,10-methenyltetrahydrofolate cyclohydrolase activity, was insensitive to oxygen and was thermolabile at temperatures above 40 degrees C . The apparent molecular mass of the enzyme was estimated by gel filtration to be 66 kDa . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of a single subunit of 34 kDa, accounting for a dimeric alpha 2 structure of the enzyme . Kinetic studies on the initial reaction velocities with different concentrations of both substrates in the absence and presence of NADPH as the reaction product were interpreted to indicate that the enzyme followed a sequential reaction mechanism . After gentle ultracentrifugation of crude extracts, the enzyme was recovered to greater than 95% in the soluble (supernatant) fraction . Sodium (10 microM to 10 mM) had no effect on enzymatic activity . The data were taken to indicate that the enzyme was similar to the methylenetetrahydrofolate dehydrogenases of other homoacetogenic bacteria and that the enzyme is not involved in energy conservation of P . productus.

Genes Dev, 1991 Feb, 5(2), 321 - 30
Characterization of a gene controlling heterocyst differentiation in the cyanobacterium Anabaena 7120; Buikema WJ et al.; Anabaena 7120 mutant 216 fails to differentiate heterocyst . We previously identified a 2.4-kb wild-type DNA fragment able to complement this mutant . We show here that the sequence of this fragment contains a single open reading frame (hetR), encoding a 299-amino-acid protein . Conjugation of deletion subclones of this fragment into strain 216 showed that the hetR-coding region is both necessary and sufficient for complementation of the Het- phenotype . The mutation in 216 is located at nucleotide 535 in the hetR gene, converting a serine at position 179 in the wild-type protein to an asparagine in the mutant . Interruption of the hetR gene in wild-type cells results in a mutant phenotype identical to that of 216 . Both 216 and wild-type cells containing wild-type hetR on a plasmid display increased frequency of heterocysts, even on media containing fixed nitrogen . These results suggest that hetR encodes a product that is not only essential for but also controls heterocyst development . This putative regulatory protein lacks known structural motifs characteristic of transcription factors and probably acts at a level one or more steps removed from its target genes.

Contact Dermatitis, 1991 Feb, 24(2), 94 - 100
Skin symptoms among workers in the fish processing industry are caused by high molecular weight compounds; Halkier-Sorensen L et al.; Scratch tests were performed with fish juice containing high and low molecular weight compounds obtained by ultrafiltration and with degradation compounds known to accumulate in fish stored on ice . 75 volunteers were tested . The peptide pattern in raw fish juice and its high and low molecular weight fractions were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and the concentration of protein in the various fractions was determined . Fish products were analysed for bacteria and algae and the concentration of degradation compounds was measured . Mainly high molecular weight compounds (polypeptides) of fish juice were found to be responsible for the skin symptoms.

FASEB J, 1991 Feb, 5(2), 171 - 7
Functional diversity of T lymphocytes due to secretion of different cytokine patterns; Street NE et al.; Different helper T cell subsets secrete different patterns of cytokines when stimulated by antigen . The TH1 and TH2 subsets differ in the secretion of at least eight cytokines, and three or more other cytokine secretion patterns also exist among both mouse and human T cell clones . Several properties of strong immune responses suggest that at least the TH1 and TH2 phenotypes can be present in vivo . As cytokines are major determinants of the functions of the T cells that produce them, these patterns lead to different properties of the T cell subsets . TH1 cells mediate several functions connected with cytotoxicity and local inflammatory reactions, and so these T cells are particularly effective at combating viruses and intracellular bacteria and parasites . TH2 cells are much more effective at stimulating B cells to produce antibody, and so should be more effective against free-living bacteria, and in inducing protective humoral immunity . Antibody and delayed inflammatory reactions are often mutually exclusive during immune responses, and this can be at least partially explained by cross-inhibition of TH1 and TH2 cells . A newly discovered cytokine, IL10, has been implicated as one of the cross-regulatory cytokines, as this TH2 product inhibits cytokine synthesis by TH1 cells.

EMBO J, 1991 Feb, 10(2), 317 - 25
A mammalian protein kinase with potential for serine/threonine and tyrosine phosphorylation is related to cell cycle regulators; Ben-David Y et al.; In a screen of mouse erythroleukemia cDNA expression libraries with anti-phosphotyrosine antibodies, designed to isolate tyrosine kinase coding sequences, we identified several cDNAs encoding proteins identical or very similar to known protein-tyrosine kinases . However, two frequently isolated cDNAs, clk and nek, encode proteins which are most closely related to protein kinases involved in regulating progression through the cell cycle, and contain motifs generally considered diagnostic of protein-serine/threonine kinases . The clk gene product contains a C-terminal cdc2-like kinase domain, most similar to the FUS3 catalytic domain . The Clk protein, expressed in bacteria, becomes efficiently phosphorylated in vitro on tyrosine as well as serine/threonine, and phosphorylates the exogenous substrate poly(glu, tyr) on tyrosine . Direct biochemical evidence indicates that both protein-tyrosine and protein-serine/threonine kinase activities are intrinsic to the Clk catalytic domain . These results suggest the existence of a novel class of protein kinases, with an unusual substrate specificity, which may be involved in cell cycle control.

Bull Tokyo Dent Coll, 1991 Feb, 32(1), 27 - 34
An ultrastructural study of the pocket epithelium in rats; Abiko Y et al.; The purpose of the present study was to elucidate the biological characteristics of pocket epithelium in experimental periodontitis . Elastic rubber was inserted between the first and second molars of the left maxilla in rats . The rubber was removed after one week, and the animals were sacrificed one week after the removal, i.e., two weeks after the insertion . Sections of the teeth and surrounding tissues were examined by electron microscopy . Periodontal pockets were evident between the tooth surface and epithelial cell layer in the coronal portion . A large number of bacteria surrounded by neutrophils were observed on the cementum surface in the pocket; however, no bacterial invasion could be seen in the epithelium . The epithelial cells were spilt in the central portion by invasion of neutrophils, so that one or two layers of surviving epithelial cells were present on the cementum surface . Numerous fenestrations of capillaries were found in the connective tissue immediately below the epithelium . These results suggest that the pocket epithelium is formed by an intercellular split of the epithelium, not between cementum surface and epithelium.

Chir Ital, 1991 Feb-Apr, 43(1-2), 49 - 54
{The ileocecal valve as a prognostic factor in extensive resection of the small intestine}; Fornaro R et al.; The aim of the study was to examine the role of the ileocaecal valve in relation to the nature and extent of symptoms following extensive bowel resection (EBR) in 13 patients with short bowel syndrome (SBS) referred to our department over the period 1962-1988 . The results obtained do not allow us to assess the effective role of the ileocaecal valve in determining the severity of SBS . The factors conditioning the extent of the aftermath of EBR and effectively affecting prognosis are, in fact, multiple and act in various interrelated ways, thus making it difficult to define the precise role of any one of them . The ileocaecal valve, however, does play a substantial role, in that, on the one hand, it performs sphincter and barrier functions against ileocolic reflux of bacteria, while, on the other, its removal involves excision of the right colon (reserve area for reabsorption of water and ions) and of the terminal ileum (a site specialized in absorption of vitamin B12 and bile salts).

Pharmazie, 1991 Feb, 46(2), 125 - 7
The protection of insulin against proteolytic processes after rectal application to normoglycemic rabbits; Hacker E et al.; In order to improve the bioavailability of insulin after rectal application to rabbits, the influence of surface-active amino acid-fatty acid condensate on absorption and, the effects of a protease inhibitor (aprotinine), of a disinfectant (methyl-hydroxybenzoate) and of chemotherapeutics (chloramphenicol, ambazone and metronidazole) were investigated . Only the application of methylhydroxybenzoate, ambazone and of metronidazole, which inhibit the anaerobic bacterial flora, improved bioavailability significantly . The examinations show that the proteolytic activity of the anaerobic bacterial flora causes the loss of the biological activity of peptides in the rectum.

Virology, 1991 Feb, 180(2), 687 - 96
A bluetongue serogroup-reactive epitope in the amino terminal half of the major core protein VP7 is accessible on the surface of bluetongue virus particles; Eaton BT et al.; Immunoelectron microscopy has been used to confirm that the core protein VP7 is accessible on the surface of bluetongue virus (BTV) particles . Monospecific antibodies generated to vaccinia virus-expressed VP7 and an anti-VP7 monoclonal antibody (MAb 20E9) bound to native virus particles and were localized by protein A-gold . In contrast, MAb 20E9 labeled directly with gold failed to gain access and bind, suggesting that VP7 is neither adventitiously adsorbed to the virion surface nor exposed in a manner such as protrusion through the outer capsid . Thus the surface layer of BTV may be considered as a net which only partially obscures the underlying core particle . Sequencing of VP7 revealed it to be an extremely hydrophobic protein, 350 amino acids in length with cysteine residues at positions 15, 65, and 154 . Examination of VP7 in the cytosol of cells infected with either BTV or a vaccinia virus recombinant expressing VP7 indicated that the protein may exist as an oligomer, whose constituent monomers are not linked by intermolecular disulfide bonds . The cysteine residues in sodium dodecyl sulfate (SDS)-denatured, dithiothreitol (DTT)-treated VP7 were labeled with the fluorescent iodoacetamide AEDANS and the protein was cleaved by V8 protease . The size of the labeled peptides and knowledge of the location of potential V8 cleavage sites suggested that the enzyme cleaved VP7 at three locations (glutamic acid residues at positions 61, 104 (or 108), and 132 (or 134 or 135) . Analysis of the fluorescent peptides generated by V8 protease cleavage of VP7 labeled with AEDANS in the absence of DTT (i.e., with any putative intramolecular disulfide bonds intact) suggested that the cysteine at position 154 was the only one accessible to AEDANS . The cysteines at positions 15 and 65 may therefore be linked via a disulfide bond . Denaturation of VP7 with SDS did not eliminate the capacity of the protein to bind MAb 20E9 . However, the sensitivity of the epitope to reduction and acetylation and its resistance to either of these processes alone suggest that it may be located near a disulfide bond linking cysteines at positions 15 and 65 . Confirmation that the epitope lay in the amino-terminal half of the VP7 came from immunoelectron microscopy experiments in which thin sections of bacteria expressing the complete VP7 and the amino-terminal half were probed with MAb 20E9 and protein A-gold.

