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1.
ESC Heart Fail ; 11(1): 126-135, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37842962

RESUMO

AIMS: Physical activity (PA) is an important target for improving clinical outcomes in heart failure (HF) patients. Nonetheless, assessing the daily PA profile in this population is a challenging task, traditionally performed using self-report questionnaires such as the International PA Questionnaire Short Form (IPAQ-SF). This study aimed to evaluate the concurrent validity of the IPAQ-SF and accelerometer-assessed PA using six published cut-points in patients with HF and reduced or mildly reduced ejection fraction. METHODS AND RESULTS: The concordance between the IPAQ-SF and a hip-worn accelerometer regarding daily time spent performing moderate to vigorous PA in bouts of at least 10 min was assessed in 53 participants for seven consecutive days using six different cut-points (Barnett, Dibben, Mark, Sanders, Troiano, and Vaha-Ypya). Spearman's correlation and Bland-Altman plots were used to evaluate concurrent validity between methods. Regressions were used to study the association between patient variables, wear protocol (waking hour or 24 h), and absolute bias. The kappa index was used to evaluate the concordance between IPAQ-SF and accelerometry for classifying patients as active or non-active. All analyses were re-run using non-bouted metrics to investigate the effect of bouted versus non-bouted analysis. The IPAQ-SF and accelerometry showed low to negligible correlation (ρ = 0.12 to 0.37), depending on the cut-point used. The regression analysis showed that the absolute bias was higher in participants following the waking-hour protocol at all cut-points except Dibben's (P ≤ 0.007). The concordance between the two methods to classify patients as active and non-active was low when using Mark (κ = 0.23) and Barnett (κ = 0.34) cut-points and poor for the remaining cut-points (κ = 0.03 to 0.18). The results of the sensitivity analysis showed negligible to low correlation using non-bouted metrics (ρ = 0.27 to 0.33). CONCLUSIONS: Moderate to vigorous PA measures using IPAQ-SF and accelerometers are not equivalent, and we do not encourage researchers to use IPAQ-SF alone when assessing PA in HF patients. Moreover, applying personalized collection and processing criteria is important when assessing PA in HF patients. We recommend following the 24 h protocol and selecting cut-points calibrated in patients with cardiovascular diseases. Finally, it is necessary to develop a new tailored questionnaire that considers walking intensity and is adjusted to the current World Health Organisation recommendations, which use non-bouted metrics.


Assuntos
Exercício Físico , Insuficiência Cardíaca , Humanos , Inquéritos e Questionários , Autorrelato , Acelerometria , Insuficiência Cardíaca/diagnóstico
2.
J Am Coll Cardiol ; 80(15): 1447-1461, 2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36007715

RESUMO

BACKGROUND: Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVES: We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS: We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers. RESULTS: At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of ≤35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS: MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare.


Assuntos
Cardiomiopatia Dilatada , Insuficiência Cardíaca , Cadeias Pesadas de Miosina , Adolescente , Adulto , Arritmias Cardíacas/complicações , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/genética , Miosinas Cardíacas/genética , Cardiomiopatia Dilatada/genética , Feminino , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/genética , Humanos , Masculino , Pessoa de Meia-Idade , Cadeias Pesadas de Miosina/genética , Fenótipo , Remodelação Ventricular/genética , Adulto Jovem
3.
JAMA Cardiol ; 6(8): 891-901, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33978673

