RESUMO
Syndemics, or comorbid and mutually reinforcing psychosocial problems, are associated with increased HIV risk among men who have sex with men (MSM). Although the dynamic interplay among syndemic indicators is theorized to be crucial for increasing risk of HIV acquisition, novel approaches are needed to understand how these syndemic problems interrelate. This study examined the associations between nine self-reported syndemic indicators in 194 MSM at high risk of HIV acquisition. We compared exploratory factor analyses (EFA) to a network analysis. In the present study, network analysis consisted of edges representing bidirectional partial polychoric correlations between nodes, which represent psychosocial syndemic indicators. EFA yielded a 1-factor solution including suicidal ideation (SI), injection drug use (IDU), depression, social anxiety, intimate partner violence, substance use, and sexual compulsivity, and excluded heavy drinking and childhood sexual abuse. Network analysis yielded a pattern of interconnectedness with the most central nodes being SI, IDU, substance use, and depression. Statistically significant relationships (absolute edge weights) were found between SI and depression, social anxiety, and IDU, and IDU and substance use. These results suggest that depression and substance use, especially more severe presentations of these conditions such as SI and IDU, are prominent interconnected components of the HIV syndemic among MSM at high risk for HIV acquisition. SI, IDU, substance use, and depression may indeed be prudent targets of intervention. Future research on the inclusion of these syndemic indicators in analytical models involving interaction terms may be warranted.
Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Transtornos Relacionados ao Uso de Substâncias , Criança , Análise Fatorial , Homossexualidade Masculina , Humanos , Masculino , Comportamento Sexual , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Sindemia , Sexo sem ProteçãoRESUMO
Schizophrenia is associated with alterations in working memory that reflect dysfunction of dorsolateral prefrontal cortex (DLPFC) circuitry. Working memory depends on the activity of excitatory pyramidal cells in DLPFC layer 3 and, to a lesser extent, in layer 5. Although many studies have profiled gene expression in DLPFC gray matter in schizophrenia, little is known about cell-type-specific transcript expression in these two populations of pyramidal cells. We hypothesized that interrogating gene expression, specifically in DLPFC layer 3 or 5 pyramidal cells, would reveal new and/or more robust schizophrenia-associated differences that would provide new insights into the nature of pyramidal cell dysfunction in the illness. We also sought to determine the impact of other variables, such as a diagnosis of schizoaffective disorder or medication use at the time of death, on the patterns of gene expression in pyramidal neurons. Individual pyramidal cells in DLPFC layers 3 or 5 were captured by laser microdissection from 36 subjects with schizophrenia or schizoaffective disorder and matched normal comparison subjects. The mRNA from cell collections was subjected to transcriptome profiling by microarray followed by quantitative PCR validation. Expression of genes involved in mitochondrial (MT) or ubiquitin-proteasome system (UPS) functions were markedly downregulated in the patient group (P-values for MT-related and UPS-related pathways were <10(-7) and <10(-5), respectively). MT-related gene alterations were more prominent in layer 3 pyramidal cells, whereas UPS-related gene alterations were more prominent in layer 5 pyramidal cells. Many of these alterations were not present, or found to a lesser degree, in samples of DLPFC gray matter from the same subjects, suggesting that they are pyramidal cell specific. Furthermore, these findings principally reflected alterations in the schizophrenia subjects were not present or present to a lesser degree in the schizoaffective disorder subjects (diagnosis of schizoaffective disorder was the most significant covariate, P<10(-6)) and were not attributable to factors frequently comorbid with schizophrenia. In summary, our findings reveal expression deficits in MT- and UPS-related genes specific to layer 3 and/or layer 5 pyramidal cells in the DLPFC of schizophrenia subjects. These cell type-specific transcriptome signatures are not characteristic of schizoaffective disorder, providing a potential molecular-cellular basis of differences in clinical phenotypes.
