Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biomacromolecules ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38961715

RESUMO

Polymer-peptide hydrogels are being designed as implantable materials that deliver human mesenchymal stem cells (hMSCs) to treat wounds. Most wounds can progress through the healing process without intervention. During the normal healing process, cytokines are released from the wound to create a concentration gradient, which causes directed cell migration from the native niche to the wound site. Our work takes inspiration from this process and uniformly tethers cytokines into the scaffold to measure changes in cell-mediated degradation and motility. This is the first step in designing cytokine concentration gradients into the material to direct cell migration. We measure changes in rheological properties, encapsulated cell-mediated pericellular degradation and migration in a hydrogel scaffold with covalently tethered cytokines, either tumor necrosis factor-α (TNF-α) or transforming growth factor-ß (TGF-ß). TNF-α is expressed in early stages of wound healing causing an inflammatory response. TGF-ß is released in later stages of wound healing causing an anti-inflammatory response in the surrounding tissue. Both cytokines cause directed cell migration. We measure no statistically significant difference in modulus or the critical relaxation exponent when tethering either cytokine in the polymeric network without encapsulated hMSCs. This indicates that the scaffold structure and rheology is unchanged by the addition of tethered cytokines. Increases in hMSC motility, morphology and cell-mediated degradation are measured using a combination of multiple particle tracking microrheology (MPT) and live-cell imaging in hydrogels with tethered cytokines. We measure that tethering TNF-α into the hydrogel increases cellular remodeling on earlier days postencapsulation and tethering TGF-ß into the scaffold increases cellular remodeling on later days. We measure tethering either TGF-ß or TNF-α enhances cell stretching and, subsequently, migration. This work provides rheological characterization that can be used to design new materials that present chemical cues in the pericellular region to direct cell migration.

2.
Healthcare (Basel) ; 11(14)2023 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-37510537

RESUMO

Students pursuing a university education are vulnerable to psychological burdens such as depression, anxiety, and stress. The frequency of vitamin D deficiency, on the other hand, is extensively recognized worldwide, and vitamin D regulates various neurological pathways in the brain that control psychological function. Therefore, the goal of this cross-sectional study was to determine the relationship between vitamin D deficiency and psychological burden among university students in Riyadh, Saudi Arabia. During March-May 2021 in Riyadh, a cross-sectional comparative study survey was delivered to university students. The DASS-21 scale was used to determine the severity of the psychological burden. Both univariate and binomial regression analyses were conducted to analyze the level of significance and influence of several factors on the development of psychological burden. The data were analyzed with SPSS-IBM, and a p value of <0.05 was considered significant. Of the 480 students recruited for the study, 287 (59.79%) had a vitamin D deficiency. Significantly (p = 0.048), a high proportion of the vitamin D-deficient students attained a low or moderate GPA compared to the control cohort. The prevalence of depression, anxiety, and stress among the vitamin D-deficient students was 60.35%, 6.31%, and 75.08%, respectively, which was significantly (p < 0.05) different from the control group. The odds of developing depression (OR = 4.96; CI 2.22-6.78; p < 0.001), anxiety (OR = 3.87; CI 2.55-6.59; p < 0.001), and stress (OR = 4.77; CI 3.21-9.33; p < 0.001) were significantly higher in the vitamin D-deficient group. The research shows a strong association between psychological stress and vitamin D deficiency. To promote the mental health and psychological wellbeing of university students, it is critical to create awareness about the adequate consumption of vitamin D. Additionally, university students should be made aware of the likelihood of a loss in academic achievement owing to vitamin D deficiency, as well as the cascade effect of psychological burden.

3.
Heart Views ; 23(3): 157-159, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36479177
4.
Heart Views ; 22(2): 134-136, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34584625

RESUMO

Electrocardiogram (ECG) is a reliable tool in the initial diagnostic workup of patients presenting to the Emergency Department (ED). However, it is not totally free of interference from artifacts due to various causes such as positional changes during capture, muscle contractions, limb tremors, etc., Such artifacts can have disastrous complications if they mimic arrhythmias and are treated as such. This case report describes two such patients in the catheterization laboratory (Cath lab) setting who developed ECG changes mimicking ventricular fibrillation. The first patient was shivering upon arrival to the Cath lab and developed ECG changes that were initially thought to be ventricular fibrillation. The patient received 2 DC shocks as a consequence. The ECG changes reflected artifacts caused by shivering and muscle activity. The second patient had similar changes induced by triggering the contrast injector during his coronary angiogram. These cases highlight the importance of staying vigilant for causes of artifacts in asymptomatic, hemodynamically stable patients, especially in Cath lab areas, where rapid management response is expected for optimal patient care.

5.
Echocardiography ; 38(8): 1365-1404, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34236091

RESUMO

BACKGROUND: The manifestations of COVID-19 as outlined by imaging modalities such as echocardiography, lung ultrasound (LUS), and cardiac magnetic resonance (CMR) imaging are not fully described. METHODS: We conducted a systematic review of the current literature and included studies that described cardiovascular manifestations of COVID-19 using echocardiography, CMR, and pulmonary manifestations using LUS. We queried PubMed, EMBASE, and Web of Science for relevant articles. Original studies and case series were included. RESULTS: This review describes the most common abnormalities encountered on echocardiography, LUS, and CMR in patients infected with COVID-19.


Assuntos
COVID-19 , Ecocardiografia , Humanos , Pulmão/diagnóstico por imagem , Espectroscopia de Ressonância Magnética , SARS-CoV-2
6.
Med Oncol ; 31(6): 958, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24770952

RESUMO

Synovial sarcoma is a rare type of sarcoma with poor prognosis. Data on relevant prognostic factors are inconsistent. The objective of this study was to determine the independent prognostic factors that govern local recurrence, distant metastasis and overall survival. A retrospective analysis of 51 patients treated for localized synovial sarcoma at a single institution by a multidisciplinary/multimodality approach over a period of 12 years. Patients, tumor and treatment characteristics were collected including age, sex, tumor site, location, depth, size, status of margins, histology subtype and involvement of bone or lymph nodes. Type of surgery, adjuvant chemotherapy and radiotherapy were also examined. The endpoints analyzed were local recurrence-free survival (LRFS), metastasis-free survival (MFS) and overall survival (OS). Median age of patients was 26 years (range 3-64 years) with 73 % above the age of 20 year. All patients received surgery, 57 % received adjuvant radiotherapy and 45 % adjuvant chemotherapy. The median survival was 111 months, and 5-year OS was 73 %. Deep seatedness of the tumor was linked to OS as the only independent risk factor. Twelve patients had local recurrence, and the 5-year LRFS was 61 %. Multivariate analysis determined negative margins and adjuvant radiotherapy as independent predicting factors for LRFS. Five-year MFS was 48 %; multivariate analysis identified monophasic subtype and site other than lower extremity as the only independent factors associated with inferior MFS. The most important factors that govern LRFS and MFS are negative margins and adjuvant radiotherapy for LRFS and tumor histology and site for MFS, while deep seatedness of the tumor is the sole independent factor that governs OS.


Assuntos
Sarcoma Sinovial/mortalidade , Sarcoma Sinovial/patologia , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia Adjuvante , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia/patologia , Prognóstico , Radioterapia Adjuvante , Estudos Retrospectivos , Sarcoma Sinovial/terapia , Resultado do Tratamento , Adulto Jovem
7.
Eur J Hum Genet ; 20(4): 420-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22353939

RESUMO

Bardet-Biedl syndrome (BBS) is a model disease for ciliopathy in humans. The remarkable genetic heterogeneity that characterizes this disease is consistent with accumulating data on the interaction between the proteins encoded by the 14 BBS genes identified to date. Previous reports suggested that such interaction may also extend to instances of oligogenic inheritance in the form of triallelism which defies the long held view of BBS as an autosomal recessive disease. In order to investigate the magnitude of triallelism in BBS, we conducted a comprehensive analysis of all 14 BBS genes as well as the CCDC28B-modifier gene in a cohort of 29 BBS families, most of which are multiplex. Two in trans mutations in a BBS gene were identified in each of these families for a total of 20 mutations including 12 that are novel. In no instance did we observe two mutations in unaffected members of a given family, or observe the presence of a third allele that convincingly acted as a modifier of penetrance and supported the triallelic model of BBS. In addition to presenting a comprehensive genotype/phenotype overview of a large set of BBS mutations, including the occurrence of nonsyndromic retinitis pigmentosa in a family with a novel BBS9 mutation, our study argues in favor of straightforward autosomal recessive BBS in most cases.


Assuntos
Alelos , Síndrome de Bardet-Biedl/genética , Proteínas de Ciclo Celular/genética , Estudos de Coortes , Proteínas do Citoesqueleto , Família , Genes Modificadores , Humanos , Masculino
8.
World J Gastroenterol ; 12(16): 2530-5, 2006 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-16688798

RESUMO

AIM: To analyze the neutralizing activity of antibodies against E1 region of hepatitis C virus (HCV). Specific polyclonal antibody was raised via immunization of New Zealand rabbits with a synthetic peptide that had been derived from the E1 region of HCV and was shown to be highly conserved among HCV published genotypes. METHODS: Hyper-immune HCV E1 antibodies were incubated over night at 4 degree Celsius with serum samples positive for HCV RNA, with viral loads ranging from 615 to 3.2 million IU/ mL. Treated sera were incubated with HepG2 cells for 90 min. Blocking of viral binding and entry into cells by anti E1 antibody were tested by means of RT-PCR and flow cytometry. RESULTS: Direct immunostaining using FITC conjugated E1 antibody followed by Flow cytometric analysis showed reduced mean fluorescence intensity in samples pre-incubated with E1 antibody compared with untreated samples. Furthermore, 13 out of 18 positive sera (72%) showed complete inhibition of infectivity as detected by RT-PCR. CONCLUSION: In house produced E1 antibody, blocks binding and entry of HCV virion infection to target cells suggesting the involvement of this epitope in virus binding and entry. Isolation of these antibodies that block virus attachment to human cells are useful as therapeutic reagents.


Assuntos
Hepacivirus/classificação , Anticorpos Anti-Hepatite C/uso terapêutico , Hepatite C/terapia , Proteínas do Envelope Viral/imunologia , Sequência de Aminoácidos , Linhagem Celular , Genótipo , Hepacivirus/genética , Hepacivirus/fisiologia , Humanos , Lipoproteínas LDL/metabolismo , Dados de Sequência Molecular , Proteínas do Envelope Viral/química , Proteínas Virais/genética , Proteínas Virais/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...