Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Infect Dis ; 93: 68-76, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31982621

RESUMO

BACKGROUND: Pregnant women are in the highest priority group for receiving influenza vaccination. However, they may be reluctant to receive the vaccination due to concerns about the influence of vaccination on the fetuses. METHODS: This prospective cohort study of 10 330 pregnant women examined the safety of influenza vaccination in terms of adverse birth outcomes. Influenza vaccination during pregnancy was determined from questionnaires before and after the 2013/2014 influenza season. All subjects were followed until the end of their pregnancy. Adverse birth outcomes, including miscarriage, stillbirth, preterm birth, low birth weight, and malformation, were assessed by obstetrician reports. RESULTS: Adverse birth outcomes were reported for 641 (10%) of the 6387 unvaccinated pregnant women and 356 (9%) of the 3943 vaccinated pregnant women. Even after adjusting for potential confounders, vaccination during pregnancy showed no association with the risk of adverse birth outcomes (odds ratio 0.90, 95% confidence interval 0.76-1.07). Vaccination during the first or second trimester displayed no association with adverse birth outcomes, whereas vaccination during the third trimester was associated with a decreased risk of adverse birth outcomes (odds ratio 0.70, 95% confidence interval 0.51-0.98). CONCLUSIONS: Influenza vaccination during pregnancy did not increase the risk of adverse birth outcomes, regardless of the trimester in which vaccination was performed, when compared to unvaccinated pregnant women.


Assuntos
Vacinas contra Influenza/efeitos adversos , Resultado da Gravidez , Aborto Espontâneo , Adulto , Estudos de Coortes , Feminino , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Influenza Humana/prevenção & controle , Japão , Razão de Chances , Gravidez , Trimestres da Gravidez , Nascimento Prematuro , Estudos Prospectivos , Natimorto , Vacinação , Adulto Jovem
2.
Clin Pharmacol Drug Dev ; 9(6): 699-708, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31833184

RESUMO

Peficitinib (ASP015K) is a novel Janus kinase inhibitor developed for the treatment of rheumatoid arthritis (RA). The impact of hepatic impairment on the peficitinib pharmacokinetic (PK) and safety profile was investigated in non-RA subjects (n = 24) in an open-label, parallel-group, multicenter comparative study in Japan. Subjects received a single, clinically relevant, oral dose of a peficitinib 150 mg tablet under fasting conditions. Plasma PK parameters were measured for peficitinib and its metabolites H1 (sulfate and methylated metabolite), H2 (sulfate metabolite), and H4 (methylated metabolite) in subjects with normal hepatic function, mild hepatic impairment, or moderate hepatic impairment. The peficitinib area under the plasma-concentration-time curve from time 0 to infinity (AUCinf ) and maximum observed concentration (Cmax ) were not markedly different in subjects with mild hepatic impairment versus normal hepatic function. In subjects with moderate hepatic impairment versus normal hepatic function, the geometric mean ratios for peficitinib AUCinf and Cmax , were 1.92 (90% CI: 1.39, 2.66) and 1.82 (90% CI: 1.24, 2.69), respectively. Five treatment-emergent adverse events (TEAEs) were experienced by 3 subjects, 1 in each group. There were no deaths, no serious TEAEs, and no TEAEs leading to withdrawal. In summary, the PK profile was unaltered in subjects with mild hepatic impairment after a single clinically relevant dose of peficitinib, but exposure almost doubled in subjects with moderate hepatic impairment. Peficitinib dose reduction may be considered in RA patients with moderate hepatic impairment.


