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1.
Perfusion ; 30(5): 410-4, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25239275

RESUMEN

We report a unique utilization of a double-lumen, bi-caval Avalon cannula for veno-venous (VV) extracorporeal membrane oxygenation (ECMO) during placement of a total artificial heart (TAH, SynCardia, Tucson, AZ). A 22-year-old female with post-partum cardiomyopathy was rescued on veno-arterial (VA) ECMO because of cardiogenic shock. The inability to wean ECMO necessitated implantation of the TAH as a bridge to transplant. In addition, the patient continued to have respiratory failure and concomitant VV ECMO was planned with the implant. During TAH implantation, the Avalon cannula was placed percutaneously from the right internal jugular vein into the inferior vena cava (IVC) under direct vision while the right atrium was open. During VV ECMO support, adequate flows on both ECMO and TAH were maintained without adverse events. VV ECMO was discontinued, without reopening the chest, once the patient's respiratory failure improved. However, the patient subsequently developed a profound respiratory acidosis and required VV ECMO for CO2 removal. The Avalon cannula was placed in the femoral vein to avoid accessing the internal jugular vein and risking damage to the TAH. The patient's oxygenation eventually improved and the cannula was removed at the bedside. The patient was supported for 22 days on VV ECMO and successfully weaned from the ventilator prior to her orthotropic heart transplantation.


Asunto(s)
Cateterismo Venoso Central , Oxigenación por Membrana Extracorpórea , Corazón Artificial , Complicaciones Posoperatorias/terapia , Implantación de Prótesis/efectos adversos , Síndrome de Dificultad Respiratoria/terapia , Adulto , Femenino , Humanos , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/fisiopatología , Radiografía , Síndrome de Dificultad Respiratoria/sangre , Síndrome de Dificultad Respiratoria/diagnóstico por imagen , Síndrome de Dificultad Respiratoria/etiología , Síndrome de Dificultad Respiratoria/fisiopatología
2.
Environ Geochem Health ; 33(2): 167-81, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20585835

RESUMEN

The metal content was determined in soils from a former, historic, contaminated land site and now a 'green' public open space in N.E. England. Using a systematic sampling grid approach, 32 soil samples were taken from locations across the site and analyzed for six potentially toxic elements (Cd, Cr, Cu, Ni, Pb, and Zn). Initially, the pseudo-total metal content of the soils was determined using acid digestion followed by inductively coupled plasma mass spectrometry analysis. This data was evaluated against published soil guideline value (SGV) and generic assessment criteria (GAC) values; it was found that 21% (i.e., 41 samples) exceeded the stated lower values. The data was then compared to the oral bioaccessibility of the soils, which was assessed by an in-vitro gastrointestinal extraction procedure. The results, determined as the % BAF, indicated that overall bioaccessibility was low (<10% BAF) for all the elements studied; the exception was Cd. Given that SGV/GAC values are based on generic land-use categories and not a public open space, as investigated in this work, further work is recommended on developing a qualitative risk assessment at the site to estimate the risks posed to human health via the direct and indirect soil ingestion pathway.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Metales/análisis , Contaminantes del Suelo/análisis , Suelo/análisis , Disponibilidad Biológica , Ciudades , Sistema Digestivo/metabolismo , Ingestión de Alimentos , Inglaterra , Humanos , Metales/farmacocinética , Medición de Riesgo/métodos , Contaminantes del Suelo/farmacocinética , Contaminantes del Suelo/toxicidad
3.
Environ Pollut ; 285: 117664, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34380230

