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Biomedical subjects

J Silk

Publications and source records attributed to J Silk.

At least 19 recordsLinked to original sources
PubMed2001

A new approach to the management of pretibial lacerations.

This paper describes a technique for the management of pretibial lacerations by deep reinforced suturing through steristrips, which are applied parallel to the wound edges. This is carried out under local anaesthesia and followed by application of gentle localised compression dressing. Typical victims of pretibial lacerations are the elderly and patients on long-term systemic steroid therapy. This suturing technique, which was used on both flap and linear lacerations, obliterates the dead space in the wound and prevents tearing of the thin, fragile skin of these patients. The dressing technique used, has a great advantage over the toes to knee pressure dressing currently used for such lacerations, because it frees the foot of bandaging and allows the patients (especially the elderly with decreased mobility) to wear their normal footwear immediately post-operatively and to maintain their normal mobility. In the total sample of 147 patients treated by this method, the average healing time was 26 days for 112 patients with flap lacerations, and 16 days for the remaining 35 patients with linear lacerations. This is significantly shorter than that reported in the medical literature using both non-operative methods and simple suturing. Moreover, none of these patients required skin grafting or hospitalisation (except for social reasons).

Adult↗
PubMed2001

Effect of alpha subunit on allosteric modulation of ion channel function in stably expressed human recombinant gamma-aminobutyric acid(A) receptors determined using (36)Cl ion flux.

Inhibitory gamma-aminobutyric acid (GABA)(A) receptors are subject to modulation at a variety of allosteric sites, with pharmacology dependent on receptor subunit combination. The influence of different alpha subunits in combination with beta3gamma2s was examined in stably expressed human recombinant GABA(A) receptors by measuring (36)Cl influx through the ion channel pore. Muscimol and GABA exhibited similar maximal efficacy at each receptor subtype, although muscimol was more potent, with responses blocked by picrotoxin and bicuculline. Receptors containing the alpha3 subunit exhibited slightly lower potency. The comparative pharmacology of a range of benzodiazepine site ligands was examined, revealing a range of intrinsic efficacies at different receptor subtypes. Of the diazepam-sensitive GABA(A) receptors (alpha1, alpha2, alpha3, alpha5), alpha5 showed the most divergence, being discriminated by zolpidem in terms of very low affinity, and CL218,872 and CGS9895 with different efficacies. Benzodiazepine potentiation at alpha3beta3gamma2s with nonselective agonist chlordiazepoxide was greater than at alpha1, alpha2, or alpha5 (P < 0.001). The presence of an alpha4 subunit conferred a unique pharmacological profile. The partial agonist bretazenil was the most efficacious benzodiazepine, despite lower alpha4 affinity, and FG8205 displayed similar efficacy. Most striking were the lack of affinity/efficacy for classical benzodiazepines and the relatively high efficacy of Ro15-1788 (53 +/- 12%), CGS8216 (56 +/- 6%), CGS9895 (65 +/- 6%), and the weak partial inverse agonist Ro15-4513 (87 +/- 5%). Each receptor subtype was modulated by pentobarbital, loreclezole, and 5alpha-pregnan-3alpha-ol-20-one, but the type of alpha subunit influenced the level of potentiation. The maximal pentobarbital response was significantly greater at alpha4beta3gamma2s (226 +/- 10% increase in the EC(20) response to GABA) than any other modulator. The rank order of potentiation for pregnanolone was alpha5 > alpha2 > alpha3 = alpha4 > alpha1, for loreclezole alpha1 = alpha2 = alpha3 > alpha5 > alpha4, and for pentobarbital alpha4 = alpha5 = alpha2 > alpha1 = alpha3.

Allosteric Regulation↗
PubMed1998

Extracting primordial density fluctuations

The combination of detections of anisotropy in cosmic microwave background radiation and observations of the large-scale distribution of galaxies probes the primordial density fluctuations of the universe on spatial scales varying by three orders of magnitude. These data are found to be inconsistent with the predictions of several popular cosmological models. Agreement between the data and the cold + hot dark matter model, however, suggests that a significant fraction of the matter in the universe may consist of massive neutrinos.

Journal Article↗