Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
1.
Acta Oncol ; 55(11): 1355-1359, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27553064

RESUMO

BACKGROUND: Whole body positron emission tomography (PET)/computed tomography (CT) is a sensitive imaging technique in patients with metastatic melanoma, but its role in the follow-up of asymptomatic high-risk patients is unclear. The aim was to study the role of PET/CT as a routine surveillance imaging tool in asymptomatic high-risk patients at the early stage of follow-up combined with a sufficient follow-up over several years. MATERIAL AND METHODS: A total of 110 asymptomatic patients with clinically local American Joint Committee on Cancer (AJCC) stage IIB-IIIB melanoma underwent routine whole body PET/CT scanning after a mean interval of seven months after initial surgery. Clinical data were retrospectively analyzed after a median follow-up time of 4.6 years. RESULTS: Recurrent melanoma was detected in 45 patients (41%) and 36 (33%) died of melanoma. In 11 asymptomatic patients (10%) occult disease was detected with a single PET/CT. In seven of these patients (64%), positive PET/CT finding had major influence in treatment decisions. Four patients underwent surgical metastasectomy and two of them remained disease-free. In 34 patients (31%) PET/CT revealed no disease, but recurrence was detected at a median time of 19 months after negative PET/CT scan. In 50 patients (45%) PET/CT finding was true negative. In 15 patients (14%) scan was false positive leading to additional management or repetitive imagings. CONCLUSION: A single PET/CT could detect 24% of all recurrences in asymptomatic melanoma patients at the early stage of follow-up, but an earlier detection of occult metastases did not improve survival.


Assuntos
Melanoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluordesoxiglucose F18 , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Metástase Linfática/diagnóstico por imagem , Masculino , Melanoma/mortalidade , Melanoma/patologia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia , Prognóstico , Compostos Radiofarmacêuticos , Neoplasias Cutâneas , Adulto Jovem , Melanoma Maligno Cutâneo
2.
AIDS Care ; 26(7): 795-803, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24093715

RESUMO

The aims of this study were to examine differences in self-schemas between persons living with HIV/AIDS with and without depressive symptoms, and the degree to which these self-schemas predict depressive symptoms in this population. Self-schemas are beliefs about oneself and include self-esteem, HIV symptom management self-efficacy, and self-compassion. Beck's cognitive theory of depression guided the analysis of data from a sample of 1766 PLHIV from the USA and Puerto Rico. Sixty-five percent of the sample reported depressive symptoms. These symptoms were significantly (p ≤ 0.05), negatively correlated with age (r = -0.154), education (r = -0.106), work status (r = -0.132), income adequacy (r = -0.204, self-esteem (r = -0.617), HIV symptom self-efficacy (r = - 0.408), and self-kindness (r = - 0.284); they were significantly, positively correlated with gender (female/transgender) (r = 0.061), white or Hispanic race/ethnicity (r = 0.047) and self-judgment (r = 0.600). Fifty-one percent of the variance (F = 177.530 (df = 1524); p < 0.001) in depressive symptoms was predicted by the combination of age, education, work status, income adequacy, self-esteem, HIV symptom self-efficacy, and self-judgment. The strongest predictor of depressive symptoms was self-judgment. Results lend support to Beck's theory that those with negative self-schemas are more vulnerable to depression and suggest that clinicians should evaluate PLHIV for negative self-schemas. Tailored interventions for the treatment of depressive symptoms in PLHIV should be tested and future studies should evaluate whether alterations in negative self-schemas are the mechanism of action of these interventions and establish causality in the treatment of depressive symptoms in PLHIV.


Assuntos
Depressão/psicologia , Infecções por HIV/psicologia , Autocuidado/métodos , Autoimagem , Autoeficácia , Adolescente , Adulto , Idoso , Canadá/epidemiologia , China/epidemiologia , Comorbidade , Estudos Transversais , Depressão/epidemiologia , Escolaridade , Emoções/fisiologia , Etnicidade/psicologia , Etnicidade/estatística & dados numéricos , Feminino , Infecções por HIV/epidemiologia , Humanos , Julgamento/fisiologia , Masculino , Pessoa de Meia-Idade , Namíbia/epidemiologia , Porto Rico/epidemiologia , Distribuição por Sexo , Inquéritos e Questionários , Tailândia/epidemiologia , Estados Unidos/epidemiologia , Adulto Jovem
3.
AIDS Care ; 25(3): 364-77, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22774796

RESUMO

The purpose of this study was to investigate the effects of stressful life events (SLE) on medication adherence (3 days, 30 days) as mediated by sense of coherence (SOC), self-compassion (SCS), and engagement with the healthcare provider (eHCP) and whether this differed by international site. Data were obtained from a cross-sectional sample of 2082 HIV positive adults between September 2009 and January 2011 from sites in Canada, China, Namibia, Puerto Rico, Thailand, and US. Statistical tests to explore the effects of stressful life events on antiretroviral medication adherence included descriptive statistics, multivariate analysis of variance, analysis of variance with Bonferroni post-hoc analysis, and path analysis. An examination by international site of the relationships between SLE, SCS, SOC, and eHCP with adherence (3 days and 30 days) indicated these combined variables were related to adherence whether 3 days or 30 days to different degrees at the various sites. SLE, SCS, SOC, and eHCP were significant predictors of adherence past 3 days for the United States (p = < 0.001), Canada (p = 0.006), and Namibia (p = 0.019). The combined independent variables were significant predictors of adherence past 30 days only in the United States and Canada. Engagement with the provider was a significant correlate for antiretroviral adherence in most, but not all, of these countries. Thus, the importance of eHCP cannot be overstated. Nonetheless, our findings need to be accompanied by the caveat that research on variables of interest, while enriched by a sample obtained from international sites, may not have the same relationships in each country.


