RESUMO
OBJECTIVES: This study:Healthy Active and in Control (HA1C), examined the feasibility and acceptability of yoga as a complementary therapy for adults with Type-2 Diabetes (T2DM). DESIGN: A 2-arm randomized clinical trial comparing Iyengar yoga with a supervised walking program. SETTING: Hospital based gym-type facility and conference rooms. INTERVENTIONS: Participants were randomized to a 12-week program of either; (1) a twice weekly Iyengar yoga, or (2) a twice-weekly program of standard exercise (SE). MAIN OUTCOME MEASURES: Primary outcomes assessed feasibility and acceptability, including enrollment rates, attendance, study completion, and participant satisfaction. Secondary outcomes included HbA1c, physical activity, and measures of diabetes-related emotional distress, self-care and quality of life (QOL). Assessments were conducted at baseline, end of treatment, 6-months and 9-months post-enrollment. RESULTS: Of 175 adults screened for eligibility, 48 (30 women, 18 men) were eligible and enrolled. The most common reasons for ineligibility were orthopedic restrictions, HbA1c levels <6.5 and BMI > 42. Session attendance was high (82% of sessions attended), as was follow-up completion rates (92%). Program satisfaction rated on a 5-point scale, was high among both Yoga (M = 4.63, SD = 0.57) and SE (M = 4.77, SD = 0.52) participants. Overall 44 adverse events (26 Yoga, 18 SE) were reported. Of these, six were deemed "possibly related" (e.g., neck strain, back pain), and 1 "probably related" (ankle pain after treadmill) to the study. Yoga produced significant reductions in HbA1c. Median HbA1c at 6 months was 1.25 units lower for Yoga compared to SE (95% CI: -2.54 -0.04). Greater improvements in diabetes self-care, quality of life, and emotional distress were seen among Yoga participants than among SE participants. Increases in mindfulness were seen in Yoga but not in SE. CONCLUSIONS: The yoga intervention was highly feasible and acceptable, and produced improvements in blood glucose and psychosocial measures of diabetes management.
Assuntos
Terapias Complementares/psicologia , Diabetes Mellitus Tipo 2/psicologia , Yoga/psicologia , Adulto , Idoso , Exercício Físico/psicologia , Feminino , Humanos , Masculino , Meditação/psicologia , Pessoa de Meia-Idade , Atenção Plena/métodos , Satisfação do Paciente , Qualidade de Vida , Autocuidado/psicologia , Caminhada/psicologiaRESUMO
The primary goal of this article is to review theoretical models utilised in designing physical activity interventions for healthy adults. Physical activity offers numerous benefits for improved physical and psychological health. However, the majority of the population is sedentary and therefore at increased risk for morbidity and mortality. Many techniques have been developed for intervening with physical activity behaviours, some of which are based on theoretical models. While some of these models show more promise than others, no model is sufficient to thoroughly explain exercise behaviours or how to best intervene. In the final section, recommendations for future research are presented, and promising areas of development in physical activity interventions are discussed. This is not an exhaustive review of theoretical models but rather focuses on models most commonly applied to physical activity.
Assuntos
Exercício Físico/fisiologia , Exercício Físico/psicologia , Comportamentos Relacionados com a Saúde , Promoção da Saúde , Adulto , Condicionamento Operante , Tomada de Decisões , Teoria da Decisão , Feminino , Humanos , Masculino , Modelos Teóricos , MotivaçãoRESUMO
The steroid hormones estrogen (E) and progesterone (P) are known to modify pain sensitivity; however, the relative role of each of these hormones in this process is not well understood. To systematically investigate the effects of E and P on nociception, pain sensitivity was assessed under several hormone conditions. Tailflick (TF) latencies were measured every other day in 10 cycling female rats and 10 female rats during luteal functioning (pseudopregnancy). Thirty ovariectomized (OVX) rats were tested for TF latency following administration of 10 micrograms estradiol benzoate (EB) and either 0.0, 0.5, or 1.0 mg of P. Significant differences in TF latency were seen across days of the estrous cycle but not during luteal functioning. Tailflick latencies during luteal functioning were elevated relative to latencies in normally cycling animals. Among OVX rats, those administered EB and P (1.0 mg) displayed significant reductions in TF latency compared to vehicle controls. As a separate line of research indicated that consumption of highly palatable foods modified pain sensitivity, whether chronic sucrose consumption might overide the influence of hormones on nociception was examined. Ovariectomized rats given EB and P (0.0, 0.5, or 1.0 mg) were allowed chronic exposure to a 32% sucrose solution. Our preliminary findings suggest that chronic sucrose consumption attenuates hormonally induced differences in nociception.
Assuntos
Nível de Alerta/fisiologia , Estrogênios/fisiologia , Estro/fisiologia , Nociceptores/fisiologia , Progesterona/fisiologia , Tempo de Reação/fisiologia , Paladar/fisiologia , Animais , Corpo Lúteo/fisiologia , Estradiol/fisiologia , Feminino , Pseudogravidez/sangue , Ratos , Receptores Opioides/fisiologia , Limiar Sensorial/fisiologia , Sacarose , Sensação Térmica/fisiologiaRESUMO
The effects of dietary mineral levels on caloric intake, nutrient choice, body weight, adipose tissue weight, interscapular brown adipose tissue (IBAT) weight, and thermogenic capacity, and plasma insulin and glucose levels were examined in adult male Sprague-Dawley rats. In Experiments 1 and 2, rats were fed a purified diet with zinc (Zn), chromium (Cr), and selenium (Se) added, or the same diet without the addition of these minerals. In Experiment 3, the effects of Zn and Cr were examined separately. In all experiments, half of the rats in each diet group were given a 32% sucrose solution in addition to their standard diet and water. Rats given sucrose consumed more calories and gained more weight than rats not given sucrose. However, mineral levels altered the effects of sucrose on these measures. Added minerals increased percent sucrose intake, reduced weight gain and feed efficiency, increased GDP binding in IBAT mitochondria, improved glucose tolerance, and reduced plasma insulin levels. The reduction in weight gain and increased feed efficiency found when Zn alone was added to the diet was independent of sucrose condition. In comparison, the alterations observed in these measures when Cr alone was added to the diet varied as a function of sucrose availability.
Assuntos
Dieta , Minerais/farmacologia , Obesidade/fisiopatologia , Sacarose/farmacologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Cromo/farmacologia , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Teste de Tolerância a Glucose , Guanosina Difosfato/metabolismo , Insulina/sangue , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Selênio/farmacologia , Aumento de Peso/efeitos dos fármacos , Zinco/farmacologiaRESUMO
PURPOSE: This study compares the efficacy of a self-help intervention tailored to the individual's stage of motivational readiness for exercise adoption with a standard self-help exercise promotion intervention. DESIGN: Interventions were delivered at baseline and 1 month; assessments were collected at baseline and 3 months. SETTING: Eleven worksites participating in the Working Healthy Research Trial. SUBJECTS: Participants (n = 1559) were a subsample of employees at participating worksites, individually randomized to one of two treatment conditions. INTERVENTION: Printed self-help exercise promotion materials either (1) matched to the individual's stage of motivational readiness for exercise adoption (motivationally tailored), or (2) standard materials (standard). MEASURES: Measures of stage of motivational readiness for exercise and items from the 7-Day Physical Activity Recall. RESULTS: Among intervention completers (n = 903), chi-square analyses showed that, compared to the standard intervention, those receiving the motivationally tailored intervention were significantly more likely to show increases (37% vs. 27%) and less likely to show either no change (52% vs. 58%) or regression (11% vs. 15%) in stage of motivational readiness. Multivariate analyses of variance showed that changes in stage of motivational readiness were significantly associated with changes in self-reported time spent in exercise. CONCLUSIONS: This is the first prospective, randomized, controlled trial demonstrating the efficacy of a brief motivationally tailored intervention compared to a standard self-help intervention for exercise adoption. These findings appear to support treatment approaches that tailor interventions to the individual's stage of motivational readiness for exercise adoption.
Assuntos
Exercício Físico/psicologia , Promoção da Saúde/métodos , Motivação , Saúde Ocupacional , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Análise de Regressão , Rhode IslandRESUMO
While body image has been found to be an important predictor for several health behaviors (abnormal dieting. weight regain, exercise), only one study to date has examined body image attitudes in women smokers (Australian sample) with results suggesting that women smokers feel less attractive than nonsmokers. The purpose of the present study was to compare body image in women smokers to normative samples of women. Subjects were 136 women (89.0% White, M age = 39.85, 74% employed. 52% married, body mass index [BMI] = 25.54) entering a randomized clinical smoking cessation trial. Subjects completed the Appearance Evaluation and Fitness Orientation subscales of the Multidimensional Body-Self Relations Questionnaire and the Silhouette Choosing Task. Pooled t-tests showed that subjects scored significantly lower on Appearance Evaluation (t = -6.58, p < .01) and Fitness Orientation (t = -5.55, p < .01) than the normative sample. For the silhouette choosing task, the present sample reported a significantly higher current silhouette (t = 2.29, p < .05) and dissatisfaction score (t = 4.04, p < .01) than the comparative sample. There were no significant differences on the ideal or attraction scores. Results suggest that women smokers may be more dissatisfied with their bodies than women in general. Possible implications include that smoking may adversely affect body image and/or body image concerns may negatively impact cessation attempts.
Assuntos
Imagem Corporal , Fumar/psicologia , Adulto , Índice de Massa Corporal , Peso Corporal , Terapia Cognitivo-Comportamental , Terapia Combinada , Exercício Físico/psicologia , Feminino , Humanos , Pessoa de Meia-Idade , Inventário de Personalidade , Abandono do Hábito de FumarRESUMO
While Major Depressive Disorder (MDD) is associated with difficulty quitting smoking, few studies have examined the role of subsyndromal depression (SubD). We examined pretreatment differences in smoking, weight concerns, and negative affect among three groups of women (N = 281) enrolling in a smoking cessation program who responded to a self-report questionnaire about the lifetime presence of MDD symptoms: self-report positive for MDD, self-report positive for SubD, and self-report negative for depression (fulfilling either DSM-III-R symptom or duration criteria, but not both). Compared to MDD Subjects (Ss), SubD Ss were more likely to report eating disordered behaviors. Compared to Non-Depressed (Non-Dep) Ss, SubD Ss initiated smoking earlier, and reported greater previous withdrawal symptoms, more eating disordered behaviors, and higher anxiety, depression, and stress. Compared to Non-Dep Ss, MDD Ss reported a greater smoking rate during their heaviest usage period, greater previous withdrawal symptoms, lower self-efficacy to manage food intake (especially during negative affect situations), and greater depression and anxiety. Many of these significant differences disappeared when SubD Ss were combined with Non-Dep Ss and compared with MDD Ss as is done traditionally. SubD does not appear to be on a continuum with Non-Dep and MDD groups, but rather warrants further investigation as a discrete subset of smokers. The implications for assessment and treatment are discussed.
Assuntos
Peso Corporal , Depressão/psicologia , Abandono do Hábito de Fumar/psicologia , Fumar/psicologia , Adulto , Ansiedade/psicologia , Depressão/complicações , Feminino , Humanos , Pessoa de Meia-Idade , Autoimagem , Estresse Psicológico , SíndromeRESUMO
This study investigated both acute and longer term ("chronic") effects of vigorous exercise training on affect, nicotine withdrawal, and cigarette craving among women enrolled in a smoking cessation research study. All subjects participated in a 12-week cognitive behavioral smoking cessation program and were randomly assigned to attend three sessions per week of either a vigorous exercise program or contact control. Measures of positive and negative affect, cigarette craving, and nicotine withdrawal were administered immediately before, and again immediately after the final exercise or contact session each week of the program. Study I enrolled 24 women who had been assigned to the exercise condition. Significant reductions in negative affect, nicotine withdrawal and cigarette craving were observed following exercise most weeks of the program. No significant changes in positive affect were observed. In Study II this protocol was repeated among 62 women (44 exercise, 18 contact control) in two consecutive cohorts of the larger study. Significant reduction were observed in negative affect, nicotine withdrawal and cigarette craving during most weeks of the program among exercise subjects but not contact condition subjects. No chronic (baseline to posttreatment) changes in positive or negative affect, cigarette craving or withdrawal symptoms were observed in either study. Vigorous exercise appears to produce acute improvements in withdrawal symptoms, cigarette craving, and negative affect among sedentary women attempting to quit smoking.
Assuntos
Afeto , Exercício Físico/psicologia , Nicotiana , Plantas Tóxicas , Abandono do Hábito de Fumar/psicologia , Síndrome de Abstinência a Substâncias/diagnóstico , Síndrome de Abstinência a Substâncias/psicologia , Adulto , Comportamento Aditivo/psicologia , Estudos de Coortes , Feminino , Humanos , Distribuição Aleatória , Inquéritos e QuestionáriosRESUMO
This study examined characteristics associated with weight control smoking among 281 sedentary women enrolled in a smoking cessation trial. A series of regression models were developed to identify predictors of weight control smoking as measured by the Smoking Situations Questionnaire. Predictor variables included demographic variables, dietary intake, weight gain following previous quit attempts, dietary restraint, self-efficacy for weight management, smoking behavior, exercise behavior, negative affect and psychological constructs relevant to smoking cessation, and exercise adoption. In the final predictor model, anticipation of weight gain in the current quit attempt, higher dietary restraint, younger age, greater Fagerstrom scores, greater number of pounds gained in previous quit attempts, and lower levels of self-efficacy to manage weight in negative affect situations were associated with smoking for weight control. Treatment implications for women who smoke for weight control reasons are discussed.
Assuntos
Atitude Frente a Saúde , Dieta Redutora/psicologia , Motivação , Fumar/psicologia , Adulto , Ansiedade/complicações , Estudos de Coortes , Estudos Transversais , Exercício Físico/psicologia , Comportamento Alimentar , Feminino , Humanos , Estilo de Vida , Pessoa de Meia-Idade , Atividade Motora , Análise de Regressão , AutoeficáciaRESUMO
PEA-15 (phosphoprotein enriched in astrocytes 15 kDa) is a death effector domain-containing protein, which is involved in the regulation of apoptotic cell death. Since PEA-15 is highly expressed in cells of glial origin, we studied the role of PEA-15 in human malignant brain tumors. Immunohistochemical analysis of PEA-15 expression shows strong immunoreactivity in astrocytomas and glioblastomas. Phosphorylation of PEA-15 at Ser(116) is found in vivo in perinecrotic areas in glioblastomas and in vitro after glucose deprivation of glioblastoma cells. Overexpression of PEA-15 induces a marked resistance against glucose deprivation-induced apoptosis, whereas small interfering RNA (siRNA)-mediated downregulation of endogenous PEA-15 results in the sensitization to glucose withdrawal-mediated cell death. This antiapoptotic activity of PEA-15 under low glucose conditions depends on its phosphorylation at Ser(116). Moreover, siRNA-mediated knockdown of PEA-15 abolishes the tumorigenicity of U87MG glioblastoma cells in vivo. PEA-15 regulates the level of phosphorylated extracellular-regulated kinase (ERK)1/2 in glioblastoma cells and the PEA-15-dependent protection from glucose deprivation-induced cell death requires ERK1/2 signaling. PEA-15 transcriptionally upregulates the Glucose Transporter 3, which is abrogated by the inhibition of ERK1/2 phosphorylation. Taken together, our findings suggest that Ser(116)-phosphorylated PEA-15 renders glioma cells resistant to glucose deprivation-mediated cell death as encountered in poor microenvironments, for example in perinecrotic areas of glioblastomas.
Assuntos
Apoptose/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , Glioblastoma/enzimologia , Glucose/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Fosfoproteínas/fisiologia , Animais , Proteínas Reguladoras de Apoptose , Neoplasias Encefálicas/enzimologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular , Glioblastoma/metabolismo , Glioblastoma/patologia , Glucose/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Camundongos , Camundongos Nus , Fosfoproteínas/biossíntese , Fosfoproteínas/genética , FosforilaçãoRESUMO
Defects in the apoptotic signaling cascades contribute to the poor therapeutic response of malignant gliomas. As glioblastomas are characterized by high expression levels of anti-apoptotic Bcl-2 family proteins, we studied the effects of the novel Bcl-2 inhibitor, ABT-737, on malignant glioma cells. ABT-737 treatment released the pro-apoptotic Bax protein from its binding partner Bcl-2 and potently induced apoptotic cell death in glioblastoma cells in vitro and in vivo. The local administration of ABT-737 prolonged the survival in an intracranial glioma xenograft model. Downregulation of Mcl-1 and overexpression of Bcl-2 sensitized the cells to ABT-737-mediated apoptosis. Moreover, ABT-737 potentiated the cytotoxicity of the chemotherapeutic drugs vincristine and etoposide, and of the death ligand TRAIL. As glioma stem cells may play a crucial role for the tumor progression and the resistance to treatment in glioblastomas, we investigated the effects of ABT-737 on the subpopulation of glioma cells exhibiting stem cell characteristics. Inhibition of proliferation and induction of apoptosis by ABT-737 were less efficient in glioma stem cells than in non-stem cell-like glioma cells. As the resistance of glioma stem cells was associated with high Mcl-1 expression levels, ABT-737 treatment combined with downregulation of Mcl-1 could represent a promising novel approach in glioblastoma treatment.
Assuntos
Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Glioblastoma/metabolismo , Glioblastoma/patologia , Nitrofenóis/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Sulfonamidas/farmacologia , Animais , Linhagem Celular Tumoral , Glioblastoma/genética , Humanos , Camundongos , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Piperazinas/farmacologia , Ligação Proteica , Proteínas Proto-Oncogênicas c-bcl-2/classificação , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Taxa de Sobrevida , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The feasibility of the emergency department (ED) as a setting for smoking interventions was examined among 159 adult patients presenting with chest pain (38% were smokers). Subjects had been admitted to a 24-h observation unit (OU) to rule out myocardial infarction. We examined the frequency and extent of physician interventions for smoking using the AHCPR guidelines as a model. We also assessed patients' perceptions of risk from smoking and motivation to quit. Results indicate that ED physicians provided incomplete and inconsistent intervention. While most patients were asked if they smoked, only half were advised to quit, and few were offered assistance with quitting. Perceived risk from smoking was low among almost half of all smokers. However, over three-quarters were willing to receive smoking cessation counseling while in the ED. The ED may be an opportune setting in which to initiate smoking cessation counseling for certain high-risk populations.
Assuntos
Dor no Peito/complicações , Serviço Hospitalar de Emergência , Conhecimentos, Atitudes e Prática em Saúde , Padrões de Prática Médica , Prevenção do Hábito de Fumar , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Autoimagem , Distribuição por Sexo , Fumar/epidemiologia , Fumar/psicologia , Estados Unidos/epidemiologiaRESUMO
The recurrence of depression following smoking cessation has been documented among smokers with a history of depression. This report examines the development of major depression following smoking cessation among three women without notable histories of depression. Shortly after smoking cessation, these women developed significant depressive symptoms requiring psychiatric intervention. These cases seem to support the hypothesis that some smokers may self-treat negative affect with nicotine and underscore the importance of monitoring depressive symptoms in patients undergoing smoking-cessation treatment.
Assuntos
Transtorno Depressivo/induzido quimicamente , Nicotina/efeitos adversos , Abandono do Hábito de Fumar/psicologia , Síndrome de Abstinência a Substâncias/psicologia , Administração Cutânea , Adulto , Transtorno Depressivo/psicologia , Feminino , Humanos , Pessoa de Meia-Idade , Nicotina/administração & dosagem , Inventário de Personalidade , Recidiva , Automedicação/psicologia , Fumar/psicologia , Síndrome de Abstinência a Substâncias/diagnósticoRESUMO
BACKGROUND: Acute Respiratory Illness accounts for over 12 million visits to emergency departments in the United States each year. Between one-fourth and one-half of these patients are smokers. We examined the frequency of physician intervention for smoking cessation among acute respiratory illness patients in the emergency department, and examined the influence of physician intervention on patients' perceived risk from smoking and motivation to quit. METHODS: This study was conducted in the emergency department of a large inner-city hospital. Adult smokers (n = 63) presenting with symptoms of acute respiratory illness were surveyed by exit interview while in the emergency department. The frequency and extent of physician interventions for smoking were examined using the Agency for Health Care Policy and Research guidelines as a model. We also assessed patients' perceptions of risk from smoking, the presence of other household smokers, and the patients' motivation to quit. RESULTS: Emergency department physicians provided incomplete and inconsistent intervention for smoking. While most patients reported being asked if they smoked, only half of smokers were advised to quit. Only 9% were offered any assistance with quitting. Risk perception was generally low, however, the majority of smokers were willing to receive on-site smoking cessation counseling while in the emergency department. CONCLUSIONS: The small sample size in this study requires that results be interpreted with caution. However, the findings of this study suggest that the emergency department setting may provide a unique "teachable moment" in which to initiate smoking cessation counseling for this high-risk population.
Assuntos
Serviço Hospitalar de Emergência , Motivação , Padrões de Prática Médica , Doenças Respiratórias/terapia , Prevenção do Hábito de Fumar , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Áreas de Pobreza , Doenças Respiratórias/complicações , Fumar/efeitos adversos , Fumar/psicologia , Abandono do Hábito de Fumar , Estados UnidosRESUMO
This study examined predictors of exercise maintenance following completion of a physical activity intervention. Sedentary adults recruited through newspaper advertisements were randomly assigned to receive either (a) a motivation-matched intervention with feedback reports that were individually tailored (IT) to psychological variables from social cognitive theory and the Transtheoretical Model via computer expert system, or (b) a standard, print-based intervention (ST). The intervention phase of the study included mailed assessments and intervention materials at baseline, 1, 3, and 6 months. An assessment-only follow-up was conducted 6 months after the end of the intervention (Month 12). Participants were assessed for current physical activity participation, motivational readiness for physical activity, a number of psychological constructs posited to influence participation in physical activity (e.g., self-efficacy), and current affect. Significantly more participants in the IT condition met or exceeded exercise participation goals at the end of the intervention period and maintained this level of physical activity through the Month 12 follow-up compared to ST participants. Prospective analyses revealed significant differences in several psychological constructs both at program entry (baseline) and the end of the intervention period between individuals who maintained their physical activity participation through Month 12 and those who did not. Results suggest that the maintenance of physical activity following the end of an active intervention program may be influenced by attitudes and behaviors acquired along with increased participation in physical activity, as well as by preexisting characteristics that individuals bring into treatment.
Assuntos
Exercício Físico/psicologia , Comportamentos Relacionados com a Saúde , Motivação , Adulto , Análise de Variância , Cognição , Feminino , Seguimentos , Humanos , Masculino , Análise Multivariada , AutoeficáciaRESUMO
Src homology 3 domain (SH3)-containing proline-rich protein kinase (SPRK)/mixed-lineage kinase (MLK)-3 is a serine/threonine kinase that upon overexpression in mammalian cells activates the c-Jun NH(2)-terminal kinase pathway. The mechanisms by which SPRK activity is regulated are not well understood. The small Rho family GTPases, Rac and Cdc42, have been shown to bind and modulate the activities of signaling proteins, including SPRK, which contain Cdc42/Rac interactive binding motifs. Coexpression of SPRK and activated Cdc42 increases SPRKs activity. SPRKs Cdc42/Rac interactive binding-like motif contains six of the eight consensus residues. Using a site-directed mutagenesis approach, we show that SPRK contains a functional Cdc42/Rac interactive binding motif that is required for SPRKs association with and activation by Cdc42. However, experiments using a SPRK variant that lacks the COOH-terminal zipper region/basic stretch suggest that this region may also contribute to Cdc42 binding. Unlike the PAK family of protein kinases, we find that the activation of SPRK by Cdc42 cannot be recapitulated in an in vitro system using purified, recombinant proteins. Comparative phosphopeptide mapping demonstrates that coexpression of activated Cdc42 with SPRK alters the in vivo serine/threonine phosphorylation pattern of SPRK suggesting that the mechanism by which Cdc42 increases SPRKs catalytic activity involves a change in the in vivo phosphorylation of SPRK. This is, to the best of our knowledge, the first demonstrated example of a Cdc42-mediated change in the in vivo phosphorylation of a protein kinase. These studies suggest an additional component or cellular environment is required for SPRK activation by Cdc42.
Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Proteína cdc42 de Ligação ao GTP/fisiologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Sequência de Bases , Primers do DNA , Ativação Enzimática , Zíper de Leucina , MAP Quinase Quinase Quinases , Dados de Sequência Molecular , Fosforilação , Ligação Proteica , Proteínas Serina-Treonina Quinases/química , Deleção de Sequência , Homologia de Sequência de Aminoácidos , MAP Quinase Quinase Quinase 11 Ativada por MitógenoRESUMO
This study compared the efficacy of two low-cost interventions for physical activity adoption. Sedentary (N = 194) adults recruited through newspaper advertisements were randomized to receive either a motivationally-matched, individually-tailored intervention (IT) or a standard self-help intervention (ST). Assessments and interventions were delivered by repeated mailings at baseline, one, three, and six months. Participants were assessed regarding current physical activity behavior, motivational readiness to adopt regular physical activity, and psychological constructs associated with physical activity participation (e.g. self-efficacy, decisional balance). Repeated measures analyses of variance (ANOVAs) revealed significant increases in physical activity participation between baseline and six months for both groups with a significantly greater increase among IT participants. The IT group outperformed the ST group on all primary outcome measures: (a) minutes of physical activity per week, (b) reaching Centers for Disease Control and American College of Sports Medicine (CDC/ACSM) recommended minimum physical activity criteria, and (c) achieving the Action stage of motivational readiness for physical activity adoption. Both groups showed significant improvement between baseline and six months on the psychological constructs associated with physical activity adoption (e.g. self-efficacy), with no significant differences observed between the treatment groups. Utilizing computer expert systems and self-help manuals to provide individually-tailored, motivationally-matched interventions appears to be an effective, low-cost approach for enhancing physical activity participation in the community.
Assuntos
Motivação , Atividade Motora , Adulto , Feminino , Humanos , Masculino , Apoio Social , Inquéritos e Questionários , Fatores de TempoRESUMO
Patients who participate in cardiac rehabilitation programs (CRP) experience significant improvements in quality of life, rehospatilization rates, and mortality associated with cardiovascular disease. The potential efficacy of CRP is limited however, by significant program dropout rates and poor patient adherence to prescribed exercise regimens following rehabilitation. Recently, models of motivational readiness for behavior change, such as the Transtheoretical Model, have been applied to understanding the process of exercise adoption and maintenance. Interventions based on this dynamic model of behavior change have produced significant improvement in adherence to exercise in community and worksite populations. This study investigates the applicability of this model to this special population. Sixty-two men and women completed measures of motivational readiness, self-efficacy, and decisional balance for exercise adoption upon entry into a 12-week cardiac rehabilitation program at posttreatment and at a 3-month follow-up. Patients made significant gains during CRP in time spent exercising and self-efficacy, but not in utilization of the cognitive processes or in the perceived benefits of exercising. Exercise maintenance at follow-up was differentially associated with self-efficacy, decisional balance and use of behavioral processes at posttreatment. Motivation-based models of exercise adoption may provide insights regarding the adoption and maintenance of regular physical activity in cardiac rehabilitation populations.