Modulation of B lymphocyte function by an aqueous fraction of the ethanol extract of Cissampelos sympodialis Eichl (Menispermaceae)

Cissampelos sympodialis Eichl species are used in folk medicine for the treatment of asthma, arthritis and rheumatism. In the present study, we investigated the immunomodulatory effect of an aqueous fraction of a 70% (v/v) ethanol extract of C. sympodialis leaves on B lymphocyte function. The hydroalcoholic extract inhibited the in vitro proliferative response of resting B cells induced by LPS (IC50 = 17.2 µg/ml), anti-delta-dextran (IC50 = 13.9 µg/ml) and anti-IgM (IC50 = 24.3 µg/ml) but did not affect the anti-MHC class II antibody-stimulated proliferative response of B cell blasts obtained by stimulation with IL-4 and anti-IgM. Incubation with the hydroalcoholic extract used at 50 µg/ml induced a 700% increase in intracellular cAMP levels. IgM secretion by resting B cells (obtained from normal mice) and polyclonally activated B cells (obtained from Trypanosoma cruzi-infected animals) was inhibited by the hydroalcoholic extract. The latter were more sensitive to the hydroalcoholic extract since 6.5 µg/ml induced a 20% inhibition in the response of cells from normal mice while it inhibited the response of B cells from infected animals by 75%. The present data indicate that the alcoholic extract of C. sympodialis inhibited B cell function through an increase in intracellular cAMP levels. The finding that the hydroalcoholic extract inhibited immunoglobulin secretion suggests a therapeutic use for the extract from C. sympodialis in conditions associated with unregulated B cell function and enhanced immunoglobulin secretion. Finally, the inhibitory effect of the hydroalcoholic extract on B cells may indicate an anti-inflammatory effect of this extract.

Níveis de chumbo e atividade da desidratase do ácido delta-aminolevulínico (delta-ALAD) no sangue da população da Grande São Paulo, Brasil

Foram feitas determinações de chumbo e atividade da delta-ALAD no sangue de 3 amostras populacionais da Grande São Paulo (Brasil). Um grupo (A) de área de escassa exposição ambiental ao chumbo, um grupo (B) exposto principalmente a fontes móveis de emissão de chumbo e um grupo (C) vizinho a uma indústria de recuperação de chumbo. Cada grupo foi subdividido conforme sexo e hábito de fumar. A plumbemia do grupo C (20,5 µg/100 ml) foi significantemente maior que as dos grupos A (11,2 µg/100 ml) e B (12,4 µg/100 ml). As correlações entre plumbemia e atividade da delta-ALAD, plumbemia e sexo e plumbemia e hábito de fumar foram investigadas.

Razões de proporções e uso do método delta para intervalos de confiança em regressão logística

OBJETIVO: Apresentar uma aplicação da regressão logística para estimar razões de prevalência ou risco relativo, e o uso do método delta para a estimativa de intervalos de confiança. MÉTODOS: Utilizou-se o método delta, visto que esta técnica é adequada para estimar variâncias de funções não lineares de variáveis aleatórias, do tipo razão de proporções. O método baseia-se na expansão da função em série de Taylor, provendo uma aproximação para o cálculo das variâncias. Para estimar as razões de proporções e as respectivas variâncias, que permitem a estimação dos intervalos de confiança, desenvolveu-se programa utilizando-se o módulo matricial do SAS. A aplicação prática do modelo proposto é feita utilizando-se dados de um estudo transversal com uma amostra de 611 mulheres, para testar a hipótese de que a falta de compartilhamento do trabalho doméstico associa-se com altos escores de sintomas psicológicos medidos através de um questionário validado. As razões de prevalência calculadas através da regressão logística, e os intervalos de confiança estimados pelo método delta foram comparadas com os resultados obtidos pela técnica de Mantel-Haenszel. RESULTADOS: As estimativas pontuais das razões de prevalência brutas, cruas ou ajustadas, obtidas através da regressão logística, foram semelhantes às encontradas na análise tabular. Também os limites dos intervalos de confianças para as razões de prevalência através do método delta foram praticamente iguais em relação aos encontrados através da técnica de Mantel-Haenszel. CONCLUSÕES: Os resultados apóiam o uso do método delta para estimar intervalos de confiança para razões de proporção. Esse método deve ser visto como uma alternativa para situações em que o efeito em estudo (variável dependente) não é raro, situação onde a "odds ratio" se afasta das medidas epidemiológicas caracterizadas como razão de proporções.

B and Delta hepatitis virus infection in a population of West Africa

Among the 424 serum samples examined, the prevalence of hepatitis virus infection turned out to be 89.6%, with 15.6% of HBsAg positivity. Some of the samples belonged to an afferent population and some other to workers of a West Africa rural hospital (Pop. Rep. of Benin). 27.3% of the positive subjects presented active replication of the virus, shown by the presence of HBeAg. Among the HBcAb positive subjects the anti-delta antibodies showed a positivity frequency of 19.7%. HBsAg presence in 15% of pregnant women suggested the importance of HBV mother-foetal transmission in the district. The examined results can be compared with those obtained in other African areas, with similar socio-economic conditions.

Modulation of parasitemia and antibody responce to Trypanosoma cruzy by cyclophosphamide in Calomys callosus (Rodentia, Cricetidae)

Calomys callosus a wild rodent, previously described as harboring Trypanosoma cruzi, has a low susceptibility to infection by this protozoan. Experiments were designed to evaluate the contribution of the immune response to the resistance to T. cruzi infection exhibited by C. calossus. Animals were submitted to injections of high (200 mg/kg body weight) and low (20 mg/kg body weight) doses of cyclophosphamide on days -1 or -1 and +5, and inoculated with 4 x 10³ T. cruzi on day O. Parasitemia, mortality and antibody response as measured by direct agglutination of trypomastigotes were observed. Two hundred mg doses of cyclophosphamide resulted in higher parasitemia and mortality as well as in suppression of the antibody response. A single dose of 20 mg enhanced antibody levels on the 20th day after infection, while an additional dose did not further increase antibody production. Parasitemia levels were not depressed, but rather increased in both these groups as compared to untreated controls. Passive transfer of hyperimmune C. callosus anti-T. cruzi serum to cyclophosphamide immunosuppressed animals resulted in lower parasitemia and mortality rates. These results indicate that the immune response plays an important role in the resistance of C. callossus to T. cruzi.

The effect of chronic ingestion of ethanol on modulation of granulomatous inflammation in experimental schistosomiasis in mice

We studied the role of ethanol on the modulation of liver granulomata around Schistosoma mansoni eggs in mice. Albino mice, receiving 7% ethanol as the sole drinking liquid, at 60 and 90 days post-infection, presented smaller granulomata than controls did, when sacrificed at 120 days post-infection. No differences in diameters could be observed, when ethanol was given 4 months before up to 120 days after infection. The results suggested that modulation of schistosome granulomata by ethanol ingestion varies with time and duration of drug consumption.

Experimental pulmonary schistosomiasis: lack of morphological evidence of modulation in schistosomal pulmonary granulomas

Numerous pulmonary schistosome egg granulomas were present in mice submitted to partial portal vein ligation (Warren's model). The granulomas were characterized by cellular aggregations formed within alveolar tissue. Main cellular types were macrophages (epithelioid cells), eosinophils, plasma cells and lymphocytes. These cells were supported by scanty fibrous stroma and exhibited close membrane contact points amongst themselves, but without forming specialized adhesion apparatus. When granulomas involved arterial structures, proliferation of cndothelial and smooth muscle cells occurred and fibrosis associated with angiogenesis became more evident. Granulomas formed around mature eggs in the pulmonary alveolar tissue presented approximately the same size and morphology regardless of the time of infection, the latter being 10, 18 and 25 weeks after cercarial exposure. This persistence of morphological appearance suggests that pulmonary granulomas do not undergo immunological modulation, as is the case with the granulomas in the liver and, to a lesser extent, in the intestines. Probably, besides general immunological factors, local (stromal) factors play an important role in schistosomal granuloma modulation.

The perception, beliefs and practices toward genitourinary schistosomiasis by inhabitants of selected endemic areas (Edo/Delta States) in south-eastern Nigeria

Well-structured questionnaire on the perception, impression and response to genitourinary bilharziasis (Genitourinary schistosomiasis) was administered and explained in local languages: 'Igbo' 'Esan' 'Ezon' Itshekiri and Bini to 33815 inhabitants of selected endemic areas in south-eastern Nigeria from January, 1999 to December, 2001. Out of this number, 3815 (11.3%) were properly filled and returned. About 42.0% of the inhabitants admitted knowledge of the disease, while 14 (0.4%) knew about the aetiologic agent. About 181 (5.0%) who responded, admitted procuring treatment, while 100 (5.0%) declined to seek treatment of any sort. The relationships between water-bodies and human activities, and infection were well discussed. Amongst those who admitted knowledge of the disease but no knowledge of its etiologic agent, declined seeking treatment of any kind, but believe the disease is a natural phenomenon in ones developmental stage and therefore of no morbidity and mortality. Laboratory analysis of urine, faeces, semen and HVS was employed to assess questionnaire responses, and in some cases, physical examination was utilized to augment laboratory analysis in confirming urinal diagnosis. Haematuria was only directly related to egg count in the early part of life. Females were significantly haematuric and excreted more ova than males (p < 0.05). Headache (43.0%) and fever (31.0%) were major clinical signs while sexual pains (22.0%) were the least.

SEROPOSITIVITY FOR ASCARIOSIS AND TOXOCARIOSIS AND CYTOKINE EXPRESSION AMONG THE INDIGENOUS PEOPLE IN THE VENEZUELAN DELTA REGION

The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.

Schistosoma mansoni in mice: modulation of granulomatous response after reinfection and chemotherapeutic treatment

Mice previously infected with Schistosoma mansoni, and cured by specific treatment (400mg/kg oxamniquine, p. o.) in the chronic phase of the disease, were reinfected 20 days after treatment to assess their capacityfor modulation ofthe granulomatous response. Histopathologic examination of the animals ' liver, at 60 days after reinfection, evidenced the presence of typical granulomas of the chronic phase in most animals. This infer that the capacity for modulation of the granulomatous response had been maintained, thus preventing a new acute phase of the disease. Conversely, a group of previously infected mice, untreated and submitted to reinfection, showed reactivation of the granulomatous response in 50% of the animals. The possible implications of these findings in human schistosomiasis mansoni are discussed.

Hepatite Delta no Estado de Mato Grosso: apresentação de cinco casos

Cinco casos graves de infecção pelos vírus das hepatites B e D foram diagnosticados em jovens oriundos do norte do Mato Grosso, onde é comum a ocorrência de hepatite B, mas não de hepatite D. A proximidade com os Estados do Acre e do Amazonas e a migração interna podem explicar a introdução do vírus da hepatite D na região. Os autores salientam a necessidade de manter vigilância epidemiológica para casos de hepatite D na região.

Ocorrência da infecção pelo vírus da hepatite B (VHB) e delta (VHD) em sete grupos indígenas do Estado do Amazonas

A infecção pelo VHB e VHD são importantes problemas de saúde na Amazônia. Este estudo avalia a prevalência da infecção por esses agentes em sete grupos indígenas do Estado do Amazonas. A taxa de infecção passada pelo VHB encontrada foi de 54,5% e a de portadores do AgHBs de 9,7%. Observa-se variação importante destes marcadores entre as aldeias, inclusive da mesma etnia. Não evidenciamos marcador de infecção aguda, os quatro AgHBe reativos eram todos Apurinã, da mesma aldeia, e três da mesma família. O VHD foi encontrado em 13,4% dos AgHBs reativos. O padrão de infecção pelo VHB e VHD encontrado possui as seguintes características: endemicidade elevada, baixo potencial de infectividade, transmissão marcada em idade precoce, provável transmissão familiar, e pouca importância da transmissão vertical. Entretanto, também sugere que esses vírus não tenham sido ainda introduzidos efetivamente em algumas das etnias estudadas.

Autonomic Modulation of the Heart in Systemic Arterial Hypertension

OBJECTIVE: To analyze the heart rate variability in patients with mild to moderate systemic arterial hypertension. METHODS: Thirty-two healthy (group I) and 70 systemic arterial hypertensive (group II) individuals, divided according to age (40 to 59 and 60 to 80 years old, respectively) and with a similar distribution by sex were studied. Thirty-one had left ventricular hypertrophy (LVH), 22 were overweight, and 16 had Type II diabetes mellitus. Smoking, alcohol ingestion, and sedentary habits were the same between groups. Variability in heart rate was analyzed in the time domain, using standard deviations of normal RR intervals (SDNN) and the differences between maximal brady- and tachycardia (D-BTmax) during sustained inspiration. Analysis of the frequency band of the power spectrum between 0.05 and 0.40 Hz at rest and during controlled respiration was chosen for analysis of the frequency domain. RESULTS: In both time and frequency domains, variables were lower in group II than in group I. Within groups, statistically significant variables were only found for individuals in the 40 to 59 year old group. The presence of LVH, overweight, or diabetes mellitus did not influence the variability in heart rate to a significant extent. CONCLUSION: Variability in heart rate was a valuable instrument for analyzing autonomic modulation of the heart in arterial hypertension. The autonomic system undergoes significant losses in cardio-modulatory capacity, more evident in subjects between 40 and 59 years old. In those over 60 years old, reduced variability in heart rate imposed by aging was not significantly influenced by the presence of systemic arterial hypertension.