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M Merle

Publications and source records attributed to M Merle.

At least 19 recordsLinked to original sources
PubMed2005

Long-term evaluation of motor function following intraneural injection of ropivacaine using walking track analysis in rats.

BACKGROUND: There is a paucity of data regarding neurologic function following nerve injury. Our objective was the long-term evaluation of motor function following intraneural injection of ropivacaine in rats using the sciatic function index (SFI), derived from walking track analysis. METHODS: Rats were randomly assigned to one of four groups of 13 animals each. A needle was inserted under magnification into the left sciatic nerve and 0.2 ml of normal saline, formalin 15%, ropivacaine 0.2 or 0.75% were injected intraneurally. The right side was sham operated. Walking track analysis was performed the day before and on days 1, 4, 7, 11, 15, 18, 21, and 67 following intraneural injection. At the end of the experiment (day 67) a semi-quantitative evaluation of neuropathologic changes was performed by three independent observers. RESULTS: Animals treated with saline and ropivacaine (0.2 and 0.75%) had no detectable impairment of motor function at any time point. In contrast, rats treated with formalin had a complete loss of motor function immediately after the intraneural injection, which persisted until day 21 and returned to normal by day 67. Important histopathologic changes (score=2) with excellent inter-observer agreement were seen only in the group treated with formalin. This applied to both axonal degeneration and Schwann cell density evaluations. CONCLUSIONS: These findings suggest that intraneural injections of ropivacaine at concentrations routinely used in clinical practice appear to have no deleterious effect on sciatic nerve motor function in this experimental rat model.

Amides↗
PubMed2005

[Melanoma of the forearm. A historical case report].

We present the case of a melanoma of the forearm notable for its depth (Breslow index 35 mm), due to a longstanding lack of interest and care by the patient as well as her physician. Because of systemic metastases, only palliative treatment, consisting of an excision of the lesion for local hygiene, could be offered. The patient survived for only three months. This case illustrates the absolute necessity to remove without delay, any cutaneous tumor that resembles a melanoma, in order to avoid diagnosis being made at a late stage when curative treatment cannot be performed.

Aged↗
PubMed2004

Gadolinium-enhanced small-animal TOF magnetic resonance angiography.

So far, magnetic resonance angiography (MRA) of rodents has only been performed by using time-of-flight (TOF) MRI techniques. This is because applications of first-passage contrast agents as in humans are hampered by pronounced physiologic differences (blood volume and heart beat rate). Here we describe the use of low-dose Gd-DOTA to enhance the performance of TOF MRA in rat brain. While no improvement in contrast was achieved, the measuring time could be reduced by almost a factor of three. This decrease in total acquisition time has been used to study the impact of a model of ligatured common carotid on the upper part of the blood system of the rat.

Animals↗
PubMed2004

[Clinical and three-dimensional kinematic features of the upper limb after replantation of the hand].

INTRODUCTION: Functional assessments of hand replantation after traumatic amputation are considered as good although frequent deficits of long fingers mobility and hand sensitiveness occur. AIMS: To evaluate the capability of handling and the compensatory mechanisms involved in handling. METHODS: Prospective study in eight right-handed males who had distal amputation of the left upper limb with hand replantation for more than two years. Eight males with paired age and handedness served as control. Skin sensitiveness (thread test), mobility (TAM), functional capability (Box and Blocks test, 400 points test) and occupational outcome were assessed. Three-dimensional analysis (opto-electronic device) of the motion of the trunk and the upper limbs (arm, forearm, hand) was made during a pointing and gripping-shifting maneuver and the time of the related phases was measured (dynamometric cube device). Correlation between clinical assessments and three-dimensional analysis were tested. RESULTS: Patients with replantation had a remarkable recovery of the absolute and relative times of the various phases of the handling maneuver. Only the gripping phase was significantly prolonged in patients, this result was correlated with the deficit in motor function and sensitiveness of the replanted hand. The visual control was higher because of the lack of superficial and deep sensitiveness. Compensatory mechanisms involved a lateral shift of the replanted limb segments, probably attributed to the lateral shift of the trunk. CONCLUSION: Patient with a replanted hand develops a homogenesis displacement of the trunk and the pectoral girdle to compensate the shortening and the reduction in active mobility of the hand. This compensatory mechanism, observed in a small scale in healthy too, is efficient with respect to the handling phases.

Activities of Daily Living↗
PubMed2003

Lactate involvement in neuron-glia metabolic interaction: (13)C-NMR spectroscopy contribution.

Glucose is commonly admitted to be the main substrate for brain energy requirement. However, it has been recently proposed that lactate, generated from glucose via glycolysis, would be the oxidative substrate for neurons, particularly during neuronal activation, according to a mechanism called the astrocyte-neuron lactate shuttle hypothesis (ANLSH). In that mechanism, glutamate released in the synaptic cleft during brain activation is taken up by astrocytes. This uptake, via the glutamate/Na(+) transporter, induces the entry of sodium, which is then excluded from the astrocytes via the Na(+)/K(+) ATPase. This exclusion consumes ATP, which stimulates glycolysis and thus lactate formation in astrocytes. This lactate is then transferred to neurons where it is utilized as oxidative substrate. This review tries to gather the recent evidences that support this hypothesis and presents the contribution of NMR to this matter.

Animals↗
PubMed2003

Nerve anastomosis with glue: comparative histologic study of fibrin and cyanoacrylate glue.

The authors report the results of a comparative experimental nerve study, using a biologic tissue glue (fibrin) and a synthetic glue (2-cyanoacrylate) in a rat model. A tension-free repair is necessary with the use of fibrin glue, or gapping may occur, thus limiting the use of the agent in promoting re-neurotization. In addition, the human origin of fibrin and thrombin allow for the possibility of viral transmission. The aim of the study was to verify if the synthetic glue is a viable alternative, or whether it causes cellular and tissue lesions. Their main finding was that the cyanoacrylate causes a foreign-body inflammatory reaction and retractile fibrosis, often reducing the nerve diameter up to two-thirds. Cyanoacrylate glue is thus not recommended for peripheral nerve repair.

Animals↗
PubMed2003

[Free flap for soft tissue loss of the limbs in trauma victims].

PURPOSE OF STUDY: We report a series of 67 free flaps performed between 1995 and 2001 for soft tissue loss of the limbs in trauma victims. We searched for elements predictive of failure in order to better identify indications. MATERIAL AND METHODS: The series was predominantly masculine (52 men, 15 women). Mean age was 38.7 years (range 18-63). Thirty-four free flaps were performed on the upper limb and 33 on the lower limb. Trauma was caused by: direct crush with or without bone injury (n=23), burns (n=10), stripping (n=5), complications of open fractures (n=29). The free flaps were performed on day 0 (day of trauma) (n=7), on day 1 or 2 (n=5), from day 3 to 7 (n=12), and from day 8 to 31 (n=43). RESULTS: There were 19 complications: hematoma (n=2), infection (n=1), vascular problem (n=16), and 7 flaps were lost (10.4%). Logistic regression analysis demonstrated that the type of trauma and vascular complications were determinant factors predictive of failure. Conversely, the limb (upper versus lower), side, gender, age, or time from trauma to flap were not found to influence chances of success. DISCUSSION: Our series demonstrated that free flap repair performed in a trauma context for loss of soft tissues of the limbs is a relatively reliable surgical technique since the rate of success is similar to that reported for pediculated flaps. The usefulness of free flaps in the trauma setting is thus demonstrated, but the most appropriate modality remains to be determined. Many authors point out the importance of early cover to limit the risk of complications (osteitis, delayed bone healing). Others have not found this factor to be determinant. In everyday practice, emergency cover is not always possible and the question is whether a flap can be successful if performed late after the initial trauma. Our study demonstrates that the chances of success of a free flap are equivalent when performed early or late after trauma. CONCLUSION: Free flaps play an important role in achieving cover of tissue loss of the limbs. The type of trauma appeared to be the only factor predictive of failure.

