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The effects of delayed nerve repair on nerve regeneration in a silicone chamber model

The silicone chamber model for nerve regeneration is suitable to test the effects of exogenous agents or surgical manipulations on nerve regeneration. The total 16-day regeneration period used in this model makes it possible to analyze the effects of certain manipulations on the sequential advancement of the individual cellular components (circumferential perineurial-like cells, vessels, Schwann c

Axonal growth in mesothelial chambers : effects of a proximal preconditioning lesion and/or predegeneration of the distal nerve stump

Preformed, autologous mesothelial chambers were utilized to study axonal growth following selective predegeneration of the distal nerve stump and/or preconditioning of the proximal nerve stump. The left and/or right sciatic nerve of rats was exposed and transected in the thigh. Two weeks after transection, the left proximal nerve stump was cross-anastomosed with the right distal nerve stump by usi

Intraneural edema following exposure to vibration

Peripheral neuropathy represents a well-known complication from long-term exposure to vibration. In the present study an experimental model is presented with the purpose of analyzing the formation of intraneural edema following vibration exposure. Vibration (82 Hz, peak-to-peak amplitude 0.21 mm) was induced in the hind limb of rats by the use of vibrating electric motors during 4 h/d for 5 d. Tra

Experimental hyperthyroidism stimulates axonal growth in mesothelial chambers

An experimental model is presented for studying axonal growth after experimental hyperthyroidism and hypothyroidism. The left sciatic nerve of the rat was transected and transposed to the back. The proximal nerve stump was inserted into a 50-mm-long mesothelial chamber leaving the distal end of the chamber open. Different groups of young adult rats were given daily injections of thyroxine (10 micr

Absence of ongoing activity in fibres arising from proximal nerve ends regenerating into mesothelial chambers

Morphological studies have indicated that proximal nerve ends of transected rat sciatic nerves regenerating into preformed mesothelial chambers show a different organization as compared to neuromas developed in contact with a muscle fascia. We have studied the physiological properties of nerve fibres arising from these types of preparations with reference to ongoing activity, response to mechanica

Mechanical effects of compression of peripheral nerves

Effects of graded compression on nerve function were analyzed in order to evaluate the relative importance of pressure level and duration of compression for functional deterioration. The pressure was applied by means of a small inflatable cuff. The effects of two pressure levels, i.e., 80 mm Hg applied for 2 hr or 400 mm Hg applied for 15 min, were studied in rabbit tibial nerves. The lower pressu

Evidence indicating trophic importance of IGF-I in regenerating peripheral nerves

The mechanisms influencing regeneration of peripheral nerves are incompletely known, but growth factors are supposed to play a key role. In the present study, we demonstrate, with the aid of immunohistochemical methods, that somatomedin C (Sm-C/insulin-like growth factor I/IGF-I) rapidly increased from low to high concentrations, reaching peak values in 2 weeks, in regenerating sciatic nerves of a

Tissue specificity in nerve regeneration

In 1944 Weiss & Taylor presented experimental evidence against "neurotropism" in nerve regeneration. We used a silicone Y-chamber system to repeat some of those experiments. The proximal stump of transected rat sciatic nerve was introduced into the proximal inlet of the Y. One of the distal outlets was left empty, plugged or occupied by a tendon graft, the other outlet being occupied by a nerv

Axonal growth in mesothelial chambers. The role of the distal nerve segment

An experimental model is presented for studying nerve regeneration over gaps of various lengths between the both ends of a severed nerve. After transferring left and right sciatic nerves of rat to the back, the gap between the two nerve ends could be bridged by a preformed, tube-shaped mesothelial chamber of a desired length. When the gap length was 10 mm or less, a well developed nerve structure

Reorganization and orientation of regenerating nerve fibres, perineurium, and epineurium in preformed mesothelial tubes - an experimental study on the sciatic nerve of rats

Regeneration of severed peripheral nerves is unfortunately often incomplete, due to loss of nerve fibers and neuroma formation. A new approach is presented with the intention of improving the conditions for nerve repair. In the first of the two stages, a pseudosynovial tube is formed around a silicone rubber rod, surrounded by a stainless steel spiral, which was placed in the backs of rats. This t

Nerve repair and axonal transport : Outgrowth delay and regeneration rate after transection and repair of rabbit hypoglossal nerve

The axonal transport and distribution of the fast phase of [3H]leucine-labeled proteins were used to monitor the outgrowth delay and regeneration rate in rabbit hypoglossal nerves 5-21 days after crush or transection. The transected nerves were repaired with mesothelial chambers or epineurial sutures. Radiolabeled proteins were transported into regenerating axons in the distal nerve segment after

Nerve repair and axonal transport. Distribution of axonally transported proteins during maturation period in regenerating rabbit hypoglossal nerve

The distribution of fast migrating [3H]leucine-labelled proteins was studied in transected and repaired rabbit hypoglossal nerves. The nerves were repaired 90 days earlier with mesothelial chamber or epineurial suture technique. Fast migrating radiolabelled proteins were transported into the distal nerve segment and neurophysiological recordings from the tongue as well as the presence of myelinate

Effects of epidural and intrathecal application of collagenase in the lumbar spine : an experimental study in rabbits

An experimental model is described in which collagenase in different concentrations and volumes were applied epidurally or intrathecally in the rabbit lumbar spine. This made it possible to study the tissue effects in a situation similar to that of collagenase leaking from a disc or accidental epidural or intrathecal injection at chemonucleolysis. Epidurally applied collagenase, in higher concentr

Microvascular effects of chondroitinase ABC and chymopapain. An in vivo experimental study on hamsters and rabbits

Immediate and long-term microvascular effects of chondroitinase ABC, 200 unit/ml, were analyzed in ten hamsters. The immediate effects on the microcirculation were studied by vital microscopy following local injection in the cheek pouch. There were no detectable effects on the microvascular blood flow during the 60 minutes of observation for chondroitinase ABC or the control. A therapeutic concent

Effects of chondroitinase ABC on intrathecal and peripheral nerve tissue. An in vivo experimental study on rabbits

The enzyme chondroitinase ABC has recently been suggested for use in chemonucleolysis. The effects of 200 U ml of chondroitinase ABC were studied on intrathecal and peripheral nerve tissue in rabbits. After the intrathecal (subarachnoid) application of 0.2 ml of either the diluent in the control group (N = 2) or chondroitinase in the study group (N = 4), no neurologic deficit was detected. Compare

Effects of nerve compression or ischaemia on conduction properties of myelinated and non-myelinated nerve fibres. An experimental study in the rabbit common peroneal nerve

Compound action potentials of both myelinated (A) and non-myelinated (C) fibres in the common peroneal nerve of rabbits were studied during and after acute, graded compression of the nerve at 200 or 400 mmHg applied for 2 h or during ischaemia created by nitrogen inhalation or aortic occlusion. Compression of the nerve at 200 mmHg blocked the AI component (large myelinated fibres) after about 23 m

Effects of sympathetic stimulation on C-fibre response after peripheral nerve compression : an experimental study in the rabbit common peroneal nerve

Non-myelinated C-fibre responses during sympathetic trunk stimulation were studied in rabbit common peroneal nerve 2 weeks after the nerve had been subjected to compression at 400 mmHg for 30 min. Our previous studies have demonstrated that during sympathetic trunk stimulation the compound action potential of uninjured somatic C-fibres is characterized by a reduced amplitude and an increased laten

Ulnar nerve repair by the silicone chamber technique. Case report

The ulnar nerve of a 21-year old man was repaired at the wrist by a silicone chamber technique 10 days after a traumatic transection. A 3 mm gap was left between the nerve ends inside the chamber. At follow-up three years later, motor and sensory recovery was excellent. At exploration at that time a macroscopically normal nerve was found in the tube.

Regeneration of the rat sciatic nerve in the silicone chamber model

The silicone nerve regeneration chamber is a useful model to investigate the cellular and molecular events underlying successful regeneration in the peripheral nervous system. In this model a transected rat sciatic nerve with a 10-mm interstump gap, is repaired with a silicone chamber. The spatial-temporal sequence of regeneration in the silicone chamber has been examined in detail. The chamber ra