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Biomedical subjects

R M Greenwood

Publications and source records attributed to R M Greenwood.

14 recordsLinked to original sources
PubMed1991

Diabetes is associated with a high incidence of endothelial-binding antibodies which do not correlate with retinopathy, von Willebrand factor, angiotensin-converting enzyme or C-reactive protein.

Increasing evidence implicates endothelial cell dysfunction in the development of diabetic microvascular disease, but its precise nature is elusive. This study sought to extend previous observations on the association between diabetes and the endothelial cell-derived glycoprotein von Willebrand factor (vWF), in a study of 777 diabetic patients. Compared with a mean of 1.07 +/- 0.18 iu/ml in a non-diabetic population, vWF was found to be elevated to 1.59 +/- 0.14 iu/ml in the whole sample, but particularly in those with retinopathy or microalbuminuria. It was studied whether such an elevation is part of an acute phase response, or is accompanied by other indicators of endothelial cell dysfunction. Plasma samples were examined for vWF, and serum for angiotensin converting enzyme (ACE), C-Reactive protein (CRP), IgG and IgM endothelial cell-binding antibodies (anti-EC Ig). A strong positive association was found (p less than 0.005) between the extent of elevation of vWF and the presence of diabetic retinopathy. ACE and CRP were rarely raised, and their levels did not correlate with either diabetic retinopathy or vWF levels. However, 52% of the patients had circulating anti-EC IgG or IgM, although their presence did not correlate with retinopathy, or with vWF, ACE or CRP. Thus diabetic retinopathy and probably nephropathy is associated with a specific but generalised disturbance of vascular endothelial cell function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Improving the quality of data in randomized clinical trials: the COMPACT computer package. COMPACT Steering Committee.

One crucial component for a successful clinical trial is that the data gathered have a high level of reliability and completeness. This paper reviews some problems of data management and describes the computer package COMPACT which has been developed to deal with such problems. The package allows range and consistency checks and can monitor complex follow-up schedules. A unique feature of the package is a PROBLEMS file which has use both for identification of queries about the data and of patients with particular characteristics of interest. The ability to monitor drug dosages and to signal deviations from the protocol is of particular value. COMPACT has the syntax necessary to create a 'flat' file for transfer to statistical packages for analysis, and the variable description files for SAS, SPSS and MINITAB. The package is written in standard FORTRAN which enables transfer to different types of mini and micro computer systems.

Clinical Trials as Topic↗
PubMed1985

Hyperthyroidism and the impalpable thyroid gland.

A retrospective analysis of 594 unselected cases of hyperthyroidism from one district was made to determine whether the thyroid gland had been palpable on presentation. The thyroid had been diffusely palpable in 374 patients (63%), nodular in 110 (19%) and impalpable in 96 (16%); there was no clinical record in 14 (2%) cases. Under 40 years of age a diffuse gland was usual, being present in 86% of cases. The proportion of nodular and impalpable glands both increased progressively with age comprising 30% and 48% respectively in patients older than 70 years. Grave's ophthalmopathy was present in 13% of hyperthyroid patients with diffuse glands, in 12% of those with impalpable glands, but in only 1.5% of those with nodular thyroids. Thyroid autoantibodies were found with a similar frequency in all three groups. There was a very good correspondence between clinical assessment of shape and nodularity of thyroid and the results of isotope scanning; the majority of patients with impalpable glands (86%) had a diffuse uptake of isotope. In the elderly hyperthyroid patient an impalpable thyroid gland is common and is not a factor to weight against the diagnosis.

Adolescent↗
PubMed1984

A simple diabetic clinic information and audit system.

A simple method for managing the records of a diabetic clinic in a District General Hospital is described. It is based on a modified manual system in which selected items of data are recorded in a computer system. This provides a Diabetic Register, information for patient and clinical management and for research projects. It simplifies the management of the clinic, is easily used by medical staff inexperienced in the use of computers and causes minimal increase in the clinic workload.

Computers↗
PubMed1984

Binding of amiodarone by serum proteins and the effects of drugs, hormones and other interacting ligands.

Amiodarone is chiefly bound to albumin (62.1%) and much of the remainder (33.5%) is carried on a high molecular weight protein, probably beta-lipoprotein. Analysis of data for amiodarone binding to albumin revealed a high affinity primary binding site (Ka 5.6 X 10(6) litre mol-1) with about four secondary sites (average Ka 1.9 X 10(5) litre mol-1). Studies of the binding of amiodarone in serum revealed one type of binding site only with an affinity constant (Ka 4.2 X 10(6) litre mol-1) similar to that of the primary site on albumin. The secondary albumin binding sites do not seem therefore to be utilized in whole serum and the affinity of the lipoprotein must be similar to that of the primary amiodarone binding site on albumin. The effects of a wide range of compounds on albumin binding of amiodarone were examined by equilibrium dialysis. Quinidine, amitriptyline, cephazolin and palmitate decreased albumin-bound [125I]amiodarone. Neither warfarin nor digoxin affected the binding of amiodarone by albumin, thus of the three drugs known to be potentiated by concomitant amiodarone administration, only potentiation of quinidine could be explained by displacement from serum albumin. Rifampicin, frusemide, phenytoin, (-)-adrenaline, bromocresol green, (-)-noradrenaline and bromocresol purple were found to increase binding of [125I]amiodarone by albumin.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiodarone↗
PubMed1983

Serum calcium concentration in hyperthyroidism at diagnosis and after treatment.

In a large, mainly outpatient, series of hyperthyroid patients who attended a district general hospital the serum concentrations of calcium and albumin were measured before and in many cases after treatment. The calcium level (mean +/- SD) before treatment (2.41 +/- 0.21 mmol/l, n = 437) was significantly higher (P less than 0.01) than afterwards (2.36 +/- 0.15 mmol/l, n = 232) and the albumin level rose when the patients became euthyroid (from 40.5 +/- 3.1 g/l to 44.0 +/- 2.4 g/l; P less than 0.01). After treatment neither value differed from those of an unselected group of out-patients. The usual relation between the serum concentrations of calcium and albumin did not hold in the hyperthyroid subjects but reverted to normal on treatment; the variation, probably due to an increase in ionized calcium, leads to an overestimate of the 'corrected calcium' when conventional methods are used to calculate this figure. Thus, using a conventional formula 8.5% of our hyperthyroid patients would appear to have a calcium greater than 2.65 mmol/l (normal mean plus 2 standard deviations) whereas using a correction factor specific for the hyperthyroid situation the figure is reduced to 5.7% which is only twice the expected proportion. The calcium level was significantly greater (P less than 0.001) in those patients in whom initial T3 concentration was high (greater than 7.2 nmol/l). There was no effect of T4 upon serum calcium which could not be accounted for by the action of T3. In this series of 437 patients there was no case of symptomatic hypercalcaemia. The maximum value was 2.80 mmol/l in a patient with coincident primary hyperparathyroidism. Significant hypercalcaemia is rare in hyperthyroidism.

Adolescent↗
PubMed1979

A prospective study of low back pain.

Consecutive patients attending hospital for the first time with backache were entered into a prospective study, provided that certain defined causes (infective, neoplastic, metabolic and inflammatory etc.) were not apparent at the first visit. Amongst 188 available for analysis, 65% were discharged and 28% defaulted, together making a total of 93% who 'recovered uneventfully' (in the sense that they were no longer attending hospital) on average in about three months, 4% came to 'myelography' (radiculography using Dimer-X or Amipaque) including 2% to discectomy, 1.5% proved to have treatable underlying diseases accounting for their backache while 1.5% became 'chronic attenders'. Information available at the first visit (patient characteristics, history, examination, radiographs and psychological questionnaire) provided few pointers to what the outcome would be or how long the patient would attend hospital. In particular, routine X-ray examination did not provide clues to any important conditions not already suspected by the clinicians. A case is made for reserving routine radiography for patients who have not recovered within about three months.

Adolescent↗
PubMed1978

MIST: a medical information storage system.

A simple but flexible storage and retrieval system for medical data is described. It functions by providing the user with a proven set of FORTRAN IV subroutines. It has been found that for a wide range of clinical data processing the user only needs to apply three FORTRAN subroutines.

Computers↗
PubMed1977

Backache in pregnancy.

Replies to a questionnaire showed that, amongst 180 women delivered in The London Hospital, 48% experienced backache during pregnancy; in one third of these it was severe. The prevalence of back pain increased with both increasing age and increasing parity, and it was difficult to separate the relative contributions of these two factors. No evidence was found of an association between backache during pregnancy and height, weight, 'obesity index', weight gain, or baby's weight. Analysis of aggravating and relieving factors indicates some differences between backache in the pregnant and 'mechanical' back pain in the non-pregnant. Slightly less backache was reported amongst patients attending antenatal physiotherapy classes but the figures do not provide clear evidence of any protective effect of this attendance.

Back Pain↗