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Biomedical subjects

D S McDonald

Publications and source records attributed to D S McDonald.

8 recordsLinked to original sources

An injectable nerve regeneration chamber for studies of unstable soluble growth factors.

Modern surgical techniques cannot guarantee functional recovery following peripheral nerve injuries. Research into factors that may influence nerve regeneration has therefore assumed a prominent potential therapeutic role. We report here on the development of an approach to allow for direct manipulation of the microenvironment of regenerating peripheral nerve axons. We show that solutions can be delivered directly to this local milieu in vivo and that such a delivery can be performed multiple times over an extended period, potentially facilitating studies of multiple molecular players that act locally. We also demonstrate that the bundle of regenerated axons are amenable to morphological analysis by 21 days and that the injection system remains patent for at least 21 days.

Animals↗

Injection pain with propofol. Reduction with aspiration of blood.

A randomised, controlled, single-blind study was performed on 100 patients to investigate a new method of reducing pain on propofol injection. Aspiration of 2 ml of the patient's blood into a syringe of propofol immediately before injection was compared with the addition of lignocaine 20 mg or normal saline 2 ml to the propofol before injection. The addition of blood was significantly more effective in reducing pain on injection than the addition of saline (p < 0.001), but was not significantly more effective than the addition of lignocaine.

Adult↗

Mutagenicity of metal salts in the L5178Y mouse lymphoma assay.

Eleven metals were examined for their potential to induce forward mutations at the thymidine kinase locus in L5178Y mouse lymphoma cells. The materials tested included AlCl3, CdSO4, HgCl2, K2CrO4, K2Cr2O7, MgCl2, MnCl2, NaAsO2, Na2HAsO4, NaCl, and Pb(NO3)2. Strong positive responses at survivals greater than 10% were observed with CdSO4, K2CrO4, K2Cr2O7, and MnCl2. Weak positive responses, yielding 2- to 3-fold increases in mutation frequency above the solvent control at greater than 10% survival, were seen with HgCl2, NaAsO2, Na2HAsO4, and Pb(NO3)2. Negative responses were obtained with MgCl2, NaCl, and AlCl3.

Animals↗