Antibodies neutralizing Nogo-A increase pan-cadherin expression and motor recovery following spinal cord injury in rats

STUDY DESIGN

A rat model of spinal cord injury was used to test the hypothesis that Nogo-A monoclonal antibody (NEP1-40) promotes morphologic and functional recoveries of injured spinal cord.

OBJECTIVE

Nogo-A is a myelin-associated neurite outgrowth inhibitory protein, which blocks elongation nerve fibers and limits neuronal regeneration after central nervous system injury.

METHODS

Forty-four rats were utilized and allocated into control (vehicle) and NEP1-40-treated groups. In all animals, the spinal cord was hemi-transected at Th-10 and phosphate-buffered saline solution was immediately applied on the injured area in the control group. NEP1-40 solution was immediately applied on the hemi-transected area in the treatment group. Each group was subdivided into three subgroups according to the postsurgical day of killing (3, 8 and 21 days). The spinal cords were removed for analysis.

RESULTS

Motor scores in the NEP1-40-treated groups were significantly higher than those in the vehicle groups both at 8 and 21 days post injury. Immunohistochemical staining for pan-cadherin, a marker of neuronal cell adhesion and axonal sprouting, revealed a significant increase in staining in the NEP1-40 treatment group at 8 and 21 days post injury. Transmission electron microscopical evaluation revealed degeneration of the myelin and loss of cytoarchitectural organization in the axons of controls. Better preservation and normal histologic features were observed in the NEP1-40-treated groups.

CONCLUSION

We have demonstrated improved preservation of injured axons and significant pan-cadherin expression after NEP1-40 treatment after the spinal cord injury. Inhibition of Nogo-A may improve the capacity for neuronal regeneration after spinal cord injury.

An unusual course of the radial artery

Radial artery variations are of importance for clinicians, whether in angiographic examinations or surgical approaches. The high origin radial artery is the most frequent arterial variation observed in the upper limb, showing an incidence of 14.27% in dissection material and 9.75% in angiographic examination. In the present study an unusual course of the radial artery and its relation with the median nerve has been evaluated. During embryological development the radial artery sprouts from two arterial buds arising from the lateral side of the brachial artery and coalescing with each other. The artery lies in the forearm and is overlapped by the brachioradial muscle. In this particular case the radial artery originated from the medial side of the brachial artery and crossed the median nerve twice in an unusual manner 8 cm below the point at which the deep brachial artery arose and 12 cm above the intercondylar line. These results will enhance anatomical knowledge of the region and reduce complication in surgical approaches.

Apoptosis and proliferation in gastric epithelium due to Helicobacter pylori: an immunohistochemical and ultrastructural study

The effect of H. pylori infection on gastric epithelial cell apoptosis and proliferation is contradictory. Using immunohistochemistry and electron microscopy, this study sought to demonstrate gastric epithelial changes (ie, apoptosis and proliferation) due to chronic H. pylori infection.

METHODS

Eighteen female 6- to 8-week old Swiss Albino mice were inoculated intragastrically with 3 doses of 10(9) CFU/mL H. pylori prepared in a Brucella Broth in 5 days. Nine others served as a control group. At the end of 28 weeks, tissue specimens from the gastric antrum were excised and examined immunohistochemically (epithelial growth factor for regeneration and Caspase-3 for apoptosis) and electron microscopically. Immunohistochemical assessment was performed using the indirect peroxidase-antiperoxidase method.

RESULTS

In the H. pylori-infected group, EGF staining in gastric epithelium was found to be decreased significantly compared to that in control group (P < 0.001). Caspase-3 reactivity was commonly observed in surface epithelial cells and glandular epithelial cells in H. pylori-infected group and totally it was statistically significant compared to Caspase-3 staining in control group (P < 0.001). Electron micrograph images demonstrated numerous apoptotic cells with condensed chromatin.

CONCLUSION

Chronic H. pylori infection of 28 weeks' duration increases apoptosis in gastric epithelium; however, increased apoptosis does not induce proliferation.

The apoptotic effects of mitomycin C on human endometrial cell cultures and reversal of its effects by beta-carotene and folic acid

Apoptosis is a complex process involving a variety of mechanisms and it has been shown to be a response of cells to various chemical agents including chemotherapeutic ones. We aimed to induce DNA breaks and apoptosis in cultured endometrial stromal cells by mitomycin C (MMC), a chemotherapeutic agent, and also we aimed to observe the effects of beta-carotene and folic acid on MMC-induced apoptosis. Cultured endometrial stromal cells were exposed to MMC for 48 and 72 hours and in order to reverse MMC effects, we added beta-carotene and folic acid to the cultures. DNA fragmentation was observed in all cells. Apoptotic cell ratios and caspase-3 activity were observed to be dependent on exposure time. Ultrastructural examinations revealed positive effects of beta-carotene and folic acid, however they were not sufficient enough to prevent apoptosis in all cells. Beta-carotene profoundy reduced caspase-3 activity whereas folic acid did not seem to have a similar effect. As apoptosis involves several mechanisms, in a cell in which all these mechanisms are triggered, we think that antioxidants and DNA repair agents alone are not enough to reverse all of them.

Effects of taurine in glucose and taurine administration

Taurine has several biological processes such as hypoglycemic action, antioxidation, detoxification, etc. To assess the effect of taurine administration on the guinea pigs with hyperglycemia, blood glucose, C-peptide levels together with morphologic alterations in the pancreatic ultrastructure were investigated in terms of hypoglycemic action and malondialdehyde and total sulfhydryl group levels with regard to oxidation-antioxidation relation. Animals were divided into four groups of six. Glucose supplementation group was administrated a single dose of glucose (400 mg/kg, i.p.) injection. Glucose and taurine supplementation group was administrated glucose treatment (a single dose, 400 mg/kg, i.p.) following taurine (a single dose, 200 mg/kg, i.p.). Taurine and glucose supplementation group was administered taurine treatment (a single dose, 200 mg/kg, i.p.) following glucose treatment (a single dose, 400 mg/kg, i.p.). Control animals received no treatment. Blood samples were collected at the end of the experiments for the determination of glucose, C-peptide (indicator of insulin secretion), lipid peroxidation (thiobarbituric acid reactive substances), and total sulfhydryl groups levels. Pancreatic tissue samples were then collected and processed for transmission electron microscopy. The findings showed that glucose supplementation following taurine administration significantly decreased blood glucose level by increasing C-peptide level and the pancreatic secretion stimulated morphologically and insignificantly changed thiobarbituric acid reactive substances and total sulfhydryl group levels. These observations suggest that taurine administration may be useful in hyperglycemia because of its hypoglycemic and protective effects.

Light and electron microscopic examination of various doses of given vitamin A on the development of cornea in mice. Partly presented in ICEM 13-Paris

Vitamin A (0.2 micrograms, 0.6 micrograms, 1.2 micrograms) was administered orally to the mice on days 8-11 of gestation. Fetuses were removed on day 17 of gestation. No external malformation of the fetuses was seen on the stereomicroscope investigation. Corneal degeneration was seen on the light and electron microscopic examination. As a result it was accepted that vitamin A taken during the critical periods of gestation affected the development of cornea.