Epidermolysis bullosa: radiological patterns in childhood.
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Child↗
Biomedical subjects
M Merle
Publications and source records attributed to M Merle.
Assessment of the clinical value of urinary trypsin inhibitory activity in elderly people.
To assess the clinical value of urinary trypsin inhibitory activity (UTIA) in elderly people, a prospective study was carried out over 4 months in our internal medicine department. Two hundred and forty-three patients of more than 60 years of age were included. A positive correlation was observed between UTIA and serum creatinine (p < 10(-3)). In the population with serum creatinine of less than 133 mumol/l (200 patients), UTIA was independent of age, sex and serum creatinine. UTIA was compared with seven serum inflammatory proteins titrated on patient admission. The principal interest of UTIA determination appeared in bacterial infections. UTIA was significantly increased in this group (p < 10(-4)). However, a positive correlation was proved only with C-reactive protein (CRP) (p = 9 x 10(-4)). Nevertheless, CRP appeared to be the best marker of bacterial infectious diseases after receiver operating characteristic curves analysis.
Acute-Phase Proteins↗
Pre-steady state study of beta-adrenergic and purinergic receptor interaction in C6 cell membranes: undelayed balance between positive and negative coupling to adenylyl cyclase.
Interactions between beta-adrenergic and ADP purinergic receptors in C6 glioma cell membrane preparations were investigated under steady state and then pre-steady state conditions of adenylyl cyclase (EC 4.6.1.1) activity, in order to determine how fast the second receptor antagonizes the transduction mechanism of the first. Cell membranes were washed to deplete them as thoroughly as possible of low molecular weight compounds, especially ATP and ADP, and to ensure better control of both substrate and agonist nucleotide concentrations. ATP concentrations were kept constant with the use of an ATP-regenerating system; the C6 cell line exhibited very active ectonucleotidases. The purinergic agonist ADP was replaced by its nonhydrolyzable congener adenosine 5'-O-(2-thio)diphosphate (ADP beta S), which was demonstrated, like ADP, to inhibit isoproterenol-stimulated adenylyl cyclase activity in intact cells (IC50 for ADP, 0.5 +/- 0.1 microM; IC50 for ADP beta S, 25 +/- 2 microM) and in membrane preparations (IC50 for ADP beta S, 79 +/- 20 microM). In the case of membrane preparations, ADP beta S did not compete with ATP, the substrate of the cyclase-catalyzed reaction, and behaved apparently as a non-competitive inhibitor of the enzyme. The pre-steady state kinetics of isoproterenol-stimulated adenylyl cyclase activity measured with a pulsed quenched-flow apparatus have previously been shown to include two steps, the first very rapid (taking place within 1-2 sec) and giving rise to a burst of cAMP synthesis and the second much slower and corresponding to the steady state reaction. ADP beta S inhibited the occurrence of both steps with comparable IC50 values (mean value, 55 +/- 20 microM). In the presence of increasing concentrations of the purinergic receptor agonist, the time constant of the exponential burst reaction was not affected, but its amplitude progressively decreased to zero. These results showed that the extinction of the beta receptor cAMP response by the purinergic ADP receptor occurred within the dead-time of the pulsed quenched-flow apparatus, which was 50 msec. Such a rapid inhibition of cAMP production excluded modulation of isoproterenol-stimulated adenylyl cyclase activity by the ADP receptor by a pathway other than its direct negative coupling to the cyclase via a Gi protein. In this respect, the P2 purinergic ADP receptor of the C6 glioma cell line appears comparable to the P2t receptor of platelets.
Adenosine Diphosphate↗
[Experimental study of the trophic effects of reinnervation of pedicled muscle flaps].
Any transplanted muscle flap undergoes atrophy to an extent depending mainly on its innervation. Other factors such as the tension at rest and the duration of ischemia play a secondary role. An experimental study was carried out in rats to quantitatively assess the extent of atrophy according to the mode of transplant reinnervation. The gracilis muscle was used as an experimental model of pedicled flap after verifying the axial nature of its vasculature. Results were assessed after three months from a histological point of view and in terms of postoperative weight in four different groups of 13 rats. The first three groups reproduced situation encountered in clinic: intact nerve, sutured nerve, resected nerve. A graft sensory neurotization technique was implemented in the fourth group by diverting a neighboring sensory nerve. The best trophic results were obtained when the motor nerve remained continuous. The sensory neurotization technique did not significantly influence the trophic evolution after three months.
Animals↗
[Use of intraosseous resorbable implants. Experimental evaluation and clinical applications in hand surgery].
The authors report about their experience with the use of absorbable intramedullary nails. After an experimental phase comprising mechanical tests and animal experiments in rabbits, the first clinical applications were for 24 cases of metacarpophalangeal arthrodesis of the thumb. For this indication, bone stabilization was achieved by associating an absorbable intramedullary nail and a metallic oblique pin. Evaluation in animals included, on one hand, a magnetic resonance imaging study, and on the other hand a histological study after the staggered sacrifice of the animals. This histological study was performed on non-decalcified bones by inclusion in methyl methacrylate resin. The mechanical results confirmed the appropriate resistance of these materials for use in the digital skeleton. The histological assessment showed that absorption begins around the 4th month by progressive fragmentation of the material and lasts over 3 years. The encouraging clinical experience and some obstacles encountered during its implementation hav led to two modifications: on one hand, a larger nail was used, on the other hand an absorbable oblique pin was developed, thus ensuring a fully absorbable osteosynthesis.
Adult↗
Primary nerve repair in the upper limb. Our preferred methods: theory and practical applications.
After years of controversy, it is now generally agreed that primary nerve repair by end-to-end coaptation, whenever feasible, yields better results than secondary procedures. We reviewed the theoretic basis of current methods of repair and described our preferred techniques and indications.
Arm↗
[The significance of arteriosclerosis in CT studies of the thorax and abdomen. Frequency and correlation with risk factors and with cardiovascular diseases].
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Abdomen↗
A mammalian tryptophanyl-tRNA synthetase shows little homology to prokaryotic synthetases but near identity with mammalian peptide chain release factor.
Determination of the amino acid sequence of beef pancreas tryptophanyl-tRNA synthetase was undertaken through both cDNA and direct peptide sequencing. A full-length cDNA clone containing a 475 amino acid open reading frame was obtained. The molecular mass of the corresponding peptide chain, 53,728 Da, was in agreement with that of beef tryptophanyl-tRNA synthetase, as determined by physicochemical methods (54 kDa). Expression of this clone in Escherichia coli led to tryptophanyl-tRNA synthetase activity in cell extracts. The open reading frame included two sequences analogous to the consensus sequences, HIGH and KMSKS, found in class I aminoacyl-tRNA synthetases. The homology with prokaryotic and yeast mitochondrial tryptophanyl-tRNA synthetases was low and was limited to the regions of the consensus sequences. However, a 90% homology was observed with the recently described rabbit peptide chain release factor (eRF) [Lee et al. (1990) Proc. Natl. Acad. Sci. 87, 3508-3512]. Such a strong homology may reveal a new group of genes deriving from a common ancestor, the products of which could be involved in tRNA aminoacylation (tryptophanyl-tRNA synthetase) or translation termination (eRF).
Amino Acid Sequence↗
Phosphorus-31 nuclear magnetic resonance of C6 glioma cells and rat astrocytes. Evidence for a modification of the longitudinal relaxation time of ATP and Pi during glucose starvation.
31P-NMR spectroscopy has been used to study the energy metabolism and the NMR visibility of ATP and intracellular Pi of the C6 glioma cell line and rat astrocyte grown on microcarrier beads with the following results. 1. In vivo NMR spectra of C6 glioma cells and rat astrocytes indicate that these cells were able to maintain their level of ATP resonances during a long anoxic period (more than an hour). Both cell types were sensitive to ischemia which induced a loss of ATP resonances within 40 min. Glucose starvation induced by 40% decrease in ATP resonances correlated to a 50% increase in the intensity of the Pi signal. These changes corresponded to a new steady state which could be reversed by reperfusing the cells with a glucose-containing medium. 2. In contrast to in vivo data, 31P-NMR analyses of perchloric acid extracts of cells incubated in a glucose-free medium showed that their ATP and Pi contents were unchanged during starvation. The changes of NMR visibility of the metabolites in living C6 cells were correlated to modifications of their macroscopic longitudinal relaxation times, evolving from 0.30 +/- 0.08 s and 6.6 +/- 1.5 s in the presence of glucose to 0.68 +/- 0.26 s and 3.2 +/- 0.9 s in the absence of glucose for ATP and Pi, respectively. The changes of the NMR detectability of ATP and Pi indicate that changes in their microenvironment occur during glucose starvation, suggesting the existence of different pools of these metabolites within the cells. 3. Under various experimental conditions, i.e. anoxia, ischemia and glucose starvation, rat astrocytes in primary culture showed a very similar behavior to that of C6 cells, suggesting a similar adaptability to the nature of the energy supply for both the normal and the malignant cell.
Adenosine Triphosphate↗
Human nerve xenografting in nude mouse: experimental study of graft revascularization.
In the nude mouse, the congenital absence of T lymphocytes makes it possible to implant human nerve grafts without rejection or iatrogenic modifications (by immunosuppression) of human and murine tissues. Medial antebrachial cutaneous nerves were harvested from human cadavers 1-18 hours after death. These nerve grafts were implanted using different techniques in nude mice. All the grafts were macroscopically and microscopically revascularized 3 days after implantation. The modifications in time of this vascularization could be studied with precision through the use of repeated biopsies. The absence of human blood group antigens on the neovessel endothelium suggested a murine origin for angiogenesis. In situ DNA hybridizations with human and mouse DNA confirmed this origin. The topography of the revascularization (maximal in the perineurium and endoneurium) and the almost complete absence of human cells other than Schwann cells in the grafts at the peak of angiogenesis (26 days after grafting) suggested that Schwann cells had a determining role in graft vascularization. The irradiation of the nerve grafts with a dose of 30 grays before implantation did not modify significantly their histologic appearance compared to the control group, whereas an irradiation of 60 grays led to massive lesions. The neurotization of murine axons led to chimerical structures of normal histologic appearance, with vascularization similar to that observed in nonneurotized nerves. Through chimerism (human Schwann cells, murine vessels and axons) this model makes it possible to dissociate the respective role of the host and of the nerve graft in angiogenesis and suggests the existence of growth factors produced by the human Schwann cells.
Adult↗
Dorsal metacarpal reverse flaps. Anatomical basis and clinical application.
The presence of distal intermetacarpal anastomoses between dorsal and palmar vascular networks makes it possible to raise distally-based cutaneous island flaps oriented along the axis of the dorsal metacarpal arteries. These flaps receive a reverse-flow vascularisation. Distal intermetacarpal anastomoses were found consistently in 35 hands from adult cadavers. The exact location of these anastomoses varied with the course of the dorsal metacarpal artery. Thus, island flaps can be raised consistently from the dorsal aspect of the hand and rotated around a distal intermetacarpal pivot. These flaps are suitable for covering the dorsal aspect of the proximal phalanx and the proximal interphalangeal joint.
Adolescent↗
Vascularised nerve grafts.
Since Taylor (1976) successfully performed the first vascularised free nerve graft, experimental and clinical data have not provided conclusive support for the superiority of this method of repairing loss of nerve substance. Experimental work yields conflicting results. Histologic results are in favour of vascularised grafts but non-vascularised fascicular grafts placed in a healthy bed recover sufficient neovascularisation within a short period of time (four to six days). In the field of brachial plexus repair, vascularised grafts give consistent results. However, if thrombosis of the anastomoses occurs, the grafts fail completely. In our experience, vascularised nerve grafts used for repairing digital nerves and arteries, have a high rate of thrombosis. There are few potential donor sites. A nerve graft cannot be considered to be physiologically vascularised if it relies only on an artery or on an arterialised vein. Given the present state of immunosuppressant treatments, vascularised allografts are not yet appropriate. Therefore, vascularised nerve grafts have limited applications. In general it is preferable to repair the tissue bed so as to promote revascularisation of conventional nerve grafts.
Adult↗
How exact should nerve stump coaptation be? A new answer given by "cell surgery".
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Animals↗
Applying "cell surgery" to nerve repair: a preliminary report on the first ten human cases.
We have applied a new technique of nerve repair, based on the principles of "cell surgery", to ten nerve lesions of the upper limb. Eight lesions were recent, five to 36 hours; they were divisions of the ulnar nerve (1), median nerve (2), sensory radial nerve (1), palmar and digital nerves (4). One lesion was 15 days old (median nerve). One eight-month-old loss of 4.5 cm. of the median nerve was grafted. In nine out of the ten cases, the short-term results were encouraging. Poor local conditions (fibrosis of the nerve bed) or poor general health (chronic alcoholism) had no adverse influence on the results. In the remaining case, the protocol was not followed in its entirety: it was not possible to crystallise properly the nerve, and trimming was done with scissors in the conventional way instead of smoothly trimming the solidified tips. The functional result in this case is a failure. These preliminary results seem to indicate that correctly applying the technique in its entirety may be more important than local conditions. We think that this technique can be applied to the majority of nerve lesions. The appropriate equipment is absolutely necessary in order to apply the method.
Adolescent↗
Magnetic resonance spectroscopy and metabolism. Applications of proton and 13C NMR to the study of glutamate metabolism in cultured glial cells and human brain in vivo.
Nuclear magnetic resonance (NMR) spectroscopy was used to study the metabolism of cells from the central nervous system both in vitro on perchloric acid extracts obtained either from cultured tumoral cells (C6 rat glioma) or rat astrocytes in primary culture, and in vivo within the human brain. Analysis of carbon 13 NMR spectra of perchloric acid extracts prepared from cultured cells in the presence of NMR [1-13C] glucose as substrate allowed determination of the glutamate and glutamine enrichments in both normal and tumoral cells. Preliminary results indicated large changes in the metabolism of these amino acids (and also of aspartate and alanine) in the C6 cell as compared to its normal counterpart. Localized proton NMR spectra of the human brain in vivo were obtained at 1.5 T, in order to evaluate the content of various metabolites, including glutamate, in peritumoral edema from a selected volume of 2 x 2 x 2 cm3. N-acetyl aspartate, glutamate, phosphocreatine, creatine, choline and inositol derivative resonances were observed in 15 min spectra. N-acetyl-aspartate was found to be at a lower level in contrast to glutamate which was detected at a higher level in the injured area as compared to the contralateral unaffected side.
Animals↗
A critical study of thumb reconstruction by second toe transfer.
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Adult↗
Pedicled or free flap transfer of the gracilis muscle in rats.
The vascularization of the gracilis muscle of the rat is oriented mainly along the longitudinal axis of the muscle and arises from a muscular artery originating in the femoral artery. Transillumination study of the muscle after vascular injection with Microfil demonstrated this anatomic disposition. The gracilis muscle was used either as a pedicled transfer or as a free flap with anastomoses placed on the femoral pedicle. Average weight of the muscle before transfer was 429 mg. The cutaneous area of the muscular artery could be used to monitor the flap or to accomplish a composite myocutaneous transfer. This muscle flap is a versatile and reliable model for experimental study of muscle transfer in rats.
Animals↗
[Arthrodesis of the wrist in manual workers. Apropos of 36 cases].
We present a review of 36 patients with final radiocarpal arthrodesis done between 1976 and 1987. The series was homogeneous: patients were about 40 years old and lesions were work-related. The most frequent reason for the arthrodesis was fracture of scaphoid bone, followed by Kienbock's disease complex trauma of carpus, severe carpal sprain, and articular fracture of the distal fourth of radial bone. Thirty-one arthrodeses were done by screwed-on iliac graft, 5 by nailing following Mannerfelt technique. The two main factors in functional results were pain and loss of strength. The latter averaged 41 per cent of that of the normal side, and only 8 wrists were completely free of pain. Indications for final radio-carpal arthrodesis are discussed, taking into account the poor functional results and their repercussions on social and professional life of the patient.
Accidents, Occupational↗