A large number of data show that melatonin has immunomodulatory properties and is produced by immunocompetent cells; also, some evidence suggests a 'feedback' of the activated immune system on the pineal gland. In this paper, we studied immune-pineal interactions in colostrum obtained from healthy puerperae and mothers with mastitis taking into account that, (a) melatonin levels in milk reflects pineal activity and (b) colostrum quiescent mononuclear and polymorphonuclear phagocytes from healthy mothers in culture are adequate for evaluating the ability of immunocompetent cells to produce melatonin. Here we compared the diurnal and nocturnal melatonin levels in colostrum from healthy puerperae and mothers with mastitis; this is a unique noninvasive model for determining pineal activity in the proinflammatory phase of a defense response. In addition, we determined the 'in vitro' production of melatonin by colostrum immunocompetent cells stimulated by enteropathogenic Escherichia coli or zymosan. Suppression of nocturnal melatonin rise in mothers with mastitis was highly correlated with increased tumor necrosis factor-alpha (TNF-alpha) secretion. This result, interpreted taking into account the presence of the transcription factor nuclear factor kappa B in pineal gland, suggest that the proinflammatory cytokine can inhibit nocturnal pineal melatonin production. On the other hand, stimulated, but not quiescent, immunocompetent cells secreted in the colostrum produced melatonin in vitro. In addition, this production ceases after bacteria killing. These results suggest that during the response to an injury the production of melatonin can be transiently shifted from an endocrine (pineal) to a paracrine (immunocompetent cells) source.

In order to obtain accurate diagnosis and treatment, especially regarding health services of areas with low-incidence of visceral leishmaniasis, the diagnosis of patients with fever and visceromegaly, who come from endemic areas, should include visceral leishmaniasis.

Medium-chain triglyceride (MCT) and long-chain triglyceride (LCT) emulsions currently used in nutritional therapy were evaluated for their in vitro effect on neutrophil oxidative metabolism, phagocytosis, and bacterial killing activities. Neutrophils from healthy adult male volunteers were assessed after blood incubation with commercially available fat emulsions containing LCT, MCT, or a mixture of 50% MCT and 50% LCT at a final triglyceride concentration of 20 mg/ml. It was observed that MCT-containing emulsions stimulated nitroblue tetrazolium (NBT) dye reduction by neutrophils as determined by a cytochemical NBT test performed directly on whole blood. This effect was dose dependent. However, after lipid removal by cell washing, the MCT-treated neutrophils showed decreased production of hydrogen peroxide (H2O2) and NBT reduction in response to bacterial lipopolysaccharide or phorbol myristate acetate stimuli as well as impaired phagocytosis and killing of Staphylococcus aureus. In contrast, the LCT emulsion did not alter any of the neutrophil functions evaluated. The present data suggest that MCTs elicit the oxidative metabolism of neutrophils, probably by phagocytosis of fat particles and, depending on the lipid concentration, this effect may not be reversible, leading to impairment of the cellular response to subsequent membrane stimuli.

Objective: to compare the clinical and laboratorial data before and after the treatment of patients with visceral leishmaniasis admitted to a pediatric hospital in a nonendemic area, highlighting the importance of recognizing visceral leishmaniasis in pediatric patients.Methods: clinical, laboratorial and treatment data of 78 patients with visceral leishmaniasis were evaluated from 1981 to 1992. We analyzed the average level of hemoglobin, leukocyte, neutrophil, platelet, albumin, gammaglobulin, class and subclass of immunoglobulin, size of the liver and spleen during the pre-and posttreatment using the paired t test.Results: we included 78 patients with visceral leishmaniasis, 44 males, with age ranging from 8 months to 13.5 years. Sixty-one patients were from Bahia. Fever and splenomegaly were present in 96.1% and 100% of the cases, respectively. The parasitological diagnosis was obtained in 74/78 patients: 67 patients through smear and/or culture of bone marrow (85.7%), five through liver biopsy and two through spleen puncture. The hematological findings and serum albumin presented significant improvement at the end of treatment (P<0.001), differently from serum gammaglobulin levels (P=0.087). There was predominance of IgG1 subclass, with two patients presenting low levels of IgG2. Initial treatment used antimoniate in 67 cases and amphotericin B in five. Eleven patients (15.7%) needed a second treatment, and were considered cured after it. There was significant improvement in the liver and spleen size at the end of the treatment (P<0.001). One patient presented spontaneous remission and five died due to bleeding.Conclusions: in order to obtain accurate diagnosis and treatment, especially regarding health services of areas with low-incidence of visceral leishmaniasis, the diagnosis of patients with fever and visceromegaly, who come from endemic areas, should include visceral leishmaniasis.J Pediatr (Rio J) 2002; 78 (2): 120-7: visceral leishmaniasis, kala-azar, infancy, diagnosis, treatment. ResumoObjetivo: comparar os dados clínicos e laboratoriais no pré e pós-tratamento de pacientes portadores de leishmaniose visceral (LV), admitidos em hospital pediátrico localizado em área não-endêmica, destacando a importância do reconhecimento da LV na faixa etária pediátrica.Métodos: avaliação dos dados clínicos, laboratoriais e de tratamento de pacientes portadores de LV no período compreendido entre 1981 e 1992, comparando-se os valores médios de hemoglobina, leucócitos, neutrófilos, plaquetas, albumina, gamaglobulina, classes e subclasses de imunoglobulinas, tamanho do fígado e baço antes e após o tratamento, utilizando-se o teste "t" para amostras pareadas.Resultados: foram incluídos 78 pacientes, com idade variando entre 8 meses e 13,5 anos, sendo 44 casos do sexo masculino e 61 provenientes da Bahia. Febre e esplenomegalia estavam presentes em 96,1% e 100% dos casos, respectivamente. O diagnóstico parasitológico foi obtido em 74/78 pacientes, com positividade pelo mielograma e/ou mielocultura em 67 casos...

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X-CGD patients from Latin America showed a high degree of molecular heterogeneity, including two novel mutations. Their clinical characteristics included early onset of infections and eventual obstructive granulomas. A47-CGD represented 50% of the reported cases, a higher prevalence than reported in other series.

The aim of this study was to investigate the effect of recombinant human interferon-gamma (rHuIFN-gamma) therapy on the release of nitric oxide (NO) by neutrophils (NEU) and mononuclear cells (MON) from patients with chronic granulomatous disease (CGD). Five patients with this rare disease received rHuIFN-gamma (50 micrograms/m2 of body surface, given by subcutaneous injection three times a week) for 6 months. Clinical and laboratory evaluations were performed before and after 1 and 6 months of rHuIFN-gamma therapy. Nitric oxide release by NEU and MON was assessed by the ability of these cells to inhibit thrombin-induced washed platelet aggregation. The nitrite (NO2-) and nitrate (NO3-) levels in the supernatant of cultured NEU and MON, as well as in plasma and urine (24 h diuresis), were quantified by high-performance liquid chromatography (HPLC). Conventional immunologic tests for assessing phagocyte and lymphocyte functions and humoral immunity were also performed. Therapy with rHuIFN-gamma for 6 months did not enhance NO synthesis by NEU or MON from the patients with CGD. The urinary but not plasma levels of NO2- and NO3- were elevated after rHuIFN-gamma therapy. Phagocyte and lymphocyte functions as well as humoral immunity were not affected by rHuIFN-gamma therapy. Although few patients were available for the study, we conclude that therapy with rHuIFN-gamma for 6 months did not enhance the synthesis of NO by NEU and MON in CGD patients. Whether the increased excretion of NO2- and NO3- in the urine of CGD patients after rHUIFN-gamma therapy reflects an induction of NO-synthase in cells other than leukocytes remains to be investigated.

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