Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Immunity ; 55(1): 115-128.e9, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35021053

RESUMO

The immune checkpoint receptor PD-1 on T follicular helper (Tfh) cells promotes Tfh:B cell interactions and appropriate positioning within tissues. Here, we examined the impact of regulation of PD-1 expression by the genomic organizer SATB1 on Tfh cell differentiation. Vaccination of CD4CreSatb1f/f mice enriched for antigen-specific Tfh cells, and TGF-ß-mediated repression of SATB1 enhanced Tfh differentiation of human T cells. Mechanistically, high Icos expression in Satb1-/- CD4+ T cells promoted Tfh cell differentiation by preventing T follicular regulatory cell skewing and resulted in increased isotype-switched B cell responses in vivo. Ovarian tumors in CD4CreSatb1f/f mice accumulated tumor antigen-specific, LIGHT+CXCL13+IL-21+ Tfh cells and tertiary lymphoid structures (TLS). TLS formation decreased tumor growth in a CD4+ T cell and CXCL13-dependent manner. The transfer of Tfh cells, but not naive CD4+ T cells, induced TLS at tumor beds and decreased tumor growth. Thus, TGF-ß-mediated silencing of Satb1 licenses Tfh cell differentiation, providing insight into the genesis of TLS within tumors.


Assuntos
Centro Germinativo/imunologia , Linfócitos do Interstício Tumoral/imunologia , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Estruturas Linfoides Terciárias/imunologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Diferenciação Celular , Regulação da Expressão Gênica , Inativação Gênica , Genótipo , Proteínas de Ligação à Região de Interação com a Matriz/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo , Fator de Crescimento Transformador beta/genética
2.
Nature ; 591(7850): 464-470, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536615

RESUMO

Most ovarian cancers are infiltrated by prognostically relevant activated T cells1-3, yet exhibit low response rates to immune checkpoint inhibitors4. Memory B cell and plasma cell infiltrates have previously been associated with better outcomes in ovarian cancer5,6, but the nature and functional relevance of these responses are controversial. Here, using 3 independent cohorts that in total comprise 534 patients with high-grade serous ovarian cancer, we show that robust, protective humoral responses are dominated by the production of polyclonal IgA, which binds to polymeric IgA receptors that are universally expressed on ovarian cancer cells. Notably, tumour B-cell-derived IgA redirects myeloid cells against extracellular oncogenic drivers, which causes tumour cell death. In addition, IgA transcytosis through malignant epithelial cells elicits transcriptional changes that antagonize the RAS pathway and sensitize tumour cells to cytolytic killing by T cells, which also contributes to hindering malignant progression. Thus, tumour-antigen-specific and -antigen-independent IgA responses antagonize the growth of ovarian cancer by governing coordinated tumour cell, T cell and B cell responses. These findings provide a platform for identifying targets that are spontaneously recognized by intratumoural B-cell-derived antibodies, and suggest that immunotherapies that augment B cell responses may be more effective than approaches that focus on T cells, particularly for malignancies that are resistant to checkpoint inhibitors.


Assuntos
Antígenos de Neoplasias/imunologia , Imunoglobulina A/imunologia , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Linfócitos T Citotóxicos/imunologia , Transcitose , Especificidade de Anticorpos , Antígenos CD/imunologia , Linhagem Celular , Progressão da Doença , Feminino , Humanos , Neoplasias Ovarianas/prevenção & controle , Receptores Fc/imunologia , Família de Moléculas de Sinalização da Ativação Linfocitária/imunologia , Transcitose/imunologia , Microambiente Tumoral/imunologia
3.
Adv Funct Mater ; 29(8)2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35586798

RESUMO

The goal of human-on-a-chip systems is to capture multi-organ complexity and predict the human response to compounds within physiologically relevant platforms. The generation and characterization of such systems is currently a focal point of research given the long-standing inadequacies of conventional techniques for predicting human outcome. Functional systems can measure and quantify key cellular mechanisms that correlate with the physiological status of a tissue, and can be used to evaluate therapeutic challenges utilizing many of the same endpoints used in animal experiments or clinical trials. Culturing multiple organ compartments in a platform creates a more physiologic environment (organ-organ communication). Here is reported a human 4-organ system composed of heart, liver, skeletal muscle and nervous system modules that maintains cellular viability and function over 28 days in serum-free conditions using a pumpless system. The integration of non-invasive electrical evaluation of neurons and cardiac cells and mechanical determination of cardiac and skeletal muscle contraction allows the monitoring of cellular function especially for chronic toxicity studies in vitro. The 28 day period is the minimum timeframe for animal studies to evaluate repeat dose toxicity. This technology could be a relevant alternative to animal testing by monitoring multi-organ function upon long term chemical exposure.

4.
Circ Res ; 110(1): 34-46, 2012 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-22076636

RESUMO

RATIONALE: Positive signals, such as vascular endothelial growth factor, direct endothelial cells (ECs) to specific locations during blood vessel formation. Less is known about repulsive signal contribution to shaping vessels. Recently, "neuronal guidance cues" have been shown to influence EC behavior, particularly in directing sprouting angiogenesis by repelling ECs. However, their role during de novo blood vessel formation remains unexplored. OBJECTIVE: To identify signals that guide and pattern the first mammalian blood vessels. METHODS AND RESULTS: Using genetic mouse models, we show that blood vessels are sculpted through the generation of stereotyped avascular zones by EC-repulsive cues. We demonstrate that Semaphorin3E (Sema3E) is a key factor that shapes the paired dorsal aortae in mouse, as sema3E(-/-) embryos develop an abnormally branched aortic plexus with a markedly narrowed avascular midline. In vitro cultures and avian grafting experiments show strong repulsion of ECs by Sema3E-expressing cells. We further identify the mouse notochord as a rich source of multiple redundant neuronal guidance cues. Mouse embryos that lack notochords fail to form cohesive aortic vessels because of loss of the avascular midline, yet maintain lateral avascular zones. We demonstrate that lateral avascular zones are directly generated by the lateral plate mesoderm, a critical source of Sema3E. CONCLUSIONS: These findings demonstrate that Sema3E-generated avascular zones are critical regulators of mammalian cardiovascular patterning and are the first to identify a repulsive role for the lateral plate mesoderm. Integration of multiple, and in some cases redundant, repulsive cues from various tissues is critical to patterning the first embryonic blood vessels.


Assuntos
Vasos Sanguíneos/embriologia , Embrião de Mamíferos/irrigação sanguínea , Endotélio Vascular/embriologia , Glicoproteínas/fisiologia , Proteínas de Membrana/fisiologia , Neovascularização Fisiológica/fisiologia , Transdução de Sinais/fisiologia , Animais , Aorta/citologia , Aorta/embriologia , Vasos Sanguíneos/citologia , Células Cultivadas , Proteínas do Citoesqueleto , Endotélio Vascular/citologia , Fatores de Transcrição Forkhead/deficiência , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/fisiologia , Glicoproteínas/deficiência , Glicoproteínas/genética , Fator 3-beta Nuclear de Hepatócito/deficiência , Fator 3-beta Nuclear de Hepatócito/genética , Fator 3-beta Nuclear de Hepatócito/fisiologia , Técnicas In Vitro , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Mesoderma/citologia , Mesoderma/embriologia , Camundongos , Camundongos Knockout , Modelos Animais , Notocorda/citologia , Notocorda/embriologia , Semaforinas
5.
Ginecol Obstet Mex ; 82(4): 246-51, 2014 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-24881358

RESUMO

In 1935 during a medical meeting behalf in New Orleans was presents a study that included seven cases of women that suffered menstrual dysfunctions, hirsutism and sterility, for laparotomy the description of the ovaries had a pearly white color and it was hypertrophic, the cuneiform resection in both ovaries resulted in correction of the menstrual dysfunction and two of them got pregnancy later on, receiving the name of polycystic ovary syndrome (PCOS). The technological advance facilitates the hormonal analyses demonstrating the hyperandrogenism existence and the mechanism of the anovulation, the PCOS showed to be heterogeneous, reason why it was hindered to define it, this advanced the current trend to question the existence of the PCOS and to accept the convenience, either to change the name or to redefine it, leaving it as a simple syndrome with several phenotypes. The endocrine component includes abnormal secretion of insulin and consequently outlying resistance to this hormone, likewise is hyperandrogenism, dislipoproteinemia and obesity. The hormonal exams are unnecessary for the diagnostic and treatment; it is convenient to demonstrate for sonography the ovarian growth. Other dysfunctions like the congenital suprarenal hyperplasia, hyperprolactinemia and hypotiroidism should be discarded. The treatment should be individualized with relationship to the reason of the consultation and the patients age. It has not been demonstrated that the sensibilitizers use to the insulin avoids long term cardiovascular illness and diabetes. Therefore, the phenotype is heterogeneous with a fickle metabolic component and for it has arisen the restlessness of a better definition of the SPO.


