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Biomedical subjects

C J Roberts

Publications and source records attributed to C J Roberts.

At least 217 records · Page 12Linked to original sources
PubMed1981

Comparison of glucose and acetate as substrates for lipid synthesis in bovine adipocytes.

The metabolic capacity of bovine adipocytes was studied using isolated cells from subcutaneous adipose tissue of four dairy cows before and after calving. The lipogenic capacity was assessed by measuring the incorporation of 14C-glucose and 14C-acetate into lipid. In the cells taken from the cows before calving, 14C-acetate was incorporated into lipid at a much higher rate than 14C-glucose but, after calving, incorporation of both substrates was very low. The results show that 14C-acetate uptake into lipid is a more sensitive indicator of the lipogenic capacity of adipocytes of dairy cows.

Acetates↗
PubMed1980

Enzyme induction and serum and lipoprotein lipids: a study of glutethimide in normal subjects.

1. Serum and lipoprotein cholesterol and triglycerides were measured before, during and after the administration of glutethimide (500 mg daily) for 21 days to six healthy volunteer subjects. 2. Evidence of enzyme induction was provided by significant rises in D-glucaric acid excretion and antipyrine clearance. 3. Concentrations of total serum cholesterol, very-low-density-lipoprotein-, low-density-lipoprotein and high-density-lipoprotein-cholesterol rose significantly during treatment. 4. The time course of these changes was delayed in comparison with the rise and fall in D-glucaric acid excretion. 5. There was no change in the triglyceride content of either whole serum or lipoprotein fractions at any time during the trial. 6. The study provides further evidence that enzyme-inducing agents cause a rise in certain lipid concentrations.

Adult↗
PubMed1980

Antenatal attendance and screening for neural tube defects.

An analysis of factors influencing the time of booking at seven hospital antenatal clinics in one Health Authority Area showed that only 52.5 per cent of patients booked before 16 weeks gestation and 78.9 per cent before 19 weeks gestation. The principle reasons for late booking were delay in the patient seeking medical advice and delay in referral to hospital by the general practitioner (GP) after pregnancy was confirmed. Possibilities for improving early attendance and hence implementing an effective screening programme for the detection of neural tube defects are discussed.

Appointments and Schedules↗
PubMed1980

The metabolic activity of bovine adipocytes before and after parturition.

Adipocytes were isolated from biopsies of the subcutaneous adipose tissue of dairy cows before and after parturition. The diameter of the cells was measured and their lipogenic and lipolytic capacities were assessed by measurement of 14C-glucose incorporation and glycerol release. The concentration of non-esterified fatty acids (NEFA) in plasma at the time of biopsy was also measured. In the post calving samples, lipogenic activity of the adipocytes was reduced to a third of the precalving level, and oxidation of glucose to carbon dioxide almost ceased. Lipolytic activity increased five-fold after calving, and this was associated with an increase in plasma NEFA concentrations.

Adipose Tissue↗
PubMed1979

Precision in estimating gestational age and its influence on sensitivity of alphafetoprotein screening.

The interpretation of maternal serum alpha-fetoprotein (AFP) concentrations in relation to fetal neural tube defects depends on accurate assessment of the gestational age. In a quadruple-blind study three antenatal methods of assessment--namely, menstrual dates, clinical examination, and ultrasound scanning--were correlated with postnatal assessment using the Dubowitz scoring system. The best agreement to +/- 1 week was obtained using menstrual dates and ultrasound in combination, such agreement being found in 91 (77%) of the 118 women studied. Since serum AFP concentrations vary with gestational age, precise gestational dating is necessary. In many cases, particularly in women who are unsure of their dates or have irregular menstrual cycles, ultrasound examination is needed to supplement clinical findings.

Clinical Trials as Topic↗
PubMed1979

Comparison of natriuretic, uricosuric, and antihypertensive properties of tienilic acid, bendrofluazide, and spironolactone.

The antihypertensive properties of the new diuretic tienilic acid were investigated. Thirteen previously untreated hypertensive patients took part in a double-blind crossover study in which 30 days' treatment with tienilic acid 250 mg, bendrofluazide 5 mg, and spironolactone 100 mg were compared. Bendrofluazide caused the greatest natriuresis on the first treatment day and the most rapid fall in blood pressure. The ultimate antihypertensive effect of all three drugs was similar. Tienilic acid caused a noticeable reduction in serum urate concentrations and a rise in urate clearance, in contrast to the other two agents, which caused slight urate retention. Tienilic acid and bendrofluazide caused falls and spironolactone a rise in plasma potassium concentrations. No untoward effects were seen from any of the drugs. It is concluded that tienilic acid is a moderately potent diuretic that lowers plasma urate concentrations. It may be the drug of first choice for hypertensive patients who already have gout or are likely to develop it when taking thiazide diuretics.

Bendroflumethiazide↗
PubMed1979

A single dose comparison of piretanide and bumetanide in congestive cardiac failure.

1 This study has compared the diuresis produced by a single oral administration of 6 mg piretanide, 9 mg piretanide and 1 mg bumetanide in a group of nine patients with cardiac failure using a balanced randomized design. 2 The natriuresis and kaliuresis produced in the first 6 h after administration of piretanide 9 mg and bumetanide 1 mg were similar. Piretanide 6 mg produced a lesser response. 3 There was evidence of sodium and water conservation following the diuresis for up to 48 h with all three treatments. 4 The patterns of urate and calcium excretion were similar for the two diuretics.

Aged↗
PubMed1979

Drug metabolism in malnourished children: a study with antipyrine.

The effect of malnutrition on hepatic drug-metabolising enzymes was investigated in 8 Sudanese children aged between 9 and 12.5 years using as a model the drug antipyrine. Antipyrine half-life and clearance were measured in the malnourished state and after 3 or 4 weeks of good nutrition. Associated with the improvement in nutritional state was a shortening of antipyrine half-life and an increase in its clearance. There was also a rise in serum triiodothyronine. It is concluded that poor nutrition is associated with impairment of drug metabolic capacity and that many factors are responsible.

Antipyrine↗
PubMed1979

Antipyrine clearance per unit volume liver: an assessment of hepatic function in chronic liver disease.

Liver size has been estimated clinically and by a non-invasive ultrasound technique in 16 normal subjects, 16 patients with cirrhosis, 10 patients with chronic biliary obstruction, and three patients with primary hepatoma. Antipyrine disposition was also measured in each subject. Hepatomegaly was not clinically detectable until there was approximately a 20% increase in liver size. Additional increases in size correlated significantly with clinical estimates of hepatomegaly. Antipyrine clearance had a three-fold range in normal subjects. Its mean value was significantly reduced in each subgroup of patients with liver disease. However, 48% of patients with liver disease had values within the normal range. In normal subjects there was a significant correlation between antipyrine clearance and liver volume. Thus, intersubject variation in clearance normalised for liver volume was less than clearance alone. Antipyrine clearance normalised for liver volume in patients with liver disease was significantly lower than in normal subjects and there was no overlap with normal subjects. In conclusion, assessment of drug metabolising efficiency per unit volume of liver increased the discrimination in differentiating subjects with normal from abnormal livers.

Aged↗