Triagem de hemoglobinopatias e avaliação da degeneração oxidativa da hemoglobina em trabalhadores portadores do traço falciforme (HbAS), expostos a riscos ocupacionais / Screening of abnormal hemoglobin and the evaluation of oxidative degeneration of hemoglobin among workers with the sickle cell trait (HbAS), exposed to occupational hazards

Desde os anos 40, quando foram realizados os primeiros trabalhos de triagem para hemoglobinas anormais na população brasileira, tem sido descrita uma elevada prevalência destas em nosso meio, especialmente a hemoglobina S que, a despeito da heterogeneidade de sua distribuição geográfica, quase sempre é a mais freqüente nas diversas regiões estudadas. Aliado a este fato, estudos recentes têm demonstrado uma maior susceptibilidade desta a oxidação, tornando-a mais sensível ao estresse oxidativo que a hemoglobina normal (HbAA), mesmo em se tratando de portadores heterozigotos (HbAS). Tendo em vista que algumas substâncias químicas são comprovadamente meta-hemoglobinizantes, que alguns fatores ambientais podem influenciar na morbidade da anemia falciforme e também o pouco e controverso conhecimento de que se dispõe a respeito de portadores do traço falciforme, este estudo, além da pesquisa de hemo-globinas anormais, avaliou também a degeneração oxidativa da hemoglobina, através da pesquisa de corpos de Heinz e dosagem de meta-hemoglobina em uma população de trabalhadores portadores do traço falciforme, expostos a riscos ocupacionais. Foram triadas 2.190 amostras sangüíneas entre Outubro de 1999 e Dezembro de 2001. A população estudada foi constituída de trabalhadores de ambos os sexos com idades variando entre 18 e 76 anos. Os resultados evidenciaram 4,7 por cento portadores de hemoglobinas anormais na população analisada, sendo que a hemoglobina S foi a mais freqüente - 3,2 por cento (71). Trabalhadores portadores do traço falciforme apresentaram uma chance 14 vezes maior de possuírem valores aumentados de meta-hemoglobina em relação aos trabalhadores com genótipo AA, porém, esta diferença não foi estatisticamente significativa.

Hemoglobinopathies are frequent hereditary diseases in Brazilian population and have been a public health problem. This study reports the screening of abnormal hemoglobin among Fiocruz`s employees, as well as the impact of exposure to some factors such as, chemical substances, radiation, excessive cold or heat in sickle cell trait carriers. This impact has been analyzed by measuring methehemoglobin level and the presence of Heinz bodies. The samples were obtained from 2190 (4,7 percent) individuals presented abnormal hemoglobin. Hemoglobin S was found in 72,3 percent of individuals with abnormal hemoglobin constituting the most prevalent. The results distribution were: sickle cell trait in 3,2 percent and associated with thalassemia in 0,2 percent; thalassemia in 0,7 percent; AC hemoglobin in 0,4 percent; thalassemia minor in 0,3 percent and finally SS and D hemoglobin in 0,05 percent. Sickle cell trait carriers employees had a 14 times higher risk of increased methehemoglobin increase levels.

Trypanosoma cruzi: susceptibility to chemotherapy with benznidazole of clones isolated from the highly resistant Colombian strain

The present investigation was performed to evaluate the susceptibility of seven clones isolated from the highly resistant Colombian strains, prototype of Biodeme Type III. Seven clones previously obtained, showed a phenotypic homogeneity and high similarity with the parental strain. Eight groups of 30 mice were inoculated with one of seven clones or the parental strain; 20 were treated with benznidazole (100mg/kg/day) and 10 were untreated controls. Cure evaluations were done by parasitological and serological tests and PCR. Cure rates varied from 0 percent (null) to 16.7 percent. Correlation between positivity of parasitological and serological tests with positive PCR reached 37 percent. The results demonstrated the high resistance of the clones, suggesting the predominance of a highly resistant principal clone in this strain. The findings apparently indicate that the possibility of cure is minimal for patients infected with this biodeme; a fact that could affect the control of Chagas' disease through treatment of chronically infected people

Hemoglobinopatias em trabalhadores expostos à riscos ocupacionais / Hemoglobinopathies in workers exposed to occupational hazards

Hemoglobinopathies have been considered the most frequent hereditary disease in Brazilian population, constituting a Public Health problem. This paper reports on screening in workers at FIOCRUZ-RJ., exposed to some hazards factors such as, chemical substances, radiation, excessive cold and heat etc., with the objective of evaluating the impact of these factors in carriers of hemoglobinopathies, mainly in sickle cell trait (AS).

Comparative analysis by polymerase chain reaction amplified minicircles of kinetiplast DNA of a stable strain of Trypanosoma cruzi from Säo Felipe, Bahia, its clones and subclones: possibility of predominance of a principal clone in this area

Molecular characterization of one stable strain of Trypanosoma cruzi, the 21 SF, representative of the pattern of strains isolated from the endemic area of Säo Felipe, State of Bahia, Brazil, maintained for 15 years in laboratory by serial passages in mice and classified as biodeme Type II and zymodene 2 has been investigated. The kinetoplast DNA (kDNA) of parental strain, 5 clones and 14 subclones were analyzed. Schizodeme was established by comparative study of the fragments obtained from digestion of the 330-bp fragments amplified by polymerase chain reation (PCR) from the variable regions of the minicicles, and digested by restriction endonucleases Rsa I and Hinf I. Our results show a high percentual of similarity between the restriction fragment lenght plymorphism (RFLP) for the parental strain and its clones and among these individual clones and their subclones at a level of 80 to 100 per cent. This homology indicates a predominance of the same "principal clone" in the 21SF strain and confirms the homogeneity previously observed at biological and isozymic analysis. These results suggest the possibility that the T. cruzi strains with similar biological and isoenzymic patterns, circulating in this endemic area, are representative of one dominant clone.