RESUMO
Accurate and efficient self-assessment is a critical skill for medical students to develop as part of their professional development. Along with clinical training reform at Fukushima Medical University, rubric-based student self-assessment and teacher assessment of students' performance using our proposed assessment tool, which includes several aspects of clinical skills and abilities, was initiated to improve the clinical clerkship process. To investigate how students identified their weaknesses and strengths, we analyzed the results of 119 fourth-year medical students' self-assessment and corresponding teacher assessment. Our study revealed substantial consistency between student self-assessment and teacher assessment, despite some overestimation and underestimation in student self-assessments. Students who incorrectly assess themselves require a variety of feedback to increase their self-efficacy and self-confidence, as well as to identify their weaknesses.
Assuntos
Estágio Clínico , Estudantes de Medicina , Humanos , Autoavaliação (Psicologia) , Competência Clínica , Estágio Clínico/métodosRESUMO
BACKGROUND: Self-efficacy is crucial in improving medical students' communication skills. This study aims to clarify where medical students' self-efficacy is greatest following an interview with a simulated patient and subsequent feedback. METHODS: A total of 162 medical students (109 men, 53 women) in their fourth or fifth year at a university in Japan participated in this study. The degree of self-efficacy in medical interviewing was measured before and after a medical interview with a simulated patient, and after the subsequent feedback session. RESULTS: ANOVA analysis revealed that self-efficacy for medical interviews was higher after both the interview and the feedback session than before the interview. Among all three time points, self-efficacy was highest after the feedback session. CONCLUSIONS: Feedback following a simulated interview with a simulated patient is important to improve the self-efficacy of medical students when learning medical interviewing skills.
Assuntos
Educação de Graduação em Medicina , Estudantes de Medicina , Competência Clínica , Comunicação , Retroalimentação , Feminino , Humanos , Japão , Masculino , AutoeficáciaRESUMO
BACKGROUND: Professional identity formation is nurtured through socialization, driven by interaction with role models, and supported through early clinical exposure (ECE) programmes. Non-healthcare professionals form part of the hospital community but are external to the culture of medicine, with their potential as role models unexplored. We employed text mining of student reflective assignments to explore the impact of socialization with non-healthcare professionals during ECE. METHODS: Assignments from 259 first-year medical students at Fukushima Medical University, Japan, underwent hierarchical cluster analysis. Interrelationships between the most-frequently-occurring words were analysed to create coding rules, which were applied to elucidate underlying themes. RESULTS: A shift in terms describing professional characteristics was detected, from "knowledge/skill" towards "pride [in one's work]" and "responsibility". Seven themes emerged: contribution of non-healthcare professionals, diversity of occupation, pride, responsibility, teamwork, patient care and gratitude. Students mentioning 'contribution of non-healthcare professionals' spoke of altruistic dedication and strong sense of purpose. These students expressed gratitude towards non-healthcare professionals for supporting clinical work, from a doctor's perspective. CONCLUSION: Socialization with non-healthcare professionals provides important insights into the hospital working environment and cultural working norms. Through role modelling altruism and responsibility, non-healthcare professionals positively influenced student professional identity formation, promoting self-conceptualisation as a doctor.
Assuntos
Estudantes de Medicina , Mineração de Dados , Humanos , Japão , Recursos Humanos em Hospital , Identificação SocialRESUMO
Lisinopril, a highly hydrophilic long-acting angiotensin-converting enzyme inhibitor, is frequently prescribed for the treatment of hypertension and congestive heart failure. Green tea consumption may reduce the risk of cardiovascular outcomes and total mortality, whereas green tea or its catechin components has been reported to decrease plasma concentrations of a hydrophilic ß blocker, nadolol, in humans. The aim of this study was to evaluate possible effects of green tea extract (GTE) on the lisinopril pharmacokinetics. In an open-label, randomized, single-center, 2-phase crossover study, 10 healthy subjects ingested 200 mL of an aqueous solution of GTE containing ~ 300 mg of (-)-epigallocatechin gallate, a major catechin component in green tea, or water (control) when receiving 10 mg of lisinopril after overnight fasting. The geometric mean ratio (GTE/control) for maximum plasma concentration and the area under the plasma concentration-time curve of lisinopril were 0.289 (90% confidence interval (CI) 0.226-0.352) and 0.337 (90% CI 0.269-0.405), respectively. In contrast, there were no significant differences in time to reach maximum lisinopril concentration (6 hours in both phases) and renal clearance of lisinopril (57.7 mL/minute in control vs. 56.9 mL/minute in GTE). These results suggest that the extent of intestinal absorption of lisinopril was significantly impaired in the presence of GTE, whereas it had no major effect on the absorption rate and renal excretion of lisinopril. Concomitant use of lisinopril and green tea may decrease oral exposure to lisinopril, and therefore result in reduced therapeutic efficacy.
