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1.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(4): 403-409, 2022 Apr 09.
Artículo en Chino | MEDLINE | ID: mdl-35368167

RESUMEN

The remained documents and archives show that the history of diagnosis and treatment of oral diseases in royal court of the Qing Dynasty was over 200 years. The departmental system of medical care in the Qing Royal Court was inherited from former Ming Dynasty. Although the departments in the system changed over reigns, the Department of Dentistry exist all the time. In a set of historical records of 38 medical cases opened to the public, the documented symptoms and diseases, in the sense of modern medical science, included periodontitis, oral mucosal diseases, dental caries, parotiditis, etc., and the patients involved various ranks in the court, showing that oral diseases were common in the Qing Royal Court. The royal doctors ranked variedly and the medication they used was diverse. Medical fuming or steaming and medical heating were some distinctive methods among the treatments. In 1600s, the western modern medical science started to be introduced into China. In the reign of Kangxi Emperor (1700s), many western doctors were employed by the royal court and they engaged in the treatment of oral diseases. The late Qing Dynasty appeared the second peak that western doctors came into China. In 1898, Dr. Jingrong Chen, a dentist who possessed knowledge of modern dentistry in Beijing city, set up a dental clinic in the royal court and gave treatment to patients in the royal members and high-ranking officials.


Asunto(s)
Caries Dental , Beijing , China , Humanos , Medicina Tradicional China
2.
Zhonghua Gan Zang Bing Za Zhi ; 29(11): 1106-1108, 2021 Nov 20.
Artículo en Chino | MEDLINE | ID: mdl-34933431

RESUMEN

In order to verify the correlation between Polygonum multiflorum-induced liver injury and HLA-B*35 : 01 alleles, six hospitalized patients diagnosed with Polygonum multiflorum-induced liver injury (PM-DILI) were selected, and their clinicopathological data were collected. Simultaneously, blood HLA-B* 35 : 01 allele detection was performed. Among the six PM-DILI cases, 4 were male, aged 38.83 ± 10.13 years old. The types of liver injury were hepatocellular injury types in all, and the severity of liver injury in five cases was grade 3. The histological presentations were acute hepatitis and acute cholestatic hepatitis. PM-DILI cases were all HLA-B*35:01 carriers, with a carrier rate of 100%. This finding indicates that PM-DILI is significantly correlated with HLA-B*35:01 alleles. Therefore, HLA-B*35 : 01 alleles can be used as an important predictive indicator for PM-DILI.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Fallopia multiflora , Antígenos HLA-B , Preparaciones de Plantas/toxicidad , Adulto , Alelos , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Fallopia multiflora/toxicidad , Femenino , Antígenos HLA-B/genética , Humanos , Masculino , Persona de Mediana Edad
3.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(3): 447-452, 2021 Jun 18.
Artículo en Chino | MEDLINE | ID: mdl-34145843

RESUMEN

OBJECTIVE: To study the effects of buckwheat-oat-pea (BOP) composite flour [buckwheat ∶ oats ∶ peas=6 ∶ 1 ∶ 1 (quality ratio)] on blood glucose in diabetic rats. METHODS: In this study, 64 male Sprague-Dawley rats were divided into 8 groups by fasting blood glucose (FBG) and body weight: normal control group, model control group, metformin group, buckwheat group, oats group, BOP low-dose group (BOP-L), medium-dose group (BOP-M), and high-dose group (BOP-H). The rats in the normal control group were fed with normal diet, the rats in the model control group and metformin group were fed with a high-fat diet (HFD), and the rats in the buckwheat group, oats group, and BOP-L, BOP-M, BOP-H groups were fed with HFD containing 10% buckwheat flour, 10% oat flour, 3.3% BOP, 10% BOP, 30% BOP, respectively. The HFD in all the groups had the same percentage of energy from fat (45%). After 30 days, the rats fed with HFD received intraperitoneal injection of streptozotocin (30 mg/kg, once a week for two weeks) to establish diabetes mellitus. After the model was successful established, the rats were fed for another 28 days. During the study, the body weight, food intake/body weight (FI/BW) and water intake/body weight (WI/BW), food utilization rate, 24 h urine volume, FBG, glucose area under curve (GAUC) of oral glucose tolerance test were measured regularly. At the end of the study, the fasting serum glucose and insulin were measured, and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. RESULTS: With the inducing of HFD and streptozotocin, compared with the normal control group, the rats in the model control group had higher FI/BW, WI/BW, 24 h urine volume, FBG, GAUC, HOMA-IR (P < 0.05), and lower body weight, food utilization rate (P < 0.05). Compared with the model control group, the rats in the three BOP groups all had higher body weight, food utilization rate (P < 0.05), and lower WI/BW, HOMA-IR (P < 0.05); the rats in the BOP-L and BOP-M groups had lower FI/BW, 24 h urine volume, FBG (P < 0.05), and the rats in the BOP-M group also had lower GAUC (P < 0.05). After the establishment of diabetes, there was no significant difference in blood glucose and the other indicators between the rats in the three BOP groups and the buckwheat group or the oats group (P>0.05). CONCLUSION: The BOP had the effects of reducing blood glucose, insulin resistance and diabetic symptoms on diabetic rats, and had the value for further development and utilization.


