RESUMEN
The organic content of municipal solid waste has long been an attractive source of renewable energy, mainly as a solid fuel in waste-to-energy plants. This study focuses on the potential to use microbial fuel cells to convert municipal solid waste organics into energy using various operational conditions. The results showed that two-chamber microbial fuel cells with carbon felt and carbon felt allocation had a higher maximal power density (20.12 and 30.47 mW m(-2) for 1.5 and 4 L, respectively) than those of other electrode plate allocations. Most two-chamber microbial fuel cells (1.5 and 4 L) had a higher maximal power density than single-chamber ones with corresponding electrode plate allocations. Municipal solid waste with alkali hydrolysis pre-treatment and K3Fe(CN)6 as an electron acceptor improved the maximal power density to 1817.88 mW m(-2) (~0.49% coulomb efficiency, from 0.05-0.49%). The maximal power density from experiments using individual 1.5 and 4 L two-chamber microbial fuel cells, and serial and parallel connections of 1.5 and 4 L two-chamber microbial fuel cells, was found to be in the order of individual 4 L (30.47 mW m(-2)) > serial connection of 1.5 and 4 L (27.75) > individual 1.5 L (20.12) > parallel connection of 1.5 and 4 L (17.04) two-chamber microbial fuel cells . The power density using municipal solid waste microbial fuel cells was compared with information in the literature and discussed.
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Electricidad , Residuos Sólidos , Fuentes de Energía Bioeléctrica , Aguas del AlcantarilladoRESUMEN
This study aimed to investigate the effects of eight metals on the anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) in bioreactors. Anaerobic bioreactors containing 200 mL MSW mixed completely with 200 m L sludge seeding. Ca and K (0, 1000, 2000 and 6,000 mg L(-1)) and Cr, Ni, Zn, Co, Mo and W (0, 5, 50 and 100 mg L(-1)) of various dose were added to anaerobic bioreactors to examine their anaerobic digestion performance. Results showed that except K and Zn, Ca (~728 to ~1,461 mg L(-1)), Cr (~0.0022 to ~0.0212 mg L(-1)), Ni (~0.801 to ~5.362 mg L(-1)), Co (~0.148 to ~0.580 mg L(-1)), Mo (~0.044 to ~52.94 mg L(-1)) and W (~0.658 to ~40.39 mg L(-1)) had the potential to enhance the biogas production. On the other hand, except Mo and W, inhibitory concentrations IC(50) of Ca, K, Cr, Ni, Zn and Co were found to be ~3252, ~2097, ~0.124, ~7.239, ~0.482, ~8.625 mg L(-1), respectively. Eight spiked metals showed that they were adsorbed by MSW to a different extent resulting in different liquid metals levels and potential stimulation and inhibition on MSW anaerobic digestion. These results were discussed and compared to results from literature.
Asunto(s)
Metales/metabolismo , Eliminación de Residuos/métodos , Adsorción , Anaerobiosis , Biocombustibles , Reactores Biológicos , Metales/química , Metales Pesados/metabolismo , Aguas del AlcantarilladoRESUMEN
This study aims at investigating the effects of MSW incinerator fly ash (FA) and bottom ash (BA) on the anaerobic co-digestion of OFMSW with FA or BA. It also simulates the biogas production from various dosed and control bioreactors. Results showed that suitable ashes addition (FA/MSW 10 and 20 g L(-1) and BA/MSW 100 g L(-1)) could improve the MSW anaerobic digestion and enhance the biogas production rates. FA/MSW 20 g L(-1) bioreactor had the higher biogas production and rate implying the potential option for MSW anaerobic co-digestion. Modeling studies showed that exponential plot simulated better for FA/MSW 10 g L(-1) and control bioreactors while Gaussian plot was applicable for FA/MSW 20 g L(-1) one. Linear and exponential plot of descending limb both simulated better for BA/MSW 100 g L(-1) bioreactor. Modified Gompertz plot showed higher correlation of biogas accumulation than exponential rise to maximum plot for all bioreactors.
Asunto(s)
Anaerobiosis , Biocombustibles , Reactores Biológicos , Compuestos Orgánicos/químicaRESUMEN
BACKGROUND: The aim was to examine whether the inhibition of selective cyclooxygenase (COX) 2 activation could suppress the development of inflammatory reaction in visceral and subcutaneous abdominal fats of high-fat-induced obese rats. MATERIALS AND METHODS: The rats were fed separately regular diet (CONT), high-fat diet ad libitum or energy-restrictedly (HFr) for 12 weeks. Rats fed high-fat diet ad libitum were further divided into those co-treated with vehicle (HFa), a selective COX2 inhibitor-celecoxib (HFa-Cel) or nimesulide (HFa-Nim). Oral glucose tolerance test (OGTT) was performed at the end of weeks 4, 8, 12. Another set of rats with similar grouping was divided into those with a 4-, 8- or 12-week intervention for tissue sampling. RESULTS: Body and epididymal fat weights were increased similarly in HFa, HFa-Cel and HFa-Nim. Time-dependent increases in plasma insulin, triglyceride, impaired OGTT shown in HFa were significantly reversed in HFa-Cel and HFa-Nim. The obese-linked increases in gene expressions of COX-2, monocyte chemoattractant protein-1 (MCP-1) and tumour necrosis factor-alpha (TNF-alpha) in epididymal and subcutaneous fats (especially in the former) were significantly suppressed in HFa-Cel and HFa-Nim. The protein contents of MCP-1 and TNF-alpha in epididymal fats were changed consistently with their gene expressions. Plasma MCP-1 was increased time-dependently in HFa and suppressed in HFa-Cel and HFa-Nim. The increased CD68 positive cells showed in both epididymal and subcutaneous fats of HFa were significantly attenuated in HFa-Cel and HFa-Nim. CONCLUSIONS: Our findings suggest that COX2 activation is crucially involved in the development of inflammatory response in adipose tissues of high-fat-induced obese rats.
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Inhibidores de la Ciclooxigenasa 2/farmacología , Grasa Intraabdominal/efectos de los fármacos , Obesidad/fisiopatología , Pirazoles/farmacología , Grasa Subcutánea Abdominal/efectos de los fármacos , Sulfonamidas/farmacología , Adiposidad/efectos de los fármacos , Animales , Antígenos CD , Antígenos de Diferenciación Mielomonocítica , Glucemia/análisis , Presión Sanguínea , Celecoxib , Quimiocina CCL2/análisis , Modelos Animales de Enfermedad , Grasas/administración & dosificación , Prueba de Tolerancia a la Glucosa , Inmunohistoquímica , Inflamación/patología , Insulina/análisis , Grasa Intraabdominal/química , Grasa Intraabdominal/patología , Obesidad/sangre , Obesidad/genética , Reacción en Cadena de la Polimerasa/métodos , Ratas , Ratas Sprague-Dawley , Grasa Subcutánea Abdominal/química , Grasa Subcutánea Abdominal/patología , Triglicéridos/sangre , Factor de Necrosis Tumoral alfa/análisisRESUMEN
Intensified food safety concern over melamine has prompted national authorities to assess its tolerable daily intake (TDI) for protection of general population including young children. TDI is calculated by dividing a no-observed-adverse-effect level (NOAEL) by a safety factor (SF). Based on appropriate choices of values, the US Food and Drug Administration determined two TDI values in the unit of mg per kg body weight per day as first 0.63 and then 0.063, while the World Health Organization, 0.5 and then 0.2, as a result of increasing the SF values in calculation. We used a similar procedure, with judicious selection of pertinent values, to obtain a TDI of 0.0081. Arguments in support of this lower TDI value were provided to alert the international community.