Assuntos
Regulação da Expressão Gênica/fisiologia , Córtex Pré-Frontal/patologia , Transtornos Psicóticos/patologia , Células Piramidais/metabolismo , Esquizofrenia/patologia , Transcriptoma/fisiologia , Adulto , Análise de Variância , Animais , Antipsicóticos/farmacologia , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Microdissecção e Captura a Laser , Macaca fascicularis , Masculino , Pessoa de Meia-Idade , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Córtex Pré-Frontal/efeitos dos fármacos , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Ubiquitina/genética , Ubiquitina/metabolismoRESUMO
A novel gene, designated byr4, was identified in Schizosaccharomyces pombe that affects the mitotic cell cycle and shows genetic interactions with the ras1 signaling pathways. Null alleles of byr4 cause cell cycle arrest in late mitosis and permit multiple rounds of septation. The multiple septa typically divide two nuclei, but the nuclei frequently do not stain equally with 4',6-diamidino-2-phenylindole (DAPI), suggesting that byr4 is required for proper karyokinesis. Overexpression of byr4 inhibits cytokinesis, but cell cycle progression continues leading to multinucleate cells. When byr4 is overexpressed, the early steps in the cytokinesis pathway, including formation of the medial F-actin ring, occur normally; however, the later steps in the pathway, including contraction of the F-actin ring, septation, and rearrangement of the medial F-actin following mitosis, rarely occur, byr4 shows two genetic interactions with ras1. The inhibition of cytokinesis by byr4 overexpression was exacerbated by null alleles of ras1 and scd1, suggesting a link between pathways needed for cell polarity and cytokinesis. Overexpression of byr4 also partially bypasses the need for ras1 for sporulation. The electrophoretic mobility of the byr4 protein varied in response to mutants that perturb cytokinesis and karyokinesis, suggesting interactions between byr4 and these gene products. A more rapidly migrating byr4 protein was found in cells with mutations in cdc16, which undergo repeated septation, and in cdc15, which fail to form a medial F-actin ring in mitosis. A slower migrating byr4 protein was found in cells with a mutation in the beta-tubulin gene, which arrests cells at the metaphase-anaphase transition.
Assuntos
Proteínas Fúngicas/genética , Genes Fúngicos/genética , Genes Supressores/genética , Genes ras/genética , Fatores de Troca do Nucleotídeo Guanina , Proteínas Repressoras , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces/citologia , Actinas/análise , Sequência de Aminoácidos , Proteínas de Ciclo Celular/genética , Divisão Celular/genética , Núcleo Celular/química , Polaridade Celular , DNA Fúngico/análise , Proteínas Fúngicas/análise , Proteínas Fúngicas/biossíntese , Genes cdc/genética , Mitose/genética , Dados de Sequência Molecular , Proteínas Proto-Oncogênicas/genética , RNA Fúngico/análise , RNA Mensageiro/análise , Schizosaccharomyces/genética , Schizosaccharomyces/fisiologia , Esporos Fúngicos , Proteínas ras/genéticaRESUMO
Glycosylphosphatidylinositol (GPI) serves as a membrane anchor for a large number of eukaryotic proteins. A genetic approach was used to investigate the biosynthesis of GPI anchor precursors in mammalian cells. T cell hybridoma mutants that cannot synthesize dolichol-phosphate-mannose (Dol-P-Man) also do not express on their surface GPI-anchored proteins such as Thy-1 and Ly-6A. These mutants cannot form mannose-containing GPI precursors. Transfection with the yeast Dol-P-Man synthase gene rescues the synthesis of both Dol-P-Man and mannose-containing GPI precursors, as well as the surface expression of Thy-1 and Ly-6A, suggesting that Dol-P-Man is the donor of at least one mannose residue in the GPI core.
Assuntos
Genes Fúngicos , Glicolipídeos/biossíntese , Fosfatidilinositóis/biossíntese , Transfecção , Animais , Antígenos Ly/metabolismo , Antígenos de Superfície/metabolismo , Membrana Celular/fisiologia , Dolicol Monofosfato Manose/metabolismo , Glicosilfosfatidilinositóis , Hibridomas , Ratos , Saccharomyces cerevisiae/genética , Antígenos Thy-1RESUMO
BACKGROUND: Spatial and temporal control of cytokinesis ensures the accurate transmission of genetic material and the correct development of multicellular organisms. An excellent model system in which to study cytokinesis is Schizosaccharomyces pombe because there are similarities between cytokinesis in S. pombe and mammals and because genes involved in S. pombe cytokinesis have been characterized. In particular, formation of the septum is positively regulated by the Spg1 GTPase and its effector, the Cdc7 kinase. Septation is negatively regulated by Cdc16, a protein similar to GTPase-activating proteins (GAPs) for Ypt GTPases, and by Byr4, a protein of unknown biochemical function. This study investigates the relationship between Byr4, Cdc16, and Spg1. RESULTS: Genetic interactions were observed between byr4, cdc16, and spg1 mutants. Byr4 bound to Cdc16 and Spg1 in yeast two-hybrid assays and in coprecipitations in vitro and in yeast. Byr4 inhibited the dissociation and hydrolysis of GTP bound to Spg1, but when Byr4 and Cdc16 were combined together they displayed Spg1GAP activity in vitro; Cdc16 alone had no detectable GAP activity. The binding of Byr4 to Spg1 and the Byr4-Cdc16 Spg1GAP activity were specific because Byr4 and Cdc16 did not bind to or affect the GTPase activities of the seven known S pombe Ypt family GTPase. CONCLUSIONS: Byr4 and Cdc16 form a two-component GAP for the Spg1 GTPase. Byr4 and Cdc16 appear to negatively regulate septation in S. pombe by modulating the nucleotide state of Spg1 possibly in a spatially or temporally controlled manner.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Fúngicas/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Proteínas Repressoras , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces/citologia , Proteínas de Ciclo Celular/genética , Divisão Celular , Ativação Enzimática , Proteínas Fúngicas/genética , GTP Fosfo-Hidrolases/genética , Guanosina Trifosfato/metabolismo , Hidrólise , Mutação , Ligação Proteica , Proteínas Recombinantes de Fusão , Schizosaccharomyces/enzimologiaRESUMO
The Saccharomyces cerevisiae DPM1 gene product, dolichol-phosphate-mannose (Dol-P-Man) synthase, is involved in the coupled processes of synthesis and membrane translocation of Dol-P-Man. Dol-P-Man is the lipid-linked sugar donor of the last four mannose residues that are added to the core oligosaccharide transferred to protein during N-linked glycosylation in the endoplasmic reticulum. We present evidence that the S. cerevisiae gene DPM1, when stably transfected into a mutant Chinese hamster ovary cell line, B4-2-1, is able to correct the glycosylation defect of the cells. Evidence for complementation includes (i) fluorescence-activated cell sorter analysis of differential lectin binding to cell surface glycoproteins, (ii) restoration of Dol-P-Man synthase enzymatic activity in crude cell lysates, (iii) isolation and high-performance liquid chromatography fractionation of the lipid-linked oligosaccharides synthesized in the transfected and control cell lines, and (iv) the restoration of endoglycosidase H sensitivity to the oligosaccharides transferred to a specific glycoprotein synthesized in the DPM1 CHO transfectants. Indirect immunofluorescence with a primary antibody directed against the DPM1 protein shows a reticular staining pattern of protein localization in transfected hamster and monkey cell lines.
Assuntos
Genes Fúngicos , Hexosiltransferases/genética , Manosiltransferases/genética , Mutação , Saccharomyces cerevisiae/genética , Transfecção , Animais , Linhagem Celular , Vetores Genéticos , Glicoproteínas/biossíntese , Glicosilação , Cinética , Manosiltransferases/metabolismo , Oligossacarídeos/isolamento & purificação , Oligossacarídeos/metabolismo , Saccharomyces cerevisiae/enzimologiaRESUMO
Further support for the pump-leak concept was obtained. Net transport was resolved into pump and leak components with the cardiac glycoside, ouabain. The specificity of ouabain as a pump inhibitor was demonstrated by its ineffectiveness when the pump was already inhibited by lack of one of the three pump substrates, sodium ion, potassium ion, or adenosine triphosphate. In the presence of ouabain the rates of passive transport of sodium and potassium ions changed almost in proportion to changes in their extracellular concentrations when one ion was exchanged for the other. In the presence of ouabain and at the extracellular concentrations which produced zero net transport, the ratio of potassium ions to sodium ions was 1.2-fold higher inside the cells than outside. This finding was attributed to a residual pump activity of less than 2% of capacity. The permeability to potassium ions was 10% greater than the permeability to sodium ions. A test was made of the independence of pump and leak. Conditions were chosen to change the rate through each pathway separately or in combination. When both pathways were active, net transport was the sum of the rates observed when each acted separately. A ratio of three sodium ions pumped outward per two potassium ions pumped inward was confirmed.
Assuntos
Transporte Biológico , Eritrócitos/metabolismo , Ouabaína/farmacologia , Potássio/metabolismo , Sódio/metabolismo , Trifosfato de Adenosina/metabolismo , Permeabilidade da Membrana Celular , Humanos , Matemática , Equilíbrio HidroeletrolíticoRESUMO
The Rheb GTPase is most similar in primary sequence to the Ras, Rap, R-Ras, and Ral GTPases, which regulate cell growth and differentiation in many cell types. A likely fission yeast homologue of mammalian Rheb, which we designated Rhb1, was identified by genome sequencing. Our investigation of rhb1 showed that rhb1(-) cells arrested cell growth and division with a terminal phenotype similar to that of nitrogen-starved cells. In particular, cells depleted of Rhb1 arrested as small, round cells with 1N DNA content, arrested more quickly in low-nitrogen medium, and induced expression of fnx1 and mei2 mRNA, two mRNAs that were normally induced by nitrogen starvation. Since mammalian Rheb binds and may regulate Raf-1, a Ras effector, we tested for functional overlap between Ras1 and Rhb1 in fission yeast. This analysis showed that Ras1 overexpression did not suppress rhb1(-) mutant phenotypes, Rhb1 overexpression did not suppress ras1(-) mutant phenotypes, and ras1(-) rhb1(-) double mutants had phenotypes equal to the sum of the corresponding single-mutant phenotypes. Hence, there is no evidence for overlapping functions between Ras1 and Rhb1. On the basis of this study, we hypothesize that Rhb1 negatively regulates entry into stationary phase when extracellular nitrogen levels are adequate for growth. If this hypothesis is correct, then Rhb1 and Ras1 regulate alternative responses to limiting nutrients.
Assuntos
Divisão Celular/genética , GTP Fosfo-Hidrolases/genética , Substâncias de Crescimento , Nitrogênio/deficiência , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces/genética , Sequência de Aminoácidos , AMP Cíclico/metabolismo , GTP Fosfo-Hidrolases/química , Dados de Sequência Molecular , Mutação , Fenótipo , Schizosaccharomyces/citologia , Homologia de Sequência de AminoácidosRESUMO
Fewer ethnic minorities, especially Asian-Americans, become organ donors. There are cultural, religious, and personal barriers to becoming a designated organ donor. Factors that promote or inhibit organ donation in Asians, especially Filipinos, are not well understood. We conducted a series of focus groups to identify barriers and facilitators to organ donation (deceased donor) among Filipinos. Six focus groups were conducted with church members, adolescents, nurses, physicians, organ recipients, and organ donor families. The mean age of adult participants (n = 57) was 52.3 +/- 15 years, 83% were Catholic, and 72% were female. A qualitative theme analysis methodology identified dominant themes related to organ donation in the participants. The major themes were: awareness of organ donation (38%), family beliefs (25%), religion/spirituality (10%), attitude/emotions (10%), personal experience with organ donation (8%), health profession (6%), and cultural issues (3%). Seventy-five percent of the comments about awareness reflected a positive awareness of cultural issues regarding organ donation, and the rest reflected a lack of awareness or misconceptions. Almost every theme was mentioned in all six focus groups. Understanding a specific ethnic group's knowledge, attitudes, and cultural beliefs regarding organ donation is important in the development of educational campaigns to encourage organ donation in ethnic minority populations.
Assuntos
Etnicidade , Conhecimentos, Atitudes e Prática em Saúde , Doadores de Tecidos/psicologia , Coleta de Tecidos e Órgãos/métodos , Adolescente , Asiático/psicologia , Povo Asiático , Cadáver , Demografia , Humanos , Pessoa de Meia-Idade , FilipinasRESUMO
A chitinase (Cht)-encoding gene from Streptomyces plicatus was previously cloned and expressed in Escherichia coli [Robbins et al., J. Biol. Chem., 263 (1988) 442-447]. We have sequenced this gene, compared its sequence with other genes encoding Cht and have explored its expression and regulation when reintroduced into Streptomyces lividans on multicopy plasmids. We have also cloned two other Streptomyces Cht-encoding genes and a beta-hexosaminidase-encoding gene in E. coli by expression in the lambda ZAP-Bluescript vector. The hexosaminidase and one of the Chts were expressed directly from the genomic library in E. coli at a high level as chimeric fusions with the beta-galactosidase alpha-complementing peptide encoded by the vector. Direct cloning and high-level expression of such chimeric proteins, which overcomes the difficulties associated with expressing Streptomyces genes in E. coli, should generally be possible wherever large numbers of transformants can be conveniently screened.
Assuntos
Quitinases/genética , Genes Bacterianos , Streptomyces/genética , Sequência de Aminoácidos , Sequência de Bases , Western Blotting , Quitinases/metabolismo , Clonagem Molecular , DNA Bacteriano , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Streptomyces/enzimologia , beta-N-Acetil-Hexosaminidases/genética , beta-N-Acetil-Hexosaminidases/metabolismoRESUMO
The activation of mitogen-activated protein (MAP) kinase cascades by the Ras GTPase is an evolutionarily conserved signal transduction mechanism. To better understand the interaction between Ras and its target kinase, we study the yeast Schizosaccharomyces pombe where the Ras1 GTPase activates the Byr2 kinase. The Byr2 kinase contains an N-terminal regulatory region and a C-terminal kinase region. The regulatory region can be divided into a sterile-alpha motif (SAM) that binds Ste4, a Ras1-binding domain (RBD) that binds activated Ras1, and a catalytic binding domain (CBD) that interacts with the Byr2 kinase domain. To analyze the importance of functional domains of the Byr2 kinase, a biological assay was used that exploited the ability of Byr2 to partially bypass the need for Ras1 in sporulation. Analysis of mutants using this assay showed that SAM and RBD were very important for Ras1-stimulated sporulation. Three activating mutations were identified within the N-terminal lobe of the Byr2 kinase domain that partially bypassed the need for Ras1 for sporulation. These activating mutations may identify a region of the Byr2 kinase domain that interacts with the CBD since mutations in the CBD which disrupt binding to the kinase domain also increase Byr2 function.
Assuntos
Proteínas Fúngicas/metabolismo , Subunidades beta da Proteína de Ligação ao GTP , Proteínas Heterotriméricas de Ligação ao GTP , MAP Quinase Quinase Quinases , Proteínas Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae , Proteínas de Schizosaccharomyces pombe , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas de Ligação ao GTP/metabolismo , Mutação , Ligação Proteica , Proteínas Quinases/química , Proteínas Quinases/genética , Deleção de Sequência , Proteínas ras/metabolismoRESUMO
A centrifugation technique was developed and used to separate fixed cells from the sputa of patients with bronchogenic squamous cell carcinoma and ones with no evidence of cancer. This article presents the relative frequencies of occurrence of five cell types (i.e., leukocytes, macrophages, squamous, columnar and atypical/cancer) in specimen fractions separated from a discontinuous aqueous Ficoll density gradient. These differential counts show that individual cell types may be selectively collected. Atypical and cancer cells are found at high-density gradient fractions (p congruent to 1.138-1.155 g/ml) with a 10-fold enrichment over unprocessed samples.
Assuntos
Carcinoma Broncogênico/patologia , Carcinoma de Células Escamosas/patologia , Separação Celular/métodos , Centrifugação com Gradiente de Concentração , Neoplasias Pulmonares/patologia , Escarro/citologia , HumanosRESUMO
Two physical parameters were investigated to automatically recognize cells in sputum from human squamous cell carcinoma of the lung and to separate them for preparation by the Papanicolaou methods, for human interactive identification and for automated high resolution image analysis. The two parameters, 0.5-15.0 degrees forward argon-ion laser light scatter to estimate total cell size and 546 nm Acridine orange fluorescence to approximate total cell DNA content, were measured in a flow-through fluorescence activated cell sorting system. Enrichment for neoplastic cells in three cases of squamous cell carcinoma of the lung averaged 7.8-fold over the original sputum when only green fluorescence was used and 10.5-fold using green fluorescence and forward light scatter. The average enrichment for neoplastic cells was 65.6-fold relative to polymorphonuclear deenrichment.
Assuntos
Carcinoma de Células Escamosas/diagnóstico , Técnicas Citológicas , Fluorescência , Neoplasias Pulmonares/diagnóstico , Espalhamento de Radiação , Diagnóstico Diferencial , Humanos , Luz , Masculino , Escarro/citologia , Coloração e RotulagemRESUMO
Two fluorescence parameters and size are used in a flow through system to enrich sputum specimens for cancer cells. Human cells in sputum which are stained with acridine orange show a characteristic distribution of red and green fluorescence from which cancer cells can be localized. The peak enrichment is obtained by selectively sorting cells with the largest values of red and green fluorescence. Cancer cells located in other distribution regions having smaller fluorescence intensities show progressively diminished nuclear and cytoplasmic tinctorial features by Papanicolaou stain, consistent with the decreased intensity of red and green fluorescence.
Assuntos
Carcinoma de Células Escamosas/diagnóstico , Técnicas Citológicas , Fluorescência , Neoplasias Pulmonares/diagnóstico , Espalhamento de Radiação , Técnicas Citológicas/instrumentação , Diagnóstico Diferencial , Humanos , Luz , Escarro/citologia , Coloração e RotulagemRESUMO
Fluorescence spectra were obtained from cells from sputum and pleural effusions stained with different fluorescent dyes and fixed by alternate methods. The spectra were referenced to a standard allowing for fluorescence comparisons of unstained and stained cells under various conditions. The metachromasia of acridine orange-stained cells offers nuclear/cytoplasmic differentiation in a single stain; mithramycin and propidium iodide do not. Unstained cells have an appreciable amount of green (546 nm) fluorescence, as does Carbowax in Saccomanno's preservative. Cytoplasm stained with acidine orange also has appreciable green fluorescence. Consequently, cells with much cytoplasm have high total fluorescence. Cytoplasmic fluorescence is negligible with mithramycin or propidium iodide. The metachromasia of acridine orange-stained cells is altered by alcohol and Carbowax levels in fixatives, keeping other factors constant.
Assuntos
Laranja de Acridina , Técnicas Citológicas , Neoplasias Pulmonares/diagnóstico , Derrame Pleural/citologia , Escarro/citologia , Diagnóstico Diferencial , Humanos , Espectrometria de Fluorescência , Coloração e RotulagemRESUMO
INTRODUCTION: The Activity Counseling Trial (ACT) was designed to compare the effectiveness of physician advice alone with physician advice plus behavioral counseling, provided by ACT-trained health educators, to increase levels of physical activity in healthy, sedentary patients. The objective was to determine health care providers' adherence to the ACT protocol for delivering initial "physician" advice on physical activity and to determine providers' satisfaction with the protocol. METHODS: Fifty-four physicians or physician assistants from 11 primary care practices located in California, Texas, and Tennessee volunteered to participate as ACT-trained physicians. Providers were trained to integrate 3 to 4 minutes of initial physical activity advice into the routine office visits of sedentary patients, aged 35 to 75 years, with no acute or serious chronic conditions. This advice included assessment of current physical activities, advising the patient about an appropriate physical activity goal, and referring the patient to the health educator. Providers initialed forms to document delivery of advice, and ACT health educators recorded their advice on a computerized tracking system. A provider survey measured length of time spent advising patients about physical activity and provider satisfaction with the program. RESULTS: Ninety-nine percent of patients received the initial physician advice about physical activity. Eighty-three percent of the providers spent less than 5 to 6 minutes, and 46% spent the recommended 3 to 4 minutes providing advice. Sixty-three percent said the advice resulted in little or no increase in the length of an office visit, and 83% said participation was an asset to their clinics. CONCLUSIONS: Providers incorporated brief physical activity advice into routine primary care visits with little disruption. Their response to the ACT advice protocol was positive and participation in the study was viewed as beneficial.
Assuntos
Exercício Físico , Promoção da Saúde , Educação de Pacientes como Assunto , Adulto , Idoso , Atitude do Pessoal de Saúde , Terapia Comportamental , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Atenção Primária à Saúde , Resultado do Tratamento , Estados UnidosRESUMO
Treatment of rats with choline during critical periods in brain development results in long-lasting enhancement of spatial memory in their offspring. Apoptosis is a normal process during brain development, and, in some tissues, is modulated by the availability of the nutrient choline. In these studies, we examined whether availability of choline influences apoptosis in fetal brain and in the PC12 cell line derived from a rat pheochromocytoma. Timed-bred Sprague Dawley rats were fed a choline-deficient (CD), choline-control, or choline-supplemented (CS) diet for 6 days and, on embryonic day 18, fetal brain slices were prepared and apoptosis was assessed using terminal dUTP nucleotide end labeling (TUNEL) to detect DNA strand breaks and by counting of apoptotic bodies. TUNEL-positive cells were detected in 15.9% (P < 0.01), 8.7% and 7.2% of hippocampal cells from fetuses of dams fed the CD, control or CS diets, respectively. A similar inverse relationship between dietary intake of choline and TUNEL positive cells was detected in an area of cerebral cortex from these fetal brain slices. Counts of apoptotic bodies in fetal brain slices correlated inversely with choline intake of the mothers (6.2% (P < 0.01), 2.5% and 1.9% of hippocampal cells had apoptotic bodies in fetuses of dams fed the CD, control and CS diets, respectively). PC12 cells were grown in DMEM/F12 media supplemented with 70 microM choline or with 0 microM choline. The number of apoptotic bodies in PC12 cells increased when cells were grown in 0 microM choline medium (1.5%; P < 0.05) compared to 70 microM choline medium (0.55%). In PC12 cells, TUNEL labeling (DNA strand breaks) increased in choline deficient (13.5%, P < 0.05) compared to sufficient medium (5.0%). In addition, cleavage of genomic DNA-into 200 bp internucleosomal fragments was detected in choline-deficient cells. These results show that choline deficiency induces-apoptotic cell death in neuronal-type cells and in whole brain. We suggest that variations in choline availability to brain modulate apoptosis rates during development.
Assuntos
Apoptose/efeitos dos fármacos , Encéfalo/citologia , Deficiência de Colina/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Meios de Cultura , Fragmentação do DNA , Dieta , Feminino , Células PC12 , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
Choline availability in the diet during pregnancy alters fetal brain biochemistry with resulting behavioral changes that persist throughout the lifetime of the offspring. In the present study, the effects of dietary choline on cell proliferation, migration, and apoptosis in neuronal progenitor cells in the hippocampus and septum were analyzed in fetal brains at different stages of embryonic development. Timed-pregnant rats on day E12 were fed AIN-76 diet with varying levels of dietary choline for 6 days, and, on days E18 or E20, fetal brain sections were collected. We found that choline deficiency (CD) significantly decreased the rate of mitosis in the neuroepithelium adjacent to the hippocampus. An increased number of apoptotic cells were found in the region of the dentate gyrus of CD hippocampus compared to controls (5.5+/-0.7 vs. 1.9+/-0.3 apoptotic cells per section; p<0.01). Using a combination of bromodeoxyuridine (BrdU) labeling and an unbiased computer-assisted image analysis method, we found that modulation of dietary choline availability changed the distribution and migration of precursor cells born on E16 in the fimbria, primordial dentate gyrus, and Ammon's horn of the fetal hippocampus. CD also decreased the migration of newly born cells from the neuroepithelium into the lateral septum, thus indicating that the sensitivity of fetal brain to choline availability is not restricted to the hippocampus. We found an increase in the expression of TOAD-64 protein, an early neuronal differentiation marker, in the hippocampus of CD day E18 fetal brains compared to controls. These results show that dietary choline availability alters the timing of the genesis, migration, and commitment to differentiation of progenitor neuronal-type cells in fetal brain hippocampal regions known to be associated with learning and memory processes in adult brain.
Assuntos
Química Encefálica/efeitos dos fármacos , Deficiência de Colina/fisiopatologia , Colina/farmacologia , Giro Denteado/embriologia , Núcleos Septais/embriologia , Animais , Antimetabólitos , Apoptose/fisiologia , Biomarcadores , Bromodesoxiuridina , Diferenciação Celular/fisiologia , Giro Denteado/citologia , Giro Denteado/metabolismo , Células Epiteliais/química , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Feminino , Marcação In Situ das Extremidades Cortadas , Mitose/fisiologia , Proteínas do Tecido Nervoso/análise , Neuroglia/química , Neuroglia/citologia , Neuroglia/metabolismo , Gravidez , Ratos , Ratos Sprague-Dawley , Núcleos Septais/citologia , Núcleos Septais/metabolismoRESUMO
Maternal changes in dietary choline availability alter brain biochemistry and hippocampal development in the offspring resulting in lifelong behavioral changes in the offspring. In order to better understand the relationship between maternal diet, brain cytoarchitecture and behavior, we investigated the effects of choline availability on cell proliferation, apoptosis and differentiation in the fetal rat brain septum. Timed-pregnant rats on day E12 were fed AIN-76 diet with varying levels of dietary choline for 6 days. We found that choline deficiency (CD) significantly decreased the rate of mitosis in the progenitor neuroepithelium adjacent to the septum. In addition, we found an increased number of apoptotic cells in the septum of CD animals compared to controls (3.5+/-0.5 vs. 1.7+/-0.5 apoptotic cells per section; p<0.05). However, CD had no effect on apoptosis in the indusium griseum (IG), a region of cortex dorsal to the septum. Using an unbiased image analysis method and a monoclonal antibody we found a decreased expression of the TOAD-64 kDa protein, a marker of commitment to neuronal differentiation during fetal development, in the dorsal lateral septum of CD animals. CD also decreased the expression of TOAD-64 kDa protein in the IG and cortical plate adjacent to the septum. These results show that dietary choline availability during pregnancy alters the timing of mitosis, apoptosis and the early commitment to neuronal differentiation by progenitor cells in regions of the fetal brain septum, as well as hippocampus, two brain regions known to be associated with learning and memory.
Assuntos
Apoptose/fisiologia , Dieta , Proteínas Fetais/análise , Troca Materno-Fetal/fisiologia , Mitose/fisiologia , Proteínas do Tecido Nervoso/análise , Septo Pelúcido/química , Animais , Desenvolvimento Embrionário e Fetal/fisiologia , Feminino , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Gravidez , Ratos , Ratos Sprague-Dawley , Septo Pelúcido/patologiaRESUMO
Medical school curriculum committees struggle not only with which topics to teach but also with how to teach them effectively. Even when curriculum committees or medical school deans decide to offer instruction in a new topic area, or an issue about which their students have a strong interest, they can find it difficult to find support for development of curriculum and faculty who are qualified to teach in the area. When the topic or course addresses family violence, there are additional challenges for the institution and for individual faculty members. This article describes the unique challenges facing faculty development in the field of family violence, reviews standard approaches to faculty development, and offers specific suggestions for accessing existing resources and faculty development opportunities.