Assuntos
Síndrome do Ovário Policístico/história , Feminino , História do Século XX , Humanos , Síndrome do Ovário Policístico/diagnóstico
6.
Materials (Basel) ; 17(12)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38930413

RESUMO

Sulfuric acid anodizing assisted by a hydrothermal sealing with inhibitors [Ce3+-Mo6+] was used to prevent pitting corrosion on spray-deposited hypereutectic Al-Si alloy (A390). An investigation concerning the evaluation of pitting corrosion resistance on the anodic oxide thin film with ions incorporated was carried out in NaCl solution using electrochemical measurements (i.e., potentiodynamic polarization and electrochemical impedance spectroscopy, EIS). The influence of Si phase morphology and size on the growth mechanism of an anodic oxide film was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results were then compared with those for its equivalent IM390 alloy (Al-17Si-4.5Cu-0.6Mg) produced through a conventional process ingot metallurgy, IM. The electrochemical findings indicate that sulfuric acid anodizing followed by a simple hot water sealing treatment was ineffective. In this manner, an intense attack was localized by pitting corrosion that occurred on the anodic oxide film in less than three days, as denoted by characteristic changes in the EIS spectra at the lowest frequencies. Improved results were achieved for Ce-Mo surface modification, which can provide better corrosion resistance on the aluminum alloys because no signs of pits were observed during the corrosion testing.

7.
Dev Dyn ; 241(6): 1034-42, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22513894

RESUMO

BACKGROUND: The cellular mechanisms regulating branching and growth of the intersegmental vessels (ISVs) are not well understood. We have carried out studies demonstrating that Hedgehog (Hh) signaling is a major regulator of intersomitic vessel growth. RESULTS: Inhibition of Hh activity by cyclopamine completely blocks formation of intersomitic vessels in the avian embryo. Examination of gene expression patterns in Hh-deficient embryos shows that components of the VEGF and Notch signaling pathways are down-regulated. However, we find no evidence that Notch signaling plays a significant role in regulation of intersomitic vessel growth. Indeed, it appears that Hh modulation of Vascular Endothelial Growth Factor, VEGF, is the primary regulator of growth of intersomitic vessels in the avian embryo. CONCLUSIONS: Inhibition of the VEGF pathway results in absence of ISVs, whereas stimulation of VEGF expression leads to precocious branching of ISVs. These results demonstrate that Hh is an essential modulator of VEGF expression during developmental angiogenesis.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas Hedgehog/metabolismo , Neovascularização Fisiológica/fisiologia , Transdução de Sinais/fisiologia , Somitos/irrigação sanguínea , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Embrião de Galinha , Primers do DNA/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas Hedgehog/deficiência , Hibridização In Situ , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/genética , Alcaloides de Veratrum
8.
Dev Dyn ; 240(6): 1354-64, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21384473

RESUMO

Signaling by the hedgehog (Hh) family of secreted growth factors is essential for development of embryonic blood vessels. Embryos lacking Hh function have abundant endothelial cells but fail to assemble vascular cords or lumenized endothelial tubes. However, the role of Hh signaling during later aspects of vascular patterning and morphogenesis is largely unexplored. We have used small molecule inhibitors and agonists to alter activity of the Hh signaling pathway in the chick embryo. When cyclopamine is added after cord formation, aortal cells form tubes, but these are small and disorganized and the density of the adjacent vascular plexus is reduced. Activation of the Hh pathway with SAG leads to formation of enlarged aortae and increased density of the plexus. The number of endothelial cell filopodia is found to correlate with Hh signaling levels. These studies show that Hh signaling levels must be tightly regulated for normal vascular patterning to be achieved.


Assuntos
Aorta/embriologia , Aves/embriologia , Vasos Sanguíneos/embriologia , Proteínas Hedgehog/fisiologia , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aves/genética , Aves/metabolismo , Vasos Sanguíneos/citologia , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/metabolismo , Contagem de Células , Embrião de Galinha , Cicloexilaminas/farmacologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas Hedgehog/agonistas , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Tamanho do Órgão/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Teratogênicos/farmacologia , Tiofenos/farmacologia , Alcaloides de Veratrum/farmacologia
9.
Cancer Res ; 82(5): 859-871, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34949671

