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Biomedical subjects

L Shaw

Publications and source records attributed to L Shaw.

At least 163 records · Page 9Linked to original sources

Prognostic importance of silent myocardial ischemia detected by intravenous dipyridamole thallium myocardial imaging in asymptomatic patients with coronary artery disease.

One hundred seven asymptomatic patients who underwent intravenous dipyridamole thallium imaging were evaluated to determine prognostic indicators of subsequent cardiac events over an average follow-up period of 14 +/- 10 months. Univariate analysis of 18 clinical, scintigraphic and angiographic variables revealed that a reversible thallium defect, a combined fixed and reversible thallium defect, number of segmental thallium defects and extent of coronary artery disease were significant predictors of subsequent cardiac events. Of the 13 patients who died or had a nonfatal infarction, 12 had a reversible thallium defect. Stepwise logistic regression analysis selected a reversible thallium defect as the only significant predictor of cardiac events. When death or myocardial infarction was the outcome variable, a combined fixed and reversible thallium defect was the only predictor of outcome. In patients without previous myocardial infarction, the cardiac event rate was significantly greater in those with an abnormal versus normal thallium scan (55% versus 12%, p less than 0.001). Thus, intravenous dipyridamole thallium scintigraphy is a useful noninvasive test to risk stratify asymptomatic patients with coronary artery disease. A reversible thallium defect most likely indicates silent myocardial ischemia in a sizable fraction of patients in this clinical subset and is associated with an unfavorable prognosis.

Aged↗

Correlation of manual dexterity and comprehension with oral hygiene and periodontal status in mentally handicapped adults.

Although there is relatively little information concerning the oral health of handicapped adults there is increasing evidence to suggest that their oral condition, particularly periodontal health, is poor. The present investigation involved assessment of 382 handicapped patients attending four different Adult Training Centres in Birmingham. The caries status, oral hygiene, and periodontal conditions were evaluated and the Community Periodontal Index of Treatment Need (CPITN) was calculated. In order to assess the manual dexterity and the comprehension of the trainees a standard test was devised. This consisted of timing each participant in carrying out simple instructions to pick up and position certain common objects. The results indicated high levels of plaque, calculus, and bleeding with a mean CPITN of 7.43. The mean time taken for the manual dexterity and comprehension test was 23.9 seconds with a range from 10 to 80 seconds, S.E.+/- 1.33. This compares with results from 34 "normal" adults of a mean time of 8.2 seconds +/- 1.8 with a range of 6 to 12 seconds. There was no significant correlation between the Manual Dexterity and Comprehension scores and the periodontal indices in the handicapped adults.

Adult↗

Which patients first: a study from the closure of a large psychiatric hospital.

The decision to close down large psychiatric hospitals has led to many districts determining current patient dependency levels by conducting surveys of their hospital inpatient populations. This paper reports on the Claybury Hospital survey, which used Baker and Hall's REHAB scale to measure the level of patient functioning. The 641 patients assessed comprised the total long-stay and elderly, mentally-ill population of the hospital, excluding only patients on admission wards. Of these, 403 (63%) patients were in the 'severe handicap' category. In contrast, only 97 (15%) had 'potential for discharge'. A comparison of Claybury scores with those from other hospitals suggests that Claybury patients function at a lower level. Evidence is presented of 'creaming off' with respect to how one particular district has chosen patients, and this leaves behind an increasingly disabled hard core of patients. These findings are discussed and compared with other similar studies, and with respect to the Government's care in the Community policy.

Activities of Daily Living↗

Size and development of the dentition in endocrine deficiency.

Two case reports are presented of boys, who were found to have pituitary and thyroid dysfunction respectively. This was treated in childhood with replacement therapy. These deficiences are known to affect normal skeletal and dental development, but the cases described also showed marked effects on the dental tissues themselves with severe microdontia and abnormalities of crown and root form.

Adult↗

The role of medications in dental caries formation: need for sugar-free medication for children.

Most paediatric medicines are prescribed in a liquid form that includes sugar in the formulation. Accumulating evidence, on a clinical and experimental basis, shows a significant association between the intake of sucrose-based medication and an increased incidence of dental caries. Many of the children on long-term medication for chronic medical problems are particularly at risk from the consequences of developing dental caries; dental disease, sepsis or treatment procedures can put the general health or even life of the child at risk. The need to use sucrose in medications should be reassessed; medicines containing sugar should be labelled accordingly; and medical and dental professionals should be aware of potential problems related to sucrose-based medications.

Adolescent↗

Histiocytosis X: an oral diagnostic problem.

A case of prepubertal periodontitis in a 6 1/2-year-old boy is described. Following failure to respond to conventional treatment including scaling, oral hygiene instruction and tetracycline therapy, a biopsy was performed and root planing carried out. The biopsy revealed histiocytic infiltration and a diagnosis of Histiocytosis X of the Hand-Schüller-Christian type was made. This case emphasises the role of biopsy in establishing a diagnosis in cases of prepubertal periodontitis that do not respond to conventional therapy.

Child↗

The biosynthesis of N-glycoloylneuraminic acid occurs by hydroxylation of the CMP-glycoside of N-acetylneuraminic acid.

The biosynthesis of N-glycoloylneuraminic acid in fractionated porcine submandibular glands was investigated. The following substrates: [3H]N-acetylmannosamine, free [14C]N-acetylneuraminic acid, CMP-[14C]N-acetylneuraminic acid, [14C]N-acetylneuraminic acid linked alpha(2----3) to galactose residues, or alpha(2----6) to Gal-beta(1----4)-GlcNAc residues of porcine submandibular mucin and [14C]N-acetylneuraminic acid linked alpha(2----6) to GalNAc residues of ovine submandibular gland mucin were incubated, in the presence of cofactors, with the soluble protein, heavy membrane and microsomal fractions of porcine submandibular glands. Radio thin-layer chromatographic analysis revealed that only one substrate, CMP-[14C]N-acetylneuraminic acid, was hydroxylated. The product was identified as CMP-[14C]N-glycoloylneuraminic acid by (i) co-chromatography with non-radioactive CMP-N-glycoloylneuraminic acid standard, (ii) acid hydrolysis to free [14C]N-glycoloylneuraminic acid, (iii) alkaline hydrolysis to yield N-glycoloylneuraminic acid and 2-deoxy-2,3-didehydro-N-glycoloylneuraminic acid and (iv) transfer of [14C]N-glycoloylneuraminic acid to asialo-fetuin by sialyltransferase. 85% of CMP-N-acetylneuraminic acid hydroxylase activity was present in the soluble protein fraction, with small amounts of activity in the two particulate fractions. The CMP-N-acetylneuraminic acid hydroxylase in the soluble protein fraction had an absolute requirement for Fe2+ ions and a reducing cofactor. NADPH and NADH were by far the most effective cofactors, smaller amounts of hydroxylation could, however, be supported by ascorbic acid and 6,7-dimethyl-5,6,7,8-tetrahydrobiopterin.

Animals↗

Irreversible binding and metabolism of propranolol by human liver microsomes--relationship to polymorphic oxidation.

Studies were performed to investigate the irreversible binding and oxidative metabolism of propranolol in human liver microsomes and the relationship of binding and metabolism to the polymorphic oxidation of debrisoquine. Incubation of microsomes with 14C-labelled propranolol in the presence of a NADPH-generating system gave rise to irreversible binding which increased linearly with time and became saturated at high substrate concentrations. The extent of binding was decreased by the exclusion of cofactors, boiling, anaerobic conditions, and the addition of reduced glutathione and SKF-525A. Trichloropropene oxide had a negligible effect on cofactor-dependent binding. However, debrisoquine, antipyrine and phenacetin decreased binding to a considerable extent. The latter compound abolished cofactor-dependent binding completely at the concentration used (1 mM). Electrophoresis of microsomes which had been incubated with tritiated propranolol revealed that binding was probably occurring to a large number of proteins particularly in the 40,000-90,000 molecular weight range. Glutathione, debrisoquine and antipyrine did not inhibit the 4'-hydroxylation and N-deisopropylation of propranolol. In contrast, phenacetin exerted a very potent inhibitory action on both routes of metabolism. It is concluded that a product or products of propranolol oxidation bind irreversibly but non-selectively to human liver microsomal protein, the enzyme system responsible for the activation of propranolol appears to be related more closely to the cytochrome P-450 system which metabolizes phenacetin than to that metabolising debrisoquine, and radiolabelled propranolol is not a sufficiently specific probe for studying these cytochrome P-450 systems.

Biotransformation↗

CoA-persulphide: a possible in vivo inhibitor of mammalian short-chain acyl-CoA dehydrogenase.

The characteristic green colour of native short-chain acyl-CoA dehydrogenases (EC 1.3.99.2) results from a charge transfer complex between the FAD prosthetic group and a tightly bound molecule of CoA-persulphide. The native enzyme from ox liver mitochondria was found to have about 60% of its FAD cofactor liganded with CoA-persulphide. When artificially fully liganded with CoA-persulphide, this enzyme was inhibited by 90% in comparison to unliganded enzyme. Enzymic activity could be slowly restored by displacing the CoA-persulphide with high concentrations of butyryl-CoA, the enzyme's physiological substrate. The results show that CoA-persulphide is a potent inhibitor of short-chain acyl-CoA dehydrogenase and may have a physiological role in the regulation of beta-oxidation.

Acyl-CoA Dehydrogenase↗

Relationship of steady-state serum concentrations of amiodarone and desethylamiodarone to therapeutic efficacy and adverse effects.

The relationship of steady-state serum levels of amiodarone and its major metabolite, desethylamiodarone, to therapeutic and toxic effects was evaluated in 111 patients treated for supraventricular and ventricular arrhythmias. All patients were treated for more than two months (mean 10 +/- 7), and repeated serum levels determined at least two months apart were within 0.5 mg/liter of each other. Effective control of arrhythmias during steady-state therapy was achieved in 91 patients (82 percent of the study populations); recurrent arrhythmias or sudden death did not correlate with levels. An adverse drug effect necessitating cessation of therapy and/or concomitant medical therapy for the adverse effect occurred in 12 patients (11 percent); an additional 33 patients (30 percent) had an adverse effect that did not require change in therapy. The mean serum concentrations of amiodarone and desethylamiodarone associated with adverse drug effects were higher (2.6 +/- 1.2 mg/liter and 2.0 +/- 0.8 mg/liter) than those in patients without adverse effects (2.1 +/- 1.0 mg/liter and 1.5 +/- 0.7 mg/liter), p less than 0.05. An amiodarone serum concentration of 2.5 mg/liter or more had a positive predictive value of 76 percent for identifying patients with an adverse effect. The level of desethyl metabolite of amiodarone correlated directly with the serum amiodarone concentration (r = 0.82). Measurement of desethylamiodarone did not increase the sensitivity or specificity of the amiodarone level alone in the identification of patients at risk for adverse drug effects.

Adult↗

Enhancing competitive position through an emergency room patient classification system.

The health care environment of the 1980's is vastly different than that of the previous two decades. Today, it is characterized by service competition and cost consciousness. As competition for emergency room services increases, hospitals need to reassess their business philosophies. A step in this direction is the establishment of a patient acuity system that will determine appropriate nurse staffing requirements and thus cost. By developing operational strategies of this type, it is perceived that hospital management will increase the emergency room's ability to compete in the volatile ambulatory care market. This article addresses the need for competitive strategies by describing development of an emergency room patient acuity system.

Data Collection↗

Dental study of handicapped children attending special schools in Birmingham, UK.

The prevalence of dental caries, the levels of oral hygiene and the periodontal treatment requirements were assessed in 3562 handicapped children and 1344 randomly selected normal children attending schools in Birmingham, UK. The effect of different types of handicapping condition on these parameters was also evaluated. This investigation showed that there were few differences in caries prevalence when comparing handicapped children with children attending normal schools. However, the provision of dental care showed significant differences, with the handicapped children receiving less restorative treatment. There were also significantly poorer levels of oral hygiene and a greater prevalence of periodontal disease in the handicapped children attending special schools. The type of handicapping condition had a significant effect on the periodontal problems observed; those children with mental retardation having the poorest levels of oral hygiene and the greatest periodontal treatment requirements.

Adolescent↗