Fermentative 2-carbon metabolism produces carcinogenic levels of acetaldehyde in Candida albicans.

Acetaldehyde is a carcinogenic product of alcohol fermentation and metabolism in microbes associated with cancers of the upper digestive tract. In yeast acetaldehyde is a by-product of the pyruvate bypass that converts pyruvate into acetyl-Coenzyme A (CoA) during fermentation. The aims of our study were: (i) to determine the levels of acetaldehyde produced by Candida albicans in the presence of glucose in low oxygen tension in vitro; (ii) to analyse the expression levels of genes involved in the pyruvate-bypass and acetaldehyde production; and (iii) to analyse whether any correlations exist between acetaldehyde levels, alcohol dehydrogenase enzyme activity or expression of the genes involved in the pyruvate-bypass. Candida albicans strains were isolated from patients with oral squamous cell carcinoma (n = 5), autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) patients with chronic oral candidosis (n = 5), and control patients (n = 5). The acetaldehyde and ethanol production by these isolates grown under low oxygen tension in the presence of glucose was determined, and the expression of alcohol dehydrogenase (ADH1 and ADH2), pyruvate decarboxylase (PDC11), aldehyde dehydrogenase (ALD6) and acetyl-CoA synthetase (ACS1 and ACS2) and Adh enzyme activity were analysed. The C. albicans isolates produced high levels of acetaldehyde from glucose under low oxygen tension. The acetaldehyde levels did not correlate with the expression of ADH1, ADH2 or PDC11 but correlated with the expression of down-stream genes ALD6 and ACS1. Significant differences in the gene expressions were measured between strains isolated from different patient groups. Under low oxygen tension ALD6 and ACS1, instead of ADH1 or ADH2, appear the most reliable indicators of candidal acetaldehyde production from glucose.

Chloroplastic phosphoadenosine phosphosulfate metabolism regulates basal levels of the prohormone jasmonic acid in Arabidopsis leaves.

Levels of the enzymes that produce wound response mediators have to be controlled tightly in unwounded tissues. The Arabidopsis (Arabidopsis thaliana) fatty acid oxygenation up-regulated8 (fou8) mutant catalyzes high rates of alpha -linolenic acid oxygenation and has higher than wild-type levels of the alpha -linolenic acid-derived wound response mediator jasmonic acid (JA) in undamaged leaves. fou8 produces a null allele in the gene SAL1 (also known as FIERY1 or FRY1). Overexpression of the wild-type gene product had the opposite effect of the null allele, suggesting a regulatory role of SAL1 acting in JA synthesis. The biochemical phenotypes in fou8 were complemented when the yeast (Saccharomyces cerevisiae) sulfur metabolism 3'(2'), 5'-bisphosphate nucleotidase MET22 was targeted to chloroplasts in fou8. The data are consistent with a role of SAL1 in the chloroplast-localized dephosphorylation of 3'-phospho-5'-adenosine phosphosulfate to 5'-adenosine phosphosulfate or in a closely related reaction (e.g. 3',5'-bisphosphate dephosphorylation). Furthermore, the fou8 phenotype was genetically suppressed in a triple mutant (fou8 apk1 apk2) affecting chloroplastic 3'-phospho-5'-adenosine phosphosulfate synthesis. These results show that a nucleotide component of the sulfur futile cycle regulates early steps of JA production and basal JA levels.

Burnout levels among Portuguese family doctors: a nationwide survey

AIM: To characterise the prevalence of burnout syndrome in a sample of family doctors (FDs) working in the Portuguese National Health System. DESIGN: Cross-sectional survey. SETTING: Primary healthcare centres from the 18 continental districts and two archipelagos of Portugal. METHOD: The Portuguese version of the Maslach Burnout Inventory-Human Services Survey was sent to 40 randomly selected healthcare centres and distributed to the FDs employed. Socio-demographic and work-related data were also collected. Participants were classified as having high, average or low levels of emotional exhaustion (EE), depersonalisation (DP) and personal accomplishment (PA) dimensions of burnout. RESULTS: 371 questionnaires were sent, of which 153 (83 women, age range 29-64 years; response rate 41%) returned. One-quarter (25.3%, 95% CI 18.6% to 33.1%) of FDs scored high for EE, 16.2% (10.7% to 23.2%) for DP and 16.7% (11.1% to 23.6%) for lack of PA. On multivariate analysis, being married, of older age, having many years of practice or working in a personalised healthcare unit tended to be associated with increased burnout components. Men tended to present higher EE and DP but lower lack of PA than women. Finally, the prevalence (95% CI) of burnout ranged between 4.1% (1.5% to 8.6%) and 32.4% (25.0% to 40.6%), depending on the definition used. CONCLUSIONS: High burnout is relatively common among Portuguese FDs. Burnout relief measures should be developed in order to prevent a further increase of burnout syndrome among Portuguese FDs.

Regulation of GABA(A) and glutamate receptor expression, synaptic facilitation and long-term potentiation in the hippocampus of prion mutant mice

Background: Prionopathies are characterized by spongiform brain degeneration, myoclonia, dementia, and periodic electroencephalographic (EEG) disturbances. The hallmark of prioniopathies is the presence of an abnormal conformational isoform (PrP(sc)) of the natural cellular prion protein (PrP(c)) encoded by the Prnp gene. Although several roles have been attributed to PrP(c), its putative functions in neuronal excitability are unknown. Although early studies of the behavior of Prnp knockout mice described minor changes, later studies report altered behavior. To date, most functional PrP(c) studies on synaptic plasticity have been performed in vitro. To our knowledge, only one electrophysiological study has been performed in vivo in anesthetized mice, by Curtis and coworkers. They reported no significant differences in paired-pulse facilitation or LTP in the CA1 region after Schaffer collateral/commissural pathway stimulation. Principal Findings: Here we explore the role of PrP(c) expression in neurotransmission and neural excitability using wild-type, Prnp -/- and PrP(c)-overexpressing mice (Tg20 strain). By correlating histopathology with electrophysiology in living behaving mice, we demonstrate that both Prnp -/- mice but, more relevantly Tg20 mice show increased susceptibility to KA, leading to significant cell death in the hippocampus. This finding correlates with enhanced synaptic facilitation in paired-pulse experiments and hippocampal LTP in living behaving mutant mice. Gene expression profiling using Illumina microarrays and Ingenuity pathways analysis showed that 129 genes involved in canonical pathways such as Ubiquitination or Neurotransmission were co-regulated in Prnp -/- and Tg20 mice. Lastly, RT-qPCR of neurotransmission-related genes indicated that subunits of GABA(A) and AMPA-kainate receptors are co-regulated in both Prnp -/- and Tg20 mice. Conclusions/Significance: Present results demonstrate that PrP(c) is necessary for the proper homeostatic functioning of hippocampal circuits, because of its relationships with GABA(A) and AMPA-Kainate neurotransmission. New PrP(c) functions have recently been described, which point to PrP(c) as a target for putative therapies in Alzheimer's disease. However, our results indicate that a "gain of function" strategy in Alzheimer's disease, or a "loss of function" in prionopathies, may impair PrP(c) function, with devastating effects. In conclusion, we believe that present data should be taken into account in the development of future therapies.

Cystamine and cysteamine increase brain levels of BDNF in Huntington disease via HSJ1b and transglutaminase

There is no treatment for the neurodegenerative disorder Huntington disease (HD). Cystamine is a candidate drug; however, the mechanisms by which it operates remain unclear. We show here that cystamine increases levels of the heat shock DnaJ-containing protein 1b (HSJ1b) that are low in HD patients. HSJ1b inhibits polyQ-huntingtin¿induced death of striatal neurons and neuronal dysfunction in Caenorhabditis elegans. This neuroprotective effect involves stimulation of the secretory pathway through formation of clathrin-coated vesicles containing brain-derived neurotrophic factor (BDNF). Cystamine increases BDNF secretion from the Golgi region that is blocked by reducing HSJ1b levels or by overexpressing transglutaminase. We demonstrate that cysteamine, the FDA-approved reduced form of cystamine, is neuroprotective in HD mice by increasing BDNF levels in brain. Finally, cysteamine increases serum levels of BDNF in mouse and primate models of HD. Therefore, cysteamine is a potential treatment for HD, and serum BDNF levels can be used as a biomarker for drug efficacy.

Alteration of amino acid metabolism in neuronal aggregate cultures exposed to hypoglycaemic conditions.

The neuronal effects of glucose deficiency on amino acid metabolism was studied on three-dimensional cultures of rat telencephalon neurones. Transient (6 h) exposure of differentiated cultures to low glucose (0.25 mm instead of 25 mm) caused irreversible damage, as judged by the marked decrease in the activities of two neurone-specific enzymes and lactate dehydrogenase, 1 week after the hypoglycemic insult. Quantification of amino acids and ammonia in the culture media supernatants indicated increased amino acid utilization and ammonia production during glucose-deficiency. Measurement of intracellular amino acids showed decreased levels of alanine, glutamine, glutamate and GABA, while aspartate was increased. Added lactate (11 mm) during glucose deficiency largely prevented the changes in amino acid metabolism and ammonia production, and attenuated irreversible damage. Higher media levels of glutamine (4 mm instead of 0.25 mm) during glucose deprivation prevented the decrease of intracellular glutamate and GABA, while it further increased intracellular aspartate, ammonia production and neuronal damage. Both lactate and glutamine were readily oxidized in these neuronal cultures. The present results suggest that in neurones, glucose deficiency enhances amino acid deamination at the expense of transamination reactions. This results in increased ammonia production and neuronal damage.

Serum androgen levels in elite female athletes.

OBJECTIVE: Prior to the implementation of the blood steroidal module of the Athlete Biological Passport, we measured the serum androgen levels among a large population of high-level female athletes as well as the prevalence of biochemical hyperandrogenism and some disorders of sex development (DSD). METHODS AND RESULTS: In 849 elite female athletes, serum T, dehydroepiandrosterone sulphate, androstenedione, SHBG, and gonadotrophins were measured by liquid chromatography-mass spectrometry high resolution or immunoassay. Free T was calculated. The sampling hour, age, and type of athletic event only had a small influence on T concentration, whereas ethnicity had not. Among the 85.5% that did not use oral contraceptives, 168 of 717 athletes were oligo- or amenorrhoic. The oral contraceptive users showed the lowest serum androgen and gonadotrophin and the highest SHBG concentrations. After having removed five doped athletes and five DSD women from our population, median T and free T values were close to those reported in sedentary young women. The 99th percentile for T concentration was calculated at 3.08 nmol/L, which is below the 10 nmol/L threshold used for competition eligibility of hyperandrogenic women with normal androgen sensitivity. Prevalence of hyperandrogenic 46 XY DSD in our athletic population is approximately 7 per 1000, which is 140 times higher than expected in the general population. CONCLUSION: This is the first study to establish normative serum androgens values in elite female athletes, while taking into account the possible influence of menstrual status, oral contraceptive use, type of athletic event, and ethnicity. These findings should help to develop the blood steroidal module of the Athlete Biological Passport and to refine more evidence-based fair policies and recommendations concerning hyperandrogenism in female athletes.

Postmenopausal circulating levels of 2- and 16α-hydroxyestrone and risk of endometrial cancer.

Background:It has been suggested that the relative importance of oestrogen-metabolising pathways may affect the risk of oestrogen-dependent tumours including endometrial cancer. One hypothesis is that the 2-hydroxy pathway is protective, whereas the 16α-hydroxy pathway is harmful.Methods:We conducted a case-control study nested within three prospective cohorts to assess whether the circulating 2-hydroxyestrone : 16α-hydroxyestrone (2-OHE1 : 16α-OHE1) ratio is inversely associated with endometrial cancer risk in postmenopausal women. A total of 179 cases and 336 controls, matching cases on cohort, age and date of blood donation, were included. Levels of 2-OHE1 and 16α-OHE1 were measured using a monoclonal antibody-based enzyme assay.Results:Endometrial cancer risk increased with increasing levels of both metabolites, with odds ratios in the top tertiles of 2.4 (95% CI=1.3, 4.6; P(trend)=0.007) for 2-OHE1 and 1.9 (95% CI=1.1, 3.5; P(trend)=0.03) for 16α-OHE1 in analyses adjusting for endometrial cancer risk factors. These associations were attenuated and no longer statistically significant after further adjustment for oestrone or oestradiol levels. No significant association was observed for the 2-OHE1 : 16α-OHE1 ratio.Conclusion:Our results do not support the hypothesis that greater metabolism of oestrogen via the 2-OH pathway, relative to the 16α-OH pathway, protects against endometrial cancer.

Increased body fat is independently and negatively related with cardiorespiratory fitness levels in children and adolescents with normal weight.

Body mass index (BMI) is related with cardiorespiratory fitness (CRF), but less is known regarding the combined relationships between BMI and body fat (BF) on CRF. Cross-sectional study included 2361 girls and 2328 boys aged 10–18 years living in the area of Lisbon, Portugal. BMI was calculated by measuring height and weight, and obesity was assessed by international criteria. BF was assessed by bioimpedance. CRF was assessed by the 20-m shuttle run and the participants were classified as normal-to-high or low-CRF level according to Fitness gram criterion-referenced standards. The prevalence of low CRF was 47 and 39% in girls and boys, respectively. The corresponding values for the prevalence of obesity were 4.8 and 5.6% (not significant) and of excess BF of 12.1 and 25.1% (P <0.001), respectively. In both sexes, BMI and BF were inversely related with CRF: r = – 0.53 and – 0.45 for BMI and % BF, respectively, in boys and the corresponding values in girls were – 0.50 and – 0.33 (all P <0.01). When compared with a participant with normal BMI and BF, the odds ratios (95% confidence interval) for low CRF were 1.94 (1.46–2.58) for a participant with normal BMI and high BF, and 6.19 (5.02–7.63) for a participant with high BMI and high BF. The prevalence of low-CRF levels is high in Portuguese youths. BF negatively influences CRF levels among children/adolescents with normal BMI.

Population-based genome-wide association studies reveal six loci influencing plasma levels of liver enzymes.

Plasma liver-enzyme tests are widely used in the clinic for the diagnosis of liver diseases and for monitoring the response to drug treatment. There is considerable evidence that human genetic variation influences plasma levels of liver enzymes. However, such genetic variation has not been systematically assessed. In the present study, we performed a genome-wide association study of plasma liver-enzyme levels in three populations (total n = 7715) with replication in three additional cohorts (total n = 4704). We identified two loci influencing plasma levels of alanine-aminotransferase (ALT) (CPN1-ERLIN1-CHUK on chromosome 10 and PNPLA3-SAMM50 on chromosome 22), one locus influencing gamma-glutamyl transferase (GGT) levels (HNF1A on chromosome 12), and three loci for alkaline phosphatase (ALP) levels (ALPL on chromosome 1, GPLD1 on chromosome 6, and JMJD1C-REEP3 on chromosome 10). In addition, we confirmed the associations between the GGT1 locus and GGT levels and between the ABO locus and ALP levels. None of the ALP-associated SNPs were associated with other liver tests, suggesting intestine and/or bone specificity. The mechanisms underlying the associations may involve cis- or trans-transcriptional effects (some of the identified variants were associated with mRNA transcription in human liver or lymphoblastoid cells), dysfunction of the encoded proteins (caused by missense variations at the functional domains), or other unknown pathways. These findings may help in the interpretation of liver-enzyme tests and provide candidate genes for liver diseases of viral, metabolic, autoimmune, or toxic origin. The specific associations with ALP levels may point to genes for bone or intestinal diseases.

A characterization of a new value and an existing value for cooperative games with levels structure of cooperation

En aquest treball presentem dues caracteritzacions de dos valors diferents en el marc dels jocs coalicionals amb cooperació restringida. Les restriccions són introduïdes com una seqüència finita de particions del conjunt del jugadors, de manera que cada una d'elles eés més grollera que l'anterior, formant així una estructura amb diferents nivells d'unions a priori.