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1.
Chemistry ; 30(39): e202401407, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38699860

RESUMO

Semiochemicals can be used to manipulate insect behaviour for sustainable pest management strategies, but their high volatility is a major issue for their practical implementation. Inclusion of these molecules within porous materials is a potential solution to this issue, as it can allow for a slower and more controlled release. In this work, we demonstrate that a series of Zr(IV) and Al(III) metal-organic frameworks (MOFs) with channel-type pores enable controlled release of three semiochemicals over 100 days by pore size design, with the uptake and rate of release highly dependent on the pore size. Insight from grand canonical Monte Carlo simulations indicates that this is due to weaker MOF-guest interactions per guest molecule as the pore size increases. These MOFs are all stable post-release and can be reloaded to show near-identical re-release profiles. These results provide valuable insight on the diffusion behaviour of volatile guests in MOFs, and for the further development of porous materials for sustainable agriculture applications.

2.
Cell Commun Signal ; 22(1): 450, 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39327600

RESUMO

Mitochondrial activity directs neuronal differentiation dynamics during brain development. In this context, the long-established metabolic coupling of mitochondria and the eukaryotic host falls short of a satisfactory mechanistic explanation, hinting at an undisclosed facet of mitochondrial function. Here, we reveal an RNA-based inter-organellar communication mode that complements metabolic coupling of host-mitochondria and underpins neuronal differentiation. We show that within minutes of exposure to differentiation cues and activation of the electron transport chain, the mitochondrial outer membrane transiently fuses with the nuclear membrane of neural progenitors, leading to efflux of nuclear-encoded RNAs (neRNA) into the positively charged mitochondrial intermembrane space. Subsequent degradation of mitochondrial neRNAs by Polynucleotide phosphorylase 1 (PNPase) located in the intermembrane space curbs the transcriptomic memory of progenitor cells. Further, acquisition of neRNA by mitochondria leads to a collapse of proton motive force, suppression of ATP production, and a resultant amplification of autophagic flux that attenuates proteomic memory. Collectively, these events force the progenitor cells towards a "tipping point" characterised by emergence of a competing neuronal differentiation program. It appears that neuronal differentiation is a consequence of reprogrammed coupling of metabolomic and transcriptomic landscapes of progenitor cells, with mitochondria emerging as key "reprogrammers" that operate by acquiring and metabolising neRNAs. However, the documented role of mitochondria as "reprogrammers" of differentiation remains to be validated in other neuronal lineages and in vivo.


Assuntos
Diferenciação Celular , Mitocôndrias , Neurônios , RNA Nuclear , Mitocôndrias/metabolismo , Neurônios/metabolismo , Neurônios/citologia , Animais , RNA Nuclear/metabolismo , RNA Nuclear/genética , Humanos , Camundongos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Neurogênese/genética
3.
Nanotechnology ; 35(27)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38373400

RESUMO

DNA Nanotechnology is being applied to multiple research fields. The functionality of DNA nanostructures is significantly enhanced by decorating them with nanoscale moieties including: proteins, metallic nanoparticles, quantum dots, and chromophores. Decoration is a complex process and developing protocols for reliable attachment routinely requires extensive trial and error. Additionally, the granular nature of scientific communication makes it difficult to discern general principles in DNA nanostructure decoration. This tutorial is a guidebook designed to minimize experimental bottlenecks and avoid dead-ends for those wishing to decorate DNA nanostructures. We supplement the reference material on available technical tools and procedures with a conceptual framework required to make efficient and effective decisions in the lab. Together these resources should aid both the novice and the expert to develop and execute a rapid, reliable decoration protocols.


Assuntos
DNA , Nanoestruturas , Nanotecnologia , DNA/química , Nanoestruturas/química , Nanotecnologia/métodos , Pontos Quânticos/química , Nanopartículas Metálicas/química
4.
Nephrology (Carlton) ; 29(8): 537-540, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38599614

RESUMO

This report details the case of a 51-year-old man with a Tiger snake bite who developed systemic envenomation, coagulopathy and thrombotic microangiopathy (TMA) requiring renal replacement therapy. He received plasma exchange as additional therapy while awaiting confirmation of the cause of the TMA. We discuss clinical decision making in detection of systemic envenomation and management of the rare complication of TMA, as well as current Australian guidelines around antivenom administration. This is the fourth known documented case of TMA from a Tiger snake bite in Australia.


