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1.
Eur J Clin Nutr ; 71(12): 1449-1454, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28901336

RESUMO

BACKGROUND/OBJECTIVES: Vitamin D and probiotics are nutrients of interest in the context of type 1 diabetes (T1D). We assessed the prevalence of and factors associated with vitamin D and probiotic supplementations among young children with genetic risk of T1D. SUBJECTS/METHODS: Use of supplements during the first 2 years of life was collected prospectively from 8674 children in The Environmental Determinants of Diabetes in the Young (TEDDY) study. RESULTS: Single and/or multivitamin/mineral (MVM) supplements were reported by 81% of the children. The majority of participants in Finland, Germany and Sweden (97-99%) and 50% in the United States received vitamin D supplements that were mostly MVMs. Probiotics use varied from 6% in the United States to 60% in Finland and was primarily from probiotics-only preparations. More than 80% of the vitamin D and probiotics supplementation was initiated during infancy, and more than half of the uses lasted longer than a year. Being the first child, longer duration of breastfeeding, born in a later year, older maternal age and higher maternal education level were associated with both vitamin D and probiotics use. Shorter gestational age and mother not smoking during pregnancy were associated with a higher likelihood of probiotics supplementation only. CONCLUSIONS: Vitamin D and probiotics supplementations are popular in children 0-2 years old and are associated with common factors. Data documented here will allow evaluation of the relationship between early childhood dietary intake and the development of islet autoimmunity and progression to T1D.


Assuntos
Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/prevenção & controle , Suplementos Nutricionais , Predisposição Genética para Doença , Probióticos/administração & dosagem , Vitamina D/administração & dosagem , Adulto , Peso ao Nascer , Pré-Escolar , Diabetes Mellitus Tipo 1/sangue , Feminino , Finlândia , Alemanha , Humanos , Lactente , Masculino , Micronutrientes/administração & dosagem , Micronutrientes/sangue , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários , Suécia , Estados Unidos , Vitamina D/sangue , Adulto Jovem
2.
Arch Gen Psychiatry ; 57(10): 968-76, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11015815

RESUMO

BACKGROUND: Patients with Alzheimer disease (AD) commonly exhibit psychosis and behavioral disturbances that impair patient functioning, create caregiver distress, and lead to institutionalization. This study was conducted to assess the efficacy and safety of olanzapine in treating psychosis and/or agitation/aggression in patients with AD. METHODS: A multicenter, double-blind, placebo-controlled, 6-week study was conducted in 206 elderly US nursing home residents with AD who exhibited psychotic and/or behavioral symptoms. Patients were randomly assigned to placebo or a fixed dose of 5, 10, or 15 mg/d of olanzapine. The primary efficacy measure was the sum of the Agitation/Aggression, Hallucinations, and Delusions items (Core Total) of the Neuropsychiatric Inventory-Nursing Home version. RESULTS: Low-dose olanzapine (5 and 10 mg/d) produced significant improvement compared with placebo on the Core Total (-7.6 vs -3.7 [P<.001] and -6.1 vs -3. 7 [P =.006], respectively). Core Total improvement with olanzapine, 15 mg/d, was not significantly greater than placebo. The Occupational Disruptiveness score, reflecting the impact of patients' psychosis and behavioral disturbances on the caregiver, was significantly reduced in the 5-mg/d olanzapine group compared with placebo (-2.7 vs -1.5; P =.008). Somnolence was significantly more common among patients receiving olanzapine (25.0%-35.8%), and gait disturbance occurred in those receiving 5 or 15 mg/d (19.6% and 17.0%, respectively). No significant cognitive impairment, increase in extrapyramidal symptoms, or central anticholinergic effects were found at any olanzapine dose relative to placebo. CONCLUSION: Low-dose olanzapine (5 and 10 mg/d) was significantly superior to placebo and well tolerated in treating agitation/aggression and psychosis in this population of patients with AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Antipsicóticos/uso terapêutico , Sintomas Comportamentais/tratamento farmacológico , Casas de Saúde , Pirenzepina/análogos & derivados , Pirenzepina/uso terapêutico , Transtornos Psicóticos/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/psicologia , Sintomas Comportamentais/psicologia , Benzodiazepinas , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Olanzapina , Placebos , Transtornos Psicóticos/psicologia , Resultado do Tratamento
3.
Stat Med ; 19(16): 2169-84, 2000 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-10931518

