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1.
Pediatr Res ; 91(7): 1669-1676, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-32977326

RESUMEN

IMPACT: Institutional racism exists within Academic Pediatrics within the United States, and it affects our work as researchers, clinicians, and educators. Confronting institutional racism is a challenging life-long struggle for people of all races, but it should be part of the professional mission of all who work in Pediatrics. Creating a path to health equity for children in the United States will involve failure. We should not be daunted by that prospect.


Asunto(s)
Equidad en Salud , Racismo , Niño , Familia , Humanos , Investigadores , Resonancia por Plasmón de Superficie , Estados Unidos
2.
Int J Mol Sci ; 23(13)2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35806070

RESUMEN

The default mode network (DMN) plays an outstanding role in psychiatric disorders. Still, gene expressional changes in its major component, the dorsomedial prefrontal cortex (DMPFC), have not been characterized. We used RNA sequencing in postmortem DMPFC samples to investigate suicide victims compared to control subjects. 1400 genes differed using log2FC > ±1 and adjusted p-value < 0.05 criteria between groups. Genes associated with depressive disorder, schizophrenia and impaired cognition were strongly overexpressed in top differentially expressed genes. Protein−protein interaction and co-expressional networks coupled with gene set enrichment analysis revealed that pathways related to cytokine receptor signaling were enriched in downregulated, while glutamatergic synaptic signaling upregulated genes in suicidal individuals. A validated differentially expressed gene, which is known to be associated with mGluR5, was the N-terminal EF-hand calcium-binding protein 2 (NECAB2). In situ hybridization histochemistry and immunohistochemistry proved that NECAB2 is expressed in two different types of inhibitory neurons located in layers II-IV and VI, respectively. Our results imply extensive gene expressional alterations in the DMPFC related to suicidal behavior. Some of these genes may contribute to the altered mental state and behavior of suicide victims.


Asunto(s)
Trastorno Depresivo Mayor , Suicidio , Trastorno Depresivo Mayor/metabolismo , Perfilación de la Expresión Génica/métodos , Humanos , Corteza Prefrontal/metabolismo , Ideación Suicida , Transcriptoma
3.
Am J Physiol Heart Circ Physiol ; 320(3): H942-H953, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33416453

RESUMEN

Ever since their origin more than one half-century ago, microneurographic recordings of sympathetic nerve activity have significantly advanced our understanding of the generation and regulation of central sympathetic outflow in human health and disease. For example, it is now appreciated that a myriad of disease states exhibit chronic sympathetic overactivity, a significant predictor of cardiovascular morbidity and mortality. Although microneurographic recordings allow for the direct quantification of sympathetic outflow, they alone do not provide information with respect to the ensuing sympathetically mediated vasoconstriction and blood pressure (BP) response. Therefore, the study of vascular and/or BP responses to sympathetic outflow (i.e., sympathetic transduction) has now emerged as an area of growing interest within the field of neural cardiovascular control in human health and disease. To date, studies have primarily examined sympathetic transduction under two distinct paradigms: when reflexively evoking sympatho-excitation through the induction of a laboratory stressor (i.e., sympathetic transduction during stress) and/or following spontaneous bursts of sympathetic outflow occurring under resting conditions (i.e., sympathetic transduction at rest). The purpose of this brief review is to highlight how our physiological understanding of sympathetic transduction has been advanced by these studies and to evaluate the primary analytical techniques developed to study sympathetic transduction in humans. We also discuss the framework by which the assessment of sympathetic transduction during stress reflects a fundamentally different process relative to sympathetic transduction at rest and why findings from investigations using these different techniques should be interpreted as such and not necessarily be considered one and the same.


