Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Science ; 344(6190): 1410-4, 2014 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-24948738

RESUMO

The importance, extent, and mode of interspecific gene flow for the evolution of species has long been debated. Characterization of genomic differentiation in a classic example of hybridization between all-black carrion crows and gray-coated hooded crows identified genome-wide introgression extending far beyond the morphological hybrid zone. Gene expression divergence was concentrated in pigmentation genes expressed in gray versus black feather follicles. Only a small number of narrow genomic islands exhibited resistance to gene flow. One prominent genomic region (<2 megabases) harbored 81 of all 82 fixed differences (of 8.4 million single-nucleotide polymorphisms in total) linking genes involved in pigmentation and in visual perception-a genomic signal reflecting color-mediated prezygotic isolation. Thus, localized genomic selection can cause marked heterogeneity in introgression landscapes while maintaining phenotypic divergence.


Assuntos
Corvos/genética , Plumas/citologia , Fluxo Gênico , Variação Genética , Melanócitos/enzimologia , Pigmentação/genética , Animais , Evolução Molecular , Plumas/enzimologia , Genômica , Hibridização Genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Seleção Genética
2.
Osteoporos Int ; 17(6): 888-96, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16541206

RESUMO

INTRODUCTION: In anorexia nervosa (AN) patients osteoporosis occurs within a framework of multiple hormonal abnormalities as a result of bone turnover uncoupling, with decreased bone formation and increased bone resorption. The aim of study was to evaluate the hormonal and nutritional relationships with both of these bone remodeling compartments and their eventual modifications with age. PATIENTS AND MEASUREMENTS: In a cohort of 115 AN patients (mean BMI:14.6 kg/m2) that included 60 mature adolescents (age: 15.5-20 years) and 55 adult women (age: 20-37 years) and in 28 age-matched controls (12 mature adolescents and 16 adults) we assessed: bone markers [serum osteocalcin, skeletal alkaline phosphatase (sALP), C-telopeptide of type I collagen (sCTX) and tartrate-resistant acid phosphatase type 5b (TRAP 5b)], nutritional markers [ body mass index (BMI, fat and lean mass), hormones (free tri-iodothyronine (T3), free T4, thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicle stimulating hormone (FSH), 17 beta estradiol, free testosterone index (FTI), dehydroepiandrosterone (DHEAS), insulin-like growth factor 1 (IGF-1), growth hormone (GH) and cortisol], plasma methoxyamines (metanephrine and normetanephrine) and calcium metabolism parameters [parathyroid hormone (PTH), Ca, vitamin D3]. RESULTS: Osteocalcin reached similar low levels in both AN age subgroups. sCTX levels were found to be elevated in all AN subjects and higher in mature adolescents than in adult AN (11,567+/-895 vs. 8976+/-805 pmol/l, p<0.05). sALP was significantly lower only in mature adolescent AN patients, while there were no significant differences in the levels of TRAP 5b between AN patients and age-matched control groups. Osteocalcin correlated with sCTX in the control subjects (r=0.65) but not in the AN patients, suggesting the independent regulation of these markers in AN patients. Osteocalcin levels strongly correlated with freeT3, IGF-I, 17 beta estradiol and cortisol, while sCTX correlated with IGF-I, GH and cortisol in both age subgroups of the AN patients. Other hormones or nutritional parameters displayed age-related correlations with bone markers, leading to different stepwise regression models for each age interval. In mature adolescent AN patients, up to 54% of the osteocalcin variance was due to BMI, cortisol and 17 beta estradiol, while 54% of the sCTX variance was determined by GH. In adult subjects, freeT3 and IGF-I accounted for 64% of osteocalcin variance, while 65% of the sCTX variance was due to GH, FTI and methoxyamines. CONCLUSIONS: We suggest a more complex mechanism of AN bone uncoupling that includes not only "classical" influence elements like cortisol, IGF-I, GH or 17 beta estradiol but also freeT3, catecholamines and a "direct" hormone-independent impact of denutrition. Continuous changes of these influences with age should be considered within the therapeutic approach to AN bone loss.


Assuntos
Anorexia Nervosa/metabolismo , Biomarcadores/metabolismo , Remodelação Óssea/fisiologia , Catecolaminas/metabolismo , Hormônios/metabolismo , Osteocalcina/sangue , Adolescente , Adulto , Fatores Etários , Densidade Óssea/fisiologia , Estudos de Coortes , Feminino , Humanos , Estado Nutricional
3.
Presse Med ; 34(20 Pt 1): 1505-10, 2005 Nov 19.
Artigo em Francês | MEDLINE | ID: mdl-16301961

RESUMO

OBJECTIVES: Anorexia nervosa is an eating disorder that combines malnutrition, amenorrhea, and distorted body image. To learn more about the course of this disease we undertook a retrospective study of girls diagnosed with anorexia nervosa in the Saint Etienne Endocrinology Department between 1979 and 2004. METHODS: Patients were diagnosed according to DSMIV criteria. Data collected to complete the Morgan-Russell outcome assessment schedule included chronology of illness, patients' morphological features, anorexia type, treatment choice, patient's gynecological history, and social status. RESULTS: The study included 206 cases. The average follow-up period was 8.3 +/- 5.3 years. Defining recovery as stable BMI>17.5 kg/m2 for at least one year and recovery of normal menstruation, full recovery was observed in 55.8% and partial recovery in 25.7%, while 18.5% remained chronically ill. Early onset (i.e., during adolescence) was associated with good prognosis, and advanced emaciation and delayed or insufficient medical care with poor prognosis. CONCLUSIONS: The seriousness of this disease is due more to the incidence of cases that become chronic than to the mortality rate. Prediction of severity would be improved by taking into account underlying personality traits, such as addictive tendencies and depression.


Assuntos
Anorexia Nervosa/mortalidade , Recuperação de Função Fisiológica , Adolescente , Adulto , Amenorreia/prevenção & controle , Índice de Massa Corporal , Criança , Feminino , Seguimentos , França/epidemiologia , Humanos , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença , Inquéritos e Questionários
5.
Int J Food Microbiol ; 66(3): 163-73, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11428575

RESUMO

The survival of Salmonella typhimurium LT2, Escherichia coli K-12 and Pseudomonas putida in several model porous media poised at a water activity of 0.94 is shown to depend critically on the microstructure of the particulate matrix and the microscopic water distribution. The porous media were made by randomly dispersing a liquid inoculum containing ca. 10(7) cells/ml throughout the pores and interparticle spaces of packed beds of silica particles and Sephadex microspheres. The purely "microstructural stress" effects were isolated by comparison with a homogeneous liquid growth medium having the same water activity. The possibility of exploiting similar microstructural stress effects in food preservation is discussed.


Assuntos
Escherichia coli/crescimento & desenvolvimento , Microbiologia de Alimentos , Pseudomonas putida/crescimento & desenvolvimento , Salmonella typhimurium/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Meios de Cultura , Microesferas , Tamanho da Partícula , Fatores de Tempo , Água
6.
Ann Pediatr (Paris) ; 38(6): 381-6, 1991 Jun.
Artigo em Francês | MEDLINE | ID: mdl-1929103

RESUMO

This study was undertaken to evaluate the reliability of ambulatory blood pressure monitoring (ABPM) in children and its diagnostic value in teenagers with borderline hypertension. The apparatus used was a Nippon Colin (NC) ABPM 630 which simultaneously obtains BP levels by the auscultatory and oscillometric methods. Among 61 children (mean age 12 +/- 3 years), proportion of measurement failures was 14% (470/3399) for oscillometry, 26.5% (893/3360) for auscultation, and 2.7% for both methods together. Comparison of conventional auscultatory blood pressure measurements (mercury manometer) and simultaneous NC-auscultatory BP values (50 pairs) showed slightly lower diastolic blood pressure values with the NC monitor (-3.8 +/- 4.9 mmHg, p less than 0.01). Comparison of blood pressure values provided by the two NC methods (1580 pairs) demonstrated slightly higher systolic blood pressure values (+2.5 +/- 4 mmHg; p less than 0.001) and slightly lower diastolic blood pressure values (-5 +/- 4 mmHg; p less than 0.001) with the oscillometric method. Thirty-four ambulatory blood pressure recordings were obtained in 28 children (mean age 13.3: range 8-17) with outpatient clinic blood pressure values suggestive of borderline hypertension. Numbers of ambulatory blood pressure readings were 44 +/- 5 during the day and 9 +/- 1 during the night. The mean of daytime blood pressure values was compared with reference blood pressure values obtained at rest in normal French children.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Assistência Ambulatorial/normas , Monitores de Pressão Arterial/normas , Hipertensão/diagnóstico , Adolescente , Criança , Estudos de Avaliação como Assunto , Feminino , França/epidemiologia , Humanos , Hipertensão/epidemiologia , Masculino , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...