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Biomedical subjects

L Shaw

Publications and source records attributed to L Shaw.

230 records · Page 13Linked to original sources
PubMedDate not supplied

A community hospital's effort to expedite treatment for patients with chest pain.

OBJECTIVE: The purpose of this study was to determine treatment times at a community hospital that does not receive prehospital electrocardiogram (ECG) transmission and to determine the effect of time to first hospital ECG on overall door-to-drug time. DESIGN: Descriptive. SETTING: 238-bed Regional Medical Center in Burlington, North Carolina. SAMPLE: One hundred four patients with a final diagnosis of acute myocardial infarction were included in this 16-month study. RESULTS: A median door-to-ECG time of 5 minutes was within the American College of Cardiology/American Heart Association recommendation of 10 minutes. Shorter treatment times to obtain the first ECG and initiate thrombolytic therapy were associated with younger patients and those arriving by ambulance. CONCLUSIONS: While efficiency in obtaining a first hospital ECG on patients with suspected acute myocardial infarctions was achieved, this did not result in low door-to-drug times. Further streamlining of protocol and the exploration of prehospital initiatives may result in a significant reduction in door-to-drug times.

Chest Pain↗
PubMedDate not supplied

Methodological considerations in the assessment of noninvasive testing using outcomes research: pitfalls and limitations.

The ongoing demands for cost-containment in medicine have radically altered the practice of medicine in general and the practice of cardiology in particular. The need to justify the use of noninvasive testing has led to the development of outcomes data to validate the use of these tests and show their cost-effectiveness when incorporated into testing strategies. The development of a supportive literature of noninvasive modalities, however, requires an understanding of the varied methodological approaches that constitute outcomes research. The proper use of these methods, the interpretation of their results, and the application of these results to clinical practice are potentially problematic. This review focuses on the use and limitations of the methods used for outcomes-based assessment of technology and examples of their application.

Cost-Benefit Analysis↗
PubMedDate not supplied

Endothelin-1 stimulates hydrolysis of phosphatidylcholine by phospholipases C and D in intact rat mesenteric arteries.

A characteristic of endothelin-1 (ET-1)-induced contraction is the prolonged duration of the response. Phosphatidylcholine (PC) hydrolysis has been implicated in sustained agonist-induced effects through the formation of the second messengers phosphatidic acid (PA) and diacylglycerol (DAG). Therefore, we have investigated the activation of PC-phospholipase D (PLD) and PC-phospholipase C (PLC) in intact rat mesenteric small arteries stimulated with ET-1 and determined whether PC-derived DAG is necessary for ET-1-induced contraction. PLD activity, measured as phosphatidylethanol (PEt) production in vessels labelled with [3H] or [14C]myristate, was increased in a concentration- and time-dependent manner following ET-1 stimulation, as were [3H]PA levels, peaking at 10 min (ET-1 100 nM) and remaining above control levels for up to 20 min. Inclusion of 0.5% ethanol during ET-1 stimulation reduced [3H]PA levels, but did not alter the time course of formation. In addition, [14C]choline release was increased, confirming PLD-mediated PC hydrolysis. In contrast, DAG levels, measured by [3H]myristate labelling and mass assay, increased transiently at 5 min of ET-1 stimulation only. Analysis of the subclasses of DAG demonstrated an increase in all types of DAG without any enrichment with arachidonate-containing species, indicating PC, not inositol lipid hydrolysis was the source of DAG. The PC-PLC inhibitor D609, 2.5 microg/ml, completely abolished the ET-1-induced increase in [14C]DAG without affecting the increase in [14C]PA, PLD activity or the contractile response. In [14C]choline-labelled vessels, [14C]phosphocholine levels were increased by ET-1 with a similar time course to DAG production. Removal of extracellular Ca2+ and addition of 0.1 or 2 mM EGTA completely inhibited ET-1-stimulated PLD activity. The tyrosine kinase inhibitor tyrphostin A23 (100 microM) abolished ET-1-induced [3H]PA, [3H]PEt and [14C]DAG increases, whilst the negative analogue A1 was without effect. These data suggest that ET-1 couples via a calcium-dependent tyrosine kinase mechanism to PLD and PC-PLC in vascular smooth muscle. PC-derived DAG did not appear to be necessary for the contractile response, whereas sustained formation of PA, generated by PLD activity, implies that this lipid second messenger could be involved in the prolonged contractile response to this peptide.

Animals↗
PubMedDate not supplied

Digoxin assay anomalies due to digoxin-specific Fab immunotherapy.

We demonstrate that digoxin-specific Fab antibody fragments, used in the treatment of severe digitalis intoxication, cause a marked interference with both fluorescence excitation transfer immunoassays and radioimmunoassays for digoxin. In addition, we describe a rapid ultrafiltration method that avoids the Fab-induced interference and affords excellent accuracy and precision. This technique will provide a useful adjunct to the clinical evaluation of patients with digoxin toxicity who are recipients of antidigoxin immunotherapy by enabling a precise determination of their serum digoxin concentrations. By separating the free and protein-bound digoxin this technique also may be useful in evaluating serum digoxin concentrations in patients with abnormal plasma protein concentrations.

Aged↗
PubMedDate not supplied

Childhood asthma and dental erosion.

The aim of this investigation was first to assess the prevalence of asthma in a random sample of fourteen-year-old children in Birmingham UK. Secondly to assess the levels of dental erosion in these children, and thirdly to see whether there was any correlation between children with asthma and the levels of dental erosion. A random sample of 418 children from twelve secondary schools was examined, 209 were male and 209 female. The level of tooth wear was recorded using a modification of the Tooth Wear Index of Smith and Knight. The prevalence of asthma in this group was 15.8 percent (66 children out of 418); the levels of dental erosion in children with asthma were higher.

Adolescent↗
PubMedDate not supplied

Use and effect of clinical photographic records on the motivation and oral hygiene practices of a group of mentally handicapped adults.

A study was undertaken to test the hypothesis that clinical photographic records can be used to motivate oral hygiene performance in mentally handicapped adults. Plaque reduction over the period of the study was shown to be higher in the test group than the control group but differences between the test and control groups were not statistically significant. The small numbers involved (29) and the difficulties in matching subjects may have mitigated against demonstrating a statistically significant difference between the two groups. All participants demonstrated high levels of toothbrushing ability during the practical aspects of the study but this was not maintained through daily oral hygiene practices in the majority of subjects.

Dental Records↗
PubMedDate not supplied

Dental erosion in four-year-old children from differing socioeconomic backgrounds.

Although there is very little epidemiological evidence on the prevalence and severity of erosion in children and adults, there have been recent case reports suggesting that the problem of erosion is increasing. This study describes the use of a simple reproducible erosion index. A total of 178 four-year-old children were assessed; almost half of these children showed signs of erosion. The most common site affected was the palatal surface of the upper incisors with 17 percent of the children examined showing visible dentine for greater than one third of the tooth surface. When considering the influence of socioeconomic group on the prevalence of erosion, four out of five children examined in the low socioeconomic group showed low levels of erosion, while a much greater prevalence was observed in the higher socioeconomic groups.

Chi-Square Distribution↗
PubMedDate not supplied

Functional and biosynthetic aspects of sialic acid diversity.

Sialic acids comprise a large family of N- and O-substituted neuraminic acid derivatives as components of glycoconjugates. N-Glycolylneuraminic acid is formed from N-acetylneuraminic acid by the action of the CMP-N-acetylneuraminic acid hydroxylase studied in various animals. O-Methylated sialic acids originate from the action of S-adenosylmethionine-8-O-methyltransferase studied in starfish. Sialic acids are O-acetylated at diverse positions by the action of acetyl-CoA-4-O- and -7-O-acetyltransferases found in various animals and, leading to the O-acetylation of sialic acid glycerol side chain, also in man. Some properties of these enzymes are described and biological implications discussed.

Acetyl-CoA C-Acetyltransferase↗
PubMedDate not supplied

Tooth wear in children: an investigation of etiological factors in children with cerebral palsy and gastroesophageal reflux.

This investigation was undertaken to establish the prevalence and distribution of tooth wear in different groups of medically compromised children and to assess the possible influence of gastroesophageal reflux, dietary factors, and parafunctional activity. Four groups of children including twenty-one with cerebral palsy were clinically examined and had in-depth, structured interviews, including information on medical history, medication, gastroesophageal reflux, feeding and drinking habits, parafunctional activity, and tooth-brushing procedures. All the children with cerebral palsy also had twenty-four-hour gastroesophageal pH monitoring. Of the fifty-one children in total, twenty-five had moderate or severe levels of dental erosion. No statistically significant differences were found between the groups as far as dietary influences, feeding habits, and tooth-brushing procedures. There was a significant association, however, between gastroesophageal reflux and erosion. It is concluded that in children with cerebral palsy this reflux may be much more important in the etiology of tooth surface loss than the parafunctional activity, which has classically been regarded as the cause.

Beverages↗