Enhancement of rat hypoglossal nerve regeneration by chitin sheet plus gangliosides

Spontaneous regeneration after resection of various lengths of hypoglossal nerve in rats

OBJECTIVES

The objective of this study was to investigate spontaneous neural regeneration and functional recovery after resection of various lengths of the hypoglossal (XII) nerve in adult rats.

METHODS

Twelve weeks after XII nerve resection at lengths ranging from 0.0 to 15.8 mm, the tongue deviation angle of rats was measured to evaluate the severity of paralysis; thereafter, the XII neurons in the XII nucleus were labeled with Fluoro-Gold (FG), which was injected into the tongue to visualize regenerated XII neurons re-innervating the tongue muscles.

RESULTS

In the XII nerve-resected rats, the regenerative rates, that is, the percentage of the total number of FG-positive neurons on the injured side relative to that on the uninjured side, were divided into two groups; the regenerative rates were more than 77% and less than 6%, respectively. Upon comparing the two groups, the boundary resection length was approximately 10.0 mm. Moreover, the former and latter groups demonstrated tongue deviation angles less than or greater than 15°, respectively.

CONCLUSIONS

The critical nerve gap length for spontaneous neural regeneration was approximately 10.0 mm in XII nerve-resected adult rats, and nerve regeneration occurred in both morphological and functional aspects after resection at less than the critical length.

Cattle Encephalon Glycoside and Ignotin Reduce Early Brain Injury and Cognitive Dysfunction after Subarachnoid Hemorrhage in Rats

Subarachnoid hemorrhage (SAH) is a well-known hemorrhagic stroke with high rates of morbidity and mortality where patients frequently experience cognitive dysfunction. This study explores a potential treatment for cognitive dysfunction following SAH with the demonstration that multi-target drug cattle encephalon glycoside and ignotin (CEGI) can relieve cognitive dysfunction by decreasing hippocampal neuron apoptosis following SAH in rats. Experimentally, 110 male SD rats were separated at random into Sham (20), SAH + Vehicle (30), SAH + 4 ml/kg CEGI (30), and SAH + 1 ml/kg CEGI groups (30) and an endovascular perforation model was created to induce SAH. We discovered that the number of TUNEL-positive neurons in the hippocampus was markedly decreased in SAH + 4 ml/kg and SAH + 1 ml/kg CEGI groups compared to the SAH + Vehicle group. This finding was associated with an observed decrease in Bax/Bcl-2 ratio, cytochrome-c and PUMA expression, and the suppression of caspase-3 activation following SAH. In Morris water maze tests, the SAH + 4 ml/kg CEGI group demonstrated a decreased escape latency time and increase in time spent in the target quadrant as well as crossing times of platform region. These results indicate that high doses of CEGI can decrease hippocampal neuron apoptosis and relieve cognitive dysfunction in rats, suggesting that multitarget-drug CEGI exhibits a neuroprotective effect in SAH via the mitochondrial apoptosis pathway.

The Sygen multicenter acute spinal cord injury study

STUDY DESIGN

Randomized, double-blind, sequential, multicenter clinical trial of two doses of Sygen versus placebo.

OBJECTIVES

To determine efficacy and safety of Sygen in acute spinal cord injury.

SUMMARY OF BACKGROUND DATA

An earlier, single-center trial in 28 patients showed an improvement (50.0% vs. 7.1%, P = 0.034) in marked recovery with Sygen.

METHODS

Standard clinical trial techniques.

RESULTS

The prospectively planned analysis at the prespecified endpoint time for all patients was negative. There was a significant effect in all patients in the primary outcome variable (the percentage of marked recovery) at week 8, the end of the dosing period. There was a significant effect in all patients in the time at which marked recovery is first achieved. Restricted to severity Group B, which has small sample size, the primary efficacy analysis showed a trend but did not reach significance. There is a large, consistent and, at some time points, significant effect in the primary outcome variable in the nonoperated patients through week 26. The American Spinal Injury Association motor, light touch, and pinprick scores showed a consistent trend in favor of Sygen, as also did bowel function, bladder function, sacral sensation, and anal contraction. The less severely injured patients appeared to have a greater beneficial drug effect. Evidence against an effect of Sygen was minimal and scattered.

CONCLUSIONS

Although not proven in the primary efficacy analysis of this trial, Sygen appears to be beneficial in patients with severe spinal cord injury.