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1.
Med Klin Intensivmed Notfmed ; 111(8): 715-722, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26596273

RESUMEN

BACKGROUND: Cardiogenic shock remains the most serious complication of patients hospitalized with acute myocardial infarction (AMI). Early revascularization is the cornerstone of invasive therapy, while mechanical support with intra-aortic balloon pump (IABP) is debatable. From our institutional shock registry we sought to determine predictors of in-hospital mortality-including the aspect of IABP timing-and to develop a clinical risk score for shock patients with AMI. METHODS: From January 2005 till December 2010, 102 patients with cardiogenic shock due to AMI treated with primary percutaneous coronary intervention (PCI) and IABP were analyzed. Univariate and multivariate logistic regression analyses were used to identify independent predictors of in-hospital mortality. Logistic regression analysis and receiver-operating curves were used to generate a mortality risk score. RESULTS: The mean age of the cohort was 70.1 ± 11.0 years and 70 % were men. One third of patients had a non-ST segment elevation myocardial infarction and 30 % had to be resuscitated before coronary intervention. Mean left ventricular ejection fraction was 25 %. After admission, 23 % of patients developed an acute renal failure and 10 % needed renal dialysis during hospital stay. In 52 % of patients IABP therapy was initiated after primary PCI, while the remaining patients had an IABP-assisted primary PCI. All-cause in-hospital mortality was 40.2 %. Using multivariate analysis, age (odds ratio [OR] 1.08, p = 0.006), resuscitation before PCI (OR 3.46, p = 0.045), vasopressor use (OR 7.88, p = 0.003), acute renal failure (OR 11.18, p = 0.001), and IABP implantation after PCI (OR 4.36, p = 0.011) were independently associated with in-hospital mortality. Based on these predictors, a mortality-risk score was calculated as follows: 1.5 × IABP timing before PCI + 0.1 × age + resuscitation before PCI + 2 × vasopressor use + 2.5 × acute renal failure. Using a cut-off value of 10.4, this score had a specificity of 83 % and a sensitivity of 82 % for prediction of in-hospital death. CONCLUSIONS: We identified age, vasopressor use, resuscitation before PCI, acute renal failure and IABP implantation after PCI as independent predictors of in-hospital mortality in patients with cardiogenic shock due to AMI. The timing of IABP insertion was the only modifiable factor predicting in-hospital mortality in our cohort. Consequently, balloon pumping should be started before PCI to improve outcome of cardiogenic shock patients.


Asunto(s)
Intervención Coronaria Percutánea , Choque Cardiogénico/mortalidad , Anciano , Anciano de 80 o más Años , Femenino , Mortalidad Hospitalaria , Humanos , Contrapulsador Intraaórtico , Masculino , Infarto del Miocardio , Choque Cardiogénico/terapia , Resultado del Tratamiento
2.
Eur J Vasc Endovasc Surg ; 48(1): 80-7, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24785647

RESUMEN

OBJECTIVES: The superiority of autogenous venous conduits in infrainguinal bypass surgery is well established. In the absence of suitable leg or arm veins the radial artery can be utilized as an alternative autogenous conduit. In contrast to cardiac surgery, experience with the radial artery as a conduit for infrainguinal bypass surgery is limited. The purpose of this study was to review the outcomes of our radial artery bypasses over the last 17 years. METHODS: All radial artery bypasses performed between 1995 and 2012 were identified from a prospective database. Patency, limb salvage, and survival were calculated using the Kaplan-Meier survival estimate method. RESULTS: Twenty-nine radial artery bypasses were performed in 28 patients. Median follow-up was 55 months (range 1-170). Twelve-month primary, assisted primary, and secondary patency rates were 49%, 62%, and 73% respectively; Both 3-year and 5-year primary, assisted primary, and secondary patency rates were 49%, 56% and 67% respectively. Limb salvage rate was 75% at 1- and 5-year follow-up. Patient survival at 1, 3, and 5 years was 96%, 88%, and 76%. CONCLUSIONS: For patients with need of challenging infrainguinal revascularization without suitable autogenous venous conduit, a radial artery bypass can be performed safely with favorable long-term patency and limb salvage rates.


