Identification and expression of human cytomegalovirus transcription units coding for two distinct Fcgamma receptor homologs

Cellular receptors for the Fc domain of immunoglobulin G (IgG) (FcgammaRs) comprise a family of surface receptors on immune cells connecting humoral and cellular immune responses. Several herpesviruses induce FcgammaR activities in infected cells. Here we identify two distinct human cytomegalovirus (HCMV)-encoded vFcgammaR glycoproteins of 34 and 68 kDa. A panel of HCMV strains exhibited a slight molecular microheterogeneity between Fcgamma-binding proteins, suggesting their viral origin. To locate the responsible genes within the HCMV genome, a large set of targeted HCMV deletion mutants was constructed. The mutant analysis allowed the identification of a spliced UL119-UL118 mRNA to encode vFcgammaR gp68 and TRL11/IRL11 to encode vFcgammaR gp34. Both vFcgammaRs are surface resident type I transmembrane glycoproteins. Significant relatedness of sequences in the extracellular chain of gpUL119-118 and gpTRL11 with particular immunoglobulin supergene family domains present in FcgammaR I and FcgammaRs II/III, respectively, indicates a different ancestry and function of gpUL119-118 and gpTRL11. The HCMV-encoded vFcgammaRs highlight an impressive diversification and redundancy of FcgammaR structures.     

Zinc and copper status in acute pancreatitis: an experimental study

Metal ions are required as active components of several proteins, including pancreatic enzymes, and they can play important roles in the etiopathogenesis of acute pancreatitis. In the present study, we measured the concentrations of zinc (Zn) and copper (Cu) in both serum and pancreatic tissue, as markers of trace element status in an experimental acute pancreatitis model. Twenty-four male Wistar rats were divided into two groups: the experimental group (N=24) and the control group (N=10). Acute pancreatitis was induced by injection of 48% ethyl alcohol into the common biliary duct. The animals were sacrificed 24 h later to detect the concentrations of Zn and Cu. There was no significant difference in tissue Zn and Cu concentrations between control and experimental groups (p<0.05). However, in the acute pancreatitis group, serum Zn and Culevels were very significantly lower (p<0.001 and p<0.0001, respectively). In conclusuion, these findings suggested that altered mineral metabolism in serum and pancreatic tissue may have contributed to the pathophysiology of acute pancreatitis.     

Prevalence of monochloroacetate degrading genotypes among soil isolates of Pseudomonas

This study reports the isolation of Pseudomonas sp strains with monochloroacetate (MCA) degradation function, from uncontaminated soil, and the use of Southern blot hybridization technique to detect MCA degrading catabolic genes and their divergence. Based on their capacity to remove Cl^- from MCA in a minimal medium containing 185 ppm Cl^-, the strains were classified into three groups: poor degraders (Cl^- release between 0–15 ppm), medium degraders (Cl^- release between 16–30 ppm), and high degraders (Cl^- release between 31–45 ppm).We have applied a gene probe assay for determining the diversity of MCA degradative genotypes of 61 strains. Two different gene probes, dehCI and dehCII were used in Southern blot hybridization assays. Majority of the DNA samples that produced signals on the membrane blots (18 out of 24)hybridized with only dehCI DNA probe, while 6strains hybridized with only dehCII probe. On the other hand, 37 isolates did not hybridize to either of the gene probes used. The results indicated the high specificity of the DNA hybridization method and the divergence of metabolic functions and/or genotypes among the native MCA-degrading Pseudomonas sp. populations in the soil. This revised version was published online in August 2006 with corrections to the Cover Date.     

