RESUMO
Nurses and midwives of Australia now is the time for change! As powerfully placed, Indigenous and non-Indigenous nursing and midwifery professionals, together we can ensure an effective and robust Indigenous curriculum in our nursing and midwifery schools of education. Today, Australia finds itself in a shifting tide of social change, where the voices for better and safer health care ring out loud. Voices for justice, equity and equality reverberate across our cities, our streets, homes, and institutions of learning. It is a call for new songlines of reform. The need to embed meaningful Indigenous health curricula is stronger now than it ever was for Australian nursing and midwifery. It is essential that nursing and midwifery leadership continue to build an authentic collaborative environment for Indigenous curriculum development. Bipartisan alliance is imperative for all academic staff to be confident in their teaching and learning experiences with Indigenous health syllabus. This paper is a call out. Now is the time for Indigenous and non-Indigenous nurses and midwives to make a stand together, for justice and equity in our teaching, learning, and practice. Together we will dismantle systems, policy, and practices in health that oppress. The Black Lives Matter movement provides us with a 'now window' of accepted dialogue to build a better, culturally safe Australian nursing and midwifery workforce, ensuring that Black Lives Matter in all aspects of health care.
Assuntos
Pessoal Administrativo/psicologia , Negro ou Afro-Americano/psicologia , Assistência à Saúde Culturalmente Competente/organização & administração , Tocologia/educação , Cuidados de Enfermagem/psicologia , Recursos Humanos de Enfermagem Hospitalar/psicologia , Racismo/prevenção & controle , Estudantes de Enfermagem/psicologia , Adulto , Austrália , Currículo , Bacharelado em Enfermagem , Feminino , Humanos , Liderança , Masculino , Pessoa de Meia-Idade , Recursos Humanos de Enfermagem Hospitalar/educação , Gravidez , Racismo/psicologiaRESUMO
UNLABELLED: Despite low rates of home birth throughout most Western countries, the topic generates considerable debate. This is reflected by the differing positions on home birth adopted by professional colleges representing obstetricians and midwives. We reviewed position statements of midwifery and obstetric colleges in the UK, USA, Australia, New Zealand, and Canada to explore how the same body of research evidence leads to different positions. Aside from a joint statement from the UK we found widely differing stances, reflecting traditional midwifery perspectives of birth as a physiological process versus obstetric perspectives of potential pathology. We feel the differences in position statements are largely the end product of significant confirmatory bias. TWEETABLE ABSTRACT: Review of organisational position on home birth suggests bias in literature interpretation.
Assuntos
Atitude do Pessoal de Saúde , Parto Domiciliar , Tocologia , Obstetrícia , Feminino , Humanos , Gravidez , Sociedades MédicasRESUMO
Clinical lore dictates that craving drives the compulsive use of drugs and alcohol - the core feature of substance dependence. Yet limited research has yielded mixed results, suggesting that craving is neither necessary nor sufficient for continued use or relapse to addictive substances. To investigate the role of craving in compulsive methamphetamine use, 31 men and women in treatment for methamphetamine dependence were asked to indicate, once each week for 12 weeks, the severity of craving that they had experienced during the previous 24 h, using a 100-mm visual analog scale. In a prospective, repeated-measures, within-subject analysis, craving intensity significantly predicted methamphetamine use in the week immediately following each craving report. Craving remained a highly significant predictor in multivariate models controlling for pharmacological intervention, and for methamphetamine use during the prior week. Craving scores that preceded use were 2.7 times higher than scores that preceded abstinence. Risk of subsequent use was 2.5 times greater for scores in the upper half of the scale relative to scores in the lower half. The results obtained demonstrate that, while craving alone may be neither necessary nor sufficient to explain substance addiction, when measured prospectively in a carefully-designed study craving emerges as a salient predictive factor in continued methamphetamine use for patients in treatment for methamphetamine dependence.
Assuntos
Comportamento Aditivo/fisiopatologia , Comportamento Aditivo/psicologia , Metanfetamina/efeitos adversos , Adulto , Comportamento Aditivo/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos de Pesquisa , Índice de Gravidade de Doença , Inquéritos e QuestionáriosRESUMO
Together with the evidence that the reduced virus growth and the antiviral state induced by interferon (IFN)-gamma, occurring only in macrophages from resistant animals, correlated with the decrease of MHV3 binding to macrophage membrane proteins, we show here the expression of cellular and viral genes in resistant (A/J) and susceptible (BALB/c) mouse macrophages after IFN-gamma activation/infection. The expression of interferon response gene 47 and interferon regulatory factor 1 genes takes place after IFN-gamma activation in both macrophages, indicating their activation. The expression of the biliary glycoprotein 1(a) (Bgp1(a), the main virus receptor) decreased only in IFN-gamma-activated A/J mouse macrophages, in contrast to the expression of the Bgp2 (alternative receptor), which was not influenced by IFN-gamma activation. The synthesis of both viral mRNA and virus particles was delayed only in IFN-gamma-activated A/J mouse macrophages compared with susceptible BALB/c macrophages. Besides the evidence that IFN-gamma may modulate the expression of the Bgp1(a) isoform of carcinoembryonic antigen family, these data show that IFN-gamma, which induces resistance against MHV3 infection, may be involved in the down-regulation of the main viral receptor expression, a key step forward in our understanding of the molecular basis of resistance against virus infection.
Assuntos
Antivirais/imunologia , Regulação para Baixo , Glicoproteínas/metabolismo , Interferon gama/imunologia , Vírus da Hepatite Murina/imunologia , Receptores Virais/metabolismo , Animais , Antígenos CD , Antivirais/metabolismo , Moléculas de Adesão Celular , Células Cultivadas , Regulação Viral da Expressão Gênica , Genes Virais/genética , Glicoproteínas/genética , Interferon gama/metabolismo , Cinética , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/virologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Vírus da Hepatite Murina/genética , Vírus da Hepatite Murina/metabolismo , Vírus da Hepatite Murina/fisiologia , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Receptores Virais/genética , Replicação ViralRESUMO
OBJECTIVE: Case studies suggest cigarette abstinence may precipitate a major depressive episode. This study examined the incidence and predictors of major depression in the 12 months after treatment for smoking cessation. METHOD: Participants (N=304, 172 women) were recruited from two trials of smoking cessation. Both trials provided psychological group intervention, but one group received treatment with nicotine gum and the other was given nortriptyline or placebo. The incidence of major depressive episodes was identified by the Inventory to Diagnose Depression, which was administered at follow-up assessments. RESULTS: The 12-month incidence of major depression after treatment for smoking cessation was 14.1% (N=43). Multiple logistic regression analyses indicated that history of depression, baseline Beck Depression Inventory score, college education, and age at smoking initiation were significant predictors of major depression after treatment. Abstinence at the end of treatment did not significantly predict major depression. CONCLUSIONS: Patients who achieved abstinence from smoking showed a risk of developing depressive episodes similar to those who failed to achieve abstinence. As expected, patients who had a history of depression were more likely to experience depressive episodes after treatment for smoking cessation. The 12-month incidence of major depression in this study group was higher than that observed in the general population, but reasons for the elevation were not clear.
Assuntos
Transtorno Depressivo/terapia , Abandono do Hábito de Fumar/psicologia , Adulto , Estimulantes do Sistema Nervoso Central/uso terapêutico , Goma de Mascar , Terapia Combinada , Comorbidade , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/epidemiologia , Feminino , Humanos , Incidência , Modelos Logísticos , Masculino , Nicotina/análogos & derivados , Nicotina/uso terapêutico , Nortriptilina/uso terapêutico , Razão de Chances , Inventário de Personalidade/estatística & dados numéricos , Placebos , Ácidos Polimetacrílicos/uso terapêutico , Polivinil/uso terapêutico , Estudos Prospectivos , Psicoterapia , Fumar/epidemiologia , Fumar/terapia , Prevenção do Hábito de Fumar , Dispositivos para o Abandono do Uso de Tabaco , Tabagismo/psicologia , Tabagismo/terapia , Resultado do TratamentoRESUMO
We examined treatment costs in an ongoing study in which 102 opioid-addicted patients had been randomly assigned to either 180-day methadone detoxification or the same treatment enhanced with contingency contracting. In the latter condition, study participants received regular reinforcers contingent on negative urine toxicology screens and breath analyses for a range of drugs and alcohol. Both conditions involved psychosocial treatment, and all participants were stabilized to a daily methadone dose of approximately 80 mg during the first 4 months, followed by a 2-month taper. Individuals participating in the enhanced condition were more likely to provide continuously drug-free urine samples and alcohol-free breath samples during the final month of treatment than were participants in the control condition. Cost of treatment was calculated individually for each participant based on actual services received. First, unit cost for each service was determined, including adjusted staff salaries for direct treatment and opportunity cost of facilities utilized during service delivery. Next, we valued each patient's use of services during the first 120 days of the study and then added the cost of methadone, laboratory work, and contingent reinforcers. A subsample (n = 45) also provided data on health care utilization during treatment, which we valued using standard Medicare unit costs. The marginal cost of enhancing the standard treatment with contingency contracting was approximately 8%. An incremental cost of $17.27 produced an additional 1% increase in the number of participants providing continuously substance-free urine and breath samples during month 4 of the study. For every additional dollar spent on treatment, a $4.87 health care cost offset was realized; however, this difference was statistically insignificant due to extreme variances and small subsample size.
Assuntos
Serviços de Saúde Mental/economia , Metadona/uso terapêutico , Entorpecentes/uso terapêutico , Negociação , Transtornos Relacionados ao Uso de Opioides/reabilitação , Análise Custo-Benefício , Relação Dose-Resposta a Droga , Humanos , Inativação Metabólica , Serviços de Saúde Mental/estatística & dados numéricos , Entorpecentes/farmacocinética , Entorpecentes/urina , Transtornos Relacionados ao Uso de Opioides/urina , Reforço Psicológico , Estados UnidosRESUMO
As hospital length-of-stays decrease for children newly diagnosed with diabetes, there is an increased need to be time efficient while still providing the best quality care. The pediatric diet history form can save time while identifying important components necessary to write an individualized, consistent carbohydrate meal plan that is both flexible and realistic.
Assuntos
Diabetes Mellitus Tipo 1/dietoterapia , Dieta para Diabéticos , Carboidratos da Dieta/administração & dosagem , Planejamento de Cardápio , Avaliação em Enfermagem/métodos , Avaliação Nutricional , Criança , Criança Hospitalizada , Humanos , Inquéritos e QuestionáriosRESUMO
BACKGROUND: A history of major depressive disorder (MDD) predicts failure to quit smoking. We determined the effect of nortriptyline hydrochloride and cognitive-behavioral therapy on smoking treatment outcome in smokers with a history of MDD. The study also addressed the effects of diagnosis and treatment condition on dysphoria after quitting smoking and the effects of dysphoria on abstinence. METHODS: This was a 2 (nortriptyline vs placebo) x 2 (cognitive-behavioral therapy vs control) x 2 (history of MDD vs no history) randomized trial. The participants were 199 cigarette smokers. The outcome measures were biologically verified abstinence from cigarettes at weeks 12, 24, 38, and 64. Mood, withdrawal, and depression were measured at 3, 5, and 8 days after the smoking quit date. RESULTS: Nortriptyline produced higher abstinence rates than placebo, independent of depression history. Cognitive-behavioral therapy was more effective for participants with a history of depression. Nortriptyline alleviated a negative affect occurring after smoking cessation. Increases in the level of negative affect from baseline to 3 days after the smoking quit date predicted abstinence at later assessments for MDD history-negative smokers. There was also a sex-by-depression history interaction; MDD history-positive women were less likely to be abstinent than MDD history-negative women, but depression history did not predict abstinence for men. CONCLUSIONS: Nortriptyline is a promising adjunct for smoking cessation. Smokers with a history of depression are aided by more intensive psychosocial treatments. Mood and diagnosis interact to predict relapse. Increases in negative affect after quitting smoking are attenuated by nortriptyline.
Assuntos
Antidepressivos Tricíclicos/uso terapêutico , Terapia Cognitivo-Comportamental , Nortriptilina/uso terapêutico , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar , Adulto , Idoso , Antidepressivos Tricíclicos/sangue , Terapia Combinada , Comorbidade , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/epidemiologia , Transtorno Depressivo/psicologia , Método Duplo-Cego , Feminino , Seguimentos , Educação em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Nortriptilina/sangue , Placebos , Fatores Sexuais , Fumar/epidemiologia , Fumar/psicologia , Resultado do TratamentoRESUMO
Earlier research indicated that a 10-session mood management (MM) intervention was more effective than a 5-session standard intervention for smokers with a history of major depressive disorder (MDD). In a 2 x 2 factorial design, the present study compared MM intervention to a contact-equivalent health education intervention (HE) and 2 mg to 0 mg of nicotine gum for smokers with a history of MDD. Participants were 201 smokers, 22% with a history of MDD. Contrary to the earlier findings, the MM and HE interventions produced similar abstinence rates: 2 mg gum was no more effective than placebo. History-positive participants had a greater increase in mood disturbance after the quit attempt. Independent of depression diagnosis, increases in negative mood immediately after quitting predicted smoking. No treatment differences were found in trends over time for measures of mood, withdrawal symptoms, pleasant activities and events, self-efficacy, and optimism and pessimism. History-positive smokers may be best treated by interventions providing additional support and contact, independent of therapeutic content.
Assuntos
Afeto/efeitos dos fármacos , Terapia Cognitivo-Comportamental , Transtorno Depressivo/induzido quimicamente , Nicotina/administração & dosagem , Abandono do Hábito de Fumar/métodos , Síndrome de Abstinência a Substâncias/prevenção & controle , Adulto , Idoso , Goma de Mascar , Terapia Combinada , Transtorno Depressivo/psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Nicotina/efeitos adversos , Recidiva , Fatores de Risco , Autoimagem , Fumar/psicologia , Abandono do Hábito de Fumar/psicologia , Síndrome de Abstinência a Substâncias/psicologia , Resultado do TratamentoRESUMO
The molecular interaction of glimepiride and glibenclamide with the beta-cell sulfonylurea receptor was investigated by kinetic and steady state binding as well as photoaffinity labeling. The novel sulfonylurea, glimepiride, exhibits a significantly higher exchange rate with the sulfonylurea receptor but a 2.5-3 fold lower binding affinity compared to glibenclamide. [3H]Glimepiride was specifically incorporated into a 65-kDa polypeptide under conditions which led to predominant labeling of a 140-kDa protein by [3H]glibenclamide. Labeling of the 140-kDa protein by [3H]glibenclamide was inhibited by unlabeled glimepiride and, vice versa, glibenclamide inhibited labeling of the 65-kDa protein by [3H]glimepiride. The 65-kDa protein was also specifically photolabeled by the sulfonylurea [125I]35623, whereas an 4-azidobenzoyl derivative of glibenclamide, N3-[3H]33055, exclusively labeled a 33-kDa protein. Solubilization of beta-cell tumor membranes led to a shift of specific [3H]glibenclamide-binding from the 140-kDa to the 65-kDa protein, exclusively and to an increased labeling of the 65-kDa protein by [3H]glimepiride. The labeling of a unique protein is in agreement with similar Kd-values for binding to the sulfonylurea receptor measured for both sulfonylureas upon solubilization of beta-cell membranes. Photoaffinity labeling of intact cultured beta-cells led also to labeling of a 140-kDa protein by [3H]glibenclamide and of a 65-kDa protein by [3H]glimepiride. These studies suggest that the beta-cell sulfonylurea receptor consists of at least two protein subunits of M(r) 140,000 and 65,000 which bind sulfonylureas of different structure with different binding affinities and kinetic parameters. Furthermore, the exchange rate of a sulfonylurea determines the insulin releasing activity in vitro more closely than the binding affinity.
Assuntos
Transportadores de Cassetes de Ligação de ATP , Trifosfato de Adenosina/farmacologia , Hipoglicemiantes/farmacologia , Ilhotas Pancreáticas/fisiologia , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/fisiologia , Receptores de Droga/fisiologia , Compostos de Sulfonilureia/farmacologia , Trifosfato de Adenosina/metabolismo , Marcadores de Afinidade , Animais , Ligação Competitiva , Linhagem Celular , Membrana Celular/fisiologia , Glibureto/metabolismo , Humanos , Hipoglicemiantes/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Cinética , Modelos Biológicos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/fisiopatologia , Canais de Potássio/efeitos dos fármacos , Canais de Potássio/metabolismo , Receptores de Droga/efeitos dos fármacos , Receptores de Droga/metabolismo , Compostos de Sulfonilureia/metabolismo , Receptores de SulfonilureiasRESUMO
Ninety-six high school students reported their own behavior and the behavior of their parents in the resolution of conflicts during the previous year, using the Conflict Tactics Scale (Straus, 1979). Parent-teen dyadic aggression levels for Americans of European, Japanese, Polynesian, and Filipino ancestry were compared in a series of orthogonal contrasts. The adolescent children of Polynesian American parents reported significantly higher parent aggression levels than did adolescents with parents of other ethnicity. Parent aggression was the best predictor of teen aggression directed toward parents. Subjects reciprocated with counteraggression toward European American parents significantly more often than toward parents of other ethnicity. Aggression by one parent was highly correlated with aggression by the other parent. Aggression by either parent was more highly correlated with teen aggression toward the mother, than with teen aggression toward the father.
Assuntos
Maus-Tratos Infantis/etnologia , Conflito Psicológico , Comparação Transcultural , Violência Doméstica/etnologia , Etnicidade/psicologia , Relações Pais-Filho , Resolução de Problemas , Adolescente , Agressão/psicologia , Asiático/psicologia , Maus-Tratos Infantis/psicologia , Violência Doméstica/psicologia , Europa (Continente)/etnologia , Feminino , Identidade de Gênero , Havaí , Humanos , Japão/etnologia , Masculino , Inventário de Personalidade , Filipinas/etnologia , Polinésia/etnologia , Fatores de RiscoRESUMO
To examine patterns of use of acute walk-in services by substance abusers, the authors studied demographic characteristics and type of substance abuse among 1,838 patients treated at a Veterans Affairs substance abuse triage unit. They found that African-American and male substance abusers appeared most likely to return for triage services. Among heroin users, the strongest predictor of return was gender. Among alcoholics, homelessness was the sole predictor of return. No predictors were found for cocaine users. The authors conclude that the relationship between return rates and type of substance abuse needs further study.
Assuntos
Alcoolismo/epidemiologia , Cocaína , Mau Uso de Serviços de Saúde/estatística & dados numéricos , Dependência de Heroína/epidemiologia , Hospitais de Veteranos/estatística & dados numéricos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Veteranos/estatística & dados numéricos , Adulto , Idoso , Alcoolismo/psicologia , Alcoolismo/reabilitação , Comorbidade , Feminino , Dependência de Heroína/psicologia , Dependência de Heroína/reabilitação , Pessoas Mal Alojadas/psicologia , Pessoas Mal Alojadas/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , São Francisco/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Transtornos Relacionados ao Uso de Substâncias/reabilitação , Resultado do Tratamento , Veteranos/psicologiaRESUMO
Escherichia coli containing a recombinant malarial protein expressed in lambda gt11 have been evaluated as an antigen delivery system in vivo. They were generated by infecting non-suppressing E. coli cells with a clone from a cDNA library of Plasmodium chabaudi chabaudi in lambda gt11. This clone (termed clone 6) expresses part of a 93 kDa blood-stage antigen of P. c. chabaudi as beta-galactosidase fusion protein. Immunization of C57B1/6 mice with these infected E. coli cells resulted in an antibody response to the malarial part of the fusion protein comparable to that obtained with purified fusion protein preparations. This method, therefore represents a rapid secondary screening of clones from lambda gt11 expression libraries for immunogenic and potentially protective components. In addition, the administration of whole infected E. coli obviates the need for an adjuvant.
Assuntos
Anticorpos Antiprotozoários/biossíntese , Escherichia coli/imunologia , Vacinas Antimaláricas/imunologia , Plasmodium chabaudi/imunologia , Adjuvantes Imunológicos , Animais , Bacteriófago lambda/genética , Bacteriófago lambda/imunologia , Western Blotting , Ensaio de Imunoadsorção Enzimática , Feminino , Biblioteca Genômica , Camundongos , Camundongos Endogâmicos C57BL , Transformação Bacteriana , Vacinas Sintéticas/imunologia , beta-GalactosidaseRESUMO
The clinical research information system (CRIS) at the San Francisco VA Medical Center was designed to provide information on use of services and treatment outcomes and to support the clinics for treatment of substance abuse. This system fills a niche often neglected by centralized hospital systems, which are usually designed to satisfy administrative demands for automated fiscal functions, but not designed to support patient care. Full integration with our central computing system remains a goal; for now, CRIS operates as a self-contained clinical system with several workstations linked by a telephone network.
Assuntos
Pesquisa sobre Serviços de Saúde , Sistemas de Informação Hospitalar , Ambulatório Hospitalar , Transtornos Relacionados ao Uso de Substâncias/terapia , Redes de Comunicação de Computadores , Hospitais de Veteranos , Humanos , São Francisco , TriagemAssuntos
Pessoas Mal Alojadas/estatística & dados numéricos , Drogas Ilícitas , Admissão do Paciente/estatística & dados numéricos , Psicotrópicos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Veteranos/estatística & dados numéricos , Adulto , Idoso , California , Feminino , Pessoas Mal Alojadas/psicologia , Hospitais de Veteranos/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Substâncias/psicologia , Veteranos/psicologiaRESUMO
Glimepiride is a novel sulfonylurea drug for treatment of non-insulin-dependent diabetes mellitus with higher blood sugar lowering efficacy in diabetic patients than glibenclamide raising the question whether this characteristics is in line with different binding of glimepiride and glibenclamide to the beta-cell sulfonylurea receptor. Scatchard plot analysis of [3H]sulfonylurea binding to membranes isolated from rat beta-cell tumors and (RINm5F) insulinoma cells and to RINm5F cells demonstrated that glimepiride has a 2.5-3-fold lower affinity than glibenclamide. This corresponded well to the 8-9-fold higher koff and 2.5-3-fold higher kon rates of glimepiride compared to glibenclamide as revealed by the dissociation and association kinetics of [3H]sulfonylurea binding and the Kd values calculated thereof. In agreement, the concentrations required for half-maximal displacement of [3H]sulfonylurea bound to beta-cell membranes were significantly higher for glimepiride compared to glibenclamide. However, the binding affinity of glimepiride measured by both equilibrium binding and kinetic binding studies upon solubilization of beta-cell tumor membranes and RINm5F cell membranes increased up to the value for glibenclamide. This was primarily based on a drastic decrease of the dissociation rate constant of glimepiride whereas the kinetics of glibenclamide binding remained largely unaffected upon solubilization. These data suggest that the Kd value alone is not sufficient for characterization of a sulfonylurea drug, since the kinetic binding parameters may also determine its acute blood sugar lowering efficacy.
Assuntos
Transportadores de Cassetes de Ligação de ATP , Glibureto/farmacologia , Hipoglicemiantes/farmacologia , Pâncreas/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/efeitos dos fármacos , Receptores de Droga/efeitos dos fármacos , Compostos de Sulfonilureia/farmacologia , Animais , Linhagem Celular , Membrana Celular/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Cinética , Canais de Potássio/metabolismo , Ratos , Receptores de Droga/metabolismo , Receptores de Sulfonilureias , TrítioRESUMO
Glimepiride is a novel sulfonylurea for the treatment of type II-diabetic patients exhibiting different receptor binding kinetics to beta-cell membranes with 8-9-fold higher koff rate and 2.5-3-fold higher kon rate compared to glibenclamide (see accompanying paper (Müller, G. et al. (1994) Biochim. Biophys. Acta 1191, 267-277)). To elucidate the molecular basis for this differential behaviour of glimepiride and glibenclamide, direct photoaffinity labeling studies using beta-cell tumor membranes were performed. [3H]Glimepiride was specifically incorporated into a membrane polypeptide of M(r) = 65,000 under conditions, which led to predominant labeling of a 140 kDa protein by [3H]glibenclamide (Kramer, W. et al. (1988) FEBS Lett. 229, 355-359). Labeling of the 140 kDa protein by [3H]glibenclamide was inhibited by unlabeled glimepiride and, vice versa, glibenclamide inhibited labeling of the 65 kDa protein by [3H]glimepiride. The 65 kDa protein was also specifically photolabeled by the sulfonylurea [125I]35623, whereas an 4-azidobenzoyl derivative of glibenclamide, N3-[3H]33055, exclusively labeled a 33 kDa protein. Competitive Scatchard analysis of [3H]glimepiride-binding and [3H]glibenclamide-binding to RINm5F cell membranes using glibenclamide and glimepiride, respectively, as heterologous displacing compounds yielded non-linear plots. These findings may be explained by cooperative interactions between the 140 and 65 kDa sulfonylurea-binding proteins. The possibility that sulfonylureas of different structure have different access to the 140 and 65 kDa receptor proteins due to the beta-cell membrane barrier was investigated by photoaffinity labeling of solubilized beta-cell membrane proteins. Interestingly, solubilization of beta-cell tumor membranes led to a shift of specific [3H]glibenclamide binding from the 140 kDa to the 65 kDa binding protein, exclusively, and to an increased labeling of the 65 kDa protein by [3H]glimepiride. The labeling of a unique protein is in agreement with similar Kd values measured for both sulfonylureas upon solubilization of beta-cell tumor and RINm5F cell membranes (see accompanying paper). Furthermore, competitive Scatchard plots of [3H]glimepiride binding to solubilized RINm5F cell membrane proteins in the presence of glibenclamide and vice versa approximate linearity suggesting loss of cooperativity between the 140 kDa glibenclamide-binding and 65 kDa glimepiride-binding proteins upon solubilization. The physiological significance of the differential interaction of glimepiride and glibenclamide with different binding proteins was also substantiated by photoaffinity labeling of RINm5F cells leading to labeling of a 140 kDa protein by [3H]glibenclamide and of a 65 kDa protein by [3H]glimepiride.(ABSTRACT TRUNCATED AT 400 WORDS)
Assuntos
Transportadores de Cassetes de Ligação de ATP , Glibureto/metabolismo , Hipoglicemiantes/metabolismo , Pâncreas/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/metabolismo , Receptores de Droga/metabolismo , Compostos de Sulfonilureia/metabolismo , Marcadores de Afinidade , Animais , Sítios de Ligação , Proteínas de Transporte/análise , Linhagem Celular , Membrana Celular/metabolismo , Glibureto/farmacologia , Hipoglicemiantes/farmacologia , Canais de Potássio/efeitos dos fármacos , Ratos , Receptores de Droga/efeitos dos fármacos , Relação Estrutura-Atividade , Compostos de Sulfonilureia/farmacologia , Receptores de Sulfonilureias , TrítioRESUMO
Screening of a cDNA library (prepared in lambda gt11) of the blood stages of Plasmodium chabaudi chabaudi (AS) with immune serum has revealed an antigen the elicits a strong antibody response in infected mice. The clone (clone 6) expressing that antigen contains a 0.7 kb insert and produces a beta-galactosidase fusion protein of about 150 kDa. In Western blot analysis performed on parasite extracts, monoclonal antibodies and polyclonal sera prepared against the fusion protein revealed that the fusion protein contains part of a malarial protein of 93 kDa. Northern hybridization with clone 6 insert as probe detected a plasmodial RNA of about 3.2 kb, which could well code for a protein of this size. The insert hybridized to a single EcoRI fragment and a single HindIII fragment in genomic Southern blotting, suggesting that the gene is present in one copy in the P. chabaudi genome. The DNA sequence of clone 6 insert predicts a hydrophilic, acidic polypeptide consisting of seven repeats of 23-34 amino acids rich in lysine (24%) and aspartic acid (17.5%).
Assuntos
Antígenos de Protozoários/genética , Ácido Aspártico , DNA de Protozoário/genética , Lisina , Plasmodium chabaudi/genética , Proteínas de Protozoários/genética , Sequências Repetitivas de Ácido Nucleico , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Antígenos de Protozoários/imunologia , Sequência de Bases , Northern Blotting , Clonagem Molecular , DNA de Protozoário/isolamento & purificação , Feminino , Biblioteca Gênica , Genoma , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Proteínas de Protozoários/biossíntese , RNA de Protozoário/genética , Proteínas Recombinantes de Fusão/biossíntese , beta-Galactosidase/biossíntese , beta-Galactosidase/genéticaRESUMO
We have studied the classic initiation elements of mRNA sequence and structure to better understand their influence on translation initiation rates in Escherichia coli. Changes introduced in the initiation codon, the Shine and Dalgarno sequence, the spacing between those two elements, and in the secondary structures within initiation domains each change the rate of 30 S ternary complex formation. We measured these differences using extension inhibition analysis, a technique we have called "toeprinting". The rate of 30 S initiation complex formation in the absence of initiation factors agrees well with in vivo translation rates in some instances, although in others a regulatory role of initiation factors in 30 S complex formation is likely. Nucleotides 5' to the Shine and Dalgarno domain facilitate ternary complex formation.