RESUMO

Importance: Truncating variants in the gene encoding filamin C (FLNCtv) are associated with arrhythmogenic and dilated cardiomyopathies with a reportedly high risk of ventricular arrhythmia. Objective: To determine the frequency of and risk factors associated with adverse events among FLNCtv carriers compared with individuals carrying TTN truncating variants (TTNtv). Design, Setting, and Participants: This cohort study recruited 167 consecutive FLNCtv carriers and a control cohort of 244 patients with TTNtv matched for left ventricular ejection fraction (LVEF) from 19 European cardiomyopathy referral units between 1990 and 2018. Data analyses were conducted between June and October, 2020. Main Outcomes and Measures: The primary end point was a composite of malignant ventricular arrhythmia (MVA) (sudden cardiac death, aborted sudden cardiac death, appropriate implantable cardioverter-defibrillator shock, and sustained ventricular tachycardia) and end-stage heart failure (heart transplant or mortality associated with end-stage heart failure). The secondary end point comprised MVA events only. Results: In total, 167 patients with FLNCtv were studied (55 probands [33%]; 89 men [53%]; mean [SD] age at baseline evaluation, 43 [18] years). For a median follow-up of 20 months (interquartile range, 7-60 months), 29 patients (17.4%) reached the primary end point (19 patients with MVA and 10 patients with end-stage heart failure). Eight (44%) arrhythmic events occurred among individuals with baseline mild to moderate left ventricular systolic dysfunction (LVSD) (LVEF = 36%-49%). Univariable risk factors associated with the primary end point included proband status, LVEF decrement per 10%, ventricular ectopy (≥500 in 24 hours) and myocardial fibrosis detected on cardiac magnetic resonance imaging. The LVEF decrement (hazard ratio [HR] per 10%, 1.83 [95% CI, 1.30-2.57]; P < .001) and proband status (HR, 3.18 [95% CI, 1.12-9.04]; P = .03) remained independent risk factors on multivariable analysis (excluding myocardial fibrosis and ventricular ectopy owing to case censoring). There was no difference in freedom from MVA between FLNCtv carriers with mild to moderate or severe (LVEF ≤35%) LVSD (HR, 1.29 [95% CI, 0.45-3.72]; P = .64). Carriers of FLNCtv with impaired LVEF at baseline evaluation (n = 69) had reduced freedom from MVA compared with 244 TTNtv carriers with similar baseline LVEF (for mild to moderate LVSD: HR, 16.41 [95% CI, 3.45-78.11]; P < .001; for severe LVSD: HR, 2.47 [95% CI, 1.04-5.87]; P = .03). Conclusions and Relevance: The high frequency of MVA among patients with FLNCtv with mild to moderate LVSD suggests that higher LVEF values than those currently recommended should be considered for prophylactic implantable cardioverter-defibrillator therapy in FLNCtv carriers.


Assuntos
Cardiomiopatia Dilatada/genética , Morte Súbita Cardíaca/prevenção & controle , Filaminas/genética , Insuficiência Cardíaca/genética , Taquicardia Ventricular/genética , Disfunção Ventricular Esquerda/genética , Adulto , Cardiomiopatia Dilatada/mortalidade , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Dilatada/terapia , Códon sem Sentido , Conectina/genética , Desfibriladores Implantáveis , Feminino , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Transplante de Coração/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Volume Sistólico , Taquicardia Ventricular/epidemiologia , Taquicardia Ventricular/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia
4.
Eur J Heart Fail ; 23(8): 1276-1286, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34050592

RESUMO

AIMS: Dilated cardiomyopathy (DCM) associated with dystrophin gene (DMD) mutations in individuals with mild or absent skeletal myopathy is often indistinguishable from other DCM forms. We sought to describe the phenotype and prognosis of DMD associated DCM in DMD mutation carriers without severe skeletal myopathy. METHODS AND RESULTS: At 26 European centres, we retrospectively collected clinical characteristics and outcomes of 223 DMD mutation carriers (83% male, 33 ± 15 years). A total of 112 individuals (52%) had DCM at first evaluation [n = 85; left ventricular ejection fraction (LVEF) 34 ± 11.2%] or developed DCM (n = 27; LVEF 41.3 ± 7.5%) after a median follow-up of 96 months (interquartile range 5-311 months). DCM penetrance was 45% in carriers older than 40 years. DCM appeared earlier in males and was independent of the type of mutation, presence of skeletal myopathy, or elevated serum creatine kinase levels. Major adverse cardiac events (MACE) occurred in 22% individuals with DCM, 18% developed end-stage heart failure and 9% sudden cardiac death or equivalent. Skeletal myopathy was not associated with survival free of MACE in patients with DCM. Decreased LVEF and increased left ventricular end-diastolic diameter at baseline were associated with MACE. Individuals without DCM had favourable prognosis without MACE or death during follow-up. CONCLUSIONS: DMD-associated DCM without severe skeletal myopathy is characterized by incomplete penetrance but high risk of MACE, including progression to end-stage heart failure and ventricular arrhythmias. DCM onset is the major determinant of prognosis with similar survival regardless of the presence of skeletal myopathy.


Assuntos
Cardiomiopatia Dilatada , Insuficiência Cardíaca , Doenças Musculares , Adolescente , Adulto , Cardiomiopatia Dilatada/epidemiologia , Cardiomiopatia Dilatada/genética , Distrofina/genética , Feminino , Insuficiência Cardíaca/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Volume Sistólico , Função Ventricular Esquerda , Adulto Jovem
5.
Rev Esp Cardiol (Engl Ed) ; 74(3): 216-224, 2021 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32616434

RESUMO

INTRODUCTION AND OBJECTIVES: According to sudden cardiac death guidelines, an implantable cardioverter-defibrillator (ICD) should be considered in patients with LMNA-related dilated cardiomyopathy (DCM) and ≥ 2 risk factors: male sex, left ventricular ejection fraction (LVEF) <45%, nonsustained ventricular tachycardia (NSVT), and nonmissense genetic variants. In this study we aimed to describe the clinical characteristics of carriers of LMNA genetic variants among individuals from a Spanish cardiac-laminopathies cohort (REDLAMINA registry) and to assess previously reported risk criteria. METHODS: The relationship between risk factors and cardiovascular events was evaluated in a cohort of 140 carriers (age ≥ 16 years) of pathogenic LMNA variants (54 probands, 86 relatives). We considered: a) major arrhythmic events (MAE) if there was appropriate ICD discharge or sudden cardiac death; b) heart failure death if there was heart transplant or death due to heart failure. RESULTS: We identified 11 novel and 21 previously reported LMNA-related DCM variants. LVEF <45% (P=.001) and NSVT (P <.001) were related to MAE, but not sex or type of genetic variant. The only factor independently related to heart failure death was LVEF <45% (P <.001). CONCLUSIONS: In the REDLAMINA registry cohort, the only predictors independently associated with MAE were NSVT and LVEF <45%. Therefore, female carriers of missense variants with either NSVT or LVEF <45% should not be considered a low-risk group. It is important to individualize risk stratification in carriers of LMNA missense variants, because not all have the same prognosis.


Assuntos
Laminopatias , Adolescente , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia , Desfibriladores Implantáveis , Feminino , Humanos , Masculino , Sistema de Registros , Fatores de Risco , Volume Sistólico , Taquicardia Ventricular , Função Ventricular Esquerda
6.
Pregnancy Hypertens ; 22: 204-209, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33091682

RESUMO

OBJECTIVES: Dysregulation of CD59 may lead to increased complement-mediated end-organ injury in preeclampsia. We sought to determine if soluble CD59 concentrations are altered in preeclampsia with severe features. STUDY DESIGN: Observational case-control study, which enrolled subjects prospectively from six centers in Colombia from 2015 to 2016. Cases had preeclampsia with severe features and controls were either healthy or had chronic hypertension, gestational hypertension, or preeclampsia without severe features. Trained coordinators collected clinical data, blood and urine. Analyses were by test of medians and Spearman's correlation. MAIN OUTCOME MEASURES: Soluble CD59 concentration in plasma and urine, using enzyme linked immunosorbent assays. RESULTS: In total, 352 subjects were enrolled (104 cases; 248 controls). Compared to healthy women or those with other hypertensive disorders of pregnancy, women with preeclampsia with severe features had increased concentration of CD59 in plasma (P < 0.001) and decreased CD59 in urine (P = 0.01). In sub-group analyses, plasma CD59 concentrations were increased in preeclampsia with severe features compared to healthy controls (P < 0.001) or controls with either chronic hypertension (P = 0.002) or gestational hypertension (P = 0.02). Increased plasma CD59 concentrations correlated with decreased platelet count and increased lactate dehydrogenase, creatinine, aspartate transaminase, urine protein/creatinine ratio, systolic blood pressure and diastolic blood pressure (P < 0.01, all correlations). CONCLUSION: In women with preeclampsia with severe features, soluble CD59 concentrations were increased in plasma and decreased in urine, and plasma levels correlated with increased blood pressure and end-organ injury. Soluble CD59 concentrations may help identify a subset of women with preeclampsia that have altered regulation of terminal complement proteins.


