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1.
Cancer Chemother Pharmacol ; 71(1): 175-82, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23064956

RESUMEN

The American Society of Clinical Oncology recently published a Clinical Practice Guideline entitled "Appropriate Chemotherapy Dosing for Obesity Adult Patients with Cancer." The panel recommended that full weight (actual weight)-based cytotoxic chemotherapy doses are used to treat obese patients with cancer, particularly when the goal of treatment is cure. However, no study has examined dosage calculation methods used for obese cancer patients in Japan. Here, we retrospectively studied the relationships between chemotherapy dose intensity, the occurrence of adverse events, and treatment outcomes in obese patients undergoing chemotherapy. Patients were divided into two groups: the actual BW group (BWg) was composed of patients receiving dosage amounts calculated using their actual BW (n = 64), and the ideal BWg was composed of patients receiving dosage amounts calculated using their ideal BW (n = 41). There were significant differences in the incidence of Grade 3/4 hematological toxicity in the actual and ideal BWg in solid tumor patients, but not in patients with hematological malignancies. In solid tumor patients with ≥30 body mass index (BMI), the incidence of Grade 3/4 hematological toxicity was significantly lower in the ideal BWg than in the actual BWg. Particularly, in patients with complications, incidence of Grade 4 hematological toxicity was significantly higher in the actual BWg than in the ideal BWg. These results suggest that the tumor type, degree of obesity, complications, and choice of chemotherapy regimen should be considered when determining chemotherapy dosage for obese patients.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Hematológicas/tratamiento farmacológico , Neoplasias/tratamiento farmacológico , Obesidad/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Superficie Corporal , Peso Corporal , Relación Dosis-Respuesta a Droga , Cálculo de Dosificación de Drogas , Femenino , Neoplasias Hematológicas/patología , Humanos , Japón , Masculino , Persona de Mediana Edad , Neoplasias/patología , Estudios Retrospectivos
2.
Phys Med Biol ; 56(17): 5525-34, 2011 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-21813962

RESUMEN

We aimed to estimate the scattered radiation from dental metallic crowns during head and neck radiotherapy by irradiating a jaw phantom with external photon beams. The phantom was composed of a dental metallic plate and hydroxyapatite embedded in polymethyl methacrylate. We used radiochromic film measurement and Monte Carlo simulation to calculate the radiation dose and dose distribution inside the phantom. To estimate dose variations in scattered radiation under different clinical situations, we altered the incident energy, field size, plate thickness, plate depth and plate material. The simulation results indicated that the dose at the incident side of the metallic dental plate was approximately 140% of that without the plate. The differences between dose distributions calculated with the radiation treatment-planning system (TPS) algorithms and the data simulation, except around the dental metallic plate, were 3% for a 4 MV photon beam. Therefore, we should carefully consider the dose distribution around dental metallic crowns determined by a TPS.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Coronas , Neoplasias de Cabeza y Cuello/radioterapia , Metales/química , Método de Montecarlo , Planificación de la Radioterapia Asistida por Computador/métodos , Dispersión de Radiación , Algoritmos , Carcinoma de Células Escamosas/diagnóstico por imagen , Simulación por Computador , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Humanos , Fantasmas de Imagen , Fotones/uso terapéutico , Dosis de Radiación , Radiografía , Radiometría/métodos , Radioterapia de Alta Energía/efectos adversos , Sensibilidad y Especificidad , Carcinoma de Células Escamosas de Cabeza y Cuello
3.
Clin Exp Immunol ; 158(3): 325-33, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19793338