Anion inhibition studies of the α-carbonic anhydrase from the pathogenic bacterium Vibrio cholerae

An α-carbonic anhydrase (CA, EC 4.2.1.1) has been recently cloned and characterized in the human pathogenic bacterium Vibrio cholerae, denominated VchCA (Del Prete et al. J. Med. Chem. 2012, 55, 10742). This enzyme shows a good catalytic activity for the CO₂ hydration reaction, comparable to that of the human (h) isoform hCA I. Many inorganic anions and several small molecules were investigated as VchCA inhibitors. Inorganic anions such as cyanate, cyanide, hydrogen sulfide, hydrogen sulfite, and trithiocarbonate were effective VchCA inhibitors with inhibition constants in the range of 33–88 μM. Other effective inhibitors were diethyldithiocarbamate, sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid, with K_Is of 7–43 μM. Halides (bromide, iodide), bicarbonate and carbonate were much less effective VchCA inhibitors, with K_Is in the range of 4.64–28.0 mM. The resistance of VchCA to bicarbonate inhibition may represent an evolutionary adaptation of this enzyme to living in an environment rich in this ion, such as the gastrointestinal tract, as bicarbonate is a virulence enhancer of this bacterium.     

The effects of vitamin C supplementation on oxidative stress and antioxidant content in the brains of chronically exercised rats

The purpose of this study was to ascertain whether vitamin C supplementation during chronic exercise training alters rat brain antioxidant content. Female Wistar albino rats were exercised on a treadmill for 30 min/day for 6.5 weeks and were administered daily intraperitoneal injections of vitamin C (20 mg/kg). After the training period, chronically exercised rats showed no significant changes in total brain thiobarbituric acid reactive substances (TBARS) levels. In contrast, rats supplemented with vitamin C during the training period showed significantly elevated brain TBARS levels. If such results were extrapolated to man, where vitamin supplementation is a common practice, this would indicate that vitamin C supplementation may not protect brain tissue against exercise-induced oxidative damage, in such circumstances, this water-soluble antioxidant behaves as a pro-oxidant. (Mol Cell Biochem xxx: 135–138, 2005)     

Alterations in promoter methylation status of tumor suppressor HIC1, SFRP2, and DAPK1 genes in prostate carcinomas

Hypermethylated genomic DNA is a common feature in tumoral tissues, although the prevalence of this modification remains poorly understood. We aimed to determine the frequency of five tumor suppressor (TS) genes in prostate cancer and the correlation between promoter hypermethylation of these genes and low and high grade of prostate carcinomas. A total of 30 prostate tumor specimens were investigated for promoter methylation status of TS hypermethylated in cancer 1 (HIC1), death-associated protein kinase 1 (DAPK1), secreted frizzled-related protein 2 (SFRP2), cyclin-dependent kinase inhibitor 2A (p16), and O-6-methylguanine-DNA methyltransferase (MGMT) genes by using bisulfite modifying method. A high frequency of promoter hypermethylation was found in HIC1 (70.9%), SFRP2 (58.3%), and DAPK1 (33.3%) genes in tumor samples that were examined. The current data show high frequency of hypermethylation changes in HIC1, SFRP2, and DAPK1 genes in prostate carcinomas of high Gleason Score (GS).     

Oxidative Stress in Helicobacter pylori Infection: Does Supplementation with Vitamins C and E Increase the Eradication Rate?

Aim: This study aims to assess the antioxidant property of vitamins E and C in Helicobacter pylori infection, and to determine if adding them to standard triple therapy plus bismuth subcitrate increases the H. pylori eradication rate. Methods: This study included 160 patients infected with H. pylori, who were randomized into one of two groups. Patients in group A (n = 80) received lansoprazole (30 mg, b.i.d.), amoxicillin (1000 mg, b.i.d.), clarithromycin (500 mg, b.i.d.), and bismuth subcitrate (300 mg, q.i.d.) for 14 days, while patients in group B (n = 80) received vitamin C (500 mg, b.i.d.) and vitamin E (200 IU, b.i.d.) for 30 days, in addition to lansoprazole (30 mg, b.i.d.), amoxicillin (1000 mg, b.i.d.), clarithromycin (500 mg, b.i.d.), and bismuth subcitrate (300 mg, q.i.d.) for 14 days. Total antioxidant capacity (TAC) was evaluated with a Randox kit. Success rate was calculated using both intention‐to‐treat (ITT) and per‐protocol (PP) analyses. Results: One hundred and sixty patients were analyzed using ITT analysis. One hundred and fifty‐three patients completed the study. In group A, H. pylori eradication was achieved in 48 (60%) of the 80 patients included in the ITT analysis, and in 48 (64%) of the 75 patients included in the PP analysis. In group B, H. pylori eradication was achieved in 73 (91.25%) of the 80 included in the ITT analysis and in 73 (93.5%) of the 78 patients included in the PP analysis. The eradication rate was significantly higher in group B than in group A (p < .005). TAC was at the lower limit of normal in both groups and the difference between them was not statistically significant (p > .05). Conclusion: In group B, H. pylori eradication rate was 91.25%, which is higher than the ideal 80% eradication rate. The results of the present study show that adding the prescribed doses of vitamins E and C to antimicrobial therapy is effective in eradicating H. pylori infection.     

