RESUMEN
Protein arginine methyltransferase 5 (PRMT5) is a well-known epigenetic regulatory enzyme. However, the role of PRMT5-mediated arginine methylation in gene transcription related to cardiac fibrosis is unknown. Here we show that fibroblast-specific deletion of PRMT5 significantly reduces pressure overload-induced cardiac fibrosis and improves cardiac dysfunction in male mice. Both the PRMT5-selective inhibitor EPZ015666 and knockdown of PRMT5 suppress α-smooth muscle actin (α-SMA) expression induced by transforming growth factor-ß (TGF-ß) in cultured cardiac fibroblasts. TGF-ß stimulation promotes the recruitment of the PRMT5/Smad3 complex to the promoter site of α-SMA. It also increases PRMT5-mediated H3R2 symmetric dimethylation, and this increase is inhibited by Smad3 knockdown. TGF-ß stimulation increases H3K4 tri-methylation mediated by the WDR5/MLL1 methyltransferase complex, which recognizes H3R2 dimethylation. Finally, treatment with EPZ015666 significantly improves pressure overload-induced cardiac fibrosis and dysfunction. These findings suggest that PRMT5 regulates TGF-ß/Smad3-dependent fibrotic gene transcription, possibly through histone methylation crosstalk, and plays a critical role in cardiac fibrosis and dysfunction.
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Fibroblastos , Disfunción Ventricular Izquierda , Animales , Masculino , Ratones , Fibroblastos/metabolismo , Fibrosis , Corazón , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Disfunción Ventricular Izquierda/genéticaRESUMEN
BACKGROUND: Leucine has unique anabolic properties, serving as a nutrient signal that stimulates muscle protein synthesis. OBJECTIVE: We tested whether the leucine concentration is the only factor determining protein quality for muscle development. METHODS: We selected 3 dietary proteins: casein (CAS), egg white protein (EWP), and albumin (ALB), representing the leucine concentrations of â¼8.3%, 7.7%, and 6.7% of the total protein (wt:wt), respectively. In the chronic feeding experiment, these proteins were pair-fed to growing male Wistar rats [110-135 g body weight (BW)] for 14 d as a protein source, providing 10% of total energy intake, after which soleus and extensor digitorum longus (EDL) muscles were used to estimate muscle growth. In the acute administration experiment, we injected CAS, ALB, and EWP to rats by oral gavage (0.3 g protein/100 g BW), and after 1 or 3 h EDL muscle was excised for capillary electrophoresis-MS-based metabolomics. In another chronic feeding experiment, rats were pair-fed either CAS or a CAS diet supplemented with arginine to the same level as in the EWP diet for 14 d. RESULTS: At the end of the 14-d feeding, soleus and EDL muscle weight was 20% and 17% higher, respectively, when rats were fed EWP as compared with CAS (P < 0.05). In addition, the 14-d EWP diet increased the expression of p70S6K by 117% compared with CAS (P < 0.05). These results suggest the possibility that some amino acids (excluding leucine), derived from EWP, promote muscle growth. Metabolomics analysis showed that muscle arginine concentration, following acute protein administration, appeared to match muscle growth over the 14-d feeding period. In addition, 14-d arginine supplementation to a CAS diet increased EDL muscle weight by 15% when compared with the plain CAS diet (P < 0.05). CONCLUSIONS: EWP promotes rat developmental muscle growth compared with CAS, which can be partly explained by the arginine-rich EWP.
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Proteínas Musculares , Roedores , Animales , Proteínas del Huevo , Leucina/metabolismo , Masculino , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Ratas , Ratas Wistar , Roedores/metabolismoRESUMEN
Drug repositioning has recently emerged as a strategy for developing new treatments at low cost. In this study, we used a library of approved drugs to screen for compounds that suppress cardiomyocyte hypertrophy. We identified the antiplatelet drug sarpogrelate, a selective serotonin-2A (5-HT2A) receptor antagonist, and investigated the drug's anti-hypertrophic effect in cultured cardiomyocytes and its effect on heart failure in vivo. Primary cultured cardiomyocytes pretreated with sarpogrelate were stimulated with angiotensin II, endothelin-1, or phenylephrine. Immunofluorescence staining showed that sarpogrelate suppressed the cardiomyocyte hypertrophy induced by each of the stimuli. Western blotting analysis revealed that 5-HT2A receptor level was not changed by phenylephrine, and that sarpogrelate suppressed phenylephrine-induced phosphorylation of ERK1/2 and GATA4. C57BL/6J male mice were subjected to transverse aortic constriction (TAC) surgery followed by daily oral administration of sarpogrelate for 8 weeks. Echocardiography showed that 5 mg/kg of sarpogrelate suppressed TAC-induced cardiac hypertrophy and systolic dysfunction. Western blotting revealed that sarpogrelate suppressed TAC-induced phosphorylation of ERK1/2 and GATA4. These results indicate that sarpogrelate suppresses the development of heart failure and that it does so at least in part by inhibiting the ERK1/2-GATA4 signaling pathway.
RESUMEN
Pathological stresses such as pressure overload and myocardial infarction induce cardiac hypertrophy, which increases the risk of heart failure. Cacao bean polyphenols have recently gained considerable attention for their beneficial effects on cardiovascular diseases. This study investigated the effect of cacao bean polyphenols on the development of cardiac hypertrophy and heart failure. Cardiomyocytes from neonatal rats were pre-treated with cacao bean polyphenols and then stimulated with 30 µM phenylephrine. C57BL/6j male mice were subjected to sham or transverse aortic constriction surgery and then orally administered with vehicle or cacao bean polyphenols. Cardiac hypertrophy and function were examined by echocardiography. In cardiomyocytes, cacao bean polyphenols significantly suppressed phenylephrine-induced cardiomyocyte hypertrophy and hypertrophic gene transcription. Extracellular signal-regulated kinase 1/2 and GATA binding protein 4 phosphorylation induced by phenylephrine was inhibited by cacao bean polyphenols treatment in the cardiomyocytes. Cacao bean polyphenols treatment at 1200 mg/kg significantly ameliorated left ventricular posterior wall thickness, fractional shortening, hypertrophic gene transcription, cardiac hypertrophy, cardiac fibrosis, and extracellular signal-regulated kinase 1/2 phosphorylation induced by pressure overload. In conclusion, these findings suggest that cacao bean polyphenols prevent pressure overload-induced cardiac hypertrophy and systolic dysfunction by inhibiting the extracellular signal-regulated kinase 1/2-GATA binding protein 4 pathway in cardiomyocytes. Thus, cacao bean polyphenols may be useful for heart failure therapy in humans.
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Cacao , Insuficiencia Cardíaca , Animales , Cardiomegalia/tratamiento farmacológico , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/tratamiento farmacológico , Humanos , Hipertrofia Ventricular Izquierda , Masculino , Ratones , Ratones Endogámicos C57BL , Miocitos Cardíacos , Polifenoles/farmacología , RatasRESUMEN
We previously reported that in rat skeletal muscle, disuse (i.e., decreased muscle contractile activity) rapidly increases thioredoxin-interacting protein (TXNIP), which is implicated in the reduced glucose uptake. Accordingly, we sought herein to (a) determine the effect of exercise (i.e., increased muscle contractile activity) on muscle TXNIP protein expression, and (b) elucidate the mechanisms underlying the changes of TXNIP protein expression in response to exercise. Rat epitrochlearis and soleus muscles were dissected out after an acute bout of 3-hr swimming (without weight loading) or 3-hr treadmill running (15% grade at 9m/min). In a separate protocol, the isolated epitrochlearis and soleus muscles were incubated for 3 hr with AMP-dependent protein kinase activator AICAR. Immediately after the cessation of the 3-hr swimming, the TXNIP protein was decreased in epitrochlearis but not in soleus muscle. Conversely, 3-hr treadmill running decreased the TXNIP protein in soleus but not in epitrochlearis muscle. TXNIP protein was decreased concomitantly with reduced postexercise muscle glycogen, showing that a decrease in TXNIP protein expression occurs in muscles that are recruited during exercise. In addition, 3-hr incubation with AICAR decreased TXNIP protein in both isolated epitrochlearis and soleus muscles. Our results suggest that (a) an acute bout of exercise downregulates TXNIP protein expression in rat contracting skeletal muscles, and (b) the reduction in TXNIP protein expression in contracting muscles is probably mediated by AMPK activation, at least in part.
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Proteínas de Ciclo Celular/metabolismo , Actividad Motora/fisiología , Músculo Esquelético/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Regulación hacia Abajo , Masculino , Contracción Muscular/fisiología , Ratas WistarRESUMEN
BACKGROUND AND AIM: Mucosal-associated invariant T (MAIT) cells constitute a novel subset of innate-like T lymphocytes characterized by a semi-invariant T-cell receptor repertoire capable of recognizing bacterial products. Considering the abundance of MAIT cells in the liver and the possible association between bacterial infections and primary biliary cholangitis (PBC), we aimed to analyze the involvement of MAIT cells in the immunopathogenesis of PBC. METHODS: Peripheral blood and liver biopsy specimens were collected from 25 patients with PBC and 19 patients with chronic viral hepatitis. Surgically removed liver tissues distant from tumors in patients with metastatic liver tumors were used as controls. Mononuclear cells were separated using Ficoll gradient, and the expression of various markers was investigated by flow cytometry. Cytokine production was investigated using blood MAIT cells after stimulation by anti-CD3/CD28-coupled beads with/without interleukin-7 (IL-7). RESULTS: Mucosal-associated invariant T cells were significantly reduced in both the blood and liver of PBC patients compared with those in controls. MAIT cells in the blood of PBC patients expressed significantly lower levels of activation markers and IL-7 receptor. Moreover, MAIT cells in the blood of PBC patients showed impaired production of cytokines, especially tumor necrosis factor alpha, after in vitro stimulation with IL-7. Interestingly, even after biochemical responses were achieved by ursodeoxycholic acid treatment, the frequencies of MAIT cells did not fully recover to normal levels. CONCLUSIONS: These findings suggested that MAIT cells were activated, exhausted, and persistently depleted in PBC patients even after ursodeoxycholic acid treatment, possibly as a consequence of persistent liver inflammation.
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Colangitis/inmunología , Células T Invariantes Asociadas a Mucosa/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Colangitis/tratamiento farmacológico , Citocinas/biosíntesis , Femenino , Humanos , Hígado/citología , Hígado/inmunología , Masculino , Persona de Mediana Edad , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Interleucina-7 , Ácido Ursodesoxicólico/uso terapéuticoRESUMEN
Cell motility plays an important role in intrahepatic metastasis of hepatocellular carcinoma (HCC), and predicts poor prognosis in patients. The present study investigated the role of a disintegrin and metalloproteinases (ADAMs) in HCC, since these proteins are known to be associated with cell motility. We confirmed the expression of 12 ADAMs with putative metalloproteinase activity in HCC cells, and established a KYN-2 HCC cell line stably expressing short interfering RNA against ADAM21 to investigate the effect of ADAM21 deficiency on HCC cell motility and metastasis in vitro and in vivo. We also examined ADAM21 expression in a cohort of 119 HCC patients by immunohistochemistry. ADAM21 was overexpressed in KYN-2 cells, and its knockdown reduced invasion, migration, proliferation, and metastasis relative to controls. In clinical specimens, ADAM21 positivity was associated with vascular invasion, large tumor size, high histological grade, and lower overall and recurrence-free survival as compared to cases that were negative for ADAM21 expression. A multivariate analysis revealed that ADAM21 positivity was an independent risk factor for overall (P = 0.003) and recurrence-free (P = 0.001) survival. These results suggest that ADAM21 plays a role in HCC metastasis and can serve as a prognostic marker for disease progression.
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Proteínas ADAM/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Proteínas de la Membrana/metabolismo , Proteínas ADAM/genética , Adulto , Anciano , Anciano de 80 o más Años , Animales , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/cirugía , Línea Celular Tumoral , Movimiento Celular , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Técnicas de Silenciamiento del Gen , Hepatectomía , Humanos , Hígado/patología , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/cirugía , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones SCID , Persona de Mediana Edad , Pronóstico , ARN Interferente Pequeño/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Analysis of NH3 gas under various humidity conditions was conducted using a waveguide surface plasmon resonance (SPR) sensor with dual sensing parts. Two pairs of Ag films/sensing polymer films were prepared separately on a waveguide core of BK-7 slide glass. Poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) were used as sensing materials. A white light was guided through the core by illuminating the substrate edge, and the SPR property was investigated by observing the output light spectrum. The thicknesses of PAA and PVA films were adjusted to induce SPR at different wavelengths. PAA exhibited remarkable response against NH3 gas, but it also exhibited a strong dependence on humidity. In contrast, PVA responded to humidity but hardly responded to NH3 gas below 20 ppm. The dual sensing would allow us to conduct precise NH3 measurements under various humidity conditions.
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Mucosal-associated invariant T (MAIT) cells are innate-like T cells involved in anti-bacterial immunity. Recent studies have demonstrated that MAIT cells might be implicated in inflammatory bowel diseases (IBDs), but their precise function in IBD remains to be elucidated. We investigated the possible involvement of MAIT cells in the immunopathogenesis of IBDs. Heparinized peripheral blood and biopsy specimens of the colon were collected from 25 patients with ulcerative colitis (UC), 15 patients with Crohn's disease (CD), and 19 heathy individuals. Lymphocytes were isolated from the blood and colon, and then MAIT cells were analyzed by flow cytometry. The frequency of MAIT cells was significantly lower in the blood of IBD patients compared to healthy donors and significantly higher in the inflamed colons compared to healthy colons (P = 0.001). Among the IBD patients, the frequency of MAIT cells in the blood and colon was correlated with disease activities. In vitro activated MAIT cells from IBD patients secreted significantly more tumor necrosis factor-α and interleukin-17 than those from healthy donors. These findings indicate that MAIT cells are activated in IBD patients, and their accumulation in the inflamed mucosa is correlated with disease activities.
Asunto(s)
Enfermedades Inflamatorias del Intestino/etiología , Enfermedades Inflamatorias del Intestino/metabolismo , Células T Invariantes Asociadas a Mucosa/inmunología , Células T Invariantes Asociadas a Mucosa/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Terapia Combinada , Citocinas/biosíntesis , Femenino , Citometría de Flujo , Humanos , Inmunohistoquímica , Inmunofenotipificación , Enfermedades Inflamatorias del Intestino/diagnóstico , Enfermedades Inflamatorias del Intestino/terapia , Activación de Linfocitos/inmunología , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Índice de Severidad de la EnfermedadRESUMEN
A 50-year-old woman had a percutaneous endoscopic gastrostomy (PEG) tube placed after surgery for pharyngeal cancer. After 21 months, the PEG tube was removed due to improvement of per-oral ingestion. She had taken prednisolone for 31 years for systemic lupus erythematosus. The post-PEG fistula did not close spontaneously. The cause of the fistula was slow wound healing and gastrostomy site inflammation due to long-term steroid therapy. We were able to close the fistula with an over-the-scope clipping (OTSC) system. This case suggests that OTSC is useful for closing persistent post-PEG fistulas in patients receiving long-term prednisolone therapy.
RESUMEN
Exercise and caloric restriction (CR) have been reported to have anti-ageing, anti-obesity, and health-promoting effects. Both interventions increase the level of dehydroepiandrosterone (DHEA) in muscle and blood, suggesting that DHEA might partially mediate these effects. In addition, it is thought that either 5'-adenosine monophosphate-activated protein kinase (AMPK) or peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mediates the beneficial effects of exercise and CR. However, the effects of DHEA on AMPK activity and PGC-1α expression remain unclear. Therefore, we explored whether DHEA in myotubes acts as an activator of AMPK and increases PGC-1α. DHEA exposure increased glucose uptake but not the phosphorylation levels of Akt and PKCζ/λ in C2C12 myotubes. In contrast, the phosphorylation levels of AMPK were elevated by DHEA exposure. Finally, we found that DHEA induced the expression of the genes PGC-1α and GLUT4. Our current results might reveal a previously unrecognized physiological role of DHEA; the activation of AMPK and the induction of PGC-1α by DHEA might mediate its anti-obesity and health-promoting effects in living organisms.
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Proteínas Quinasas Activadas por AMP/metabolismo , Deshidroepiandrosterona/metabolismo , Transportador de Glucosa de Tipo 4/genética , Fibras Musculares Esqueléticas/metabolismo , Factores de Transcripción/genética , Animales , Línea Celular , Deshidroepiandrosterona/administración & dosificación , Activación Enzimática , Glucosa/metabolismo , Isoenzimas/metabolismo , Ratones , Fibras Musculares Esqueléticas/efectos de los fármacos , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Fosforilación , Proteína Quinasa C/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Regulación hacia ArribaRESUMEN
AIM: Hepatocellular carcinoma (HCC) is frequently complicated with cirrhosis, and it is not unusual for treatment options to be limited as a result of pancytopenia due to hypersplenism. Partial splenic embolization (PSE) has been performed for thrombocytopenia resulting from hypersplenism. We studied the efficacy in terms of hepatic functional reserve and safety in patients who underwent concurrent transcatheter arterial chemoembolization (TACE) with PSE for HCC. METHODS: The study population consisted of 101 HCC patients with thrombocytopenia. Fifty-three patients were treated with concurrent TACE/PSE (PSE group), and the remaining 48 TACE patients without PSE (non-PSE group) were investigated hepatic functional reserve. RESULTS: Platelet counts were significantly higher in the PSE group after 2 weeks, 2 months and 6 months after TACE than the non-PSE group. Child-Pugh score significantly deteriorated from 7.13 ± 1.16 to 7.60 ± 1.20 at 2 weeks, to 7.71 ± 1.25 at 2 months, and 7.71 ± 1.35 at 6 weeks after TACE in the non-PSE group. Hence, it worsened from 7.04 ± 1.05 to 7.21 ± 0.99 at 2 weeks temporally, but improved to 7.00 ± 1.17 after 2 months and 6.70 ± 1.16 at 6 weeks after TACE in the PSE group. CONCLUSION: Thrombocytopenia has been improved and treatment continued using concurrent PSE. In addition, hepatic functional reserve could be maintained even after treatment for HCC. Concurrent TACE and PSE for HCC with thrombocytopenia can be expected to help maintain hepatic reserve, and may contribute to improving the prognosis of HCC.
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BACKGROUND/AIMS: The Child-Pugh classification system is the most widely used system for assessing hepatic functional reserve in HCC treatment. In the Child-Pugh classification system, serum albumin levels are used to accurately assess the status of protein metabolism and nutrition. To date, a lack of attention has been given to amino acid metabolism. In the present study, we investigated whether the branched-chain amino acids to tyrosine ratio (BTR) as an indicator of amino acid metabolism can serve as both a prognostic factor for early HCC and a predictive factor for recurrence. METHODOLOGY: We conducted a cohort study of 50 patients with stage I/II HCC enrolled between May 2002 and December 2010. It was investigated whether BTR can serve as both a prognostic factor and a predictive factor for HCC recurrence. RESULTS: Overall survival rates were significantly higher in patients with high baseline BTR than in those with low BTR. Multivariate analysis showed that both BTR and serum albumin were prognostic factors, and that BTR was the best predictive factor for recurrence. CONCLUSIONS: BTR was a prognostic factor for early HCC and the most predictive factor for intrahepatic distant recurrence and contributing factors for survival.
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Aminoácidos de Cadena Ramificada/sangre , Biomarcadores de Tumor/sangre , Carcinoma Hepatocelular/sangre , Neoplasias Hepáticas/sangre , Recurrencia Local de Neoplasia , Tirosina/sangre , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/terapia , Femenino , Humanos , Estimación de Kaplan-Meier , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/terapia , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Albúmina Sérica/análisis , Albúmina Sérica Humana , Tasa de Supervivencia , Factores de TiempoRESUMEN
OBJECTIVE: Postsplenectomy sepsis (PSS) and overwhelming postsplenectomy infection (OPSI) following splenectomy or the development of hyposplenism are associated with a high mortality rate. The presence of Howell-Jolly bodies (HJBs) in peripheral erythrocytes is attracting attention as a parameter of hyposplenism. To date, whether HJBs appear following partial splenic embolization (PSE) has not been investigated. Therefore, we examined the prevalence of HJBs in patients who have undergone PSE. METHODS: Whether HJBs were present in 95 patients who underwent PSE between November 2007 and August 2012 was assessed. RESULTS: No serious complications occurred due to PSE; however, 17 of the 95 patients (17.89%) exhibited HJBs during the follow-up. The residual spleen volume and splenic infarction rate did not differ significantly compared to those observed in the HJB-negative group. CONCLUSION: With the recent increase in the use of autoanalyzers, the opportunities to perform microscopic examinations have been decreasing. Therefore, the presence of HJBs, which can only be confirmed visually, may be overlooked, and the clinical significance of these bodies tends to be disregarded. However, the presence of HJBs is associated with a risk of PSS and OPSI due to hyposplenism. Because HJBs are common in the peripheral erythrocytes of patients who have undergone PSE, irrespective of the residual spleen volume or splenic infarction rate, the presence or absence of HJBs should be assessed visually. In HJB-positive patients, preventing serious infections, for example, by administering the pneumococcal vaccine, is important.
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Embolización Terapéutica/efectos adversos , Inclusiones Eritrocíticas/patología , Hipertensión Portal/diagnóstico , Hipertensión Portal/epidemiología , Esplenectomía/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Hipertensión Portal/terapia , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
AIM: To determine whether fluid injection during radiofrequency ablation (RFA) can increase the coagulation area. METHODS: Bovine liver (1-2 kg) was placed on an aluminum tray with a return electrode affixed to the base, and the liver was punctured by an expandable electrode. During RFA, 5% glucose; 50% glucose; or saline fluid was infused continuously at a rate of 1.0 mL/min through the infusion line connected to the infusion port. The area and volume of the thermocoagulated region of bovine liver were determined after RFA. The Joule heat generated was determined from the temporal change in output during the RFA experiment. RESULTS: No liquid infusion was 17.3 ± 1.6 mL, similar to the volume of a 3-cm diameter sphere (14.1 mL). Mean thermocoagulated volume was significantly larger with continuous infusion of saline (29.3 ± 3.3 mL) than with 5% glucose (21.4 ± 2.2 mL), 50% glucose (16.5 ± 0.9 mL) or no liquid infusion (17.3 ± 1.6 mL). The ablated volume for RFA with saline was approximately 1.7-times greater than for RFA with no liquid infusion, representing a significant difference between these two conditions. Total Joule heat generated during RFA was highest with saline, and lowest with 50% glucose. CONCLUSION: RFA with continuous saline infusion achieves a large ablation zone, and may help inhibit local recurrence by obtaining sufficient ablation margins. RFA during continuous saline infusion can extend ablation margins, and may be prevent local recurrence.
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Ablación por Catéter , Hígado/cirugía , Cloruro de Sodio/administración & dosificación , Animales , Ablación por Catéter/instrumentación , Bovinos , Electrodos , Diseño de Equipo , Infusiones Parenterales , Hígado/patología , Modelos Animales , Factores de TiempoRESUMEN
Heterogeneity of ribosome structure, due to variations in ribosomal protein composition, has been shown to be of physiological significance in plants and yeast. Mammalian genomics have demonstrated numerous genes that are paralogous to genes encoding ribosomal proteins. Although the vast majority are considered to be pseudogenes, mRNA expression of a few paralogues, such as human ribosomal protein L39-like/L39-2, has been reported. In the present study, ribosomes from the liver, mammary gland, and testis of rodents were analyzed using a combination of two-dimensional gel electrophoresis under radical-free and highly reducing conditions, and mass spectrometry. This system allowed identification of 78 ribosomal proteins and Rack1 from a single gel. The degree of heterogeneity was far less than that reported for plant and yeast ribosomes, and was in accord with published biochemical and genetic data for mammalian ribosomes. Nevertheless, an uncharacterized paralogue of ribosomal protein L22, ribosomal protein L22-like 1, was identified as a minor ribosomal component. Ribosomal proteins L10-like and L39-like, paralogues of ribosomal proteins L10 and L39, respectively, were found in ribosomes only from the testis. Reverse transcription-polymerase chain reaction yielded supportive evidence for specific expression of L10-like and L39-like in the testis. Newly synthesized L39-like is likely to be transported to the nucleolus, where ribosome biosynthesis occurs, and then incorporated into translating ribosomes in the cytoplasm. Heterogeneity of mammalian testicular ribosomes is structurally non-negligible, and may offer valuable insights into the function of the customized ribosome.
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Hígado/química , Glándulas Mamarias Humanas/química , Proteómica/métodos , Proteínas Ribosómicas/análisis , Testículo/química , Secuencia de Aminoácidos , Animales , Línea Celular , Nucléolo Celular/química , Nucléolo Celular/metabolismo , Electroforesis en Gel Bidimensional , Femenino , Humanos , Masculino , Mamíferos , Glándulas Mamarias Humanas/metabolismo , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Especificidad de Órganos , Ratas , Ratas Sprague-Dawley , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Alineación de Secuencia , Testículo/metabolismoRESUMEN
The transesterification reactions of triolein with ethanol using various ion-exchange resin catalysts were conducted to produce ethyl oleate as a biodiesel. The anion-exchange resins exhibited much higher catalytic activities than the cation-exchange resin. The anion-exchange resin with a lower cross-linking density and a smaller particle size gave a high reaction rate as well as a high conversion. By combining the three-step regeneration method, the resin could be repeatedly used for the batch transesterification without any loss in the catalytic activity. A continuous transesterification reaction was carried out using an expanded bed reactor packed with the most active resin. The reactor system permitted the continuous production of ethyl oleate with a high conversion.
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Aniones/química , Gasolina , Resinas de Intercambio Iónico/química , Catálisis , Etanol/química , Trioleína/químicaRESUMEN
Enzymatic synthesis of GlcNAc-terminated poly-N-acetyllactosamine beta-glycosides GlcNAcbeta1,3(Galbeta1,4GlcNAcbeta1,3)(n)Galbeta1,4GlcNAcbeta-pNP (n=1-4) was demonstrated using a transglycosylation reaction of Escherichia freundii endo-beta-galactosidase. The enzyme catalyzed a transglycosylation reaction on GlcNAcbeta1,3Galbeta1,4GlcNAcbeta-pNP (1), which served both as a donor and an acceptor, and converted 1 into p-nitrophenyl beta-glycosides GlcNAcbeta1,3(Galbeta1,4GlcNAcbeta1,3)(1)Galbeta1,4GlcNAcbeta-pNP (2), GlcNAcbeta1,3(Galbeta1,4GlcNAcbeta1,3)(2)Galbeta1,4GlcNAcbeta-pNP (3), GlcNAcbeta1,3(Galbeta1,4GlcNAcbeta1,3)(3)Galbeta1,4GlcNAcbeta-pNP (4) and GlcNAcbeta1,3(Galbeta1,4GlcNAcbeta1,3)(4)Galbeta1,4GlcNAcbeta-pNP (5). When 2 was used as an initial substrate, it led to the preferential synthesis of nonasaccharide beta-glycoside 4 to heptasaccharide beta-glycoside 3. This suggests that 4 is directly synthesized by transferring the tetrasaccharide unit GlcNAcbeta1,3Galbeta1,4GlcNAcbeta1,3Gal to nonreducing end GlcNAc residue of 2 itself. The efficiency of production of poly-N-acetyllactosamines by E. freundii endo-beta-galactosidase was significantly enhanced by the addition of BSA and by a low-temperature condition. Resulting 2 and 3 were shown to be useful for studying endo-beta-galactosidase-catalyzed hydrolytic and transglycosylation reactions.