SUTURE VERSUS FIBRIN GLUE MICRONEURAL ANASTOMOSIS OF THE FEMORAL NERVE IN SPRAGUE DEWLY RAT MODEL. A COMPARATIVE EXPERIMENTAL ASSESSMENT OF THE CLINICAL, HISTOLOGICAL AND STATISTICAL FEATURES

INTRODUCTION

Peripheral nerve injury is a frequently encountered clinical problem that leads to functional losses at the long-term. Although microsurgical repair has been introduced to clinical practice in peripheral nerve injuries, unsatisfactory outcomes regarding functional recovery in target organ cause an increasing interest on studies about nerve injury and biology of the recovery in nerve injuries1.

MATERIAL AND METHODS

Sciatic nerves of seventy adult Sprague Dewly rats were transected and primary anastomosis was performed. Rats were then divided into three groups: Control group, while 30 rats were repaired with sutures, and the remaining 30 were repaired with fibrin glue. After 30 days the rats were sacrified and the sciatic nerves were investigated histologically with morphometrical and statistical analyses.

RESULTS

In microsurgical nerve repair, suture placement has been thought to cause hindrance to the sprouting axons and compress the blood supply to the fascicles, thereby impairing the regeneration of the transected nerve ends after repair, with possible neuroma formation. On the other hand, fibrin glue is a simple, effective technique, less time consuming than suturing. Another advantage of this suture-free technique is that it avoids injuring the axon with needles, and the lack of foreign bodies minimizes the inflammatory reaction.

CONCLUSION

We recommend using fibrin glue as it demonstrates less inflammatory reaction, less scar tissue formation, it is less time consuming and provides better outcomes.

Effect of major burns on early and late activating markers of peripheral blood T lymphocytes

It is known that lymphocytes immunophenotype is a reflection of the functional level of the immune system. The immunosuppressive effect of major burns is also known for many years. T lymphocytes of 50 major burn patients were analyzed in base line (BL) samples at 24 hours and at 1 week and 2 weeks after burn, using monoclonal antibodies of CD3, CD4, CD8, CD25 (IL2R) and HLA-DR by flow cytometry and β2-microglobulin (β2-m) by ELISA. Recorded values were compared with those of 50 healthy donors. There was statistically significant reduction in absolute number of CD3 positive cells (CD3+) (p<0.000) and CD4/CD8 ratio (p=0.01) in the first 24 hours in comparison with controls. CD25 (IL-2R) shows insignificant upregulation on T lymphocytes after burn with significant upregulation of HLA-DR. The absolute number of CD3+ cells began to increase after 2 weeks (p=0.03) but remained less than controls (p=0.08). CD4/CD8 ratio was more or less same as healthy controls after 2 weeks. Upregulation of CD25 was insignificantly increased and that of HLA-DR was markedly increased after 2 weeks (p=0.001). Significant negative correlations were detected between mean values of β2-m and both absolute numbers of CD3 and CD4 positive cells in BL and one week samples. In addition there was significant correlation between mean values of β2-m and values of CD25 expression in the BL samples. The obtained data is suggestive of persistent activation of T lymphocytes two weeks after major burns whereas early shedding of β2-m is related to activation of lymphocytes increasing their susceptibility to apoptosis, both indicative of altered immune response. Burn intensivists and surgeons should be keen to support the patients' immune system in the first hours following major burns. This support will ensure free-bacteremic blood with a consequent better prognosis.

Derivatized Nanoparticle Coated Capillaries for Purification and Micro-extraction of Proteins and Peptides

Various methods are used to enrich or purify a protein of interest from other proteins and components in a crude cell lysate or other sample. One of the most powerful methods is affinity purification, also called affinity chromatography, whereby the proteins of interest are purified by virtue of their specific binding properties to an immobilized ligand. Affinity purification is becoming more widely used for exploring post-translation modifications and protein-protein interactions, especially with a view toward developing new general tag systems and strategies of chemical derivatization on peptides for affinity selection. Our work was aimed to immobilize proteins or ligands for affinity purification of antibodies, fusion-tagged proteins and other proteins and peptides. Selected proteins or peptides are efficiently extracted and enriched using chemically derivatized walls of a fused silica capillary column. In this paper, we present an open tubular capillary, where the inner wall of a fused silica capillary was derivatized by covalent binding of modified polystyrene latex particles. The capillaries were derivatized with iminodiacetic acid and loaded with Fe3+ or Ni2+ for the purification and enrichment of phosphopeptides or His-tagged proteins, respectively. The latex coated capillaries have been successfully applied to enrich phosphopeptides from beta-casein tryptic digest and ovalbumin tryptic digest at a micro volume scale with recoveries ranging from 92 to 95%. The capillaries have been eluted under conditions compatible with MALDI-MS without any prior desalting step. In another approach, concanavalin A (Con A) or Protein G were immobilized on the epoxy modified latex on the inner wall of the fused silica capillary for the purification of glycoproteins and immunoglobulin, respectively. The design of the capillary and the protocols used for purification permits the direct detection of eluted proteins and peptides with gel electrophoresis or with mass spectrometry. The elution volumes are passed as discrete segments of few microliters over the inner surface of the open-tube capillary, achieving enrichment factors of more than 20-fold from starting samples.