Assuntos
Elapidae , Mordeduras de Serpentes , Microangiopatias Trombóticas , Microangiopatias Trombóticas/etiologia , Microangiopatias Trombóticas/terapia , Coagulação Intravascular Disseminada/etiologia , Coagulação Intravascular Disseminada/terapia , Mordeduras de Serpentes/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Terapia de Substituição Renal , Troca Plasmática , Austrália , Antivenenos/uso terapêutico , Resultado do Tratamento , Anticoagulantes/uso terapêutico , Heparina/uso terapêutico
5.
J Strength Cond Res ; 38(6): 1072-1081, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38489587

RESUMO

ABSTRACT: Hughes, W, Healy, R, Lyons, M, Higginbotham, C, Lane, A, and Beattie, K. The strength characteristics of elite and subelite female Gaelic football players. J Strength Cond Res 38(6): 1072-1081, 2024-There is currently an underrepresentation of sports science research focused on the female athlete, specifically in the context of Gaelic football. The aims of this study are to (a) compare the strength characteristics of elite and subelite players and (b) establish normative-based values and percentile scores for the strength characteristics of female Gaelic football players. Ninety-two female Gaelic football players were recruited for this study and subsequently categorized as elite (intercounty n = 30, age; 25.1 ± 5.3 years, stature; 1.69 ± 0.06 m, mass; 69.5 ± 5.9 kg) or subelite (club n = 62, age; 25.4 ± 6.8 years, stature; 1.66 ± 0.06 m, mass; 65.1 ± 8.9 kg). The physical strength characteristics of the subjects were assessed through the isometric midthigh pull (IMTP), countermovement jump (CMJ), and 10-5 repeated jump test. Statistically significant differences were found in the physical strength characteristics between the groups with elite players demonstrating greater peak force (large effect), relative peak force (moderate effect), and reactive strength index (large effect). Statistically significant differences were also observed for key CMJ phase characteristics with elite players producing greater RSI mod (moderate effect), jump height (large effect), and propulsion peak power (large effect) than subelite players. This study demonstrated that there are moderate to large differences between playing standards with elite players displaying superior reactive-, explosive-, and maximal-strength than their subelite counterparts. The strength characteristics evaluated in this study may be used in conjunction with other performance indices to distinguish between elite and subelite playing standards in female Gaelic football players.


Assuntos
Força Muscular , Humanos , Feminino , Força Muscular/fisiologia , Adulto Jovem , Adulto , Desempenho Atlético/fisiologia , Atletas , Teste de Esforço , Músculo Esquelético/fisiologia
6.
Heart Lung Circ ; 33(8): 1221-1226, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38719696

RESUMO

BACKGROUND: Socio-economic status (SES) has a large impact on health through a complex interplay of upstream, midstream and downstream factors. However, little is known about the predictive role of SES on long-term major adverse cardiovascular, cerebrovascular events, and mortality (MACCE). AIM: To determine the long-term relationship between SES and MACCE for men and women. The secondary endpoint was to determine the relationship between SES and all-cause mortality. METHOD: A total of 3,034 participants (1,494 women and 1,540 men) were assessed at baseline in the Geelong Osteoporosis Study, a large regional Australian population cohort study. Area-based SES was assessed, utilising the Index of Relative Socio-Economic Disadvantage (IRSD) and grouped into quintiles. The primary endpoint, MACCE, was defined as a composite of myocardial infarction, heart failure hospitalisation, malignant arrhythmias, stroke, and all-cause mortality. The secondary endpoint was all-cause mortality. Baseline data including age, sex, smoking status and alcohol use, and comorbidities were collected between 1993-1997 for women, and 2001-2006 for men, with follow-up over 30 and 22 years, respectively. Logistic regression was utilised to assess MACCE and all-cause mortality outcomes across the SES quintiles. RESULTS: Participants lost to follow-up or with incomplete data collection were excluded leaving 2,173 participants eligible for analysis. SES was associated with MACCE outcomes. Compared with Quintile I (lowest SES stratum), the odds of MACCE for each IRSD stratum were: Quintile II, odds ratio (OR) 0.85 (95% confidence interval [CI] 0.65-1.13); Quintile III, OR 0.69 (95% CI 0.51-0.91); Quintile IV, OR 0.66 (95% CI 0.50-0.88); and, Quintile V, OR 0.55 (95% CI 0.41-0.72). In the adjusted model, an inverse trend was noted, with reducing MACCE outcomes with an increasing SES status; IRSD Quintile II, OR 0.85 (95% CI 0.62-1.17); Quintile III, OR 0.70 (95% CI 0.50-0.97); Quintile IV, OR 0.73 (95% CI 0.52-1.02); and, Quintile V, OR 0.54 (95% CI 0.39-0.74). SES was inversely associated with all-cause mortality; IRSD Quintile II (OR 0.87, 95% CI 0.66-1.16) failed to achieve significance however IRSD Quintile III (OR 0.65, 95% CI 0.48-0.88), Quintile IV (OR 0.59, 95% CI 0.44-0.80) and Quintile V (OR 0.46, 95% CI 0.34-0.62) had a lower risk of mortality compared with Quintile I. In the adjusted model, an inversely proportional trend was noted between SES and all-cause mortality; IRSD Quintile II (OR 0.82, 95% CI 0.59-1.15), IRSD Quintile III (OR 0.63, 95% CI 0.49-0.95), Quintile IV (OR 0.59, 95% CI 0.45-0.90) and Quintile V (OR 0.44, 95% CI 0.31-0.61) had fewer mortality events compared with IRSD Quintile I. CONCLUSIONS: Our research indicates that being part of a lower socio-economic stratum is linked to a higher likelihood of experiencing negative cardiovascular and cerebrovascular events, along with an increased risk of overall mortality. SES is an important risk stratification marker for long-term prognosis of cardiovascular diseases and stroke, and warrants further investigation.