Assuntos
Adamantano/análogos & derivados , Povo Asiático , Inibidores de Janus Quinases/administração & dosagem , Hepatopatias/fisiopatologia , Niacinamida/análogos & derivados , Adamantano/administração & dosagem , Adamantano/efeitos adversos , Adamantano/farmacocinética , Administração Oral , Idoso , Área Sob a Curva , Feminino , Humanos , Inibidores de Janus Quinases/efeitos adversos , Inibidores de Janus Quinases/farmacocinética , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Niacinamida/administração & dosagem , Niacinamida/efeitos adversos , Niacinamida/farmacocinética , Índice de Gravidade de Doença
3.
Clin Drug Investig ; 40(2): 149-159, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31729626

RESUMO

BACKGROUND AND OBJECTIVE: This study measured and compared the exposure and safety of peficitinib (ASP015K), a novel oral Janus kinase inhibitor, in subjects with normal and impaired renal function after a single oral, clinically relevant peficitinib dose. METHODS: This was an open-label, parallel-group study conducted at two centres in Japan. Subjects with normal and mildly, moderately, or severely impaired renal function received a single oral dose of peficitinib (one 150 mg tablet) under fasting conditions in a hospital setting. Blood samples were collected prior to administration and up to 72 h post-dose for pharmacokinetic assessment. Safety was assessed up to 7 days post-dose. RESULTS: Peficitinib plasma concentration-time profiles were similar between those with normal and impaired renal function. In subjects with impaired renal function, area under the plasma concentration-time curve and maximum concentration were 0.8- to 1.1-fold those in subjects with no impairment. Two subjects (one in the normal group and one in the mildly impaired group) each experienced a treatment-emergent adverse event (TEAE). There were no serious TEAEs, deaths or TEAEs leading to treatment withdrawal. CONCLUSIONS: Peficitinib exposure and TEAEs were similar in subjects with and without renal impairment after a single oral 150 mg dose. Based on these findings, it is not expected that peficitinib dose adjustment will be required in clinical practice, according to the degree of renal impairment. CLINICALTRIALS. GOV IDENTIFIER: NCT02603497.


Assuntos
Adamantano/análogos & derivados , Inibidores de Janus Quinases/farmacocinética , Niacinamida/análogos & derivados , Insuficiência Renal/metabolismo , Adamantano/efeitos adversos , Adamantano/farmacocinética , Administração Oral , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Niacinamida/efeitos adversos , Niacinamida/farmacocinética , Adulto Jovem
4.
J Infect Dis ; 217(6): 878-886, 2018 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-29216373

RESUMO

Background: Infants <6 months of age are too young to receive influenza vaccine, despite being at high risk for severe influenza-related complications. Methods: To examine the effectiveness of maternal influenza vaccination in preventing influenza in their infants, we conducted a prospective cohort study of 3441 infants born at participating hospitals before the 2013-2014 influenza season. At the time of recruitment, their mothers completed a questionnaire about influenza vaccination status for the 2013-2014 season. A follow-up survey was conducted after the end of the 2013-2014 season to collect information regarding influenza diagnosis and hospitalization among infants. Results: During the 2013-2014 influenza season, 71 infants (2%) had influenza diagnosed, and 13 infants (0.4%) were hospitalized with influenza. Maternal influenza vaccination (especially prenatal vaccination) decreased the odds of influenza among infants. The effectiveness of prenatal vaccination was 61% (95% confidence interval, 16%-81%), whereas that of postpartum vaccination was 53% (-28%-83%). Although maternal influenza vaccination was also associated with a decreased odds of influenza-related hospitalization among infants, vaccine effectiveness (73%) did not reach statistical significance, owing to the limited number of infants hospitalized because of influenza. Conclusions: The present findings indicated that pregnant women and postpartum women should receive influenza vaccination to protect their infants.


Assuntos
Imunidade Materno-Adquirida , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Complicações Infecciosas na Gravidez/prevenção & controle , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Gravidez , Estudos Prospectivos
5.
Vaccine ; 35(36): 4811-4816, 2017 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-28818474

