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STATE OF THE ART In humans, it is currently believed that peripheral nerves remain intact after central nervous system (CNS) injuries. This should lead us to observe a lack of amyotrophy in the peripheral projection areas of CNS damage. Nevertheless, the appearance of amyotrophy, described as underuse amyotrophy, is common in victims of CNS injury. Its pathophysiology remains poorly understood and is currently being debated. Amyotrophy could result directly from the structural deterioration of a nervous fiber in the muscular area corresponding to the CNS injury caused by neuromuscular junction (NMJ) changes. AIMS OF THIS STUDY The aims of this study were to assess the repercussions of a CNS injury on the NMJ and peripheral nerve complex and to evaluate the involvement of peripheral nerves and NMJs in plasticity. METHODOLOGY Peripheral nerve and muscle biopsies were collected from a group of 35 female Wistar rats that had previously undergone a thoracic spinal cord hemisection (15 rats at the T2 level (group 1), 15 rats at the T6 level (group 2), and 5 matched rats used as controls). We studied the localization and expression of the NMJ molecular components in muscle specimens by immunohistochemistry using confocal microscopy. We also searched for signs of nerve and muscle degeneration using light and electron microscopy. RESULTS We observed nonpathologic NMJs coexisting with completely denervated and partially reinnervated NMJs. We also found characteristics of embryonic behavior in rat axons secondary to axonal caliber distortions. Some authors associate this decrease in axonal activity with physiological denervation. CONCLUSION This project was designed to improve the understanding of the mechanisms involved in the interactions between the first and second motoneurons after different types of CNS injuries, with variable functional repercussions. Our results strongly suggest that CNS injuries lead to both morphological and functional repercussions at the NMJ and the peripheral nerve.

Na/K-ATPase electrogenic activity and its indispensable role in maintaining gradients suggest that the modifications in isoform distribution and the functioning of the sodium pump have a major influence on both the neuronal functions, including excitability, and motor efficiency. This article proposes to clarify the involvement of Na/K-ATPase in the transmission of nerve influx within the peripheral nerve and then in the genesis, the maintenance, and the physiology of muscle contraction by comparing the data found in the literature with our work on neuron and muscle characterization of Na/K-ATPase activity and isoforms.

It has been shown that the onset of a central nervous system lesion in the rat results in morphological modifications of the peripheral nerves and the underlying neuromuscular junctions, without suggesting a functional correlation between recuperation of motor functions and sublesional metabolic activity. Using double lesion localization (T2 and T6) in a spinal rat model has nevertheless pointed out the functional importance of the T2-T6 metameric interval in the reinnervation phenomena observed, raising the problem of spinal generation in locomotor movements. Motivated by electrophysiological data that have given support to the concept of an anatomic substrate for these intramedullary rhythm generators, we attempted to establish a relation between the functional recuperation possible after a central nervous system lesion and modifications within the metabolism of the underlying neuromuscular system. We notably focused on Na/K-ATPase, whose crucial role in neuromuscular transmission has been evidenced. This paper proposes to demonstrate the involvement in the mechanisms of metabolic regulation after trans-synaptic denervation, i.e., a central nervous system lesion. Our study includes the Na/K-ATPase activity analysis on the sublesional peripheral nerve and the combined analysis of the expression of different RNA messengers within the corresponding muscle groups. We have also investigated the spatiotemporal organization of the compensating processes of the nerves underlying the lesion using magnetic resonance spectroscopy.

Resume Objectifs L'abord du plexus lombaire s'est longtemps limite a une approche inguinale anterieure, le femoral. L'approche posterieure constitue un veritable bloc plexique, permettant une extension plus constante de l'anesthesie aux trois principaux nerfs du plexus lombaire. Le but de l'etude etait d'evaluer la pratique du bloc lombaire posterieur sous anesthesie generale. Type d'etude Etude prospective, descriptive, non randomisee. Patients et methodes Au total, 93 patients ayant eu une chirurgie orthopedique de hanche ont ete etudies apres consentement libre et eclaire. Outre les donnees demographiques, ont ete recueillis les elements de la technique de ponction, les complications eventuelles, les antalgiques per- et postoperatoires. Resultats Le bloc etait pratique par l'interne seul supervise par un senior, par le senior seul, et par l'interne puis le senior dans respectivement 44, 45 et 11 % des cas. La duree moyenne de procedure etait de 6 ± 3 min pour les internes, versus 5 ± 2 min pour les seniors, et 9 ± 4 min pour les deux reunis. Le contact osseux etait trouve sans reorientation de l'aiguille dans 72 % des cas lors de la premiere approche, apres reorientation de l'aiguille dans les autres cas sauf pour trois echecs de reperage. Le plexus lombaire etait trouve entre 60 et 90 mm de profondeur, avec une mediane de 75 mm. La reponse motrice etait de type femoral seul, parfois associe a une reponse obturatrice (six cas) ou sciatique (un cas) ; l'intensite minimale de stimulation observee etait comprise entre 0,3 et 1 mA, avec une mediane a 0,6 mA. La duree du bloc analgesique etait en moyenne de 16,5 ± 4,5 heures, avec une mediane a 18 heures. La consommation moyenne de morphine dans les 24 premieres heures postoperatoires etait de 8 ± 8 mg, avec une mediane a 5,6 mg. Aucune complication neurologique du bloc lombaire n'a ete retrouvee a la sortie du patient. Conclusion Le bloc du plexus lombaire par voie posterieure sous anesthesie generale est une technique relativement aisee et efficace pour assurer l'analgesie per- et postoperatoire initiale de la chirurgie de la prothese totale de hanche.

In skeletal muscle the relationship between Na+,K+-ATPase activity and isoform content remains controversial (9,6). It could be due to the fiber-type content, membrane isolation and analytical methods. We investigated the distribution of subunit α1 and α2 Na+,K+-ATPase catalytic isoforms and the Na+,K+-ATPase activity in isolated membranes from white ( type I and glycolitic fibers) and red (type II and oxidative fibers) skeletal muscles. Red Gastrocnemius and White Gastrocnemius muscles were sampled from 8 week-old female Wistar rats and crude membranes were performed. The Na+,K+-ATPase activity and membrane distribution of Na+,K+-ATPase α1 and α2 isoforms were assessed by ouabain sensitive K-phosphatase (Kpase) measurements and Western Blot respectively. The Na+,K+-ATPase activity was 6 fold lower in White Gastrocnemius membranes than in Red Gastrocnemius membranes. The α1 and α2-isoform levels are higher in RG than in White Gastrocnemius. The α1 and α2-subunit Red Gastrocnemius content was significantly higher than in WG. The correlation between crude membrane Kpase activity and both catalytic α-subunit of the Na+,K+-ATPase exist.These data suggest that the Na+,K+-ATPase phosphatase activity correlates with the α1 and α2 isoforms levels in Red Gastrocnemius and White Gastrocnemius and confirms the fiber-specific Na+,K+-ATPase catalytic α-subunits and α2-isoform as the major catalytic isoform in rat skeletal muscle.

Na/K-ATPase electrogenic activity and its indispensable role in maintaining gradients suggest that the modifications in isoform distribution and the functioning of the sodium pump have a major influence on both the neuronal functions, including excitability, and motor efficiency. This article proposes to clarify the involvement of Na/K-ATPase in the transmission of nerve influx within the peripheral nerve and then in the genesis, the maintenance, and the physiology of muscle contraction by comparing the data found in the literature with our work on neuron and muscle characterization of Na/K-ATPase activity and isoforms.

It has been shown that the onset of a central nervous system lesion in the rat results in morphological modifications of the peripheral nerves and the underlying neuromuscular junctions, without suggesting a functional correlation between recuperation of motor functions and sublesional metabolic activity. Using double lesion localization (T2 and T6) in a spinal rat model has nevertheless pointed out the functional importance of the T2-T6 metameric interval in the reinnervation phenomena observed, raising the problem of spinal generation in locomotor movements. Motivated by electrophysiological data that have given support to the concept of an anatomic substrate for these intramedullary rhythm generators, we attempted to establish a relation between the functional recuperation possible after a central nervous system lesion and modifications within the metabolism of the underlying neuromuscular system. We notably focused on Na/K-ATPase, whose crucial role in neuromuscular transmission has been evidenced. This paper proposes to demonstrate the involvement in the mechanisms of metabolic regulation after trans-synaptic denervation, i.e., a central nervous system lesion. Our study includes the Na/K-ATPase activity analysis on the sublesional peripheral nerve and the combined analysis of the expression of different RNA messengers within the corresponding muscle groups. We have also investigated the spatiotemporal organization of the compensating processes of the nerves underlying the lesion using magnetic resonance spectroscopy.

In humans, it is currently believed that peripheral nerves remain intact after central nervous system (CNS) injuries. This should lead us to observe a lack of amyotrophy in the peripheral projection areas of CNS damage. Nevertheless, the appearance of amyotrophy, described as underuse amyotrophy, is common in victims of CNS injury. Its pathophysiology remains poorly understood and is currently being debated. Amyotrophy could result directly from the structural deterioration of a nervous fiber in the muscular area corresponding to the CNS injury caused by neuromuscular junction (NMJ) changes.The aims of this study were to assess the repercussions of a CNS injury on the NMJ and peripheral nerve complex and to evaluate the involvement of peripheral nerves and NMJs in plasticity.Peripheral nerve and muscle biopsies were collected from a group of 35 female Wistar rats that had previously undergone a thoracic spinal cord hemisection (15 rats at the T2 level (group 1), 15 rats at the T6 level (group 2), and 5 matched rats used as controls). We studied the localization and expression of the NMJ molecular components in muscle specimens by immunohistochemistry using confocal microscopy. We also searched for signs of nerve and muscle degeneration using light and electron microscopy.We observed nonpathologic NMJs coexisting with completely denervated and partially reinnervated NMJs. We also found characteristics of embryonic behavior in rat axons secondary to axonal caliber distortions. Some authors associate this decrease in axonal activity with physiological denervation.This project was designed to improve the understanding of the mechanisms involved in the interactions between the first and second motoneurons after different types of CNS injuries, with variable functional repercussions. Our results strongly suggest that CNS injuries lead to both morphological and functional repercussions at the NMJ and the peripheral nerve.

To our knowledge, there is little reference in literature with regards to alpha3-isoform of Na+,K+-ATPase in human peripheral nerves. The aim of this study was to determine the expression of the neuronal alpha3-isoform of Na+,K+-ATPase in human sural nerves from patients with a permanent medullary central nervous system injury.We studied the immunolocalization of alpha3-isoform of Na+,K+-ATPase using a polyclonal antibody against the amino sequence near the phosphorylation site of the alpha3-isoforms of Na+,K+-ATPase using immunohistochemistry and confocal laser scanning microscopy. An antibody specific for alpha2-isoform of Na+,K+-ATPase was used to label the Schwann cells.Morphometric analysis of longitudinal section of human sural nerves showed that the alpha3-isoform of Na+,K+-ATPase was distributed along the length of axolemma. The myelin sheath of the Schwann cells showed clearly a distribution of alpha3- but not alpha2-isoforms of Na+,K+-ATPase at the level of Schmidt-Lanterman incisures.The human sural nerve shows a specific localization of the Na+,K+-ATPase alpha3-isoform in the Schmidt-Lanterman incisures of Schwann cells in addition to its localization in axonal membranes.

During many years the approach to the lumbar plexus has been the anterior paravascular technique described as a "3-1" block by Winnie. The posterior approach results in a complete block of the principal nerves of the lumbar plexus. The goal of the study was to evaluate the performance of the psoas compartment block with general anaesthesia.Prospective, descriptive, non randomized study.Ninety-three patients scheduled for hip surgery were studied after informed consent. Demographic data, technical aspects of the puncture, complications, and intra- and postoperative analgesics were recorded.The block was performed by resident alone, senior alone, both in respectively 44%, 45, and 11% of cases. The mean duration of the procedure was 6+/-3 min for the residents, 5+/-2 min for the seniors, and 9+/-4 min for both. The transverse process was reach in 72% of cases during the first approach, after reorientation of the needle in the others cases, except 3 failures of attempt. The lumbar plexus was assessed within 60-90 mm of depth, with a median of 75 mm. The motor response was mainly a femoral response; the minimal intensity of stimulation was ranged between 0.3 and 1 mA, with a median of 0.6 mA. The duration of analgesic block was 16.5+/-4.5 hours, with a median of 18 hours. The morphine use during the first postoperative 24 hours was 8+/-8 mg, with a median of 5.6 mg. No neurologic complication was recorded at discharge from the hospital.The psoas compartment block with general anaesthesia have shown it feasibility and efficiency on intra- and postoperative analgesia during hip surgery.

The authors perform a retrospective study of a series of 147 patients aged 75 and more, who were treated for gallstone. AMong them, 104 had conventional surgery and 43 a nonsurgical treatment. The noticeable elements produced by this analysis are: the frequency of common bile duct lithiasis and of severe septic complication in elderly patients, the frequency of previous gallstone, sometimes remote in time, a significantly higher mortality when the treatment is non-surgical (p less than 0.001), mainly due to the septic complications of the lithiasis. the influence of the diathesis on mortality, and finally, the greater inocuity of the right infracostal approach in view of respiratory complications.

Eighty-three patients (more than one half of whom were at high surgical risk) presenting with haemorrhages from a gastric or duodenal ulcer were treated with endoscopic injections of an epinephrine-hypertonic saline mixture. The overall rate of definitive haemostasis was 83 p. 100. Depending on the degree of haemorrhagic activity, this rate was 64 p. 100 in pulsatile lesions, 90.5 p. 100 in oozing lesions, 85.7 p. 100 in cases with visible vessels and 81.2 p. 100 when signs of recent bleeding were present. There was no dangerous complication related to the technique. The overall survival rate was 67.5 p. 100 and 20 out of the 26 deaths were due to other causes than haemorrhages. On follow-up, 94.7 p. 100 of the ulcers healed under antisecretory treatment within the usual length of time. This simple, effective and inexpensive technique is suggested as initial treatment of gastric or duodenal haemorrhages in subjects at high surgical risk, especially since the haemorrhage has no influence on the course of the ulcer.