Asunto(s)
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Fagopyrum , Resistencia a la Insulina , Animales , Avena , Glucemia , Dieta Alta en Grasa/efectos adversos , Insulina , Masculino , Pisum sativum , Ratas , Ratas Sprague-Dawley
4.
J Intern Med ; 284(4): 399-417, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30019399

RESUMEN

BACKGROUND: Prevailing dietary guidelines recommend regular fish consumption. However, the associations of fish and long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFAs) intakes with mortality remain unclear. OBJECTIVES: To examine the associations of fish and LCn-3 PUFAs intakes with total and cause-specific mortality. METHODS: A total of 240 729 men and 180 580 women from NIH-AARP Diet and Health Study were prospectively followed-up for 16 years. Dietary intakes were assessed using a validated NIH Diet History Questionnaire. RESULTS: A total of 54 230 men and 30 882 women died during 6.07 million person-years of follow-up. Higher fish and LCn-3 PUFAs intakes were significantly associated with lower total mortality (P < 0.0001). Comparing the highest with lowest quintiles of fish intake, men had 9% (95% confidence interval, 6-11%) lower total mortality, 10% (6-15%) lower cardiovascular disease (CVD) mortality, 6% (1-10%) lower cancer mortality, 20% (11-28%) lower respiratory disease mortality and 37% (17-53%) lower chronic liver disease mortality, while women had 8% (5-12%) lower total mortality, 10% (3-17%) lower CVD mortality and 38% (20-52%) lower Alzheimer's disease mortality. Fried fish consumption was not related to mortality in men whereas positively associated with mortality from all causes (P = 0.011), CVD and respiratory disease in women. LCn-3 PUFAs intake was associated with 15% and 18% lower CVD mortality in men and women across extreme quintiles, respectively. CONCLUSION: Consumption of fish and LCn-3 PUFAs was robustly associated with lower mortality from major causes. Our findings support current guidelines for fish consumption while advice on non-frying preparation methods is needed.


Asunto(s)
Causas de Muerte , Conducta Alimentaria , Peces , Mortalidad , Terapia PUVA/métodos , Anciano , Enfermedad de Alzheimer/mortalidad , Enfermedad de Alzheimer/prevención & control , Animales , Enfermedades Cardiovasculares/mortalidad , Enfermedades Cardiovasculares/prevención & control , Enfermedad Hepática en Estado Terminal/mortalidad , Enfermedad Hepática en Estado Terminal/prevención & control , Femenino , Adhesión a Directriz , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/mortalidad , Neoplasias/prevención & control , Estudios Prospectivos , Enfermedades Respiratorias/mortalidad , Enfermedades Respiratorias/prevención & control , Estados Unidos
5.
Phytomedicine ; 17(1): 14-8, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19819682

RESUMEN

The tea polyphenol epigallocatechin-3-O-gallate (EGCG) displays some antidiabetic effects; however the mechanisms are incompletely understood. In the present study, the investigation of the effects of EGCG on insulin resistance was performed in rat L6 cells treated with dexamethasone. We found that dexamethasone increased Ser307 phosphorylation of insulin receptor substrate-1 (IRS-1) and reduced phosphorylation of AMPK and Akt. Furthermore, glucose uptake and glucose transporter (GLUT4) translocation were inhibited by dexamethasone. However, the treatment of EGCG improved insulin-stimulated glucose uptake by increasing GLUT4 translocation to plasma membrane. Furthermore, we also demonstrated these EGCG effects essentially depended on the AMPK and Akt activation. Together, our data suggested that EGCG inhibited dexamethasone-induced insulin resistance through AMPK and PI3K/Akt pathway.


Asunto(s)
Catequina/análogos & derivados , Dexametasona/farmacología , Trastornos del Metabolismo de la Glucosa/prevención & control , Glucosa/metabolismo , Resistencia a la Insulina , Células Musculares/efectos de los fármacos , Extractos Vegetales/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Transporte Biológico , Camellia sinensis/química , Catequina/farmacología , Línea Celular , Membrana Celular/metabolismo , Flavonoides/farmacología , Glucocorticoides/farmacología , Trastornos del Metabolismo de la Glucosa/inducido químicamente , Transportador de Glucosa de Tipo 4/metabolismo , Proteínas Sustrato del Receptor de Insulina/metabolismo , Fenoles/farmacología , Fosforilación , Fitoterapia , Polifenoles , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Serina ,
6.
Neuroscience ; 163(3): 741-9, 2009 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-19596052

RESUMEN

The senescence-accelerated mouse prone-8 (SAMP8) is characterized by early onset of learning and memory deficits along with spontaneous overproduction of soluble beta-amyloid peptide (Abeta) in the brain. In our study, 4 month old male SAMP8 mice were orally administered 0.05% and 0.1% green tea catechins (GTC, w/v) in drinking water for 6 months. We found that a supplementation with 0.05% or 0.1% GTC prevented spatial learning and memory impairments of mice in the Morris water maze. Better performance of GTC-treated mice was associated with decreased levels of Abeta(1-42) oligomers in the hippocampus. The activity of the protein kinase A/cAMP-response element binding protein (PKA/CREB) pathway, one of the molecular targets of Abeta oligomers which is crucial for late long-term potentiation and long-term memory formation, was significantly increased after GTC administration. We also found that chronic 0.05% or 0.1% GTC consumption prevented the reductions of three representative proteins of synaptic function and synaptic structure, including brain-derived neurotrophic factor(BDNF), post-synaptic density protein-95 (PSD95) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII). These results demonstrated that long-term 0.05% or 0.1% green tea catechin administration may prevent spatial learning and memory decline of SAMP8 mice by decreasing Abeta(1-42) oligomers and upregulating synaptic plasticity-related proteins in the hippocampus.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Factor Neurotrófico Derivado del Encéfalo/biosíntesis , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/biosíntesis , Catequina/farmacología , Hipocampo/efectos de los fármacos , Aprendizaje/efectos de los fármacos , Proteínas de la Membrana/biosíntesis , Fragmentos de Péptidos/metabolismo , Conducta Espacial/efectos de los fármacos , Envejecimiento , Animales , Camellia sinensis , Catequina/administración & dosificación , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Homólogo 4 de la Proteína Discs Large , Guanilato-Quinasas , Hipocampo/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Masculino , Memoria/efectos de los fármacos , Ratones , Ratones Endogámicos , Actividad Motora/efectos de los fármacos , Plasticidad Neuronal , Fosforilación , Sinapsis/fisiología , Factores de Tiempo , Regulación hacia Arriba
7.
Neuroscience ; 159(4): 1208-15, 2009 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-19409206

RESUMEN

Flavonoid-rich foods have been shown to be effective at reversing age-related deficits in learning and memory in both animals and humans. However, little investigation of the preventative effects of flavonoids on the naturally aged animals was reported. In our study, 14-month-old female C57BL/6 J mice were orally administered 0.025%, 0.05% and 0.1% green tea catechins (GTC, w/v) in drinking water for 6 months; we found that a supplementation with 0.05% or 0.1% GTC prevented age-related spatial learning and memory decline of mice in the Morris water maze. Better performance of GTC-treated mice was associated with increased levels of cAMP-response element binding protein (CREB) phosphorylation in the hippocampus. The expressions of brain-derived neurotrophic factor (BDNF) and Bcl-2, two target genes of CREB which can exhibit long-term regulatory roles in synaptic plasticity and synaptic structure, were also increased. We also found that long-term 0.05% or 0.1% GTC administration prevented age-related reductions of two representative post-synaptic density proteins PSD95 and Ca(2+)/calmodulin-dependent protein kinase II, suggesting that synaptic structural changes may be involved. These results demonstrated that long-term 0.05% or 0.1% green tea catechin administration may prevent age-related spatial learning and memory decline of female C57BL/6 J mice by regulating hippocampal CREB signaling cascade.


