Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 279
Filtrar
1.
J Neonatal Perinatal Med ; 15(4): 837-844, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36155532

RESUMO

A preterm infant was born emergently at 29 weeks gestation to a mother with active coronavirus disease 2019 (COVID-19). Clinical presentation and evaluation were consistent with in utero transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The neonate experienced progressive, refractory respiratory failure and catastrophic intracranial hemorrhage which ultimately led to limitation of care.


Assuntos
COVID-19 , Doenças do Recém-Nascido , Complicações Infecciosas na Gravidez , Gravidez , Lactente , Feminino , Recém-Nascido , Humanos , SARS-CoV-2 , Estado Terminal , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/terapia , Recém-Nascido Prematuro , Transmissão Vertical de Doenças Infecciosas
2.
Sci Rep ; 11(1): 11872, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099760

RESUMO

Exposure to microgravity (µG) during space flights produces a state of immunosuppression, leading to increased viral shedding, which could interfere with long term missions. However, the cellular mechanisms that underlie the immunosuppressive effects of µG are ill-defined. A deep understanding of human immune adaptations to µG is a necessary first step to design data-driven interventions aimed at preserving astronauts' immune defense during short- and long-term spaceflights. We employed a high-dimensional mass cytometry approach to characterize over 250 cell-specific functional responses in 18 innate and adaptive immune cell subsets exposed to 1G or simulated (s)µG using the Rotating Wall Vessel. A statistically stringent elastic net method produced a multivariate model that accurately stratified immune responses observed in 1G and sµG (p value 2E-4, cross-validation). Aspects of our analysis resonated with prior knowledge of human immune adaptations to µG, including the dampening of Natural Killer, CD4+ and CD8+ T cell responses. Remarkably, we found that sµG enhanced STAT5 signaling responses of immunosuppressive Tregs. Our results suggest µG exerts a dual effect on the human immune system, simultaneously dampening cytotoxic responses while enhancing Treg function. Our study provides a single-cell readout of sµG-induced immune dysfunctions and an analytical framework for future studies of human immune adaptations to human long-term spaceflights.


Assuntos
Adaptação Fisiológica/imunologia , Citometria de Fluxo/métodos , Sistema Imunitário/imunologia , Análise de Célula Única/métodos , Simulação de Ausência de Peso , Adaptação Fisiológica/genética , Adulto , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/metabolismo , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/imunologia , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Voo Espacial/métodos , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transcriptoma/imunologia , Adulto Jovem
3.
J Dent Res ; 98(9): 985-993, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31226001

RESUMO

Chronic periodontitis (ChP) is a prevalent inflammatory disease affecting 46% of the US population. ChP produces a profound local inflammatory response to dysbiotic oral microbiota that leads to destruction of alveolar bone and tooth loss. ChP is also associated with systemic illnesses, including cardiovascular diseases, malignancies, and adverse pregnancy outcomes. However, the mechanisms underlying these adverse health outcomes are poorly understood. In this prospective cohort study, we used a highly multiplex mass cytometry immunoassay to perform an in-depth analysis of the systemic consequences of ChP in patients before (n = 28) and after (n = 16) periodontal treatment. A high-dimensional analysis of intracellular signaling networks revealed immune system-wide dysfunctions differentiating patients with ChP from healthy controls. Notably, we observed exaggerated proinflammatory responses to Porphyromonas gingivalis-derived lipopolysaccharide in circulating neutrophils and monocytes from patients with ChP. Simultaneously, natural killer cell responses to inflammatory cytokines were attenuated. Importantly, the immune alterations associated with ChP were no longer detectable 3 wk after periodontal treatment. Our findings demarcate systemic and cell-specific immune dysfunctions in patients with ChP, which can be temporarily reversed by the local treatment of ChP. Future studies in larger cohorts are needed to test the boundaries of generalizability of our results.


