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1.
Cell ; 153(1): 166-77, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23540697

RESUMO

Many bacteria contain an ortholog of the Ro autoantigen, a ring-shaped protein that binds noncoding RNAs (ncRNAs) called Y RNAs. In the only studied bacterium, Deinococcus radiodurans, the Ro ortholog Rsr functions in heat-stress-induced ribosomal RNA (rRNA) maturation and starvation-induced rRNA decay. However, the mechanism by which this conserved protein and its associated ncRNAs act has been obscure. We report that Rsr and the exoribonuclease polynucleotide phosphorylase (PNPase) form an RNA degradation machine that is scaffolded by Y RNA. Single-particle electron microscopy, followed by docking of atomic models into the reconstruction, suggests that Rsr channels single-stranded RNA into the PNPase cavity. Biochemical assays reveal that Rsr and Y RNA adapt PNPase for effective degradation of structured RNAs. A Ro ortholog and ncRNA also associate with PNPase in Salmonella Typhimurium. Our studies identify another ribonucleoprotein machine and demonstrate that ncRNA, by tethering a protein cofactor, can alter the substrate specificity of an enzyme.


Assuntos
Deinococcus/química , Complexo Multienzimático de Ribonucleases do Exossomo/química , Estabilidade de RNA , RNA Bacteriano/química , RNA não Traduzido/metabolismo , Ribonucleoproteínas/metabolismo , Salmonella typhimurium/metabolismo , Animais , Sequência de Bases , Deinococcus/genética , Deinococcus/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Dados de Sequência Molecular , Polirribonucleotídeo Nucleotidiltransferase/química , Polirribonucleotídeo Nucleotidiltransferase/ultraestrutura , RNA Bacteriano/ultraestrutura , RNA não Traduzido/ultraestrutura , Ribonucleoproteínas/química , Ribonucleoproteínas/genética , Xenopus laevis/metabolismo
2.
J Biol Chem ; 300(10): 107758, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39260696

RESUMO

Salmonella Typhi, the cause of typhoid fever, is a bacterial pathogen of substantial global importance. Typhoid toxin is a secreted AB-type toxin that is a key S. Typhi virulence factor encoded within a 5-gene genetic islet. Four genes in this islet have well-defined roles in typhoid toxin biology; however, the function of the fifth gene is unknown. Here, we investigate the function of this gene, which we name ttaP. We show that ttaP is cotranscribed with the typhoid toxin subunit cdtB, and we perform genomic analyses that indicate that TtaP is very highly conserved in typhoid toxin islets found in diverse salmonellae. We show that TtaP is a distant homolog of group XIV secreted phospholipase A2 (PLA2) enzymes, and experimentally demonstrate that TtaP is a bona fide PLA2. Sequence and structural analyses indicate that TtaP differs substantially from characterized PLA2s, and thus represents a novel class of PLA2. Secretion assays revealed that TtaP is neither cosecreted with typhoid toxin, nor is it required for toxin secretion. Although TtaP is a phospholipase that remains associated with the S. Typhi cell, assays that probed for altered cell envelope integrity failed to identify any differences between WT S. Typhi and a ttaP deletion strain. Collectively, this study identifies a biochemical activity for the lone uncharacterized typhoid toxin islet gene and lays the groundwork for exploring how this gene factors into S. Typhi pathogenesis. This study further identifies a novel class of PLA2, enzymes that have a wide range of industrial applications.


Assuntos
Toxinas Bacterianas , Fosfolipases A2 , Salmonella typhi , Fosfolipases A2/metabolismo , Fosfolipases A2/genética , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/genética , Toxinas Bacterianas/química , Salmonella typhi/genética , Salmonella typhi/metabolismo , Salmonella typhi/enzimologia , Salmonella typhi/patogenicidade , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Humanos , Febre Tifoide/metabolismo , Febre Tifoide/microbiologia , Febre Tifoide/genética , Fatores de Virulência/metabolismo , Fatores de Virulência/genética
3.
PLoS Genet ; 18(2): e1010019, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35120121

RESUMO

Accurate prediction of vectors dispersal, as well as identification of adaptations that allow blood-feeding vectors to thrive in built environments, are a basis for effective disease control. Here we adopted a landscape genomics approach to assay gene flow, possible local adaptation, and drivers of population structure in Rhodnius ecuadoriensis, an important vector of Chagas disease. We used a reduced-representation sequencing technique (2b-RADseq) to obtain 2,552 SNP markers across 272 R. ecuadoriensis samples from 25 collection sites in southern Ecuador. Evidence of high and directional gene flow between seven wild and domestic population pairs across our study site indicates insecticide-based control will be hindered by repeated re-infestation of houses from the forest. Preliminary genome scans across multiple population pairs revealed shared outlier loci potentially consistent with local adaptation to the domestic setting, which we mapped to genes involved with embryogenesis and saliva production. Landscape genomic models showed elevation is a key barrier to R. ecuadoriensis dispersal. Together our results shed early light on the genomic adaptation in triatomine vectors and facilitate vector control by predicting that spatially-targeted, proactive interventions would be more efficacious than current, reactive approaches.


Assuntos
Doença de Chagas/epidemiologia , Doença de Chagas/genética , Rhodnius/genética , Adaptação Biológica/genética , Animais , Vetores de Doenças , Ecossistema , Equador/epidemiologia , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Fluxo Gênico , Insetos Vetores/genética , Metagenômica/métodos , Polimorfismo de Nucleotídeo Único/genética , Densidade Demográfica , Rhodnius/patogenicidade , Transcriptoma/genética , Trypanosoma cruzi/genética
4.
Am J Physiol Endocrinol Metab ; 327(4): E430-E440, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39110417

RESUMO

Lactate, a product of glycolysis, is formed under aerobic conditions. Extensive work has shown lactate flux in young and exercising humans; however, the effect of age is not known. We tested the hypothesis that postprandial lactate shuttling (PLS) would be diminished in older adults. We used [3-13C]lactate and [6,6-2H]glucose tracers, an oral glucose tolerance test (OGTT), and arterialized blood sampling to determine postprandial lactate rates of appearance (Ra), disappearance (Rd), and oxidation (Rox) in 15 young (28.1 ± 1.4 yr) and 13 older (70.6 ± 2.4 yr) healthy men and women. In young participants, fasting blood [lactate] (≈0.5 mM) rose after the glucose challenge, peaked at 15 min, dipped to a nadir at 30 min, and rose again peaking at 60 min (≈1.0 mM). Initial responses in lactate Ra of older participants were delayed and diminished until 90 min rising by 0.83 mg·kg-1·min-1. Lactate Rox was higher throughout the entire trial in young participants by a difference of ∼0.5 mg·kg-1·min-1. Initial peaks in lactate Ra and concentration in all volunteers demonstrated the presence of an enteric PLS following an OGTT. Notably, in the systemic, but not enteric, PLS phase, lactate Ra correlated highly with glucose Rd (r2 = 0.92). Correspondence of second peaks in lactate Ra and concentration and glucose Rd shows dependence of lactate Ra on glucose Rd. Although results show both enteric and systemic PLS phases in young and older study cohorts, metabolic responses were delayed and diminished in healthy older individuals.NEW & NOTEWORTHY We used isotope tracers, an oral glucose tolerance test, and arterialized blood sampling to determine postprandial lactate flux rates in healthy young and older men and women. Lactate rates of appearance and oxidation and the lactate-pyruvate exchange were delayed and diminished in both enteric and systemic postprandial lactate shuttle phases in older participants.


Assuntos
Glicemia , Teste de Tolerância a Glucose , Ácido Láctico , Período Pós-Prandial , Humanos , Período Pós-Prandial/fisiologia , Masculino , Feminino , Adulto , Ácido Láctico/sangue , Ácido Láctico/metabolismo , Idoso , Glicemia/metabolismo , Envelhecimento/metabolismo , Voluntários Saudáveis , Glucose/metabolismo , Oxirredução
5.
Am J Physiol Endocrinol Metab ; 327(2): E217-E228, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38895979

RESUMO

Our purpose was to determine how age affects metabolic flexibility and underlying glucose kinetics in healthy young and older adults. Therefore, glucose and lactate tracers along with pulmonary gas exchange data were used to determine glucose kinetics and respiratory exchange ratios [RER = carbon dioxide production (V̇co2)/oxygen consumption (V̇o2)] during a 2-h 75-g oral glucose tolerance test (OGTT). After an 12-h overnight fast, 28 participants, 15 young (21-35 yr; 7 men and 8 women) and 13 older (60-80 yr; 7 men and 6 women), received venous primed-continuous infusions of [6,6-2H]glucose and [3-13C]lactate with a [Formula: see text] bolus. After a 90-min metabolic stabilization and tracer equilibration period, volunteers underwent an OGTT. Arterialized glucose concentrations ([glucose]) started to rise 15 min post glucose consumption, peaked at 60 min, and remained elevated. As assessed by rates of appearance (Ra) and disposal (Rd) and metabolic clearance rate (MCR), glucose kinetics were suppressed in older compared to young individuals. As well, unlike in young individuals, fractional gluconeogenesis (fGNG) remained elevated in the older population after the oral glucose challenge. Finally, there were no differences in 12-h fasting baseline or peak RER values following an oral glucose challenge in older compared to young men and women, making RER an incomplete measure of metabolic flexibility in the volunteers we evaluated. Our study revealed that glucose kinetics are significantly altered in a healthy aged population after a glucose challenge. Furthermore, those physiological deficits are not detected from changes in RER during an OGTT.NEW & NOTEWORTHY To determine metabolic flexibility in response to an OGTT, we studied healthy young and older men and women to determine glucose kinetics and changes in RER. Compared to young subjects, glucose kinetics were suppressed in older healthy individuals during an OGTT. Surprisingly, the age-related changes in glucose flux were not reflected in RER measurements; thus, RER measurements do not give a complete view of metabolic flexibility in healthy individuals.


Assuntos
Envelhecimento , Glicemia , Teste de Tolerância a Glucose , Glucose , Humanos , Feminino , Masculino , Adulto , Idoso , Pessoa de Meia-Idade , Envelhecimento/metabolismo , Envelhecimento/fisiologia , Glucose/metabolismo , Adulto Jovem , Idoso de 80 Anos ou mais , Glicemia/metabolismo , Cinética , Consumo de Oxigênio/fisiologia , Gluconeogênese/fisiologia , Ácido Láctico/metabolismo , Ácido Láctico/sangue , Troca Gasosa Pulmonar/fisiologia , Taxa de Depuração Metabólica
6.
Biol Reprod ; 110(2): 275-287, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-37930247

RESUMO

The timing of puberty onset is reliant on increased gonadotropin-releasing hormone (GnRH). This elicits a corresponding increase in luteinizing hormone (LH) due to a lessening of sensitivity to the inhibitory actions of estradiol (E2). The mechanisms underlying the increase in GnRH release likely involve a subset of neurons within the arcuate (ARC) nucleus of the hypothalamus that contain kisspeptin, neurokinin B (NKB), and dynorphin (KNDy neurons). We aimed to determine if KNDy neurons in female sheep are critical for: timely puberty onset; the LH surge; and the response to an intravenous injection of the neurokinin-3 receptor (NK3R) agonist, senktide. Prepubertal ewes received injections aimed at the ARC containing blank-saporin (control, n = 5) or NK3-saporin (NK3-SAP, n = 6) to ablate neurons expressing NK3R. Blood samples taken 3/week for 65 days following surgery were assessed for progesterone to determine onset of puberty. Control ewes exhibited onset of puberty at 33.2 ± 3.9 days post sampling initiation, whereas 5/6 NK3-SAP treated ewes didn't display an increase in progesterone. After an artificial LH surge protocol, surge amplitude was lower in NK3-SAP ewes. Finally, ewes were treated with senktide to determine if an LH response was elicited. LH pulses were evident in both groups in the absence of injections, but the response to senktide vs saline was similar between groups. These results show that KNDy cells are necessary for timely puberty onset and for full expresson of the LH surge. The occurrence of LH pulses in NK3-SAP treated ewes may indicate a recovery from an apulsatile state.


Assuntos
Núcleo Arqueado do Hipotálamo , Hormônio Luteinizante , Fragmentos de Peptídeos , Substância P/análogos & derivados , Feminino , Animais , Ovinos , Hormônio Luteinizante/farmacologia , Núcleo Arqueado do Hipotálamo/metabolismo , Saporinas/farmacologia , Progesterona/farmacologia , Hormônio Liberador de Gonadotropina/farmacologia , Hormônio Liberador de Gonadotropina/metabolismo , Neurocinina B/metabolismo , Dinorfinas/farmacologia , Dinorfinas/metabolismo , Kisspeptinas/metabolismo
7.
Biol Reprod ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39375014

RESUMO

Kisspeptin is a major regulator of gonadotropin secretion in pigs. Previously, CRISPR/Cas9 knockout of KISS1 was used to develop a mosaic parental line of pigs to generate offspring that would not need castration due to loss of kisspeptin. The current goal was to characterize growth and reproductive development of F1 pigs from this parental line. Body weights, gonadotropin concentrations and gonadal development were measured from birth through development (boars to 220 d of age, n = 42; gilts to 160 d of age, n = 36). Testosterone, skatole, and androstenone were also measured in boars. Blood samples were collected by jugular venipuncture for quantification of serum hormones, gonadal tissues collected for gross morphology and histology, and a fat biopsy collected (boars) for skatole and androstenone analysis. Body weight did not differ with genotype. There were no differences between KISS1+/+ and heterozygote KISS1+/- animals for most parameters measured. Gonadotropin concentrations were reduced in KISS1-/- boars and gilts compared with KISS1+/+ and KISS1+/- animals (P < 0.05). Concentrations of testosterone in serum and both androstenone and skatole in adipose were less in KISS1-/- boars than in KISS1+/+ and KISS1+/- boars (P < 0.05). Hypogonadism was in all KISS1-/- gilts and boars. These data indicate that knocking out KISS1 causes hypogonadotropic hypogonadism but does not negatively affect growth in pigs. Only one KISS1 allele is needed for normal gonadotropin secretion and gonadal development, and accumulation of compounds in adipose leading to boar taint.

8.
Mol Ecol ; 33(18): e17500, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39188095

RESUMO

Disentangling the roles of structural landscape factors and animal movement behaviour can present challenges for practitioners managing landscapes to maintain functional connectivity and achieve conservation goals. We used a landscape genetics approach to combine robust demographic, behavioural and genetic datasets with spatially explicit simulations to evaluate the effects of anthropogenic barriers (dams, culverts) and natural landscape resistance (gradient, elevation) affecting dispersal behaviour, genetic connectivity and genetic structure in a resident population of Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi). Analyses based on 10 years of sampling effort revealed a pattern of restricted dispersal, and population genetics identified discrete population clusters between distal tributaries and the mainstem stream and no structure within the mainstem stream. Demogenetic simulations demonstrated that, for this population, the effects of existing anthropogenic barriers on population structure are redundant with effects of restricted dispersal associated with the underlying environmental resistance. Our approach provides an example of how extensive field sampling combined with landscape genetics can be incorporated into spatially explicit simulation modelling to explore how, together, movement ecology and landscape resistance can be used to inform decisions around restoration and connectivity.


Assuntos
Genética Populacional , Animais , Rios , Distribuição Animal , Oncorhynchus/genética , Simulação por Computador , Ecossistema , Repetições de Microssatélites/genética , Meio Ambiente , Efeitos Antropogênicos
9.
Brain Behav Immun ; 120: 532-542, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38925415

RESUMO

Individuals with substance use problems show lower executive control and alterations in prefrontal brain systems supporting emotion regulation and impulse control. A separate literature suggests that heightened inflammation also increases risk for substance use, in part, through targeting brain systems involved in executive control. Research on neural and inflammatory signaling in substance use, however, has occurred in parallel. Drawing on recent neuroimmune network models, we used fMRI to examine the relationships between executive control-related brain activity (as elicited by an n-back working memory task), peripheral inflammation, as quantified by inflammatory cytokines and C-reactive protein (CRP), and substance use for the past month in 93 participants [mean age = 24.4 (SD = 0.6)]. We operationalized low executive control as a neural inefficiency during the n-back task to achieve normative performance, as reflected in higher working memory-related brain activity and lower activity in the default mode network (DMN). Consistent with prediction, individuals with low executive control and high inflammation reported more substance use over the past month, controlling for behavioral performance on the n-back, sex, time between assessments, body-mass-index (BMI), and personal socioeconomic status (SES) (interaction between inflammation and working memory-related brain activity, b = 0.210, p = 0.005; interaction between inflammation and DMN, b = -0.219, p < 0.001). Findings suggest that low executive control and high inflammation may be associated with higher substance use. This has implications for understanding psychological, neural, and immunological risk for substance use problems and the development of interventions to target each of these components.


Assuntos
Encéfalo , Função Executiva , Inflamação , Imageamento por Ressonância Magnética , Memória de Curto Prazo , Transtornos Relacionados ao Uso de Substâncias , Humanos , Função Executiva/fisiologia , Masculino , Feminino , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Inflamação/fisiopatologia , Inflamação/metabolismo , Adulto , Adulto Jovem , Memória de Curto Prazo/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Proteína C-Reativa/metabolismo , Citocinas/metabolismo , Rede de Modo Padrão/diagnóstico por imagem
10.
Brain Behav Immun ; 117: 215-223, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38244947

RESUMO

BACKGROUND: Severe, chronic stress during childhood accentuates vulnerability to mental and physical health problems across the lifespan. To explain this phenomenon, the neuroimmune network hypothesis proposes that childhood stressors amplify signaling between peripheral inflammatory cells and developing brain circuits that support processing of rewards and threats. Here, we conducted a preliminary test of the basic premises of this hypothesis. METHODS: 180 adolescents (mean age = 19.1 years; 68.9 % female) with diverse racial and ethnic identities (56.1 % White; 28.3 % Hispanic; 26.1 % Asian) participated. The Childhood Trauma Interview was administered to quantify early adversity. Five inflammatory biomarkers were assayed in antecubital blood - C-reactive protein, tumor necrosis factor-a, and interleukins-6, -8, and -10 - and were averaged to form a composite score. Participants also completed a functional MRI task to measure corticostriatal responsivity to the anticipation and acquisition of monetary rewards. RESULTS: Stress exposure and corticostriatal responsivity interacted statistically to predict the inflammation composite. Among participants who experienced major stressors in the first decade of life, higher inflammatory activity covaried with lower corticostriatal responsivity during acquisition of monetary rewards. This relationship was specific to participants who experienced major stress in early childhood, implying a sensitive period for exposure, and were evident in both the orbitofrontal cortex and the ventral striatum, suggesting the broad involvement of corticostriatal regions. The findings were independent of participants' age, sex, racial and ethnic identity, family income, and depressive symptoms. CONCLUSIONS: Collectively, the results are consistent with hypotheses suggesting that major stress in childhood alters brain-immune signaling.


Assuntos
Experiências Adversas da Infância , Adolescente , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , Encéfalo , Proteína C-Reativa , Hispânico ou Latino , Renda , Brancos , Asiático , Recompensa , Estresse Psicológico
11.
Neurocrit Care ; 40(1): 262-271, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37322326

RESUMO

BACKGROUND: Dual antiplatelet therapy (DAPT) is commonly employed for neuroendovascular stenting due to the significant risk of thromboembolism. Clopidogrel and aspirin are most often selected as initial DAPTs; however, there is limited literature available to support guidance of DAPT in this setting. The objective of this study was to evaluate safety and efficacy in patients whose final regimen included either DAPT with aspirin and clopidogrel (DAPT-C) or DAPT with aspirin and ticagrelor (DAPT-T). METHODS: This was a multicenter, retrospective cohort of patients who underwent neuroendovascular stenting and received DAPT between July 1, 2017, and October 31, 2020. Study participants were allocated into groups based on discharge DAPT regimen. The primary outcome was incidence of stent thrombosis at 3-6 months on DAPT-C versus DAPT-T, as defined by the presence of thrombus on imaging or new onset stroke. Secondary outcomes included major and minor bleeding and death within 3-6 months after the procedure. RESULTS: Five hundred and seventy patients were screened across 12 sites. Of those, 486 were included (DAPT-C n = 360, DAPT-T n = 126). There was no difference in the primary outcome of stent thrombosis between the DAPT-C and DAPT-T groups (8% vs. 8%, p = 0.97) and no difference in any of the secondary safety outcomes. CONCLUSIONS: Using DAPT-C or DAPT-T regimens in a broad population of neuroendovascular stenting procedures appears to have similar safety and efficacy profiles. Further prospective evaluation is warranted to streamline the practice of DAPT selection and monitoring to determine the impact on clinical outcomes.


Assuntos
Inibidores da Agregação Plaquetária , Trombose , Humanos , Clopidogrel/uso terapêutico , Ticagrelor/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Estudos Retrospectivos , Aspirina/uso terapêutico , Stents/efeitos adversos , Trombose/tratamento farmacológico , Resultado do Tratamento
12.
J Sport Rehabil ; : 1-7, 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39374925

RESUMO

CONTEXT: Evidence indicates a 2 to 3 times increased risk of musculoskeletal injury after return to play from concussion. Undetected neuromuscular control deficits at return to play may relate to increased musculoskeletal injury risk. Rehabilitation to improve neuromuscular control may benefit patients with concussion, but access to rehabilitation professionals and/or poor adherence may limit efficacy. Our purpose was to determine the feasibility of an 8-week virtual neuromuscular training (NMT) program administered through a novel smartphone application among physically active, uninjured adults. DESIGN: Feasibility trial. METHODS: Participants were instructed to complete an NMT program administered via a smartphone application and returned for follow-up questionnaires 8 weeks later. They were instructed to complete 3 asynchronous self-guided workouts per week during the 8-week intervention period. Workouts included balance, plyometrics, strengthening, and dual-task exercises. The application provided instructions for each exercise using video, text, and audio descriptions. Our primary feasibility measure was participant adherence, calculated as the percentage of workouts completed out of the total possible 24 workouts. We recorded the average duration of each workout using start/stop/advance features within the application. RESULTS: Twenty participants were enrolled, of which 15 (age = 26.3 [2.7] y, 67% female) returned for follow-up (75% retention). Participant adherence was 57.2% (25.0%; range: 16.7%-91.7%). Participants spent 17.3 (8.0) minutes per workout (range: 7.4-37.9 min). There were no adverse reactions or injuries. Most participants (60%) reported time availability as a primary barrier to intervention completion. CONCLUSIONS: Participants were moderately (>50%) adherent to a virtual NMT program, without any reported injuries. We identified several barriers to participation and pathways for improved adherence in the future. The virtual NMT program completed by uninjured adults provides evidence of its feasibility and future scalability to those with a recent concussion to address neuromuscular control deficits and reduce future injury risk.

13.
Mol Ecol ; 32(19): 5211-5227, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37602946

RESUMO

Understanding how human infrastructure and other landscape attributes affect genetic differentiation in animals is an important step for identifying and maintaining dispersal corridors for these species. We built upon recent advances in the field of landscape genetics by using an individual-based and multiscale approach to predict landscape-level genetic connectivity for grizzly bears (Ursus arctos) across ~100,000 km2 in Canada's southern Rocky Mountains. We used a genetic dataset with 1156 unique individuals genotyped at nine microsatellite loci to identify landscape characteristics that influence grizzly bear gene flow at multiple spatial scales and map predicted genetic connectivity through a matrix of rugged terrain, large protected areas, highways and a growing human footprint. Our corridor-based modelling approach used a machine learning algorithm that objectively parameterized landscape resistance, incorporated spatial cross validation and variable selection and explicitly accounted for isolation by distance. This approach avoided overfitting, discarded variables that did not improve model performance across withheld test datasets and spatial predictive capacity compared to random cross-validation. We found that across all spatial scales, geographic distance explained more variation in genetic differentiation in grizzly bears than landscape variables. Human footprint inhibited connectivity across all spatial scales, while open canopies inhibited connectivity at the broadest spatial scale. Our results highlight the negative effect of human footprint on genetic connectivity, provide strong evidence for using spatial cross-validation in landscape genetics analyses and show that multiscale analyses provide additional information on how landscape variables affect genetic differentiation.


Assuntos
Ecossistema , Ursidae , Humanos , Animais , Ursidae/genética , Deriva Genética , Fluxo Gênico
14.
J Exp Biol ; 226(24)2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-38095228

RESUMO

Insects are the most diverse animal group on the planet. Their success is reflected by the diversity of habitats in which they live. However, these habitats have undergone great changes in recent decades; understanding how these changes affect insect health and fitness is an important challenge for insect conservation. In this Review, we focus on the research that links the nutritional environment with infection and immune status in insects. We first discuss the research from the field of nutritional immunology, and we then investigate how factors such as intracellular and extracellular symbionts, sociality and transgenerational effects may interact with the connection between nutrition and immunity. We show that the interactions between nutrition and resistance can be highly specific to insect species and/or infection type - this is almost certainly due to the diversity of insect social interactions and life cycles, and the varied environments in which insects live. Hence, these connections cannot be easily generalised across insects. We finally suggest that other environmental aspects - such as the use of agrochemicals and climatic factors - might also influence the interaction between nutrition and resistance, and highlight how research on these is essential.


Assuntos
Insetos , Estado Nutricional , Animais
15.
J Hered ; 114(4): 341-353, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-36738446

RESUMO

The complexity of global anthropogenic change makes forecasting species responses and planning effective conservation actions challenging. Additionally, important components of a species' adaptive capacity, such as evolutionary potential, are often not included in quantitative risk assessments due to lack of data. While genomic proxies for evolutionary potential in at-risk species are increasingly available, they have not yet been included in extinction risk assessments at a species-wide scale. In this study, we used an individual-based, spatially explicit, dynamic eco-evolutionary simulation model to evaluate the extinction risk of an endangered desert songbird, the southwestern willow flycatcher (Empidonax traillii extimus), in response to climate change. Using data from long-term demographic and habitat studies in conjunction with genome-wide ecological genomics research, we parameterized simulations that include 418 sites across the breeding range, genomic data from 225 individuals, and climate change forecasts spanning 3 generalized circulation models and 3 emissions scenarios. We evaluated how evolutionary potential, and the lack of it, impacted population trajectories in response to climate change. We then investigated the compounding impact of drought and warming temperatures on extinction risk through the mechanism of increased nest failure. Finally, we evaluated how rapid action to reverse greenhouse gas emissions would influence population responses and species extinction risk. Our results illustrate the value of incorporating evolutionary, demographic, and dispersal processes in a spatially explicit framework to more comprehensively evaluate the extinction risk of threatened and endangered species and conservation actions to promote their recovery.


Assuntos
Salix , Aves Canoras , Animais , Mudança Climática , Melhoramento Vegetal , Espécies em Perigo de Extinção , Ecossistema , Extinção Biológica , Aves Canoras/genética
16.
Ann Vasc Surg ; 96: 166-175, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37169247

RESUMO

BACKGROUND: Cardiovascular complications are a major cause of morbidity and mortality in the postoperative period after major vascular surgery. Depending on the study population, up to 25% of patients have troponin elevation after noncardiac surgery, yet many do not meet the diagnosis of myocardial infarction (MI). Although outcomes of routine troponin elevation in patients undergoing mixed major vascular surgery have been evaluated, this has not been studied exclusively in elective, open abdominal aortic aneurysm repair (oAAA), especially regarding perioperative and overall mortality. METHODS: We conducted a single-center, retrospective review of routine troponin surveillance for consecutive, oAAA from 2014 to 2019. A total of 319 patients were identified and analyzed for management patterns and interventions. The cohort was stratified into groups for comparison based on those in whom troponin was routinely checked (RC) as part of a care strategy during the study period, not routinely checked (NRC), elevated troponin (ET) >0.001 ng/mL, and not elevated. The median follow-up was 21.5 ± 23.8 months. Groups were compared on demographic data, cardiac comorbidities, 30-day and 3-year outcomes for MI and death using two-sample t-tests, Wilcoxon rank sum tests, Pearson chi-square tests, and Fisher exact tests when appropriate. RESULTS: Troponin was measured in 83.7% (267/319) of patients who underwent elective oAAA repair. Routine troponin checks were obtained in 79.9% (255/319) of patients. ET was identified in 16.5% of those with RC (42/255) and 4.7% of those with NRC (3/64). Of patients with ET, 37.8% (17/45) had a cardiology consultation, 4.4% (2/45) had a percutaneous coronary intervention (PCI), and 4.4% (2/45) had another cardiac intervention. All 4 patients undergoing PCI or other cardiac intervention had received routine troponin checks. Patients with ET were older (71.2 vs. 68.6; P = 0.04), more likely to receive intraoperative blood products (P = 0.003), had longer operative times (P = 0.011), higher length of stay (9 vs. 7 days; P < 0.01), and higher 30-day MI rate (3 vs. 0; P = 0.04). They had neither longer aortic clamp times nor worse preoperative cardiac function, and the proximal clamp position during oAAA repair did not impact troponin detection. Additionally, 3-year overall mortality was increased in patients who had ET but there was not a significant difference in 3-year mortality between groups receiving routine troponin checks versus not. CONCLUSIONS: ET, identified after elective oAAA repair, was associated with a higher risk of 30-day MI and lower overall survival. However, it was not demonstrated that routine assessment of troponin levels postoperatively leads to decreased 3-year mortality in this setting.


Assuntos
Aneurisma da Aorta Abdominal , Infarto do Miocárdio , Intervenção Coronária Percutânea , Procedimentos de Cirurgia Plástica , Humanos , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/etiologia , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/cirurgia
17.
Retina ; 43(1): 25-33, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36542081

RESUMO

PURPOSE: AR-1105 is a novel biodegradable sustained-release dexamethasone implant designed to deliver 6-month durability. This Phase 2 study evaluated two AR-1105 formulations with different release profiles in patients with macular edema due to retinal vein occlusion. METHODS: Patients received a single intravitreal injection with 340 µg dexamethasone. In the initial phase, five patients received clinical formulation (CF) 1. In the randomized phase, 44 patients were randomized 1:1 to CF1 or CF2. The follow-up was 6 months. Patients had vision loss due to macular edema diagnosed ≥9 (central retinal vein occlusion) or ≥12 months (branch retinal vein occlusion) before screening, and could be treatment-naive or -experienced (if received prior steroids, must have demonstrated response). RESULTS: Both formulations improved vision and reduced retinal thickening from baseline across all visits. At Month 6, mean changes in best-corrected visual acuity were +4.3 and +8.0 letters, and mean changes in central subfield thickness were -93 µm and -211 µm in CF1 and CF2 randomized patients, respectively. Most common adverse events were reduced visual acuity, worsening macular edema, conjunctival hemorrhage, and increased intraocular pressure. No patients required surgery or laser for intraocular pressure control. CONCLUSION: Both formulations were well tolerated and demonstrated clinically meaningful and sustained improvements in vision and retinal thickening in patients with retinal vein occlusion with longstanding edema.


Assuntos
Edema Macular , Oclusão da Veia Retiniana , Humanos , Oclusão da Veia Retiniana/complicações , Oclusão da Veia Retiniana/diagnóstico , Oclusão da Veia Retiniana/tratamento farmacológico , Edema Macular/diagnóstico , Edema Macular/tratamento farmacológico , Edema Macular/etiologia , Dexametasona , Glucocorticoides , Resultado do Tratamento , Implantes de Medicamento , Tomografia de Coerência Óptica , Injeções Intravítreas
18.
Am J Ind Med ; 66(5): 411-423, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35864570

RESUMO

BACKGROUND: Firefighters have occupational and environmental exposures to per- and polyfluoroalkyl substances (PFAS). The goal of this study was to compare serum PFAS concentrations across multiple United States fire departments to National Health and Nutrition Examination Survey (NHANES) participants. METHODS: Nine serum PFAS were compared in 290 firefighters from four municipal fire departments (coded A-D) and three NHANES participants matched to each firefighter on sex, ethnicity, age, and PFAS collection year. Only Departments A and C had sufficient women study participants (25 and six, respectively) to compare with NHANES. RESULTS: In male firefighters compared with NHANES, geometric mean perfluorohexane sulfonate (PFHxS) was elevated in Departments A-C, sum of branched perfluoromethylheptane sulfonate isomers (Sm-PFOS) was elevated in all four departments, linear perfluorooctane sulfonate (n-PFOS) was elevated in Departments B and C, linear perfluorooctanoate (n-PFOA) was elevated in Departments B-D, and perfluorononanoate (PFNA) was elevated in Departments B-D, but lower in A. In male firefighters compared with NHANES, perfluoroundecanoate (PFUnDA) was more frequently detected in Departments B and D, and 2-(N-methyl-perfluorooctane sulfonamido) acetate (MeFOSAA) was less frequently detected in Departments B-D. In female firefighters compared with NHANES, PFHxS and Sm-PFOS concentrations were elevated in Departments A and C. Other PFAS concentrations were elevated and/or reduced in only one department or not significantly different from NHANES in any department. CONCLUSIONS: Serum PFHxS, Sm-PFOS, n-PFOS, n-PFOA, and PFNA concentrations were increased in at least two of four fire departments in comparison to NHANES.


Assuntos
Poluentes Ambientais , Fluorocarbonos , Humanos , Masculino , Feminino , Estados Unidos , Inquéritos Nutricionais , Fluorocarbonos/análise , Exposição Ambiental , Alcanossulfonatos
19.
Sensors (Basel) ; 23(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36772625

RESUMO

The treatment of mood disorders, which can become a lifelong process, varies widely in efficacy between individuals. Most options to monitor mood rely on subjective self-reports and clinical visits, which can be burdensome and may not portray an accurate representation of what the individual is experiencing. A passive method to monitor mood could be a useful tool for those with these disorders. Some previously proposed models utilized sensors from smartphones and wearables, such as the accelerometer. This study examined a novel approach of processing accelerometer data collected from smartphones only while participants of the open-science branch of the BiAffect study were typing. The data were modeled by von Mises-Fisher distributions and weighted networks to identify clusters relating to different typing positions unique for each participant. Longitudinal features were derived from the clustered data and used in machine learning models to predict clinically relevant changes in depression from clinical and typing measures. Model accuracy was approximately 95%, with 97% area under the ROC curve (AUC). The accelerometer features outperformed the vast majority of clinical and typing features, which suggested that this new approach to analyzing accelerometer data could contribute towards unobtrusive detection of changes in depression severity without the need for clinical input.


Assuntos
Depressão , Smartphone , Humanos , Depressão/diagnóstico , Afeto , Aprendizado de Máquina , Acelerometria
20.
Int J Mol Sci ; 24(17)2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37686002

RESUMO

Brain injuries (BI) are highly disruptive, often having long lasting effects. Inadequate standard of care (SOC) energy support in the hospital leads to dietary energy deficiencies in BI patients. However, it is unclear how underfeeding (UF) affects protein synthesis post-BI. Therefore, in a rat model, we addressed the issue of UF on the protein fractional synthesis rate (fSR) post-BI. Compared to ad libitum (AL)-fed animals, we found that UF decreased protein synthesis in hind-limb skeletal muscle and cortical mitochondrial and structural proteins (p ≤ 0.05). BI significantly increased protein synthesis in the left and right cortices (p ≤ 0.05), but suppressed protein synthesis in the cerebellum (p ≤ 0.05) as compared to non-injured sham animals. Compared to underfeeding alone, UF in conjunction with BI (UF+BI) caused increased protein synthesis rates in mitochondrial, cytosolic, and whole-tissue proteins of the cortical brain regions. The increased rates of protein synthesis found in the UF+BI group were mitigated by AL feeding, demonstrating that caloric adequacy alleviates the effects of BI on protein dynamics in cortical and cerebellar brain regions. This research provides evidence that underfeeding has a negative impact on brain healing post-BI and that protein reserves in uninjured tissues are mobilized to support cortical tissue repair following BI.


Assuntos
Lesões Encefálicas , Desnutrição , Animais , Ratos , Encéfalo , Cerebelo , Córtex Cerebral , Citosol
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