Effectiveness of muscle basal lamina carrying neural stem cells and olfactory ensheathing cells in spinal cord repair.

We examined the effect of muscle basal lamina (MBL) with neural stem cells (NSCs) and olfactory ensheathing cells (OECs) on spinal cord injury repair. Seventy-two Sprague-Dawley rats were subjected to spinal cord hemisection and divided into 6 groups. In blank control group (group A), the ends of the spinal cord hemisection model were flushed with physiological saline. In NSC transplantation group (B), OEC transplantation group (C), MBL with NSC transplantation group (D), MBL with OEC transplantation group (E), and MBL with NSC and OEC transplantation group (F), NSCs, OECs, MBL with NSCs, MBL with OECs, and MBL with NSCs and OECs were implanted into the ends of the hemisection model. Survival and migration of transplanted cells were detected by immunohistochemistry and immunofluorescence after 4 and 8 weeks. Hind limb function repair was evaluated by Bundle branch block score at various time points before and after surgery. MBL could promote NSC growth along its lumen and promote host cell advancement in the lumen, reducing local inflammatory responses. Using MBL with NSCs and/or OECs for spinal cord repair shows advantages over simple cell transplantation. Group F contained more nerve cells in muscle basal lamina than group E. This method is useful for forming more axons, synaptic connections, and signal transduction pathways. However, these new axons showed nerve demyelination, which may greatly limit nerve signal conduction. In group F, OECs could induce neural stem cells, axonal growth, and synaptic connection formation, but its role is limited.

An improved reverse dot hybridization for simple and rapid detection of adefovir dipivoxil-resistant hepatitis B virus.

Early detection of adefovir dipivoxil-resistant mutants during long-term treatment of chronic hepatitis B virus (HBV) infection with this drug is of great clinical importance. We developed an improved reverse dot hybridization test for simple and rapid detection of the rtA181V/T and rtN236T mutations associated with adefovir dipivoxil resistance in chronic hepatitis B patients. Probes were designed for genotypes B, C, and D of this resistance characteristic; a total of 70 clinical samples were analyzed with this improved reverse dot hybridization assay. Its usefulness was validated by comparing with sequencing data. Discordant results were confirmed by subclone sequencing. This reverse dot hybridization assay was sufficiently sensitive to detect 10(3) copies/mL; it also detected adefovir dipivoxil-resistant mutant strains when they comprised more than 5% of a mixed virus population. This reverse dot hybridization array correctly identified adefovir dipivoxil-resistant mutants; it had high concordance (98.5%) with direct sequencing data. There was no clear relationship between the HBV genotype and the development of adefovir dipivoxil-resistant mutants. This reverse dot hybridization assay proved to be simple and rapid for detection of rtA181V/T and rtN236T mutations associated with resistance to adefovir dipivoxil.