Human genetic influence on susceptibility of tuberculosis: from infection to disease.

There is substantial evidence from studies on racial variation in susceptibility to tuberculosis (TB) that human genetic variation is an important determinant of the outcome of infection with Mycobacterium tuberculosis (M tb). In only a minority of cases is there an obvious identifiable risk factor such as human immunodeficiency virus (HIV) infection, advanced age, diabetes, corticosteroid usage or alcohol abuse. In the remainder, a complex interaction of genetic and environmental factors causes the development of clinical TB. Assessment of the contribution of genetics of host resistance to human TB is a long-standing challenge of human genetics research. Several studies demonstrated the association of various human leukocyte antigens (HLA) with disease susceptibility in different ethnic populations. There are likely to be many more TB-susceptibility genes to be identified.

Spectrum of bone tumors in Chiang Mai University Hospital, Thailand according to WHO classification 2002: A study of 1,001 cases.

OBJECTIVE: The aim of the present study was to determine the spectrum, frequency and demographics of bone tumors. MATERIAL AND METHOD: A retrospective study of the 1,001 bone tumor specimens from the files at the Pathology Department of the Chiang Mai University Hospital, Thailand from 2000 to 2004. RESULTS: From the study, 41 were non-neoplastic mass lesions, and 960 were neoplastic, with 856 (89%) as primary and 104 (11%) as metastatic tumors. In the primary tumor group, 654 (76%) cases were of hematologic origin, and 202 (24%) were non-hematologic. The most common benign bone tumors were giant cell tumor (n = 37), osteochondroma (n = 25), and chondroma (n = 15). The most common malignant bone tumors were lymphoma-leukemia (n = 583), metastatic malignancy (n = 104), plasma cell myeloma (n = 71), and osteosarcoma (n = 58). CONCLUSION: The present study showed a higher frequency of osteosarcoma (68%), lower frequencies of chondrosarcoma (12%) and Ewing sarcoma (4%) among primary non-hematologic malignant bone tumors when compared with similar studies based on Western patients. Whether these differences reflect differences in the ethnic population or in practice patterns remains to be determined