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1.
Appl Environ Microbiol ; 90(6): e0073224, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38819127

RESUMO

Chloroform (CF) and dichloromethane (DCM) are groundwater contaminants of concern due to their high toxicity and inhibition of important biogeochemical processes such as methanogenesis. Anaerobic biotransformation of CF and DCM has been well documented but typically independently of one another. CF is the electron acceptor for certain organohalide-respiring bacteria that use reductive dehalogenases (RDases) to dechlorinate CF to DCM. In contrast, known DCM degraders use DCM as their electron donor, which is oxidized using a series of methyltransferases and associated proteins encoded by the mec cassette to facilitate the entry of DCM to the Wood-Ljungdahl pathway. The SC05 culture is an enrichment culture sold commercially for bioaugmentation, which transforms CF via DCM to CO2. This culture has the unique ability to dechlorinate CF to DCM using electron equivalents provided by the oxidation of DCM to CO2. Here, we use metagenomic and metaproteomic analyses to identify the functional genes involved in each of these transformations. Though 91 metagenome-assembled genomes were assembled, the genes for an RDase-named acdA-and a complete mec cassette were found to be encoded on a single contig belonging to Dehalobacter. AcdA and critical Mec proteins were also highly expressed by the culture. Heterologously expressed AcdA dechlorinated CF and other chloroalkanes but had 100-fold lower activity on DCM. Overall, the high expression of Mec proteins and the activity of AcdA suggest a Dehalobacter capable of dechlorination of CF to DCM and subsequent mineralization of DCM using the mec cassette. IMPORTANCE: Chloroform (CF) and dichloromethane (DCM) are regulated groundwater contaminants. A cost-effective approach to remove these pollutants from contaminated groundwater is to employ microbes that transform CF and DCM as part of their metabolism, thus depleting the contamination as the microbes continue to grow. In this work, we investigate bioaugmentation culture SC05, a mixed microbial consortium that effectively and simultaneously degrades both CF and DCM coupled to the growth of Dehalobacter. We identified the functional genes responsible for the transformation of CF and DCM in SC05. These genetic biomarkers provide a means to monitor the remediation process in the field.


Assuntos
Proteínas de Bactérias , Clorofórmio , Cloreto de Metileno , Consórcios Microbianos , Clorofórmio/metabolismo , Cloreto de Metileno/metabolismo , Consórcios Microbianos/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Água Subterrânea/microbiologia , Metagenômica , Poluentes Químicos da Água/metabolismo
2.
Environ Sci Technol ; 58(27): 12042-12050, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38934904

RESUMO

Compound-specific isotope analysis (CSIA) is an established tool to track the in situ transformation of organic chemicals at contaminated sites. In this work, we evaluated the potential of multi-element CSIA to assess biodegradation of 2,3-dichloroaniline (2,3-DCA), which is a major industrial feedstock. Using controlled laboratory experiments, we determined, for the first time, negligible carbon (<0.5‰) and hydrogen (<10‰) isotope fractionation and a significant inverse nitrogen isotope fractionation (>10‰) during aerobic 2,3-DCA biodegradation by a mixed enrichment culture. The tentative identification of a glutamate conjugate of 2,3-DCA as a reaction intermediate indicates that the initial multistep enzymatic reaction may be rate-limiting. The formation of the glutamate adduct would increase the bond energy at the N atom, thus likely explaining the observed inverse N isotope fractionation. The corresponding nitrogen enrichment factor was +6.8 ± 0.6‰. This value was applied to investigate the in situ 2,3-DCA biodegradation at a contaminated site where the carbon and nitrogen isotope signatures from field samples suggested similar aerobic processes by native microorganisms. Under the assumption of the applicability of the Rayleigh model in a pilot wetland treating contaminated groundwater, the extent of biodegradation was estimated to be up to 80-90%. This study proposes multi-element CSIA as a novel application to study 2,3-DCA fate in groundwater and surface water and provides insights into biodegradation pathways.


Assuntos
Biodegradação Ambiental , Compostos de Anilina/metabolismo , Isótopos de Carbono , Isótopos de Nitrogênio , Aerobiose , Nitrogênio/metabolismo
3.
Appl Environ Microbiol ; 89(5): e0002523, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37098974

RESUMO

The Candidate Phyla Radiation (CPR), also referred to as superphylum Patescibacteria, is a very large group of bacteria with no pure culture representatives discovered by 16S rRNA sequencing or genome-resolved metagenomic analyses of environmental samples. Within the CPR, candidate phylum Parcubacteria, previously referred to as OD1, is prevalent in anoxic sediments and groundwater. Previously, we had identified a specific member of the Parcubacteria (referred to as DGGOD1a) as an important member of a methanogenic benzene-degrading consortium. Phylogenetic analyses herein place DGGOD1a within the clade "Candidatus Nealsonbacteria." Because of its persistence over many years, we hypothesized that "Ca. Nealsonbacteria" DGGOD1a must play an important role in sustaining anaerobic benzene metabolism in the consortium. To try to identify its growth substrate, we amended the culture with a variety of defined compounds (pyruvate, acetate, hydrogen, DNA, and phospholipid), as well as crude culture lysate and three subfractions thereof. We observed the greatest (10-fold) increase in the absolute abundance of "Ca. Nealsonbacteria" DGGOD1a only when the consortium was amended with crude cell lysate. These results implicate "Ca. Nealsonbacteria" in biomass recycling. Fluorescence in situ hybridization and cryogenic transmission electron microscope images revealed that "Ca. Nealsonbacteria" DGGOD1a cells were attached to larger archaeal Methanothrix cells. This apparent epibiont lifestyle was supported by metabolic predictions from a manually curated complete genome. This is one of the first examples of bacterial-archaeal episymbiosis and may be a feature of other "Ca. Nealsonbacteria" found in anoxic environments. IMPORTANCE An anaerobic microbial enrichment culture was used to study members of candidate phyla that are difficult to grow in the lab. We were able to visualize tiny "Candidatus Nealsonbacteria" cells attached to a large Methanothrix cell, revealing a novel episymbiosis.


