Association of insulinase gene polymorphisms with type 2 diabetes mellitus in patients from the Moscow population

Association of 13 single nucleotide polymorphisms (SNPs) of insulinase (IDE) gene with type 2 diabetes mellitus (T2D) in the Moscow population has been examined. Three polymorphic markers (rs7078413, rs7899603, and rs551266) associated with the risk of T2D development have been revealed. Allele and genotype frequency distribution for these three markers differed significantly only in the sample of females between T2D patients and control individuals, while only in case of rs7078413 SNP genotype frequencies varied significantly in the total population.     

The antidepressant-like effect of Ocimum basilicum in an animal model of depression

We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus.     

Metabolomic linkage reveals functional interaction between glucose-dependent insulinotropic polypeptide and ghrelin in humans

The gastric peptide ghrelin promotes energy storage, appetite, and food intake. Nutrient intake strongly suppresses circulating ghrelin via molecular mechanisms possibly involving insulin and gastrointestinal hormones. On the basis of the growing evidence that glucose-dependent insulinotropic polypeptide (GIP) is involved in the control of fuel metabolism, we hypothesized that GIP and/or insulin, directly or via changes in plasma metabolites, might affect circulating ghrelin. Fourteen obese subjects were infused with GIP (2.0 pmol·kg(-1)·min(-1)) or placebo in the fasting state during either euglycemic hyperinsulinemic (EC) or hyperglycemic hyperinsulinemic clamps (HC). Apart from analysis of plasma ghrelin and insulin levels, GC-TOF/MS analysis was applied to create a hormone-metabolite network for each experiment. The GIP and insulin effects on circulating ghrelin were analyzed within the framework of those networks. In the HC, ghrelin levels decreased in the absence (19.2% vs. baseline, P = 0.028) as well as in the presence of GIP (33.8%, P = 0.018). Ghrelin levels were significantly lower during HC with GIP than with placebo, despite insulin levels not differing significantly. In the GIP network combining data on GIP-infusion, EC+GIP and HC+GIP experiments, ghrelin was integrated into hormone-metabolite networks through a connection to a group of long-chain fatty acids. In contrast, ghrelin was excluded from the network of experiments without GIP. GIP decreased circulating ghrelin and might have affected the ghrelin system via modification of long-chain fatty acid pools. These observations were independent of insulin and offer potential mechanistic underpinnings for the involvement of GIP in systemic control of energy metabolism.     

Productivity of forests in the Eurosiberian boreal region and their potential to act as a carbon sink –- a synthesis

Based on review and original data, this synthesis investigates carbon pools and fluxes of Siberian and European forests (600 and 300 million ha, respectively). We examine the productivity of ecosystems, expressed as positive rate when the amount of carbon in the ecosystem increases, while (following micrometeorological convention) downward fluxes from the atmosphere to the vegetation (NEE = Net Ecosystem Exchange) are expressed as negative numbers. Productivity parameters are Net Primary Productivity (NPP=whole plant growth), Net Ecosystem Productivity (NEP = CO₂ assimilation minus ecosystem respiration), and Net Biome Productivity (NBP = NEP minus carbon losses through disturbances bypassing respiration, e.g. by fire and logging). Based on chronosequence studies and national forestry statistics we estimate a low average NPP for boreal forests in Siberia: 123 gC m^–2 y^–1. This contrasts with a similar calculation for Europe which suggests a much higher average NPP of 460 gC m^–2 y^–1 for the forests there. Despite a smaller area, European forests have a higher total NPP than Siberia (1.2–1.6 vs. 0.6–0.9 × 10¹⁵ gC region^–1 y^–1). This arises as a consequence of differences in growing season length, climate and nutrition. For a chronosequence of Pinus sylvestris stands studied in central Siberia during summer, NEE was most negative in a 67-y old stand regenerating after fire (– 192 mmol m^–2 d^–1) which is close to NEE in a cultivated forest of Germany (– 210 mmol m^–2 d^–1). Considerable net ecosystem CO₂-uptake was also measured in Siberia in 200- and 215-y old stands (NEE:174 and – 63 mmol m^–2 d^–1) while NEP of 7- and 13-y old logging areas were close to the ecosystem compensation point. Two Siberian bogs and a bog in European Russia were also significant carbon sinks (– 102 to – 104 mmol m^–2 d^–1). Integrated over a growing season (June to September) we measured a total growing season NEE of – 14 mol m^–2 summer^–1 (– 168 gC m^–2 summer^–1) in a 200-y Siberian pine stand and – 5 mol m^–2 summer^–1 (– 60 gC m^–2 summer^–1) in Siberian and European Russian bogs. By contrast, over the same period, a spruce forest in European Russia was a carbon source to the atmosphere of (NEE: + 7 mol m^–2 summer^–1 = + 84 gC m^–2 summer^–1). Two years after a windthrow in European Russia, with all trees being uplifted and few successional species, lost 16 mol C m^–2 to the atmosphere over a 3-month in summer, compared to the cumulative NEE over a growing season in a German forest of – 15.5 mol m^–2 summer^–1 (– 186 gC m^–2 summer^–1; European flux network annual averaged – 205 gC m^–2 y^–1). Differences in CO₂-exchange rates coincided with differences in the Bowen ratio, with logging areas partitioning most incoming radiation into sensible heat whereas bogs partitioned most into evaporation (latent heat). Effects of these different surface energy exchanges on local climate (convective storms and fires) and comparisons with the Canadian BOREAS experiment are discussed. Following a classification of disturbances and their effects on ecosystem carbon balances, fire and logging are discussed as the main processes causing carbon losses that bypass heterotrophic respiration in Siberia. Following two approaches, NBP was estimated to be only about 13–16 mmol m^–2 y^–1 for Siberia. It may reach 67 mmol m^–2 y^–1 in North America, and about 140–400 mmol m^–2 y^–1 in Scandinavia. We conclude that fire speeds up the carbon cycle, but that it results also in long-term carbon sequestration by charcoal formation. For at least 14 years after logging, regrowth forests remain net sources of CO₂ to the atmosphere. This has important implications regarding the effects of Siberian forest management on atmospheric concentrations. For many years after logging has taken place, regrowth forests remain weaker sinks for atmospheric CO₂ than are nearby old-growth forests.     

Using wintergreen oil for mounting mosquito larvae: a safer alternative to xylene

Permanent mounting of fourth instar mosquito larvae is essential for identifying Aedes spp. This procedure requires extensive exposure to xylene, a clearing agent in the mounting process. We investigated wintergreen oil as a substitute for xylene. Five hundred larvae were mounted on slides to evaluate shrinkage or expansion of specimens after clearing using xylene or wintergreen oil. We examined the ventral brush and siphonal hair tufts for species identification and for preservation of morphological characteristics after clearing specimens in xylene or wintergreen oil. Shrinkage of the length of whole larvae and width of the head, thorax and abdomen after mounting was significantly greater after clearing with xylene than with wintergreen oil. The length of the comb scale nearest the ventral brush was similar for both clearing agents. The clarity of the specimens after mounting was improved by clearing with wintergreen oil, but the integrity of the ventral brush and siphonal hair tufts were similar for both clearing agents.     

Ghrelin is not suppressed in hyperglycemic clamps by gastric inhibitory polypeptide and arginine

Systemic ghrelin concentration falls rapidly after nutrient ingestion in vivo. The effect incretins on ghrelin secretion in humans remains unclear. We quantified circulating ghrelin concentrations under hyperglycemic conditions combined with infusion of gastric inhibitory polypeptide (GIP) and arginine. METHODS: Eight healthy volunteers were studied with a hyperglycemic clamp followed by addition of GIP (2 pmol.kg(-1).min(-1), 60-115 min) and an arginine-bolus and -infusion (10 mg.kg(-1).min(-1), 90-115 min). RESULTS: Hyperglycemia alone increased circulating insulin concentrations (p<0.01), and decreased ghrelin concentrations to 89.8% of basal (p=0.208). GIP-infusion resulted in circulating insulin concentration of 1109+/-942 pmol/l (p<0.02) and no further decrease of ghrelin (86.2% of baseline, p=0.050). Under arginine- and GIP-infusion together, insulin concentrations increased progressively to 3005+/-1604 pmol/l (p<0.01) without further decreasing in ghrelin concentrations (98.9% of baseline, p=0.575). CONCLUSIONS: Hyperglycemic hyperinsulinemia and further increases of hyperinsulinemia to supraphysiological and high supraphysiological concentrations under GIP- and arginine-infusion do not significantly decrease ghrelin concentrations in healthy subjects. Moreover, there is no dose-dependent suppression of ghrelin by insulin in the hyperglycemic condition. Neither GIP nor arginine affected ghrelin release.