Asunto(s)
Enfermedad Arterial Periférica/cirugía , Arteria Radial/trasplante , Injerto Vascular , Anciano , Anciano de 80 o más Años , Angioplastia de Balón , Autoinjertos , Estudios de Factibilidad , Femenino , Oclusión de Injerto Vascular/etiología , Oclusión de Injerto Vascular/fisiopatología , Oclusión de Injerto Vascular/terapia , Humanos , Estimación de Kaplan-Meier , Recuperación del Miembro , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/mortalidad , Enfermedad Arterial Periférica/fisiopatología , Arteria Radial/diagnóstico por imagen , Arteria Radial/fisiopatología , Radiografía , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Trombectomía , Factores de Tiempo , Resultado del Tratamiento , Injerto Vascular/efectos adversos , Injerto Vascular/mortalidad , Grado de Desobstrucción Vascular , Victoria
3.
Am J Transplant ; 6(1): 161-8, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16433770

RESUMEN

Cardiac allograft vasculopathy (CAV) is a major cause of death more than 1 year after heart transplantation. We evaluated the role and possible predictive value of different etiological factors on development of CAV as diagnosed by quantitative coronary angiography (QCA). A total of 121 patients were studied with baseline QCA and 117 had a follow-up study at 1 year to assess the relationship of mean lumen diameter loss (MLDL) in main coronary arteries to immunological and non-immunological factors potentially affecting long-term survival. Out of them, 103 patients were males (85%), 114 (94%) patients were Caucasians and mean age was 48.5 +/- 10 years. Univariate analysis showed that MLDL at 1 year was inversely related to echocardiographic fractional shortening (FS) measured within the first week after transplantation (p = 0.0098) and to intracranial hemorrhage as cause of donor death (p = 0.04) and was directly related to male donors (p = 0.0008), domino transplants (p = 0.037) and donor negative cytomegalovirus (CMV) status (p = 0.022). Multivariate analysis showed that initial FS (p = 0.006) and donor intracranial hemorrhage as a cause of death (p = 0.042) were inversely related to MLDL whereas donor male sex (p = 0.003) and prednisolone treatment throughout the first year (p = 0.012) were directly related. Thus, left ventricular systolic dysfunction early after heart transplantation was associated with subsequent development of CAV.


Asunto(s)
Enfermedad Coronaria/etiología , Trasplante de Corazón , Disfunción Ventricular Izquierda/complicaciones , Angiografía Coronaria/métodos , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/patología , Ecocardiografía , Femenino , Trasplante de Corazón/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Sístole , Trasplante Homólogo , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/etiología
4.
Z Kardiol ; 94(2): 121-7, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15674742

RESUMEN

Endoaneurysmorrhaphy (EAR) has become an important therapeutic option in the treatment of patients with left ventricular (LV) aneurysm and congestive heart failure. Today, more and more patients are referred for EAR with a dilated akinetic LV rather than a classic dyskinetic LV aneurysm. Little is known about the contribution of the extent of akinesis to perioperative mortality. We reviewed the data of 147 patients with anterior left ventricular aneurysms undergoing EAR. Seventy percent of the patients were male; mean age was 62+/-9 years. Demographic, hemodynamic, angiographic and surgical variables were analyzed using univariate statistic tests in order to determine risk factors for in-hospital mortality.Eighty-two percent of the LV aneurysms had at least some dyskinesia, but 70% were mainly akinetic. 133 patients had additional bypass surgery, one had additional mitral valve replacement. In-hospital mortality was 4.1% (n=6). Risk factors for in-hospital mortality were the total extent of akinetic myocardium (p=0.027) in the 30 degrees RAO view and the duration of cardiopulmonary bypass (CPB, p=0.0068) which was itself dependent on the LV ejection fraction (p=0.001), the number of stenosed coronary arteries (p=0.004), and the extent of akinesis (p=0.023). The extent of dyskinesia was not associated with either perioperative mortality (p=0.36) or CPB duration. EAR can be performed with acceptable perioperative results. Because akinesis increases in many patients with time, and because the duration of ECC was dependent on variables reflecting the severity of the underlying heart disease, our findings underscore the importance of optimal timing for the surgical intervention.


Asunto(s)
Aneurisma Cardíaco/cirugía , Insuficiencia Cardíaca/cirugía , Mortalidad Hospitalaria , Complicaciones Posoperatorias/mortalidad , Disfunción Ventricular Izquierda/cirugía , Anciano , Volumen Cardíaco/fisiología , Terapia Combinada , Puente de Arteria Coronaria , Femenino , Aneurisma Cardíaco/mortalidad , Insuficiencia Cardíaca/mortalidad , Ventrículos Cardíacos/cirugía , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Implantación de Prótesis , Análisis de Supervivencia , Técnicas de Sutura , Resultado del Tratamiento , Disfunción Ventricular Izquierda/mortalidad
5.
Neurogastroenterol Motil ; 16(1): 113-24, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14764211

RESUMEN

Visceral pain is the most common form of pain produced by disease and is thus of interest in the study of gastrointestinal (GI) complaints such as irritable bowel syndrome, in which sensory signals perceived as GI pain travel in extrinsic afferent neurones with cell bodies in the dorsal root ganglia (DRG). The DRG from which the primary spinal afferent innervation of the mouse descending colon arises are not well defined. This study has combined retrograde labelling and immunohistochemistry to identify and characterize these neurones. Small to medium-sized retrogradely labelled cell bodies were found in the DRG at levels T8-L1 and L6-S1. Calcitonin gene-related peptide (CGRP)- and P2X3-like immunoreactivity (LI) was seen in 81 and 32%, respectively, of retrogradely labelled cells, and 20% bound the Griffonia simplicifolia-derived isolectin IB4. CGRP-LI and IB4 were co-localized in 22% of retrogradely labelled cells, whilst P2X3-LI and IB4 were co-localized in 7% (vs 34% seen in the whole DRG population). Eighty-two per cent of retrogradely labelled cells exhibited vanilloid receptor 1-like immunoreactivity (VR1-LI). These data suggest that mouse colonic spinal primary afferent neurones are mostly peptidergic CGRP-containing, VR1-LI, C fibre afferents. In contrast to the general DRG population, a subset of neurones exist that are P2X3 receptor-LI but do not bind IB4.


Asunto(s)
Vías Aferentes/anatomía & histología , Colon/inervación , Ganglios Espinales/anatomía & histología , Glicoproteínas , Neuronas Aferentes/citología , Vías Aferentes/metabolismo , Animales , Péptido Relacionado con Gen de Calcitonina/metabolismo , Ganglios Espinales/metabolismo , Inmunohistoquímica , Lectinas/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Neuronas Aferentes/metabolismo , Nociceptores/anatomía & histología , Nociceptores/metabolismo , Receptores de Droga/metabolismo , Receptores Purinérgicos P2/metabolismo , Receptores Purinérgicos P2X3 , Coloración y Etiquetado
6.
EMBO J ; 20(23): 6700-11, 2001 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-11726506

RESUMEN

Cell differentiation in Trypanosoma brucei involves highly regulated changes in morphology, proliferation and metabolism. However, the controls of these developmental processes are unknown. We have identified two novel proteins from the rare CCCH zinc finger family, each <140 amino acids in length and implicated in life cycle regulation. TbZFP1 is transiently enriched during differentiation from the bloodstream to procyclic form, whereas tbZFP2, when ablated in bloodstream forms by RNA interference, inhibits this developmental step. Moreover, expressing an ectopic copy of tbZFP2 results in a dramatic procyclic stage-specific remodelling of the trypanosome cytoskeleton similar to the morphogenic events of differentiation. This phenotype, we term 'nozzle', involves polar extension of microtubules at the posterior end of the cell and is dependent upon a motif hitherto restricted to E3 ubiquitin ligases. TbZFP1 and tbZFP2 represent the first molecules implicated in the control of trypanosome differentiation to the procyclic form.


Asunto(s)
Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/química , Proteínas Protozoarias/biosíntesis , Proteínas Protozoarias/química , Trypanosoma brucei brucei/fisiología , Dedos de Zinc , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Western Blotting , Diferenciación Celular , Citoesqueleto/metabolismo , Cartilla de ADN/química , Proteínas de Unión al ADN/genética , Ligasas/metabolismo , Microscopía Fluorescente , Microtúbulos/metabolismo , Modelos Biológicos , Datos de Secuencia Molecular , Fenotipo , Plásmidos/metabolismo , Estructura Terciaria de Proteína , Proteínas Protozoarias/genética , ARN/metabolismo , Homología de Secuencia de Aminoácido , Factores de Tiempo , Trypanosoma brucei brucei/metabolismo , Ubiquitina-Proteína Ligasas
7.
EMBO J ; 20(15): 4099-106, 2001 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-11483513

RESUMEN

Import of the ADP/ATP carrier (AAC) into mitochondria requires the soluble TIM10 complex to cross the intermembrane space. We report here that Tim9 and Tim10 purified from Escherichia coli can form a complex of the same size as the endogenous complex from yeast mitochondria. This shows that no other mitochondrial protein is required for the formation of the TIM10 complex. Co-expression of both proteins rendered Tim9 more soluble and allowed purification of the reconstituted complex in a single step. Urea/EDTA treatment of recombinant Tim10 allowed its import into tim10-ts mitochondria that lack endogenous Tim10 and cannot import AAC. In this way, we were able to (i) reconstitute the TIM10 complex in the intermembrane space and (ii) restore import of AAC to almost wild-type levels. The reconstituted TIM10 complex not only facilitated passage of AAC across the outer membrane but also ensured its accurate membrane insertion. We conclude that the TIM10 complex can be formed exclusively from Tim9 and Tim10 and that the reconstituted complex efficiently restores AAC import in a strain lacking the TIM10 complex.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Transporte de Membrana , Translocasas Mitocondriales de ADP y ATP/metabolismo , Proteínas Mitocondriales , Proteínas de Saccharomyces cerevisiae , Transporte Biológico , Proteínas Portadoras/genética , Fraccionamiento Celular , Membrana Celular/metabolismo , Citoplasma/metabolismo , Escherichia coli/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/aislamiento & purificación , Expresión Génica , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana Mitocondrial , Proteínas del Complejo de Importación de Proteínas Precursoras Mitocondriales , Pruebas de Precipitina , Saccharomyces cerevisiae/metabolismo
8.
Behav Modif ; 25(3): 406-42, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11428247

RESUMEN

The authors examine stigmatization and mental illness, focusing on the role of perceived group variability in stereotype use. Consumers' and providers' in-group and out-group stereotypes were assessed. Although providers had extensive experience, they judged consumers more stereotypically and just as negatively as did the consumers themselves. Consumers' education and involvement in services were weakly predictive of more stereotypic, less variable, and more negative views of providers, whereas providers' education and involvement in services predicted more stereotypic but also more variable views of both groups. Perceived group stereotypicality predicted more stereotypic judgments of individuals, whereas perceived variability predicted less confidence in judgments. Because providers perceived greater variability, they were less confident in applying the stereotype to individuals. We suggest that increasing perceptions of the variability among consumers may lead to more sensitive use of diagnostic criteria, more individualized treatment, and a decrease in the negative effects of stigmatization.


Asunto(s)
Terapia Conductista , Servicios Comunitarios de Salud Mental , Trastornos Mentales/psicología , Grupo de Atención al Paciente , Estereotipo , Adulto , Enfermedad Crónica , Femenino , Humanos , Masculino , Relaciones Profesional-Paciente , Identificación Social
9.
J Virol ; 75(11): 5159-73, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11333897

RESUMEN

Chemokines induce chemotaxis, cell migration, and inflammatory responses. We report the identification of an interleukin-8 (IL-8) homolog, termed vIL-8, encoded within the genome of Marek's disease virus (MDV). The 134-amino-acid vIL-8 shares closest homology to mammalian and avian IL-8, molecules representing the prototype CXC chemokine. The gene for vIL-8 consists of three exons which map to the BamHI-L fragment within the repeats flanking the unique long region of the MDV genome. A 0.7-kb transcript encoding vIL-8 was detected in an n-butyrate-treated, MDV-transformed T-lymphoblastoid cell line, MSB-1. This induction is essentially abolished by cycloheximide and herpesvirus DNA polymerase inhibitor phosphonoacetate, indicating that vIL-8 is expressed with true late (gamma2) kinetics. Baculovirus-expressed vIL-8 was found to be secreted into the medium and shown to be functional as a chemoattractant for chicken peripheral blood mononuclear cells but not for heterophils. To characterize the function of vIL-8 with respect to MDV infection in vivo, a recombinant MDV was constructed with a deletion of all three exons and a soluble-modified green fluorescent protein (smGFP) expression cassette inserted at the site of deletion. In two in vivo experiments, the vIL-8 deletion mutant (RB1BvIL-8DeltasmGFP) showed a decreased level of lytic infection in comparison to its parent virus, an equal-passage-level parent virus, and to another recombinant MDV containing the insertion of a GFP expression cassette at the nonessential US2 gene. RB1BvIL-8DeltasmGFP retained oncogenicity, albeit at a greatly reduced level. Nonetheless, we have been able to establish a lymphoblastoid cell line from an RB1BvIL-8DeltasmGFP-induced ovarian lymphoma (MDCC-UA20) and verify the presence of a latent MDV genome lacking vIL-8. Taken together, these data describe the identification and characterization of a chemokine homolog encoded within the MDV genome that is dispensable for transformation but may affect the level of MDV in vivo lytic infection.


Asunto(s)
Factores Quimiotácticos/genética , Herpesvirus Gallináceo 2/inmunología , Interleucina-8/biosíntesis , Secuencia de Aminoácidos , Animales , Animales Recién Nacidos , Baculoviridae/genética , Secuencia de Bases , Línea Celular , Línea Celular Transformada , Pollos , Clonación Molecular , Cicloheximida , Eliminación de Gen , Proteínas Fluorescentes Verdes , Herpesvirus Gallináceo 2/genética , Interleucina-8/genética , Leucocitos Mononucleares/metabolismo , Proteínas Luminiscentes/genética , Datos de Secuencia Molecular , Mutagénesis Insercional , Ácido Fosfonoacético , ARN Mensajero/análisis , Proteínas Recombinantes/biosíntesis , Alineación de Secuencia , Proteínas Virales/biosíntesis , Proteínas Virales/genética , Replicación Viral
10.
Transplantation ; 71(7): 886-92, 2001 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-11349721

RESUMEN

BACKGROUND: Transplant-associated coronary artery disease (TxCAD) is the most serious long-term complication after cardiac transplantation. Anti-endothelial antibodies are associated with disease, and one of the major endothelial antigens recognized in the sera of patients has been shown to be the protein filament vimentin. In this study, we investigated whether antivimentin antibodies are associated with TxCAD and whether their presence can be used to identify patients at high risk of developing angiographically detectable TxCAD. METHODS: Up to 5 years after transplantation, 880 sequential sera (7.07+/-1.8 samples/patient) were collected retrospectively from 109 patients; the majority were collected in the first 2 years. Sera were assessed for antivimentin antibodies using ELISA. TxCAD was assessed by annual angiography. RESULTS: Mean titres of antivimentin antibodies, calculated up to 1, 2, and 5 years, were significantly higher in patients who developed TxCAD than those who remained disease free (P<0.0001, P<0.0038, and P<0.0001, respectively). A predictive test based on the first-year mean vimentin titre alone (> or = 120) produced a test with 63% sensitivity and 76% specificity. Inclusion of persistent rejection or high 1-year mean titre (> or = 270) as a risk factor produced a test with 66% sensitivity and 82% specificity. Multivariate analysis of time to occurrence of transplant vasculopathy showed that mean titre at 1 or 2 years was an independent predictor of time until disease in the presence of all other variables. CONCLUSIONS: Antivimentin antibodies are an independent predictor of TxCAD and can be used to identify some of the patients who are at high risk of developing this complication.


Asunto(s)
Anticuerpos/análisis , Enfermedad Coronaria/etiología , Trasplante de Corazón/efectos adversos , Vimentina/inmunología , Adolescente , Adulto , Anciano , Enfermedad Coronaria/epidemiología , Ensayo de Inmunoadsorción Enzimática , Femenino , Rechazo de Injerto , Trasplante de Corazón/inmunología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Análisis de Supervivencia , Factores de Tiempo
11.
J Cell Biol ; 153(4): 725-34, 2001 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-11352934

RESUMEN

Kinetoplast DNA (kDNA), the mitochondrial DNA of the trypanosomatid Crithidia fasciculata, is a unique structure containing 5,000 DNA minicircles topologically linked into a massive network. In vivo, the network is condensed into a disk-shaped structure. Replication of minicircles initiates at unique origins that are bound by universal minicircle sequence (UMS)-binding protein (UMSBP), a sequence-specific DNA-binding protein. This protein, encoded by a nuclear gene, localizes within the cell's single mitochondrion. Using immunofluorescence, we found that UMSBP localizes exclusively to two neighboring sites adjacent to the face of the kDNA disk nearest the cell's flagellum. This site is distinct from the two antipodal positions at the perimeter of the disk that is occupied by DNA polymerase beta, topoisomerase II, and a structure-specific endonuclease. Although we found constant steady-state levels of UMSBP mRNA and protein and a constant rate of UMSBP synthesis throughout the cell cycle, immunofluorescence indicated that UMSBP localization within the kinetoplast is not static. The intramitochondrial localization of UMSBP and other kDNA replication enzymes significantly clarifies our understanding of the process of kDNA replication.


Asunto(s)
ADN de Cinetoplasto/fisiología , ADN Mitocondrial/fisiología , Proteínas de Unión al ADN/genética , Animales , Ciclo Celular/fisiología , Crithidia fasciculata , Proteínas de Unión al ADN/análisis , Técnicas Microbiológicas , Mitocondrias/química , Mitocondrias/genética , Proteínas Protozoarias/análisis , Proteínas Protozoarias/genética , ARN Mensajero/análisis , Origen de Réplica/fisiología
12.
Oncogene ; 19(49): 5548-57, 2000 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-11114734

RESUMEN

As the sequencing of the human genome is completed by the Human Genome Project, the analysis of this rich source of information will illuminate many areas in medicine and biology. The protein tyrosine kinases are a large multigene family with particular relevance to many human diseases, including cancer. A search of the human genome for tyrosine kinase coding elements identified several novel genes and enabled the creation of a nonredundant catalog of tyrosine kinase genes. Ninety unique kinase genes can be identified in the human genome, along with five pseudogenes. Of the 90 tyrosine kinases, 58 are receptor type, distributed into 20 subfamilies. The 32 nonreceptor tyrosine kinases can be placed in 10 subfamilies. Additionally, mouse orthologs can be identified for nearly all the human tyrosine kinases. The completion of the human tyrosine kinase family tree provides a framework for further advances in biomedical science.


Asunto(s)
Genoma Humano , Proteínas Tirosina Quinasas/genética , Animales , Humanos
13.
Mol Biochem Parasitol ; 111(2): 283-97, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11163437

RESUMEN

In Trypanosoma brucei, we have cloned a gene approximately 5 kb downstream of the glucose transporter gene cluster, containing a variable number of 102 bp repeats. This gene encodes a protein with no homologues in the data bases. Antibodies raised against the 34 amino acids repeated motif recognized proteins ranging from 145 to 270 kDa, depending on strains, in both bloodstream and procyclic forms of T. brucei. A correlation was established between the apparent molecular mass of the detected proteins and the number of 34 amino acid repeats which varies from 3 to 40. We have called this protein the flagellum transition zone component (FTZC) due to its localization to the proximal region of the axoneme, within the transition zone. FTZC is the only reported example of a trypanosomal protein present in the transition zone. To determine the role of FTZC we developed a new strategy of gene inactivation based on conditional expression of double-stranded RNA. In the presence of tetracycline, expression of the double-stranded RNA, we observed a complete disappearance of FTZC in the EATRO 1125 and EATRO 427 strains of T. hrucei. Molecular ablation of FTZC does not generate any obvious phenotype such as, lethality, modification of growth rate or cellular shape, in the growth conditions used.


Asunto(s)
Proteínas Portadoras/genética , Flagelos/metabolismo , Proteínas Protozoarias/genética , ARN Bicatenario/metabolismo , Trypanosoma brucei brucei/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Western Blotting , Proteínas Portadoras/metabolismo , Proteínas del Citoesqueleto , Flagelos/ultraestructura , Técnica del Anticuerpo Fluorescente , Eliminación de Gen , Ratones , Datos de Secuencia Molecular , Proteínas Protozoarias/metabolismo , ARN Bicatenario/genética , Conejos , Ratas , Secuencias Repetitivas de Aminoácido , Fracciones Subcelulares/metabolismo , Transfección , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/crecimiento & desarrollo , Trypanosoma brucei brucei/ultraestructura
14.
J Cell Sci ; 112 ( Pt 24): 4641-50, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10574712

RESUMEN

Trypanosoma brucei has a single nucleus and a single kinetoplast (the mitochondrial genome). Each of these organelles has a distinct S phase, which is followed by a segregation period, prior to cell division. The segregation of the two genomes takes place in a specific temporal order by interaction with microtubule-based structures, the spindle for nuclear DNA and the flagellum basal bodies for the kinetoplast DNA. We used rhizoxin, the anti-microtubule agent and polymerisation inhibitor, or the nuclear DNA synthesis inhibitor aphidicolin, to interfere with cell cycle events in order to study how such events are co-ordinated. We show that T. brucei cytokinesis is not dependent upon either mitosis or nuclear DNA synthesis, suggesting that there are novel cell cycle checkpoints in this organism. Moreover, use of monoclonal antibodies to reveal cytoplasmic events such as basal body duplication shows that some aphidicolin treated cells appear to be in G(1) phase (1K1N) but have activated some cytoplasmic events characteristic of G(2) phase (basal body segregation). We discuss a possible dominant role in trypanosomes for kinetoplast/basal body segregation in control of later cell cycle events such as cytokinesis


Asunto(s)
Ciclo Celular , Mitosis , Trypanosoma brucei brucei/citología , Animales , Afidicolina/farmacología , Ciclo Celular/efectos de los fármacos , Ciclo Celular/fisiología , Núcleo Celular/fisiología , ADN de Cinetoplasto/genética , Lactonas/farmacología , Macrólidos , Mitocondrias/fisiología , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma brucei brucei/genética
16.
J Virol ; 73(3): 1909-17, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9971770

RESUMEN

Kaposi's sarcoma-associated herpesvirus (KSHV) is a recently discovered human gamma herpesvirus strongly implicated in AIDS-related neoplasms. We report here the identification in the KSHV genome of a gene for a protein designated K-bZIP and belonging to the basic-leucine zipper (bZIP) family of transcription factors. K-bZIP shows significant homology to BZLF1, which plays a key role in the replication and reactivation of Epstein-Barr virus. K-bZIP is a homodimerizing protein of 237 amino acids with a prototypic bZIP domain at the C terminus. The N-terminal portion of K-bZIP is derived from the K8 open reading frame which, through in-frame splicing, adjoins the ZIP domain. This structure was revealed by rapid analysis of cDNA ends, followed by cloning of the entire cDNA. A 1.35-kb transcript encoding K-bZIP was detected in BCBL-1 cells treated with 12-O-tetradecanoylphorbol-13-acetate. The synthesis of this transcript was blocked by the protein synthesis inhibitor cycloheximide but not by the viral DNA synthesis inhibitor phosphonoacetate, a result which classifies it as an early lytic gene. RNase protection analysis further mapped the major transcription start site for the 1.35-kb K-bZIP mRNA and identified two other splice variants which encode proteins with the N-terminal portion of K-bZIP but lacking the C-terminal ZIP domain. Full-length K-bZIP forms dimers with itself, and the C terminus encompassing the ZIP domain is required for this process. Our studies set the stage for understanding the role of K-bZIP in the replication and reactivation of the KSHV genome.


Asunto(s)
Proteínas de Unión al ADN/genética , Herpesvirus Humano 8/genética , Transactivadores/genética , Factores de Transcripción/genética , Proteínas Virales , Secuencia de Aminoácidos , Secuencia de Bases , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Clonación Molecular , Proteínas de Unión al ADN/química , Dimerización , Factores de Unión a la G-Box , Humanos , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Transactivadores/química , Factores de Transcripción/química , Transcripción Genética
17.
Cancer Res ; 59(1): 63-6, 1999 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-9892186

RESUMEN

Malignant neoplasms, including colon cancers, are thought to arise from a single initiated progenitor cell. Aberrant crypt foci (ACF) are putative precursors of at least some colon cancers. The pattern of X chromosomal inactivation, which is identified by the differential methylation of a site near a polymorphic CAG repeat in the androgen receptor gene, was used to determine the clonality status of 11 ACF from eight female patients. Ten of 11 ACF were found to be monoclonal aberrations. The eleventh ACF appeared monoclonal, but nonrandom inactivation of the X chromosome was also seen in normal crypts from this patient. These results clearly demonstrate that: (a) a high percentage of ACF lesions are neoplastic rather than hyperplastic; and (b) ACF are the earliest identified neoplastic lesions in the colon.


Asunto(s)
Colon/patología , Neoplasias Colorrectales/patología , Lesiones Precancerosas , Cromosoma X , Aberraciones Cromosómicas , Neoplasias Colorrectales/genética , Metilación de ADN , Femenino , Humanos , Masculino , Polimorfismo Genético , Receptores Androgénicos/genética
18.
J Control Release ; 57(1): 9-18, 1999 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-9863034

RESUMEN

A plasmid DNA encoding bacterial beta-galactosidase gene was encapsulated in poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres. Plasmid DNA extracted from PLGA microspheres retained both structural and functional integrity as evidenced by its restriction endonuclease digestion pattern and its ability to transfect COS-1 cells in vitro. PLGA microspheres protected plasmid DNA from digestion by deoxyribonuclease I (DNase I) in vitro. The encapsulation efficiency of plasmid DNA and its release rate depended on the molecular mass of PLGA. Lastly, J-774A macrophages phagocytosed PLGA microspheres loaded with plasmid DNA. Co-encapsulated monophosphoryl lipid A increased the rate of phagocytosis. These results suggest that biodegradable PLGA microspheres can deliver intact and functional plasmid DNA at controlled rates. Thus, PLGA microspheres may be used to jointly deliver genes and other biologically active molecules, e.g., immunomodulators, to antigen presenting cells.


Asunto(s)
ADN/administración & dosificación , ADN/inmunología , Técnicas de Transferencia de Gen , Animales , Materiales Biocompatibles , Células COS , Línea Celular , ADN/química , Desoxirribonucleasa I/metabolismo , Composición de Medicamentos/métodos , Ácido Láctico , Ratones , Microscopía Electrónica de Rastreo , Microesferas , Tamaño de la Partícula , Fagocitosis/efectos de los fármacos , Plásmidos/genética , Plásmidos/inmunología , Plásmidos/ultraestructura , Ácido Poliglicólico , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros , Transfección , beta-Galactosidasa/genética
19.
Coron Artery Dis ; 9(11): 747-52, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9919422

RESUMEN

OBJECTIVE: To examine the clinical characteristics and 30-day fatality rate among patients with electrocardiograms (ECGs) ineligible for fibrinolysis in a consecutive series in four general hospitals in the UK. METHODS: We studied 2439 consecutive patients who were identified from regular ward visits, surveillance of results from hospital laboratories, and hospital discharge coding. RESULTS: Thirty percent (732) of patients did not have ECGs eligible for fibrinolysis therapy, while indications were uncertain in 55 (2%). Within the ineligible group, patients presenting with ST depression (n = 294) had a higher 30-day fatality rate than those with ST elevation or left bundle branch block (26% versus 17%; P < 0.001); they represented 40% of the group ineligible for fibrinolysis therapy, or 12% of the total cohort. Thirty-day fatality rates in patients presenting with pathological Q waves and no diagnostic ST segment changes (n = 130), those with T wave changes but no other abnormality (n = 168) and those with a normal ECG (n = 128) were 10%, 5% and 3%, respectively. Despite their high fatality rate, fewer patients with ST depression were admitted to coronary care units than those with ECGs eligible for fibrinolysis therapy (61% versus 85%; P < 0.001) and 23% did not receive heparin. The coronary anatomy in a subset of patients with ST depression showed two- or three-vessel disease in 79% and left main stenosis in 9%. The rates of coronary revascularisation were low in all groups (< 10%). CONCLUSION: Patients with ECGs ineligible for fibrinolysis therapy are a disparate group, with a high rate of fatality occurring in patients who present with ST depression. The high prevalence of multiple vessel coronary disease in patients with ST depression suggests that a more active management strategy is required.


Asunto(s)
Electrocardiografía , Infarto del Miocardio/terapia , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/mortalidad , Pronóstico , Estudios Prospectivos , Análisis de Supervivencia , Terapia Trombolítica
20.
Biochem Pharmacol ; 54(7): 773-80, 1997 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-9353131

RESUMEN

Heat shock (HS) proteins (HSP) function as molecular chaperones and protect cells from thermal and oxidative injury. The signals leading to HSP synthesis, i.e. the "cellular thermometer(s)," are still a matter of debate. In the human premonocytic line U937, we investigated the effects of specific modification of membrane fatty acid (FA) composition by incubation with various saturated and unsaturated fatty acids (UFA) on the HS response and on hydrogen peroxide (H2O2)-induced cell death. FA readily incorporated into U937 cell membranes. UFA did not modulate the HS response but potentiated H2O2-mediated damage, while pre-exposure to HS protected the UFA-treated cells from this increased H2O2 toxicity.


Asunto(s)
Ácidos Grasos/farmacología , Proteínas de Choque Térmico/biosíntesis , Peróxido de Hidrógeno/toxicidad , Lípidos de la Membrana/análisis , Calcio/metabolismo , División Celular/efectos de los fármacos , Línea Celular , ADN/biosíntesis , Ácidos Grasos/análisis , Calor , Humanos , Monocitos/metabolismo , Especies Reactivas de Oxígeno
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