RESUMO

Recent studies suggest that B cells could play an important role in the tumor microenvironment. However, the role of humoral responses in endometrial cancer remains insufficiently investigated. Using a cohort of 107 patients with different histological subtypes of endometrial carcinoma, we evaluated the role of coordinated humoral and cellular adaptive immune responses in endometrial cancer. Concomitant accumulation of T, B, and plasma cells at tumor beds predicted better survival. However, only B-cell markers corresponded with prolonged survival specifically in high-grade endometrioid type and serous tumors. Immune protection was associated with class-switched IgA and, to a lesser extent, IgG. Expressions of polymeric immunoglobulin receptor (pIgR) by tumor cells and its occupancy by IgA were superior predictors of outcome and correlated with defects in methyl-directed DNA mismatch repair. Mechanistically, pIgR-dependent, antigen-independent IgA occupancy drove activation of inflammatory pathways associated with IFN and TNF signaling in tumor cells, along with apoptotic and endoplasmic reticulum stress pathways, while thwarting DNA repair mechanisms. Together, these findings suggest that coordinated humoral and cellular immune responses, characterized by IgA:pIgR interactions in tumor cells, determine the progression of human endometrial cancer as well as the potential for effective immunotherapies. SIGNIFICANCE: This study provides new insights into the crucial role of humoral immunity in human endometrial cancer, providing a rationale for designing novel immunotherapies against this prevalent malignancy. See related commentary by Osorio and Zamarin, p. 766.


Assuntos
Neoplasias do Endométrio , Receptores de Imunoglobulina Polimérica , Linfócitos B/metabolismo , Neoplasias do Endométrio/patologia , Feminino , Humanos , Imunidade Humoral , Imunoglobulina A/metabolismo , Receptores de Imunoglobulina Polimérica/genética , Receptores de Imunoglobulina Polimérica/metabolismo , Microambiente Tumoral
10.
Reprod Biol Endocrinol ; 9: 8, 2011 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-21247496

RESUMO

BACKGROUND: Natural Killer (NK) cells are the most abundant lymphocytes in the decidua during early gestation. The interactions of NK cells with the extravillous cytotrophoblast have been associated with a normal spiral artery remodeling process, an essential event for a successful pregnancy. Recent data indicate that alterations in the amount of decidual NK (dNK) cells contribute to the development of preeclampsia (PE). Moreover, genetic studies suggest that Killer Immunoglobulin-like Receptors (KIR) expressed in dNK cells influence the susceptibility to PE. Although dNK cells have been well characterized during early pregnancy, they have been scarcely studied in the third trimester of gestation. The aim of this work was to characterize dNK cells at the last trimester of gestation and to analyze the KIR genotype of healthy and PE women. METHODS: Decidual samples were obtained during Caesarean section from control (n = 10) and PE (n = 9) women. Flow cytometric analysis of CD3, CD56, CD16 and CD9 was used to characterize and quantify dNK cells in both groups. Cell surface markers from decidual leukocytes were compared with PBMC from healthy donors.KIR genotyping was performed in genomic DNA (control, n = 86; PE, n = 90) using PCR-SSP. RESULTS: The results indicate that dNK cells persist throughout pregnancy. They represented 20% of total leukocytes in control and PE groups, and they expressed the same cell surface markers (CD3-, CD56+, CD16- and CD9+) as dNK in the first trimester of gestation. There were no significant differences in the percentage of dNK cells between control and PE groups. The analysis of KIR gene frequencies and genotypes was not statistically different between control and PE groups. The ratio of activating to inhibitory genes indicated that the overall inhibitory balance (0.2-0.5) was more frequent in the PE group (control, 31.3% vs PE, 45.5%), and the activating balance (0.6-1.1) was more frequent in the control group (control, 68.6% vs PE, 54.4%). However this difference was not significant. CONCLUSION: We demonstrated the persistence of dNK cells in PE and control women at the third trimester of pregnancy; these dNK cells had a similar phenotype to those found during early pregnancy. The predominance of a KIR inhibitory balance in the PE group could be associated to the physiopathology of PE.


Assuntos
Decídua/citologia , Células Matadoras Naturais/metabolismo , Pré-Eclâmpsia/patologia , Terceiro Trimestre da Gravidez/imunologia , Receptores KIR/metabolismo , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Humanos , Pré-Eclâmpsia/metabolismo , Gravidez
11.
Arch Gynecol Obstet ; 284(6): 1443-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21243502