RESUMO

To evaluate influenza disease burden among pregnant women, an epidemiological study using the self-control method was conducted. Study subjects were 12,838 pregnant women who visited collaborating maternity hospitals and clinics in Osaka Prefecture, Japan, before the 2013/14 influenza season. As a study outcome, hospitalization due to respiratory illnesses between the 2010/11 and 2013/14 seasons was collected from each study subject through a baseline survey at the time of recruitment and a second survey after the 2013/14 season. The hospitalization rates during pregnancy and non-pregnancy periods was calculated separately. To compare the hospitalization rate during pregnancy with that during non-pregnancy within the same single study subject, Mantel-Haenzel rate ratios (RRMH) were calculated. During the four seasons examined in this study, nine and 17 subjects were hospitalized due to respiratory illnesses during pregnancy and non-pregnancy periods, respectively. The hospitalization rate was 2.54 per 10,000 woman-months during pregnancy and 1.08 per 10,000 woman-months during non-pregnancy. The RRMH for the hospitalization rate during pregnancy compared with that during non-pregnancy was 4.30 (95% confidence interval, 1.96-9.41). Our results suggest that during the influenza season, pregnant women have a higher risk than non-pregnant women for hospitalization due to respiratory illnesses. The self-control method appears to be an appropriate epidemiological method for evaluating the disease burden of influenza among pregnant women.


Assuntos
Efeitos Psicossociais da Doença , Influenza Humana/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Adolescente , Adulto , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Vacinas contra Influenza , Japão/epidemiologia , Pessoa de Meia-Idade , Gravidez , Projetos de Pesquisa , Estações do Ano , Adulto Jovem
6.
Brain Behav ; 7(3): e00635, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28293475

RESUMO

OBJECTIVES: There have been no nationwide epidemiological studies of idiopathic normal pressure hydrocephalus (iNPH) in Japan. Therefore, a nationwide epidemiologic survey of iNPH was performed to determine the number of cases and clinical characteristics by sex and diagnostic level. METHODS: The first survey examined the numbers of cases that met the diagnostic criteria of iNPH and those who underwent shunt operations in 2012. The second survey gathered patients' details to clarify their clinical background characteristics. RESULTS: The estimated number of cases meeting the diagnostic criteria in 2012 was 12,900, with 6,700 undergoing shunt operations. The estimated crude prevalence was 10.2/100,000 persons. The age of onset was in the 70s in more than 50% of both men and women. Significantly higher (p < .05) frequencies of gait impairment in men and cognitive decline in women were observed as initial symptoms. At the time of definitive diagnosis, gait impairment was observed most frequently in patients with definite iNPH (77.7%). Hypertension was the most frequent comorbidity (40.0%), followed by diabetes mellitus (17.8%) and Alzheimer's disease (14.8%). Hypertension was observed more frequently in men, but diabetes was observed more frequently in women (p < .05). An LP shunt was the first-choice (55.1%) treatment of iNPH, followed by a VP shunt (43.2%). CONCLUSION: This study showed that iNPH occurs most frequently in the 70s, gait impairment and cognitive decline are the most frequent initial symptoms in men and women, respectively, and hypertension and diabetes are the most frequent comorbidities in men and women, respectively.


Assuntos
Doença de Alzheimer/epidemiologia , Disfunção Cognitiva/epidemiologia , Diabetes Mellitus/epidemiologia , Transtornos Neurológicos da Marcha/epidemiologia , Hidrocefalia de Pressão Normal/epidemiologia , Hipertensão/epidemiologia , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/etiologia , Comorbidade , Feminino , Transtornos Neurológicos da Marcha/etiologia , Inquéritos Epidemiológicos , Hospitais/estatística & dados numéricos , Humanos , Hidrocefalia de Pressão Normal/complicações , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade
7.
Int J Clin Pharmacol Ther ; 51(3): 200-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23211396

RESUMO

BACKGROUND: Darexaban is a potent direct factor Xa (FXa) inhibitor developed for prophylaxis of venous and arterial thromboembolic disease. This drug is rapidly and extensively metabolized to darexaban glucuronide (YM-222714), which is a pharmacologically active metabolite. The potential effects of food on the harmacokinetics of darexaban glucuronide after darexaban administration were assessed in two studies. METHODS: Both studies were conducted as open-label, two-way crossover studies. Healthy non-elderly Japanese male subjects received darexaban as a single 15 mg tablet (Study 1, n = 24) or a single 30 mg tablet (Study 2, n = 24). The geometric mean ratio (GMR) (fed/fasted) for AUClast and Cmax were evaluated as primary parameters. RESULTS: GMR(fed/fasted) for AUClast emonstrated slight decreases as 0.797 (90% CI: 0.758 - 0.838) in Study 1 and 0.821 (90% CI: 0.752 - 0.896) in Study 2. For Cmax, the GMR was 0.908 (90%CI: 0.835 - 0.988) in Study 1 and 1.039 (90% CI: 0.953 - 1.131) in Study 2. There were no serious adverse events during the two studies. None was considered to be drug-related. CONCLUSION: These studies demonstrated that there was no clinically significant effect of food on the pharmacokinetics after administration of darexaban. We therefore conclude that darexaban can be administered without regard to food intake.


Assuntos
Azepinas/farmacocinética , Benzamidas/farmacocinética , Inibidores do Fator Xa , Interações Alimento-Droga , Administração Oral , Adulto , Estudos Cross-Over , Humanos , Masculino
8.
Heart Vessels ; 22(6): 404-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18043999

RESUMO

The aim of this study was to investigate whether cilnidipine, an N- and L-type calcium channel blocker, and nisoldipine, an L-type calcium channel blocker, have different effects on sympathetic activity, using an identical group of healthy male subjects. Eight healthy men (22-28 years) were given 10 mg of cilnidipine or 10 mg of nisoldipine in a randomized crossover design. In each trial, in subjects without medication on day 1 (control) and with medication on day 2, we measured heart rate (HR), low frequency (LF)/high frequency (HF) of HR variability, and plasma noradrenaline (NA) in a resting supine position and during head-up tilt, and palmar sweating during a mental arithmetic test, before and at 1, 2, 4, 6, and 8 h after administration. Time-plasma concentration profiles of the two drugs were similar. Measurements in controls on the two days showed no significant difference in any of these parameters. Nisoldipine, but not cilnidipine, slightly increased HR and LF/HF at rest. Head-up tilt increased HR, LF/HF, and plasma NA. As evaluated with repeated-measures analysis of variance, head-up tilt induced a significant increase in LF/HF, but not HR or plasma NA, and the effect of cilnidipine was significantly less than that of nisoldipine (P = 0.017). Postural hypotension was not observed. There was no difference in mental arithmetic-induced sweating between the two drugs. Cilnidipine, but not nisoldipine, might have a weak inhibitory effect on reflex sympathetic activity.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Di-Hidropiridinas/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Nisoldipino/farmacologia , Sistema Nervoso Simpático/efeitos dos fármacos , Adulto , Humanos , Masculino , Norepinefrina/sangue , Postura
9.
Ann Pharmacother ; 40(10): 1724-30, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16940405

RESUMO

BACKGROUND: Pharmacokinetic studies of oseltamivir in very elderly patients (> or = 80 y) have not previously been performed. OBJECTIVE: To compare the pharmacokinetics of oseltamivir and the active carboxylate metabolite in healthy young and very elderly Japanese subjects. METHODS: Young (20-35 y, fasting, n = 7) and very elderly subjects (> or = 80 y, fed, n = 5) were enrolled in single-center studies and received a single oral dose of oseltamivir 75 mg. Plasma and urine samples were collected (24 h) for pharmacokinetic analysis, and safety was assessed. RESULTS: The time to maximum plasma concentration (tmax) for oseltamivir was delayed in the very elderly compared with the young subjects (2.30 vs 0.71 h, respectively). Furthermore, oseltamivir maximum plasma concentration (Cmax) and AUC(inf) were 52% and 80% higher, respectively, in the very elderly compared with the young subjects. Oral clearance was 45% lower in elderly patients, possibly due to the effects of administration of oseltamivir with a meal. For the active metabolite, oseltamivir carboxylate, Cmax and AUC(inf) values were, respectively, 22% and 91% higher in the very elderly subjects than in the young subjects, while oral clearance was 50% lower in the elderly population. The increased exposure of the active metabolite is likely to correlate with an age-related decline in renal function. For both oseltamivir and the active metabolite, there was large interpatient variability in the Cmax values. The data reported here indicate that oseltamivir would be effective in both of these populations, as trough concentrations for the active metabolite at 12 and 24 hours exceeded the 50% inhibitory concentration against the neuraminidase of influenza A and B isolates by more than 50-fold. Oseltamivir was well tolerated in both groups. CONCLUSIONS: Exposures (AUC(inf)) to both the parent drug and active metabolite were increased by more than 80% in the small number of very elderly subjects presented here. However, oseltamivir was well tolerated by these subjects.


