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Biomedical subjects

M Gentilini

Publications and source records attributed to M Gentilini.

At least 55 records · Page 3Linked to original sources

Association of lipid accumulation in small intestinal mucosa with decreased serum triglyceride and cholesterol levels in AIDS.

Lipid accumulation has been described in the duodenal lamina propria of human immunodeficiency virus (HIV)-infected patients with diarrhea and malabsorption. Using light and electron microscopy, we studied duodenal biopsies obtained from 54 consecutive HIV-infected patients by means of upper gastrointestinal endoscopy after an overnight fast. The presence of diarrhea and weight loss were recorded, and all the patients had standard stool study for ova, parasites, and bacteria. Serum levels of albumin, triglycerides, and cholesterol were obtained within one week of the endoscopy. Fecal fat and fecal alpha 1-antitrypsin clearance were measured in 11 patients. Lipid accumulation was observed in nine patients (16.6%). Fat droplets were seen in enterocytes, in their basolateral membrane spaces, and in the lamina propria. The mean serum levels of triglycerides (1.85 +/- 0.20 mmol/liter) and cholesterol (2.81 +/- 0.30 mmol/liter) were significantly lower in the patients with enteric steatosis than in patients without this anomaly (respectively, 3.38 +/- 0.39 and 3.97 +/- 0.18 mmol/liter, P < 0.001 P < 0.01). The mean amount of fecal fat in the three patients with lipid accumulation (16 +/- 1.60 g/24 hr) was significantly larger than in the eight patients without lipid accumulation (4.50 +/- 0.62 g/24 hr, P < 0.01). These findings suggest that fat malabsorption in HIV-infected individuals is due to a blockage of transport through the duodenal mucosa. The frequency of diarrhea, weight loss, or identified enteric pathogens did not differ significantly between patients with and without enteric steatosis. Both the etiology and the pathophysiology of these alterations remain to be documented.

Acquired Immunodeficiency Syndrome↗

Cytokines and T-cell response in malaria.

The intracellular protozoan Plasmodium sp induces a complex immune response which sometimes implies serious pathological effects for the host. According to in vitro studies and epidemiological surveys, several effector mechanisms are displayed against plasmodial blood stages and a large interaction between humoral and cell-mediated immunity is presumed to occur among protected individuals. The key role of T cells in the antiplasmodial immune response is now well established, but all the regulatory heterogenous mechanisms are not yet fully known. An increasing body of data shows a dual role during malaria attack for some cytokines released by monocytes and macrophages (TNF, IL-1, IL-6) or by T cells (IFN-gamma, lymphotoxin (LT), IL-4). The importance of some plasmodial proteins in the cytokine-induced pathology and the stimulation of a preferential TH1 or TH2 mediated immune response to achieve protective immunity against Plasmodium sp are discussed.

Animals↗

Effect of corticosteroids on the incidence of adverse cutaneous reactions to trimethoprim-sulfamethoxazole during treatment of AIDS-associated Pneumocystis carinii pneumonia.

We retrospectively studied all courses of treatment with trimethoprim-sulfamethoxazole (TMP-SMZ) alone and with adjuvant corticosteroids for AIDS-associated Pneumocystis carinii pneumonia. The corticosteroids were administered for 8-21 days (mean, 14 days) because of hypoxemia. We evaluated the influence of corticosteroids on the incidence of cutaneous adverse reactions to TMP-SMZ and on the course of AIDS during 3 months of follow-up. Of 38 patients treated with TMP-SMZ alone, 18 (47%) developed cutaneous side effects, whereas three (13%) of the 23 patients who received adjuvant corticosteroid therapy experienced such effects (P = .014). Of the 21 reactive patients, 14 were treated throughout the duration of hypersensitivity. Therapy was interrupted for seven patients (18%) treated with TMP-SMZ alone and for none of those who were given adjuvant corticosteroid therapy (P = .23). During follow-up, the incidence of mucocutaneous herpes simplex virus infection was higher among patients who received adjuvant corticosteroids than among those treated with TMP-SMZ alone (P = .005). Adjuvant corticosteroids thus reduce the incidence of adverse cutaneous reactions to TMP-SMZ in patients with AIDS who are treated for hypoxemic P. carinii pneumonia.

AIDS-Related Opportunistic Infections↗

Identification of a 94-kilodalton antigen on Leishmania promastigote forms and its specific recognition in human and canine visceral leishmaniasis.

