RESUMEN
In the field of endothelial biology, the term "shear forces" is tied to the forces exerted by the flowing blood on the quiescent cells. But endothelial cells themselves also exert physical forces on their immediate and distant neighbors. Specific factors of such intrinsic mechanical signals most relevant to immediate neighbors include normal (Fn) and shear (Fs) components of intercellular tractions, and those factors most relevant to distant neighbors include contractile or dilatational (Mc) and shear (Ms) components of the moments of cytoskeletal forces. However, for cells within a monolayer, Fn, Fs, Mc, and Ms remain inaccessible to experimental evaluation. Here, we present an approach that enables quantitative assessment of these properties. Remarkably, across a collectively migrating sheet of pulmonary microvascular endothelial cells, Fs was of the same order of magnitude as Fn. Moreover, compared to the normal components (Fn, Mc) of the mechanical signals, the shear components (Fs, Ms) were more distinctive in the cells closer to the migration front. Individual cells had an innately collective tendency to migrate along the axis of maximum contractile moment - a collective migratory process we referred to as cellular plithotaxis. Notably, larger Fs and Ms were associated with stronger plithotaxis, but dilatational moment appeared to disengage plithotactic guidance. Overall, cellular plithotaxis was more strongly associated with the "shear forces" (Fs, Ms) than with the "normal forces" (Fn, Mc). Finally, the mechanical state of the cells with fast migration speed and those with highly circular shape were reminiscent of fluid-like and solid-like matter, respectively. The results repeatedly pointed to neighbors imposing shear forces on a cell as a highly significant event, and hence, the term "shear forces" must include not just the forces from flowing fluid but also the forces from the substrate and neighbors. Collectively, these advances set the stage for deeper understanding of mechanical signaling in cellular monolayers.
Asunto(s)
Movimiento Celular , Espacio Extracelular/fisiología , Animales , Forma de la Célula , Ratas , Resistencia al CorteRESUMEN
Intratumoural metabolic demands result in excessive angiogenic cytokine release leading to unorganised vasculature. Resultant fluid dynamics oppose blood flow and drug penetration due to a marked increase in interstitial fluid hydrostatic pressure. It is hypothesised that anti-angiogenic therapy may function to 'prune' vasculature and lead to improved chemotherapeutic penetration. Subcutaneous, OSC19 tumour bearing mice (n = 5/dose/agent) were administered varying doses of an anti-mouse VEGFR2 (DC101) or an anti-mouse VEGFR3 (31C1) -3 d, -1 d, 0 d, +1 d and +3 d prior to 200 µg of cetuximab fluorescently labelled with IRDye800CW. Fluorescence imaging of tumours was performed 10 d post cetuximab-IRDye800CW dose to monitor therapeutic uptake. Co-administration of dual anti-angiogenic agents at 50-50%, 75-25% and 25-75% using optimal dose and time (-1 d 10 mg/kg anti-VEGFR2 and -1 d 40 mg/kg anti-VEGFR3) was also evaluated. In order to establish vessel normalisation, NG2 (pericyte marker) and CD31 (endothelial cells) ratios were assessed during immunohistochemical staining of tumour sections. Twenty-mg/kg anti-VEGFR3 + 5 mg/kg anti-VEGFR2 significantly (p < .0005) reduced tumour size (-73%) compared to control (59%). The 20 mg/kg anti-VEGFR3 + 5 mg/kg anti-VEGFR2 and 30 mg/kg anti-VEGFR3 + 2.5 mg/kg anti-VEGFR2 significantly (p < .0004) improved percent-injected cetuximab-IRDye800CW dose/gram tumour tissue compared to other groups. Adjuvant, dual anti-angiogenic therapy targeting VEGFR2 and VEGFR3 significantly enhances tumour chemotherapeutic uptake compared to control.
Asunto(s)
Antineoplásicos Inmunológicos/uso terapéutico , Cetuximab/uso terapéutico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neovascularización Patológica/tratamiento farmacológico , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Antineoplásicos Inmunológicos/administración & dosificación , Bencenosulfonatos/química , Bencenosulfonatos/farmacología , Línea Celular Tumoral , Cetuximab/química , Quimioterapia Adyuvante , Femenino , Indoles/química , Indoles/farmacología , Ratones , Ratones Desnudos , Neoplasias ExperimentalesRESUMEN
Several studies have reported reprogramming of fibroblasts into induced cardiomyocytes; however, reprogramming into proliferative induced cardiac progenitor cells (iCPCs) remains to be accomplished. Here we report that a combination of 11 or 5 cardiac factors along with canonical Wnt and JAK/STAT signaling reprogrammed adult mouse cardiac, lung, and tail tip fibroblasts into iCPCs. The iCPCs were cardiac mesoderm-restricted progenitors that could be expanded extensively while maintaining multipotency to differentiate into cardiomyocytes, smooth muscle cells, and endothelial cells in vitro. Moreover, iCPCs injected into the cardiac crescent of mouse embryos differentiated into cardiomyocytes. iCPCs transplanted into the post-myocardial infarction mouse heart improved survival and differentiated into cardiomyocytes, smooth muscle cells, and endothelial cells. Lineage reprogramming of adult somatic cells into iCPCs provides a scalable cell source for drug discovery, disease modeling, and cardiac regenerative therapy.
Asunto(s)
Proliferación Celular , Técnicas de Reprogramación Celular/métodos , Reprogramación Celular , Fibroblastos/metabolismo , Mioblastos Cardíacos/metabolismo , Factores de Transcripción/biosíntesis , Animales , Supervivencia Celular , Fibroblastos/citología , Ratones , Ratones Transgénicos , Mioblastos Cardíacos/citología , Factores de Transcripción/genéticaRESUMEN
RATIONALE: 17ß-Estradiol (E2) attenuates hypoxic pulmonary vasoconstriction and hypoxic pulmonary hypertension (HPH) through an unknown mechanism that may involve estrogen receptors (ER) or E2 conversion to catecholestradiols and methoxyestradiols with previously unrecognized effects on cardiopulmonary vascular remodeling. OBJECTIVES: To determine the mechanism by which E2 exerts protective effects in HPH. METHODS: Male rats were exposed to hypobaric hypoxia while treated with E2 (75 µg/kg/d) or vehicle. Subgroups were cotreated with pharmacologic ER-antagonist or with inhibitors of E2-metabolite conversion. Complementary studies were performed in rats cotreated with selective ERα- or ERß-antagonist. Hemodynamic and pulmonary artery (PA) and right ventricular (RV) remodeling parameters, including cell proliferation, cell cycle, and autophagy, were measured in vivo and in cultured primary rat PA endothelial cells. MEASUREMENTS AND MAIN RESULTS: E2 significantly attenuated HPH endpoints. Hypoxia increased ERß but not ERα lung vascular expression. Co-treatment with nonselective ER inhibitor or ERα-specific antagonist rendered hypoxic animals resistant to the beneficial effects of E2 on cardiopulmonary hemodynamics, whereas ERα- and ERß-specific antagonists opposed the remodeling effects of E2. In contrast, inhibition of E2-metabolite conversion did not abolish E2 protection. E2-treated hypoxic animals exhibited reduced ERK1/2 activation and increased expression of cell-cycle inhibitor p27(Kip1) in lungs and RV, with up-regulation of lung autophagy. E2-induced signaling was recapitulated in hypoxic but not normoxic endothelial cells, and was associated with decreased vascular endothelial growth factor secretion and cell proliferation. CONCLUSIONS: E2 attenuates hemodynamic and remodeling parameters in HPH in an ER-dependent manner, through direct antiproliferative mechanisms on vascular cells, which may provide novel nonhormonal therapeutic targets for HPH.
Asunto(s)
Estradiol/farmacología , Hipertensión Pulmonar/tratamiento farmacológico , Hipoxia/complicaciones , Receptores de Estrógenos/efectos de los fármacos , Remodelación de las Vías Aéreas (Respiratorias)/efectos de los fármacos , Remodelación de las Vías Aéreas (Respiratorias)/fisiología , Animales , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Gasto Cardíaco/efectos de los fármacos , Gasto Cardíaco/fisiología , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/efectos de los fármacos , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/fisiología , Estradiol/análogos & derivados , Estradiol/uso terapéutico , Antagonistas de Estrógenos/farmacología , Fulvestrant , Hipertensión Pulmonar/etiología , Hipertensión Pulmonar/fisiopatología , Hipoxia/tratamiento farmacológico , Hipoxia/fisiopatología , Pulmón/irrigación sanguínea , Pulmón/fisiopatología , Masculino , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/fisiopatología , Ratas , Ratas Sprague-Dawley , Receptores de Estrógenos/fisiología , Remodelación Ventricular/efectos de los fármacos , Remodelación Ventricular/fisiologíaRESUMEN
The risk and threat of bioterrorism and biocrime have become a large concern and challenge for governments and society to enhance biosecurity. Law enforcement plays an important role in assessing and investigating activities involved in an event of bioterrorism or biocrime. Key to a successful biosecurity program is increased awareness and early detection of threats facilitated by an integrated network of responsibilities and capabilities from government, academic, private, and public assets. To support an investigation, microbial forensic sciences are employed to analyze and characterize forensic evidence with the goal of attribution or crime scene reconstruction. Two different molecular biology-based assays--real time polymerase chain reaction (PCR) and repetitive element PCR--are described and demonstrate how molecular biology tools may be utilized to aid in the investigative process. Technologies relied on by microbial forensic scientists need to be properly validated so that the methods used are understood and so that interpretation of results is carried out within the limitations of the assays. The three types of validation are preliminary, developmental, and internal. The first is necessary for rapid response when a threat is imminent or an attack has recently occurred. The latter two apply to implementation of routinely used procedures.
Asunto(s)
Bioterrorismo , Ciencias Forenses , Técnicas Genéticas , Aplicación de la Ley , Técnicas Microbiológicas , Bioterrorismo/prevención & control , Genética Microbiana , Humanos , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido SimpleRESUMEN
Chronic dyspnea is defined as dyspnea lasting more than one month. In approximately two thirds of patients presenting with dyspnea, the underlying cause is cardiopulmonary disease. Establishing an accurate diagnosis is essential because treatment differs depending on the underlying condition. Asthma, congestive heart failure, chronic obstructive pulmonary disease, pneumonia, cardiac ischemia, interstitial lung disease, and psychogenic causes account for 85 percent of patients with this principal symptom. The history and physical examination should guide selection of initial diagnostic tests such as electrocardiogram, chest radiograph, pulse oximetry, spirometry, complete blood count, and metabolic panel. If these are inconclusive, additional testing is indicated. Formal pulmonary function testing may be needed to establish a diagnosis of asthma, chronic obstructive pulmonary disease, or interstitial lung disease. High-resolution computed tomography is particularly useful for diagnosing interstitial lung disease, idiopathic pulmonary fibrosis, bronchiectasis, or pulmonary embolism. Echocardiography and brain natriuretic peptide levels help establish a diagnosis of congestive heart failure. If the diagnosis remains unclear, additional tests may be required. These include ventilation perfusion scans, Holter monitoring, cardiac catheterization, esophageal pH monitoring, lung biopsy, and cardiopulmonary exercise testing.
Asunto(s)
Disnea/diagnóstico , Algoritmos , Diagnóstico Diferencial , Técnicas y Procedimientos Diagnósticos , Disnea/etiología , Humanos , Anamnesis , Examen FísicoRESUMEN
Protease C1 (E.C. 3.4.21.25), the soybean (Glycine max L. Merrill) proteolytic enzyme responsible for initiating the degradation of soybean storage proteins in seedling cotyledons appears at even higher levels in seedling leaves. This was manifested at the mRNA level through northern blot analysis, at the protein level through western blot analysis, through determination of enzyme activity, and also through isolation and partial sequencing of active leaf enzyme. Comparison of cDNA and amino acid sequences, as well as characterization of enzyme activity, is consistent with the leaf enzyme being identical to or highly similar to the cotyledon enzyme. Protease C1 mRNA and protein are also present in stems of soybean seedlings, but is very low to absent in the roots. This presence in the aerial tissues is consistent with the higher steady state level of gene expression at both the mRNA and protein levels when the seedlings are grown in a 12-h light: 12-h dark photoperiod as compared to seedlings grown in continuous darkness. Transfer of dark-grown seedlings to light is followed by marked elevation in protease C1 protein as seen in western blots.
Asunto(s)
Endopeptidasas/metabolismo , Glycine max/enzimología , Hojas de la Planta/enzimología , Subtilisinas/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Endopeptidasas/química , Endopeptidasas/genética , Luz , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Plantones/enzimologíaRESUMEN
The authors report the case of a systemic embolism of a cusp of a Hancock pericardial aortic bioprosthesis. This rare complication has not been previously reported to the authors' knowledge, and should lead to immediate valve replacement.
Asunto(s)
Bioprótesis , Embolia/etiología , Prótesis Valvulares Cardíacas/efectos adversos , Válvula Aórtica , Bioprótesis/efectos adversos , Migración de Cuerpo Extraño/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Pericardio , Arteria Poplítea , Falla de Prótesis , Reoperación , Rotura EspontáneaRESUMEN
The authors report the case of a 59-year-old woman with a complex cardiac lesion consisting of degenerative major mitral insufficiency masking partial abnormal pulmonary venous return. These cardiac abnormalities fell within a context of genetic disease since the patient had Turner's syndrome, confirmed at the age of 58 by a 45 x 0 karyotype. They detail the originality of the clinical manifestations of partial abnormal pulmonary venous return and review the literature concerning cardiac malformations in Turner's syndrome.
Asunto(s)
Aberraciones Cromosómicas/genética , Síndrome de Turner/complicaciones , Angiografía , Femenino , Cardiopatías Congénitas/complicaciones , Cardiopatías Congénitas/genética , Humanos , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/etiología , Venas Pulmonares/anomalías , Venas Pulmonares/diagnóstico por imagen , Síndrome de Turner/genéticaRESUMEN
Twenty six patients with acute (less than 5 days) pulmonary embolism (PE) confirmed by bilateral pulmonary angiography with a Miller index greater than 15 were given tissue plasminogen activator (Alteplase) (rt-PA) intravenously (n = 20) or directly into the pulmonary artery (n = 6). The dosage was 100 mg/7 hours (bolus 10 mg + 40 mg/2 hours + 50 mg/5 hours). Heparin (5000 IV as a bolus and 1000 IV/hour) was associated in all cases. The Miller index decreased from 24 +/- 1 (n = 26) before treatment to 12 +/- 1 (n = 25) (p less than 0.001) after 100 mg of Alteplase, and from 25 +/- 0.4 (n = 14) to 22 +/- 0.5 (n = 14) (p less than 0.001) after 50 mg. The mean pulmonary arterial pressures fell from 30 +/- 2 mmHg to 21 +/- 2 mmHg after 50 mg (n = 26) (p less than 0.001) and to 14 +/- 1 (n = 25) (p less than 0.001) after 100 mg of Alteplase. A decrease in mean pulmonary artery pressures (-22%, p less than 0.001) and total pulmonary resistances (-29%, p less than 0.001) was obtained after one hour of thrombolysis in 12 monitored patients. There were no fatalities. Severe haemorrhage occurred in 6 cases. Therefore, Alteplase induced a rapid dissolution of recent intrapulmonary thrombi without inacceptable haemorrhagic complications. Its action could be particularly beneficial in patients with right ventricular failure due to life threatening pulmonary embolism.