Prevention of chronic experimental cerebral vasospasm with ibuprofen and high-dose methylprednisolone

Severe chronic cerebral vasospasm was reliably induced in dogs by two injections, 2 days apart, of autologous blood into the cisterna magna. Treatment with ibuprofen or high-dose methylprednisolone after the first injection prevented or reduced vasospasm. Both drugs reduced meningismus and accelerated the rate of neurological recovery. Compared with specimens from normal dogs, rings of basilar arteries obtained from untreated dogs contracted weakly in response to 5-hydroxytryptamine, prostaglandin F2 alpha, potassium chloride, and barium chloride. Rings of arteries from dogs who received ibuprofen or methylprednisolone contracted more strongly. Electron micrographs of basilar arteries from untreated dogs showed degeneration of smooth muscle, whereas those from treated dogs did not. Thus, what is termed "chronic cerebral vasospasm" probably represents a structural derangement of the blood vessel wall leading to its narrowing, rather than a sustained contraction of the vascular smooth muscle. Administration of high-dose methylprednisolone and ibuprofen can prevent its occurrence.     

Interhemispheric steal. An experimental study

In 21 cats the pressure in the occluded middle cerebral artery (MCA) was recorded by way of a catheter, introduced in the most proximal portion of this artery by way of the transorbital approach. The effect of temporary occlusion of the ipsilateral and contralateral common carotid artery on the pressure in the occluded MCA was studied. The results seem to prove the existence of the so-called "interhemispheric steal" syndrome.     

Catheter-associated bacteriuria. An experimental study

A bacteriologically-stressed catheterized animal model was developed to evaluate the comparative importance of the intraluminal versus the extraluminal route of catheter-acquired urinary tract infections. This study indicated that in short-term catheterization (less than 7 days), contamination of the drainage spout or accidental disconnection of the drainage tube resulted in bacteriuria within a short time (32-48 hours). If a strict sterile closed drainage system was maintained, the extraluminal route assumed more importance in the development of bacteriuria, however this pathway was considerably slower (72-168 hours). It appeared that catheter-associated bacteriuria results from ascending bacterial colonization within glycocalyx-enclosed biofilm on the inside and/or outside surfaces of the catheter and drainage systems. Development of a biomaterial that inhibits bacterial adherence and does not allow upstream colonization of bacteria on the catheter drainage system would significantly influence the rate of catheter-acquired urinary tract infection.     

Neovascularisation of the meniscus with angiogenin. An experimental study in rabbits.

Angiogenin, a potent blood vessel inducing protein, was implanted into experimentally injured menisci of 75 New Zealand white rabbits. Localised neovascularisation occurred in 52% of the angiogenin-treated animals, and in 9% of the controls. Neovascularisation induced by angiogenin may enhance healing of injuries within the poorly vascularised meniscal fibrocartilage, and improve the results of meniscal repair.     

Reconstruction of ligaments with expanded polytetrafluoroethylene. An experimental study in rabbits.

The medial collateral ligaments in the knee joints of 15 rabbits were replaced with expanded polytetrafluoroethylene (E-PTFE). The joints were not immobilised postoperatively, and their structure and function were evaluated after 12 months. Range of motion was equal in all groups. Stability of the knee joints and breaking strength of the ligaments were similar in the group in which the ligament had been reconstructed and in the sham operated control group (n = 8). The group in which the ligament had been severed and left to heal by formation of scar tissue (n = 7) had significantly reduced joint stability and the breaking strength of the medial collateral ligament was significantly less. The E-PTFE ligaments were well incorporated into the surrounding tissues. There were no adverse tissue reactions and the articular cartilage looked normal both macroscopically and microscopically. These results indicate that E-PTFE might be a useful substitute for damaged ligaments, at least in smaller joints like metacarpophalangeal and interphalangeal joints.     

Polydioxanone in digestive surgery. An experimental study

An experimental study was carried out to analyze the reaction of polydioxanone suture. Two hundred ten single layer colonic anastomoses were performed in rats and histopathologically studied at nine different times between the 2nd and 180th postoperative days. Eighteen of 105 abdominal wound closures were studied in the same way between the 7th and 90th days. Polydioxanone was resorbed slowly in approximately 6 months with minimum inflammation. We believe that polydioxanone is actually the suture material of choice for all biliary and biliodigestive sutures.     

Treatment of gut-derived endotoxemia with lactulose. An experimental study

Endotoxemia plays an important role in the origination and development of many dangerous clinical diseases, for which there has been little medication so far. To determine whether lactulose has an effect on endotoxemia, we treated experimental, gut-derived endotoxemia using lactulose in vitro and in vivo. The results showed that 55 mg lactulose inactivated the activity of 0.01 mg endotoxin on limulus lysate in vitro, suggesting that lactulose may have a direct anti-endotoxin effect. In vivo study in rats showed that blood endotoxin level was significantly decreased from 78.61 +/- 6.54 pg/ml to 20.26 +/- 2.38 pg/ml (P less than 0.01), and liver damage significantly reduced after lactulose treatment. It is suggested that lactulose can prevent absorbtion of endotoxin from gut and may have an effect on gut-derived endotoxemia. The mechanism of lactulose for treating endotoxemia is discussed.     

兔慢性细菌性前列腺炎形成过程中纤维连接蛋白和层粘连蛋白的分布变化

用免疫组化技术（ＰＡＰ法）动态观察了兔慢性细菌性前列腺炎形成过程中纤维连接蛋白（ＦＮ）、层粘连蛋白（ＬＮ）的分布变化。发现ＦＮ从病变早期迅速增多，至慢性期逐渐减少；ＬＮ在病变全过程均有不同程度增加。提示ＦＮ主要参与慢性细菌性前列腺炎的急性、亚急性期及间质纤维化早期的发生、发展，ＬＮ参与慢性细菌性前列腺炎及间质纤维化病变全过程。