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Biomedical subjects

M C Lynch

Publications and source records attributed to M C Lynch.

29 records · Page 2Linked to original sources
PubMed1987

Periosteal division and longitudinal growth in the tibia of the rat.

Growth at the proximal tibial epiphyseal plate of the rat has been measured following three different growth-stimulating procedures. These were proximal periosteal release, distal periosteal release and full periosteal stripping of the diaphysis. A new radiographic method using a photographic technique has made it possible to take accurate measurements of the rate of long-bone growth in small experimental animals. From the results of this animal series we conclude that proximal tibial periosteal division is likely to be the most effective of the three procedures when used to correct leg-length discrepancy in the growing child.

Animals↗
PubMed1986

Percutaneous accessory collateral ligament release in the treatment of proximal interphalangeal joint flexion contracture.

A percutaneous release or capsulo-ligamentous proximal interphalangeal joint contracture is described, the indications are outlined and the advantage over open releases are discussed. The results of a small pilot study are reported which we feel are comparable to the results of open techniques. The procedure in itself, however, merely allows operative correction to be achieved. Its maintenance depends upon a stringent post-operative rehabilitation regime.

Adult↗
PubMed1986

Facet joint injection for low back pain. A clinical study.

Therapeutic injection of facet joints is now widely practised, but British experience has been infrequently reported. We studied the results of injecting facet joints with a corticosteroid preparation in 50 patients suffering from the "facet syndrome". Our series included a number of extra-articular injections and these "failed injections" provide a useful control group. Results indicate that only intra-articular injections are effective; certainty of joint penetration can be ensured only by the routine use of joint arthrography.

Adult↗
PubMed1975

Catalytic and thermodynamic properties of the urocanate hydratase reaction.

Urocanate hydratase (4-imidazolone-5-propionate hydro-lyase, EC 4.2.1.49) isolated from Pseudomonas putida contains covalently bound alpha-ketobutyrate as its cofactor. In the process of examining the mechanism by which alpha-ketobutyrate serves in this capacity, various thermodynamic parameters and temperature effects on urocanate hydratase activity were determined. As the equilibrium constant at 15 degrees C for imidazooone propionate formation from urocanate is approximately 69, regardless of whether urocanic acid or chemically synthesized imidazolone propionate is used as the initial substrate, it is concluded that the reaction is freely reversible. DeltaG degrees ', deltaH degrees ' and deltaS degrees ' were --2.5 kcal/mole, +5.2 kcal/mole and +26 cal/deg mole, respectively. Measurement of first-order reaction rates at various temperatures, in order to calculate the Arrhenius activation energy, showed a sharp break in the Arrhenius plot at 29 degrees C. Further examination of this phenomenon by determining s20,w values of urocanate hydratase as a function of temperature revealed a dramatic change at 31 degrees C. Since the enzyme in both experiments reverts to its original state when the temperature is lowered back below the transition point, it is proposed that urocanate hydratase undergoes a reversible conformational change or partial dissociation which affects its catalytic properties in the range of 29--31 degrees C.

Binding Sites↗