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1.
Mol Pharm ; 16(6): 2364-2375, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31018096

RESUMO

This study focused on formulating conjugate vaccines targeting oxycodone and heroin for technology transfer, good manufacturing practice (GMP), and clinical evaluation. Lead vaccines used the highly immunogenic carrier protein keyhole limpet hemocyanin (KLH), which poses formulation problems because of its size. To address this barrier to translation, an oxycodone-based hapten conjugated to GMP-grade subunit KLH (OXY-sKLH) and adsorbed on alum adjuvant was studied with regard to carbodiimide coupling reaction time, buffer composition, purification methods for conjugates, conjugate size, state of aggregation, and protein/alum ratio. Vaccine formulations were screened for post-immunization antibody levels and efficacy in reducing oxycodone distribution to the brain in rats. While larger conjugates were more immunogenic, their size prevented characterization of the haptenation ratio by standard analytical methods and sterilization by filtration. To address this issue, conjugation chemistry and vaccine formulation were optimized for maximal efficacy, and conjugate size was measured by dynamic light scattering prior to adsorption to alum. An analogous heroin vaccine (M-sKLH) was also optimized for conjugation chemistry, formulated in alum, and characterized for potency against heroin in rats. Finally, this study found that the efficacy of OXY-sKLH was preserved when co-administered with M-sKLH, supporting the proof of concept for a bivalent vaccine formulation targeting both heroin and oxycodone. This study suggests methods for addressing the unique formulation and characterization challenges posed by conjugating small molecules to sKLH while preserving vaccine efficacy.


Assuntos
Transtornos Relacionados ao Uso de Opioides/prevenção & controle , Vacinas Conjugadas/química , Animais , Hemocianinas/metabolismo , Heroína/toxicidade , Humanos , Oxicodona/toxicidade , Ratos , Vacinas/química , Vacinas/uso terapêutico , Vacinas Conjugadas/uso terapêutico
2.
J Prev Alzheimers Dis ; 11(2): 285-293, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38374734

RESUMO

BACKGROUND: Alzheimer's disease (AD) biomarker tests can be ordered as part of the diagnostic workup of patients with mild cognitive impairment (MCI). Little is known about how patients with MCI and their care partners decide whether to pursue testing. OBJECTIVE: To examine factors that influence AD biomarker testing decisions among patients with MCI and their care partners. DESIGN: We performed structured research interviews with patients with MCI and their study partners to assess the importance of eight factors in the decision whether to undergo AD biomarker testing (6-point Likert scale; 1-extremely unimportant to 6-extremely important): cost, fear of testing procedures, learning if AD is the cause of cognitive problems, concern about health insurance, instructing future planning, informing treatment decisions, family members' opinions, and doctor recommendation. SETTING: Two researchers administered interviews with participants in-person (i.e., participant home, research center) or remotely (i.e., telephone, video-conference). PARTICIPANTS: We completed interviews with 65 patients with a diagnosis of MCI and 57 study partners, referred by dementia specialist clinicians from the University of California, Irvine health system. MEASUREMENTS: We used generalized estimating equations (GEE) to examine the mean importance of each factor among patients and study partners, and the mean difference in importance of each factor within dyads. RESULTS: One third of participants reported the patient had previously undergone AD biomarker testing. Fifty-five percent of patients and 65% of study partners who reported no previous testing indicated a desire for the patient to be tested. GEE analyses found that patients and study partners rated the following factors with highest importance: informing treatment decisions (mean score 5.29, 95% CI: 5.06, 5.52 for patients; mean score 5.56, 95% CI: 5.41, 5.72 for partners); doctor recommendation (4.94, 95% CI: 4.73, 5.15 for patients; 5.16, 95% CI: 4.97, 5.34 for partners); and instructing future planning (4.88, 95% CI: 4.59, 5.16 for patients; 5.11, 95% CI: 4.86, 5.35 for partners). High dyadic agreement was observed for all factors except fear of testing, which patients rated with lower importance than their study partners. CONCLUSIONS: Biomarker testing for AD in patients with MCI is a rapidly evolving practice and limited data exist on patient perspectives. In this study, most patients and their care partners were interested in testing to help inform treatment decisions and to plan for the future. Participants placed high importance on clinician recommendations for biomarker testing, highlighting the need for clear communication and education on the options, limitations, risks, and benefits of testing.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/psicologia , Cuidadores , Progressão da Doença , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Biomarcadores
3.
J Pharmacol Exp Ther ; 344(2): 397-406, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23220743

RESUMO

Morphine conjugate vaccines have effectively reduced behavioral effects of heroin in rodents and primates. To better understand how these effects are mediated, heroin and metabolite distribution studies were performed in rats in the presence and absence of vaccination. In non-vaccinated rats 6-monoacetylmorphine (6-MAM) was the predominant opioid in plasma and brain as early as 1 minute after i.v. administration of heroin and for up to 14 minutes. Vaccination with morphine conjugated to keyhole limpet hemocyanin (M-KLH) elicited high titers and concentrations of antibodies with high affinity for heroin, 6-MAM, and morphine. Four minutes after heroin administration vaccinated rats showed substantial retention of all three opioids in plasma compared to controls and reduced 6-MAM and morphine, but not heroin, distribution to brain. Administration of 6-MAM rather than heroin in M-KLH vaccinated rats showed a similar drug distribution pattern. Vaccination reduced heroin-induced analgesia and blocked heroin-induced locomotor activity throughout 2 weeks of repeated testing. Higher serum opioid-specific antibody concentrations were associated with higher plasma opioid concentrations, lower brain 6-MAM and morphine concentrations, and lower heroin-induced locomotor activity. Serum antibody concentrations over 0.2 mg/ml were associated with substantial effects on these measures. These data support a critical role for 6-MAM in mediating the early effects of i.v. heroin and suggest that reducing 6-MAM concentration in brain is essential to the efficacy of morphine conjugate vaccines.


Assuntos
Comportamento Animal/efeitos dos fármacos , Heroína , Morfina/imunologia , Vacinas Conjugadas/imunologia , Adjuvantes Imunológicos , Animais , Anticorpos/sangue , Ligação Competitiva , Encéfalo/metabolismo , Relação Dose-Resposta Imunológica , Ensaio de Imunoadsorção Enzimática , Hemocianinas/imunologia , Heroína/efeitos adversos , Heroína/imunologia , Heroína/farmacocinética , Injeções Intravenosas , Masculino , Morfina/sangue , Morfina/farmacocinética , Derivados da Morfina/sangue , Derivados da Morfina/imunologia , Derivados da Morfina/metabolismo , Atividade Motora/efeitos dos fármacos , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Distribuição Tecidual , Vacinas Conjugadas/administração & dosagem
4.
J Prev Alzheimers Dis ; 10(3): 471-477, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37357287

RESUMO

BACKGROUND: Cohort effects in study populations can impact clinical trial conclusions and generalizability, particularly in trials with planned interim analyses. Long recruitment windows may exacerbate these risks in Alzheimer's disease (AD) trials. OBJECTIVES: To investigate the presence of cohort effects mild-to-moderate AD trials. DESIGN: Retrospective analysis using pooled participant-level data from nine randomized, placebo-controlled trials conducted by the Alzheimer's Disease Cooperative Study (ADCS). SETTING: Trials were multicenter studies conducted by an academic trial network. PARTICIPANTS: The trials enrolled participants with mild, mild-to-moderate, or moderate AD who were over age 50 and had mini mental state exam scores between 12 and 26. Interventions/Exposure: We defined a participant's site-standardized enrollment time as the number of days between their screening date and the first screening date among randomized participants at their site within their study. MAIN OUTCOME(S) AND MEASURE(S): Our primary outcome was the 12-month change in the AD assessment scale - cognitive subscale (ADAS-Cog). Secondary outcomes were participant demographics and time to study discontinuation. RESULTS: The pooled sample consisted of N=2,754 at baseline with N=2,191 participants completing a 12-month visit. We found no meaningful differences in the distributions of sex, race and ethnicity, age, years of education or baseline ADAS-Cog score across enrollment time. We found a significant association between enrollment time and 12-month change in ADAS-Cog, with participants enrolling 100 days later tending to experience an increase on the ADAS-Cog of 0.16 points greater (reflecting greater cognitive decline; 95% CI: (0.021, 0.294), p = 0.02), after controlling for potential confounding factors. CONCLUSION: We found minimal evidence of clinically relevant cohort effects in ADCS trials. Our results reinforce the original findings of these trials.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Pessoa de Meia-Idade , Doença de Alzheimer/diagnóstico , Estudos Retrospectivos , Efeito de Coortes , Disfunção Cognitiva/diagnóstico , Projetos de Pesquisa
5.
Epilepsy Behav ; 24(3): 365-72, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22658432

RESUMO

This is the first study of the effect of topiramate on linguistic behavior and verbal recall using a computational linguistics system for automated language and speech analysis to detect and quantify drug-induced changes in speech recorded during discourse-level tasks. Healthy volunteers were administered a single, 100-mg oral dose of topiramate in two double-blind, randomized, placebo-controlled, crossover studies. Subjects' topiramate plasma levels ranged from 0.23 to 2.81 µg/mL. We found a significant association between topiramate levels and impairment on measures of verbal fluency elicited during a picture description task, correct number of words recalled on a paragraph recall test, and reaction time recorded during a working memory task. Using the tools of clinical pharmacology and computational linguistics, we elucidated the relationship between the determinants of a drug's disposition as reflected in plasma concentrations and their impact on cognitive functioning as reflected in spoken language discourse.


Assuntos
Frutose/análogos & derivados , Memória de Curto Prazo/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Fala/efeitos dos fármacos , Aprendizagem Verbal/efeitos dos fármacos , Adolescente , Adulto , Estudos Cross-Over , Método Duplo-Cego , Feminino , Frutose/sangue , Frutose/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Tempo de Reação/efeitos dos fármacos , Topiramato
6.
J Biomed Inform ; 45(5): 862-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22564551

RESUMO

The main objective of this study was to investigate the feasibility of using PharmGKB, a pharmacogenomic database, as a source of training data in combination with text of MEDLINE abstracts for a text mining approach to identification of potential gene targets for pathway-driven pharmacogenomics research. We used the manually curated relations between drugs and genes in PharmGKB database to train a support vector machine predictive model and applied this model prospectively to MEDLINE abstracts. The gene targets suggested by this approach were subsequently manually reviewed. Our quantitative analysis showed that a support vector machine classifiers trained on MEDLINE abstracts with single words (unigrams) used as features and PharmGKB relations used for supervision, achieve an overall sensitivity of 85% and specificity of 69%. The subsequent qualitative analysis showed that gene targets "suggested" by the automatic classifier were not anticipated by expert reviewers but were subsequently found to be relevant to the three drugs that were investigated: carbamazepine, lamivudine and zidovudine. Our results show that this approach is not only feasible but may also find new gene targets not identifiable by other methods thus making it a valuable tool for pathway-driven pharmacogenomics research.


Assuntos
Biologia Computacional/métodos , Mineração de Dados/métodos , Bases de Dados Genéticas , Bases de Conhecimento , Farmacogenética/métodos , Descoberta de Drogas , Genes , Humanos , MEDLINE , Máquina de Vetores de Suporte
7.
J Am Coll Health ; : 1-9, 2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35348421

RESUMO

Objective: To assess perceptions of university institutional climate related to sexual violence and whether these differed by race/ethnicity. Participants: Matriculated undergraduates > age 18 (n = 1028). Methods: Students were invited via campus email to participate in an online survey. Results: Overall, only 20% agreed that the university is creating an environment in which unwanted sexual experiences seemed common or normal, but these findings differed by race. Black students were more likely than their white peers to feel the university is creating an environment in which unwanted sexual experiences seem common or normal (37.3% vs. 19.7%, p < .001) and creating an environment in which such instances were more likely to occur (33.3% vs. 13.4%, p < .001). Conclusions: Data suggest that while students generally perceive that the university is working to create a positive and safe climate, these perceptions vary by race. Further investigation is necessary to better understand the concerns of students of color.