Assuntos
Classe Social , Humanos , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Seguimentos , Austrália/epidemiologia , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/epidemiologia , Transtornos Cerebrovasculares/mortalidade , Transtornos Cerebrovasculares/epidemiologia , Fatores de Risco , Fatores de Tempo
7.
BMC Bioinformatics ; 24(1): 160, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37085766

RESUMO

Deoxyribonucleic acid (DNA) is emerging as an alternative archival memory technology. Recent advancements in DNA synthesis and sequencing have both increased the capacity and decreased the cost of storing information in de novo synthesized DNA pools. In this survey, we review methods for translating digital data to and/or from DNA molecules. An emphasis is placed on methods which have been validated by storing and retrieving real-world data via in-vitro experiments.


Assuntos
DNA , DNA/genética , Análise de Sequência de DNA/métodos
8.
J Physiol ; 601(3): 469-481, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36575638

RESUMO

Microvascular dysfunction predicts adverse cardiovascular events despite absence of large vessel disease. A shift in the mediator of flow-mediated dilatation (FMD) from nitric oxide (NO) to mitochondrial-derived hydrogen peroxide (H2 O2 ) occurs in arterioles from patients with coronary artery disease (CAD). The underlying mechanisms governing this shift are not completely defined. Lipid phosphate phosphatase 3 (LPP3) is a transmembrane protein that dephosphorylates lysophosphatidic acid, a bioactive lipid, causing a receptor-mediated increase in reactive oxygen species. A single nucleotide loss-of-function polymorphism in the gene coding for LPP3 (rs17114036) is associated with elevated risk for CAD, independent of traditional risk factors. LPP3 is suppressed by miR-92a, which is elevated in the circulation of patients with CAD. Repression of LPP3 increases vascular inflammation and atherosclerosis in animal models. We investigated the role of LPP3 and miR-92a as a mechanism for microvascular dysfunction in CAD. We hypothesized that modulation of LPP3 is critically involved in the disease-associated shift in mediator of FMD. LPP3 protein expression was reduced in left ventricle tissue from CAD relative to non-CAD patients (P = 0.004), with mRNA expression unchanged (P = 0.96). Reducing LPP3 expression (non-CAD) caused a shift from NO to H2 O2 (% maximal dilatation: Control 78.1 ± 11.4% vs. Peg-Cat 30.0 ± 11.2%; P < 0.0001). miR-92a is elevated in CAD arterioles (fold change: 1.9 ± 0.01 P = 0.04), while inhibition of miR-92a restored NO-mediated FMD (CAD), and enhancing miR-92a expression (non-CAD) elicited H2 O2 -mediated dilatation (P < 0.0001). Our data suggests LPP3 is crucial in the disease-associated switch in the mediator of FMD. KEY POINTS: Lipid phosphate phosphatase 3 (LPP3) expression is reduced in heart tissue patients with coronary artery disease (CAD). Loss of LPP3 in CAD is associated with an increase in the LPP3 inhibitor, miR-92a. Inhibition of LPP3 in the microvasculature of healthy patients mimics the CAD flow-mediated dilatation (FMD) phenotype. Inhibition of miR-92a restores nitric oxide-mediated FMD in the microvasculature of CAD patients.


Assuntos
Doença da Artéria Coronariana , MicroRNAs , Animais , Humanos , Óxido Nítrico , Arteríolas/metabolismo , Doença da Artéria Coronariana/genética , Dilatação , Células Cultivadas , MicroRNAs/genética , MicroRNAs/metabolismo , Vasodilatação/fisiologia
9.
EMBO J ; 38(17): e100772, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31355487

RESUMO

Bacterial usage of the cyclic dinucleotide c-di-GMP is widespread, governing the transition between motile/sessile and unicellular/multicellular behaviors. There is limited information on c-di-GMP metabolism, particularly on regulatory mechanisms governing control of EAL c-di-GMP phosphodiesterases. Herein, we provide high-resolution structures for an EAL enzyme Bd1971, from the predatory bacterium Bdellovibrio bacteriovorus, which is controlled by a second signaling nucleotide, cAMP. The full-length cAMP-bound form reveals the sensory N-terminus to be a domain-swapped variant of the cNMP/CRP family, which in the cAMP-activated state holds the C-terminal EAL enzyme in a phosphodiesterase-active conformation. Using a truncation mutant, we trap both a half-occupied and inactive apo-form of the protein, demonstrating a series of conformational changes that alter juxtaposition of the sensory domains. We show that Bd1971 interacts with several GGDEF proteins (c-di-GMP producers), but mutants of Bd1971 do not share the discrete phenotypes of GGDEF mutants, instead having an elevated level of c-di-GMP, suggesting that the role of Bd1971 is to moderate these levels, allowing "action potentials" to be generated by each GGDEF protein to effect their specific functions.


