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4.
Am Heart J ; 237: 135-146, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33762179

RESUMO

BACKGROUND: The literature reports no randomized trial in chronic coronary artery disease (CAD) of a comprehensive management strategy integrating intense lifestyle management, maximal medical treatment to specific goals and high precision quantitative cardiac positron emission tomography (PET) for identifying high mortality risk patients needing essential invasive procedures. We hypothesize that this comprehensive strategy achieves greater risk factor reduction, lower major adverse cardiovascular events and fewer invasive procedures than standard practice. METHODS: The CENTURY Study (NCT00756379) is a randomized-controlled-trial study in patients with stable or at high risk for CAD. Patients are randomized to standard of care (Standard group) or intense comprehensive lifestyle-medical treatment to targets and PET guided interventions (Comprehensive group). Comprehensive Group patients are regularly consulted by the CENTURY team implementing diet/lifestyle/exercise program and medical treatment to target risk modification. Cardiac PET at baseline, 24-, and 60-months quantify the physiologic severity of CAD and guide interventions in the Comprehensive group while patients and referring physicians of the Standard group are blinded to PET results. The primary end-point is the CENTURY risk score reduction during 5 years follow-up. The secondary endpoint is a composite of death, non-fatal myocardial infarction, stroke, and coronary revascularization. CONCLUSIONS: The CENTURY Study is the first study in stable CAD to test the incremental benefit of a comprehensive strategy integrating intense lifestyle modification, medical treatment to specific goals, and high-precision quantitative myocardial perfusion imaging to guide revascularization. A total of 1028 patients have been randomized, and the 5 years follow-up will conclude in 2022.


Assuntos
Terapia Comportamental/métodos , Angiografia Coronária/métodos , Doença da Artéria Coronariana/terapia , Circulação Coronária/fisiologia , Estilo de Vida , Tomografia por Emissão de Pósitrons/métodos , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
5.
Risk Anal ; 41(3): 456-465, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32088928

RESUMO

The recognition that organizations are a part of adverse outcomes has become commonplace in risk research. Social organization is a key theme in relation to risk minimization through institutional control and monitoring, and in how organizations are connected to society's perceptions of risk (beyond outcomes). The article reviews progress made in research on organizational risk over the last four decades and the contributions made to the field by fieldwork and descriptive approaches, understanding risk as partly determined by organizational context. A key issue for risk analysis is to figure out what these insights mean for risk professionals, such as while developing assessment methodologies and management approaches. Analysis of the literature shows that what to model if organizational factors are to be included in risk assessments remains as big a question as how to model. Integrating fieldwork and descriptive approaches for analyzing organizational risk, accidents, and safety is argued to be a main task for the risk analysis community.

6.
Theriogenology ; 84(2): 277-85, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-25917881

RESUMO

Transgenic nonhuman primate models are an increasingly popular model for neurologic and neurodegenerative disease because their brain functions and neural anatomies closely resemble those of humans. Transgenic Huntington's disease monkeys (HD monkeys) developed clinical features similar to those seen in HD patients, making the monkeys suitable for a preclinical study of HD. However, until HD monkey colonies can be readily expanded, their use in preclinical studies will be limited. In the present study, we confirmed germline transmission of the mutant huntingtin (mHTT) transgene in both embryonic stem cells generated from three male HD monkey founders (F0) and in second-generation offspring (F1) produced via artificial insemination by using intrauterine insemination technique. A total of five offspring were produced from 15 females that were inseminated by intrauterine insemination using semen collected from the three HD founders (5 of 15, 33%). Thus far, sperm collected from the HD founder (rHD8) has led to two F1 transgenic HD monkeys with germline transmission rate at 100% (2 of 2). mHTT expression was confirmed by quantitative real-time polymerase chain reaction using skin fibroblasts from the F1 HD monkeys and induced pluripotent stem cells established from one of the F1 HD monkeys (rHD8-2). Here, we report the stable germline transmission and expression of the mHTT transgene in HD monkeys, which suggest possible expansion of HD monkey colonies for preclinical and biomedical research studies.