Assessment of DNA damage in women using oral contraceptives

The effect of the use of an oral contraceptive (OC) on the frequency of sister chromatid exchanges (SCEs) and on the response in the alkaline comet assay (single-cell gel electrophoresis (SCGE)) was investigated in 18 women taking contraceptive pills daily for 24 months. As controls, fertile women were included with regular menstrual cycles who received no OC drugs. A significant increase in the number of lymphocytes with DNA migration and an increased frequency of SCE per metaphase were observed in OC users as compared with their age-matched untreated controls (P<0.005). As higher incidences of spontaneous SCEs in peripheral blood lymphocytes have been reported to occur in females during pregnancy due to profound changes in the levels of certain sex hormones such as progesterone and estrogen, particularly during the last trimester, 17 pregnant women served as positive controls in this study in order to test the rate of genetic damage due to those changes. Higher frequencies of SCEs and comet responses were observed in pregnant women than in their matched controls. However, no statistically significant difference in DNA damage was observed between OC users and pregnant women (P>0.05). This study underscores the fact that prolonged and extensive use of these drugs in our daily life may be hazardous and also, that OC users should be aware of multifactorial risk factors (environmental, genetic and life style patterns) that may be responsible for additional DNA damage.     

Free oxygen radical-induced lipid peroxidation and antioxidant in infants receiving total parenteral nutrition

OBJECTIVE: Increased oxygen-derived free radical activity has been reported during total parenteral nutrition (TPN) in infants particularly linked to the fat infusion. It is possible that partial enteral feeding can ameliorate some of the complications of TPN. By this study we aimed to investigate free radical formation and antioxidant activity in term and preterm infants during TPN and/or enteral feeding. STUDY DESIGN: We had 6 groups of term and preterm infants made up of 10 patients each. Group I had only enteral feeding, Group II enteral plus parenteral feeding, Group III only parenteral feeding. Plasma malondialdehyde (MDA), superoxide dismutase (SOD), vitamin E and vitamin C levels were measured in all infants. Blood samples of infants receiving only TPN and TPN plus enteral feeding were measured on the 1st and 5th days, and 3h after the end of lipid infusion. RESULTS: There was no difference between the term and preterm infants in terms of MDA, SOD, vitamin C and E levels taken baseline and after parenteral, and enteral plus parenteral feeding on the 1st and 5th days. When 3 groups of both term and preterm infants were compared with each other none of the parameters showed a statistically significant difference. In addition, we compared baseline and 1st and 5th days of TPN therapy in both term and preterm infants fed only parenterally and enteral plus parenteral feedings. In term infants fed both parenterally and parenteral plus enterally, the MDA levels before TPN were significantly higher than that of the levels of patients on parenteral nutrition on the 5th day. On the 1st and 5th days of TPN therapy, the levels of vitamin C was significantly decreased, in term and preterm infants fed only parenterally, levels of vitamin E was increased, in term and preterm infants fed both parenterally and parenteral plus enterally. Also, when compared to their base line the SOD levels of the term infants detected on the 1st and 5th days were significantly high. CONCLUSION: Free radical production is increased by the administration of TPN and may be linked to its adverse effects. It may be assumed that long-term complications of preterm infants receiving TPN may be reduced by further strengthening the antioxidant capacities of the TPN solutions.