Assuntos
Catequina/análogos & derivados , Interações Alimento-Droga , Lisinopril/farmacocinética , Chá/química , Administração Oral , Adulto , Catequina/administração & dosagem , Catequina/farmacocinética , Estudos Cross-Over , Jejum , Feminino , Voluntários Saudáveis , Humanos , Absorção Intestinal , Lisinopril/administração & dosagem , Masculino , Adulto JovemRESUMO
AIMS: The aim of this study was to investigate the effects of a single green tea (GT), administered concomitantly or 1 hour before nadolol intake on nadolol pharmacokinetics. METHODS: In a randomized 3-phase crossover study, 11 healthy volunteers received an oral administration of nadolol with, or 1 hour after preingestion of brewed GT, or with water in a volume of 150 mL. RESULTS: Geometric mean ratio with 90% confidence interval for nadolol AUC0-48 was 0.371 (0.303-0.439) with concomitant GT. In addition, ingestion of GT 1 hour before nadolol administration resulted in a significant reduction of nadolol AUC0-48 with geometric mean ratio of 0.536 (0.406-0.665). There were no differences in time to maximal plasma concentration and renal clearance of nadolol among groups. CONCLUSION: These results suggest that single concomitant ingestion of GT substantially decreases plasma concentrations of nadolol. Moreover, the reduction in nadolol bioavailability could persist for at least 1 hour after drinking a cup of GT.
Assuntos
Catequina , Nadolol , Catequina/análise , Estudos Cross-Over , Ingestão de Alimentos , Voluntários Saudáveis , Humanos , CháRESUMO
OBJECTIVES: To clarify (1) the prevalence and associating factors of work-life conflict (WLC);(2) the details of gender-based discrimination;and (3) the association between WLC and gender-based discrimination among various professionals in a medical university organization. METHODS: This cross-sectional study, conducted in 2017, included all employees working at a public medical university and two affiliated hospitals that lie in provincial cities in Japan. The outcome of interest was time-based WLC in the work-to-family or family-to-work direction, measured with a shortened version of an existing scale. Gender-based discrimination was measured according to a three-point scale. RESULTS: Among the 3,347 employees, complete data sets were available for 2,285 (complete response rate, 68.3%). Of these, approximately 30% of respondents had perceived WLC. Multivariable logistic regression analysis showed that faculty members, nurses, and employees between 30 and 39 years old had a greater risk of WLC regardless of gender. Men were more likely to perceive gender-based discrimination in the contents of their work and the number of incidental tasks, while women were more likely to perceive discrimination with promotions and evaluation of academic achievements. Both men and women respondents who perceived gender-based discrimination had an increased risk of WLC. CONCLUSIONS: When promoting organizational well-being in a medical university, increased attention should be paid to faculty members, nurses and employees between 30 and 39 years old, as they have a greater risk of WLC. Our results also suggest that promoting gender equality is important to help achieve appropriate work-life balance.
