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1.
Eur J Haematol ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38994568

RESUMO

OBJECTIVES: Delays in the evaluation and treatment of iron deficiency can lead to increased disease-related morbidity and mortality. Electronic consultation (e-consult) is a referral modality that allows providers quicker access to recommendations from a specialist based on electronic chart review. While the use of e-consult is expanding in classical hematology, gaps exist in the understanding of patient outcomes related to its use for iron deficiency. METHODS: We randomly selected 200 e-consults and 200 traditional referrals from 3,336 hematology referrals for iron deficiency at a single center. The primary outcomes of the retrospective analysis were: time to completion of the referral, and time to treatment with intravenous iron. Secondary outcomes included recurrence of iron deficiency, need for repeat e-consult, conversion to in-person evaluation, and assessment of whether the etiology of iron deficiency was addressed. RESULTS: E-consults significantly reduced the time from referral to intravenous iron repletion (e-consult, 33 days; traditional referral, 68 days; p < .05). Assessment of the underlying etiology occurred in 70.7% of the e-consult encounters compared to 92.5% of traditional referrals (p < .05). CONCLUSIONS: These findings highlight advantages of e-consults in improving care delivery in iron deficiency, and identifying gaps that can be improved through practice standardization to ensure equitable, high-value care.

2.
Cancer Res Commun ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39007351

RESUMO

Aged melanoma patients (>65 years old) have more aggressive disease relative to young patients (<55 years old) for reasons that are not completely understood. Analysis of the young and aged secretome from human dermal fibroblasts identified >5-fold levels of insulin-like growth factor binding protein 2 (IGFBP2) in the aged fibroblast secretome. IGFBP2 functionally triggers upregulation of the PI3K-dependent fatty acid biosynthesis program in melanoma cells. Melanoma cells co-cultured with aged dermal fibroblasts have higher levels of lipids relative to co-cultured with young dermal fibroblasts, which can be lowered by silencing IGFBP2 expression in fibroblasts, prior to treating with conditioned media. Conversely, ectopically treating melanoma cells with recombinant IGFBP2 in the presence of conditioned media from young fibroblasts, or overexpressing IGFBP2 in melanoma cells promoted lipid synthesis and accumulation in the melanoma cells. Treatment of young mice with rIGFBP2 increases tumor growth. Neutralizing IGFBP2 in vitro reduces migration and invasion in melanoma cells, and in vivo studies demonstrate that neutralizing IGFBP2 in syngeneic aged mice reduces tumor growth amd metastasis. Our results suggest that aged dermal fibroblasts increase melanoma cell aggressiveness through increased secretion of IGFBP2, stressing the importance of considering age when designing studies and treatment.

3.
Ecol Evol ; 14(7): e11623, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38957695

RESUMO

The colours of insects function in intraspecific communication such as sexual signalling, interspecific communication such as protection from predators, and in physiological processes, such as thermoregulation. The expression of melanin-based colours is temperature-dependent and thus likely to be impacted by a changing climate. However, it is unclear how climate change drives changes in body and wing colour may impact insect physiology and their interactions with conspecifics (e.g. mates) or heterospecific (e.g. predators or prey). The aim of this review is to synthesise the current knowledge of the consequences of climate-driven colour change on insects. Here, we discuss the environmental factors that affect insect colours, and then we outline the adaptive mechanisms in terms of phenotypic plasticity and microevolutionary response. Throughout we discuss the impact of climate-related colour change on insect physiology, and interactions with con-and-heterospecifics.

5.
Pediatr Crit Care Med ; 25(7): 643-675, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38959353

RESUMO

OBJECTIVES: To present recommendations and consensus statements with supporting literature for the clinical management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus conference. DATA SOURCES: Systematic review was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial meetings of international, interprofessional experts in the management ECMO for critically ill children. STUDY SELECTION: The management of ECMO anticoagulation for critically ill children. DATA EXTRACTION: Within each of eight subgroup, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. DATA SYNTHESIS: A systematic review was conducted using MEDLINE, Embase, and Cochrane Library databases, from January 1988 to May 2021. Each panel developed evidence-based and, when evidence was insufficient, expert-based statements for the clinical management of anticoagulation for children supported with ECMO. These statements were reviewed and ratified by 48 PEACE experts. Consensus was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 23 recommendations, 52 expert consensus statements, and 16 good practice statements covering the management of ECMO anticoagulation in three broad categories: general care and monitoring; perioperative care; and nonprocedural bleeding or thrombosis. Gaps in knowledge and research priorities were identified, along with three research focused good practice statements. CONCLUSIONS: The 91 statements focused on clinical care will form the basis for standardization and future clinical trials.