Asunto(s)
Sistema Cardiovascular/inervación , Electrodiagnóstico , Hemodinámica , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/inervación , Sistema Nervioso Simpático/fisiología , Factores de Edad , Velocidad del Flujo Sanguíneo , Femenino , Humanos , Masculino , Modelos Cardiovasculares , Contracción Muscular , Factores Raciales , Flujo Sanguíneo Regional , Factores Sexuales
4.
Colorectal Dis ; 23(6): 1463-1473, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33387373

RESUMEN

AIM: The aim of this work was to evaluate the effectiveness, patient satisfaction and quality of life (QoL) and the safety of sacral neuromodulation (SNM) with the InterStimTM system for the treatment of faecal incontinence (FI) and establish whether results published predominantly by expert sites are generalisable. METHOD: This is a prospective, multicentre, observational study that invited all French sites treating FI with the InterStim™ system to enrol subjects indicated for an SNM therapy evaluation. Data were collected at three follow-up visits within 1 and 15 months. Therapeutic effectiveness was evaluated by the reduction in leakages per week and improvements over time in the ability to defer defaecation and QoL (as measured with the Faecal Incontinence Quality of Life score). Safety was assessed through reported adverse events. RESULTS: A total of 221 subjects with a mean age of 62.1 years were tested (184 women) and 178 received a permanent implant. For all implanted subjects with diary data at baseline and follow-up, a reduction in leakage of more than 50% was observed in 80%, 76% and 83% at 1-3, 4-8 and 9-15 months, respectively. The mean number of leakage episodes and urgency improved significantly compared with the baseline (p < 0.0001). Subjects showed improvements in QoL and time to defer defaecation and were generally satisfied with their therapy. The main device-related adverse event was the requirement to undertake reprogramming (in 52% of subjects with actions following an event). The rates of infection (in 6% of subjects) and surgical revision (in 10% of subjects) were in agreement with literature reports. CONCLUSION: This study confirms the clinical effectiveness, safety and positive effect of SNM on QoL as well as high patient satisfaction for the treatment of FI in real-life.


Asunto(s)
Terapia por Estimulación Eléctrica , Incontinencia Fecal , Incontinencia Fecal/terapia , Femenino , Humanos , Plexo Lumbosacro , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Sacro , Resultado del Tratamiento
5.
Int J Mol Sci ; 22(4)2021 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-33546359

RESUMEN

(1) Background: Preoptic region of hypothalamus is responsible to control maternal behavior, which was hypothesized to be associated with gene expressional changes. (2) Methods: Transcriptome sequencing was first applied in the preoptic region of rat dams in comparison to a control group of mothers whose pups were taken away immediately after parturition and did not exhibit caring behavior 10 days later. (3) Results: Differentially expressed genes were found and validated by quantitative RT-PCR, among them NACHT and WD repeat domain containing 1 (Nwd1) is known to control androgen receptor (AR) protein levels. The distribution of Nwd1 mRNA and AR was similar in the preoptic area. Therefore, we focused on this steroid hormone receptor and found its reduced protein level in rat dams. To establish the function of AR in maternal behavior, its antagonist was administered intracerebroventricularly into mother rats and increased pup-directed behavior of the animals. (4) Conclusions: AR levels are suppressed in the preoptic area of mothers possibly mediated by altered Nwd1 expression in order to allow sustained high-level care for the pups. Thus, our study first implicated the AR in the control of maternal behaviors.


Asunto(s)
Conducta Materna , Periodo Posparto , Área Preóptica/metabolismo , Receptores Androgénicos/fisiología , Animales , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Madres , Ratas , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Análisis de Secuencia de ARN
6.
Am J Physiol Regul Integr Comp Physiol ; 319(3): R323-R328, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32783690

RESUMEN

Black men have attenuated increases in forearm vascular conductance (FVC) and forearm blood flow (FBF) during moderate- and high-intensity rhythmic handgrip exercise compared with White men, but the underlying mechanisms are unclear. Here, we tested for the first time the hypothesis that functional sympatholysis (i.e., attenuation of sympathetic vasoconstriction in the exercising muscles) is impaired in Black men compared with White men. Thirteen White and 14 Black healthy young men were studied. FBF (duplex Doppler ultrasound) and mean arterial pressure (MAP; Finometer) were measured at rest and during rhythmic handgrip exercise at 30% maximal voluntary contraction. FVC was calculated as FBF/MAP. Sympathetic activation was induced via lower body negative pressure (LBNP) at -20 Torr for 2 min at rest and from the 3rd to the 5th min of handgrip. Sympathetic vasoconstriction was assessed as percent reductions in FVC during LBNP. The groups presented similar resting FVC, FBF, and MAP. During LBNP at rest, reductions in FVC were not different between White (-35 ± 10%) and Black men (-32 ± 14%, P = 0.616), indicating similar reflex-induced sympathetic vasoconstriction. During handgrip exercise, there were minimal reductions in FVC with LBNP in either group (White: -1 ± 7%; Black: +1 ± 8%; P = 0.523), indicating functional sympatholysis in both groups. Thus, contrary to our hypothesis, our findings indicate a preserved functional sympatholysis in healthy young Black men compared with White men, suggesting that this mechanism does not appear to contribute to reduced exercise hyperemia during moderate-intensity rhythmic handgrip in this population.


Asunto(s)
Ejercicio Físico/fisiología , Fuerza de la Mano/fisiología , Consumo de Oxígeno/fisiología , Vasoconstricción/fisiología , Adulto , Humanos , Masculino , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Flujo Sanguíneo Regional/fisiología , Sistema Nervioso Simpático/fisiopatología
7.
Exp Physiol ; 105(7): 1102-1110, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32362031

RESUMEN

NEW FINDINGS: What is the central question of this study? The prevalence of hypertension in black individuals exceeds that in other racial groups. Despite this well-known heightened risk, the underlying contributory factors remain incompletely understood. We hypothesized that young black men would exhibit augmented beat-to-beat blood pressure variability compared with white men and that black men would exhibit augmented total peripheral resistance variability. What is the main finding and its importance? We demonstrate that young, healthy black men exhibit greater resting beat-to-beat blood pressure variability compared with their white counterparts, which is accompanied by greater variability in total peripheral resistance. These swings in blood pressure over time might contribute to the enhanced cardiovascular risk profile in black individuals. ABSTRACT: The prevalence of hypertension in black (BL) individuals exceeds that in other racial groups. Recently, resting beat-to-beat blood pressure (BP) variability has been shown to predict cardiovascular risk and detect target organ damage better than ambulatory BP monitoring. Given the heightened risk in BL individuals, we hypothesized young BL men would exhibit augmented beat-to-beat BP variability compared with white (WH) men. Furthermore, given studies reporting reduced vasodilatation and augmented vasoconstriction in BL individuals, we hypothesized that BL men would exhibit augmented variability in total peripheral resistance (TPR). In 45 normotensive men (24 BL), beat-to-beat BP (Finometer) was measured during 10-20 min of quiet rest. Cardiac output and TPR were estimated (Modelflow method). Despite similar resting BP, BL men exhibited greater BP standard deviation (e.g. systolic BP SD; BL, 7.1 ± 2.2 mmHg; WH, 5.4 ± 1.5 mmHg; P = 0.006) compared with WH men, which was accompanied by a greater TPR SD (P = 0.003), but not cardiac output SD (P = 0.390). Other traditional measures of variability provided similar results. Histogram analysis indicated that BL men exhibited a greater percentage of cardiac cycles with BPs higher (> +10 mmHg higher) and lower (< -8 mmHg lower) than mean systolic BP compared with WH men (interaction, P < 0.001), which was accompanied by a greater percentage of cardiac cycles with high/low TPR (P < 0.001). In a subset of subjects (n = 30), reduced sympathetic baroreflex sensitivity was associated with augmented BP variability (r = -0.638, P < 0.001), whereas cardiac baroreflex sensitivity had no relationship (P = 0.447). Herein, we document an augmented beat-to-beat BP variability in young BL men, which coincided with fluctuations in vascular resistance and reduced sympathetic BRS.


Asunto(s)
Negro o Afroamericano , Presión Sanguínea , Resistencia Vascular , Adulto , Barorreflejo/fisiología , Gasto Cardíaco , Corazón/fisiología , Frecuencia Cardíaca , Humanos , Hipertensión/epidemiología , Masculino , Descanso , Población Blanca , Adulto Joven
8.
Am J Physiol Heart Circ Physiol ; 317(4): H777-H789, 2019 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31397168

RESUMEN

Cardiovascular disease (CVD) accounts for a third of all deaths in the United States making it the leading cause of morbidity and mortality. Although CVD affects individuals of all races/ethnicities, the prevalence of CVD is highest in non-Hispanic black (BL) individuals relative to other populations. The mechanism(s) responsible for elevated CVD risk in the BL population remains incompletely understood. However, impaired vascular vasodilator capacity and exaggerated vascular vasoconstrictor responsiveness are likely contributing factors, both of which are present even in young, otherwise healthy BL individuals. Within this review, we highlight some historical and recent data, collected from our laboratories, of impaired vascular function, in terms of reduced vasodilator capacity and heightened vasoconstrictor responsiveness, in the peripheral and cerebral circulations in BL individuals. We provide data that such impairments may be related to elevated oxidative stress and subsequent reduction in nitric oxide bioavailability. In addition, divergent mechanisms of impaired vasodilatory capacity between BL men and women are discussed. Finally, we propose several directions where future research is needed to fill in knowledge gaps, which will allow for better understanding of the mechanisms contributing to impaired vascular function in this population. Ultimately, this information will allow for better lifestyle and therapeutic approaches to be implemented in an effort to minimize the increased CVD burden in the BL population.


Asunto(s)
Negro o Afroamericano , Vasos Sanguíneos/fisiopatología , Enfermedades Cardiovasculares/etnología , Disparidades en el Estado de Salud , Vasoconstricción , Vasodilatación , Vasos Sanguíneos/metabolismo , Enfermedades Cardiovasculares/metabolismo , Enfermedades Cardiovasculares/fisiopatología , Arterias Cerebrales/metabolismo , Arterias Cerebrales/fisiopatología , Femenino , Humanos , Masculino , Óxido Nítrico/metabolismo , Estrés Oxidativo , Prevalencia , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Estados Unidos/epidemiología
9.
Pediatr Res ; 95(3): 598-599, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38160220
10.
Am J Physiol Heart Circ Physiol ; 315(5): H1316-H1321, 2018 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-30118345

RESUMEN

Previous studies have demonstrated that African-American (AA) individuals have heightened vasoconstrictor and reduced vasodilator responses under resting conditions compared with Caucasian-American (CA) individuals. However, potential differences in vascular responses to exercise remain unclear. Therefore, we tested the hypothesis that, compared with CA subjects, AA subjects would present an attenuated increase in forearm vascular conductance (FVC) during rhythmic handgrip exercise. Forearm blood flow (FBF; duplex Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured in healthy young CA ( n = 10) and AA ( n = 10) men during six trials of rhythmic handgrip performed at workloads of 4, 8, 12, 16, 20, and 24 kg. FVC (calculated as FBF/MAP), FBF, and MAP were similar between groups at rest (FVC: 63 ± 7 ml·min-1·100 mmHg-1 in CA subjects vs. 62 ± 7 ml·min-1·100 mmHg-1 in AA subjects, P = 0.862). There was an intensity-dependent increase in FVC during exercise in both groups; however, AA subjects presented lower FVC (interaction P < 0.001) at 8-, 12-, 16-, 20-, and 24-kg workloads (e.g., 24 kg: 324 ± 20 ml·min-1·100 mmHg-1 in CA subjects vs. 241 ± 21 ml·min-1·100 mmHg-1 in AA subjects, P < 0.001). FBF responses to exercise were also lower in AA subjects (interaction P < 0.001), whereas MAP responses did not differ between groups (e.g., ∆MAP at 24 kg: +19 ± 2 mmHg in CA subjects vs. +19 ± 2 mmHg in AA subjects, interaction P = 0.950). These findings indicate lower hyperemic responses to rhythmic handgrip exercise in AA men compared with CA men. NEW & NOTEWORTHY It is known that African-American individuals have heightened vasoconstriction and reduced vasodilation under resting conditions compared with Caucasian-American individuals. Here, we identified that the hyperemic response to moderate and high-intensity rhythmic handgrip exercise was lower in healthy young African-American men.


Asunto(s)
Negro o Afroamericano , Arteria Braquial/fisiología , Ejercicio Físico/fisiología , Fuerza de la Mano , Hemodinámica , Contracción Muscular , Músculo Esquelético/irrigación sanguínea , Población Blanca , Factores de Edad , Velocidad del Flujo Sanguíneo , Arteria Braquial/diagnóstico por imagen , Antebrazo , Humanos , Hiperemia/fisiopatología , Masculino , Flujo Sanguíneo Regional , Factores Sexuales , Ultrasonografía Doppler Dúplex , Adulto Joven
11.
Matern Child Health J ; 22(11): 1580-1588, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29926246

RESUMEN

Objectives The Family-Centered Medical Home (FCMH) has become a model of effective and efficient primary care. However, efforts to measure the FCMH may ignore its complexity. We sought to determine whether U.S. primary care pediatricians view structure-focused and relationship-focused practice activities of the FCMH as distinct constructs and how these constructs are associated with practice functions. Methods We analyzed data from the 2012 American Academy of Pediatrics Periodic Survey of Fellows #79 (n = 572) addressing opinions and practice activities related to the FCMH. Through a modified Delphi expert process, we selected items believed to be primarily structure-focused and items that were relationship-focused. Confirmatory factor analysis was used to test whether these constructs were distinct. Separate structural equation models assessed whether structure-focused and relationship-focused activities predicted three broader survey items: (1) interest in FCMH; (2) application for FCMH recognition; and (3) whether a team meets to discuss FCMH improvements. Results The initial two-factor model did not fit well, but improved with movement of two items from the structure to the relationship-focused group. The two factors correlated at r = 0.70. Respondents with increased relationship-focused activities had statistically higher odds of having medium/high interest in FCMH, and having a team meet to discuss FCMH improvements. Respondents with increased structure-focused activities also had higher odds of having team meetings to discuss FCMH improvements, but lower odds of applying for FCMH recognition. Conclusions for Practice The FCMH is multi-dimensional, with relationship- and structure-focused activities differentially linked to pediatrician reports of broader FCMH functions.


Asunto(s)
Grupo de Atención al Paciente/organización & administración , Atención Dirigida al Paciente/organización & administración , Pediatras/psicología , Atención Primaria de Salud/organización & administración , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pediatras/organización & administración
12.
J Ment Health ; 27(6): 574-582, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28990831

RESUMEN

BACKGROUND: The patient-centered medical home (PCMH) model is designed to improve health outcomes while containing the cost of care. However, the evidence is inconclusive. AIMS: The aim of this study was to examine the associations between receipt of care consistent with the PCMH and healthcare services utilization and expenditures for non-elderly adults with mental illness in the USA. METHOD: A surveillance study was conducted using self-reported data for 6908 non-elderly adults with mental illness participating in the 2007-2012 Medical Expenditure Panel Survey. Healthcare services utilization and expenditures were compared for study participants who received care consistent with the PCMH, participants with a non-PCMH usual source of care (USC), and participants without a USC. RESULTS: Differences in utilization and expenditures between participants who received care consistent with the PCMH and participants who had a non-PCMH USC were not statistically significant for any healthcare services category. CONCLUSIONS: Receipt of care consistent with the PCMH was not significantly associated with differences in healthcare services utilization or expenditures compared to having a non-PCMH USC. Research assessing whether the PCMH is cost-effective for non-elderly adults with mental illness is needed.


Asunto(s)
Trastornos Mentales/economía , Servicios de Salud Mental/economía , Atención Dirigida al Paciente/economía , Adolescente , Adulto , Utilización de Instalaciones y Servicios , Femenino , Gastos en Salud , Humanos , Masculino , Trastornos Mentales/rehabilitación , Servicios de Salud Mental/estadística & datos numéricos , Persona de Mediana Edad , Atención Dirigida al Paciente/estadística & datos numéricos , Adulto Joven
15.
J Neurophysiol ; 116(1): 81-7, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27075533

RESUMEN

Multiple sclerosis (MS), a progressive neurological disease, can lead to impairments in the autonomic control of cardiovascular function. We tested the hypothesis that individuals with relapsing-remitting MS (n = 10; 7 females, 3 males; 13 ± 4 yr from diagnosis) exhibit impaired carotid baroreflex control of blood pressure and heart rate compared with sex, age, and body weight-matched healthy individuals (CON: n = 10; 7 females, 3 males). At rest, 5-s trials of neck pressure (NP; +40 Torr) and neck suction (NS; -60 Torr) were applied to simulate carotid hypotension and hypertension, respectively, while mean arterial pressure (MAP; finger photoplethysmography), heart rate (HR), cardiac output (CO; Modelflow), and total vascular conductance (TVC) were continuously measured. In response to NP, there was a blunted increase in peak MAP responses (MS: 5 ± 2 mmHg) in individuals with MS compared with healthy controls (CON: 9 ± 3 mmHg; P = 0.005), whereas peak HR responses were not different between groups. At the peak MAP response to NP, individuals with MS demonstrated an attenuated decrease in TVC (MS, -10 ± 4% baseline vs. CON, -15 ± 4% baseline, P = 0.012), whereas changes in CO were similar between groups. Following NS, all cardiovascular responses (i.e., nadir MAP and HR and percent changes in CO and TVC) were not different between MS and CON groups. These data suggest that individuals with MS have impaired carotid baroreflex control of blood pressure via a blunted vascular conductance response resulting in a diminished ability to increase MAP in response to a hypotensive challenge.


Asunto(s)
Barorreflejo/fisiología , Presión Sanguínea/fisiología , Arterias Carótidas/fisiopatología , Esclerosis Múltiple Recurrente-Remitente/fisiopatología , Adulto , Impedancia Eléctrica , Electrocardiografía , Femenino , Dedos/fisiopatología , Frecuencia Cardíaca/fisiología , Humanos , Hipertensión/fisiopatología , Hipotensión/fisiopatología , Masculino , Fotopletismografía , Estimulación Física , Presión , Respiración
16.
J Pediatr ; 178: 261-267, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27546203

RESUMEN

OBJECTIVE: To assess the impact of a Massachusetts Medicaid policy change (the Children's Behavioral Health Initiative; CBHI, which required and reimbursed behavioral health [BH] screening with standardized tools at well child visits and developed intensive home- and community-based BH services) on primary care practice examining the relationship of BH screening to subsequent BH service utilization. STUDY DESIGN: Using a repeated cross-sectional design, our 2010 and 2012 Medicaid study populations each included 2000 children/adolescents under the age of 21 years. For each year, the population was randomly selected and stratified into 4 age groups, with 500 members selected per group. Two data sources were used: medical records and Medicaid claims. RESULTS: The CBHI had a large impact on formal BH screening and treatment utilization among children/adolescents enrolled in Medicaid. Screening increased substantially (73%: 2010; 74%: 2012) since the baseline/premandate period (2007) when only 4% of well child visits included a formal screen. BH utilization increased among those formally screened but decreased among those with informal assessments. CONCLUSIONS: CBHI implementation transformed the relationship between primary care and BH services. Changes in regulation and payment resulted in widespread BH screening in Massachusetts primary care practices caring for children/adolescents on Medicaid.


Asunto(s)
Trastornos de la Conducta Infantil/epidemiología , Servicios de Salud del Niño/estadística & datos numéricos , Tamizaje Masivo/métodos , Atención Primaria de Salud/estadística & datos numéricos , Adolescente , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Tamizaje Masivo/estadística & datos numéricos , Massachusetts , Medicaid , Estados Unidos , Adulto Joven
18.
Am J Physiol Regul Integr Comp Physiol ; 311(4): R735-R741, 2016 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-27488886

RESUMEN

Whole body heat stress (WBH) results in numerous cardiovascular alterations that ultimately reduce orthostatic tolerance. While impaired carotid baroreflex (CBR) function during WBH has been reported as a potential reason for this decrement, study design considerations may limit interpretation of previous findings. We sought to test the hypothesis that CBR function is unaltered during WBH. CBR function was assessed in 10 healthy male subjects (age: 26 ± 3; height: 185 ± 7 cm; weight: 82 ± 10 kg; BMI: 24 ± 3 kg/m2; means ± SD) using 5-s trials of neck pressure (+45, +30, and +15 Torr) and neck suction (-20, -40, -60, and -80 Torr) during normothermia (NT) and passive WBH (Δ core temp ∼1°C). Analyses of stimulus response curves (four-parameter logistic model) for CBR control of heart rate (CBR-HR) and mean arterial pressure (CBR-MAP), as well as separate two-way ANOVA of the hypotensive and hypertensive stimuli (factor 1: thermal condition, factor 2: chamber pressure), were performed. For CBR-HR, maximal gain was increased during WBH (-0.73 ± 0.11) compared with NT (-0.39 ± 0.04, mean ± SE, P = 0.03). In addition, the CBR-HR responding range was increased during WBH (33 ± 5) compared with NT (19 ± 2 bpm, P = 0.03). Separate analysis of hypertensive stimulation revealed enhanced HR responses during WBH at -40, -60, and -80 Torr (condition × chamber pressure interaction, P = 0.049) compared with NT. For CBR-MAP, both logistic analysis and separate two-way ANOVA revealed no differences during WBH. Therefore, in response to passive WBH, CBR control of heart rate (enhanced) and arterial pressure (no change) is well preserved.


Asunto(s)
Presión Arterial/fisiología , Barorreflejo/fisiología , Cuerpo Carotídeo/fisiología , Frecuencia Cardíaca/fisiología , Respuesta al Choque Térmico/fisiología , Termotolerancia/fisiología , Adulto , Humanos , Masculino
19.
Phys Chem Chem Phys ; 18(2): 781-91, 2016 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-26625981

RESUMEN

In the current work, pristine α-Fe2O3 metal oxide was doped with Mg in an attempt to modulate its electronic properties. To this end, we employed an experimental high throughput strategy, including scanning XRD and optical spectroscopy, which were complimented by atomistic density functional theory (DFT) calculations. The combined study reveals that at Mg/Fe atomic ratios up to ∼1/3, the bandgaps of the hematite-Mg composite materials are similar to that of the pure material. The observed bandgaps are rationalized by electronic band structure and density of states calculations. Additional rationale for the similar bandgaps in pure and doped hematite is provided by topological Bader charge analyses, which indicate that the Mg and Fe ions in the hematite matrix have similar partial atomic charges. Nonetheless, the small charge density difference between the Mg and Fe ions induces a slight spin polarization on both oxygen and Fe ions, resulting in changes in the band edges. Further charge density analyses, using charge density maps and chemical-bonding analyses with the crystal orbital Hamiltonian population scheme, indicate that Mg forms ionic bonds with the neighboring oxygen atoms. This change from iron-oxygen covalent bonds to a more ionic nature for magnesium-oxygen bonds is probably responsible for the reduction observed in the computed bulk modulus of α-Mg(0.17)Fe(1.83)O3 (193 GPa) compared to α-Fe2O3 (202 GPa).

20.
Appl Microbiol Biotechnol ; 100(10): 4595-605, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26952108

RESUMEN

Probiotics are microorganisms that confer beneficial effects on the host; nevertheless, before being allowed for human consumption, their safety must be verified with accurate protocols. In the genomic era, such procedures should take into account the genomic-based approaches. This study aims at assessing the safety traits of Bacillus coagulans GBI-30, 6086 integrating the most updated genomics-based procedures and conventional phenotypic assays. Special attention was paid to putative virulence factors (VF), antibiotic resistance (AR) genes and genes encoding enzymes responsible for harmful metabolites (i.e. biogenic amines, BAs). This probiotic strain was phenotypically resistant to streptomycin and kanamycin, although the genome analysis suggested that the AR-related genes were not easily transferrable to other bacteria, and no other genes with potential safety risks, such as those related to VF or BA production, were retrieved. Furthermore, no unstable elements that could potentially lead to genomic rearrangements were detected. Moreover, a workflow is proposed to allow the proper taxonomic identification of a microbial strain and the accurate evaluation of risk-related gene traits, combining whole genome sequencing analysis with updated bioinformatics tools and standard phenotypic assays. The workflow presented can be generalized as a guideline for the safety investigation of novel probiotic strains to help stakeholders (from scientists to manufacturers and consumers) to meet regulatory requirements and avoid misleading information.


Asunto(s)
Bacillus coagulans/genética , Genoma Bacteriano , Probióticos , Bacillus coagulans/efectos de los fármacos , Bacillus coagulans/metabolismo , Aminas Biogénicas/metabolismo , Seguridad de Productos para el Consumidor , Farmacorresistencia Bacteriana Múltiple/genética , Kanamicina/farmacología , Fenotipo , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Estreptomicina/farmacología
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