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21.
This case-control study was conducted to examine the association between the CYP1A1 and CYP2D6 genotypes and lung cancer risk among North Indians. The estimated relative risk for lung cancer associated with the CYP1A1 Val/Val allele was 2.68, and was four-fold when cases with small cell lung cancer (SCLC) were considered alone. With regard to the metabolism of debrisoquine, no poor metabolizers were found amongst the subjects. The odds ratio of risk with the heterozygous extensive metabolizer (HEM) genotype was 1.5. However, in the presence of at least a single copy of the variant CYP1A1 MspI allele and the CYP2D6 HEM genotype, the risk was two-fold for squamous cell carcinoma (SQCC). When the CYP1A1 Val/Val and CYP2D6 HEM genotypes were taken together, the risk for SCLC was four-fold. Stratified analysis indicated an interaction between bidi smoking and variant CYP1A1 genotypes on the risk for SQCC and SCLC. Heavy smokers (Brinkman index>400) with Val/Val genotypes were at a very high risk of developing lung cancer (odds ratio 29.30, 95% confidence interval 2.42-355, p=0.008). Heavy smokers with CYP1A1 MspI (CYP1A1*1/2A or CYP1A1*2A/*2A) genotype had a seven-fold risk for SCLC compared with non-smokers. This study is the first to be carried out on a North Indian population, and, although small, suggests that CYP1A1 and CYP2D6 polymorphisms might have a role in determining the risk for lung cancer and should be investigated further.  相似文献   
22.
An extracellular, highly thermostable and alkaline CMCase was purified from Bacillus sp. VG1 using ion exchange and gel filtration chromatography. Enzyme was optimally produced in a medium containing 1.0% CMC and 0.5% tryptone. The purified CMCase had a pH optimum of 9–10 and a half life of 12 min even at 100 °C. The enzyme activity was reduced by Hg2+ and stimulated by Co2+, Na+ and K+. Various detergents and proteinases moderately inhibited the CMCase activity. The molecular weight studies showed a single band on SDS–PAGE.  相似文献   
23.
The present study investigates in a experimental system in vitro the relationship between the non-enzymatic (ascorbate-Fe2+) and enzymatic (NADPH) lipid peroxidation in rat liver microsomes and nuclei. Chemiluminescence was measured as cpm/mg protein during 180 min at 37 degrees C. Approximately 50-55% of the fatty acids located in rat liver microsomes and nuclei are polyunsaturated with a prevalence of C18:2 n6 and C20:4 n6. The values of total light emission during the non-enzymatic and enzymatic lipid peroxidation were highest in microsomes than in nuclei. A significant decrease of C20:4 n6 and C22:6 n3 in rat liver microsomes and nuclei was observed during the lipid ascorbate-Fe2+-dependent peroxidation, whereas a significant decrease of C20:4 n6 in rat liver microsomes was observed during enzymatic lipid peroxidation. Over the time course studies, analysis of chemiluminescence in microsomes and nuclei demonstrated that the lipid peroxidation in the presence of ascorbate-Fe2+ reach a maximum at 50 and 30 min, respectively, whereas in the presence of NADPH it reachs a maximum at 20 min in both organelles. In liver microsomes and nuclei the peroxidizability index (pi) which indicates the degree of vulnerability to degradation of a selected membrane showed statistically significant differences between control versus ascorbate-Fe2+ when microsomes or nuclei were compared. Our results indicate that non-enzymatic (ascorbate-Fe2+) and enzymatic (NADPH) lipid peroxidation are operative in rat liver microsomes and nuclei but the sensitivities of both organelles to lipid peroxidation evidenced by chemiluminescence was greater in the presence of ascorbate-Fe2+ when compared with NADPH.  相似文献   
24.
Partial 16S gene fragments were amplified by using specific primers in few species/populations of termites of the genus Odontotermes (Isoptera:Termitidae:Macrotermitinae), and the PCR products were subjected to SSCP analysis. Three haplotypes obtained were subjected to sequencing. The sequences obtained were characterized to see the frequencies of each nucleotide bases. High A + T content was observed. The inter-specific pairwise sequence divergence in Odontotermes spp. ranged from 0% to 4.8% across the entire 16S gene fragment. Identical sequences were found between two populations of O. horni. Individuals of different species having Type-I conformational pattern, i.e. O. obesus (-AI) and O. horni (-MI), as well as Type-II of O. obesus (-UII) and O. bhagwatii (-CHII) had no percent diversity. Phylogenetic trees drawn on the basis of distance Neighbour-joining method revealed clustering of individuals according to their genera and families.  相似文献   
25.
The present study was aimed to get the nucleotide sequences of a part of COII mitochondrial gene amplified from individuals of five species of Termites (Isoptera: Termitidae: Macrotermitinae). Four of them belonged to the genus Odontotermes (O. obesus, O. horni, O. bhagwatii and Odontotermes sp.) and one to Microtermes (M. obesi). Partial COII gene fragments were amplified by using specific primers. The sequences so obtained were characterized to calculate the frequencies of each nucleotide bases and a high A + T content was observed. The interspecific pairwise sequence divergence in Odontotermes species ranged from 6.5% to 17.1% across COII fragment. M. obesi sequence diversity ranged from 2.5 with Odontotermes sp. to 19.0% with O. bhagwatii. Phylogenetic trees drawn on the basis of distance neighbour-joining method revealed three main clades clustering all the individuals according to their genera and families.  相似文献   
26.