RESUMEN

The impacts of COVID-19 lockdown restrictions have provided a valuable global experiment into the extent of improvements in air quality possible with reductions in vehicle movements. Mexico City, London and Delhi all share the problem of air quality failing WHO guideline limits, each with unique situations and influencing factors. We determine, discuss and compare the air quality changes across these cities during the COVID-19, to understand how the findings may support future improvements in their air quality and associated health of citizens. We analysed ground-level PM10, PM2.5, NO2, O3 and CO changes in each city for the period 1st January to August 31, 2020 under different phases of lockdown, with respect to daily average concentrations over the same period for 2017 to 2019. We found major reductions in PM10, PM2.5, NO2 and CO across the three cities for the lockdown phases and increases in O3 in London and Mexico City but not Delhi. The differences were due to the O3 production criteria across the cities, for Delhi production depends on the VOC-limited photochemical regime. Levels of reductions were commensurate with the degree of lockdown. In Mexico City, the greatest reduction in measured concentration was in CO in the initial lockdown phase (40%), in London the greatest decrease was for NO2 in the later part of the lockdown (49%), and in Delhi the greatest decrease was in PM10, and PM2.5 in the initial lockdown phase (61% and 50%, respectively). Reduction in pollutant concentrations agreed with reductions in vehicle movements. In the initial lockdown phase vehicle movements reduced by up to 59% in Mexico City and 63% in London. The cities demonstrated a range of air quality changes in their differing geographical areas and land use types. Local meteorology and pollution events, such as forest fires, also impacted the results.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Ciudades , Control de Enfermedades Transmisibles , Monitoreo del Ambiente , Humanos , India , Londres , México , Pandemias , Material Particulado/análisis , SARS-CoV-2
5.
Med Oncol ; 26(3): 257-64, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19016010

RESUMEN

VB4-845 is a novel recombinant fusion protein that targets the epithelial cellular adhesion molecule (EpCAM). This initial clinical trial was conducted to determine the maximum tolerated dose of intratumoral injections in patients with advanced squamous cell carcinoma of the head and neck and to assess pharmacokinetics and immunogenicity. Twenty-four patients with advanced, recurrent squamous cell carcinoma of the head and neck received two cycles of five daily intratumoral VB4-845 injections of 20, 40, 80, 130, 200, or 280 microg. The maximum tolerated dose was established to be 280 microg administered daily for 5 days. Common adverse events were pain due to intratumoral injection and reversibly elevated liver enzymes. Of the 24 patients, 15 had detectable blood levels with a mean drug half-life of 4.0 +/- 0.3 h. VB4-845 reduced or stabilized tumors in 71.4% of epithelial cell adhesion molecule-positive patients. VB4-845 intratumoral injection therapy was well tolerated and feasible.


Asunto(s)
Carcinoma de Células Escamosas/tratamiento farmacológico , Moléculas de Adhesión Celular/antagonistas & inhibidores , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Proteínas Recombinantes de Fusión/administración & dosificación , Anciano , Antígenos de Neoplasias , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Carcinoma de Células Escamosas/metabolismo , Esquema de Medicación , Molécula de Adhesión Celular Epitelial , Femenino , Neoplasias de Cabeza y Cuello/metabolismo , Humanos , Inyecciones Intralesiones , Masculino , Persona de Mediana Edad , Proteínas Recombinantes de Fusión/efectos adversos , Proteínas Recombinantes de Fusión/farmacocinética
6.
Gene ; 174(2): 299-306, 1996 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-8890751

RESUMEN

A full-length human RHAMM cDNA clone was isolated by a combination of screening a human breast cDNA expression library with the murine RHAMM 2 cDNA as well as 5' RACE and RT-PCR using messenger RNA from human breast cell line (MCF-10A). The full-length cDNA contained 725 aa that encoded an 84 kDa protein. Although the coding region of the human RHAMM cDNA resembles the murine RHAMM v4, it has additional unique N-terminal (489 bp) and C-terminal (33 bp) regions. Also, only 1 of 5 repeat sequences encoded in the murine cDNA are present in human cDNA. The overall homology between the overlapping region of human and mouse RHAMM v4 cDNA clone is 85%, but the HA binding motif (B[X7]B), shown to be critical for the signaling capability of this receptor, is 100% conserved.


Asunto(s)
Mama/química , ADN Complementario/genética , Proteínas de la Matriz Extracelular/genética , Receptores de Hialuranos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Western Blotting , Mama/citología , Células Cultivadas , Clonación Molecular , Femenino , Biblioteca de Genes , Humanos , Ácido Hialurónico/genética , Ratones , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Sondas ARN , ARN Mensajero/genética , Secuencias Repetitivas de Ácidos Nucleicos , Homología de Secuencia de Ácido Nucleico
7.
Gene ; 163(2): 233-8, 1995 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-7590272

