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1.
J Stroke Cerebrovasc Dis ; : 107786, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38782166

RESUMO

OBJECTIVES: Periodic imaging follow-up for patients with unruptured intracranial aneurysms (UIA) is crucial, as studies indicate higher rupture risk with aneurysm growth. However, few studies address patient adherence to follow-up recommendations. This study aims to identify compliance rates and factors influencing follow-up adherence. METHODS: Patients with a UIA were identified from our institution's database from 2011-2021. Follow-up imaging (CT/MR Angiogram) was advised at specific intervals. Patients were categorized into compliant and non-compliant groups based on first-year compliance. Factors contributing to compliance were assessed through multivariate logistic regression. Phone interviews were conducted with non-compliant patients to understand reasons for non-adherence. RESULTS: Among 923 UIA diagnosed patients, 337 were randomly selected for analysis. The median follow-up period was1.4 years, with a 42% first-year compliance rate. The mean aneurysm size was 3.3 mm. Five patients had a rupture during follow-up, of which 4 died. Compared with patients consulting specialists at the initial diagnosis, those seen by non-specialists exhibited lower compliance (OR0.25, p <0.001). Loss to follow-up was greatest during transition from emergency service to specialist appointments. Patients who spoke languages other than English exhibited poorer compliance than those speaking English (OR0.420, p =0.01). Patients who practiced no religion showed poorer compliance relative to the Christian religion (OR0.37, p =0.04). CONCLUSIONS: Significant amounts of UIA patients at low rupture risk were lost to follow-up before seeing UIA specialists. Main non-compliance factors include inadequate comprehension of follow-up instructions, poor care transfer from non-specialists to specialist, and insurance barriers.

2.
Atherosclerosis ; 324: 27-37, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33812168

RESUMO

BACKGROUND AND AIMS: Clinical trials have demonstrated reductions in major adverse cardiovascular events with purified high-dose eicosapentaenoic acid (EPA), independent of effects on lipids. We aimed to investigate whether omega-3 fatty acids reduce vascular inflammation, a critical mediator of atherosclerosis, and hypothesised that EPA is superior to docosahexaenoic acid (DHA). METHODS: In a double-blind randomised controlled trial and cell-culture study, 40 healthy volunteers were supplemented with 4 g daily of either EPA, DHA, fish oil (2:1 EPA:DHA), or placebo for 30 days. Serum was incubated with TNF-stimulated human umbilical vein endothelial cells (HUVECs), and markers of acute vascular inflammation (AVI) were measured. The effects of EPA, DHA (600 mg/kg/day), olive oil, or no treatment were also measured in preclinical models of [1] AVI using a periarterial collar (C57Bl/6J; n = 40 mice) and [2] atherosclerosis where ApoE-/- mice (n = 40) were fed a 16-week atherogenic diet. RESULTS: EPA supplementation reduced expression of C-C motif chemokine ligand 2 (CCL2) by 25% compared to placebo (p = 0.03). In the AVI model, EPA reduced vascular expression of VCAM1 by 43% (p = 0.02) and CCL2 by 41% (p = 0.03). Significant inverse correlations were observed between EPA levels and vascular expression of VCAM1 (r = -0.56, p = 0.001) and CCL2 (r = -0.56, p = 0.001). In ApoE-/- mice, EPA reduced aortic expression of Il1b by 44% (p = 0.04) and Tnf by 49% (p = 0.04), with similar inverse correlations between EPA levels and both Il1b (r = -0.63, p = 0.009) and Tnf (r = -0.50, p = 0.04). CONCLUSIONS: Supplementation with EPA, more so than DHA, ameliorates acute and chronic vascular inflammation, providing a rationale for the cardiovascular benefit observed with high dose omega-3 fatty acid administration.


Assuntos
Células Endoteliais , Ácidos Graxos Ômega-3 , Animais , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Ácidos Graxos , Ácidos Graxos Ômega-3/farmacologia , Óleos de Peixe , Inflamação/prevenção & controle , Camundongos
3.
J Community Health ; 46(3): 502-508, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32700174

RESUMO

In the United States (U.S.), up to 2.2 million individuals have been chronically infected with hepatitis B virus (HBV). Many nail salon workers are at risk for HBV as they are coming from high-risk and traditionally underserved communities. To understand barriers and knowledge associated with HBV in the Vietnamese nail salon community, the Health Belief Model (HBM) was used to qualitatively assess the health needs for the prevention of HBV among Vietnamese nail salon workers in Philadelphia through focus groups and interviews (N = 19). Results revealed several themes that highlight barriers within the Vietnamese nail community. Major themes were the lack of knowledge related to hepatitis B, including significant misconceptions related to symptoms, and how hepatitis B is transmitted and prevented. There were also several barriers to health care access within the Vietnamese nail community including the cost of health care, long work hours, lack of insurance and lack of understanding of current community resources. Additionally, discrimination and stigma related to those infected with hepatitis B emerged as a theme from this data. Those interviewed also noted that the nail training and licensing they received did not highlight hepatitis B and other infectious diseases that can be spread within the nail salon.


Assuntos
Hepatite B , Exposição Ocupacional , Povo Asiático , Indústria da Beleza , Humanos , Philadelphia
5.
Appl Environ Microbiol ; 85(3)2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30446552

RESUMO

Members of the genera Hydrogenovibrio, Thiomicrospira, and Thiomicrorhabdus fix carbon at hydrothermal vents, coastal sediments, hypersaline lakes, and other sulfidic habitats. The genome sequences of these ubiquitous and prolific chemolithoautotrophs suggest a surprising diversity of mechanisms for the uptake and fixation of dissolved inorganic carbon (DIC); these mechanisms are verified here. Carboxysomes are apparent in the transmission electron micrographs of most of these organisms but are lacking in Thiomicrorhabdus sp. strain Milos-T2 and Thiomicrorhabdus arctica, and the inability of Thiomicrorhabdus sp. strain Milos-T2 to grow under low-DIC conditions is consistent with the absence of carboxysome loci in its genome. For the remaining organisms, genes encoding potential DIC transporters from four evolutionarily distinct families (Tcr_0853 and Tcr_0854, Chr, SbtA, and SulP) are located downstream of carboxysome loci. Transporter genes collocated with carboxysome loci, as well as some homologs located elsewhere on the chromosomes, had elevated transcript levels under low-DIC conditions, as assayed by reverse transcription-quantitative PCR (qRT-PCR). DIC uptake was measureable via silicone oil centrifugation when a representative of each of the four types of transporter was expressed in Escherichia coli The expression of these genes in the carbonic anhydrase-deficient E. coli strain EDCM636 enabled it to grow under low-DIC conditions, a result consistent with DIC transport by these proteins. The results from this study expand the range of DIC transporters within the SbtA and SulP transporter families, verify DIC uptake by transporters encoded by Tcr_0853 and Tcr_0854 and their homologs, and introduce DIC as a potential substrate for transporters from the Chr family.IMPORTANCE Autotrophic organisms take up and fix DIC, introducing carbon into the biological portion of the global carbon cycle. The mechanisms for DIC uptake and fixation by autotrophic Bacteria and Archaea are likely to be diverse but have been well characterized only for "Cyanobacteria" Based on genome sequences, members of the genera Hydrogenovibrio, Thiomicrospira, and Thiomicrorhabdus have a variety of mechanisms for DIC uptake and fixation. We verified that most of these organisms are capable of growing under low-DIC conditions, when they upregulate carboxysome loci and transporter genes collocated with these loci on their chromosomes. When these genes, which fall into four evolutionarily independent families of transporters, are expressed in E. coli, DIC transport is detected. This expansion in known DIC transporters across four families, from organisms from a variety of environments, provides insight into the ecophysiology of autotrophs, as well as a toolkit for engineering microorganisms for carbon-neutral biochemistries of industrial importance.


Assuntos
Dióxido de Carbono/metabolismo , Piscirickettsiaceae/isolamento & purificação , Piscirickettsiaceae/metabolismo , Sulfetos/metabolismo , Processos Autotróficos , Ciclo do Carbono , Dióxido de Carbono/análise , Ecossistema , Fontes Hidrotermais/química , Fontes Hidrotermais/microbiologia , Filogenia , Piscirickettsiaceae/classificação , Piscirickettsiaceae/genética
6.
Hum Immunol ; 79(12): 839-847, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30240896

RESUMO

The development of next-generation sequencing (NGS) methods for HLA genotyping has already had an impact on the scope and precision of HLA research. In this study, allelic resolution HLA typing was obtained for 402 individuals from Cape Town, South Africa. The data were produced by high-throughput NGS sequencing as part of a study of T-cell responses to Mycobacterium tuberculosis in collaboration with the University of Cape Town and Stanford University. All samples were genotyped for 11 HLA loci, namely HLA-A, -B, -C, -DPA1, -DPB1, -DQA1, -DQB1, -DRB1, -DRB3, -DRB4, and -DRB5. NGS HLA typing of samples from Cape Town inhabitants revealed a unique cohort, including unusual haplotypes, and 22 novel alleles not previously reported in the IPD-IMGT/HLA Database. Eight novel alleles were in Class I loci and 14 were in Class II. There were 62 different alleles of HLA-A, 72 of HLA-B, and 47 of HLA-C. Alleles A∗23:17, A∗43:01, A∗29:11, A∗68:27:01, A∗01:23, B∗14:01:01, B∗15:10:01, B∗39:10:01, B∗45:07, B∗82:02:01 and C∗08:04:01 were notably more frequent in Cape Town compared to other populations reported in the literature. Class II loci had 21 different alleles of DPA1, 46 of DPB1, 27 of DQA1, 26 of DQB1, 41 of DRB1, 5 of DRB3, 4 of DRB4 and 6 of DRB5. The Cape Town cohort exhibited high degrees of HLA diversity and relatively high heterozygosity at most loci. Genetic distances between Cape Town and five other sub-Saharan African populations were also calculated and compared to European Americans.


Assuntos
Técnicas de Genotipagem/métodos , Antígenos HLA/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Adolescente , Alelos , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Desequilíbrio de Ligação , Masculino , África do Sul
7.
Atherosclerosis ; 265: 110-116, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28881268

RESUMO

BACKGROUND AND AIMS: Little is known about the relation between serum lipid parameters and serial change in plaque composition using in vivo coronary imaging. The aim of this study was to examine the association between serum lipids and change in coronary plaque lipid burden assessed by near-infrared spectroscopy (NIRS). METHODS: We performed serial NIRS-intravascular ultrasound studies in 49 patients who underwent coronary angiography for an acute coronary syndrome (ACS) or stable ischemic symptoms. Univariable and multivariable linear regression analyses were applied to evaluate the relationship between serum lipid parameters and change in lipid core burden index at the 4-mm maximal segment (max LCBI4mm). RESULTS: Mean patient age was 61 ± 9 y, 29% were women, 35% had an ACS clinical presentation, 78% received statin therapy at baseline, and median low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), total cholesterol and triglyceride levels were 101, 43, 174 and 133 mg/dL, respectively. During a median follow-up period of 13 months, max LCBI4mm significantly decreased from 277 to 194 (p = 0.001). On univariable analysis, the percent change in HDL-C negatively associated with the change in max LCBI4mm (ß = -3.19, p = 0.004). There were no significant associations between the other lipid parameters and change in max LCBI4mm. On multivariable analysis, percent change in HDL-C remained significantly associated with the change in max LCBI4mm (p = 0.002). CONCLUSIONS: Change in HDL-C, but not other lipids parameters, associated with changes in coronary plaque lipid burden assessed by NIRS. These findings highlight the potential therapeutic importance of high-density lipoprotein on serial change in plaque composition.


Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/diagnóstico por imagem , HDL-Colesterol/sangue , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Placa Aterosclerótica , Espectroscopia de Luz Próxima ao Infravermelho , Ultrassonografia de Intervenção , Síndrome Coronariana Aguda/patologia , Idoso , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Angiografia Coronária , Doença da Artéria Coronariana/patologia , Vasos Coronários/patologia , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Valor Preditivo dos Testes , Índice de Gravidade de Doença
8.
Cardiovasc Diagn Ther ; 7(3): 252-263, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28567351

RESUMO

BACKGROUND: CER-001 is an engineered pre-beta high-density lipoprotein (HDL) mimetic, which rapidly mobilizes cholesterol. Infusion of CER-001 3 mg/kg exhibited a potentially favorable effect on plaque burden in the CHI-SQUARE (Can HDL Infusions Significantly Quicken Atherosclerosis Regression) study. Since baseline atheroma burden has been shown as a determinant for the efficacy of HDL infusions, the degree of baseline atheroma burden might influence the effect of CER-001. METHODS: CHI-SQUARE compared the effect of 6 weekly infusions of CER-001 (3, 6 and 12 mg/kg) vs. placebo on coronary atherosclerosis in 369 patients with acute coronary syndrome (ACS) using serial intravascular ultrasound (IVUS). Baseline percent atheroma volume (B-PAV) cutoff associated with atheroma regression following CER-001 infusions was determined by receiver-operating characteristics curve analysis. 369 subjects were stratified according to the cutoff. The effect of CER-001 at different doses was compared to placebo in each group. RESULTS: A B-PAV ≥30% was the optimal cutoff associated with PAV regression following CER-001 infusions. CER-001 induced PAV regression in patients with B-PAV ≥30% but not in those with B-PAV <30% (-0.45%±2.65% vs. +0.34%±1.69%, P=0.01). Compared to placebo, the greatest PAV regression was observed with CER-001 3mg/kg in patients with B-PAV ≥30% (-0.96%±0.34% vs. -0.25%±0.31%, P=0.01), whereas there were no differences between placebo (+0.09%±0.36%) versus CER-001 in patients with B-PAV <30% (3 mg/kg; +0.41%±0.32%, P=0.39; 6 mg/kg; +0.27%±0.36%, P=0.76; 12 mg/kg; +0.32%±0.37%, P=0.97). CONCLUSIONS: Infusions of CER-001 3 mg/kg induced the greatest atheroma regression in ACS patients with higher B-PAV. These findings identify ACS patients with more extensive disease as most likely to benefit from HDL mimetic therapy.

9.
Cardiovasc Diagn Ther ; 7(1): 45-51, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28164012

RESUMO

BACKGROUND: High-density lipoprotein (HDL) is believed to have atheroprotective properties, but an effective HDL-based therapy remains elusive. Early studies have suggested that infusion of reconstituted HDL promotes reverse cholesterol transport and vascular reactivity. The CER-001 Atherosclerosis Regression Acute Coronary Syndrome Trial (CARAT) is investigating the impact of infusing an engineered pre-beta HDL mimetic containing sphingomyelin (SM) and dipalmitoyl phosphatidlyglycerol (CER-001) on coronary atheroma volume in patients with a recent acute coronary syndrome (ACS). METHODS: The CARAT is a phase 2, multicenter trial in which 292 patients with an ACS undergoing intracoronary ultrasonography and showing percent atheroma volume (PAV) greater than 30% are randomly assigned to treatment with ten infusions of CER-001 3 mg/kg or matching placebo, administered at weekly intervals. Intracoronary ultrasonography is repeated at the end of the treatment period. RESULTS: The primary endpoint is the nominal change in PAV. Safety and tolerability will also be evaluated. CONCLUSIONS: CARAT will establish whether serial 3 mg/kg infusions of an engineered pre-beta HDL mimetic containing SM and dipalmitoyl phosphatidlyglycerol (CER-001) will regress atherosclerotic plaque in patients with a recent ACS.

10.
Invest Ophthalmol Vis Sci ; 55(7): 4673-81, 2014 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-24970254

RESUMO

PURPOSE: CD147/basigin is a chaperone for lactate:H(+) cotransporters (monocarboxylate transporters) MCT1 and MCT4. We tested the hypothesis that MCT1 and -4 in corneal endothelium contribute to lactate efflux from stroma to anterior chamber and that silencing CD147 expression would cause corneal edema. METHODS: CD147 was silenced via small interfering ribonucleic acid (siRNA) transfection of rabbit corneas ex vivo and anterior chamber lenti-small hairpin RNA (shRNA) pseudovirus in vivo. CD147 and MCT expression was examined by Western blot, RT-PCR, and immunofluorescence. Functional effects were examined by measuring lactate-induced cell acidification, corneal lactate efflux, [lactate], central cornea thickness (CCT), and Azopt (a carbonic anhydrase inhibitor) sensitivity. RESULTS: In ex vivo corneas, 100 nM CD147 siRNA reduced CD147, MCT1, and MCT4 expression by 85%, 79%, and 73%, respectively, while MCT2 expression was unaffected. CD147 siRNA decreased lactate efflux from 3.9 ± 0.81 to 1.5 ± 0.37 nmol/min, increased corneal [lactate] from 19.28 ± 7.15 to 56.73 ± 8.97 nmol/mg, acidified endothelial cells (pHi = 6.83 ± 0.07 vs. 7.19 ± 0.09 in control), and slowed basolateral lactate-induced acidification from 0.0034 ± 0.0005 to 0.0012 ± 0.0005 pH/s, whereas apical acidification was unchanged. In vivo, CD147 shRNA increased CCT by 28.1 ± 0.9 µm at 28 days; Azopt increased CCT to 24.4 ± 3.12 vs. 12.0 ± 0.48 µm in control, and corneal [lactate] was 47.63 ± 6.29 nmol/mg in shCD147 corneas and 17.82 ± 4.93 nmol/mg in paired controls. CONCLUSIONS: CD147 is required for the expression of MCT1 and MCT4 in the corneal endothelium. Silencing CD147 slows lactate efflux, resulting in stromal lactate accumulation and corneal edema, consistent with lactate efflux as a significant component of the corneal endothelial pump.


Assuntos
Basigina/fisiologia , Endotélio Corneano/metabolismo , Ácido Láctico/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Animais , Câmara Anterior/metabolismo , Western Blotting , Inibidores da Anidrase Carbônica/farmacologia , Substância Própria/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Inativação Gênica/fisiologia , Concentração de Íons de Hidrogênio , Transporte de Íons , RNA Interferente Pequeno/genética , Coelhos , Reação em Cadeia da Polimerase em Tempo Real , Sulfonamidas/farmacologia , Tiazinas/farmacologia , Transfecção
11.
Mol Cell Endocrinol ; 363(1-2): 62-73, 2012 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-22863478

RESUMO

In the ovarian follicular membrana granulosa there are morphological and functional differences between cells adjacent to the follicular fluid lumen, or aligning the basal lamina. Amongst the observed functional differences are steroidogenic capacity and expression levels of a novel basal lamina, focimatrix; both of which increase in the later stages of antral follicle growth. A number of different studies have produced apparently inconsistent results as to which cell layers are more steroidogenic. To examine this systematically, individual bovine follicles, confirmed as healthy by post hoc histological examination, were used to isolate populations of apical and basal granulosa cells. Cell counts revealed that the respective groups did not differ in the numbers of cells, thus confirming the separation of these populations. We measured gene expression (quantitative RT-PCR, n=8-10, follicle diameter 14.0±0.5 mm) and protein levels (Western immunoblotting, n=14, follicle diameter 11.9±0.5 mm) and hormone production from granulosa cells (2.5×10(5) viable cells/well in serum-free conditions for 24 h, n=15, diameter 12±0.5 mm). Levels of mRNA of HSD3B1 and CYP19A1 and three focimatrix genes COL4A1, HSPG2 and LAMB2 and LHCGR were significantly lower in apical granulosa cells (P<0.05), whereas, expression of CYP11A1 and HSD17B1 were not different (P>0.05). The protein levels of steroidogenic enzymes P450scc and P450arom were significantly higher in apical cells (P<0.05), whereas those of 3ß-hydroxysteroid dehydrogenase and 17ß-hydroxysteroid dehydrogenase type 1 were not different (P>0.05). Progesterone production was significantly lower and oestradiol production was significantly higher in apical granulosa cells (P<0.05). These results confirm that apical and basal cells are functionally different, and the differences might be explained by the location of cells of different ages and maturity within the membrana granulosa. Discrepancies in the literature on their steroidogenic capacity may reflect differences in the steroidogenic parameters measured.