Assuntos
Archaea , Euryarchaeota , Archaea/metabolismo , Benzeno/metabolismo , Filogenia , Biomassa , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Hibridização in Situ Fluorescente , Bactérias/genética , Euryarchaeota/metabolismo
4.
Am J Physiol Regul Integr Comp Physiol ; 325(2): R164-R171, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37306399

RESUMO

The acute effect of exercise on ß-cell function during a high-fat meal (HFM) in young adults (YA) versus old adults (OA) is unclear. In this randomized crossover trial, YA (n = 5 M/7 F, 23.3 ± 3.9 yr) and OA (n = 8 M/4 F, 67.7 ± 6.0 yr) underwent a 180-min HFM (12 kcal/kg body wt; 57% fat, 37% CHO) after a rest or exercise [∼65% heart rate peak (HRpeak)] condition ∼12 h earlier. After an overnight fast, plasma lipids, glucose, insulin, and free fatty acid (FFA) were determined to estimate peripheral, or skeletal muscle, insulin sensitivity (Matsuda index) as well as hepatic [homeostatic model assessment of insulin resistance (HOMA-IR)] and adipose insulin resistance (adipose-IR). ß-Cell function was derived from C-peptide and defined as early-phase (0-30 min) and total-phase (0-180 min) disposition index [DI, glucose-stimulated insulin secretion (GSIS) adjusted for insulin sensitivity/resistance]. Hepatic insulin extraction (HIE), body composition [dual-energy X-ray absorptiometry (DXA)], and peak oxygen consumption (V̇o2peak) were also assessed. OA had higher total cholesterol (TC), LDL, HIE, and DI across organs as well as lower adipose-IR (all, P < 0.05) and V̇o2peak (P = 0.056) despite similar body composition and glucose tolerance. Exercise lowered early-phase TC and LDL in OA versus YA (P < 0.05). However, C-peptide area under the curve (AUC), total phase GSIS, and adipose-IR were reduced postexercise in YA versus OA (P < 0.05). Skeletal muscle DI increased in YA and OA after exercise (P < 0.05), whereas adipose DI tended to decline in OA (P = 0.06 and P = 0.08). Exercise-induced skeletal muscle insulin sensitivity (r = -0.44, P = 0.02) and total-phase DI (r = -0.65, P = 0.005) correlated with reduced glucose AUC180min. Together, exercise improved skeletal muscle insulin sensitivity/DI in relation to glucose tolerance in YA and OA, but only raised adipose-IR and reduced adipose-DI in OA.NEW & NOTEWORTHY High-fat diets may induce ß-cell dysfunction. This study compared how young and older adults responded to a high-fat meal with regard to ß-cell function and whether exercise comparably impacted glucose regulation. Older adults secreted more insulin during the high-fat meal than younger adults. Although exercise increased ß-cell function adjusted for skeletal muscle insulin sensitivity in relation to glucose tolerance, it raised adipose insulin resistance and reduced pancreatic ß-cell function relative to adipose tissue in older adults. Additional work is needed to discern nutrient-exercise interactions across age to mitigate chronic disease risk.


Assuntos
Resistência à Insulina , Adulto Jovem , Humanos , Idoso , Peptídeo C , Tecido Adiposo , Glucose , Insulina , Obesidade , Glicemia
5.
Environ Sci Technol ; 57(48): 19912-19920, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37962431

RESUMO

Chloroform (CF) and dichloromethane (DCM) contaminate groundwater sites around the world but can be cleaned up through bioremediation. Although several strains of Dehalobacter restrictus can reduce CF to DCM and multiple Peptococcaceae can ferment DCM, these processes cannot typically happen simultaneously due to CF sensitivity in the known DCM-degraders or electron donor competition. Here, we present a mixed microbial culture that can simultaneously metabolize CF and DCM and create an additional enrichment culture fed only DCM. Through genus-specific quantitative polymerase chain reaction, we find that Dehalobacter grows while either CF alone or DCM alone is converted, indicating its involvement in both metabolic steps. Additionally, the culture was maintained for over 1400 days without the addition of an exogenous electron donor, and through electron balance calculations, we show that DCM metabolism would produce sufficient reducing equivalents (likely hydrogen) for CF respiration. Together, these results suggest intraspecies electron transfer could occur to continually reduce CF in the culture. Minimizing the addition of electron donor reduces the cost of bioremediation, and "self-feeding" could prolong bioremediation activity long after donor addition ends. Overall, understanding this mechanism informs strategies for culture maintenance and scale-up and benefits contaminated sites where the culture is employed for remediation worldwide.