Asunto(s)
Antioxidantes/administración & dosificación , Catequina/administración & dosificación , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Aprendizaje/efectos de los fármacos , Memoria/efectos de los fármacos , Percepción Espacial/efectos de los fármacos , Envejecimiento/efectos de los fármacos , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Homólogo 4 de la Proteína Discs Large , Femenino , Guanilato-Quinasas , Hipocampo/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Aprendizaje por Laberinto/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Fosforilación , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Distribución Aleatoria , Transducción de Señal/efectos de los fármacos
8.
J Nanosci Nanotechnol ; 7(9): 3323-7, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18019168

RESUMEN

Low-energy cathodoluminescence (CL) imaging and spectroscopy technique was employed to study the impurity distribution in individual ZnO hexagonal nanotubes fabricated by metalorganic chemical vapor deposition on the sapphire (0001) substrate. The CL spectra at 10 K show that acceptor and donor impurities are incorporated in the ZnO nanotubes. CL monochromatic images indicate that the concentration of donor is higher at the bottom part and the distribution of acceptors is more inhomogeneous at the surface of the nanotubes. The non-uniform defects and impurities distributions are explained by unstable growth conditions and contamination from the environment. These results indicate that the low-energy CL is a very powerful method to investigate the inhomogeneity of luminescence properties in the individual nanostructures.


Asunto(s)
Nanopartículas del Metal/química , Nanotecnología/métodos , Óxido de Zinc/química , Óxido de Aluminio , Química Orgánica/métodos , Electrodos , Electrones , Luminiscencia , Microscopía Electrónica de Rastreo , Nanopartículas/química , Nanoestructuras/química , Nanotubos , Nanotubos de Carbono/química , Fotones , Temperatura
9.
Phytomedicine ; 14(5): 353-9, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17097281

RESUMEN

In Europe, swainsonine has been studied widely for prevention of metastasis and cancer therapy. In order to investigate the effects and mechanisms of swainsonine on the human gastric carcinoma SGC-7901 cell, we carried out in vivo and in vitro experiments. After treatment with swainsonine, an effective dose and IC50 value of swainsonine for SGC-7901 cells were examined by MTT assay. Cell-cycle distribution and apoptotic rates were analyzed using FCM, and [Ca2+]i was measured using LSCM. The expression of p53, c-myc and Bcl-2 were determined using an immunocytochemical method. Simultaneously, 50 mice were divided randomly into five groups. Three groups were administrated swainsonine at dose of 3, 6 and 12 mg/kg body wt., two control groups were administrated N.S. 20 ml/kg body wt. and 5-Fu 20 mg/kg body wt., respectively, by intraperitoneal injection. The inhibition rate was calculated and pathological sections were observed. The growth of SGC-7901 cell is inhibited by swainsonine in vitro, with an IC50 value at 24 h of 0.84 microg/ml, and complete inhibition concentration is 6.2 microg/ml. After treatment with swainsonine at the concentrations of 0.5, 1.5 and 4.5 microg/ml for 24 h, the expression of apoptosis inhibiting gene p53 and bcl-2 decreases, and the apoptotic trigger gene c-myc increases markedly (p<0.05), as well as [Ca2+]i overloading, SGC-7901 cell is induced to apoptosis in the end. It is also found that the percentages of S phase are 38.8%, 39.7% and 29.6%, respectively (20.0% in control group and 23.2% in 5-Fu group). The rates of inhibition were 13.2%, 28.9%, 27.3%, respectively, when the nude mice were administered swainsonine (p<0.05 or 0.01). The structure of the tumor showed hemorrhage, necrosis and inflammatory cell infiltration. We therefore conclude that swainsonine could inhibit cell proliferation in vitro and the growth of human gastric carcinoma in vivo. The mechanisms of swainsonine-induced apoptosis may relate to [Ca2+]i overloading and the expression of apoptosis-related genes.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Fabaceae , Fitoterapia , Swainsonina/farmacología , Animales , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/uso terapéutico , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral/efectos de los fármacos , Humanos , Técnicas In Vitro , Concentración 50 Inhibidora , Inyecciones Intraperitoneales , Ratones , Ratones Desnudos , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/patología , Swainsonina/administración & dosificación , Swainsonina/uso terapéutico , Trasplante Heterólogo
10.
Brain Res ; 898(2): 204-14, 2001 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-11306006