Assuntos
Anticoagulantes , Estado Terminal , Oxigenação por Membrana Extracorpórea , Oxigenação por Membrana Extracorpórea/métodos , Humanos , Anticoagulantes/uso terapêutico , Anticoagulantes/administração & dosagem , Criança , Estado Terminal/terapia , Recém-Nascido , Lactente , Pré-Escolar
6.
Pediatr Crit Care Med ; 25(7 Suppl 1): e44-e52, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38959359

RESUMO

OBJECTIVES: To derive systematic-review informed, modified Delphi consensus regarding antifibrinolytic and adjunct hemostatic agents in neonates and children supported with extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE consensus conference. DATA SOURCES: A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021. STUDY SELECTION: Use of antifibrinolytics (epsilon-aminocaproic acid [EACA] or tranexamic acid), recombinant factor VII activated (rFVIIa), or topical hemostatic agents (THAs). DATA EXTRACTION: Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Eleven references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. MEASUREMENTS AND MAIN RESULTS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. One weak recommendation and three consensus statements are presented. CONCLUSIONS: Evidence supporting recommendations for administration of antifibrinolytics (EACA or tranexamic acid), rFVIIa, and THAs were sparse and inconclusive. Much work remains to determine effective and safe usage strategies.


Assuntos
Antifibrinolíticos , Técnica Delphi , Oxigenação por Membrana Extracorpórea , Hemostáticos , Ácido Tranexâmico , Humanos , Antifibrinolíticos/uso terapêutico , Antifibrinolíticos/administração & dosagem , Oxigenação por Membrana Extracorpórea/métodos , Criança , Hemostáticos/uso terapêutico , Hemostáticos/administração & dosagem , Ácido Tranexâmico/uso terapêutico , Ácido Tranexâmico/administração & dosagem , Fator VIIa/uso terapêutico , Fator VIIa/administração & dosagem , Proteínas Recombinantes/uso terapêutico , Proteínas Recombinantes/administração & dosagem , Recém-Nascido , Ácido Aminocaproico/uso terapêutico , Ácido Aminocaproico/administração & dosagem , Hemorragia/prevenção & controle , Anticoagulantes/administração & dosagem , Anticoagulantes/uso terapêutico , Lactente , Consenso
7.
Pediatr Crit Care Med ; 25(7 Suppl 1): e35-e43, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38959358

RESUMO

OBJECTIVES: To derive systematic review informed, modified Delphi consensus regarding monitoring and replacement of specific coagulation factors during pediatric extracorporeal membrane oxygenation (ECMO) support for the Pediatric ECMO Anticoagulation CollaborativE. DATA SOURCES: A structured literature search was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021. STUDY SELECTION: Included studies assessed monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric ECMO support. DATA EXTRACTION: Two authors reviewed all citations independently, with conflicts resolved by a third reviewer if required. Twenty-nine references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. A panel of 48 experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. We developed one weak recommendation and four expert consensus statements. CONCLUSIONS: There is insufficient evidence to formulate recommendations on monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric patients on ECMO. Optimal monitoring and parameters for replacement of key hemostasis parameters is largely unknown.


Assuntos
Antitrombinas , Técnica Delphi , Oxigenação por Membrana Extracorpórea , Fibrinogênio , Fator de von Willebrand , Oxigenação por Membrana Extracorpórea/métodos , Humanos , Fibrinogênio/análise , Antitrombinas/uso terapêutico , Criança , Fator de von Willebrand/análise , Anticoagulantes/administração & dosagem , Anticoagulantes/uso terapêutico
8.
Pediatr Crit Care Med ; 25(7 Suppl 1): e78-e89, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38959362

RESUMO

OBJECTIVES: To identify and prioritize research questions for anticoagulation and hemostasis management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus. DATA SOURCES: Systematic review was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial consensus conferences of international, interprofessional experts in the management of ECMO for critically ill neonates and children. STUDY SELECTION: The management of ECMO anticoagulation for critically ill neonates and children. DATA EXTRACTION: Within each of the eight subgroups, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. DATA SYNTHESIS: Following the systematic review of MEDLINE, EMBASE, and Cochrane Library databases from January 1988 to May 2021, and the consensus process for clinical recommendations and consensus statements, PEACE panel experts constructed research priorities using the Child Health and Nutrition Research Initiative methodology. Twenty research topics were prioritized, falling within five domains (definitions and outcomes, therapeutics, anticoagulant monitoring, protocolized management, and impact of the ECMO circuit and its components on hemostasis). CONCLUSIONS: We present the research priorities identified by the PEACE expert panel after a systematic review of existing evidence informing clinical care of neonates and children managed with ECMO. More research is required within the five identified domains to ultimately inform and improve the care of this vulnerable population.


