Relation of smoking and alcohol and coffee consumption to active Helicobacter pylori infection: cross sectional study.

OBJECTIVE: To assess the relation of smoking and alcohol and coffee consumption to active Helicobacter pylori infection. DESIGN: Cross sectional study of patients attending a general practitioner. Active H pylori infection was measured by the 15C-urea breath test and detailed quantitative information on smoking and on alcohol and coffee consumption was obtained by a standardised self administered questionnaire. SETTING: One general practice in Germany. SUBJECTS: 447 patients aged 15-79 who had not had peptic ulcer disease or treatment for H pylori infection. MAIN OUTCOME MEASURES: Prevalence of H pylori infection according to smoking and alcohol and coffee consumption. RESULTS: Overall prevalence of infection was 21% (94/447). There was no significant relation between smoking and active H pylori infection. Alcohol consumption showed a negative dose-response relation and coffee consumption a positive dose-response relation with active infection. After adjustment for potential confounders, the odds ratios for patients who drank < or = 75 g and > 75 g of ethanol a week compared with non-drinkers were 0.90 (95% confidence interval 0.55 to 1.59) and 0.33 (0.16 to 0.68), respectively (P value for trend 0.005, assuming that 1 litre of beer and 0.51 of wine contain on average 50 g of ethanol in south Germany). Adjusted odds ratios for patients who drank < 3 cups and > or = 3 cups of coffee per day compared with those who did not drink coffee were 1.49 (0.71 to 3.12) and 2.49 (1.23 to 5.03), respectively (P value for trend 0.007). CONCLUSION: These results suggest a protective effect of alcohol consumption against active infection with H pylori and an opposite effect of coffee consumption.     

Liver cytosolic fatty acids binding proteins in rats and Psammomys obesus: modulation in diabetes

The effect of insulin on [3H]oleate binding to delipidated liver cytosolic proteins was studied in four groups of animals: untreated rats, streptozotocin induced diabetic rats, Psammomys obesus fed salt bush diet, and Psammomys obesus fed ordinary laboratory chow. The distribution of the protein bound [3H]oleate between low and high molecular weight cytosolic proteins in Psammomys differed from the distribution found in rats. Diet induced high insulin diabetes in Psammomys and streptozotocin induced low insulin diabetes in rats, modulated [3H]oleate binding in the same manner.     

The roles of abiotic factors, dispersal, and species interactions in structuring stream assemblages of black flies (Diptera: Simuliidae)

ABSTRACT: BACKGROUND: The patterns and drivers of species assemblages represent the core of community ecology.We focus on the assemblages of a single family of ubiquitous lotic insects, the Simuliidae(black flies), of which the larvae play a critical role in resource turnover in steams. We useMantel tests and null models to tease out the potential influence of abiotic stream conditions,species interactions, and dispersal on the assemblage patterns of larval black flies over twospatial scales (within and across ecoregions) and two seasons (spring and summer). RESULTS: When stream sites were considered across ecoregions in the spring, stream conditions anddispersal were correlated significantly with species similarity; however, within ecoregions inthe spring, dispersal was important only in the Piedmont and Sandhills and abiotic factorsonly in the Mountains. In contrast, results of the summer analyses within and acrossecoregions were congruent; assemblage similarity was significantly correlated with streamconditions both across and within ecoregions. Null models suggested that patterns of speciessegregation in the spring were consistent with a community structured by competition,whereas patterns in the summer were consistent with species assemblages influenced byabiotic factors. CONCLUSIONS: Species composition of black flies at streams sites is correlated with dispersal factors andstream conditions, but results vary over spatial and temporal scales. Communities of blackflies can be viewed within a metacommunity context; local assemblages are consistent withspecies sorting and mass effects. Given that black flies have a terrestrial stage, with femalesdeciding where to place the eggs, a full understanding of the processes that determine local aquatic assemblages will require integration of the dynamics of the aquatic immature stagesand the terrestrial adults.     

Metamorphosestudien an Batrachierlarven

Ohne Zusammenfassung     

The ecological significance of toxic nectar

Although plant-herbivore and plant-pollinator interactions have traditionally been studied separately, many traits are simultaneously under selection by both herbivores and pollinators. For example, secondary compounds commonly associated with herbivore defense have been found in the nectar of many plant species, and many plants produce nectar that is toxic or repellent to some floral visitors. Although secondary compounds in nectar and toxic nectar are geographically and phylogenetically widespread, their ecological significance is poorly understood. Several hypotheses have been proposed for the possible functions of toxic nectar, including encouraging specialist pollinators, deterring nectar robbers, preventing microbial degradation of nectar, and altering pollinator behavior. All of these hypotheses rest on the assumption that the benefits of toxic nectar must outweigh possible costs; however, to date no study has demonstrated that toxic nectar provides fitness benefits for any plant. Therefore, in addition to these adaptive hypotheses, we should also consider the hypothesis that toxic nectar provides no benefits or is tolerably detrimental to plants, and occurs due to previous selection pressures or pleiotropic constraints. For example, secondary compounds may be transported into nectar as a consequence of their presence in phloem, rather than due to direct selection for toxic nectar. Experimental approaches are necessary to understand the role of toxic nectar in plant-animal interactions.