Assuntos
Periodontite Crônica/imunologia , Células Matadoras Naturais/imunologia , Monócitos/imunologia , Neutrófilos/imunologia , Adulto , Citocinas/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Porphyromonas gingivalis , Estudos Prospectivos
4.
Eur J Paediatr Dent ; 20(2): 139-142, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31246091

RESUMO

AIM: Early prosthodontic treatment for cases of ectodermal dysplasia (ED) is usually difficult because of oligodontia, undeveloped alveolar ridges, and the young age of the patients. Although some cases of prosthetic management of ED patients have been reported in the literature, there have been few cases about prosthetic treatment in children younger than 5 years of age. CASE REPORT: This case report presents early prosthetic oral rehabilitation of 2 twin sisters with ectodermal dysplasia and severe hypodontia in the primary dentition. Fixed partial dentures with bands retained on deciduous molars were fabricated when the girls were 3 years old. New flexible removable partial dentures were made when the girls turned 6 years to accommodate the ongoing alveolar development. After the dental treatment, the two girls' aesthetics, phonetics, and chewing functions all improved significantly, which in turn raised the girls' self-esteem and increased their overall quality of life. CONCLUSION: These two cases demonstrated that properly timed and managed early prosthodontic intervention can improve the overall life quality of young patients with ectodermal dysplasia.


Assuntos
Anodontia , Prótese Parcial Removível , Displasia Ectodérmica , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Prostodontia , Qualidade de Vida , Adulto Jovem
5.
Nano Lett ; 19(7): 4543-4550, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31150580

RESUMO

The precise measurement of mechanical stress at the nanoscale is of fundamental and technological importance. In principle, all six independent variables of the stress tensor, which describe the direction and magnitude of compression/tension and shear stress in a solid, can be exploited to tune or enhance the properties of materials and devices. However, existing techniques to probe the local stress are generally incapable of measuring the entire stress tensor. Here, we make use of an ensemble of atomic-sized in situ strain sensors in diamond (nitrogen-vacancy defects) to achieve spatial mapping of the full stress tensor, with a submicrometer spatial resolution and a sensitivity of the order of 1 MPa (10 MPa) for the shear (axial) stress components. To illustrate the effectiveness and versatility of the technique, we apply it to a broad range of experimental situations, including mapping the stress induced by localized implantation damage, nanoindents, and scratches. In addition, we observe surprisingly large stress contributions from functional electronic devices fabricated on the diamond and also demonstrate sensitivity to deformations of materials in contact with the diamond. Our technique could enable in situ measurements of the mechanical response of diamond nanostructures under various stimuli, with potential applications in strain engineering for diamond-based quantum technologies and in nanomechanical sensing for on-chip mass spectroscopy.

6.
Artigo em Inglês | MEDLINE | ID: mdl-29997894

RESUMO

BACKGROUND: Studies conducted in sub-Saharan Africa suggest a high prevalence of depression and suicidality among adolescents living with HIV (ALWH). This is an important public health issue because depression is known to compromise HIV treatment adherence. However, the drivers of depression and suicidality in this population are unclear. We conducted a cross-sectional study to estimate the associations between internalized stigma, bullying, major depressive disorder, and suicidality. METHODS: We conducted a cross-sectional survey between November 2016 and March 2017, enrolling a consecutive sample of 224 ALWH aged 13-17 years. We collected information on demographic characteristics, internalized HIV-related stigma (using the six-item Internalized AIDS-Related Stigma Scale), bullying victimization (using the nine-item Social and Health Assessment Peer Victimization Scale), major depressive disorder [using the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID)], and suicidality (also using the MINI-KID). We fitted multivariable logistic regression models to estimate the associations between stigma, bullying, major depressive disorder, and suicidality. RESULTS: Thirty-seven participants (16%) had major depressive disorder, 30 (13%) had suicidality, and nine (4%) had high-risk suicidality. Ninety-one participants (41%) had high levels of internalized stigma, while 97 (43%) reported two or more bullying events in the past year. In multivariable logistic regression models, major depressive disorder had a statistically significant association with bullying (AOR = 1.09; 95% CI 1.00-1.20; p = 0.04); while suicidality (low, moderate, high risk) had statistically significant associations with both bullying (AOR = 1.09; 95% CI 1.01-1.17; p = 0.02) and stigma (AOR = 1.30; 95% CI 1.03-1.30; p = 0.02). CONCLUSIONS: Among ALWH in rural Uganda, stigma and bullying are strongly associated with major depressive disorder and suicidality. There is a need to incorporate psychological interventions in the mainstream HIV care to address these challenges for optimal management of HIV among ALWH.