RESUMO

PURPOSE: To assess the relationship between ovarian morphology, hormonal levels and anthropometrical characteristics in a group of patients with polycystic ovary syndrome (PCOS). METHODS: This prospective, cross-sectional study included 82 patients with diagnosis of PCOS and 21 women with regular menstrual cycles without hyperandrogenism. They were submitted to endovaginal pelvic ultrasound. Anthropometric measures and hormonal levels of LH, FSH, insulin, total testosterone (T), free T, dehydroepiandrosterone and dehydroepiandrosterone sulfate were evaluated. The morphology of polycystic ovary (PCO) was considered when 12 or more follicles, less than 10 mm in diameter, in one or both ovaries, were observed. PCOS patients were divided into two groups: with PCO (n = 51) and without PCO (n = 31). RESULTS: In 51 out of 82 (62%) patients with PCOS, an image of PCO was observed. PCOS Patients with PCO showed a significantly greater body mass index and hip perimeter than PCOS patients without PCO. Higher levels of total T and free T were found in PCOS patients with PCO compared to those without PCO. CONCLUSION: PCOS patients with PCO on ultrasound present greater hyperandrogenism and obesity than PCOS patients without PCO. The presence of PCO appears to indicate a major clinical alteration of PCOS.


Assuntos
Antropometria , Desidroepiandrosterona/sangue , Ovário/patologia , Síndrome do Ovário Policístico/patologia , Testosterona/sangue , Adulto , Índice de Massa Corporal , Estudos de Casos e Controles , Estudos Transversais , Feminino , Hormônios Esteroides Gonadais/sangue , Humanos , Hiperandrogenismo/etiologia , Insulina/sangue , Obesidade/etiologia , Ovário/diagnóstico por imagem , Hormônios Adeno-Hipofisários/sangue , Síndrome do Ovário Policístico/sangue , Síndrome do Ovário Policístico/complicações , Síndrome do Ovário Policístico/diagnóstico por imagem , Estudos Prospectivos , Ultrassonografia , Relação Cintura-Quadril , Adulto Jovem
12.
J Nurs Educ ; 50(8): 483-6, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21524019

RESUMO

A 6-week online course was developed and delivered to nursing students and instructors at universities in two countries. The course exposed students and faculty to nursing and health concerns in both countries. All course communications were conducted in both English and Spanish, with support from online translation software as needed. Course content covered professional nursing, global health issues, and nursing interventions used with clinical problems. Although students were initially intimidated by the course language requirements, students valued the opportunity to learn about cultural and health issues. Faculty experienced a learning curve as well and enjoyed this international experience.


Assuntos
Educação a Distância , Bacharelado em Enfermagem , Intercâmbio Educacional Internacional , Interface Usuário-Computador , Educação a Distância/métodos , Educação a Distância/organização & administração , Bacharelado em Enfermagem/métodos , Bacharelado em Enfermagem/organização & administração , Humanos , Peru , Avaliação de Programas e Projetos de Saúde , Wisconsin
13.
Gynecol Obstet Invest ; 69(4): 274-80, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20110726

RESUMO

BACKGROUND/AIMS: Polycystic ovary syndrome (PCOS) has been found to affect 4-8% of women of reproductive age; however, in Mexican-Americans a prevalence of 12.8% has been reported. This study determines the prevalence of PCOS in a sample of Mexican women. METHODS: This prospective cross-sectional study included 150 female Mexican volunteers aged 20-45 years. Menstrual cycles were recorded and hirsutism was graded. Pelvic ultrasound was performed and androgen levels were measured. PCOS was diagnosed by hyperandrogenism and/or hyperandrogenemia, and oligo-ovulation (NIH 1990 criteria), and also by 2 of 3 findings: oligo-ovulation, clinical and/or biochemical hyperandrogenism and polycystic ovaries (PCO) (Rotterdam 2003 criteria), excluding other disorders. RESULTS: Nine of the 150 women were diagnosed with PCOS, a prevalence of 6.0% (95% CI: 1.9-10.1%), according to NIH criteria. The ultrasound morphology added one patient to give ten PCOS patients, a prevalence of 6.6% (95% CI: 2.3-10.9%) according to Rotterdam criteria. All PCOS patients presented oligo-ovulation, 9 had hirsutism and 7 of them had acne. Eight of the 10 PCOS patients had morphologic characteristics of PCO. CONCLUSION: The prevalence of PCOS in Mexican women is approximately 6.0%, similar to other populations, but lower than 12.8% reported in Mexican-American women.