Assuntos
Bdellovibrio bacteriovorus/metabolismo , AMP Cíclico/metabolismo , Diester Fosfórico Hidrolases/química , Diester Fosfórico Hidrolases/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bdellovibrio bacteriovorus/química , Bdellovibrio bacteriovorus/genética , Sítios de Ligação , Cristalografia por Raios X , Regulação Bacteriana da Expressão Gênica , Modelos Moleculares , Nucleotídeos/metabolismo , Diester Fosfórico Hidrolases/genética , Ligação Proteica , Conformação Proteica , Transdução de Sinais
10.
Mol Ecol ; 32(21): 5709-5723, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37789741

RESUMO

Insect pollination is fundamental for natural ecosystems and agricultural crops. The bumblebee species Bombus terrestris has become a popular choice for commercial crop pollination worldwide due to its effectiveness and ease of mass rearing. Bumblebee colonies are mass produced for the pollination of more than 20 crops and imported into over 50 countries including countries outside their native ranges, and the risk of invasion by commercial non-native bumblebees is considered an emerging issue for global conservation and biological diversity. Here, we use genome-wide data from seven wild populations close to and far from farms using commercial colonies, as well as commercial populations, to investigate the implications of utilizing commercial bumblebee subspecies in the UK. We find evidence for generally low levels of introgression between commercial and wild bees, with higher admixture proportions in the bees occurring close to farms. We identify genomic regions putatively involved in local and global adaptation, and genes in locally adaptive regions were found to be enriched for functions related to taste receptor activity, oxidoreductase activity, fatty acid and lipid biosynthetic processes. Despite more than 30 years of bumblebee colony importation into the UK, we observe low impact on the genetic integrity of local B. terrestris populations, but we highlight that even limited introgression might negatively affect locally adapted populations.


Assuntos
Ecossistema , Insetos , Abelhas/genética , Animais , Polinização/genética , Biodiversidade
11.
Opt Express ; 31(20): 32619-32636, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37859061

RESUMO

We present a study on the optical losses of Fabry-Pérot cavities subject to realistic transverse mirror misalignment. We consider mirrors of the two most prevalent surface forms: idealised spherical depressions, and Gaussian profiles generated by laser ablation. We first describe the mode mixing phenomena seen in the spherical mirror case and compare to the frequently-used clipping model, observing close agreement in the predicted diffraction loss, but with the addition of protective mode mixing at transverse degeneracies. We then discuss the Gaussian mirror case, detailing how the varying surface curvature across the mirror leads to complex variations in round trip loss and mode profile. In light of the severe mode distortion and strongly elevated loss predicted for many cavity lengths and transverse alignments when using Gaussian mirrors, we suggest that the consequences of mirror surface profile are carefully considered when designing cavity experiments.

12.
Diabetologia ; 65(6): 984-996, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35316840

RESUMO

AIMS/HYPOTHESIS: Pancreatic beta cell dedifferentiation, transdifferentiation into other islet cells and apoptosis have been implicated in beta cell failure in type 2 diabetes, although the mechanisms are poorly defined. The endoplasmic reticulum stress response factor X-box binding protein 1 (XBP1) is a major regulator of the unfolded protein response. XBP1 expression is reduced in islets of people with type 2 diabetes, but its role in adult differentiated beta cells is unclear. Here, we assessed the effects of Xbp1 deletion in adult beta cells and tested whether XBP1-mediated unfolded protein response makes a necessary contribution to beta cell compensation in insulin resistance states. METHODS: Mice with inducible beta cell-specific Xbp1 deletion were studied under normal (chow diet) or metabolic stress (high-fat diet or obesity) conditions. Glucose tolerance, insulin secretion, islet gene expression, alpha cell mass, beta cell mass and apoptosis were assessed. Lineage tracing was used to determine beta cell fate. RESULTS: Deletion of Xbp1 in adult mouse beta cells led to beta cell dedifferentiation, beta-to-alpha cell transdifferentiation and increased alpha cell mass. Cell lineage-specific analyses revealed that Xbp1 deletion deactivated beta cell identity genes (insulin, Pdx1, Nkx6.1, Beta2, Foxo1) and derepressed beta cell dedifferentiation (Aldh1a3) and alpha cell (glucagon, Arx, Irx2) genes. Xbp1 deletion in beta cells of obese ob/ob or high-fat diet-fed mice triggered diabetes and worsened glucose intolerance by disrupting insulin secretory capacity. Furthermore, Xbp1 deletion increased beta cell apoptosis under metabolic stress conditions by attenuating the antioxidant response. CONCLUSIONS/INTERPRETATION: These findings indicate that XBP1 maintains beta cell identity, represses beta-to-alpha cell transdifferentiation and is required for beta cell compensation and prevention of diabetes in insulin resistance states.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Células Secretoras de Insulina , Proteína 1 de Ligação a X-Box/metabolismo , Animais , Transdiferenciação Celular/genética , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Insulina/metabolismo , Resistência à Insulina/genética , Células Secretoras de Insulina/metabolismo , Camundongos , Estresse Fisiológico , Proteína 1 de Ligação a X-Box/genética
13.
Arterioscler Thromb Vasc Biol ; 41(1): 446-457, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33232201

RESUMO

OBJECTIVE: Coronary artery disease (CAD) is associated with a compensatory switch in mechanism of flow-mediated dilation (FMD) from nitric oxide (NO) to H2O2. The underlying mechanism responsible for the pathological shift is not well understood, and recent reports directly implicate telomerase and indirectly support a role for autophagy. We hypothesize that autophagy is critical for shear stress-induced release of NO and is a crucial component of for the pathway by which telomerase regulates FMD. Approach and Results: Human left ventricular, atrial, and adipose resistance arterioles were collected for videomicroscopy and immunoblotting. FMD and autophagic flux were measured in arterioles treated with autophagy modulators alone, and in tandem with telomerase-activity modulators. LC3B II/I was higher in left ventricular tissue from patients with CAD compared with non-CAD (2.8±0.2 versus 1.0±0.2-fold change; P<0.05), although p62 was similar between groups. Shear stress increased Lysotracker fluorescence in non-CAD arterioles, with no effect in CAD arterioles. Inhibition of autophagy in non-CAD arterioles induced a switch from NO to H2O2, while activation of autophagy restored NO-mediated vasodilation in CAD arterioles. In the presence of an autophagy activator, telomerase inhibitor prevented the expected switch (Control: 82±4%; NG-Nitro-l-arginine methyl ester: 36±5%; polyethylene glycol catalase: 80±3). Telomerase activation was unable to restore NO-mediated FMD in the presence of autophagy inhibition in CAD arterioles (control: 72±7%; NG-Nitro-l-arginine methyl ester: 79±7%; polyethylene glycol catalase: 38±9%). CONCLUSIONS: We provide novel evidence that autophagy is responsible for the pathological switch in dilator mechanism in CAD arterioles, demonstrating that autophagy acts downstream of telomerase as a common denominator in determining the mechanism of FMD.


Assuntos
Tecido Adiposo/irrigação sanguínea , Arteríolas/enzimologia , Autofagia , Doença da Artéria Coronariana/enzimologia , Vasos Coronários/enzimologia , Telomerase/metabolismo , Vasodilatação , Adulto , Idoso , Arteríolas/patologia , Arteríolas/fisiopatologia , Estudos de Casos e Controles , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/fisiopatologia , Vasos Coronários/patologia , Vasos Coronários/fisiopatologia , Feminino , Humanos , Peróxido de Hidrogênio/metabolismo , Lisossomos/enzimologia , Lisossomos/patologia , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Transdução de Sinais
14.
Nutr Metab Cardiovasc Dis ; 32(3): 710-714, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35090799

RESUMO

BACKGROUND & AIMS: Peripheral artery disease (PAD) is characterized by elevated blood pressure (BP), low nitric oxide availability (NO), and exaggerated pressor responses to sympatho-excitatory stressors. Inorganic nitrate reduces peripheral BP in healthy and chronically diseased populations. The objective of this study was to investigate the effects of eight-weeks of sodium nitrate (NaNO3) supplementation on indices of BP in PAD patients. METHODS: 21 patients with PAD were recruited to participate in this study, undergoing 8-weeks of NaNO3 (n = 13; 73 ± 9 years) or placebo (n = 8; 69 ± 10 years) supplementation. BP responsiveness to a cold pressor test (CPT) were examined prior to and following the supplementation period. The systolic BP response (change from rest) during the first (26 ± 10 vs. 19 ± 11 mmHg) and second minutes (32 ± 10 vs. 26 ± 12 mmHg) of CPT were reduced following NaNO3 (P < 0.05 for both) but not after placebo (first minute: 22 ± 10 vs. 24 ± 10 mmHg, P = 0.30; second minute 26 ± 10 vs 27 ± 10 mmHg, P = 0.72) supplementation. CONCLUSION: Our data suggest that eight-weeks of NaNO3 supplementation reduces BP responsiveness to sympatho-excitatory stimuli. CLINICAL TRIALS REGISTRATION NUMBER: NCT01983826.


Assuntos
Nitratos , Doença Arterial Periférica , Pressão Sanguínea , Suplementos Nutricionais , Humanos , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/tratamento farmacológico
15.
Br J Cancer ; 125(7): 983-993, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34253873

RESUMO

BACKGROUND: Breast cancer stem cells (BCSCs) are drivers of therapy-resistance, therefore are responsible for poor survival. Molecular signatures of BCSCs from primary cancers remain undefined. Here, we identify the consistent transcriptome of primary BCSCs shared across breast cancer subtypes, and we examine the clinical relevance of ITGA7, one of the genes differentially expressed in BCSCs. METHODS: Primary BCSCs were assessed using immunohistochemistry and fluorescently labelled using Aldefluor (n = 17). Transcriptomes of fluorescently sorted BCSCs and matched non-stem cancer cells were determined using RNA-seq (n = 6). ITGA7 expression was examined in breast cancers using immunohistochemistry (n = 305), and its functional role was tested using siRNA in breast cancer cells. RESULTS: Proportions of BCSCs varied from 0 to 9.4%. 38 genes were significantly differentially expressed in BCSCs; genes were enriched for functions in vessel morphogenesis, motility, and metabolism. ITGA7 was found to be significantly downregulated in BCSCs, and low expression significantly correlated with reduced survival in patients treated with chemotherapy, and with chemoresistance in breast cancer cells in vitro. CONCLUSIONS: This study is the first to define the molecular profile of BCSCs from a range of primary breast cancers. ITGA7 acts as a predictive marker for chemotherapy response, in accordance with its downregulation in BCSCs.


