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C L da Silva

Publications and source records attributed to C L da Silva.

12 recordsLinked to original sources
PubMed2001

The molluscicidal activity of the latex of Euphorbia splendens var. hislopii on Melanoides tuberculata (Thiaridae), a snail associated with habitats of Biomphalaria glabrata (Planorbidae).

The use of the latex of Euphorbia splendens var. hislopii was considered as an effective control method for Biomphalaria glabrata in Sumidouro, Rio de Janeiro. However, the appearance and expansion of the snail Melanoides tuberculata since August 1997, with the concomitant reduction of the population of B. glabrata suggest that competitive exclusion might be taking place. Depending on the susceptibility of the thiarid to the E. splendens toxin, the natural control that is occurring could be interrupted by the employment of the latex if the planorbid were less susceptible to the toxin. The aim of this study is to investigate the molluscicidal activity of the latex on M. tuberculata. We used 420 M. tuberculata, from Sumidouro. Fourteen different latex concentrations were tested using World Health Organization general methodology. Probit analysis was used for LD90 and LD50 determination. The LD50 was 3.57 mg/l and LD90 was 6.22 mg/l. At the highest concentration (10 mg/l) there was no survival. No significant differences among replicas (chi2 = 8.31; gl = 13; p > 0.05) were found. The LD90 dose for M. tuberculata was 13.8 times greater than that for B. glabrata, so that the molluscicide in the presence of the thiarid may have a synergic effect on reduction of Biomphalaria populations.

Animals↗
PubMed2001

Cluster of Candida parapsilosis primary bloodstream infection in a neonatal intensive care unit.

Candida parapsilosis is an increasingly important bloodstream pathogen in neonatal intensive care units (NICU). We investigated a cluster of bloodstream infections in a NICU to determine whether nosocomial transmission occurred. During a 3-day period, 3 premature infants hospitalized in the same unit presented with sepsis caused by C. parapsilosis. Electrophoretic karyotype of the organisms was performed by using pulsed field gel electrophoresis in a countour-clamped homogeneous electric field system. The isolate from 1 newborn could not be typed, and the isolates from the remaining 2 infants had identical patterns. All 3 cases are described. We conclude that nosocomial transmission of C. parapsilosis occurred and that neonates under intensive care may represent a risk group for this pathogen.

Amphotericin B↗
PubMed2000

Determination of Cu, Pb, Cd, and Zn in river sediment extracts by sequential injection anodic stripping voltammetry with thin mercury film electrode.

Determination of Cu, Pb, Cd and Zn was performed in sediment extracts obtained according to the three steps sequential extraction procedure proposed by the European Community Standards, Measurements and Testing Program. The metal content was determined by anodic stripping voltammetry with a thin mercury film electrode controlled by a sequential injection (SIA) system. The proposed method improved the reproducibility of conventional anodic stripping voltammetry, as well as the sample throughput, allowing analysis of 30 to 45 samples per hour. The influence of flow rate and sample volume was studied to achieve an adequate sensitivity for the leachate studied. No interferences due to adsorption of organic matter, colloids, or complexes with slow rate of dissociation were observed. The intermetallic formation of Cu-Zn was avoided by forming the mercury film in presence of Ga(III) ions in the SIA system, resulting in low consumption of reagent in comparison to flow injection or continuous flow systems. Results were in good agreement with those obtained by Induced Coupled Plasma - Atomic Emission Spectroscopy (ICP-AES).

Brazil↗
PubMed1998

[Nongovernmental organizations and AIDS, social intervention, and new ties in social solidarity].

Starting with a brief contextual analysis of the social scenario in which the AIDS epidemic is occurring in Brazil, the article focuses on the formation of the country's first nongovernmental organizations in the struggle against AIDS. There are peculiarities to AIDS NGOs to the extent that they display an ambivalence between the characteristics of a professional institution and a lobbying group, apart from the fact that dealing with sexuality and death breaks down the line between the public and the private spheres. The case in point is the Grupo Pela Vidda (For Life Group) in Rio de Janeiro, which seeks to represent the enhancement of a group of individuals and the principle of universality. The study supports the hypothesis that AIDS NGOs renew ties of social solidarity through the relationships established between various researchers involved in this sector and other NGOs with governmental spheres.

Acquired Immunodeficiency Syndrome↗
PubMed1997

[Neuro-AIDS].

The human immunodeficiency virus (HIV) type 1 is the retrovirus which is responsible for the human immunodeficiency syndrome (AIDS) described in infancy in 1983. It is the most serious disorder caused by HIV, by a neurotropic virus, and is particularly severe in infancy. In children infected by vertical transmission of HIV, there is a shorter clinical latent period than in adults, and more viraemia than in children over the age of three months infected by blood transfusion. The neurological disorder caused by HIV is a complex clinical syndrome in which there may be varying degrees of retardation of cognition, movement or behaviour. A growing number of HIV+ children are being followed-up in the Hospital de Clinicas de Porto Alegre (HCPA) to treat the neuropsychomotor development and the presence of neurological behaviour in these children. The neurological, analytical (laboratory), electro-encephalographic and tomographic changes seen in a sample of 344 HIV+ children were studied. Analysis of these results showed a significant difference between affected and non-affected children. Encephalopathy occurred in 36% of the cases, being progressive in 29% and static in 17%. There was a relationship between neurological involvement at the first consultation and progress to encephalopathy. The RDNPM showed a tendency towards encephalopathy, usually between 1 and 5 years of age, which might also be the first sign of the disease. We found a significant relationship between being infected and having alterations not seen in cerebrospinal fluid, EEG, TCC and neurological progress.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Schistosomiasis in a low prevalence area: incomplete urbanization increasing risk of infection in Paracambi, RJ, Brazil.

The risk of schistosomiasis infection and heavy infection in the locality of Sabugo was evaluated in relation to housing in areas with different urbanization development and to residential supply with snail-infested water. Critical sanitary conditions were found in areas of incomplete urbanization, where healthy water supply sources were scarce, and draining of sewage, without previous treatment, was made directly to the water-bodies used for domestic and leisure activities, despite being Biomphalaria tenagophila snail breeding-places. Stool examinations (Kato-Katz and Lutz methods) showed prevalence of 2.9% mean intensity of 79 eggs per gram of stool and 47% of positive cases presenting intense infection. The use of snail-contaminated water for domestic purposes was considered a risk factor for infection. It is concluded that incomplete urbanization would facilitate transmission, probably enhancing the intensity of infection and that a low prevalence could hide a highly focal transmission. The relevance of these facts upon the efficiency of epidemiologic study methods and disease control planning are then discussed.

Animals↗
PubMedDate not supplied

[AIDS in childhood: basic guidance for attending].

The pandemic expansion of AIDS demands that all health care staff and institutions are prepared to diagnose and control this disease. The HIV virus destroys the immune response and causes a series of other organ and system dysfunctions, leading to diverse clinical manifestations. This article reviews the pathophysiology, clinical manifestations, diagnosis, treatment and prevention of HIV infection. The role of the health care worker as an educator is also reviewed.

English Abstract↗