Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
PLoS One ; 17(10): e0273015, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36190945

RESUMO

A narrative systematic literature review was conducted to explore resilient performance in defence and security settings. A search strategy was employed across a total of five databases, searching published articles from 2001 onwards that assessed performance and optimal function in relation to resilience, in defence and security personnel. Following narrative synthesis, studies were assessed for quality. Thirty-two articles met inclusion criteria across a range of performance domains, including, but not limited to, course selection, marksmanship, land navigation, and simulated captivity. Some of the key findings included measures of mental toughness, confidence, and a stress-is-enhancing mindset being positively associated with performance outcomes. There was mixed evidence for the predictive value of biomarkers, although there was some support for cortisol, dehydroepiandrosterone sulfate (DHEA-S) and neuropeptide-y (NPY), and vagal reactivity. Interventions to improve resilient performance were focused on mindfulness or general psychological skills, with effects generally clearer on cognitive tasks rather than direct performance outcomes in the field. In sum, no single measure, nor intervention was consistently associated with performance over a range of domains. To inform future work, findings from the present review have been used to develop a framework of resilient performance, with the aim to promote theoretically informed work.


Assuntos
Atenção Plena , Neuropeptídeos , Biomarcadores , Sulfato de Desidroepiandrosterona , Hidrocortisona
2.
Metallomics ; 14(10)2022 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-36138538

RESUMO

Nickel (Ni) is an essential yet toxic trace element. Although a cofactor for many metalloenzymes, nickel function and metabolism is not fully explored in eukaryotes. Molecular biology and metallomic methods were utilized to explore the new physiological functions of nickel in Saccharomyces cerevisiae. Here we showed that MTM1 knockout cells displayed much stronger nickel tolerance than wild-type cells and mitochondrial accumulations of Ni and Fe of mtm1Δ cells dramatically decreased compared to wild-type cells when exposed to excess nickel. Superoxide dismutase 2 (Sod2p) activity in mtm1Δ cells was severely attenuated and restored through Ni supplementation in media or total protein. SOD2 mRNA level of mtm1Δ cells was significantly higher than that in the wild-type strain but was decreased by Ni supplementation. MTM1 knockout afforded resistance to excess nickel mediated through reactive oxygen species levels. Meanwhile, additional Ni showed no significant effect on the localization of Mtm1p. Our study reveals the MTM1 gene plays an important role in nickel homeostasis and identifies a novel function of nickel in promoting Sod2p activity in yeast cells.


Assuntos
Metaloproteínas , Proteínas de Saccharomyces cerevisiae , Oligoelementos , Proteínas de Transporte/metabolismo , Metaloproteínas/metabolismo , Proteínas Mitocondriais/metabolismo , Níquel/metabolismo , Níquel/toxicidade , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Oligoelementos/metabolismo
3.
Water Res ; 200: 117257, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34077838

RESUMO

Estrogenic compounds enter waterways via effluents from wastewater treatment works (WWTW), thereby indicating a potential risk to organisms inhabiting adjacent receiving waters. However, little is known about the loads or concentrations of estrogenic compounds that enter Australian WWTWs, the efficiency of removing estrogenic compounds throughout the various stages of tertiary WWTW processes (which are common in Australia), nor the concentrations released into estuarine or marine receiving waters, and the associated risk for aquatic taxa residing in these environments. Therefore, seven estrogenic compounds, comprising the natural estrogens estrone (E1), 17ß-estradiol (E2) and estriol (E3), the synthetic estrogen (EE2), and the industrial chemicals bisphenol A (BPA), 4-t-octyl phenol (4-t-OP) and 4-nonyl phenol (4-NP), in wastewater samples were quantified via liquid chromatographic-mass spectrometry (LC-MS) after solid-phase extraction at different stages of wastewater treatment and associated receiving waters. The concentrations of the target compounds in wastewater ranged from < LOQ (limit of quantification) to 158 ng/L for Tanilba Bay WWTW and < LOQ to 162 ng/L for Belmont WWTW. Most target compounds significantly declined after the secondary treatment phase. Appreciable removal efficiency throughout the treatment process was observed with removal from 39.21 to 99.98% of influent values at both WWTWs. The reduction of the natural estrogens (E1, E2 and E3) and 4-t-OP were significantly greater than EE2, BPA, and 4-NP in both WWTWs. Risk quotients (RQs) were calculated to assess potential ecological risks from individual estrogenic compounds. In predicted diluted effluents, no targeted compounds showed any ecological risk (RQ ≤1.65 × 10-2) at both WWTWs. Similarly, all RQs for shore samples at both WWTWs were below 1. Finally, the hazard index (HI), which represents combined estrogenic contaminants' ecological risk, indicated no mentionable risk for predicted diluted effluents (HI = 0.0097 to 0.0218) as well as shoreline samples (HI = 0.393 to 0.522) in the receiving estuarine or marine waters.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Austrália , Monitoramento Ambiental , Estrogênios/análise , Estrona/análise , Poluentes Químicos da Água/análise
4.
Curr Opin Psychiatry ; 33(1): 51-56, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31577542

RESUMO

PURPOSE OF REVIEW: Personality disorders, mental disorders marked by long-term deviations from societal expectations that cause distress, and substance use and related disorders (SUDs), mental disorders marked by engaging with substances or behaviors that activate the brain's reward system to the point that normal activities are neglected, are common debilitating conditions. Personality disorders and SUDs are highly comorbid, potentially resistant to treatment, and their presence increases all-cause mortality, particularly when found together. RECENT FINDINGS: The present review highlights the most notable findings on prevalence, comorbidity, biological and behavioral pathways between the disorders, impact on incarcerated people and treatment for the disorders. SUMMARY: Personality disorders and SUDs are relatively common, highly comorbid, and increase the risk of all-cause mortality: particularly in those who have both conditions. Possible shared pathways between personality disorders and SUDs include emotional dysregulation, shared genes, and certain neurotransmitters. Personality disorders and SUDs are common in people who have been incarcerated, and this morbidity and comorbidity has been found throughout the world. Finally, comorbidity between personality disorders and SUDs greatly complicates treatment, with emerging treatment modalities such as mentalization-based treatment, schema modes, and attentional training showing potential, but lacking strong evidence of efficacy.


Assuntos
Transtornos da Personalidade/epidemiologia , Transtornos da Personalidade/psicologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Comorbidade , Feminino , Humanos , Masculino , Prevalência
5.
Microbiologyopen ; 8(6): e00772, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30739392

RESUMO

Staphylococcus aureus is a versatile bacterium that can adapt to survive and grow in a wide range of salt concentrations. This study investigated whether the cells could mount a response to survive a challenge of 5% NaCl in a minimal incubation medium that would not support cell replication. Cells were grown in liquid culture, washed and then incubated for 90 min at 37°C in a medium that contained only glycine and glucose as substrates in PBS plus trace elements. The control cells were compared with a treatment group which was incubated with an additional 5% NaCl. Significantly more glycine was taken up by the cells exposed to 5% NaCl compared with control cells, and both groups consumed 99% of the glucose supplied. The NaCl treated cells had significantly higher cytoplasmic levels of proline and glutamic acid as well as lower levels of alanine and methionine compared with the controls (p < 0.05). The levels of the two major cytoplasmic amino acids, aspartic acid and glycine, remained constant in control and treated cells. Proteomic analyses revealed that 10 proteins showed differential responses between the control and treatment groups. The reductions in proteins were primarily associated with processes of protein biosynthesis, pathogenicity, and cell adhesion. Since cell numbers remained constant during the incubation period in minimal medium, it was concluded that there was no cell division to support population growth. The results provided evidence that the cells in the minimal medium exposed to the NaCl treatment underwent in situ homeostatic changes to adjust to the new environmental conditions. It was proposed that this represented a phenotypic shift to form cells akin to small colony variants, with lower metabolic rates and lower levels of key proteins associated with pathogenicity.


Assuntos
Aminoácidos/metabolismo , Cloreto de Sódio/metabolismo , Staphylococcus aureus/metabolismo , Aclimatação , Alanina/metabolismo , Ácido Aspártico/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Meios de Cultura/metabolismo , Prolina/metabolismo , Proteômica , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimento
6.
Biol Reprod ; 93(4): 104, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26316064

RESUMO

The spermatozoa of many stallions do not tolerate being cooled, restricting the commercial viability of these animals and necessitating the development of a chemically defined room temperature (RT) storage medium. This study examined the impact of two major modulators of oxidative phosphorylation, pyruvate (Pyr) and L-carnitine (L-C), on the storage of stallion spermatozoa at RT. Optimal concentrations of Pyr (10 mM) and L-C (50 mM) were first identified and these concentrations were then used to investigate the effects of these compounds on sperm functionality and oxidative stress at RT. Mitochondrial and cytosolic reactive oxygen species, along with lipid peroxidation, were all significantly suppressed by the addition of L-C (48 h MitoSOX Red negative: 46.2% vs. 26.1%; 48 and 72 h dihydroethidium negative: 61.6% vs. 43.1% and 64.4% vs. 46.9%, respectively; 48 and 72 h 4-hydroxynonenal negative: 37.1% vs. 23.8% and 41.6% vs. 25.7%, respectively), while the Pyr + L-C combination resulted in significantly higher motility compared to the control at 72 h (total motility: 64.2% vs. 39.4%; progressive motility: 34.2% vs. 15.2%). In addition, supplementation with L-C significantly reduced oxidative DNA damage at 72 h (9.0% vs. 15.6%). To investigate the effects of L-C as an osmolyte, comparisons were made between media that were osmotically balanced with NaCl, choline chloride, or L-C. This analysis demonstrated that spermatozoa stored in the L-C balanced medium had significantly higher total motility (55.0% vs. 39.0%), rapid motility (44.0% vs. 25.7%), and ATP levels (70.9 vs. 12.8 ng/ml) following storage compared with the NaCl treatment, while choline chloride did not significantly improve these parameters compared to the control. Finally, mass spectrometry was used to demonstrate that a combination of Pyr and L-C produced significantly higher acetyl-L-carnitine production than any other treatment (6.7 pg/10(6) spermatozoa vs. control at 4.0 pg/10(6) spermatozoa). These findings suggest that Pyr and L-C could form the basis of a novel, effective RT storage medium for equine spermatozoa.


Assuntos
Carnitina/farmacologia , Cavalos , Ácido Pirúvico/farmacologia , Preservação do Sêmen , Espermatozoides/efeitos dos fármacos , Acrossomo/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Colina/farmacologia , Cromatina/efeitos dos fármacos , Cromatina/ultraestrutura , Dano ao DNA , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Concentração Osmolar , Espécies Reativas de Oxigênio/metabolismo , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Temperatura
7.
Nat Med ; 19(12): 1643-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24240184

RESUMO

Ammonia is a ubiquitous waste product of protein metabolism that can accumulate in numerous metabolic disorders, causing neurological dysfunction ranging from cognitive impairment to tremor, ataxia, seizures, coma and death. The brain is especially vulnerable to ammonia as it readily crosses the blood-brain barrier in its gaseous form, NH3, and rapidly saturates its principal removal pathway located in astrocytes. Thus, we wanted to determine how astrocytes contribute to the initial deterioration of neurological functions characteristic of hyperammonemia in vivo. Using a combination of two-photon imaging and electrophysiology in awake head-restrained mice, we show that ammonia rapidly compromises astrocyte potassium buffering, increasing extracellular potassium concentration and overactivating the Na(+)-K(+)-2Cl(-) cotransporter isoform 1 (NKCC1) in neurons. The consequent depolarization of the neuronal GABA reversal potential (EGABA) selectively impairs cortical inhibitory networks. Genetic deletion of NKCC1 or inhibition of it with the clinically used diuretic bumetanide potently suppresses ammonia-induced neurological dysfunction. We did not observe astrocyte swelling or brain edema in the acute phase, calling into question current concepts regarding the neurotoxic effects of ammonia. Instead, our findings identify failure of potassium buffering in astrocytes as a crucial mechanism in ammonia neurotoxicity and demonstrate the therapeutic potential of blocking this pathway by inhibiting NKCC1.


Assuntos
Amônia/farmacologia , Astrócitos/efeitos dos fármacos , Inibição Neural/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Potássio/metabolismo , Convulsões/induzido quimicamente , Animais , Animais Recém-Nascidos , Astrócitos/metabolismo , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/fisiologia , Ratos , Ratos Wistar , Convulsões/fisiopatologia
8.
Cochrane Database Syst Rev ; (6): CD008563, 2010 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-20556793

RESUMO

BACKGROUND: Diarrhoea is a major cause of morbidity and mortality among infants and children worldwide, especially in low- and middle-income countries. Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is a condition that similarly disproportionately affects low- and middle-income countries; of the nearly 2.1 million children under age 15 years living with HIV/AIDS, the large majority reside in sub-Saharan Africa. Infants and children with HIV infection have more frequent and more severe diarrhoea than children without HIV. Interventions including vitamin A, zinc and cotrimoxazole may contribute substantially to preventing diarrhoea in children with HIV infection or exposure to HIV. OBJECTIVES: We perform a systematic review of randomised controlled trials and nonrandomised studies that examine the effectiveness of vitamin A, zinc and cotrimoxazole on mortality and morbidity from diarrhoea in HIV-infected and -exposed infants and children. SEARCH STRATEGY: Electronic databases including Pubmed, Central and EMBASE were searched without limits to language from 1980 to April 2010. Conference database searches were performed, experts were contacted and bibliographies were handsearched. SELECTION CRITERIA: Randomised controlled trials (RCTs) and nonrandomised studies (NRSs) that examined the effectiveness of the three interventions were included. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed citations for eligibility and double-extracted included studies. Assessment of bias of individual studies was performed independently by both reviewers. Only two summary estimates were performed due to heterogeneity in study design and interventions. MAIN RESULTS: Four RCTs were identified for vitamin A. One RCT was identified for zinc. One RCT and two NRSs were identified for cotrimoxazole. Vitamin A reduced mortality overall in children with HIV infection (four studies). A pooled estimate of three studies for reduction in mortality from vitamin A compared to placebo had a relative risk (DerSimonian and Laird method, random effects) of 0.50 (95% confidence interval (CI): 0.31 to 0.79) in 267 patients. Diarrheoa-specific mortality did not reach statistical significance and diarrhoeal morbidity outcomes were variable in three trials. Zinc supplementation reduced the number of physician visits for watery diarrhoea in one trial. Cotrimoxazole reduced mortality and hospitalisations compared to placebo in one RCT, although diarrhoea-specific morbidities were not significant. AUTHORS' CONCLUSIONS: Vitamin A shows benefits in reduction of mortality in HIV-infected children. The effect of vitamin A on children with HIV exposure is not clear and needs further review. Zinc and combination vitamin A, zinc and micronutrient supplementation did not show an effect compared to vitamin A alone in children with HIV infection. Cotrimoxazole reduced mortality and some morbidity in children with HIV infection. Further research may clarify the effects of these interventions on morbidity from diarrhoea and in the population of children with HIV exposure.


Assuntos
Diarreia/prevenção & controle , Infecções por HIV/complicações , Anti-Infecciosos/uso terapêutico , Aleitamento Materno/efeitos adversos , Criança , Diarreia/mortalidade , Feminino , Infecções por HIV/mortalidade , Infecções por HIV/transmissão , Humanos , Lactente , Transmissão Vertical de Doenças Infecciosas , Micronutrientes/uso terapêutico , Gravidez , Complicações Infecciosas na Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Vitamina A/uso terapêutico , Vitaminas/uso terapêutico , Zinco/administração & dosagem , Zinco/deficiência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA