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Biomedical subjects

M Merle

Publications and source records attributed to M Merle.

At least 199 records · Page 11Linked to original sources
PubMed1983

[An unusual form of macrodactylia].

The authors report a rare case of macrodactyly of the thumb in a 36 year old woman. The hypertrophy predominates on the epiphyseal tissue with complete ankylosis of the trapezo-metacarpal metacarpo-phalangeal, and interphalangeal joints in an abnormal position. This results in total functional incapacity of the thumb. The cosmetic and psychological impact are important to consider. Treatment consisted of two operative procedures. First a silastic implant for the trapezo-metacarpal joint and an arthrodesis of the metacarpophalangeal joint in a normal position was done. Three months later, the volume of the thumb was reduced by a longitudinal bone resection. The functional and cosmetic result is assessed. The literature is reviewed and the different modes of treatment utilized in such a malformation are presented. A relation between macrodactyly and lipomatous macrodystrophy is considered.

Adult↗
PubMed1983

On the mechanism of tRNATrp aminoacylation catalysed by beef tryptophanyl-tRNA synthetase using presteady-state kinetics.

The dimeric tryptophanyl-tRNA synthetase from beef pancreas has been found to activate 2 tryptophans/mol enzyme [Eur. J. Biochem. (1982) 128, 389-398]. By using quenched-flow and stopped-flow methods under presteady-state conditions, we show that only one enzyme subunit operates at a time in the aminoacylation of tRNATrp and that the transfer reaction is not the rate-limiting step in the overall aminoacylation process.

Amino Acyl-tRNA Synthetases↗
PubMed1983

Fascicular nerve graft using an empty perineurial tube: an experimental study in the rabbit.

An experimental model of a free, empty perineurial tube for use as a nerve graft is presented as an alternative to existing methods. The technique is described and the model compared with conventional nerve graft in the sciatic nerve of a rabbit. Results are evaluated with EMG studies, angiography, and histology. The experimental model compared favorably with the standard graft. Further avenues of investigation and clinical use are suggested.

Angiography↗
PubMed1983

Systemization of the vascularization of the ulnar nerve in its upper arm.

Vascularized free nerve grafts make possible the repair of extensive defects of large nerve trunks. Since the original observations of Taylor and Ham in 1976 many cases have been published. The ulnar nerve in the upper arm in most cases has a simple arteriovenous pedicle the anatomy of which has been precisely defined by cadaver dissections and intravascular injections. The arterial supply, 47 times out of 50, is the proximal ulnar collateral and 2 times the distal collateral ulnar artery. It takes its origin from the medial side of the brachial artery in the upper or middle third of the arm. Its external diameter is on the average 1.8 mm at its origin. The accompanying vein enters a brachial vein 2 to 3 cm below the origin of the artery. The removal of the graft is done through a straight incision on the inner aspect of the arm. The brachial artery is dissected from above downward and its medial branches noted. The nerve and its arteriovenous pedicle are separated in a block along with adjacent cellular tissue by dissection from below upwards. The average length of the pedicle thus produced is 13 cm, but a much longer section of the nerve can certainly be taken. A case report illustrates the procedure.

Adult↗
PubMed1982

Kinetic anticooperativity in pre-steady-state formation of tryptophanyl adenylate by tryptophanyl-tRNA synthetase from beef pancreas. A consequence of the tryptophan anticooperative binding.

The kinetics of formation of tryptophanyl adenylate by tryptophanyl-tRNA synthetase from beef pancreas has been followed by stopped-flow, using the quenching of fluorescence of the enzyme linked to the amino acid activation reaction. Both subunits of this alpha 2 enzyme catalyze the adenylate formation. At saturation with substrates the rate constant of the activation reaction is the same for both subunits. The same behaviour is observed for the pyrophosphorolysis reaction. Both subunits exhibit the same affinity for ATP-Mg in the forward reaction and the same affinity for magnesium pyrophosphate in the backward reaction. On the contrary the formation of tryptophanyl adenylate follows biphasic kinetics when tryptophan concentration is much below saturation. This is independent of ATP-Mg concentration and is the consequence of different affinities of the two subunits for tryptophan as already observed by Graves et al. (1979, Eur. J. Biochem. 96, 509-518) in equilibrium dialysis experiments. A monoadenylate-enzyme complex on one subunit has been prepared. This complex made possible the study of the formation of the second adenylate on the other subunit. The formation of this second adenylate followed first-order kinetics at all ATP-Mg and tryptophan concentrations. The tryptophan concentration dependence of the rate of formation of this second adenylate leads to a Michaelis constant close to the dissociation constant of the low affinity tryptophan site of the enzyme. No isomerization step could be evidenced. The experiments were carried out under two conditions corresponding to those used by Merault et al. (1978. Eur. J. Biochem. 87, 541-550) in the steady state of the tRNATrp aminoacylation reaction (10 mM total magnesium in 100 mM KCl and 1 mM free magnesium ions, both at pH 8.0.25 C). No great difference either in the mechanism or in the dissociation and rate constants was observed but an inhibitory effect of KCl. It is concluded that the enzyme is symmetrical as far as the ATP-Mg and the magnesium pyrophosphate sites are concerned and that the rate of the activation reaction reflects the anticooperative occupancy of the tryptophan sites carried by the two subunits.

Adenosine Monophosphate↗
PubMed1982

[Subcutaneous angioma of the hand].

The authors describe the specific features of hemangiomas of the hand in adults (three cases). The clinical syndrome is described. The main examination is by arteriography of the hand which shows three principal aspects: the vascular topography; the volume of the tumors; the extension of the neighbouring tissue. The treatment is analysed: surgical exeresis; in some cases, microvascular transplants are necessary (especially for the distal reconstruction of a finger); embolization is normally avoided because of the risk of necrosis of the finger.

Adult↗
PubMed1982

[Prosthetic replacement of the semilunar bone].

Twenty-two protheses of the lunate were implanted in the osteonecrosis stage III described by Decoulx. The authors chose palmar approach to release the median nerve in the carpal tunnel. A dorsal incision is sometimes necessary to fix taut the dorsal capsular ligament. The wrist is immobilised for six weeks. The dislocation (5 cases) is the complication the most to be feared and comes from: a weakness of the capsular ligament system, a badly fithing implant, insufficient immobolisation. This implant decreases the pain and improves the mobility of the wrist but the grasp remains poor (50% operated cases give excellent or good results). The indications of these implants demand serious discussion for manual workers (more than 30% of these operated cases had to change job).

Adolescent↗
PubMed1982

[An unusual form of macrodactyly].

The authors report a rare case of macrodactyly of the thumb in a 36 year old woman. The hypertrophy predominates on the epiphyseal tissue with complete ankylosis of the trapezo-metacarpal joints. The metacarpo-phalangeal joint and interphalangeal joints in an abnormal position. This results total functional incapacity of the thumb. The cosmetic and psychological impact are important to consider. Treatment consisted of two operative procedures. First a silastic implant for the trapezo-metacarpal joint and an arthrodesis of the metacarpophalangeal joint in a normal position was done. Three months later, the volume of the thumb was reduced by a longitudinal bone resection. The functional and cosmetic result are being assessed. The literature is reviewed and the different modes of treatment utilised in such a malformation is presented. A relation between macrodactyly and lipomatous macrodystrophy is considered.

Adult↗
PubMed1982

[The reversed de-epithelialized flap].

The reversed deepithelialized flap was used by Clodius for the lower limb and Pakian was the first to report on the use of this procedure in the hand. In the operation a classical cross-finger is deepithelialized and turned over on to an adjacent finger. The dermal part comes in contact with the exposed structures of the defect to be covered. This technique increases the indications for the cross-finger flap to many cases, where the classical flap is not possible.

Finger Injuries↗
PubMed1982

[Malunions of the metacarpals and phalanges. Results of surgical treatment].

The authors have made an analysis of the results obtained after surgical correction of 30 malunited metacarpals and phalanges. Nine involved joints, but the remainder did not. In 25 cases, there was limited movement associated with the malunion. The surgical devices were specially designed for surgical treatment and the technique employed is described. It is concluded that the correction of malunion needs to be made but that this alone is not sufficient to obtain a satisfactory result. The effectiveness of added tenolysis, arthrolysis, post-operative bracing and rehabilitation is even more important. The indications for treatment are given according to the level and location of the malunion.

Adolescent↗
PubMed1981

[Transplantation of the second toe in the reconstruction of fingers (author's transl)].

Transplantation of the second toe to replace a finger has been suggested more recently than has transplantation of the great toe to replace the thumb. The technique is described in detail. There is no plantar skin incision in the foot. The arterial suture is made at the level of the digital artery. Two toes can be transplanted when several fingers are missing. 11 cases have been operated on and the results analysed. In all cases, pinch grip between the thumb and the transplanted finger was made possible.

Amputation, Traumatic↗