The analgesic effect of crotoxin on neuropathic pain is mediated by central muscarinic receptors and 5-lipoxygenase-derived mediators

Crotoxin (CTX). a neurotoxin isolated from the venom of the South American rattlesnake Crotalus durissus terrificus. induces analgesia. In this study, we evaluated the antinociceptive effect of CTX in a model of neuropathic pain induced by rat sciatic nerve transection. Hyperalgesia was detected 2 h after nerve transection and persisted for 64 days. Immersion of proximal and distal nerve stumps in CTX solution (0.01 mM for 10 s), immediately after nerve transection, blocked hyperalgesia. The antinociceptive effect of CTX was long-lasting, since it was detected 2 h after treatment and persisted for 64 days. CTX also delayed, but did not block, neurectomy-induced neuroma formation. The effect of CTX was blocked by zileuton (100 mg/kg, p.o.) and atropine (10 mg/kg. i.p.), and reduced by yohimbine (2 mg/kg, i.p.) and methysergide (5 mg/kg, i.p.). on the other hand. indomethacin (4 mg/kg, i.v.). naloxone (1 mg/kg, i.p.). and N-methyl atropine (30 mg/kg, i.p.) did not interfere with the effect of CTX. These results indicate that CTX induces a long-lasting antinociceptive effect in neuropathic pain, which is mediated by activation of central muscarinic receptors and partially, by activation of alpha-adrenoceptors and 5-HT receptors. Eicosanoids derived from the lipoxygenase pathway modulate the action of crotoxin. (C) 2008 Elsevier B.V. All rights reserved.

Early Pancreas Transplant Improves Motor Nerve Conduction in Alloxan-Induced Diabetic Rats

The purpose of this study was to assess the temporal relationship between pancreas transplant and the development of electrophysiological changes in the sciatic and caudal nerves of alloxan-induced diabetic rats. Nerve conduction studies were performed in diabetic rats subjected to pancreas transplantation at 4, 12, and 24 weeks after diabetes onset, using nondiabetic and untreated diabetic rats as controls. Nerve conduction data were significantly altered in untreated diabetic control rats up to 48 weeks of follow-up in all time points. Rats subjected to pancreas transplantation up to 4 and 12 weeks after diabetes onset had significantly increased motor nerve conduction velocity with improvement of wave amplitude, distal latency, and temporal dispersion of compound muscle action potential in all follow-up periods (P<0.05); these parameters remained abnormal when pancreas transplantation were performed late at 24 weeks. Our results suggest that early pancreas transplant (at 4-12 weeks) may be effective in controlling diabetic neuropathy in this in vivo model.

Inferior alveolar nerve transposition with involvement of the mental foramen for implant placement

Inferior Alveolar Nerve (IAN) transposition is an option for prosthetic rehabilitation in cases of moderate or even severe bone reabsorption for patients that do not tolerate removable dentures. The aim of the present report is to describe an inferior alveolar nerve transposition with involvement of the mental foramen for implant placement. The surgical procedure was performed under local anesthesia, by the inferior alveolar, lingual and buccal nerve blocking technique. Centripetal osteotomy was performed, and bone tissue was removed, leaving the nerve tissue free in the foramen area. After that, transsection of the incisor nerve was performed, and lateral osteotomy was started from the buccal direction, toward the trajectory of the IAN. The procedure was concluded, by making use of a delicate resin spatula to manipulate the vascular-nervous bundle. The drilling sequence for placing the dental implants was performed, and autogenous bone was harvested using a bone collector attached to the surgical suction appliance. After the implants were placed, the bone tissue previously collected during the osteotomies and drilling processes was placed in order to protect the IAN from contact with the implants. The surgical protocol for inferior alveolar nerve transposition, followed by implant placement presented excellent results, with complete recovery of the sensitivity, seven months after the surgical procedure.

Nerve grafts prevent paraplegic pressure ulcers

We present an optimistic neural solution to the depressing challenge of decubitus pressure ulcers in the paraplegic patient. This is a limited study of two paraplegic men followed for several years. Sural nerve grafts, performed end-to-side, successfully bridged the sciatic nerve to intercostal nerves with surprising benefits for both men.

Guanidine Affects Differentially the Twitch Response of Diaphragm, Extensor Digitorum Longus and Soleus Nerve-Muscle Preparations of Mice

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Static balance and function in children with cerebral palsy submitted to neuromuscular block and neuromuscular electrical stimulation: Study protocol for prospective, randomized, controlled trial

Background: The use of botulinum toxin A (BT-A) for the treatment of lower limb spasticity is common in children with cerebral palsy (CP). Following the administration of BT-A, physical therapy plays a fundamental role in potentiating the functionality of the child. The balance deficit found in children with CP is mainly caused by muscle imbalance (spastic agonist and weak antagonist). Neuromuscular electrical stimulation (NMES) is a promising therapeutic modality for muscle strengthening in this population. The aim of the present study is to describe a protocol for a study aimed at analyzing the effects of NMES on dorsiflexors combined with physical therapy on static and functional balance in children with CP submitted to BT-A.Methods/Design: Protocol for a prospective, randomized, controlled trial with a blinded evaluator. Eligible participants will be children with cerebral palsy (Levels I, II and III of the Gross Motor Function Classification System) between five and 12 years of age, with independent gait with or without a gait-assistance device. All participants will receive BT-A in the lower limbs (triceps surae). The children will then be randomly allocated for either treatment with motor physical therapy combined with NMES on the tibialis anterior or motor physical therapy alone. The participants will be evaluated on three occasions: 1) one week prior to the administration of BT-A; 2) one week after the administration of BT-A; and 3) four months after the administration of BT-A (end of intervention). Spasticity will be assessed by the Modified Ashworth Scale and Modified Tardieu Scale. Static balance will be assessed using the Medicapteurs Fusyo pressure platform and functional balance will be assessed using the Berg Balance Scale.Discussion: The aim of this protocol study is to describe the methodology of a randomized, controlled, clinical trial comparing the effect of motor physical therapy combined with NMES on the tibialis anterior muscle or motor physical therapy alone on static and functional balance in children with CP submitted to BT-A in the lower limbs. This study describes the background, hypotheses, methodology of the procedures and measurement of the results.

Acupuntura e implante de fragmentos de ouro em pontos de acupuntura e pontos Acupuntura e implante de fragmentos de ouro em pontos de acupuntura e pontos gatilho para o tratamento de displasia coxo-femoral em Pastor Alemão

Background: Canine hip dysplasia (HD) is characterized by hip joint laxity and subluxation. It is the most common cause of osteoarthritis in dogs, especially in larger breeds. Its management includes nutritional supplements, nonsteroidal anti-inflammatory drugs, physical therapy, acupuncture or surgical procedures. Implantation of gold beads in acupuncture points and trigger points around a joint has been used in the treatment of osteoarthritis in dogs for at least 30 years. Gold bead implants(GBI) acts as continuous acupuncture stimulation and trigger point treatment in canine HD with long lasting results. Electrophysiological investigations of trigger points reveal dysfunctional muscle spindles which indicate that the electrical activity of active loci arises from extrafusal motor endplates.Case: This is a report on the use of acupuncture and GBI for bilateral HD in a nine year old female German Shepherd. The patient has a HD non-responsive to anti-inflammatory drugs and was unable to stand up or walk by its own. Radiographs showed marked dysplasia, significant subluxation with the femoral head partly out of a shallow acetabulum and massive secondary arthritic bone changes, mainly on the right side. The animal was submitted to eight acupuncture sessions with seven days interval. After the first acupuncture session the use of NSAID was interrupted. After eight weeks the dog was considered rehabilitated and underwent GBI in acupoints and trigger points as maintenance treatment. During the one-year follow-up period the improvement remained unchanged with no need of analgesics.Discussion: It has been suggested that acupuncture or GBI can treat the chronic pain resulting from osteoarthritis induced by HD. According to AP theory, GBI is permanent and long-lasting acupoint stimulation. Moreover, the method is inexpensive, quick and easy to perform, with no postoperative pain or need of exercise restriction. Although gold is extremely corrosion-resistant, the surface of the gold implants stimulates a reaction from the immune system causing an oxidative liberation of gold ions with anti-inflammatory actions. It is well known that gold ions are effective inhibitors of the respiratory burst of neutrophils and monocytes and the proliferation of lymphocytes. These findings suggest that gold implantation, on a local scale, mimics the anti-inflammatory and pain-relieving effect of drugs with chemically bound gold ions. The relatively slow speed of the process results in a limited liberation of gold ions securing that they are taken up almost exclusively by cells close to the implant. The nine year old female German shepherd had a positive response to acupuncture with pain relieve and locomotor rehabilitation. For the nine year old female German shepherd previous acupuncture sessions to GBI resulted in no post-implant worsening period. Indeed, the association acupuncture/GBI does not have the anti-inflammatory drugs undesirable effects and brings long lasting results. In conclusion, GBI therefore should be considered for canine HD when conservative or medical treatments fail to give the desired effect.

Fine structure of lamellated nerve endings in the gingiva of man and the Cebus apella monkey

Gingival mucosae of man and the adult Cebus apella monkey were fixed for 3 hr in modified Karnovsky fixative containing 2.5% glutaraldehyde, 2% formaldehyde in 0.1 M sodium phosphate buffer (pH=7.4). The specimens were postfixed in 1% osmium tetroxide in 0.1 M sodium phosphate buffer at 4°C for 2 hr, dehydrated in a graded alcohol series and embedded in Epon 812. Thick sections of 1-3 μm and ultrathin sections of 40-80 nm in thickness were cut with glass knives on an LKB ultramicrotome. The thick sections were stained with toluidine blue solution, and the grids were stained with uranyl acetate and lead citrate and examined under a Philips EM-301 electron microscope. Our observations permitted us to conclude that: both gingival mucosae, of man and the Cebus apella monkey, have lamellar nerve endings; these corpuscles are localized in the papillar space of the epithelium and do not contact closely with the basement membrane; the nerve endings are composed of an afferent fiber which subdivides several times and forms irregular flattened or discoidal expansions; the laminae of the lamellar cells are very thin near the terminal axon and are larger and irregular in shape at the peripheral portion of the corpuscle; the terminal axon shows abundant mitochondria, myelin figures, clear vesicles, and multivesicular bodies; between the axoplasm membrane and adjacent cytoplasmic lamina and between the lamellae, small desmosome type junctions are noted; and the cytoplasmic material of the lamellae cells is characterized by the presence of numerous microfilaments, microtubules, mitochondria, rough endoplasmic reticulum, and caveolae.

Experimental surgery of the facial nerve. Assessment of the intraperitoneal use of exogenous gangliosides

Compression and section of the facial nerve were performed in 48 rats in order to study the anatomopathological alterations occurring after daily intraperitoneal injections of 100 mg of exogenous gangliosides (Sinaxial®) for 45, 90, 180 days. In groups submitted to nerve compression, the histopathological changes were discrete and in the 180-day subgroups the nerve was practically normal. In animals submitted to section and neurorrhaphy there was formation of an amputation neuroma, a granuloma around the suture, axonal unstructuration and inter and perineural fibrosis. No significant differences were observed between the groups submitted or not to injection of exogenous gangliosides, indicating that the major factors involved in the quality of nerve regeneration were the technique and the formation of fibrosis and of an amputation neuroma.

Compression of the peripheral branches of the sciatic nerve by lipoma

The authors report two female patients with chronic sensitive and motor findings in lower limbs caused by compression of distal branches of sciatic nerve by lipoma. Similar eases were not described on literature. Nerve conduction studies allowed to localize the exact site of compression. At surgery, lipomas compressing the deep peroneal nerve (case 1) and the posterior tibial nerve (case 2) were observed. Histologic studies of tumors confirmed the diagnoses.

Tempo de latencia do rocuronio e da succinilcolina e condicoes de intubacao traqueal

Background and Objectives - Pulmonary aspiration of gastric content during induction of anesthesia for emergency surgical procedures is a serious complication; fast endotracheal intubation under these circumstances is of vital importance to secure the airways. Despite its numerous side effects, succinylcholine is used for this purpose. Rocuronium is the most recently introduced aminoesteroid neuromuscular blocking drug with short onset. The objective of this study was to compare the onset time and intubating conditions of rocuronium and succinylcholine. Methods - After informed consent, forty-five patients were randomly allocated into three groups of 15: Group I (GI) = succinylcholine 1 mg.kg-1; Group II (GII) = rocuronium 0.6 mg.kg-1; Group III (GIII) = rocuronium 0.9 mg.kg-1. Every patient was premedicated with midazolam 15 mg per os and induction of anesthesia was made with fentanyl 10 μg.kg-1 and etomidate 0.3 mg.kg-1. The neuromuscular block was monitored with the TOP-Guard neuromuscular transmission monitor. The TOP-Guard neuromuscular monitor uses an accelerometer to measure the response to nerve stimulation. The stimulating electrodes were placed close to the course of the ulnar nerve at the wrist. The onset time was considered as the time between the end of neuromuscular drug injection and the twitch height (T1) decrease to 10%. Heart rate and arterial blood pressure were registered at 6 moments before and after induction of anesthesia. Results - The onset time results were: Group I, 71 s; Group II, 120 s and Group III, 70 s or GI = GIII < GII (F = 8.862; p < 0.01). There were 43 patients exhibiting excellent intubating conditions and 2 with good intubating conditions. Heart rate and arterial blood pressure showed alterations due to induction of anesthesia and intubation. Conclusions - Rocuronium 0.9 mg.kg-1 can be used in rapid sequence induction because it has a short onset time which is similar to that of succnylcholine. It is likely that rocuronium would be a good indication in patients with high intracranial pressure, burns and neuromuscular diseases.

Inside-out vs. standard vein graft to repair a sensory nerve in rats

Nerve regeneration in a sensory nerve was obtained by the application of different techniques: inside-out vein graft (IOVG group) and standard vein graft (SVG group). These techniques provide a good microenvironment for axon regeneration in motor nerves, but their efficiency for regeneration of sensory nerves is controversial. The saphenous nerve was sectioned and repaired by the inside-out and standard vein graft techniques in rats. After 4, 12, and 20 weeks the graft and the distal stump were observed under electron microscopy. In each studied period, the pattern, diameters, and thickness of the myelin sheaths of the regenerated axons were measured in the graft and distal stump. A comparative study about the regenerated nerve fibers by these two different techniques was performed. Regenerated nerve fibers were prominent in both vein grafts 4 weeks after the surgical procedures. On the other hand, in the distal stump, regenerated nerve fibers were observed only from 12 weeks. In both inside-out vein graft and standard vein graft statistical difference was not observed about the diameters and thickness of the myelinated fibers after 20 weeks. On the other hand, the inside-out group had greater regenerated axon number when compared to the standard group. There is a capillary invasion in both graft and distal stump, especially in the IOVG group. The regenerated axons follow these capillaries all the time like satellite microfascicles. After 20 weeks, the diameters of regenerated fibers repaired by the standard vein graft technique were closer to the normal fibers compared to the inside-out vein graft. On the other hand, the pattern of these regenerated axons was better in the IOVG group.

Tempo de latencia e duracao do efeito do brometo de rocuronio no paciente submetido ao transplante renal

Background and Objectives - Successful cadaver kidney transplantation relies on a fast procedure. Patients with chronic renal failure may present with a delayed gastric emptying making it critical a fast tracheal intubation and airway maintenance. Rocuronium a recently introduced nondepolarizing neuromuscular blocker with a fast onset. The aim of this study was to evaluate onset time and duration of rocuronium effects in patients undergoing renal transplantation. Methods - Sixty patients were allocated into two groups of 30: Group R (GR) = patients undergoing renal transplantation and Group N (GN) = patients with normal renal function. All patients were premedicated with oral midazolam (15 mg) and anesthesia was induced with 30 μg.kg-1 alfentanil, 0.3 mg.kg-1 etomidate and 0.6 mg.kg-1 rocuronium injected through a central venous catheter. neuromuscular block was monitored by acceleromyography in the ulnar nerve pathway. The following parameters were evaluated: time between administration of rocuronium and first twitch reduction to 5% after supra-maximal stimulation (T1) (onset time = OT); time for first twitch to return to 25% (clinical duration = R25); time elapsed between 25% and 75% recovery of first twitch (relaxation recovery time = R25-75). Heart rate (HR) and mean blood pressure (MBP) were recorded in 6 moments. Results - Median OT was 31 sec. in GR and 47 sec. in GN. Median R25 was 51.5 min in GR and 33.5 min in GN. Median R25-75 was 28 min in GR and 20 min in GN. MBP and HR were higher in GR. Tracheal intubation conditions were excellent for most patients in both groups. Conclusions - These results open the possibility of 0.6 mg.kg-1 rocuronium being injected through a central venous catheter when a faster onset is needed. Due to wide differences in individual responses, monitoring of neuromuscular block is recommended.

Ulnar-to-median nerve anastomosis in the forearm. Review and report of 2 new cases

The ulnar-to-median nerve anastomosis in the forearm is a very rare occurrence, not mentioned in many anatomical text books. We found only 4 cases cited in medical literature. Here we describe 2 new cases, for which diagnosis was suspected when the compound muscle action potential of the abductor pollicis brevis muscle (APB), obtained by maximal stimulation of the median nerve at the elbow, was lower than that obtained at the wrist. The diagnosis was confirmed by stimulation of the ulnar nerve at the elbow, which evoked a compound muscle action potential of the APB with a clear negative initial deflection without volume-conducted potential.

Características estruturais da parede das artérias renal e femoral de coelho (Oryctolagus cuniculus)

In the renal and femoral arteries of rabbit was verified that both vessels had walls structured by myostromal components, despite of their different distributive of blood, being the renal artery a visceral blood vessel and the femoral artery a parietal vessel. This wall pattern in these vessels concerned to presence of connective stromal elements (collagen and elastic fibres and lamellae) and smooth muscle cells coexisting with some equilibrium in the wall structure of the renal and femoral arteries, mainly in the medial layer architecture. An intimal folding pattern was verified around the vascular lumen, possibly related to capacitance of the both arteries regarding to variability of pressure levels in cardiac cycle. Furthermore, myostromal relations of connective elements and smooth muscle cells verified in the medial layer and the network formed by connective elements in the adventitial layer of these arteries contributed to maintenance of wall viscoelasticity properties of the vessels.