Assuntos
Clorofórmio , Cloreto de Metileno , Clorofórmio/metabolismo , Cloreto de Metileno/metabolismo , Biodegradação Ambiental , Halogenação , Peptococcaceae/metabolismo
6.
Birth ; 50(4): 773-780, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36939318

RESUMO

BACKGROUND: Performing an episiotomy where clinically indicated is a key intervention in the Obstetric Anal Sphincter Injury Care Bundle (OASI-CB) implemented across England and Wales to reduce the risk and increase the detection of severe perineal trauma after birth. Standards of consent provided to people in maternity care generally and for episiotomy specifically have been reported as suboptimal. Compromising birthing people's personal autonomy or sense of control has been linked to a dissatisfying birth experience, negative psychological sequelae, and litigation. METHODS: This study explored experienced midwives' practice of informed consent for episiotomy during a midwife-led birth. We sampled 43 midwives across eight NHS Trusts in England and Wales using online focus groups and telephone interviews about their experience of consent in episiotomy. Using qualitative content analysis and art-based co-analysis methods with eight midwives from across the research sites, we co-analyzed and co-constructed three themes and four practice recommendations from the data. RESULTS: Three themes were constructed from the data: Assent rather than consent, Change in culture to support best practice, and Standardized information. These themes informed the shaping of four recommendations for best practice in episiotomy informed consent. CONCLUSION: This study has shown how variations in midwifery practice and culture may impact birthing people's experience of informed consent in episiotomy. Midwives may not have the knowledge or skills to conduct a detailed consent conversation, leading to variation in practice and messages for birthing people. The use of antenatal discussion aids can offer women the opportunity to become informed and fully participate in the decision-making process.


Assuntos
Serviços de Saúde Materna , Tocologia , Enfermeiros Obstétricos , Feminino , Gravidez , Humanos , Tocologia/métodos , Episiotomia , Enfermeiros Obstétricos/psicologia , Consentimento Livre e Esclarecido
7.
Int J Mol Sci ; 24(8)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37108682

RESUMO

Naphthoquinone (1,4-NQ) and its derivatives (NQs, juglone, plumbagin, 2-methoxy-1,4-NQ, and menadione) have a variety of therapeutic applications, many of which are attributed to redox cycling and the production of reactive oxygen species (ROS). We previously demonstrated that NQs also oxidize hydrogen sulfide (H2S) to reactive sulfur species (RSS), potentially conveying identical benefits. Here we use RSS-specific fluorophores, mass spectroscopy, EPR and UV-Vis spectrometry, and oxygen-sensitive optodes to examine the effects of thiols and thiol-NQ adducts on H2S-NQ reactions. In the presence of glutathione (GSH) and cysteine (Cys), 1,4-NQ oxidizes H2S to both inorganic and organic hydroper-/hydropolysulfides (R2Sn, R=H, Cys, GSH; n = 2-4) and organic sulfoxides (GSnOH, n = 1, 2). These reactions reduce NQs and consume oxygen via a semiquinone intermediate. NQs are also reduced as they form adducts with GSH, Cys, protein thiols, and amines. Thiol, but not amine, adducts may increase or decrease H2S oxidation in reactions that are both NQ- and thiol-specific. Amine adducts also inhibit the formation of thiol adducts. These results suggest that NQs may react with endogenous thiols, including GSH, Cys, and protein Cys, and that these adducts may affect both thiol reactions as well as RSS production from H2S.


Assuntos
Sulfeto de Hidrogênio , Naftoquinonas , Compostos de Sulfidrila/química , Tiossulfatos , Cisteína/metabolismo , Sulfeto de Hidrogênio/química , Oxirredução , Glutationa/metabolismo , Proteínas/metabolismo , Oxigênio , Naftoquinonas/metabolismo
8.
J Med Syst ; 47(1): 109, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37858009

RESUMO

Problematic smartphone use has been associated with poorer mental health in different population groups; however, little is known about how levels of smartphone use were associated with mental health outcomes of adults in Australia. Using data from a cross-sectional survey among Australian adults aged 18-59 years (n = 655, Mean = 24.55 [SD = 5.59] years; 66% female), the current study aimed to examine association between problematic smartphone use and different psychological outcomes. Participants completed measures of problematic smartphone use with Mobile Phone Problem Use Scale (MPPUS), mental health outcomes with Depression, Anxiety, and Stress Scale (DASS-21), and Pittsburgh Sleep Quality Index (PSQI), in addition to some socio-demographics. Smartphone use was categorised into three groups: low-moderate, moderate-high, and high-severe. A total of 160 adults (24.4%) reported high-severe smartphone use. Multivariable linear regression analyses showed that smartphone use was inversely associated with psychological outcomes in a dose-dependent manner with high-severe smartphone uses having the most adverse effects. Compared to low-moderate use, average depression score was 3.5 points higher for moderate-high smartphone use (ß = 3.51, 95% CI: 1.63-5.40) and 6.9 points higher for high-severe smartphone use (ß = 6.91, 95% CI: 4.74-9.07). Similarly, average stress score was 3.4 points higher for moderate-high smartphone use (ß = 3.40, 95% CI: 1.75-5.06) and 7.0 points higher for high-severe smartphone use (ß = 7.02, 95% CI: 5.11-8.93). Similar association estimates were found for anxiety and sleep quality. Reducing smartphone use has the potential to optimise depression, anxiety, stress, and sleep quality; however, longitudinal research is warranted to establish directionality of the association.


Assuntos
Depressão , Qualidade do Sono , Humanos , Adulto , Feminino , Masculino , Depressão/epidemiologia , Smartphone , Estudos Transversais , Austrália/epidemiologia , Ansiedade/epidemiologia
9.
Chembiochem ; 23(1): e202100414, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34643018

RESUMO

l-2-Haloacid dehalogenases, industrially and environmentally important enzymes that catalyse cleavage of the carbon-halogen bond in S-2-halocarboxylic acids, were known to hydrolyse chlorinated, brominated and iodinated substrates but no activity towards fluorinated compounds had been reported. A screen for novel dehalogenase activities revealed four l-2-haloacid dehalogenases capable of defluorination. We now report crystal structures for two of these enzymes, Bpro0530 and Rha0230, as well as for the related proteins PA0810 and RSc1362, which hydrolyse chloroacetate but not fluoroacetate, all at ∼2.2 Šresolution. Overall structure and active sites of these enzymes are highly similar. In molecular dynamics (MD) calculations, only the defluorinating enzymes sample more compact conformations, which in turn allow more effective interactions with the small fluorine atom. Structural constraints, based on X-ray structures and MD calculations, correctly predict the defluorination activity of the homologous enzyme ST2570.


Assuntos
Hidrolases/metabolismo , Sequência de Aminoácidos , Cristalografia por Raios X , Halogenação , Hidrolases/química , Hidrolases/isolamento & purificação , Simulação de Dinâmica Molecular , Conformação Proteica , Alinhamento de Sequência
10.
Appl Environ Microbiol ; 88(3): e0199321, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-34851719

RESUMO

Reductive dehalogenases (RDases) are a family of redox enzymes that are required for anaerobic organohalide respiration, a microbial process that is useful in bioremediation. Structural and mechanistic studies of these enzymes have been greatly impeded due to challenges in RDase heterologous expression, potentially because of their cobamide-dependence. There have been a few successful attempts at RDase production in unconventional heterologous hosts, but a robust method has yet to be developed. Here we outline a novel respiratory RDase expression system using Escherichia coli. The overexpression of E. coli's cobamide transport system, btu, and anaerobic expression conditions were found to be essential for production of active RDases from Dehalobacter-an obligate organohalide respiring bacterium. The expression system was validated on six enzymes with amino acid sequence identities as low as 28%. Dehalogenation activity was verified for each RDase by assaying cell extracts of small-scale expression cultures on various chlorinated substrates including chloroalkanes, chloroethenes, and hexachlorocyclohexanes. Two RDases, TmrA from Dehalobacter sp. UNSWDHB and HchA from Dehalobacter sp. HCH1, were purified by nickel affinity chromatography. Incorporation of the cobamide and iron-sulfur cluster cofactors was verified; however, the precise cobalamin incorporation could not be determined due to variance between methodologies, and the specific activity of TmrA was consistent with that of the native enzyme. The heterologous expression of respiratory RDases, particularly from obligate organohalide respiring bacteria, has been extremely challenging and unreliable. Here we present a relatively straightforward E. coli expression system that has performed well for a variety of Dehalobacter spp. RDases. IMPORTANCE Understanding microbial reductive dehalogenation is important to refine the global halogen cycle and to improve bioremediation of halogenated contaminants; however, studies of the family of enzymes responsible are limited. Characterization of reductive dehalogenase enzymes has largely eluded researchers due to the lack of a reliable and high-yielding production method. We are presenting an approach to express reductive dehalogenase enzymes from Dehalobacter, a key group of organisms used in bioremediation, in Escherichia coli. This expression system will propel the study of reductive dehalogenases by facilitating their production and isolation, allowing researchers to pursue more in-depth questions about the activity and structure of these enzymes. This platform will also provide a starting point to improve the expression of reductive dehalogenases from many other organisms.


Assuntos
Escherichia coli , Oxirredutases , Bactérias/metabolismo , Biodegradação Ambiental , Escherichia coli/genética , Escherichia coli/metabolismo , Oxirredutases/metabolismo , Vitamina B 12/metabolismo
11.
Biotechnol Bioeng ; 119(6): 1343-1358, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35182428

RESUMO

Glycosylation can be a critical quality attribute in biologic manufacturing. In particular, it has implications on the half-life, immunogenicity, and pharmacokinetics of therapeutic monoclonal antibodies (mAbs), and must be closely monitored throughout drug development and manufacturing. To address this, advances have been made primarily in upstream processing, including mammalian cell line engineering, to yield more predictably glycosylated mAbs and the addition of media supplements during fermentation to manipulate the metabolic pathways involved in glycosylation. A more robust approach would be a conjoined upstream-downstream processing strategy. This could include implementing novel downstream technologies, such as the use of Fc γ-based affinity ligands for the separation of mAb glycovariants. This review highlights the importance of controlling therapeutic antibody glycosylation patterns, the challenges faced in terms of glycosylation during mAb biosimilar development, current efforts both upstream and downstream to control glycosylation and their limitations, and the need for research in the downstream space to establish holistic and consistent manufacturing processes for the production of antibody therapies.


Assuntos
Antineoplásicos Imunológicos , Medicamentos Biossimilares , Animais , Anticorpos Monoclonais/metabolismo , Glicosilação , Mamíferos/metabolismo
12.
Br J Nutr ; 127(5): 687-695, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-34134790

RESUMO

A single high-fat, high-carbohydrate meal (HFHC) results in elevated postprandial glucose (GLU), triglycerides (TAG) and metabolic load index (MLI; TAG (mg/dl) + GLU (mg/dl)) that contributes to chronic disease risk. While disease risk is higher in older adults (OA) compared to younger adults (YA), the acute effects of exercise on these outcomes in OA is understudied. Twelve YA (age 23.3 ± 3.9 yrs, n = 5 M/7 F) and 12 OA (age 67·7 ± 6.0 yrs, n = 8 M/4 F) visited the laboratory in random order to complete a HFHC with no exercise (NE) or acute exercise (EX) condition. EX was performed 12 hours prior to HFHC at an intensity of 65 % of maximal heart rate to expend 75 % of the kcals consumed in HFHC (Marie Callender's Chocolate Satin Pie; 12 kcal/kgbw; 57 % fat, 37 % CHO). Blood samples were taken at 0, 30, 60, 90 minutes, and then every hour until 6 hours post-meal. TAG levels increased to a larger magnitude in OA (Δ∼61 ± 31 %) compared to YA (Δ∼37 ± 34 %, P < 0·001), which were attenuated in EX compared to NE (P < 0·05) independent of age. There was no difference in GLU between OA and YA after the HFM, however, EX had attenuated GLU independent of age (NE: Δ∼21 ± 26 %; EX: Δ∼12 ± 18 %, P = 0·027). MLI was significantly lower after EX compared to NE in OA and YA (P < 0·001). Pre-prandial EX reduced TAG, GLU and MLI post-HFHC independent of age.


Assuntos
Glicemia , Glucose , Glicemia/metabolismo , Exercício Físico/fisiologia , Insulina , Refeições , Período Pós-Prandial/fisiologia , Triglicerídeos
13.
Environ Sci Technol ; 56(2): 907-916, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34978445

RESUMO

The microbial transformation potential of 6:2 chlorinated polyfluorooctane ether sulfonate (6:2 Cl-PFESA) was explored in anaerobic microbial systems. Microbial communities from anaerobic wastewater sludge, an anaerobic digester, and anaerobic dechlorinating cultures enriched from aquifer materials reductively dechlorinated 6:2 Cl-PFESA to 6:2 hydrogen-substituted polyfluorooctane ether sulfonate (6:2 H-PFESA), which was identified as the sole metabolite by non-target analysis. Rapid and complete reductive dechlorination of 6:2 Cl-PFESA was achieved by the anaerobic dechlorinating cultures. The microbial community of the anaerobic dechlorinating cultures was impacted by 6:2 Cl-PFESA exposure. Organohalide-respiring bacteria originally present in the anaerobic dechlorinating cultures, including Geobacter, Dehalobacter, and Dehalococcoides, decreased in relative abundance over time. As the relative abundance of organohalide-respiring bacteria decreased, the rates of 6:2 Cl-PFESA dechlorination decreased, suggesting that the most likely mechanism for reductive dechlorination of 6:2 Cl-PFESA was co-metabolism rather than organohalide respiration. Reductive defluorination of 6:2 Cl-PFESA was not observed. Furthermore, 6:2 H-PFESA exhibited 5.5 times lower sorption affinity to the suspended biosolids than 6:2 Cl-PFESA, with the prospect of increased mobility in the environment. These results show the susceptibility of 6:2 Cl-PFESA to microbially mediated reductive dechlorination and the likely persistence of the product, 6:2 H-PFESA, in anaerobic environments.


Assuntos
Chloroflexi , Anaerobiose , Biodegradação Ambiental , Chloroflexi/metabolismo , Éter/metabolismo , Éteres/metabolismo
14.
Environ Sci Technol ; 56(18): 13036-13045, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36083837

RESUMO

We investigated the impact of oxygen on a strictly anaerobic, methanogenic benzene-degrading enrichment culture derived decades ago from oil-contaminated sediment. The culture includes a benzene fermenter from Deltaproteobacteria candidate clade Sva0485 (referred to as ORM2) and methanogenic archaea. A one-time injection of 0.1 mL air , simulating a small leak into 30 mL batch culture bottle, had no measurable impact on benzene degradation rates, although retrospectively, a tiny enrichment of aerobic taxa was detected. A subsequent 100 times larger injection of air stalled methanogenesis and caused drastic perturbation of the microbial community. A benzene-degrading Pseudomonas became highly enriched and consumed all available oxygen. Anaerobic benzene-degrading ORM2 cell numbers plummeted during this time; re-growth and associated recovery of methanogenic benzene degradation took almost 1 year. These results highlight the oxygen sensitivity of this methanogenic culture and confirm that the mechanism for anaerobic biotransformation of benzene is independent of oxygen, fundamentally different from established aerobic pathways, and is carried out by distinct microbial communities. The study also highlights the importance of including microbial decay in characterizing and modeling mixed microbial communities.


Assuntos
Benzeno , Euryarchaeota , Biodegradação Ambiental , Euryarchaeota/metabolismo , Oxigênio , RNA Ribossômico 16S , Estudos Retrospectivos
15.
Environ Sci Technol ; 56(17): 12237-12246, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-35951369

RESUMO

Chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile, TePN) is one of the most widely used fungicides all over the world. Its major environmental transformation product 4-hydroxy-chlorothalonil (4-hydroxy-2,5,6-trichloroisophthalonitrile, 4-OH-TPN) is more persistent, mobile, and toxic and is frequently detected at a higher concentration in various habitats compared to its parent compound TePN. Further microbial transformation of 4-OH-TPN has never been reported. In this study, we demonstrated that 4-OH-TPN underwent complete microbial reductive dehalogenation to 4-hydroxy-isophthalonitrile via 4-hydroxy-dichloroisophthalonitrile and 4-hydroxy-monochloroisophthalonitrile. 16S rRNA gene amplicon sequencing demonstrated that Dehalogenimonas species was enriched from 6% to 17-22% after reductive dechlorination of 77.24 µmol of 4-OH-TPN. Meanwhile, Dehalogenimonas copies increased by one order of magnitude and obtained a yield of 1.78 ± 1.47 × 108 cells per µmol Cl- released (N = 6), indicating that 4-OH-TPN served as the terminal electron acceptor for organohalide respiration of Dehalogenimonas species. A draft genome of Dehalogenimonas species was assembled through metagenomic sequencing, which harbors 30 putative reductive dehalogenase genes. Syntrophobacter, Acetobacterium, and Methanosarcina spp. were found to be the major non-dechlorinating populations in the microbial community, who might play important roles in the reductive dechlorination of 4-OH-TPN by the Dehalogenimonas species. This study first reports that Dehalogenimonas sp. can also respire on the seemingly dead-end product of TePN, paving the way to complete biotransformation of the widely present TePN and broadening the substrate spectrum of Dehalogenimonas sp. to polychlorinated hydroxy-benzonitrile.


Assuntos
Chloroflexi , Biodegradação Ambiental , Biotransformação , Chloroflexi/metabolismo , Nitrilas , RNA Ribossômico 16S/genética
16.
BMC Med Educ ; 22(1): 259, 2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35397566

RESUMO

BACKGROUND: It is well recognised that medical students need to acquire certain procedural skills during their medical training, however, agreement on the level and acquisition of competency to be achieved in these skills is under debate. Further, the maintenance of competency of procedural skills across medical curricula is often not considered. The purpose of this study was to identify core procedural skills competencies for Australian medical students and to establish the importance of the maintenance of such skills. METHODS: A three-round, online Delphi method was used to identify consensus on competencies of procedural skills for graduating medical students in Australia. In Round 1, an initial structured questionnaire was developed using content identified from the literature. Respondents were thirty-six experts representing medical education and multidisciplinary clinicians involved with medical students undertaking procedural skills, invited to rate their agreement on the inclusion of teaching 74 procedural skills and 11 suggested additional procedures. In Round 2, experts re-appraised the importance of 85 skills and rated the importance of maintenance of competency (i.e., Not at all important to Extremely important). In Round 3, experts rated the level of maintenance of competence (i.e., Observer, Novice, Competent, Proficient) in 46 procedures achieving consensus. RESULTS: Consensus, defined as > 80% agreement, was established with 46 procedural skills across ten categories: cardiovascular, diagnostic/measurement, gastrointestinal, injections/intravenous, ophthalmic/ENT, respiratory, surgical, trauma, women's health and urogenital procedures. The procedural skills that established consensus with the highest level of agreement included cardiopulmonary resuscitation, airway management, asepsis and surgical scrub, gown and gloving. The importance for medical students to demonstrate maintenance of competency in all procedural skills was assessed on the 6-point Likert scale with a mean of 5.03. CONCLUSIONS: The findings from the Delphi study provide critical information about procedural skills for the Clinical Practice domain of Australian medical curricula. The inclusion of experts from medical faculty and clinicians enabled opportunities to capture a range of experience independent of medical speciality. These findings demonstrate the importance of maintenance of competency of procedural skills and provides the groundwork for further investigations into monitoring medical students' skills prior to graduation.


Assuntos
Estudantes de Medicina , Austrália , Competência Clínica , Consenso , Currículo , Técnica Delphi , Feminino , Humanos
17.
Rev Panam Salud Publica ; 46: e213, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-36415785

RESUMO

Hypertension and diabetes are modifiable cardiovascular disease (CVD) risk factors that contribute to nearly one-third of all deaths in the Americas Region each year (2.3 million deaths). Despite advances in the detection and clinical management of hypertension and diabetes, there are substantial gaps in their implementation globally and in the Region. The considerable overlap in risk factors, prognosis, and treatment of hypertension and diabetes creates a unique opportunity for a unified implementation model for management at the population level. This report highlights one such high-profile effort, the Pan American Health Organization's "HEARTS in the Americas" program, based on the World Health Organization's HEARTS Technical Package for Cardiovascular Disease Management in Primary Health Care. The HEARTS program aims to improve the implementation of preventive CVD care in primary health systems using six evidence-based, pragmatic components: Healthy-lifestyle counseling, Evidence-based protocols, Access to essential medicines and technology, Risk-based CVD management, Team-based care, and Systems for monitoring. To date, HEARTS implementation projects have focused primarily on hypertension given that it is the leading modifiable CVD risk factor and can be treated cost-effectively. The objective of this report is to describe opportunities for integration of diabetes clinical care and policy within the HEARTS hypertension framework. A substantial global burden of disease could be averted with integrated primary care management of these conditions. Thus, there is an urgency in applying lessons from HEARTS to close these implementation gaps and improve the integrated detection, treatment, and control of diabetes and hypertension.


Hipertensão e diabetes são fatores de risco modificáveis para doenças cardiovasculares (DCV) que contribuem para quase um terço de todas as mortes na Região das Américas a cada ano (2,3 milhões de mortes). Apesar dos avanços na detecção e no manejo clínico da hipertensão e do diabetes, existem lacunas importantes em sua implementação mundialmente e na região. A sobreposição considerável de fatores de risco, prognóstico e tratamento da hipertensão e do diabetes cria uma oportunidade única para um modelo de implementação unificado para o manejo dessas doenças em nível populacional. Este relatório destaca um desses esforços de alto nível, o programa "HEARTS nas Américas" da Organização Pan-Americana da Saúde, baseado no Pacote Técnico HEARTS da Organização Mundial da Saúde para o manejo de DCV na atenção primária à saúde. O programa HEARTS visa melhorar a implementação de cuidados preventivos de DCV nos sistemas de atenção primária utilizando seis componentes pragmáticos e baseados em evidências: Hábitos saudáveis (aconselhamento a pacientes), protocolos baseados em Evidências, Acesso a medicamentos e tecnologias essenciais, manejo das DCV baseado em Risco, Trabalho de equipe como base para a atenção e Sistemas de monitoramento. Até hoje, os projetos de implementação do HEARTS têm se concentrado principalmente na hipertensão, considerando que é o principal fator de risco modificável de DCV e pode ser tratada de forma custo-efetiva. O objetivo deste relatório é descrever as oportunidades de integração do manejo clínico e de políticas para o diabetes dentro da estrutura HEARTS de manejo da hipertensão. Uma importante carga global de doença poderia ser evitada com o manejo integrado dessas duas afecções na atenção primária. Assim, há uma urgência na aplicação das lições de HEARTS para fechar estas lacunas de implementação e melhorar a detecção, o tratamento e o controle integrados do diabetes e da hipertensão.

18.
Rev Panam Salud Publica ; 46: e150, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36071915

RESUMO

Hypertension and diabetes are modifiable cardiovascular disease (CVD) risk factors that contribute to nearly one-third of all deaths in the Americas Region each year (2.3 million deaths). Despite advances in the detection and clinical management of hypertension and diabetes, there are substantial gaps in their implementation globally and in the Region. The considerable overlap in risk factors, prognosis, and treatment of hypertension and diabetes creates a unique opportunity for a unified implementation model for management at the population level. This report highlights one such high-profile effort, the Pan American Health Organization's "HEARTS in the Americas" program, based on the World Health Organization's HEARTS Technical Package for Cardiovascular Disease Management in Primary Health Care. The HEARTS program aims to improve the implementation of preventive CVD care in primary health systems using six evidence-based, pragmatic components: Healthy-lifestyle counseling, Evidence-based protocols, Access to essential medicines and technology, Risk-based CVD management, Team-based care, and Systems for monitoring. To date, HEARTS implementation projects have focused primarily on hypertension given that it is the leading modifiable CVD risk factor and can be treated cost-effectively. The objective of this report is to describe opportunities for integration of diabetes clinical care and policy within the HEARTS hypertension framework. A substantial global burden of disease could be averted with integrated primary care management of these conditions. Thus, there is an urgency in applying lessons from HEARTS to close these implementation gaps and improve the integrated detection, treatment, and control of diabetes and hypertension.


La hipertensión y la diabetes son los factores de riesgo modificables de las enfermedades cardiovasculares asociados a casi un tercio de todas las muertes en la Región de las Américas cada año (2,3 millones). A pesar de los avances en la detección y el manejo clínico de la hipertensión y la diabetes, existen brechas sustanciales en la implementación a nivel regional y mundial. El considerable solapamiento en los factores de riesgo, el pronóstico y el tratamiento de la hipertensión y la diabetes crea una oportunidad única para un modelo unificado de implementación para el manejo a nivel poblacional. En este informe se pone de relieve una iniciativa importante de este tipo, el programa HEARTS en las Américas de la Organización Panamericana de la Salud, basado en el paquete técnico HEARTS para el manejo de las enfermedades cardiovasculares en la atención primaria de salud. El programa HEARTS tiene como objetivo mejorar la implementación de la atención preventiva de las enfermedades cardiovasculares en los sistemas de atención primaria de salud mediante seis componentes pragmáticos basados en la evidencia: Hábitos y estilos de vida saludables: asesoramiento para los pacientes; Evidencia: protocolos basados en la evidencia; Acceso a medicamentos y tecnologías esenciales; Riesgo cardiovascular: manejo de las enfermedades cardiovasculares basado en el riesgo; Trabajo en equipos; y Sistemas de monitoreo. Hasta la fecha, los proyectos de implementación de HEARTS se han centrado principalmente en la hipertensión, dado que es el principal factor de riesgo modificable de las enfermedades cardiovasculares y puede tratarse de una manera costo-eficaz. El objetivo de este informe es describir las oportunidades para la integración de la política y la atención clínica en el marco HEARTS para la hipertensión. Se podría evitar una significativa carga mundial de enfermedad con un manejo integrado de la atención primaria de estos problemas de salud. Por lo tanto, existe una urgencia en la aplicación de las enseñanzas de HEARTS para salvar estas brechas en la implementación y mejorar la detección, el tratamiento y el control integrados de la diabetes y la hipertensión.


Hipertensão e diabetes são fatores de risco modificáveis para doenças cardiovasculares (DCV) que contribuem para quase um terço de todas as mortes na Região das Américas a cada ano (2,3 milhões de mortes). Apesar dos avanços na detecção e no manejo clínico da hipertensão e do diabetes, existem lacunas importantes em sua implementação mundialmente e na região. A sobreposição considerável de fatores de risco, prognóstico e tratamento da hipertensão e do diabetes cria uma oportunidade única para um modelo de implementação unificado para o manejo dessas doenças em nível populacional. Este relatório destaca um desses esforços de alto nível, o programa "HEARTS nas Américas" da Organização Pan-Americana da Saúde, baseado no Pacote Técnico HEARTS da Organização Mundial da Saúde para o manejo de DCV na atenção primária à saúde. O programa HEARTS visa melhorar a implementação de cuidados preventivos de DCV nos sistemas de atenção primária utilizando seis componentes pragmáticos e baseados em evidências: Hábitos saudáveis (aconselhamento a pacientes), protocolos baseados em Evidências, Acesso a medicamentos e tecnologias essenciais, manejo das DCV baseado em Risco, Trabalho de equipe como base para a atenção e Sistemas de monitoramento. Até hoje, os projetos de implementação do HEARTS têm se concentrado principalmente na hipertensão, considerando que é o principal fator de risco modificável de DCV e pode ser tratada de forma custo-efetiva. O objetivo deste relatório é descrever as oportunidades de integração do manejo clínico e de políticas para o diabetes dentro da estrutura HEARTS de manejo da hipertensão. Uma importante carga global de doença poderia ser evitada com o manejo integrado dessas duas afecções na atenção primária. Assim, há uma urgência na aplicação das lições de HEARTS para fechar estas lacunas de implementação e melhorar a detecção, o tratamento e o controle integrados do diabetes e da hipertensão.

19.
Pers Individ Dif ; 198: 111826, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35891922

RESUMO

The present study investigated the relationship between anxiety, social support, living arrangements and cognitive performance of university students during the global pandemic. Two hundred and fifteen students participated by completing online questionnaires. Separate moderated multiple regression models were used to test whether social support (Family, Friends, Significant Other subscales of the Multidimensional Scale of Perceived Social Support) moderated the relationship between anxiety (Anxiety subscale of Depression, Anxiety Stress Scale), living arrangements (Living Alone vs Living with Friends and Family) and cognitive performance (Cognitive Failures Questionnaire), after controlling for comorbid depression. The results for each level of perceived social support suggested that anxiety was negatively associated with cognitive performance. Our most significant finding was that for students living alone, social support from a significant other offered a protective factor, whereby buffering the anxiety related cognitive deficits prevalent in those who reported lower social support. These data have important practical implications for supporting the social-emotional and academic needs of university students during the global pandemic.

20.
Circulation ; 141(5): 387-398, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31983221

RESUMO

BACKGROUND: Dilated cardiomyopathy (DCM) is genetically heterogeneous, with >100 purported disease genes tested in clinical laboratories. However, many genes were originally identified based on candidate-gene studies that did not adequately account for background population variation. Here we define the frequency of rare variation in 2538 patients with DCM across protein-coding regions of 56 commonly tested genes and compare this to both 912 confirmed healthy controls and a reference population of 60 706 individuals to identify clinically interpretable genes robustly associated with dominant monogenic DCM. METHODS: We used the TruSight Cardio sequencing panel to evaluate the burden of rare variants in 56 putative DCM genes in 1040 patients with DCM and 912 healthy volunteers processed with identical sequencing and bioinformatics pipelines. We further aggregated data from 1498 patients with DCM sequenced in diagnostic laboratories and the Exome Aggregation Consortium database for replication and meta-analysis. RESULTS: Truncating variants in TTN and DSP were associated with DCM in all comparisons. Variants in MYH7, LMNA, BAG3, TNNT2, TNNC1, PLN, ACTC1, NEXN, TPM1, and VCL were significantly enriched in specific patient subsets, with the last 2 genes potentially contributing primarily to early-onset forms of DCM. Overall, rare variants in these 12 genes potentially explained 17% of cases in the outpatient clinic cohort representing a broad range of adult patients with DCM and 26% of cases in the diagnostic referral cohort enriched in familial and early-onset DCM. Although the absence of a significant excess in other genes cannot preclude a limited role in disease, such genes have limited diagnostic value because novel variants will be uninterpretable and their diagnostic yield is minimal. CONCLUSIONS: In the largest sequenced DCM cohort yet described, we observe robust disease association with 12 genes, highlighting their importance in DCM and translating into high interpretability in diagnostic testing. The other genes analyzed here will need to be rigorously evaluated in ongoing curation efforts to determine their validity as Mendelian DCM genes but have limited value in diagnostic testing in DCM at present. This data will contribute to community gene curation efforts and will reduce erroneous and inconclusive findings in diagnostic testing.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Cardiomiopatia Dilatada/genética , Predisposição Genética para Doença , Testes Genéticos , Proteínas Adaptadoras de Transdução de Sinal/genética , Adolescente , Adulto , Cardiomiopatia Dilatada/diagnóstico , Exoma/genética , Feminino , Heterogeneidade Genética , Humanos , Masculino , Adulto Jovem
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