RESUMEN

We describe the isolation and characterization of the murine gene encoding RHAMM, a hyaluronan receptor which regulates focal adhesion turnover, is required for cell locomotion and is a critical downstream regulator of ras transformation. The RHAMM gene spans at least 20 kb and comprises 14 exons ranging in size from 75 to 1099 bp. Primer extension studies indicate that the major transcription start point is in position -31, relative to the start Met. Northern blot analysis of mouse fibroblast RNA identified two hybridizing species of 4.2 and 1.7 kb. Comparison of cDNA clones and RT-PCR products with the genomic clones identified alternately spliced exons in both the coding and 5' noncoding regions of RHAMM. In the coding region exon 4 is alternately spliced. The major RHAMM transcript (RHAMM1) in 3T3 fibroblasts does not contain exon 4 and encodes a protein of 70 kDa. A minor transcript containing exon 4, namely RHAMM v4, encodes a 73-kDa protein, as demonstrated by isoform-specific antibodies. Western analysis demonstrated both a major 70-kDa (RHAMM 1) and minor 73-kDa RHAMM protein (v4) in 3T3 murine fibroblast cell lysates. The functional significance of these two isoforms is currently being investigated.


Asunto(s)
Receptores de Hialuranos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , Ratones , Datos de Secuencia Molecular
8.
Ann Thorac Surg ; 58(4): 1282-4, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7944806

RESUMEN

After certain periods of myocardial ischemia and reperfusion, cardiac dysfunction exists in the absence of myonecrosis. In a blood-perfused isolated rat heart model, we have demonstrated early gene changes that are associated with global myocardial "stunning." Early gene changes included elevations in the expression of messenger RNAs for HSP70, c-myc and c-fos. Increased expression of messenger RNAs for protooncogenes is an important observation because of the role of protooncogenes as nuclear transcription factors. From these study findings, it would appear that the stunning state is associated with early gene changes that may signal the induction of a hypertrophic process. Subsequent studies are required to demonstrate the exact events which take place in the course of stunning that directly initiate an alteration in gene expression.


Asunto(s)
Expresión Génica , Aturdimiento Miocárdico/genética , Animales , Genes fos/genética , Genes myc/genética , Proteínas HSP70 de Choque Térmico/genética , Daño por Reperfusión Miocárdica/genética , Aturdimiento Miocárdico/patología , ARN Mensajero/genética , Conejos , Ratas
9.
Ann Thorac Surg ; 71(3 Suppl): S67-72; discussion S82-5, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11265869

RESUMEN

BACKGROUND: Mechanical circulatory assist industries have developed ventricular assist devices (VAD) for short-, intermediate-, and long-term use. The purpose of this report is to describe the progress made with the ABIOMED Biventricular System (BVS) 5000 (ABIOMED, Inc, Danvers, MA) short-term VAD. METHODS: From June 1994 through August 2000, all cardiogenic shock patients who required short-term mechanical assist were supported with the ABIOMED BVS 5000. Insertion criteria included any condition that may potentially result in cardiac recovery. A formal algorithm for timing of insertion was established to standardize implantation criteria. RESULTS: A total of 45 patients were supported at Hahnemann University Hospital, Philadelphia, PA. There were 26 male and 19 female patients, with a mean age of 57.9 years (range 33 to 80 years). Devices were inserted for postcardiotomy shock in 36 patients (80%) and precardiotomy shock in 9 patients (20%). The average duration of support was 8.3 days (range 1 to 31 days). Overall, there were 22 (49%) patients weaned from support and 14 (31%) discharged from the hospital. For patients in whom the device was implanted in accordance with an established protocol (group A), the wean and discharge rates were 60% and 43%, respectively. The most common morbidities included bleeding and adverse neurologic events. CONCLUSIONS: The ABIOMED BVS 5000 VAD continues to be a valuable form of short-term mechanical assist for acute cardiogenic shock. The formation of a uniform VAD insertion algorithm has helped to standardize protocols in management.