Assuntos
Sexismo , Equilíbrio Trabalho-Vida , Adulto , Idoso , Estudos Transversais , Feminino , Equidade de Gênero , Hospitais Universitários , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-IdadeRESUMO
Glucocorticoid (GC) resistance is associated with poor response to the following chemotherapy in lymphoid malignancies, such as lymphoma and leukemia. However, it remains unclear whether GCs interfere with the cytotoxic effects of anti-cancer drugs on GC-resistant cells. In this study, we examined whether GCs affected the sensitivities to vincristine (VCR)/doxorubicin (DOX) and the expression of drug transporters in GC-resistant cells. The dexamethasone (DEX)/prednisolone (PSL)-resistant lymphoid and non-lymphoid cell lines Raji and HL60 were cultured with DEX for 7 days and then treated with VCR or DOX for 3 days. Seven days of DEX treatment increased the IC50s of both VCR and DOX in Raji cells but not in HL60 cells. The mRNA and protein expression levels of organic cation/carnitine transporter (OCTN) 2, one of the drug uptake transporters expressed in both cell lines, were decreased only in Raji cells. When Raji cells were cultured with PSL, the IC50 of DOX but not VCR increased as the expression of OCTN2 decreased. No significant increases in efflux transporter expression were induced by DEX or PSL. When siRNA against OCTN2 was introduced into Raji cells, the IC50 of DOX but not VCR increased significantly. These data suggested that both DEX and PSL decreased the sensitivity of the DEX/PSL-resistant Raji cells to DOX, a change that was at least partially due to reductions in OCTN2. Thus, the continuous usage of GCs may interfere with the effects of chemotherapy on GC-resistant lymphoid cells.
Assuntos
Dexametasona/farmacologia , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glucocorticoides/farmacologia , Linfócitos/metabolismo , Proteínas de Neoplasias/metabolismo , Prednisolona/farmacologia , Membro 5 da Família 22 de Carreadores de Soluto/metabolismo , Células HL-60 , Humanos , Leucemia/tratamento farmacológico , Leucemia/metabolismo , Leucemia/patologia , Linfócitos/patologia , Linfoma/tratamento farmacológico , Linfoma/metabolismo , Linfoma/patologiaRESUMO
PURPOSE: The aim of the present study is to investigate a possible role of a single dose of (-)-epigallocatechin gallate (EGCG), the major catechin in green tea, for the pharmacokinetic interaction between green tea and nadolol in humans. METHODS: In a randomized three-phase crossover study, 13 healthy volunteers received single doses of 30 mg nadolol orally with water (control), or an aqueous solution of EGCG-concentrated green tea extract (GTE) at low or high dose. Plasma concentrations and urinary excretion of nadolol were determined up to 48 h. In addition, blood pressure and pulse rate were monitored. In vitro transport kinetic experiments were performed using human embryonic kidney 293 cells stably expressing organic anion transporting polypeptide (OATP)1A2 to evaluate the inhibitory effect of EGCG on OATP1A2-mediated substrate transport. RESULTS: Single coadministration of low and high dose GTE significantly reduced the plasma concentrations of nadolol. The geometric mean ratios with 90% CI for area under the plasma concentration-time curves from 0 to infinity of nadolol were 0.72 (0.56-0.87) for the low and 0.60 (0.51-0.69) for the high dose. There were no significant differences in Tmax, elimination half-life, and renal clearance between GTE and water phases. No significant changes were observed for blood pressure and pulse rate between phases. EGCG competitively inhibited OATP1A2-mediated uptake of sulphobromophthalein and nadolol with Ki values of 21.6 and 19.4 µM, respectively. CONCLUSIONS: EGCG is suggested to be a key contributor to the interaction of green tea with nadolol. Moreover, even a single coadministration of green tea may significantly affect nadolol pharmacokinetics.