Assuntos
Envelhecimento/metabolismo , Oseltamivir/farmacocinética , Adulto , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Envelhecimento/urina , Antivirais/sangue , Antivirais/farmacocinética , Antivirais/urina , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Oseltamivir/sangue , Oseltamivir/urina
10.
Pharmacogenet Genomics ; 15(12): 851-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16272957

RESUMO

OBJECTIVES: The aim of this study was to investigate the impact of CYP2C19 polymorphism on the extent of the interaction and on the pharmacokinetics and pharmacodynamics of ticlopidine. METHODS: Homozygous (hmEMs) and heterozygous extensive metabolizers (htEMs), and poor metabolizers (PMs, n = 6 each) took an oral dose (20 mg) of omeprazole. After a 1-week washout period, each subject received ticlopidine (200 mg) for 8 days, and ticlopidine pharmacokinetics were studied on days 1 and 7. On day 8, omeprazole was given again and its kinetic disposition was compared with that in the first dose. ADP-induced platelet aggregation was measured as a pharmacodynamic index. RESULTS: In contrast to the PMs, whose mean kinetic parameters were not altered by the repeated dosings of ticlopidine, an eight- to 10-fold increase in the mean AUC ratio of omeprazole to 5-hydroxyomeprazole was observed in both the EM groups. No significant intergenotypic differences in the pharmacokinetic parameters of ticlopidine were observed, although the accumulation ratio tended to be greater in hmEMs than in PMs (2.4 +/- 0.2 versus 1.7 +/- 0.2). A significantly positive correlation (P = 0.031) was observed between the individual percent inhibition of platelet aggregation and AUC0-24 of ticlopidine regardless of the CYP2C19 polymorphism. CONCLUSIONS: Ticlopidine is a potent inhibitor for CYP2C19 and may be associated with the phenocopy when CYPC19 substrates are co-administered to EMs. Whether and to what extent CYP2C19 would be involved in the metabolism of ticlopidine remain unanswered from the present in-vivo study.


Assuntos
Hidrocarboneto de Aril Hidroxilases/metabolismo , Inibidores Enzimáticos/farmacocinética , Oxigenases de Função Mista/metabolismo , Ticlopidina/metabolismo , Ticlopidina/farmacocinética , Adulto , Citocromo P-450 CYP2C19 , Interações Medicamentosas , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Genótipo , Humanos , Omeprazol/análogos & derivados , Omeprazol/farmacologia , Ticlopidina/farmacologia
11.
Hepatol Res ; 30(2): 91-95, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15519273

RESUMO

To assess the contribution of OATP-C to the hepatobiliary transport of bilirubin, a pharmacogenomic evaluation with regard to polymorphisms of three candidate genes, OATP-C, MRP2, and UGT1A1, was performed. Serum total and direct (conjugated) bilirubin levels were used as phenotypic indexes. Pharmacokinetic variables of pravastatin, a typical substrate for OATP-C, were obtained from our previous study. Among 23 volunteers, two variants (Val417Ile and Ser789Phe) were observed in the MRP2 gene. While there was no apparent effect of these two variants and the UGT1A1*28 on direct bilirubin levels, the OATP-C variants were associated with differences in unconjugated bilirubin levels. Subjects with the OATP-C*15 allele had higher bilirubin levels; unconjugated bilirubin levels in *1b/*1b (n = 3), *1b/*15 (n= 7), and *15/*15 (n = 1) subjects were 0.40 +/- 0.10, 0.77 +/- 0.35, and 0.70 (mg/dL), respectively. In addition, the correlation between unconjugated bilirubin levels and pharmacokinetic parameters of pravastatin revealed that the subjects with higher bilirubin levels had lower non-renal clearance values, and then higher serum concentrations of pravastatin. Large clinical studies are needed to confirm a role of OATP-C in the carrier-mediated uptake of bilirubin in the human liver.

12.
Pharmacogenetics ; 14(8): 549-56, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15284537

RESUMO

OBJECTIVES AND METHODS: We assessed the relationship between the metabolism of R- and S-mephobarbital (MPB) and genetic polymorphisms of cytochrome P450 (CYP) 2C19 and CYP2B6. Nine homozygous extensive metabolizers (homo-EMs, 2C19*1/2C19*1) of CYP2C19, ten heterozygous EMs (hetero-EMs, 2C19*1/2C19*2, 2C19*1/2C19*3) and eleven poor metabolizers (PMs, 2C19*2/2C19*2, 2C19*3/2C19*3, 2C19*2/2C19*3) recruited from a Japanese population, received an oral 200 mg-dose of racemic MPB. Blood and urine samples were collected, and R-MPB, S-MPB and the metabolites, phenobarbital (PB) and 4'-hydroxy-MPB, were measured. Each subject was also genotyped for CYP2B6 gene. RESULTS: The mean area under the plasma concentration-time curve (AUC) of R-MPB was 92-fold greater in PMs than in homo-EMs. R/S ratios for AUC of MPB were much higher in PMs than in EMs (homo- and hetero-). The cumulative urinary excretion of 4'-hydroxy-MPB up to 24 h postdose was 21-fold less in PMs than in homo-EMs. The metabolic ratio of AUCPB/(AUCS-MPB + AUCR-MPB) was higher in PMs than in EMs (homo- and hetero-). In addition, this metabolic ratio was lower in the carriers of CYP2B6*6 compared with that in its non-carriers. CONCLUSIONS: Our results indicate that the 4'-hydroxylation of R-MPB is mediated via CYP2C19 and that the rapid 4'-hydroxylation of R-MPB results in a marked difference in the pharmacokinetic profiles between R-MPB and S-MPB in the different CYP2C19 genotypic individuals. In addition, a minor fraction of the interindividual variability in PB formation from MPB may be explainable by the CYP2B6*6 allele.


Assuntos
Hidrocarboneto de Aril Hidroxilases/genética , Mefobarbital/farmacocinética , Oxigenases de Função Mista/genética , Oxirredutases N-Desmetilantes/genética , Polimorfismo Genético/genética , Adulto , Área Sob a Curva , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP2C19 , Genótipo , Heterozigoto , Homozigoto , Humanos , Hidroxilação , Japão , Masculino , Estrutura Molecular , Farmacogenética , Fenobarbital/sangue , Fenobarbital/urina , Estereoisomerismo
13.
Glia ; 43(2): 167-74, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12838508

RESUMO

The extrusion of protons is considered a very general parameter of the activation of many kinds of membrane or intracellular molecules, such as receptors, ion channels, and enzymes. We found that pepstatin A caused a reproducible, concentration-related increase in the extracellular acidification rate in two microglial cell lines, Ra2 and 6-3. Washing abolished pepstatin A-induced acidification immediately. However, pepstatin A did not cause the extracellular acidification in other cell types, such as CHO, C6 glioma, and NIH3T3 cells. These observations strongly suggest that pepstatin A interacts with certain membrane proteins specific to both Ra2 and 6-3 cells from outside. N-methylmaleimide and N,N'-dicyclohexylcarbodiimide, inhibitors of H(+)-ATPase, were found to reduce pepstatin A-induced response strongly, while bafilomycin A1, a vacuolar H(+)-ATPase inhibitor, vanadate, a P-type H(+)-ATPase inhibitor, and NaN3, an F1 ATPase inhibitor, virtually did not. 5-(N-ethyl-N-isopropyl) amiloride, an inhibitor of Na(+)/H(+) exchanger isoform 1, greatly enhanced pepstatin-induced response, while amiloride did not. Zn(2+), a voltage-dependent proton channel blocker, did not affect pepstatin-induced response neither. Staurosporine, a nonspecific inhibitor of protein kinase C, inhibited pepstatin A-induced response, while chelerythrine, more selective inhibitor of protein kinase C, greatly enhanced it. H-7 and H-8 did not affected the response. These findings suggest that pepstatin A induces extracellular acidification in microglia cell lines, Ra2 and 6-3, through an N-methylmaleimide- and N,N'-dicyclohexylcarbodiimide-sensitive, but bafilomycin A1-insensitive, ATPase, which seems to be distinct from protein kinase C-dependent process.


Assuntos
Ácido Aspártico Endopeptidases/antagonistas & inibidores , Espaço Extracelular/efeitos dos fármacos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Microglia/efeitos dos fármacos , Pepstatinas/farmacologia , Inibidores de Proteases/farmacologia , Animais , Células Cultivadas , Cricetinae , Relação Dose-Resposta a Droga , Interações Medicamentosas , Espaço Extracelular/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Microglia/citologia , Microglia/enzimologia , Ratos
14.
Clin Pharmacol Ther ; 73(6): 554-65, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12811365

RESUMO

OBJECTIVE: Our objective was to quantitate the contribution of the genetic polymorphisms of the genes for 2 human organic anion transporters-organic anion transporting polypeptide C (OATP-C) and organic anion transporter 3 (OAT3)-to the pharmacokinetics of pravastatin. METHODS: Genetic polymorphisms were screened by polymerase chain reaction-single-strand conformation polymorphism analysis, after sequencing with deoxyribonucleic acid obtained from 120 healthy volunteers. To examine whether polymorphisms in these 2 genes of interest alter transport activity, we conducted a clinical study (n = 23) with pravastatin as a selective probe drug. RESULTS: Among 120 healthy individuals, 5 nonsynonymous variants and 1 nonsynonymous variant were observed in the OATP-C and OAT3 genes, respectively. The polymorphisms in the OAT3 gene did not appear to be associated with changes in renal and tubular secretory clearance. In contrast, the OATP-C variants were associated with differences in the disposition kinetics of pravastatin. Subjects with the OATP-C*15 allele (Asp130Ala174) had a reduced total and nonrenal clearance, as compared with those with the OATP-C*1b allele (Asp130Val174); nonrenal clearance values in *1b/*1b (n = 4), *1b/*15 (n = 9), and *15/*15 (n = 1) subjects were 2.01 +/- 0.42 L. kg(-1). h(-1), 1.11 +/- 0.34 L. kg(-1). h(-1), and 0.29 L. kg(-1). h(-1), respectively, and the difference between *1b/*1b and *1b/*15 subjects was significant (P <.05). CONCLUSION: Certain commonly occurring single-nucleotide polymorphisms in OATP-C, such as T521C (Val174Ala), are likely to be associated with altered pharmacokinetics of pravastatin. Large clinical studies are needed to confirm these observations.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Pravastatina/farmacocinética , Adulto , Alelos , Área Sob a Curva , Povo Asiático , Biotransformação , População Negra , DNA/análise , DNA/biossíntese , DNA/genética , Frequência do Gene , Haplótipos , Humanos , Japão , Polimorfismo Genético/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Terminologia como Assunto , População Branca
15.
Clin Pharmacol Ther ; 72(2): 209-19, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12189368