RESUMO

Currently available antidepressants have a delayed onset of action and there is considerable interest in developing new products which exhibit a shorter time to response. Previous authors have suggested using a cure model to characterize the time to response for the combination of the patients who respond and the patients who do not respond. In this paper, we use the cure model and propose a Cramer-von Mises statistic to compare the time to response distributions for patients who respond to therapy. The asymptotic null distribution of the statistic is derived. A bootstap procedure is also proposed for sample sizes typical in antidepressant clinical trials. Results of the simulation study suggest that for common designs and sample sizes used in such trials, the statistic has reasonable size and power properties as long as censoring is moderate.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Antidepressivos de Segunda Geração/administração & dosagem , Antidepressivos/administração & dosagem , Ensaios Clínicos como Assunto/estatística & dados numéricos , Transtorno Depressivo/tratamento farmacológico , Fluoxetina/administração & dosagem , Modelos Estatísticos , Pindolol/administração & dosagem , Algoritmos , Humanos , Tamanho da Amostra , Distribuições Estatísticas , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento
4.
J Clin Psychiatry ; 60(6): 389-94, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10401918

RESUMO

BACKGROUND: Although a period of 6 to 12 months of antidepressant therapy is recommended for most patients with depression, systematic examinations of the course of adverse events over time, the resolution of early-onset events, and the possible emergence of later-onset events are limited. We examined the safety of fluoxetine, 20 mg/day, in a large, prospective, long-term treatment trial, and we report a comparison of early- and late-onset adverse events and the course of adverse events over 26 weeks of treatment. METHOD: Adverse events were recorded at each visit in a uniform format by open-ended questioning, regardless of perceived causality. New or worsened events reported in either the first 4 weeks of treatment (early-reporting interval) or weeks 22 through 26 of treatment (late-reporting interval) were compared. RESULTS: Patients (N = 299) whose depression (DSM-III-R) remitted with 12 weeks of fluoxetine treatment entered continuation therapy, and 174 completed 26 weeks of therapy. All events that occurred in > or =5% of patients early in treatment decreased in frequency over time (p<.05), and no events occurred significantly more frequently during continuation therapy. No previously uncommon adverse events became common during long-term treatment. CONCLUSION: Common adverse events associated with initiating fluoxetine treatment in depressed patients, including nausea, insomnia, nervousness, and somnolence, resolve in the majority of patients and become significantly less frequent with continued treatment over a 6-month period. No adverse events present initially become more frequent late in treatment. Therapy with fluoxetine, 20 mg/day, is well tolerated over 6 months, and most adverse events observed early in treatment resolve.


Assuntos
Transtorno Depressivo/tratamento farmacológico , Fluoxetina/efeitos adversos , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Ansiedade/induzido quimicamente , Ansiedade/epidemiologia , Transtorno Depressivo/psicologia , Método Duplo-Cego , Esquema de Medicação , Fluoxetina/uso terapêutico , Seguimentos , Cefaleia/induzido quimicamente , Cefaleia/epidemiologia , Humanos , Náusea/induzido quimicamente , Náusea/epidemiologia , Placebos , Prevenção Secundária , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Distúrbios do Início e da Manutenção do Sono/induzido quimicamente , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Fases do Sono , Inquéritos e Questionários , Resultado do Tratamento
5.
Br J Psychiatry ; 174: 23-30, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10211147

RESUMO

BACKGROUND: Tardive dyskinesia is important in the side-effect profile of antipsychotic medication. AIMS: The development of tardive dyskinesia was evaluated in patients treated with double-blind, randomly assigned olanzapine or haloperidol for up to 2.6 years. METHODS: Tardive dyskinesia was assessed by the Abnormal Involuntary Movement Scale (AIMS) and Research Diagnostic Criteria for Tardive Dyskinesia (RD-TD), it was defined as meeting RD-TD criteria at two consecutive assessments. The risk of tardive dyskinesia, the relative risk, incidence rate, and incidence rate ratio were estimated. RESULTS: The relative risk of tardive dyskinesia for the overall follow up period for haloperidol (n = 522) v. olanzapine (n = 1192) was 2.66 (95% CI = 1.50-4.70). Based on data following the initial six weeks of observation (during which patients underwent medication change and AIMS assessments as frequently as every three days), the one-year risk was 0.52% with olanzapine (n = 513) and 7.45% with haloperidol (n = 114). The relative risk throughout this follow-up period was 11.37 (95% CI = 2.21-58.60). CONCLUSION: Our results indicated a significantly lower risk of tardive dyskinesia with olanzapine than with haloperidol.


Assuntos
Antipsicóticos/efeitos adversos , Discinesia Induzida por Medicamentos/etiologia , Haloperidol/efeitos adversos , Pirenzepina/análogos & derivados , Esquizofrenia/tratamento farmacológico , Benzodiazepinas , Método Duplo-Cego , Humanos , Olanzapina , Pirenzepina/efeitos adversos , Fatores de Risco , Análise de Sobrevida
6.
Am J Psychiatry ; 155(11): 1570-7, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9812120

RESUMO

OBJECTIVE: Although panic attacks account for only a portion of the morbidity of panic disorder and panic attack frequency assessments are unreliable, studies of drug efficacy in panic disorder have generally used reduction in panic attack frequency as the primary measure of improvement. The authors studied the efficacy of fluoxetine treatment in panic disorder and measured the relative contributions of changes in symptoms to overall improvement. METHOD: Patients with a diagnosis of panic disorder (N = 243) were randomly assigned to treatment with 10 or 20 mg/day of fluoxetine or placebo. Primary outcome measures were change in panic attack frequency and clinician-rated Clinical Global Impression improvement scores. Other assessments included a panic attack inventory, clinician-rated and patient-rated versions of the Panic and Phobic Disorder Change Scale, a phobia rating scale, the Hamilton Anxiety Rating Scale, the 21-item Hamilton Depression Rating Scale, and the Sheehan Disability Scale. Correlations were determined between outcomes in individual symptom domains and overall clinical outcome. RESULTS: Fluoxetine, particularly the 20-mg/day dose, was associated with more improvement than was placebo in patients with panic disorder across multiple symptom measures, including global improvement, total panic attack frequency, phobic symptoms, and functional impairment. Global improvement was most highly correlated with reductions in overall anxiety and phobic symptoms and least correlated with reduction in panic attacks. Fluoxetine treatment for panic disorder was well tolerated, with a safety profile consistent with that observed for fluoxetine in other disorders. CONCLUSIONS: These data provide support for the efficacy and safety of fluoxetine treatment in reducing panic attacks, phobic symptoms, anxiety, and depressive symptoms in patients with panic disorder. Reductions in panic attack frequency in subjects given either fluoxetine or placebo were less closely related to overall clinical improvement than reductions in phobic avoidance, anxiety, depressive symptoms, and functional impairment, suggesting that outcome measures in this disorder should be more broadly based.


Assuntos
Fluoxetina/uso terapêutico , Transtorno de Pânico/tratamento farmacológico , Adulto , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Transtorno de Pânico/diagnóstico , Transtorno de Pânico/psicologia , Inventário de Personalidade , Placebos , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Índice de Gravidade de Doença , Resultado do Tratamento
7.
J Biopharm Stat ; 8(1): 55-67, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9547427

RESUMO

In this paper, an exact test for analyzing the homogeneity of treatment effect in adaptive multicenter clinical trials is proposed. Extensive simulation studies are performed to investigate the large sample behavior of a commonly used test statistic for testing homogeneity of treatment effect. When the sample size in each center is large relative to the number of centers, the asymptotic null distribution of the test statistic is reasonable. On the other hand, when the data are relatively sparse, the proposed exact test should be used to incorporate the adaptive nature of the design.


Assuntos
Estudos Multicêntricos como Assunto/estatística & dados numéricos , Projetos de Pesquisa/estatística & dados numéricos , Algoritmos , Simulação por Computador , Interpretação Estatística de Dados , Tamanho da Amostra
8.
Am J Psychiatry ; 154(9): 1248-54, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9286184

RESUMO

OBJECTIVE: Tardive dyskinesia is a serious and common complication of neuroleptic treatment. Olanzapine is a novel antipsychotic agent exhibiting regional mesolimbic dopaminergic selectivity and a broad-based pharmacology encompassing serotonin, dopamine, muscarinic, and adrenergic receptor binding affinities. The authors' goal was to compare the incidence of tardive dyskinesia among patients receiving olanzapine and those receiving the conventional dopamine 2 antagonist haloperidol. METHOD: Data were analyzed from three actively controlled and blind long-term responder studies of subjects meeting DSM-III-R criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder treated with olanzapine (N = 707, up to 20 mg/day, 237 median days of exposure) or haloperidol (N = 197, up to 20 mg/day, 203 median days of exposure) who did not have evidence of tardive dyskinesia at baseline. All of the subjects had a chronic disease course (mean greater than 10 years), and there were no significant between-treatment group differences in demographic or disease characteristics. The Abnormal Involuntary Movement Scale and research diagnostic criteria for tardive dyskinesia were used to define the comparative incidence rates of long-term treatment-emergent tardive dyskinesia. RESULTS: The incidence of newly emergent tardive dyskinesia at any visit after baseline, at the final visit, and at the final two clinical assessments was statistically significantly lower among olanzapine-treated patients than among haloperidol-treated patients. CONCLUSIONS: These findings support an atypical extrapyramidal symptom profile and the potential of a significantly lower risk of tardive dyskinesia with olanzapine than with haloperidol among patients requiring maintenance antipsychotic treatment.


Assuntos
Antipsicóticos/efeitos adversos , Discinesia Induzida por Medicamentos/epidemiologia , Haloperidol/efeitos adversos , Pirenzepina/análogos & derivados , Adulto , Antipsicóticos/uso terapêutico , Benzodiazepinas , Relação Dose-Resposta a Droga , Esquema de Medicação , Discinesia Induzida por Medicamentos/etiologia , Feminino , Haloperidol/uso terapêutico , Humanos , Incidência , Masculino , Olanzapina , Pirenzepina/efeitos adversos , Pirenzepina/uso terapêutico , Placebos , Transtornos Psicóticos/tratamento farmacológico , Esquizofrenia/tratamento farmacológico , Índice de Gravidade de Doença , Resultado do Tratamento
9.
J Periodontal Res ; 32(3): 287-94, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9138194

RESUMO

The formation of a biological seal around the transmucosal portion of dental implants may be crucial for the long-term success of these therapies. Data to date suggest that the gingival epithelium attaches to dental implants through the formation of hemidesmosomes. Biochemical and genetic data indicate that the laminin isoform, laminin-5, a component of basement membranes, plays a crucial role in the assembly and maintenance of hemidesmosomes. We report the use of soluble laminin-5 as a biological coating of titanium-alloy to promote cell attachment of the gingival epithelial cell line, IHGK. Monoclonal antibodies reactive with laminin-5 depleted the coating solution of all cell attachment activity and blocked cell attachment to laminin-5-coated disks. Immunodepletion with antibodies to fibronectin had no effect. Finally, we demonstrate that IHGK cells assembled hemidesmosomes within 24 h of attachment to laminin-5-coated titanium alloy but not to the titanium alloy alone. These results suggest that soluble laminin-5 may have clinical applications as a dental implant coating to promote the formation of a biological seal.


Assuntos
Moléculas de Adesão Celular/farmacologia , Adesão Celular/efeitos dos fármacos , Inserção Epitelial/efeitos dos fármacos , Ligas , Sequência de Aminoácidos , Animais , Antígenos CD/química , Moléculas de Adesão Celular/fisiologia , Células Cultivadas , Ligas Dentárias/química , Desmossomos/fisiologia , Inserção Epitelial/citologia , Inserção Epitelial/fisiologia , Humanos , Integrina beta4 , Microscopia Eletrônica , Dados de Sequência Molecular , Doenças Periodontais/microbiologia , Ratos , Propriedades de Superfície , Titânio/química , Calinina
10.
Am J Psychiatry ; 154(4): 457-65, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9090331

RESUMO

OBJECTIVE: This international, multicenter double-blind trial was designed to compare the therapeutic profile of an atypical antipsychotic, olanzapine, with that of a conventional dopamine D2 antagonist, haloperidol. METHOD: A total of 1,996 patients at 174 sites in Europe and North America were randomly assigned to treatment with olanzapine (N = 1,336) or haloperidol (N = 660) over 6 weeks. The primary efficacy analysis involved the mean change from baseline to endpoint in total scores on the Brief Psychiatric Rating Scale (BPRS). Secondary analyses included comparisons of the mean change in positive and negative symptoms, comorbid depression, extrapyramidal symptoms, and overall drug safety. RESULTS: Olanzapine demonstrated clinical results superior to those of haloperidol on overall improvement according to the BPRS and on every secondary measure, including depression. Olanzapine was also associated with significantly fewer discontinuations of treatment due to lack of drug efficacy or adverse events. Substantially more olanzapine-treated patients (66.5%) than haloperidol-treated patients (46.8%) completed 6 weeks of therapy. Statistically significant advantages of olanzapine treatment were related to 1) change in negative symptoms, 2) extrapyramidal symptom profile, 3) effect on prolactin levels, and 4) response rate. CONCLUSIONS: Olanzapine shows a superior and broader spectrum of efficacy in the treatment of schizophrenic psychopathology, with a substantially more favorable safety profile, than haloperidol. It meets several of the criteria for a novel atypical antipsychotic agent.


Assuntos
Antipsicóticos/uso terapêutico , Haloperidol/uso terapêutico , Pirenzepina/análogos & derivados , Transtornos Psicóticos/tratamento farmacológico , Esquizofrenia/tratamento farmacológico , Adolescente , Adulto , Antipsicóticos/efeitos adversos , Doenças dos Gânglios da Base/induzido quimicamente , Doenças dos Gânglios da Base/epidemiologia , Benzodiazepinas , Comorbidade , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/epidemiologia , Método Duplo-Cego , Europa (Continente) , Feminino , Haloperidol/efeitos adversos , Humanos , Masculino , América do Norte , Olanzapina , Pacientes Desistentes do Tratamento , Pirenzepina/efeitos adversos , Pirenzepina/uso terapêutico , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Transtornos Psicóticos/epidemiologia , Transtornos Psicóticos/psicologia , Esquizofrenia/epidemiologia , Psicologia do Esquizofrênico , Resultado do Tratamento
11.
J Biopharm Stat ; 6(2): 127-37, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8732909

RESUMO

The proportional odds model is illustrated in the analysis of two efficacy scales used in a phase II clinical trial involving 81 schizophrenic patients. The proportional odds model preserves the discrete, ordinal nature of one of the scales. The analysis of this data suggested that the relationship between the two scales is not captured by a linear proportional odds model. A linear model and a piecewise linear model for the explanatory variable were therefore compared using likelihood-based analyses. Residuals from both models were compared. Predicted probabilities for the ordinal categories were constructed from the estimated model. Extensions and limitations of the model for interpretation of other trials and for the planning of future trials are discussed.


Assuntos
Ensaios Clínicos Fase II como Assunto/métodos , Modelos de Riscos Proporcionais , Psiquiatria/métodos , Antipsicóticos/uso terapêutico , Benzodiazepinas , Humanos , Modelos Lineares , Estudos Multicêntricos como Assunto , Olanzapina , Pirenzepina/análogos & derivados , Pirenzepina/uso terapêutico , Esquizofrenia/tratamento farmacológico
12.
J Invest Dermatol ; 105(4): 557-61, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7561158

RESUMO

HaCaT cells, an immortalized keratinocyte line, incubated in plastic wells in the presence of conditioned medium from 804G cells adhered and spread rapidly in less than 30 min. In contrast, cells plated in fibroblast or keratinocyte conditioned medium adhered poorly and remained rounded at 30 min. Immunodepletion of 804G conditioned medium with polyclonal antisera to laminin-5r, but not control antisera, abolished rapid cell spreading. Electron microscopy of HaCaT cells spread by incubation in 804G conditioned medium, but not control medium, revealed mature hemidesmosomes after 24 h. Rapid spreading was also observed in wells precoated with 804G conditioned medium or 804G cell-deposited matrix, but not with fibronectin, vitronectin, or laminin-1. Immunoblotting of 804G conditioned medium with anti-laminin-5r antibodies unveiled polypeptides of 150, 140, 135, and 100 kDa, identical by electrophoretic mobility to immunoreactive polypeptides in 804G deposited matrix. Our results suggest that addition of laminin-5r in a soluble form is sufficient to promote rapid spreading and hemidesmosome assembly in keratinocytes. The mechanism of soluble laminin-5r action may include efficient surface "priming" for cell adhesion. Soluble laminin-5r may have a physiologic role in morphogenesis and repair of the epidermis and may be of use for therapeutic applications.


Assuntos
Junções Intercelulares/metabolismo , Queratinócitos/efeitos dos fármacos , Laminina/farmacologia , Proteínas de Neoplasias/farmacologia , Animais , Carcinoma/patologia , Adesão Celular/fisiologia , Linhagem Celular Transformada , Tamanho Celular , Meios de Cultivo Condicionados/farmacologia , Proteínas da Matriz Extracelular/farmacologia , Humanos , Soros Imunes/farmacologia , Queratinócitos/metabolismo , Queratinócitos/ultraestrutura , Ratos , Solubilidade , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/patologia , Cicatrização
13.
J Cell Sci ; 107 ( Pt 12): 3339-49, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7706390

RESUMO

In epithelial cells integrins are segregated on discrete domains of the plasma membrane. Redistribution may also occur during migration or differentiation. However, little is known about the mechanisms that control such redistribution. Receptor internalization may be a part of one such mechanism. We developed a quantitative assay and measured internalization of two epithelial integrin heterodimers, alpha 6 beta 1 and alpha 6 beta 4, induced by cross-linking with specific antibodies. alpha 6 beta 1 is a receptor for EHS laminin, while alpha 6 beta 4 is a receptor for a component of the basement membrane. alpha 6 beta 4 plays an important role in the establishment of hemidesmosomes, and becomes redistributed on the epithelial cell surface when cells are in a migratory phase. We report that alpha 6 beta 4 is efficiently internalized in human keratinocytes. More than 25% of cell surface alpha 6 beta 4 was internalized at 30 minutes, after cross-linking with A9, an anti-beta 4 monoclonal antibody. alpha 6 beta 1 is also internalized, in melanoma and teratocarcinoma cells, with maximum values of 20% of total receptors expressed at the cell surface. No significant difference was observed between the alpha 6 isoforms A and B in these assays. To determine whether alpha 6 cytoplasmic domains could influence integrin endocytosis, we prepared chimeric constructs with the extracellular domain of a reporter protein (CD8), and the cytoplasmic domains of either alpha 6 A or alpha 6 B. Both alpha 6 cytoplasmic domains but not a control cytoplasmic domain promoted internalization of the chimeric proteins, after cross-linking with antibody. Internalization of alpha 6 integrins may have a role in redistributing these receptors at the cell surface. Furthermore, the cytoplasmic domains of alpha 6 may be involved in regulating integrin internalization.


Assuntos
Antígenos de Superfície/metabolismo , Endocitose/fisiologia , Integrinas/metabolismo , Receptores de Laminina/metabolismo , Animais , Transporte Biológico , Antígenos CD8/biossíntese , Antígenos CD8/genética , Adesão Celular/fisiologia , Reagentes de Ligações Cruzadas , Imunofluorescência , Humanos , Integrina alfa6 , Integrina alfa6beta1 , Integrina alfa6beta4 , Integrinas/genética , Queratinócitos/fisiologia , Melanoma/metabolismo , Camundongos , Testes de Precipitina , Proteínas Recombinantes de Fusão/biossíntese , Relação Estrutura-Atividade , Teratocarcinoma/metabolismo , Células Tumorais Cultivadas
15.
Biometrics ; 49(1): 249-58, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8513107

RESUMO

The use of valid constrained randomization is presented for a therapeutic efficacy trial. The construction and evaluation of randomization schemes are studied for two treatment replicates per block and for hypothesized linear gradients. Two different isomorphism classes of designs are compared using the variance of the mean squared error criterion. The results indicate that valid constrained randomization schemes can be constructed that are superior to ordinary randomization. A mastitis efficacy trial provided the specific problem to be solved.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Animais , Biometria , Bovinos , Feminino , Mastite Bovina/tratamento farmacológico , Modelos Estatísticos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/veterinária
16.
Neurotoxicol Teratol ; 14(3): 205-10, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1635541

RESUMO

In many toxicology studies, it is common to take the same measurements on an individual animal at several time points (e.g., body weight across days or weeks, activity levels either within a single test session or across days). Such repeated measures for both maternal and offspring endpoints routinely are incorporated into developmental toxicology studies to allow characterization of the profile of treatment-related effects over time. To permit a valid statistical analysis, repeated measures studies are characterized by: random assignment of treatment to experimental units, measurement of the variable(s) of interest at the same time points for all animals, and avoidance of systematic overlaying of treatment and potential response gradients. Assumptions for and advantages of the use of a repeated measures analysis of variance versus single-factor analyses at each time point are illustrated in two data sets from a rat perinatal and postnatal study. The variance-covariance structure of repeated measures designs dictates that adjustments are necessary to provide protection against inflated Type 1 error rates. Communication between statisticians and toxicologists which allow the implementation of such analyses can improve the interpretation of data resulting from repeated measures study designs.


Assuntos
Interpretação Estatística de Dados , Sistema Nervoso/efeitos dos fármacos , Análise de Variância , Animais , Sistema Nervoso/embriologia , Sistema Nervoso/crescimento & desenvolvimento
17.
J Cell Biol ; 115(3): 843-50, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1833411

RESUMO

Laminin is the first extracellular matrix protein expressed in the developing mouse embryo. It is known to influence morphogenesis and affect cell migration and polarization. Several laminin receptors are included in the integrin family of extracellular matrix receptors. Ligand binding by integrin heterodimers results in signal transduction events controlling cell motility. We report that the major laminin receptor on murine embryonic stem (ES) cells is the integrin heterodimer alpha 6 beta 1, an important receptor for laminin in neurons, lymphocytes, macrophages, fibroblasts, platelets and other cell types. However, the cytoplasmic domain of the ES cell alpha 6 (alpha 6 B) differs totally from the reported cytoplasmic domain amino acid sequence of alpha 6 (alpha 6 A). Comparisons of alpha 6 cDNAs from ES cells and other cells suggest that the alpha 6 A and alpha 6 B cytoplasmic domains derive from alternative mRNA splicing. Anti-peptide antibodies to alpha 6 A are unreactive with ES cells, but react with mouse melanoma cells and embryonic fibroblasts. When ES cells are cultured under conditions that permit their differentiation, they become positive for alpha 6 A, concurrent with the morphologic appearance of differentiated cell types. Thus, expression of the alpha 6 B beta 1 laminin receptor may be favored in undifferentiated, totipotent cells, while the expression of alpha 6 A beta 1 receptor occurs in committed lineages. While the functions of integrin alpha chain cytoplasmic domains are not understood, it is possible that they contribute to transferring signals to the cell interior, e.g., by delivering cytoskeleton organizing signals in response to integrin engagement with extracellular matrix ligands. It is therefore reasonable to propose that the cellular responses to laminin may vary, according to what alpha subunit isoform (alpha 6 A or alpha 6 B) is expressed as part of the alpha 6 beta 1 laminin receptor. The switch from alpha 6 B to alpha 6 A, if confirmed in early embryos, could then be of striking potential relevance to the developmental role of laminin.


Assuntos
Integrinas/genética , Receptores de Antígenos/genética , Receptores Imunológicos/genética , Células-Tronco/fisiologia , Sequência de Aminoácidos , Animais , Anticorpos , Sequência de Bases , Adesão Celular , Linhagem Celular , Embrião de Mamíferos , Proteínas da Matriz Extracelular/análise , Integrinas/análise , Camundongos , Dados de Sequência Molecular , Peso Molecular , Peptídeos/síntese química , Peptídeos/imunologia , Reação em Cadeia da Polimerase/métodos , Receptores Imunológicos/análise , Receptores de Laminina , Homologia de Sequência do Ácido Nucleico , Células-Tronco/citologia
18.
Proc Natl Acad Sci U S A ; 88(22): 10183-7, 1991 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-1946438

RESUMO

The integrin heterodimers composed of the alpha 6 subunit with the beta 1 or beta 4 subunit (alpha 6 beta 1 and alpha 6 beta 4) are receptors for laminin and basement membrane components, respectively. The alpha 3 beta 1 integrin recognizes laminin, collagen, fibronectin, or epiligrin. We report the identification of structural variants (A and B) of the alpha 6 and alpha 3 subunits, containing distinct cytoplasmic domains. The expression of one cytoplasmic domain or the other, based probably on alternative exon usage, is cell-type dependent. Most transformed cell lines express both alpha 6A and alpha 6B isoforms, as determined by mRNA amplification or antibody immunoprecipitation. In contrast, embryonic fibroblasts express exclusively alpha 6A, and embryonic stem cells express exclusively alpha 6B. In most normal tissues, both alpha 6 isoforms are detectable, but several tissues express either alpha 6A or alpha 6B. The alpha 3B mRNA was amplified from heart and brain, while all other tissues and cell lines tested contained only alpha 3A mRNA. Alternative cytoplasmic domains may provide a means for varying the cellular responses to the ligands of alpha 6 and alpha 3 integrins according to the cell type.


Assuntos
Variação Genética , Integrinas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Cricetinae , Citoplasma/fisiologia , Expressão Gênica , Humanos , Immunoblotting , Substâncias Macromoleculares , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , Homologia de Sequência do Ácido Nucleico
19.
Fundam Appl Toxicol ; 17(3): 482-93, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1794652

RESUMO

The toxicity and leukopenia produced by vinblastine or desacetyl vinblastine were established in 1-month studies in rats. Groups of male Fischer 344 rats were given weekly intravenous doses of vinblastine or desacetyl vinblastine at doses of 0.08, 0.16, 0.32, 0.64, or 1.28 mg/kg. The target organ toxicity was similar for both compounds. Decreased cell production in the thymus, testes, and bone marrow was produced in the animals of the two highest dose groups for both compounds with the degree of severity greater in the highest dose group. All high dose rats (1.28 mg/kg) given desacetyl vinblastine and three rats given vinblastine died prior to study termination. Body weight loss was more pronounced in high dose rats given desacetyl vinblastine, but at lower doses there were no significant differences in body weight reduction for rats receiving either compound. Leukopenia occurred at all dose levels of 0.32 mg/kg and higher. During the first 2 weeks of the study, rats given 1.28 mg/kg of desacetyl vinblastine had a greater leukopenic response than rats given 1.28 mg/kg of vinblastine. It is concluded that both compounds produced similar target organ toxicity and leukopenia without deaths at doses of 0.32 and 0.64 mg/kg given once a week for 4 weeks. At the high dose (1.28 mg/kg) desacetyl vinblastine was more toxic than vinblastine resulting in greater mortality and body weight reduction.


Assuntos
Leucopenia/induzido quimicamente , Vimblastina/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Medula Óssea/patologia , Injeções Intravenosas , Contagem de Leucócitos/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos F344 , Testículo/efeitos dos fármacos , Timo/efeitos dos fármacos
20.
J Cell Biol ; 113(2): 405-16, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1826298

RESUMO

The integrin alpha 6 beta 1 is a prominent laminin receptor used by many cell types. In the present work, we isolate clones and determine the primary sequence of the chick integrin alpha 6 subunit. We show that alpha 6 beta 1 is a prominent integrin expressed by cells in the developing chick retina. Between embryonic days 6 and 12, both retinal ganglion cells and other retinal neurons lose selected integrin functions, including the ability to attach and extend neurites on laminin. In retinal ganglion cells, we show that this is correlated with a dramatic decrease in alpha 6 mRNA and protein, suggesting that changes in gene expression account for the developmental regulation of the interactions of these neurons with laminin. In other retinal neurons the expression of alpha 6 mRNA and protein remains high while function is lost, suggesting that the function of the alpha 6 beta 1 heterodimer in these cells is regulated by posttranslational mechanisms.


Assuntos
Regulação da Expressão Gênica , Integrinas/genética , Receptores Imunológicos/genética , Retina/crescimento & desenvolvimento , Sequência de Aminoácidos , Animais , Sequência de Bases , Embrião de Galinha , Clonagem Molecular , DNA , Humanos , Integrinas/metabolismo , Dados de Sequência Molecular , Testes de Precipitina , Biossíntese de Proteínas , Receptores Imunológicos/metabolismo , Receptores de Laminina , Mapeamento por Restrição , Retina/metabolismo , Células Ganglionares da Retina/metabolismo , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica
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