Role of bone marrow derived pluripotent stem cells in peripheral nerve repair in adult rats: A morphometric evaluation

Objectives: Semi-quantitative and quantitative assessment of the effect of bone marrow-derived mononuclear cells (BM-MNC) on early and late phase of nerve regeneration in rat sciatic nerve model. Materials and Methods: Sciatic nerve transection and repair was performed in 50 inbred female Wistar albino rats divided equally in two groups. In the test group the gap was filled with BM-MNCs obtained from the two male rats and fibrin sealant, while in the control group only fibrin sealant was used. Sciatic nerve was harvested at 15 days and at 60 days interval. Parameters of regeneration were assessed at anastomosis (G), intermediate distal (C), and distal site (A). Semi-quantitative (histopathological) and quantitative (morphometric) parameters were analyzed. Results: At 15 days there was a statistically significant difference found in mean axon diameter, mean nerve thickness and myelin thickness at the repair site (P < 0.05). However, in the distal areas, the axons were sparse and myelin rings were very thin in both the groups. At 60 days, the difference in above-mentioned parameters was statistically significant at the distal most sites. FISH assay confirmed the presence of Y chromosome, confirming the presence of BM-MNCs from the male rats. Conclusions: Transplanting BM-MNC S at the site of peripheral nerve injury leads to significantly better recovery. These differences were evident at the repair site and at the intermediate distal site at 15 days and at the distal most sites at 60 days. With practically no ethical issue regarding their isolation and application, they can be easily used for clinical trials

Predictive factors for early symptomatic recurrence in pilocytic astrocytoma: does angiogenesis have a role to play?

We studied predictive factors with respect to angiogenesis and proliferative indices for early symptomatic recurrences in patients with pilocytic astrocytoma (PA). One hundred and eighteen patients who underwent surgery for PA were divided into non-recurrent and early symptomatic recurrence groups to analyze clinicoradiological and immunohistopathological (n=33) parameters. Patients with non-recurrent tumors presented with synptoms for a mean duration of 10.2 ± 9.1 months while those with recurrent tumors presented slightly earlier (6.9 ± 4.5 months). Common tumor locations were the cerebellum (38.1%), optic chiasm (27.9%), supratentorial region (19.4%) and brainstem (9.3%). Recurrent tumors were mostly located in the cerebellum (44%) and brainstem (33%). Strong contrast enhancement was noted in 70 (59.3%) tumors, while 48 (40.7%) showed poor contrast. Resection was complete in 53% of patients while near total excision was achieved for the remaining patients. Cellularity and plemorphism were similar in both groups. Extensive endothelial proliferation was observed in 18.1% of patients while the remainder showed a focal pattern. Diffuse vascular endothelial growth factor (VEGF) expression was observed in 36.3% of patients while 63.6% showed mild-to-moderate focal expression. Endothelial proliferation and VEGF expression were more pronounced in patients with non-recurrent tumors, but this was not statistically significant. MIB-I labeling indices were similar (1-5%) for both groups. Symptomatic recurrences were common in infratentorial PAs. Radiology, histopathology and proliferative indices did not offer any prognostic information. Angiogenesis markers such as endothelial proliferation and VEFG expression did not predict early symptomatic recurrence. Diffuse VEGF expression and endothelial proliferation were observed in tumors that showed strong contrast enhancement