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Biomedical subjects

D Matthews

Publications and source records attributed to D Matthews.

At least 19 recordsLinked to original sources
PubMed1992

Sub-acute, transmissible spongiform encephalopathies: current concepts and future needs.

The first diagnosis of bovine spongiform encephalopathy (BSE) in the United Kingdom in 1986 was to stimulate the most intensive epidemiological study of any animal disease of all time in that country. It led also to the initiation of a broad-based research programme with an international flavour. This principally involved scientists and veterinarians in Europe (especially the United Kingdom) and the United States of America, especially those with experience of slow infections in general and experimental scrapie in particular. This final chapter highlights some of the significant discoveries made in the study of BSE and related diseases of this group but also emphasises the deficits in knowledge which need to be corrected before such diseases as scrapie in sheep and goats can be brought under control. The benefits resultant upon effective disease control will be manifest as improvement in animal production, welfare and, importantly, the removal of trading barriers currently in place to protect countries in which diseases such as BSE and scrapie do not exist. Of key importance is the development of a simple, cheap and effective diagnostic test for use in the live animal before the onset of clinical signs. This will be difficult since the nature of the causal agents is uncertain and none provokes either a detectable immune response or inflammatory reaction in the host. The earlier chapters, written by acknowledged specialists from around the world, deal with the specific diseases in detail and all present some of the most recent knowledge available. Here the authors emphasise the important role that major national and international agencies have in effecting the highest level of control possible in the absence of key information. International collaboration with countries in which these diseases exist, and as well as those where they are absent, is of paramount importance. It is essential that the BSE epidemic which has severely affected the cattle industry of the United Kingdom is not allowed to happen in developing countries. Whereas the former has implemented stringent control measures based on scientific knowledge and is well on the way to eradicating the disease, the latter could have much greater difficulty in establishing control. The answer is clear. BSE must be prevented from occurring elsewhere. To do that, knowledge of BSE and other members of the group should be widely dispersed and it is the purpose of this issue to do just that.

Animals↗
PubMed1991

Critically ill patients have high basal growth hormone levels with attenuated oscillatory activity associated with low levels of insulin-like growth factor-I.

OBJECTIVE: The aim was to study the relationship between growth hormone (GH) and insulin-like growth factor-I (IGF-I) in critically ill patients. DESIGN: Case-control study of critically ill patients admitted to the intensive care unit was carried out. PATIENTS: Six critically ill patients (51-78 years) who required ventilation and parenteral nutrition and six age, weight, height, and sex-matched healthy adults were studied. MEASUREMENTS: The patients and controls were studied for two 24-hour periods; the patients before and after starting parenteral feeding, and the controls during a 36-hour fast and when taking meals equivalent in calories and protein to the patients' parenteral feed. Serum GH was measured at 20-minute intervals and analysed by a pulse detection algorithm (Pulsar) and Fourier transformation. IGF-I was measured at 0, 12, and 24 hours. RESULTS: Patients had low serum IGF-I levels compared with controls, whether fasted or fed, despite having mean GH levels similar to fasted controls. For fasted patients vs fasted controls the mean (+/- 1 SD) GH levels were 4.5 +/- 2.0 vs 4.0 +/- 2.4 mU/l respectively, and IGF-I levels at the end of the fast were 0.17 +/- 0.11 vs 0.78 +/- 0.29 U/ml (P = 0.003). Patients showed elevated baseline GH levels compared with controls when fasted and during parenteral feeding (patients vs controls fasted 3.1 +/- 1.9 vs 0.8 +/- 0.5 mU/l, P = 0.01; patients vs controls fed 4.2 +/- 4.5 vs 0.5 +/- 0.04 mU/l, P = 0.028). Fourier transformation confirmed oscillatory GH levels in the controls, fasted or fed, but this activity was attenuated in the patients. Parenteral feeding had no effect on the GH profiles or IGF-I levels of patients, but controls showed greater mean GH levels during their fast than when fed. CONCLUSIONS: We have demonstrated that critically ill patients have low IGF-I levels associated with augmented baseline GH levels which show reduced oscillatory activity. The results would be compatible with the hypothesis that there is an adaptive change in critically ill patients away from the indirect effects of GH (stimulation of IGF-I production and anabolism) and toward the direct effects (lipolysis and insulin antagonism) which increase the availability of energy substrates. The pattern of GH levels seen in our patients may be important in this adaptation.

Abdomen↗
PubMed1991

Bovine spongiform encephalopathy.

Two years after the introduction of a slaughter policy for BSE, the author summarizes the development of the epidemic and introduction of Government controls. In conclusion, the risk to humans is discussed.

Abattoirs↗
PubMed1990

The role of private practitioners in accelerated lambing.

Sheep producers throughout the United States have begun using accelerated lambing programs to enlarge their net income by increasing the number of lambs produced per ewe per year. These new intensive systems have produced some unique problems and concerns. This article attempts to educate the veterinarian as to the justification for these programs. Areas in which veterinary intervention can greatly influence the success or failure of these new accelerated lambing systems are identified. Selection of ewe type, ultrasound pregnancy diagnosis, ram evaluation, specific flock health concerns, and critical ewe nutrition are discussed.

Animal Husbandry↗
PubMed1990

Alagille syndrome and deletion of 20p.

We add five cases of 20p deletion to the 10 cases already published. Four had craniofacial, vertebral, ocular, and cardiovascular features of Alagille syndrome, which adds weight to the assignment of this disorder to the short arm of chromosome 20. Included in our series is the first report of familial transmission of a 20p deletion.

Abnormalities, Multiple↗
PubMed1989

A trial of the calcium antagonist felodipine in hypertensive type 2 diabetic patients.

Although calcium antagonists may impair insulin release in vitro, clinical studies have produced conflicting results. Felodipine is a highly selective dihydropyridine calcium antagonist effective in the treatment of hypertension. The efficacy of felodipine was assessed in a double-blind randomized placebo cross-over study of 21 Type 2 diabetic patients with primary hypertension, 13 men and 8 women, with an age of 61 (range 46-73) years. Thirteen were controlled on oral hypoglycaemic therapy and 8 on diet alone. Mean (SD) blood pressure (mmHg) was 176(20)/102(8) after a 2-4 week placebo run-in period, 169(21)/101(8) during the subsequent placebo period compared with 151(15)/88(9) after 4 weeks felodipine therapy (p less than 0.001). Nineteen patients required 5 mg twice daily and 2 patients 10 mg twice daily to achieve a target diastolic pressure of 95 mmHg. Side-effects seen with felodipine included ankle oedema, facial flushing, headache, and dizziness. During oral glucose tolerance tests performed after the felodipine and placebo phases, mean (SD) fasting blood glucose was 9.5(3.1) and 9.0(3.0) mmol l-1, respectively (NS), and the 90 min (peak) blood glucose was 19.1(4.8) and 18.1(4.8) mmol l-1, respectively (NS). Glycosylated haemoglobin and fructosamine concentrations likewise showed no significant changes.

Apolipoproteins↗
PubMed1989

Glucocorticosteroids increase leucine oxidation and impair leucine balance in humans.

High-dose glucocorticoid treatment results in protein wasting. To determine whether such therapy affects leucine oxidation in the postabsorptive state and the disposal of dietary amino acids, eight normal subjects were studied twice in random order, once after 5 days of prednisone (20 mg three times daily) and on a second occasion without prednisone as a control. In the postabsorptive state prednisone therapy increased (P less than 0.05) plasma concentrations of leucine, alpha-ketoisocaproate, glucose, insulin, and C-peptide, as well as leucine carbon flux and oxidation calculated by means of isotope dilution techniques and [1-13C]leucine. During infusion of a chemically defined meal, total leucine carbon flux and oxidation increased similarly on both study days, but leucine oxidation was greater (P less than 0.01) during prednisone treatment; net leucine balance became positive on the control day but remained negative or zero on the prednisone study day despite higher (P less than 0.05) plasma insulin concentrations. These studies demonstrate that high-dose glucocorticoid treatment impairs the balance of the essential amino acid leucine in both the postabsorptive and absorptive states in humans.

Adult↗
PubMed1989

Medically unexplained physical symptoms, somatization disorder and abridged somatization: studies with the Diagnostic Interview Schedule.

This paper reviews recent research that used the Diagnostic Interview Schedule (DIS) to characterize medically unexplained symptoms and their clustering in clinical and community populations. While the type of symptom(s) differed little across samples, the distribution of a less restrictive construct of somatization ('abridged' somatization) showed interesting differences across the various groups. The authors propose that in view of its relatively high prevalence, abundant psychiatric comorbidity and the simple and unintrusive nature of the assessment, use of the abridged construct may have practical value particularly when exploring psychopathology among medical and community populations.

Fatigue Syndrome, Chronic↗
PubMed1988

Outbreaks of classical swine fever in Great Britain in 1986.

Classical swine fever was confirmed in 10 herds in Britain between April 10 and June 25, 1986 and typical acute disease was seen in nine of them. Serological evidence of exposure to classical swine fever virus was found in a further seven herds which, together with another nine, were slaughtered as dangerous contacts. Altogether 7781 pigs in 26 herds were slaughtered at a cost of 450,101 pounds for compensation alone. In order to detect subclinical disease, the majority of traced herds were blood sampled as well as inspected. A total of 119,169 pigs were inspected in 506 herds and 8302 blood samples were collected. Three primary outbreaks were identified, all attributed to the feeding of unprocessed waste food containing imported pig meat products. There was no spread of disease from two of these primary outbreaks.

Acute Disease↗