Assuntos
Estradiol/biossíntese , Proteínas da Matriz Extracelular/metabolismo , Expressão Gênica , Células da Granulosa/metabolismo , Progesterona/biossíntese , 3-alfa-Hidroxiesteroide Desidrogenase (B-Específica)/genética , 3-alfa-Hidroxiesteroide Desidrogenase (B-Específica)/metabolismo , Animais , Aromatase/genética , Aromatase/metabolismo , Bovinos , Células Cultivadas , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Proteínas da Matriz Extracelular/genética , Feminino , Células da Granulosa/enzimologia , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Folículo Ovariano/citologia , Receptores da Gonadotropina/genética , Receptores da Gonadotropina/metabolismo
12.
Invest Ophthalmol Vis Sci ; 53(4): 2020-9, 2012 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-22410572

RESUMO

PURPOSE: To confirm the expression of monocarboxylate transporters (MCT) 1, 2, and 4 in rabbit CE and to test the hypothesis that cellular buffering contributed by HCO3⁻, NBCe1, and carbonic anhydrase (CA) activity facilitates lactate-H⁺ efflux thereby controlling corneal hydration in vivo. METHODS: MCT1-4 expression of rabbit endothelium was examined by Western blotting and immunofluorescence staining. Lactate-induced acidification (LIA) was measured in perfused CE in the presence and absence of HCO3⁻ and acetazolamide (ACTZ) using tissue treated with siRNA specific to MCT1, 2, and 4. Corneal thickness and lactate concentration were measured in New Zealand White rabbits treated with the topical CA inhibitor Azopt, and from eyes that were injected intracamerally with ouabain, disodium 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS), and shRNA specific to the 1Na⁺:2HCO3⁻ cotransporter NBCe1. RESULTS: MCT1 and MCT4 are localized to the lateral membrane, while MCT2 is apical. Cell pH measurements showed LIA in response to 40 mM lactate in bicarbonate free (BF) Ringer's that was inhibited by niflumic acid and by MCT siRNA knockdown, and significantly reduced in the presence of HCO3⁻. Lactate-dependent proton flux in vitro was not significantly greater in the presence of HCO3⁻ or reduced by ACTZ. However, when active transport, NBCe1, or CA activity was disrupted in vivo, corneal edema ensued and was associated with significant corneal lactate accumulation. CONCLUSIONS: MCT1, 2, and 4 are expressed in rabbit CE on both the apical and basolateral surfaces and function to transport lactate-H⁺. Lactate-H⁺ flux is facilitated by active transport, HCO3⁻ transport and CA activity, disruption of which causes corneal edema in vivo and indicates that facilitation of lactate efflux is a component of the endothelial pump.


Assuntos
Endotélio Corneano/metabolismo , Ácido Láctico/metabolismo , Transportadores de Ácidos Monocarboxílicos/biossíntese , Proteínas Musculares/biossíntese , Simportadores/biossíntese , Animais , Transporte Biológico Ativo/fisiologia , Western Blotting , Endotélio Corneano/citologia , Concentração de Íons de Hidrogênio , Transporte de Íons , Coelhos
13.
PLoS One ; 7(12): e51427, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23284695

RESUMO

Human corneal endothelial cells (HCEnCs) form a monolayer of hexagonal cells whose main function is to maintain corneal clarity by regulating corneal hydration. HCEnCs are derived from neural crest and are arrested in the post-mitotic state. Thus cell loss due to aging or corneal endothelial disorders leads to corneal edema and blindness-the leading indication for corneal transplantation. Here we show the existence of morphologically distinct subpopulations of HCEnCs that are interspersed among primary cells and exhibit enhanced self-renewal competence and lack of phenotypic signs of cellular senescence. Colonies of these uniform and hexagonal HCEnCs (HCEnC-21) were selectively isolated and demonstrated high proliferative potential that was dependent on endogenous upregulation of telomerase and cyclin D/CDK4. Further transduction of HCEnC-21 with telomerase yielded a highly proliferative corneal endothelial cell line (HCEnT-21T) that was devoid of oncogenic transformation and retained critical corneal endothelial cell characteristics and functionality. This study will significantly impact the fields of corneal cell biology and regenerative medicine.


Assuntos
Endotélio Corneano/citologia , Telomerase/metabolismo , Biomarcadores/metabolismo , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Forma Celular , Senescência Celular , Ciclina D/metabolismo , Quinase 4 Dependente de Ciclina/metabolismo , Endotélio Corneano/enzimologia , Endotélio Corneano/metabolismo , Humanos , Bombas de Íon/metabolismo , Transporte de Íons , Telomerase/genética , Transdução Genética , Proteína Supressora de Tumor p53/metabolismo
14.
Invest Ophthalmol Vis Sci ; 52(11): 8086-93, 2011 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-21896839

RESUMO

PURPOSE: To identify and localize the monocarboxylate transporters (MCTs) expressed in bovine corneal endothelial cells (BCEC) and to test the hypothesis that buffering contributed by HCO(3)(-), sodium bicarbonate cotransporter (NBCe1), sodium hydrogen exchanger (NHE), and carbonic anhydrase (CA) activity facilitates lactate flux. METHODS: MCT1-4 expression was screened by RT-PCR, Western blot analysis, and immunofluorescence. Endogenous lactate efflux and/or pH(i) were measured in BCEC in HCO(3)(-)-free or HCO(3)(-)-rich Ringer, with and without niflumic acid (MCT inhibitor), acetazolamide (ACTZ, a CA inhibitor), 5-(N-Ethyl-N-isopropyl)amiloride (EIPA) (Na(+)/H(+) exchange blocker), disodium 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS; anion transport inhibitor), or with NBCe1-specific small interfering (si) RNA-treated cells. RESULTS: MCT1, 2, and 4 are expressed in BCEC. MCT1 was localized to the lateral membrane, MCT2 was lateral and apical, while MCT4 was apical. pH(i) measurements showed significant lactate-induced cell acidification (LIA) in response to 20-second pulses of lactate. Incubation with niflumic acid significantly reduced the rate of pHi change (dpH(i)/dt) and lactate-induced cell acidification. EIPA inhibited alkalinization after lactate removal. Lactate-dependent proton flux was significantly greater in the presence of HCO(3)(-) but was reduced by ACTZ. Efflux of endogenously produced lactate was significantly faster in the presence of HCO(3)(-), was greater on the apical surface, was reduced on the apical side by ACTZ, as well as on the apical and basolateral side by NBCe1-specific siRNA, DIDS, or EIPA. CONCLUSIONS: MCT1, 2, and 4 are expressed in BCEC on both the apical and basolateral membrane (BL) surfaces consistent with niflumic acid-sensitive lactate-H(+) transport. Lactate dependent proton flux can activate Na(+)/H(+) exchange and be facilitated by maximizing intracellular buffering capacity through the presence of HCO(3)(-), HCO(3)(-) transport, NHE and CA activity.


Assuntos
Bicarbonatos/metabolismo , Anidrases Carbônicas/metabolismo , Endotélio Corneano/metabolismo , Ácido Láctico/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Simportadores de Sódio-Bicarbonato/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Amilorida/análogos & derivados , Amilorida/farmacologia , Animais , Western Blotting , Inibidores da Anidrase Carbônica/farmacologia , Bovinos , Células Cultivadas , Endotélio Corneano/efeitos dos fármacos , Técnica Indireta de Fluorescência para Anticorpo , Concentração de Íons de Hidrogênio , Ácido Niflúmico/farmacologia , Reação em Cadeia da Polimerase em Tempo Real
15.
Invest Ophthalmol Vis Sci ; 51(10): 5190-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20445126

RESUMO

PURPOSE: To evaluate the role of the sodium bicarbonate cotransporter (NBCe1) as a component of the corneal endothelial pump in the in vivo rabbit eye. METHODS: Lentiviruses with NBCe1 shRNA and GFP expression cassettes were injected intracamerally. Knockdown efficacy was determined 1 week to 4 weeks later by immunofluorescence, Western blot analysis, and PCR. Functional effects were monitored by corneal thickness (CT) and brinzolamide sensitivity. RESULTS: Within 24 hours there was a modest anterior chamber inflammation that resolved within 48 hours. At 4 × 10(6) IFU, more than 95% of the corneal endothelial surface showed GFP fluorescence above background within 7 days. At 14 to 21 days, signs of anterior chamber inflammation reemerged, and endothelial cell GFP fluorescence disappeared within 40 days after injection. The second phase of inflammation could be avoided by using GFP-less viruses. There was no significant difference in CT between scrambled sequence and NBCe1 shRNA-injected eyes over 3 weeks. Two drops of 1% brinzolamide produced 7.85% ± 3.3% corneal swelling within 5 hours of topical instillation. However, in corneas showing more than 25% NBCe1 knockdown (30 of 42 rabbits; 59% ± 15% knockdown), corneal swelling was significantly higher (10.1% ± 2.9%) relative to control eyes. CONCLUSIONS: FIV-based lentiviral vectors can transfect CE with shRNA in rabbits. The response to GFP is consistent, with previous studies showing the production of anti-GFP antibodies. Partial knockdown of NBCe1 did not affect baseline CT, which is consistent with the corneal endothelium having a substantial functional reserve. Provocative testing using, brinzolamide, however, revealed an underlying deficiency, confirming the importance of NBCe1 bicarbonate transport and demonstrating the concerted action between NBCe1 and carbonic anhydrases.


Assuntos
Endotélio Corneano/metabolismo , Inativação Gênica/fisiologia , Proteínas de Membrana Transportadoras/fisiologia , Simportadores de Sódio-Bicarbonato/fisiologia , Animais , Bicarbonatos/metabolismo , Transporte Biológico Ativo/efeitos dos fármacos , Western Blotting , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/fisiologia , Técnicas de Silenciamento de Genes , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Vírus da Imunodeficiência Felina/genética , Pressão Intraocular , Microscopia de Fluorescência , Interferência de RNA , Coelhos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfonamidas/farmacologia , Tiazinas/farmacologia , Transfecção
16.
BMC Med Genomics ; 2: 33, 2009 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-19500411

RESUMO

BACKGROUND: The use of gene expression in venous blood either as a pharmacodynamic marker in clinical trials of drugs or as a diagnostic test requires knowledge of the variability in expression over time in healthy volunteers. Here we defined a normal range of gene expression over 6 months in the blood of four cohorts of healthy men and women who were stratified by age (22-55 years and > 55 years) and gender. METHODS: Eleven immunomodulatory genes likely to play important roles in inflammatory conditions such as rheumatoid arthritis and infection in addition to four genes typically used as reference genes were examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), as well as the full genome as represented by Affymetrix HG U133 Plus 2.0 microarrays. RESULTS: Gene expression levels as assessed by qRT-PCR and microarray were relatively stable over time with approximately 2% of genes as measured by microarray showing intra-subject differences over time periods longer than one month. Fifteen genes varied by gender. The eleven genes examined by qRT-PCR remained within a limited dynamic range for all individuals. Specifically, for the seven most stably expressed genes (CXCL1, HMOX1, IL1RN, IL1B, IL6R, PTGS2, and TNF), 95% of all samples profiled fell within 1.5-2.5 Ct, the equivalent of a 4- to 6-fold dynamic range. Two subjects who experienced severe adverse events of cancer and anemia, had microarray gene expression profiles that were distinct from normal while subjects who experienced an infection had only slightly elevated levels of inflammatory markers. CONCLUSION: This study defines the range and variability of gene expression in healthy men and women over a six-month period. These parameters can be used to estimate the number of subjects needed to observe significant differences from normal gene expression in clinical studies. A set of genes that varied by gender was also identified as were a set of genes with elevated expression in a subject with iron deficiency anemia and another subject being treated for lung cancer.

17.
Mol Ecol ; 18(12): 2588-601, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19457186

RESUMO

Mediterranean annual grasses have invaded California and have replaced vast areas of native grassland. One of these invasive grasses is Brachypodium distachyon, a new model species for the grasses with extensive genomic resources and a nearly completed genome sequence. This study shows that the level of genetic variation in invaded California grasslands is lower compared to the native range in Eurasia. The invaded regions are characterized by highly differentiated populations of B. distachyon isolated by distance, most likely as a result of founder effects and a dearth of outcrossing events. EXP6 and EXP10 encoding alpha-expansins responsible for rapid growth, and AGL11 and AGL13 encoding proteins involved in vegetative phase regulation, appear to be under purifying selection with no evidence for local adaptation. Our data show that B. distachyon has diverged only recently from related Brachypodium species and that tetraploidization might have been as recent as a few thousand years ago. Observed low genetic variation in EXP10 and AGL13 appears to have been present in Eurasia before tetraploidization, potentially as a result of strong selective pressures on advantageous mutations, which are most likely responsible for its fast growth and rapid completion of its life cycle.


Assuntos
Evolução Molecular , Genética Populacional , Poaceae/genética , California , DNA de Plantas/genética , Genes de Plantas , Variação Genética , Genótipo , Repetições de Microssatélites , Poliploidia , Análise de Sequência de DNA
18.
Cell Signal ; 20(6): 1190-7, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18407463

RESUMO

The G(s) and G(i) pathways interact to control the levels of intracellular cAMP. Although coincident signaling through G(s) and G(i)-coupled receptors can attenuate G(s)-stimulated cAMP levels, it is not known if prior activation of the G(i) pathway can affect signaling by G(s)-coupled receptors. We have found that activated Galpha(o/i) interact with RGS20, a GTPase activating protein for members of the Galpha(omicron/i) family. Interaction between Galpha(o/i) and RGS20 results in decreased cellular levels of RGS20. This decrease was induced by activated Galpha(o) and Galpha(i2) but not by Galpha(q), Galpha(i1) or Galpha(i3.) The Galpha(o/i)-induced decrease in RGS20 can be blocked by proteasomal inhibitors lactacystin or MG132. Activated Galpha(o) stimulates the ubiquitination of RGS20. The serotonin-1A receptor that couples to G(o/i) reduces the levels of RGS20 and this effect is blocked by lactacystin, suggesting that G(o/i) promotes the degradation of RGS20. Expression of RGS20 attenuates the inhibition of beta-adrenergic receptor-induced cAMP levels mediated by the serotonin-1A receptor. Prior activation of the serotonin-1A receptor results in loss of the RGS20-mediated attenuation, and the loss of attenuation is blocked when lactacystin is included during the prior treatment. These observations suggest that G(o/i)-coupled receptors, by stimulating the degradation of RGS20, can regulate how subsequent activation of the G(s) and G(i) pathways controls cellular cAMP levels, thus allowing for signal integration.


Assuntos
Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas RGS/metabolismo , Animais , Células COS , Chlorocebus aethiops , Receptor 5-HT1A de Serotonina/metabolismo , Transdução de Sinais , Ubiquitinação
19.
Exp Biol Med (Maywood) ; 232(3): 445-53, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17327479

RESUMO

To develop new and safe approaches to protect and preserve the function of the human corneal endothelium (HCE), we have established an in vitro model of cell loss using an HCE cell line and have examined the potential for hypoxia conditioning to protect HCE from death induced by two ROS generating cytotoxins (tertiary butyl hydroperoxide [tBHP] and paraquat [PQ]). Cell death was assessed by flow cytometric analysis of Annexin-V (An) and propidium iodide (PI) double staining and oligonucleosome production. Mitochondrial membrane potential (MMP) was measured with JC-1 fluorescent dye to determine possible associations between MMP preservation and cell survival. PQ and tBHP both induced HCE cell death in a dose-dependent manner, with 48% and 32% of An(+) cells observed with 60 microM tBHP and 500 microM PQ, respectively. In addition, this level of tBHP and PQ resulted in 66% and 49% decreases in MMP, respectively. Hypoxia (0.6% +/- 0.1% oxygen) pretreatment (8 hrs) significantly reduced An(+) cells caused by 60 microM tBHP to 15%, whereas hypoxia had no effect on the decreased MMP. Hypoxia pretreatments (24 hrs) slightly reduced An(+) cells caused by 500 microM PQ to 25% and completely prevented the induced MMP reduction. Conversely, hypoxia posttreatment (24 hrs) resulted in a greater inhibition of cell death than pretreatment and yet failed to prevent the PQ-induced MMP collapse. In conclusion, these results suggest that hypoxia can sufficiently protect HCE cells against cell death caused by tBHP and PQ, although no direct link between hypoxia cell protection and MMP preservation was observed.


Assuntos
Endotélio Corneano/efeitos dos fármacos , Paraquat/toxicidade , terc-Butil Hidroperóxido/toxicidade , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Hipóxia Celular/fisiologia , Linhagem Celular , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Endotélio Corneano/citologia , Endotélio Corneano/fisiologia , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Nucleossomos/efeitos dos fármacos
20.
Eye Contact Lens ; 32(1): 39-45, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16415693

RESUMO

PURPOSE: To evaluate long-term safety and effectiveness of overnight orthokeratology in a large sample of myopes by using three different lens designs and the highly gas-permeable Boston XO material (Bausch & Lomb, Rochester, NY). METHODS: A total of three hundred forty-two subjects, 99 of whom were juveniles, were enrolled in the investigation at 26 clinical centers in the United States and Canada. Three different lens designs in Boston XO material were used. Subjects were limited to a measured visual need for correction of myopia less than or equal to 4.00 diopters and astigmatism less than or equal to 1.50 diopters with best-corrected Snellen visual acuity of 20/40 or better. Refractive error and unaided visual acuity were used to determine the effectiveness of the procedure at short-term (1 month) and long-term (12 months). The safety of the procedure was determined by the symptoms reported, and slitlamp findings suggested physiologic rejection of the procedure. RESULTS: One hundred thirty-three adults and 68 juveniles completed the 12-month study. More than 60% of the subjects reached 20/20 vision or better at the end of 1 month of overnight lens wear, and this number remained stable during the next 11 months. A reduction in myopia of 70% and of more than 90% was measured at the 1- and 12-month visits, respectively. Safety data indicate a decrease in symptoms and in general a decrease in positive slitlamp findings with time. CONCLUSIONS: The procedure with all three lenses in Boston XO material is effective. However, the safe use of orthokeratology lenses is predicated on the emphasis of clear patient direction on how to wear and take care of the lenses followed by regular examinations by an eye care practitioner.


Assuntos
Lentes de Contato , Miopia/terapia , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Desenho de Prótese , Refração Ocular , Fatores de Tempo , Resultado do Tratamento , Acuidade Visual
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