Polymorphism of the thiopurine S-methyltransferase gene in African- Americans

The molecular basis for the genetic polymorphism of thiopurine S - methyltransferase (TPMT) has been estab-lished for Caucasians, but it remains to be elucidated in African populations. In the current study, we determined TPMT genotypes in a population of 248 African-Americans and compared it with allele frequencies in 282 Caucasian Americans. TPMT genotype was determined in all individuals with TPMT activity indicative of a heterozygous genotype (</=10.1 U/ml pRBC, n = 23African- Americans, n = 21 Caucasians) and a control group with TPMT activity indicative of a homozygous wild-type genotype (>10.2 U/ml pRBC, n = 23 African-Americans, n = 21 Caucasians). No mutant alleles were found in the high activity control groups. The overall mutant allele frequencies were similar in African-Americans and Caucasians (4.6 and 3.7% of alleles, respectively). However, while TPMT*3C was the most prevalent mutant allele in African-Americans (52.2% of mutant alleles), it represented only 4.8% of mutant alleles in Caucasians ( P < 0.001). In contrast, TPMT*3A and TPMT*2 were less common in African-Americans (17.4 and 8.7% of mutant alleles), whereas TPMT*3A was the most prevalent mutant allele in Caucasians (85.7% of mutant alleles). A novel allele ( TPMT*8 ), containing a single nucleotide transition (G644A), leading to an amino acid change at codon 215 (Arg-->His), was found in one African-American with intermediate activity. These data indicate that the same TPMT mutant alleles are found in American black and white populations, but that the predominant mutant alleles differ in these two ethnic groups.      

Correlates and trend of HIV prevalence among female sex workers attending sexually transmitted disease clinics in Pune, India (1993-2002)

In India, substantial efforts have been made to increase awareness about HIV/AIDS among female sex workers (FSWs). We assessed the impact of awareness regarding safe sex in a cohort of FSWs by studying trends in HIV prevalence, sexually transmitted diseases (STDs), and risk behaviors measured from 1993 to 2002 in Pune, India. A total of 1359 FSWs attending 3 STD clinics were screened for HIV infection, and data on demographics, sexual behaviors, and past and current STDs were obtained. The overall HIV prevalence among FSWs was 54%. Not being married (adjusted odds ratio [AOR] = 1.74, 95% confidence interval [CI]: 1.17 to 2.59), being widowed (AOR = 2.10, 95% CI: 1.16 to 3.80), inconsistent condom use (AOR = 1.60, 95% CI: 1.02 to 2.50), clinical presence of genital ulcer disease (GUD; AOR = 1.66, 95% CI: 1.07 to 2.56), and genital warts (AOR = 4.70, 95% CI: 1.57 to 14.08) were independently associated with HIV infection among FSWs. The prevalence of HIV remained stable over 10 years (46% in 1993 and 50% in 2002; P = 0.80). The prevalence of GUD decreased over time (P < 0.001), whereas that of observed genital discharge remained stable. Reported consistent condom use as well as the proportion of FSWs who refused sexual contact without condoms increased over time (P < 0.001). These data collectively suggest that safe sex interventions have had a positive impact on FSWs in Pune, India.     

Surgical management of extensive gnathophyma

Rhinophyma is an uncommon disease of the nose characterized by irregular skin thickening and nodular deformation. The extensive growth causing 'whisky nose' is due to hyperplasia of the sebaceous glands and the surrounding connective tissue. Other facial regions may concomitantly be affected. We present a case of extensive gnathophyma accompanying minor lesions of the nose. Surgical treatment led to an excellent cosmetic result.     

Is growth hormone a radioprotective agent?

There is currently substantial clinical interest in growth hormone (GH) as a protective agent against radiation-related normal tissue injury. To further assess the potential radiation injury-preventive effects of GH, these effects were studied in rats by using a radiation-induced skin injury model. Group 1 received neither GH nor irradiation (control group). Group 2 received 30 Gy of gamma irradiation as a single dose to the right hind legs of the rats (radiation group). Group 3 and 4 received the same irradiation plus either 0.01 U/kg/day GH (RT + 0.01 GH group) or 0.02 U/kg/day GH (RT + 0.02 GH group) subcutaneously. Clinically and histopathologically, acute skin reactions were assessed by two independent experts in radiation oncology and pathology, respectively. Irradiation increased dermatitis in rats when compared with the control group. The severity of radiodermatitis in the rats in the RT + 0.01 GH and RT + 0.02 GH groups was significantly lower than that in the RT group; radiodermatitis developed earlier in the RT group than in the other groups. GH was efficacious in preventing epidermal atrophy, dermal degeneration such as oedema and collagen fibre loss, and hair follicle atrophy, but not better than in the control group. These results are preliminary to studies that will be performed with higher doses of GH in radiation-treated cancer patients, with the aim of reducing radiation-induced toxicity.     

Preparation, characterization and in vitro biocompatibility evaluation of poly(butylene terephthalate)/wollastonite composites

The aim of the study was to prepare composites of poly(butylene terepthalate)/wollastonite (PBT/W), evaluate their properties and in vitro biocompatibility. Composites of PBT with wollastonite in two different proportions, viz. 70/30 (PW-30), 50/50 (PW-50) were prepared. The DSC studies indicate marginal changes in the melting behavior and enhanced crystallization in PBT/W composites. The mechanical properties of the composites such as tensile modulus shows remarkable improvement as a result of incorporation of wollastonite. SEM studies of fractured surfaces of impact samples showed no evidence of bonding between PBT and wollastonite. Water contact angle of PW30 and PW50 was 73.7 and 78.7, respectively. In vitro biocompatibility of PW-30 was evaluated as a representative composite. Direct cell contact test did not show deleterious effects on NIH3T3 fibroblast morphology and DNA integrity indicating its compatibility. Leach out products (LOP) of PW-30 were evaluated non-toxic as tested by MTT assay. Mouse peritoneal macrophages in contact with PW-30 showed comparable expression of CD 11b/18, CD45, CD14 and B7.2 to macrophages in contact with PTFE control indicating its non-activating nature. LOP did not induce proliferation of mouse splenic lymphocytes suggesting its immuno-tolerance. PW-30 also exhibited preliminary blood compatibility. These physical properties and biocompatibility of PBT/W composites show their suitability as potential biomaterials.