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1.
Child Dev ; 95(4): e287-e304, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38456563

RESUMO

Independent decision making requires forming stable estimates of one's preferences. We assessed whether adolescents learn about their preferences through choice deliberation and whether depressive symptoms disrupt this process. Adolescents aged 11-18 (N = 214; participated 2021-22; Female: 53.9%; White/Black/Asian/Mixed/Arab or Latin American: 26/21/19/9/8%) rated multiple activities, chose between pairs of activities and re-rated those activities. As expected, overall, participants uprated chosen and downrated unchosen activities (dz = .20). This value refinement through choice was not evident in younger participants but emerged across adolescence. Contrary to our predictions, depressive symptoms were associated with greater value refinement. Despite this, more depressed adolescents reported lower value certainty and choice confidence. The cognitive processes through which choice deliberation shapes preference develop over adolescence, and are disrupted in depression.


Assuntos
Comportamento de Escolha , Depressão , Humanos , Feminino , Adolescente , Masculino , Criança , Comportamento de Escolha/fisiologia , Comportamento do Adolescente/fisiologia , Desenvolvimento do Adolescente/fisiologia
2.
Cogn Dev ; 61: None, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35125644

RESUMO

Adolescence is a period of self-concept development. In the current study, females aged 11-30 years (N = 210) completed two self-referential tasks. In a memory task, participants judged the descriptiveness of words for themselves or a familiar other and their recognition of these words was subsequently measured. In an associative-matching task, participants associated neutral shapes to either themselves or a familiar other and the accuracy of their matching judgements was measured. In the evaluative memory task, participants were more likely to remember self-judged than other-judged words and there was an age-related decrease in the size of this self-reference effect. Negative self-judgements showed a quadratic association with age, peaking around age 19. Participants were more likely to remember positive than negative words and there was an age-related increase in the magnitude of this positivity bias. In the neutral shapes task, there were no age-related changes in the self-reference effect. Overall, adolescent girls showed enhanced processing of self-relevant stimuli when it could be used to inform their self-concept and especially when it was negative.

3.
Mol Psychiatry ; 15(8): 816-22, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19274051

RESUMO

This longitudinal study examined the relationship between 2-year change in white matter hyperintense lesion (WML) volume and polymorphisms in genes coding for the angiotensin-II type 1 and type 2 receptors, AGTR1 A1166C and AGTR2 C3123A, respectively. 137 depressed and 94 non-depressed participants aged >or=60 years were enrolled. Standard clinical evaluations were performed on all participants and blood samples obtained for genotyping. 1.5-T MRI (magnetic resonance imaging) data were obtained at baseline and approximately 2 years later. These scans were processed using a semi-automated segmentation process, which allowed for the calculation of WML volume at each time point. Statistical models were tested for the relationship between change in WML volume and genotype, while also controlling for age, sex, diagnostic strata, baseline WML volume and comorbid cerebrovascular risk factors. In men, AGTR1 1166A allele homozygotes exhibited significantly less change in WML volume than 1166C carriers. We also found that men reporting hypertension (HTN) with the AGTR2 3123C allele exhibit less change in WML volume than hypertensive men with the 3123A allele, or men without HTN. There were no significant relationships between these polymorphisms and change in WML volume in women. No significant gene-gene or gene-depression interactions were observed. Our results parallel earlier observed gender differences of the relationship between other renin-angiotensin system polymorphisms and HTN. Further work is needed to determine whether these observed relationships are secondary to polymorphisms affecting response to antihypertensive medication, and whether antihypertensive medications can slow WML progression and lower the risk of morbidity associated with WMLs.


Assuntos
Encéfalo/patologia , Depressão/genética , Depressão/patologia , Fibras Nervosas Mielinizadas/patologia , Polimorfismo Genético/genética , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 2 de Angiotensina/genética , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Antidepressivos/uso terapêutico , Encéfalo/efeitos dos fármacos , Distribuição de Qui-Quadrado , Depressão/tratamento farmacológico , Feminino , Genótipo , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Fatores Sexuais
4.
J Nutr Health Aging ; 13(2): 117-20, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19214339

RESUMO

OBJECTIVE: The goal of this study was to determine if brain lesion volume was correlated with dietary glycemic index and glycemic load in elderly individuals. DESIGN AND SETTING: This cross-sectional study was performed at an academic medical center as part of a clinical study of late-life depression. PARTICIPANTS: Subjects (n=137) were age 60 or over, and were participating as non-depressed comparison subjects. MEASUREMENTS: Food intake was assessed using the Block 1998 food frequency questionnaire. Glycemic index and glycemic load measures were derived from reported food intake. Brain lesion volumes were calculated from magnetic resonance imaging (MRI). RESULTS: No significant associations were found between glycemic index or glycemic load, and brain lesion volume. CONCLUSION: Dietary glycemic measures may be unrelated to brain lesions or may be related to brain lesions only in individuals with impaired glycemic control or other vascular risk factors. Further studies are needed to confirm this finding and to determine if glycemic control moderates this association.


Assuntos
Encefalopatias/etiologia , Encéfalo/patologia , Índice Glicêmico , Idoso , Encefalopatias/patologia , Estudos Transversais , Dieta , Inquéritos sobre Dietas , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino
5.
J Nutr Health Aging ; 22(10): 1259-1265, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30498835

RESUMO

OBJECTIVE: To examine the bi-directional associations of a weight loss intervention with quality of life and mental health in obese older adults with functional limitations. DESIGN: Combined-group analyses of secondary variables from the MEASUR-UP randomized controlled trial. SETTING: Academic medical center. PARTICIPANTS: Obese community-dwelling men and women (N = 67; age ≥60; BMI ≥30) with functional limitations (Short Physical Performance Battery [SPPB] score of 4-10 out of 12). INTERVENTION: Six-month reduced calorie diet at two protein levels. MEASUREMENTS: Weight, height, body composition, physical function, medical history, and mental health and quality of life assessments (Center for Epidemiologic Studies Depression Scale [CES-D]; Profile of Mood States [POMS], Pittsburgh Sleep Quality Index [PSQI]; Perceived Stress Scale [PSS]; Satisfaction with Life Scale [SWLS]; and Short Form Health Survey [SF-36]) were acquired at 0, 3 and 6 months. RESULTS: Physical composite quality of life (SF-36) improved significantly at 3 months (ß = 6.29, t2,48 = 2.60, p = 0.012) and 6 months (ß = 10.03, t2,48 = 4.83, p < 0.001), as did several domains of physical quality of life. Baseline depression symptoms (CES-D and POMS) were found to predict lower amounts of weight loss; higher baseline sleep latency (PSQI) and anger (POMS) predicted less improvement in physical function (SPPB). CONCLUSION: The significant bi-directional associations found between a weight loss intervention and mental health/quality of life, including substantial improvements in physical quality of life with obesity treatment, indicate the importance of considering mental health and quality of life as part of any weight loss intervention for older adults.


Assuntos
Fragilidade/psicologia , Saúde Mental/normas , Obesidade/psicologia , Qualidade de Vida/psicologia , Redução de Peso/fisiologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Biol Psychiatry ; 48(10): 971-5, 2000 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11082470

RESUMO

BACKGROUND: Postmortem studies have documented abnormalities in the medial orbital frontal cortex in depressed patients. In this study we evaluated whether atrophy of this region can be identified in older depressed patients using magnetic resonance imaging. METHODS: Twenty elderly patients meeting DSM-IV criteria for major depression and 20 matched control subjects were studied. The orbital frontal cortex was measured in both hemispheres using magnetic resonance imaging. RESULTS: Depressive patients had reduced volume in the total orbital frontal cortex, right orbital frontal cortex, and left orbital frontal cortex. CONCLUSIONS: Our finding of a reduction in orbital frontal cortex volume in both sides of the brain suggests that this region of the brain may have a critical role in the development of depression and raises questions about the etiology of the changes.


Assuntos
Transtorno Depressivo/patologia , Córtex Pré-Frontal/patologia , Idoso , Transtorno Depressivo/psicologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Escalas de Graduação Psiquiátrica
7.
Biol Psychiatry ; 49(9): 803-6, 2001 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-11331089

RESUMO

BACKGROUND: Early studies using magnetic resonance (MR) imaging suggested that subcortical vascular changes are more prevalent in late-life depression and that they may play a role in the pathophysiology of depression. Studying the location of the lesion relative to the occurrence of depression could be critical in delineating the neuroanatomic substrates of depression. Our purpose was to characterize these lesions in terms of location by development of statistical parametric maps of lesions that differentiate patients from control subjects. METHODS: Magnetic resonance images were acquired on 88 elderly depressed subjects ("patients," unipolar major depression assessed using the Duke Depression Evaluation Schedule, age range 63-80 years) enrolled in the Duke University Clinical Research Center for the Study of Late-Life Depression and 47 age- and gender-matched nondepressed subjects ("control subjects"). The MR protocol includes a volumetric, dual-contrast fast spin-echo pulse sequence. A statistical parametric map was formed from a two-group t test to test for differences in lesion density between patients and control subjects. Additional testing was performed to evaluate whether there were regions that correlated with the severity of depression using the 17-item Hamilton Depression rating. RESULTS: The statistical parametric mapping analysis between groups showed two major regions of increased lesion density in the patients in the medial orbital prefrontal white matter. Severity of depression among depressed patients was correlated with lesions in the medial orbital region. CONCLUSIONS: This study supports recent evidence implicating the medial orbital frontal cortex in depression.


Assuntos
Transtorno Depressivo Maior/psicologia , Órbita , Córtex Pré-Frontal/patologia , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/epidemiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
8.
Biol Psychiatry ; 48(4): 301-9, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10960161

RESUMO

BACKGROUND: There is a growing literature on the importance of hippocampal volume in geriatric depression. METHODS: We examined hippocampal volume in a group of elderly depressed patients and a group of elderly control subjects (N = 66 geriatric depressed patients and 18 elderly nondepressed control subjects) recruited through Duke's Mental Health Clinical Research Center for the Study of Depression in the Elderly. The subjects received a standardized evaluation, including a magnetic resonance imaging scan of the brain. Patients had unipolar major depression and were free of comorbid major psychiatric illness and neurologic illness. Differences were assessed using t tests and linear regression modeling. RESULTS: Accounting for the effects of age, gender, and total brain volume, depressed patients tended to have smaller right hippocampal volume (p =.014) and left hippocampal volume (p =.073). Among depressed patients, age of onset was negatively but not significantly related to right hippocampal volume (p =.052) and to left hippocampal volume (p =.062). We noted that among subjects with either right or left hippocampal volume of 3 mL or less, the vast majority were patients rather than control subjects. CONCLUSIONS: These results support a role for hippocampal dysfunction in depression, particularly in late-age onset depression. Longitudinal studies examining both depressive and cognitive outcomes are needed to clarify the relationships between the hippocampus, depression, and dementia.


Assuntos
Transtorno Depressivo Maior/patologia , Hipocampo/anatomia & histologia , Idoso , Estudos Transversais , Transtorno Depressivo Maior/diagnóstico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
9.
Biol Psychiatry ; 50(3): 179-83, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-11513816

RESUMO

BACKGROUND: Diffusion tensor imaging (DTI) of brain tissue measures the apparent diffusion coefficient (ADC), or isotropic diffusion, and anisotropy, or diffusion as influenced by tissue structure. We hypothesized that hyperintensities, when compared with normal tissue by DTI, would show evidence of damage through an increased ADC and decreased anisotropy. We also hypothesized that DTI changes in hyperintensities would be similar between depressed subjects and control subjects. METHODS: Fourteen depressed geriatric patients and nineteen control subjects received DTI. The ADC and aniso-tropy of normal tissue from standard regions were compared with hyperintensities from these regions. The Students' t test compared individual regions and averaged white matter results. RESULTS: Hyperintensities showed higher ADC and lower anisotropy than normal regions. Gray matter exhibited similar trends. There was no significant difference in diffusion characteristics of hyperintensities between subjects and control subjects. CONCLUSIONS: Hyperintensities damage the structure of brain tissue, and do so comparably in depressed subjects and control subjects.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/patologia , Transtorno Depressivo/psicologia , Imageamento por Ressonância Magnética , Idoso , Anisotropia , Transtorno Depressivo/diagnóstico , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Índice de Gravidade de Doença
10.
J Heart Lung Transplant ; 10(5 Pt 1): 738-42, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1958680

RESUMO

Although the majority of heart transplant recipients have a satisfactory heart rate, a substantial number require a permanent pacemaker. In 7 of 46 heart transplant patients at our institution symptomatic bradycardia developed, necessitating implantation of a transvenous pacemaker. The average time from heart transplantation to pacer insertion was 25 days. The average donor age, ischemic period, and crossclamp time was 28 years, 182 minutes, and 113 minutes, respectively. A long aortic crossclamp time (greater than 83 minutes) increased the risk for conduction abnormalities in the sinoatrial node. No patient had rejection before the pacer implantation. Five of the seven patients continue to be paced a significant amount of a 24-hour period. Only one patient has had considerable improvement in 3 years, requiring pacing only 3% of a monitored 24-hour period. This patient had the longest ischemic time and the most rejection episodes after implantation of the pacemaker. One patient was paced 100% until a second heart transplantation was done, without a subsequent need for pacing. The other five patients' hearts continue to be paced between 80% and 100% of a 24-hour monitored period. The donor intrinsic heart rates of these five patients produce symptomatic bradycardia. The success of AAI pacing in all patients indicates normal conduction below the sinoatrial node. The injury or dysfunction resulting in bradycardia was isolated to the sinoatrial node. Long-term follow-up in three patients (greater than 3 years) shows the need for pacing to be intermittent but long term. Most patients never fully recover from symptomatic bradycardia.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Bradicardia/terapia , Estimulação Cardíaca Artificial , Transplante de Coração/efeitos adversos , Adulto , Bradicardia/etiologia , Bradicardia/fisiopatologia , Estimulação Cardíaca Artificial/métodos , Eletrocardiografia Ambulatorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
11.
Can J Public Health ; 83(6): 433-6, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1286445

RESUMO

This paper focuses on the implementation evaluation strategy of a smoking prevention program and examines differences in instructional experience and implementation of the grade six curriculum in relation to provider type. Arbaseline, nurses (n = 40), compared with teachers (n = 39), reported (a) less previous classroom teaching experience, (b) greater reliance on lecturing and audio/visual materials, (c) less use of small group classroom activities, and (d) less confidence using small group and role playing methods in the classroom. More nurses than teachers believed smoking to be a significant problem in the schools. Nurses had less confidence than teachers in their ability to teach the smoking prevention curriculum. Nonetheless, behavioural observation indicated that nurses implemented the curriculum more completely. However, teachers, at least those who received workshop training, showed some evidence of greater utilization of teaching styles thought to be desirable.


Assuntos
Educação em Saúde , Enfermagem em Saúde Pública/normas , Serviços de Saúde Escolar , Abandono do Hábito de Fumar , Ensino/normas , Adulto , Currículo , Avaliação de Desempenho Profissional , Educação em Saúde/normas , Humanos , Variações Dependentes do Observador , Ontário , Avaliação de Processos e Resultados em Cuidados de Saúde , Enfermagem em Saúde Pública/educação , Serviços de Saúde Escolar/normas , Ensino/métodos , Recursos Humanos
12.
Nat Commun ; 5: 5642, 2014 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-25466276

RESUMO

The crystalline structure of organic materials dictates their physical properties, but while significant research effort is geared towards understanding structure-property relationships in such materials, the details remain unclear. Many organic crystals exhibit transitions in their electrical properties as a function of temperature. One example is the 1:1 charge-transfer complex trans--stilbene-2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane. Here we show that the mobility and resistivity of this material undergo a transition from being thermally activated at temperatures above 235 K to being temperature independent at low temperatures. On the basis of our experimental and theoretical results, we attribute this behaviour to the presence of a glass-like transition and the accompanied freezing-in of orientational disorder of the stilbene molecule.

13.
J Dev Orig Health Dis ; 1(6): 386-95, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25142010

RESUMO

The hypothesis that vitamin content of the diet during gestation alters macronutrient choice, food intake and the expression of serotonin receptors and proopiomelanocortin (POMC) in the hypothalamus of the offspring was investigated. Pregnant Wistar rats (n = 10/group) were fed the AIN-93G diet containing a multivitamin mix at the recommended (RV) content or10-fold higher (high vitamin, HV) content. Male offspring were weaned to a choice of 10% and 60% casein diets. Intake regulation by the serotonergic system was determined by measuring food choice daily for 7 weeks, and following tryptophan (TRP) or mCPP (a serotonin receptor agonist) injections at 4 and 6 weeks post-weaning. mRNA expressions of hypothalamic serotonin receptor and POMC were measured at birth, weaning and sacrifice (7 weeks post-weaning). No differences were found in body weight at birth or weaning. HV offspring had lower food intake for the duration of the study (P < 0.001), and 11% lower body weight (P < 0.05) and 23% lower fat pad mass (P < 0.05) at 7 weeks post-weaning. They selected less protein following 12 h of food deprivation (P < 0.05) and were less responsive to TRP (P = 0.05) and mCPP (P < 0.05) injections at 6 weeks post-weaning. Expressions of mRNA for serotonin receptors 5-HT1A/2A/2C at weaning (P < 0.01) and of POMC at weaning and 7 weeks post-weaning (P < 0.05) were lower. In conclusion, intake of multivitamins above the requirements during pregnancy affected macronutrient choice, food intake and the expression of serotonin receptors and POMC in the hypothalamus.

15.
Recruit Retent Restruct Rep ; 10(4): 4-7, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9287870

RESUMO

Current trends in health care system hiring practices make it clear that new graduates need to consider additional alternatives for a successful job search in this highly competitive environment. Nurse executives, recruiters, human resource directors and faculty can help new graduates to find jobs, even during this period of tight job market. Strategies that executives, recruiters and faculty can use are discussed in this article.


Assuntos
Aconselhamento , Emprego , Enfermeiras e Enfermeiros , Humanos , Relações Interprofissionais , Enfermeiras e Enfermeiros/psicologia , Autoimagem , Voluntários
16.
J Biol Chem ; 255(17): 8054-6, 1980 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-6251041

RESUMO

A cAMP-independent glycogen synthase kinase has been purified from rabbit liver. This kinase is completely dependent on the presence of calmodulin and Ca2+ for activity. Half-maximal activation required about 0.1 microM calmodulin. Complete inhibition was obtained in the presence of ethylene glycol bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid or trifluoperazine. This calmodulin-dependent synthase kinase does not phosphorylate phosphorylase, myosin light chain, casein, or histone. It rapidly incorporates 0.4 to 0.5 mol of 32P/mol of synthase subunit into the NH2-terminal domain, resulting in partial inactivation of glycogen synthase. These results indicate the existence of a calmodulin-dependent kinase which may be specific for glycogen synthase.


Assuntos
Proteínas de Ligação ao Cálcio/farmacologia , Calmodulina/farmacologia , Fígado/enzimologia , Proteínas Quinases/metabolismo , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Quinases da Glicogênio Sintase , Cinética , Proteínas Quinases/isolamento & purificação , Coelhos , Especificidade por Substrato , Trifluoperazina/farmacologia
17.
J Biol Chem ; 261(35): 16346-50, 1986 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-3782123

RESUMO

Turkey gizzard smooth muscle myosin light chain kinase is a calmodulin-dependent enzyme containing 2 serine residues that can be phosphorylated by cAMP-dependent protein kinase. One of these sites can be phosphorylated only when calmodulin is not bound to the enzyme; the amino acid sequence around this site has been reported recently (Lukas, T. J., Burgess, W. H., Prendergast, F. G., Lau, W., and Watterson, D. M. (1986) Biochemistry 25, 1458-1464). Here we report the sequence around the site that is phosphorylated by cAMP-dependent protein kinase whether or not calmodulin is bound: Lys-Ala-Ser(P)-Gly-Ser-Ser-Pro-Thr-Ser-Pro-Ile-Asn-Ala-Asp-Lys-Val-Glu-A sn-Glu- . This sequence conforms to the previously defined criteria for substrates of cAMP-dependent protein kinase.


Assuntos
Calmodulina/metabolismo , Músculo Liso/enzimologia , Quinase de Cadeia Leve de Miosina/metabolismo , Proteínas Quinases/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Moela das Aves/enzimologia , Cinética , Fosforilação , Ligação Proteica , Perus
18.
J Biol Chem ; 258(4): 2376-82, 1983 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-6296143

RESUMO

A rabbit liver cAMP-independent glycogen synthase kinase has been purified 4500-fold to a specific activity of 2.23 mumol of 32P incorporated per min per mg of protein using ion exchange chromatography on DEAE-Sephacel and phosphocellulose, gel filtration chromatography on Sepharose 6B, and affinity chromatography on calmodulin-Sepharose. This synthase kinase, which was completely dependent on the presence of calmodulin (apparent K0.5 = 0.1 microM) and calcium for activity, also catalyzed the phosphorylation of purified smooth muscle myosin light chain but not of smooth muscle myosin. Using 0.5 mM ATP, a maximal rate of phosphorylation of glycogen synthase was achieved in the presence of 10 mM magnesium acetate with a pH optimum of 7.8. Gel filtration experiments indicated a Stokes radius of about 70 A and sucrose density gradient centrifugation data gave a sedimentation coefficient of 10.6 S. A molecular weight of approximately 300,000 was calculated. A definitive subunit structure was not determined, but major bands observed after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate corresponded to a doublet at 50,000 to 53,000. The calmodulin-dependent glycogen synthase kinase incorporated about 1 mol of 32P per mol of synthase subunit into sites 2 and 1b associated with a decrease in the synthase activity ratio from 0.8 to about 0.4. The calmodulin-dependent glycogen synthase kinase may mediate the effects of alpha-adrenergic agonists, vasopressin, and/or angiotensin II on glycogen synthase in liver.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Calmodulina/metabolismo , Fígado/enzimologia , Proteínas Quinases/isolamento & purificação , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Centrifugação com Gradiente de Concentração , Eletroforese em Gel de Poliacrilamida , Feminino , Quinases da Glicogênio Sintase , Miosinas/metabolismo , Fosforilação , Coelhos , Especificidade por Substrato
19.
Arch Biochem Biophys ; 224(1): 77-86, 1983 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-6307155

RESUMO

We have purified a calmodulin-dependent glycogen synthase kinase from livers of normal and phosphorylase kinase-deficient (gsd/gsd) rats. No differences between normal and gsd/gsd rats were apparent in either (a) the ability of liver extracts to phosphorylate exogenous glycogen synthase in a Ca2+- and calmodulin-dependent manner or (b) the purification of the calmodulin-dependent synthase kinase. Although extracts from rat liver, when compared to rabbit liver extracts, had a significantly reduced ability to phosphorylate exogenous synthase, the calmodulin-dependent synthase kinase could be purified from rat liver using a protocol identical to that described for rabbit liver. Moreover, the synthase kinase purified from rat liver had properties very similar to those of the rabbit liver enzyme. The enzyme was completely dependent on calmodulin for activity against glycogen synthase, was unable to phosphorylate phosphorylase b, catalyzed the rapid incorporation of 0.4 mol phosphate/mol of glycogen synthase subunit, selectively phosphorylated sites 1b and 2 in the glycogen synthase molecule, had a Stokes' radius of about 70 A, and appeared to be composed of subunits of Mr 56,000 and 57,000. These observations led us to conclude that (1) calmodulin-dependent glycogen synthase kinase is distinct from other kinases previously described and (2) the rat liver kinase and the rabbit liver kinase are very similar enzymes.


Assuntos
Proteínas de Ligação ao Cálcio/fisiologia , Calmodulina/fisiologia , Fígado/enzimologia , Fosforilase Quinase/deficiência , Proteínas Quinases/metabolismo , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Cromatografia/métodos , Quinases da Glicogênio Sintase , Masculino , Fosforilação , Proteínas Quinases/isolamento & purificação , Coelhos , Ratos , Ratos Endogâmicos
20.
J Biol Chem ; 262(18): 8696-701, 1987 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-3036821

RESUMO

The structure of the rat parvalbumin gene has been elucidated from analysis of six overlapping clones isolated from a rat lambda Charon 4A genomic library. Two of the clones were mapped in detail, and all exons were localized by Southern hybridization using fragments of a full-length parvalbumin cDNA (Epstein, P., Means, A. R., and Berchtold, M. W. (1986) J. Biol. Chem. 261, 5886-5891). The rat parvalbumin transcription unit is 15.5 kilobase pairs in length and contains four introns. The first intron divides the 5'-nontranslated region, whereas the other three interrupt coding DNA. All intron/extron boundaries were sequenced as was 377 base pairs immediately 5' from the putative transcription initiation site. The promoter region contains eukaryotic regulatory homologies to the "TATA" box at -24 and "CAAT" box at -47 and -156. In addition, two doublets consisting of 11-base pair direct repeats exist in the promoter region. Parvalbumin binds two Ca2+, whereas many other members of the same superfamily bind four. Comparison of the genes that encode these proteins provides a strong confirmation of the hypothesis that parvalbumin evolved from an ancestral gene specifying a four-domain Ca2+-binding protein. The rat parvalbumin gene was also utilized to assign its human counterpart to chromosome 22 from data obtained by hybridization to DNA from a somatic cell hybrid panel. It was also used to isolate a 7.5-kilobase pair EcoRI fragment from a human chromosome 22 DNA library.


Assuntos
Genes , Proteínas Musculares/genética , Parvalbuminas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Mapeamento Cromossômico , Clonagem Molecular , DNA/metabolismo , Enzimas de Restrição do DNA , Íntrons , Conformação Proteica , Ratos
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