Assuntos
Acontecimentos que Mudam a Vida , Adesão à Medicação/psicologia , Relações Profissional-Paciente , Adulto , Fármacos Anti-HIV/uso terapêutico , Canadá , China , Estudos Transversais , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Adesão à Medicação/estatística & dados numéricos , Pessoa de Meia-Idade , Análise Multivariada , Namíbia , Porto Rico , Inquéritos e Questionários , Tailândia , Estados Unidos
4.
Eur J Appl Physiol ; 113(7): 1775-82, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23417482

RESUMO

The purpose of the present study was to investigate the regional differences in glucose and fatty acid uptake within skeletal muscle during exercise. Blood flow (BF), glucose uptake (GU) and free fatty acid uptake (FFAU) were measured in four different regions (vastus lateralis, VL; rectus femoris, RF; vastus intermedius, VI; and vastus medialis, VM) of the quadriceps femoris (QF) muscle during low-intensity, knee-extension exercise using positron emission tomography. BF was higher in VI than in VL, RF and VM (P < 0.05). FFAU was higher in VI (P < 0.001) but also in VM (P < 0.05) compared with VL and RF. In contrast, GU was higher in RF compared with VL (P < 0.05) but was not significantly different to VM or VI (both P = NS). FFAU within these four muscle regions correlated significantly with BF (r = 0.951, P < 0.05), whereas no significant relationship was observed between GU and BF (r = 0.352, P = NS). Therefore, skeletal muscle FFAU, but not GU, appears to be associated with BF during low-intensity exercise. The present results also indicate considerable regional differences in substrate use within working QF muscle. As such, an important methodological outcome from these results is that one sample from a specific part of the QF muscle does not represent the response in the entire QF muscle group.


Assuntos
Exercício Físico , Ácidos Graxos não Esterificados/metabolismo , Glucose/metabolismo , Joelho/fisiologia , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/metabolismo , Humanos , Joelho/diagnóstico por imagem , Masculino , Músculo Esquelético/diagnóstico por imagem , Especificidade de Órgãos , Tomografia por Emissão de Pósitrons , Fluxo Sanguíneo Regional , Adulto Jovem
5.
Int Nurs Rev ; 60(4): 477-86, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24251940

RESUMO

AIM: This study represents an initial effort at examining the association between the construct of self-compassion and human immunodeficiency virus (HIV)-related anxiety in a multinational population with HIV disease. BACKGROUND: Previous studies have found that self-compassion is a powerful predictor of mental health, demonstrating positive and consistent linkages with various measures of affect, psychopathology and well-being, including anxiety. METHODS: Cross-sectional data from a multinational study conducted by the members of the International Nursing Network for HIV Research (n = 1986) were used. The diverse sample included participants from Canada, China, Namibia, the United States of America and the territory of Puerto Rico. Study measures included the anxiety subscale of the Symptom Checklist-90 instrument, the Brief Version Self-Compassion Inventory and a single item on anxiety from the Revised Sign and Symptom Checklist. FINDINGS: Study findings show that anxiety was significantly and inversely related to self-compassion across participants in all countries. We examined gender differences in self-compassion and anxiety, controlling for country. Levels of anxiety remained significantly and inversely related to self-compassion for both males (P = 0.000) and females (P = 0.000). Levels of self-compassion and anxiety varied across countries. CONCLUSIONS: Self-compassion is a robust construct with cross-cultural relevance. A culturally based brief treatment approach aimed at increasing self-compassion may lend itself to the development of a cost effective adjunct treatment in HIV disease, including the management of anxiety symptoms.


Assuntos
Ansiedade/psicologia , Empatia , Infecções por HIV/psicologia , Adulto , Lista de Checagem , Estudos Transversais , Demografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Autoimagem , Autorrelato
6.
AIDS Care ; 22(9): 1159-70, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20824569

RESUMO

Depressive symptoms are highly prevalent yet undertreated in people living with HIV/AIDS (PLHAs). As part of a larger study of symptom self-management (N=1217), this study examined the prevalence, correlates, and characteristics (intensity, distress, and impact) of depressive symptoms, and the self-care strategies used to manage those symptoms in PLHAs in five countries. The proportion of respondents from each country in the total sample reporting depressive symptoms in the past week varied and included Colombia (44%), Norway (66%), Puerto Rico (57%), Taiwan (35%), and the USA (56%). Fifty-four percent (n=655) of the total sample reported experiencing depressive symptoms in the past week, with a mean of 4.1 (SD 2.1) days of depression. Mean depression intensity 5.4 (SD 2.7), distressfulness 5.5 (SD 2.86), and impact 5.5 (SD 3.0) were rated on a 1-10 scale. The mean Center for Epidemiologic Studies Depression Scale score for those reporting depressive symptoms was 27 (SD 11; range 3-58), and varied significantly by country. Respondents identified 19 self-care behaviors for depressive symptoms, which fell into six categories: complementary therapies, talking to others, distraction techniques, physical activity, medications, and denial/avoidant coping. The most frequently used strategies varied by country. In the US sample, 33% of the variance in depressive symptoms was predicted by the combination of education, HIV symptoms, psychological and social support, and perceived consequences of HIV disease.


