Assuntos
Humanos , Masculino , Adolescente , Adulto Jovem , Dor Lombar , Região Lombossacral/fisiologiaRESUMO
Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM) muscle's motor units using high-density surface electromyography (EMGs) at different bite force levels. Twenty healthy natural dentate participants (men: 4; women: 16; age 20±2 years; mass: 60±12 kg, height: 163±7 cm) were selected from 316 volunteers and included in this study. Using a gnathodynamometer, bites from 20 to 100% maximum voluntary bite force (MVBF) were randomly requested. Using a two-dimensional grid (four columns, six electrodes) located on the dominant SM, EMGs in the anterior, middle-anterior, middle-posterior and posterior portions were simultaneously recorded. In bite ranges from 20 to 60% MVBF, the EMG activity was higher in the anterior than in the posterior portion (p-value = 0.001).The center of mass of the EMG activity was displaced towards the posterior part when bite force increased (p-value = 0.001). The topographic distribution of EMGs was more homogeneous at high levels of MVBF (p-value = 0.001). The results of this study show that the superficial masseter is organized into three functional compartments: an anterior, a middle and a posterior compartment. However, this compartmentalization is only seen at low levels of bite force (20-60% MVBF).
Assuntos
Músculo Masseter/fisiologia , Força de Mordida , Eletromiografia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
OBJECTIVE: To assess the association between epicardial adipose tissue thickness (EAT) and plasma adrenomedullin plasma levels in patients with metabolic syndrome (MS). METHODS: Twenty-one patients (12 females and 9 males) with MS according to the International Diabetes Federation guidelines, aged 22-58 years, were enrolled into the study and compared to 19 age-matched control subjects without MS. Plasma glucose, lipid, and adrenomedullin levels were assessed. EAT, left ventricular mass, and carotid intima-media thickness were evaluated by transthoracic two-dimensional echocardiography. RESULTS: No statistically significant differences were found between the groups in age, sex, and height. Body weight, abdominal circumference (AC), body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were significantly higher (p=0.0001) in MS patients; this group also showed significantly higher glucose (p=0.001), total cholesterol (p=0.01), LDL-C (p=0.03), VLDL-C (p=0.005), triglyceride (p=0.002), Tg/HDL ratio (p=0.0001), and plasma adrenomedullin (3.49±1.21 vs 1.69±0.92 ng/mL; p=0.0001) levels and lower HDL-C (p=0.02) levels as compared to the control group. EAT was significantly thicker in MS patients compared to the control group (8.45±3.14 vs 5.43±0.96; p=0.0001), showed a positive correlation to BMI (r=0.347; p=0.02), AC (r=0.350; p=0.02), DBP (r=0.346; p=0.02), and adrenomedullin levels (r=0.741; p=0.0001). In multiple linear regression analysis, adrenomedullin was the only parameter associated to EAT (R(2)=0.550; p=0.0001). CONCLUSION: In this small patient group, a statistically significant association was found between EAT and plasma adrenomedullin levels, which may be considered as a potential biomarker of MS.
Assuntos
Tecido Adiposo/patologia , Adrenomedulina/sangue , Síndrome Metabólica/sangue , Síndrome Metabólica/patologia , Pericárdio/patologia , Adipócitos/metabolismo , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo/metabolismo , Adrenomedulina/biossíntese , Adulto , Antropometria , Aterosclerose/patologia , Biomarcadores , Glicemia/análise , Artérias Carótidas/diagnóstico por imagem , Feminino , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/etiologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Pericárdio/diagnóstico por imagem , Pericárdio/metabolismo , Células Estromais/metabolismo , Ultrassonografia , Adulto JovemRESUMO
INTRODUCTION AND OBJECTIVES: To investigate the hemodynamic sympathetic response evoked by NaCI microinjection into the third ventricle anteroventral brain area (AV3V) in rats long-term fed with high fructose diet. METHODS: Twelve male rats received 60% fructose enriched diet for 6 months. Control rats (n=12) received regular diet. RESULTS: Fructose diet increased (P< .01) body weight; plasma glucose, triglycerides; cholesterol, insulin; systolic (SBP) and diastolic blood pressure (DBP). Basal heart rate (HR) did not change. AV3V microinjection of 2 microL of hypertonic 1.5 M NaCI in fructose fed rats increased SBP 44.64(3.6) mm Hg, DBP 19.9(2.4) mm Hg and HR 66.2(8.4) beats/min over basal values (P< .01). In control rats, smaller responses were observed, SBP increased 28.33(3.10) mm Hg, DBP 13.0(1.9) mm Hg and HR 23.0(5.0) beats/min over basal values (P< .01). CONCLUSIONS: Long-term fructose diet in rats induces cardiovascular hyperactivity of AV3V neurons to sodium chloride, and is associated to hypertension and insulin-resistance.