Assuntos
Animais Geneticamente Modificados , Doença de Huntington/genética , Macaca mulatta , Espermatozoides , Animais , Diferenciação Celular , Modelos Animais de Doenças , Células-Tronco Embrionárias , Feminino , Genótipo , Células Germinativas , Proteína Huntingtina , Células-Tronco Pluripotentes Induzidas , Inseminação Artificial/métodos , Inseminação Artificial/veterinária , Masculino , Proteínas do Tecido Nervoso/genética , Neurônios , Células-Tronco Pluripotentes , Gravidez , Transgenes/genética
7.
Healthc Financ Manage ; 68(3): 88-92, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24701850

RESUMO

A competitive landscape for providers and changing market conditions require an understanding of key capital sources: tax-exempt bonds remain an attractive capital source. Credit enhancement for bonds is more expensive and more difficult to find than it was in years past. Direct bond purchases by commercial banks mitigate the traditional risks.


Assuntos
Financiamento de Capital/organização & administração , Recessão Econômica , Administração Financeira de Hospitais , Estados Unidos
8.
J Cardiovasc Pharmacol ; 53(1): 60-5, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19129734

RESUMO

The family of secretory phospholipase A2 (sPLA2) enzymes has been associated with inflammatory diseases and tissue injury including atherosclerosis. A-001 is a novel inhibitor of sPLA2 enzymes discovered by structure-based drug design, and A-002 is the orally bioavailable prodrug currently in clinical development. A-001 inhibited human and mouse sPLA2 group IIA, V, and X enzymes with IC50 values in the low nM range. A-002 (1 mg/kg) led to high serum levels of A-001 and inhibited PLA2 activity in transgenic mice overexpressing human sPLA2 group IIA in C57BL/6J background. In addition, the effects of A-002 on atherosclerosis in 2 ApoE mouse models were evaluated using en face analysis. (1) In a high-fat diet model, A-002 (30 and 90 mg/kg twice a day for 16 weeks) reduced aortic atherosclerosis by 50% (P < 0.05). Plasma total cholesterol was decreased (P < 0.05) by 1 month and remained lowered throughout the study. (2) In an accelerated atherosclerosis model, with angiotensin II-induced aortic lesions and aneurysms, A-002 (30 mg/kg twice a day) reduced aortic atherosclerosis by approximately 40% (P < 0.05) and attenuated aneurysm formation (P = 0.0096). Thus, A-002 was effective at significantly decreasing total cholesterol, atherogenesis, and aneurysm formation in these 2 ApoE mouse models.


Assuntos
Apolipoproteínas E/deficiência , Aterosclerose/enzimologia , Aterosclerose/patologia , Fosfolipases A2 Secretórias/antagonistas & inibidores , Acetatos , Aneurisma , Animais , Aorta/patologia , Apolipoproteínas E/genética , Arteriosclerose/enzimologia , Proteínas Sanguíneas , Colesterol , Fosfolipases A2 do Grupo II , Humanos , Indóis , Cetoácidos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos
9.
Mol Reprod Dev ; 76(4): 321-33, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18932214

RESUMO

Successful cryopreservation of oocytes of the rhesus monkey (Macaca mulatta) would facilitate the use of this valuable animal model in research on reproduction and development, while providing a stepping stone towards human oocyte cryopreservation and the conservation of endangered primate species. To enable rational design of cryopreservation techniques for rhesus monkey oocytes, we have determined their osmotic and permeability characteristics in the presence of dimethylsulfoxide (DMSO), ethylene glycol (EG), and propylene glycol (PROH), three widely used cryoprotectants. Using nonlinear regression to fit a membrane transport model to measurements of dynamic cell volume changes, we estimated the hydraulic conductivity (L(p)) and cryoprotectant permeability (P(s)) of mature and immature oocytes at 23.5 degrees C. Mature oocyte membranes were most permeable to PROH (P(s) = 0.56 +/- 0.05 microm/sec) and least permeable to DMSO (P(s) = 0.24 +/- 0.02 microm/sec); the permeability to EG was 0.34 +/- 0.07 microm/sec. In the absence of penetrating cryoprotectants, mature oocytes had L(p) = 0.55 +/- 0.05 microm/min/atm, whereas the hydraulic conductivity increased to 1.01 +/- 0.10, 0.61 +/- 0.07, or 0.86 +/- 0.06 microm/min/atm when mature oocytes were exposed to DMSO, EG, or PROH, respectively. The osmotically inactive volume (V(b)) in mature oocytes was 19.7 +/- 2.4% of the isotonic cell volume. The only statistically significant difference between mature and immature oocytes was a larger hydraulic conductivity in immature oocytes that were exposed to DMSO. The biophysical parameters measured in this study were used to demonstrate the design of cryoprotectant loading and dilution protocols by computer-aided optimization.


Assuntos
Permeabilidade da Membrana Celular , Crioprotetores/metabolismo , Macaca mulatta , Oócitos , Animais , Tamanho Celular , Sobrevivência Celular , Criopreservação/métodos , Dimetil Sulfóxido/metabolismo , Etilenoglicol/metabolismo , Feminino , Humanos , Membranas/metabolismo , Modelos Teóricos , Oócitos/citologia , Oócitos/metabolismo , Pressão Osmótica , Propilenoglicol/metabolismo
10.
Biol Reprod ; 79(3): 407-12, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18495682

RESUMO

A long postreproductive lifespan may distinguish women from all other female primates. A long-held consensus among reproductive scientists has been that our closest living relative, the chimpanzee (Pan troglodytes), experiences menstrual cycles until death. However, a recent study of biannual assessments of gonadotropins, but lacking observations of menstruation, concluded that menopause occurs in chimpanzees between 35 and 40 yr of age. A separate report, but on wild chimpanzees, documented fertility through the 40-44 age range in all populations studied. These contradictory reports pose questions about differences between wild and captive populations and about assessments of menopause. The present study revisits this controversy by analyzing longitudinal records of anogenital swelling and menstruation in 89 female chimpanzees aged 6 to 59 yr (n = 2386 records on cycle length), monitored for most of their adult lives at the Yerkes National Primate Research Center. Twenty of these chimpanzees were observed past 39 yr of age; all 20 displayed menstrual cycles beyond this age, as confirmed by at least two observations of menses about 35 days apart. Three of these were older than 50 yr and still displayed menstrual cycles. Only the oldest female appeared menopausal, with cycles of anogenital swelling ceasing 2 yr prior to her death at age 59. Random-effects statistical modeling reveals a slight decrease in cycle length until 20 yr of age and a slight lengthening thereafter. Mean cycle length across the lifespan is 35.4 days. Our findings, based upon actual observations of menstrual cycles, suggest that menopause in the chimpanzee is rare, occurring near the end of the lifespan.


Assuntos
Envelhecimento/fisiologia , Ciclo Menstrual/fisiologia , Pan troglodytes/fisiologia , Fatores Etários , Animais , Feminino , Genitália Feminina/fisiologia , Fatores de Tempo
11.
J Lipid Res ; 49(6): 1353-63, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18349418

RESUMO

Sensitive method for chemical analysis of free cholesterol (FC) and cholesterol esters (CE) was developed. Mouse arteries were dissected and placed in chloroform-methanol without tissue grinding. Extracts underwent hydrolysis of cholesteryl esters and derivatization of cholesterol followed by liquid chromatography/mass spectrometry (LC/MS/MS) analysis. We demonstrated that FC and CE could be quantitatively extracted without tissue grinding and that lipid extraction simultaneously worked for tissue fixation. Delipidated tissues can be embedded in paraffin, sectioned, and stained. Microscopic images obtained from delipidated arteries have not revealed any structural alterations. Delipidation was associated with excellent antigen preservation compatible with traditional immunohistochemical procedures. In ApoE(-/-) mice, LC/MS/MS revealed early antiatherosclerotic effects of dual PPARalpha,gamma agonist LY465606 in brachiocephalic arteries of mice treated for 4 weeks and in ligated carotid arteries of animals treated for 2 weeks. Reduction in CE and FC accumulation in atherosclerotic lesions was associated with the reduction of lesion size. Thus, a combination of LC/MS/MS measurements of CE and FC followed by histology and immunohistochemistry of the same tissue provides novel methodology for sensitive and comprehensive analysis of experimental atherosclerotic lesions.


Assuntos
Aterosclerose/metabolismo , Colesterol/metabolismo , Animais , Colesterol/química , Cromatografia Líquida de Alta Pressão , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Padrões de Referência , Espectrometria de Massas em Tandem
12.
Biomark Insights ; 3: 147-157, 2008 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-19578502

RESUMO

BACKGROUND: Current drug therapy of atherosclerosis is focused on treatment of major risk factors, e.g. hypercholesterolemia while in the future direct disease modification might provide additional benefits. However, development of medicines targeting vascular wall disease is complicated by the lack of reliable biomarkers. In this study, we took a novel approach to identify circulating biomarkers indicative of drug efficacy by reducing the complexity of the in vivo system to the level where neither disease progression nor drug treatment was associated with the changes in plasma cholesterol. RESULTS: ApoE-/- mice were treated with an ACE inhibitor ramipril and HMG-CoA reductase inhibitor simvastatin. Ramipril significantly reduced the size of atherosclerotic plaques in brachiocephalic arteries, however simvastatin paradoxically stimulated atherogenesis. Both effects occurred without changes in plasma cholesterol. Blood and vascular samples were obtained from the same animals. In the whole blood RNA samples, expression of MMP9, CD14 and IL-1RN reflected pro-and anti-atherogenic drug effects. In the plasma, several proteins, e.g. IL-1beta, IL-18 and MMP9 followed similar trends while protein readout was less sensitive than RNA analysis. CONCLUSION: In this study, we have identified inflammation-related whole blood RNA and plasma protein markers reflecting anti-atherogenic effects of ramipril and pro-atherogenic effects of simwastatin in a mouse model of atherosclerosis. This opens an opportunity for early, non-invasive detection of direct drug effects on atherosclerotic plaques in complex in vivo systems.

14.
Cryobiology ; 51(1): 1-14, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15922321

RESUMO

Biophysical characteristics of the plasma membrane, such as osmotic sensitivity and water and cryoprotectant permeability are important determinants of the function of spermatozoa after cryopreservation. A series of experiments was conducted with rhesus macaque spermatozoa at 23 degrees C to determine their: (1) cell volume and osmotically inactive fraction of the cell volume; (2) permeability coefficients for water and the cryoprotectants dimethyl sulfoxide, glycerol, propylene glycol, and ethylene glycol; (3) tolerance to anisosmotic conditions; and (4) motility after a one step addition and removal of the four cryoprotectants. An electronic particle counter and computer aided semen analysis were used to determine the cell volume and permeability coefficients, and motility, respectively. Rhesus spermatozoa isosmotic cell volume was 27.7+/-3.0 microm3 (mean+/-SEM) with an osmotically inactive cell fraction of 51%. Hydraulic conductivity in the presence of dimethyl sulfoxide, glycerol, propylene glycol, and ethylene glycol was 1.09+/-0.30, 0.912+/-0.27, 1.53+/-0.53, and 1.94+/-0.47 microm/min/atm, respectively. Cryoprotectant permeability was 1.39+/-0.31, 2.21+/-0.32, 3.38+/-0.63, and 6.07+/-1.1 (x10(-3)cm/min), respectively. Rhesus sperm tolerated all hyposmotic exposures. However, greater than 70% motility loss was observed after exposure to solutions of 600 mOsm and higher. A one step addition and removal of all four cryoprotectants did not cause significant motility loss. These data suggest that rhesus sperm are tolerant to hyposmotic conditions, and ethylene glycol may be the most appropriate cryoprotectant for rhesus sperm cryopreservation, as it has the highest permeability coefficient of the tested cryoprotectants.


Assuntos
Criopreservação/métodos , Osmose , Preservação do Sêmen/métodos , Espermatozoides/metabolismo , Animais , Permeabilidade da Membrana Celular , Movimento Celular , Criopreservação/instrumentação , Crioprotetores/farmacologia , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Glicerol/farmacologia , Humanos , Macaca mulatta , Masculino , Camundongos , Modelos Estatísticos , Permeabilidade , Propilenoglicol/farmacologia , Sêmen , Preservação do Sêmen/instrumentação , Especificidade da Espécie , Espermatozoides/citologia , Suínos , Temperatura , Fatores de Tempo , Água/química
15.
J Androl ; 26(4): 470-7, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15955885

RESUMO

Osmotic properties of chimpanzee spermatozoa were studied at 22 degrees C. An electronic particle counter was used to determine the isosmotic cell volume, and the volume response after exposure to four commonly used cryoprotectants: dimethyl sulfoxide, glycerol, propylene glycol, and ethylene glycol. The data were analyzed to determine the hydraulic conductivity and the permeability coefficients for the four cryoprotectants. The osmotically inactive volume fraction was determined using a Boyle van't Hoff plot of cells exposed to sodium chloride solutions. A computer-assisted semen analysis system was used to determine the osmotic tolerance of chimp spermatozoa, as well as the effects of a one-step addition and removal of 1 M permeating cryoprotectant on sperm motility. The isosmotic volume of chimpanzee sperm is 27.7 microm3. The osmotically inactive cell fraction is 69%. Hydraulic conductivity was higher in the presence of ethylene glycol: 4.09 +/- 0.76 (mean +/- SEM) and propylene glycol: 3.91 +/- 0.71 as compared to dimethyl sulfoxide: 3.49 +/- 0.79 and glycerol: 2.83 +/- 0.40 microm/min per atmosphere. The permeability of chimpanzee sperm in ethylene glycol (2.18 +/- 0.40 x 10(-3) cm/min) and propylene glycol (1.75 +/- 0.17 x 10(-3) cm/min) was higher than in glycerol (1.42 +/- 0.12 x 10(-3) cm/min) and dimethyl sulfoxide (0.82 +/- 0.015 x 10(-3) cm/min). Although chimpanzee sperm tolerated osmotic stress in the range of 169-400 mOsm very well, loss of motility was observed as the solution concentrations diverged from isosmotic condition. Exposure to the four cryoprotectants at 1 M did not cause a significant reduction in sperm motility. This information on membrane permeability characteristics and cryoprotectant tolerance will aid in designing more reliable cryopreservation protocols for chimpanzee sperm.


Assuntos
Permeabilidade da Membrana Celular/efeitos dos fármacos , Crioprotetores/farmacologia , Pan troglodytes/fisiologia , Preservação do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Animais , Crioprotetores/química , Dimetil Sulfóxido/química , Dimetil Sulfóxido/farmacologia , Etilenoglicol/química , Etilenoglicol/farmacologia , Glicerol/química , Glicerol/farmacologia , Masculino , Pressão Osmótica , Propilenoglicol/química , Propilenoglicol/farmacologia , Preservação do Sêmen/métodos , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/química , Espermatozoides/fisiologia
16.
Biochem Biophys Res Commun ; 332(3): 735-42, 2005 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-15907797

RESUMO

Stearoyl-CoA desaturase (SCD) is an integral membrane protein of the endoplasmic reticulum (ER) that catalyzes the formation of monounsaturated fatty acids from saturated fatty acids. Recent studies suggest that SCD is a key regulator of energy metabolism and has implications in dislipidemia and obesity. Four SCD isoforms (SCD1-4) have been identified in mouse. In human, only one SCD isoform has been characterized so far. Here we report that the previously reported human ACOD4 gene encodes a distinct stearoyl-CoA desaturase, hSCD5. GenBank database mining revealed orthologues of hSCD5 in the primates, but not in the rodents. In transiently transfected 293 cells, hSCD5 co-localized with calnexin on ER membrane. Microsome fractions prepared from hSCD1 and hSCD5 transfected cells displayed similar delta 9 desaturase activity. Quantitative real-time RT-PCR analysis suggested that hSCD5 was abundantly expressed in adult brain and pancreas. These data suggested that hSCD5 plays a role distinct from that of hSCD1 during development and in normal physiological conditions.


Assuntos
Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA/genética , Evolução Molecular , Humanos , Técnicas In Vitro , Dados de Sequência Molecular , Filogenia , Primatas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Estearoil-CoA Dessaturase/química , Frações Subcelulares/enzimologia
17.
J Mol Cell Cardiol ; 37(3): 705-15, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15350844

RESUMO

Mixed lineage kinase 7 (MLK7) is a recently identified mitogen-activated protein kinase kinase kinase with enriched expression in skeletal muscle and heart. When over-expressed in cardiac myocytes, MLK7 activates both the p38 and c-Jun N-terminal kinase (JNK) stress-activated pathways and induces a cellular phenotype characteristic of cardiac hypertrophy, including a fetal gene expression pattern and increased protein synthesis. We sought to determine the effect of MLK7 on cardiac function in vivo by generating transgenic (Tg) mice with cardiac restricted over-expression of the enzyme. The mice were viable and demonstrated no visible signs of distress at rest. Microscopic examination of the hearts showed myocardial fibrosis and hypertrophy. Hemodynamic analysis of the Tg mice revealed impaired systolic function and significant diastolic dysfunction. Furthermore, significant mortality was observed in MLK7 Tg mice following 24-48 h of isoproterenol administration. Isoproterenol activation of JNK and p38, but not extracellular signal-regulated kinase, was significantly greater in the MLK7 Tg mice compared to littermate controls. These data indicate that MLK7 is an important signal transducer in cardiac compensation. Simultaneous activation of JNK and p38 by MLK7 may contribute to cardiac decompensation during the periods of acute cardiac stress.


Assuntos
Agonistas Adrenérgicos beta/administração & dosagem , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/mortalidade , Isoproterenol/administração & dosagem , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Animais , Cardiomegalia/genética , Cardiomegalia/metabolismo , Cardiomegalia/mortalidade , Cardiomegalia/patologia , Fibrose/genética , Fibrose/metabolismo , Fibrose/patologia , Regulação da Expressão Gênica/genética , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MAP Quinase Quinase 4 , Camundongos , Camundongos Transgênicos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Músculo Esquelético , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
18.
J Clin Endocrinol Metab ; 88(10): 4874-83, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14557468

RESUMO

The importance of leptin in regulating sexual maturation is supported by data showing that deletions of the leptin gene or alterations in the leptin receptor result in infertility. However, attempts to define a role for leptin in normal puberty have produced equivocal results, leading to the conclusion that, if leptin is involved in puberty, its role is permissive and not obligatory. To better define the importance of leptin in primate puberty, the present study tested the hypothesis that a premature elevation in nocturnal leptin concentrations would accelerate indices of puberty, including nocturnal LH secretion in female rhesus monkeys (Macaca mulatta). Juvenile, gonadally intact females were treated daily with leptin (n = 6; 30 micro g/kg, sc at 1700 h) from 12-30 months of age and were compared with age-matched control females (n = 13). Chronic elevation in peripheral concentrations of leptin increased serum levels of both daytime and nighttime bioactive LH at a significantly younger age compared with control females. The earlier rise in LH in leptin-treated females was associated with an earlier increase in serum estradiol and occurrence of menarche. Despite this effect of leptin, nocturnal serum LH was significantly higher at each age assessed in non-leptin-treated ovariectomized controls (n = 6). In addition, leptin increased skeletal lengths and maturity that were associated with significantly higher serum levels of nocturnal GH and daytime IGF-I. Although body weights were not consistently affected by treatment, body mass index, as an index of body fat, was consistently lower in leptin-treated females. Taken together, these data indicate that the chronic elevation in serum leptin concentrations advances the nocturnal increase in serum LH as well as other parameters of female puberty. Furthermore, the observation that nocturnal LH was higher in age-matched, agonadal females compared with the leptin-treated females suggests that the nongonadal drive to LH secretion is operative in female macaques as early as 14 months of age, suggesting that the effect of leptin on puberty in female primates may involve a diminution in gonadal negative feedback suppression of LH secretion. Such a role would suggest that leptin is permissive yet critical for advancing female puberty.


Assuntos
Hormônio do Crescimento/sangue , Leptina/farmacologia , Hormônio Luteinizante/sangue , Maturidade Sexual/efeitos dos fármacos , Fatores Etários , Animais , Ritmo Circadiano , Feminino , Crescimento/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/metabolismo , Macaca mulatta
19.
Am J Physiol Heart Circ Physiol ; 282(2): H615-21, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11788410

RESUMO

Young mice tolerate myocardial loss after coronary artery ligation (CAL) without congestive heart failure (CHF) signs or mortality. We predicted a CHF phenotype after CAL in aged mice. Left coronary artery ligation produced permanent myocardial infarcts (MI). Mortality was higher in male 14-mo-old C57BL/6N mice (Older mice) than in 2-mo-old mice (Young mice) (16 of 25 Older mice died vs. 0 of 10 Young mice, P < 0.02). After 8 wk, rales, weight loss, and lethargy preceded deaths. Captopril (50 mg x kg(-1) x day(-1)) increased Older mouse survival (6 of 22 died, P < 0.02). Captopril improved systolic function (peak aortic blood velocity) from 76 +/- 6% of baseline in untreated Older mice to 93 +/- 8% (P < 0.036). At 24 h, MI comprised 28 +/- 4% of the left ventricle in Young mice, surprisingly larger than that in Older mice (18 +/- 2%, P < 0.011). Endocardial area underlying the infarct scar was significantly larger in Older mice than in Young mice. Captopril did not reduce expansion but markedly reduced septal hypertrophy. Aging reduces compensatory ability in mice despite smaller acute infarcts. Less effective myocardial repair, greater infarct expansion, and septal hypertrophy are seen with aging. Aging is a more relevant murine model of post-MI heart failure in patients.


Assuntos
Envelhecimento/fisiologia , Modelos Animais de Doenças , Insuficiência Cardíaca/patologia , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/patologia , Fatores Etários , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Velocidade do Fluxo Sanguíneo , Captopril/farmacologia , Cardiomegalia/tratamento farmacológico , Cardiomegalia/mortalidade , Cardiomegalia/patologia , Doença das Coronárias/tratamento farmacológico , Doença das Coronárias/mortalidade , Doença das Coronárias/patologia , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/mortalidade , Septos Cardíacos/patologia , Ligadura , Masculino , Camundongos , Análise Multivariada , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/mortalidade , Taxa de Sobrevida
20.
Am J Primatol ; 31(4): 287-297, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-31936994

RESUMO

This study provides baseline data on reproductive endocrine parameters of the male chimpanzee. A colony group of 47 male chimpanzees were classified by age as juvenile, ages 4-6 years (n = 7); adolescent, ages 7-9 (n = 9); and adult, ages 10-33 years (n = 31). Blood samples (n = 112) obtained from these animals [juveniles (n = ll), adolescents (n = 25), and adults (n = 76)] were analyzed for testosterone (T), luteinizing hormone (LH), and follicle stimulating hormone (FSH). There was a significant increase (mean ± SE) in T (ng/ml) between the juvenile (0.2 ± 0.1) and adolescent group (2.4 ± 0.3) and between the adolescent (2.4 ± 0.3) and the 10-14‒year-old adult age group (4.2 ± 0.2). T peaked at 15-24 years of age and then declined. There was a significant difference in T between animals aged 20-24 years (5.3 ± 0.4) and 25-29 years (3.0 ± 0.4). There was no significant change in serum LH (mlU/ml) with age. Serum FSH (mlU/ml) increased significantly between 4-6 years of age (90.0 ± 11.6) and 10-14 years of age (120.5 ± 8.3), plateaued between 10 and 19 years of age and was significantly lower in males older than 20 years (92.6 ± 4.2). Blood samples (n = 5) obtained from an experimental group of six adult male chimpanzees, ages 10 to 15 years, were analyzed for T, LH, and FSH, Pituitary response to challenge with exogenous GnRH and to hypotha-lamic stimulation with NMA also was assessed. T, LH, and FSH in the experimental group did not differ significantly from animals of equivalent age in the colony group. Challenge with 50, 100, 200, and 500µg GnRH stimulated LH release. The response was not directly dose related. Challenge with 3 and 6 mg/kg NMA stimulated LH release. The response was dose related. © 1993 Wiley-Liss, Inc.

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