Taste difference thresholds for monosodium glutamate and sodium chloride in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi)

The purpose of this study was to determine taste difference thresholds for monosodium glutamate (MSG) and sodium chloride (NaCl) in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi). Using a two-bottle preference test of brief duration, three animals of each species were presented with four different reference concentrations of 50, 100, 200, and 400 mM of a tastant and tested for their ability to discriminate these from lower concentrations of the same tastant. The just noticeable differences (JNDs), expressed as Weber ratios (DeltaI/I), were found to range from 0.1 to 0.5 for MSG and 0.2 to 0.45 for NaCl in the pigtail macaques, with a significant tendency for higher Weber ratios with higher reference concentrations. In the spider monkeys, JNDs ranged from 0.15 to 0.4 for MSG and 0.1 to 0.25 for NaCl, with Weber ratios staying fairly constant across the reference concentrations tested. Thus, the JNDs were found to be generally similar in both species and to be at least as low as those found in humans for MSG and NaCl, as well as those found in spider monkeys for sucrose. The results support the assumption that both pigtail macaques and spider monkeys may use differences in perceived intensity of MSG and NaCl as a criterion for food selection.     

Hepatic minerals of white-tailed and mule deer in the southern Black Hills, South Dakota

Because there is a paucity of information on the mineral requirements of free-ranging deer, data are needed from clinically healthy deer to provide a basis for the diagnosis of mineral deficiencies. To our knowledge, no reports are available on baseline hepatic mineral concentrations from sympatric white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) using different habitats in the Northern Great Plains. We assessed variation in hepatic minerals of female white-tailed deer (n = 42) and mule deer (n = 41). Deer were collected in February and August 2002 and 2003 from study areas in Custer and Pennington Counties, South Dakota, in and adjacent to a wildfire burn. Hepatic samples were tested for levels (parts per million; ppm) of aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), boron (B), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), mercury (Hg), molybdenum (Mo), nickel (Ni), phosphorus (P), potassium (K), selenium (Se), sodium (Na), sulfur (S), thalium (Tl), and zinc (Zn). We predicted that variability in element concentrations would occur between burned and unburned habitat due to changes in plant communities and thereby forage availability. We determined that Zn, Cu, and Ba values differed (P 相似文献   

Preliminary biological evaluation of poli(amidoamine) (PAMAM) dendrimer G3.5 on selected parameters of rat liver mitochondria

Polyamidoamino (PAMAM) dendrimer of generation 3.5 (G3.5) specific interactions with rat liver mitochondria were studied. Selected parameters of mitochondria (transmembrane potential and uptake of Ca2+ ions) were investigated after the exposure to G3.5 used at the concentration of 10, 30 and 50 microM and Ca2+ ions used at 1mM. The times of preincubation of isolated liver mitochondria with dendrimer were 5, 15 and 30 min at room temperature. The mitochondrial membrane potential was monitored spectrofluorimetrically by fluorescence quenching of Rhodamine 123 (Rh 123). The changes in calcium homeostasis upon dendrimer exposure were detected using flow cytometric analysis with Fluo-3. On the one hand the obtained results revealed an impact of the tested chemical on rat liver mitochondrial function. We found that dendrimer G3.5 in a concentration above 10 microM contributes to the reduction in the transmembrane potential and hinders in the influx of Ca2+ ions to mitochondria added externally, or accelerates their efflux from mitochondria. The most effective preincubation time was observed to be 15 min for all tested concentrations. On the other hand the combined treatment of dendrimer G3.5 with Ca2+ demonstrated the protective effect of G3.5 against mitochondrial depolarization caused by calcium ions. These preliminary studies suggest that tested dendrimer can significantly affect the mitochondria and modulate their functionality.     

Anthocyanins: from plant to health

Anthocyanins are a group of natural occurring pigments responsible for the red-blue colour of many fruits and vegetables. Anthocyanins are of interest for two reasons because they cannot only be used in the technological field as natural colorants but also have important implications in the field of human health. Numerous studies indicate the potential effect that this family of flavonoids may have in reducing the incidence of cardiovascular disease, cancer, hyperlipidemias and other chronic diseases through the intake of anthocyanin-rich foods. This review examines existing literature in this area: from plant content and distribution to health implications, including the effect of agronomic and genetic modifications on the anthocyanin content of plants as well as other biotechnological factors and food processing. The bioavailability, metabolism, bioactivity, and epidemiology of anthocyanins will also be reviewed.     

Quantification of nicotine, cotinine, trans-3'-hydroxycotinine, nornicotine and norcotinine in human meconium by liquid chromatography/tandem mass spectrometry

There are no analytical methods that simultaneously quantify nicotine, cotinine, trans-3'-hydroxycotinine, nornicotine and norcotinine in human meconium. Such a method could improve identification of in utero tobacco exposure, determine if maternal dose-meconium concentration relationships exist, and whether nicotine meconium concentrations predict neonatal outcomes. The first liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry method for simultaneous quantification of these analytes in meconium was developed and validated. Specimen preparation included homogenization, enzyme hydrolysis and solid phase extraction. The linear range was 1.25 or 5-500ng/g. Method applicability was evaluated with meconium collected from an in utero tobacco exposed infant.     

Purinergic receptors in the splanchnic circulation

There is considerable evidence that purines are vasoactive molecules involved in the regulation of blood flow. Adenosine is a well known vasodilator that also acts as a modulator of the response to other vasoactive substances. Adenosine exerts its effects by interacting with adenosine receptors. These are metabotropic G-protein coupled receptors and include four subtypes, A(1), A(2A), A(2B) and A(3). Adenosine triphosphate (ATP) is a co-transmitter in vascular neuroeffector junctions and is known to activate two distinct types of P2 receptors, P2X (ionotropic) and P2Y (metabotropic). ATP can exert either vasoconstrictive or vasorelaxant effects, depending on the P2 receptor subtype involved. Splanchnic vascular beds are of particular interest, as they receive a large fraction of the cardiac output. This review focus on purinergic receptors role in the splanchnic vasomotor control. Here, we give an overview on the distribution and diversity of effects of purinergic receptors in splanchnic vessels. Pre- and post-junctional receptormediated responses are summarized. Attention is also given to the interactions between purinergic receptors and other receptors in the splanchnic circulation.     

The FTO gene is associated with adulthood obesity in the Mexican population

Common polymorphisms in the fat mass and obesity-associated gene (FTO) have shown strong association with obesity in several populations. In the present study, we explored the association of FTO gene polymorphisms with obesity and other biochemical parameters in the Mexican population. We also assessed FTO gene expression levels in adipose tissue of obese and nonobese individuals. The study comprised 788 unrelated Mexican-Mestizo individuals and 31 subcutaneous fat tissue biopsies from lean and obese women. FTO single-nucleotide polymorphisms (SNPs) rs9939609, rs1421085, and rs17817449 were associated with obesity, particularly with class III obesity, under both additive and dominant models (P = 0.0000004 and 0.000008, respectively). These associations remained significant after adjusting for admixture (P = 0.000003 and 0.00009, respectively). Moreover, risk alleles showed a nominal association with lower insulin levels and homeostasis model assessment of B-cell function (HOMA-B), and with higher homeostasis model assessment of insulin sensitivity (HOMA-S) only in nonobese individuals (P (dom) = 0.031, 0.023, and 0.049, respectively). FTO mRNA levels were significantly higher in subcutaneous fat tissue of class III obese individuals than in lean individuals (P = 0.043). Risk alleles were significantly associated with higher FTO expression in the class III obesity group (P = 0.047). In conclusion, FTO is a major risk factor for obesity (particularly class III) in the Mexican-Mestizo population, and is upregulated in subcutaneous fat tissue of obese individuals.     

Transparent adult zebrafish as a tool for in vivo transplantation analysis

The zebrafish is a useful model for understanding normal and cancer stem cells, but analysis has been limited to embryogenesis due to the opacity of the adult fish. To address this, we have created a transparent adult zebrafish in which we transplanted either hematopoietic stem/progenitor cells or tumor cells. In a hematopoiesis radiation recovery assay, transplantation of GFP-labeled marrow cells allowed for striking in vivo visual assessment of engraftment from 2 hr-5 weeks posttransplant. Using FACS analysis, both transparent and wild-type fish had equal engraftment, but this could only be visualized in the transparent recipient. In a tumor engraftment model, transplantation of RAS-melanoma cells allowed for visualization of tumor engraftment, proliferation, and distant metastases in as little as 5 days, which is not seen in wild-type recipients until 3 to 4 weeks. This transparent adult zebrafish serves as the ideal combination of both sensitivity and resolution for in vivo stem cell analyses.     

Glutamate release and synapsin-I phosphorylation induced by P2X7 receptors activation in cerebellar granule neurons

The present work reports that activation of P2X7 receptor induces synaptic vesicle release in granule neurons and phosphorylation of synapsin-I by calcium-calmodulin-dependent protein kinase II (CaMKII), which in turn modulates secretory event. ATP, in absence of magnesium, induced a concentration-dependent glutamate release with an EC50 value of 1.95 microM. The involvement of P2X7 receptor was suggested when maximal secretory response was significantly reduced by the selective P2X7 antagonist Brilliant Blue G (BBG; 100 nM) and abolished by removing extracellular Ca2+. The involvement of P2X7 receptor on synaptic vesicle release was confirmed by measuring the release of FM 1-43 dye. In this case, pharmacological activation of P2X7 was achieved with the more selective agonist 2'-3'-o-(4-benzoylbenzoyl)-adenosine 5'-triphosphate (BzATP; 100 microM) showing a significant FM 1-43 release that was blocked by BBG (100 nM), by Zn2+ ions (100 microM), both P2X7 blockers, but not by suramin (100 microM), antagonist of P2X1, P2X2, P2X3 and P2X5. In addition, BzATP, through P2X7 receptor activation, significantly increased the phosphorylation of synapsin-I, the main presynaptic target of CaMKII. Both effects mediated by BzATP were inhibited by the CaMKII inhibitors KN-62 (10 microM) and KN-93 (10 microM). These results suggest, therefore, that Ca2+ entrance mediated by P2X7 receptor induces glutamate release and in parallel synapsin-I phosphorylation.