Effect of growth retardants (paclobutrazol or ancymidol) was studied in Lilium plantlets growing in liquid culture. A significant increase in leaf chlorophyll, epicuticular wax, plant dry weight and bulb starch contents were found in plantlets treated with growth retardants. A similar increase in the number of leaves, roots and bulbs was also noted. However, total leaf area and the fresh weight increased only marginally. These features resulted in robust plantlets that showed significantly improved ex vitro survival. Based on these features, a comprehensive index (CI) was calculated as a measure of quality of the plantlets, and it correlated well with their ex vitro survival. Treatment of plantlets with 3.4 μM paclobutrazol was found to be the best and its carry over effects were also minimal.  相似文献   
27.
To investigate the involvement of the CYP17, SRD5A2, CYP1B1, and CYP2D6 variants with prostate cancer, a case-control study of 100 patients and an equal number of age-matched control men was conducted. There appears to be a nonsignificant increase with risk of prostate cancer for individuals carrying one copy of the CYP17 A2 allele (OR, 1.80; 95% CI, 0.99-3.29, P=0.05). The risk was increased in individuals having two A2 alleles (OR; 2.81, 95% CI, 1.06-7.40, P=0.03). Compared with men having the VV genotype of SRD5A2 gene, there was no significant association between the VL genotype and the risk of prostate cancer (OR; 0.54, 95% CI; 0.29-1.03, P=0.06). There was no difference in the occurrence of the genotype LL between controls and prostate cancer patients (OR; 0.90, 95% CI; 0.43-1.89, P=0.79). There was a nonsignificant increased risk of prostate cancer for individuals carrying the CYP1B1Leu/Val genotype (OR, 1.70, 95% CI, 0.91-3.17, P =0.09), which was increased in those having the Val/Val allele (OR, 3.38; 95% CI, 1.13-10.07, P=0.02). Relative to men homozygous for the wild-type allele in CYP2D6 gene, those heterozygous for the B allele had an odds ratio of 1.78 (95% CI, 0.76-4.17, P=0.18) for patients, and for homozygous individuals, it was 1.95 (0.55-6.93, P=0.30). These observations have suggested that the CYP17 A2/A2, CYP1B1 Val/Val, and CYP2D6 genotypes may be associated with an altered risk of prostate cancer, while the CYP2D6 and SRD5A2 V89L polymorphism have no association with its risk in the North Indian population.  相似文献   
28.
DNA ligases play an essential role in repair, replication, and recombination of DNA, and catalyzes the formation of a phosphodiester bond at a nick junction on single- and double-strand breaks. We have conducted a hospital-based case-control study to examine the role of polymorphism of DNA repair gene ligase I (LIGI) in the context of lung cancer risk for north Indian population. One hundred, fifty-one primary lung cancer cases and an equal number of matching hospital controls were collected. The LIGI polymorphism was determined by using the PCR-RFLP method. The association between polymorphisms in the LIGI gene with the risk of lung cancer was estimated by computing odds ratios (ORs) and a 95% confidence interval (CI) using a Multivariate Logistic Regression Analysis. The risk for lung cancer was not associated for individuals featuring LIGI (AC) (OR -0.8, 95% CI = 0.44-1.40) and (AA) (OR -0.8, 95% CI = 0.41-1.80) genotypes. The DNA repair gene (LIGI) may not be playing an important role in modulating the risk of lung cancer in the north Indian population.  相似文献   
29.
Vascular endothelial growth factor (VEGF) is a potent angiogenic growth factor that has been shown to play a significant role in neovascularization during inflammation in atherosclerotic plaques, formation of collateral vessels to an area of ischemic myocardium and neovascularization at the edges of a myocardial infarction during its repair. Interleukin-4 (IL-4) has important role in immune cell chemotaxis, formation of endothelial cell adhesion molecules and has numerous anti-inflammatory effects which prevent the complications of atherosclerosis, the primary cause of coronary heart disease (CHD). In this study, we have analyzed the effect of 1154 A/G polymorphism of VEGF and 70 bp VNTR polymorphism of intron 3 in IL-4 genes in coronary heart disease (CHD) patients (n = 300) and their age matched controls (n = 300). To analyze polymorphic alleles, ARMS-PCR and RFLP techniques were used. Multiple logistic regression analysis was carried out with statistical software. GG genotype was associated with a decreased risk of development of CHD (OR 0.22, 95% CI 0.12–0.38, P < 0.001). However, A allele showed an increased risk whereas G allele decreased the risk of CHD with diabetes mellitus, hypertension, chronic mental stress and positive familial history of myocardial infarction (MI)/CHD. GG genotype was found to have protective effect with alcohol intake (OR 0.34, 95% CI 0.14–0.82, P < 0.01) and central obesity (OR 0.15, 95% CI 0.04–0.56, P < 0.001). GG genotype of VEGF has also shown significant association with IL-4 (P2P2 and P1P2) genotypes.  相似文献   
30.
The epigenetic modifications have been reported to be key factors in breast carcinogenesis. In the current study, it has been tried to determine the methylation status of two tumour suppressor genes p14/ARF and p16/INK4a in 150 breast cancer patients as well as 150 controls by using MSP-PCR. There was, highly significant difference in methylation of p14/ARF and p16/INK4a (P = 0.000) between patients and controls. Methylation of both the genes together significantly increased the risk of breast cancer by 12.31 folds. The present study concludes that hypermethylation of p14/ARF and p16/INK4a promoters demonstrate significant association with the risk of breast cancer, hence indicating these as important tumour suppressor genes involved in the pathogenesis of breast cancer in North Indian population (i.e. Punjab, Haryana, Uttar Pradesh, Himachal Pradesh as well as Union Territory of Chandigarh).  相似文献   
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