[The mechanism and role of autologous peritoneum transplantation to enterocystoplasty in porcine model]

Objective: To explore the pathological mechanism and role of autologous peritoneum transplantation onenterocystoplasty in porcine model. Methods: Randomly, four experimental female swine were chosen, and each of their body weight was 28-33 kg. By intravenous anesthesia, the transplantation of autologous peritoneum for bladder reconstruction operation was carried out (to transplant the peritoneum onto an ileum segment of which the mucosa and submucosa had been removed. These flaps were used to mend and augment the bladder by suturing the edge of detective bladders). After removal of ureteral catheters and balloon catheter at day 5 respectively, their voiding behaviors were monitored, and respectively 2 swine were euthanized at week 3/6 for routine pathology, immunohistochemistry, and electron microscopic examinations. Results: Four swine underwent reconstruction, but none died for complications such as peritonitis, ileus and urinary fistula. The length of ileum was 35 cm, and the area of peritoneum was 15 cm×10 cm. Voiding behaviorsof the swine were normal, with clear urine after removal of their catheters. At autopsy, reconstructed bladders were healthy. Pathological examination showed the neobladder had been covered by continuous urothelium while the peritoneum disappeared without ileal mucosa regrowth or residual. Scanning electron microscope showed that the transitional cells of neobladder of swine were complete and orderly, and urothelium around suture border was continuous withoutmalposition. Conclusions: In porcine model, autologous peritoneal transplantation witnessed no immune rejection response for itself, which was replaced by crawling transitional epithelium around anastomosis, rather than by metaplasia.

[Analysis of factors affecting the noise-induced high frequency hearing loss of male workers in a vehicle manufacturing enterprise]

Objective: To analyze the relationships between the exposure of occupational noise and the occurrence of noise-induced high frequency hearing loss in automobile manufacturing industry. Methods: From June to November 2017, 1579 male workers were selected for exposure to noise hazards in the automobile manufacturing industry in Guangzhou for more than one year (including one year) using the convenient sampling method. According to the hearing test results, 276 people in the high frequency hearing loss group and 1303 in the normal hearing group were surveyed, occupational health tests were conducted, and the noise intensity in the workplace was measured. The cumulative noise exposure (CNE) was calculated. The relationship between shift work and high frequency hearing loss of noise work is analyzed. Results: Compared with the normal hearing group, the noise exposure intensity, age, length of service, marital status, working system, and physical exercise of the high frequency hearing loss group were statistically significant (P<0.05). Through logistic regression analysis, after correcting the effects of organic solvent contact, marital status, and physical exercise, CNE, age, and shift operations (double-shift operations, three-shift operations) are the risk factors for high frequency hearing loss to occur. Conclusion: The risk of hearing loss of workers exposed to noise in the whole vehicle manufacturing industry may be related to CNE, age, and shift work. Two-shift and three-shift work are possible risk factors for noise-induced high frequency hearing loss.

[Comparative effects of carvedilol and metoprolol in preventing from left ventricular remodeling after acute myocardial infarction in rats]

OBJECTIVE

To compare the effects of carvedilol and metoprolol in preventing from left ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in rats.

METHODS

Twenty-four hours after ligating left coronary artery, 105 surviving female SD rats were randomly assigned to AMI control, carvedilol 1 mg/(kg.d) and metoprolol 2 mg/(kg.d) groups. Sham-operated rats (n = 16) were selected randomly as non-infarction control. After four weeks of drugs therapy, hemodynamic studies and pathologic analysis were performed. Exclusive of MI size < 35% or > 55%, complete experimental variables were obtained in 46 rats, which were comprised of AMI (n = 11), carvedilol (n = 12), metoprolol (n = 11), and Sham-operated (n = 12) groups.

RESULTS

Compared with sham-operated group, left ventricular (LV) end diastolic pressure (LVEDP), volume (LVV) and weight (LVW), were all significantly increased (P < 0.05-0.001), while maximal rate of rise and fall (+/- dp/dt) of LV pressure as well as their corrected values (+/- dp/dt/LVSP) were all significantly decreased (P < 0.01-0.001) in AMI group. In comparison with AMI group, the LVEDP and LVV were all significantly decreased (all P < 0.001), while +/- dp/dt and +/- dp/dt/LVSP were significantly increased (P < 0.05-0.001) in both carvedilol and metoprolol group, with LVW and RVW only decreased in carvedilol group (P < 0.05-0.01).

CONCLUSIONS

1. Carvedilol can effectively attenuate LVRM, and improve hemodynamics and LV function after AMI in rats, 2. Metoprolol has equivalent beneficial effects as carvedilol on hemodynamics, LV dilatation and function, but not LV hypertrophy.

[Experimental studies on inhibitory effects of radix Peucedani on hypoxic pulmonary hypertension in rats]

Light microscopic and morphometric methods along with the measurement of right ventricular systolic pressure (RVSP) and right ventricle hypertrophy index (RBHI) were performed by the authors in studying the inhibitory effects of Radix Peucedani (RP) on structural remodeling of intraacinar pulmonary arteries (IAPA) and pulmonary hypertension (PHT) in hypoxic rats. The results showed that, RP could not only antagonize IAPA contraction caused by hypoxia and lower the resistance of pulmonary circulation, inhibit the cell proliferation and hypertrophy of adventitial cells of pulmonary artery, but also reverse the change in structure and function of pulmonary artery. It suggests that RA plays a key role in inhibiting hypoxic structural remodeling of IAPA and pulmonary hypertension.

Transcoronary ethanol ablation of experimental ventricular tachycardia after epicardial ice mapping and localizing

Thirty-seven reproducible ventricular tachycardias (VTs) were induced in 19 dogs after the onset of myocardial infarction. The site of origin of VT was localized in 19 (59%) of 32 VTs by ice epicardial mapping. After 0.3-1.2 ml of 95% ethanol was injected into a small coronary artery supplying the arrhythmogenic area, VT was no longer inducible in 10 of 14 dogs. Intramyocardial ethanol (1-3 ml) was injected into the site of origin of VT in 9 dogs including 4 with VTs reinduced after intracoronary ethanol. Six of these VTs were not reinduced. Thus, the total efficacy rate was 84%. In 7 dogs, after injection of 0.4-1.2 ml (mean 0.5 ml) of 95% ethanol into a small normal coronary artery, the extent of the changes in ECG, CK-MB and pathology was found to be related to the size of myocardial damage and to the dose of ethanol. The smaller the dose of ethanol was given and the more distal the branch of coronary artery into which the ethanol was injected, the smaller the myocardial damage was. The data demonstrated that intracoronary or intramyocardial injection of ethanol may ablate the experimental VT induced by programmed heart stimulation in dogs after myocardial infarction, indicating that this approach may be useful and meaningful in some selected instances. However, it is necessary to limit the myocardial damage as far as possible.

[Clinico-pathological analysis of 100 autopsy cases of massive or submassive pulmonary thrombo-obstruction in cardiovascular and pulmonary diseases]

A clinico-pathological analysis of 100 autopsy cases of thrombo-obstruction in the segmental and those bigger arteries of the lungs caused by cardiovascular and pulmonary disease was reported. These complications of pulmonary thrombosis and/or embolism were more commonly observed in rheumatic heart disease (29% of the same disease in autopsies), congestive cardiomyopathy (26%) and cor pulmonale (19%). There were 2-4% of the autopsy cases of other cardiovascular and pulmonary diseases. The pulmonary thrombo-obstruction and/or infarction were more frequent in right lower lobes of the lungs and they were often multiple. The pulmonary infarction occurred in 76% of these cases. 35% of 100 cases occurred with sudden death. Only 13% of 100 patients with pulmonary thrombosis and/or embolism were diagnosed before autopsy. The causes of pulmonary thrombo-obstruction and the diagnostic suggestion were discussed in this paper.