We have analysed by immunoblotting sera from humans and dogs with visceral leishmaniasis, from the Old World as well as the New. When lysates of promastigotes are used as antigens, antibodies against a 94 kDa Leishmania component are detected, regardless of the age and geographical origin of the patient, the serum antibody titre as measured by indirect immunofluorescence, and the number of arcs in counterimmunoelectrophoresis. Low dilutions of sera from patients with Old and New World cutaneous leishmaniasis did not react with the 94-kDa antigen, whatever the species of Leishmania used as antigens. Sera from patients with other infections than leishmaniases, or without infection, are negative, even at low dilution. Anti-94 kDa antibodies were detected in the sera of Leishmania-infected dogs from both the Old and the New World. When lysates of Leishmania mexicana axenic amastigotes are used as antigens, the 94-kDa antigen was little or none identified by sera from humans and dogs with visceral leishmaniasis, and never recognized by control sera. Thus, the specific recognition of the 94-kDa promastigote antigen in human and canine visceral leishmaniasis suggests that this antigen could be a potential candidate in the differential immunodiagnosis of the disease.

Animals↗

[Cerebral lymphoma in AIDS: clinical study and clinicopathological correlations].

We report the natural history of 17 brain lymphomas (11 primary, 6 disseminated) from a post-mortem series of 130 patients with AIDS. Primary lymphomas appeared lately in the course of AIDS. They were often associated with a severe T-cell immunodepression and with more frequent opportunistic disorders than disseminated lymphomas. Associated Kaposi's sarcomas were surprisingly frequent. All patients presented with neurological manifestations. Heterogeneous features were seen at CT examination. The CSF was abnormal in 12/13 cases, with an increase of protein contents and secretion of immunoglobulins; it contained activated lymphocytes in 5/6 cases of disseminated lymphomas, and malignant cells in only one case. Cellular density never exceeded 8/mm3 for primary lymphomas, and the lymphocytes were considered normal. The pre-mortem diagnosis of cerebral lymphomas was made in five patients, with a time lapse of 1 to 7 months between the first neurological symptoms and death, and of 5 to 30 days between the diagnosis and death. Cerebral biopsy was diagnostic in 4 cases of primary cerebral lymphomas. In only 1/6 patients with disseminated lymphomas, the diagnosis had been made when the patient was still alive, based on CSF and bone marrow lymphomatous infiltrations. The diagnosis of cerebral lymphoma (7 primary, 5 disseminated) was post-mortem in 12 cases. It was made only at microscopic examination in 2/12 cases of primary lymphomas. The histopathological study frequently showed a multicentric involvement, and always an immunoblastic cell type with plasmablastic differentiation and frequent medium size cells. Marked gliosis and significant necrosis were often observed. Neuropathological lesions associated with HIV-1 infection (toxoplasmosis, CMV and HIV-1 encephalitis) were seen in 8 cases with primary lymphomas.

Adult↗

[Fixation and immunological reactivity of parasitic protozoa in sol-gel matrices].

Parasitic protozoa have been entrapped within sol-gel silica matrices. Stationary phase promastigote cells of Leishmania donovani infantum are mixed with a silicon alkoxide solution. They remain trapped within the growing oxide network formed upon hydrolysis and condensation of the alkoxide. Electron microscopy shows the preservation of the cellular organization and the integrity of the plasma membrane of entrapped parasites. Specific antigen-antibody reactions have been performed within the sol-gel matrix via enzyme-linked immunosorbent assays (ELISA) currently used for the diagnostic of visceral leishmaniasis. A clear-cut difference in optical density was measured between positive and negative sera from dogs. Entrapped protozoa antigens are still able to react with specific antibodies through the open porosity of the silica network. These results suggest that sol-gel matrices could be used for the development of immunodiagnostic assays requiring whole cell parasites as antigens.

Animals↗

Adverse cutaneous reactions to trimethoprim-sulfamethoxazole in patients with the acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia.

