Isolation and analysis of partial cDNA sequence coding for superoxide dismutase in Wuchereria bancrofti.

Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response.     

Novel explant model to study mechanotransduction and cell-cell communication.

To understand in situ behavior of osteocytes, we characterized a model of osteocytes in their native bone matrix and demonstrated real-time biologic activity of osteocytes while bending the bone matrix. Using 43 male Sprague-Dawley rats, dumbbell-shaped explants were harvested from stainless steel femoral implants after 6-12 weeks and incubated in culture medium or fixed. Sixteen specimens were used to determine bone volume density (BV/TV), volumetric bone mineral density (BMD) and histology for different implantation periods. Osteocyte viability was evaluated by L-lactate dehydrogenase (LDH) activity in 12 cultured explants. Confocal microscopy was used to assess tracer diffusion in three explants and changes in osteocyte pH of a mechanically loaded explant. From 6 to 12 weeks, explant BV/TV and volumetric BMD trended up 92.5% and 101%, respectively. They were significantly and highly correlated. Tissues were uniformly intramembranous and all bone cell types were present. Explants maintained LDH activity through culture day 8. Diffusion at 200 microM was limited to 1,209 Da. Explants appeared capable of reproducing complex bone biology. This model may be useful in understanding osteocyte mechanotransduction in the context of a physiologically relevant bone matrix.     

Vagal nerve stimulator implantation: an otolaryngologist's perspective.

OBJECTIVE: This study was conducted to compare an otolaryngologist's experience with a cohort of epilepsy patients implanted with a vagal nerve stimulator (VNS) to previously published data. METHODS: Demographics, preoperative seizure frequency, medications, and complications were retrospectively collected from patients implanted by the senior author. Postoperative medications and seizure frequency were obtained from referring neurologists. RESULTS: Seventeen patients were implanted over a 24-month period. Average age was 28.3 years. Patients presented with petit mal (n = 3), tonic-clonic (n = 6), complex partial (n = 5), and grand mal (n = 8) seizures. Mean follow-up postimplantation was 13.5 months. Most patients had at least a 50% reduction of seizure frequency, with 3 patients being seizure free. There were no postoperative infections. One patient had left vocal cord immobility. The most common side effect was voice disturbance during device activation. CONCLUSION: Otolaryngologists are well equipped to perform VNS implantation and to diagnose and treat possible laryngeal side effects. EBM rating: C-4.     

Report of National Cardiac Surgical Registry, 2004

Conclusions Limitation of this analysis is participation of limited centers. Though all the regions of the country are represented total number of procedures reported are less. Isolated CABG is commonest procedure performed in 2004. Congenital surgical procedures are more than the valvular heart disease procedure. For appropriate categorization we need standard nomenclature for various congenital surgical procedures.     

Theoretical QSAR study on carcinogenic potency of N-nitrosamines

A mechanistic QSAR study on N-nitrosamines (NA) was performed with the aid of the semiempirical MINDO/3 method. Both the chemical reactivity and the transport in biological medium were taken into account. The parent NA molecules and their first reaction intermediates in the metabolic activation pathway were examined for possible determinants of the relative carcinogenic potency. The correlations found support the previous suggestions concerning the metabolic C alpha radical hydroxylation of NA. The role of transport properties in the early stage of NA biotransformation was also demonstrated.     

Effect of diffusion chamber pore size on differentiation and proliferation of periosteal cells. An experimental study

The influence of the pore size of Nucleopore diffusion-chamber filters on the rate of proliferation and differentiation of periosteal cells in muscle was studied in 44 growing rabbits. Periosteal grafts were placed in chambers (16-19 in each experimental group) sealed with filters with a pore size of 0.4, 0.6, 0.8, 1.0, or 2.0 micron. Each chamber was implanted into the paraspinal muscle of the rabbit, where it remained for 16 weeks. The osteochondrogenic activity of the graft grew linearly when the pore size increased from 0.4 to 1.0 micron. In the chambers with a pore size of 2.0 micron, both bone and cartilage were found in only one chamber. Bone and cartilage were not found outside any of the chambers. The present results showed that the pore size of the filters significantly affected the ability of the periosteal graft to form bone and cartilage.     

The effects of bulk versus particulate polymethylmethacrylate on bone

Twenty-one mature New Zealand white female rabbits were allocated into three groups of seven rabbits. Group I received a bolus of doughy Simplex polymethylmethacrylate (PMMA) cement injected into the proximal tibia through a drill hole. Group II received a preformed, cooled, bulk PMMA pellet. Group III had particulate PMMA powder implanted. The operated, but nonimplanted, left tibiae served as controls. Animals were killed after four months. Histologically, both Group I and Group II demonstrated a thin, fibrous tissue membrane at the implant interface. Particulate PMMA (Group III) stimulated a much thicker, florid, foreign body reaction composed of histiocytes and giant cells. The foreign body response to particulate acrylic cement was similar to that seen in failed cemented joint replacement arthroplasty in humans.