Assuntos
Transtorno Depressivo/terapia , Infecções por HIV/psicologia , Autocuidado/métodos , Adaptação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Antidepressivos/uso terapêutico , Colômbia/epidemiologia , Comunicação , Terapias Complementares/métodos , Transtorno Depressivo/complicações , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Porto Rico/epidemiologia , Índice de Gravidade de Doença , Apoio Social , Taiwan/epidemiologia , Estados Unidos/epidemiologia , Adulto Jovem
7.
AIDS Behav ; 13(2): 258-67, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17705096

RESUMO

Research has shown that the perceptions that form the cognitive representation of an illness (illness representation) are fundamental to how persons cope with illness. This study examined the relationship of illness representation of HIV with self-care behavior and health outcomes. Data were collected at 16 sites in the United States, Taiwan, Norway, Puerto Rico and Colombia via survey. HIV seropositive participants (n = 1,217, 31% female, 38% African-American/Black, 10% Asian/Pacific Islander and 26% White/Anglo) completed measures of illness representation based on the commonly accepted five-component structure: identity, time-line, consequences, cause, and cure/controllability (Weinman et al. 1996, Psychology and Health, 11, 431-445). Linear regression analyses were conducted to investigate relationships among illness representation, self-care behaviors and quality-of-life outcomes. Components of illness representation were associated with self-care and health outcomes, indicating that the cognitive representation of HIV has consequences for effective illness management. For example, perception that there is little that can be done to control HIV was significantly associated with fewer and less effective self-care activities (F = 12.86, P < .001) and poorer health function in the domain of quality-of-life (F = 13.89, P < .001). The concept of illness representation provides a useful framework for understanding HIV symptom management and may be useful in directing development of effective patient-centered interventions.


Assuntos
Atitude Frente a Saúde , Infecções por HIV/etnologia , Infecções por HIV/psicologia , Autocuidado , Adulto , Idoso , Idoso de 80 Anos ou mais , Comparação Transcultural , Estudos Transversais , Feminino , Infecções por HIV/terapia , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Adulto Jovem
8.
Clin Oncol (R Coll Radiol) ; 30(8): 507-514, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29753662

RESUMO

AIMS: To prospectively evaluate the use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in the definition of the treatment response after primary treatment of advanced epithelial ovarian cancer (EOC). MATERIALS AND METHODS: Forty-nine patients with advanced EOC had an 18F-FDG PET/CT scan before and after primary treatment. The treatment response was defined with the currently used radiological and serological Response Criteria in Solid Tumors (RECIST1.1/GCIC) criteria and the modified PET Response Criteria in Solid Tumors (PERCIST). The concordance of the two methods was analysed. If the patient had a complete response to primary treatment by conventional criteria, the end of treatment 18F-FDG PET/CT scan (etPET/CT) was not opened until retrospectively at the time of disease progression. The ability of etPET/CT to predict the time to disease recurrence was analysed. The recurrence patterns were observed with an 18F-FDG PET/CT at the first relapse. RESULTS: The agreement of the RECIST1.1/GCIC and modified PERCIST criteria in defining the primary treatment response in the whole patient cohort was good (weighted kappa coefficient = 0.78). Of the complete responders (n = 28), 34% had metabolically active lesions present in the etPET/CT, most typically in the lymph nodes. The same anatomical sites tended to activate at disease relapse, but were seldom the only site of relapse. In patients with widespread intra-abdominal carsinosis at diagnosis, the definition of metabolic response was challenging due to problems in distinguishing the physiological FDG accumulation in the bowel loops from the residual tumour in the same area. The presence of metabolically active lesions in the etPET/CT did not predict earlier disease relapse in the complete responders. CONCLUSIONS: In the present study, etPET/CT revealed metabolically active lesions in complete responders after EOC primary therapy, but they were insignificant for the patient's prognosis. The current study does not favour routine use of 18F-FDG PET/CT after EOC primary treatment for complete responders.