Assuntos
Antagonistas Adrenérgicos beta/farmacocinética , Antioxidantes/farmacologia , Camellia sinensis , Catequina/análogos & derivados , Nadolol/farmacocinética , Extratos Vegetais/farmacologia , Antagonistas Adrenérgicos beta/sangue , Antagonistas Adrenérgicos beta/urina , Adulto , Antioxidantes/análise , Proteínas Sanguíneas/metabolismo , Catequina/análise , Catequina/farmacologia , Estudos Cross-Over , Interações Medicamentosas , Feminino , Células HEK293 , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Nadolol/sangue , Nadolol/urina , Transportadores de Ânions Orgânicos , Extratos Vegetais/análise , Ligação Proteica , Adulto JovemRESUMO
PURPOSE: The objective of this study is to assess the effects of green tea and its major catechin component, (-)-epigallocatechin gallate (EGCG), on CYP2C9-mediated substrate metabolism in vitro, and the pharmacokinetics of fluvastatin in healthy volunteers. METHODS: The metabolism of diclofenac and fluvastatin in human recombinant CYP2C9 was investigated in the presence of EGCG. In a randomized three-phase crossover study, 11 healthy volunteers ingested a single 20-mg dose of fluvastatin with green tea extract (GTE), containing 150 mg of EGCG, along with water (300 mL), brewed green tea (300 mL), or water (300 mL) after overnight fasting. Plasma concentrations of fluvastatin and EGCG were measured by ultra-performance liquid chromatography with fluorescence detection and a single mass spectrometer. RESULTS: EGCG inhibited diclofenac 4'-hydroxylation and fluvastatin degradation with IC50 of 2.23 and 48.04 µM, respectively. Brewed green tea used in the clinical study also dose-dependently inhibited the metabolism of diclofenac and fluvastatin in vitro. However, no significant effects of GTE and brewed green tea were observed in plasma concentrations of fluvastatin. The geometric mean ratios with 90% CI for area under the plasma concentration-time curve (AUC0-∞) of fluvastatin were 0.993 (0.963-1.024, vs. brewed green tea) and 0.977 (0.935-1.020, vs. GTE). CONCLUSIONS: Although in vitro studies indicated that EGCG and brewed green tea produce significant inhibitory effects on CYP2C9 activity, the concomitant administration of green tea and fluvastatin in healthy volunteers did not influence the pharmacokinetics of fluvastatin.
Assuntos
Catequina/análogos & derivados , Citocromo P-450 CYP2C9/metabolismo , Ácidos Graxos Monoinsaturados/farmacocinética , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Indóis/farmacocinética , Chá , Adulto , Anti-Inflamatórios não Esteroides/farmacocinética , Catequina/análise , Catequina/sangue , Catequina/farmacocinética , Catequina/farmacologia , Estudos Cross-Over , Diclofenaco/farmacocinética , Ácidos Graxos Monoinsaturados/sangue , Feminino , Fluvastatina , Interações Alimento-Droga , Voluntários Saudáveis , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/sangue , Indóis/sangue , Masculino , Chá/química , Adulto JovemRESUMO
In myelodysplastic syndromes (MDS), functional defects of neutrophils result in high mortality because of infections; however, the molecular basis remains unclear. We recently found that miR-34a and miR-155 were significantly increased in MDS neutrophils. To clarify the effects of the aberrant microRNA expression on neutrophil functions, we introduced miR-34a, miR-155, or control microRNA into neutrophil-like differentiated HL60 cells. Ectopically introduced miR-34a and miR-155 significantly attenuated migration toward chemoattractants fMLF and IL-8, but enhanced degranulation. To clarify the mechanisms for inhibition of migration, we studied the effects of miR-34a and miR-155 on the migration-regulating Rho family members, Cdc42 and Rac1. The introduced miR-34a and miR-155 decreased the fMLF-induced active form of Cdc42 to 29.0 ± 15.9 and 39.7 ± 4.8% of that in the control cells, respectively, although Cdc42 protein levels were not altered. miR-34a decreased a Cdc42-specific guanine nucleotide exchange factor (GEF), dedicator of cytokinesis (DOCK) 8, whereas miR-155 reduced another Cdc42-specific GEF, FYVE, RhoGEF, and PH domain-containing (FGD) 4. The knockdown of DOCK8 and FGD4 by small interfering RNA suppressed Cdc42 activation and fMLF/IL-8-induced migration. miR-155, but not miR-34a, decreased Rac1 protein, and introduction of Rac1 small interfering RNA attenuated Rac1 activation and migration. Neutrophils from patients showed significant attenuation in migration compared with healthy cells, and protein levels of DOCK8, FGD4, and Rac1 were well correlated with migration toward fMLF (r = 0.642, 0.686, and 0.436, respectively) and IL-8 (r = 0.778, 0.659, and 0.606, respectively). Our results indicated that reduction of DOCK8, FGD4, and Rac1 contributes to impaired neutrophil migration in MDS.
