Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
1.
Pediatr Res ; 94(2): 564-574, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36650307

RESUMO

BACKGROUND: Although investigations have begun to differentiate biological and neurobiological responses to a variety of adversities, studies considering both endocrine and immune function in the same datasets are limited. METHODS: Associations between proximal (family functioning, caregiver depression, and anxiety) and distal (SES-D; socioeconomic disadvantage) early-life adversities with salivary inflammatory biomarkers (IL-1ß, IL-6, IL-8, and TNF-α) and hair HPA markers (cortisol, cortisone, and dehydroepiandrosterone) were examined in two samples of young U.S. children (N = 142; N = 145). RESULTS: Children exposed to higher SES-D had higher levels of TNF-α (B = 0.13, p = 0.011), IL-1ß (B = 0.10, p = 0.033), and DHEA (B = 0.16, p = 0.011). Higher family dysfunction was associated with higher cortisol (B = 0.08, p = 0.033) and cortisone (B = 0.05, p = 0.003). An interaction between SES-D and family dysfunction was observed for cortisol levels (p = 0.020) whereby children exposed to lower/average levels of SES-D exhibited a positive association between family dysfunction and cortisol levels, whereas children exposed to high levels of SES-D did not. These findings were partially replicated in the second sample. CONCLUSIONS: Our results indicate that these biological response systems may react differently to different forms of early-life adversity. IMPACT: Different forms of early-life adversity have varied stress signatures, and investigations of early-life adversities with inflammation and HPA markers are lacking. Children with higher socioeconomic disadvantage had higher TNF-α, IL-1ß, and DHEA. Higher family dysfunction was associated with higher hair cortisol and cortisone levels, and the association between family dysfunction and cortisol was moderated by socioeconomic disadvantage. Biological response systems (immune and endocrine) were differentially associated with distinct forms of early-life adversities.


Assuntos
Cortisona , Hidrocortisona , Humanos , Criança , Fator de Necrose Tumoral alfa , Estresse Psicológico , Saliva , Sistema Hipotálamo-Hipofisário , Sistema Hipófise-Suprarrenal , Desidroepiandrosterona
2.
Pacing Clin Electrophysiol ; 46(9): 1141-1144, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36790011

RESUMO

Effective rate-adaptive pacing may be difficult in the presence of atrial fibrillation (AF), and is important during high-intensity exercise. This case presents a 74-year-old elite cyclist with AF and a biventricular pacemaker after atrioventricular (AV) node ablation. He reported sudden breathlessness due to heart rate drops, caused by breaching the artefact threshold on the minute-ventilation sensor. He was exchanged to a generator with an impedance-derived contractility sensor (closed-loop stimulation), resulting in resolution of symptoms, and no further rate drops. This is the first description of the utility of closed-loop stimulation in high-intensity exercise.


Assuntos
Fibrilação Atrial , Marca-Passo Artificial , Masculino , Humanos , Idoso , Impedância Elétrica , Frequência Cardíaca/fisiologia , Fibrilação Atrial/cirurgia , Estimulação Cardíaca Artificial/métodos
3.
Proc Natl Acad Sci U S A ; 117(50): 31789-31799, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33268495

RESUMO

Current approaches for the production of high-value compounds in microorganisms mostly use the cytosol as a general reaction vessel. However, competing pathways and metabolic cross-talk frequently prevent efficient synthesis of target compounds in the cytosol. Eukaryotic cells control the complexity of their metabolism by harnessing organelles to insulate biochemical pathways. Inspired by this concept, herein we transform yeast peroxisomes into microfactories for geranyl diphosphate-derived compounds, focusing on monoterpenoids, monoterpene indole alkaloids, and cannabinoids. We introduce a complete mevalonate pathway in the peroxisome to convert acetyl-CoA to several commercially important monoterpenes and achieve up to 125-fold increase over cytosolic production. Furthermore, peroxisomal production improves subsequent decoration by cytochrome P450s, supporting efficient conversion of (S)-(-)-limonene to the menthol precursor trans-isopiperitenol. We also establish synthesis of 8-hydroxygeraniol, the precursor of monoterpene indole alkaloids, and cannabigerolic acid, the cannabinoid precursor. Our findings establish peroxisomal engineering as an efficient strategy for the production of isoprenoids.


Assuntos
Engenharia Metabólica/métodos , Peroxissomos/metabolismo , Saccharomyces cerevisiae/metabolismo , Terpenos/metabolismo , Aldose-Cetose Isomerases/genética , Aldose-Cetose Isomerases/metabolismo , Difosfatos/metabolismo , Diterpenos/metabolismo , Microbiologia Industrial/métodos , Liases Intramoleculares/genética , Liases Intramoleculares/metabolismo , Redes e Vias Metabólicas/genética , Ácido Mevalônico/metabolismo , Peroxissomos/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Biologia Sintética/métodos
4.
Am J Perinatol ; 40(13): 1446-1453, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-34674212

RESUMO

OBJECTIVE: The objective of this study was to determine the degree of progressive posthemorrhagic ventricular dilatation (PHVD) that is associated with a significant decrease in regional cerebral oxygen saturation (rScO2) in premature infants at risk for periventricular-intraventricular hemorrhage (PIVH). STUDY DESIGN: Cranial ultrasound (US) and near-infrared spectroscopy (NIRS) measurements of rScO2 were performed on inborn infants with birth weights less than 1,250 g on admission and at 1, 4, and 8 weeks of age. Infants with severe PIVH were studied weekly. A 1-hour average of rScO2 was compared with the frontal-occipital horn ratio (FOHR) measured the same day. Generalized linear models were used to analyze the relationship between FOHR and rScO2, by severity of PIVH, and adjusted for gestational age. Cut-off points of 0.55 for FOHR and 45% for rScO2 were used to calculate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The study cohort included 63 infants with normal US, 15 with grade-1 or -2 PIVH (mild group), and 21 with grade-3 or -4 PIVH (severe group). Increases in FOHR in the severe group were associated with decreases in rScO2 at 1 week (p = 0.036), 4 weeks (p = 0.013), and 8 weeks of life (p = 0.001) compared with the normal and mild groups. Infants with FOHR greater than 0.55 were 92% more likely to have rScO2 less than 45% when compared with infants with FOHR less than 0.55 (OR = 0.08, 95% CI: [0.04, 0.13], p < 0.001). CONCLUSION: Progressive PHVD (FOHR > 0.55) is a strong predictor of compromised cerebral oxygenation. A combination of rScO2 and FOHR measurements may aid in identifying infants with PHVD that would benefit from early intervention. KEY POINTS: · Earlier intervention in PHVD may improve outcomes.. · PHVD is diagnosed with US measurements of ventricular size.. · FOHR > 0.55 is associated with decreased cerebral perfusion..


Assuntos
Hidrocefalia , Doenças do Prematuro , Recém-Nascido , Lactente , Humanos , Dilatação , Recém-Nascido Prematuro , Hidrocefalia/complicações , Idade Gestacional , Hemorragia Cerebral/diagnóstico por imagem
7.
J Allergy Clin Immunol ; 141(3): 1036-1049.e5, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29241729

RESUMO

BACKGROUND: Immunodysregulation polyendocrinopathy enteropathy x-linked (IPEX) syndrome is a monogenic autoimmune disease caused by FOXP3 mutations. Because it is a rare disease, the natural history and response to treatments, including allogeneic hematopoietic stem cell transplantation (HSCT) and immunosuppression (IS), have not been thoroughly examined. OBJECTIVE: This analysis sought to evaluate disease onset, progression, and long-term outcome of the 2 main treatments in long-term IPEX survivors. METHODS: Clinical histories of 96 patients with a genetically proven IPEX syndrome were collected from 38 institutions worldwide and retrospectively analyzed. To investigate possible factors suitable to predict the outcome, an organ involvement (OI) scoring system was developed. RESULTS: We confirm neonatal onset with enteropathy, type 1 diabetes, and eczema. In addition, we found less common manifestations in delayed onset patients or during disease evolution. There is no correlation between the site of mutation and the disease course or outcome, and the same genotype can present with variable phenotypes. HSCT patients (n = 58) had a median follow-up of 2.7 years (range, 1 week-15 years). Patients receiving chronic IS (n = 34) had a median follow-up of 4 years (range, 2 months-25 years). The overall survival after HSCT was 73.2% (95% CI, 59.4-83.0) and after IS was 65.1% (95% CI, 62.8-95.8). The pretreatment OI score was the only significant predictor of overall survival after transplant (P = .035) but not under IS. CONCLUSIONS: Patients receiving chronic IS were hampered by disease recurrence or complications, impacting long-term disease-free survival. When performed in patients with a low OI score, HSCT resulted in disease resolution with better quality of life, independent of age, donor source, or conditioning regimen.


Assuntos
Diabetes Mellitus Tipo 1/congênito , Diarreia , Fatores de Transcrição Forkhead , Doenças Genéticas Ligadas ao Cromossomo X , Transplante de Células-Tronco Hematopoéticas , Doenças do Sistema Imunitário/congênito , Terapia de Imunossupressão , Mutação , Adolescente , Adulto , Aloenxertos , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/mortalidade , Diabetes Mellitus Tipo 1/terapia , Diarreia/genética , Diarreia/imunologia , Diarreia/mortalidade , Diarreia/terapia , Intervalo Livre de Doença , Feminino , Seguimentos , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/imunologia , Doenças Genéticas Ligadas ao Cromossomo X/mortalidade , Doenças Genéticas Ligadas ao Cromossomo X/terapia , Humanos , Doenças do Sistema Imunitário/genética , Doenças do Sistema Imunitário/imunologia , Doenças do Sistema Imunitário/mortalidade , Doenças do Sistema Imunitário/terapia , Lactente , Masculino , Estudos Retrospectivos , Taxa de Sobrevida
10.
Psychosom Med ; 78(9): 998-1007, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27551989

RESUMO

OBJECTIVE: We tested the hypothesis that socioeconomic status (SES) would predict children's physical health problems at the end of kindergarten among children whose parent reported greater parent-child relationship (PCR) negativity and/or who exhibited greater parasympathetic (RSA) reactivity. We also tested whether RSA and PCR negativity mediated the SES-health association. METHODS: Data were collected from 338 children (mean [SD] age, 5.32 [.32] years) and their primary caregivers (87% biological mothers) during the fall and subsequent spring of kindergarten. In the fall, parents reported income and education level (SES) and PCR negativity, and RSA reactivity was assessed via a standardized challenge protocol for young children. In the fall and then spring, parents reported children's chronic medical conditions and physical health impairments. Multivariate regression was conducted within a structural equation-modeling framework to test hypotheses. RESULTS: Significant interactions were found between SES and PCR negativity (b = -0.074, p = .035) and between SES and RSA reactivity (b = 0.169, p = .019) as predicts children's spring health impairment, adjusting for health in the preceding fall. Lower SES was associated with greater health impairment among children whose parents reported more PCR negativity (b = -0.110, p = .024) and children who showed greater RSA reactivity (b = -0.106, p = .011). Socioeconomic status was unrelated to physical health at low PCR negativity or RSA reactivity. Mediation models were not supported. CONCLUSION: Parent-child relationship quality and individual differences in stress reactivity may modulate the influence of SES on physical health in childhood.


Assuntos
Afeto/fisiologia , Desenvolvimento Infantil/fisiologia , Nível de Saúde , Sistema Nervoso Parassimpático/fisiologia , Relações Pais-Filho , Arritmia Sinusal Respiratória/fisiologia , Classe Social , Estresse Psicológico/fisiopatologia , Criança , Pré-Escolar , Conflito Psicológico , Escolaridade , Feminino , Humanos , Estudos Longitudinais , Masculino
11.
J Transl Med ; 12: 181, 2014 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-24962100

RESUMO

BACKGROUND: Therapeutic hypothermia is a treatment modality that is increasingly used to improve clinical neurological outcomes for ischemia-reperfusion injury-mediated diseases. Antibody-initiated classical complement pathway activation has been shown to contribute to ischemia-reperfusion injury in multiple disease processes. However, how therapeutic hypothermia affects complement activation is unknown. Our goal was to measure the independent effect of temperature on complement activation, and more specifically, examine the relationship between clinical hypothermia temperatures (31-33°C), and complement activation. METHODS: Antibody-sensitized erythrocytes were used to assay complement activation at temperatures ranging from 0-41°C. Individual complement pathway components were assayed by ELISA, Western blot, and quantitative dot blot. Peptide Inhibitor of complement C1 (PIC1) was used to specifically inhibit activation of C1. RESULTS: Antibody-initiated complement activation resulting in eukaryotic cell lysis was increased by 2-fold at 31°C compared with 37°C. Antibody-initiated complement activation in human serum increased as temperature decreased from 37°C until dramatically decreasing at 13°C. Quantitation of individual complement components showed significantly increased activation of C4, C3, and C5 at clinical hypothermia temperatures. In contrast, C1s activation by heat-aggregated IgG decreased at therapeutic hypothermia temperatures consistent with decreased enzymatic activity at lower temperatures. However, C1q binding to antibody-coated erythrocytes increased at lower temperatures, suggesting that increased classical complement pathway activation is mediated by increased C1 binding at therapeutic hypothermia temperatures. PIC1 inhibited hypothermia-enhanced complement-mediated cell lysis at 31°C by up to 60% (P = 0.001) in a dose dependent manner. CONCLUSIONS: In summary, therapeutic hypothermia temperatures increased antibody-initiated complement activation and eukaryotic cell destruction suggesting that the benefits of therapeutic hypothermia may be mediated via other mechanisms. Antibody-initiated complement activation has been shown to contribute to ischemia-reperfusion injury in several animal models, suggesting that for diseases with this mechanism hypothermia-enhanced complement activation may partially attenuate the benefits of therapeutic hypothermia.


Assuntos
Ativação do Complemento , Hipotermia/fisiopatologia , Temperatura , Ensaio de Imunoadsorção Enzimática , Humanos , Hipotermia/metabolismo , Hipotermia/patologia , Ligação Proteica
12.
Neurourol Urodyn ; 33(5): 493-501, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23908139

RESUMO

AIMS: This aim of this study is to identify the brain mechanisms involved in bladder control. METHODS: We used fMRI to identify brain regions that are activated during bladder filling. We then used resting state connectivity fMRI (rs-fcMRI) to assess functional connectivity of regions identified by fMRI with the rest of the brain as the bladder is filled to capacity. RESULTS: Female participants (n = 20) were between ages 40 and 64 with no significant history of symptomatic urinary incontinence. Main effect of time (MET) fMRI analysis resulted in 20 regions of interest (ROIs) that have significant change in BOLD signal (z = 3.25, P <0.05) over the course of subtle bladder filling and emptying regardless of full versus empty bladder state. Bladder-state by time (BST) fMRI analysis resulted in three ROIs that have significant change in BOLD signal (z = 3.25, P <0.05) over the course of bladder runs comparing full versus empty bladder state. Rs-fcMRI fixed effects analysis identified significant changes in connectivity between full and empty bladder states in seven brain regions (z = 4.0) using the three BST ROIs and sixteen brain regions (z = 7) using the twenty MET ROIs. Regions identified include medial frontal gyrus, posterior cingulate (PCC), inferiolateral temporal and post-central gyrus, amygdale, the caudate, inferior parietal lobe as well as anterior and middle cingulate gyrus. CONCLUSIONS: There is significant and vast changes in the brain's functional connectivity when bladder is filled suggesting that the central process responsible for the increased control during the full bladder state appears to largely rely on the how distributed brain systems are functionally integrated.


Assuntos
Encéfalo/fisiologia , Vias Neurais/fisiologia , Bexiga Urinária/fisiologia , Adulto , Tonsila do Cerebelo/fisiologia , Mapeamento Encefálico , Núcleo Caudado/fisiologia , Feminino , Neuroimagem Funcional , Giro do Cíngulo/fisiologia , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Lobo Parietal/fisiologia , Córtex Pré-Frontal/fisiologia , Lobo Temporal/fisiologia
14.
Traffic Inj Prev ; 25(3): 249-267, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38436586

RESUMO

OBJECTIVE: The objective of this paper is to provide a history of the National Highway Traffic Safety Administration's (NHTSA's) extensive efforts of incorporating advanced airbag technology capability beyond that available in first-generation airbag systems into FMVSS No. 208. METHODS: In the paper, NHTSA's actions and their collaborative efforts with automakers, automaker suppliers, insurance industry, academia, and other Federal agencies were reviewed, and the key efforts have been highlighted. Through their efforts, NHTSA developed its strategy by first undertaking near term actions and then undertaking the strategy for longer term actions. Rulemaking was undertaken in three steps. Then, as sufficient data became available, NHTSA documented the effectiveness of the rulemakings. RESULTS: The approach taken by NHTSA with the goal of preserving the safety benefits of the first-generation of frontal airbags while minimizing their danger to children and at-risk adults paved the way for the advanced airbags final rule and an interim final rule issued on May 12, 2000 (see Federal Register Notice 65 FR 30680). A follow-up final rule was issued on August 31, 2006, to change the test speed of the belted 5th percentile female dummy from 48 km/h to 56 km/h (30 mph to 35 mph). The final rule was updated on November 2, 2007, to permit manufacturers to earn advance credits for vehicles that are certified in compliance with the new higher speed requirement one year in advance of the regulatory requirements. CONCLUSION: NHTSA engagement in efforts with multiple partners toward identifying the safety issues, was an integral part of NHTSA's strategy in addressing the problem, arriving at immediate actions that NHTSA took, and detailing a comprehensive look at the longer-term approach required to resolve the safety issues. The approach taken by NHTSA paved the way for the advanced airbags final rule and an interim final rule issued on May 12, 2000 (Federal Register Notice 65 FR 30680). NHTSA had undertaken a successful collaboration of the Federal Government, the automobile industry, equipment suppliers, insurance companies, traffic safety advocates, law enforcement agencies from across the country, and the media to solve the airbag related safety issue.


Assuntos
Air Bags , Adulto , Criança , Feminino , Humanos , Acidentes de Trânsito , Automóveis
15.
Front Med (Lausanne) ; 11: 1380632, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39219790

RESUMO

Hypertension affects an estimated 1.3 billion people worldwide and is considered the number one contributor to mortality via stroke, heart failure, renal failure, and dementia. Although the physiologic mechanisms leading to the development of essential hypertension are poorly understood, the regulation of cerebral perfusion has been proposed as a primary cause. This article proposes a novel etiology for essential hypertension. Our hypothesis developed from a review of nuclear medicine scans, where the authors observed a significantly abnormal increase in nasal turbinate vasodilation in hypertensive patients using quantitative region of interest analysis. The authors propose that nasal turbinate vasodilation and resultant blood pooling obstruct the flow of cerebrospinal fluid passing through nasal turbinate lymphatics, thereby increasing intracranial pressure. The authors discuss the glymphatic/lymphatic clearance system which is impaired with age, and at which time hypertension also develops. The increased intracranial pressure leads to compensatory hypertension via Cushing's mechanism, i.e., the selfish brain hypothesis. The nasal turbinate vasodilation, due to increased parasympathetic activity, occurs simultaneously along with the well-established increased sympathetic activity of the cardiovascular system. The increased parasympathetic activity is likely due to an autonomic imbalance secondary to the increase in worldwide consumption of processed food. This hypothesis explains the rapid worldwide rise in essential hypertension in the last 50 years and offers a novel mechanism and a new paradigm for the etiology of essential hypertension. This new paradigm offers compelling evidence for the modulation of parasympathetic nervous system activity as a novel treatment strategy, specifically targeting nasal turbinate regulation, to treat diseases such as hypertension, idiopathic intracranial hypertension, and degenerative brain diseases. The proposed mechanism of essential hypertension presented in this paper is a working hypothesis and confirmatory studies will be needed.

16.
Synapse ; 67(10): 678-91, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23564259

RESUMO

N-[(4-trifluoromethyl) benzyl] 4-methoxybutyramide (GET73) is a newly synthesized compound displaying anti-alcohol and anxiolytic properties. In light of the importance of the hippocampal CA1 subregion in alcohol addiction and anxiety-like behaviors-this in vivo microdialysis study characterized the effect of GET73 on extracellular GABA levels in the hippocampal CA1 region of the freely moving rat-including a possible role for mGlu5 receptor in mediating this effect. Both intraperitoneal administration (2-10 mg/kg) and local intra-hippocampal CA1 perfusion with GET73 (50-1000 nM) were associated with a transient, step-wise increase in dialysate hippocampal CA1 GABA levels. The GET73 (10 mg/kg)-induced increase in GABA levels was not affected by intra-CA1 perfusion with either the GABA reuptake inhibitor SKF89976A (0.5 mM) or by local GABAA (bicuculline; 1µM) and GABAB (CGP35348; 500 µM) receptor antagonists. On the contrary, the GET73-induced increase in GABA levels was partially counteracted by the intra-CA1 perfusion with the mGlu5 receptor negative allosteric modulator MPEP (300 µM). Interestingly, GET73 at the lowest (2 mg/kg) dose tested, by itself ineffective, fully counteracted the increase in GABA levels induced by the mGlu5 receptor agonist CHPG (1000 µM). Taken together, these findings suggest that the GET73-induced increase in hippocampal CA1 GABA levels operates independently of local GABA reuptake and/or GABAA or GABAB receptors. Furthermore, the present data lead to hypothesize a possible interaction between GET73 and mGluR5-mediated regulation of hippocampal CA1 GABA transmission, an effect which may be relevant to the ability of GET73 to reduce alcohol intake in an alcohol-preferring rat strain.


Assuntos
Anilidas/farmacologia , Ansiolíticos/farmacologia , Região CA1 Hipocampal/efeitos dos fármacos , Espaço Extracelular/metabolismo , Receptor de Glutamato Metabotrópico 5/metabolismo , Ácido gama-Aminobutírico/metabolismo , Anilidas/administração & dosagem , Animais , Ansiolíticos/administração & dosagem , Região CA1 Hipocampal/metabolismo , Inibidores da Captação de GABA/farmacologia , Antagonistas de Receptores de GABA-A/farmacologia , Antagonistas de Receptores de GABA-B/farmacologia , Injeções Intraperitoneais , Injeções Intraventriculares , Masculino , Ratos , Ratos Sprague-Dawley
17.
Eur J Obstet Gynecol Reprod Biol ; 289: 74-78, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37639818

RESUMO

BACKGROUND/AIMS: The effect of pregnancy on gastric emptying has not been established, although the predominant clinical assumption is that gastric emptying is delayed during pregnancy. We hypothesized that the rate of emptying of nutrients during pregnancy is not delayed, but is actually more rapid when compared to the non-pregnant state. The rate of gastric emptying is a major determinant of postprandial glucose elevations. MATERIALS AND METHODS: 24 female and 4 male Spague-Dawley rats were used. Female rats were randomly divided into two groups: eight rats for the control group and sixteen rats for the pregnant group. Using physiologic, non-traumatic nuclear medicine scintigraphy imaging methodology, the authors studied gastric emptying of a liquid mixed meal in pregnant rats and non-pregnant controls. Body weights, daily food ingestion, and the rate of nutrient gastric emptying were recorded in both groups at pre-pregnancy, early pregnancy, and late pregnancy. RESULTS: The authors found that pregnancy in this rat model is associated with a 37-43% increased rate of nutrient gastric emptying from the stomach in late pregnancy as compared to non-pregnant control rats and pre-pregnancy rats. CONCLUSION: These findings contradict the current clinical assumption that gastric emptying is delayed in pregnancy. If further studies confirm a more rapid gastric emptying rate during human pregnancy, new therapies aimed at slowing the rate of nutrient absorption should be considered for the prevention and treatment of pregnancy-associated nausea, gestational diabetes, and other insulin-resistant pregnancy-associated states such as pre-eclampsia.


Assuntos
Diabetes Gestacional , Êmese Gravídica , Humanos , Animais , Ratos , Feminino , Masculino , Gravidez , Esvaziamento Gástrico , Peso Corporal , Cistografia , Glucose
18.
Cell Rep ; 42(10): 113142, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37742193

RESUMO

Hippocampus place cell discharge is temporally unreliable across seconds and days, and place fields are multimodal, suggesting an "ensemble cofiring" spatial coding hypothesis with manifold dynamics that does not require reliable spatial tuning, in contrast to hypotheses based on place field (spatial tuning) stability. We imaged mouse CA1 (cornu ammonis 1) ensembles in two environments across three weeks to evaluate these coding hypotheses. While place fields "remap," being more distinct between than within environments, coactivity relationships generally change less. Decoding location and environment from 1-s ensemble location-specific activity is effective and improves with experience. Decoding environment from cell-pair coactivity relationships is also effective and improves with experience, even after removing place tuning. Discriminating environments from 1-s ensemble coactivity relies crucially on the cells with the most anti-coactive cell-pair relationships because activity is internally organized on a low-dimensional manifold of non-linear coactivity relationships that intermittently reregisters to environments according to the anti-cofiring subpopulation activity.


Assuntos
Hipocampo , Células de Lugar , Camundongos , Animais , Região CA1 Hipocampal
19.
Nat Commun ; 14(1): 7265, 2023 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-37945568

RESUMO

The TMEM63 family proteins (A, B, and C), calcium-permeable channels in animals that are preferentially activated by hypo-osmolality, have been implicated in various physiological functions. Deficiency of these channels would cause many diseases including hearing loss. However, their structures and physiological roles are not yet well understood. In this study, we determine the cryo-electron microscopy (cryo-EM) structure of the mouse TMEM63C at 3.56 Å, and revealed structural differences compared to TMEM63A, TMEM63B, and the plant orthologues OSCAs. Further structural guided mutagenesis and calcium imaging demonstrated the important roles of the coupling of TM0 and TM6 in channel activity. Additionally, we confirm that TMEM63C exists primarily as a monomer under physiological conditions, in contrast, TMEM63B is a mix of monomer and dimer in cells, suggesting that oligomerization is a regulatory mechanism for TMEM63 proteins.


Assuntos
Canais de Cálcio , Cálcio , Animais , Camundongos , Microscopia Crioeletrônica , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Concentração Osmolar
20.
BMJ Case Rep ; 15(1)2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983813

RESUMO

Multiligament injury of the knee usually occurs as a result of high-energy trauma causing tibiofemoral dislocation. These are rare but potentially limb-threatening injuries, frequently involving nerve or arterial damage and often leading to severe complex instability. Management generally favours surgical reconstruction of the affected ligaments, with controversy regarding optimal treatment. We present a severe multiligament knee injury (Schenk classification KD-IV involving both cruciate and both collateral ligaments) in a competitive showjumper. A combined arthroscopic/open technique of single-stage surgical repair and suture augmentation was used, repairing all affected ligaments. The patient made an excellent recovery, returning to work after 12 weeks and riding after 22 weeks. After 5-year follow-up, she has regained her previous level of competition without subsequent injury. Multiligament repair with suture augmentation is a viable approach to the management of knee dislocation injuries. We propose that this could provide superior outcomes to traditional reconstruction techniques using autograft or synthetic reconstruction.


Assuntos
Lesões do Ligamento Cruzado Anterior , Ligamentos Colaterais , Luxação do Joelho , Traumatismos do Joelho , Lesões do Ligamento Cruzado Anterior/cirurgia , Feminino , Humanos , Luxação do Joelho/cirurgia , Traumatismos do Joelho/cirurgia , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Transplante Autólogo , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA