Search results for "Denervation"

Irreversible changes occurring in long-term denervated Schwann cells affect delayed nerve repair.

2017

OBJECTIVEMultiple factors may affect functional recovery after peripheral nerve injury, among them the lesion site and the interval between the injury and the surgical repair. When the nerve segment distal to the lesion site undergoes chronic degeneration, the ensuing regeneration (when allowed) is often poor. The aims of the current study were as follows: 1) to examine the expression changes of the neuregulin 1/ErbB system during long-term nerve degeneration; and 2) to investigate whether a chronically denervated distal nerve stump can sustain nerve regeneration of freshly axotomized axons.METHODSThis study used a rat surgical model of delayed nerve repair consisting of a cross suture betw…

Effects of botulinum toxin type A on vibration induced facilitation of motor evoked potentials in spasmodic torticollis.

2004

It has not been clarified if botulinum toxin (BTX) injection leads to muscle spindle dysfunction in man. This study aimed to test the hypothesis that BTX application reduces the facilitation of a magnetic evoked response (MEP).We used the vibration induced facilitation of an MEP of the sternocleidomastoid muscle (SCM) as a surrogate marker for muscle spindle function in 20 healthy subjects and 10 patients with idiopathic rotational torticollis in whom BTX was injected unilaterally.The increase in the amplitude and area of the MEPs in the clinically not affected and untreated SCM of the patients did not differ significantly from the controls. At baseline, the vibration induced increase in th…

Sacral bladder denervation for treatment of detrusor hyperreflexia and autonomic dysreflexia

2001

Objectives. Detrusor hyperreflexia after spinal cord injury may cause urinary incontinence and chronic renal failure. In patients refractory to conservative treatment and not eligible for ventral sacral root stimulation for electrically induced micturition, we investigated the therapeutic value of sacral bladder denervation as a stand-alone procedure. Methods. Nine patients (8 men and 1 woman) between 21 and 58 years old (mean 30.2) with traumatic suprasacral spinal cord lesions underwent sacral bladder denervation for treatment of detrusor hyperreflexia and/or autonomic dysreflexia. Results. Detrusor hyperreflexia and autonomic dysreflexia were eliminated in all cases. Bladder capacity inc…

Immunolocalization of Tenascin-C in Human Type II Fiber Atrophy

2000

Tenascin-C is a multifunctional extracellular matrix glycoprotein with stimulatory and anti-adhesive or inhibitory properties for axon growth. Its location and discontinuous expression are restricted in innervated muscle tissues. Tenascin-C accumulated interstitially among human denervated muscle fibers and close to normal-sized fibers. To expand our knowledge of the expression of tenascin-C in human neuromuscular disorders, we investigated immunohistologically 20 human muscle specimens with type II myofiber atrophy of children and adults. Tenascin-C immunoreactivity in adult type II atrophy was frequent, and accumulation in children was sparse and weak. In both groups, tenascin-C immunorea…

Repair of the mandibular nerve by means of autologous nerve grafting after resection of the lower jaw

1973

Summary On the basis of two cases we demonstrate our method of autologous nerve grafting for substitution of the mandibular nerve after mandibular resection. The sural nerve served as a donor nerve, the graft was imbedded microsurgically at the juncture points by means of a perineurial interfascicular nerve suture. Oversized grafts of about 20 cm in length were chosen intentionally in order to insert them without tension between the stumps of the recipient nerve and outside the regeneration zone of the bone. In both cases complete resensibilization of the lower lip was reached after about six months.

Alcohol-Mediated Renal Sympathetic Neurolysis for the Treatment of Hypertension: The Peregrine™ Infusion Catheter.

2020

Renal sympathetic denervation using conventional non-irrigated radiofrequency catheters has potential technical shortcomings, including limited penetration depth and incomplete circumferential nerve damage, potentially impacting therapeutic efficacy. Against this background, second generation multi-electrode, radiofrequency and ultrasound renal denervation systems have been developed to provide more consistent circumferential nerve ablation. Irrigated catheters may allow deeper penetration while minimizing arterial injury. In this context, catheter-based chemical denervation, with selective infusion of alcohol, a potent neurolytic agent, into the perivascular space, may minimize endothelial…

Ouabain enhances release of acetylcholine in the heart evoked by unilateral vagal stimulation.

1986

The aim of the study was to elucidate peripheral effects of ouabain on the parasympathetic innervation of the heart, effects that could contribute to the experimentally and clinically well established “vagal effect of cardiac glycosides”. The experiments were carried out with ouabain concentrations of 3×10−7 and 10−6 mol/l, which were considered “therapeutic”, as they increased force of contraction and did not elicit arrhythmias in incubated chicken atria. In atrial preparations of chickens and guinea-pigs the negative chronotropic and inotropic effects of acetylcholine (ACh) were not altered by 3×10−7 mol/l ouabain. Resting efflux of ACh from perfused chicken hearts was increased by ouabai…

The fine structure of denervated and reinnervated muscle spindles: morphometric study of intrafusal muscle fibers.

1979

The fine structure of normal, denervated, and reinnervated muscle spindles in lower lumbrical muscles of rats was studied morphometrically at time intervals ranging from 3-14 months. In control spindles, the mean transverse area of mitochondria was estimated to be more than twice as large in nuclear chain than in typical nuclear bag fibers. Following denervation, there was a severe decrease of the mean number and transverse area of mitochondria, and a moderate, but statistically significant decrease of the mean transverse area of intrafusal muscle fibers (IMFs) despite an increase of the number of IMFs. At 12-14 months of reinnervation, changes of the transverse areas of IMFs were statistic…

Selective Sacral Nerve Blockade for the Treatment of Unstable Bladders

1987

38 patients with severe urge or urge incontinence, who did not respond to conservative therapy, were treated with selective sacral nerve blockade using a local anesthetic (bupivacaine). 6 patients of this group had definite selective sacral denervation with phenol. In 31 patients a urodynamic study was done previous to the sacral nerve block as well as 10 and 90 min after the injection. Within the first 2-7 weeks the success rate was about 70% in regard to bladder capacity and mean volume at first desire to void. On long-term follow-up (greater than 7 months), the success rate decreased to about 16%. Only 1 patient of the phenol group still has complete detrusor areflexia for now more than …

2020

Skeletal muscle atrophy is characterized by a decrease in muscle fiber size as a result of a decreased protein synthesis, which leads to degradation of contractile muscle fibers. It can occur after denervation and immobilization, and glucocorticoids (GCs) may also increase protein breakdown contributing to the loss of muscle mass and myofibrillar proteins. GCs are already used in vitro to induce atrophic conditions, but until now no studies with primary human skeletal muscle existed. Therefore, this study deals with the effects of the GC dexamethasone (dex) on primary human myoblasts and myotubes. After incubation with 1, 10, and 100 µM dex for 48 and 72 h, gene and protein expression analy…