The Physiological Significance of A-Waves in Early Diabetic Neuropathy: Assessment of Motor Nerve Fibers by Neurophysiological Techniques.

Objective: This study aimed to investigate how early A-waves could occur in type II diabetes, and what it implied functionally. Methods: We performed conduction velocity distribution (CVD) test in peroneal nerves of 37 type II diabetic patients with normal nerve conduction study (NCS) and 22 age-matched controls. The electrophysiological data and clinical information were analyzed. Results: A-waves were observed in 45.9% of diabetic patients and only in 1 person in healthy controls, all detected in the tibial nerves. The diabetic patients with A-waves showed faster conduction velocity in all quartiles in the motor peroneal nerves compared to the patients without A-waves, and their CVD histograms were shifted to the right side, consisting of a significantly larger percentage of fast conducting fibers. There was no significant difference in the CVD values of the upper extremity nerves among the patients with and without A-waves and the healthy controls. Conclusion: A-waves could occur in type II diabetes as early as when NCS showed normal, and represented as a sign of neuropathy as well as a sign of rescued motor nerve function.

Beclin 1 knockdown retards re-endothelialization and exacerbates neointimal formation via a crosstalk between autophagy and apoptosis.

OBJECTIVE: Endothelial regeneration is an essential process for the prevention of excessive neointimal formation following endothelial denudation. Beclin 1, a mammalian autophagy gene, is a link between autophagy and apoptosis. We hypothesized that the interference of Beclin 1 can influence re-endothelialization and ultimately affect neointimal formation by regulating autophagy and apoptosis. METHODS: A rat carotid injury model of endothelial denudation was used, and small interfering RNA of Beclin 1 was perivascularly administered. Neointima was evaluated by morphological analysis. von Willebrand factor, Beclin 1, LC3, autophagic substrate p62 and caspase-3 levels were detected by immunofluorescence or Western blotting. Terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP-biotin nick-end labeling assay was performed to evaluate apoptosis. RESULTS: Carotid injury induced an upregulation of Beclin 1 protein which was down regulated by more than 50% with small RNA interference. Beclin 1 knockdown significantly retarded re-endothelialization 7 days after injury and subsequently augmented neointima by more than 2 folds at 14 and 21 days. Autophagy and apoptosis were detected to reveal the regulatory effect of Beclin 1. The injury-activated autophagy, shown by the increased levels of punctate LC3 and LC3II as well as decreased p62 expression, was significantly inhibited by Beclin 1 knockdown. Meanwhile, the apoptotic endothelial cell number was increased and caspase-3 was up-regulated, though the expression of truncated BID was not significantly influenced. CONCLUSION: Beclin 1 knockdown exacerbated neointimal formation after rat carotid injury, associated with retarded re-endothelialization due to enhanced apoptosis, while simultaneously prohibiting autophagic activation. The data suggested an essential role of Beclin 1 as a regulator between autophagy and apoptosis in the setting of neointimal formation.

[Clinical manifestations and molecular genetics of spinal bulbar muscular atrophy: report of 5 cases].

OBJECTIVE: To study the clinical and molecular genetic characteristics of spinal bulbar muscular atrophy (SBMA). METHODS: The clinical data, including case history, physical examination, biochemical analyses of blood, EMG, and muscle biopsy, of 5 Chinese patients with SBMA, all males, aged 29 - 58, with the onset age of 36 (17 - 49), were collected the information of in 5 cases. Four patients underwent PCR to examine the number of copies of CAG repeat region in androgen receptor (AR) gene. RESULTS: The clinical characteristics of the 5 patients included atrophy of lingualis, dysarthria, weakness and waste of the limbs, especially in the hands, and elevated creatine kinase (CK), fasting glucose, testosterone, and progesterone in the blood. EMG showed denervation motor potentials in all cases. The muscle biopsy in one case showed neurogenic atrophy. The number of (CAG) n repeat in AR gene was 50 - 62 in the, remarkably from that of 13 normal controls (19 - 20) without overlapping. CONCLUSION: SBMA affects the middle age males, shows a slowly progressing muscular atrophy in spinal and bulbar muscles. The different number of (CAG) n repeat of AR gene between the SBMA patients and the normal controls may be an important identification to differentiate SBMA from other motor neuron diseases.