A novel genetic polymorphism of inducible nitric oxide synthase is associated with an increased risk of gastric cancer

AIM: Inducible nitric oxide synthase (iNOS) plays a central role in the pathway of reactive oxygen and nitrogen species metabolism when Helicobacter pylori (H pylon) infection occurs in humans, iNOS Ser^608 Leu allele, a novel genetic polymorphism (C/T) occurring within exon 16 of the iNOS reductase domain, may have a dramatic effect on the enzymatic activity. The aim of this study was to determine whether iNOS C/T polymorphism was associated with increased susceptibility to gastric cancer. METHODS: We conducted a population based case-control study in a high gastric cancer incidence area, Yangzhong, China. Questionnaires from 93 patients with intestinal type gastric cancer (IGC), 50 with gastric cardia cancer (GCC) and 246 healthy controls were obtained between 1997 and 1998, and iNOS genotyping was carried out. Odds ratios (ORs), interaction index (γ), and 95% confidence intervals for the combined effects of iNOS genotype and H pylori infection, cigarette smoking or alcohol drinking were estimated. RESULTS: The frequency of (CT+TT) genotypes was higher in cases than in control group (24.48% vs 23.17%), but the difference was not statistically significant. After adjusting for age and gender, past cigarette smokers with (CT+TT) genotypes had a significantly increased risk of IGC (OR=3.62, 95% CI:1.23-10.64), while past alcohol drinkers with (CT+TT) genotypes had a significantly increased risk of GCC (OR=3.33, 95% CI:1.14-9.67). H pylori CagA negative subjects with (CT+TT) genotypes had a significantly increased risk of both IGC and GCC (OR=2.19 and 3.52, respectively). CONCLUSION: iNOS Ser^608 Leu allele may be a potential determinant of susceptibility to cigarette -alcohol induced gastric cancer, but larger studies are needed to confirm the observations.

Urinary follicle stimulating hormone can be used as a biomarker to assess male reproductive function

Aim: To develop an algorithm for use in population-based studies to assess testicular function by measurements of totalurinary follicle stimulating hormone (FSH). Methods: Total concentrations of urinary FSH were measured in a groupof 44 men at the University of California, Davis (UCD) and were compared to FSH measurements in serum. On thebasis of these and other published data, a urinary FSH value of >2 ng/mg creatinine (Cr) was selected as the cutoffpoint to identify men with elevated serum FSH ( > 12 IU/L) or low sperm counts ( < 20 million/mL). Results: Thesensitivity and specificity of this algorithm for detecting elevated serum FSH in a group of 58 agricultural workers in thePeople's Republic of China were 100 % and 50 %, respectively. The sensitivity and specificity of this algorithm fordetecting low sperm counts in a population of 105 infertility patients at UCD were 58 % and 76 %, respectively.Conclusion: This test may have particular value in identifying populations with no evidence of testicular toxicity, andin which labor-intensive semen studies may not be feasible.