Cerebrospinal fluid levels of lysozyme, IgM and C-reactive protein in the identification of bacterial meningitis.

Lysozyme (LZM), immunoglobulin M (IgM) and C-reactive protein (CRP) levels were determined in cerebrospinal fluid (CSF) from patients classified on the basis of clinical and laboratory findings into three groups: bacterial meningitis (n = 33), lymphocytic meningitis (n = 21) and controls (n = 54). IgM and CRP levels were determined by enzyme-linked immunosorbent assay (ELISA) and LZM by the lysoplate method. Discriminant analysis demonstrated that 93.94% (31/33) and 96.97% (32/33) of patients with bacterial meningitis were correctly classified on the basis of CSF determinations of IgM and LZM, respectively. However, the measurement of CRP levels in CSF correctly classified 100% of these patients (33/33), thus representing a useful additional marker for the screening of bacterial meningitis. Moreover, no more than 4% (3/75) of patients were incorrectly classified as belonging to the bacterial group on the basis of the CRP test. Thus, CRP titres less than or equal to 80 identify cases belonging to one of the non-bacterial groups, whereas titres greater than or equal to 640 classify the bacterial group, with a very low chance of misclassification. The authors recommend that CSF IgM or LZM levels be also measured for patients with CSF CRP titres of 160 and 320, for a more accurate diagnosis. The probability of these cases being of bacterial aetiology, as calculated from the combined results of these measurements, is presented.

Trypanosoma cruzi: course of infection in platelets-depleted mice.

The effect of platelet depletion on the course of Trypanosoma cruzi infection in BALB/c mice was investigated. Thrombocytopenia was achieved by inoculation of rabbit anti-platelet IgG during the parasitemic phase of the infection. The number of parasites in the blood of anti-platelet IgG treated was significantly higher than that of non-treated control mice, during the phase of high parasitemia. Cumulative mortality of platelet-depleted mice was consistently but not significantly higher than that of control mice up to the 32nd day of infection; from the 33rd day on they were equivalent, no mortalities occurring from then on, until observations were discontinued on the 60th day. These results suggest that platelets participate of the mechanisms of parasites removal from the bloodstream, but do not have an effective role in the mechanisms of defence against T. cruzi, during the acute phase of infection.

Eosinophil levels in the acute phase of experimental Chagas' disease.

Eosinophil dynamics, in bone marrow, blood and peritoneal exudate, of resistant C57B1/6 (C57) and susceptible A/Snell (A/Sn) mice was comparatively studied during the acute phase of infection by Trypanosoma cruzi Y strain. A decline was observed in bone marrow eosinophil levels in A/Sn, but not in C57 mice, soon after infection, those of the former remaining significantly below those of the latter up to the 4th day of infection. Bone marrow eosinophil levels of C57 mice declined subsequently to levels comparable to those of A/Sn mice, the number of these cells in this compartment remaining 50% those of non infected controls, in both strains, up to the end of the experiment on the 14th day of infection. The fluctuations in eosinophil levels in blood and peritoneal space were similar in both mice strains studied. Concomitantly with depletion of eosinophils in the marrow, depletion in blood and a marked rise of these cells in the peritoneal space. initial site of infection, occurred in both strains. The difference in eosinophil bone marrow levels, between C57 and A/Sn mice, observed in the first four days of infection, suggests a higher eosinopoiesis capacity of the former in this period, which might contribute to their higher resistance to T. cruzi infection.

Complemento hemolitico total, C3 e taxa de conversao de C3 nas formas cardiaca e indeterminada da Doenca de Chagas. / Total hemolytic complement, C3 and C3 convertase levels in cardiac and indeterminate forms of Chagas' disease

Os valores de complemento hemolitico total C3 total (nativo + produtos de degradacao) e o grau de conversao de C3 nativo foram estudados em dois subgrupos de pacientes chagasicos, nas formas cardiaca e indeterminada, e em um subgrupo de individuos nao chagasicos, clinicamente sadios.Os niveis de C3 total e as taxas de conversao de C3 em seus produtos de degradacao foram semelhantes nos tres subgrupos. Os valores de complemento hemolitico total foram estatisticamente diferentes nos tres subgrupos (nivel de significancia descritivo p= 0,0757), tendo sido observada media aritmetica mais baixa no subgrupo de cardiacos e mais elevada no subgrupo de controles.Maior amplitude de variacao dos niveis de complemento hemolitico total foi notada no subgrupo de cardiacos, no qual se encontraram os valores extremos (maximo e minimo), considerando-se todos os subgrupos

Inquerito-soro epidemiologico da malaria na regiao do Rio Limpopo; Mocambique

The authors present the results of a seroepid emiological survey of malaria in seven villages of the Limpopo river balley (Mozambique); in some of which the fight to the endemy has already started a few years ago. The methods used was that of immunofluorescence

Conversion of the C3 component of complement in sera of hanseniasis patients.

The levels of total C3 (native C3 plus its degradation products) and the degree of conversion of native C3 into its breakdown products were studied in sera of Virchowian (V), tuberculoid (T), indeterminate (I), and Virchowian with erythema nodosum Hansenicum (ENH) patients. Sera from normal individuals (N) were also analysed. While the levels of total C3 were not significantly different among the groups, the percentage of conversion of C3 into its degradation products was significantly higher in V and ENH sera. The activation of the complement system and the involvement of immune complexes (IC) are discussed.

Conversion of the C3 component of complement in sera of hanseniasis patients.

Os niveis de C3 total (C3 nativo mais seus produtos de degradacao) e o grau de conversao do C3 nativo em seus produtos de degradacao foram estudados em soros de pacientes V, T, I e de V com ENH. Soros de individuos normais foram tambem analisados, enquanto os niveis de C3 total nao diferiram significativamente entre os grupos, a conversao de C3 em seus produtos de degradacao foi significativamente maior nos soros de pacientes V e naqueles com ENH. A ativacao do sistema complemento e o envolvimento dos IC neste processo sao discutidos

The complement system and the inflammatory response in experimental Chagas' disease.

Camundongos SW, machos, infectados com a cepa FL ou com a Y do T.cruzi foram decomplementados com CVF. A parasitemia dos camundongos decomplementados e infectados com a cepa FL foi significativamente mais alta no 10o dia de infeccao do que a do grupo controle, infectado mas normocomplementemico, mas nao no 12o dia. A parasitemia dos camundongos decomplementados e infectados com a cepa Y nao foi significativamente diferente da dos controles nem no 5o, nem no 7o dia de infeccao. O exame histopatologico do coracao demonstrou que a intensidade da resposta inflamatoria dos camundongos infectados com a cepa Y e pouco menor para os controles. Nao foram observadas diferencas significativas no grau da resposta inflamatoria entre os camundongos decomplementados e os nao decomplementados, infectados com a cepa FL do T.cruzi

Ativacao da via alternativa do complemento pelas promastigotas da Leishmania donovani. / Activation of the alternative pathway of complement by promastigotes of Leishmania donovani

Promastigotas da Leishmania donovani submetidas em condicoes favoraveis a acao do Complemento (C), ativado apenas pela via alternativa, apresentaram 90% de lise. Em nenhum experimento houve lise total, mesmo com uso de quantidade tres vezes maior de C e periodo de incubacao prolongado. As promastigotas resistentes a acao do C, apresentam-se sem alteracoes morfologicas evidentes, ao microscopio optico comum