Assuntos
Antígenos CD59/sangue , Síndrome HELLP/sangue , Pré-Eclâmpsia/sangue , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Antígenos CD59/urina , Estudos de Casos e Controles , Feminino , Síndrome HELLP/urina , Humanos , Pré-Eclâmpsia/urina , Gravidez , Estudos Prospectivos , Índice de Gravidade de Doença
7.
J Am Coll Cardiol ; 76(2): 186-197, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32646569

RESUMO

BACKGROUND: PRKAG2 gene variants cause a syndrome characterized by cardiomyopathy, conduction disease, and ventricular pre-excitation. Only a small number of cases have been reported to date, and the natural history of the disease is poorly understood. OBJECTIVES: The aim of this study was to describe phenotype and natural history of PRKAG2 variants in a large multicenter European cohort. METHODS: Clinical, electrocardiographic, and echocardiographic data from 90 subjects with PRKAG2 variants (53% men; median age 33 years; interquartile range [IQR]: 15 to 50 years) recruited from 27 centers were retrospectively studied. RESULTS: At first evaluation, 93% of patients were in New York Heart Association functional class I or II. Maximum left ventricular wall thickness was 18 ± 8 mm, and left ventricular ejection fraction was 61 ± 12%. Left ventricular hypertrophy (LVH) was present in 60 subjects (67%) at baseline. Thirty patients (33%) had ventricular pre-excitation or had undergone accessory pathway ablation; 17 (19%) had pacemakers (median age at implantation 36 years; IQR: 27 to 46 years), and 16 (18%) had atrial fibrillation (median age 43 years; IQR: 31 to 54 years). After a median follow-up period of 6 years (IQR: 2.3 to 13.9 years), 71% of subjects had LVH, 29% had AF, 21% required de novo pacemakers (median age at implantation 37 years; IQR: 29 to 48 years), 14% required admission for heart failure, 8% experienced sudden cardiac death or equivalent, 4% required heart transplantation, and 13% died. CONCLUSIONS: PRKAG2 syndrome is a progressive cardiomyopathy characterized by high rates of atrial fibrillation, conduction disease, advanced heart failure, and life-threatening arrhythmias. Classical features of pre-excitation and severe LVH are not uniformly present, and diagnosis should be considered in patients with LVH who develop atrial fibrillation or require permanent pacemakers at a young age.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Cardiomiopatias/genética , DNA/genética , Doença de Depósito de Glicogênio/genética , Mutação , Miocárdio/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Adolescente , Adulto , Cardiomiopatias/diagnóstico , Cardiomiopatias/metabolismo , Criança , Análise Mutacional de DNA , Ecocardiografia , Eletrocardiografia , Feminino , Seguimentos , Doença de Depósito de Glicogênio/diagnóstico , Doença de Depósito de Glicogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Retrospectivos , Adulto Jovem
8.
Sci Rep ; 9(1): 8852, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221970

RESUMO

Petunia × hybrida cv 'Mitchell Diploid' floral volatile benzenoid/phenylpropanoid (FVBP) biosynthesis ultimately produces floral volatiles derived sequentially from phenylalanine, cinnamic acid, and p-coumaric acid. In an attempt to better understand biochemical steps after p-coumaric acid production, we cloned and characterized three petunia transcripts with high similarity to p-coumarate 3-hydroxylase (C3H), hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT), and caffeoyl shikimate esterase (CSE). Transcript accumulation of PhC3H and PhHCT was highest in flower limb tissue during open flower stages. PhCSE transcript accumulation was also highest in flower limb tissue, but it was detected earlier at initial flower opening with a bell-shaped distribution pattern. Down regulation of endogenous PhC3H transcript resulted in altered transcript accumulation of many other FVBP network transcripts, a reduction in floral volatiles, and the emission of a novel floral volatile. Down regulation of PhHCT transcript did not have as large of an effect on floral volatiles as was observed for PhC3H down regulation, but eugenol and isoeugenol emissions were significantly reduced on the downstream floral volatiles. Together these results indicate that PhC3H is involved in FVBP biosynthesis and the reduction of PhC3H transcript influences FVBP metabolism at the network level. Additional research is required to illustrate PhHCT and PhCSE functions of petunia.


Assuntos
Flores/metabolismo , Oxigenases de Função Mista/metabolismo , Petunia/enzimologia , Compostos Orgânicos Voláteis/metabolismo , Aciltransferases , Hidrolases de Éster Carboxílico , Ácidos Cumáricos , Regulação para Baixo , Propionatos/química , Volatilização
9.
Clin Cancer Res ; 24(15): 3767-3780, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29691292

RESUMO

Purpose: Hepatocellular carcinoma (HCC) ranks second in cancer mortality and has limited therapeutic options. We recently described the synergistic effect of allosteric and ATP-site competitive inhibitors against the mTOR for the treatment of HCC. However, such inhibitors induce hyperglycemia and increase mitochondrial efficiency. Here we determined whether the mitochondrial complex I inhibitor phenformin could reverse both side effects, impose an energetic stress on cancer cells, and suppress the growth of HCC.Experimental Design: Human HCC cell lines were used in vitro to access the signaling and energetic impact of mTOR inhibitors and phenformin, either alone or in combination. Next, the therapeutic utility of these drugs alone or in combination was investigated preclinically in human orthotopic tumors implanted in mice, by analyzing their impact on the tumor burden and overall survival.Results: We found phenformin caused mitochondrial dysfunction and fragmentation, inducing a compensatory shift to glycolysis. In contrast, dual inhibition of mTOR impaired cell growth and glycolysis, while increasing mitochondrial fusion and efficiency. In a mouse model of human HCC, dual inhibition of mTOR, together with phenformin, was highly efficacious in controlling tumor burden. However, more strikingly, pretreatment with phenformin sensitized tumors to dual inhibition of mTOR, leading to a dramatic improvement in survival.Conclusions: Treatment of HCC cells in vitro with the biguanide phenformin causes a metabolic shift to glycolysis, mitochondrial dysfunction and fragmentation, and dramatically sensitizes orthotopic liver tumors to dual inhibition of mTOR. We therefore propose this therapeutic approach should be tested clinically in HCC. Clin Cancer Res; 24(15); 3767-80. ©2018 AACR.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Fenformin/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Everolimo/farmacologia , Glicólise/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Biol Reprod ; 75(2): 261-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16707772

RESUMO

In mammals, removal of one testis results in compensatory testicular hypertrophy (CTH) of the remaining gonad. Although CTH is ubiquitous among juveniles of many species, laboratory rats, laboratory mice, and humans unilaterally castrated in adulthood fail to display CTH. We documented CTH in pre- and postpubertally hemi-castrated Syrian and Siberian hamsters and tested whether day length affects CTH in juvenile and adult Siberian hamsters. Robust CTH was evident in long-day hemi-castrates of both species and was preceded by increased serum FSH concentrations in juvenile Siberian hamsters. In sharp contrast, CTH was undetectable in short-day hemi-castrated Siberian hamsters for several months and only made its appearance with the development of neuroendocrine refractoriness to short day lengths; serum FSH concentrations of juveniles also did not increase above sham-castrate values until the onset of refractoriness. Long-day hemi-castrated Siberian hamsters with hypertrophied testes underwent complete gonadal regression after transfer to short days, albeit at a reduced rate for the first 3 weeks of treatment. Blood testosterone concentrations of adult hamsters did not differ between long-day hemicastrates and sham-castrates 9-12 weeks after surgery. We conclude that CTH is suppressed by short day lengths in Siberian hamsters at all ages and stages of reproductive development; in short day lengths, but not long day lengths, the remaining testis produces sufficient negative feedback inhibition to restrain FSH hypersecretion and prevent CTH.


Assuntos
Phodopus/fisiologia , Fotoperíodo , Testículo/patologia , Testículo/fisiologia , Adaptação Fisiológica , Fatores Etários , Animais , Cricetinae , Hormônio Foliculoestimulante/metabolismo , Hipertrofia , Masculino , Mesocricetus , Orquiectomia , Testosterona/metabolismo
11.
Horm Behav ; 45(3): 214-21, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15047017

RESUMO

Gonadal steroids are essential for the long-term maintenance of the full repertoire of sexual behavior in male rodents. Typically, all individuals of several species cease to display the ejaculatory reflex within a few weeks of castration. The present study documents the persistence of the ejaculatory reflex 19 weeks after orchidectomy in 40% of male Siberian hamsters maintained in long or short day lengths; testosterone was undetectable in the circulation of these animals. Intact hamsters transferred from a long to a short photoperiod underwent gonadal regression: 50% of these animals continued to display mating behavior culminating in ejaculation throughout 25 weeks of testing. The remaining animals failed to ejaculate after approximately 11 weeks of short day treatment but resumed mating coincident with spontaneous gonadal recrudescence. Activation of sex behavior in the latter cohort appears to depend on gonadal steroids and is in contrast to the copulatory behavior of the substantial proportion of the study population that sustains the full sexual repertoire in the long-term absence of gonadal steroids. Sex behavior of the latter animals may be dependent on nongonadal steroids or mediation by steroid-independent mechanisms.


Assuntos
Ejaculação/fisiologia , Ejaculação/efeitos da radiação , Fotoperíodo , Comportamento Sexual Animal/fisiologia , Comportamento Sexual Animal/efeitos da radiação , Adaptação Fisiológica , Animais , Castração , Cricetinae , Feminino , Luz , Masculino , Phodopus , Testículo/fisiologia , Testículo/efeitos da radiação , Fatores de Tempo
12.
Eur J Biochem ; 269(3): 902-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11846791

RESUMO

The Phycomyces blakesleeanus wild-type is yellow, because it accumulates beta-carotene as the main carotenoid. A new carotenoid mutant of this fungus (A486) was isolated, after treatment with ethyl methane sulfonate (EMS), showing a whitish coloration. It accumulates large amounts of phytoene, small quantities of phytofluene, zeta-carotene and neurosporene, in decreasing amounts, and traces of beta-carotene. This phenotype indicates that it carries a leaky mutation affecting the enzyme phytoene dehydrogenase (EC 1.3.-.-), which is specified by the gene carB. Biochemical analysis of heterokaryons showed that mutant A486 complements two previously characterized carB mutants, C5 (carB10) and S442 (carB401). Sequence analysis of the carB gene genomic copy from these three strains revealed that they are all altered in the gene carB, giving information about the nature of the mutation in each carB mutant allele. The interallelic complementation provides evidence for the multimeric organization of the P. blakesleeanus phytoene dehydrogenase.


Assuntos
Fungos/genética , Oxirredutases/genética , Oxirredutases/metabolismo , Alelos , Sequência de Aminoácidos , Clonagem Molecular , Metanossulfonato de Etila/química , Fungos/isolamento & purificação , Fungos/metabolismo , Teste de Complementação Genética , Dados de Sequência Molecular , Mutação , Oxirredutases/química
13.
Biomédica (Bogotá) ; 21(2): 128-133, jun. 2001. tab, graf
Artigo em Espanhol | LILACS | ID: lil-315769

RESUMO

En Cali se realizó un estudio de perros con el fin de determinar la frecuencia de dermatofitos. La toma de muestra se hizo en hocico, cabeza, dorso, vientre y zonas laterales por la técnica del tapete y para cada sitio y perro muestreado se utilizó una alfombra diferente. Las muestras se sembraron en agar selectivo para hongos patógenos. Se examinaron 251 perros, 86 callejeros y 165 caseros, entre los cuales se encontraron 34 (13,5 por ciento) positivos para dermatofitos; de éstos, 23 correspondieron a perros caseros y 11 a callejeros. No se establecieron diferencias significativas entre estas dos categorías. Tampoco se encontró asociación con la edad, el sexo, la raza o la longitud del pelo, pero sí hubo relación entre la presencia de lesiones en la piel y el aislamiento de hongos (P<,0,05). El dermatofito más aislado fue el Microsporum gypseum (55,9 por ciento), seguido por Microsporum canis y Trichophyton mentagrophytes var mentagrophytes, cada uno con el 14,7 por ciento y Trichophyton rubrum con 2,9 por ciento de los aislamientos. Estos dos últimos hongos sólo se hallaron en los perros caseros


Assuntos
Cães , Arthrodermataceae , Dermatomicoses
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