Comparative assays of the rpoB gene for identification of Mycobacterium tuberculosis isolated from patients in Sudan.

OBJECTIVES: To characterise mycobacterial clinical isolates based on amplification of the rpoB gene. SETTING: One hundred and thirty-five mycobacterial isolates cultured from suspected pulmonary tuberculosis (TB) patients were identified phenotypically. Molecular characterisation of the isolates was performed based on amplification of the rpoB gene, using duplex polymerase chain reaction (DPCR), PCR-restriction fragment length polymorphism (RFLP) and nested PCR-based sequence analysis techniques. RESULTS: The DPCR assay identified 129 of 135 (95.5%) clinical isolates as Mycobacterium tuberculosis complex species. Restriction enzyme analysis of the rpoB PCR product using Hind II identified 134 of the 135 (99.3%) isolates as M. tuberculosis complex, while nested PCR sequence analysis of the rpoB gene identified 133/133 examined isolates (100%) as M. tuberculosis species. No mycobacteria other than M. tuberculosis (MOTT) were detected among the studied isolates. CONCLUSION: DPCR, PCR/RFLP Hind II and nested PCR sequence analysis of the rpoB gene techniques showed comparable efficiency in the characterisation of Mycobacterium isolates. Nested PCR sequence analysis of the rpoB gene was superior to PCR/RFLP for characterisation of suspected M. tuberculosis isolates, while the DPCR technique showed less sensitivity. As PCR-RFLP requires less sophisticated laboratory facilities than nested PCR sequence analysis, it would be more appropriate to be adopted for accurate characterisation of mycobacteria in countries with a weak infrastructure.     

Monoclonal antibodies directed characterization of epidermal and hepatic cytochrome P-450 isozymes induced by skin application of therapeutic crude coal tar

A single application of crude coal tar (CCT) solution (USP) to the skin of neonatal rats was shown to induce epidermal and hepatic cytochrome P-450(P-450)-dependent monooxygenase activities. To further characterize the induction response, in this study we have utilized highly specific monoclonal antibodies (MoAb) 1-7-1, 2-66-3, and 1-98-1 directed against highly purified rat liver P-450s induced by 3-methyl-cholanthrene, phenobarbital and ethanol, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of hepatic microsomes prepared from CCT-treated animals showed a significant increase in the coomassie blue stainable proteins in the P-450 region; however, this was not evident in epidermal microsomes. Immunoblot analysis of epidermal and hepatic microsomes with MoAb 1-7-1 revealed strong immunoprecipitin bands in both tissues. MoAb 2-66-3 showed significant immunoreactivity only with hepatic microsomes. Interestingly, CCT treatment resulted in suppression of immunoreactivity with MoAb 1-98-1 in hepatic microsomes. MoAb 1-7-1 and 2-66-3 exhibited concentration-dependent inhibitory effects in aryl hydrocarbon hydroxylase and 7-ethoxycoumarin-O-deethylase activities induced by CCT application. MoAb 1-7-1 was substantially more effective in this respect. Epidermal and hepatic microsomes prepared from CCT-treated rats showed significantly greater metabolism of benzo(a)pyrene (BP). MoAb 1-7-1 and MoAb 2-66-3 inhibited BP metabolism in both the tissues. However, MoAb 1-7-1 was more inhibitory in this regard as compared to MoAb 2-66-3. These studies indicate that topical application of therapeutic CCT to the skin of neonatal rats results in induction of P-450 isozyme c in epidermis and isozymes b and c in liver, and that this induction is associated with the suppression of P-450 isozyme j in liver.     

Survival after acute myocardial infarction in Asian and white patients in Birmingham.

OBJECTIVE--To compare outcome after infarction in South Asian patients, comprising Indians, Pakistanis, Bangladeshis and individuals of East African origin, in Birmingham with that in white patients in the same city. DESIGN--A prospective case-control study. SETTING--Three large district general hospitals. PATIENTS--102 South Asian patients discharged from hospital after an acute myocardial infarction were matched for age, sex, time and season of infarct, and hospital of admission with white patients. MAIN OUTCOME MEASURES--Survival and complication. RESULTS--There was no significant difference in survival or complications during the four years after an acute myocardial infarction in South Asian and white patients. CONCLUSION--The survival and clinical course of South Asian and white patients discharged after an acute myocardial infarction were similar over a four year period.     