RESUMO

OBJECTIVE: Our objective was to quantitate the contribution of the genetic polymorphism of the human MDR1 gene to the bioavailability and interaction profiles of digoxin, a substrate of P-glycoprotein. METHODS: The pharmacokinetics of digoxin was studied in 15 healthy volunteers, who were divided into 3 groups (n = 5 each) on the basis of genotyping for the MDR1 gene, in a 4-dose study after single doses of digoxin alone (0.5 mg orally and intravenously) and coadministered with clarithromycin (400 mg orally for 8 days). The dose of digoxin was reduced during the clarithromycin phase (0.25 mg orally and intravenously). RESULTS: The bioavailability of digoxin in G/G2677C/C3435, G/T2677C/T3435, and T/T2677T/T3435 subjects were 67.6% +/- 4.3%, 80.9% +/- 8.9%, and 87.1% +/- 8.4%, respectively, and the difference between G/G2677C/C3435 and T/T2677T/T3435 subjects was statistically significant (P <.05). The MDR1 variants were also associated with differences in disposition kinetics of digoxin, with the renal clearance being almost 32% lower in T/T2677T/T3435 subjects (1.9 +/- 0.1 mL/min per kilogram) than G/G2677C/C3435 subjects (2.8 +/- 0.3 mL/min per kilogram), and G/T2677C/T3435 subjects having an intermediate value (2.1 +/- 0.6 mL/min per kilogram). Coadministration of clarithromycin did not consistently affect digoxin clearance or renal clearance. However, a significant increase in digoxin bioavailability was observed in G/G2677C/C3435 subjects (67.6% +/- 4.3% versus 85.4% +/- 6.1%; P <.05) but not in the other 2 genotype groups. CONCLUSION: The allelic variants in the human MDR1 gene are likely to be associated with altered absorption and/or disposition profiles of digoxin and P-glycoprotein-mediated drug interaction


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Povo Asiático/genética , Claritromicina/farmacocinética , Digoxina/farmacocinética , Genes MDR , Polimorfismo Genético , Administração Oral , Adulto , Alelos , Antibacterianos/farmacocinética , Área Sob a Curva , Disponibilidade Biológica , Cardiotônicos/farmacocinética , Claritromicina/administração & dosagem , Sistema Enzimático do Citocromo P-450/metabolismo , Digoxina/administração & dosagem , Esquema de Medicação , Interações Medicamentosas , Inibidores Enzimáticos/farmacocinética , Genótipo , Humanos , Injeções Intravenosas , Japão , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Valores de Referência
16.
J Clin Pharmacol ; 42(2): 151-6, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11831537

RESUMO

The objective of this study was to develop a new simplified method using thin-layer chromatography (TLC) for determining isoniazid (INH) compliance in patients receiving antituberculosis chemotherapy. TLC was performed on silica gel plates using a standard solution of INH and acetylisoniazid (AcINH) and ethyl acetate-methanol (70:30 v/v) as the developing solvent. The spots of compound were detected by iodine. In the human study, fractional urine samples were collected over 24 hours from 4 healthy human subjects genotyped for NAT2* and to whom 400 mg of INH were administered orally. These samples were used for TLC analysis. The results of TLC were compared with those of high-performance liquid chromatography (HPLC). This method indicated good separation between INH and AcINH in standard solutions. The detection limits for INH and AcINH (applied volume; 20 microl of standard solution) were 2.2 nmole and 5 nmole, respectively, as detected by iodine. In the human study, the INH spot in urine was not detected on the TLC plate, except in one sample over the 0- to 4-hour period from 1 volunteer. However, the AcINH spot was detected in all urine samples from all volunteers. The total experimental time from application of the urine sample to analysis on TLC was 30 minutes. The results suggest that this method for detecting AcINH on TLC is an excellent, convenient, and simple method for determining INH compliance in patients receiving standard antituberculosis chemotherapy regimen or INH preventative therapy, regardless of the patient's NAT2* genotype.


Assuntos
Antituberculosos/uso terapêutico , Isoniazida/uso terapêutico , Cooperação do Paciente/estatística & dados numéricos , Tuberculose Pulmonar/tratamento farmacológico , Acetilação , Adulto , Antituberculosos/administração & dosagem , Antituberculosos/urina , Arilamina N-Acetiltransferase/genética , Biotransformação , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , DNA/genética , Feminino , Genótipo , Humanos , Isoniazida/administração & dosagem , Isoniazida/urina , Japão , Masculino , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...