Assuntos
Síndrome do Ovário Policístico/epidemiologia , Acne Vulgar/epidemiologia , Adulto , Androgênios/sangue , Índice de Massa Corporal , Estudos Transversais , Feminino , Hirsutismo/epidemiologia , Humanos , Hiperandrogenismo/epidemiologia , Americanos Mexicanos , México/epidemiologia , México/etnologia , Pessoa de Meia-Idade , Ovário/diagnóstico por imagem , Ovulação , Síndrome do Ovário Policístico/diagnóstico , Estudos Prospectivos , Ultrassonografia , Estados Unidos
14.
Sensors (Basel) ; 10(8): 7146-56, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-22163596

RESUMO

This work reports on the development of a Lead Lanthanum Zirconate Titanate (PLZT) bulk ferroelectric poled ceramic structure as a Piezoelectric Plethysmograph (PZPG) sensor. The ceramic was implanted during its fabrication with a platinum (Pt) wire which works as an internal electrode. The ceramic was then submitted to an experimental setup in order to validate and determine the Pt-wire mechanical effects. This PZPG sensor was also mounted on a finger splint in order to measure the blood flow that results from the pulsations of blood occurring with each heartbeat. Fingertip pulses were recorded jointly with an ECG signal from a 25 year old male to compare the time shift; the PZPG sensor guarantees the electrical isolation of the patient. The proposed PZPG has several advantages: it can be adjusted for fingertip measurements, but it can easily be extended by means of spare bands, therefore making possible PZPG measurements from different body locations, e.g., forehead, forearm, knee, neck, etc.


Assuntos
Técnicas Biossensoriais/métodos , Cerâmica/química , Lantânio/química , Chumbo/química , Platina/química , Pletismografia/métodos , Titânio/química , Zircônio/química , Adulto , Desenho de Equipamento , Dedos/irrigação sanguínea , Humanos , Masculino , Fluxo Pulsátil , Fluxo Sanguíneo Regional , Reprodutibilidade dos Testes
15.
Rev Invest Clin ; 62(3): 252-60, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-20815131

RESUMO

Preeclampsia (PE) is one of the most severe complications of pregnancy. PE is responsible for the highest rates of morbidity and mortality for both pregnant women and the neonate. In this review, we first address general aspects of PE and its diagnosis, along with some epidemiological aspects of this disease in the mexican population, in particular the experience from the Instituto Mexicano del Seguro Social. Even though over the last 20 years a great deal of evidence has accumulated regarding PE's pathophysiology, an exact mechanism to explain its etiology has not been established. This review aims to cover the status of two of the most important hypotheses in the etiology of PE: the immunological and the placental ischemia hypotheses. Recent data suggest that Natural Killer cells (NK) play a major role in the decidual spiral arteriole remodeling and in normal placental development. In genetic studies, KIR receptors present in NK cells have been involved in the susceptibility for the disease. In this review, we discuss data of our group regarding the presence of NK cells in the decidua, at the end of pregnancy and the genotypes of KIR receptors in normal and preeclamptic Mexican population. PE is characterized by abnormal placentation and hypoxia with an increase of anti-angiogenic factors; the Hypoxia-inducible factor 1-alfa (HIF1-alfa) is over expressed in PE. In this review, we also included some of our results concerning the polymorphisms and regulation of HIF in preeclamptic women.


Assuntos
Pré-Eclâmpsia/etiologia , Feminino , Haplótipos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Isquemia/complicações , México , Placenta/irrigação sanguínea , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/epidemiologia , Pré-Eclâmpsia/genética , Pré-Eclâmpsia/imunologia , Gravidez
16.
Lab Chip ; 20(4): 749-759, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31970354

RESUMO

Body-on-a-chip in vitro systems are a promising technology that aims to increase the predictive power of drug efficacy and toxicity in humans when compared to traditional animal models. Here, we developed a new heart-liver body-on-a-chip system with a skin surrogate to assess the toxicity of drugs that are topically administered. In order to test the utility of the system, diclofenac, ketoconazole, hydrocortisone and acetaminophen were applied topically through a synthetic skin surrogate (Strat-M membrane) and the toxicity results were compared to those of acute drug exposure from systemically applying the compounds. The heart-liver system was successful in predicting the effects for both cardiac and liver functions changes due to the compounds. The difference in the concentrations of drugs applied topically compared to systemically indicates that the barrier properties of the skin surrogate were efficient. One important advantage of this heart-liver system was the capability of showing differential effects of acute and chronic drug exposure which is necessary as part of the International Conference in Harmonisation (ICH) tri-partate guidelines. In conclusion, this work indicates a promising heart-liver body-on-a-chip system that can be used for the assessment of potential drug toxicity from dermal absorption as well as evaluate transport dynamics through the skin in the same system.