Assuntos
Anticoagulantes , Oxigenação por Membrana Extracorpórea , Oxigenação por Membrana Extracorpórea/métodos , Humanos , Anticoagulantes/uso terapêutico , Anticoagulantes/administração & dosagem , Criança , Recém-Nascido , Estado Terminal/terapia , Pesquisa Biomédica/métodos , Lactente , Pré-Escolar
9.
Immunity ; 57(7): 1648-1664.e9, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38876098

RESUMO

Allogeneic T cell expansion is the primary determinant of graft-versus-host disease (GVHD), and current dogma dictates that this is driven by histocompatibility antigen disparities between donor and recipient. This paradigm represents a closed genetic system within which donor T cells interact with peptide-major histocompatibility complexes (MHCs), though clonal interrogation remains challenging due to the sparseness of the T cell repertoire. We developed a Bayesian model using donor and recipient T cell receptor (TCR) frequencies in murine stem cell transplant systems to define limited common expansion of T cell clones across genetically identical donor-recipient pairs. A subset of donor CD4+ T cell clonotypes differentially expanded in identical recipients and were microbiota dependent. Microbiota-specific T cells augmented GVHD lethality and could target microbial antigens presented by gastrointestinal epithelium during an alloreactive response. The microbiota serves as a source of cognate antigens that contribute to clonotypic T cell expansion and the induction of GVHD independent of donor-recipient genetics.


Assuntos
Doença Enxerto-Hospedeiro , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/microbiologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T CD4-Positivos/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Microbiota/imunologia , Seleção Clonal Mediada por Antígeno , Transplante Homólogo , Teorema de Bayes , Transplante de Células-Tronco/efeitos adversos , Camundongos Endogâmicos BALB C , Microbioma Gastrointestinal/imunologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos
10.
Polymers (Basel) ; 16(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38891509

RESUMO

Abattoirs dispose of sheepskins as solid waste due to low price and poor demand for sheepskin leather. In principle, as an alternative to being disposed of in landfill, sheepskins can serve as a source of the protein collagen or the hydrolysis product, gelatin. In this research, sheepskins collected from abattoirs were used as a source of collagen. Three extraction methods were compared: acid extraction, acid with enzymes, and alkali extraction. The extracted material was characterized using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR), small angle X-ray scattering (SAXS), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The collagen and gelatin extraction yield ranged from 3.1% to 4.8% with the product purity determined by hydroxyproline, ranging from 7.8% for the alkali process to 59% and 68% for the acid and acid-enzyme processes. SDS PAGE showed that the acid process produced fragments with molecular weights in the range 100 to >250 kDa, while acid-enzyme resulted in smaller fragments, below 30 kDa. The FTIR region of the amide I band at 1800-1550 cm-1, which was used as an indicator of the collagen and gelatin content, showed that the gelatin dominated in the acid extracts, and the alkaline extract contained a large portion of keratin. SAXS was found to be a sensitive method for showing the presence of intact collagen fibrils in materials from all of the extraction methods, albeit at low concentrations. Herein, sheepskin is shown to be a useful source for collagen-gelatin material of varying molecular weights.

13.
Foods ; 13(12)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38928732

RESUMO

Despite the numerous sensory, organoleptic and nutritional qualities, fish meat may also contain some toxic compounds with negative effects on human health. Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals resulting from incomplete combustion, found at high levels in thermally processed foods, especially in smoked fish. This research studied the influence of wood type (beech, plum and oak) and fish species (rainbow trout, carp and Siberian sturgeon) on PAH contamination in hot smoked fish. Benzo(a)Piren, Σ4PAHs and Σ15PAHs were considered as main indicators of PAH contamination. All-PAHs was quantified in all samples, indicating a specific dynamic of values due to the influence of variables. Generally, BaP (benzo(a)pyrene) content in the samples ranged from 0.11 µg/kg to 8.63 µg/kg, Σ4PAHs from 0.70 µg/kg to 45.24 µg/kg and Σ15PAHs from 17.54 µg/kg to 450.47 µg/kg. Thus, plum wood promoted the highest levels of PAHs, followed by oak and beech. Carp and Siberian sturgeon presented the highest concentrations of PAHs. Some of these parameters had levels that exceeded the limits allowed by legislation via Commission Regulation (EU) No 835/2011. Results revealed BaP levels > 2 µg/kg when plum wood was used in rainbow trout (4.04 µg/kg), carp (4.47 µg/kg) and Siberian sturgeon (8.63 µg/kg). Moreover, the same trend was found for Σ4PAHs, which exceeded 12 µg/kg in rainbow trout (17.57 µg/kg), carp (45.24 µg/kg) and Siberian sturgeon (44.97 µg/kg).

14.
Nutrients ; 16(12)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38931303

RESUMO

Consumers often cite cognitive improvements as reasons for making dietary changes or using dietary supplements, a motivation that if leveraged could greatly enhance public health. However, rarely is it considered whether standardized cognitive tests that are used in nutrition research are aligned to outcomes of interest to the consumer. This knowledge gap presents a challenge to the scientific substantiation of nutrition-based cognitive health benefits. Here we combined focus group transcript review using reflexive thematic analysis and a multidisciplinary expert panel exercise to evaluate the applicability of cognitive performance tools/tasks for substantiating the specific cognitive benefits articulated by consumers with the objectives to (1) understand how consumers comprehend the potential benefits of nutrition for brain health, and (2) determine the alignment between consumers desired brain benefits and validated tests and tools. We derived a 'Consumer Taxonomy of Cognitive and Affective Health in Nutrition Research' which describes the cognitive and affective structure from the consumers perspective. Experts agreed that validated tests exist for some consumer benefits including focused attention, sustained attention, episodic memory, energy levels, and anxiety. Prospective memory, flow, and presence represented novel benefits that require the development and validation of new tests and tools. Closing the gap between science and consumers and fostering co-creative approaches to nutrition research are critical to the development of products and dietary recommendations that support realizable cognitive benefits that benefit public health.


Assuntos
Encéfalo , Cognição , Suplementos Nutricionais , Humanos , Encéfalo/fisiologia , Comportamento do Consumidor , Grupos Focais
15.
BMJ Open Diabetes Res Care ; 12(3)2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937276

RESUMO

INTRODUCTION: We previously reported predictors of mortality in 1786 adults with diabetes or stress hyperglycemia (glucose>180 mg/dL twice in 24 hours) admitted with COVID-19 from March 2020 to February 2021 to five university hospitals. Here, we examine predictors of readmission. RESEARCH DESIGN AND METHODS: Data were collected locally through retrospective reviews of electronic medical records from 1786 adults with diabetes or stress hyperglycemia who had a hemoglobin A1c (HbA1c) test on initial admission with COVID-19 infection or within 3 months prior to initial admission. Data were entered into a Research Electronic Data Capture (REDCap) web-based repository, and de-identified. Descriptive data are shown as mean±SD, per cent (%) or median (IQR). Student's t-test was used for comparing continuous variables with normal distribution and Mann-Whitney U test was used for data not normally distributed. X2 test was used for categorical variable. RESULTS: Of 1502 patients who were alive after initial hospitalization, 19.4% were readmitted; 90.3% within 30 days (median (IQR) 4 (0-14) days). Older age, lower estimated glomerular filtration rate (eGFR), comorbidities, intensive care unit (ICU) admission, mechanical ventilation, diabetic ketoacidosis (DKA), and longer length of stay (LOS) during the initial hospitalization were associated with readmission. Higher HbA1c, glycemic gap, or body mass index (BMI) were not associated with readmission. Mortality during readmission was 8.0% (n=23). Those who died were older than those who survived (74.9±9.5 vs 65.2±14.4 years, p=0.002) and more likely had DKA during the first hospitalization (p<0.001). Shorter LOS during the initial admission was associated with ICU stay during readmission, suggesting that a subset of patients may have been initially discharged prematurely. CONCLUSIONS: Understanding predictors of readmission after initial hospitalization for COVID-19, including older age, lower eGFR, comorbidities, ICU admission, mechanical ventilation, statin use and DKA but not HbA1c, glycemic gap or BMI, can help guide treatment approaches and future research in adults with diabetes.