8.
Epilepsy Res ; 68 Suppl 1: S49-63, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16207524

RESUMO

In this article, epidemiological and clinical aspects related to the use of antiepileptic drugs (AEDs) in the elderly are highlighted. Studies have shown that people with epilepsy receiving AED treatment show important deficits in physical and social functioning compared with age-matched people without epilepsy. To what extent these deficits can be ascribed to epilepsy per se or to the consequences of AED treatment remains to be clarified. The importance of characterizing the effects of AEDs in an elderly population is highlighted by epidemiological surveys indicating that the prevalence of AED use is increased in elderly people, particularly in those living in nursing homes. Both the pharmacokinetics and the pharmacodynamics of AEDs may be altered in old age, which may contribute to the observation that AEDs are among the drug classes most commonly implicated as causing adverse drug reactions in an aged population. Age alone is one of several contributors to alterations in AED response in the elderly; other factors include physical frailty, co-morbidities, dietary influences, and drug interactions. Individualization of dosage, avoidance of unnecessary polypharmacy, and careful observation of clinical response are essential for an effective and safe utilization of AEDs in an elderly population.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Veteranos/estatística & dados numéricos , Idoso , Envelhecimento/fisiologia , Anticonvulsivantes/farmacocinética , Anticonvulsivantes/farmacologia , Instituição de Longa Permanência para Idosos , Humanos , Casas de Saúde , Fenitoína/farmacocinética , Polimedicação
9.
Genetics ; 72(4): 739-58, 1972 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-4652881

RESUMO

A random phenotype is defined as a probability distribution over any given set of phenotypes. This includes as special cases the kinds of phenotypes usually considered (qualitative, quantitative, and threshold characters) and all others. Correspondingly general methods are indicated for analyzing data of all forms in terms of the classical Mendelian factor concept (as distinct from the biometrical methods usually applied to measurement and graded data, associated with the effective factor concept). These are applied in a new analysis of the data of E. L. Green (1951, 1954, 1962) on skeletal variation in the mouse. The adequacies of various classical one-factor and several-factor models are considered. Indications of an underlying scale are found from this new standpoint. The results are compared with those obtained by Green using the scaling approach. An illustrative application is also made to some of Bruell's (1962) continuous behavioural data on mice. This work was substantially completed in 1959 but not previously prepared for publication. The same approach was originated and developed independently by R. L. Collins who has treated a wider range of theoretical problems (cf. Collins 1967, 1968a, 1969b, 1970c) and a wider range of applications (cf. Collins and Fuller 1968; Collins 1968b, 1969a, 1970a). A less general independent development is that of Mode and Gasser 1972.


Assuntos
Genética Populacional , Fenótipo , Probabilidade , Animais , Análise Fatorial , Variação Genética , Camundongos , Modelos Biológicos
10.
Free Radic Biol Med ; 14(6): 643-7, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8325536

RESUMO

UNLABELLED: Pentane, a product of lipid peroxidation, has been detected in situations involving ischemic injury. Such injury may be limited if lipid peroxidation can be controlled by antioxidants. The role of lipid peroxidation in chronic heart failure (CHF) was assessed by measuring breath pentane in patients with CHF vs. age matched controls. The effect of a free radical scavenger on pentane released during CHF was also measured. Pentane levels were correlated with the daily dose of captopril, a sulfhydril-containing drug used to treat CHF, which is an angiotensin converting enzyme inhibitor. To separate the scavenging effects of captopril from the pharmacologic effects of converting enzyme inhibitors, a crossover study using a nonsulfhydril inhibitor was used. Patients with CHF excreted (p < 0.005) high concentrations of pentane (5.7 +/- 2.1 vs. control 3.6 +/- 1.2 nmol/l). Patients treated with captopril also had significantly higher (p < 0.05) excretion of pentane than the control patients (4.7 +/- 1.3 vs. 3.6 +/- 1.2 nmol/l). The dose of captopril was inversely proportional to the concentration of pentane excreted (r = 0.55, p < 0.05). Pentane excretion during captopril therapy was significantly lower before (p < 0.01) and after (p < 0.02) nonsulfhydril inhibitor therapy. CONCLUSION: breath pentane is elevated in CHF and it can be reduced by a free radical scavenger. This reduction of pentane excretion is not a converting enzyme inhibitor class effect.


Assuntos
Insuficiência Cardíaca/metabolismo , Pentanos/metabolismo , Idoso , Captopril/uso terapêutico , Enalapril/uso terapêutico , Feminino , Sequestradores de Radicais Livres , Radicais Livres/metabolismo , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo , Respiração
11.
Transplantation ; 69(4): 675-6, 2000 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-10708131