Asunto(s)
Insuficiencia Cardíaca/cirugía , Corazón Auxiliar , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad
10.
Nucl Med Commun ; 22(5): 587-95, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11388583

RESUMEN

H11 is a human IgM monoclonal antibody which recognizes a novel tumour-associated antigen expressed on melanoma, glioma, breast cancer, colon cancer, prostate cancer, lung cancer and B-cell lymphoma. In this study, a recombinant single-chain Fv (scFv) fragment of H11 labelled with 111In was investigated for tumour imaging in athymic mice implanted subcutaneously with A-375 human melanoma xenografts. H11 scFv was derivatized with diethylenetriaminepentaacetic acid (DTPA) for labelling with 111In. The immunoreactivity of DTPA-H11 scFv against A-375 cells in vitro ranged from 23% to 36%. 111In-DTPA-H11 scFv was rapidly eliminated from the blood and most normal tissues (except the kidneys) reaching maximum tumour/blood ratios of 12:1 at 48 h post-injection. Tumours were imaged as early as 40 min after injection. The kidneys accumulated the highest concentration of radioactivity (up to 185% injected dose/g). Tumour uptake was 1-3% injected dose/g. The whole-body radiation absorbed dose predicted for administration of 185 MBq of 111In-DTPA-H11 scFv to humans was 37 mSv. The radiation absorbed dose estimates for the kidneys, spleen and intestines were 405 mSv, 698 mSv and 412 mSv, respectively. The results of this preclinical study and a concurrent phase I trial suggest a promising role for H11 scFv for tumour imaging.


Asunto(s)
Radioisótopos de Indio , Melanoma/diagnóstico por imagen , Radioinmunodetección/métodos , Radiofármacos , Animales , Anticuerpos Monoclonales , Femenino , Humanos , Región Variable de Inmunoglobulina , Radioisótopos de Indio/farmacocinética , Cinética , Ratones , Ratones Desnudos , Ácido Pentético , Radiofármacos/farmacocinética , Distribución Tisular , Trasplante Heterólogo , Células Tumorales Cultivadas
11.
J Pediatr Surg ; 29(12): 1528-9, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7877016

RESUMEN

A nonfunctioning parathyroid cyst occurred in an 8-year-old girl, the youngest patient reported to have this diagnosis. Most cysts are asymptomatic; a few are associated with signs and symptoms of hyperparathyroidism. In asymptomatic patients with a lateral neck cyst, aspiration of clear fluid with an elevated parathyroid hormone level is diagnostic of a parathyroid cyst. If this results in disappearance of the cyst, without recurrence, no further treatment is necessary. If the cyst recurs, aspiration may be repeated. However, persistence of the cyst despite aspiration or recurrence after the second aspiration should prompt surgical removal, with intraoperative identification of all parathyroid glands, because functioning parathyroid cysts are associated with a high risk of hyperplasia or adenoma.


Asunto(s)
Quistes/diagnóstico , Enfermedades de las Paratiroides/diagnóstico , Niño , Quistes/cirugía , Femenino , Humanos , Enfermedades de las Paratiroides/cirugía , Succión
12.
Health Phys ; 75(6): 646-7, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9827512

RESUMEN

The development of hot particles was observed in a pure quartz sand as well as in "Ea" horizon material from a humo ferric podzol after ionic contamination with radiocesium. Therefore, fallout that contaminates soil with radiocesium in an ionic form can lead to the formation of hot particles for which health impact must be assessed differently compared to homogeneously contaminated soil.


Asunto(s)
Radioisótopos de Cesio , Contaminantes Radiactivos del Suelo , Suelo/análisis , Radioisótopos de Cesio/análisis , Contaminación Ambiental , Dosimetría por Película , Cuarzo , Radiación Ionizante
13.
Environ Int ; 60: 56-70, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24013020

RESUMEN

Internationally publicized impacts upon human health associated with potentially harmful element (PHE) exposure have been reported amongst internally displaced populations (IDPs) in Mitrovica, Kosovo, following the Kosovan War. Particular concern has surrounded the exposure to Pb indicated by the presence of highly elevated concentrations of Pb in blood and hair samples. This study utilizes a physiologically-based in-vitro extraction method to assess the bioaccessibility of PHEs in surface soils and metallurgical waste in Mitrovica and assesses the potential daily intake of soil-bound PHEs. Maximum As (210mgkg(-1)), Cd (38mgkg(-1)), Cu (410mgkg(-1)), Pb (18790mgkg(-1)) and Zn (8500mgkg(-1)) concentrations in surface soils (0-10cm) are elevated above guideline values. Samples with high PHE concentrations (e.g. As >1000mgkg(-1); Pb >1500mgkg(-1)) exhibit a wide range of bioaccessibilities (5.40 - 92.20% in the gastric (G) phase and 10.00 - 55.80% in the gastric-intestinal (G-I) phase). Samples associated with lower bioaccessibilities typically contain a number of XRD-identifiable primary and secondary mineral phases, particularly As- and Pb-bearing arsenian pyrite, beudantite, galena and cerrusite. Quantification of the potential human exposure risk associated with the ingestion of soil-associated PHEs indicates that on average, 0.01µg Cd kg(-1) BW d(-1), 0.16µg Cu kg(-1) BW d(--1), 0.12µg As kg(-1) BW d(-1), 7.81µg Pb kg(-1) BW d(-1), and 2.68µg Zn kg(-1) BW d(-1) could be bioaccessible following ingestion of PHE-rich soils in the Mitrovica region, with Pb, and to a lesser extent As, indicating the likely possibility of local populations exceeding the recommended tolerable daily intake. Lead present within surface soils of the area could indeed have contributed to the human Pb burden due to the high bioaccessibility of Pb present within these soils (13.40 - 92.20% in the gastric phase). Data for Pb levels in scalp hair (≤120µgg(-1)) and blood (≥650µgdL(-1); WHO, 2004) for children that have lived within IDP camps in Mitrovica indicate significant Pb uptake has indeed taken place. The highly bioaccessible nature of soil-associated PHEs in this study highlights the need for appropriate environmental management approaches that limit the exposure of local populations to these contaminated soils.


Asunto(s)
Monitoreo del Ambiente/métodos , Cabello/química , Plomo/análisis , Metalurgia , Contaminantes del Suelo/análisis , Suelo/química , Residuos/análisis , Disponibilidad Biológica , Niño , Contaminación Ambiental/análisis , Humanos , Secreciones Intestinales/química , Kosovo , Plomo/farmacocinética , Metales/análisis , Metales/farmacocinética , Minerales/análisis , Minerales/farmacocinética , Saliva/química , Contaminantes del Suelo/farmacocinética
14.
Carlsberg Res Commun ; 53(4): 247-58, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3255313

RESUMEN

The nucleotide sequence of a 2065 base pair HindIII fragment, containing a gene (lambda hor1-14) belonging to the Hor1 locus in barley, has been determined. The fragment consists of 1044 bp of coding region interrupted by an amber codon at base 481, a 5' non-coding region of 428 bp and a 3' non-coding region with 593 bp. The deduced amino acid sequence of the mature protein (327 amino acids) is characterized by an octapeptide motif PQQPFPQQ which is repeated throughout the peptide chain between a unique 12 amino acid long NH2-terminal and an equally unique 10 amino acid long COOH-terminal end. The proline + glutamine content is 62% and the next three most abundant amino acids are leucine (9%), phenylalanine (8%) and isoleucine (3%). In the 5' non-coding region there is a TATA box at -98 bp from the start methionine. The 3' non-coding region has a polyadenylation signal 76 bp downstream from the TAA stop codon. The deduced amino acid sequences of the NH2- and COOH-terminals of lambda hor1-14 are very similar but not identical to those known from the Edman degradation and carboxypeptidase Y analysis of C-hordein polypeptides. The 3' coding and non-coding region of lambda hor1-14 is closely similar but different in detail to the known C-hordein cDNA clones. One polyadenylation signal is found in lambda hor1-14 whereas two are present in each of the three known C-hordein cDNAs. These differences and the amber codon interrupting the open reading frame indicate that this gene is silent.


Asunto(s)
Proteínas de Plantas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Codón , Glútenes , Hordeum , Datos de Secuencia Molecular
15.
Plant Mol Biol ; 17(6): 1217-31, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1932695

RESUMEN

A 1420 bp genomic fragment (lambda-hor1-17) encompassing a Hor-1 gene encoding a C-hordein polypeptide is presented. The deduced amino acid sequence is 261 residues long. It comprises a 20 amino acid signal peptide, unique NH2- and COOH-terminal regions and a coding region comprised of pentapeptide (PQQPY) and octapeptide (PQQPFPQQ) repeat motifs. The 431 bp of 5' non-coding region contains a 'TATA box' at -105, a 'CACA box' (-181 to -201) and a -300 prolamin element. In the 3' non-coding region there are two putative polyadenylation signals located 88 and 142 bp downstream of the stop codon. The structure of lambda-hor1-17 is compared with that of another gene (lambda-hor1-14) encoding a C-hordein polypeptide, which contains an amber codon interrupting the ORF. A functional assay in which the 5' non-coding regions of the two genes were fused to the beta-glucuronidase (GUS) gene demonstrated that both genes were transcriptionally active and that circa 430 bp of the C-hordein promoters were sufficient to drive the expression of the GUS gene in developing barley endosperms. It also demonstrated that both promoters had transcriptional efficiencies comparable with that of the 35S CaMV promoter. The in vitro translation of the coding region of lambda-hor1-14 in the wheat germ system showed that the premature stop codon could be partially suppressed. The suppression was also demonstrated in a transient expression assay in vivo using isolated barley endosperms.


Asunto(s)
Codón , Hordeum/genética , Proteínas de Plantas/genética , Supresión Genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN , Glútenes , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Biosíntesis de Proteínas , Transcripción Genética
16.
J Cell Biochem ; 61(4): 569-77, 1996 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-8806080

RESUMEN

Hyaluronan (HA) is a ubiquitous component of the extracellular matrix (ECM) and occurs transiently in both the cell nucleus and cytoplasm. It has been shown to promote cell motility, adhesion, and proliferation and thus it has an important role in such processes as morphogenesis, wound repair, inflammation, and metastasis. These processes require massive cell movement and tissue reorganization and are always accompanied by elevated levels of HA. Many of the effects of HA are mediated through cell surface receptors, three of which have been molecularly characterized, namely CD44, RHAMM, and ICAM-1. Binding of the HA ligand to its receptors triggers signal transduction events which, in concert with other ECM and cytoskeletal components, can direct cell trafficking during physiological and pathological events. The HA mediated signals are transmitted, at least in part, by the activation of protein phosphorylation cascades, cytokine release, and the stimulation of cell cycle proteins. A variety of extracellular signals regulate the expression of both HA and the receptors necessitating that HA-receptor signalling is a tightly controlled process. Regulated production of soluble forms of the receptors, alternately spliced cell surface isoforms, and glycosylation variants of these receptors can dramatically modulate HA binding, ligand specificity, and stimulation of the signalling pathway. When these processes are deregulated cell behaviour becomes uncontrolled leading to developmental abnormalities, abnormal physiological responses, and tumorigenesis. The elucidation of the molecular mechanisms regulating HA-mediated events will not only contribute greatly to our understanding of a variety of disease processes but will also offer many new avenues of therapeutic intervention.


Asunto(s)
Citoesqueleto/fisiología , Receptores de Hialuranos/fisiología , Transducción de Señal/fisiología , Animales , Proteínas de la Matriz Extracelular/fisiología , Ácido Hialurónico/metabolismo , Molécula 1 de Adhesión Intercelular/fisiología , Ligandos
17.
J Card Surg ; 9(3 Suppl): 537-42, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8069049

RESUMEN

Regional and global myocardial ischemia and reperfusion have been demonstrated to induce expression of the stress response protein heat shock 70 (HSP70) and of immediate early genes, c-jun, c-fos, and c-myc. Because of the models that have been utilized, it has not been possible to discriminate whether this response is the consequence of ischemia, reperfusion, or abnormal hemodynamic stress superimposed on stunned myocardium. In a nonworking isolated and blood-perfused rat heart model, we evaluated the mRNAs for c-fos, c-myc, and hsp70. The heart was subjected to varying periods of ischemia and reperfusion. Significant increases in hsp70 and c-fos were observed, which increased with longer periods of ischemia. No significant increase in c-myc was measured. In addition, mRNA encoding the Ca2+/glucose responsive stress protein GRP78 was evaluated. No increase in this early response gene was noted despite the use of a model associated with cellular calcium loading. Based on these observations, we suggest that the induction of hsp70 and c-fos is the consequence of ischemia and reperfusion and not dependent upon an early hypertrophy response such as would be observed in afterload mismatching or on calcium loading. Further investigations are necessary to isolate the effects of ischemia from those of reperfusion.


Asunto(s)
Expresión Génica , Genes fos/fisiología , Genes myc/fisiología , Proteínas de Choque Térmico/fisiología , Reperfusión Miocárdica , Aturdimiento Miocárdico/genética , Animales , Proteínas de Choque Térmico/genética , ARN Mensajero/genética , Ratas , Ratas Sprague-Dawley
18.
J Biol Chem ; 271(25): 15279-84, 1996 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-8663000

RESUMEN

The receptor for hyaluronan mediated motility (RHAMM) gene expression is markedly elevated in fibrosarcomas exposed to transforming growth factor-beta1 (TGF-beta1). The half-life of RHAMM mRNA was increased by 3 fold in cells treated with TGF-beta1, indicating that growth factor regulation of RHAMM gene expression at least in part involves a posttranscriptional mechanism. Our studies demonstrated that a unique 30-nucleotide (nt) region that has three copies of the sequence, GCUUGC, was the TGF-beta1-responsive region in the 3'-untranslated region (3'-UTR) that mediated message stability. This region interacted specifically with cytoplasmic trans-factors to form multiple protein complexes of approximately 175, 97, 63, 26, and 17 kDa post-TGF-beta1 treatment, suggesting a role for these complexes in the mechanism of action of TGF-beta1-induced message stabilization. Insertion of the 3'-UTR into the chloramphenicol acetyltransferase gene conferred TGF-beta1 induced stability of chloramphenicol acetyltransferase-hybrid RNA in stably transfected cells, while the same insert carrying a deletion containing the 30-nt region had no significant effect on mRNA stability. These results provide a model of RHAMM message regulation in which TGF-beta1-mediated alteration of RHAMM message stability involves the up-regulation of multiple protein interactions with a 30-nt cis-element stability determinant in the 3'-UTR. This model also suggests that this 30-nt base region functions in cis to destabilize RHAMM mRNA in resting normal cells.


Asunto(s)
Proteínas de la Matriz Extracelular/biosíntesis , Regulación de la Expresión Génica/efectos de los fármacos , Receptores de Hialuranos/biosíntesis , ARN Mensajero/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Animales , Secuencia de Bases , Sitios de Unión , Línea Celular , Cloranfenicol O-Acetiltransferasa/biosíntesis , Fibrosarcoma , Ratones , Datos de Secuencia Molecular , Sondas de Oligonucleótidos , Oligorribonucleótidos , Biosíntesis de Proteínas/efectos de los fármacos , ARN Mensajero/química , Proteínas Recombinantes/biosíntesis , Transcripción Genética , Transfección , Células Tumorales Cultivadas
19.
Mol Genet Genomics ; 268(5): 684-91, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12589443

RESUMEN

We describe the isolation of a gene (clxA) encoding calnexin from laboratory and industrial strains of Aspergillus niger. Calnexin is a chaperone, which specifically recognises monoglucosylated glycoproteins in the endoplasmic reticulum, and is thus an essential component of the process that assesses the folded state of nascent secreted glycoproteins. Manipulation of chaperones has previously been adopted in attempts to overcome some of the problems associated with the secretion of heterologous proteins from filamentous fungi. The A. niger clxA gene encodes a 562-residue protein with strong homology to the calnexin of Schizosaccharomyces pombe. The clxAgene product complements a S. pombe cnx1 mutant. Motifs associated with genes controlled via the Unfolded Protein Response (UPR) were identified by sequence homology in the promoter of clxA. Steady-state levels of clxA mRNA were elevated in a strain expressing bovine prochymosin fused to the catalytic domain of glucoamylase. The ORF is punctuated by four introns, and contains two sets of four repeated peptide motifs that are characteristic of the calnexin family, together with a putative membrane-spanning domain. Deletion studies indicate that clxA is not an essential gene in A. niger.


Asunto(s)
Aspergillus niger/genética , Calnexina/genética , Proteínas Fúngicas/genética , Genes Fúngicos , Animales , Aspergillus niger/metabolismo , Secuencia de Bases , Calnexina/metabolismo , Bovinos , Quimosina/biosíntesis , Quimosina/genética , ADN de Hongos/genética , Precursores Enzimáticos/biosíntesis , Precursores Enzimáticos/genética , Proteínas Fúngicas/metabolismo , Eliminación de Gen , Expresión Génica , Prueba de Complementación Genética , Glucano 1,4-alfa-Glucosidasa/biosíntesis , Glucano 1,4-alfa-Glucosidasa/genética , Datos de Secuencia Molecular , Mutación , Regiones Promotoras Genéticas , ARN de Hongos/genética , ARN de Hongos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Homología de Secuencia de Aminoácido
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