Asunto(s)
Exposición a Riesgos Ambientales/normas , Contaminación de Alimentos/prevención & control , Triazinas , United States Food and Drug Administration/normas , Adolescente , Niño , Preescolar , Humanos , Concentración Máxima Admisible , Nivel sin Efectos Adversos Observados , Medición de Riesgo , Estados Unidos , Organización Mundial de la Salud , Adulto JovenRESUMEN
Cadmium (Cd) levels in paddy fields across Taiwan have increased due to emission from industry. To ensure the production of rice that meets food quality standards, predictive models or suitable soil tests are needed to evaluate the quality of soils to be used for rice cropping. Levels of Cd in soil and rice grains were measured in 19 paddy fields across the western plains in Taiwan. Cadmium levels in soil range from less than 0.1 mg kg(-1) to 30 mg kg(-1). Measured Cd levels in brown rice were predicted very well (R(2) > 0.8) based on Cd and Zinc in a 0.01 M CaCl(2) extract or a soil-plant transfer model using the reactive soil Cd content, pH, and cation exchange capacity. In contrast to current soil quality standards used in Taiwan, such models are effective in identifying soils where Cd in rice will exceed food quality standards.
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Agricultura/métodos , Cadmio/metabolismo , Oryza/metabolismo , Contaminantes del Suelo/metabolismo , Cadmio/análisis , Guías como Asunto , Modelos Biológicos , Modelos Químicos , Medición de Riesgo , Suelo/química , Contaminantes del Suelo/análisisRESUMEN
Three types of adaptive network-based fuzzy inference system (ANFIS) in which the online monitoring parameters served as the input variable were employed to predict suspended solids (SS(eff)), chemical oxygen demand (COD(eff)), and pH(eff) in the effluent from a biological wastewater treatment plant in industrial park. Artificial neural network (ANN) was also used for comparison. The results indicated that ANFIS statistically outperforms ANN in terms of effluent prediction. When predicting, the minimum mean absolute percentage errors of 2.90, 2.54 and 0.36% for SS(eff), COD(eff) and pH(eff) could be achieved using ANFIS. The maximum values of correlation coefficient for SS(eff), COD(eff), and pH(eff) were 0.97, 0.95, and 0.98, respectively. The minimum mean square errors of 0.21, 1.41 and 0.00, and the minimum root mean square errors of 0.46, 1.19 and 0.04 for SS(eff), COD(eff), and pH(eff) could also be achieved.
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Lógica Difusa , Eliminación de Residuos Sanitarios/estadística & datos numéricos , Redes Neurales de la Computación , Eliminación de Residuos Líquidos/estadística & datos numéricos , Concentración de Iones de Hidrógeno , Residuos Industriales/estadística & datos numéricos , Eliminación de Residuos Sanitarios/normas , Sistemas en Línea , Oxígeno , Taiwán , Eliminación de Residuos Líquidos/normasRESUMEN
A new modeling concept to evaluate the effects of cadmium and copper on heterotrophic growth rate constant (mu(H)) and lysis rate constant (b(H)) in activated sludge was introduced. The oxygen uptake rate (OUR) was employed to measure the constants. The results indicated that the mu(H) value decreased from 4.52 to 3.26 d(-1) or by 28% when 0.7 mg L(-1) of cadmium was added. Contrarily the b(H) value increased from 0.31 to 0.35 d(-1) or by 11%. When adding 0.7 mg L(-1) of copper, the mu(H) value decreased to 2.80 d(-1) or by 38%. The b(H) value increased to 0.42 d(-1) or by 35%. After regression, the inhibitory effect was in a good agreement with non-competitive inhibition kinetic. The inhibition coefficient values for cadmium and copper were 1.82 and 1.21 mg L(-1), respectively. The relation between the b(H) values and heavy metal concentrations agreed with exponential type well. The heavy metal would enhance b(H) value. Using these data, a new kinetic model was established and used to simulate the degree of inhibition. It was evident that not only the inhibitory effect on mu(H) but also that the enhancement effect on b(H) should be considered when heavy metal presented.
Asunto(s)
Bacterias/efectos de los fármacos , Biodegradación Ambiental , Cadmio/farmacología , Cobre/farmacología , Modelos Teóricos , Aguas del Alcantarillado/microbiología , Bacterias/crecimiento & desarrollo , CinéticaRESUMEN
Municipal solid waste incinerator (MSWI) fly ash has been examined for possible use as landfill interim cover. For this aim, three anaerobic bioreactors, 1.2m high and 0.2m in diameter, were used to assess the co-digestion or co-disposal performance of MSW and MSWI fly ash. Two bioreactors contained ratios of 10 and 20 g fly ash per liter of MSW (or 0.2 and 0.4 g g(-1) VS, that is, 0.2 and 0.4 g fly ash per gram volatile solids (VS) of MSW). The remaining bioreactor was used as control, without fly ash addition. The results showed that gas production rate was enhanced by the appropriate addition of MSWI fly ash, with a rate of approximately 6.5l day(-1)kg(-1)VS at peak production in the ash-added bioreactors, compared to approximately 4l day(-1)kg(-1)VS in control. Conductivity, alkali metals and VS in leachate were higher in the fly ash-added bioreactors compared to control. The results show that MSW decomposition was maintained throughout at near-neutral pH and might be improved by release of alkali and trace metals from fly ash. Heavy metals exerted no inhibitory effect on MSW digestion in all three bioreactors. These phenomena indicate that proper amounts of MSWI fly ash, co-disposed or co-digested with MSW, could facilitate bacterial activity, digestion efficiency and gas production rates.
Asunto(s)
Anaerobiosis , Reactores Biológicos , Carbono , Material Particulado , Ceniza del Carbón , Concentración de Iones de HidrógenoRESUMEN
This paper aims to investigate the six heavy metal levels (Cd, Cr, Cu, Pb, Ni and Zn) in municipal solid waste (MSW) at different pHs. It intends to provide the baseline information of metals solubility in MSW co-disposed or co-digested with MSW incinerator ashes in landfill or anaerobic bioreactors or heavy metals contaminated in anaerobic digesters. One milliliter (equal to 1mg) of each metal was added to the 100ml MSW and the batch reactor test was carried out. The results showed that higher HNO3 and NaOH were consumed at extreme pH of 1 and 13 compared to those from pH 2 to 11 due to the comparably higher buffer capacity. Pb was found to have the least soluble level, highest metal adsorption (%) and highest partitioning Kd (lg(-1)) between pH 3 and 12. In contrast, Ni showed the highest soluble level, lowest metal adsorption (%) and lowest Kd (lg(-1)) between pH 4 and 12. Except Ni and Cr, other four metals seemed to show the amphibious properties as comparative higher solubility was found in the acidic and basic conditions.
Asunto(s)
Ciudades , Metales Pesados/análisis , Metales Pesados/química , Eliminación de Residuos/métodos , Adsorción , Concentración de Iones de Hidrógeno , SolubilidadRESUMEN
The kinetic study of a microbial system requires the determination of kinetic parameters under a set of operating variables. Previous researchers indicated that initial conditions, such as S0/X0 and S0/KS may influence the reliability of the parameter estimation. However, little study has been done to identify the sensitivity of system variables to the parameter estimation. This study proposes a novel dimensional analysis and identifies six dimensionless groups: mu(m)/fw, kd/fw, Yg, S0/KS, KS/S0, and 1/(fw theta(c) - 1). By incorporating the SP-moving algorithm proposed by Wu and coworkers in 2001, an algorithm was proposed in this study to perform a sensitivity analysis on the six dimensionless groups. Results of this analysis reveal that S0/X0 is more sensitive than S0/KS, as also evidenced by the fact that gross growth yield (Yg) is sensitive and affecting S0/X0. The analysis also suggests that the theta(c)-based wasting frequency (fw theta(c)) is more sensitive than the daily wasting frequency (fw). A critical minimum value of 1.3 for S0/X0 and a maximum value of 0.1 for S0/KS were suggested to establish the testing criteria for the kinetic study under the respirometric conditions.
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Algoritmos , Modelos Teóricos , Oxígeno/metabolismo , Biomasa , Cinética , Eliminación de Residuos LíquidosRESUMEN
The green fluorescent protein (GFP) is highly resistant to proteolysis and remains uncleaved after prolonged incubation with trypsin or pronase despite several putative tryptic and chymotryptic sites in exposed loops. We have rendered GFP sensitive to proteolysis by inserting five amino acids, IEGRS, in loops at position 157, 172, or 189. Excitation and emission maxima of the three insertion mutants were similar to those of wild type, but quantum yields of mutants Omega172 and Omega189 were lower, indicating increased freedom of the fluorophore. Trypsin cleaved the native (folded) form of each mutant at a unique site defined by the insert. Pronase also yields similar digestion patterns in these variants, but further proteolysis was also observed, suggesting that the primary cleavage relaxes GFP structure and reveals previously inaccessible sites. Fluorescence of Omega189 changed little upon digestion with trypsin but decreased progressively by as much as 40% upon digestion with increasing amounts of pronase. Fluorescence of other variants was not affected significantly by the proteases, further confirming the remarkable stabilities of GFP variants. These constructs define a new conformation-sensitive site around residue 189 of GFP and show that GFP may be useful for design of protease-susceptible molecules for monitoring of specific proteolytic activities in vivo.
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Proteínas Luminiscentes/química , Proteínas Luminiscentes/genética , Péptido Hidrolasas/química , Sitios de Unión/genética , Electroforesis en Gel de Poliacrilamida , Fluorescencia , Proteínas Fluorescentes Verdes , Mutagénesis Sitio-Dirigida , Fragmentos de Péptidos/análisis , Pronasa/química , Estructura Secundaria de Proteína/fisiología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Relación Estructura-Actividad , Especificidad por Sustrato/fisiología , Tripsina/químicaRESUMEN
A full-scale autothermal thermophilic aerobic treatment (ATAT) of food-processing wastewater was evaluated in this study. The wastewater was rich in oil and grease at concentrations of 1,500-2,000 mg/L. The system has been operated for more than one and a half years since the startup. Under steady state conditions, the ATAT process was capable of spontaneous reaction at temperatures of 45-55 degrees C without the addition of external heat. Treatment efficiency was as high as 95% in COD reduction at a volumetric COD loading of 4.1 kg/m3-d. A mathematical heat balance model was developed based on the theoretical considerations of heat sources and losses for the ATAT process. A computer algorithm was established to evaluate specific heat potential (Hs) of the wastewater under steady state conditions. Six months of steady-state data were used for the evaluation. The result shows that on average the wastewater had a specific heat potential (Hs) of 4,720 kcal/kg-COD removed and the biological heat contributed 41.4% of the total heat input. A net heat flux of 4,270 kcal/min and volumetric heat intensity (Hv) of 38.0 kcal/L was necessary to maintain reaction temperature at 48.2 degrees C for the ATAT process. The full-scale ATAT process showed the typical characteristics of high removal rate, low sludge yield, and poor solids settleability for thermophilic aerobic treatment reported in the literature.
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Industria de Procesamiento de Alimentos/métodos , Oxígeno/metabolismo , Aguas del Alcantarillado/química , Purificación del Agua/métodos , Aerobiosis , Aire , Algoritmos , Reactores Biológicos , Grasas/metabolismo , Calor , Aceites/metabolismo , Aguas del Alcantarillado/microbiologíaRESUMEN
The aim of this study was to investigate the effect of dietary fat levels, with or without cholesterol, on lipid peroxidation and the activities of antioxidant enzymes in rats. Thirty-two Wistar rats aged 4 weeks were divided into 4 groups and fed high (20%; HF) or low (5%; LF) fat, with or without 1% cholesterol, for 6 weeks. Cholesterol feeding resulted in significantly higher concentrations of serum cholesterol, but lowered serum triacylglycerol levels. Cholesterol feeding also led to markedly decreased levels of hepatic thiobarbituric acid reactive substances (TBARS) and lower activities of hepatic superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase, and glucose-6-phosphate dehydrogenase (G6PDH) when compared with cholesterol-free counterparts in both HF and LF diets. On the other hand, rats fed high-fat diets showed increased serum and liver TBARS, but decreased hepatic GSH-Px, SOD, and G6PDH activities. Hepatic catalase activity was lower in rats fed cholesterol-containing diets, but higher in rats fed high-fat diets, and interaction existed between cholesterol and fat feeding. These results suggested that dietary cholesterol might delay lipid peroxidation and decrease the activities of the hepatic antioxidant enzymes. The degree of lipid peroxidation was also influenced by dietary fat levels.
Asunto(s)
Antioxidantes/metabolismo , Colesterol en la Dieta/administración & dosificación , Colesterol en la Dieta/farmacología , Grasas de la Dieta/administración & dosificación , Grasas de la Dieta/farmacología , Enzimas/metabolismo , Peroxidación de Lípido/fisiología , Hígado/enzimología , Hígado/metabolismo , Análisis de Varianza , Animales , Colesterol en la Dieta/sangre , Grasas de la Dieta/sangre , Ácidos Grasos/metabolismo , Lípidos/sangre , Masculino , Ratas , Ratas Wistar , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismoRESUMEN
The benefit of invitation to mammographic screening observed in this trial is maintained as a highly significant 32% reduction in breast cancer mortality. Mammographic screening for breast cancer continues to save lives after up to 20 years. Screening derives this benefit by improving the distribution of tumors diagnosed with respect to prognostic categories based on node status, size, and histology of tumors. There is potential for modern screening programs with shorter interscreening intervals to achieve even greater improvements in prognostic category and greater reductions in breast cancer mortality. Mammography can discriminate a subpopulation of high-risk cases, those displaying casting-type calcifications on the mammogram, among very small tumors, with fundamental implications for diagnosis and treatment.
Asunto(s)
Neoplasias de la Mama/mortalidad , Tamizaje Masivo , Ensayos Clínicos Controlados Aleatorios como Asunto , Adulto , Anciano , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/prevención & control , Calcinosis/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Mamografía , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , SueciaRESUMEN
BACKGROUND: Women with small mammographically detected breast cancers generally have good long-term outcomes, but a few with T1a (1-5 mm) and T1b (6-10 mm) tumours will eventually die from breast cancer. We investigated whether women at high risk of breast-cancer death could be identified with mammographic criteria and differentiated from women with small cancers of the breast and good outcomes. METHODS: We prospectively applied mammographic classifications of tumour type to a consecutive series of 343 mammograms of invasive breast cancers of size 1-14 mm. Classifications were: stellate (spiculated) mass with no calcifications; circular or oval lesions with no calcifications; spiculated or circular lesions with non-casting-type calcifications; and casting-type calcifications. FINDINGS: 20-year survival for women with 1-14 mm invasive tumours with casting-type calcifications was 55%. 14% of 138 women with 1-9 mm tumours had casting-type calcifications on mammography, which accounted for 73% of all breast-cancer deaths (p<0.001). T1a, T1b, and 10-14 mm tumours with casting-type calcifications behaved as if they were larger lesions, since the rate of death was similar to that for women with advanced high-grade tumours. Most women who died were node-negative. The long-term survival of women who had tumours of 1-9 mm with no casting-type calcifications was about 95%. INTERPRETATION: Mammographic classification seemed to reliably predict good and bad long-term outcomes for survival in tumours of 14 mm or smaller, and especially for those smaller than 10 mm. The implications for therapy are substantial.
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Neoplasias de la Mama/mortalidad , Carcinoma in Situ/mortalidad , Carcinoma Ductal de Mama/mortalidad , Neoplasias de la Mama/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Carcinoma in Situ/diagnóstico por imagen , Carcinoma Ductal de Mama/diagnóstico por imagen , Femenino , Humanos , Mamografía , Estudios Prospectivos , Tasa de Supervivencia , Factores de TiempoRESUMEN
Cytotoxic CD8+ lymphocytes (CTLs) kill virally infected target cells by releasing cytotoxic granules. The primary objective of this study was to determine whether the activity of granzyme A, a serine protease in the killing granules of CTLs is altered in HIV-infected hemophiliacs. A sensitive colorimetric assay that measures cleavage of a synthetic substrate, N alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester (BLT), was used to quantitate granzyme A activity. Granzyme A activities from hemophiliacs were normalized to to granzyme A activities of healthy donors run concurrently. Granzyme A activity in CD8+ T cells from HIV-seropositive hemophiliacs was significantly lower than granzyme A activity in cells from HIV-seronegative hemophiliacs (0.48 units +/- 0.086/CD8+ T cell and 1.573 +/- 0.434 units/CD8+ T cell, respectively; p < 0.005). These results indicate that cytotoxic cells in HIV-infected hemophiliacs have reduced granzyme A activity, which may result in a defect in CTL-mediated cell killing in these patients.
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Seropositividad para VIH/complicaciones , Hemofilia A/enzimología , Hemofilia B/enzimología , Serina Endopeptidasas/metabolismo , Linfocitos T Citotóxicos/enzimología , Estudios de Cohortes , Femenino , Granzimas , Seronegatividad para VIH , Seropositividad para VIH/sangre , Seropositividad para VIH/enzimología , Hemofilia A/sangre , Hemofilia A/complicaciones , Hemofilia B/sangre , Hemofilia B/complicaciones , Humanos , Lisina/análogos & derivados , Lisina/metabolismo , MasculinoRESUMEN
The chlorpromazine-sensitive GTPase from the cell membrane of rat cerebral cortex was purified to homogenity by using DEAE Bio-Gel A agarose, hydroxyapatite and heparin agarose chromatography. The purified chlorpromazine-sensitive GTPase was purified 370-fold to obtain a final specific activity of 40 mumol GTP hydrolyzed2min/mg protein. The purified enzyme was inhibited by chlorpromazine but not by compound 48/80. Magnesium was required for its activity instead of calcium. The purified enzyme had an apparent pH optimum of 8.0, and molecular weight was estimated to be 58,000.
Asunto(s)
Corteza Cerebral/enzimología , Clorpromazina/farmacología , GTP Fosfohidrolasas/aislamiento & purificación , Animales , Membrana Celular/enzimología , Ácido Cólico , Ácidos Cólicos , Cromatografía/métodos , Durapatita , Inhibidores Enzimáticos/farmacología , GTP Fosfohidrolasas/antagonistas & inhibidores , GTP Fosfohidrolasas/metabolismo , Heparina , Concentración de Iones de Hidrógeno , Magnesio/farmacología , Peso Molecular , Ratas , Ratas Sprague-Dawley , p-Metoxi-N-metilfenetilamina/farmacologíaRESUMEN
Phospholipase C from rat cerebral cortex was purified to homogeneity by use of DEAE Bio-Gel A agarose, hydroxyapatite, and heparin agarose chromatography. The purified phospholipase C (PLC) was purified 622.4-fold and its molecular weight is estimated to be 97,500. We obtained a final specific activity of 3.112 mumol of phosphatidylinositol hydrolyzed/min/mg of protein. It is specific for inositol phospholipids. The purified enzyme has an apparent optimum pH 7.0. Calcium is required for its activity. Western blotting analysis showed that two proteins were recognized by anti-PLC antiserum.
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Corteza Cerebral/enzimología , Fosfolipasas de Tipo C/aislamiento & purificación , Animales , Western Blotting , Calcio/farmacología , Cromatografía , Concentración de Iones de Hidrógeno , Peso Molecular , Fosfatidilinositoles/metabolismo , Ratas , Ratas Sprague-Dawley , Especificidad por Sustrato , Fosfolipasas de Tipo C/química , Fosfolipasas de Tipo C/metabolismoRESUMEN
Phospholipase C activity, GTPase activity and cytosolic-free calcium concentration in mast cells were stimulated by compound 48/80. Accumulation of inositol phosphates in rat mast cells was stimulated by guanosine 5'-[gamma-thio]-triphosphate. Guanosine 5'-[gamma-thio]triphosphate, however, exhibited no effect upon the purified phospholipase C activity and upon phospholipase C in the mast cell homogenate. The stimulatory effect of compound 48/80 upon phospholipase C activity of intact mast cells was observed to have been well correlated with that on GTPase activity of mast cell homogenate. Compound 48/80 exhibited no effect upon the binding of radioactive guanosine 5'-[gamma-thio]triphosphate to mast cell homogenate. Phospholipase C activity was verified by the above results to become affected by compound 48/80 through guanine nucleotide-binding regulatory protein.