RESUMEN

Clinical studies using omega-3 polyunsaturated fatty acids (omega3-PUFA) to Crohn's disease (CD) are conflicting. Beneficial effects of dietary omega3-PUFA intake in various experimental inflammatory bowel disease (IBD) models have been reported. However, animal models of large intestinal inflammation have been used in all previous studies, and the effect of omega3 fat in an animal model of small intestinal inflammation has not been reported. We hypothesized that the effects of omega3 fat are different between large and small intestine. The aim of this study was to determine whether the direct effect of omega3 fat is beneficial for small intestinal inflammation. Senescence accelerated mice (SAM)P1/Yit mice showed remarkable inflammation of the terminal ileum spontaneously. The numbers of F4/80-positive monocyte-macrophage cells as well as beta7-integrin-positive lymphocytes in the intestinal mucosa were increased significantly compared with those in the control mice (AKR-J mice). The area of mucosal addressin cell adhesion molecule-1 (MAdCAM-1)-positive vessels was also increased. The degree of expression levels of monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6 and interferon (IFN)-gamma mRNA were increased significantly compared with those in the control mice. The feeding of two different kinds of omega3 fat (fish-oil-rich and perilla-oil-rich diets) for 16 weeks to SAMP1/Yit mice ameliorated inflammation of the terminal ileum significantly. In both the omega3-fat-rich diet groups, enhanced infiltration of F4/80-positive monocytes/macrophages in intestinal mucosa of SAMP1/Yit mice cells and the increased levels of MCP-1, IL-6 and IFN-gamma mRNA expression were ameliorated significantly compared with those in the control diet group. The results suggest that omega3 fat is beneficial for small intestinal inflammation by inhibition of monocyte recruitment to inflamed intestinal mucosa.


Asunto(s)
Ácidos Grasos Omega-3/uso terapéutico , Ileítis/tratamiento farmacológico , Envejecimiento Prematuro/inmunología , Envejecimiento Prematuro/patología , Animales , Peso Corporal/efectos de los fármacos , Recuento de Linfocito CD4 , Moléculas de Adhesión Celular/metabolismo , Quimiotaxis de Leucocito/efectos de los fármacos , Quimiotaxis de Leucocito/inmunología , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Aceites de Pescado/uso terapéutico , Ileítis/inmunología , Ileítis/patología , Íleon/inmunología , Inmunidad Mucosa/efectos de los fármacos , Interferón gamma/biosíntesis , Interferón gamma/genética , Interleucina-6/biosíntesis , Interleucina-6/genética , Mucosa Intestinal/inmunología , Masculino , Ratones , Ratones Endogámicos AKR , Monocitos/inmunología , Mucoproteínas , Aceites de Plantas/uso terapéutico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Ácido alfa-Linolénico/uso terapéutico
4.
J Phys Chem B ; 111(35): 10365-72, 2007 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-17696390

RESUMEN

Interchain interaction, i.e., pi-pi stacking, can benefit the carrier transport in conjugated regio-regular poly(3-hexylthiophene) (P3HT) thin films. However, the existence of the insulating side hexyl chains in the surface region may be detrimental to the charge transfer between the polymer backbone and overlayer molecules. The control of the molecular orientation in the surface region is expected to alter the distribution of the pi electron density at the surface to solve such problems, which can be achieved by controlling the solvent removal rate during solidification. The evidence that the pi-electron density distribution at the outermost surface can be controlled is demonstrated by the investigation using the powerful combination of near edge X-ray absorption fine structure spectroscopy, ultraviolet photoelectron spectroscopy, and the most surface-sensitive technique: Penning ionization electron spectroscopy. From the spectroscopic studies, it can be deduced that the slower removal rate of the solvent makes the polymer chains even at the surface have sufficient time to adopt a more nearly equilibrium structure with edge-on conformation. Thus, the side hexyl chains extend outside the surface, which buries the pi-electron density contributed from the polymer backbone. Contrarily, the quench of obtaining a thermo-equilibrium structure in the surface region due to the faster removal of the solvent residual can lead to the surface chain conformation without persisting to the strong bulk orientation preference. Therefore, the face-on conformation of the polymer chain at the surface of thin films coated with high spin coating speed facilitate the electron density of the polymer backbone exposed outside the surface. Finally, thickness dependence of the surface electronic structure of P3HT thin films is also discussed.