Assuntos
COVID-19 , Diabetes Mellitus , Hemoglobinas Glicadas , Hiperglicemia , Readmissão do Paciente , SARS-CoV-2 , Humanos , COVID-19/mortalidade , COVID-19/complicações , Readmissão do Paciente/estatística & dados numéricos , Masculino , Feminino , Hiperglicemia/mortalidade , Hiperglicemia/epidemiologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Idoso , Hemoglobinas Glicadas/análise , Diabetes Mellitus/mortalidade , Diabetes Mellitus/epidemiologia , Hospitalização/estatística & dados numéricos , Adulto , Fatores de Risco , Idoso de 80 Anos ou mais , Glicemia/análise
16.
Prev Med ; 185: 108039, 2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38862030

RESUMO

This study examines the association between Afghan women's autonomy (WA) and experience of domestic violence (physical, sexual, and emotional) in the previous 12 months, and whether this association is moderated by education status. We used data from 19,098 married women aged 15-49, who completed the 2015 Afghanistan Demographic and Health Survey- the first and only national survey administered in the country. WA was measured across 5 domains (healthcare, visiting family, household purchases, spending, and contraceptive use). Adjusted odds ratios and 95% confidence intervals for the association between domestic violence in the past 12 months (any vs. none) and WA were estimated using multiple logistic regression and adjusted for covariates. Interaction terms between education status and WA were also assessed. We found that the experience of physical, emotional, and sexual violence was 45% 30%, and 7%, and at least 1 in 2 had no autonomy. After adjustment, compared to women without autonomy, WA in healthcare decisions, spending, visiting families, and household purchases significantly decreased the odds of physical violence. Similarly, WA in healthcare decisions and spending significantly decreased the odds of sexual violence. Lastly, WA in spending and not using contraception was associated with reduced odds of emotional violence. We also found a greater protective effect of WA in visiting family among women with any education across each domestic violence outcome. These findings provide insights into areas for intervention to address gender inequalities (Sustainable Development Goal 3) and mitigate adverse health outcomes for mothers and their children (Goal 5).

17.
Curr Opin Obstet Gynecol ; 36(4): 324-329, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38837721

RESUMO

PURPOSE OF REVIEW: Climate change has immediate impacts on women's health. Hospitals and operating rooms are large contributors to greenhouse gas (GHG) emissions and waste. This article will review current green initiatives designed to minimize environmental impact in the operating room and highlight areas for future improvement. RECENT FINDINGS: From a materials perspective, reusable goods result in less GHG emissions while being just as efficacious, well tolerated, and easy to use. Materials should be opened judiciously, only as necessary. Processing regulated medical waste produces greater GHG emissions, so waste should be properly sorted, and items which are not biohazard waste should be processed separately. Choosing appropriate anesthesia and utilizing an 'off' setting, in which operating rooms are shut down when not in use, can also drastically decrease the environmental impact of surgery. Further research is needed to determine effective implementation in hospitals. SUMMARY: This article summarizes current attempts to make operating rooms more sustainable. Many practices result in a decreased carbon footprint and cost savings without adversely affecting patient outcomes. Gynecologic surgeons and the hospitals in which they practice need to focus on implementing these changes in a timely fashion.


Assuntos
Pegada de Carbono , Gases de Efeito Estufa , Salas Cirúrgicas , Humanos , Feminino , Procedimentos Cirúrgicos em Ginecologia , Mudança Climática , Resíduos de Serviços de Saúde/prevenção & controle , Ginecologia , Conservação dos Recursos Naturais , Eliminação de Resíduos de Serviços de Saúde/métodos
18.
bioRxiv ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38854150

RESUMO

Piezo1 is a mechanically activated ion channel that senses forces with short latency and high sensitivity. Piezos undergo large conformational changes, induce far-reaching deformation onto the membrane, and modulate the function of two-pore potassium (K2P) channels. Taken together, this led us to hypothesize that Piezos may be able to signal their conformational state to other nearby proteins. Here, we use chemical control to acutely restrict Piezo1 conformational flexibility and show that Piezo1 conformational changes, but not ion permeation through it, are required for modulating the K2P channel TREK1. Super-resolution imaging and stochastic simulations further reveal that both channels do not co-localize, which implies that modulation is not mediated through direct binding interactions; however, at high Piezo1 densities, most TREK1 channels are within the predicted Piezo1 membrane footprint, suggesting the footprint may underlie conformational signaling. We speculate that physiological roles originally attributed to Piezo1 ionotropic function could, alternatively, involve conformational signaling.

19.
DNA Repair (Amst) ; 140: 103700, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38897003

RESUMO

Mutations in isocitrate dehydrogenase isoform 1 (IDH1) are primarily found in secondary glioblastoma (GBM) and low-grade glioma but are rare in primary GBM. The standard treatment for GBM includes radiation combined with temozolomide, an alkylating agent. Fortunately, IDH1 mutant gliomas are sensitive to this treatment, resulting in a more favorable prognosis. However, it's estimated that up to 75 % of IDH1 mutant gliomas will progress to WHO grade IV over time and develop resistance to alkylating agents. Therefore, understanding the mechanism(s) by which IDH1 mutant gliomas confer sensitivity to alkylating agents is crucial for developing targeted chemotherapeutic approaches. The base excision repair (BER) pathway is responsible for repairing most base damage induced by alkylating agents. Defects in this pathway can lead to hypersensitivity to these agents due to unresolved DNA damage. The coordinated assembly and disassembly of BER protein complexes are essential for cell survival and for maintaining genomic integrity following alkylating agent exposure. These complexes rely on poly-ADP-ribose formation, an NAD+-dependent post-translational modification synthesized by PARP1 and PARP2 during the BER process. At the lesion site, poly-ADP-ribose facilitates the recruitment of XRCC1. This scaffold protein helps assemble BER proteins like DNA polymerase beta (Polß), a bifunctional DNA polymerase containing both DNA synthesis and 5'-deoxyribose-phosphate lyase (5'dRP lyase) activity. Here, we confirm that IDH1 mutant glioma cells have defective NAD+ metabolism, but still produce sufficient nuclear NAD+ for robust PARP1 activation and BER complex formation in response to DNA damage. However, the overproduction of 2-hydroxyglutarate, an oncometabolite produced by the IDH1 R132H mutant protein, suppresses BER capacity by reducing Polß protein levels. This defines a novel mechanism by which the IDH1 mutation in gliomas confers cellular sensitivity to alkylating agents and to inhibitors of the poly-ADP-ribose glycohydrolase, PARG.


Assuntos
DNA Polimerase beta , Glutaratos , Isocitrato Desidrogenase , DNA Polimerase beta/metabolismo , Humanos , Isocitrato Desidrogenase/metabolismo , Isocitrato Desidrogenase/genética , Glutaratos/metabolismo , Linhagem Celular Tumoral , Reparo do DNA , Antineoplásicos Alquilantes/farmacologia , Temozolomida/farmacologia , Mutação , Glioma/metabolismo , Glioma/genética , Glioma/tratamento farmacológico , Alquilantes/farmacologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Dano ao DNA
20.
J Clin Endocrinol Metab ; 109(8): 1948-1954, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38828961

RESUMO

A long-held precept is that vitamin D supplementation primarily, if not exclusively, benefits individuals with low circulating 25-hydroxyvitamin D (25[OH]D) concentrations at baseline. However, the most appropriate 25(OH)D threshold to distinguish unacceptably low vs reliably adequate concentrations remains controversial. Such threshold proposals have largely been based on observational studies, which provide less robust evidence compared to randomized clinical trials (RCTs). Since the Endocrine Society's first vitamin D-related guideline was published in 2011, several large vitamin D-related RCTs have been published, and a newly commissioned guideline development panel (GDP) prioritized 4 clinical questions related to the benefits and harms of vitamin D supplementation in generally healthy individuals with 25(OH)D levels below a threshold. The GDP determined that available clinical trial evidence does not permit the establishment of 25(OH)D thresholds that specifically predict meaningful benefit with vitamin D supplementation. The panel noted important limitations in the available evidence, and the panel's overall certainty in the available evidence was very low. Nonetheless, based on the GDP's analyses and judgments, the Endocrine Society no longer endorses its previously proposed definition of vitamin D "sufficiency" (ie, at least 30 ng/mL [75 nmol/L]) or its previously proposed definition of vitamin D "insufficiency" (ie, greater than 20 ng/mL [50 nmol/L] but lower than 30 ng/mL [75 nmol/L]). The Endocrine Society's rationale for such is the subject of this Guideline Communication.

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