Assuntos
Quimiotaxia de Leucócito , MicroRNAs/imunologia , Síndromes Mielodisplásicas/imunologia , Ativação de Neutrófilo , Neutrófilos/fisiologia , Idoso , Idoso de 80 Anos ou mais , Proliferação de Células , Quimiotaxia/imunologia , Feminino , Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/imunologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Células HL-60 , Humanos , Interleucina-8/imunologia , Masculino , MicroRNAs/genética , MicroRNAs/fisiologia , Proteínas dos Microfilamentos/deficiência , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Pessoa de Meia-Idade , Neutrófilos/imunologia , RNA Interferente Pequeno , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/imunologia , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/imunologiaRESUMO
High-mobility group AT-hook 2 (HMGA2) is crucial for the self-renewal of fetal hematopoietic stem cells (HSCs) but is downregulated in adult HSCs via repression by MIRlet-7 and the polycomb-recessive complex 2 (PRC2) including EZH2. The HMGA2 messenger RNA (mRNA) level is often elevated in patients with myelofibrosis that exhibits an advanced myeloproliferative neoplasm (MPN) subtype, and deletion of Ezh2 promotes the progression of severe myelofibrosis in JAK2V617F mice with upregulation of several oncogenes such as Hmga2. However, the direct role of HMGA2 in the pathogenesis of MPNs remains unknown. To clarify the impact of HMGA2 on MPNs carrying the driver mutation, we generated ΔHmga2/JAK2V617F mice overexpressing Hmga2 due to deletion of the 3' untranslated region. Compared with JAK2V617F mice, ΔHmga2/JAK2V617F mice exhibited more severe leukocytosis, anemia and splenomegaly, and shortened survival, whereas severity of myelofibrosis was comparable. ΔHmga2/JAK2V617F cells showed a greater repopulating ability that reproduced the severe MPN compared with JAK2V617F cells in serial bone marrow transplants, indicating that Hmga2 promotes MPN progression at the HSC level. Hmga2 also enhanced apoptosis of JAK2V617F erythroblasts that may worsen anemia. Relative to JAK2V617F hematopoietic stem and progenitor cells (HSPCs), over 30% of genes upregulated in ΔHmga2/JAK2V617F HSPCs overlapped with those derepressed by Ezh2 loss in JAK2V617F/Ezh2Δ/Δ HSPCs, suggesting that Hmga2 may facilitate upregulation of Ezh2 targets. Correspondingly, deletion of Hmga2 ameliorated anemia and splenomegaly in JAK2V617F/Ezh2Δ/wild-type mice, and MIRlet-7 suppression and PRC2 mutations correlated with the elevated HMGA2 mRNA levels in patients with MPNs, especially myelofibrosis. These findings suggest the crucial role of HMGA2 in MPN progression.
RESUMO
BACKGROUND: Pediatric apheresis for peripheral blood stem cell transplantation should be carried out with due concern for low corporeal blood volume and vulnerability to hypocalcemia-related complications, hypovolemic shock, and hypervolemic cardiac overload. STUDY DESIGN AND METHODS: We retrospectively investigated a total of 267 apheresis procedures from 1990 to 2013 on 93 children between 0 and 10 years old, including 89 patients and 4 healthy donors, with body weights of 6.3 to 44.0 kg. RESULTS: The median CD34+ cell yield per apheresis procedure was 2.3 × 106 CD34+ cells/kg (0.2-77.9 × 106 CD34+ cells/kg). Adverse events occurred in 11.6% of procedures (n = 31), including mild perivascular pain (n = 12), emesis (n = 9), hypotension (n = 3), urticaria (n = 2), numbness (n = 2), chest pain (n = 1), facial flush (n = 1), and abdominal pain (n = 1). Among hypotensive events, shock in a 9.6 kg one-year-old boy required emergency treatment in 1996. Thereafter, we adopted continuous injection of calcium gluconate, ionized calcium monitoring, central venous catheter access and circuit priming with albumin in addition to concentrated red cells. Since then we have had fewer complications: 16.4% per apheresis during 1990-1997 versus 5.8% during 1998-2013. No healthy pediatric donors suffered from any late-onset complications related to apheresis or G-CSF administration. CONCLUSION: By employing appropriate measures, peripheral blood stem cell apheresis for small children can have an improved safety profile, even for children weighing <10 kg.
Assuntos
Remoção de Componentes Sanguíneos/métodos , Mobilização de Células-Tronco Hematopoéticas/métodos , Assistência ao Paciente/métodos , Células-Tronco de Sangue Periférico/citologia , Antígenos CD34/metabolismo , Remoção de Componentes Sanguíneos/efeitos adversos , Doadores de Sangue , Pressão Sanguínea , Peso Corporal/efeitos dos fármacos , Cálcio/administração & dosagem , Cálcio/farmacologia , Criança , Pré-Escolar , Suplementos Nutricionais , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Dor/etiologia , Células-Tronco de Sangue Periférico/efeitos dos fármacosRESUMO
Although increased TNF-α has been considered to cause ineffective hematopoiesis in myelodysplastic syndromes (MDS), the mechanisms of TNF-α elevation are not known. We recently found that c-Fos mRNA stabilization under translation-inhibiting stimuli was impaired in MDS-derived neutrophilic granulocytes. In the current study, we identified overexpression of c-Fos-targeting miR-34a and miR-155 as the cause of impairment. Expression levels of miR-34a but not miR-155 inversely correlated with ratios of c-Fos-positive cells in MDS-derived CD16+ neutrophils (r = -0.618, P<0.05), which were analyzed by flow cytometry. Among the seventeen patients, c-Fos was detectable in less than 60% of CD16+ cells in eight patients (Group A), while five (Group B) expressed c-Fos in more than 80% of CD16+ cells, which was consistent with the controls (88.6 ± 7.8%). Group A-derived granulocytes secreted more TNF-α in response to 1 µM LPS for 3 hours (735.4 ± 237.5 pg/mL) than Group B (143.5 ± 65.7 pg/mL, P<0.05) and healthy controls (150.8 ± 91.5 pg/mL, P<0.05). Knockdown of c-Fos in neutrophil-like differentiated HL60 increased the binding of NF-κB p65 to the promoter region of TNF-α DNA. Thus, c-Fos reduction via overexpression of miR-34a contributes to TNF-α overproduction under inflammatory stimuli in MDS.
Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , MicroRNAs/genética , Síndromes Mielodisplásicas/metabolismo , Proteínas Proto-Oncogênicas c-fos/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Diferenciação Celular/efeitos dos fármacos , Feminino , Granulócitos/efeitos dos fármacos , Granulócitos/metabolismo , Granulócitos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/imunologia , NF-kappa B/genética , NF-kappa B/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Neutrófilos/patologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
We applied our new method, maturity-dependent fractionation of bone marrow-derived neutrophil progenitors, to a study of gene expression profiles during granulopoiesis in myelodysplastic syndromes. CD34+ cells with low density [F1], CD11b-/CD16- [F2], CD11b+/CD16- [F3] and CD11b+/CD16low [F4] with intermediate density, CD11b+/CD16int [F5] and CD11b+/CD16high [F6] with high density were isolated from six patients. Although AML1 and C/EBP-ϵ mRNA peaked at F1 and F4, respectively, in healthy individuals, C/EBP-ϵ was maximized at F2/F3 in all patients, two of whom showed simultaneous peaks of AML1 at F2. Thus, this fractionation is useful to detect mistimed induction of granulopoiesis-regulating genes in myelodysplastic syndromes.
RESUMO
We previously reported a case of pulmonary hypertension, where the symptoms were improved by oral L-arginine (arginine) administration. Arginine may increase nitric oxide (NO) production in the pulmonary artery. Exhaled NO may reflect pulmonary artery NO production. It has been demonstrated that exhaled NO concentration is higher in patients with allergic diseases, but whether oral arginine administration alters exhaled NO is unknown. Therefore, in this study, we investigated whether oral arginine administration increases exhaled NO among healthy volunteers with and without a history of allergy. Eleven subjects were given a single oral dose (200 mg/kg) of arginine, and their plasma arginine concentrations and exhaled NO were measured up to 150 minutes. Baseline values of exhaled NO concentration were significantly higher in those with a history of allergy (56.4±20.3 ppb, n=5, P< 0.05) than those without (16.8±4.0 ppb, n=6). Oral arginine increased exhaled NO, which peaked at 60 minutes after the administration in those with a history of allergy (85.2±44.8 ppb, n=5). However, the increase in exhaled NO was not significant compared to the baseline values. In contrast, plasma arginine concentration was increased significantly by arginine administration (P< 0.01), regardless of an allergy history. These results suggested that the difference in exhaled NO concentration was not due to a difference in arginine absorption. Serum IgE level was significantly higher in the group with a history of allergy. Eosinophils and white blood cells were within normal range in all subjects. We conclude that oral arginine administration does not significantly increase exhaled NO, regardless of allergy history. However, as arginine administration has been reported to be effective in patients with pulmonary hypertension, it will be necessary to test exhaled NO in subjects with pulmonary hypertension in the future.
