N-acetyltransferase 1 and 2 gene sequence variants and risk of head and neck cancer

Polymorphisms that alter the function of genes involved in the activation or detoxification of carcinogenic compounds can influence an individuals risk of developing cancer. Polymorphic changes modulating the acetylation capacity of the N-acetyltransferase (NAT) genes have been implicated in the risk of developing cancer. In this study the role of genetically determined individual NAT1 and NAT2 genotypes, haplotypes and haplotype combinations in the predisposition to head and neck cancer was investigated. Polymorphic regions of the NAT1 and NAT2 genes were analyzed in patients with head and neck cancer and healthy individuals by polymerase chain reaction-restriction fragment length polymorphism. Distribution of the genotypes, allele frequencies, diplotypes and haplotypes and correlation with clinical characteristics were evaluated. No association was observed between the NAT1*3, NAT1*10, NAT1*11, NAT2*5 and NAT2*6 genotypes and risk of head and neck cancer. The NAT2*7 slow genotype was associated with reduced risk of disease. A significant association was observed between the fast acetylator NAT2*4/NAT1*10 diplotype and risk of head and neck cancer. Combined haplotypes harboring the T1088A and C1095A variants characterizing the NAT1*10 allele were associated with increased risk. Our results suggest that NAT1 and NAT2 gene combinations may influence the risk of developing head and neck cancer.     

Double Staining of Skeleton Using Microwave Irradiation

The fetal skeleton double staining method is used to reveal developmental abnormalities in the skeletal system. We used alizarin red S and al-cian blue successfully with microwave irradiation for skeletal double staining. The fixation time was reduced from 4-7 days to 2-2.5 min and the staining time was reduced from 4 days to 23 min.     

Coronary arteriolar vasoconstriction to angiotensin II is augmented in prediabetic metabolic syndrome via activation of AT1 receptors

The metabolic syndrome is associated with activation of the renin-angiotensin system. However, whether the coronary vascular response to ANG II is altered under this condition is unknown. Experiments were conducted in control and chronically high-fat-fed dogs with the prediabetic metabolic syndrome both in vitro (isolated coronary arterioles, 60-110 microm) and in vivo (anesthetized and conscious). We found that plasma renin activity and ANG II levels are elevated in high-fat-fed dogs and that this increase in ANG II is associated with a significant increase in ANG II-mediated coronary vasoconstriction in isolated coronary arterioles and in anesthetized open-chest dogs. The vasoconstriction to ANG II is abolished by ANG II type 1 (AT1) receptor blockade. In conscious chronically instrumented dogs, AT1 receptor blockade with telmisartan improved the balance between coronary blood flow and myocardial oxygen consumption in the high-fat-fed dogs but not in normal control dogs, i.e., the relationship between coronary venous Po2 and myocardial oxygen consumption was shifted upward, toward normal control values. Quantitative assessment of coronary arteriolar AT1 and ANG II type 2 (AT2) receptor mRNA levels by real-time PCR revealed no significant difference between normal control and high-fat-fed dogs; however, Western blot analysis showed a significant increase in AT1 receptor protein level with no change in AT2 receptor protein density. These findings indicate that AT1 receptor-mediated coronary constriction is augmented in the prediabetic metabolic syndrome and contributes to impaired control of coronary blood flow via increases in circulating ANG II and/or coronary arteriolar AT1 receptor density.     

Eater: a big bite into phagocytosis

The phagocytosis of invading microorganisms by specialized blood cells is a crucial element of innate immunity in both mammals and insects. In this issue of Cell, Kocks et al. (2005) demonstrate that Eater, a scavenger receptor, plays an important role in the recognition and phagocytosis of bacteria in the fruit fly Drosophila.     

Neolignan glucosides from Phlomis chimerae Boiss

From the aerial parts of the plant Phlomis chimerae, a new neolignan glucoside, (-)-4-O-methyldihydrodehydrodiconiferyl alcohol-9'-O-beta-D-glucopyranoside (1) was characterized along with the known neolignan glucosides, (-)-4-O-methyldehydrodiconiferyl alcohol-9'-O-beta-D-glucopyranoside (= longifloroside A) (2) and (-)-dihydrodehydrodiconiferyl alcohol-9-O-beta-D-glucopyranoside (3). The structure of the new compound was established on the basis of spectroscopic evidence.     

Hepatic adverse events during highly active antiretroviral therapy containing nevirapine: a case report

Background  

Hepatotoxicity is one of the most serious complications of highly active antiretroviral therapy (HAART). The aim of this report is to analyse an HIV infected patient on HAART including nevirapine and taking antidepressive agents, with acute toxic hepatitis.