Comparison of flow capacities of arterial and venous grafts for coronary artery bypass grafting: evaluation with exercise thallium-201 single-photon emission tomography

Stress thallium-201 tomography was performed to compare the flow capacities of arterial and saphenous vein grafts in patients with coronary artery bypass grafting (CABG). One hundred and seven consecutive patients (95 male and 12 female; mean age 58±9.1 years) underwent exercise-redistribution ²⁰¹Tl myocardial single-photon emission tomography 4–5 weeks after CABG. When a reversible perfusion defect was present in the area covered by a patent bypass graft, the flow capacity of the graft was defined as insufficient. Of all 285 grafts, 211 were considered as complete bypass. Reversible perfusion defects were present in 29 (27%) of 108 myocardial areas supplied by patent arterial grafts but in only 5 (5%) of 103 myocardial areas supplied by patent saphenous vein grafts (P<0.0001). In the LAD area reversible defects were observed in 22 of 82 areas covered by arterial grafts, in contrast to only 1 of 29 areas covered by venous grafts (P<0.01); in the RCA area reversible defects were observed in 7 of 17 and 4 of 41 areas respectively (P<0.01). There was no difference between the native coronary artery stenosis bypassed by patent arterial and venous grafts (88%±12% vs 86%±14% respectively, P=0.27). In conclusion, flow capacities during peak myocardial demand were more frequently insufficient in arterial bypass grafts than in saphenous vein grafts. Received 23 May and in revised form 7 August 1997     

HtrA2 is up-regulated in the rat testis after experimental cryptorchidism

AIM: The aim of the present study was to elucidate the role of high temperature requirement A2 (HtrA2) in germ cell loss in the heat-stressed testis. METHODS: We examined the expression of HtrA2, caspase-9 activity and proteolytic activity of HtrA2 in the rat testis, and their in vivo responses to experimental cryptorchid treatment. RESULTS: Northern analysis revealed the expression of HtrA2 mRNA peaked at days 1 and 7 after cryptorchid treatment. While expression of HtrA2 mRNA was seen in the spermatogonium, spermatocytes and some spermatids in normal adult rat testis, experimental cryptorchidism treatment resulted in a marked increase in its signal intensity in spermatocytes and some spermatids, and the layers of spermatogonium and early primary spermatocytes became negative at days 1 and 7 after the treatment. However, the spermatogonium, Sertoli cells and interstitial cells appeared to have strong intensities at days 14, 28 and 56 after the treatment. Western analysis revealed the expression of HtrA2 protein peaked at day 2 coinciding with the increase of positive spermatogonium, the appearance of protein-positive interstitial cells, and day 28 coinciding with the reappearance of protein-positive interstitial cells. Caspase-9 activity peaked at day 2 and HtrA2 proteolytic activity peaked at day 28. Consequently, the first peak of HtrA2 mRNA expression was followed by the peak of caspase-9 activity and the second peak was followed by the peak of proteolytic activity; however, the second peak of mRNA expression had considerable chronological difference from that of the protein. CONCLUSION: These findings suggest the probabilities that the heat stress results in germ cell death by a caspase-independent manner with the elevation of HtrA2 proteolytic activity, as well as a caspase-dependent manner with the elevation of caspase-9 activity.     

Laparoscopic radical cystectomy and bilateral ureteric ligation for muscle-invasive bladder cancer in a patient on hemodialysis

Laparoscopic cystectomy and bilateral ureteric ligation were performed on a 52-year-old woman with end-stage renal disease on hemodialysis (HD) for muscle-invasive bladder cancer. Her volume of urine production was approximately 100 mL/day. Excisions of the bladder and uterus with ligation of the bilateral ureter were conducted completely laparoscopically. Total operative time was 280 min and the amount of blood loss was 60 mL. No complications were seen perioperatively and no adverse events regarding ureteric ligation arose. HD was performed on the second postoperative day. At a 12-month follow-up, the patient showed no evidence of disease.     

Experimental Assessment of Right Ventricular Function in Normal Pigs with a Left Ventricular Assist Device

Abstract: Right ventricular (RV) failure during the use of a left ventricular assist device (LVAD) is the leading cause of death in circulatory support patients. Previous work, both experimentally and clinically, has shown the difficulties in predicting the behavior of the right ventricle at the start of LVAD. An experimental study has been designed to evaluate RV functional changes during LVAD and its relation to preload changes. The model used adult mongrel pigs (n = 10). Right ventricular functional parameters were measured with a thermodilution RV ejection fraction catheter. The left ventricle was supported by a Nippon Zeon blood pump. Two groups were studied, the first one was the LVAD–off group (n = 5) and the other was the LVAD–on group (n = 5) which was supported by LVAD at maximum flow. Change of cardiac output, mean pulmonary artery pressure (PAP), RV stroke work, and RV ejection fraction in both groups were not significantly different. However, the relationship between right ventricular end–diastolic pressure (RV–EDP) and right ventricular stroke volume (RVSV) was significantly changed at a high level of RV–EDP. When RV–EDP was over 6. 5 mm Hg in the LVAD–off group, RVSV decreased to 52. 3 ± 11. 5 ml while in the LVAD–on group, RVSV increased to 97. 2 ± 22. 0 ml. The change in PAP in the LVAD–on group was lower than in the LVAD–off group. We conclude that, at the volume overload state, LVAD can reduce the afterload of the right ventricle and maintain Frank–Starling's effect, thus having a beneficial effect on right ventricular performance.