Assuntos
Arginina/farmacologia , Testes Respiratórios , Óxido Nítrico/biossíntese , Administração Oral , Adulto , Arginina/sangue , Arginina/uso terapêutico , Humanos , Hipertensão Pulmonar/tratamento farmacológico , Imunoglobulina E/sangue , Pessoa de Meia-Idade , Óxido Nítrico/análiseRESUMO
To evaluate effects of itraconazole, rifampicin and grapefruit juice on pharmacokinetics and pharmacodynamics of a hydrophilic non-selective ß-adrenoceptor blocker nadolol, we conducted an open-label, four-way crossover study in 10 healthy male volunteers. A single oral dose of 30 mg nadolol was administered with water (control), itraconazole (100 mg), or grapefruit juice (300 mL), or after a 6-day pretreatment with rifampicin (450 mg/day). Plasma concentrations and urinary excretions of nadolol were measured over 48 hours after its dosing. Systolic and diastolic blood pressures and pulse rate were periodically recorded after nadolol administration as pharmacodynamic parameters. Itraconazole increased the peak plasma concentration and the area under the plasma concentration-time curve (AUC0-∞ ) of nadolol by 468% and 224% of control, respectively (P < .001). A slight, but not statistically significant, decrease in AUC0-∞ of nadolol was observed in rifampicin and grapefruit juice phases as compared to control. Elimination half-life for nadolol did not differ among the four phases. During itraconazole phase, nadolol reduced pharmacodynamic parameters to a greater extent than the other phases. These results suggest that itraconazole substantially increases the oral availability of nadolol possibly by the inhibition of intestinal P-glycoprotein, whereas grapefruit juice has little effect on nadolol pharmacokinetics.
Assuntos
Bebidas/efeitos adversos , Citrus paradisi , Itraconazol/farmacologia , Nadolol/farmacologia , Nadolol/farmacocinética , Rifampina/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Administração Oral , Antagonistas Adrenérgicos beta/farmacocinética , Antagonistas Adrenérgicos beta/uso terapêutico , Adulto , Área Sob a Curva , Pressão Sanguínea/efeitos dos fármacos , Estudos Cross-Over , Interações Medicamentosas , Interações Alimento-Droga , Meia-Vida , Frequência Cardíaca/efeitos dos fármacos , Humanos , Itraconazol/farmacocinética , Masculino , Rifampina/farmacocinética , Adulto JovemRESUMO
Although quantitative and qualitative granulocyte defects have been described in myelodysplastic syndromes (MDS), the underlying molecular basis of granulocyte dysfunction in MDS is largely unknown. We recently found that FOS mRNA elevation under translation-inhibiting stimuli was significantly smaller in granulocytes from MDS patients than in healthy individuals. The aim of this study is to clarify the cause of the impaired FOS induction in MDS. We first examined the mechanisms of FOS mRNA elevation using granulocytes from healthy donors cultured with the translation inhibitor emetine. Emetine increased both transcription and mRNA stability of FOS. p38 MAPK inhibition abolished the emetine-induced increase of FOS transcription but did not affect FOS mRNA stabilization. The binding of an AU-rich element (ARE)-binding protein HuR to FOS mRNA containing an ARE in 3'UTR was increased by emetine, and the knockdown of HuR reduced the FOS mRNA stabilizing effect of emetine. We next compared the emetine-induced transcription and mRNA stabilization of FOS between MDS patients and healthy controls. Increased rates of FOS transcription by emetine were similar in MDS and controls. In the absence of emetine, FOS mRNA decayed to nearly 17% of initial levels in 45 min in both groups. In the presence of emetine, however, 76.7±19.8% of FOS mRNA remained after 45 min in healthy controls, versus 37.9±25.5% in MDS (P<0.01). To our knowledge, this is the first report demonstrating attenuation of stress-induced FOS mRNA stabilization in MDS granulocytes.