RESUMEN

By metabolically labeling tissue slices from striatum and thalamus with [32P]orthophosphoric acid and immunoprecipitating the receptor with mu receptor-specific antiserum, we found that the endogenous mu receptor in the brain tissue did undergo phosphorylation. The phosphorylation occurred at basal level (no drug treatment) and was enhanced with DAMGO-treatment. The enhancement of the phosphorylation was blocked by naloxone. Morphine stimulation also increased the phosphorylation, but the amount of enhancement was less than that caused by DAMGO-treatment. Mu receptor phosphorylation in the thalamus was much greater than the striatum, while no phosphorylation of the mu receptor in the cerebellum was detected, even with DAMGO treatment. The extent of mu receptor phosphorylation identified in the thalamus, striatum and cerebellum is consistent with the previous studies of mu receptor distribution. The time course and dose-response studies demonstrated that mu receptor phosphorylation was a rapid event, exhibited a positive dose-dependent response, and was similar to that observed in the cloned mu receptor in CHO cells. Furthermore, we correlated the change of mu receptor phosphorylation with the desensitization of the mu receptor function, specifically, inhibition of adenylyl cyclase activity in the thalamus of morphine-tolerant rats. We found that in the thalamus of rats chronically treated with morphine, the enhancement of mu receptor phosphorylation in basal and DAMGO-treated samples paralleled the desensitization of DAMGO-mediated inhibition of adenylyl cyclase. Our results suggest that mu receptor phosphorylation in vivo may play an important role in the modulation of mu receptor function following both acute exposure to morphine and during the development of morphine tolerance.


Asunto(s)
Narcóticos/farmacología , Receptores Opioides mu/agonistas , Tálamo/efectos de los fármacos , Adenilil Ciclasas/efectos de los fármacos , Adenilil Ciclasas/metabolismo , Analgésicos Opioides/farmacología , Animales , Cerebelo/efectos de los fármacos , Cerebelo/metabolismo , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Tolerancia a Medicamentos/fisiología , Encefalina Ala(2)-MeFe(4)-Gli(5)/farmacología , Inmunohistoquímica , Masculino , Morfina/farmacología , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Neostriado/efectos de los fármacos , Neostriado/metabolismo , Técnicas de Cultivo de Órganos , Fosforilación/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores Opioides mu/metabolismo , Tálamo/metabolismo , Factores de Tiempo
11.
Zhongguo Zhong Yao Za Zhi ; 26(2): 95-9, 2001 Feb.
Artículo en Chino | MEDLINE | ID: mdl-12525104

RESUMEN

OBJECTIVE: To obtain the hairy root of Panax ginseng (HRPG). METHOD: HRPG was obtained by infecting the germ-free seedling, cotyledon, leaf the blade, Petiole with Agrobacterium rhizogenes 15,834 harbouring agropine-type Ri plasmid. The transformation was proved by PCR and TLC. RESULT: HRPG grew rapidly on hormone-free medium and showed typical phenotype of hairy root. The induced rate and time can be improved by adding exogenous hormone and AS(hydroxyacetosyringone). PCR analysis confirmed the integration of TL-DNA, including 564 bp rolC sequence in the HRPG. Opine analysis evidenced the integration and expression of TL-DNA. The total saponin in HRPG (2.486%) was higher the than control(1.403% Panax ginseng). CONCLUSION: HRPG grows rapidly and proves high in content of ginseng saponin. This culture system of HRPG will be useful for the production of active components in ginseng.


Asunto(s)
Panax/genética , Plantas Medicinales/genética , Rhizobium/genética , Panax/química , Panax/crecimiento & desarrollo , Raíces de Plantas/química , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Plantas Medicinales/química , Plantas Medicinales/crecimiento & desarrollo , Plásmidos , Saponinas/análisis , Transformación Genética
12.
J Air Waste Manag Assoc ; 50(2): 227-33, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10680352

RESUMEN

With the advances made in the past decade, catalytic incineration of volatile organic compounds (VOCs) has become the technology of choice in a wide range of pollution abatement strategies. In this study, a test was undertaken for the catalytic incineration, over a chromium oxide (Cr2O3) catalyst, of n-hexane, benzene, and an emission air/vapor mixture collected from an oil/water separator of a refinery. Reactions were carried out by controlling the feed stream to constant VOC concentrations and temperatures, in the ranges of 1300-14,700 mg/m3 and 240-400 degrees C, respectively. The destruction efficiency for each of the three VOCs as a function of influent gas temperature and empty bed gas residence time was obtained. Results indicate that n-hexane and the oil vapor with a composition of straight- and branch-chain aliphatic hydrocarbons exhibited similar catalytic incineration effects, while benzene required a higher incineration temperature or longer gas retention time to achieve comparable results. In the range of the VOC concentrations studied, at a given gas residence time, increasing the operating temperature of the catalyst bed increased the destruction efficiency. However, the much higher temperatures required for a destruction efficiency of over 99% may be not cost-effective and are not suggested. A first-order kinetics with respect to VOC concentration and an Arrhenius temperature dependence of the kinetic constant appeared to be an adequate representation for the catalytic oxidation of these volatile organics. Activation energy and kinetic constants were estimated for each of the VOCs. Low-temperature destruction of the target volatile organics could be achieved by using the Cr2O3 catalyst.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Benceno/análisis , Carcinógenos/análisis , Compuestos de Cromo/química , Hexanos/análisis , Industrias/instrumentación , Petróleo , Catálisis , Cinética , Oxidación-Reducción
13.
J Natl Cancer Inst ; 91(4): 347-54, 1999 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-10050868

RESUMEN

BACKGROUND: Residents of Qidong, People's Republic of China, are at high risk for development of hepatocellular carcinoma, in part due to consumption of foods contaminated with aflatoxins, which require metabolic activation to become carcinogenic. In a randomized, placebo-controlled, double-blind phase IIa chemoprevention trial, we tested oltipraz, an antischistosomal drug that has been shown to be a potent and effective inhibitor of aflatoxin-induced hepatocarcinogenesis in animal models. METHODS: In 1995, 234 adults from Qidong were enrolled. Healthy eligible individuals were randomly assigned to receive by mouth 125 mg oltipraz daily, 500 mg oltipraz weekly, or a placebo. Sequential immunoaffinity chromatography and liquid chromatography coupled to mass spectrometry or to fluorescence detection were used to identify and quantify phase 1 and phase 2 metabolites of aflatoxin B1 in the urine of study participants. Reported P values are two-sided. RESULTS: One month of weekly administration of 500 mg oltipraz led to a 51% decrease in median levels of the phase 1 metabolite aflatoxin M1 excreted in urine compared with administration of a placebo (P = .030), but it had no effect on levels of a phase 2 metabolite, aflatoxin-mercapturic acid (P = .871). By contrast, daily intervention with 125 mg oltipraz led to a 2.6-fold increase in median aflatoxin-mercapturic acid excretion (P = .017) but had no effect on excreted aflatoxin M1 levels (P = .682). CONCLUSIONS: Intermittent, high-dose oltipraz inhibited phase 1 activation of aflatoxins, and sustained low-dose oltipraz increased phase 2 conjugation of aflatoxin, yielding higher levels of aflatoxin-mercapturic acid. While both mechanisms can contribute to protection, this study highlights the feasibility of inducing phase 2 enzymes as a chemopreventive strategy in humans.


Asunto(s)
Aflatoxina B1/antagonistas & inhibidores , Anticarcinógenos/uso terapéutico , Carcinógenos/antagonistas & inhibidores , Neoplasias Hepáticas/prevención & control , Neoplasias Hepáticas/orina , Pirazinas/uso terapéutico , Acetilcisteína/orina , Aflatoxina B1/orina , Anticarcinógenos/administración & dosificación , Carcinógenos/metabolismo , China , Citocromo P-450 CYP1A2/metabolismo , Método Doble Ciego , Esquema de Medicación , Estudios de Factibilidad , Cromatografía de Gases y Espectrometría de Masas , Glutatión Transferasa/metabolismo , Humanos , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/enzimología , Pirazinas/administración & dosificación , Reproducibilidad de los Resultados , Tionas , Tiofenos , Resultado del Tratamiento
14.
J Pharmacol Exp Ther ; 270(1): 296-309, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8035327

RESUMEN

The drug 3 beta-[4'-iodophenyl]tropan-2 beta-carboxylic acid methyl ester (RTI-55) is a cocaine congener with high affinity for the dopamine transporter (Kd < 1 nM). The present study characterized [125I]RTI-55 binding to membranes prepared from rat, monkey and human caudates and COS cells transiently expressing the cloned rat dopamine (DA) transporter. Using the method of binding surface analysis, two binding sites were resolved in rat caudate: a high-capacity binding site (site 1, Bmax = 11,900 fmol/mg of protein) and a low-capacity site (site 2, Bmax = 846 fmol/mg of protein). The Kd (or Ki) values of selected drugs at the two sites were as follows: (Ki for high-capacity site and Ki for low-capacity site, respectively): RTI-55 (0.76 and 0.21 nM), 1-[2-diphenyl-methoxy)ethyl]-4-(3-phenylpropyl)piperazine (0.79 and 358 nM), mazindol (37.6 and 631 nM), 2 beta-carbomethoxy-3 beta-(4-fluorophenyl)tropane (45.0 and 540 nM) and cocaine (341 and 129 nM). Nisoxetine, a selective noradrenergic uptake blocker, had low affinity for both sites. Serotonergic uptake blockers had a high degree of selectivity and high affinity for the low-capacity binding site (Ki of citalopram = 0.38 nM; Ki of paroxetine = 0.033 nM). The i.c.v. administration of 5,7-dihydroxytryptamine to rats pretreated with nomifensine (to protect dopaminergic and noradrenergic nerve terminals) selectively decreased the Bmax of site 2, strongly supporting the idea that site 2 is a binding site on the serotonin (5-HT) transporter. This serotonergic lesion also increased the affinity of [125I]RTI-55 for the DA transporter by 10-fold. The ligand selectivity of the caudate 5-HT transporter was different from the [I125]RTI-55 binding site on the 5-HT transporter present in membranes prepared from whole rat brain minus caudate. The [125I]RTI-55 binding to the DA transporter was further resolved into two components, termed sites 1a and 1b, by using human and monkey (Macaca mulatta) caudate membranes but not the membranes prepared from rat caudate or COS cells that transiently expressed the cloned cocaine-sensitive DA transporter complementary DNA. Similar experiments also resolved two components of the caudate 5-HT transporter. Viewed collectively, these data provide evidence that [125I]RTI-55 labels multiple binding sites associated with the DA and 5-HT transporters.


Asunto(s)
Proteínas Portadoras/metabolismo , Núcleo Caudado/metabolismo , Núcleo Caudado/ultraestructura , Cocaína/análogos & derivados , Proteínas de Transporte de Membrana , Proteínas del Tejido Nervioso , Animales , Sitios de Unión , Unión Competitiva , Cocaína/metabolismo , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Radioisótopos de Yodo , Cinética , Ligandos , Masculino , Glicoproteínas de Membrana/metabolismo , Membranas/metabolismo , Membranas/ultraestructura , Piperazinas/metabolismo , Ensayo de Unión Radioligante , Ratas , Ratas Sprague-Dawley , Sensibilidad y Especificidad , Proteínas de Transporte de Serotonina en la Membrana Plasmática
15.
Neuroreport ; 5(4): 507-9, 1994 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-8003685

RESUMEN

The recently cloned rat mu opiate receptor cDNA has been expressed in COS and Chinese hamster ovary (CHO) cells to examine the coupling of this receptor to G-protein linked second messenger systems and examine possible coupling to multiple second messenger systems. Morphine (1 microM) reduced both forskolin-stimulated cAMP levels and IP3 levels by 20 +/- 5 and 34 +/- 8% respectively in COS and CHO cell cultures expressing the cloned rat mu receptor cDNA. Both effects could be blocked by naloxone and Gpp(NH)p. These results represent the first clear representation of the second messenger system promiscuity possible with a single cloned opiate receptor.


