Modulatory effects of Azadirachta indica leaf extract on cutaneous and hepatic biochemical status during promotion phase of DMBA/TPA-induced skin tumorigenesis in mice.

The modulation in biochemical status of skin and hepatic tissue at the time point of commencement of promotion stage of skin carcinogenesis in mice and its intervention with aqueous Azadirachta indica leaf extract (AAILE) were investigated. 7,12-Dimethylbenz(a)anthracene (DMBA, 500 nmol/100 ul of acetone) was applied topically for 2 weeks (twice weekly), followed by phorbol-12-myristate-13-acetate (TPA, 1.7 nmol/100 ul) twice weekly for 6 weeks on the depilated skin of mice and AAILE was administered orally at a dose level of 300 mg/kg body wt thrice a week for 10 weeks. DMBA/TPA treatment upregulated the phase I enzymes in skin and hepatic tissue, as revealed by the increased cytochrome P450 (CYP) and cytochrome b5 (cyt b5) levels and aryl hydrocarbon hydroxylase (AHH) activity when compared to the control group and differentially modulated the activities of phase II enzymes like glutathione-s-transferase (GST), DT-diaphorase (DTD) and uridine diphosphate glucuronosyltransferase (UDP-GT). AAILE treatment decreased the DMBA/TPA-induced increase in cutaneous CYP level and enhanced the DTD and UDP-GT activities when compared with DMBA/TPA group. In the hepatic tissue of AAILE + DMBA/TPA group, an increase in UDP-GT activity was observed when compared to DMBA/TPA group. DMBA/TPA treatment did not alter the skin lipid peroxidation (LPO) level when compared to control group, however, in the animals that received AAILE treatment along with DMBA/TPA, a significant increase in LPO was observed when compared to control group. This was associated with a decrease in cutaneous reduced glutathione (GSH) level of AAILE + DMBA/TPA group. Enhanced LPO level was observed in the hepatic tissue of DMBA/TPA and AAILE + DMBA/TPA groups when compared to control group. However, no alteration was observed in their hepatic GSH levels. The micronuclei score in hepatic tissue did not exhibit significant inter-group differences. The results of the present study suggest that apart from skin, liver may be affected during DMBA/TPA-induced skin tumorigenesis. AAILE treatment has the ability to modulate these changes potentially influencing the process of tumor formation. These findings seem to be important to carcinogenesis and its intervention with anti-cancer agents.

Persistence of goitre in the post-iodization phase: micronutrient deficiency or thyroid autoimmunity.

Background & objectives: Despite years of salt iodization, goitre continues to be a major public health problem worldwide. We examined the prevalence of goitre in the post-iodization phase and the relationship of goitre with micronutrient status and thyroid autoimmunity in school children of Chandigarh, north India. Methods: Two phase study; in the first phase, 2148 children of 6 to 16 yr were screened for goitre by two independent observers as per the WHO grading system. In the second phase, a case-control study, 191 children with goitre and 165 children without goitre were compared with respect to urinary iodine, iodine content of salt, serum levels of T3, T4, TSH, anti-TPO (thyroid peroxidase) antibody, haemoglobin, ferritin and selenium. Results: Prevalence of goitre in the studied subjects was 15.1 per cent (13.9% in 6 to 12 yr and 17.7% in 13 to 16 yr age group, P= 0.03). Median urinary iodine excretion in both the groups was sufficient and comparable (137 and 130 µg/l). 3.2 per cent children with goitre and 2.4 per cent without goitre had hypothyroidism (subclinical and clinical) and only one child with goitre had subclinical hyperthyroidism. Nine (4.9%) children in the goitre group and 3 (1.9%) in control group had anti-TPO antibody positivity. The median serum selenium levels were not different in both the groups (181.9 and 193.5 µg/l). Seventy one (37.4%) of the goitrous children had anaemia (haemoglobin <12 g/dl) as compared to 41 (24.8%) of the control group (P <0.01). More number of goitrous children (39, 20.6%) were depleted of tissue iron stores (serum ferritin <12 µg/l) as compared to controls (11, 6.4%; P<0.001). Serum ferritin level negatively correlated with the presence of goitre (r = - 0.22, P =0.008) and had an OR of 2.8 (CI 1.20 - 6.37, P =0.017). Interpretation & conclusions: There was a high prevalence of goitre in young children despite iodine repletion and low thyroid autoimmunity. The concurrent iron deficiency correlated with the presence of goiter. However, the cause and effect relationship between iron deficiency state and goitre requires further elucidation.

