Effects of proton pump inhibitor on gastric mucosa hemodynamics and tissue oxygenation in anesthetized rats.

Proton pump inhibitors have been reported to have a cytoprotective action in addition to the anti-secretory action of acid. The precise mechanism, however, remains obscure. In this study, the effects of proton pump inhibitors (omeprazole and NC-1300) on gastric mucosa hemodynamics and tissue oxygenation were investigated using organ reflectance spectrophotometry in a hemorrhagic shock-reperfusion model involving anesthetized rats. Neither drug affected gastric mucosa hemodynamics nor tissue oxygenation in the basal state before hemorrhage. During the hemorrhagic shock state, however, these drugs maintained tissue oxygenation and reduced ulcer formation, although they did not show a significant effect on gastric mucosa blood volume. The results suggest that both proton pump inhibitors have an anti-ulcer action by maintaining mucosal oxygenation in addition to the anti-secretory activity of acid.     

Increase in venous outflow from the corpora cavernosa during mild erection in dogs.

The venous outlet of the corpus cavernosum is generally believed to be obstructed during erection. Some researchers, however, have demonstrated an increased venous outflow during erection. To elucidate this discrepancy, we carried out a pressure-flow study using a perfusion model of the penile deep artery in dogs. Various states of the corpus cavernosum, which were different in cavernous pressure, were induced by a delicate control of electrostimulation to the cavernous nerve. Inflow rate into the corpus cavernosum, inflow resistance and outflow resistance were simultaneously evaluated. The inflow rate in mild erection was higher than in the flaccid state, and the outflow rate was estimated to be also higher than in the flaccid state. A probable reason for the increased outflow rate was that the arterial resistance decreased remarkably, while the venous resistance only slightly increased. In full erection, both the inflow and outflow rates were lower than in the flaccid state because of a great venous resistance. Histological observation of the canine penis indicated that compression of draining veins passing through the tunica albuginea was weak in mild erection, while intense in full erection. It was proposed that in mild erection, the effect of venous occlusion was slight though that of arterial dilation was noticeable, resulting in an increase in the venous outflow.     

Electron microscopic study of monkey retina after photodynamic treatment

The purpose of this histological study was to determine the effects of photodynamic treatment, using a hematoporphyrin derivative and argon laser, on normal retinas of monkeys. Ten cynomolgus monkeys were treated with a hematoporphyrin derivative, given intravenously at a dose of 2.5 mg/kg. Forty minutes or 1 or 3 days after the injection, argon laser photoradiation was given over a 2.0-mm-diameter with a 10-min exposure and at an intensity of 40, 100, or 200 mW. The eyes were enucleated 1, 3, 4, 15, 18, 21, 35, or 38 days after the photoradiation and tissue samples were observed under a transmission electron microscope. The most fragile regions in the retina were the retinal nerve fibers, the outer segments of the visual cells, and the retinal pigment epithelium. Vascular endothelial cells were also fragile. The retinal capillary was easily obstructed, and the choriocapillaris was also occluded in an animal with severe retinal damage. The Mueller cells had the highest tolerance to the photodynamic treatment. Thus, exposing the normal part of the retina to light during photodynamic therapy should be avoided.     

Allogeneic cell stimulation enhances cytomegalovirus replication in the early period of primary infection in an experimental rat model.

BACKGROUND: Cytomegalovirus (CMV) diseases commonly occur in allograft recipients in the early post-transplant period. However, factors responsible for the high incidence of CMV diseases during this period are not yet fully defined. METHODS: Wistar-Furth (WF; RT-1(u)) rats were inoculated with 10(4) plaque-forming units (PFU) of rat CMV (RCMV) intraperitoneally, and then transplanted with allogeneic lungs from Dark Agouti (DA; RT-1avl) rats or stimulated with 10(7) mitomycin C-treated spleen cells from DA rats by daily sub-cutaneous injections for 2 weeks. No immunosuppressive agent was used. Naive WF rats and WF rats grafted with syngeneic lungs or cells were used as controls. The level of RCMV replication in rats was assessed by infectious virus titers in tissues. RESULTS: The virus titers in salivary glands of allogeneic and syngeneic lung graft recipients were significantly higher than in naive WF rats. The level of RCMV replication in rats stimulated with allogeneic spleen cells was significantly higher than in the syngeneic recipient rats: virus titers in the salivary gland of allogeneic and syngeneic recipients reached 4.61 +/- 0.33 and 4.00 +/- 0.37 log(10) PFU/g tissue, respectively, at 14 days post-infection (p = 0.015). The augmented viral replication in allogeneic recipients was confirmed by an increase in the number of RCMV antigen-positive macrophages present in tissue sections of the salivary gland. CONCLUSIONS: Acute lung allograft rejection and allogeneic spleen cell stimulation enhance CMV replication in the salivary gland of rats. Various responses to allogeneic antigens occurring in the process of acute allograft rejection could be risk factors for post-transplant CMV replication and infection.     

A surgical case of combined valvular disease complicated by absent right superior vena cava and persistent left superior vena cava.

A 74-year-old man with combined valvular disease with a recent cerebral infarction was admitted. While undergoing thorough examination for valvular disease, absent right superior vena cava (RSVC) and persistent left superior vena cava (PLSVC) were recognized. Chest X-ray film suggested a right arch protrusion, and CT and venogram confirmed the diagnosis. During surgery, replacement of the mitral and aortic valves and annuloplasty of the tricuspid valve were performed. A blood draining cannula was inserted in retrograde fashion from the coronary sinus into the PLSVC, without any difficulties in the tricuspid valve repair. Due to bradycardic atrial fibrillation, we believed that it would be difficult to insert an endocardial electrode postoperatively, hence myocardial electrode was placed in the right ventricular wall. Absent RSVC combined with PLSVC is very rare, and a patient who underwent combined valve surgery with this rare anatomical abnormality is herein presented.     

Prevention of Acute Lung Allograft Rejection in Rat by CTLA4Ig

CTLA4 immunoglobulin (CTLA4Ig), which binds with a high affinity to B7-1 and B7-2, interrupts T-cell activation by inhibiting costimulatory signal. CTLA4Ig has been used in hopes of achieving antigen-specific tolerance induction in several solid organ transplants. In lung allograft rejection, however, its use has been controversial in terms of its effect on prevention of rejection. In the present study, the effect of murine CTLA4Ig on rat-lung allograft rejection was investigated. Rat left-lung transplantation was performed in an RT1 incompatible donor (Brown Norway; BN)-recipient (F344) combination. All allografts (n = 12) without any treatment were rejected within 7 days after transplantation. A single injection of murine form CTLA41g at a dose of 100 microg intraperitoneally (ip) or intravenously (iv) on day 1 post-transplantation achieved long-term graft survival (>90days) in 2/5 (40%) and 3/8 (38%), respectively. Moreover, 6/7 (86%) allografts in rats that received iv injection of 500 microg CTLA4Ig survived more than 90days. Allograft survival in the CTLA4Ig 500 microg iv recipient group was significantly longer than that in the no-treatment control or control immunoglobulin group (p <0.01). Four out of seven recipients bearing functional allografts for more than 90 days with the CTLA4Ig treatment accepted donor-specific skin grafts, whereas all third-party skin grafts (n=3) were rejected. Prevention of rat-lung allograft rejection could be achieved by intravenous administration of CTLA4Ig, resulting in long-term allograft survival with acceptance of donor-specific skin grafts.     

二氧化硅对大鼠血浆中微量元素含量的影响

给大鼠经气管分别注入４、１６、６４ｍｇ石英粉尘生理盐水混悬液。在染尘后第７，１５和３０天解剖动物，测定血浆中Ｃｕ、Ｚｎ，Ｍｎ、Ｍｏ、Ｓｉ、Ｒｂ和Ｓｒ等７种微量元素的含量。实验结果表明，随着染尘剂量的增加，血浆中铜的含量明显增高，呈正相关，相关系数为０．９９９。而血浆锌的含量随着染尘剂量的增加而明显的降低，呈负相关，相关系数为－０．９９８。血浆中Ｍｏ、Ｍｎ、Ｓｉ、Ｒｂ和Ｓｒ含量与对照组比无明显差异。     

Spontaneous mesenteric hemorrhage associated with ehlers-danlos syndrome

The vascular type of Ehlers-Danlos syndrome is a genetic disorder of connective tissue and is frequently associated with catastrophic arterial complications. Its surgical treatment is extremely difficult because of the fragility of vessels. This article describes three patients with vascular type of Ehlers-Danlos syndrome who developed mesenteric hemorrhage due to spontaneous arterial rupture. The clinical and molecular characteristics of the disease are briefly reviewed.