Assuntos
Antígenos CD/genética , Neoplasias da Mama/genética , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Cadeias alfa de Integrinas/genética , Células-Tronco Neoplásicas/metabolismo , Antígenos CD/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Cadeias alfa de Integrinas/metabolismo , Células MCF-7 , Análise de Sequência de RNA , Análise de Sobrevida
16.
Am J Physiol Heart Circ Physiol ; 321(6): H1096-H1102, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34714691

RESUMO

Cerebral blood flow and perfusion are tightly maintained through autoregulation despite changes in transmural pressure. Oxidative stress impairs cerebral blood flow, precipitating cerebrovascular events. Phosphorylation of the adaptor protein p66Shc increases mitochondrial-derived oxidative stress. The effect of p66Shc gain or loss of function in nonhypertensive rats is unclear. We hypothesized that p66Shc gain of function would impair autoregulation of cerebral microcirculation under physiological and pathological conditions. Three previously established transgenic [salt-sensitive (SS) background] p66Shc rats were used, p66-Del/SS (express p66Shc with a nine-amino acid deletion), p66Shc-knockout (KO)/SS (frameshift premature termination codon), and p66Shc signaling and knock-in substitution of Ser36Ala (p66Shc-S36A)/SS (substitution of Ser36Ala). The p66Shc-Del were also bred on Sprague-Dawley (SD) backgrounds (p66-Del/SD), and a subset was exposed to a hypertensive stimulus [NG-nitro-l-arginine methyl ester (l-NAME)] for 4 wk. Active and passive diameters to increasing transmural pressure were measured and myogenic tone was calculated in all groups (SS and SD). Myogenic responses to increasing pressure were impaired in p66Shc-Del/SS rats relative to wild-type (WT)/SS and knock-in substitution of Ser36Ala (S36A; P < 0.05). p66-Del/SD rats did not demonstrate changes in active/passive diameters or myogenic tone relative to WT/SD but did demonstrate attenuated passive diameter responses to higher transmural pressure relative to p66-Del/SS. Four weeks of a hypertensive stimulus (l-NAME) did not alter active or passive diameter responses to increasing transmural pressure (P = 0.86-0.99), but increased myogenic responses relative to p66-Del/SD (P < 0.05). Collectively, we demonstrate the functional impact of p66Shc within the cerebral circulation and demonstrate that the genetic background of p66Shc rats largely drives changes in cerebrovascular function.NEW & NOTEWORTHY We demonstrate that the modulation of p66Shc signaling impairs cerebral artery myogenic tone in a low renin model of hypertension. This impairment is dependent upon the genetic background, as modulated p66Shc signaling in Sprague-Dawley rats does not impair cerebral artery myogenic tone.


Assuntos
Pressão Sanguínea , Circulação Cerebrovascular , Hipertensão/enzimologia , Artéria Cerebral Média/enzimologia , Óxido Nítrico/metabolismo , Renina/metabolismo , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Homeostase , Hipertensão/induzido quimicamente , Hipertensão/genética , Hipertensão/fisiopatologia , Masculino , Artéria Cerebral Média/fisiopatologia , NG-Nitroarginina Metil Éster , Ratos Endogâmicos Dahl , Ratos Sprague-Dawley , Ratos Transgênicos , Cloreto de Sódio na Dieta , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/genética
17.
Am J Physiol Heart Circ Physiol ; 321(5): H985-H1003, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34559580