5.
Aliment Pharmacol Ther ; 22(1): 67-74, 2005 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-15963082

RESUMEN

BACKGROUND: Famotidine increases Helicobacter pylori-eradication rates by a triple lansoprazole/amoxicillin/clarithromycin therapy in patients with the rapid extensive metabolizer genotype of CYP2C19. AIM: To determine the effect of famotidine on the gastric acid inhibition by lansoprazole in relation to CYP2C19 genotypes. METHODS: Twenty healthy volunteers with different CYP2C19 genotypes--consisting of six rapid extensive metabolizers, nine intermediate metabolizers and five poor metabolizers--underwent three 7-day courses with placebo, lansoprazole 30 mg twice daily, and lansoprazole 30 mg twice plus famotidine 20 mg twice daily. Lansoprazole was dosed after breakfast and dinner. Famotidine was dosed after lunch and at bedtime. Intragastric pH monitoring was performed for 24 h on day 7 of each course. RESULTS: With placebo, no difference was observed in intragastric pH profiles among the three CYP2C19 genotype groups. With lansoprazole 30 mg twice daily, the median of 24-h intragastric pH in poor metabolizers (6.1) was significantly higher than those of rapid extensive metabolizers (4.5) and intermediate metabolizers (5.0), respectively (P = 0.0176 and 0.0388), whereas with lansoprazole 30 mg twice and famotidine 20 mg twice daily, the medians were 5.4, 5.7, and 6.1, respectively (not significant). CONCLUSION: Acid inhibition by lansoprazole was influenced by CYP2C19 genotype status. This influence was offset by the concomitant use of famotidine.


Asunto(s)
Antiulcerosos/farmacología , Hidrocarburo de Aril Hidroxilasas/genética , Famotidina/farmacología , Ácido Gástrico/metabolismo , Oxigenasas de Función Mixta/genética , Omeprazol/análogos & derivados , 2-Piridinilmetilsulfinilbencimidazoles , Adulto , Estudios Cruzados , Citocromo P-450 CYP2C19 , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Interacciones Farmacológicas , Famotidina/administración & dosificación , Femenino , Genotipo , Humanos , Concentración de Iones de Hidrógeno , Lansoprazol , Masculino , Omeprazol/administración & dosificación , Omeprazol/farmacología
6.
Aliment Pharmacol Ther ; 21(4): 491-7, 2005 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-15710002

RESUMEN

BACKGROUND: Proton-pump inhibitors, such as lansoprazole, are metabolized in the liver by CYP2C19 and cannot inhibit acid sufficiently in homozygous extensive metabolizers of CYP2C19. AIM: To examine whether famotidine would increase the cure rates of Helicobacter pylori infection by a standard triple therapy. METHODS: A total of 177 H. pylori-positive patients were randomly assigned to either lansoprazole 30 mg b.d., clarithromycin 200 mg b.d. and amoxicillin 750 mg b.d. for 1 week (LCA group; n = 89) or famotidine 20 mg b.d., lansoprazole 30 mg b.d., clarithromycin 200 mg b.d. and amoxicillin 750 mg b.d. for 1 week (FLCA group; n = 88). Famotidine was administered after lunch and before sleep, and the others were after breakfast and dinner. CYP2C19 genotypes were determined by a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: In the LCA group, the eradication rates for homozygous extensive metabolizers, heterozygous extensive metabolizers, and poor metabolizers were 63%, 87%, and 100%, respectively (P = 0.014). Those in the FLCA group were 85%, 85%, and 100%, respectively (N.S.). The cure rate for homozygous extensive metabolizers in the FLCA group was significantly higher than that in the LCA group (P = 0.035). CONCLUSION: Famotidine improves the cure rate of H. pylori infection by a triple therapy in CYP2C19 homozygous extensive metabolizers patients.


Asunto(s)
Antiulcerosos/uso terapéutico , Hidrocarburo de Aril Hidroxilasas/genética , Famotidina/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Oxigenasas de Función Mixta/genética , Adulto , Antibacterianos , Citocromo P-450 CYP2C19 , Quimioterapia Combinada/uso terapéutico , Úlcera Duodenal/tratamiento farmacológico , Úlcera Duodenal/genética , Úlcera Duodenal/microbiología , Gastritis Atrófica/tratamiento farmacológico , Gastritis Atrófica/genética , Gastritis Atrófica/microbiología , Genotipo , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/genética , Humanos , Masculino , Persona de Mediana Edad , Úlcera Gástrica/tratamiento farmacológico , Úlcera Gástrica/genética , Úlcera Gástrica/microbiología , Resultado del Tratamiento
7.
J Synchrotron Radiat ; 5(Pt 3): 1044-6, 1998 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-15263739

RESUMEN

Angle-resolved UV photoelectron spectra (ARUPS) were measured for thin films of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) deposited on cleaved MoS(2) surfaces. The take-off angle (theta) dependence of the photoelectron intensity of the highest pi band showed a sharp maximum at theta = 32-34 degrees. A spectral feature of the binding energy at approximately 8.9 eV, which is believed to originate from a pi state, showed a remarkably different theta dependence from that of the pi band. A quantitative analysis of the observed theta dependencies clearly indicates that (a) the feature at approximately 8.9 eV originates from the oxygen 2p non-bonding states and (b) the molecules lie flat on the substrate surface.

8.
J Synchrotron Radiat ; 5(Pt 3): 1047-9, 1998 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-15263740

RESUMEN

Angle-resolved UV photoelectron spectra were measured for thin films of chloroaluminum phthalocyanine deposited on cleaved MoS(2) surfaces. The take-off angle (theta) dependence of the photoelectron intensity of the highest pi band showed a remarkable sharpening upon cooling the film, indicating that thermal excitation of molecular vibrations gives a considerable broadening of the photoelectron angular distribution. The theta dependence observed at approximately 120 K agrees well with that calculated.

9.
Epilepsia ; 38(8): 950-3, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9579899

RESUMEN

PURPOSE: We evaluated the efficacy of direct hemoperfusion (DHP) for treatment of acute valproate (VPA) intoxication and speculate on the biochemical perturbations that suggest a mechanism of coma induced by VPA overdose. PATIENT AND METHODS: The comatose patient was hospitalized approximately 6 h after ingesting 18 g VPA. DHP, with 200 g activated charcoal, was performed for 6 h. The plasma concentrations of VPA and Glasgow coma scale scores after admission were estimated. Before and after DHP, urine samples were tested in serial fashion for VPA metabolites, organic acids, and acyl carnitine esters of fatty acids. RESULTS: Plasma VPA was efficiently adsorbed on activated charcoal. The patient's plasma concentration of VPA decreased from 471 microg/ml (2,830 microM) to 45 microg/ml (270 microM), at which point the patient became alert. The half-life (t1/2) of VPA was calculated as 4.4 h before DHP and as 1.8 h during DHP. Before DHP, lactate and VPA-glucuronide markedly increased in urine samples, but beta-keto-VPA, a major mitochondrial metabolite, was not detected. Urinary excretion of carnitine esters of medium chain (C8-C10) dicarboxylic acids was increased. After DHP, lactate and VPA-glucuronide decreased, but a significant amount of beta-keto-VPA was demonstrated. Carnitine esters of medium chain dicarboxylic acids were decreased. CONCLUSIONS: DHP with activated charcoal was effective treatment for the patient with acute VPA intoxication and coma. The onset of coma may have been related to inhibition of beta-oxidation in the mitochondria, which was reversible by elimination of plasma VPA by DHP.


Asunto(s)
Coma/inducido químicamente , Coma/terapia , Hemoperfusión/métodos , Ácido Valproico/envenenamiento , Enfermedad Aguda , Adulto , Carnitina/orina , Carbón Orgánico , Coma/diagnóstico , Sobredosis de Droga/sangre , Sobredosis de Droga/terapia , Femenino , Escala de Coma de Glasgow , Humanos , Lactatos/orina , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Ácido Valproico/sangre
10.
Seishin Shinkeigaku Zasshi ; 98(4): 203-12, 1996.
Artículo en Japonés | MEDLINE | ID: mdl-8710994

RESUMEN

There are different opinions about the cause of chronic psychiatric symptoms observed in drug abusers between Japanese and foreign psychiatrists. The Japanese seem to recognize the chronic psychosis as the result of drug abuse. In the other hand, foreigners diagnose these cases as dual diagnosis of drug abuse and psychosis. Authors studied the problem in this research. One of the authors has examined 120 inhalant abusers of all, in- and out-patients in Kanagawa Prefectural Center of Psychiatry, Serigaya Hospital from 1991 to 1995. These patients were classified into three groups: psychosis group (23 patients), dependence group (51 patients) and abuse group (46 patients) according to their clinical courses and psychiatric symptoms. The psychosis group consists of patients who showed psychiatric symptoms such as hallucination, delusion and thought disturbance for long time after detoxification. The dependence group contains patients whose inhalant dependence was severe and met DSM-4 Diagnostic Criteria for Substance Dependence, but manifested no chronic psychiatric symptoms after detoxification. The patients belonging to abuse group were at the earlier stages of inhalant abuse and had no chronic psychiatric symptoms. The average age of the first inhalant abuse was 14.7 years old in the psychosis group, 14.8 years in the dependence group and 14.7 years in the abuse group. The average years of abuse was 9.0 years in the psychosis group, and 8.5 years in the dependence group. There was little difference between these two groups. The psychosis patients manifested chronic symptoms 5.7 years on average after the first abuse of inhalants. About one forth (26.1%) of the psychosis patients and only 5.9% of the dependence patients had family history of schizophrenia. The difference was statistically significant. These results suggest that chronic psychiatric symptoms are caused not only by inhalant abuse, but also by the genetic factors of psychosis of each patient. There have been several reports that many patients with dual diagnosis of substance dependence and other mental disorders are poly-drug abusers. In our study, 43.4% of the psychosis group patients and 19.6% of the dependence group patients had the past history of abuse of other drugs including methamphetamine and marijuana. The difference was, however, not statistically significant.


Asunto(s)
Trastornos Psicóticos/etiología , Esquizofrenia/etiología , Solventes , Trastornos Relacionados con Sustancias/complicaciones , Adolescente , Adulto , Factores de Edad , Niño , Enfermedad Crónica , Femenino , Humanos , Masculino , Trastornos Psicóticos/epidemiología , Esquizofrenia/epidemiología , Trastornos Relacionados con Sustancias/epidemiología
11.
Arukoru Kenkyuto Yakubutsu Ison ; 29(3): 185-9, 1994 Jun.
Artículo en Japonés | MEDLINE | ID: mdl-8080401

RESUMEN

The authors studied the clinical problems of alcoholics with a history of methamphetamine abuse as compared with alcoholics with no history. The samples were in- and out-patients of Kanagawa Prefectural Center of Psychiatry, Serigaya Hospital, from January to December 1992. This study covered 26 alcoholics who had abused methamphetamine from 1 to 40 years before, with an average age at admission was 43.5 years. This compared with a 50.4 year average for 89 alcoholics who had no history of methamphetamine abuse. Hepatitis C antibodies (HCVAb) were significantly more commonly observed in ex-methamphetamine abusers than in non-abusers (73.1% vs. 18.0%). Hepatitis B antigens (HBsAg) were no more common among abusers than non-abusers (0% vs. 2.2%). Blood transfusion history tended to be greater in ex-methamphetamine abusers than non-abusers (38.5% vs. 29.2%) but the difference did not reach conventional levels of statistical significance. Ex-abusers often wore tattoos (23.1%) whereas none of the non-abusers did, a significant difference. Significantly more ex-methamphetamine abusers were diagnosed as suffering from alcoholic hallucinosis than non-abusers (42.3% vs. 7.9%). As more ex-methamphetamine abusers than non-abusers were living alone (61.5% vs. 31.5%), were on welfare (61.5% vs. 23.8%), and living in skid-row areas (15.4% vs. 5.6%), the authors concluded that their living conditions were unstable.


