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Biomedical subjects

E A Ramos

Publications and source records attributed to E A Ramos.

10 recordsLinked to original sources
PubMed1996

Association of hepatosplenic schistosomiasis with HLA-DQB1*0201.

Major histocompatibility class II alleles of 351 persons living in an area endemic for Schistosoma mansoni in northeastern Brazil were characterized at three loci (DRB1, DQA1, and DQB1). Contingency analyses were used to compare allele frequencies with high egg excretion, proliferative response to schistosome soluble egg antigens (SEA), and occurrence of severe, biopsy-confirmed hepatosplenic disease. There were no associations of HLA-DR or DQ with egg excretion. Patients positive for DRB1*01, DQA1*0101, or DQB1*0501 were less likely to respond to SEA than was the overall study population. However, using stringent Bonferroni correction (multiplying P values by the number of alleles tested; P x 35), none of these associations with SEA responsiveness remained significant. Hepatosplenic disease was less likely in patients positive for DRB1*11 and was more likely in patients positive for DRB1*07 or DQB1*0201. However, only the DQB1*0201 association remained significant (odds ratio = 3.72; P < .005) following Bonferroni correction.

Adolescent↗
PubMed1994

Soluble intercellular adhesion molecules in human schistosomiasis: correlations with disease severity and decreased responsiveness to egg antigens.

Granuloma formation, the principal pathologic consequence of infection with Schistosoma mansoni, is a complex process involving intricate cell-cell interactions in which intercellular adhesion molecules are likely to participate. To examine this possibility, sera of schistosomiasis patients in various clinical groups were assayed for the presence of soluble intercellular adhesion molecule 1 (sICAM-1) and soluble E-selectin (sE-selectin). Comparisons were made between groups with different infection intensities (as predicted by fecal egg count) as well as between groups with severe (hepatosplenic) or milder (intestinal) pathology. All groups had elevated levels of sICAM-1 compared with controls. Also, patients in the high egg-excreting and hepatosplenic groups had significantly higher levels of serum sICAM-1 than patients in the low-egg-excreting and intestinal groups, respectively. The levels of sE-selectin were significantly elevated in the sera of all patients except those in the hepatosplenic group compared with controls. Patients in the intestinal group had significantly higher levels of sE-selectin in their sera than did hepatosplenic group patients, but serum sE-selectin levels of high- and low-egg-excreting patients were comparable. A striking finding of this study was the inverse correlation observed between sICAM-1 levels and peripheral blood mononuclear cell responses to schistosome soluble egg antigens (SEA) but not with responses to other schistosome antigens, purified protein derivative, or mitogen. Because ICAM-1 can perform a costimulatory function in antigen-presenting cell-T cell interactions, it is possible that shedding of ICAM-1 in the granuloma microenvironment interrupts proper costimulation, leading to unresponsive SEA-specific T cells. In this way, sICAM-1 could be one factor contributing to the observed modulation of cellular responses to SEA in chronic human schistosomiasis.

Adolescent↗
PubMed1994

Failure of schistosomiasis to significantly decrease testosterone levels in Brazilian men.

Schistosomes can decrease the reproductive potential or castrate both invertebrate (snail) hosts as well as vertebrate (mouse, rat, and hamster) hosts. To determine if host castration occurs in human males, we examined testosterone levels in the sera of 38 Brazilian males, 16-35 years of age, who had Schistosoma mansoni infections. We found that individuals with intestinal schistosomiasis exhibited serum testosterone levels similar to those of noninfected controls. Four subjects with severe hepatosplenic disease also exhibited testosterone levels within the normal range. We did observe a negative correlation between parasite load (as predicted by fecal egg count) and testosterone levels but could not dissociate this relationship from the effect of age on either parameter. Therefore, in contrast to rodent models, host castration does not appear to be a usual side effect of human schistosomiasis.

