Expression of CXCR4 in the brain of feline immunodeficiency virus infected cat.

Advances in understanding the mechanisms of human immunodeficiency virus (HIV)-1 entry have revealed that the cell surface CD4 expression alone is insufficient and needs an additional molecule on its surface for the viral entry. These are G-protein coupled seven transmembrane (7-TM) family molecules (chemokine receptor) and amongst them one is CXCR4. Feline homologue of CXCR4 acting as a co-receptor for feline immunodeficiency virus (FIV) entry is already reported for the Crandle feline kidney cells strain (CrFK) of FIV. An experiment was carried out to search the expression of CXCR4 retrospectively in FIV (CrFK) infected cat brain tissues using immunohistochemically in the formalin fixed paraffin sections against 12G5, a mouse monoclonal antibody to CXCR4. We observed the expression of this receptor in feline neurons, astrocytes and in some vascular endothelial cells. The study of expression of CXCR4 in the brain, which is one of the many chemokine receptors in the central nervous system, may provide further insight into the interactions between brain cells, pathogens, and the immune system, and help understand the pathogenesis of HIV dementia.

Human T-lymphotropic retrovirus type-1 in Thailand.

Seroprevalence of antibodies to human T-lymphotropic virus type-1 (HTLV-1) was surveyed among the Thai population by the particle agglutination test and Western blotting test. None of a total of 727 individuals from seven ethnic groups were positive for the specific antibody to HTLV-1. Among hospital based 3,427 subjects in Southern Thailand, one patient with a brain tumor showed positivity in the Western blotting test, however, HTLV-1 proviral genome was not identified by PCR. The present data suggest that HTLV-1 is not endemic in the Thai population and that HTLV-1 is not a major public health problem in Thailand because HTLV-1 rarely causes its associated diseases.

Preliminary report on the short stature of Southeast Asian forest dwellers, the Manni, in southern Thailand: lack of an adolescent spurt in plasma IGF-I concentration.

Plasma concentration of insulin-like growth factor type-I (IGF-I) was studied among the Mannis in Thailand to find a possible cause of their short stature. The Mannis are hunting and gathering indigenous tribal peoples living in Asian tropical rain forests. A total of 50 plasma specimens from three different Manni groups in southern Thailand were used in this study. The concentrations of acid-ethanol extract of plasma IGF-I were measured by radio-immunoassay. We found that (1) plasma concentration of IGF-I in the Mannis was low, (2) there was no adolescent spurt in IGF-I levels, and (3) the post adolescent plasma IGF-I level of the Manni was significantly lower than that of age-matched Japanese. Low IGF-I levels among the Mannis may account for their short stature.

Serotyping of Duffy blood group in several Thai ethnic groups.

Duffy blood groups were serologically investigated in 434 individuals from Black Lahu (N = 54), Shan (N = 62), Lisu (N = 74), Red Karen (N = 112), White Karen (N = 102) and Manni (N = 30) in Thailand. High frequency of Fya (0.917-1.0) which is comparable with other Mongoloid populations was observed. The presence of weak-Fya antigen was detected in eight individuals of northern ethnic groups.

Study of genotoxic effects of antidiarrheal medicinal herbs on human cells in vitro.

The use of medicinal herbs has been a common practice in Asia but their genotoxic properties are little known. In the present study, genotoxic effects of three antidiarrheal herbs, guava leaf, mangosteen peel and pomegranate peel, were examined using established human cell lines, Raji and P3HR-1. Cells were treated with boiled-water extract of the herbs at various concentrations for 24 and 48 hours in vitro. Cell growth and viability were dose dependently reduced. No apparent chromosomal aberrations were induced by the treatment. Administration of pomegranate extract induced apoptotic DNA fragmentation. This genotoxicity test system is simple and convenient for the primary screening.

Human T-lymphotropic retrovirus type-1 (HTLV-1) and its distribution in Asian populations.

Distribution of human T-lymphotropic retrovirus type1 (HTLV-1) among Asian populations is reviewed from an anthropological point of view. The incidence of HTLV-1 infection among New Mongoloid and Indo-Aryan populations was quite low. There were no close phylogenetic relations among HTLV-1 endemic populations. HTLV-1 has been retained among peoples who have been isolated and/or depended on a primitive mode of living.

Absence of HTLV-I infection in some Indian populations.

A total of 946 adults belonging to ten population groups of Uttar Pradesh and West Bengal were screened for HTLV-I using a gelatin particle agglutination test. The percentage of seroreactive cases varied from 0 to 5.8 per cent. The overall prevalence of seroreactivity was 2 per cent. Of the 19 seroreactive cases, 15 were subjected to Western blot analysis, none could be confirmed. HTLV-I infection is, therefore, absent in these populations.

High prevalence of HTLV antibodies in wild-caught bonnet monkeys in southern India.

The prevalence of human T-lymphotropic virus (HTLV) type-1 antibodies was determined in the bonnet monkeys, living naturally, within about 30 km radius of Vellore (south India). Sera from 157 animals, collected between January 1982 and May 1993 were screened for the presence of HTLV-I infection by a particle agglutination test (PAT). When sera repeatedly reactive in PAT were subjected to indirect immunofluorescence and western blot tests, 63 (40%) were confirmed to be positive for HTLV-1 antibody. These findings are significant in the light of recent reports that HTLV infection is endemic to southern India.