Seroprevalence of HIV antibodies and risk factors in healthy young males from upper north Thailand.

In the Spring of 1991 a random sample of young men from Upper Northern Thailand (mean age = 21 years) was interviewed by trained medical students from Chiang Mai University, serum samples were obtained and analyzed for prevalence of HIV-1 antibodies and for syphilis, and risk factors for HIV infection were assessed. It was found that Commercial Sex Workers (CSW) were the principal risk factor, that consistent condom use is rare, and the rates of HIV infection are rising rapidly. Sociodemographic background, homosexual behavior, drug use, and history of STD's were found to be not significant risk factors. The conclusions are that the education campaigns should be intensified to reduce the frequency of contact with CSW and to encourage consistent use of condoms.

Cholinesterase activity in the chondrocranium of normal and exencephalic mouse fetus with trisomy 12.

Cholinesterase (ChE) activity in the chondrocranium of normal and exencephalic trisomy 12 mouse fetuses was studied. Non-specific cholinesterase activity was found strongly in the developing bone cells at the central zone and weakly in the more maturely developed bone cells at the peripheral zone of the chondrocranium of both normal and exencephalic trisomy 12 mouse fetuses. In exencephalic mouse fetuses, the ChE-activity was lesser than in the normal ones which corresponded to hypoplastic chondrocranium. The centrifugal direction of the maturity of individual bone cells could be demonstrated by the activity of cholinesterase. The young bone cells showed strong ChE-activity while the more matured cells showed weak ChE-activity. The enzyme activity disappeared when the definite tissue structure was well developed. From this study, it may be concluded that ChE plays a role in chondrocranium development which is different from its known function in the adult tissue.

Studies of human leprosy lesions in situ using suction-induced blisters: cell changes with IgM antibody to PGL-1 and interleukin-2 receptor in clinical subgroups of erythema nodosum leprosum.

To examine the immunopathogenesis of type 2 erythema nodosum leprosum (ENL) reactions in leprosy, we studied cellular and soluble immunologic components of skin lesions in 57 patients with reactions (19 acute ENL and 38 chronic ENL), 61 active patients without reactions, and 33 control patients whose leprosy had been treated and cured. Cells, IgM antibody to PGL-1 and Tac peptide levels were obtained from fluid aspirated from blisters induced by suction directly over representative skin lesions. During ENL reactions: a) the lesions in chronic ENL showed a decreased number of CD8+ (T-suppressor) cells and increased helper/suppressor ratio as compared to those in acute ENL and non-reactional leprosy; b) Tac peptide and IgM antibody to PGL-1 levels were elevated in the chronic ENL lesions; c) and systemic administration of corticosteroids appeared to cause a reduction in the intralesional CD4+ cell population and IgM antibody to PGL-1 but did not change CD8+ cell population and the levels of Tac peptide in the lesions. The elevated levels of Tac peptide were localized in the skin lesions while increased levels of IgM anti-PGL-1 seemed to be filtered from the peripheral blood. We conclude that spontaneous lymphocyte activation in situ, primarily of decreased CD8+ and relatively increased CD4+ cells, are important features of chronic, recurrent ENL reactions and may be an intermittent or cyclic phenomenon during the reaction. Understanding the mechanisms of these spontaneous changes in immunity in leprosy will enlarge our knowledge of reactions and of the underlying determinants of delayed type hypersensitivity and cell-mediated immunity in leprosy, which in turn will allow us to realize the potential for artificially manipulating these responses as proposed with vaccines or immunotherapy.

Cell changes and soluble interleukin-2 receptors (Tac peptide) in leprosy reversal reactions using suction-induced blisters.

The cellular contents and soluble interleukin-2 receptor (IL-2R) [Tac peptide] of skin blisters induced by suction over 7 reversal reaction (RR) patients were examined using immunoperoxidase and ELISA techniques respectively. The helper T activity (CD4+ cells) and helper:suppressor ratio were significantly greater in borderline lepromatous (BL) lesions with RR than in quiescent BL lesions. Interestingly, the intracutaneous levels of Tac peptide were elevated and directly correlated with the increases in CD4+ cells. The systemic administration of corticosteroids revealed a reduction in the numbers of CD4+ cells in the lesions. These results indicate that RRs are manifestations of a spontaneous increase in delayed type hypersensitivity (DTH) and possibly cell mediated immunity (CMI) in leprosy patients. The mechanism of such changes in immunity is of considerable value in understanding reversal reactions and the underlying determinants of DTH and CMI in leprosy and this in turn will have a bearing on the potential for proposed vaccines or immunotherapy.

Epidermal carcinoma: a five year (1981-1985) pathological analysis at Chiang Mai University Hospital.

A total of 414 cases of epidermal carcinoma registered at the Department of Pathology, Faculty of Medicine, Chiang Mai University during the years 1981 to 1985 were analysed in detail. The disease was more prevalent in males than in females. The incidence was 55.56 per cent in males and 44.44 per cent in females. At the age interval between 50 to 79, epidermal cancers were most frequently seen. Most of the patients were farmers. The patients usually came to the hospital with signs and symptoms of mass and ulcer. The histological cell types were squamous cell carcinoma (50.25%), basal cell carcinoma (34.54%), malignant melanoma (14.01%) and other (1.21%). The etiology of epidermal carcinoma is not definitely known, therefore, the possible epidemiologic etiology was briefly discussed.