Inhibition by alkylamines of NADPH oxidase through blocking the assembly of enzyme components.

Alkylamines inhibit NADPH oxidase both in intact neutrophils and in a cell-free system. The aim of this study was to examine the mechanism underlying this inhibitory effect. Among alkylamines with different chain lengths, the C12 compound (laurylamine) showed the greatest inhibitory effect on the cell-free NADPH oxidase activity induced by arachidonic acid (AA) in the presence of GTPgammaS. The inhibition was overcome by further addition of AA, and it was observed irrespective of whether laurylamine was added before or after the enzyme activation by AA. When added prior to the enzyme activation, laurylamine blocked translocation to the membrane of all three cytosolic components (p47-phox, p67-phox and rac) in a cell-free translocation assay. When added after the activation, laurylamine released only rac from the membrane. Laurylamine did not inhibit the reduction of cytochrome c by xanthine oxidase, suggesting that it does not have superoxide-scavenging activity. These results indicate that laurylamine inhibits both the activation process of NADPH oxidase and the activated enzyme itself by blocking the assembly of the oxidase components.     

Discovery of orally active nonpeptide bradykinin B2 receptor antagonists

Orally active nonpeptide bradykinin (BK) B2 receptor antagonists have been discovered by using directed random screening and chemical modification. These compounds displaced [3H]BK binding to B2 receptors in guinea-pig ileum membranes, rat uterus membranes and human lung fibroblasts with nanomolar IC50s. They did not inhibit different specific radio-ligand bindings to other receptor sites including B2 receptors. In isolated guinea-pig ileum preparations, these compounds had no agonistic effect on smooth muscle contraction at 10(-6) M, and caused parallel rightward shifts of the concentration-response curves to BK on contraction with higher p A2 values. They also blocked human B2 receptor-mediated phosphatidylinositol hydrolysis without agonistic effect. In vivo, the oral administrations of these antagonists potently inhibited BK-induced bronchoconstriction in guinea-pigs. They also reduced carrageenin-induced paw edema and caerulein-induced pancreatitis in rats. Moreover, these compounds alleviated kaolin-induced pain in mice by oral administration. These results show that our compounds are potent, selective, and orally active BK B2 receptor antagonists and that they may have therapeutic potential against inflammatory diseases and pain.     

Immunolocalization of basic fibroblast growth factor during wound repair in rat retina after laser photocoagulation

Background: Basic fibroblast growth factor (bFGF) stimulates the mitogenesis of various cells and plays a key role in wound repair. We studied the immunohistochemical localization of bFGF during wound repair in the rat retina after laser photocoagulation. Methods: Krypton laser photocoagulation was performed on the eyes of pigmented rats. The eyes were enucleated on days 1, 3, 7, 14 and 28 after the photocoagulation, and the immunohistochemical localization of bFGF was assessed. Two different monoclonal antibodies and one polyclonal antibody against bFGF as first antibodies were used. Results: Marked immunoreactivity for bFGF was found in the ganglion cell layer, and weak immunoreactivity for bFGF was found in the retinal pigment epithelial (RPE) cells of the normal adult rat retina. On day 3 after laser photocoagulation, the nuclei and cytoplasm of proliferating RPE cells at the center of the photocoagulated lesion showed intense bFGF immunoreactivity. The nuclei of RPE cells around the lesion showed intense bFGF immunoreactivity. Macrophages that migrated into the lesion showed positive staining for bFGF. These immunoreactivity decreased with time. Controls (0.05 M Tris-HCl buffer, normal serum, or these same antibodies preabsorbed with bFGF) did not show positive staining. Conclusion: The finding of an elevated expression of bFGF immunoreactivity in the photocoagulated lesion suggests that bFGF may play a role in wound repair in the rat retina after laser photocoagulation.     

Thrombin inhibitor ameliorates secondary damage in rat brain injury: suppression of inflammatory cells and vimentin-positive astrocytes

The effects of the thrombin inhibitor argatroban on the number of inflammatory cells and reactive astrocytes were investigated in a rat brain injury model. Gelatin sponge soaked with thrombin inhibitor (treatment group) or saline (control group) was placed in the brain defect to assess the infiltration of inflammatory cells by hematoxylin-eosin and immunohistochemical staining. Expression of polymorphonuclear leukocytes (PMNs) and monocyte/macrophage (Mo/Mo) cells, and vimentin (VIM)-positive astrocytes and glial fibrillary acidic protein (GFAP)-positive astrocytes were compared between groups. In the treatment group, infiltration of both PMNs and Mo/Mo cells, and the number of VIM-positive astrocytes were significantly reduced, but the number of GFAP-positive astrocytes was not different from the control group. Thrombin inhibitor suppresses the infiltration of inflammatory cells and excessive gliosis caused by VIM-positive astrocytes, but not expression of GFAP-positive astrocytes, suggesting minimization of secondary brain damage and promotion of the conditions required for neural regeneration.     

Patent ductus venosus with a hypoplastic intrahepatic portal system presenting intrapulmonary shunt: a case treated with banding of the ductus venosus

A case of patent ductus venosus (PDV) presenting intrapulmonary shunting is described. Although retrograde venography of ductus venosus showed few intrahepatic branches, banding of PDV resulted in increased intrahepatic portal branches and disappearance of symptoms 10 months after the operation. Banding of the ductus venosus may be effective in PDV even with hypoplastic intrahepatic portal system.     

Prolonged oral treatment with an essential amino acid L-leucine does not affect female reproductive function and embryo-fetal development in rats.

L-leucine, an essential amino acid, is one of the most popular ingredients in dietary supplements. To investigate a possibility of its embryo-fetal toxicity in rats, 11- to 12-week old dams were orally administered an aqueous solution of L-leucine at doses of 300 or 1000 mg/kg body weight on gestational days 7-17. Body weight and feed intake was evaluated throughout the whole course of pregnancy (days 0-20). L-Leucine did not influence body weight, but at a dose of 1000 mg/kg, slightly enhanced feed intake on days 14 and 18 of pregnancy. Caesarean section (day 20) revealed no influences on the litter size and weight of live-born fetuses, the number of corpora lutea, implantation index or the quality of placenta, and the minor increase in feed intake was considered irrelevant to the pregnancy outcomes. Fetuses were evaluated in a battery of external, visceral and skeletal examinations. No effects of L-leucine on gender ratio and external abnormalities, and no significant treatment-related variations in visceral and skeletal pathologies were observed. These results suggested that L-leucine, administered orally during organogenesis at doses up to 1000 mg/kg body weight, did not affect the outcome of pregnancy and did not cause fetotoxicity in rats.     

Risk factors for acetabular retroversion in developmental dysplasia of the hip: does the Pemberton osteotomy contribute?

BackgroundThe purpose of this study was to investigate residual acetabular retroversion after skeletal maturity in patients with Pemberton osteotomy.Patients and methodsWe compared 40 hips in 36 patients treated with a Pemberton osteotomy (Pemberton group) and 30 hips in 26 patients treated only with a Pavlik harness (Rb group) for developmental dysplasia of the hip. The average age at operation in the Pemberton group was 94.5 months and the follow-up duration was 151.8 months. Radiographic parameters included the acetabular index (a angle) and the center-edge angle of Wiberg, preoperatively and at skeletal maturity. We examined the crossover sign (COS) at the latest follow-up as a sign of acetabular retroversion (AR). We compared the parameters between the two groups and examined the risk factors for acetabular retroversion using a multivariate Cox model.ResultA COS (+) was significantly more frequent in the Pemberton group compared to the Rb group [15 hips (37.5 %) vs 3 hips (10 %); p = 0.0077]. In the Pemberton group, the average age at operation in COS (+) hips was significantly older than that in COS (—) hips (126.9 vs 72.8 months; p = 0.0005). The preoperative α angle did not vary between hips with and without COS; however, the postoperative α angle was significantly smaller in COS (+) hips. A multiple logistic regression analysis for prediction of COS (+) showed that the age at operation and the amount change of α angle were significant predictors for COS (+) hips. The cut-off of the age at operation was 7 years and 9 months old.ConclusionsAR was present in 37.5 % of the hips in the Pemberton group after skeletal maturity. Remodeling of acetabular version was observed in younger patients; however, hips in older patients (> 8 years) at the time of operation and greater degrees of correction tended to result in AR.