1,007 research outputs found
Oligosaccharides Isolated from MGO™ Manuka Honey Inhibit the Adhesion of Pseudomonas aeruginosa, Escherichia Coli O157:H7 and Staphylococcus Aureus to Human HT-29 cells
peer-reviewedHistorically, honey is known for its anti-bacterial and anti-fungal activities and its use
for treatment of wound infections. Although this practice has been in place for millennia, little
information exists regarding which manuka honey components contribute to the protective nature
of this product. Given that sugar accounts for over 80% of honey and up to 25% of this sugar is
composed of oligosaccharides, we have investigated the anti-infective activity of manuka honey
oligosaccharides against a range of pathogens. Initially, oligosaccharides were extracted from a
commercially-available New Zealand manuka honey—MGO™ Manuka Honey (Manuka Health New
Zealand Ltd.)—and characterized by High pH anion exchange chromatography coupled with pulsed
amperiometric detection. The adhesion of specific pathogens to the human colonic adenocarcinoma
cell line, HT-29, was then assessed in the presence and absence of these oligosaccharides. Manuka
honey oligosaccharides significantly reduced the adhesion of Escherichia coli O157:H7 (by 40%),
Staphylococcus aureus (by 30%), and Pseudomonas aeruginosa (by 52%) to HT-29 cells. This activity was
then proven to be concentration dependent and independent of bacterial killing. This study identifies
MGO™ Manuka Honey as a source of anti-infective oligosaccharides for applications in functional
foods aimed at lowering the incidence of infectious diseases
An in vitro method for determining the bioaccessibility of pharmaceuticals in wildlife
Wildlife can be exposed to human pharmaceuticals via prey that have accumulated the compounds from wastewater, surface water, sediment and soil. One factor affecting internal absorption of pharmaceuticals is bioaccessibility, the proportion of the compound that enters solution in the gastrointestinal tract. Currently, the bioaccessibility of most pharmaceuticals in prey remains unknown for most wildlife species. Here, we evaluate the potential of a two-compartment in vitro gastrointestinal tract model to compare the bioaccessibility of the antidepressant fluoxetine from invertebrate prey for birds and mammals. Samples of gizzard (or stomach) and intestinal phase digestive juices were obtained from the in vitro models along with the residual solid material. HPLC analysis revealed that the bioaccessibility of fluoxetine in the avian in vitro models (75.9% and 78.6%) was statistically significantly lower than in the mammalian models (88.2-89.6%) as a percentage of what was recovered; however there were no statistically or biologically significant inter-species difference in terms of the amount recovered per gram of 'food' inserted at the start of the simulation. Nevertheless, this in vitro model provides a useful method of comparing the bioaccessibility of pharmaceuticals in different prey for species with different gastrointestinal conditions. There may be merit for ecological risk assessments in further developing this in vitro approach to improve estimates of internal exposure for organics. This article is protected by copyright. All rights reserved
FACS-sorted putative oogonial stem cells from the ovary are neither DDX4-positive nor germ cells
Whether the adult mammalian ovary contains oogonial stem cells (OSCs) is controversial. They have been isolated by a live-cell sorting method using the germ cell marker DDX4, which has previously been assumed to be cytoplasmic, not surfacebound. Furthermore their stem cell and germ cell characteristics remain disputed. Here we show that although OSC-like cells can be isolated from the ovary using an antibody to DDX4, there is no good in silico modelling to support the existence of a surfacebound DDX4. Furthermore these cells when isolated were not expressing DDX4, and did not initially possess germline identity. Despite these unremarkable beginnings, they acquired some pre-meiotic markers in culture, including DDX4, but critically never expressed oocyte-specific markers, and furthermore were not immortal but died after a few months. Our results suggest that freshly isolated OSCs are not germ stem cells, and are not being isolated by their DDX4 expression. However it may be that culture induces some pre-meiotic markers. In summary the present study offers weight to the dogma that the adult ovary is populated by a fixed number of oocytes and that adult de novo production is a rare or insignificant event
A modeling tool to evaluate regional coral reef responses to changes in climate and ocean chemistry
This is the published version.We developed a spreadsheet-based model for the use of managers, conservationists, and biologists for projecting the effects of climate change on coral reefs at local-to-regional scales. The COMBO (Coral Mortality and Bleaching Output) model calculates the impacts to coral reefs from changes in average SST and CO2 concentrations, and from high temperature mortality (bleaching) events. The model uses a probabilistic assessment of the frequency of high temperature events under a future climate to address scientific uncertainties about potential adverse effects. COMBO offers data libraries and default factors for three selected regions (Hawai’i, Great Barrier Reef, and Caribbean), but it is structured with user-selectable parameter values and data input options, making possible modifications to reflect local conditions or to incorporate local expertise. Preliminary results from sensitivity analyses and simulation examples for Hawai’i demonstrate the relative importance of high temperature events, increased average temperature, and increased CO2 concentration on the future status of coral reefs; illustrate significant interactions among variables; and allow comparisons of past environmental history with future predictions
Reduced chromosome cohesion measured by interkinetochore distance is associated with aneuploidy even in oocytes from young mice
It is becoming clear that reduced chromosome cohesion is an important factor in the rise of maternal age-related aneuploidy. This reduction in cohesion has been observed both in human and mouse oocytes, and it can be measured directly by an increase with respect to maternal age in interkinetochore (iKT) distance between a sister chromatid pair. We have observed variations in iKT distance even in oocytes from young mice and wondered if such differences may predispose those oocytes displaying the greatest iKT distances to be becoming aneuploid. Therefore, we used two methods, one pharmacological (Aurora kinase inhibitor) and one genetic (Fzr1 knockout), to raise aneuploidy rates in oocytes from young mice (age, 1-3 mo) and to examine if those oocytes that were aneuploid had greater iKT distances. We observed that for both Aurora kinase inhibition and Fzr1 knockout, iKT distances were significantly greater in those oocytes that became aneuploid compared to those that remained euploid. Based on these results, we propose that individual oocytes undergo loss in chromosomal cohesion at different rates and that the greater this loss, the greater the risk for becoming aneuploid.Supported by an NHMRC project grant (569202) to K.T.J., S.M., and E.A.M. J.E.H. is supported by an Australian Research Council DECRA Fellowship. I.G.-H. and S.M. are supported by grants BFU2007-67464, BFU2008-01808, Consolider CSD2007-00015, and Junta de Castilla y León Grupo de Excelencia GR 265.Peer Reviewe
HLA Class I and Genetic Susceptibility to Type 1 Diabetes: Results From the Type 1 Diabetes Genetics Consortium
OBJECTIVE-We report here genotyping data and type 1 diabetes association analyses for HLA class I loci (A, B, and C) on 1,753 multiplex pedigrees from the Type 1 Diabetes Genetics Consortium (T1DGC), a large international collaborative study. RESEARCH DESIGN AND METHODS-Complete eight-locus HLA genotyping data were generated. Expected patient class I (HLA-A, -B, and -C) allele frequencies were calculated, based on linkage disequilibrium (LD) patterns with observed HLA class II DRB1-DQA1-DQB1 haplotype frequencies. Expected frequencies were compared to observed allele frequencies in patients. RESULTS-Significant type 1 diabetes associations were observed at all class I HLA loci. After accounting for LD with HLA class II, the most significantly type 1 diabetes-associated alleles were B*5701 (odds ratio 0.19; P = 4 x 10(-11)) and B*3906 (10.31; P = 4 X 10(-10)). Other significantly type 1 diabetes-associated alleles included A*2402, A*0201, B*1801, and C*0501 (predisposing) and A*1101, A*3201, A*6601, B*0702, B*4403, B*3502, C*1601, and C*0401 (protective). Some alleles, notably B*3906, appear to modulate the risk of all DRB1-DQA1-DQB1 haplotypes on which they reside, suggesting a class I effect that is independent of class H. Other class I type 1 diabetes associations appear to be specific to individual class H haplotypes. Some apparent associations (e.g., C*1601) could be attributed to strong LD to another class I susceptibility locus (B*4403). CONCLUSIONS-These data indicate that HLA class I alleles, in addition to and independently from HLA class H alleles, are associated with type 1 diabetes. Diabetes 59:2972-2979, 201
Distinct inactive conformations of the dopamine D2 and D3 receptors correspond to different extents of inverse agonism
By analyzing and simulating inactive conformations of the highly-homologous dopamine D2 and D3 receptors (D2R and D3R), we find that eticlopride binds D2R in a pose very similar to that in the D3R/eticlopride structure but incompatible with the D2R/risperidone structure. In addition, risperidone occupies a sub-pocket near the Na+ binding site, whereas eticlopride does not. Based on these findings and our experimental results, we propose that the divergent receptor conformations stabilized by Na+-sensitive eticlopride and Na+-insensitive risperidone correspond to different degrees of inverse agonism. Moreover, our simulations reveal that the extracellular loops are highly dynamic, with spontaneous transitions of extracellular loop 2 from the helical conformation in the D2R/risperidone structure to an extended conformation similar to that in the D3R/eticlopride structure. Our results reveal previously unappreciated diversity and dynamics in the inactive conformations of D2R. These findings are critical for rational drug discovery, as limiting a virtual screen to a single conformation will miss relevant ligands
Paternal obesity induces metabolic and sperm disturbances in male offspring that are exacerbated by their exposure to an "obesogenic" diet
Obesity and related comorbidities are becoming increasingly prevalent globally. In mice preconception paternal exposure to a high fat diet (HFD) impairs the metabolic and reproductive health of male offspring, despite their control diet (CD) consumption. However, offspring share lifestyle, including diet, with parents. We assessed if male offspring from HFD fathers have a heightened susceptibility to HFD-induced metabolic and reproductive derangements. This 2 × 2 design saw founder males (F0) and their offspring (F1) fed either a HFD or a nutritionally matched CD. Regardless of paternal diet, HFD fed male offspring had greater total body weight and adiposity. Offspring sired by a HFD male and fed a HFD were the heaviest, had the greatest adiposity and had the greatest concentration of serum cholesterol, triglyceride, HDL, and NEFA compared with CD sired/fed littermates. A synergistic increase in serum insulin was unmasked by both father/son HFD consumption, concomitant with increased sera glucose. Either a paternal or offspring HFD was associated with similar reductions to offspring sperm motility. Whereas sperm ROS concentrations and sperm-oocyte binding saw detrimental effects of both F0 HFD and F1 HFD with an interaction evident between both, culminating in the most impaired sperm parameters in this group. This indicates that metabolic and fertility disturbances in male offspring sired by HFD fathers are exacerbated by a "second-hit" of exposure to the same obesogenic environment postnatally. If translatable to human health, this suggests that adverse reproductive and metabolic outcomes may be amplified across generations through a shared calorie dense diet, relevant to the current worldwide obesity epidemic.Tod Fullston, Nicole O. McPherson, Julie A. Owens, Wan Xian Kang, Lauren Y. Sandeman & Michlle Lan
Paternal obesity induces metabolic and sperm disturbances in male offspring that are exacerbated by their exposure to an "obesogenic" diet
Un membre de la Garde civile espagnole sur la frontière entre l'Espagne et le Maroc à Melilla, le 17 octobre 2013. (Photo Pierre-Philippe Marcou. AFP) Un Africain est mort mardi en escaladant le triple grillage qui entoure l'enclave espagnole au Maroc. Une centaine de ses compagnons a réussi à passer en Europe. " Ultracontroversée depuis déjà une bonne dizaine d’années, le triple grillage qui sert de frontière entre le Maroc et Melilla, petite enclave espagnole du nord de l’Afrique, suscite..
Paternal under-nutrition programs metabolic syndrome in offspring which can be reversed by antioxidant/vitamin food fortification in fathers
There is an ever increasing body of evidence that demonstrates that paternal over-nutrition prior to conception programs impaired metabolic health in offspring. Here we examined whether paternal under-nutrition can also program impaired health in offspring and if any detrimental health outcomes in offspring could be prevented by micronutrient supplementation (vitamins and antioxidants). We discovered that restricting the food intake of male rodents reduced their body weight, fertility, increased sperm oxidative DNA lesions and reduced global sperm methylation. Under-nourished males then sired offspring with reduced postnatal weight and growth but somewhat paradoxically increased adiposity and dyslipidaemia, despite being fed standard chow. Paternal vitamin/antioxidant food fortification during under-nutrition not only normalised founder oxidative sperm DNA lesions but also prevented early growth restriction, fat accumulation and dyslipidaemia in offspring. This demonstrates that paternal under-nutrition reduces postnatal growth but increases the risk of obesity and metabolic disease in the next generation and that micronutrient supplementation during this period of under-nutrition is capable of restoring offspring metabolic health
- …