Effect of phospodiesterase 5 inhibitors on apoptosis and nitric oxide synthases in testis torsion: an experimental study

To investigate the effects of phosphodiesterase (PDE) 5 inhibitors, sildenafil citrate and vardenafil HCl, on testicular germ cell apoptosis and also on the expressions of eNOS and iNOS within the bilateral testis after a unilateral torsion in a rat model. Forty-eight Wistar Albino rats, weighing between 210 and 262 g, were housed in individual cages. The rats were randomly assigned into four main groups and each group received drugs. Saline, sildenafil citrate and vardenafil HCl were given to each for 1 month and the last received no drug. After 1 month, testicular torsion was created for 1 h of ischemia and the left testis was untwisted and replaced to the scrotum for 2 h of reperfusion. At the end of 3 h, contralateral and ipsilateral testes were removed for histopathologic and biochemical examinations. Under light microscopy; the histopathological patterns of the contralateral testes in all groups were not affected. Mean apoptotic cell, eNOS and iNOS levels were increased in saline study group. The rats treated with vardenafil and sildenafil (groups 2s and 3s) showed significantly increased apoptotic cell, eNOS and iNOS values in ipsilateral testis (P < 0.05). Sildenafil citrate and vardenafil HCl caused an exaggerated testicular apoptosis after IR injury in rats. Additionally these drugs increased the NOSs levels in the testicular tissue.     

Effect of allopurinol on germ cell apoptosis following testicular ischemia–reperfusion injury in a rat

Recent evidence suggests that apoptosis is involved in germ cell loss following testicular ischemia-reperfusion (IR) injury. Allopurinol (Allo) is as a free radical scavenger which prevents tissue damage caused by reperfusion and oxygenation after ischemia; however, its effect on apoptosis in this type of injury has not been studied. To examine the effect of allopurinol on germ cell apoptosis following testicular IR in a rat. Forty rats were divided randomly into 4 experimental groups of 10 rats each: group A (Sham)-Sham operated animals; group B (Sham-Allo)-Sham operated rats treated with allopurinol given PO (by gavage) at a dose of 200 mg/kg, once daily, immediately before and 24 h following operation; group C (IR)-rats underwent 90 min of unilateral testicular ischemia and 48 h of reperfusion; group D (IR-Allo)-rats underwent IR and were treated with allopurinol similar to group B. The ipsilateral and contralateral testes were harvested 48 h following operation. Johnsen's criteria and the number of germinal cell layers were used to categorize spermatogenesis. TUNEL assay was used to determine germ cell apoptosis. Statistical analysis was performed using one-way ANOVA test, with P < 0.05 considered statistically significant. Testicular ischemia in rats led to histological damage in the ipsilateral testis. In the contralateral testis minimal damage was observed. Treatment with allopurinol increased significantly Johnsen's score in both the ischemic (7.3 +/- 0.5 vs 5.6 +/- 0.5, P < 0.05) and contralateral (8.9 +/- 0.1 vs 8.3 +/- 0.2, P < 0.05) testis, compared to IR-animals. Germ cell apoptosis in both the ischemic and the contralateral testis increased significantly after IR. Treatment with allopurinol resulted in a significant decrease in germ cell apoptosis in the ipsilateral testis, expressed as the number of positive tubules per 100 tubules (AI-1, (apoptotic index) threefold decrease, P < 0.005) and the number of apoptotic cells per 100 tubules (AI-2, fivefold decrease, P < 0.005) as well as a significant decrease in germ cell apoptosis in the contralateral testis (AI-1, 3.5-fold decrease, P < 0.05, AI-2- sixfold decrease, P < 0.005) compared to IR animals. In a rat model of testicular IR, treatment with allopurinol decreases germ cell apoptosis in both ischemic and contralateral testes and improves spermatogenesis.     

心肌缺血/再灌注前处置时血浆一氧化氮的变化及意义

目的：在兔心肌缺血／再灌注前处置模型的基础上，了解NO在心肌缺血前处置中所起的作用及意义。方法：采用免麻醉后开胸结扎左冠状动脉降支，反复结扎（缺血）10分钟，放开（再灌）5分钟，最后结扎30分钟再灌20分钟造成缺血／再灌注前处置模型后，对比观察了各组动物血浆中NO、TXB2、6－K－PGF1α、SOD和MDA浓度的变化，以及各组动物球结膜微循环及心肌病理学的变化。结果：前处置组血浆NO、6－K－PGF1α、SOD浓度显著高于缺血／再灌注组，而MDA、TXB2浓度明显低于缺血／再灌注组。前处置组心肌超微结构损伤明显轻于缺血／再灌注组，球结膜微循环基本正常。结论：心肌缺血前处置可增加心血管内皮细胞合成NO，而NO具有减轻心肌缺血／再灌注损伤、改善微循环障碍的作用。     

A prospective randomized,controlled trial of eculizumab to prevent ischemia‐reperfusion injury in pediatric kidney transplantation

Ischemia‐reperfusion injury has multiple effects on a transplanted allograft, including delayed or impaired graft function, compromised long‐term survival, and an association with an increased incidence of rejection. Eculizumab, a monoclonal antibody blocking terminal complement activation, has been postulated to be an effective agent in the prevention or amelioration of IRI. We performed a single‐center prospective, randomized controlled trial involving 57 pediatric kidney transplant recipients between 2012 and 2016. The immunosuppressive protocol included two doses of alemtuzumab; half of the patients were randomized to receive a single dose of eculizumab prior to transplantation. Maintenance immunosuppression was based on a combination of low‐dose tacrolimus and mycophenolate, without steroids. Eculizumab‐treated patients had a significantly better early graft function, less arteriolar hyalinosis and chronic glomerulopathy on a protocol biopsies taken on day 30, 1 year, and 3 years after transplantation. In the eculizumab group, four non‐vaccinated children lost their grafts during the course of a flu‐like infection. Eculizumab is associated with better early graft function and improved graft morphology; however, there was an unacceptably high number of early graft losses among the eculizumab‐treated children. While a promising strategy, the best approach to complement inhibition remains to be established.     

Successful new treatment for intractable cervical esophageal stenosis of a jejunal segment transpositioned with a vascular anastomosis: report of a case

Strictures of the alimentary tract are conventionally treated by fluoroscopically guided bouginage and endoscopic balloon dilation, which is often very effective. However, severe and recurrent stenosis associated with ischemic injury in a jejunal segment transpositioned with a vascular anastomosis after reconstruction for cervical esophageal cancer is an intractable problem. We describe a new method using a Steno-Cutter to successfully treat a patient with this type of stricture following surgery for cervical esophageal cancer. The positive results achieved in this case suggest that our new method could represent a promising option of treatment for strictures when conventional modalities fail. Received: October 25, 2001 / Accepted: May 7, 2002 Acknowledgment. This work was supported in part by the 29th award from the Japanese Society for Advancement of Surgical Techniques. Reprint requests to: S. Shimada     

Graded reoxygenation with chemical inhibition of oxidative phosphorylation improves posthypoxic recovery in murine hippocampal slices

Rapid and complete tissue reoxygenation is a prime goal of present stroke therapy. However, reoxygenation may trigger detrimental cascades that partially antagonize beneficial effects. It was our goal to investigate selective grading of reoxygenation with targeting of single mitochondrial complexes in murine hippocampal slices. Population spike amplitude (PSAP) and NADH were measured during hypoxic hypoxia (15 min) and recovery (45 min). With onset of reoxygenation, slices were treated for different times with amobarbital (1 mM), malonate (2 mM), or cyanide (1 mM), inhibitors of mitochondrial complex I, II, or IV, respectively. Other slices were treated with nicotinamide (1 mM). Posthypoxic recovery of PSAP increased from 32% +/- 43% of onset in control slices to 52% +/- 59% (P <.05) upon treatment with amobarbital for 1 min and to 62% +/- 37% (P <.05) upon treatment with malonate. With nicotinamide, posthypoxic recovery improved to 73% +/- 25% (P <.05). Oxidation of NADH was prolonged upon treatment with amobarbital, whereas no change in NADH oxidation was observed with malonate and nicotinamide. Thus, grading of reoxygenation with selective targeting of mitochondrial complex I or II but not of complex IV improves outcome upon reoxygenation in murine hippocampal slices.     

Neuroprotective effects of nitrone radical scavenger S-PBN on reperfusion nerve injury in rats

The nitrone-based free radical scavengers have potent neuroprotective activities in models of stroke in which oxidative stress plays a key role in its development. We examined the effects of S-PBN (sodium 4-[(tert-butylimino) methyl]benzene-3-sulfonate N-oxide), a spin trap nitrone, on reperfusion injury in rat peripheral nerves. Immediately after the onset of 4-h ischaemia in rat right hindlimb, S-PBN was administered via mini-osmotic pumps, containing 2 ml of S-PBN (1.2 M), inserted subcutaneously. S-PBN, in addition, was given by a single injection (50 mg/kg BW, i.p.). Mean plasma concentrations of S-PBN were significantly greater in S-PBN-treated rats than in controls after 24, 48 and 72 h of reperfusion. Pump and dosing solution analysis indicated that the rats received between 82 and 99% of the target S-PBN concentration. Morphology in sciatic, tibial and peroneal nerves was assessed after 4 h of ischaemia followed by 72 h and 7 days of reperfusion. After 72 h of reperfusion, saline-treated control rats showed endoneurial oedema at the thigh level and diffuse axonal degeneration of myelinated nerve fibres distally. S-PBN-treated nerves were normal or revealed less severe abnormalities in myelinated fibres after 72 h and 7 days of reperfusion, when compared with those in saline-treated control nerves. Morphometrically, the frequency of abnormal myelinated fibres at calf levels was significantly less in S-PBN-treated nerves than in controls. In conclusion, post-ischaemic administration of S-PBN exhibits substantial neuroprotective properties in ischemia/reperfusion nerve injury.     

Revascularization of myocardial scar tissue following prostaglandin E1-therapy in patients with ischemic heart disease

Prostaglandin E1 (PGE-1) treatment has proved to stimulate angiogenesis in vital non-infarcted myocardium of patients with ischemic cardiomyopathy (ICMP). We investigated infarcted myocardial tissue for a possible angiogenic response to PGE-1. Neovascularization was investigated in infarcted areas of 12 hearts explanted from patients with ICMP who had been treated with PGE-1 before heart transplantation (HTX). In transmural sections containing myocardial scar tissue, CD34 and VEGF were immunohistochemically quantified to estimate capillary density and the extent of angiogenesis. To investigate a possible effect of PGE-1 on collagen turnover, the collagen content was determined in myocardial scar tissue by assessing the intensity of the area positively stained with sirius red. PGE-1-treated patients had significantly more CD34- and VEGF-positive cells in infarcted areas, and showed a significant reduction in collagen content as compared with the non-PGE-1 group (CD34: 120.3 +/- 6.1 vs. 47.7 +/- 6.1 capillary profiles/mm2; VEGF: 52.8 +/- 5.6 vs. 24.0 +/- 4.8 capillary profiles/mm2, and collagen content: 2.18 +/- 0.4 eU vs. 3.59 +/- 0.38 eU). Our data demonstrate that PGE-1 stimulates angiogenesis by upregulating VEGF expression, and reduces fibrosis in cardiac scar tissue of ischemic origin. The induction of therapeutic angiogenesis in vital and at sites of putative dead myocardial scar tissue, along with the hemodynamic improvement in patients with severe ICMP, might explain the favorable clinical outcome in PGE-1-treated patients before HTX.     

Genetic susceptibility to ischemic cerebrovascular disease in Koreans

Ischemic cerebrovascular disease (ICVD) is a multifactorial disease caused by the interactions of several genetic and environmental factors. Tobacco smoke is a major cause of both cancer and vascular disease. Although its carcinogenic role via induction of DNA damage and mutation is well established, the mechanisms involved in vascular disease remain unclear. One possibility is that DNA damage causes smooth muscle cell proliferation in the intima of arteries, thereby contributing to atherothrombotic processes. The binding of chemicals to DNA is modulated by detoxification enzymes, including glutathione S-transferase (GST). We examined whether polymorphisms in this gene, as well as the angiotensin-converting enzyme (ACE) gene influence the risk of ICVD on smoking status. DNA was analyzed for deletions in the GST M1, T1, and ACE genes by polymerase chain reaction (PCR). No significant association was observed between GST null genotype and ICVD, even in smokers. However, a significant association between ACE and ICVD was observed only in smokers (X ²=0.023, p<0.05). We conclude that GST polymorphism is not a risk factor for the development of ICVD through smoking and suggest a high probability that ACE polymorphism may contribute to the odds of ICVD in smokers.