Effect of vitamin E on alcohol-induced changes in oxidative stress and expression of transcription factors NFkappaB and AP-1 in mice brain cerebral hemispheres.

Redox sensitive transcription factors nuclear factor kappaB (NF-kappaB) and activator protein-1 are involved in the pathogenesis of alcohol-induced disorders. Because of its antioxidative properties, vitamin E may help prevent oxidative stress-induced disorders. The aim of the present study was to delineate the molecular mechanisms associated with alcohol-induced oxidative stress and to see whether vitamin E supplementation counters the alcohol-induced adverse effects. The results showed that vitamin E supplementation restored the redox status and thus prevented the alcohol-induced oxidative stress. Further measurements of the mRNA expressions of cjun, cfos, p65 (NFkappaB) indicated an increase in their expression during oxidative stress. Although Vit E inhibited NFkappaB activation, it stimulated AP1 expression. The results support the findings that alcohol induces oxidative stress in nervous tissue. The data further show that vitamin E can mitigate the toxic effects of alcohol and thus can be suitable as a potential therapeutic agent for alcohol-induced oxidative damage in brain.

Selenium, a versatile trace element: current research implications.

Selenium (Se), a trace element, has evolved from its toxic properties to an essential element. Se was known a potent antioxidant through glutathione peroxidase (selenium being part of this molecule). Later, many other selenium-binding proteins were discovered and their functions were tried to be known with unsuccessful results in many cases. Se is known to be involved in carcinogenesis, immune function, male reproduction, cardiovascular diseases etc. The specific mechanism of the involvement of the element is still not known. Recent research with application of modern research tools viz. bioinformatics, cDNA microarray and transgenesis have revealed the mechanism of selenium involvement in various processes. This review highlights mysterious and useful roles of selenium in biological processes.

Effect of cholesterol and 7-beta hydroxycholesterol on glutathione status and nitric oxide production in murine peritoneal macrophages.

Present study was conducted to observe the effect of cholesterol and oxidized cholesterol (7beta-hydroxycholesterol,7beta-OH) on the nitric oxide (NO) production and the redox ratio by lipopolysaccharide-stimulated macrophages. Dose-dependent decrease in NO levels was seen with both cholesterol and 7beta-OH at different incubation intervals (6,12,18,24 hr) and concentrations (2.5,5,7.5microg/ml). On comparison, a significant decrease in the NO was observed at 24 hr interval in 7beta-OH exposed cells with all respective concentrations of cholesterol. Incubation with 7beta-OH also resulted in significant increase in levels of oxidized glutathione (GSSG) and decrease in reduced glutathione (GSH), while cholesterol showed no effect on GSSG levels. Moreover, GSH levels were lowered only at highest concentration (7.5microg/ml), and at longer incubation intervals (18,24 hr) with cholesterol exposure. This altered the redox status in both cholesterol/7beta-OH treated macrophages. Increased redox ratio and decreased NO levels indicated increased oxidative stress and decreased vasodilation by 7beta-OH compared to cholesterol.

Selenium supplementation protects from high fat diet-induced atherogenesis in rats: role of mitogen stimulated lymphocytes and macrophage NO production.

The present study was designed to demonstrate the involvement of immune response in experimental atherogenesis. The mitogenic stimulation of lymphocytes and NO production by macrophages in experimental atherogenesis were studied. Further, influence of selenium a potent antioxidant was also studied in the disease process. Three different treatment groups of rats undertaken for study were: group 1, control; group II, high fat diet (HFD) fed group and group III, HFD+Se supplemented group. Atherogenic conditions induced have already been explained earlier [Kang BPS et al. Gen Physiol Biophys, 17 (1998) 71]. Significant increase in 3H-thymidine incorporation was obtained in lymphocytes from HFD fed animals in both presence and absence of mitogen (Con-A). However, these values decreased in group III animals, which were supplemented with selenium. Similarly, NO levels with LPS+ and LPS- macrophages also found to be higher in HFD fed group and decreased in group III. These studies reveal the protective role of selenium in HFD-induced atherogenic process.

Influence of 7beta-hydroxycholesterol on glutathione status and nitric oxide production in macrophages: in vitro studies.

Incubation of murine peritoneal macrophages with 7beta-hydroxycholesterol (7beta-OH) for 24 hr led to dose-dependent reduction in cellular glutathione content as well as nitrite levels in the medium. Treatment with an inorganic form of selenium, sodium selenite which is a potent antioxidant, elevated the cellular glutathione levels and decreased nitrite levels. Our results suggest that 7beta-OH may exert its pro-atherogenic effect by inhibiting glutathione synthesis and nitric oxide production by macrophages present in the arterial wall and thus, impair the cellular antioxidant defense system.

In vivo and in vitro influence of selenium on DNA/RNA synthesis in spleen and lymphocytes in culture--possible mediation of changes in GSH/GSSG ratio.

Effect of superanutritional levels of selenium (Se) as sodium selenite (0.5 and 1.5 ppm) given orally to Balb/c mice for one and two weeks was observed on the rate of DNA/RNA synthesis, levels of reduced as well as oxidized glutathione (GSH and GSSG) and glutathione peroxidase (GSH-Px)/glutathione-S-transferase (GSH-S-transferase) activities in spleen. Similar effect of three different concentrations of Se (10(-7), 10(-5) and 10(-3) M) in culture media was also observed on the rate of DNA/RNA synthesis in proliferating lymphocytes taken from mice spleen. The results of the present study indicated that with increasing concentration and duration of Se treatment in vivo and in vitro, a marked inhibition of the rate of DNA/RNA synthesis was observed. Levels of total glutathione and GSSG in spleen were elevated significantly only after two weeks in 1.5 ppm treatments. Glutathione peroxidase activities in spleen decreased (p < 0.05) in 1.5 ppm group at one week and in 0.5 ppm group at two week treatment. At higher Se treatment, the activity recovered towards control. However, GSH-S-transferase in spleen remained unchanged at all treatment intervals. The results indicated that changes in glutathione system by increasing Se concentration might account for inhibition of rate of DNA/RNA synthesis.

Incidence of Vibrio cholerae in different age groups and sex in Aurangabad Province isolated during January 1994 to December 1994.

In our study age group 1-10 years was mostly affected as also in 1992 and 1993 because of low health consciousness and poor personal hygiene at this age.

Characterization of mycobacterial species in clinically diagnosed cases of pulmonary tuberculosis and their HIV status.

A total of 75 clinically diagnosed and radiologically evident cases suggestive of pulmonary tuberculosis were selected for study. Sputum sample of each patient was screened for AFB by Ziehl Neelsen staining and culture. On examination 20 smears were found positive for AFB and 55 smears were negative by concentration method. A total of 23 samples were found to be culture positive and 52 were culture negative. Of these, 22 stains were identified as Mycobacterium tuberculosis, one was identified as M. Scrofulaceum. Of the 75 patients 3 were seropositive for HIV-I antibodies. Out of these 3, one was found to be smear and culture positive and was identified as M. scrofulaceum. Other two seropositive patients were smear and culture negative for AFB.

Isolation and characterization of soluble antigens of sheep poxvirus.

A soluble antigen fraction of sheep poxvirus (SPV) isolated from infectious virus particles by ultracentrifugation and purified by subtractive immunoaffinity chromatography was characterized. Exclusion chromatography studies revealed 10 proteins of molecular weight (MW) 220, 168, 87.3, 71.5, 52.5, 36.7, 31.0, 23.4, 18.3 and 14.2 kDa. Nine of them were found to be precipitinogens and 5 were identified as structural components of the virus particles. SDS-PAGE analysis revealed a polypeptide profile of 10 bands with 2 prominent polypeptides of 64 and 42 kDa. Western blotting, however, detected 2 immunogenic polypeptides of MW 100 and 64 kDa. Moreover, crossed immunoelectrophoresis showed the presence of proteins of varied electrophoretic mobility and sharing of antigenic determinants among a few soluble antigens. Physico-chemical characterization further revealed that these precipitinogens can withstand ambient temperatures, but were sensitive to trypsin and ether whereas, chloroform had no effect on immunoprecipitation pattern of soluble antigens.

HIV-1 seropositivity in pulmonary tuberculosis (study of 340 cases from Marathwada).

An investigative study was carried out in 340 cases of established pulmonary and presumed pleural tuberculosis for co-occurrence of HIV-1 infection in them. Confirmatory screening for HIV-1 was carried out with both ELISA (Vironostika) and Serodia commercial kits in all reactive samples on first screening. In all, 16 cases proved to be having HIV-1 coexistent infection with pulmonary tuberculosis. Their preliminary vital clinical observations and roentogenic finding are summarized and literature reviewed briefly.