7.
AJNR Am J Neuroradiol ; 39(8): 1562-1567, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29930095

RESUMO

BACKGROUND AND PURPOSE: The C1-2 intrathecal puncture is routinely performed when lumbar puncture is not feasible. Usage has steadily decreased in part because of the perceived high risk of injury to the cervical cord. Up to this point, vague fluoroscopic guidelines have been used, creating uncertainty about the actual needle location relative to the spinal cord. We present a novel osseous landmark to aid in C1-2 intrathecal puncture, corresponding to the posterior spinal cord margin on lateral fluoroscopic views. This landmark, which we have termed the "flare point," represents the triangular "flaring" of the posterior C1 arch at its junction with the anterior arch. MATERIALS AND METHODS: Cervical spine CT myelograms were reviewed. High-resolution axial images were reformatted into the sagittal plane, and maximum-intensity-projection images were created to simulate a lateral fluoroscopic view. Tangential lines were drawn along the superior cortices of the anterior and posterior C1 arches, with the point of intersection used to approximate the flare point. Chart review was performed for all C1-2 punctures using the flare point technique in the past 3 years. RESULTS: Forty-two cervical myelograms were reviewed. The average flare point was 0.2 ± 0.5 mm posterior to the dorsal spinal cord margin. In 37/42 subjects, the flare point was localized posterior to the spinal cord. Targeting by means of the flare point was used in 16 C1-2 punctures without complications. CONCLUSIONS: The C1 posterior arch flare point accurately approximates the dorsal spinal cord margin on myelography. Targeting between the flare point and the spinolaminar line, at the mid-C1-2 interspace, allows safe and optimal needle positioning.


Assuntos
Pontos de Referência Anatômicos/diagnóstico por imagem , Vértebras Cervicais/diagnóstico por imagem , Punção Espinal/métodos , Adulto , Feminino , Fluoroscopia , Humanos , Masculino , Mielografia/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
8.
Obes Sci Pract ; 4(1): 46-51, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29479464

RESUMO

Background: Experience suggests that some physicians view obesity as a purely lifestyle condition rather than a chronic metabolic disease. Physicians may not be aware of the role of biological factors in causing weight regain after an initial weight loss. Methods: A questionnaire was administered at continuing medical education conferences, both primary care and obesity-specific. The questionnaire included items about biological and behavioral factors that predispose to weight regain and general items about treatment of obesity. The sample was separated into primary care physicians (PCPs) and physicians preparing for the obesity medicine (OMs) exam. Results: Among all respondents, behavioral factors were given higher importance ratings, relative to biological factors in causing weight regain. Respondents rated behaviour modification as more effective, relative to medications or surgery to treat obesity. OMs gave higher importance ratings to biological factors, relative to PCPs. OMs also gave higher effectiveness ratings for medications and surgery, relative to PCPs. However, even OMs gave higher effectiveness ratings for behaviour modification, relative to medications or surgery. Respondents who reported a belief in the role of behavioral factors rated lifestyle modification as more effective. Respondents who reported a belief in both behavioral and biological factors rated medications as more effective. Conclusions: Physicians rate biological factors as less important, relative to behavioral factors in causing weight regain. Physicians rate medications and surgery as less effective, relative to lifestyle modification alone. Belief in the importance of behavioral factors correlated with a higher effectiveness rating for lifestyle modification. A better understanding of the biological basis for weight regain may help to increase comfort with the use of biological treatments for obesity.

