Biomedical subjects

Peter Watkins

Publications and source records attributed to Peter Watkins.

At least 19 recordsLinked to original sources

PubMed2005

Analysis of methoxypyrazines in wine using headspace solid phase microextraction with isotope dilution and comprehensive two-dimensional gas chromatography.

This study reports an optimized headspace-solid phase microextraction (HS-SPME) method for the determination of methoxypyrazines in wine. Analysis was performed by using comprehensive two-dimensional gas chromatography with novel detection capabilities, including nitrogen phosphorus detection (GC x GC-NPD) and time-of-flight mass spectrometry (GC x GC-TOFMS). In the latter, stable isotope dilution was performed for the quantitation of 2-methoxy-3-(2-methylpropyl) pyrazine (IBMP), using labelled 2-(2H3)methoxy-3-(2-methylpropyl)pyrazine (d3-IBMP) as the internal standard, and resolution of the two analogues was facilitated using the deconvolution capabilities of the TOFMS. This research represents the first report of HS-SPME with isotope dilution and GC x GC-TOFMS (GC x GC-IDTOFMS). Analysis by GC x GC-NPD enabled detection limits of 0.5 ng/L for the quantitation of IBMP, which was superior to that obtained using GC x GC-IDTOFMS (1.95 ng/L). Nevertheless, both methods were adequately sensitive for real wine analysis, yielding highly comparable IBMP concentrations of 26.1 and 27.8 ng/L, respectively, from a Sauvignon blanc wine. The complexity of the real wine headspace was simplified as a result of selective detection using GC x GC-NPD and, in the case of GC x GC-IDTOFMS, the use of extracted ion chromatograms (EICs).

Chromatography, Gas↗

PubMed2004

Determination of mono- and di-acylglycerols in milk lipids.

A simple and rapid method based on solid phase extraction and gas chromatography has been developed for the determination of monoacylglycerols (MAG) and diacylglycerols (DAG) at low-concentration levels typically found in milk and dairy ingredients. The method enabled measurement of individual milk MAG (including isomeric forms) with the exception of glycerol, monobutyrate. The DAG were separated and quantified as groups according to their carbon numbers. However, it was possible to identify the major DAG components within a group. The minimum detection limits for MAG and DAG were in the range of 5-8 and 10-17 microg/ml, respectively. The corresponding R.S.D. values were 1.7-3.9 and 0.2-9.9%, respectively. C8-C18 MAG and C26-C36 DAG were present in the lipids extracted from whole milk, anhydrous milk fat and buttermilk. The concentrations of MAG and DAG in buttermilk were, respectively, thirteen- and three-folds higher than that in whole milk or anhydrous milk fat. In dairy lipids, 1,2(2,3)-DAG isomers predominated almost to the exclusion of 1,3-isomers.

Animals↗

PubMed2003

Delivery of diabetes care in rural Ethiopia: an experience from Gondar.

Diabetes is an increasing health problem in African countries. This study was undertaken to ascertain differences in the demography of diabetes in rural and urban populations, and to assess mortality, following a programme aiming to decentralise care to Health Centres nearer to patient's homes. The study population comprised 871 diabetic patients registered in Gondar between June 1995 and August 2000. Four hundred and thirty two were town residents and 439 came from remote rural areas. Most of the rural patients (77%) had Type 1 diabetes whereas in urban areas only 29% had Type 1 and 71% Type 2 diabetes. Review of the mortality of Type 1 diabetic patients up to August 2000 shows that 117 (32%) have died at a mean age of 32.0 +/- 10.4 years, and a duration of diabetes 6.1 +/- 5.0 years. Of the 871 patients, 729 are under regular review from Gondar: the care of 82 percent of the rural patients has been decentralised and is now undertaken in village health centres nearer to their homes. The management of chronic disorders such as diabetes in rural African communities needs to be decentralised to improve access to treatment and reduce mortality. The patients could achieve better health if methods of tracking non-attenders were developed, and if the need to travel large distances at frequent intervals to obtain insulin supplies could be eliminated.

Adolescent↗

PubMed2002

Observations on haematological and cardiovascular effects of erythropoietin treatment in multiple system atrophy with sympathetic failure.

Symptomatic autonomic neuropathy and in particular sympathetic failure mediated postural hypotension often accompanies Multiple System Atrophy (MSA). Release of erythropietin is under sympathetic control and we and others have previously reported that severe autonomic failure may be associated with a normocytic normochromic anaemia and erythopietin (EPO) deficiency. In this paper we describe the haematological, cardiovascular and clinical observations on a patient with MSA and severe symptomatic autonomic neuropathy who had haematological and clinical improvement (substantial increase in standing blood pressure) following subcutaneous EPO treatment.

Aged↗

PubMedDate not supplied