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Biomedical subjects

M A de Sousa

Publications and source records attributed to M A de Sousa.

At least 19 recordsLinked to original sources
PubMed1991

Acute respiratory viral infections in ambulatory children of urban northeast Brazil.

The morbidity of acute respiratory infections in young children and the role of respiratory viruses were evaluated in a 29-month household-based study in an impoverished urban population in Fortaleza, Brazil; subjects were 175 children less than 5 years of age in 63 families. Home visits were conducted three times weekly during which staff recorded the presence of respiratory and systemic symptoms and collected upper respiratory tract samples for viral isolation. A large and sustained burden of respiratory illness was observed, and respiratory viruses were isolated in 35% of the samples collected. Of the isolates, 45.6% were rhinoviruses, 16% parainfluenza viruses, 15.8% enteroviruses, 9.9% adenoviruses, 7.0% herpes simplex viruses, and 5.7% influenza viruses. The results indicate that poor children in northeast Brazil have a high prevalence of respiratory illness and that rhinovirus is the most frequent respiratory virus.

Acute Disease↗
PubMed1990

[Seroprevalence and risk factors for hepatitis B virus infection by AgHBs and anti-HBs markers in prisoners and prime blood donors].

Two cross-sectional surveys on hepatitis B virus (HBV) infection were carried out among 1,033 volunteer first-time blood donors in five blood banks (3 private, 2 public) and among 201 prisoners in the Penitentiary Center of Industrial Activity, in Goiania, Central Brazil, between June 1988 and February 1989. Those surveys were part of a major study designed to estimate seroprevalence of HBsAg and anti-HBsAg markers by ELISA test, and to study risk factors associated with seropositivity. The presence of any serum marker was considered as previous exposure to HBV. A standard questionnaire was applied to both populations to evaluate previous blood transfusion, number of sexual partners, homo/bisexual activity, history of sexually transmitted diseases, drug abusers, use of parenteral medicine, acupuncture, tattooing and VDRL seropositivity. Seroprevalence varied from 12.8% to 26.4% in blood donors and prisoners, respectively, (p less than 0.05) and increased with age (X2 trend=14.0 p less than 0.05%). Prisoners had higher percentages of all risk factors investigated than blood donors, with the exception of number of sexual partners. Among all risk factors studied, age, imprisonment and tattooing were statistically associated with seropositivity, even after multivariate analysis controlling for age and reclusion. The paper discusses the methodologic issues related to this epidemiologic investigation.

Adult↗
PubMed1983

Prospective study of diarrheal illnesses in northeastern Brazil: patterns of disease, nutritional impact, etiologies, and risk factors.

Diarrhea is a leading cause of death in tropical countries. One of the highest childhood mortalities is in northeastern Brazil, where little is known about the morbidity, etiology, and risk factors of diarrhea. Prospective village surveillance over 30 months revealed diarrhea attack rates of more than seven episodes per child-year at six to 11 months of age among the children of the poorest families. Other risk factors included early weaning and the lack of toilets. Diarrhea led to weight loss and stunted growth. Enterotoxigenic Escherichia coli and rotaviruses were the most common pathogens, accounting for 21% and 19% of cases, respectively, followed by Shigella species (8.0%), Campylobacter jejuni (7.5%), Giardia species (6.7%), Strongyloides species (5.3%), and enteropathogenic E coli serotypes (4.6%). Most (84%) enterotoxigenic E coli were isolated during the rainy season of October to March (P less than 0.03), whereas 71% of rotaviral illnesses occurred during the drier months of June to October (P less than 0.03). In the present study, the early occurrence and nutritional impact of diarrhea and weaning, as well as the major etiologic agents of diarrhea and their different seasonal patterns have been defined for this region in which life-threatening diarrhea is endemic.

Adolescent↗
PubMed1976

Microcirculation of the lymph node with metastases.

Microangiographic and histologic examination of the popliteal lymph node was performed on 49 rabbits 3 to 55 days after V2 tumor implantation into the hind paw. Control animals received subcutaneous tissue extract from normal rabbit donors. During the first 10 days after the tumor implant from an allogeneic animal donor, the draining lymph node exhibited a hypervascular response which after 2 weeks gradually subsided. Subsequently, during the early stages of lymph node metastasis there was still hypervascularity adjacent to the metastatic deposit. In about 4 weeks the metastases became more established and surrounded by layers of plasma cells. The hypervascular changes of the surrounding lymph node subsided by this time. In lymph node metastases the microvasculature could be an indicator of the immunologic activity of the host.

Angiography↗
PubMed1969

Induction and recall in contact sensivitity. Changes in skin and draining lymph nodes of intact and thymectomized mice.

The cellular events in the ear skin and draining lymph node during the induction of contact sensitivity to 2-ethoxy methylene-5-oxazolone (oxazolone) have been studied in three strains of mice. The principal findings in the skin during the first 24 hr were invasion of polymorphs and destruction of pilosebaceous units, in both intact and thymectomized mice. Subsequently, the dermal cellular infiltrate increased and there was acanthosis of the epidermis. No lymphocytes were seen in the dermis or penetrating the epidermal basal cell layer in thymectomized mice. During the first 24 hr in the draining node, polymorphs and macrophages bearing a pigment with staining properties similar to melanin were seen in the marginal and medullary sinuses, in intact and thymectomized mice. Major differences, however, were revealed during 2-4 days when massive proliferation of large pyroninophilic blast cells occurred in the thymus-dependent area of the nodes from intact mice only. On testing, there was a prompt, measurable increase in ear thickness only in intact mice. This increase reached a peak at 24 hr - typical of a delayed type reaction. At testing, the ears from intact mice showed epidermal vesiculation and a considerable dermal cellular infiltrate with a substantial number of lymphocytes. This was in contrast with the completely quiescent appearance of the ear skin of thymectomized mice. Finally, we have discussed the use of the mouse as an experimental tool for studying contact sensitivity and have analyzed the role of the thymus-derived lymphocyte and the site where it becomes sensitized, in the light of current theory on the origin of cells and site where sensitization takes place in cell-mediated reactions.

Animals↗
PubMedDate not supplied

[Seroprevalence and risk factors for syphilis in prisoners in Goiás, Brazil].

A cross-sectional survey was carried-out among 299 prisoners in the Penitentiary Center of Industrial Activity of Goiás (CEPAIGO), to determine the seroprevalence to T. pallidum and to identify risk factors associated to seropositivity. The seropositivity criterion was a positive VDRL test at any titer. A questionnaire was applied to evaluate the following risk factors: time of imprisonment, clinical evidence of sexually transmitted diseases (STD), history of syphilis or others STD, homo/bisexuality and number of sexual partners. The positive (PPV) and negative (NPV) predictive values of the history of syphilis were calculated. Seroprevalence of 18.4% was found and no difference was detected in the different age groups. The PPV of history of syphilis was 26% indicating that 74% of the individuals who have reported syphilis in the past presented a negative VDRL test. Among all the risk factors studied, homo/bisexuality was the only one with statistically significant association with seropositivity (relative risks 5.7-95% CL1.2-26, p = 0.03). The paper discusses the methodological problems related with the investigation.

Adolescent↗
PubMedDate not supplied

Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains.

Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones.

Animals↗