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Objective: To analyze the association between high density lipoprotein cholesterol (HDL-C) and the risk of cardiovascular disease mortality. Methods: A total of 71 618 residents aged over 18 years with complete baseline data, who were filed on the health information big data platform of Yinzhou district, Ningbo city, Zhejiang Province from 2009 to 2014, were selected as the research population. The research population were divided into four groups according to the level of HDL-C: low-level group (HDL-C<1.0 mmol/L), intermediate-level group (1.0 mmol/L≤HDL-C<1.5 mmol/L), medium-high-level group (1.5 mmol/L≤HDL-C<2.0 mmol/L) and high-level group (HDL-C≥2.0 mmol/L). Cox proportional hazard model was used to calculate the risk ratio of cardiovascular diseases mortality in different groups. Results: The study population was followed up for a total of 427 989.4 person-years, follow-up time of (5.98±1.04)years. During the follow-up period, there were 799 deaths due to cardiovascular diseases. After adjusting for confounding factors, compared with the medium-high-level group as the reference group, the HR (95%CI) for cardiovascular diseases mortality was 1.43 (1.13-1.82) in the low-level group and 1.22 (1.02-1.46) in the high-level group. Conclusion: The low level of HDL-C (<1.5 mmol/L) is associated with a higher risk of cardiovascular disease deaths. The level of HDL-C can be used as a biological indicator to monitor the development of cardiovascular diseases and guide treatment.
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Enfermedades Cardiovasculares , Adulto , HDL-Colesterol , Humanos , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Factores de RiesgoRESUMEN
The mRNA expression levels of key genes (Smads, MSTN, and MyoG) in the TGF-ß/Smad signaling pathway in Hu sheep at different growth stages (2 days, 2 months, and 6 months of age) and in different skeletal muscles (longissimus dorsi muscle and soleus muscle) and different genders were detected; and correlation of the Smad family (Smad2, Smad3, Smad4, and Smad7), MSTN, MyoG expressions was analyzed in Hu sheep. The results showed that the expression of Smads was higher in the soleus muscle than in the longissimus dorsi muscle; the expressions of Smad2, Smad3, and Smad4 were significantly higher in 2-day-old sheep than in sheep belonging to the other age groups (P < 0.05); the expressions of Smad2, Smad4, and Smad7 were higher in rams than in 2-day-old ewes, but lower in rams than in 2-month-old and 6-month-old ewes; and the expression of Smad3 was higher in rams than in 2-day-old and 2-month-old ewes, but lower in rams than in 6-month-old ewes. In the 2 different muscle tissues, expression of Smad2 was significantly positively correlated (P < 0.01) with that of Smad3. The expression of Smad3 was significantly positively correlated (P < 0.01) with that of Smad4, which showed that the Smad family genes could have an inhibitory effect on the TGF-ß/Smad signaling pathway.
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Ovinos/genética , Proteína Smad2/biosíntesis , Proteína smad3/biosíntesis , Proteína Smad4/biosíntesis , Factor de Crecimiento Transformador beta/biosíntesis , Animales , Regulación del Desarrollo de la Expresión Génica , Desarrollo de Músculos/genética , Músculos/metabolismo , Ovinos/crecimiento & desarrollo , Transducción de Señal/genética , Proteína Smad2/genética , Proteína smad3/genética , Proteína Smad4/genética , Proteína smad7/biosíntesisRESUMEN
The temporal and spatial patterns of Smad and Yes-associated protein 1 (YAP1) expression were investigated in skeletal muscle (gastrocnemius muscle and extensor digitorum longus) at different growth stages (2 days old, 2 and 6 months old) in Hu sheep. Smads were differentially expressed in sheep skeletal muscle, with high expression in the gastrocnemius muscle and lower expression in the extensor digitorum longus. Expression of Smad2, Smad3, and Smad4 at the 2-day-old stage was significantly higher than at other stages (P < 0.05). The expression of Smad7 in 2-day-old sheep was lower than in 6-month-old sheep, with the lowest levels at 2 months. Smad expression was higher in males than in females at the 2-day-old stage, and expression in 2- and 6-month-old males was lower than that in 2-day-old females. Smad3 expression was higher in the 2-day- and 2-month-old males than in the females. There was a positive correlation (P < 0.01) between YAP1 and Smad2 expression in gastrocnemius muscle at the 2-month-old stage. YAP1 and Smad4/7 expression were positively correlated (P < 0.01) in extensor digitorum longus at the 2-day-old stage. YAP1 expression was negatively correlated with Smad7 in the extensor digitorum longus at 6 months. A significant difference between Smad2 and Smad3 (P < 0.01) expression in muscle was observed, consistent with Smad3 and Smad4 expression, indicating that these inhibit transforming growth factor-ß signaling in the same way. There was a positive correlation (P < 0.01) between YAP1 and MSTN expression, suggesting that YAP1 participates in muscle growth in sheep.
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Proteínas Adaptadoras Transductoras de Señales/genética , Envejecimiento/genética , Músculo Esquelético/metabolismo , Proteína Smad2/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Envejecimiento/metabolismo , Animales , Animales Recién Nacidos , Femenino , Regulación del Desarrollo de la Expresión Génica , Masculino , Músculo Esquelético/crecimiento & desarrollo , Miostatina/genética , Miostatina/metabolismo , Ovinos , Oveja Doméstica , Transducción de Señal , Proteína Smad2/metabolismo , Proteína smad3/genética , Proteína smad3/metabolismo , Proteína Smad4/genética , Proteína Smad4/metabolismo , Proteína smad7/genética , Proteína smad7/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Objective: To evaluate the effects of application of vancomycin in the early stage of patients with extremely severe burn, in order to provide reference to drug for anti-infection treatment in the early stage of patients with extremely severe burn. Methods: Data of 15 patients of Kunshan explosion on August 2nd, 2014, admitted to the Department of Intensive Care in our hospital were retrospectively analyzed. The clinical efficacy of continuously intravenous dripping of vancomycin (combined with imipenem) in the early stage of burns (before and on post burn day 14) was analyzed. (1) The steady state plasma concentration of vancomycin was monitored respectively 30 min before the third, sixth, and tenth medication with direct chemiluminescent imaging method. (2) The distribution of Gram-positive bacteria of patients during hospitalization and their drug resistance to 14 antibiotics commonly used in clinic were analyzed. (3) Serum level of procalcitonin (PCT), white blood cell count, percentage of neutrophils before and after treatment, and efficacy grade of anti-infection treatment in the early stage of burns were analyzed. (4) Serum levels of aspartate transaminase (AST), alanine aminotransferase (ALT), creatinine before and after treatment, and the adverse effects during medication were analyzed. The WHONET 5.5 statistical software was used to analyze the distribution of Gram-positive bacteria in all the pathogens, and the status of drug resistance of Gram-positive bacteria to 14 antibiotics. Data were processed with Wilcoxon rank sum test. Results: (1) Twenty-nine times of steady state plasma concentration monitoring were performed in the patients in total, with the steady state plasma concentration of vancomycin from 4.3 to 42.1 µg/mL. In the monitoring before third, sixth, and tenth medication, the percentages of result reaching the standard were respectively 1, 3/14, and 2/7. (2) A total of 79 Gram-positive bacteria were isolated, including 49 (62.03%) strains of Staphylococcus aureus, 9 (11.39%) strains of Staphylococcus haemolyticus, 7 (8.86%) strains of Staphylococcus epidermidis, 12 (15.19%) strains of Enterococcus faecium, and 2 (2.53%) strains of Enterococcus faecalis. The above-mentioned Staphylococcus strains were with high drug resistance to antibiotics including penicillins, erythromycin, ciprofloxacin, and low drug resistance to linezolid, teicoplanin, and nitrofurantoin. The above-mentioned Enterococcus strains were with high drug resistance to antibiotics including erythromycin, ciprofloxacin, gentamicin, and low drug resistance to linezolid and teicoplanin. The above-mentioned Staphylococcus strains were all sensitive to vancomycin. Two strains of vancomycin-resistant Enterococcus were detected in the above-mentioned Enterococcus strains. (3) Serum level of PCT, white blood cell count, percentage of neutrophils of patients were (8.1±7.5) ng/mL, (24±10)×10(9)/L, and 0.898±0.029 before treatment, which were significantly higher than (3.0±2.8) ng/mL, (12±5)×10(9)/L, and 0.867±0.016 after treatment (with Z values respectively -2.103, -3.237, and -3.068, P<0.05 or P<0.01). After the early treatment, excellence, progess, and invalid results were achieved in 7, 5, and 3 patients, with the effective percentage of 4/5 in clinic. (4) There were no statistically significant differences in serum levels of AST, ALT, and creatinine of patients between before and after treatment (with Z values respectively-0.057, -1.508, and -1.363, P values above 0.05). Only one patient had liver and renal dysfunction during treatment. Conclusions: The positive and reasonable use of vancomycin can remove most of the Gram-positive bacteria, and control the development of sepsis combined with imipenem in the early stage of patients with extremely severe burn. However, the dose of vancomycin should be individualized and the steady state plasma concentration should be monitored to maintain the blood concentration within the safe and effective range, so as to improve the rational use of vancomycin.
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Antibacterianos/uso terapéutico , Quemaduras/sangre , Calcitonina/sangre , Imipenem/uso terapéutico , Sepsis/sangre , Vancomicina/uso terapéutico , Humanos , Pruebas de Sensibilidad Microbiana , Estudios Retrospectivos , Sepsis/diagnóstico , Infecciones Estafilocócicas , Staphylococcus aureusRESUMEN
We have recently shown that multidrug resistance-associated protein (MRP) and gamma-glutamylcysteine synthetase (gamma-GCS) heavy subunit genes are coordinately overexpressed in cisplatin-resistant human leukemia cells (T. Ishikawa et al. J. Biol. Chem., 271: 14981-14988, 1996). Using the RNase protection assay, we examined expression levels of these genes in colon tumor and nontumorous biopsy specimens from 32 cancer patients who had not been treated with chemotherapy. Increased mRNA levels (P < 0.001) of MRP and gamma-GCS genes were observed in 16 (50%) and 20 (62%) tumor samples, respectively. More importantly, all of the 16 (100%) MRP-overexpressing tumor specimens also exhibited higher levels of gamma-GCS mRNA than those in the matched nontumorous specimens. The correlation coefficient between MRP and gamma-GCS mRNA levels was r = 0.78 for all of the tumor samples studied. These results strongly suggest that MRP and gamma-GCS genes are coordinately up-regulated during colorectal carcinogenesis.
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Transportadoras de Casetes de Unión a ATP/genética , Neoplasias Colorrectales/metabolismo , Regulación Neoplásica de la Expresión Génica , Glutamato-Cisteína Ligasa/genética , Secuencia de Bases , Humanos , Datos de Secuencia Molecular , Proteínas Asociadas a Resistencia a Múltiples Medicamentos , ARN Mensajero/análisisRESUMEN
To evaluate the applicability of recombinant adenoviral vectors in gene transfer to liver cancers, we infused the recombinant adenoviruses AD5CMV-LacZ and Ad5CMV-p53 through the portal veins into two lines of transgenic mice, one bearing the SV40 T antigen and the other the human hepatitis B viral envelope protein. These transgenic animals develop hepatocellular carcinomas (HCC) with predictable pathological manifestations. The levels of expression of the transgenes were dependent upon the viral doses. In all cases, high levels of expression were detected within 2 or 3 days after infusion, but were drastically reduced 7 days after infusion. Significant toxicities were found in the infused animals: > 80% of them died within 7 days after infusion with 10(10) pfu, and transgenic animals bearing HCC apparently were more sensitive to viral toxicity. Although a lower dose (10(9) pfu/animal) produced less toxicity, the levels of expression were substantially reduced (only about 10% of that in animals infused with 10(10) pfu). When Ad5CMV-p53 was infused into animals with nodular hyperplastic stage, the expression of the reporter gene seemed to distribute preferentially at the peripheries of the tumor nodules, and low levels of transgene expression were seen inside the nodules. In tumors in which necrotic lesions were evident, p53 was also expressed at the perpheries of the lesions. These distribution patterns were seen in both tumor models. There was no apparent suppression of tumor growth in the Ad5CMV-p53-infused animals. Our results suggest that alternative methods for gene therapy for HCC need to be explored.
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Adenovirus Humanos/genética , ADN Recombinante/administración & dosificación , Virus Defectuosos/genética , Genes p53 , Terapia Genética , Vectores Genéticos/genética , Neoplasias Hepáticas Experimentales/terapia , Proteína p53 Supresora de Tumor/uso terapéutico , Adenovirus Humanos/patogenicidad , Animales , Antígenos Transformadores de Poliomavirus/genética , Virus Defectuosos/patogenicidad , Femenino , Genes Reporteros , Vectores Genéticos/administración & dosificación , Vectores Genéticos/toxicidad , Humanos , Inyecciones Intravenosas , Neoplasias Hepáticas Experimentales/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos ICR , Ratones Transgénicos , Vena Porta , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/uso terapéutico , Proteína p53 Supresora de Tumor/biosíntesis , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/toxicidad , beta-Galactosidasa/biosíntesisRESUMEN
Ovarian cancers migrate and metastasize over the surface of the peritoneal cavity. Consequently, dysregulation of mechanisms that limit cell migration may be particularly important in the pathogenesis of the disease. ARHI is an imprinted tumor-suppressor gene that is downregulated in >60% of ovarian cancers, and its loss is associated with decreased progression-free survival. ARHI encodes a 26-kDa GTPase with homology to Ras. In contrast to Ras, ARHI inhibits cell growth, but whether it also regulates cell motility has not been studied previously. Here we report that re-expression of ARHI decreases the motility of IL-6- and epidermal growth factor (EGF)-stimulated SKOv3 and Hey ovarian cancer cells, inhibiting both chemotaxis and haptotaxis. ARHI binds to and sequesters Stat3 in the cytoplasm, preventing its translocation to the nucleus and localization in focal adhesion complexes. Stat3 siRNA or the JAK2 inhibitor AG490 produced similar inhibition of motility. However, the combination of ARHI expression with Stat3 knockdown or inhibition produced greatest inhibition in ovarian cancer cell migration, consistent with Stat3-dependent and Stat3-independent mechanisms. Consistent with two distinct signaling pathways, knockdown of Stat3 selectively inhibited IL-6-stimulated migration, whereas knockdown of focal adhesion kinase (FAK) preferentially inhibited EGF-stimulated migration. In EGF-stimulated ovarian cancer cells, re-expression of ARHI inhibited FAK(Y397) and Src(Y416) phosphorylation, disrupted focal adhesions, and blocked FAK-mediated RhoA signaling, resulting in decreased levels of GTP-RhoA. Re-expression of ARHI also disrupted the formation of actin stress fibers in a FAK- and RhoA-dependent manner. Thus, ARHI has a critical and previously uncharacterized role in the regulation of ovarian cancer cell migration, exerting inhibitory effects on two distinct signaling pathways.
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Proteína-Tirosina Quinasas de Adhesión Focal/fisiología , Genes Supresores de Tumor/fisiología , Neoplasias Ováricas/genética , Factor de Transcripción STAT3/fisiología , Transducción de Señal/fisiología , Proteínas de Unión al GTP rho/genética , Proteína de Unión al GTP rhoA/fisiología , Línea Celular Tumoral , Movimiento Celular , Femenino , Proteína-Tirosina Quinasas de Adhesión Focal/antagonistas & inhibidores , Adhesiones Focales , Humanos , Janus Quinasa 2/fisiología , Neoplasias Ováricas/patología , Factor de Transcripción STAT3/antagonistas & inhibidores , Proteína de Unión al GTP rhoA/antagonistas & inhibidoresAsunto(s)
Fotorradiación con Hematoporfirina , Hematoporfirinas/farmacología , Fotoquimioterapia , Neoplasias del Cuello Uterino/ultraestructura , Carcinoma de Células Escamosas/ultraestructura , Línea Celular , Femenino , Humanos , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Mitocondrias/ultraestructura , Dilatación Mitocondrial/efectos de los fármacosRESUMEN
Capillary electrophoretic immunoassay (CEIA) has recently emerged as a new analytical technique. CEIA, when combined with sensitive detection methods such as laser induced fluorescence (LIF), offers several advantages over conventional immunoassays. CEIA can perform rapid separations with high mass sensitivity, simultaneously determine multiple analytes and is compatible with automation. The objective of this review is to describe the applications of CE in antibody related studies, focussing especially on recent developments of CEIA technique. The principles for competitive and non-competitive CEIA are described with examples. Several detection methods and various applications are summarized and future developments in CEIA are speculated. CEIA has many potential applications, especially if the throughput is improved by using either multicapillary array or microchips with multiple channels.
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Anticuerpos/química , Electroforesis Capilar/métodos , Inmunoensayo/métodos , Anticuerpos/inmunología , Anticuerpos/metabolismo , Reacciones Antígeno-Anticuerpo , Antígenos/metabolismo , Unión Competitiva , Ligandos , Sistemas en LíneaRESUMEN
Capillary electrophoretic analysis of enzymes, co-enzymes, substrates and other chemical species that can be linked to an enzymatic reaction is reviewed with 80 references. Both off-line and on-line assays of minute enzymatic activities are discussed. In addition to heterogeneous on-line enzyme assays, a special emphasis is given to a newly established on-line technique called electrophoretically mediated microanalysis (EMMA). The basic principle, procedure, and various detection modes of EMMA are discussed. The recent developments in on-line determination of various enzyme substrates as well as on-line enzyme kinetic studies are also summarized. Some potential future developments in the determination of enzymatic activities by means of CE are also presented.
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Electroforesis Capilar/métodos , Enzimas/análisis , Enzimas/metabolismo , Cinética , Sistemas en LíneaRESUMEN
Reliable methods based on capillary electrophoresis (CE) have been developed for the separation and quantitation of azimilide, an antiarrhythmic drug under development at Procter & Gamble Pharmaceuticals (P&GP). Both capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) were employed in the separation of azimilide from its impurities, degradants and/or metabolites. Separation of azimilide from NE-11178, F-410, F-1054 and F-1292 was obtained by MECC at pH 9 with 50 mM sodium dodecyl sulfate (SDS). The separation of azimilide and NE-10171, a key metabolite of azimilide, was difficult because their structures differ by only a single methyl group. The best separation was achieved under acidic pH conditions with cetyltriethyl ammonium chloride (CTAC) additive in the buffer. All of the CE separations were completed within a substantially shorter time and with better resolution than the corresponding high-performance liquid chromatography (HPLC) separations. Quantitation was done with azimilide and NE-10171. Calibration curves ranging from 10 to 1000 microg/ml were obtained with R2 greater than 0.997 for both azimilide and NE-10171. The back-calculated concentrations of the calibration standards and the recoveries of the quality control (QC) samples were within the acceptance range currently used for HPLC methods. These results demonstrated the viability of CE as an alternative technique for drug metabolism studies in support of pharmaceutical development.
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Antiarrítmicos/aislamiento & purificación , Electroforesis Capilar/métodos , Imidazoles/aislamiento & purificación , Imidazolidinas , Piperazinas/aislamiento & purificación , Antiarrítmicos/metabolismo , Hidantoínas , Concentración de Iones de Hidrógeno , Imidazoles/metabolismo , Piperazinas/metabolismo , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta , TensoactivosRESUMEN
alpha 1-Antichymotrypsin belongs to a supergene family that includes alpha 1-antitrypsin, antithrombin III, ovalbumin, and angiotensinogen. The human chromosomal alpha 1-antichymotrypsin gene has been cloned and its molecular structure established. The gene is approximately 12 kb in length and contains five exons and four introns. The locations of the introns within the alpha 1-antichymotrypsin gene are identical with those of the human alpha 1-antitrypsin and angiotensinogen genes. Other members of this supergene family contain introns located at nonhomologous positions of the genes. The homologous organization of the alpha 1-antichymotrypsin and alpha 1-antitrypsin genes corresponds with the high degree of homology between their protein sequences and suggests that these loci arose by recent gene duplication. A model is presented for the evolution of both the genomic structure and the protein sequences of the serine protease inhibitor superfamily.
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Evolución Biológica , Genes , alfa 1-Antiquimotripsina/genética , alfa 1-Antitripsina/genética , Animales , Secuencia de Bases , Humanos , Datos de Secuencia Molecular , Homología de Secuencia de Ácido Nucleico , Especificidad de la EspecieRESUMEN
A 7.7-kb EcoRI genomic DNA fragment highly homologous to the human alpha 1-antitrypsin (AAT) gene has been cloned. This antitrypsin-related sequence is physically linked to the authentic AAT gene and both are present in a single cosmid clone. Nucleotide sequencing of the AAT-related genomic fragment demonstrated extensive homology with the authentic AAT gene in the introns as well as in the exons. The conservation of all RNA splice sites and lack of internal termination codons in the exonic regions suggest that it may not be a classical pseudogene. If expressed, it could result in a protein of 420 amino acid residues exhibiting a 70% overall homology with human alpha 1-antitrypsin. The signal peptide sequence is well conserved in the related gene, but the active site for protease inhibition of Met-Ser in alpha 1-antitrypsin has been changed to Trp-Ser. These data suggest that the putative protein encoded by the AAT-related gene is a secretory serine protease inhibitor with an altered substrate specificity. Interestingly, even the intronic regions in the related gene exhibit a 65% overall nucleotide sequence homology with those of the authentic AAT gene. These results suggest that the AAT-related gene is derived from a recent duplication of the authentic AAT gene and represents a new member of the serine protease inhibitor superfamily.
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Secuencia de Bases , Inhibidores de Proteasas/genética , Homología de Secuencia de Ácido Nucleico , alfa 1-Antitripsina/genética , Secuencia de Aminoácidos , Evolución Biológica , Cósmidos , Enzimas de Restricción del ADN , Procesamiento Automatizado de Datos , Exones , Ligamiento Genético , Humanos , Datos de Secuencia Molecular , Familia de MultigenesRESUMEN
We recently reported that GS-X pump activity, as assessed by ATP-dependent transport of the glutathione-platinum complex and leukotriene C4, and intracellular glutathione (GSH) levels were remarkably enhanced in cis-diamminedichloroplatinum(II) (cisplatin)-resistant human leukemia HL-60 cells (Ishikawa, T., Wright, C. D., and Ishizuka, H. (1994) J. Biol. Chem. 269, 29085-29093). Now, using Northern hybridization and RNase protection assay, we provide evidence that the multidrug resistance-associated protein (MRP) gene, which encodes a human GS-X pump, is expressed at higher levels in cisplatin-resistant (HL-60/R-CP) cells than in sensitive cells, whereas amplification of the MRP gene is not detected by Southern hybridization. Culturing HL-60/R-CP cells in cisplatin-free medium resulted in reduced MRP mRNA levels, but these levels could be induced to rise within 30 h by cisplatin and heavy metals such as arsenite, cadmium, and zinc. The increased levels of MRP mRNA were closely related with enhanced activities of ATP-dependent transport of leukotriene C4 (LTC4) in plasma membrane vesicles. The glutathione-platinum (GS-Pt) complex, but not cisplatin, inhibited ATP-dependent LTC4 transport, suggesting that the MRP/GS-X pump transports both LTC4 and the GS-Pt complex. Expression of gamma-glutamylcysteine synthetase in the cisplatin-resistant cells was also co-induced within 24 h in response to cisplatin exposure, resulting in a significant increase in cellular GSH level. The resistant cells exposed to cisplatin were cross-resistant to melphalan, chlorambucil, arsenite, and cadmium. These observations suggest that elevated expression of the MRP/GS-X pump and increased GSH biosynthesis together may be important factors in the cellular metabolism and disposition of cisplatin, alkylating agents, and heavy metals.
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Transportadoras de Casetes de Unión a ATP/biosíntesis , Arsenitos/farmacología , Cadmio/farmacología , Proteínas Portadoras/biosíntesis , Glutamato-Cisteína Ligasa/biosíntesis , Transcripción Genética/efectos de los fármacos , Zinc/farmacología , Antineoplásicos/toxicidad , Secuencia de Bases , División Celular/efectos de los fármacos , Clorambucilo/toxicidad , Cisplatino/toxicidad , Cartilla de ADN , Resistencia a Múltiples Medicamentos , Inducción Enzimática , Glutatión/metabolismo , Células HL-60 , Humanos , Cinética , Melfalán/toxicidad , Proteínas de Transporte de Membrana , Datos de Secuencia Molecular , Proteínas Asociadas a Resistencia a Múltiples Medicamentos , Proteínas de Neoplasias/biosíntesis , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesisRESUMEN
Recent studies have shown that expression levels of the multidrug resistance gene MDR1, which encodes the drug transporter P-glycoprotein, correlate with prognostic outcomes of certain tumor types. These findings suggest that expression of MDR1 may affect tumor behaviors. To address this issue further, we investigated the expression of mdr1a, a human MDR1 homolog, on the development of hepatocellular carcinoma in a transgenic mouse model carrying the liver-targeted expression of human hepatitis-B virus (HBV) surface antigen. The pathogenetic program was compared in HBV mice carrying either mdr1a(+/+) or mdr1a(-/-). We found that the expressions of proliferative activity markers, Ki67 nuclear antigen, and proliferating cell nuclear antigen were elevated in mdr1a(-/-) mice younger than 10 wk in comparison with those in the same age group of wild-type animals. Replication in the hepatic population as determined by bromodeoxyuridine incorporation tended to support observation that mdr1a(-/-) mice exhibited elevated labeling indices in this age group. Moreover, histologic staining and flow-cytometric analysis showed that the mdr1a(-/-) animals exhibited a higher cell population with polyploidy than did the mdr1a(+/+) counterparts of the same age. However, no significant differences in the expression of the liver-injury markers serum alanine transaminase and aspartate transaminase were observed. Although our results showed that absence of mdr1a expression is correlated with modest enhanced proliferative characteristics in the livers at stage before the development of hepatocellular carcinoma, the overall life spans between these two strains of mice were not significantly different. The implication of these findings to the role of P-glycoprotein in tumor development and cancer chemotherapy is discussed.
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Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/genética , Virus de la Hepatitis B/genética , Antígeno Ki-67/biosíntesis , Neoplasias Hepáticas Experimentales/genética , Antígeno Nuclear de Célula en Proliferación/biosíntesis , Subfamilia B de Transportador de Casetes de Unión a ATP/biosíntesis , Transportadoras de Casetes de Unión a ATP/biosíntesis , Alanina Transaminasa/metabolismo , Animales , Aspartato Aminotransferasas/metabolismo , División Celular/genética , Cruzamientos Genéticos , Modelos Animales de Enfermedad , Resistencia a Múltiples Medicamentos/genética , Femenino , Expresión Génica , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/inmunología , Antígeno Ki-67/genética , Hígado/enzimología , Neoplasias Hepáticas Experimentales/metabolismo , Neoplasias Hepáticas Experimentales/virología , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Ploidias , Antígeno Nuclear de Célula en Proliferación/genéticaRESUMEN
Microchip capillary electrophoresis (CE) was used with a model enzyme assay to demonstrate its potential application to combinatorial drug screening. Hydrolysis with beta-glucuronidase of the conjugated glucuronide, fluorescein mono-beta-D-glucuronide (FMG), liberated the fluorescent product, fluorescein. FMG and fluorescein were detected by fluorescence, with excitation and emission at 480 and 520 nm, respectively. Microchip CE was used to separate FMG and fluorescein. Fluorescein production was monitored to assess beta-glucuronidase activity. Michaelis-Menten enzyme kinetics analysis yielded the Km value. The results were compared with those from experiments done by conventional CE. The Km value for beta-glucuronidase with FMG is being reported for the first time as 18 microM. The inhibition of beta-glucuronidase by the competitive inhibitor D-saccharic acid-1,4-lactone (SL) was also determined using microchip CE. Reactions were done with various concentrations of inhibitor and constant beta-glucuronidase and FMG concentrations. A dose-response plot was acquired and the IC50 value for SL was determined to be 3 microM.