Assuntos
Carcinoma Epitelial do Ovário/diagnóstico por imagem , Carcinoma Epitelial do Ovário/tratamento farmacológico , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/tratamento farmacológico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Antineoplásicos/uso terapêutico , Carcinoma Epitelial do Ovário/patologia , Feminino , Fluordesoxiglucose F18 , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Prognóstico , Compostos Radiofarmacêuticos , Resultado do Tratamento
9.
Cancer Res ; 56(21): 4956-64, 1996 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-8895750

RESUMO

The long-standing strategy for the treatment of metastatic prostate cancer has been to reduce androgenic stimulation of tumor growth by removal of the testes, the primary site of testosterone synthesis. However, a low level of androgenic stimulation may continue, even after castration, by the conversion of adrenal androgens to 5alpha-dihydrotestosterone (DHT) in the prostate tumor cells. Two important enzymes of the androgen biosynthetic pathway are 17alpha-hydroxylase/C17,20-lyase, which regulates an early step in the synthesis of testosterone and other androgens in both the testes and adrenal glands, and 5alpha-reductase, which converts testosterone to the more potent androgen, DHT, in the prostate. We have identified new inhibitors of these enzymes that may be of use in achieving a more complete ablation of androgens in the treatment of metastatic prostate cancer. Three derivatives of androstene were shown to inhibit 17alpha-hydroxylase/C17,20-lyase with potencies 2-20-fold greater than that of ketoconazole, a previously established inhibitor of this enzyme. Derivatives of pregnane and pregnene displayed activities against 5alpha-reductase that were comparable to that of N-(1,1-dimethyl-ethyl)-3-oxo-4-aza-5alpha-androst-1-ene-17beta-car boxamide. All of the 5alpha-reductase inhibitors were able to at least partially inhibit the mitogenic effect of testosterone in either histocultures of human benign prostatic hypertrophic tissue or in cultures of the LNCaP human prostatic tumor cell line. For these compounds, it appears that this inhibition can be attributed to a reduction of DHT synthesis in these cultures, because no inhibitory effect was observed in DHT-treated cultures, and none of the compounds had a cytotoxic effect. Surprisingly, one of the inhibitors of 17alpha-hydroxylase/C17,20-lyase, 17beta-(4-imidazolyl)-5-pregnen-3beta-ol, was also able to inhibit the mitogenic effect of testosterone in both the histoculture and cell culture assays and had an effect against DHT as well. In transcriptional activation assays, it was found that this compound is an antagonist of both the wild-type androgen receptor and the mutant androgen receptor, which is present in LNCaP cells. In conclusion, the abilities of these compounds to inhibit androgen synthesis and, in some cases, to exert antiandrogen activity, did in fact translate to an inhibitory effect on the growth of human prostatic tissue in vitro, suggesting their potential utility in the treatment of prostatic cancer.


Assuntos
Antagonistas de Androgênios/farmacologia , Androgênios/biossíntese , Oxirredutases/antagonistas & inibidores , Neoplasias da Próstata/tratamento farmacológico , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores , Colestenona 5 alfa-Redutase , DNA/biossíntese , Humanos , Masculino , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Testosterona/biossíntese , Células Tumorais Cultivadas
10.
Scand J Surg ; 105(2): 133-8, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26378129

RESUMO

BACKGROUND AND AIMS: The detection of graft viability is challenging in the multiligament reconstructed knee. Magnetic resonance imaging gives structural information but lacks the capability to assess biological activity of the grafts. (18)F-labeled fluorodeoxyglucose positron emission tomography combined with computer tomography is shown to be a sensitive method for imaging tissue metabolism and viability. The aim of the present study was to evaluate the feasibility of fluorodeoxyglucose positron emission tomography combined with computer tomography imaging in the detection of the replacement graft metabolism in multiligament reconstructed knees. MATERIALS AND METHODS: Seven patients (17-44 years) with multiligament reconstructed knee underwent fluorodeoxyglucose positron emission tomography combined with computer tomography to evaluate the biological activity of replacement grafts. The degree of fluorodeoxyglucose uptake reported as standard uptake values from the region of interest was analyzed 3-24 months postoperatively. RESULTS: In all patients, the fluorodeoxyglucose positron emission tomography combined with computer tomography showed increased fluorodeoxyglucose uptake in all replacement grafts at different follow-up time points. Furthermore, fluorodeoxyglucose was higher at femoral condyles of operated knees compared to contralateral reference values. CONCLUSION: This pilot study shows a significant increase in tendon graft metabolism during two first years of postoperative healing. The fluorodeoxyglucose positron emission tomography combined with computer tomography imaging seems to be adequate method of assessment of graft metabolism and viability during postoperative healing. The clinical value of fluorodeoxyglucose positron emission tomography combined with computer tomography imaging, however, warrants further evaluation with longitudinal studies with a larger patient population.


Assuntos
Reconstrução do Ligamento Cruzado Anterior , Sobrevivência de Enxerto , Traumatismos do Joelho/cirurgia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Reconstrução do Ligamento Cruzado Posterior , Tendões/diagnóstico por imagem , Cicatrização , Adolescente , Adulto , Assistência ao Convalescente/métodos , Reconstrução do Ligamento Cruzado Anterior/métodos , Estudos de Viabilidade , Feminino , Fluordesoxiglucose F18/metabolismo , Seguimentos , Humanos , Traumatismos do Joelho/diagnóstico por imagem , Masculino , Projetos Piloto , Reconstrução do Ligamento Cruzado Posterior/métodos , Compostos Radiofarmacêuticos/metabolismo , Estudos Retrospectivos , Tendões/metabolismo , Tendões/transplante , Adulto Jovem
11.
Diabetes ; 49(7): 1084-91, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10909962

RESUMO

In vitro studies have shown that insulin and exercise stimulate glucose uptake in part via distinct mechanisms. We determined whether a high rate of insulin-stimulated glucose uptake (good insulin sensitivity) is associated with an enhanced ability of exercise to increase glucose uptake in vivo in humans. In our study, 22 normal subjects performed one-legged isometric exercise for 105 min (45-150 min) under intravenously maintained euglycemic-hyperinsulinemic conditions (0-150 min). Rates of oxygen consumption, blood flow, and glucose uptake were quantitated simultaneously in skeletal muscle of both legs using [15O]O2, [15O]H2O, [18F]fluoro-deoxy-glucose, and positron emission tomography. The one-legged exercise, performed at an intensity of 11% of maximal isometric force, was designed to induce similar increases in oxygen consumption in both groups. In the entire group, exercise increased oxygen consumption from 2.3 +/- 0.3 ml x kg(-1) muscle x min(-1) (insulin) to 34.2 +/- 3. ml x kg(-1) muscle x min(-1) (insulin and exercise) (P < 0.001) and muscle glucose uptake from 60 +/- 6 pmol x kg(-1) muscle x min(-1) (insulin) to 220 +/- 22 micromol x kg(-1) muscle x min(-1) (insulin and exercise) (P < 0.001). The exercise-induced increase in glucose uptake was due to marked increases in blood flow (36 +/- 5 ml x kg(-1) muscle x min(-1) [insulin] vs. 262 +/- 20 ml x kg(-1) muscle x min(-1) [insulin and exercise], P < 0.001) rather than glucose extraction, which decreased from 2.0 +/- 0.2 mmol/l (insulin) to 1.0 +/- 0.1 mmol/1 (insulin and exercise) (P < 0.001). The subjects were classified according to their mean rate of whole-body insulin-stimulated glucose uptake into those with high (49 +/- 3 micromol x kg(-1) x min(-1)) and normal (27 +/- 2 micromol x kg(-1) x min(-1)) rates of insulin-stimulated glucose uptake. Both insulin-stimulated (2.4 +/- 1.1 vs. 2.3 +/- 1.2 ml x kg(-1) muscle x min(-1), normal vs. high insulin sensitivity) and exercise- and insulin-stimulated (33 +/- 6 vs. 34 +/- 4 ml x kg(-1) muscle x min(-1)) rates of oxygen consumption were comparable between the groups. Exercise increased glucose uptake more in the group with high insulin sensitivity (195 +/- 25 pmol x kg(-1) muscle x min(-1)) than in the group with normal insulin sensitivity (125 +/- 19 micromol x kg(-1) muscle x min(-1)) (P < 0.05). Muscle blood flow was closely correlated with the rate of oxygen consumption (r = 0.91, P < 0.0001), and insulin-stimulated (30 +/- 5 vs. 35 +/- 6 ml x kg(-1) muscle x min(-1)) and exercise-induced increments (222 +/- 31 vs. 228 +/- 23 ml x kg(-1) muscle x min(-1)) in muscle blood flow were similar between the groups. Glucose extraction remained higher in the group with high insulin sensitivity (1.2 +/- 0.2 mmol/l) than in the group with normal insulin sensitivity (0.7 +/- 0.1 mmol/l, P < 0.05). We conclude that whereas acute exercise per se increases glucose uptake via increasing glucose delivery, good insulin sensitivity modulates exercise-induced increases in glucose uptake by enhancing cellular glucose extraction.


Assuntos
Exercício Físico/fisiologia , Fluordesoxiglucose F18/farmacocinética , Glucose/metabolismo , Insulina/farmacologia , Músculo Esquelético/fisiologia , Radioisótopos de Oxigênio/farmacocinética , Esforço Físico/fisiologia , Adulto , Técnica Clamp de Glucose , Humanos , Hiperinsulinismo/fisiopatologia , Infusões Intravenosas , Insulina/administração & dosagem , Contração Isométrica/fisiologia , Masculino , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/efeitos dos fármacos , Compostos Radiofarmacêuticos/farmacocinética , Fluxo Sanguíneo Regional/efeitos dos fármacos , Tomografia Computadorizada de Emissão , Água/metabolismo
12.
Mol Endocrinol ; 9(5): 605-15, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7565807

RESUMO

Full-length wild type and deletion mutant human androgen receptors (AR) were transiently expressed in monkey kidney COS cells to identify the phosphorylated amino acid residues. Phosphoamino acid analysis indicated serine (Ser) and threonine (Thr) residues as the major sites of phosphorylation. Both NH2- and carboxyl-terminal fragments containing the DNA-binding domain were highly phosphorylated, suggesting the presence of phosphorylation sites throughout the protein. Site-directed mutagenesis of wild type and deletion mutant AR at proline-directed consensus phosphorylation sites replaced Ser or Thr residues with Ala; wild type and mutant ARs were expressed in the presence of [32P]orthophosphate and isolated by immunoprecipitation using AR-specific antipeptide antibodies. Three proline-directed phosphorylation sites were identified: Ser 81 and 94 in the NH2-terminal region and Ser 650 in the hinge region. Expression of a series of NH2-terminal AR fragments provided evidence for additional sites in the NH2-terminal region. The effect of loss of each phosphorylation site on receptor function was determined by introducing the Ser to Ala mutations into full-length AR. Substituting Ser 81 and 94 with Ala had little effect on transcriptional activity when assayed by transient cotransfection. Substituting Ser 650 with Ala in the hinge region reduced transcriptional activity up to 30%. The results suggest at least three proline-directed phosphorylation sites in AR, one of which, serine 650, contributes to optimal gene activation by AR.


Assuntos
Prolina/metabolismo , Prolina/farmacologia , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Alanina/metabolismo , Animais , Sítios de Ligação , Humanos , Mutação , Fosforilação , Deleção de Sequência , Serina/metabolismo , Relação Estrutura-Atividade , Transcrição Gênica
13.
Mol Endocrinol ; 13(3): 440-54, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10077001

RESUMO

Natural and pharmacological androgen receptor (AR) ligands were tested for their ability to induce the AR NH2-terminal and carboxyl-terminal (N/C) interaction in a two-hybrid protein assay to determine whether N/C complex formation distinguishes in vivo AR agonists from antagonists. High-affinity agonists such as dihydrotestosterone, mibolerone, testosterone, and methyltrienolone at concentrations between 0.1 and 1 nM induce the N/C interaction more than 40-fold. The lower affinity anabolic steroids, oxandrolone and fluoxymesterone, require concentrations of 10-100 nM for up to 23-fold induction of the N/C interaction. However no N/C interaction was detected in the presence of the antagonists, hydroxyflutamide, cyproterone acetate, or RU56187, at concentrations up to 1 microM, or with 1 microM estradiol, progesterone, or medroxyprogesterone acetate; each of these steroids at 1-500 nM inhibited the dihydrotestosterone-induced N/C interaction, with medroxyprogesterone acetate being the most effective. In transient and stable cotransfection assays using the mouse mammary tumor virus reporter vector, all ligands displayed concentration-dependent AR agonist activity that paralleled induction of the N/C interaction, with antagonists and weaker agonists failing to induce the N/C interaction. AR dimerization and DNA binding in mobility shift assays and AR stabilization reflected, but were not dependent on, the N/C interaction. The results indicate that the N/C interaction facilitates agonist potency at low physiological ligand concentrations as detected in transcription, dimerization/DNA binding, and stabilization assays. However the N/C interaction is not required for agonist activity at sufficiently high ligand concentrations, nor does its inhibition imply antagonist activity.


Assuntos
Antagonistas de Androgênios/farmacologia , Antagonistas de Receptores de Andrógenos , Androgênios , Di-Hidrotestosterona/farmacologia , Acetato de Medroxiprogesterona/farmacologia , Animais , Células COS/efeitos dos fármacos , Células COS/metabolismo , DNA/metabolismo , Dimerização , Relação Dose-Resposta a Droga , Imidazóis/farmacologia , Luciferases/efeitos dos fármacos , Luciferases/genética , Luciferases/metabolismo , Vírus do Tumor Mamário do Camundongo/genética , Metribolona/farmacologia , Camundongos , Nandrolona/análogos & derivados , Nandrolona/farmacologia , Nitrilas/farmacologia , Fragmentos de Peptídeos/metabolismo , Congêneres da Progesterona/farmacologia , Receptores Androgênicos/fisiologia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Congêneres da Testosterona/farmacologia , Transcrição Gênica , Transfecção
14.
Mol Endocrinol ; 9(2): 208-18, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7776971

RESUMO

The molecular basis for the different physiological effects of testosterone (T) and dihydrotestosterone (DHT) was investigated using recombinantly expressed wild-type and mutant androgen receptor (AR). Rates of androgen dissociation from nuclear and cytoplasmic AR were compared with hormone- and concentration-dependent receptor degradation rates. T dissociates from AR 3 times faster than DHT or methyltrienolone (R1881) and is less effective in stabilizing the receptor. Analysis of AR deletion mutants and AR/glucocorticoid receptor chimeras indicates that the AR NH2-terminal domain has a specific role in stabilizing the receptor by slowing the rate of ligand dissociation and AR degradation. Amino acid mutations that abolish receptor dimerization, nuclear localization, or DNA-binding activity have no significant effect on androgen dissociation or AR degradation. A naturally occurring steroid-binding domain mutation (Val889 to Met) that causes androgen insensitivity, but does not alter equilibrium androgen binding affinity, lowered the androgen-binding capacity as a result of increased rates of androgen dissociation and AR degradation. Thus, AR stabilization and function require prolonged receptor occupancy with androgen, with a similar extent of stabilization observed at higher concentrations of faster dissociating androgens and lower concentrations of slower dissociating androgens. Retention of receptor-bound androgen is enhanced by an interaction between the AR NH2-terminal and steroid-binding domains. The ligand specificity and concentration dependence of receptor stabilization provide an explanation for physiological differences in the actions of T and DHT.


Assuntos
Di-Hidrotestosterona/metabolismo , Receptores Androgênicos/metabolismo , Testosterona/metabolismo , Animais , Linhagem Celular , Cinética , Mutagênese Sítio-Dirigida , Conformação Proteica , Receptores Androgênicos/química , Proteínas Recombinantes de Fusão/metabolismo , Transfecção
15.
Mol Endocrinol ; 10(12): 1527-35, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8961263

RESUMO

The molecular basis for partial androgen insensitivity associated with adult onset spinal/bulbar muscular atrophy was investigated by transient transfection of human androgen receptor (AR) expression vectors containing increasing CAG repeat lengths in the first exon. An inverse relationship was observed between CAG repeat length and AR mRNA and protein levels. Trinucleotide repeat lengths of 43 and 65 associated with spinal/bulbar muscular atrophy decreased AR mRNA and protein levels but did not alter equilibrium binding affinity for [3H]R1881 or inherent transcriptional activity of AR, expressed as androgen-dependent fold induction of a mouse mammary tumor virus promoter-luciferase reporter vector. The findings indicate that glutamine expansion up to 66 residues in the NH2-terminal domain of AR does not alter AR functional activity. Rather, CAG repeat expansion in the region of the first exon reduces AR mRNA and protein expression. The study reveals a previously unrecognized effect of CAG repeat length on AR mRNA expression and a novel molecular mechanism for androgen resistance.


Assuntos
Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Repetições de Trinucleotídeos , Androgênios/metabolismo , Animais , Células COS/metabolismo , Humanos , Immunoblotting , Atrofia Muscular Espinal/genética , RNA Mensageiro/biossíntese , Receptores Androgênicos/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade , Transcrição Gênica , Transfecção
16.
Mol Endocrinol ; 4(9): 1399-407, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2172802

RESUMO

Full-length rat and human androgen receptor (AR) cDNA clones were expressed in COS-7 and CV1 monkey kidney cells to analyze the AR protein using immunological and cotransfection techniques. The studies were aided by the development of two rabbit polyclonal antibodies, designated AR32 and AR52, directed against epitopes within the N-terminal region of AR. Each antibody recognizes native AR by sucrose gradient analysis and detects a 114-kilodalton protein in COS cells transfected with human or rat AR cDNA. Covalent binding of the synthetic androgen [3H]methyltrienolone (R1881) to the 114-kDa protein was saturable. The endogenous native AR was similarly 114 kDa on immunoblots of a human prostate adenocarcinoma cell line, LNCaP, and rat sex accessory gland extracts. AR was localized in nuclei of transfected COS cells and in LNCaP cells by immunocytochemical staining. Androgen induction of CAT activity was dose dependent in CV1 cells cotransfected with the AR expression vector and a reporter plasmid containing the mouse mammary tumor virus promoter linked to the chloramphenicol acetyltransferase gene. It is concluded that antipeptide antibodies are useful reagents in characterizing both native and denatured forms of the AR protein. The 114-kDa protein expressed transiently in cultured cells represents the full-length AR protein, has a molecular size equivalent to that of endogenous AR, and mediates androgen-dependent transcriptional activation in CV1 cells.


Assuntos
Expressão Gênica , Receptores Androgênicos/genética , Proteínas Recombinantes/genética , Sequência de Aminoácidos , Animais , Linhagem Celular , Cloranfenicol O-Acetiltransferase/genética , DNA/genética , Haplorrinos , Humanos , Immunoblotting , Técnicas Imunoenzimáticas , Rim , Masculino , Vírus do Tumor Mamário do Camundongo/genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Ratos , Ratos Endogâmicos , Receptores Androgênicos/química , Proteínas Recombinantes/química , Transfecção
17.
AIDS Patient Care STDS ; 15(3): 117-27, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11313024

RESUMO

The objective of this study was to identify the factors that influence adherence to antiretroviral medication regimens in culturally diverse populations with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) related to age, ethnicity, and intravenous drug use. The critical incident technique was used to identify factors determining adherence. Through a series of brief, focused interviews, patients were asked to recall specific incidents that affected their adherence to HIV medications. Patients' responses were grouped into categories using Ethnograph software. Two nurse experts, with 94% agreement, determined the reliability of the category listings. A chi(2) analysis compared the proportion of patients reporting each factor across age, ethnicity, and intravenous drug use categories. The total sample of 52 participants included 46 male outpatients with HIV/AIDS receiving care through a Veteran's Administration Hospital in northern California and 6 health care providers. The interviews yielded a total of 294 incidents. Six major categories were identified, and a taxonomy of critical factors determining highly active antiretroviral therapies (HAART) adherence was developed. The categories included reminders and cues (30%), planning (18%), response to HIV/AIDS (17%), HIV medication characteristics (14%), interactions with others (12%), and patient characteristics (10%). The two largest categories representing patient-related factors accounted for nearly half of the incidents. Patients most influenced by positive support from others included non-Caucasians, those under the age of 50 years, and those with fewer years of education. The taxonomy of adherence behaviors provides important information for developing culturally relevant patient adherence education programs and an essential foundation for developing future studies.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade/psicologia , Negro ou Afro-Americano/psicologia , Diversidade Cultural , Infecções por HIV/tratamento farmacológico , Infecções por HIV/etnologia , Hispânico ou Latino/psicologia , Cooperação do Paciente/etnologia , População Branca/psicologia , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Fatores Etários , Idoso , Terapia Antirretroviral de Alta Atividade/estatística & dados numéricos , California , Intervenção em Crise , Escolaridade , Hispânico ou Latino/estatística & dados numéricos , Hospitais de Veteranos , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente/estatística & dados numéricos , Autoadministração/métodos , Autoadministração/psicologia , Autoadministração/estatística & dados numéricos , Fatores Socioeconômicos , Inquéritos e Questionários , Estados Unidos , United States Department of Veterans Affairs , População Branca/estatística & dados numéricos
18.
Environ Toxicol Chem ; 20(6): 1325-31, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11392143

RESUMO

Effluent from a paper mill discharging into the Fenholloway River, Taylor County, Florida, USA, contains chemicals that masculinize females of the resident population of eastern mosquitofish (Gambusia holbrooki), as evidenced in females by elongated anal fins, which is normally a male-specific trait. To identify androgenic components in the effluent, water collected from the Fenholloway River and a control tributary was fractionated using solid-phase extraction and reverse-phase high-performance-liquid chromatography. Two Fenholloway River fractions induced androgen receptor-dependent transcriptional activity in transient transfection cell culture assays. Of these, androstenedione was confirmed by liquid chromatography-mass spectrometry with multiple reaction monitoring.


Assuntos
Androstenodiona/análise , Ciprinodontiformes/genética , Resíduos Industriais/análise , Papel , Poluentes Químicos da Água/análise , Animais , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Feminino , Florida , Masculino , Espectrometria de Massas , Receptores Androgênicos/genética , Caracteres Sexuais , Espectrofotometria Ultravioleta , Transcrição Gênica/genética
19.
J Assoc Nurses AIDS Care ; 12(1): 61-70, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11211673

RESUMO

BACKGROUND: While much work has been completed in relation to measuring and defining the varying dimensions of quality of life in HIV/AIDS, very little research attention has been directed toward identifying factors that influence or enhance quality of life. OBJECTIVE: This study examined whether variables relating to demographic characteristics, severity of illness, psychological status, or level of engagement in nursing care would predict quality of life in persons with advanced or late stage HIV/AIDS. METHODS: A convenience sample of 162 hospitalized male and female patients with AIDS participated in this study. The participants completed the HIV Symptom Checklist, the Beck Depression Inventory, the HIV-QAM (a measure of changes in the status of hospitalized AIDS patients due to nursing care), and two measures of engagement in nursing care. The Living With HIV Scale was used as the measure of quality of life. The two components of this scale were analyzed independently. RESULTS: The strongest predictor of decreased quality of life scores was depression (accounting for 23% of the variance), with symptoms accounting for 9.75% and female gender accounting for an additional 8%. Two measures of patient engagement with nursing care providers contributed a total of 13.44% of the variance in quality of life scores. CONCLUSIONS: The findings emphasize the importance of recognizing and treating depression in persons with HIV/AIDS. The number of symptoms and their frequency also has a profound effect on quality of life. Although modest, study findings suggest that quality of life for an acutely ill, hospitalized patient with AIDS is enhanced through more active involvement or engagement in the process of nursing care.


Assuntos
Síndrome da Imunodeficiência Adquirida/enfermagem , Síndrome da Imunodeficiência Adquirida/psicologia , Depressão , Qualidade de Vida , Adulto , Idoso , California , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
20.
Int J Nurs Stud ; 35(6): 330-8, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9871823

RESUMO

The purpose of this study is to identify the behavioral responses of hospitalized patients with HIV/AIDS to nursing care providers. The critical incident technique, developed by Flanagan (1954) was used to obtain a listing of the behavioral responses. Patients were asked to recall brief descriptions of caregiving events. A purposive sample included 118 men and women with HIV/AIDS from broad socioeconomic and cultural backgrounds. A total of 273 critical incidents yielded a listing of 393 behaviors. The analysis of data was facilitated by a computer program which allowed for the creation of coding systems and refinement of coded items into behavioral response categories. The inductive content analysis yielded 10 major response categories: participate, anger, appreciate, come close, stay away, match respect, match disrespect, dependent, complaint, and self care. In the largest category, 41% of the patients described ways in which they participate actively in their nursing care. These behavioral responses sharply contrast with current literature which continues to place a negative emphasis on the attitudes and behaviors of nurses. One third of the patients listed angry behaviors which were directed at nurses. Behavioral descriptions of anger reflected increased irritability with advancing illness, intense psychological responses toward an AIDS diagnosis, or a violent and angry style of relating to others in street settings. Two of the response categories describe the reciprocal nature of nurse-patient interactions. By becoming aware of patient responses, nurses will obtain a greater understanding of what changes would influence outcomes in patient behavior.


Assuntos
Síndrome da Imunodeficiência Adquirida/enfermagem , Síndrome da Imunodeficiência Adquirida/psicologia , Adaptação Psicológica , Comportamento , Relações Enfermeiro-Paciente , Recursos Humanos de Enfermagem Hospitalar/psicologia , Adulto , Idoso , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , São Francisco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA