Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Biomaterials ; 302: 122363, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37898021

RESUMO

Despite numerous efforts to generate mature human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs), cells often remain immature, electrically isolated, and may not reflect adult biology. Conductive polymers are attractive candidates to facilitate electrical communication between hPSC-CMs, especially at sub-confluent cell densities or diseased cells lacking cell-cell junctions. Here we electrospun conductive polymers to create a conductive fiber mesh and assess if electrical signal propagation is improved in hPSC-CMs seeded on the mesh network. Matrix characterization indicated fiber structure remained stable over weeks in buffer, scaffold stiffness remained near in vivo cardiac stiffness, and electrical conductivity scaled with conductive polymer concentration. Cells remained adherent and viable on the scaffolds for at least 5 days. Transcriptomic profiling of hPSC-CMs cultured on conductive substrates for 3 days showed upregulation of cardiac and muscle-related genes versus non-conductive fibers. Structural proteins were more organized and calcium handling was improved on conductive substrates, even at sub-confluent cell densities; prolonged culture on conductive scaffolds improved membrane depolarization compared to non-conductive substrates. Taken together, these data suggest that blended, conductive scaffolds are stable, supportive of electrical coupling in hPSC-CMs, and promote maturation, which may improve our ability to model cardiac diseases and develop targeted therapies.


Assuntos
Miócitos Cardíacos , Células-Tronco Pluripotentes , Humanos , Polímeros/metabolismo , Linhagem Celular , Diferenciação Celular , Condutividade Elétrica
2.
Curr Opin Biotechnol ; 74: 122-128, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34861477

RESUMO

Applications for stem cells have ranged from therapeutic interventions to more conventional screening and in vitro modeling, but significant limitations to each is due to the lack of maturity from decades old monolayer protocols. While those methods remain the 'gold standard,' newer three-dimensional methods, when combined with engineered niche, stand to significantly improve cell maturity and enable new applications. Here in three parts, we first discuss past methods, and where and why we believe those methods produced suboptimal myocytes. Second, we note how newer methods are moving the field into an era of cell mechanical, electrical, and biological maturity. Finally, we highlight how these improvements will solve issues of scale and engraftment to yield clinical success. It is our conclusion that only through a combination of diverse cell populations and engineered niche will we create an engineered heart tissue with the maturity and vasculature to integrate successfully into a host.


Assuntos
Coração , Engenharia Tecidual , Diferenciação Celular , Engenharia Tecidual/métodos
3.
Horm Res Paediatr ; 94(1-2): 1-8, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34044395

RESUMO

BACKGROUND: The effects of hyperandrogenism and steroid treatment on bone mineral density (BMD) in patients with congenital adrenal hyperplasia (CAH) are controversial. OBJECTIVES: The objectives of this study were to characterize BMD and fractures in patients with CAH and to identify whether there is an association between alterations in BMD, nutritional status, and variables related to the disease. METHODS: A cross-sectional descriptive study was conducted to explore clinical, hormonal, dairy consumption, physical activity, and BMD variables in patients with CAH due to 21-hydroxylase deficiency and controls matched by age, gender, skin color, body mass index, and Tanner scale. RESULTS: Fifty subjects (CAH n = 25; females n = 42 [84%]) with a mean age of 15.9 ± 5.8 years were included in the study. White skin color predominated in 34 subjects (68%), mestizo in 11 (22%), and black in 5 (10%). In patients with CAH, BMD lumbar spine was decreased compared to that in controls (0.83 ± 0.23 vs. 0.98 ± 0.26 g/cm3, p = 0.004). BMD femur was also decreased in patients with CAH; however, this was not significant (0.95 ± 0.20 vs. 1.04 ± 0.24 g/cm3, p = 0.17). There was a positive relationship between age at diagnosis, age of initiation of glucocorticoid treatment, and testosterone levels with all measurements of BMD. The daily glucocorticoid dose was negatively related to BMD. No fractures were found. CONCLUSIONS: Patients with CAH had decreased BMD, especially in lumbar spine. Increased androgen exposure seemed to improve, while increased glucocorticoid dose impaired BMD.


Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico por imagem , Densidade Óssea/efeitos dos fármacos , Fêmur/diagnóstico por imagem , Fludrocortisona/uso terapêutico , Glucocorticoides/uso terapêutico , Hidrocortisona/uso terapêutico , Vértebras Lombares/diagnóstico por imagem , Absorciometria de Fóton , Adolescente , Hiperplasia Suprarrenal Congênita/tratamento farmacológico , Adulto , Criança , Estudos Transversais , Feminino , Fêmur/efeitos dos fármacos , Fludrocortisona/administração & dosagem , Glucocorticoides/administração & dosagem , Humanos , Hidrocortisona/administração & dosagem , Vértebras Lombares/efeitos dos fármacos , Masculino , Adulto Jovem
4.
In. Licea Puig, Manuel Emiliano. Diabetes mellitus. Una mirada integral. La Habana, Editorial Ciencias Médicas, 2021. .
Monografia em Espanhol | CUMED | ID: cum-77382
5.
Rev. cuba. endocrinol ; 31(3): e188, sept.-dic. 2020. tab, graf
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1156391

RESUMO

Introducción: La terapia de reemplazo con glucocorticoides sigue siendo el paradigma de tratamiento en las formas clásicas de la hiperplasia suprarrenal congénita. Sus efectos sobre la mineralización ósea no están totalmente claros. Objetivo: Describir las variables relacionadas con la masa ósea en pacientes con HSC que reciben tratamiento esteroideo sustitutivo. Método: Se realizó un estudio descriptivo transversal que exploró variables clínicas, bioquímicas, hormonales y de mineralización óseaen 25 pacientes con hiperplasia suprarrenal congénita por déficit de 21OHasa y tratamiento esteroideo. Resultados: 21 (84,0 por ciento) femeninas, el mayor grupo correspondió a los adolescentes entre 10 y 19 años (52 por ciento). Predominaron las formas clásicas con 22 pacientes (88,0 por ciento), de ellas 13 (52 por ciento) fueron perdedoras de sal, 9 virilizantes simples (36,0 por ciento) y solo 3 (12,0 por ciento) formas no clásicas. El esteroide más utilizado fue la hidrocortisona en 16 pacientes (64 por ciento), a una dosis media de 22,10±12,00 mg diarios, correspondiendo con 17,09±5,71 mg/m2sc/día y como promedio llevaban 14,02±6,57 años de terapéutica sustitutiva. No se detectaron alteraciones del metabolismo fosfocálcico. La densidad y el contenido mineral óseo en columna y en fémur mostraron valores superiores en las formas no clásicas de la enfermedad, seguidos de la virilizante simple y finalmente los pacientes perdedores de sal, en ninguno de los casos con significación estadística. Conclusiones: Los pacientes con hiperplasia suprarrenal congénita del presente estudio mostraron en su mayoría una masa ósea conservada(AU)


Introduction: Glucocorticoid replacement therapy is still the treatment´s paradigm in the classic forms of congenital adrenal hyperplasia. Its effects on bone mineralization are not entirely clear. Objective: Describe bone mass-related variables in congenital adrenal hyperplasia patients receiving substitute steroid treatment. Method: A cross-sectional descriptive study was conducted exploring clinical, biochemical, hormonal and bone mineralization variables in 25 patients with congenital adrenal hyperplasia caused by 21OHase deficiency and steroid treatments. Results: 21 women (84.0 percent); the largest group was of adolescents between the age of 10 and 19 years (52 percent).Classical forms predominated with 22 patients (88.0 percent), including 13 of them (52 percent) that were salt losers, 9 simple virilizers (36.0 percent) and only 3 (12.0 percent) of non-classical forms. The most commonly used steroid was hydrocortisone in 16 patients (64 percent), at an average dose of 22.10±12.00 mg daily, corresponding to 17.09±5.71 mg/m2sc/day and on average carried 14.02±6.57 years of substitute therapy. No alterations in the phosphocalcic metabolism were detected. Density and bone mineral content in the spinal column and femur showed higher values in non-classical forms of the disease, followed by simple virilizing and finally the salt loser patients, in none of the cases with statistical significance. Conclusions: Patients with congenital adrenal hyperplasia in this study showed mostly preserved bone mass(AU)


Assuntos
Humanos , Feminino , Criança , Adolescente , Calcificação Fisiológica/fisiologia , Hidrocortisona/uso terapêutico , Densidade Óssea , Hiperplasia Suprarrenal Congênita/terapia , Epidemiologia Descritiva , Estudos Transversais
6.
Int Wound J ; 6(1): 67-72, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19291119