BACKGROUND AND DESIGN: Patients with the acquired immunodeficiency syndrome are predisposed to cutaneous drug reactions. The reasons are poorly understood and the circumstances in which such patients can be treated through hypersensitivity are a matter of discussion. We assessed the value of clinical and laboratory parameters for predicting trimethoprim-sulfamethoxazole-induced skin reactions and the effects of continued trimethoprim-sulfamethoxazole therapy in such patients. We retrospectively studied all episodes of nonhypoxemic Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome who were treated with trimethoprim-sulfamethoxazole. RESULTS: No clinical or laboratory parameters were found to be predictive of trimethoprim-sulfamethoxazole-induced cutaneous reactions. Of 38 patients treated with trimethoprim-sulfamethoxazole, 18 (47%) developed cutaneous reactions; these occurred within a median of 11 days (range, 7 to 20 days). Of these 18 patients, 12 (67%) continued to be treated with trimethoprim-sulfamethoxazole through hypersensitivity. Trimethoprim-sulfamethoxazole treatment was continued in 19 (95%) of the 20 patients who did not develop cutaneous reactions (P = .067). The mean duration of trimethoprim-sulfamethoxazole therapy was shorter (18 days) in patients who developed skin reactions than in those who did not (20 days) (P = .016). Noncutaneous side effects accounted for all but one interruption of therapy. CONCLUSION: No clinical or laboratory parameters were found to be predictive of cutaneous reactions. By treating through hypersensitivity, 67% of our patients, who otherwise might have had to stop taking trimethoprim-sulfamethoxazole, were able to continue this essential drug therapy.

AIDS-Related Opportunistic Infections↗

[Subacute Plasmodium falciparum malaria in 43 patients returning from areas with chloroquine in Africa].

PURPOSE: To identify clinical and biological features of subacute falciparum malaria, risk factors, and to evaluate the efficacy of curative treatment. PATIENTS AND METHODS: Diagnostic criteria were the association of apyrexia, anemia, little or no parasitemia and a high titer of anti-Plasmodium antibodies. Forty-three cases were observed in subjects returning from chloroquine-resistant areas in Africa. They were matched with controls for age, country of residence and duration of stay. Controls were missionaries who attended our unit for a routine medical check-up during the study period. RESULTS: The clinical presentation and biological features were similar to "malarial cachexia", a condition mainly described in non-immune children in endemic areas. Splenomegaly was present in 58% of the patients. Biological features included little or no parasitemia, an overall decrease in the blood cell count, an increased erythrocyte sedimentation rate and a high titer of anti-Plasmodium antibodies. This syndrome was not correlated with the frequency of chloroquine resistance, the area of stay (urban or rural) or to the kind of chemoprophylaxis. CONCLUSIONS: This study describes subacute resistant falciparum malaria in patients who had prolonged stay in chloroquine-resistant areas of Africa associating splenomegaly, cytopenia and a low or absent parasitemia. Subacute chloroquine-resistant malaria could be due to host factors which remained to be determined by prospective immunological studies. Curative treatment with mefloquine is effective.

Adult↗

[Cell-mediated immunity and protection against blood stages of Plasmodium falciparum].

In recent years, cell-mediated immunity against malaria has been the subject of intensive investigation either in humans from malaria endemic areas, or experimental models. Cellular immune mechanisms have been regarded as secondary to humoral immunity but, there is increasing evidence that shows its critical role in protection against blood stage plasmodium parasites. In the context of a large humoral-cellular interaction, T helper lymphocytes and monocytes/macrophages may play a key role in the elimination of plasmodial blood stages, particularly P. falciparum. IL-2, IL-4, IL-5, IFN-gamma cytokines secreted principally by CD4+ T lymphocytes and oxygen and nitrogen radicals produced by activated macrophages, are involved in the control of plasmodial infection. The spleen also plays a very important function in the anti-malarial protection by its increased capacity for filtration/destruction of parasitized red blood cells and by induction of B and T memory lymphocytes. Successful vaccination against malaria needs a choice of plasmodial antigens or B and T immunodominants epitopes able to stimulate plasmodium-specific lymphocytes and functional modification in the spleen.

Antibodies, Protozoan↗

[Symptoms and development of Schistosoma haematobium infestation seen in a metropolis].

Urogenital schistosomiasis is often diagnosed in France where, contrary to its severity, its initial presentation (mainly haematuria) has not changed. The frequency of major renal abnormalities seems to have diminished since 1965, but above all cystoscopy and intravenous urography have been superseded by ultrasonography, a totally harmless and painless method which provides the same information as that obtained with the previous two methods, except as regards the ureters. In particular, cystoscopy is now indicated only when tumours of the bladder are suspected at ultrasonography. Cutaneous schistosomiasis, with its characteristic features, deserves to be known and recognized.

Female↗