The effect of aluminum on the stromal cells (in vitro) on bone marrow in rats.

The aim of this study was to describe the effects of aluminum on the stromal cells of rat bone marrow using a combination of in vivo exposure and in vitro culture of bone marrow. The toxic effects of aluminum are manifested by a decrease in the erythrocyte count and hemoglobin level in the peripheral blood. Aluminum stimulated an increase in the number of fibroblasts while the macrophage count dropped. The number of adipocytes remained unaffected. An increase in mean corpuscular hemoglobin (MCH) was also found in the peripheral blood of experimental animals.     

(-)-Epigallocatechin-3-gallate in Camellia sinensis leaves from Himalayan region of Sikkim: inhibitory effects against biochemical events and tumor initiation in Sencar mouse skin.

Recently, we and others showed that the components of green tea may be useful cancer chemopreventive agents. It has been suggested that (-)-epigallocatechin-3-gallate (EGCG), the major constituent in green tea, may possess antitumor-promoting and/or anticarcinogenic effects in rodent tumor bioassay systems. During the chemical analysis of various green tea products, we found a traditionally preserved preparation of green tea used by tribes in the Himalayan region of Sikkim, India that was rich in EGCG. EGCG was isolated from this tea product, and its inhibitory effects were evaluated against the binding of topically applied 3H-labeled polycyclic aromatic hydrocarbons (PAHs) to epidermal DNA and 12-O-tetradecanoylphorbol-13-acetate (TPA) caused induction of epidermal ornithine decarboxylase (ODC) activity in Sencar mice, the short-term markers of tumor initiation and tumor promotion, respectively. Preapplication of EGCG resulted in significant inhibition (p less than 0.05) in the binding of [3H]PAH to epidermal DNA. Similarly, the topical application of EGCG resulted in significant inhibition (p less than 0.005) in TPA-caused induction of epidermal ODC activity. In further studies, we assessed the anti-skin tumor-initiating effect of EGCG in Sencar mice in an initiation-promotion protocol. The application of EGCG before challenge with 7,12-dimethylbenz[a]anthracene as tumor initiator resulted in significant reduction both in percentage of mice with tumors and number of tumors per mouse compared with a non-EGCG-pretreated group of animals. The results of the present study suggest that the green tea preparation from Sikkim may be a good source for the isolation of EGCG and that this compound may have significant potential as a cancer chemopreventive agent.     

A world-wide survey on kidney transplantation practices in breast cancer survivors: The need for new management guidelines

Kidney transplantation reduces mortality in patients with end stage renal disease (ESRD). Decisions about performing kidney transplantation in the setting of a prior cancer are challenging, as cancer recurrence in the setting of immunosuppression can result in poor outcomes. For cancer of the breast, rapid advances in molecular characterization have allowed improved prognostication, which is not reflected in current guidelines. We developed a 19-question survey to determine transplant surgeons’ knowledge, practice, and attitudes regarding guidelines for kidney transplantation in women with breast cancer. Of the 129 respondents from 32 states and 14 countries, 74.8% felt that current guidelines are inadequate. Surgeons outside the United States (US) were more likely to consider transplantation in a breast cancer patient without a waiting period (p = .017). Within the US, 29.2% of surgeons in the Western region would consider transplantation without a waiting period, versus 3.6% of surgeons in the East (p = .004). Encouragingly, 90.4% of providers surveyed would consider eliminating wait-times for women with a low risk of cancer recurrence based on the accurate prediction of molecular assays. These findings support the need for new guidelines incorporating individualized recurrence risk to improve care of ESRD patients with breast cancer.     

Preliminary evidence for the presence of glutathione-s-transferase activity in mammalian and avian brain

Glutathione-S-transferase activity has been demonstrated in the brain of rabbit, guinea pig, rat, mouse, and pigeon. The activity was in the following order: rabbit > (guinea pig = mouse) > rat > pigeon. The activity of brain was about 1/3 to 1/9 of that present in liver depending upon the species. In the rat brain glutathione-S-transferase activity was found to be distributed equally in cerebrum, cerebellum, and brain stem and localized mainly in the organelle-free cytosol fraction.