SUMMARY OF THESIS^*

CAVALHEIRO, Norma de Paula – Análise dos sorotipos do VHC identificados em pacientes da cidade de São Paulo, através de método imunoenzimático. São Paulo, 1999. (Dissertação de Mestrado - Faculdade de Medicina da Universidade de São Paulo).

ANALYSIS OF SEROTYPES OF HVC IN PATIENTS FROM THE CITY OF SÃO PAULO, BY MEANS OF A ENZYME-IMMUNOASSAY METHOD

With the objective of analyzing the prevalence of the different types of Hepatitis C Virus (HCV) in a population of chronic carriers of HCV, through a serologic method (MUREX HCV Serotyping Assay), 219 patients were studied who showed a positive polymerase chain reaction. This sera were submitted to immunoenzymatic tests for the detection of antibodies in relation to HCV types 1,2,3,4,5 and 6. The samples were diluted and incubated in the presence of heterologous competing peptides, with microwells coated with serotype-specific antigens of HCV. Of the 219 patients, it was possible to detect the HCV serotype in 166, revealing a sensitivity of 75.8%. The results showed a predominance of type 1 (70.0%) in our medium, followed by type 3 (22.3%) and type 2 (4.2%). Serotypes 4 and 5 were present in 1.8% of the patients, but always associated with serotype 1. These samples, in spite of fulfilling the prerequisites of validity for testing, showed a very high optical density reading for all types of viruses tested, including positive and negative controls. The possibility of cross reactions in these cases should be considered. Confirmation by genotyping and a more detailed investigation on the origin and mode of acquisition of the HCV of these patients should be researched. Type 6 was not confirmed in any of the samples tested and probably was not present in this particular collection. The epidemiological parameters evaluated were: age, sex and means of transmission. Of the 166 patients diagnosed with the HCV, 108 (65.1%) were men and 58 (34.9%) were women. The age of the patients varied from 12 to 73 years, the average being 41.1 years. The means of transmission mentioned were blood transfusion in 52 (31.3%) cases, intravenous drug use in 18 (10.8%) cases, by tattoos in 8 (4.8%) cases, 6 (3.6%) cases were sexually transmitted, 3 (1.8%) were by accident with a needle, 2 (1.2%) through work in the health field, one (0.6%) through acupuncture and one by being hemophiliac. Sixty one (36.7%) patients were not able to offer any risk factor which justified the acquisition of the HCV infection. No significant difference was verified among the different types of HCV found and the different epidemiological parameters studied. The predominance of types 1, 3 and 2 is compatible with other genotyping studies which involved Brazilian samples, particularly in the city of São Paulo. The samples which showed high or low dense optical reading for all the wells of the same samples tested even the positive or negative controls, suggested confirmation by sequencing or genotyping. The practicality obtained by the HCV serotyping test, in spite of the fact that it does not identify the sub type, can be useful in clinical practice and helpful in the prognostication of the disease, not needing the technology demanded by the tests which involve molecular biology.

NASCIMENTO, Maria Cláudia do – Estudo da prevalência de úlceras perianais em pacientes com AIDS e fatores associados. São Paulo, 1999. (Dissertação de Mestrado – Faculdade de Medicina da Universidade de São Paulo).

PERIANAL ULCERATED LESIONS IN AIDS PATIENTS: PREVALENCE AND ASSOCIATED FACTORS

Ulcerated perianal lesions are commonly observed in patients with AIDS, especially in advanced HIV disease. These lesions may continue to enlarge peripherally, causing pain and discomfort. Even though herpes simplex virus has been pointed out as the main etiologic agent, some other causes can be associated with perianal ulceration. There is a lack of information about risk factors associated with perianal ulcers in AIDS patients.

Mucocutaneous ulcers caused by herpes simplex virus are usually diagnosed by viral culture from a swab sample obtained from the lesion. Polymerase chain reaction has been used to diagnose genital herpetic ulcers and asymptomatic anogenital shedding detection of herpes simplex virus.

To estimate the association of ulcerated perianal ulcer with advanced HIV disease, 272 patients hospitalized at Instituto de Infectologia Emílio Ribas were included during 8 months. All of them were interviewed and had the perianal region examined in search of ulceration.

Perianal ulceration was found in 9.2% of patients. In multivariate analysis, the conditions significantly associated with the presence of perianal ulcer were: history of esophageal candidiasis and history of perianal ulcer. Herpes simplex virus was detected by polymerase chain reaction in 22/23 (95.6%) and by viral culture in 12/23 (52.2%) patients.

SZTAJNBOK, Sérgio – Impacto da qualidade de água na doença diarréica aguda em dois bairros do município de Taboão da Serra. São Paulo, 1999. (Dissertação de Mestrado – Faculdade de Medicina da Universidade de São Paulo).

IMPACT OF WATER QUALITY IN ACUTE DIARRHEA IN TWO DIFFERENT NEIGHBORHOODS IN THE MUNICIPALITY OF TABOÃO DA SERRA

Acute diarrhea (AD) is an important infant morbidity-mortality cause in developing countries. It is estimated that 1.3 billion annual episodes of diarrhea are observed in children younger than 5 years of age, and are the cause of 4 million deaths. In the last two decades, several studies have reported the relevance of social-economic and environmental factors in the genesis of AD. Unfortunately, despite the vast knowledge and governmental measures to assure acceptable basic sanitation conditions for the population, the problem has not been appropriately solved. This is observed in the municipality of Taboão da Serra, in the neighborhood of Sílvio Sampaio. Because it is far from downtown, is suffers from frequent supply pressures by SABESP, and is therefore known by the technical term of "end of net". This makes water supply intermittent and forces the population of the neighborhood to search for alternative water sources (wells and springs) every other day. To correlate water quality and frequency of Acute Diarrhea, AD cases seen throughout 1996 in two health centers in two different neighborhoods in Taboão da Serra were evaluated: Local Health Unit (LHU) Sílvio Sampaio, located in the neighborhood of Sílvio Sampaio, the previously mentioned "end of net" neighborhood and LHU Taboão da Serra, located in the a downtown neighborhood which is not affected by intermittent supply. The number of patients seen for AD in LHU Sílvio Sampaio was four times greater, a statistically significant difference (p<0,001). In addition, the water quality of the alternative sources used by the Sílvio Sampaio population was evaluated (7 samples from wells and springs), by microbiologic evaluation carried out by CETESB, according to the rules established by the Health Ministry. Of the seven samples, only one was considered potable for human consumption, however the amount of heterotrophic bacteria in this sample was within the upper normal range established by the above mentioned rules. To evaluate other relevant factors in the genesis of acute diarrhea according to literature, the social-economic profile of the studied populations was established and a statistical difference was observed in some parameters: the numbers of rooms in the downtown households was greater in the Sílvio Sampaio neighborhood; the number of individuals per room was greater in the Sílvio Sampaio neighborhood; per capita income in the downtown neighborhood was approximately 70% greater than in the Sílvio Sampaio neighborhood, the parents of the children in the downtown neighborhood had a higher education level than those in the Sílvio Sampaio neighborhood and finally, the number of homes provided with a sewage system was significantly higher in the downtown neighborhood. Therefore, it was concluded that the data above does not allow a correlation of water quality alone with the higher number of AD observed in the Sílvio Sampaio neighborhood, once other environmental and classical AD-related factors had a statistically significant difference as well. However, the influence of water quality in the genesis of acute diarrhea is clear, and supports the need of Public Health interventions to improve water supply in the neighborhood and stimulate educational programs, showing the population the risks related to the use of alternative sources.

CARDOSO, André Gustavo Tempone – Ação do veneno de Bothrops moojeni e sua fração L-aminoácido oxidase, submetida ao tratamento com raios gama de ⁶⁰CO, em Leishmania spp. São Paulo, 1999. (Dissertação de Mestrado – Instituto de Pesquisas Energéticas e Nucleares da Universidade de São Paulo).

ACTION OF Bothrops moojeni VENOM D ITS L-AMINO ACID OXIDADE FRACTION, TREATED WITH ⁶⁰ CO GAMMA RAYS, IN Leishmania spp.

Bothrops moojeni venom showed an antileishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with antileishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homodimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L.(L). amazonensis of 1.80 mg/ml (EC₅₀), L.(V.) panamensis (0.78 mg/ml) and L.(L.) chagasi (0.63 mg/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC₅₀ of 11mg/ml. Irradiation of LAO with ⁶⁰Co gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC₅₀ of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis.

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This thesis is available at the Library of the Instituto de Medicina Tropical de São Paulo

Publication Dates

• Publication in this collection
  29 Mar 2000
• Date of issue
  Feb 2000