Asunto(s)
Adenilil Ciclasas/metabolismo , Fosfatidilinositoles/metabolismo , Receptores Opioides mu/biosíntesis , Sistemas de Mensajero Secundario/fisiología , Animales , Células CHO , Línea Celular , Clonación Molecular , Colforsina/farmacología , Cricetinae , ADN Complementario/biosíntesis , Guanilil Imidodifosfato/farmacología , Morfina/farmacología , Naloxona/farmacología , Ratas , Receptores Opioides mu/genética , Proteínas Recombinantes/biosíntesis
16.
J Biol Chem ; 268(35): 26447-51, 1993 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-8253772

RESUMEN

A rat brain opioid receptor protein was isolated by binding [epsilon-biotinyl-Lys32] beta-endorphin to membranes, solubilizing the receptor-ligand (R.L) complex with deoxycholate-lysophosphatidylcholine and purifying on immobilized streptavidin and wheat germ agglutinin. The purified glycoprotein had a molecular mass of 60-70 kDa. Recovery of this protein was blocked by the nonselective opioid antagonist naloxone and the highly mu-selective agonist [D-Ala2,N-methyl-Phe4,Glyol5]-enkephalin but not by the highly delta-selective agonist [D-Pen2,4'-Cl-Phe4,D-Pen5]enkephalin when these compounds were added as competitors at the binding step. The 60-70-kDa receptor protein co-purified through the streptavidin column with 40-kDa protein recognized by anti-Gi alpha antibodies. GTP and Na+ influenced dissociation of the solubilized R.125I-L complex and elution of the receptor and G protein from streptavidin in fashions consistent with the pharmacology of mu-opioid receptors. A 23-amino acid residue sequence from the purified receptor differs at 4 positions from a similar sequence in the murine delta-opioid receptor and is encoded within a novel rat brain cDNA isolated by polymerase chain reaction with oligonucleotide primers related to the murine delta-opioid receptor gene.


Asunto(s)
Química Encefálica , Receptores Opioides mu/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Biotina , Membrana Celular/química , Cromatografía de Afinidad , ADN Complementario , Electroforesis en Gel de Poliacrilamida , Proteínas de Unión al GTP/metabolismo , Glicosilación , Radioisótopos de Yodo , Masculino , Datos de Secuencia Molecular , Ratas , Receptores Opioides mu/química , Solubilidad , betaendorfina
17.
Neuron ; 7(1): 27-33, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1712603

RESUMEN

Expression of brain mRNA or cRNAs in Xenopus oocytes was used to determine what subunits of the GABAA receptor are required for modulation by barbiturates, benzodiazepines, and ethanol. Mouse brain mRNA was hybridized with antisense oligonucleotides complementary to sequences unique to specific subunits and injected into oocytes. Antisense oligonucleotides to the alpha 1, beta 1, gamma 1, gamma 2S + 2L, gamma 2L, or gamma 3 subunits did not alter GABA action or enhancement by pentobarbital. Action of diazepam was prevented by antisense oligonucleotides to gamma 2S + 2L and reduced by antisense sequences to gamma 2L, but was not affected by the other oligonucleotides. Ethanol enhancement of GABA action was prevented only by antisense oligonucleotides to gamma 2L (which differs from gamma 2S by the addition of 8 amino acids). Expression of either the alpha 1 beta 1 gamma 2S or the alpha 1 beta 1 gamma 2L subunit cRNA combination in oocytes resulted in GABA responses that were enhanced by diazepam or pentobarbital, but only the combination containing the gamma 2L subunit was affected by ethanol.


Asunto(s)
Etanol/farmacología , Oocitos/metabolismo , Receptores de GABA-A/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Encéfalo/metabolismo , Diazepam/farmacología , Ratones , Datos de Secuencia Molecular , Oligonucleótidos Antisentido/farmacología , Pentobarbital/farmacología , ARN/metabolismo , ARN Complementario , ARN Mensajero/metabolismo , Receptores de GABA-A/química , Receptores de GABA-A/genética , Xenopus
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