RESUMO

Previous studies have shown that an epidermal growth factor-based formulation (Heberprot-P) can enhance granulation of high-grade diabetic foot ulcers (DFU). The aim of this study was to explore the clinical effects of this administration up to complete wound closure. A pilot study in 20 diabetic patients with full-thickness lower extremity ulcers of more than 4 weeks of evolution was performed. Mean ulcer size was 16.3 +/- 21.3 cm(2). Intralesional injections of 75 microg of Heberprot-P three times per week were given up to complete wound healing. Full granulation response was achieved in all 20 patients in 23.6 +/- 3.8 days. Complete wound closure was obtained in 17 (85%) cases in 44.3 +/- 8.9 days. Amputation was not necessary in any case and only one relapse was notified. The most frequent adverse events were tremors, chills, pain and odour at site of administration and local infection. The therapeutic scheme of intralesional Heberprot-P administration up to complete closure can be safe and suitable to improve the therapeutic goal in terms of healing of chronic DFU.


Assuntos
Pé Diabético/tratamento farmacológico , Fator de Crescimento Epidérmico/administração & dosagem , Idoso , Pé Diabético/patologia , Formas de Dosagem , Esquema de Medicação , Feminino , Seguimentos , Humanos , Injeções Intralesionais , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Resultado do Tratamento , Cicatrização
7.
Cases J ; 1(1): 105, 2008 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-18710555

RESUMO

INTRODUCTION: Phendimetrazine is a medication currently being used to help patients with weight loss. It shares a chemical structure with amphetamines. As such, it shares some of the same toxicities, which can include cardiac toxicity. This case highlights this principle. CASE PRESENTATION: a 54 year old Caucasian female presented to our urgent care facility with complaints of chest pains and other symptoms suggestive of acute coronary syndrome. Ultimately, she was transferred to the emergency room. After evaluation there, it appeared she was having demand ischemia from prescription diet pills CONCLUSION: This case report demonstrates the potential dangers of amphetamine based diet pills. There have been other cases of cardiomyopathies related to phendimetrazine, but it is something that is rarely recognized in an outpatient setting. A case such as this demonstrates the importance of obtaining a careful medication history in all patients and in recognizing diet pills with an amphetamine base can cause cardiac toxicity.

8.
Pharm Res ; 25(10): 2447-61, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18633694

RESUMO

PURPOSE: Tubulointerstitial fibrosis is a final common pathway to end-stage chronic kidney diseases, which are characterized by elevated renal angiotensin II (AngII) production. This peptide participates in kidney damage inducing fibrosis and epithelial mesenchymal transition (EMT). Our aim was to describe potential therapeutic targets in AngII-induced EMT, investigating the blockade of different intracellular pathways. METHODS: Studies were done in human tubular epithelial cells (HK2 cell line), evaluating changes in phenotype and EMT markers (Western blot and immunofluorescence). RESULTS: Treatment of HK2 cells with AngII for 3 days caused transdifferentiation into myofibroblast-like cells. The blockade of MAPKs cascade, using specific inhibitors of p38 (SB203580), extracellular signal-regulated kinase1/2 (ERK; PD98059) and Jun N-terminal kinase (JNK) (SP600125), diminished AngII-induced EMT. The blockade of RhoA/ROCK pathway, by transfection of a RhoA dominant-negative vector or by ROCK inhibition with Y-27632 or fasudil, inhibited EMT caused by AngII. Connective tissue growth factor (CTGF) is a downstream mediator of AngII-induced EMT. MAPKs and ROCK inhibitors blocked CTGF overexpression induced by AngII. HMG-CoA reductase inhibitors, although blocked AngII-mediated kinases activation, only partially diminished EMT and did not regulate CTGF. CONCLUSIONS: These data suggest a potential therapeutic use of kinase inhibitors in renal fibrosis.


Assuntos
Angiotensina II/metabolismo , Transdiferenciação Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Túbulos Renais Proximais/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Quinases Associadas a rho/antagonistas & inibidores , Atorvastatina , Linhagem Celular , Fator de Crescimento do Tecido Conjuntivo , Células Epiteliais/enzimologia , Células Epiteliais/patologia , Fibrose , Ácidos Heptanoicos/farmacologia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Proteínas Imediatamente Precoces/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Túbulos Renais Proximais/enzimologia , Túbulos Renais Proximais/patologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fenótipo , Pirróis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sinvastatina/farmacologia , Fatores de Tempo , Transfecção , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...