Stereotypes of special admission students: peer perceptions of athlete and non-athlete special admit students.

The purpose of this study was to evaluate the different stereotypes that individuals, within a university’s general student population, held toward studentathletes and non-athlete students admitted to the university on a special admission basis (students admitted with requirements less than the stated minimum for admission). Two studies, one qualitative in nature and the other with a quantitative focus, were conducted to assess students’ perceptions of special admission students. The results of this study show that students from a university’s general population have more of a negative stereotype or perception of athlete special admissions, as compared to a non-athlete special admission student, when interacting in an academic setting. On the other hand, the general student population indicated a more positive perception for allowing special admission to athletes than they did for allowing special admission to non-athlete students

Vitamin B12, folate, and the methionine remethylation cycle-biochemistry, pathways, and regulation

Vitamin B12 (cobalamin, Cbl) is a nutrient essential to human health. Due to its complex structure and dual cofactor forms, Cbl undergoes a complicated series of absorptive and processing steps before serving as cofactor for the enzymes methylmalonyl-CoA mutase and methionine synthase. Methylmalonyl-CoA mutase is required for the catabolism of certain (branched-chain) amino acids into an anaplerotic substrate in the mitochondrion, and dysfunction of the enzyme itself or in production of its cofactor adenosyl-Cbl result in an inability to successfully undergo protein catabolism with concomitant mitochondrial energy disruption. Methionine synthase catalyzes the methyl-Cbl dependent (re)methylation of homocysteine to methionine within the methionine cycle; a reaction required to produce this essential amino acid and generate S-adenosylmethionine, the most important cellular methyl-donor. Disruption of methionine synthase has wide-ranging implications for all methylation-dependent reactions, including epigenetic modification, but also for the intracellular folate pathway, since methionine synthase uses 5-methyltetrahydrofolate as a one-carbon donor. Folate-bound one-carbon units are also required for deoxythymidine monophosphate and de novo purine synthesis; therefore, the flow of single carbon units to each of these pathways must be regulated based on cellular needs. This review provides an overview on Cbl metabolism with a brief description of absorption and intracellular metabolic pathways. It also provides a description of folate-mediated one-carbon metabolism and its intersection with Cbl at the methionine cycle. Finally, a summary of recent advances in understanding of how both pathways are regulated is presented

Cryptic Exon Activation by Disruption of Exon Splice Enhancer

3-Methylcrotonyl-CoA carboxylase (MCC) deficiency is an autosomal recessive disorder of leucine catabolism. MCC is a heteromeric mitochondrial enzyme composed of biotin-containing α (MCCA) and smaller β (MCCB) subunits encoded by MCCA and MCCB, respectively. We report studies of the c.1054G→A mutation in exon 11 of MCCB detected in the homozygous state in a patient with MCC deficiency. Sequence analysis of MCCB cDNA revealed two overlapping transcripts, one containing the normal 73 bp of exon 11 including the missense mutation c.1054G→A (p.G352R), the other with exon 11 replaced by a 64-bp sequence from intron 10 (cryptic exon 10a) that maintains the reading frame and is flanked by acceptable splice consensus sites. In expression studies, we show that both transcripts lack detectable MCC activity. Western blot analysis showed slightly reduced levels of MCCB using the transcript containing the missense mutation, whereas no MCCB was detected with the transcript containing the cryptic exon 10a. Analysis of the region harboring the mutation revealed that the c.1054G→A mutation is located in an exon splice enhancer sequence. Using MCCB minigene constructs to transfect MCCB-deficient fibroblasts, we demonstrate that the reduction in utilization of exon 11 associated with the c.1054G→A mutation is due to alteration of this exon splice enhancer. Further, we show that optimization of the weak splice donor site of exon 11 corrects the splicing defect. To our knowledge, this is the first demonstration of a point mutation disrupting an exon splice enhancer that causes exon skipping along with utilization of a cryptic exon

Molecular mechanisms leading to three different phenotypes in the cblD defect of intracellular cobalamin metabolism

The cblD defect of intracellular vitamin B12 metabolism can lead to isolated methylmalonic aciduria (cblD-MMA) or homocystinuria (cblD-HC), or combined methylmalonic aciduria and homocystinuria (cblD-MMA/HC). We studied the mechanism whereby MMADHC mutations can lead to three phenotypes. The effect of various expression vectors containing MMADHC modified to contain an enhanced mitochondrial leader sequence or mutations changing possible downstream sites of reinitiation of translation or mutations introducing stop codons on rescue of adenosyl- and methylcobalamin (MeCbl) formation was studied. The constructs were transfected into cell lines derived from various cblD patient's fibroblasts. Expression of 10 mutant alleles from 15 cblD patients confirmed that the nature and location of the mutations correlate with the biochemical phenotype. In cblD-MMA/HC cells, improving mitochondrial targeting of MMADHC clearly increased the formation of adenosylcobalamin (AdoCbl) with a concomitant decrease in MeCbl formation. In cblD-MMA cells, this effect was dependent on the mutation and showed a negative correlation with endogenous MMADHC mRNA levels. These findings support the hypothesis that a single protein exists with two different functional domains that interact with either cytosolic or mitochondrial targets. Also a delicate balance exists between cytosolic MeCbl and mitochondrial AdoCbl synthesis, supporting the role of cblD protein as a branch point in intracellular cobalamin trafficking. Furthermore, our data indicate that the sequence after Met116 is sufficient for MeCbl synthesis, whereas the additional sequence between Met62 and Met116 is required for AdoCbl synthesis. Accordingly, western blot studies reveal proteins of the size expected from the stop codon position with subsequent reinitiation of translatio

Hydrocarbon Biogeochemical Setting of the Baffin Island Oil Spill Experimental Sites. I. Sediments

A baseline for petroleum residues in the sediments of the Cape Hatt Island in arctic Canada was obtained in anticipation of controlled oil releases of the Baffin Island Oil Spill (BIOS) Project. In subtidal sediments, the existing background of petroleum residues has an upper limit in the low to sub micro g/g concentration range. Petroleum was one of a variety of sources identified, including plant paraffin waxes and combustion products. Beach sediment hydrocarbons were quantitatively and qualitatively similar to those of subtidal sediments. The hydrocarbon baseline in sediments of the BIOS study area was found to be as low as might be found anywhere on earth and therefore ideally suited to the BIOS study.Key words: BIOS, arctic marine Canada, hydrocarbon baseline, sedimentsMots clés: BIOS, Arctique marin canadien, niveau de référence d'hydrocarbures, sédiment

Hydrocarbon Biogeochemical Setting of the Baffin Island Oil Spill Experimental Sites. II. Water

A baseline for petroleum residues in the waters of the Cape Hatt region of Baffin Island in arctic Canada was obtained in anticipation of controlled oil releases of the Baffin Island Oil Spill (BIOS) Project. Total aliphatic and aromatic residues reflecting multiple sources were found to be in the low to sub micro g/l concentrations range. Alkylated naphthalenes, phenanthrenes and dibenzothiophenes were present in the sub ng/l concentrations range. The hydrocarbon baseline for the waters of the BIOS study area was found to be as low as might be found anywhere on earth and therefore ideally suited to the BIOS study.Key words: BIOS, arctic marine Canada, hydrocarbon baseline, waterMots clés: BIOS, Arctique marin canadien, niveau de référence d’hydrocarbures, ea

Effects of Environmental Cold on the Preruminant Calf

This study examined effects of sustained environmental cold on growth and health of dairy calves. Functional measures of energy metabolism, fat-soluble vitamin and mineral status, and immune competency were also evaluated. Newborn calves were assigned to warm or cold environments for 7wk. Cold environment temperature were maintained as close to 2°C as possible. Frequent wetting of the environment and calves augmented effects of the cold. The warm environment was maintained as close to 15°C as possible and humidity was not manipulated. Preventative medications or vaccinations were not administered. All calves were fed a non-medicated MR (20% CP and 20% fat fed at .45 kg/d) and non-medicated starter ad libitum. Cold environment averaged 12 o C lower than warm environment during the study period. Humidity averaged 10% higher in the cold environment. Respiratory health of the warm environment calves was moderately better than that of cold environment calves. Scour scores were unaffected by cold exposure. Growth rate was unaffected by environmental temperature; however, cold environment calves consumed more starter from wk 5 to 7. Blood glucose concentrations were lower and NEFA concentrations were higher in cold environment calves, indicative of a state of mild negative energy balance. Serum cytokine and fat-soluble vitamin concentrations, and antibody responses to vaccination were not impacted by sustained exposure to cold

Emerging Multidrug Resistance of Methicillin-Resistant Staphylococcus aureus in Hand Infections.

BACKGROUND: Methicillin-resistant Staphylococcus aureus has been the most commonly identified pathogen in hand infections at urban centers, but the evolving antibiotic sensitivity profiles of methicillin-resistant Staphylococcus aureus are not known. The purposes of this study are to determine if multidrug resistance in methicillin-resistant Staphylococcus aureus is emerging and to provide current recommendations for empiric antibiotic selection for hand infections in endemic regions. METHODS: An eight-year longitudinal, retrospective chart review was performed on all culture-positive hand infections encountered by an urban hospital from 2005 to 2012. The proportions of all major organisms were calculated for each year. Methicillin-resistant Staphylococcus aureus infections were additionally analyzed for antibiotic sensitivity. RESULTS: A total of 683 culture-positive hand infections were identified. Overall, methicillin-resistant Staphylococcus aureus grew on culture in 49% of cases; the annual incidence peaked at 65% in 2007. Over the study period, methicillin-resistant Staphylococcus aureus was universally resistant to penicillin, oxacillin, and ampicillin. Clindamycin resistance significantly increased, approaching 20% by 2012 (p = 0.02). Levofloxacin resistance linearly increased from 12% to 50% (p \u3c 0.01). Resistance to trimethoprim-sulfamethoxazole, tetracycline, gentamicin, and moxifloxacin was only sporadically observed. Resistance to vancomycin, daptomycin, linezolid, and rifampin was not observed. CONCLUSIONS: Significant increases in resistance to clindamycin and levofloxacin were observed in recent years, and empiric therapy with these drugs may have limited efficacy, especially in urban centers. CLINICAL RELEVANCE: Hand infections caused by methicillin-resistant Staphylococcus aureus may be developing increasing resistance to clindamycin and levofloxacin in recent years. This longitudinal study examines the effectiveness of a variety of antibiotics to methicillin-resistant Staphylococcus aureus

Fat-Soluble Vitamin and Micromineral Concentrations in Preruminant Dairy Calves Fed to Achieve Different Growth Rates

Effects of neonatal growth rate on plasma concentrations of fat-soluble vitamins, zinc, and copper in preruminant calves were evaluated. Calves were assigned to dietary treatments designed to achieve three targeted rates of gain [No-Growth (NG) = 0.0 kg/d, Low-Growth (LG) = 0.55 kg/d, or High-Growth (HG) = 1.2 kg/d] over a 7 wk period. MR intakes needed to achieve specified growthrates were estimated using the NRC Nutrient Requirements of Dairy Cattle calf model computer program. Calves were fed a 30% CP, 20% fat, MR reconstituted to 14% DM. Because vitamin levels in the MR were based on DM intake of HG calves, NG and LG calves were supplemented with additional vitamins once weekly to compensate for reduced MR consumption. Growth rates for NG (0.11 kg/d), LG (0.58 kg/d), and HG (1.16 kg/d) calves differed throughout the study. Although vitamins A and D, and Zn concentrations were unaffected by growth rate, their concentrations increased and Zn/Cu concentrations decreased with time. Throughout the study their concentrations remained within normal ranges for the preruminant calf. Vitamin E and copper were affected by growth rate. At wk 7, HG calves had lower vitamin E concentrations than LG and NG calves. Copper concentrations were greater for HG calves than LG and NG calves from wk 4 to wk 7. Copper and vitE concentrations, however, remained within ranges considered normal for preruminant calves. These results suggest that growth rate during the neonatal period influences vitE and Cu availabilit