Adolescent↗
PubMed1980

Glucagon kinetics in fasting: physiological elevations in serum 3,5,3'-triiodothyronine increase the metabolic clearance rate of glucagon.

We have attempted to determine if the elevated plasma glucagon concentration and delayed MCR of glucagon (MCRg) observed during caloric restriction are related to the decreased serum T3 that also occurs during fasting. Twelve obese subjects received a 3-h iv glucagon infusion during a 4-day fed period (1000 kCal/day) and again on approximately the third fasting day. Five patients fasted without receiving exogenous T3 (control group), whereas seven subjects fasted but also received 5 micrograms T3 orally every 4 h (T3 group) to maintain approximately the same serum T3 levels in the fed and fasting periods. Glucagon production rates (GPR) were derived by multiplying the MCRg by the respective basal plasma glucogon concentrations. In the control group, the MCRg was 442 +/- 55 ml/m2 . min in the postabsorptive state and decreased to 312 +/- 49 ml/m2 . min (P < 0.025) during fasting, whereas in the T3-treated group, the postabsorptive MCRg was 304 +/- 22 ml/m2 . min and increased during fasting to 417 +/- 47 ml/m2 . min (P < 0.025). The GPRs in the control group were statistically unaltered between the fed (27.7 +/- 3.0 ng/m2 . min) and fasted (22.9 +/- 1.8 ng/m2 . min) intervals, but GPR increased from 37.9 +/- 6.1 ng/m2 . min during fasting to 49.2 +/- 9.1 ng/m2 . min when T3 was administered (5 micrograms every 4 h). The net plasma glucose increment in response to glucagon decreased from 18 mg/dl (fed) to 5 mg/dl (fast) in the control patients and from 10 mg/dl (fed) to 7 mg/dl (fast) in the T3-treated subjects. In the T3-treated patients, serum T3 averaged 124 ng/dl during both feeding and fasting, and rT3 was 55 +/- 6 ng/dl during feeding and 49 +/- 5 ng/dl during fasting. In summary, the results from this study indicate that during fasting 1) slight physiological alterations in serum T3 influence the MCRg, and 2) T3 increases the GPR and blocks the customary fasting-induced rise in rT3. Conceivably, decreased T3 is an early event in the fasting state which serves to decrease the MCRg, a process which subsequently regulates glucose homeostasis.

Adult↗
PubMed1979

[Anatomo-pathological study of the brain in idiopathic cardiomegaly].

The pathological findings in the brain of patients who died with idiopathic cardiomegaly are reported. The major findings in the 38 studied cases were cerebral infarcts (10,5%) and cerebral atrophy (7,9%) besides the nonspecific histological changes represented by neuronal ischemic alteration, satellitosis of nerve cells and swollen and hyperplasia of endothelial cells in capilaries of the cerebral cortex. These findings were considered a consequence of the venous stasis of the congestive heart failure. These data were compared to those seen in the brain of patients with heart failure in the course of chronic Chagas disease. The morphological findings were similar. The frequence of infarcts and atrophy was higher in the cases of Chagas disease and the cerebral atrophy was seen in an younger group of patients compared to the cases of idiopathic cardiomegaly. It seems that there is another factor also responsible for the occurrence of cerebral atrophy in Chagas disease, since from the clinical and hemodynamic point of view both cardiopathies have many similarities.

Adult↗
PubMed1979

A new form of abdominal zygomycosis different from mucormycosis: report of two cases and review of the literature.

Two cases of abdominal zygomycosis occurring in apparently healthy individuals are presented. They had chronic evolution and histologic aspects similar to those found in subcutaneous zygomycosis. In both cases there was involvement of stomach and transverse colon. In one case the liver, biliary system, pancreas, and duodenum were also involved. Fungal cultures were negative. These cases apparently represent a new form of zygomycosis because, although visceral in localization, the disease presents an evolution and histologic features different from the classical form of visceral zygomycosis. Since this infection can be treated the importance of early diagnosis is stressed.

Abdomen↗