Adolescent↗
PubMed2002

[Four bone versus capito-lunate limited carpal fusion. Report of 40 cases].

Fourty patients with limited carpal fusion have been retrospectively reviewed. The aim of this study was to compare the results of four bone fusions (30 wrists) versus capitolunate fusion (11 wrists). Follow-up averaged 30 months with a range of 15-96 months. Twelve patients presented SLAC-wrist (scapho-lunate advanced collapse) and fourteen with SNAC-wrist (sapho-non union advanced collapse). There were seven cases of primitive wrist arthritis, one mid-carpal instability, one sequella of Fenton's syndrome, one Preiser's disease and two Kienbock's disease. All 40 patients were evaluated by the same observer. In terms of range of motion, the capito-lunate fusion led to better results than the four bone fusions with a gain of 10 degrees in volar flexion and 12 degrees in radial deviation. Results in term of post operative pain are similar in the two groups of patients with 90% painless wrist in four bone fusion and 81% with capito-lunate fusion. Results for strength were equivalent. Radiological bone fusion was obtained within nine weeks. Absence of fusion was observed in two patients with capito-lunate fusion. Our result in terms of joint motion and strength are similar to those found in the literature. Correction or not of the DISI deformity during the procedure did not affect the results (on 19 patients). The Four bone fusion procedure is still a good treatment in SLAC or SNAC wrist. Capito-lunate fusion remains a good choice, despite the risk of non-fusion.

Adult↗
PubMed2002

[Rupture of the radial collateral ligament of the fifth metacarpopharyngeal joint. A case report with Stener effect].

We report a case of complete rupture of the radial collateral ligament of the fifth metacarpophalangeal joint. At surgical exploration, a Stener like lesion was identified in which the ruptured and of the ligament was trapped by the proximal portion of the extensor hood and sagittal band; thus reattachment to its original site (the base of proximal phalanx) was performed. Postoperative care consisted of protected active motion exercises which were begun immediately. An early functional recovery was obtained with full range of motion, normal joint stability and complete pain relief. The purpose of this study was to present an uncommon injury and to analyse the literature.

Adult↗
PubMed2001

Effect of exogenous lactate on rat glioma metabolism.

Glioma-bearing rats were infused intravenously with a solution containing either [3-(13)C]lactate or both glucose and [3-(13)C]lactate for 20 min or 1 hr. Perchloric acid extracts of healthy and tumoral brain tissues were prepared and analyzed by (13)C- and (1)H-observed (13)C-edited nuclear magnetic resonance (NMR) spectroscopy to determine (13)C-label incorporation into brain tissue and glioma metabolites. Moreover, (13)C enrichments in blood lactate and glucose were determined from (1)H-NMR spectra. In the nontumoral tissue, (13)C labeling of amino acids indicated that [3-(13)C]lactate entered the brain and was metabolized. There was no labeling difference between the contralateral and the ipsilateral hemispheres. Lactate metabolism appeared more specifically neuronal, in agreement with our previous results obtained with normal rat brain (Bouzier et al. [2000] J. Neurochem. 75:480-486). In the glioma tissue, comparison of Ala C3, Glu C4, and Gln C4 labeling indicated that the contributions of blood glutamine and tricarboxylic acid (TCA) cycle to glutamate labeling were about 80% and 20%, respectively, after 1 hr of [3-(13)C]lactate infusion. In contrast, these contributions were about 10% and 90%, respectively, when [1-(13)C]glucose was infused in the absence of lactate. This indicated a major effect of the exogenous lactate on glioma metabolism, which may be due to the following process: The high blood lactate level might hinder the drain of glycolytic lactate produced inside the glioma and thus generate a change in redox potential such that the tumor cells are unable to restore it with oxidative phosphorylation. Thereafter, the high NADH level might inhibit glycolysis and the TCA cycle, and glutamine could become the major carbon source for glutamate labeling.

Animals↗
PubMed2001

Use of osteocutaneous "double-barrel fibular flaps" in limb reconstruction: four clinical cases.

The use of a vascularized fibular transfer is a technique used for the reconstruction of large defects in long bones. A technical variation that consists of osteotomizing the transplant, giving two distinct segments, is adapted in the reconstruction of long bones with a large diameter, in particular, the femur or the proximal tibia. The results obtained using this technique in four clinical cases are presented here. The length of the bone defects was between 7.5 and 11 cm. There were two cases involving the tibia, one case the distal humerus, and one case the pelvis.

Adolescent↗
PubMed2001

Metabolism of [1-(13)C)glucose and [2-(13)C]acetate in the hypoxic rat brain..

The effects of hypoxia on the metabolism of the central nervous system were investigated in rats submitted to a low oxygen atmosphere (8% O(2); 92% N(2)). [1-(13)C]glucose and [2-(13)C]acetate were used as substrates, this latter being preferentially metabolized by glial cells. After 1-h substrate infusion, the incorporation of 13C in brain metabolites was determined by NMR spectroscopy. Under hypoxia, an important hyperglycemia was noted. As a consequence, when using labeled glucose, the specific enrichment of brain glucose C1 was lower (48.2+/-5.1%) than under normoxia (66.9+/-2.5%). However, relative to this specific enrichment, the (13)C incorporation in amino acids was increased under hypoxia. This suggested primarily a decreased exchange between blood and brain lactate. The glutamate C2/C4 enrichment ratio was higher under hypoxia (0.62+/-0.01) than normoxia (0.51+/-0.06), indicating a lower glutamate turnover relative to the neuronal TCA cycle activity. The glutamine C2/C4 enrichment ratio was also higher under hypoxia (0.87+/-0.07 instead of 0.65+/-0.11), indicating a new balance in the contributions of different carbon sources at the acetyl-CoA level. When using [2-(13)C]acetate as substrate, no difference in glutamine enrichment appeared under hypoxia, whereas a significant decrease in glutamate, aspartate, alanine and lactate enrichments was noted. This indicated a lower trafficking between astrocytes and neurons and a reduced tricarboxylic acid cycle intermediate recycling of pyruvate.

Acetates↗
PubMed2001

[The supramalleolar flap. Our experience in 35 cases].

The authors report 35 cases of use of the supramalleolar flap described by Masquelet et al. in 1988. In 27 cases, the arterial blood supply was in a mixed (anterograde and retrograde) fashion since the perforating branch of the peroneal artery was spared. In eight cases the arterial blood supply was in a retrograde fashion due to the location of the skin loss. As described by Valenti et al. In 1991, the authors recommend the use of a distal subcutaneous pedicled to avoid skin grafting over the tendons at the distal part of the lag. In main cases of anterograde blood supply the superficial peroneal nerve could be spread. In 33 cases the plastic result was assessed as satisfactory. The coverage of the weight-bearing portion of the heel was done two times with no satisfactory result. Coverage of the medial malleolus area, Achilles tendon and dorsal skin of the foot represent the main indications and the best results. Five times, a venous congestion was observed with three cases of partial necrosis of the flap. The use of a large subcutaneous pedicle did not always prevent such venous problems, though this technical aspect improves the vascular reliability of the flap. The main local alternative is the distal pedicled sural flap that needs to divide the sural nerve and not allows coverage as distal as the supramalleolar flap. Except the distal coverage of the foot, the indications of these previous both flaps are similar. In case of foot coverage, the medial plantar flap based on the lateral plantar vascular bundle, as described by Martin et al. in 1991, is the other one local alternative. Free flaps are indicated for extensive skin losses, or when a poor distal vascularity of the leg does not allow reliability of distal pedicled flaps.

Adolescent↗
PubMed2001

[Comparison between 1.5% lidocaine with adrenaline and 1.5% plain mepivacaine in axillary brachial plexus block].

OBJECTIVES: To evaluate the distribution of sensory blockade, the onset time and the duration of the axillary plexus block obtained after the administration of 40 mL of 1.5% lignocaine with adrenaline or 40 mL of plain 1.5% mepivacaine. STUDY DESIGN: Prospective, randomised, comparative, double blind study. PATIENTS AND METHODS: One hundred and fifty five patients undergoing hand surgery were randomised into two groups: in group L, 73 patients were given 1.5% lignocaine with 1/200,000 adrenaline and in group M, 82 patients received 1.5% mepivacaine. The entire volume was injected on the first evoked motor activity obtained for a current less than 0.5 mA. Sensory and motor block of each of the four major nerves of the hand and forearm were assessed using light touch and motor strength respectively. The block was considered complete when all nerves were anaesthetised (median, radial, musculocutaneous and ulnar). RESULTS: The percentage of complete sensitive blockade was 22% in group L and 24% in group M. Complete motor blockade was respectively 27% in group L and 40% in group M. The median time required to obtain a complete sensory blockade was 18 min for both group. The median time required to obtain a complete motor blockade was 17 min in-group L and 16 min in-group M. The duration of the sensory blockade was not different for both groups (i.e., 255 +/- 76 min versus 231 +/- 70 min in group L and M respectively. The duration of the motor blockade was longer in group L compared to group M (199 +/- 64 min versus 231 +/- 74 min respectively, p < 0.05). CONCLUSION: Following axillary plexus block, 1.5% mepivacaine improves neither the extension nor the duration of sensory blockade achieved by 1.5% lignocaine with adrenaline.

Anesthetics, Local↗
PubMed2001

[Rehabilitation protocols after repairs of zone 2 of the flexor tendon of the hand: presentation and indications].

We report the results of a retrospective study of 47 adult patients corresponding to 54 fingers, operated on in the emergency room at Nancy University Hospital between December 1996 and October 1998. These patients were managed using three different postoperative therapy protocols: passive mobilisation according to the Duran technique, active-passive mobilisation according to the Kleinert technique and immediate active mobilisation as described by Strickland. Patients were evaluated in three different ways; active range of movement obtained according to the Strickland scale, the "400 points" flexor function test and the delay in returning to work. Combining all three evaluations showed a 65% rate of satisfactory results, 22% fair and bad results and 13% ruptures. Analysis according to the re-education technique showed a strong superiority of the Strickland protocol. This now needs to be confirmed by a more extensive prospective study. Delay before return to work is not affected by the type or re-education technique chosen, but side-effects are less frequent with the Strickland method. A result in terms of range of active movement alone did not fully evaluate the result of a flexor tendon repair: functional testing was better at this end and the global "400" points test score gave more useful information than each of its component tests taken individually (Purdue pegboard, Minnesota test, Box and Block). Functional testing seemed more helpful in guiding the medical team in its treatment strategy.

Adult↗
PubMed2001

A comparative clinical and electromyographic study of median and ulnar nerve injuries at the wrist in children and adults.

The outcome of 38 median and ulnar nerve injuries at the wrist in 15 adults and 15 children were studied with a follow-up of at least 1 year. Each patient was assessed clinically and with nerve conduction studies. The results confirm a markedly superior sensory recovery in children. However the children had persistent motor deficiencies. This difference in the clinical results of adults and children was not reflected in the nerve conduction results which were similar in both groups.

Adolescent↗
PubMed2001

A comparison between clinical results and electromyographic analysis after median or ulnar nerve injuries in children's wrists.

The purpose of this study was to analyze the results of median or ulnar nerve transections to the wrist in 14 children between 1994 and 1999. On sustaining their injury, all patients underwent treatment at the University Hospital of Nancy. They were all seen afterward for clinical and electromyographic evaluations. The clinical examination was mainly to judge the quality of sensory recovery, using the Weber and Dellon tests, as well as motor recovery. Electromyographic examination of the motor and sensory tissues was carried out systematically on each patient. The analysis of these results highlights discordance between the quality of the clinical results and nerve regrowth identified via electromyography. Good nerve regrowth does not necessarily mean a good sensory recovery.

Adolescent↗