9.
Acc Chem Res ; 50(12): 2879-2885, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29219300

RESUMO

A clear correlation between electronic structure and CO2 selectivity for steam reforming of methanol (SRM) was obtained with PdZn, PtZn, NiZn, and PdCd intermetallics on the basis of experiments and calculations. In order to rule out the effects of oxide supports, the intermetallic powders were simply prepared by alloying in an arc furnace followed by crushing in a mortar. PdZn and PdCd exhibit valence electronic densities of states similar to that of Cu and significant chemical shifts (larger than 1 eV) of Pd 3d states with respect to pure Pd, as verified by high-resolution hard X-ray photoelectron spectroscopy (HXPS) measurements and density functional theory (DFT) calculations. Consequently, they show the similar high selectivity of CO2 for the SRM reaction. However, this is not the case for PtZn and NiZn because of the slight differences in their valence electronic structures from that of PdZn. The interval between the Fermi level and the top of the d band is closely related to the selectivity of CO2 for the SRM: the larger the interval is, the higher is the selectivity of CO2. According to DFT calculations for bulk PdZn performed by Chen et al. ( Phys. Rev. B 2003 , 68 , 075417 ), the (111) and (100) surfaces exposing Zn and Pd in an equimolar ratio are more stable than the (001) or (110) surfaces terminated by alternative Zn or Pd layers. First-principles slab calculations for PdZn, PtZn, and NiZn show that bond breaking on the surface leads to a reduction in the d bandwidth but that the d band for stable (111) or (100) surfaces remains essentially unchanged from that of the bulk. It is intriguing that PdZn and PdCd do not contain Cu but show similar valence electronic structure and catalytic selectivity, and hence, a concept is proposed where PdZn and PdCd are regarded as pseudoelements of Cu. The basis of this concept is like electronic structure, like catalysis, which has been demonstrated by experiments and calculations. This is a logical way to enable us to look for new catalysts in which precious metals are partially or completely replaced by base metals. We do not expect that this concept can be applied to all catalytic reactions, but this approach is one of most promising ways to derive a better understanding of the origin of catalytic mechanisms and eventually allow us to design useful catalysts intentionally in the future. This Account reviews the authors' published works on this topic.

10.
Artigo em Inglês | MEDLINE | ID: mdl-29230311

RESUMO

BACKGROUND: School attendance rates in sub-Saharan Africa are among the lowest worldwide, placing children at heightened risk for poor educational and economic outcomes. One understudied risk factor for missed schooling is household water insecurity, which is linked to depression among women and may increase children's water-fetching burden at the expense of educational activities, particularly among children of depressed caregivers. In this study conducted in rural Uganda, we assessed the association between household water insecurity and child school participation and the mediating pathways behind these associations. METHOD: We conducted a population-based, cross-sectional study of female household heads (N = 257) and their children ages 5-17 (N = 551) in the rural regions surrounding the town of Mbarara, in southwestern Uganda. We used multivariable linear regressions to estimate the association between water insecurity and missed schooling. We then assessed the extent to which the association was mediated by caregiver depression. RESULTS: Among children, water insecurity had a statistically significant association with the number of missed school days (a standard deviation increase in water insecurity resulted in 0.30 more missed school days in the last week). The estimated association was partially mediated by caregiver depression. When stratified by sex, this mediating pathway remained significant for boys, but not among girls. CONCLUSIONS: Water insecurity is a risk factor for missed schooling among children in rural Uganda. Caregiver depression partially mediated this relationship. Also addressing caregiver mental health in water insecure families may more fully address the needs of sub-Saharan African families and promote educational participation among youth.

13.
Indoor Air ; 27(5): 1022-1029, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28267233

RESUMO

The literature on the contribution of kerosene lighting to indoor air particulate concentrations is sparse. In rural Uganda, kitchens are almost universally located outside the main home, and kerosene is often used for lighting. In this study, we obtained longitudinal measures of particulate matter 2.5 microns or smaller in size (PM2.5 ) from living rooms and kitchens of 88 households in rural Uganda. Linear mixed-effects models with a random intercept for household were used to test the hypotheses that primary reported lighting source and kitchen location (indoor vs outdoor) are associated with PM2.5 levels. During initial testing, households reported using the following sources of lighting: open-wick kerosene (19.3%), hurricane kerosene (45.5%), battery-powered (33.0%), and solar (1.1%) lamps. During follow-up testing, these proportions changed to 29.5%, 35.2%, 18.2%, and 9.1%, respectively. Average ambient, living room, and kitchen PM2.5 levels were 20.2, 35.2, and 270.0 µg/m3 . Living rooms using open-wick kerosene lamps had the highest PM2.5 levels (55.3 µg/m3 ) compared to those using solar lighting (19.4 µg/m3 ; open wick vs solar, P=.01); 27.6% of homes using open-wick kerosene lamps met World Health Organization indoor air quality standards compared to 75.0% in homes using solar lighting.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Querosene , Iluminação/métodos , Material Particulado/análise , Adulto , Carbono/análise , Culinária , Feminino , Habitação , Humanos , Exposição por Inalação , Doenças Respiratórias/epidemiologia , População Rural , Fuligem/análise , Uganda
15.
Tech Coloproctol ; 20(12): 811-824, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27853973

RESUMO

Transanal total mesorectal excision (TaTME) has been developed to improve quality of TME for patients with mid and low rectal cancer. However, despite enthusiastic uptake and teaching facilities, concern exists for safe introduction. TaTME is a complex procedure and potentially a learning curve will hamper clinical outcome. With this systematic review, we aim to provide data regarding morbidity and safety of TaTME. A systematic literature search was performed in MEDLINE (PubMed), EMBASE (Ovid) and Cochrane Library. Case reports, cohort series and comparative series on TaTME for rectal cancer were included. To evaluate a potential effect of case volume, low-volume centres (n ≤ 30 total volume) were compared with high-volume centres (n > 30 total volume). Thirty-three studies were identified (three case reports, 25 case series, five comparative studies), including 794 patients. Conversion was performed in 3.0% of the procedures. The complication rate was 40.3, and 11.5% were major complications. The quality of the mesorectum was "complete" in 87.6%, and the circumferential resection margin (CRM) was involved in 4.7%. In low- versus high-volume centres, the conversion rate was 4.3 versus 2.7%, and major complication rates were 12.2 versus 10.5%, respectively. TME quality was "complete" in 80.5 versus 89.7%, and CRM involvement was 4.8 and 4.5% in low- versus high-volume centres, respectively. TaTME for mid and low rectal cancer is a promising technique; however, it is associated with considerable morbidity. Safe implementation of the TaTME should include proctoring and quality assurance preferably within a trial setting.


Assuntos
Competência Clínica/estatística & dados numéricos , Hospitais com Alto Volume de Atendimentos/estatística & dados numéricos , Hospitais com Baixo Volume de Atendimentos/estatística & dados numéricos , Neoplasias Retais/cirurgia , Cirurgia Endoscópica Transanal/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Conversão para Cirurgia Aberta/estatística & dados numéricos , Feminino , Humanos , Curva de Aprendizado , Masculino , Mesocolo/cirurgia , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Reto/cirurgia , Cirurgia Endoscópica Transanal/métodos , Resultado do Tratamento
16.
Front Neurosci ; 10: 398, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27656121

RESUMO

Associations between brain structure and early adversity have been inconsistent in the literature. These inconsistencies may be partially due to methodological differences. Different methods of brain segmentation may produce different results, obscuring the relationship between early adversity and brain volume. Moreover, adolescence is a time of significant brain growth and certain brain areas have distinct rates of development, which may compromise the accuracy of automated segmentation approaches. In the current study, 23 adolescents participated in two waves of a longitudinal study. Family aggression was measured when the youths were 12 years old, and structural scans were acquired an average of 4 years later. Bilateral amygdalae and hippocampi were segmented using three different methods (manual tracing, FSL, and NeuroQuant). The segmentation estimates were compared, and linear regressions were run to assess the relationship between early family aggression exposure and all three volume segmentation estimates. Manual tracing results showed a positive relationship between family aggression and right amygdala volume, whereas FSL segmentation showed negative relationships between family aggression and both the left and right hippocampi. However, results indicate poor overlap between methods, and different associations were found between early family aggression exposure and brain volume depending on the segmentation method used.

