Estudo das relações anatômicas e suas variações entre o nervo ciático e o músculo piriforme / Study on anatomical relationships and variations between the sciatic nerve and piriform muscle

CONTEXTO: A síndrome do músculo piriforme pode ter como causa a passagem anormal do nervo ciático ou de uma de suas partes pelo ventre do músculo piriforme. OBJETIVO: Analisar as relações anatômicas e métricas entre o músculo piriforme e o nervo ciático, contribuindo com o conhecimento anátomo-clínico da região glútea. MÉTODO: Foram utilizados 20 cadáveres adultos de ambos os sexos. O nervo ciático e o músculo piriforme foram dissecados, medidos e fotodocumentados. RESULTADOS: Observou-se que 85 por cento das 40 regiões glúteas apresentaram o nervo como tronco único, passando pela borda inferior do músculo piriforme, e 15 por cento mostraram uma variação bilateral, caracterizada pela passagem do nervo fibular comum através do músculo piriforme. Os dados obtidos não revelaram diferenças estatisticamente significantes.

CONTEXT: Piriform muscle syndrome can be caused by abnormal passage of the sciatic nerve or one of its parts through the belly of the piriform muscle. OBJECTIVE: To analyze the anatomical and measurement relationships between the piriform muscle and the sciatic nerve in order to contribute towards better anatomoclinical understanding of the gluteal region. METHOD: Twenty adult cadavers of both sexes were used. The sciatic nerve and piriform muscle were dissected, measured and photodocumented. RESULTS: The sciatic nerve was seen to be a single trunk passing through the lower margin of the piriform muscle in 85 percent of the 40 gluteal regions, and 15 percent showed bilateral variation characterized by the passage of the common fibular nerve through the piriform muscle. The data obtained did not show any statistically significant differences.

Expression of class mu glutathione-S-transferase in human liver and its association with hepatopathies.

We studied the distribution of GSTM1 phenotypes in 611 individuals from an ethnically mixed sample of the Brazilian population who died from various causes. No influence of age, gender, or ethnicity was detected on the phenotypic distribution. In a sub-sample of 66 alcoholic individuals compared with 399 non-alcoholics there was almost a doubling of the odds ratio for GSTM1(0) individuals in the alcoholic category. The incidence of hepatopathies was higher in this group as well, and we observed a significant association of the null phenotype with cirrhosis. An excess of null phenotypes (374/611) was observed, and the allelic distribution was: GSTM1*A = 0.168, *B = 0.089, and *0 (null) = 0.743.