Asunto(s)
Alcoholismo , Metanfetamina , Trastornos Relacionados con Sustancias , Adulto , Factores de Edad , Transfusión Sanguínea , Femenino , Hepacivirus/inmunología , Anticuerpos Antihepatitis/sangre , Antígenos de Superficie de la Hepatitis B/sangre , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Bienestar Social , Tatuaje
12.
Pharm Res ; 9(9): 1152-6, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1409396

RESUMEN

The role of the multispecific bile acid transporter for cardiac glycoside uptake is still controversial. This study was designed to examine the inhibitory effects of basic drugs (verapamil, dipyridamole, nifedipine, chlorpromazine, disopyramide, quinidine, propranolol, and lidocaine) on taurocholate uptake by isolated rat hepatocytes and to compare these effects with inhibition of ouabain uptake. Sodium-dependent taurocholate uptake was significantly reduced, to 50-70% of the control value, by 50 microM verapamil, dipyridamole, and nifedipine. Sodium-independent taurocholate uptake was more extensively inhibited, to 20-40%, by these basic drugs. The inhibition of ouabain uptake correlated better with sodium-independent taurocholate uptake (gamma = 0.918) than with sodium-dependent taurocholate uptake (gamma = 0.714). Taurocholate competitively inhibited ouabain uptake in the absence of sodium. These results indicate that the cardiac glycoside transport system is similar to the sodium-independent taurocholate transport system.


Asunto(s)
Hígado/efectos de los fármacos , Ouabaína/farmacocinética , Ácido Taurocólico/metabolismo , Animales , Clorpromazina/farmacología , Dipiridamol/farmacología , Disopiramida/farmacología , Interacciones Farmacológicas , Técnicas In Vitro , Lidocaína/farmacología , Hígado/citología , Hígado/metabolismo , Masculino , Nifedipino/farmacología , Propranolol/farmacología , Quinidina/farmacología , Ratas , Ratas Wistar , Sodio/fisiología , Verapamilo/farmacología
13.
Carcinogenesis ; 13(9): 1663-6, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1394853

RESUMEN

A dose-response study on covalent binding to forestomach protein was performed using male F344 rats following oral administration of [14C]3-tert-butyl-4-hydroxyanisole (3-BHA). The order of tissue distribution of radioactivity 6 h after oral administration of 1% [14C]3-BHA was forestomach greater than glandular stomach greater than liver greater than kidney greater than plasma. The covalent binding levels to forestomach protein were very low until 0.1% 3-BHA, but rapidly increased at concentrations of 1% and 2% 3-BHA. The dose-response relations of 3-BHA levels to the covalent binding to protein coincided well with the incidence of forestomach papilloma reported previously. The binding levels of forestomach and glandular stomach were compared. In case of i.v. administration, both binding levels were almost the same, however, in case of 0.1% p.o. administration, the forestomach level was approximately 8-fold higher than the glandular stomach level. The binding level of forestomach protein by p.o. administration was approximately 54-fold higher than that by i.v. administration. Although the amount of tert-butylhydroquinone (BHQ) was very low compared with the amount of covalent binding, the BHQ levels in forestomach were dependent upon the dose levels of 3-BHA. Our study indicates that the dose-response study on covalent binding to target tissue protein is an efficient method for the quantitative estimation of the active metabolites coming from the chemicals which form the quinone metabolites.


Asunto(s)
Hidroxianisol Butilado/metabolismo , Carcinógenos/metabolismo , Mucosa Gástrica/metabolismo , Proteínas/metabolismo , Animales , Hidroxianisol Butilado/farmacocinética , Hidroxianisol Butilado/toxicidad , Radioisótopos de Carbono , Carcinógenos/farmacocinética , Carcinógenos/toxicidad , Relación Dosis-Respuesta a Droga , Hiperplasia/inducido químicamente , Riñón/metabolismo , Hígado/metabolismo , Masculino , Papiloma/inducido químicamente , Unión Proteica , Ratas , Ratas Endogámicas F344 , Estómago/patología , Neoplasias Gástricas/inducido químicamente , Distribución Tisular
14.
Biopharm Drug Dispos ; 13(4): 295-304, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1600115

RESUMEN

Although antiarrhythmic drugs are used to treat digitalis-induced cardiac disorders, some of these drugs have been reported to increase the serum digoxin concentration in patients, causing the severe side-effects. We have previously shown that many basic drugs including antiarrhythmic drugs inhibited the hepatic uptake of cardiac glycosides into isolated rat hepatocytes, which could be a cause for the increased serum digoxin concentration. The present study was designed to examine the mechanism of this inhibition using isolated rat sinusoidal plasma membrane vesicles. The effect of nine basic drugs (dipyridamole, nifedipine, verapamil, chlorpromazine, lidocaine, quinidine, ajmaline, disopyramide, and propranolol) on the uptake of ouabain was studied. Quinidine reduced the initial uptake rate of ouabain (30 s) while it did not change the uptake of ouabain in an equilibrium condition (30 min). Other basic drugs, such as verapamil, dipyridamole, and nifedipine also significantly reduced the initial uptake rate of ouabain. These basic drugs had no effect on the membrane fluidity. The inhibitory effects on the vesicular uptake were significantly correlated with the inhibitory effects on ouabain uptake by the isolated rat hepatocytes. These findings may suggest that the mechanism of the inhibition involves the inhibition of the transport process via the sinusoidal plasma membrane.


Asunto(s)
Membrana Celular/fisiología , Hígado/metabolismo , Ouabaína/farmacocinética , Animales , Membrana Celular/efectos de los fármacos , Permeabilidad de la Membrana Celular , Técnicas In Vitro , Masculino , Quinidina/farmacología , Ratas , Ratas Endogámicas , Tritio
15.
J Pharmacobiodyn ; 14(10): 567-75, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1818098

RESUMEN

Four commercial controlled-release tablets of d-chlorpheniramine maleate, which showed various drug release properties, were administered to beagle dogs, and the correlation between in vitro drug release and in vivo absorption was studied. The mean in vivo absorption amount-time profile for each product showed good accordance with the in vitro drug release profile until 2-3 h after administration. However, absorption of the drug in dogs terminated at about 3 h. This short absorption time may be due to a short intestinal residence time for these dosage forms in the dog. In the present study, the deconvolution method was proved to be useful for in vitro/in vivo comparison, which clarified the in vivo absorption of controlled-release dosage forms having various release profiles.


Asunto(s)
Clorfeniramina/administración & dosificación , Animales , Clorfeniramina/farmacocinética , Preparaciones de Acción Retardada , Perros , Técnicas In Vitro , Absorción Intestinal , Masculino , Comprimidos
16.
Ryumachi ; 30(4): 255-63, 1990 Aug.
Artículo en Japonés | MEDLINE | ID: mdl-2287966

RESUMEN

One hundred seventeen deaths of RA patients (30 males and 87 females) at National Sagamihara Hospital for 13 years (1975-1988) were analysed. The average duration of disease were 10.5 years in male patients and 17.7 years in female. The average life span of the patients with RA, revealing 65.8 years in male and 63.7 years in female, were much shorter than of general population. The causes of all deaths were investigated by ourselves and/or autopsy. The autopsy was performed in 56.6%. The most common causes of death in RA patients were infectious diseases (20.5%), respiratory diseases (16%, mainly interstitial pneumonia and chronic obstructive lung diseases), and gastrointestinal diseases (14.7% chiefly perforation or bleeding of peptic ulcer). The distribution of causes of death in RA patients was quite different from in general population. The gastrointestinal disease decreased from 20% in the early half (1975-1981) to 12.6% in the latter half (1982-1987). It seems likely that H2-receptor antagonist played a major role for preventing the death by perforation or bleeding of ulcer, because the drug has been used since 1982 in Japan. Renal insufficiency including amyloidosis increased markedly in the latter half (14.9%) compared with in the early half (6.7%). Frequency of infectious diseases, respiratory diseases, and basilar impression remain unchanged in all course. Although our study are case-analysis in only one institute and further study will be necessary, the accumulation of the data investigated by rheumatologist will be helpful to grasp correct cause of death in patients with RA.


Asunto(s)
Artritis Reumatoide/mortalidad , Causas de Muerte , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/tratamiento farmacológico , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad , Factores Sexuales
17.
Pharm Res ; 6(3): 235-8, 1989 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2726680

RESUMEN

The possible mechanism of hepatic uptake of colchicine (CLC), a microtubule system disrupting agent, was examined using isolated rat hepatocytes. The existence of a carrier-mediated active transport system for CLC was demonstrated. This transport system is saturable, is affected by metabolic inhibitors (dinitrophenol, KCN) and a SH-group blocker (p-hydroxymercuribenzoic acid but not N-ethylmaleimide), and is sensitive to temperature. Ouabain, an inhibitor of Na+, K+-ATPase, does not affect the transport system of CLC.


Asunto(s)
Colchicina/farmacocinética , Hígado/metabolismo , Microtúbulos/efectos de los fármacos , Animales , Células Cultivadas , Colchicina/farmacología , Cinética , Ratas , Compuestos de Sulfhidrilo/farmacología
18.
J Pharmacobiodyn ; 12(1): 24-30, 1989 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2656984

RESUMEN

Effect of quinidine on the hepatic uptake of digoxin was studied using isolated guinea pig hepatocytes and with the multiple indicator dilution method using perfused livers. The initial uptake rate of digoxin by isolated hepatocytes was significantly (p less than 0.05) decreased in the presence of quinidine or ouabain and at low temperature (27 degrees C). The influx rate constant to the liver (K1) of unbound digoxin was also decreased by quinidine or the metabolic inhibitor 2,4 dinitrophenol (DNP) in isolated perfused livers, while K1 of diazepam, which is thought to be taken up by a passive transport system, was not significantly changed in the presence of DNP. These findings suggest that an active transport system for digoxin may exist in the liver and may be inhibited by quinidine. We concluded that the quinidine-induce decreases in the hepatic distribution of digoxin may be attributed both to the decreased tissue binding and to the inhibition of uptake, which might be related to the decreased hepatic clearance.


Asunto(s)
Digoxina/metabolismo , Hígado/metabolismo , Quinidina/farmacología , Animales , Diazepam/farmacología , Cobayas , Técnicas In Vitro , Técnicas de Dilución del Indicador , Hígado/citología , Hígado/efectos de los fármacos , Ouabaína/farmacología , Temperatura
19.
Biochem Pharmacol ; 37(15): 2949-55, 1988 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-3395368

RESUMEN

The effects of some basic and acidic drugs on the hepatic uptake of digoxin and ouabain were studied in isolated rat hepatocytes. Digoxin accumulated against a concentration gradient, and its initial uptake was energy- and temperature-dependent. Digoxin competitively inhibited the uptake of ouabain (Ki = 1.3 microM), which was reported to be transported by a carrier-mediated active transport system. All basic drugs tested (verapamil, dipyridamole, amiodarone, nifedipine, diltiazem, ajmaline, chlorpromazine, imipramine, disopyramide, quinidine, procainamide, propranolol and lidocaine: 50 microM) except for procainamide, propranolol and lidocaine significantly (P less than 0.05) reduced the uptake of digoxin, whereas acidic drugs (salicylic acid and phenytoin) had no effect. The same inhibitory effects were observed for ouabain uptake, whereas the uptake of alanine was not changed by these drugs. Quinidine inhibited the uptake of ouabain in a noncompetitive manner (Ki = 88 microM). These basic drugs had no effect on the permeability of the cells assessed by the trypan blue exclusion test and succinate-simulated oxygen consumption. But carbonylcyanide-m-chlorophenyl hydrazone-stimulated oxygen consumption decreased in the presence of some basic drugs and correlated with their inhibitory effects on digoxin uptake. Therefore, one of the mechanisms of the inhibitory effects of these drugs on digoxin uptake was the inhibition of oxidative phosphorylation. These basic drugs had no effect on the microtubular system, which was assessed by the measurement of tubulin polymerization and colchicine binding to tubulin. The results of our study suggested that many basic drugs have a potential to inhibit the hepatocellular uptake of cardiac glycosides.


Asunto(s)
Antiarrítmicos/farmacología , Glicósidos Cardíacos/farmacocinética , Hígado/metabolismo , Vasodilatadores/farmacología , Animales , Células Cultivadas , Clorpromazina/farmacología , Digoxina/farmacocinética , Imipramina/farmacología , Técnicas In Vitro , Cinética , Hígado/citología , Hígado/efectos de los fármacos , Masculino , Ouabaína/farmacocinética , Ratas , Ratas Endogámicas
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