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Six hundred and ninety three male inmates from three penitentiaries, two (A and B) maximum-security systems and one (C) minimum-security facility, located in Campinas, State of São Paulo, Brazil were studied for the presence of human immunodeficiency virus (HIV) antibodies, using a cross-sectional design. The search for anti-HIV antibodies in 693 samples of sera collected was carried out by two serological tests: (a) the Microparticle enzyme immunoassay-HIV-1 and HIV-2 (MEIA) (Abbott Laboratories) and (b) the Western Blot-HIV-1 (WB) (Cambridge Biotech Corporation) to confirm positive results with MEIA. Sera reactivity for HIV antibodies was 14.4%. The highest frequency of anti-HIV antibodies was found in the A and B maximum-security prisons: 17% and 21.5%, respectively. In prison C, the frequency of reagents was 10.9%. Seventy three inmates, initially negative in the MEIA test, were checked again five and seven months later. Three of them, all from the maximum-security facilities, became reactive in the MEIA test, with confirmation in the WB, suggesting that serological conversion had occurred after imprisonment.

Plusieurs facteurs antigeniques de colonisation (CFA) et facteurs presumes de colonisation (PCF) ont ete decrits chez des souches de Escherichia coli enterotoxinogenes (ETEC). Toutefois, il existe encore de nombreuses souches d'ETEC, isolees chez des patients diarrheiques, qui ne presentent aucun de ces antigenes. Etudiant 87 ETECs isolees au Bresil chez des enfants atteints de diarrhee, nous avons selectionne deux souches appartenant au type serologique O2 :H1 et qui sont capables de s'agglutiner en presence de D-mannose et de cellules sanguines humaines ou de bovins, poulets, hamsters, moutons et chevaux. L'hemaglutination resistante au D-mannose (MRHA), les reactions serologiques specifiques et les ultrastructures fimbrillaires ont pu etre observees chez les souches cultivees a 37°C, mais non chez celles cultivees a 16°C. L'analyse, par SDS-PAGE (sodium dodecyl sulphate/polyacrylamide gel electrophoresis), de la fraction fimbrillaire purifiee a revele une bande de 32,5 kDa. Les tests d'hybridation utilisant la sonde LT (toxine thermolabile) ont identifie la codification de l'enterotoxine sur un seul plasmide a environ 34MDa. Par ailleurs, chez les souches isolees sur le critere LT, le phenotype fimbrie a ete confirme. Les caracteres specifiques des fimbrilles decrites correspondent a un nouveau facteur presume de colonisation des ETECs, et le code propose est PCF02.

Literature has shown that immunosuppression observed in systemic mycosis can be related to damage in primary lymphoid organs. We have studied the immunopathological alterations induced experimentally by Paracoccidioides brasiliensis in these organs. In this work, thymic alterations induced in BALB/c mice during acute and chronic stages of infection are described. It was observed that P. brasiliensis is able to invade the thymic microenvironment, inducing severe atrophy characterized by degeneration of the cortical area, organ weight decrease, loss of corticomedullary delimitation and increase in histiocyte number. Occurrence of polymorphonuclear infiltration in the subcapsular area was also observed. Our results demonstrate that P. brasiliensis induces profound thymic atrophy and raises the question of whether this could be a fungal strategy to achieve successful establishment in the host over the long term.

Some viruses of the families Retroviridae, such as Human T Lymphotropic Virus (HTLV); Herpesviridae as the Cytomegalovirus (CMV) and Hepadnaviridae such as the Hepatitis B Virus (HBV) are liable to be co-transmitted with the Human Immunodeficiency Virus (HIV). Since prisoners are exposed to several and important risk factors involved in the transmission of HIV and the above mentioned viruses, male inmates from the penitentiary complex of Campinas, SP, Brazil, including HIV + and HIV - ones, were examined for the presence of HTLV-I and/or II antibodies; IgG and IgM anti-CMV antibodies, and the research of the superficial hepatitis B antigen (HBsAg). The presence of anti-HTLV-I and/or II was determined by the Western Blot (WB) technique, whereas IgG and IgM anti-CMV and the search of HBsAg were carried out by the Microparticle Enzyme Immunoassay (MEIA-Abbott Lab).With regard to anti-HTLV-I and/or II, 58.3% (14/24-Number of positive reactions/number of sera examined) were reactive among the anti-HIV positive sera. Conversely, only 12.5% (3/24) among the HIV- negative sera showed positive reactions to HTLV-I and/or II antibodies. When looking for IgG anti-CMV percentages of 97.7% (43/44) and 95% (38/40) were obtained for anti-HIV positive and negative sera, respectively. As to IgM anti-CMV antibodies 11.36% (5/44) and 2.5% (1/40) of reactive sera were found for anti-HIV positive and negative, respectively. The HBsAg was found in 12.8% (5/39) of the sera which were anti-HIV positive.Alguns vírus das famílias Retroviridae, tais como, o Vírus do Linfoma Humano de Células T ( HTLV); Herpesviridae, tais como o Vírus Citomegálico (CMV) e da Hepatite B (HBV) podem ser co-transmitidos com o Vírus da Imunodeficiência Adquirida (HIV). Uma vez que prisioneiros estão expostos a diversos fatores de risco envolvidos na transmissão do HIV e dos vírus acima mencionados, prisioneiros do sexo masculino do Complexo Penitenciário de Campinas, SP, Brasil, incluindo aqueles que eram HIV+ e HIV-, foram examinados para a presença de anticorpos anti- HTLV-I/II; anticorpos IgG e IgM anti-vírus citomegálico e a presença do antígeno de superfície do HBV (HbsAg). A presença de anti- HTLV-I/II foi determinada pela técnica de Western Blot, enquanto IgG e IgM anti-CMV e a pesquisa do HbsAg foram feitas por ensaio Imunoenzimático (MEIA-Abbott Lab). Com relação à pesquisa de anti-HTLV-I/II, 58,3% (14/24- número de positivos/número total de soros examinados) foram reagentes entre os soros HIV+. Contrariamente, apenas 12,5% (3/24) entre os soros HIV- mostraram reações positivas para anti- HTLV-I/II. Porcentagens de 97,7% (43/44) e 95% (38/40) foram obtidas, respectivamente para os soros anti-HIV+ e anti-HIV-, em relação à pesquisa de IgG anti-CMV. No que concerne à IgM anti-CMV 11,36% (5/44) e 2,5% (1/40) foram os achados para os soros anti-HIV+ e anti-HIV-, respectivamente. A presença do HbsAg foi encontrada em 12,8% (5/39) dos soros que eram HIV+.

GM1 ganglioside has been identified as the receptor for cholera toxin (CT) and heat-labile (LT) enterotoxin of Escherichia coli in many cell types. Using the radial immune hemolysis (RIH) and indirect hemagglutination (IH) tests described for the detection of these enterotoxins, a study was conducted on the 100% inhibition of these reactions by pre-incubating these enterotoxins with GM1, GD1a and GT1 gangliosides. GM1 was found to be much more efficient than the other two. With respect to the RIH test, GT1 was more efficient than GD1a as an inhibitor of enterotoxin binding. Similar results were obtained with the IH test. These data also showed that sheep red blood cells provide a good model system for the study of receptors for CT, LT and probably other enterotoxins which bind to gangliosides.

An indirect haemagglutination (IH) test is described for the detection of Clostridium perfringens type A enterotoxin, produced by strains isolated from human cases of food poisoning and from contaminated food. Though no strict relationship could be observed between titers in the IH test and the time it took mice to die from the intravenous inoculation of mice (IIM test), results of the supernatants examined by both methods demonstrated that the IH test was more sensitive than the IIM one. No unspecific reaction was obtained in the IH with a negative control and the inhibitions of the IH and IIM tests by specific antiserum against C. perfringens enterotoxin showed that the IH test is very specific. The IH assay is recommended for its sensitivity and easy performance by less-equipped laboratories, by these and other data.

The purpose of this article is to give the clinician not proficient in biochemistry an understanding of the biochemical research data on neurotransmitters and suicide. This literature review reports the current findings on serotonin (5-HT), dopamine (DA), and norepinephrine (NE) as possible biochemical markers of depression and suicide. In conjunction with known environmental and behavioral indicators of suicide, neurotransmitter balance could be a factor in determining the severity of depression and the possible suicidal ideation in patients. Numerous studies have been performed on the monoamines: Serotonin, Dopamine and Norepinephrine, neurotransmitters that innervate parts of the spinal cord and all areas of the brain. Studies appear to suggest a relationship among monoamine levels, depression, and suicide. Significantly low levels of serotonin and the neurotransmitter metabolite (5-HIAA) may be correlated with suicidal behavior.

Many scrological reactions using red blood cells (RBC) such as radial immune haemolysis (RIH) and indirect haemagglutination (IH) tests have often been used for the detection of cholera toxin (CT) and heat-labile (LT) enterotoxin produced by porcine and human Escherichia coli strains. In these tests, the enterotoxins bind to sheep, bovine and guinea-pig RBC without any ligand. We studied several factors which might interfere with such binding, as well as the nature of the receptors involved. Treatment of erythrocytes with different enzymes revealed that proteolytic enzymes had no effect on the adsorption of enterotoxins to RBC. Conversely, treatment with neuraminidase increased the adsorption. Experiments carried out with delipidized RBC revealed that none of the enterotoxins under study bound to the cells thus treated. Pre-incubation of ganglioside fractions with the enterotoxins blocked RIH and IH reactions and the biological effect of them on Vero cells. Assaying RBC ganglioside fractions by thin-layer chromatography revealed the presence of GM1. Our results suggest that the receptors for GT and LT enterotoxins in sheep, bovine and guinea pig RBC are gangliosides: mainly GM1.

Foi realizada uma pesquisa na região de Campinas, SP, Brasil, sobre a presença de Escherichia coli enterotoxigênica (ETEC), rotavírus e Clostridium perfringens enterotoxigênico em fezes diarréicas de crianças com até 2 anos de idade. Dos 132 espécimens fecais examinados quanto à presença de ETEC 27 (20,45%) foram positivos. Destes foram isoladas 41 amostras de ETEC, das quais 40 produziram apenas a enterotoxina termolábil (LT) detectada pelo teste de imuno hemólise radial modifi cado. Entre as 183 amostras de fezes examinadas para rotavírus, 29 (15,84%) foram positivas pelas técnicas de eletroforese em gel de poliacrilamida (PAGE) e ensaio imunoenzimático (EIE), sendo que destas, 15 (51,7% ) foram provenientes de materiais coletados nos meses de inverno. Todas as amostras pertenciam ao grupo A e, através da técnica de PAGE, pode-se observar que o tipo eletroforético mais freqüente (9 amostras) foi designado Ib, IIc, Illb, IVa, de acordo com a classificação por nós adotada. Apenas 113 amostras de fezes foram examinadas para a presença de C. perfringens enterotoxigênico. Para a detecção da enterotoxina nos sobrenadantes das culturas foram utilizadas as técnicas de hemaglutinação passiva reversa e inoculação intravenosa em camundongos, sendo encontradas 12 (10,61%) amostras entero-toxigênicas. Diante destes resultados é chamada a atenção sobre o valor apenas relativo de uma coprocultura convencional para fins de diagnóstico, ressaltando-se a importância da criação de métodos simplificados que favoreçam a detecção e identificação dos grupos de agentes enteropatogênicos estudados na presente pesquisa.

The effect of Escherichia coli enterotoxin STa on the primary and secondary immune response in F1 (CBA × C57 B1/10) mice immunized against sheep red blood cells (SRBC) was investigated. Modulating action on the IgM and IgG response was found to be dependent on the dose-time administration of the toxin. Immunosuppression of the primary response on the 4th day after immunization was observed when the toxin was injected 15 min before the SRBC, followed by immunostimulation on the 6th day after antigen (Ag) injection. Moreover, toxin administration 48 h before SRBC caused immunosuppression of the primary immune response on the 4th and 6th days. On the other hand, the IgM and IgG secondary immune response, determined 6 days after boosting, was greatly enhanced by toxin administration 15 min before priming (day 0) or boosting (day 26) and 48 h before priming. The same response was suppressed by toxin administration 48 h before booster antigen injection.

The production of thermolabile (LT) enterotoxin was compared in a defined medium reported by Staples et al. (SAG medium) for the production of thermostable (ST) enterotoxin and the Casamino acids-Yeast extract (CAYE) medium. Aliquots were drawn frum cultures of an enterotoxigenic (LT+, ST+) E. coli in both media at different times, growth curves were plotted, and culture filtrates tested for toxin activity. Levels of LT and ST and in the SAG showed that it is as suitable as CAYE for the production of LT. The addition of either glucose (1%) or lincomycin (90 microgram/ml) to SAG medium increased LT levels, but no synergistic effort could be observed if both substances were added concomitantly. Cultures in SAG medium incubated stationarily for 72 h at 37 degrees C yielded more LT than shaking cultures incubated similarly.

A survey for the detection of enterotoxigenic Escherichia coli (ETEC), rotavirus and enterotoxigenic Clostridium perfringens in diarrheic stools of children up to 2 years old was carried out in the region of Campinas, SP, Brazil. Twenty-seven (20.45%) faecal specimens were positive for ETEC. From these samples 41 strains of ETEC were isolated from which 40 produced only thermolabile (LT) enterotoxin, as detected by a modified radial immune haemolysis test. Among the 183 faecal specimens examined for the detection of rotavirus, 29 (15.84%) were positive when examined by polyacrilamide gel electrophoresis (PAGE) and immunoenzymatic assay (EIA) being 15 (51.7%), derived from stools collected from winter months. All strains of rotavirus belonged to group A and through the PAGE technique, it was observed that the most frequent (9 strains) electrophoretype, according to the adopted classification, was Ib, IIc, IIIb, IVa. Only 113 fecal specimens were examined for the presence of enterotoxigenic C. perfringens. For the detection of enterotoxin in culture supernatants the reverse passive haemagglutination and intravenous inoculation of mice were used. Twelve (10.61%) enterotoxigenic C. perfringens strains were found. Taking into consideration these findings the authors call the attention of the relative value of conventional coprocultures for diagnostic purposes, pointing out the important of establishing simplified methods which would render easier, the detection and identification of the groups of enteropathogenic agents studied in this research.

Made available in DSpace on 2022-04-29T07:20:29Z (GMT). No. of bitstreams: 0 Previous issue date: 1994-01-01 Paracoccidioides brasiliensis probably uses many different mechanisms to establish itself in the host and cause disease. In this work, we assess an in vitro model system which uses cultured mammalian cells to investigate the virulence factors of P. brasiliensis. We were able to demonstrate an invasion process of the yeast form of this fungus in Vero cell cultures. We deduced that the overall invasive process involved three steps: adhesion, followed by invasion of individual epithelial cells and spread to adjacent cells. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted. Department of Clinical Analysis, Faculty of Pharmaceutical Sciences, UNESP, Araraquara Department of Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo Department of Clinical Analysis, Faculty of Pharmaceutical Sciences, UNESP, Araraquara