Association between cardiac changes and stress, and the effect of peroxisome proliferator-activated receptor-γ on stress-induced myocardial injury in mice.

This study was aimed to investigate the effect of stress induced by high-intensity exercises on the cardiovascular system. In the epidemiological investigation, 200 subjects (test group) engaged in special high-intensity exercises, and 97 who lived and worked in the same environment and conditions as those in the test group, but did not participate in the exercises served as controls. In the second part of the study, 50 mice were randomly divided into control group, exhaustive swimming group, white noise group, exhaustive swimming plus white noise group, and pioglitazone intervention group. The results showed that the plasma concentrations of the myocardial injury markers heart fatty acid-binding protein (H-FABP), C-reactive protein (CRP), ß-endorphin (ß-EP) and levels of psychological stress were significantly increased in test group as compared with control group; special high-intensity exercises resulted in a significant elevation of the incidence of cardiac arrhythmias. Animal experiments showed that the plasma levels of corticosterone (CORT) and troponin I (TnI) were raised while the level of SOD was reduced in exhaustive swimming group, white noise group, and exhaustive swimming plus white noise group. The expression levels of PPARγ mRNA and protein were decreased in myocardial tissues in these groups as well. HE staining showed no remarkable change in myocardial tissues in all the groups. Treatment with pioglitazone significantly decreased the plasma levels of TnI and CORT, while increased the level of SOD and the expression levels of PPARγ mRNA and protein. It was concluded that the high-intensity exercises may induce a heavy physical and psychological stress and predispose the subjects to accumulated fatigue and sleep deprivation; high-intensity exercises also increases the incidence of arrhythmias and myocardial injury. PPARγ may be involved in the physical and psychological changes induced by high-intensity exercises.

Hypoxia training attenuates left ventricular remodeling in rabbit with myocardial infarction.

OBJECTIVE: Previous studies showed that hypoxia preconditioning could protect cardiac function against subsequent myocardial infarction injury. However, the effect of hypoxia on left ventricular after myocardial infarction is still unclear. This study therefore aims to investigate the effects of hypoxia training on left ventricular remodeling in rabbits post myocardial infarction. METHODS: ADULT MALE RABBITS WERE RANDOMLY DIVIDED INTO THREE GROUPS: group SO (sham operated), group MI (myocardial infarction only) and group MI-HT (myocardial infarction plus hypoxia training). Myocardial infarction was induced by left ventricular branch ligation. Hypoxia training was performed in a hypobaric chamber (having equivalent condition at an altitude of 4000 m, FiO214.9%) for 1 h/day, 5 days/week for four weeks. At the endpoints, vascular endothelial growth factor (VEGF) in the plasma was measured. Infarct size and capillary density were detected by histology. Left ventricular remodeling and function were assessed by echocardiography. RESULTS: After the 4-week experiment, compared with the group SO, plasma VEGF levels in groups MI (130.27 ± 18.58 pg/mL, P < 0.01) and MI-HT (181.93 ± 20.29 pg/mL, P < 0.01) were significantly increased. Infarct size in Group MI-HT (29.67% ± 7.73%) was deceased remarkably, while its capillary density (816.0 ± 122.2/mm(2)) was significantly increased. For both groups MI and MI-HT, left ventricular end-diastolic and end-systolic dimensions were increased whereas left ventricular ejection fraction was decreased. However, compared with group MI, group MI-HT diminished left ventricular end-diastolic (15.86 ± 1.09 mm, P < 0.05) and end-systolic dimensions (12.10 ± 1.20 mm, P < 0.01) significantly and improved left ventricular ejection fraction (54.39 ± 12.74 mm, P < 0.05). CONCLUSION: Hypoxia training may improve left ventricular function and reduce remodeling via angiogenesis in rabbits with MI.

Effects of nerve growth factor on the action potential duration and repolarizing currents in a rabbit model of myocardial infarction.

OBJECTIVES: To investigate the effect of nerve growth factor (NGF) on the action potential and potassium currents of non-infarcted myocardium in the myocardial infarcted rabbit model. METHODS: Rabbits with occlusion of the left anterior descending coronary artery were prepared and allowed to recover for eight weeks (healed myocardial infarction, HMI). During ligation surgery of the left coronary artery, a polyethylene tube was placed near the left stellate ganglion in the subcutis of the neck for the purpose of administering NGF 400 U/d for eight weeks (HMI + NGF group). Cardiomyocytes were isolated from regions of the non-infarcted left ventricular wall and the action potentials and ion currents in these cells were recorded using whole-cell patch clamps. RESULTS: Compared with HMI and control cardiomyocytes, significant prolongation of APD50 or APD90 (Action potential duration (APD) measured at 50% and 90% of repolarization) in HMI + NGF cardiomyocytes was found. The results showed that the 4-aminopyridine sensitive transient outward potassium current (I to), the rapidly activated omponent of delayed rectifier potassium current (I Kr), the slowly activated component of delayed rectifier potassium current (I Ks), and the L-type calcium current (I CaL) were significantly altered in NGF + HMI cardiomyocytes compared with HMI and control cells. CONCLUSIONS: Our results suggest that NGF treatment significantly prolongs APD in HMI cardiomyocytes and that a decrease in outward potassium currents and an increase of inward Ca(2+) current are likely the underlying mechanism of action.

[Effect of carvedilol on T-type calcium current in myocytes of non-infarcted area of the rabbit healed myocardial infarction].

This article reports the investigation of the effect of carvedilol (Car) on T-type calcium current (I(Ca,T)) of noninfarcted ventricular myocytes in rabbit models of healed myocardial infarction (HMI). Rabbits with left anterior descending artery ligation were prepared and allowed to recover for 8 weeks, as HMI group. Animals undergoing an identical surgical procedure without coronary ligation were served as the sham-operated group (sham group). Whole cell voltage-clamp techniques were used to measure and compare currents in cells from the different groups. Noting that I(Ca,T) density in HMI cells increased markedly to -2.36 +/- 0.12 pA/pF (at -30 mV) compared with cells of sham, where little I(Ca,T) (-0.35 +/- 0.02 pA/pF) was observed. Meanwhile, further analysis revealed a significant hyperpolarizing shift of steady-state activation curve of I(Ca,T) in HMI cells, where the time constants of deactivation were prolonged and the time of recovery from inactivation was shortened. Finally, the amplitude of I(Ca,T) was increased. Carvedilol (1 micromol x L(-1)) was found to decrease the amplitude of I(Ca,T) to -1.38 +/- 0.07 pA/pF through inhibiting process of I(Ca,T) activation. Furthermore, carvedilol delayed recovery from inactivation of I(Ca,T) and shortened the time constants of deactivation in HMI cells. This study suggested that the application of carvedilol in HMI cells contributes to the dynamic changes in I(Ca,T) and may account for reduction of incidence of arrhythmia after myocardial infarction.

Bilateral unipedicle flaps combined with levator sling plasty for the repair of complete cleft palate at the age of 6 - 12 months / 中华整形外科杂志

<p><b>OBJECTIVE</b>To repair the complete cleft palate with the most popular technique at optimal time.</p><p><b>METHODS</b>Bilateral unipedicle flaps (Bardach method) combined with levator sling plasty were employed to repair complete cleft palate at the age of 6 - 12 months. Computer-aided FFT vocal analysis was performed before and after surgery.</p><p><b>RESULTS</b>All patients had primary wound healing without any complication. The FFT vocal analysis showed great improvement in velopharyngeal incompetence after surgery.</p><p><b>CONCLUSIONS</b>It is technically safe and feasible to repair the complete cleft palate at the age of 6 - 12 months with bilateral unipedicle flaps. Encouraging speech improvement can be expected with this method.</p>

Effect of Interaction in Children Speech Therapy / 中国康复理论与实践

@#Objective To observe the effect of interaction in children speech therapy.Methods 90 cases with children aphasis were assessed with evaluation for delayed speech and language development by Sign-significance (S-S) method made by Chinese Rehabilitation Research Center and dysarthria evaluation, and treated.Results After treatment, all cases had different improvment on their own level and were in the process of rehabilitation care.Conclusion The speech therapy interaction is easy, economical and can stimulate children' interest to learn speech and get the training goal.