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1.
Rev. esp. cardiol. (Ed. impr.) ; 75(9): 718-727, sept. 2022. tab
Artículo en Español | IBECS | ID: ibc-208225

RESUMEN

Introducción y objetivos La identificación de biomarcadores de fibrilación auricular (FA) subclínica en los pacientes con ictus criptogénico (ICr) es de gran interés. Con dicho objetivo, se evaluó el perfil de microARN circulante de los pacientes con ICr y FA frente a aquellos en ritmo sinusal. Métodos Se incluyó a 64 pacientes con ICr consecutivos monitorizados mediante Holter subcutáneo. Se seleccionó a 18 pacientes (9 con FA y 9 en ritmo sinusal persistente) para determinación de 754 microARN mediante tecnología de alto rendimiento. Se incluyó a 9 pacientes adicionales con ictus y FA concomitante para guiar la selección de microARN. Los microARN de interés se replicaron en una cohorte independiente (n=46). La asociación de biomarcadores con FA a los 6 y 12 meses se analizó mediante regresión logística. Resultados Ocho microARN mostraron expresión diferencial entre los pacientes con y sin FA. El miR-1-3p, un regulador génico involucrado en la arritmogénesis cardiaca, fue el único que permaneció significativamente más elevado en pacientes con ICr y FA de la cohorte de repetición, y además mostró una discreta asociación con la carga arrítmica. Los valores de miR-1-3p por encima de la mediana y la fracción de eyección de la aurícula izquierda se asociaron de forma independiente con la presencia de FA a los 6 y 12 meses. Conclusiones En nuestra cohorte, los valores plasmáticos de miR-1-3p fueron más altos en los pacientes con ICr y FA en el seguimiento. Nuestros resultados indican que el miR-1-3p podría ser un nuevo biomarcador de FA oculta en los pacientes con ICr (AU)


Introduction and objectives Identifying biomarkers of subclinical atrial fibrillation (AF) is of most interest in patients with cryptogenic stroke (CrS). We sought to evaluate the circulating microRNA (miRNA) profile of patients with CrS and AF compared with those in persistent sinus rhythm. Methods Among 64 consecutive patients with CrS under continuous monitoring by a predischarge insertable monitor, 18 patients (9 with AF and 9 in persistent sinus rhythm) were selected for high-throughput determination of 754 miRNAs. Nine patients with concomitant stroke and AF were also screened to improve the yield of miRNA selection. Differentially expressed miRNAs were replicated in an independent cohort (n=46). Biological markers were stratified by the median and included in logistic regression analyses to evaluate their association with AF at 6 and 12 months. Results Eight miRNAs were differentially expressed between patients with and without AF. In the replication cohort, miR-1-3p, a gene regulator involved in cardiac arrhythmogenesis, was the only miRNA to remain significantly higher in patients with CrS and AF vs those in sinus rhythm and showed a modest association with AF burden. High (= above the median) miR-1-3p plasma values, together with a low left atrial ejection fraction, were independently associated with the presence of AF at 6 and 12 months. Conclusions In this cohort, plasma levels of miR-1-3p were elevated in CrS patients with subsequent AF. Our results preliminarily suggest that miR-1-3p could be a novel biomarker that, together with clinical parameters, could help identify patients with CrS and a high risk of occult AF (AU)


Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Fibrilación Atrial , MicroARNs/genética , Estudios de Casos y Controles , Estudios Prospectivos , Fibrilación Atrial/complicaciones , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/genética , Biomarcadores
2.
Rev. cir. (Impr.) ; 73(3): 347-350, jun. 2021. ilus
Artículo en Español | LILACS | ID: biblio-1388828

RESUMEN

Resumen Objetivo: Reportamos un caso clínico con presentación atípica de una úlcera duodenal benigna que simula el cuadro clínico y radiológico de una neoplasia de páncreas. Materiales y Método: Presentamos el caso de un varón de 83 años que debuta con un cuadro clínico de astenia e ictericia mucocutánea. En estudio de imagen se identifica una masa en cabeza pancreática. En estudio endoscópico se observa úlcera duodenal benigna penetrada a cabeza de páncreas que condiciona obstrucción de vía biliar. Discusión y Conclusiones: El manejo de estos pacientes suele ser quirúrgico porque desarrollan un deterioro asociado a sepsis o perforación. Si la situación clínica lo permite se puede intentar un tratamiento conservador. En nuestro caso el paciente precisó un mes de hospitalización con antibioticoterapia intravenosa de amplio espectro, reposo alimentario, nutrición parenteral y tratamiento con inhibidores de la bomba de protones (IBP) para la resolución del cuadro. La penetración o fistulización a la cabeza del páncreas es una complicación grave e infrecuente de la enfermedad ulcerosa péptica. Su manejo puede ser conservador en casos seleccionados donde no exista perforación de la úlcera a la cavidad peritoneal, ni exista deterioro séptico ni hemodinámico.


Aim: To report an atypical presentation of a benign duodenal ulcer that simulates pancreatic neoplasia. Materials and Method: A case of a 83 years old male patient with astenia and jaundice due to a benign duodenal ulcer penetrating into the pancreas with obstruction of common bile duct. Imagining study identified a pancreatic head mass. The patient required one month admission, receiving broad-spectrum antibiotics, parenteral nutrition and intravenous proton pump inhibitors. Discussion and Conclusion: Due to frequent complications associated to this condition, such as haemodynamic failure, sepsis or free peritoneal perforation, surgery is the main treatment. However, in mild cases, as in our patient, conservative management can be considered. Penetration or fistulization to the head of the pancreas is a rare and serious complication of peptic ulcer disease. Its management can be conservative in selected cases where there is no perforation of the ulcer into the peritoneal cavity, nor septic or hemodynamic deterioration.


Asunto(s)
Humanos , Masculino , Anciano de 80 o más Años , Páncreas/patología , Úlcera Duodenal/complicaciones , Úlcera Duodenal/tratamiento farmacológico , Conductos Biliares/patología , Úlcera Duodenal/diagnóstico por imagen , Tratamiento Conservador/métodos
3.
Cell Biosci ; 11(1): 89, 2021 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-34001233

RESUMEN

BACKGROUND: Iron deficiency (ID) is common in patients with heart failure (HF) and is associated with poor outcomes, yet its role in the pathophysiology of HF is not well-defined. We sought to determine the consequences of HF neurohormonal activation in iron homeostasis and mitochondrial function in cardiac cells. METHODS: HF was induced in C57BL/6 mice by using isoproterenol osmotic pumps and embryonic rat heart-derived H9c2 cells were subsequently challenged with Angiotensin II and/or Norepinephrine. The expression of several genes and proteins related to intracellular iron metabolism were assessed by Real time-PCR and immunoblotting, respectively. The intracellular iron levels were also determined. Mitochondrial function was analyzed by studying the mitochondrial membrane potential, the accumulation of radical oxygen species (ROS) and the adenosine triphosphate (ATP) production. RESULTS: Hearts from isoproterenol-stimulated mice showed a decreased in both mRNA and protein levels of iron regulatory proteins, transferrin receptor 1, ferroportin 1 and hepcidin compared to control mice. Furthermore, mitoferrin 2 and mitochondrial ferritin were also downregulated in the hearts from HF mice. Similar data regarding these key iron regulatory molecules were found in the H9c2 cells challenged with neurohormonal stimuli. Accordingly, a depletion of intracellular iron levels was found in the stimulated cells compared to non-stimulated cells, as well as in the hearts from the isoproterenol-induced HF mice. Finally, neurohormonal activation impaired mitochondrial function as indicated by the accumulation of ROS, the impaired mitochondrial membrane potential and the decrease in the ATP levels in the cardiac cells. CONCLUSIONS: HF characteristic neurohormonal activation induced changes in the regulation of key molecules involved in iron homeostasis, reduced intracellular iron levels and impaired mitochondrial function. The current results suggest that iron could be involved in the pathophysiology of HF.

5.
Transfus Apher Sci ; 59(6): 102921, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32928663

RESUMEN

The Hematology Department and its Hematopoietic Cell Transplantation (HCT) program implemented several measures during COVID-19 outbreak in order to keep clinical activities with the maximum security for both donors and recipients. Nevertheless, there was a lack of evidence whether blood products and specifically bone marrow can cause transfusion-transmitted infection. Initially, there were many uncertainties and did not exist formal recommendations. Before official statements were available, we performed an allogeneic HCT in a 57-year-old male from a related matched donor in the incubation period of COVID-19 where the patient did not develop the disease. Actual epidemiology data suggest that transmission may occur early in the course of infection, even from asymptomatic patients in the incubation period. In our knowledge this is the first case report of an adult hematopoietic cell donor with COVID-19 in the incubation period where the transplant is successfully completed with no transmission of SARS-CoV-2. The low concentration of viral RNA in plasma of patients with COVID-19 could support the safety of blood products, including peripheral blood hematopoietic cells. In conclusion, blood products including hematopoietic stem cells are safe in the context of COVID-19 pandemic.


Asunto(s)
COVID-19/sangre , Trasplante de Células Madre Hematopoyéticas , Linfoma de Células del Manto , SARS-CoV-2 , Donantes de Tejidos , Aloinjertos , Femenino , Humanos , Linfoma de Células del Manto/sangre , Linfoma de Células del Manto/terapia , Masculino , Persona de Mediana Edad
6.
Eur J Neurol ; 27(2): 244-250, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31424609

RESUMEN

BACKGROUND AND PURPOSE: Subclinical atrial fibrillation (AF) is known to underlie a number of cases of cryptogenic stroke (CrS). However, there is need to define the most effective strategy for AF detection. The diagnostic usefulness was analysed of a strategy based on ultra-early continuous monitoring in patients with CrS in terms of AF detection, oral anticoagulation treatment and stroke recurrence, in comparison to a standard outpatient strategy. METHODS: Patients with ischaemic stroke of undetermined origin and confirmed to be cryptogenic after extensive work-up were searched for AF with (i) a conventional strategy (historical cohort, n = 101) with serial electrocardiograms and 24-h Holter monitoring or (ii) an ultra-early monitoring strategy with insertable cardiac monitor (ICM) implanted before discharge (prospective cohort, n = 90). AF episodes lasting >1 min, anticoagulant treatment and stroke recurrence were recorded. RESULTS: During admission, AF was similarly detected in both cohorts (24% of patients). After discharge (mean follow-up 30 ± 10 months), AF detection rates were 17/80 (21.3%) and 38/65 (58.5%) for patients in the conventional versus the ultra-early ICM group (P < 0.001). Up to 41% of AF cases in the ICM cohort were detected within the first month. Oral anticoagulation was initiated in 37.6% versus 65.5% (P < 0.001) and stroke recurrence was recorded in 10.9% versus 3.3% (P 0.04) in the conventional versus the ICM cohort. CONCLUSIONS: Pre-discharge ICM implant allows detection of AF during follow-up in up to 58% of selected patients with CrS. Compared to a conventional strategy, ultra-early ICM implant results in higher anticoagulation rates and a decrease in stroke recurrence.


Asunto(s)
Fibrilación Atrial/diagnóstico , Corazón/fisiopatología , Accidente Cerebrovascular/fisiopatología , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/etiología , Estudios de Cohortes , Electrocardiografía Ambulatoria , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Monitorización Neurofisiológica , Pronóstico , Accidente Cerebrovascular/complicaciones , Resultado del Tratamiento
7.
Sci Rep ; 7(1): 2901, 2017 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-28588269

RESUMEN

Induced seismicity associated with energy production is becoming an increasingly important issue worldwide for the hazard it poses to the exposed population and structures. We analyze one of the rare cases of induced seismicity associated with the underwater gas storage operations observed in the Castor platform, located in the Valencia gulf, east Spain, near a complex and important geological structure. In September 2013, some gas injection operations started at Castor, producing a series of seismic events around the reservoir area. The larger magnitude events (up to 4.2) took place some days after the end of the injection, with EMS intensities in coastal towns up to degree III. In this work, the seismic sequence is analyzed with the aim of detecting changes in statistical parameters describing the earthquake occurrence before and after the injection and identifying possible proxies to be used for monitoring the sequence evolution. Moreover, we explore the potential predictability of these statistical parameters which can be used to control the field operations in injection/storage fluid reservoirs. We firstly perform a retrospective approach and next a perspective analysis. We use different techniques for estimating the value of the expected maximum magnitude that can occur due to antropogenic activities in Castor.

8.
Acta Medica Philippina ; : 216-222, 2017.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-997777

RESUMEN

@#Objectives. Polymorphisms in metabolic genes which alter rates of bioactivation and detoxification have been shown to modulate susceptibility to colorectal cancer. This study sought to evaluate the colorectal cancer risk from environmental factors and to do polymorphism studies on genes that code for Phase I and II xenobiotic metabolic enzymes among Filipino colorectal cancer patients and matched controls. Methods. A total of 224 colorectal cancer cases and 276 controls from the Filipino population were genotyped for selected polymorphisms in GSTM1, GSTP1, GSTT1, NAT1 and NAT2. Medical and diet histories, occupational exposure and demographic data were also collected for all subject participants.Results. Univariate logistic regression of non-genetic factors identified exposure to UV (sunlight) (OR 1.99, 95% CI: 1.16-3.39) and wood dust (OR 2.66, 95% CI: 1.21-5.83) and moldy food exposure (OR 1.61, 95% CI:1.11-2.35) as risk factors; while the NAT2*6B allele (recessive model OR 1.51, 95% CI :1.06-2.16; dominant model OR 1.87, 95% CI: 1.05-3.33) and homozygous genotype (OR 2.19, 95% CI: 1.19-4.03) were found to be significant among the genetic factors. After multivariate logistic regression of both environmental and genetic factors, only UV radiation exposure (OR 2.08, 95% CI: 1.21-3.58) and wood dust exposure (OR 2.08, 95% CI: 0.95-5.30) remained to be significantly associated with increasing colorectal cancer risk in the study population.Conclusion. This study demonstrated that UV sunlight and wood dust exposure play a greater role in influencing colorectal cancer susceptibility than genotype status from genetic polymorphisms of the GST and the NAT` genes.


Asunto(s)
Neoplasias Colorrectales , Polimorfismo Genético
9.
Acta Medica Philippina ; : 207-215, 2017.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-997776

RESUMEN

Objectives@#The highly polymorphic nature of the CYP2D6 gene and its central role in the metabolism of commonly used drugs make it an ideal candidate for pharmacogenetic screening. This study aims to determine the prevalence of CYP2D6 polymorphisms among Filipinos and their association to lung cancer. @*Method@#Forty seven single nucleotide polymorphisms (SNPs) of the CYP2D6 gene were genotyped from DNA samples of 115 cases with lung cancer and age- and sex-matched 115 controls. @*Results@#Results show that 18 out of 47 polymorphisms have significant genotypic variability (>1% for at least 2 genotypes). No variant is associated with lung cancer. However, rs1135840, rs16947 and rs28360521, were found to be highly variable among Filipinos. @*Conclusion@#This study demonstrated that CYP2D6 polymorphisms are present among Filipinos, which, although not found to be associated with lung cancer, can be useful biomarkers for future pharmacogenetic studies. The SNP rs16947 is found to be associated with cancer and timolol-induced bradycardia; the SNP rs1135840, on the other hand, is only shown to be linked with cancer. The genetic variant rs28360521 is known to be associated with low-dose aspirin-induced lower gastrointestinal bleeding.


Asunto(s)
Farmacogenética , Citocromo P-450 CYP2D6 , Neoplasias Pulmonares , Biomarcadores
10.
Clin Genet ; 77(1): 37-48, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19863551

RESUMEN

In a cohort of patients with confirmed or suspected arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), genetic testing is useful in confirming the diagnosis, particularly in individuals who do not completely fulfil Task Force criteria for the disease, thereby also enabling the adoption of preventive measures in family members. Due to the high percentage of novel mutations that are expected to be identified in ARVC/D, the use of genetic screening technology based on the identification of known mutations seems to have very restricted value. Our results support that the presence of certain genetic variations could play a role in the final phenotype of patients with ARVC/D, where single and compound mutation carriers would have more symptomatic forms of the disease and the polymorphism P366L could be associated to a more benign phenotype.


Asunto(s)
Displasia Ventricular Derecha Arritmogénica/genética , Pruebas Genéticas , Adulto , Displasia Ventricular Derecha Arritmogénica/diagnóstico , Estudios de Cohortes , Desmocolinas/genética , Desmogleína 2/genética , Desmoplaquinas/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Placofilinas/genética , Polimorfismo Genético
11.
Heart ; 94(3): 311-5, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17639094

RESUMEN

OBJECTIVE: To investigate the combination of clinical data, exercise testing and biomarkers for the evaluation of patients with chest pain without ST-segment deviation or troponin elevation. DESIGN: Prospective cohort design. SETTTING: Two teaching hospitals in Spain. PATIENTS: 422 patients presenting to the emergency department were studied. Leukocyte count, C-reactive protein (CRP), pregnancy-associated plasma protein A (PAPP-A) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were determined. A validated clinical risk score (number of points according to pain characteristics and risk factors) was used for clinical evaluation and early exercise testing was performed. MAIN OUTCOME MEASURES: Adverse events (death, myocardial infarction or revascularisation) during a median 60 weeks follow-up. RESULTS: By receiver operating characteristic curve analysis, the association between death or myocardial infarction and adverse events was not significant with leukocyte count (p = 0.3, p = 0.3) or CRP (p = 0.5, p = 0.8), was borderline significant with PAPP-A (p = 0.07, p = 0.04) and strongly significant with NT-pro-BNP (p = 0.0001, p = 0.0001). By Cox regression including clinical risk score, exercise testing result and biomarkers, exercise testing was the independent predictor of revascularisation (p = 0.0001), whereas risk score (p = 0.03) and NT-proBNP (p = 0.0004) predicted death or myocardial infarction. The inclusion of NT-proBNP improved the accuracy of the model for death or myocardial infarction (C-statistic 0.84 versus 0.76, p = 0.01). The combination of clinical score and NT-proBNP afforded the stratification in high (17.2%, p = 0.0001), intermediate (5.3%) and low (1.1%) risk categories of death or myocardial infarction. CONCLUSIONS: NT-proBNP provides incremental prognostic information above that given by clinical history and exercise testing in patients with chest pain without ST-segment deviation and negative troponin.


Asunto(s)
Dolor en el Pecho/sangre , Infarto del Miocardio/sangre , Troponina/sangre , Biomarcadores/sangre , Dolor en el Pecho/mortalidad , Métodos Epidemiológicos , Prueba de Esfuerzo , Humanos , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Péptido Natriurético Encefálico/sangre , Fragmentos de Péptidos/sangre
13.
Transplant Proc ; 38(9): 3012-5, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17112887

RESUMEN

UNLABELLED: Endomyocardial biopsy is the gold-standard procedure to diagnose acute cellular rejection after heart transplantation. This study assessed whether the blood levels of cytokines involved in inflammation and immune activation are useful to detect the presence of acute cellular rejection. METHODS: Blood specimens collected before 275 endomyocardial biopsies in 66 patients were assayed for levels of TNFalpha, IL6, IL1beta, and IL2 receptor. The biopsies were grouped according to the presence (n = 41) or absence (n = 234) of acute cellular rejection grade > or = 3A of the International Society for Heart and Lung Transplantation. We compared the levels of cytokines in the two groups. RESULTS: Circulating IL6 levels were significantly higher when there was a low grade (0-2) cellular rejection in the biopsy versus the group of biopsies grade > or = 3A (19.8 +/- 27 versus 12.9 +/- 10 pg/mL; P = .001). An IL6 level higher than 30 pg/mL showed a negative predictive value of 95% for the presence of acute rejection grade > or = 3A. CONCLUSION: In heart transplant patients, high levels of serum IL6 were associated with low grade cellular rejection. Determination of IL6 levels may be useful to reduce the number of endomyocardial biopsies during follow-up in these patients.


Asunto(s)
Rechazo de Injerto/inmunología , Trasplante de Corazón/inmunología , Interleucina-6/sangre , Adulto , Biomarcadores/sangre , Biopsia , Citocinas/sangre , Rechazo de Injerto/sangre , Trasplante de Corazón/patología , Humanos , Estudios Retrospectivos
14.
J Bacteriol ; 183(10): 3251-5, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11325955

RESUMEN

Two genes encoding Na(+)-ATPases from Debaryomyces hansenii were cloned and sequenced. The genes, designated ENA1 from D. hansenii (DhENA1) and DhENA2, exhibited high homology with the corresponding genes from Schwanniomyces occidentalis. DhENA1 was expressed in the presence of high Na(+) concentrations, while the expression of DhENA2 also required high pH. A mutant of Saccharomyces cerevisiae lacking the Na(+) efflux systems and sensitive to Na(+), when transformed with DhENA1 or DhENA2, recovered Na(+) tolerance and also the ability to extrude Na(+).


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Proteínas de Transporte de Catión , Clonación Molecular , Proteínas de Saccharomyces cerevisiae , Saccharomycetales/genética , Cloruro de Sodio/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Adenosina Trifosfatasas/genética , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Saccharomycetales/crecimiento & desarrollo , Saccharomycetales/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/genética
15.
Mol Microbiol ; 35(5): 1079-88, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10712689

RESUMEN

Using PCR, reverse transcription-PCR (RT-PCR) and colony hybridization in a genomic library, we isolated six genes which encode type II P-type ATPases in Neurospora crassa. The six full-length cDNAs were cloned in a yeast expression vector and transformed into Saccharomyces cerevisiae null Ca2+- or Na+-ATPase mutants. Three cDNAs suppressed the defect of the Ca2+ mutant and two of these protected from Mn2+ toxicity. One cDNA suppressed the defect of the Na+ mutant and two cDNAs were not functional in S. cerevisiae. The expression of the transcripts of the six genes in the presence of Ca2+, Na+, high pH or supporting an osmotic shock indicated that, with the exception of one of the Ca2+-ATPases, the main function of the cloned ATPases is the adaptation to stress conditions. The relationship between the cloned fungal Ca2+- and Na+-ATPases and plant type II P-ATPases is discussed.


Asunto(s)
Adenosina Trifosfatasas/genética , ATPasas Transportadoras de Calcio/genética , Proteínas de Transporte de Catión , Neurospora crassa/enzimología , Adenosina Trifosfatasas/química , Adenosina Trifosfatasas/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Calcio/metabolismo , ATPasas Transportadoras de Calcio/química , ATPasas Transportadoras de Calcio/metabolismo , Clonación Molecular , Cartilla de ADN , ADN Complementario , Datos de Secuencia Molecular , Neurospora crassa/metabolismo , Biosíntesis de Proteínas , Homología de Secuencia de Aminoácido
16.
Eur J Endocrinol ; 141(2): 169-79, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10427161

RESUMEN

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene expression was studied in differentiating brown adipocytes. Northern blot analysis showed that GAPDH mRNA levels increased during differentiation of precursor cells into mature adipocytes, mainly in the initial stages of the differentiation process. Insulin, tri-iodothyronine (T(3)) and norepinephrine, the main regulators of brown adipose tissue function, upregulated GAPDH mRNA levels, whereas retinoic acid inhibited them. The effect of insulin was present on all culture days examined, was time- and dose-dependent, and was exerted through its own receptors, as demonstrated by comparing insulin and insulin-like growth factor (IGF)-I and -II potencies in this system. Using the transcriptional inhibitor, actinomycin D, we demonstrated that T(3), and to a lesser extent insulin, stabilized GAPDH mRNA. Experiments with cycloheximide indicated that both hormones require de novo protein synthesis to achieve their effects. Using cAMP analogs, we showed that the effect of norepinephrine is probably exerted through this second messenger. Co-operation was elucidated between norepinephrine- and insulin-mediated induction of GAPDH mRNA levels. In summary, we have demonstrated that GAPDH mRNA is subjected to multifactorial regulation in differentiating brown adipocytes that includes differentiation of precursor cells and the lipogenic/lipolytic regulators of the tissue.


Asunto(s)
Tejido Adiposo Pardo/citología , Tejido Adiposo Pardo/metabolismo , Regulación Enzimológica de la Expresión Génica , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Insulina/metabolismo , Norepinefrina/metabolismo , ARN Mensajero/metabolismo , Triyodotironina/metabolismo , Tejido Adiposo Pardo/efectos de los fármacos , Animales , Northern Blotting , Diferenciación Celular/efectos de los fármacos , AMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Gliceraldehído-3-Fosfato Deshidrogenasas/efectos de los fármacos , Insulina/farmacología , Norepinefrina/farmacología , ARN Mensajero/efectos de los fármacos , Ratas , Tretinoina/metabolismo , Triyodotironina/farmacología , Regulación hacia Arriba/efectos de los fármacos
17.
Biochim Biophys Acta ; 1328(2): 214-26, 1997 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-9315618

RESUMEN

The ENA1 gene of Saccharomyces cerevisiae encodes a putative ATPase necessary for Na+ efflux. Plasma membranes and intracellular membranes of a yeast strain overexpressing the ENA1 gene contain significant amounts of ENA1 protein. Consequences of the overexpression with reference to the wild-type strain are: (1) a 5-fold higher content of the ENA1-protein in plasma membranes; (2) lower Na+ and Li+ effluxes; (3) slightly higher Na+ tolerance; and (4) much higher Li+ tolerance. The ENA1-specific ATPase activity in plasma membrane preparations of the overexpressing strain was low, but an ENA1 phosphoprotein was clearly detected when the plasma membranes were exposed to ATP in the presence of Na+ or to Pi in the absence of Na+. The characteristics of this phosphoprotein, which correspond to the acyl phosphate intermediaries of P-type ATPases, the absolute requirement of Na+ or other alkali cations for phosphorylation, and the Na+ and pH dependence of phosphorylation from ATP and Pi suggest that the product of the ENA1 gene may be a Na,H-ATPase, which can also pump other alkali cations. The role of the intracellular membranes structures produced with the overexpression of ENA1 in Na+ and Li+ tolerances and the existence of a beta-subunit of the ENA1 ATPase are discussed.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/metabolismo , Proteínas de Transporte de Catión , Fosfatos/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/enzimología , Membrana Celular/enzimología , Litio/metabolismo , Fosfoproteínas/metabolismo , Proteínas Recombinantes/metabolismo , Sodio/metabolismo , ATPasa Intercambiadora de Sodio-Potasio , Fracciones Subcelulares/enzimología
18.
Electrophoresis ; 16(7): 1273-83, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7498176

RESUMEN

The effects of cyclosporine A (CsA), a potent immunosuppressive drug, were examined in rat liver and kidney samples using two-dimensional electrophoretic protein analysis. Of a total of 370 liver and 336 kidney spots analyzed, 8% (29 spots) and 6% (19 spots), respectively, showed a significant drug-induced change (p < 0.01), which was predominantly reflected in increased protein abundance (62% and 74% of the changes, respectively). Of the 48 proteins changed in either organ, 14 were most probably common to both tissues and one of these was significantly increased in both the liver and the kidney. Most of the other 13 showed similar trends (either increases or decreases) in both organs. However, the most striking drug effect seen in this study concerned an unidentified protein present only in the kidney, which completely disappeared upon CsA treatment. It was also investigated whether the drug-induced changes could be prevented by the coadministration of the radical scavengers vitamin E and C with CsA. Spots changed by the administration of the drug were classified according to three different categories, based on their response profiles in rats treated with CsA in combination with the vitamins: (i) spots which were changed by CsA as well as by CsA in combination with the vitamins (12 liver and 4 kidney spots), (ii) spots which were changed by CsA and showed an additional increase of this change by CsA plus the vitamins (no liver and 4 kidney spots), and (iii) spots which were changed by CsA but not by CsA in combination with the vitamins (8 liver and 6 kidney spots). These results showed that in both organs the vitamins were able to prevent around 30% of the effects caused by CsA, and that two-dimensional gel electrophoresis is an excellent tool to demonstrate such drug interactions at the molecular level.


Asunto(s)
Ácido Ascórbico/farmacología , Ciclosporina/farmacología , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Proteínas/análisis , Vitamina E/farmacología , Animales , Quimioterapia Combinada , Depuradores de Radicales Libres , Riñón/química , Hígado/química , Masculino , Ratas , Ratas Wistar
19.
Mol Endocrinol ; 8(10): 1361-9, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7854353

RESUMEN

Diabetes in rats is characterized by insulin deficiency accompanied by a decrease in lipogenic enzymes. The malic enzyme (ME) gene, which encodes an important lipogenic enzyme, was used to investigate insulin regulation of gene expression. ME mRNA levels were reduced by more than 90% in the liver of diabetic rats. The administration of insulin (3 U/15 days) to either control or diabetic rats increased ME mRNA by 2- to 10-fold, respectively. Since diabetes reduces circulating T3 and the levels of nuclear T3-receptors, the potential role of thyroid hormone on insulin regulation of ME gene expression was also evaluated in thyroidectomized-diabetic rats. In these animals the levels of ME mRNA were undetectable but were increased by insulin even in the absence of thyroid hormones. These in vivo effects of insulin and T3 were not additive. The transcription rate of the gene was also reduced in the diabetic liver and recovered after insulin therapy. By computer analyses we have identified two different putative insulin response elements (IREs) in the ME gene promoter, hereafter referred to as IRE-I (-683 to -692), which is similar to the phosphoenol pyruvate carboxy kinase promoter IRE and IRE-II (-161 to -170), which is similar to the glyceraldehyde phosphate dehydrogenase gene promoter IRE-A. Results from gel retardation assays suggest that a single nuclear protein binds to IRE-I whereas two different nuclear proteins bind to IRE-II. The protein/IRE-I complex increased in liver nuclear extracts from diabetic rats and decreased after insulin administration.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
ADN/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Insulina/farmacología , Malato Deshidrogenasa/genética , Proteínas Nucleares/metabolismo , Animales , Secuencia de Bases , Sitios de Unión , Núcleo Celular/metabolismo , Diabetes Mellitus Experimental/metabolismo , Hígado/metabolismo , Hígado/ultraestructura , Masculino , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Tiroidectomía , Transcripción Genética/efectos de los fármacos , Triyodotironina/farmacología , Triyodotironina/fisiología
20.
J Bacteriol ; 174(9): 3065-9, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1314809

RESUMEN

It has been reported by several laboratories that maltose transport in Saccharomyces cerevisiae consists of two components with high- and low-affinity constants for maltose. We have investigated the characteristics of the low-affinity component and have found that it shows an abnormal behavior without similarity to any transport mechanism described in this organism. The results strongly indicate that this apparent transport activity is due not to a genuine transport process but to nonspecific binding of maltose to the cell wall and plasma membrane.


Asunto(s)
Maltosa/metabolismo , Saccharomyces cerevisiae/metabolismo , Transporte Biológico , División Celular , Membrana Celular/metabolismo , Pared Celular/metabolismo , Glucosa/metabolismo , Marcaje Isotópico , Cinética , Protones
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