17.
Lab Chip ; 16(4): 668-78, 2016 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-26725379

RESUMO

The miniaturization of integrated fluidic processors affords extensive benefits for chemical and biological fields, yet traditional, monolithic methods of microfabrication present numerous obstacles for the scaling of fluidic operators. Recently, researchers have investigated the use of additive manufacturing or "three-dimensional (3D) printing" technologies - predominantly stereolithography - as a promising alternative for the construction of submillimeter-scale fluidic components. One challenge, however, is that current stereolithography methods lack the ability to simultaneously print sacrificial support materials, which limits the geometric versatility of such approaches. In this work, we investigate the use of multijet modelling (alternatively, polyjet printing) - a layer-by-layer, multi-material inkjetting process - for 3D printing geometrically complex, yet functionally advantageous fluidic components comprised of both static and dynamic physical elements. We examine a fundamental class of 3D printed microfluidic operators, including fluidic capacitors, fluidic diodes, and fluidic transistors. In addition, we evaluate the potential to advance on-chip automation of integrated fluidic systems via geometric modification of component parameters. Theoretical and experimental results for 3D fluidic capacitors demonstrated that transitioning from planar to non-planar diaphragm architectures improved component performance. Flow rectification experiments for 3D printed fluidic diodes revealed a diodicity of 80.6 ± 1.8. Geometry-based gain enhancement for 3D printed fluidic transistors yielded pressure gain of 3.01 ± 0.78. Consistent with additional additive manufacturing methodologies, the use of digitally-transferrable 3D models of fluidic components combined with commercially-available 3D printers could extend the fluidic routing capabilities presented here to researchers in fields beyond the core engineering community.

19.
J Am Heart Assoc ; 3(6): e001274, 2014 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-25468659

RESUMO

BACKGROUND: Heparanase is the major enzyme involved in degradation of endothelial heparan sulfates, which is associated with impaired endothelial nitric oxide synthesis. However, the effect of heparan sulfate chain length in relation to endothelial function and nitric oxide availability has never been investigated. We studied the effect of heterozygous mutations in heparan sulfate elongation genes EXT1 and EXT2 on endothelial function in vitro as well as in vivo. METHODS AND RESULT: Flow-mediated dilation, a marker of nitric oxide bioavailability, was studied in Ext1(+/-) and Ext2(+/-) mice versus controls (n=7 per group), as well as in human subjects with heterozygous loss of function mutations in EXT1 and EXT2 (n=13 hereditary multiple exostoses and n=13 controls). Endothelial function was measured in microvascular endothelial cells under laminar flow with or without siRNA targeting EXT1 or EXT2. Endothelial glycocalyx and maximal arteriolar dilatation were significantly altered in Ext1(+/-) and Ext2(+/-) mice compared to wild-type littermates (glycocalyx: wild-type 0.67±0.1 µm, Ext1(+/-) 0.28±0.1 µm and Ext2(+/-) 0.25±0.1 µm, P<0.01, maximal arteriolar dilation during reperfusion: wild-type 11.3±1.0%), Ext1(+/-) 15.2±1.4% and Ext2(+/-) 13.8±1.6% P<0.05). In humans, brachial artery flow-mediated dilation was significantly increased in hereditary multiple exostoses patients (hereditary multiple exostoses 8.1±0.8% versus control 5.6±0.7%, P<0.05). In line, silencing of microvascular endothelial cell EXT1 and EXT2 under flow led to significant upregulation of endothelial nitric oxide synthesis and phospho-endothelial nitric oxide synthesis protein expression. CONCLUSIONS: Our data implicate that heparan sulfate elongation genes EXT1 and EXT2 are involved in maintaining endothelial homeostasis, presumably via increased nitric oxide bioavailability.


Assuntos
Artéria Braquial/enzimologia , Endotélio Vascular/enzimologia , Exostose Múltipla Hereditária/enzimologia , Exostose Múltipla Hereditária/genética , Mutação , N-Acetilglucosaminiltransferases/genética , Óxido Nítrico/metabolismo , Vasodilatação , Adulto , Animais , Artéria Braquial/fisiopatologia , Estudos de Casos e Controles , Linhagem Celular , Endotélio Vascular/fisiopatologia , Exostose Múltipla Hereditária/diagnóstico , Exostose Múltipla Hereditária/fisiopatologia , Feminino , Predisposição Genética para Doença , Glicocálix/enzimologia , Heterozigoto , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , N-Acetilglucosaminiltransferases/deficiência , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Fenótipo , Fosforilação , Transfecção
20.
Acta Physiol (Oxf) ; 211(4): 544-58, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24825168

RESUMO

AIM: Nicotine stimulation of α3ß2-nicotinic acetylcholine receptors (α3ß2-nAChRs) located on sympathetic nerves innervating basilar arteries causes calcium-dependent noradrenaline release, leading to activation of parasympathetic nitrergic nerves and dilation of basilar arteries. This study aimed to investigate the major subtype of calcium channels located on cerebral peri-vascular sympathetic nerves, which is involved in nicotine-induced α3ß2-nAChR-mediated nitrergic vasodilation in basilar arteries. METHODS: Nicotine- and transmural nerve stimulation (TNS)-induced dilation of isolated porcine basilar arteries was examined using in vitro tissue bath. Nicotine-induced calcium influx, nicotine-induced noradrenaline release and nicotine-induced inward currents were evaluated in rat superior cervical ganglion (SCG) neurones, peri-vascular sympathetic nerves of porcine basilar arteries and α3ß2-nAChRs-expressing oocytes respectively. mRNA and protein expression of Cav 1.2 and Cav 1.3 channels were detected by RT-PCR, Western blotting and immunohistochemistry. RESULTS: Nicotine-induced vasodilation was not affected by ω-agatoxin TK (selective P/Q-type calcium channel blocker) or ω-conotoxin GVIA (N-type calcium channel blocker). The vasodilation, however, was inhibited by nicardipine (L-type calcium channel blocker) in concentrations which did not affect TNS-induced vasodilation, suggesting the specific blockade. Nicardipine concentration-dependently inhibited nicotine-induced calcium influx in rat SCG neurones and reduced nicotine-induced noradrenaline release from peri-vascular sympathetic nerves of porcine basilar arteries. Nicardipine (10 µm), which significantly blocked nicotine-induced vasorelaxation by 70%, did not appreciably affect nicotine-induced inward currents in α3ß2-nAChRs-expressing oocytes. Furthermore, the mRNAs and proteins of Cav 1.2 and Cav 1.3 channels were expressed in porcine SCG and peri-vascular nerve terminals. CONCLUSION: The sympathetic neuronal calcium influx through L-type calcium channels is modulated by α3ß2-nAChRs. This calcium influx causes noradrenaline release, initiating sympathetic-parasympathetic (axo-axonal) interaction-induced nitrergic dilation of porcine basilar arteries.


Assuntos
Artéria Basilar/metabolismo , Canais de Cálcio Tipo L/metabolismo , Receptores Nicotínicos/metabolismo , Sistema Nervoso Simpático/fisiologia , Vasodilatação/fisiologia , Animais , Artéria Basilar/inervação , Western Blotting , Encéfalo/irrigação sanguínea , Circulação Cerebrovascular/fisiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Imuno-Histoquímica , Masculino , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Neurônios Nitrérgicos/metabolismo , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...