Assuntos
Dispositivos Lab-On-A-Chip , Preparações Farmacêuticas , Animais , Humanos , Fígado/metabolismo , Preparações Farmacêuticas/metabolismo , Pele/metabolismo , Absorção Cutânea
17.
Cell Motil Cytoskeleton ; 65(8): 652-61, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18548613

RESUMO

It is generally believed that proteins of the troponin complex are not expressed in smooth muscle. We have directly assayed for expression of troponin transcripts in mouse vascular smooth muscle and found that troponin sequences normally associated with fast twitch skeletal muscle (fTnT, fTnI, fTnC) were present at significant levels in the thoracic aorta. In situ hybridization experiments demonstrated that fTnT, fTnI and fTnC transcripts were expressed in the smooth muscle layer of mouse blood vessels of all sizes. Protein blot analysis using rat tissue showed that at least two members of the troponin complex, Troponin T and Troponin I, were translated in vascular smooth muscle of the aorta. Finally, immuno-fluorescence microscopy of rat aortic smooth muscle revealed that TnT and TnI are localized in a unique pattern, coincident with the distribution of tropomyosin. It seems likely therefore, that a complete troponin complex is expressed in vascular smooth muscle and is associated with the contractile machinery of the cell. These observations raise the possibility that troponins play a role in regulation of smooth muscle function.


Assuntos
Fibras Musculares de Contração Rápida/metabolismo , Músculo Liso Vascular/metabolismo , Troponina C/metabolismo , Troponina I/metabolismo , Troponina T/metabolismo , Actinas/metabolismo , Animais , Aorta Torácica/citologia , Aorta Torácica/metabolismo , Vasos Sanguíneos/citologia , Vasos Sanguíneos/metabolismo , Western Blotting , Cromatografia Líquida , Expressão Gênica , Imunoprecipitação , Hibridização In Situ , Mucosa Intestinal/metabolismo , Intestinos/citologia , Camundongos , Microscopia de Fluorescência , Fibras Musculares de Contração Rápida/citologia , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Massas em Tandem , Troponina C/genética , Troponina I/genética , Troponina T/genética
18.
J Mech Behav Biomed Mater ; 97: 385-395, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31170672

RESUMO

Ceramic-metal (CaO·Al2O3-Al and CaO·Al2O3-Ag) compounds were prepared by mechanical milling and consolidated through an in-situ sintering process. The aim of this work is to study the effects of the Al and Ag particles to ceramic-base compound, primarily in the microstructure, and its mechanical and antimicrobial properties. Chemical systems with a 1:1 M ratio between CaCO3 and Al2O3 powder were formed, with the addition of 10 wt% Al or 10 wt% Ag, respectively. The compound material that consolidated were microstructurally characterized through X-ray diffraction, scanning electron microscopy, optic microscopy, and X-ray computed tomography. In addition, the hardness, the fracture toughness, the transversal elastic modulus, and the antimicrobial property were evaluated. The results of X-ray diffraction identified the formation of the calcium aluminate phases, such as CaO·6Al2O3 (hibonite:CA6), CaO·2Al2O3 (grossite:CA2), and CaO·Al2O3 (krotite:CA); as well as Al and Ag were identified in its respective system. In addition, the mechanical properties show changes compared to the reference material that was synthesized under the same conditions and, finally, these materials also have an antimicrobial effect, against the Staphylococcus bacterium that is common in the oral cavity, when studied in synthetic saliva.


Assuntos
Compostos de Alumínio/química , Óxido de Alumínio/química , Alumínio/química , Anti-Infecciosos/farmacologia , Compostos de Cálcio/química , Óxidos/química , Prata/química , Materiais Biocompatíveis/química , Cerâmica/química , Módulo de Elasticidade , Elétrons , Dureza , Teste de Materiais , Microscopia , Microscopia Eletrônica de Varredura , Pós , Saliva/microbiologia , Espalhamento de Radiação , Staphylococcus/efeitos dos fármacos , Estresse Mecânico , Tomografia Computadorizada por Raios X , Difração de Raios X
19.
Biomaterials ; 182: 176-190, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30130706

RESUMO

Regulation of cosmetic testing and poor predictivity of preclinical drug studies has spurred efforts to develop new methods for systemic toxicity. Current in vitro assays do not fully represent physiology, often lacking xenobiotic metabolism. Functional human multi-organ systems containing iPSC derived cardiomyocytes and primary hepatocytes were maintained under flow using a low-volume pumpless system in a serum-free medium. The functional readouts for contractile force and electrical conductivity enabled the non-invasive study of cardiac function. The presence of the hepatocytes in the system induced cardiotoxic effects from cyclophosphamide and reduced them for terfenadine due to drug metabolism, as expected from each compound's pharmacology. A computational fluid dynamics simulation enabled the prediction of terfenadine-fexofenadine pharmacokinetics, which was validated by HPLC-MS. This in vitro platform recapitulates primary aspects of the in vivo crosstalk between heart and liver and enables pharmacological studies, involving both organs in a single in vitro platform. The system enables non-invasive readouts of cardiotoxicity of drugs and their metabolites. Hepatotoxicity can also be evaluated by biomarker analysis and change in metabolic function. Integration of metabolic function in toxicology models can improve adverse effects prediction in preclinical studies and this system could also be used for chronic studies as well.