J Exp Med, 1991 Feb 1, 173(2), 499 - 502
Expression of perforin and serine esterases by human gamma/delta T cells; Koizumi H et al.; gamma/delta T cells have recently been described in association with a number of disorders, including autoimmune diseases . gamma/delta T cells are thought to play a cytotoxic role, but their mechanism of action is not known . Several granule mediators of cytotoxicity, including a pore-forming protein (perforin), and a family of serine esterases, have been isolated from cytotoxic T lymphocytes (CTL), lymphokine-activated killer (LAK) cells, and natural killer (NK) cells . We demonstrate here that gamma/delta T cells also express these mediators . Northern blots show that gamma/delta T cells express perforin, serine esterase 1 (SE 1), and SE 2 . Three polyclonal antisera - raised against murine perforin, a peptide composed of amino acids 1-34 of human perforin, and human peforin expressed in bacteria - all reacted with a 70-kD protein in gamma/delta T cells on Western blots . Immunostaining with antiperforin antisera shows that primary gamma/delta T cells also contain perforin . Electron microscopy reveals that the granules of gamma/delta T cells resemble those of CTL, LAK, and NK cells . Gamma/delta T cells also resemble LAK cells in possessing inclusion bodies in their nuclei . These results imply that gamma/delta T cells resemble other cytolytic lymphocytes in their mechanism of action.

Bull Tokyo Dent Coll, 1991 Feb, 32(1), 1 - 7
The inhibitory effect of plant extracts on the collagenolytic activity and cytotoxicity of human gingival fibroblasts by Porphyromonas gingivalis crude enzyme; Osawa K et al.; It is well known that plant extracts inhibit some enzymatic activities . The present study examined the inhibitory effects of natural plant extracts against the collagenolytic activity of Porphyromonas gingivalis . The enzyme was isolated from a culture supernatant of P . gingivalis 381 . The aqueous and 50% ethanolic extracts of Ginkgo biloba, Mosla chinensis, Salvia officinalis, Cinnamomum cassia, and a catechin extract of Camellia sinensis exhibited strong inhibitory effects on collagenolytic activity . The activities of these plant extracts were higher than that of tetracycline-HCl . They also inhibited the cytotoxicity of P . gingivalis crude enzyme against human gingival fibroblasts . C . sinensis catechin was the most effective agent in neutralizing the cytotoxicity of P . gingivalis . The aqueous and 50% ethanolic extracts of C . cassia had relatively strong anti-cytotoxic activity . Although the other samples strongly inhibited the collagenolytic activity of P . gingivalis, they were not effectively anti-cytotoxic . The present findings suggest that C . sinensis and C . cassia extracts are effective in reducing the pathogenicity of periodontopathic bacteria.

Oral Microbiol Immunol, 1991 Feb, 6(1), 24 - 9
Collagenase activity in gingival crevicular fluid of patients with juvenile periodontitis; Suomalainen K et al.; The nature and origin of collagenases in gingival crevicular fluid of juvenile periodontitis patients was investigated . Gingival crevicular fluid collected from deep untreated periodontal pockets of juvenile periodontitis patients was found to contain only vertebrate collagenase (EC 3.4.24.7) activity that cleaved soluble type-I and -III collagens into 3/4 and 1/4 length fragments, as analyzed by SDS-polyacrylamide gel electrophoresis . Type II collagen was degraded at a markedly slower rate . This substrate specificity is indicative of collagenases produced by fibroblasts, epithelial cells and macrophages . We have previously found that collagenase in gingival crevicular fluid of adult periodontics patients appears to be mainly derived from polymorphonuclear leukocytes (PMN) . The reasons for the apparent difference in collagenase source between the groups were investigated . We examined whether the pathogen characteristic for juvenile periodontitis, Actinobacillus actinomycetemcomitans, can release collagenase from normal human PMNs . All 10 A . actinomycetemcomitans strains tested, freshly isolated from the subgingival plaque of juvenile periodontitis patients, caused release of collagenase from PMNs in vitro . These results suggest that the lack of normally functioning PMNs in the periodontium of juvenile periodontitis patients may result in a colonization of bacteria that activate the resident periodontal cells to produce increased amounts of collagenase.

HPB Surg, 1991 Feb, 3(2), 117 - 25; discussion 125-7
The effect of incomplete bile duct obstruction on diisopropanolnitrosamine-induced cholangiocarcinoma; Kinami Y et al.; This study was carried out to clarify the influence of incomplete bile duct obstruction (IBDO) on the occurrence and proliferation of cholangiocarcinoma and to evaluate the effect of release of IBDO at an early stage, using 175 Syrian golden hamsters . These hamsters received 500 mg/kg body weight of diisopropanolnitrosamine (DIPN) once weekly for 10 weeks, and then were divided into 3 groups, consisting of the simple laparotomy group (SL group), the IBDO group and 2 week IBDO group, in which IBDO was released after 2 weeks . The occurrence rates of cholangiocarcinoma at 20 weeks were 42% in the SL group, 76% in the IBDO group and 30% in the 2 week IBDO group . The mean numbers of tumors per hamster in the IBDO group were significantly greater than those in other groups (p less than 0.05) . Both occurrence rates and numbers of tumors in the 2 week IBDO group were similar to those in the SL group . The proliferation of bile ductules and isolation of bacteria from bile in the IBDO group had higher rates at 15, 20 weeks than those found in the other groups . These results suggest that IBDO has an influence, as promoter, on the occurrence of cholangiocarcinoma induced by DIPN, and the disappearance of its promoting effect is caused by release of the obstruction.

Cell, 1991 Jan 25, 64(2), 381 - 91
Expression of positional information during cell differentiation of Caulobacter; Gober JW et al.; The asymmetric targeting of proteins to the Caulobacter predivisional cell poles yields dissimilar progeny . We show that the products of transcriptional reporter gene fusions to a flagellin gene and to the flagellar hook operon are segregated to the progeny swarmer cell . This segregation does not depend on sequences within the mRNA, but on the upstream regulatory region . The subset of developmentally regulated flagellar genes that exhibit mRNA segregation has the same upstream cis-acting elements: an activator-binding site known as the ftr sequence and an IHF-binding site . We propose that these genes are preferentially transcribed from the chromosome in the incipient swarmer cell pole of the predivisional cell.

Nucleic Acids Res, 1991 Jan 25, 19(2), 209 - 15
SRP-RNA sequence alignment and secondary structure; Larsen N et al.; The secondary structures of the RNAs from the signal recognition particle, termed SRP-RNA, were derived buy comparative analyses of an alignment of 39 sequences . The models are minimal in that only base pairs are included for which there is comparative evidence . The structures represent refinements of earlier versions and include a new short helix.

Nature, 1991 Jan 24, 349(6307), 293 - 9
Man-made antibodies; Winter G et al.; Monoclonal antibodies can now be genetically engineered and endowed with new properties . In the future, gene technology could enable antigen-binding fragments to be made by exploiting repertoires of variable domain genes derived from immunized animals and expressed in bacteria . How readily can this approach be extended to production of 'in vitro' repertoires of variable domain genes, and obviate the immunization of animals?

J Mol Biol, 1991 Jan 20, 217(2), 247 - 57
Identification of cis and trans-elements involved in the timed control of a Caulobacter flagellar gene; Gober JW et al.; The genes encoding the structural components of the Caulobacter crescentus flagellum are temporally controlled and their order of expression reflects the sequence of assembly . Transcription of the operon containing the structural gene for the flagellar hook protein occurs at a defined time in the cell cycle, and information necessary for transcription is contained within a region between -81 and -120 base-pairs from the transcription start site . To identify the sequence elements that contribute to the temporal control of hook operon transcription, we constructed deletions and base changes in the 5' region and fused the mutagenized regulatory region to transcription reporter genes . We demonstrate that sequences 3' to the transcription start site do not contribute to temporal control . We confirm that upstream sequences between -81 and -120 base-pairs are necessary for temporal activation, and that transcription also requires sequences at -26 to -46 base-pairs . A specific binding activity for the region between -81 and -122 base-pairs was shown to be temporally controlled, appearing prior to the activation of hook operon transcription . This binding activity was missing from strains containing mutations in flaO and flaW, two genes near the top of the flagellar hierarchy known to be required for hook operon transcription . Thus, the hook operon upstream region contains a sequence element that responds to a temporally controlled trans-acting factor(s), and in concert with a second sequence element causes the timed activation of transcription.

Blood, 1991 Jan 15, 77(2), 294 - 305
Retroviral transformation of cerebral microvascular endothelial cells: macrophage-like and microvascular endothelial cell properties; Robinson DH et al.; We report that L-cell-conditioned medium (LCM) transforms porcine cerebral microvascular (PCMV) endothelial cells into cells with macrophage-like properties . LCM is known to contain both cytokine(s) and the L-cell virus, a murine retrovirus found in the L929 cell and LCM . Our evidence suggests that both LCM cytokine(s) and the L-cell virus are involved in this PCMV endothelial cell transformation . Criteria for transformation include focus formation, decreased serum requirements for growth, changes in morphology including nonadherence, propagation in suspension culture, and a decreased growth response to stimulation with a known endothelial cell mitogen . Macrophage-like characteristics of this transformed cell, designated as RVTE, include pinocytosis of low-density lipoprotein, Fc receptor-mediated phagocytosis, phagocytosis of bacteria and zymosan, the expression of macrophage enzyme markers, and constitutive production of colony-stimulating factor 1 . However, the transformed cell retains several properties of the nontransformed cell including the expression of FVIII:RAg and in vitro self-organization into capillary-like structures . Cloning of RVTE cells clearly shows that both macrophage-like and cerebral microvascular endothelial cell properties are present in the same cell . During self-organization, nontransformed cells express morphologic and functional characteristics classically associated with the macrophage . These findings suggest that some brain capillary pathophysiologies could involve macrophage-like cerebral microvascular endothelial cells . Furthermore, the "reticuloendothelial" phenotypic repertoire expressed by this transformed cerebral microvascular endothelial cell may show that the cerebral capillary endothelial cell in vivo is derived from a hematopoietic and/or phagocytic precursor.

J Am Vet Med Assoc, 1991 Jan 15, 198(2), 264 - 6
Panfibrinonecrotic colitis in a dog treated by subtotal colectomy; Dvorak J et al.; A dog with signs of small intestinal disease developed signs of severe large intestinal disease after being treated with multiple agents . Endoscopy and biopsy revealed total destruction of the colonic mucosa, which necessitated total parenteral nutrition plus subtotal colectomy . It was hypothesized that the multiple prior treatments led to an overgrowth of toxigenic or cytotoxic bacteria, which caused this colonic mucosal destruction.

Mutat Res, 1991 Jan, 259(1), 103 - 10
Clastogenicity of 1-nitropyrene, dinitropyrenes, fluorene and mononitrofluorenes in cultured Chinese hamster cells; Matsuoka A et al.; The chromosomal aberration test using a Chinese hamster lung cell line (CHL) was carried out on 1-nitropyrene (NP), 3 dinitropyrenes (DNPs), fluorene and 4 mononitrofluorenes with and without metabolic activation (rat S9 mix) . The 3 DNPs (1,3-, 1,6- and 1,8-DNP) induced chromosomal aberrations in the absence of S9 mix . The frequencies of cells with aberrations after treatment for 48 h were 43% at 2 micrograms/ml of 1,3-DNP, 55% at 0.1 microgram/ml of 1,6-DNP and 45% at 0.025 microgram/ml of 1,8-DNP, indicating the order of clastogenic potency as 1,8- greater than 1,6- greater than 1,3-DNP . On the other hand, 1-NP, which is known to be a direct-acting mutagen in bacteria, was negative in the chromosomal aberration test without S9 mix, but clearly positive with S9 mix . This effect was dependent on the concentration of the S9 fraction in the reaction mixture . High-pressure liquid chromatography analysis showed that 1-NP was converted by S9 mix to several metabolites, including 1-aminopyrene (AP) . The clastogenic activity of 1-AP, however, was equivocal without S9 mix, suggesting that active clastogens other than 1-AP exist . Fluorene induced chromosomal aberrations only in the presence of S9 mix (61.8% at 25 micrograms/ml) . 1-, 2-, 3- and 4-nitrofluorene (NF) were more clastogenic in the presence of S9 mix than in the absence of S9 mix, suggesting that NFs were converted to more active clastogens by S9 mix.

J Bone Joint Surg Am, 1991 Jan, 73(1), 37 - 51
Skeletal involvement in children who have chronic granulomatous disease; Sponseller PD et al.; Chronic granulomatous disease is a rare disorder of the oxidative metabolism of the white blood cells that results in immunodeficiency . In a retrospective review of the records of forty-two patients who had chronic granulomatous disease, we identified thirteen patients who had a total of twenty skeletal infections . Two types of infection were noted: Type 1, which resulted from a direct spread of the infection from an adjacent focus, usually of fungus or mycobacteria, and Type 2, which resulted from hematogenous spread, usually of Nocardia or more common bacteria . The thoracic vertebrae, ribs, and metatarsals were the most commonly involved bones . All four patients in whom the vertebrae were involved had a Type-1 fungal infection . Paresis developed in three of these patients, and two of them died . Antibiotics alone effectively eradicated the infection in only one patient . Wide operative debridement combined with administration of antibiotics was the most successful treatment . Comprehensive preoperative imaging and several cultures are necessary to locate the infection in the bone and to identify the organism.

Biochim Biophys Acta, 1991 Jan 8, 1076(1), 1 - 8
Primary structure and analysis of the location of the regulatory disulfide bond of pea chloroplast NADP-malate dehydrogenase; Scheibe R et al.; Purified pea chloroplast NADP-malate dehydrogenase (S)-malate: NADP+ oxidoreductase, EC 1.1.1.82) was digested with trypsin and the resulting peptides were separated by HPLC and sequenced . Together with the information from earlier work (Fickenscher, K . et al . (1987) Eur . J . Biochem . 168, 653-658) the total sequence is not known to an extent of 78% . Comparison with the sequence of the corn NADP-malate dehydrogenase deduced from its cDNA (Metzler, M.C . et al . (1989) Plant Mol . Biol . 12, 713-722) showed 84% agreement; however, the 11 N-terminal residues exhibit only 27% similarity . The N- and C-terminal extrapeptides of the pea NADP-malate dehydrogenase when aligned with non-regulatory NAD-malate dehydrogenases from bacteria or mammals consist of 30 and 17 amino acids, respectively . Since all cysteine-containing peptides were sequenced, the number of eight cysteines per subunit of the pea enzyme was established . The native, oxidized enzyme is characterized by an extremely slow reactivity of two thiols . Titration of the thiols of the denatured, oxidized enzyme both with DTNB and with pCMB resulted in six thiols not involved in disulfide formation . Therefore, one disulfide bridge must be present per 38.9 kDa subunit . Analysis of disulfide bonds by urea gel electrophoresis confirmed this finding . Using digestion products of NADP-malate dehydrogenase with aminopeptidase K, the location of the single disulfide bridge was established to be on the N-terminal arm (Cys-12 and Cys-17) of the polypeptide chain.

J Biol Chem, 1991 Jan 5, 266(1), 58 - 65
Molecular cloning of the genes encoding two chaperone proteins of the cyanobacterium Synechocystis sp . PCC 6803; Chitnis PR et al.; Molecular chaperones help other proteins in their correct folding and assembly . We have cloned the genes, cpn60 and dnaK, which encode proteins belonging to the chaperonin-60 and the 70-kDa heat shock protein families from the transformable cyanobacterium Synechocystis sp . PCC 6803 . These genes are present in single copies in the genome, and the major transcripts for each gene are monocistronic . Comparison of deduced amino acid sequences reveals that cyanobacterial chaperonin-60 is equally homologous to bacterial and plant chaperonin-60 proteins while the product of dnaK is more similar to its bacterial homologues than to its eukaryotic counterparts . The DNA fragments sequenced in these studies also contain five other open reading frames . One of them, ORF60-5, encodes a protein whose deduced amino acid sequence shows remarkable similarity to those of a family of peripheral membrane proteins involved in metabolite transport in bacteria . The transcript levels of dnaK and cpn60 of Synechocystis sp . PCC 6803 increase in response to stress conditions such as heat shock, ultraviolet exposure, and oxidative stress . This is one of the first examples of cyanobacterial gene expression being regulated by environmental stresses.

Magn Reson Imaging, 1991, 9(1), 89 - 92
Magnetic resonance imaging and histopathology of hydronephrosis in the rat; Acara MA et al.; Magnetic resonance imaging revealed conspicuously hyperintense regions in the papillary area of kidneys of three untreated rats . When the kidneys were examined histologically, a hydronephrosis associated with the presence of bacteria was found . This study relates magnetic resonance images of an early stage of hydronephrosis to its histological picture.

Cytobios, 1991, 65(260), 55 - 62
Fluorescence assay to monitor phagocytosis by bloodclot derived polymorphonuclear leucocytes . 2 . Study of patients with psoriasis and the effect of exposing leucocytes to psoriatic skin scales; Musclow CE et al.; Comparisons of phagocytic parameters were carried out by a recently developed fluorescence test which is reproducible, simple and fast . Phagocytosis by polymorphonuclear leucocytes (PMNs) obtained from patients with psoriasis was compared with that of healthy individuals . Psoriatic skin scales, non-sterile and sterile, were tested for stimulatory effect on PMNs and compared with the effect of normal skin scrapings . Results confirm enhanced phagocytosis of bacteria by PMNs from patients with psoriasis over that of PMNs from healthy volunteers . Furthermore, the supernatant fluid from suspensions of psoriatic skin scales, non-sterile and sterile, stimulated PMNs activity.

Biol Neonate, 1991, 59(3), 121 - 5
The high lectin-binding capacity of human secretory IgA protects nonspecifically mucosae against environmental antigens; Davin JC et al.; The anti-infectious role of human milk may be, at least partly, ascribed to its content in secretory IgA . As lectins are present in various infectious antigens, the binding of different types of IgA to three lectins (concanavalin A, peanut agglutinin, wheat germ agglutinin) was studied by Elisa . The specificity of those bindings was assessed by inhibitory experiments performed with the corresponding oligosaccharides . The following were found for the three lectins: (1) the lectin-binding capacity of colostrum secretory IgA was markedly greater than that of normal plasma IgA1 (p less than 0.001); (2) the lectin-binding capacity of polymeric IgA1 was greater than that of monomeric IgA1 (p less than 0.001) . This property of mucosal IgA may be responsible of a nonimmune opsonization able to prevent the early step of some infectious mucosal diseases, i.e . the attachment of bacteria to epithelial cells by lectin-like bonds and also the penetration into the body of some antigens able to favor the development of allergy . Milk mucosal IgA, present in significant amounts in human colostrum and mature milk - but not in infant formulas - may therefore play an important polyvalent protective role in newborns.

Urol Int, 1991, 46(2), 121 - 5
Nonbacterial prostatitis: a comprehensive review; de la Rosette JJ et al.; The term 'prostatitis' denotes a condition of inflammation of the prostate . Prostatitis is usually employed to describe any unexplained symptom or condition that might possibly emanate from a disorder of the prostate gland . The diagnosis of nonbacterial prostatitis is reserved for those patients with symptoms localized to the prostate, but without bacteria in the expressed prostatic secretion . The purpose of this article is to review etiology, pathology and the recent advances in diagnosis and therapy of nonbacterial prostatitis.

Pharmacol Ther, 1991, 49(3), 181 - 222
Therapeutic potential of plant photosensitizers; Hudson JB et al.; Many bioactive phytochemicals have been shown in recent years to be photosensitizers, i.e . their toxic activities against viruses, micro-organisms, insects or cells are dependent on or are augmented by light of certain wavelengths . These activities are often selective, and this has led to the concept of therapeutic prospects in the control of infectious diseases, pests and cancer . Reaction mechanisms commonly involve singlet oxygen and radicals, which are thought to cause photodamage to membranes or macromolecules . The main classes of plant photosensitizers reviewed here are polyyines (acetylenes, thiophenes and related compounds); furanyl compounds; beta-carbolines and other alkaloids; and complex quinones . We propose that within each group of phytochemicals there are several representatives that merit further study for therapeutic abilities in appropriate animal models.

Dev Genet, 1991, 12(1-2), 88 - 97
Structure, expression, and regulation of members of the developmentally controlled V and H gene classes from Dictyostelium; Singleton CK et al.; We have examined the expression and structure of vegetative specific genes belonging to the V and H gene classes . Both classes of genes are deactivated at the onset of development by a reduction in the rate of transcription . Thus, the genes must be reactivated when the terminally differentiated spores germinate and the resulting amebae return to the vegetative state . During germination, activation of expression of most members of the V gene class was found to parallel the emergence of amoebae from the spore coats . The activation of the V genes did not occur when protein synthesis was inhibited . The timing of activation of the H genes was more heterogeneous and did not parallel emergence . H gene activation occurred even when protein synthesis was inhibited . V4 was found to be the only vegetative specific gene that was responsive to the presence of bacteria . V4 expression was induced by 25-100 fold via transcriptional activation when bacteria were added to amebae growing axenically . Isolation and sequence analysis of the corresponding genomic clones revealed that two V genes, V18 and V1, encode ribosomal proteins . Promoter analysis has delineated the sequences necessary for expression and regulation for several of the V and H genes . In all cases, expression was determined by sequences within the first several hundred base pairs of the transcription start site . For V18 and V14, a positive constitutive element was identified in addition to the sequences involved in regulation . Finally, all of the characterizations and findings are discussed in terms of postulated models for V and H gene expression and regulation.

Dev Genet, 1991, 12(1-2), 154 - 62
Regulation of cysteine proteinases during different pathways of differentiation in cellular slime molds; North MJ et al.; Cysteine proteinase activities have been determined using gelatin-SDS-PAGE analysis and assays based on peptide nitroanilides . Vegetative myxamoebae of all species examined contain high levels of cysteine proteinase activity present in multiple forms . In both Dictyostelium discoideum and Polysphondylium pallidum the proteinase content is dependent on whether the cells are grown axenically or in association with bacteria . In all instances development is accompanied by a decreased intracellular cysteine proteinase activity . This occurs during the formation of fruiting bodies in D . discoideum, microcysts in P . pallidum, and macrocysts in Dictyostelium mucoroides . Significant quantities of proteinase activity are always secreted by myxamoebae immediately on starvation . In D . mucoroides this leads to an almost total depletion of intracellular cysteine proteinases by the aggregation stage . As a consequence of this depletion it has been relatively easy to detect a developmentally regulated accumulation of cysteine proteinases at the enzyme activity level, something which has not yet proved possible with D . discoideum . Three cysteine proteinases are produced as D . mucoroides macrocysts develop and mature . In the case of microcyst formation in P . pallidum the proteinase contents of the developing cells and of the microcysts are dependent on how the myxamoebae are grown . In this developmental pathway at least, there is no absolute requirement for specific proteinases to be present (or absent) at a particular stage . The diversity of cysteine proteinases found in cellular slime molds and the variety of features apparent in their regulation suggest that they will prove to be very useful for investigating features of the structure/function relationships in this important group of enzymes.

Res Vet Sci, 1991 Jan, 50(1), 18 - 22
Endothelial cytotoxicity of Actinobacillus pleuropneumoniae; Serebrin S et al.; The cytotoxicity of Actinobacillus pleuropneumoniae serotype 1 strain CM5 for porcine and bovine endothelial cells in vitro, was dose-dependent . This strain and its attenuated and avirulent substrain CM5A were equally cytotoxic . The cytotoxicity observed during five hours of exposure of endothelial cells to bacterial products was abolished if the bacteria were inactivated by heat or sonication . Exposure of the endothelial cells for five hours to 100 and 200 micrograms of purified lipopolysaccharide resulted in a partial cytotoxicity only, which was not enhanced in the presence of fresh guinea pig serum . The cytotoxicity of viable bacteria could be neutralised by a polyclonal rabbit antiserum to the purified 104kD haemolysin . A bacteria-free supernate of a culture of strain CM5 had both haemolytic and cytotoxic activity . The haemolytic activity could be neutralised completely by the anti-serum to the 104kD haemolysin, whereas the cytotoxic activity was only partially neutralisable . Hence A pleuropneumoniae is cytotoxic for endothelial cells and this cytotoxicity is possibly mediated by the 104kD haemolysin.

J Clin Periodontol, 1991 Jan, 18(1), 20 - 5
Scanning electron microscopic investigation of changes in the dentogingival area during experimental gingivitis; Walsh TF et al.; The purpose of this study was to investigate the changes that occur in the dentogingival area during experimental gingivitis using a replication technique and scanning electron microscopy (SEM) . The upper 1st premolars of 20 subjects were examined prior to plaque accumulation, after plaque had become clinically visible and after 3 weeks plaque accumulation . 3 distinct zones were examined: the tooth surface and its integuments, the gingival crevice and the oral gingiva . Surface features such as perichymata, pits, depressions and cracks were rapidly covered by plaque deposits . These had a raised globular surface with occasional embedded desquamated epithelial cells . Raised plaque colonies were frequently seen by the end of the study . Initially, the gingival crevice presented a layered undulating appearance . With plaque accumulation many desquamating epithelial cells were seen and variations occurred in the width of the crevice . These changes were mirrored in the oral gingiva . The junctional epithelium was initially smooth with occasional pores and emigrating leucocytes . As plaque accumulated, the presence of pores and leucocytes increased and considerable disruption by desquamating epithelial cells was noted . No subject proved resistant to the influence of plaque-induced changes.

Arch Pharm (Weinheim), 1991 Jan, 324(1), 35 - 7
Synthesis and biological activities of some pyrrolopyrazoles and 2-pyrazolines; Ead HA et al.; Cycloaddition reactions of the nitrilimines 4-6 with N-arylmaleimides 7 and acrylamide (11) yield the pyrrolopyrazole derivatives 8-10 and 2-pyrazolines 12, respectively, in excellent yield . The regioselectivity and biological activities of some of the new compounds were investigated.

Appl Environ Microbiol, 1991 Jan, 57(1), 69 - 76
Partial characterization of the steroidsulfatases in Peptococcus niger H4; Van Eldere J et al.; The strictly anaerobic intestinal Peptococcus niger H4 synthesizes three different steroidsulfatase enzymes: a constitutive arylsulfatase and two inducible alkylsteroidsulfatases . The arylsulfatase desulfates estrogen-3-sulfates and phenylsulfates . The two alkylsteroidsulfatases desulfate, respectively, 3 alpha-sulfates and 3 beta-sulfates of delta 5, 5 alpha, and 5 beta androstanes, pregnanes, and bile acids . Cholesterol-3 beta-sulfate was not desulfated by the alkylsteroidsulfatases nor were steroids or bile acids that were sulfated in positions other than the 3 position . The alkylsteroidsulfatases were induced by their substrates; bile acid sulfates, however, were poor inducers of the 3 beta-sulfatase and did not induce the 3 alpha-sulfatase activity . In intact bacterial cells, taurine and sulfite suppressed the induction of the alkylsteroidsulfatases and inhibited the activity of the arylsulfatase and alkylsteroidsulfatases . In cell homogenates, the arylsulfatase and alkylsteroidsulfatases activities were inhibited by sulfite and sulfate but not by taurine . Our results support the hypothesis that the main function of the steroidsulfatases in P . niger H4 is to provide the bacteria with sulfur for dissimilatory purposes.

Microbios, 1991, 65(264-265), 147 - 53
Characterization of monoclonal antibodies to two Treponema denticola serotypes by the indirect fluorescent-antibody assay; Kearns EA et al.; Members of the genus Treponema have been implicated as possible aetiologic agents of periodontal disease . Previously developed murine monoclonal antibodies (MAbs) to two Treponema denticola strains were characterized by an indirect fluorescent-antibody (IFA) technique . Fifteen T . denticola strains and 32 other bacteria commonly isolated from periodontal pockets were used in the screening process . Two monoclonal antibodies to T . denticola ATCC 33521, serotype B, reacted with five T . denticola isolates, and one monoclonal antibody to T . denticola ATCC 33520, serotype c, reacted with two T . denticola isolates . There was no cross-reactivity between MAbs to the two serotypes . Preliminary tests of the MAbs on human periodontal samples show that they are useful in detecting these bacteria in clinical samples.

Urol Res, 1991, 19(1), 35 - 8
Induction of controlled prostatic tissue necrosis by bacille Calmette-Guérin derivatives; Morales A et al.; Intraprostatic administration of live bacille Calmette-Guerin (BCG) in humans has been found to produce tumor necrosis; unfortunately, the number of severity of complications have made its clinical use prohibitive . Previous studies have shown that soluble and microparticulate components present in the supernatants obtained after centrifugation of a reconstituted BCG preparation exhibit similar immunogenicity to the one shown by live bacteria . The supernatants, however, are not associated with disseminated infection of the progressive regional tissue destruction observed with the use of viable vaccine . Experiments were conducted to determine the effect of intraprostatic injection of BCG and its supernatants . Adult dogs, after positive conversion to protein purified derivative (PPD), were randomly assigned to three groups . Under direct vision and with digital rectal control, intraprostatic injections of various agents were given as follows: group I, normal saline; group II, live BCG; group III, 200 micrograms of BCG supernatants . Two months later the animals were sacrificed, and the prostates removed in toto and submitted for a thorough histological examination . Extensive but variable tissue necrosis was noted in groups II and III . No histological alterations were present in group I . The histological picture of the animals receiving BCG supernatants conclusively demonstrated circumscribed necrosis of the gland . Side effects and complications were present in animals receiving live BCG but conspicuously absent in the ones receiving supernatants . The observed effectiveness and safety of BCG supernatants for intraprostatic administration in an experimental system may lead to a simple, safe, and efficacious therapeutic modality for localized carcinoma of the prostate in humans.

Eur Respir J, 1991 Jan, 4(1), 40 - 9
Proteolytic inactivation of alpha 1-proteinase inhibitor in infected bronchial secretions from patients with cystic fibrosis; Suter S et al.; The chronic, progressively destructive bronchitis of patients with cystic fibrosis (CF) is characterized by an important imbalance between tissue destroying granulocyte proteases such as granulocyte elastase (GE) and its physiological inhibitors in bronchial secretions . Recent in vitro studies suggest, that proteases derived from bacteria or endogenous proteases may contribute to inactivation of physiological inhibitors of GE . Since only trypsin-unreactive alpha 1-proteinase inhibitor (alpha 1-PI) was detected in CF bronchial secretions, we attempted to identify the mechanism of inactivation of alpha 1-PI . We found a heat stable, serine protease-like enzymatic activity capable of degrading 125I-labelled alpha 1-PI extensively in 22 infected but not in one non-infected CF bronchial secretion . In infected secretions, only degraded alpha 1-PI, which did not migrate like oxidized alpha 1-PI in tandem-crossed immunoelectrophoresis, was detectable . We conclude, that free GE in excess as well as GE bound to bronchial mucosal inhibitor may partly account for the alpha 1-PI-cleaving activity, but that other yet unknown bacterial or host serine proteases also contribute to alpha 1-PI inactivation.

Biopolymers, 1991 Jan, 31(1), 23 - 44
Zinc ion-DNA polymer interactions; Jia X et al.; The adjacent GN7-M-GN7 cross-linking and adjacent G-M-G sandwich-complex models for DNA metal ion binding were evaluated both with native DNAs differing in GC content as well as with the synthetic polymers poly {(dGdC)}2, poly{(dAdT)}2, and poly{(dAdC)(dGdT)} . The effect of Zn2+ was studied in depth, and limited studies were also performed with Co2+ and Mg2+ . The results were compared to the extensive information available on Cu2+ binding to native DNAs and poly{(dAdT)}2 . At high ratios of metal/base (R), Zn2+ caused all native DNAs to denature with the same melting temperature Tm, approximately 61 degrees C . A similar pattern was reported previously for Cu2+, but the typical Tm was approximately 35 degrees C . The extent of renaturation on cooling DNAs denatured in the presence of Zn2+ increased with GC content, as reported previously for Cu2+ . These results, together with previously reported similarities, strongly indicate that the DNA binding characteristics of the two cations are similar . By comparison of the Tm values and hyperchromicity changes monitored at 260 and 282 nm, it is clear that, during thermal denaturation in the presence of Zn2+, both AT and GC regions were denatured, even at high R . The Tm vs R profile for the native DNAs was typical . The rise at low R and subsequent decrease at high R were inversely and directly related, respectively, to GC content . Except for poly{(dAdT)}2, where Tm increased with R, the other synthetic polymers exhibited the increase/decrease pattern . Poly{(dAdC)(dGdT)} gave a Tm value at high R of 54 degrees C . In the absence of Zn2+, this polymer exhibited little hypochromicity on cooling of denatured polymer . However, in the presence of Zn2+, nearly complete hypochromicity was observed, although the midpoint of the cooling curve was lower than the Tm value by approximately 15 degrees C at R = 10 . These characteristics were similar to those with native DNAs, although viscosity and CD studies suggested that the "renatured" polymer was not identical to the unheated polymer . Furthermore, addition of Zn2+ after denaturation nearly completely reversed the absorption increase . This finding contrasts with those for native DNAs, where the Zn2+ must be present during denaturation in order to reverse the absorption increase nearly completely on cooling . With some caveats, poly{(dAdC)(dGdT)} appears to be a good model for native DNAs since its properties, including CD and uv changes on addition of Zn2+ to premelted and melted polymer, parallel those of the native polymers.(ABSTRACT TRUNCATED AT 400 WORDS)

J Burn Care Rehabil, 1991 Jan-Feb, 12(1), 46 - 50
Initial dosage regimens of gentamicin in patients with burns; Zaske DE et al.; For 95 patients with burns the gentamicin dosage regimen necessary to achieve optimal serum concentrations was determined . Individual elimination rates and distribution volumes for gentamicin were determined and correlated with renal function parameters and age . In patients with burns who had normal serum creatinine levels (less than 1.5 mg/dl), gentamicin clearance and thus dosage regimens can be stratified by age . Gentamicin's clearance decreased inversely with age . Initial dosage guidelines were calculated for different age groups of patients with normal levels of serum creatinine . The guidelines were developed to assist the clinician in attaining therapeutic concentrations with initial doses of gentamicin . Therapeutic serum concentrations were reached in most patients with burns dosed by these guidelines . Serum gentamicin concentrations should always be monitored during therapy, and dosages should be adjusted to ensure optimal concentrations during the course of therapy.

Schweiz Monatsschr Zahnmed, 1991, 101(4), 417 - 23
{An in vitro trial of the chemomechanical treatment of root caries: the Caridex system}; Romand-Roeloffs N et al.; This study was aimed to verify the debridement potential of the Caridex system against radicular cervical caries . 14 freshly extracted teeth with cervical caries were split and the fragments were freed from the dentinal caries using three methods: root planning (with a white stone), conventional excavation with a bur (tungsten) and the Caridex system . The results show that the Caridex system can partially dissolve the decayed dentin but leaves behind smeared surfaces as well as part of dentin infiltrated by bacteria . The root planning treatment smears the dentinal surface and thus blocks the tubules which also appeared to be infiltrated with bacteria . The excavation method allowed for a complete elimination of the decayed dentinal tissue down to the hypermineralized zone.

Vet Clin North Am Small Anim Pract, 1991 Jan, 21(1), 1 - 26
Biology of ticks; Cupp EW; Ticks are an ancient group of obligate bloodsucking ectoparasites that has evolved over millions of years . Two general types of ticks are evident today: argasid or soft ticks, and ixodid or hard ticks . Each lineage exhibits distinct patterns of host coevolution and preference . However, about 10% of the approximately 850 species are of medical importance because of their indiscriminate host selection and catholic feeding behavior . As a result, a number of diseases have begun to emerge in the temperate zones, including Lyme borreliosis and several others putatively associated with ticks . Ticks may serve as both pathogens and disease vectors . Because of the unique physiology of the salivary glands and the contents in tick saliva of toxins, feeding alone may cause disease . Ticks also transmit a number of different types of pathogens (viruses, rickettsiae, spirochetes and bacteria, fungi, protozoa, filarial nematodes) and even exceed mosquitoes in this regard . Abatement and control of ticks emphasizes a broad approach because of the differing types of habitats in which pest species may be found . The use of repellents and acaricides as well as cultural and management practices are of primary importance . Other approaches (ivermectin) may be beneficial; with the advent of molecular genetics and its usefulness in immunology, the development of tick vaccines for common pest species appears promising.

Infection, 1991 Jan-Feb, 19(1), 58 - 60
Concentrations of ampicillin and sulbactam in serum and tissues of patients undergoing ENT surgery; Wildfeuer A et al.; 2 g ampicillin and 1 g sulbactam were given by infusion to 24 patients who were to be operated on in the ENT region . About 1 hour later during the operation samples of serum and of various tissues were taken and analysed for ampicillin and sulbactam . The mean serum concentrations of ampicillin and sulbactam were 59.2 mg/l and 31.6 mg/l, respectively . At the same time the concentrations of the two drugs were usually lower in the tissues than in serum . About 1 hour after the infusion the mean tissue concentration of ampicillin was 33.5 mg/kg and of sulbactam 19.5 mg/kg . The results show that ampicillin and sulbactam penetrate within an hour into the different tissues affected by the operation and maintain about the same ratio as in serum (2:1) . The concentrations of ampicillin and sulbactam measured in the different compartments are capable of inhibiting the bacteria most frequently involved in ENT infections . These measurements unequivocally support the use of the ampicillin/sulbactam combination in the treatment and perioperative prophylaxis of bacterial infections of the ENT tract.

Mol Immunol, 1991 Jan-Feb, 28(1-2), 99 - 105
Phase separation analysis of recombinant interleukin 2; Bergmann CA et al.; Phase separation in the detergent Triton X-114 has been used as a physical characteristic to distinguish secreted proteins from amphipathic proteins . Since recombinant interleukin 2 is not secreted by bacteria, but is instead obtained from bacterial lysates, we have analysed several different recombinant interleukin 2 molecules as well as the naturally synthesized cytokine by phase separation in Triton X-114 . Although naturally synthesized interleukin 2 and recombinant interleukin 2 from R&D Systems partitioned into the aqueous phase as expected for secreted molecules, recombinant interleukin 2 from Cetus separated into the detergent phase, indicating a high degree of amphipathicity . A recombinant AMGEN interleukin 2 mutated protein (mutein) exhibited intermediate behavior . Cetus and AMGEN interleukin 2 differ from the R&D Systems recombinant molecule and from the native lymphokine by a change in amino acid position 125 . Spontaneous dimerization of the Cetus and AMGEN interleukin 2 muteins to a 31 kD form has also been observed whereas multimeric structures have not been found in the other interleukin 2 preparations . These distinct biochemical differences between the two recombinant molecules appear to be related to small changes in the primary structure, and they may be relevant to the therapeutic use of interleukin 2.

Chem Biol Interact, 1991, 77(3), 291 - 302
Ames assay mutagenicity and electronic structure calculations of bromomethylfluoranthenes, chloromethylfluoranthenes, and hydroxymethylfluoranthenes; Ball JC et al.; The mutagenicities of the five possible isomers of bromomethylfluoranthene, chloromethylfluoranthene, and hydroxymethylfluoranthene were determined in the Ames assay using strains TA100 and TA98 without the addition of rat-liver S9 tissue extract . The mutagenicities of the bromomethyl and chloromethylfluoranthenes ranged from 25 to 6000 rev./nmol . The most mutagenic compound was 8-chloromethylfluoranthene in strain TA98 (6000 rev./nmol) . The reactivities of the bromomethylfluoranthenes and the chloromethylfluoranthenes were estimated from electronic structure calculations using the MNDO and the PM3 semi-empirical methods . The bromomethylfluoranthenes showed the smallest differences between the heats of formation of the carbocations and the heats of formation of the parent bromomethyl derivatives . Therefore, the bromomethylfluoranthenes were estimated to be the most reactive of the halomethylfluoranthenes studied . The compound that showed the largest change in heat of formation (the most stable halomethylfluoranthene) going from the halomethylfluoranthene to the carbocation was 2-chloromethylfluoranthene . However, neither the most reactive nor the most stable halomethylfluoranthenes were the most mutagenic in either strain of bacteria . These results are interpreted to suggest that the reactivity of the parent halomethylfluoranthene is not a critical factor in the mechanism by which these compounds are mutagenic, but some other factor, perhaps intercalation, must be a critical step in the mechanism of mutagenesis of these compounds.

J Cell Biochem, 1991 Jan, 45(1), 49 - 53
A novel suicide inhibitor strategy for antiparasitic drug development; Wang CC; DL-alpha-Difluoromethylornithine (DFMO), a suicide inhibitor of eukaryotic ornithine decarboxylase (ODC), has therapeutic activities against African trypanosomiasis . The Ki value of DFMO for ODC of Trypanosoma brucei is somewhat higher than that for mouse ODC . The therapeutic efficacy of DFMO cannot therefore be attributed to a preferential inhibition of the parasite enzyme . The T . brucei gene encoding ODC was cloned and sequenced, and the derived amino acid sequence has 61.5% homology with that of mouse ODC, except that the C-terminal 36 amino acids of the mouse enzyme are missing from the parasite enzyme . The cloned T . brucei and mouse ODC genes were expressed in ODC-deficient Chinese hamster ovary cells (CHO) where the T . brucei enzyme was stable, but mouse ODC was unstable . Thus, the observed difference in intracellular stability is a property of the ODC protein itself, rather than of the cellular environment in which it is expressed . A chimeric ODC composed of the amino terminus of trypanosome ODC and the C-terminus of mouse ODC also was rapidly degraded in CHO cells, suggesting that peptide sequences in the mouse ODC carboxy-terminus determine its stability . The relatively slow turnover of the parasite enzyme constitutes the basis of selective antitrypanosomal action of DFMO . By this same token, many other proteins known to perform crucial functions in bacteria, fungi, protozoa, helminths, etc., also may have shorter half-lives in the mammalian hosts than in parasites . Suicide inhibitors of these proteins may have desirable characteristics as good chemotherapeutic agents . This new approach could provide an additional strategy for controlling infectious diseases.

J Clin Microbiol, 1991 Jan, 29(1), 96 - 8
Comparison of the lysis-centrifugation and agitated biphasic blood culture systems for detection of fungemia; Murray PR; Although the detection of fungemia has been improved by the use of vented or biphasic blood culture bottles, the best recovery and earliest detection have been reported in the Isolator lysis-centrifugation system . It was recently demonstrated that improved detection of both bacteria and fungi was accomplished by mechanically agitating blood culture bottles for the first 24 h of incubation . In this study the detection of fungemia by use of the Isolator system was compared with that of an agitated biphasic system . A total of 182 fungi were isolated from blood specimens inoculated into both culture systems . No difference in the overall recovery of fungi or individual species of yeasts was observed between the two systems . However, all seven isolates of Histoplasma capsulatum were recovered in the Isolator system only . The time required to detect fungemia with each of the two systems was also compared . No statistically significant difference was observed . From the data collected during this 18-month study, it can be concluded that the overall recovery and time of detection of yeasts are equivalent in the lysis-centrifugation system and the agitated biphasic blood culture system . The lysis-centrifugation system is still superior for the detection of filamentous fungi such as H . capsulatum.

Exp Parasitol, 1991 Jan, 72(1), 54 - 62
Trypanosoma cruzi: cellular and antibody response against the parasite in mice immunized with a 19-amino acid synthetic peptide; Bua J et al.; Several monoclonal antibodies were prepared against the flagellar fraction of Trypanosoma cruzi epimastigotes (Tulahuen strain, stock Tul 2) . One of them, FCH-F8-4, has previously shown biologic activity against the parasite (complement-mediated lysis and neutralization of the trypomastigote infectivity) . Immunopurified antigens using this monoclonal antibody elicited a protective immune response in mice . Two recombinant cDNA clones were detected with this anti-flagellar fraction monoclonal antibody on a lambda gt11 expression library prepared from T . cruzi epimastigote mRNA . The insert of one of these cDNA clones, lambda(FCH-F8-4)1 (150 bp) coded for a 19-amino acid peptide (PAFLGCSSRFSGSFSGVEP) . This insert hybridized with a 5.0-kb mRNA from epimastigotes . The beta-galactosidase fusion protein was produced in lysogenic bacteria . The monoclonal antibody recognized the epitope present in the fusion protein after western blotting of the crude lysate . A synthetic peptide (SP4) containing the complete sequence of lambda(FCH-F8-4)1 was constructed on solid phase . This peptide was able to inhibit the ELISA reactivity (in a range from 13 to 52%) of flagellar fraction immunized mouse sera and when administered (coupled to KLH or alone) to BALB/c mice with Bordetella pertussis as adjuvant, it induced a humoral and cellular immune response which was detected by ELISA, immunofluorescence, blotting, and DTH reactions against T . cruzi antigens . The immune response obtained indicates that this synthetic peptide resembles the parasite antigen conformation and could be useful for diagnosis purposes or be able to elicit immunoprotection against T . cruzi infection.

Rev Environ Contam Toxicol, 1991, 118, 1 - 85
Toxaphene: chemistry, biochemistry, toxicity and environmental fate; Saleh MA; The chemistry of toxaphene is now well developed; 20 isomers have been isolated and identified . The molecular weight and molecular formula are known for the remaining major components . The major metabolic degradation mechanisms for toxaphene in all organisms from bacteria to primates are now believed to the reductive dechlorination, reductive dehydrochlorination, and in some cases, oxidative dechlorination to produce hydroxyl derivatives, acids or ketones . Earlier reports that toxaphene was biodegradable were published before the advent of state-of-the-art analytical methodology which has permitted detection at levels in the range of ppb . Toxaphene residues have recently been documented throughout the biosphere as well as in human milk, even though its use was banned in 1982 . This global persistence is against previous beliefs that toxaphene was easily biodegradable . During the last decade advances have been achieved in the selectivity, accuracy, and sensitivity of detection techniques so that the presence of toxaphene throughout the biosphere has been extensively documented . Through the use of GC/MS and electron capture GC, toxaphene can now be detected at ppb levels, making possible a more consistent and accurate assessment of the compound's presence in organisms as well as in soil, water, and ground water . Toxaphene residues have been detected in human populations, fish and wildlife, soil, water, and ground water as well as in food . An FDA Food Survey study found residues of toxaphene exceeding regulatory limits in only 1% of the 14,492 food samples . Toxaphene was reported to be among the most frequently occurring residues found in total dietary foods for the period 1982-84 . It was found 48 times based on two food consumption surveys, a level higher than the frequency of DDT, DCPA, pentachloroaniline, and methoxychlor . Toxaphene has been detected in two large, pooled samples of human milk collected from mothers living in Uppsala and Stockholm at a concentration of 0.1 mg/kg of milk fat . Accumulation of toxaphene occurs in water in areas where the insecticide is in use, and it may be quite persistent . In some Canadian lakes it was found in toxic concentrations up to five yr after fish have been killed . Several studies have documented the presence of toxaphene in rain water, e.g . 9 ng/L in rain samples from Lake Michigan . It is now clear that toxaphene is a global pollutant like DDT, PCBs, and other organochlorines . Toxaphene is persistent in soils and lake sediments and has been found in fish, in the ringed seal, in rain water, and in human milk.(ABSTRACT TRUNCATED AT 400 WORDS)

J Dent Res, 1991 Jan, 70(1), 55 - 8
Microleakage of three cement bases; Heys RJ et al.; The purpose of this study was to evaluate the ability of a glass-ionomer cement-base material to prevent bacterial penetration along the dentin interface and to compare it with two conventional cement-base materials . A total of 107 Class 5 restorations was placed in Rhesus monkey teeth by means of three test materials {zinc oxide-eugenol (ZOE), copalite varnish + zinc phosphate cement base (V + ZP), and a glass-ionomer lining cement (GI)}, with unetched and unbonded resin composite used alone as a control material and as a final restoration over the test base materials . Following disinfection, Class 5 cavities were prepared on the buccal surfaces of the teeth to the inner one-half of dentin . A sterile filter-paper disk was then placed on the axial wall and covered with a Teflon disk . Next, the cavities were based to the dento-enamel junction with one of the test base materials and finally restored with unetched and unbonded resin composite . After five and 16 weeks, the filter-paper disks were retrieved and cultivated for the presence and type of bacteria . The five-week results showed positive growth in two groups: the composite-only controls and the V + ZP group . The 16-week results showed growth in all of the test groups, but only one of nine teeth showed growth in the zinc oxide-eugenol group and one of 16 teeth in the glass-ionomer group . The results of this study indicate that under the conditions tested, a glass-ionomer base was capable of minimizing bacterial penetration along the material-tooth interface.

FASEB J, 1991 Jan, 5(1), 8 - 11
Origins of the Human Genome Project; Watson JD et al.; The Human Genome Project has become a reality . Building on a debate that dates back to 1985, several genome projects are now in full stride around the world, and more are likely to form in the next several years . Italy began its genome program in 1987, and the United Kingdom and U.S.S.R . in 1988 . The European communities mounted several genome projects on yeast, bacteria, Drosophila, and Arabidospis thaliana (a rapidly growing plant with a small genome) in 1988, and in 1990 commenced a new 2-year program on the human genome . In the United States, we have completed the first year of operation of the National Center for Human Genome Research at the National Institutes of Health (NIH), now the largest single funding source for genome research in the world . There have been dedicated budgets focused on genome-scale research at NIH, the U.S . Department of Energy, and the Howard Hughes Medical Institute for several years, and results are beginning to accumulate . There were three annual meetings on genome mapping and sequencing at Cold Spring Harbor, New York, in the spring of 1988, 1989, and 1990; the talks have shifted from a discussion about how to approach problems to presenting results from experiments already performed . We have finally begun to work rather than merely talk . The purpose of genome projects is to assemble data on the structure of DNA in human chromosomes and those of other organisms . A second goal is to develop new technologies to perform mapping and sequencing . There have been impressive technical advances in the past 5 years since the debate about the human genome project began . We are on the verge of beginning pilot projects to test several approaches to sequencing long stretches of DNA, using both automation and manual methods . Ordered sets of yeast artificial chromosome and cosmid clones have been assembled to span more than 2 million base pairs of several human chromosomes, and a region of 10 million base pairs has been assembled for Caenorhabditis elegans by a collaboration between Washington University and the Medical Research Council laboratory in Cambridge, U.K . This project is now turning to sequencing C . elegans DNA as a logical extension of this work . These are but the first fruits of the genome project . There is much more to come.

Mutat Res, 1991 Jan, 257(1), 27 - 47
Pentachlorophenol; Seiler JP; Pentachlorophenol (PCP) is a substance whose widespread use, mainly in wood protection and pulp and paper mills, has led to a substantial environmental contamination . This in turn accounts for a significant exposure of the general human population, with rather high exposure levels being attained in occupational settings . Investigations on the genotoxic activity of PCP have given rise to divergent results which would seem to make an evaluation difficult . By grouping them into 3 categories a somewhat clearer picture, allowing finally an (admittedly tentative) assessment, can be obtained . PCP does seem to be at most a weak inducer of DNA damage: it produces neither DNA-strand breaks nor clear differential toxicity to bacteria in rec-assays in the absence of metabolic activation . Also in SCE induction no increase can be observed in vivo, while PCP is found marginally active in a single in vitro experiment . Metabolic activation, however, leads to prophage induction and to DNA strand breaks in human lymphocytes, presumably through the formation of oxygen radicals . A possible further exception in this area might be the positive results in the yeast recombination tests, although their inadequate reporting makes a full evaluation difficult . PCP does not seem to induce gene (point) mutations, as most bacterial assays, the Drosophila sex-linked recessive lethal test and in vitro assays with mammalian cells did not demonstrate any effects . Marginally positive results were obtained in the mammalian spot test in vivo and in one bacterial test; the positive result in the yeast assay for cycloheximide resistance is fraught somewhat with its questionable genetic basis . PCP does, however, induce chromosomal aberrations in mammalian cells in vitro and in lymphocytes of exposed persons in vivo . Those in vivo results that were unable to provide evidence of chromosomal damage are hampered either by methodological inadequacies or by too low exposure levels . The (rodent) metabolite tetrachlorohydroquinone might be a real genotoxic agent, capable of binding to DNA and producing DNA strand breaks; this activity is probably due to semiquinone radical formation and partly mediated through active oxygen species . Since this compound has not been tested in the common bacterial and mammalian mutagenicity assays, the few ancillary results on this substance cannot be used in a meaningful human risk assessment of PCP . Furthermore, this metabolite has only been produced by human liver microsomes in vitro, but has not been detected in exposed humans in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)

J Bacteriol, 1991 Jan, 173(2), 541 - 8
Nucleotide sequence and analysis of a gene encoding anthranilate synthase component I in Spirochaeta aurantia; Brahamsha B et al.; A Spirochaeta aurantia DNA fragment containing the trpE gene and flanking chromosomal DNA was cloned, and the sequence of the trpE structural gene plus 870 bp upstream and 1,257 bp downstream of trpE was determined . The S . aurantia trpE gene codes for a polypeptide of 482 amino acid residues with a predicted molecular weight of 53,629 that showed sequence similarity to TrpE proteins from other organisms . The S . aurantia TrpE polypeptide is not more closely related to the other published spirochete TrpE sequence (that of Leptospira biflexa) than to TrpE polypeptides of other bacteria . Two additional complete open reading frames and one partial open reading frame were identified in the sequenced DNA . One of the complete open reading frames and the partial open reading frame are upstream of trpE and are encoded on the DNA strand opposite that containing trpE . The other open reading frame is downstream of trpE and on the same DNA strand as trpE . On the basis of the results of a protein sequence data base search, it appears that trpE is the only tryptophan biosynthesis gene in the sequenced DNA . This is in contrast to L . biflexa, in which trpE is separated from trpG by only 64 bp.

Infect Immun, 1991 Jan, 59(1), 323 - 9
Pulsed-field gel electrophoretic analysis of leptospiral DNA; Taylor KA et al.; The genomic structures of spirochete species are not well characterized, and genetic studies on these organisms have been hampered by lack of a genetic exchange mechanism in these bacteria . In view of these observations, pulsed-field gel electrophoresis was used to examine the genomes of Leptospira species . Live cells, prepared in agarose plugs, were lysed in situ, and the DNA was analyzed under different electrophoretic conditions . Pulsed-field gel electrophoresis of DNA digested with infrequently cutting restriction enzymes showed that the genome of Leptospira interrogans serovar canicola is approximately 3.1 Mb, while that of the saprophytic L . biflexa serovar patoc I is 3.5 Mb . DNA forms of approximately 2,000 and 350 kb which were present in samples from L . interrogans serovars were not readily detected in nonpathogenic serovars . Three distinct populations, designated type alpha, beta, and gamma, of L . interrogans DNA molecules were further analyzed with two-dimensional gel electrophoresis . Evidence suggested that two of these DNA forms, type alpha and gamma, were linear structures . Pulsed-field gel electrophoresis has proven to be a valuable tool with which to size bacterial genomes and to take the first steps toward characterization of a form of leptospiral DNA which behaves as a linear molecule and which may be related to the virulence of L . interrogans.

Infect Immun, 1991 Jan, 59(1), 126 - 30
Beneficial effect of liposome-encapsulated muramyl tripeptide in experimental septicemia in a porcine model; Izbicki JR et al.; In a porcine model of pneumococcal septicemia, animals were pretreated with 1 mg of liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (MTP-PE) or with liposomes alone . After 24 h each animal received an injection of either 10(9) or 10(10) pneumococcal serotype 6B cells . MTP-PE pretreatment resulted in less pronounced leukocytopenia, with a nadir of 6,700 (versus 4,100) leukocytes per mm3 after injection of 10(9) bacteria and a nadir of 4,400 (versus 3,800) leukocytes per mm3 after injection of 10(10) bacteria . At the same time bacterial clearance was substantially improved by MTP-PE pretreatment . Finally, pretreatment with MTP-PE dramatically reduced mortality; the average death rates for both series of animals used were 55% for liposome-pretreated animals and 3% for animals pretreated with MTP-PE-containing liposomes . These results in a preclinical model suggest that treatment with MTP-PE-containing liposomes might be beneficial in controlling septicemia in patients at risk.

Am J Clin Nutr, 1991 Jan, 53(1 Suppl), 247S - 250S
Inhibition of nitrosamine formation by ascorbic acid; Tannenbaum SR et al.; Nitrosation occurs under a wide variety of conditions by reaction of most types of amines with any of a large number of nitrosating species . Nitrite can be formed in vivo via bacterial reduction of nitrate and by activated macrophages and endothelial cells . The mechanism of nitrite formation by mammalian cells is via enzymatic oxidation of arginine to NO followed by oxidation to N2O3 and N2O4 . Nitrosatable amines are found in many foods and some, eg, dimethylamine, are synthesized in the body . Precursors of N-nitroso compounds are thus almost constantly present together under favorable reaction conditions in vivo and there is, consequently, considerable interest concerning possible human health risks arising from endogenous formation of this class of compounds . Among many nitrosation inhibitors, most attention has focused on ascorbic acid, which reacts with many nitrosating agents and which is virtually nontoxic . This presentation discusses the chemistry of ascorbic acid inhibition of nitrosation reactions.

Am J Clin Nutr, 1991 Jan, 53(1 Suppl), 238S - 246S
Effects of carotenoids in cellular and animal systems; Krinsky NI; It has been suggested that carotenoid pigments may function as chemopreventive agents for reducing the risk of cancer in humans . Part of this suggestion rests on epidemiological evidence, and part rests on work done in cellular and animal systems . In this article, the experimental evidence for carotenoid inhibition of mutagenicity, malignant transformation, tumor formation, and immunoenhancement is reviewed . Although a mechanism for these effects cannot yet be identified, it is clear that the overwhelming evidence in these systems would indicate that carotenoids exert an important influence in modulating the actions of carcinogens.

J Virol, 1991 Jan, 65(1), 254 - 62
Analysis of murine coronavirus surface glycoprotein functions by using monoclonal antibodies; Routledge E et al.; The murine coronavirus surface glycoprotein gene was expressed as a fusion protein in bacteria, and the expressed protein was used to generate S protein-specific monoclonal antibodies (MAbs) . Three of the MAbs, 11F, 30B, and 10G, were able to neutralize virus infectivity, and two of them, 11F and 10G, were able to block virus-induced, cell-to-cell fusion . The binding sites of the 11F, 30B, and 10G MAbs were determined by Western immunoblotting and epitope mapping . The 11F and 30B MAbs bound to sites located, respectively, between amino acids 33 to 40 and 395 to 406 in the amino-terminal (S1) subunit of the S protein, and the 10G MAb bound to a site located between amino acids 1123 and 1137 in the carboxy-terminal (S2) subunit . These data define more precisely the interactions between the S1 and S2 subunits of the murine coronavirus S protein and provide further insights into its structure and function.

Comp Immunol Microbiol Infect Dis, 1991, 14(3), 209 - 21
The polymerase chain reaction: basic methodology and applications; Xu LZ et al.; The "polymerase chain reaction" (PCR) is a high-power molecular biology technique allowing in vitro enzymatic amplification of a given DNA sequence . This exponential amplification can reach 10(7)-10(9), even a single DNA molecule can be detected . Also the use of non-radioactive probes, considered to be less sensitive than their radioactive counterparts, is possible for the molecular hybridization, to retain a high level of sensitivity . PCR is defined as a "free bacteria" cloning technique, which has many applications in fundamental research and in the clinical analysis of genetic disease, infectious diseases and cancers . Thus PCR is a revolutionary method which is capable of greatly stimulating scientific research and modifying the diagnostic area in the near future.

Cytobios, 1991, 67(269), 117 - 26
Major antigens in Methylobacterium species and their location in cells using immuno-electron microscopic methods; Corpe WA et al.; This work is a first step in the development of a specific probe for the study of the distribution and colonization of leaf surfaces by pink-pigmented, facultatively methylotrophic (PPFM) bacteria of the genus Methylobacterium . A polyclonal antiserum was produced in rabbits against whole cells of PPFM strain PC1, isolated from surfaces of white clover leaves . Major heat labile antigens were found in extracts of sonicated cells using the Ouchterlony double diffusion method . Very small amounts of a heat stable antigen were also observed . The major antigens were found in extracts of each of fifteen PPFM strains tested but were not found in extracts of other clover heterotrophs nor in extracts of other methylotrophs tested . The distribution of antigens in ultrathin sections of PPFM cells was investigated using PC1 antisera and gold labelled protein A . Gold particles were seen mainly in the outermost layer of the homologous strain, but isolated and washed cell envelopes of strain PC1 like other strains retained very little antigen . Sections of other PPFM strains showed the major antigens were located mainly in the cytoplasm.

Crit Rev Biochem Mol Biol, 1991, 26(3-4), 261 - 300
Enzymology of the acetyl-CoA pathway of CO2 fixation; Ragsdale SW; We know of three routes that organisms have evolved to synthesize complex organic molecules from CO2: the Calvin cycle, the reverse tricarboxylic acid cycle, and the reductive acetyl-CoA pathway . This review describes the enzymatic steps involved in the acetyl-CoA pathway, also called the Wood pathway, which is the major mechanism of CO2 fixation under anaerobic conditions . The acetyl-CoA pathway is also able to form acetyl-CoA from carbon monoxide . There are two parts to the acetyl-CoA pathway: (1) reduction of CO2 to methyltetrahydrofolate (methyl-H4folate) and (2) synthesis of acetyl-CoA from methyl-H4folate, a carboxyl donor such as CO or CO2, and CoA . This pathway is unique in that the major intermediates are enzyme-bound and are often organometallic complexes . Our current understanding of the pathway is based on radioactive and stable isotope tracer studies, purification of the component enzymes (some extremely oxygen sensitive), and identification of the enzyme-bound intermediates by chromatographic, spectroscopic, and electrochemical techniques . This review describes the remarkable series of enzymatic steps involved in acetyl-CoA formation by this pathway that is a key component of the global carbon cycle.

Appl Biochem Biotechnol, 1991 Spring, 28-29, 33 - 42
Avoiding digester imbalance through real-time expert system control of dilution rate; Pullammanappallil P et al.; Process control of anaerobic digesters is a particularly challenging problem because of the diversity of possible causes that can lead to digester imbalance . Conventional control schemes can fail in consequence of a reversal in the sign of the steady-state gain caused by some type of disturbance . In this work we present an expert system approach that takes into account the particularity of this process . The developed algorithm is demonstrated to compensate successfully for changes in the digester feed medium when simulated against a model for a continuous anaerobic digester.

Zentralbl Chir, 1991, 116(9), 587 - 92
{Errors in lavage therapy in diffuse peritonitis}; Imhof M; The suppurative peritonitis is still one of the major clinical concerns for surgeons in these days . The presence of bacteria and endotoxins within the peritoneal cavity activate a chain of reactions, which mostly are still unknown, but frequently determinate the course of the disease . Because of the multifactorial system of the biochemical processes, we are coming to the paint to ask for a final chemical reaction of all these processes . The final reaction in this high toxic systems is taken place in an acidic pH range . Our experiments show, that the intraperitoneal alcalisation by lifting up the pH in the physiological range or even higher produces a stop in the septical reactions . Consequently because of these results we changed our treatment for severe peritonitis as followed: 1 . Focus sanitation: Consequent treatment for the underlying cause of infection . 2 . Continuous abdominal lavage over 4 catheters in each of the quadrants of the abdominal cavity with 101 of saline solution together with 8.4% Na-bicarbonate up to a pH-range of 7.6 . 3 . First revision of abdomen after 12 h after removing the catheters the normal intraoperative lavage with 10-15 1 saline solution with 8,5% Na-bicarbonate is performed . 4 . The abdomen remains open and daily revisions and lavage with Na-bicarbonate are performed . 5 . Early clinical data support the experimental findings.

Rev Mal Respir, 1991, 8(4), 381 - 6
{Cheese-washer's disease . A current stable form of extrinsic allergic alveolitis in a rural setting}; Galland C et al.; Inhalation of organic particles (bacteria, fungi or animal proteins) by sensitized subjects is known to induce extrinsic allergic alveolitis (EAA) . The most frequent type of EAA and the best known in rural environment is farmer's lung disease . Nevertheless a rarer form is also to be considered in rural environment: cheesewasher's disease . Here we report 4 cases of cheesewasher's disease, who all presented with relevant aspects of the disease: diversity of antigens involved, prophylaxis problems, severity of the disease, rapidity of onset, reversibility and importance of history in the diagnosis . Penicillium casei usually is the responsible antigen, and precipitating antibodies against these moulds, but against other moulds such as Aspergillus, Circinomucor circilloides, Fusarium as well, can be detected in the patient's serum . Thus, in a rural environment, a respiratory symptomatology suggestive of EAA should lead to thorough search for antigens and cheesewasher's disease should be considered . Among the many other diagnostic tests, precipitin determinations are cheap and non invasive and can be very useful in the diagnostic approach.

Nahrung, 1991, 35(5), 491 - 502
{Mass spectrometric structure analysis of fatty acid mixtures from biological material after gas capillary chromatographical separation}; Petrzika M et al.; The identification of mixtures of fatty acids from biological materials is possible by electron impact ionization mass spectra of methyl esters after their capillary gas chromatographic separation . Mass spectra of pyrrolidine derivatives are used for the determination of double bond positions in unsaturated fatty acids . 97 different fatty acids (saturated, unsaturated, branched, cyclic, hydroxy, oxo, epoxy and methoxy) and other compounds (alkanes, halogens, phthalates, ketones, aldehydes) were identified in yeast and bacterial biomasses, lipid-containing animal tissues and human sera as well as fish and plant oils (77 preparations).

Environ Mol Mutagen, 1991, 18(3), 207 - 11
Antimutagenic activities of naturally occurring polyamines in Chinese hamster ovary cells in vitro; Cozzi R et al.; Spermine and spermidine, ubiquitous polyamines present in bacteria and animal cells, are also involved in cell growth . Since they interact with the double helix, they can stabilize the DNA molecule . Recent evidence of the antimutagenic and anticarcinogenic capacity of spermine has focused attention on the mechanism(s) by which such agents can protect cells from induced damages . In the present paper we show the ability of spermine and spermidine to decrease the level of sister chromatid exchanges induced in Chinese hamster ovary cells cultivated in vitro, by treating them with Psoralen + UVA irradiation (able to induce mainly monoadducts and DNA cross-links) . Two different mechanisms of polyamine action can be invoked to explain the preservative activity of this class of agents.

Crit Rev Oral Biol Med, 1991, 2(1), 65 - 81
The role of complement in periodontal diseases; Schenkein HA; The complement system has been implicated as both a pathogenic mechanism and a means of protection in periodontal diseases . It is well known that bacteria activate complement; such activation can initiate a number of events, including bacterial opsonization and killing, release of inflammatory agents, and modulation of other immune reactions . Cleavage of complement proteins has been observed in gingival fluids from individuals with periodontal disease and some investigators have observed complement deposition in diseased gingival tissues . Furthermore, a number of bacterial from individuals with periodontal diseases have been found to activate complement in vitro; some of these organisms appear to have the capacity to evade opsonization due to their proteolytic capacity . However, concrete evidence is not yet available that indicates that complement activation occurs in human periodontal disease and is important in either its pathogenesis or in protection against bacterial virulence factors.

Arch Oral Biol, 1991, 36(3), 233 - 8
The pH of gingival crevices and periodontal pockets in children, teenagers and adults; Eggert FM et al.; Gingival crevice and periodontal pocket pH, measured directly with glass micro-electrodes, was near neutral at most sites in most individuals (mean pH 6.92 +/- 0.03 SEM, 69 subjects) . Periodontal state ranged from healthy to periodontitis but neither clinical evidence of gingivitis at a site nor pocket depth were associated with crevicular pH different from that at healthy sites . This finding contradicts earlier reports that gingivitis is associated with a crevicular pH as alkaline as pH 9.06 . Metallic antimony electrodes as used by earlier investigators were found to give pH readings that were too high by as much as 1.5 pH units in the presence of organic reducing agents of the type produced by oral bacteria within gingival crevices . In contrast, glass micro-electrodes respond only to hydrogen ions and thereby provided accurate measurements of pH even in the presence of organic reducing agents . Loss of CO2 to the atmosphere from biological fluids that are bicarbonate buffered resulted in a shift to alkaline pH by as much as 1 pH unit . As a result, only measurements taken within gingival crevices or periodontal pockets can provide accurate measurements of crevice or pocket pH.

Pharmazie, 1991 Jan, 46(1), 26 - 8
Synthesis and biological activity of some 4-substituted pyrimidines and fused pyrimidines; el-Bahaie S et al.; The synthesis of 4-beta-cyanoethylthiopyrimidine 2 and 4-chloropyrimidine 8a was chieved from 4-mercapto-5-acetylpyrimidine (1a) . Also the synthesis of thienopyrimidine-7,7-dioxide 6, 4-arylaminopyrimidines 9a-e, 4-alkoxypyrimidines 11a, b, pyrimidoquinazoline 10, thienopyrimidines 19a, b and tetrazolopyrimidine 18 was described.

Biofactors, 1991 Jan, 3(1), 41 - 7
Queuine metabolism and cadmium toxicity in Drosophila melanogaster; Siard TJ et al.; Queuine can replace guanine in the anticodon of certain tRNAs and is a hypermodified guanine derivative that can be synthesized by bacteria but not by mice . The study demonstrates that Drosophila can incorporate dietary queuine into tRNA but cannot synthesize it de novo for this purpose . Since an earlier study had shown that dietary CdCl2 caused Drosophila to increase greatly the proportion of queuine-containing tRNA over non-queuine tRNA the ability of dietary queuine to counteract cadmium toxicity was evaluated . When queuine was present in the cadmium-containing medium more pupae matured into adults than when queuine was absent . Other studies had demonstrated that the transglycosylase enzyme, that catalyzes the replacement of guanine in the anticodon of tRNA by queuine, is present in Drosophila larvae but the tRNA is virtually devoid of queuine . This study shows that in the presence of dietary queuine the larval tRNA contains abundant amounts of queuine . Therefore, we postulate a significant role for bacteria in supplying queuine to Drosophila for its incorporation into tRNA and that the control of this process by Drosophila is passive, i.e . is not an essential feature in differentiation.

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