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D M Lake

Publications and source records attributed to D M Lake.

5 recordsLinked to original sources
PubMed1985

Determination of catecholamines in tissue and body fluids using microbore HPLC with amperometric detection.

Performance of microbore reverse phase HPLC coupled with amperometric detection is detailed for the analysis of catecholamines in small tissue samples and human blood plasma and cerebrospinal fluid. Extraction procedures for pre-concentration and clean-up of these samples are described. Marked signal enhancement is observed due to the smaller column volume as well as the increased coulometric yield which results from the lower flow rates used with this technique. Detection limits of 0.2 to 0.5 picograms are obtained allowing analysis of catecholamines in extremely small tissue samples or small volumes of cerebrospinal fluid or plasma.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1985

An improved technique for extracting catecholamines from body fluids.

This paper describes a technique for selectively extracting catecholamines from body fluids prior to quantification by high-performance liquid chromatography with electrochemical detection. The technique is a two-stage process, the first stage involves the extraction of cations from the sample whilst the second stage is a liquid-liquid extraction involving the complexation of the cationic catecholamines with diphenylborate. This technique provides a very specific extraction procedure which results in chromatograms with no interfering compounds, and gives absolute recoveries of 70-80% for noradrenaline (NA), adrenaline (A) and dihydroxybenzylamine (internal standard), with similar relative recoveries of the 3 compounds. The intra-assay coefficients of variation for the measurement of catecholamines in venous plasma taken from resting subjects, are 8-9% for both NA and A, whilst the inter-assay values are 8% for NA and 20% for A.

Aluminum Oxide↗
PubMed1982

Circumstances influencing umbilical-cord plasma catecholamines at delivery.

Blood gases and plasma catecholamines were measured in umbilical arterial and venous blood samples after delivery. In all cases umbilical arterial noradrenaline concentrations were higher than venous levels. The lowest concentrations of noradrenaline were found after elective caesarean section. Vaginal delivery, particularly when accompanied by instrumental manipulation, was associated with significantly higher concentrations of arterial noradrenaline. High concentrations of catecholamines were commonly recorded in those deliveries showing evidence of acid-base disturbance. Noradrenaline was the predominant catecholamine in all cases. A linear relation was demonstrated between arterial noradrenaline and arteriovenous noradrenaline difference.

Anesthesia, Obstetrical↗
PubMedDate not supplied

Outpatient percutaneous heel cord lengthening in children.

Outpatient percutaneous tendo Achillis lengthening is a quick, complication-free, inexpensive approach to a common pediatric orthopedic problem. The procedure is a known alternative to conventional open procedures, but it is not widely used. This study outlines the advantage of the percutaneous procedure performed in outpatient surgery with the patient under a general anesthetic. Fifty-five patients were operated on between December 1980 and March 1984. Overall results were excellent, with 97% improvement in gait. There were no infections. Percutaneous heel cord lengthening in children is a safe and simple operation, yielding results equal to those of open procedures. The advantage of outpatient surgery adds a further positive dimension to this procedure.

Achilles Tendon↗