Assuntos
Ciclofosfamida/toxicidade , Hepatócitos/efeitos dos fármacos , Antagonistas não Sedativos dos Receptores H1 da Histamina/toxicidade , Imunossupressores/toxicidade , Dispositivos Lab-On-A-Chip , Miócitos Cardíacos/efeitos dos fármacos , Terfenadina/toxicidade , Cardiotoxicidade/etiologia , Linhagem Celular , Células Cultivadas , Técnicas de Cocultura/instrumentação , Ciclofosfamida/metabolismo , Avaliação Pré-Clínica de Medicamentos/instrumentação , Desenho de Equipamento , Hepatócitos/citologia , Hepatócitos/metabolismo , Antagonistas não Sedativos dos Receptores H1 da Histamina/metabolismo , Humanos , Imunossupressores/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Terfenadina/metabolismo
20.
Hum Reprod Update ; 23(5): 580-599, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28582566

RESUMO

BACKGROUND: Non-classic congenital hyperplasia (NCAH) due to 21-hydroxylase deficiency is a common autosomal recessive disorder characterized by androgen excess. OBJECTIVE AND RATIONALE: We conducted a systematic review and critical assessment of the available evidence pertaining to the epidemiology, pathophysiology, diagnosis and management of NCAH. A meta-analysis of epidemiological data was also performed. SEARCH METHODS: Peer-reviewed studies evaluating NCAH published up to October 2016 were reviewed. Multiple databases were searched including MEDLINE, EMBASE, Cochrane, ERIC, EBSCO, dissertation abstracts, and current contents. OUTCOMES: The worldwide prevalence of NCAH amongst women presenting with signs and symptoms of androgen excess is 4.2% (95% confidence interval: 3.2-5.4%). The clinical consequences of NCAH expand from infancy, i.e. accelerated growth, to adolescence and adulthood, i.e. premature pubarche, cutaneous symptoms and oligo-ovulation in a polycystic ovary syndrome (PCOS)-like clinical picture. The diagnosis of NCAH relies on serum 17-hydroxyprogesterone (17-OHP) concentrations. A basal 17-OHP concentration ≥2 ng/ml (6 nmol/l) should be used for screening if more appropriate in-house cut-off values are not available. Definitive diagnosis requires a 17-OHP concentration ≥10 ng/ml (30 nmol/l), either basally or after cosyntropin-stimulation. Molecular genetic analysis of the CYP21A2 gene, which is responsible for 21-hydroxylase activity, may be used for confirmation purposes and should be offered to all patients with NCAH along with genetic counseling because these patients frequently carry alleles that may result in classic CAH, the more severe form of the disease, in their progeny. Treatment must be individualized. Glucocorticoid replacement therapy may benefit pediatric patients with accelerated growth or advanced bone age or adult women seeking fertility, whereas adequate control of menstrual irregularity, hirsutism and other cutaneous symptoms is best served by the use of oral contraceptive pills and/or anti-androgens. Some women may need ovulation induction or assisted reproductive technology to achieve pregnancy. Patients with NCAH have a higher risk of miscarriage and may benefit from glucocorticoid treatment during pregnancy. WIDER IMPLICATIONS: Evidence-based diagnostic and treatment strategies are essential for the proper management of women with NCAH, especially considering that these patients may need different therapeutic strategies at different stages during their follow-up and that appropriate genetic counseling may prevent the occurrence of CAH in their children.


Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico , Hiperplasia Suprarrenal Congênita/tratamento farmacológico , 17-alfa-Hidroxiprogesterona/sangue , Adolescente , Hiperplasia Suprarrenal Congênita/epidemiologia , Hiperplasia Suprarrenal Congênita/genética , Adulto , Antagonistas de Androgênios/uso terapêutico , Feminino , Hirsutismo/etiologia , Humanos , Infertilidade Feminina/etiologia , Distúrbios Menstruais/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA