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1.
JAMA ; 331(7): 573-581, 2024 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-38324415

RESUMO

Importance: Atrial cardiopathy is associated with stroke in the absence of clinically apparent atrial fibrillation. It is unknown whether anticoagulation, which has proven benefit in atrial fibrillation, prevents stroke in patients with atrial cardiopathy and no atrial fibrillation. Objective: To compare anticoagulation vs antiplatelet therapy for secondary stroke prevention in patients with cryptogenic stroke and evidence of atrial cardiopathy. Design, Setting, and Participants: Multicenter, double-blind, phase 3 randomized clinical trial of 1015 participants with cryptogenic stroke and evidence of atrial cardiopathy, defined as P-wave terminal force greater than 5000 µV × ms in electrocardiogram lead V1, serum N-terminal pro-B-type natriuretic peptide level greater than 250 pg/mL, or left atrial diameter index of 3 cm/m2 or greater on echocardiogram. Participants had no evidence of atrial fibrillation at the time of randomization. Enrollment and follow-up occurred from February 1, 2018, through February 28, 2023, at 185 sites in the National Institutes of Health StrokeNet and the Canadian Stroke Consortium. Interventions: Apixaban, 5 mg or 2.5 mg, twice daily (n = 507) vs aspirin, 81 mg, once daily (n = 508). Main Outcomes and Measures: The primary efficacy outcome in a time-to-event analysis was recurrent stroke. All participants, including those diagnosed with atrial fibrillation after randomization, were analyzed according to the groups to which they were randomized. The primary safety outcomes were symptomatic intracranial hemorrhage and other major hemorrhage. Results: With 1015 of the target 1100 participants enrolled and mean follow-up of 1.8 years, the trial was stopped for futility after a planned interim analysis. The mean (SD) age of participants was 68.0 (11.0) years, 54.3% were female, and 87.5% completed the full duration of follow-up. Recurrent stroke occurred in 40 patients in the apixaban group (annualized rate, 4.4%) and 40 patients in the aspirin group (annualized rate, 4.4%) (hazard ratio, 1.00 [95% CI, 0.64-1.55]). Symptomatic intracranial hemorrhage occurred in 0 patients taking apixaban and 7 patients taking aspirin (annualized rate, 1.1%). Other major hemorrhages occurred in 5 patients taking apixaban (annualized rate, 0.7%) and 5 patients taking aspirin (annualized rate, 0.8%) (hazard ratio, 1.02 [95% CI, 0.29-3.52]). Conclusions and Relevance: In patients with cryptogenic stroke and evidence of atrial cardiopathy without atrial fibrillation, apixaban did not significantly reduce recurrent stroke risk compared with aspirin. Trial Registration: ClinicalTrials.gov Identifier: NCT03192215.


Assuntos
Fibrilação Atrial , Cardiopatias , AVC Isquêmico , Pirazóis , Acidente Vascular Cerebral , Humanos , Feminino , Idoso , Masculino , Fibrilação Atrial/complicações , Fibrilação Atrial/tratamento farmacológico , Método Duplo-Cego , Canadá , Acidente Vascular Cerebral/prevenção & controle , Acidente Vascular Cerebral/complicações , Aspirina/efeitos adversos , Piridonas/efeitos adversos , Piridonas/administração & dosagem , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Cardiopatias/complicações , AVC Isquêmico/tratamento farmacológico , Anticoagulantes/efeitos adversos , Anticoagulantes/administração & dosagem , Hemorragias Intracranianas/induzido quimicamente
2.
Am J Physiol Heart Circ Physiol ; 320(6): H2339-H2350, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33989081

RESUMO

Mutations to the sarcomere-localized cochaperone protein Bcl2-associated athanogene 3 (BAG3) are associated with dilated cardiomyopathy (DCM) and display greater penetrance in male patients. Decreased protein expression of BAG3 is also associated with nongenetic heart failure; however, the factors regulating cardiac BAG3 expression are unknown. Using left ventricular (LV) tissue from nonfailing and DCM human samples, we found that whole LV BAG3 expression was not significantly impacted by DCM or sex; however, myofilament localized BAG3 was significantly decreased in males with DCM. Females with DCM displayed no changes in BAG3 compared with nonfailing. This sex difference appears to be estrogen independent, as estrogen treatment in ovariectomized female rats had no impact on BAG3 expression. BAG3 gene expression in noncardiac cells is primarily regulated by the heat shock transcription factor-1 (HSF-1). We show whole LV HSF-1 expression and nuclear localized/active HSF-1 each displayed a striking positive correlation with whole LV BAG3 expression. We further found that HSF-1 localizes to the sarcomere Z-disc in cardiomyocytes and that this myofilament-associated HSF-1 pool decreases in heart failure. The decrease of HSF-1 was more pronounced in male patients and tightly correlated with myofilament BAG3 expression. Together our findings indicate that cardiac BAG3 expression and myofilament localization are differentially impacted by sex and disease and are linked to HSF-1.NEW & NOTEWORTHY Myofilament BAG3 expression decreases in male patients with nonischemic DCM but is preserved in female patients with DCM. BAG3 expression in the human heart is tightly linked to HSF-1 expression and nuclear translocation. HSF-1 localizes to the sarcomere Z-disc in the human heart. HSF-1 expression in the myofilament fraction decreases in male patients with DCM and positively correlates with myofilament BAG3.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Cardiomiopatia Dilatada/metabolismo , Ventrículos do Coração/metabolismo , Fatores de Transcrição de Choque Térmico/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Sarcômeros/metabolismo , Adulto , Idoso , Animais , Feminino , Expressão Gênica , Humanos , Masculino , Microscopia de Fluorescência , Pessoa de Meia-Idade , Miocárdio/patologia , Miócitos Cardíacos/patologia , Miofibrilas/metabolismo , Ovariectomia , Ratos , Sarcômeros/patologia , Fatores Sexuais
3.
Am J Physiol Cell Physiol ; 319(4): C624-C629, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783657

RESUMO

MicroRNAs (miRNAs) are short, noncoding RNAs that are evolutionarily conserved across many different species. miRNA regulation of gene expression, specifically in the context of the mammalian brain, has been well characterized; however, the regulation of miRNA degradation is still a focus of ongoing research. This review focuses on recent findings concerning the cellular mechanisms that govern miRNA degradation, with an emphasis on target-mediated miRNA degradation and how this phenomenon is uniquely poised to maintain homeostasis in neuronal systems.


Assuntos
Encéfalo/metabolismo , MicroRNAs/genética , Estabilidade de RNA/genética , Animais , Encéfalo/patologia , Homeostase/genética , Humanos , Mamíferos , MicroRNAs/metabolismo , Neurônios/metabolismo
4.
N Engl J Med ; 374(14): 1321-31, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-26886418

RESUMO

BACKGROUND: Patients with ischemic stroke or transient ischemic attack (TIA) are at increased risk for future cardiovascular events despite current preventive therapies. The identification of insulin resistance as a risk factor for stroke and myocardial infarction raised the possibility that pioglitazone, which improves insulin sensitivity, might benefit patients with cerebrovascular disease. METHODS: In this multicenter, double-blind trial, we randomly assigned 3876 patients who had had a recent ischemic stroke or TIA to receive either pioglitazone (target dose, 45 mg daily) or placebo. Eligible patients did not have diabetes but were found to have insulin resistance on the basis of a score of more than 3.0 on the homeostasis model assessment of insulin resistance (HOMA-IR) index. The primary outcome was fatal or nonfatal stroke or myocardial infarction. RESULTS: By 4.8 years, a primary outcome had occurred in 175 of 1939 patients (9.0%) in the pioglitazone group and in 228 of 1937 (11.8%) in the placebo group (hazard ratio in the pioglitazone group, 0.76; 95% confidence interval [CI], 0.62 to 0.93; P=0.007). Diabetes developed in 73 patients (3.8%) and 149 patients (7.7%), respectively (hazard ratio, 0.48; 95% CI, 0.33 to 0.69; P<0.001). There was no significant between-group difference in all-cause mortality (hazard ratio, 0.93; 95% CI, 0.73 to 1.17; P=0.52). Pioglitazone was associated with a greater frequency of weight gain exceeding 4.5 kg than was placebo (52.2% vs. 33.7%, P<0.001), edema (35.6% vs. 24.9%, P<0.001), and bone fracture requiring surgery or hospitalization (5.1% vs. 3.2%, P=0.003). CONCLUSIONS: In this trial involving patients without diabetes who had insulin resistance along with a recent history of ischemic stroke or TIA, the risk of stroke or myocardial infarction was lower among patients who received pioglitazone than among those who received placebo. Pioglitazone was also associated with a lower risk of diabetes but with higher risks of weight gain, edema, and fracture. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT00091949.).


Assuntos
Fraturas Ósseas/induzido quimicamente , Hipoglicemiantes/uso terapêutico , Resistência à Insulina , Ataque Isquêmico Transitório/tratamento farmacológico , Infarto do Miocárdio/prevenção & controle , Acidente Vascular Cerebral/tratamento farmacológico , Tiazolidinedionas/uso terapêutico , Idoso , Isquemia Encefálica/tratamento farmacológico , Método Duplo-Cego , Feminino , Humanos , Hipoglicemiantes/efeitos adversos , Masculino , Pessoa de Meia-Idade , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Pioglitazona , Prevenção Secundária , Acidente Vascular Cerebral/prevenção & controle , Tiazolidinedionas/efeitos adversos , Aumento de Peso/efeitos dos fármacos
5.
Genet Med ; 19(11): 1276-1279, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28541281

RESUMO

PurposeNonclassic 21-hydroxylase deficiency, a mild form of congenital adrenal hyperplasia (CAH), is estimated to be the most common autosomal recessive condition, with an especially high prevalence in Ashkenazi Jews (3.7% affected, 30.9% carriers), based on a 1985 HLA-B linkage study of affected families. Affected individuals, especially women, may suffer from hyperandrogenism and infertility. State-of-the-art genetic studies have not been done to confirm these remarkable rates.MethodsCYP21A2 genotyping was performed in 200 unrelated healthy Ashkenazi Jewish subjects and 200 random US Caucasians who did not self-identify as a specific ethnicity using multiplex minisequencing, real-time polymerase chain reaction and junction site analysis.ResultsNonclassic CAH carriership was found similarly in 15% (95% confidence interval (CI): 10.4-20.7) of Ashkenazi Jews and 9.5% (95% CI: 5.8-14.4) of Caucasians (P=0.13). The proportion of Ashkenazi Jewish nonclassic CAH carriers (0.15 versus 0.309, P<0.0001) and disease affected (0.005 versus 0.037, P=0.009) was not as high as previously reported. The estimated prevalence of nonclassic CAH in Caucasians was 1 in 200 (0.5%, 95% CI: 0.01-2.8).ConclusionNonclassic CAH is a common condition, regardless of ethnicity, and should be considered with preconception and infertility counseling.


Assuntos
Hiperplasia Suprarrenal Congênita/epidemiologia , Judeus , Hiperplasia Suprarrenal Congênita/genética , Frequência do Gene , Técnicas de Genotipagem , Heterozigoto , Humanos , Mutação , Prevalência , Esteroide 21-Hidroxilase/genética , Estados Unidos/epidemiologia , População Branca/genética
6.
J Endocrinol Invest ; 40(7): 787-788, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28255822

RESUMO

This short note illustrates facial and head features found in a stone sculpture of the ancient, Precolumbian period in a temple of the Mayan city of Copan (Honduras). The authors believe that this observation may support paleoanthropological evidence of Paget's disease of bone, an osteodystrophy described in the Mesoamerican Indian populations before the first millennium A.D.


Assuntos
Doenças Ósseas Metabólicas/patologia , Osteíte Deformante/patologia , Escultura/história , Crânio/patologia , Idoso , Feminino , História Antiga , Humanos , Indígenas Centro-Americanos
8.
Mol Cell Proteomics ; 13(3): 760-79, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24390426

RESUMO

Recent clinical evidence suggests that the neuroprotective and beneficial effects of hormone therapy may be limited by factors related to age and reproductive status. The patient's age and length of time without circulating ovarian hormones are likely to be key factors in the specific neurological outcomes of hormone therapy. However, the mechanisms underlying age-related changes in hormone efficacy have not been determined. We hypothesized that there are intrinsic changes in estrogen receptor ß (ERß) function that determine its ability to mediate the actions of 17ß-estradiol (E2) in brain regions such as the ventral hippocampus. In this study, we identified and quantified a subset of ERß protein interactions in the ventral hippocampus that were significantly altered by E2 replacement in young and aged animals, using two-dimensional differential gel electrophoresis coupled with liquid chromatography-electrospray ionization-tandem mass spectrometry. This study demonstrates quantitative changes in ERß protein-protein interactions with E2 replacement that are dependent upon age in the ventral hippocampus and how these changes could alter processes such as transcriptional regulation. Thus, our data provide evidence that changes in ERß protein interactions are a potential mechanism for age-related changes in E2 responsiveness in the brain after menopause.


Assuntos
Envelhecimento/metabolismo , Estradiol/farmacologia , Receptor beta de Estrogênio/metabolismo , Hipocampo/metabolismo , Mapeamento de Interação de Proteínas , Adenosina Trifosfatases/metabolismo , Envelhecimento/efeitos dos fármacos , Animais , Anexina A5/metabolismo , Proteínas de Ciclo Celular/metabolismo , Receptor beta de Estrogênio/genética , Feminino , Gelsolina/metabolismo , Técnicas de Silenciamento de Genes , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Células HEK293 , Hipocampo/efeitos dos fármacos , Humanos , Processamento de Imagem Assistida por Computador , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Endogâmicos F344 , Elementos de Resposta/genética , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Transcrição Gênica/efeitos dos fármacos , Proteína com Valosina
9.
J Biol Chem ; 288(45): 32149-32159, 2013 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-24062309

RESUMO

Senescent cells accumulate in aged tissue and are causally linked to age-associated tissue degeneration. These non-dividing, metabolically active cells are highly secretory and alter tissue homeostasis, creating an environment conducive to metastatic disease progression. IL-1α is a key senescence-associated (SA) proinflammatory cytokine that acts as a critical upstream regulator of the SA secretory phenotype (SASP). We established that SA shifts in steady-state H2O2 and intracellular Ca(2+) levels caused an increase in IL-1α expression and processing. The increase in intracellular Ca(2+) promoted calpain activation and increased the proteolytic cleavage of IL-1α. Antioxidants and low oxygen tension prevented SA IL-1α expression and restricted expression of SASP components IL-6 and IL-8. Ca(2+) chelation or calpain inhibition prevented SA processing of IL-1α and its ability to induce downstream cytokine expression. Conditioned medium from senescent cells treated with antioxidants or Ca(2+) chelators or cultured in low oxygen markedly reduced the invasive capacity of proximal metastatic cancer cells. In this paracrine fashion, senescent cells promoted invasion by inducing an epithelial-mesenchymal transition, actin reorganization, and cellular polarization of neighboring cancer cells. Collectively, these findings demonstrate how SA alterations in the redox state and Ca(2+) homeostasis modulate the inflammatory phenotype through the regulation of the SASP initiator IL-1α, creating a microenvironment permissive to tumor invasion.


Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Senescência Celular/fisiologia , Interleucina-1alfa/biossíntese , Proteólise , Calpaína/genética , Calpaína/metabolismo , Linhagem Celular Tumoral , Ativação Enzimática/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Humanos , Peróxido de Hidrogênio/farmacologia , Interleucina-1alfa/genética , Interleucina-6/biossíntese , Interleucina-6/genética , Interleucina-8/biossíntese , Interleucina-8/genética , Invasividade Neoplásica , Metástase Neoplásica , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Oxidantes/farmacologia , Oxirredução , Comunicação Parácrina/fisiologia , Microambiente Tumoral
10.
Pflugers Arch ; 465(5): 655-67, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23397171

RESUMO

Over the past 20 years, our understanding of the basic mechanisms of gene regulation has vastly expanded due to the unexpected roles of small regulatory RNAs, in particular microRNAs (miRNAs). miRNAs add another layer of complexity to the regulation of effector molecules for nearly every physiological process, making them excellent candidate molecules as therapeutic targets, biomarkers, and disease predictors. Hormonal contributions to mature miRNA expression, biosynthetic processing, and downstream functions have only just begun to be investigated. Elucidating the physiological consequences of miRNA sexual dimorphism, and their associated regulatory processes, may be key toward understanding both normal and pathological processes in the brain. This short review provides a basic overview of miRNA biosynthesis, their role in normal brain development, and potential links to neurological diseases. We conclude with a brief discussion of the current knowledge of sex-specific miRNA processes in both the brain and the heart to conceptually integrate the relevance of miRNAs with the overarching theme ("sex differences in health and disease: brain and heart connections") of this special topics issue.


Assuntos
Encéfalo/metabolismo , MicroRNAs/metabolismo , Caracteres Sexuais , Animais , Encéfalo/crescimento & desenvolvimento , Feminino , Inativação Gênica , Humanos , Masculino , Transtornos Mentais/metabolismo , MicroRNAs/genética , Doenças Neurodegenerativas/metabolismo
11.
BMJ Open Qual ; 12(2)2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37253530

RESUMO

Mortality reviews are intended to produce transparent, non-punitive personal and organisational learning that leads to systematic improvement in care. Mayo Clinic has a well-established care review process that has accomplished that objective within our system. The establishment of a new hospital, a joint venture between Mayo Clinic and Sheikh Shakhbout Medical City (SSMC) in Abu Dhabi, provided a unique opportunity to share this care review process internationally.During a baseline measurement period, only 78.3% of mortality reviews at SSMC were completed within 45 days, 16.7 percentage points below the target of 95%. A collaboration between SSMC and Mayo Clinic aimed to accelerate the design and implementation of a care review process system. Collaboration was constrained by travel restrictions imposed by COVID-19, language barriers, legal privacy concerns, and differing electronic health records.Mayo Clinic facilitated a 12-week virtual engagement with SSMC using weekly video meetings, education and training regarding Mayo Clinic's care review process.The engagement led to implementation of weekly mortality review huddles, restructuring of the mortality review committee to be multidisciplinary, use of a standardised taxonomy to characterise opportunities to improve care and creation of an education/communication plan regarding identified improvement opportunities using change management strategies.After the care review process for mortality reviews was instituted, SSMC achieved and sustained a target of 100% of mortality reviews completed within 45 days. The new process resulted in improved mortality review indicators and provided quality feedback to staff with engagement in performance improvement efforts.A virtual collaboration led to successful implementation of a care review process and substantial gains in the effectiveness of the quality programme at SSMC. This could serve as a model to assist other organisations, even if in-person engagement is hindered.


Assuntos
COVID-19 , Humanos , Comunicação , Aprendizagem , Hospitais , Emirados Árabes Unidos
12.
Noncoding RNA ; 9(6)2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38133208

RESUMO

Aging in women is accompanied by a dramatic change in circulating sex steroid hormones. Specifically, the primary circulating estrogen, 17ß-estradiol (E2), is nearly undetectable in post-menopausal women. This decline is associated with a variety of cognitive and mood disorders, yet hormone replacement therapy is only effective within a narrow window of time surrounding the menopausal transition. Our previous work identified microRNAs as a potential molecular substrate underlying the change in E2 efficacy associated with menopause in advanced age. Specifically, we showed that E2 regulated a small subset of mature miRNAs in the aging female brain. In this study, we hypothesized that E2 regulates the stability of mature miRNAs by altering their subcellular localization and their association with argonaute proteins. We also tested the hypothesis that the RNA binding protein, hnRNP A1, was an important regulator of mature miR-9-5p expression in neuronal cells. Our results demonstrated that E2 treatment affected miRNA subcellular localization and its association with argonaute proteins differently, depending on the length of time following E2 deprivation (i.e., ovariectomy). We also provide strong evidence that hnRNP A1 regulates the transcription of pri-miR-9 and likely plays a posttranscriptional role in mature miR-9-5p turnover. Taken together, these data have important implications for considering the optimal timing for hormone replacement therapy, which might be less dependent on age and more related to how long treatment is delayed following menopause.

13.
Med Educ Online ; 28(1): 2182188, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36861296

RESUMO

The University of Alabama at Birmingham Heersink School of Medicine established the Pittman Scholars Program in 2015 to elevate scientific impact and to support the recruitment and retention of highly competitive junior faculty. The authors examined the impact of this program on research productivity and on faculty retention. The authors evaluated publications and extramural grant awards and available demographic data for the Pittman Scholars compared to all junior faculty in the Heersink School of Medicine. From 2015 to 2021, the program awarded a diverse group of 41 junior faculty members across the institution. For this cohort, ninety-four new extramural grants were awarded and 146 grant applications were submitted since the inception of the scholar award. Pittman Scholars published a total of 411 papers during the term of the award. The faculty retention rate of the scholars was 95%, comparable to that of all Heersink junior faculty, with 2 recipients being recruited to other institutions. The implementation of the Pittman Scholars Program has been an effective strategy to celebrate scientific impact and acknowledge junior faculty members as outstanding scientists at our institution. The Pittman Scholars award allows junior faculty to use funds for their research program, publications, collaborations, and career advancement. The Pittman Scholars are recognized at local, regional, and national levels for the work they are contributing to academic medicine. The program has served as an important pipeline faculty development program and an avenue for individual recognition for research-intensive faculty.


Assuntos
Docentes , Medicina , Médicos , Humanos , Universidades
14.
J Interpers Violence ; 36(7-8): 3755-3777, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-29806565

RESUMO

Marianismo is a Latino cultural value that describes both positive and negative aspects of traditional Latina femininity. Marianismo emphasizes culturally valued qualities such as interpersonal harmony, inner strength, self-sacrifice, and morality. Endorsement of marianismo is hypothesized to correlate with individual economic, educational, and personal variables. Marianismo also is theorized to potentially influence attitudes about, experiences of, and responses to intimate partner violence (IPV) among Latina women. The present study examined whether endorsement of marianismo beliefs mitigated or exacerbated psychological distress after experiences of IPV in a sample of 205 recently immigrated Latina women, aged 18 to 23 years. Latina women experiencing higher levels of IPV and endorsing greater marianismo beliefs were hypothesized to indicate greater psychological distress. Unexpectedly, women who endorsed more Subordinate to Others/Self-Silencing to Maintain Harmony marianismo beliefs indicated more psychological distress (p = .05), greater symptoms of psychological distress (p = .01), and greater average distress (p = .03) when they also reported less IPV than peers. Implications for understanding Latinas' responses to and reporting of IPV, as well as for culturally tailored counseling interventions for this underserved and understudied population, are discussed.


Assuntos
Violência por Parceiro Íntimo , Angústia Psicológica , Atitude , Feminino , Hispânico ou Latino , Humanos , Adulto Jovem
15.
Adv Sci (Weinh) ; 8(17): e2101663, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34240575

RESUMO

The success of metal halide perovskites in photovoltaic and light-emitting diodes (LEDs) motivates their application as a solid-state thin-film laser. Various perovskites have shown optically pumped stimulated emission of lasing and amplified spontaneous emission (ASE), yet the ultimate goal of electrically pumped stimulated emission has not been achieved. As an essential step toward this goal, here, a perovskite diode structure that simultaneously exhibits stable operation at high current density (≈1 kA cm-2 ) and optically excited ASE (with a threshold of 180 µJ cm-2 ) is reported. This diode structure achieves an electroluminescence quantum efficiency of 0.8% at 850 A cm-2 , which is estimated to be ≈3% of the charge carrier population required to reach ASE in the same device. It is shown that the formation of a large angle waveguide mode and the reduction of parasitic absorption losses are two major design principles for diodes to obtain a positive gain for stimulated emission. In addition to its prospect as a perovskite laser, a new application of electrically pumped ASE is proposed as an ideal perovskite LED architecture allowing 100% external radiation efficiency.

16.
Endocrinology ; 162(9)2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34147032

RESUMO

The rapid decline of circulating 17ß-estradiol (E2) at menopause leads to negative neurological consequences, although hormone therapy paradoxically has both harmful and positive effects depending on the age at which it is delivered. The inconsistent response to E2 suggests unappreciated regulatory mechanisms for estrogen receptors (ERs), and we predicted it could be due to age-related differences in ERß phosphorylation. We assessed ERß phosphorylation using a sensitive mass spectrometry approach that provides absolute quantification (AQUA-MS) of individually phosphorylated residues. Specifically, we quantified phosphorylated ERß in the hippocampus of women (aged 21-83 years) and in a rat model of menopause at 4 residues with conserved sequence homology between the 2 species: S105, S176, S200, and Y488. Phosphorylation at these sites, which spanned all domains of ERß, were remarkably consistent between the 2 species, showing high levels of S105 phosphorylation (80%-100%) and low levels of S200 (20%-40%). Further, S200 phosphorylation decreased with aging in humans and loss of E2 in rats. Surprisingly, Y488 phosphorylation, which has been linked to ERß ligand-independent actions, exhibited approximately 70% phosphorylation, unaltered by species, age, or E2, suggesting ERß's primary mode of action may not require E2 binding. We further show phosphorylation at 2 sites directly altered ERß DNA-binding efficiency, and thus could affect its transcription factor activity. These findings provide the first absolute quantification of ERß phosphorylation in the human and rat brain, novel insights into ERß regulation, and a critical foundation for providing more targeted therapeutic options for menopause in the future.


Assuntos
Receptor beta de Estrogênio/análise , Hipocampo/química , Menopausa/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Envelhecimento/patologia , Aminoácidos/análise , Aminoácidos/metabolismo , Animais , Estradiol/análise , Estradiol/metabolismo , Receptor beta de Estrogênio/metabolismo , Feminino , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Pessoa de Meia-Idade , Modelos Animais , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/metabolismo , Fosforilação , Ratos , Ratos Endogâmicos F344 , Adulto Jovem
17.
Noncoding RNA ; 7(3)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34564315

RESUMO

Clinical studies demonstrated that the ovarian hormone 17ß-estradiol (E2) is neuroprotective within a narrow window of time following menopause, suggesting that there is a biological switch in E2 action that is temporally dependent. However, the molecular mechanisms mediating this temporal switch have not been determined. Our previous studies focused on microRNAs (miRNA) as one potential molecular mediator and showed that E2 differentially regulated a subset of mature miRNAs which was dependent on age and the length of time following E2 deprivation. Notably, E2 significantly increased both strands of the miR-9 duplex (miR-9-5p and miR-9-3p) in the hypothalamus, raising the possibility that E2 could regulate miRNA stability/degradation. We tested this hypothesis using a biochemical approach to measure miRNA decay in a hypothalamic neuronal cell line and in hypothalamic brain tissue from a rat model of surgical menopause. Notably, we found that E2 treatment stabilized both miRNAs in neuronal cells and in the rat hypothalamus. We also used polysome profiling as a proxy for miR-9-5p and miR-9-3p function and found that E2 was able to shift polysome loading of the miRNAs, which repressed the translation of a predicted miR-9-3p target. Moreover, miR-9-5p and miR-9-3p transcripts appeared to occupy different fractions of the polysome profile, indicating differential subcellular. localization. Together, these studies reveal a novel role for E2 in modulating mature miRNA behavior, independent of its effects at regulating the primary and/or precursor form of miRNAs.

18.
Int J Gynaecol Obstet ; 152(1): 72-77, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33026115

RESUMO

OBJECTIVE: To investigate factors associated with colposcopy attendance in HPV-positive women in São Paulo, Brazil. METHODS: We analyzed data from a prospective cohort of women positive for high-risk HPV (hr-HPV) undergoing cervical cancer screening in primary care services in São Paulo, Brazil. Non-pregnant women attending routine screening between December 2014 and March 2016 were offered an hr-HPV test, and those testing positive and aged 25 years or older were invited for colposcopy. Sociodemographic information was recorded at study enrollment. We compared variables between women who did and did not attend colposcopy within a logistic regression framework. RESULTS: Of 1537 hr-HPV-positive women, 1235 (80.4%) attended for colposcopy, with a median time from primary test to colposcopy of 132 days. Younger age (P<0.001) and concurrent negative cytology results (P=0.025) were associated with lower attendance. Women registered at units providing both the primary test and colposcopy were more likely to attend than those at units making external referrals (788/862 [91.4%] versus 447/675 [66.2%], P<0.001). CONCLUSION: Non-attendance for colposcopy may limit the success of future screening programs based on hr-HPV testing in Brazil. Transfer of colposcopy services to primary care is a simple and effective facilitator of attendance.


Assuntos
Colposcopia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/patologia , Cooperação do Paciente , Displasia do Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia , Adulto , Brasil , Estudos de Coortes , Estudos de Viabilidade , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos
19.
Acad Med ; 96(10): 1401-1407, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33830950

RESUMO

The University of Alabama at Birmingham academic medical center (UAB AMC) had achieved great success and growth during the 50 years since its founding. However, the challenging and more competitive environment of the 2000s left the UAB AMC on a downward trajectory. The UAB AMC had to overcome difficult internal cultural and structural barriers that stood in the way of the transformational change needed to remain competitive. Competition rather than collaborative and strategic financial investment were the primary cultural barriers for the UAB AMC, while people were the primary structural barrier. Leadership identified 5 steps that were critical for the transformation that occurred between 2013 and 2018: alignment of leadership; creating a compelling and credible shared vision; identifying cultural and structural barriers; creating a thoughtful, data-driven intervention; and improved communication and accountability. Following these steps enabled the UAB AMC to transform its institutional structure and culture. As a result, the UAB AMC thrived, returning to substantial growth in research and clinical care. UAB AMC School of Medicine grew by $100 million in National Institutes of Health funding and moved up 10 spots in ranking. In 2018, UAB Hospital had 10 specialties ranked by U.S. News & World Report, 7 more than in 2013. This article outlines the approach taken and provides a conceptual framework for other AMCs eager to transform their structure and culture and position themselves for growth.


Assuntos
Centros Médicos Acadêmicos/organização & administração , Gestão de Mudança , Centros Médicos Acadêmicos/economia , Alabama , Financiamento Governamental , Humanos , Liderança , Cultura Organizacional , Objetivos Organizacionais , Apoio à Pesquisa como Assunto , Comunicação Acadêmica , Responsabilidade Social
20.
Am J Physiol Endocrinol Metab ; 298(2): E320-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19952347

RESUMO

Maternal alcohol consumption during critical periods of fetal brain development leads to devastating long-term consequences on adult reproductive physiology, cognitive function, and social behaviors. However, very little is known about the long-term consequences of alcohol consumption during puberty, which is perhaps an equally dynamic and critical period of brain development. Alcohol abuse during adulthood has been linked with an increase in clinically diagnosed anxiety disorders, yet the etiology and neurochemical mechanisms of alcohol-induced anxiety behavior is unknown. In this study, we determined the effects of binge ethanol exposure during puberty on two critical central regulators of stress and anxiety behavior: corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP). Our results showed that ethanol increased plasma corticosterone (CORT) levels in both sexes, yet binge-treated animals had significantly lower CORT levels than animals exposed to a single dose, suggesting that the hypothalamo-pituitary-adrenal (HPA) axis habituated to the repeated stressful stimuli of ethanol. Binge ethanol exposure also significantly increased CRH and AVP gene expression in the paraventricular nucleus of males, but not females. Overall, our results demonstrate that binge ethanol exposure during puberty changes the central expression of stress-related genes in a sex-specific manner, potentially leading to permanent dysregulation of the HPA axis and long-term behavioral consequences.


Assuntos
Arginina Vasopressina/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Depressores do Sistema Nervoso Central/intoxicação , Hormônio Liberador da Corticotropina/efeitos dos fármacos , Etanol/intoxicação , Maturidade Sexual/efeitos dos fármacos , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Consumo de Bebidas Alcoólicas/efeitos adversos , Animais , Arginina Vasopressina/genética , Arginina Vasopressina/metabolismo , Encéfalo/crescimento & desenvolvimento , Hormônio Liberador da Corticotropina/metabolismo , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/metabolismo , RNA Mensageiro/análise , Distribuição Aleatória , Ratos , Ratos Wistar , Caracteres Sexuais
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