Time course of DNA adduct formation in peripheral blood granulocytes and lymphocytes after drinking alcohol

Alcohol consumption is an established risk factor for cancers of the head and neck, colorectum, liver and female breast. Acetaldehyde, the primary metabolite of ethanol, is suspected to play a major role in alcohol-related carcinogenesis. Acetaldehyde binds to DNA resulting in formation of adducts. DNA adducts are involved in mutagenesis and carcinogenesis. N (2)-Ethylidenedeoxyguanosine (N (2)-ethylidene-dGuo) is the major adduct formed in this reaction. Studies have shown an association between alcohol drinking and levels of this DNA adduct, suggesting its potential use as a biomarker for studying alcohol-related carcinogenesis. However, there are no reports on the kinetics of formation and repair of N (2)-ethylidene-dGuo after alcohol consumption. Therefore, we investigated levels of N (2)-ethylidene-dGuo in DNA from human peripheral blood cells at several time points after consumption of increasing doses of alcohol. Ten healthy non-smokers were recruited and asked to abstain from alcohol consumption except for the study doses. The subjects were given measured doses of alcohol once a week for 3 weeks, targeting increasing blood alcohol levels. Blood was collected at several time points before and after each dose, DNA was isolated from granulocytes and lymphocytes and N (2)-ethylidene-dGuo was quantified as its NaBH(3)CN reduction product N ( 2 )-ethyldeoxyguanosine by liquid chromatography-electrospray ionisation-tandem mass spectrometry. Significant increases in N (2)-ethylidene-dGuo were observed after all doses and in both cell types. However, there was substantial intraindividual variability, indicating that there are other important sources of this adduct in peripheral blood DNA. Further studies are needed to better understand the origins of N (2)-ethylidene-dGuo in blood cells, the exposures it reflects, and thus its potential use as a marker of alcohol's genotoxic effects.     

Effect of Lactobacillus GG and breast-feeding in the prevention of rotavirus nosocomial infection

BACKGROUND: Rotavirus is one of the leading etiologic agents of nosocomial infections among children. The development of preventive measures is therefore important. The efficacy of GG in the treatment of rotavirus infection has been reported in literature, but there is only one recent study about its effectiveness in prevention of infection. The role of breast-feeding in the prevention of rotavirus infection is still debated. The aim of our study was to assess the efficacy of GG and breast-feeding in the prevention of nosocomial rotavirus infections. METHODS: In a randomized, placebo-controlled, double-blind study, 220 children aged 1 to 18 months hospitalized from December 1999 to May 2000, received GG (n = 114) at a dose of 10 colony-forming units or a comparable placebo (n = 106) every day of their hospital stay. Rotavirus testing on stool samples was performed for every patient on admission, during hospitalization, and after discharge. RESULTS: The total incidence of nosocomial rotavirus infections was 27.7% (61 of 220 patients). The attack rate of rotavirus infections among the patients who received probiotic was 25.4% (29 of 114 patients), while for the placebo group it was 30.2% (32 of 106 patients). The difference is not significant (P = 0.432). Forty-seven of 220 infants (21.4%) were breast-fed, and 173 of 220 (78.6%) were non-breast-fed. The attack rate of rotavirus infections among breast-fed infants was 10.6% (5 of 47 infants), while for non-breast-fed infants it was 32.4% (56 of 173 infants). The difference is significant (P = 0.003). CONCLUSION: In our study, GG was ineffective in preventing nosocomial rotavirus infections, whereas breast-feeding was effective.     

Duodenal–Jejunal Bypass Surgery Enhances Glucose Tolerance and Beta-Cell Function in Western Diet Obese Rats

Background  

The aim of this study was to investigate the effect of the duodenal–jejunal bypass (DJB) on glucose homeostasis and islet insulin secretion in Western diet (WD) obese rats.     

Increased expression of the CD80 accessory molecule by alveolar macrophages in asthmatic subjects and its functional involvement in allergen presentation to autologous TH2 lymphocytes.

BACKGROUND: Alveolar macrophages (AMs) are more efficient antigen-presenting cells in allergic individuals than in nonatopic subjects. OBJECTIVE: We studied whether this difference may be correlated to increased expression of membrane costimulatory molecules, such as the B7 molecules (CD80 and CD86). METHODS: Eleven subjects with allergic asthma sensitized to Dermatophagoides pteronyssinus and 5 healthy nonatopic volunteers underwent bronchoalveolar lavage, and the costimulatory molecule expression on AMs was evaluated. Peripheral blood T cells, either freshly isolated or as established D pteronyssinus -specific cell lines, were cultured with autologous monocytes or AMs as antigen-presenting cells. In vitro allergen-induced proliferation and cytokine production were evaluated in the presence of B7-blocking reagents. RESULTS: Allergic individuals had a significantly higher proportion of AMs expressing the CD80 molecule than control subjects (28.5% +/- 14.8% vs 1.4% +/- 1.2%; P <.001), whereas no difference was observed in CD86 expression (2.0% +/- 2.3% vs 1.1% +/- 0.6; P >.1). In a large proportion of the asthmatic subjects we studied, AMs were presenting soluble antigens (tetanus toxoid and streptolysin-O) to freshly isolated T cells more efficiently than AMs from nonatopic control subjects. Finally, both T-cell proliferation and cytokine production of D pteronyssinus- specific established T-cell lines were inhibited by a CD80-blocking antibody in a dose-dependent manner. CONCLUSION: Costimulation by means of CD80 expressed by AMs is probably involved in the amplification of the allergen-specific T-lymphocyte response in the airways of asthmatic subjects.     

Improvement in antipsychotic-related metabolic disturbances in patients with schizophrenia switched to ziprasidone

PURPOSE: This study evaluated changes in weight, glucose and lipid metabolism in patients with schizophrenia and antipsychotic-related metabolic disturbances who were switched to ziprasidone. METHODS: Eighty-four outpatients with schizophrenia or schizoaffective disorder also having glucose intolerance, diabetes, dyslipidemia or weight gain related to their antipsychotic treatment were switched to ziprasidone. Clinical status was assessed using the Clinical Global Impression of Severity (CGI-S) and Improvement (CGI-I) scales and the Positive and Negative Syndrome Scale (PANSS). Assessment scales, weight, glucose and lipids were measured at baseline and at three and six months of ziprasidone treatment. RESULTS: Significant baseline to endpoint reductions were seen in mean weight (-5.1 kg), Body Mass Index (BMI; -1.6 kg/m(2)), serum glucose (-14.0 mg/dL), total cholesterol (-24.1 mg/dL), and triglyceride leves (-46.2 mg/dL). Mean PANSS total score improved 13.9% after 6 months of treatment with ziprasidone. A proportion (34.3%) of patients were classified as much improved in the CGI-I. CONCLUSIONS: Switching patients with schizophrenia to ziprasidone when metabolic disturbances are detected may improve these side effects and result in an improved overall outcome.     

Autocrine activation of human monocyte/macrophages by monocyte-derived microparticles and modulation by PPARγ ligands

BACKGROUND AND PURPOSE

Microparticles (MPs), small membrane-bound particles originating from different cell types during activation or apoptosis, mediate intercellular communication, exert pro-coagulant activity and affect inflammation and other pathophysiological conditions. Monocyte-derived MPs have undergone little investigation and, to our knowledge, have never been evaluated for their possible autocrine effects. Therefore, we assessed the ability of monocyte-derived MPs to stimulate human monocytes and monocyte-derived macrophages (MDM).

EXPERIMENTAL APPROACH

MPs were generated from supernatants of human monocytes stimulated by the calcium ionophore A23187 (12 µM), and then characterized. Human monocytes and MDM of healthy donors were isolated by standard procedures. Cells were challenged by MPs or phorbol 12-myristate 13-acetate (PMA, used as standard stimulus), in the absence or presence of PPARγ agonists and antagonists. Superoxide anion production (measured spectrophotometrically), cytokine release (elisa), PPARγ protein expression (immunoblotting) and NF-κB activation (EMSA assay) were evaluated.

KEY RESULTS

Monocyte-derived MPs induced, in a concentration-dependent manner, oxygen radical production, cytokine release and NF-κB activation in human monocytes and macrophages, with lower effects than PMA. In both cell types, the PPARγ agonists rosiglitazone and 15-deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂) inhibited MPs-induced stimulation and this inhibition was reversed by a PPARγ antagonist. In human monocyte/macrophages, MPs as well as rosiglitazone and 15d-PGJ₂ induced PPARγ protein expression.

CONCLUSION AND IMPLICATIONS

In human monocyte/macrophages, monocyte-derived MPs exert an autocrine activation that was modulated by PPARγ ligands, inducing both pro-inflammatory (superoxide anion production, cytokine release and NF-κB activation) and anti-inflammatory (PPARγ expression) effects.     

Benefits of <Emphasis Type="SmallCaps">l</Emphasis>-alanine or <Emphasis Type="SmallCaps">l</Emphasis>-arginine supplementation against adiposity and glucose intolerance in monosodium glutamate-induced obesity

Purpose

l-alanine (Ala) and l-arginine (Arg) have been reported to regulate pancreatic β-cell physiology and to prevent body fat accumulation in diet-induced obesity. Here, we assessed growth and adiposity parameters, glucose tolerance, insulin secretion and the expression of insulin and nutrient-regulated proteins in monosodium glutamate (MSG)-obese mice supplemented with either Ala or Arg.

Methods

Male newborn C57Bl/6 mice received a daily subcutaneous injection of MSG or saline solution (CTL group), during the first 6 days of life. From 30 to 90 days of age, MSG and CTL mice received or not 2.55 % Ala (CAla or MArg groups) or 1.51 % Arg-HCl (CArg or MArg groups) in their drinking water.

Results

Adult MSG mice displayed higher adiposity associated with lower phosphorylation of the adipogenic enzyme, ACC, in adipose tissue. Glucose intolerance in MSG mice was linked to lower insulin secretion and to lower expression of IRβ in adipose tissue, as well as AS160 phosphorylation in skeletal muscle. Perigonadal fat depots were smaller in Ala and Arg mice, while retroperitoneal fat pads were decreased by Ala supplementation only. Both Ala and Arg improved fed-state glycemia as well as IRβ and pAS160 content, but only Ala led to improved glucose tolerance and insulin secretion. Adipostatic signals were increased in MAla mice, as indicated by enhanced AMPK phosphorylation and pACC content in fat depots.

Conclusions

Ala supplementation led to more pronounced metabolic improvements compared to Arg, possibly due to suppression of lipogenesis through activation of the AMPK/ACC pathway.