RESUMO

Ventilation with gases containing enhanced fractions of oxygen is the cornerstone of therapy for patients with hypoxia and acute respiratory distress syndrome. Yet, hyperoxia treatment increases free reactive oxygen species (ROS)-induced lung injury, which is reported to disrupt autophagy/mitophagy. Altered extranuclear activity of the catalytic subunit of telomerase, telomerase reverse transcriptase (TERT), plays a protective role in ROS injury and autophagy in the systemic and coronary endothelium. We investigated interactions between autophagy/mitophagy and TERT that contribute to mitochondrial dysfunction and pulmonary injury in cultured rat lung microvascular endothelial cells (RLMVECs) exposed in vitro, and rat lungs exposed in vivo to hyperoxia for 48 h. Hyperoxia-induced mitochondrial damage in rat lungs [TOMM20, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)], which was paralleled by increased markers of inflammation [myeloperoxidase (MPO), IL-1ß, TLR9], impaired autophagy signaling (Beclin-1, LC3B-II/1, and p62), and decreased the expression of TERT. Mitochondrial-specific autophagy (mitophagy) was not altered, as hyperoxia increased expression of Pink1 but not Parkin. Hyperoxia-induced mitochondrial damage (TOMM20) was more pronounced in rats that lack the catalytic subunit of TERT and resulted in a reduction in cellular proliferation rather than cell death in RLMVECs. Activation of TERT or autophagy individually offset mitochondrial damage (MTT). Combined activation/inhibition failed to alleviate hyperoxic-induced mitochondrial damage in vitro, whereas activation of autophagy in vivo decreased mitochondrial damage (MTT) in both wild type (WT) and rats lacking TERT. Functionally, activation of either TERT or autophagy preserved transendothelial membrane resistance. Altogether, these observations show that activation of autophagy/mitophagy and/or TERT mitigate loss of mitochondrial function and barrier integrity in hyperoxia.NEW & NOTEWORTHY In cultured pulmonary artery endothelial cells and in lungs exposed in vivo to hyperoxia, autophagy is activated, but clearance of autophagosomes is impaired in a manner that suggests cross talk between TERT and autophagy. Stimulation of autophagy prevents hyperoxia-induced decreases in mitochondrial metabolism and sustains monolayer resistance. Hyperoxia increases mitochondrial outer membrane (TOMM20) protein, decreases mitochondrial function, and reduces cellular proliferation without increasing cell death.


Assuntos
Células Endoteliais/enzimologia , Hiperóxia/complicações , Lesão Pulmonar/enzimologia , Pulmão/irrigação sanguínea , Microvasos/enzimologia , Mitocôndrias/enzimologia , Mitofagia , Telomerase/metabolismo , Animais , Proteínas Relacionadas à Autofagia/metabolismo , Permeabilidade Capilar , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/patologia , Feminino , Técnicas de Inativação de Genes , Mediadores da Inflamação/metabolismo , Lesão Pulmonar/etiologia , Lesão Pulmonar/genética , Lesão Pulmonar/patologia , Masculino , Proteínas de Membrana Transportadoras/metabolismo , Microvasos/patologia , Mitocôndrias/genética , Mitocôndrias/patologia , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Ratos Sprague-Dawley , Ratos Transgênicos , Receptores de Superfície Celular/metabolismo , Telomerase/deficiência , Telomerase/genética , Receptor 4 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismo
18.
J Anim Ecol ; 90(2): 415-431, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33084067

RESUMO

Bumblebees are constantly exposed to a wide range of biotic and abiotic stresses which they must defend themselves against to survive. Pathogens and pesticides represent important stressors that influence bumblebee health, both when acting alone or in combination. To better understand bumblebee health, we need to investigate how these factors interact, yet experimental studies to date generally focus on only one or two stressors. The aim of this study is to evaluate how combined effects of four important stressors (the gut parasite Nosema ceranae, the neonicotinoid insecticide thiamethoxam, the pyrethroid insecticide cypermethrin and the EBI fungicide tebuconazole) interact to affect bumblebees at the individual and colony levels. We established seven treatment groups of colonies that we pulse exposed to different combinations of these stressors for 2 weeks under laboratory conditions. Colonies were subsequently placed in the field for 7 weeks to evaluate the effect of treatments on the prevalence of N. ceranae in inoculated bumblebees, expression levels of immunity and detoxification-related genes, food collection, weight gain, worker and male numbers, and production of worker brood and reproductives. Exposure to pesticide mixtures reduced food collection by bumblebees. All immunity-related genes were upregulated in the bumblebees inoculated with N. ceranae when they had not been exposed to pesticide mixtures, and bumblebees exposed to the fungicide and the pyrethroid were less likely to have N. ceranae. Combined exposure to the three-pesticide mixture and N. ceranae reduced bumblebee colony growth, and all treatments had detrimental effects on brood production. The groups exposed to the neonicotinoid insecticide produced 40%-76% fewer queens than control colonies. Our findings show that exposure to combinations of stressors that bumblebees frequently come into contact with have detrimental effects on colony health and performance and could therefore have an impact at the population level. These results also have significant implications for current practices and policies for pesticide risk assessment and use as the combinations tested here are frequently applied simultaneously in the field. Understanding the interactions between different stressors will be crucial for improving our ability to manage bee populations and for ensuring pollination services into the future.


Los abejorros están constantemente expuestos a una amplia gama de agentes estresantes bióticos y abióticos de los que deben defenderse para sobrevivir. Los patógenos y los pesticidas son importantes factores estresantes que influyen en la salud de los abejorros, tanto cuando actúan solos como en combinación. Para tener un mejor conocimiento sobre la salud de los abejorros, debemos investigar cómo interactúan estos factores estresantes, pero los estudios experimentales hasta la fecha generalmente se centran en estudiar solo uno o dos factores. El objetivo de nuestro estudio es evaluar cómo los efectos combinados de cuatro importantes factores estresantes (el parásito intestinal Nosema ceranae, el insecticida neonicotinoide tiametoxam, el insecticida piretroide cipermetrina y el fungicida EBI tebuconazol) interactúan para afectar a los abejorros a nivel individual y de colonia. Establecimos siete grupos de tratamiento de colonias de abejorros que expusimos a diferentes combinaciones de estos factores estresantes durante dos semanas en condiciones de laboratorio, y posteriormente se colocaron en el campo durante siete semanas, para evaluar el efecto de los tratamientos sobre la prevalencia de N. ceranae en abejorros inoculados, los niveles de expresión de genes relacionados con la inmunidad y la desintoxicación, la recolección de alimentos, el aumento de peso, el número de obreras y machos, y la producción de cría de obreras, machos y reinas. La exposición a mezclas de pesticidas redujo la recolección de alimentos por parte de los abejorros. Todos los genes relacionados con la inmunidad se sobre-expresaron en los abejorros inoculados con N. ceranae cuando no habían estado expuestos a mezclas de pesticidas, y los abejorros expuestos al fungicida y al piretroide presentaron menos probabilidades de tener N. ceranae. La exposición combinada a la mezcla de tres pesticidas y N. ceranae redujo el crecimiento de la colonia de abejorros y todos los tratamientos tuvieron efectos perjudiciales en la producción de crías. Los grupos expuestos al insecticida neonicotinoide produjeron entre un 40 y un 76% menos de reinas que las colonias control. Nuestros hallazgos muestran que la exposición a combinaciones de factores estresantes con los que los abejorros entran frecuentemente en contacto tiene efectos perjudiciales sobre la salud y el rendimiento de la colonia y, por lo tanto, podría tener un impacto a nivel poblacional. Estos resultados también tienen importantes implicaciones para las prácticas y políticas actuales de evaluación de riesgos y uso de plaguicidas, ya que las combinaciones probadas aquí se aplican con frecuencia simultáneamente en el campo. Comprender las interacciones entre los diferentes factores de estrés es fundamental para mejorar nuestra capacidad de gestión de las poblaciones de abejas y así garantizar los servicios de polinización en el futuro.


Assuntos
Inseticidas , Nosema , Animais , Abelhas , Inseticidas/toxicidade , Masculino , Polinização , Reprodução
19.
Curr Urol Rep ; 22(2): 13, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33471204

RESUMO

PURPOSE OF REVIEW: To review the current literature on acute management of traumatic penile fracture, with a specific discussion of those injuries following collagenase clostridium histolyticum (CCH) injections for the treatment of Peyronie's disease. RECENT FINDINGS: The immediate repair of traumatic penile fracture injury is associated with significantly better prognosis for long-term sexual health. Corporal disruption following CCH administration has several distinct features, and the trend is to manage these patients conservatively in the absence of urethral injury. Traumatic penile fracture repair continues to have excellent results when performed immediately following injury. The post-CCH treatment setting portends increased difficulty during surgical management and can be successfully managed in most cases by conservative measures.


Assuntos
Colagenase Microbiana/administração & dosagem , Induração Peniana/tratamento farmacológico , Pênis/lesões , Agentes Urológicos/administração & dosagem , Tratamento Conservador , Humanos , Injeções Intralesionais , Masculino , Colagenase Microbiana/uso terapêutico , Doenças do Pênis/tratamento farmacológico , Doenças do Pênis/cirurgia , Doenças do Pênis/terapia , Induração Peniana/complicações , Pênis/cirurgia , Ruptura/cirurgia , Resultado do Tratamento , Agentes Urológicos/uso terapêutico
20.
J Fish Biol ; 99(1): 186-196, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33625732

RESUMO

Fishing is the major threat to marine fish populations, particularly to higher trophic-level predators such as sharks. Many sharks, and other fish, are caught as commercial by-catch or for recreational purposes and then released; therefore, it is important to understand the effects of capture stress on their physiology and subsequent survival. Nonetheless, although important data have been collected for some sharks, there can be substantial interspecific differences, and the consequences of capture stress are still poorly understood for most species. In this study, the authors quantified the physiological effect of capture on four catshark species endemic to Southern Africa, which are regularly discarded as by-catch and targeted by recreational fisheries. Fifteen pyjama sharks, nine leopard sharks and nine shysharks were captured, and a blood sample was collected to measure their physiological response to capture stress. Stressed blood biochemistry was compared to samples obtained after the sharks recovered for 24 h in an underwater pen. Levels of pH and K+ were significantly lower, and lactate levels were significantly higher, in sharks immediately after capture stress compared to after the 24 h recovery period. Although the species showed a similar response to capture stress, they differed significantly in pH, K+ and lactate levels, and there was some evidence of size affecting the strength of the response to capture stress. The substantial physiological response elicited by even the relatively quick capture event in this study suggests that common fishing practices will have a stronger impact on catshark homeostasis because of longer hooking times and more disruptive fishing gear. Although the relationship between survival and physiological changes elicited by capture needs further investigation, the results provide further evidence that minimizing stress would be beneficial to maximize the survival of sharks and other fish following capture-and-release fishing practices.


Assuntos
Tubarões , Estresse Fisiológico , África Austral , Animais , Pesqueiros , Homeostase
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