RESUMO

BACKGROUND: Sickle cell intrahepatic cholestasis is a potentially catastrophic complication of sickle cell anemia Once acute liver failure develops, transplantation is the only option. We describe a patient with sickle cell intrahepatic cholestasis who underwent liver transplantation. METHODS: Data were obtained from the chart. Serial hemoglobin S levels were monitored, and measures were taken to maintain hemoglobin S <20% to prevent sickle cell crisis. RESULTS: Although the allograft functioned well initially, the patient developed veno-occlusive disease and required repeat transplantation at 5 months after transplant. Histologic examination of the explant revealed occlusion of the terminal hepatic venules due to fibrosis and packed red cells. Repeat transplant was complicated by thrombosis of the intrahepatic portion of the hepatic artery, and sepsis. The patient died of sepsis after a third transplant. CONCLUSION: Liver transplantation for sickle cell disease involving the liver may carry a high risk of graft loss due to vascular problems. Repeat transplantation may not be feasible if disease recurs.


Assuntos
Anemia Falciforme/complicações , Colestase Intra-Hepática/complicações , Falência Hepática/cirurgia , Transplante de Fígado , Biópsia , Criança , Humanos , Fígado/patologia , Falência Hepática/etiologia , Transplante de Fígado/patologia , Masculino
12.
Transplantation ; 67(3): 416-8, 1999 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10030288

RESUMO

Alagille's syndrome is a common cause of liver disease in children and may lead to the need for orthotopic liver transplantation. Alagille's syndrome is inherited in an autosomal dominant manner, with variable penetration, and may also be present in patients' parents, who may be considered potential donors for living-related transplantation. We report here on two cases in which the living-related donors for children with Alagille's syndrome had no liver function abnormalities or characteristic features of Alagille's syndrome. In both cases, the operation for living-related donation had to be aborted because of a paucity of bile ducts discovered intraoperatively. Given the variable presentation of Alagille's syndrome, we believe that it is necessary preoperatively to evaluate the biliary system of family members who are potential living-related donors for patients with this condition.


Assuntos
Síndrome de Alagille/cirurgia , Ductos Biliares/anormalidades , Transplante de Fígado , Fígado/anatomia & histologia , Doadores Vivos , Adulto , Feminino , Humanos , Lactente , Mães
13.
Brain Res Mol Brain Res ; 28(1): 72-80, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7707880

RESUMO

We functionally expressed alpha 2-adrenergic, beta 2-adrenergic, and delta-opioid receptors in Xenopus laevis oocytes. We detected receptor function as changes in currents carried by adenosine 3',5'-cyclic monophosphate (cAMP)-regulated chloride channels provided by the cystic fibrosis transmembrane conductance regulator (CFTR) and recorded by two-electrode voltage clamp. Co-application of forskolin and isobutylmethylxanthine (IBMX) or IBMX alone produced currents with a reversal potential indicative of chloride ions only in oocytes previously injected with mRNA encoding CFTR. Isoproterenol produced concentration-dependent responses in oocytes injected with mRNA encoding beta 2-adrenergic receptors and CFTR, and co-administration of propranolol antagonized these responses. Similarly, the alpha 2-adrenergic agonist UK14304 increased IBMX-induced currents only in oocytes injected with mRNA encoding alpha 2-adrenergic receptors and CFTR, and idazoxan antagonized these enhancements. The delta-opioid agonist DADLE produced concentration-related, naloxone-reversible increases in IBMX- and forskolin-induced currents only in oocytes injected with mRNA encoding delta-opioid receptors and CFTR. In oocytes co-injected with alpha 2, beta 2, and CFTR mRNAs, isobolographic analysis revealed an additive interaction between alpha 2- and beta 2-adrenergic receptors. These studies establish the oocyte as a cell system for studying the interactions among cAMP-modulating G protein-coupled receptors and provide another example of alternative coupling of alpha 2-adrenergic and delta-opioid receptors to G proteins, possibly Gs proteins, other than Gi proteins.


Assuntos
Isoproterenol/farmacologia , Naloxona/farmacologia , Propranolol/farmacologia , Receptores Adrenérgicos alfa 2/fisiologia , Receptores Adrenérgicos beta 2/fisiologia , Adenilil Ciclases , Animais , Tartarato de Brimonidina , AMP Cíclico , Proteínas Quinases Dependentes de AMP Cíclico , Fibrose Cística , Relação Dose-Resposta a Droga , Modelos Biológicos , Oócitos , Quinoxalinas/farmacologia , RNA Mensageiro , Receptores Opioides , Xenopus laevis
14.
Brain Res Mol Brain Res ; 44(1): 55-65, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9030698

RESUMO

The objective of this study was to characterize the signaling mechanisms of the mu-opioid receptor in its coupling to the cystic fibrosis transmembrane conductance regulator (CFTR) when coexpressed in Xenopus oocytes. Because oocytes do not contain endogenous cAMP-regulated ion channels, the cAMP-modulated CFTR was coexpressed with receptors as a 'reporter' channel. Agonist treatment of oocytes coexpressing mu-opioid receptors, beta2-adrenergic receptors and CFTR produced Cl- currents in a dose-related manner and immunocytochemical analysis confirmed receptor expression. These data suggest that opioid agonists could activate adenylyl cyclase in this system to elevate cAMP levels. Heterotrimeric G protein betagamma-subunits acting on adenylyl cyclase type II would increase cAMP levels. The probable presence of adenylyl cyclase type II and other components of opioid signal transduction such as G(i alpha2), were demonstrated by RT-PCR. However, measurement of cAMP levels in individual oocytes by radioimmunoassay showed that opioid agonist application to oocytes expressing mu-opioid receptors, beta2-adrenergic receptors and CFTR did not increase cAMP levels, whereas application of the beta2-adrenergic agonist, isoproterenol, or IBMX alone did increase cAMP levels. Opioid-induced CFTR activation was not affected by either application of the broad spectrum kinase inhibitor, H7, nor by application of the specific PKA inhibitor, KT5720. Injection of free betagamma-subunits, which could activate the endogenous type II cyclase, was unable to produce measurable currents in oocytes expressing the CFTR. These studies indicate that opioid activation of the CFTR is not mediated through a cAMP/PKA pathway, by either betagamma-subunit activation of an adenylyl cyclase type II or promiscuous coupling to G(s alpha).


Assuntos
AMP Cíclico/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Receptores Opioides mu/efeitos dos fármacos , Sequência de Aminoácidos , Analgésicos/farmacologia , Animais , Relação Dose-Resposta a Droga , Ala(2)-MePhe(4)-Gly(5)-Encefalina , Encefalinas/farmacologia , Imuno-Histoquímica , Isoproterenol/farmacologia , Dados de Sequência Molecular , Oócitos/metabolismo , Xenopus
15.
Cancer Chemother Pharmacol ; 49(6): 461-7, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12107550

RESUMO

PURPOSE: To establish the cytochrome P450 (CYP) isozymes involved in the metabolism of the alkylating agent, thiotepa, to the pharmacologically active metabolite, TEPA. METHODS: In vitro chemical inhibition studies were conducted by incubating thiotepa and pooled human hepatic microsomes in the presence of known inhibitors to CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4. Studies were also performed with cloned, expressed CYP3A4, CYP2A6, CYP2E1 and CYP2B6 microsomes, and anti-CYP2B6 monoclonal antibody. RESULTS: Known CYP3A4 inhibitors reduced TEPA production. Inhibition with CYP2E1 inhibitors was inconsistent. All other inhibitors produced little or no change in TEPA formation. Cloned, expressed CYP2B6 and CYP3A4 microsomes catalyzed TEPA formation, whereas CYP2A6 and CYP2E1 did not. Incubation of thiotepa with anti-CYP2B6 antibody and cloned, expressed CYP2B6 microsomes resulted in reductions in the formation of TEPA, but no change in TEPA formation occurred in human liver microsomes. CONCLUSIONS: Thiotepa is metabolized in human liver microsomes by CYP3A4 (major) and CYP2B6 (minor). There is a potential for CYP-mediated drug interactions with thiotepa. Pharmacokinetic variability of thiotepa may be related to expression of hepatic CYP isozymes.


Assuntos
Antineoplásicos Alquilantes/metabolismo , Hidrocarboneto de Aril Hidroxilases , Sistema Enzimático do Citocromo P-450/metabolismo , Microssomos Hepáticos/enzimologia , Oxigenases de Função Mista/metabolismo , Oxirredutases N-Desmetilantes/metabolismo , Tiotepa/metabolismo , Trietilenofosforamida/metabolismo , Anticorpos/farmacologia , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP3A , Inibidores das Enzimas do Citocromo P-450 , Inibidores Enzimáticos/farmacologia , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Cinética , Microssomos Hepáticos/efeitos dos fármacos , Oxigenases de Função Mista/antagonistas & inibidores , Oxirredutases N-Desmetilantes/antagonistas & inibidores , Tiotepa/antagonistas & inibidores , Transfecção
16.
Pharmacotherapy ; 21(2): 158-62, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11213851

RESUMO

STUDY OBJECTIVE: To determine the relative bioavailability of lamotrigine (LTG) chewable dispersible tablets after rectal administration. DESIGN: Two-period, crossover study with a 2-week washout between dosing periods. SETTING: Clinical research center. PATIENTS: Twelve healthy adult volunteers. INTERVENTION: One hundred milligrams of a LTG chewable dispersible tablet was administered by oral and rectal routes. MEASUREMENTS AND MAIN RESULTS: Plasma samples were collected before and up to 120 hours after drug administration. The samples were analyzed for LTG by high-performance liquid chromatography, and the relative bioavailability was determined. Drug concentrations were lower after rectal than after oral administration. The relative bioavailability (F = AUC(rectal)/AUC(oral)) was 0.52 +/- 0.23 (SD). CONCLUSION: Drug prepared from LTG chewable dispersible tablets is absorbed rectally, although not to the same extent as when given orally. Rectal administration of suspension of these tablets can be an acceptable route of administration.


Assuntos
Anticonvulsivantes/farmacocinética , Triazinas/farmacocinética , Administração Retal , Adulto , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/sangue , Disponibilidade Biológica , Estudos Cross-Over , Feminino , Humanos , Lamotrigina , Masculino , Triazinas/administração & dosagem , Triazinas/sangue
17.
Epilepsy Res ; 44(1): 71-82, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11255075

RESUMO

Several case reports have indicated that the selective serotonin re-uptake inhibitor (SSRI) fluoxetine increases phenytoin blood levels when given concurrently. The mechanism of this drug-drug interaction has been attributed to inhibition of CYP2C9-catalyzed hydroxylation of phenytoin to its major oxidative metabolite in humans, para-hydroxyphenyl phenyl hydantoin (HPPH). With a bank of human liver microsomes (HLM), four SSRIs (fluoxetine, norfluoxetine, sertraline, and paroxetine) were tested for inhibition of HPPH formation. Initially, the K(m) and V(max) values of phenytoin hydroxylation to HPPH were determined in the individual HLM samples. The average K(m) (n=8) was 9.7+/-2.9 microM. The V(max) varied fivefold, with an average value of 113+/-53 pmol HPPH/min/nmol CYP450. All of the SSRIs inhibited HPPH formation; resulting Ki values were 31.1+/-10.1 microM (fluoxetine) (n=5), 51.1+/-9.4 microM (norfluoxetine) (n=3), 52.2+/-21.5 microM (sertraline) (n=3), and 80.0+/-7.2 microM (paroxetine) (n=3). Sulfaphenazole (10 microM), utilized as a positive control for inhibition of HPPH formation, inhibited phenytoin hydroxylation (>95%) in all HLM samples. Diclofenac hydroxylation to 4'-OH diclofenac, a specific marker for CYP2C9 activity, was determined in HLM1-HLM6 and was highly correlated with HPPH formation in HLM1-HLM6, indicating that phenytoin hydroxylation in human liver microsomes is largely due to CYP2C9. This work presents direct evidence that the effect of fluoxetine on phenytoin blood levels may be explained by inhibition of CYP2C9-catalyzed phenytoin hydroxylation. In light of typical SSRI blood levels observed in patients, this study also suggests that the risk of a SSRI-phenytoin interaction is highest with fluoxetine and norfluoxetine, and less likely with sertraline and paroxetine.


Assuntos
Anticonvulsivantes/metabolismo , Hidrocarboneto de Aril Hidroxilases , Sistema Enzimático do Citocromo P-450/metabolismo , Fluoxetina/análogos & derivados , Microssomos Hepáticos/metabolismo , Fenitoína/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/metabolismo , Esteroide 16-alfa-Hidroxilase , Esteroide Hidroxilases/metabolismo , Idoso , Pré-Escolar , Citocromo P-450 CYP2C9 , Interações Medicamentosas , Feminino , Fluoxetina/metabolismo , Humanos , Hidroxilação/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Paroxetina/metabolismo , Sertralina/metabolismo
18.
Acad Emerg Med ; 1(3): 213-7, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7621199

RESUMO

OBJECTIVE: To determine whether previously developed triage criteria for refusal of care to patients presenting to an emergency department (ED) with nonurgent problems could be validated for an independent patient population. METHODS: A convenience sample of 534 adults presenting to a municipal hospital ED between July 1, 1992, and October 15, 1992, who met preestablished criteria for refusal of care were entered into a prospective, observational, cohort study. The single target outcome variable was hospitalization. In order to optimize the criteria's performance, both the triage nurse and the physician caring for the patient had to agree that all criteria for "refusal of care" were specifically met. No patient was refused care, nor was a patient's management or disposition interfered with in any way by the investigators. All patients were followed until hospital admission or release from the ED. RESULTS: Six (1.1%) of 534 patients (95% CI 0.4-2.4) who met the criteria for refusal of care were hospitalized. This represents a greater than 50-fold difference in incidence of hospitalization when compared with that found by other investigators, who reported that only 0.02% (95% CI 0.0004-0.04) of those patients who were refused care subsequently required hospitalization (p < 10 (-7)). CONCLUSION: The authors were unable to validate a previously developed predictive model for refusal of care to patients presenting to an ED. Refusal of care to selected ED patients based on current guidelines is not a viable solution to overcrowding. Alternative strategies must be sought.


Assuntos
Serviço Hospitalar de Emergência/organização & administração , Modelos Organizacionais , Recusa em Tratar , Triagem , Adulto , Hospitalização , Humanos , Estudos Prospectivos , Reprodutibilidade dos Testes
19.
Acad Emerg Med ; 3(3): 246-51, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8673781

RESUMO

OBJECTIVE: To determine whether a diurnal discordance exists between need and availability of services for victims of domestic violence. METHODS: A consecutive sample of women presenting to a municipal hospital ED with physical injuries suspected to be related to domestic violence were entered into a registry. Date and time of presentation and perceived need for services information were collected from all patients who answered affirmatively a screening question for domestic violence and whose conditions did not preclude administration of the data collection instrument. The Social Service Departments of all of the 53 911-receiving hospitals in New York City were contacted to ascertain availability of social services for victims of domestic violence by time of day. RESULTS: Twenty-eight of 32 (88%; 95% CI: 71%, 97%) victims of domestic violence presented to the ED during hours other than weekday 9 AM to 5 PM. Of these, 63% desired counseling, 32% lacked a safe place to go, and 82% had children. Of those who had children, 48% were concerned for the children's safety. In-hospital social services were universally available weekday daytime (9 AM to 5 PM) but were available in only 11% of hospital (95% CI: 4%, 23%) at other times. CONCLUSION: Approximately nine of ten victims of domestic violence presented to the ED during hours when only about one hospital in ten can provide the special services these patients require. A marked diurnal mismatch appears to exist between availability of domestic violence services in New York City and the need for these services as measured by a representative sample drawn from an ED population.


Assuntos
Intervenção em Crise , Violência Doméstica , Acessibilidade aos Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde , Adulto , Estudos Transversais , Violência Doméstica/tendências , Serviço Hospitalar de Emergência , Feminino , Humanos , Sistema de Registros , Serviço Social , Maus-Tratos Conjugais/tendências , Tempo
20.
Mt Sinai J Med ; 65(1): 1-4, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9458677

RESUMO

BACKGROUND: To define the onset, pattern, and earliest manifestations of malnutrition related to HIV infection. METHODS: A retrospective cross-sectional analysis of changes in weight and growth in a group of 54 children with perinatally acquired HIV infection was conducted. Eight children had asymptomatic HIV infection, 26 had symptomatic infection, and 20 had symptomatic infection and were referred for nutritional support. RESULTS: We found an early decline in the rate of linear growth with a relative preservation of the weight-for-age. Weight-for-height measurements were preserved until there was advanced HIV-related disease. CONCLUSIONS: This pattern can result in a false impression of adequate nutrition and emphasizes the importance of longitudinal growth data of the child with HIV infection. Evidence of linear growth failure before clinical wasting is apparent is an absolute indication for aggressive nutritional support.


Assuntos
Transtornos do Crescimento/etiologia , Síndrome de Emaciação por Infecção pelo HIV/complicações , Síndrome de Emaciação por Infecção pelo HIV/diagnóstico , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Humanos , Lactente , Estudos Retrospectivos , Estatísticas não Paramétricas
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