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Biomedical subjects

J M Potter

Publications and source records attributed to J M Potter.

At least 91 records · Page 5Linked to original sources
PubMed1981

Enterohepatic circulation of prednisolone in rats.

In the present study human equivalent doses of the synthetic glucocorticoid, prednisolone, were administered intravenously into male rats. The prednisolone was rapidly cleared from blood and accumulated in the liver, from where it and metabolized prednisolone was excreted into the small intestine after a short time. By cannulation of the common bile duct with serial collection of bile it was shown that liver was able to handle relatively large doses of the steroid. There was good evidence of an enterohepatic circulation of steroid with relationships of time and content of prednisolone in liver and small intestine.

Animals↗
PubMed1980

Subcutaneous continuous insulin infusion and control of blood glucose concentration in diabetics in third trimester of pregnancy.

The effect of subcutaneous continuous insulin infusion on the control of blood glucose concentrations was assessed in eight pregnant diabetics in the third trimester. Twenty-four-hour glucose profiles were obtained after strict inpatient control on conventional insulin regimens and after the start of the continuous infusion, which was maintained for 5-55 days. Mean 24-hour glucose concentrations (6.2 mmol/l on conventional regimen, 5.9 mmol/l on continuous infusion; 111.6 and 106.2 mg/100 ml respectively) and mean fasting concentrations (5.3 v 6.2 mmol/l; 95.4 v 111.6 mg/100 ml) were not significantly changed by continuous infusion. Diurnal variations in glucose concentration tended to be smaller on continuous infusion: standard deviation from mean 24-hour glucose concentration was reduced from 2.5 to 2.0 mmol/l (from 45 to 36 mg/100 ml), maximum excursion from 8.4 to 7.4 mmol/l (151.2 to 133.2 mg/100 ml), and M value from 16 to 14. Subcutaneous continuous insulin infusion may be useful in limiting diurnal variations of blood glucose concentrations and warrants further investigation since such an action may be beneficial in the management of pregnant diabetics, in whom the best possible control of blood glucose concentrations is sought for the good of the fetus.

Adult↗
PubMed1980

Potentiation by gentamicin of non-depolarizing neuromuscular block in the cat.

Gentamicin 1-5 mg/kg was injected into 14 anaesthetised cats in the presence of a constant, partial, non-depolarizing neuromuscular block. Twitch response in tibialis anterior was significantly depressed from 83% to 71% of control by a dose of 1.0 mg/kg. In soleus the same dose reduced twitch response from 76% to 71%. After a cumulative dose of 10 mg/kg twitch response in tibialis anterior and soleus was 34% and 37% of control respectively. Calcium chloride 20 mg/kg restored twitch response to 66% in both muscles. Smaller doses of calcium chloride caused partial reversal which was maintained for five minutes in only 50% of instances.

Animals↗
PubMed1979

The hyperlipidemia of pregnancy in normal and complicated pregnancies.

Alterations in the concentrations of the cholesterol and triglyceride moieties of lipoproteins separated by ultracentrifugation and precipitation methods were studied at frequent intervals throughout pregnancy and the puerperium in a group of 43 women. The plasma cholesterol concentration rose on the average by about 50 per cent, the major increase occurring in the second trimester. The plasma triglyceride concentration rose threefold, reaching its peak during the third trimester. All major lipoproteins participated in these changes: in very-low-density lipoproteins, both lipids rose in proportion to the ratio in nonpregnant women, but in low-density and high-density lipoproteins, the ratio of triglyceride to cholesterol rose. The triglyceride enrighment in low-density lipoproteins reflected the inclusion of intermediate-density lipoproteins (d 1.006 to 1.019). The occurrence of hypertension or pre-eclampsia led to a further increase in lipids in very-low-density lipoproteins. Hypercholesterolemia was greatest in women with pre-existing hypercholesterolemia, and women in the third pregnancy showed higher plasma cholesterol concentrations than women in the first pregnancy. Both cholesterol and triglyceride concentrations decreased significantly within 24 hours of delivery and this was reflected in all lipoproteins. However, while triglyceride levels continued to decrease rapidly returning to nonpregnant levels during the puerperium, cholesterol in low-density lipoprotein remained elevated for at least six to seven weeks post partum.

Adult↗
PubMed1979

Primary type I hyperlipoproteinaemia--a metabolic and family study.

Primary Type I Hyperlipoproteinaemia is the rarest phenotype of the inherited hyperlipidaemias. A study of the plasma lipids, lipoprotein distribution and apoprotein concentrations has been carried out in a propositus and in three generations of her immediate family, as has associated post heparin lipolytic activity (PHLA). The propositus presented in infancy with spontaneous bruising and abdominal pain. She has gross chylomicronaemia in the presence of depressed PHLA, which is due to deficiency of lipoprotein lipase. Apo Al and B levels are depressed in concert with low density and high density lipoproteins. Introduction of a low fat diet has resulted in loss of symptoms but plasma lipids remain abnormal. Within her immediate family, six of nine members have depressed PHLA. Two such members have elevated plasma triglycerides, one associated with hypercholesterolaemia and peripheral vascular disease. Low PHLA in this family is then associated with different lipoprotein phenotypes.

Adolescent↗
PubMed1978

Clinical trial experience by simulation: a workshop report.

A new computer program for experimental design simulation was used in a three-day postgraduate workshop on clinical trials. Participants were given information on a fictitious new drug and asked to design a trial to evaluate it. On the first day they reviewed the data and designed a protocol, and results for these specifications were generated on the computer. The second day was spent analysing results, and on the last day the findings of the different studies were presented at a symposium. Flexibility of the program ensured a high degree of realism in all trials and emphasised the influence of design on results and conclusions.

Adolescent↗
PubMed1977

Perinatal plasma lipid concentrations.

The effect of the maternal environment on umbilical cord plasma lipid concentrations was studied in a group of mothers and babies. Changes in neonatal plasma concentrations during the first week of life were followed in a small group of infants. The lipoprotein distribution of the cholesterol and triglyceride content of umbilical cord plasma was similar to that seen in maternal plasma at delivery. Neonatal plasma cholesterol was significantly correlated with the cholesterol content of maternal low density lipoprotein. Neonatal plasma triglyceride concentration was related to maternal parity, duration of labour and the existence of maternal hypertension and to the occurrence of foetal distress and dysmaturity.

Cholesterol↗
PubMed1977

Facial nerve injury. A short review.

Despite considerable advances in technique, experience and skill, the precise place of surgery in the treatment of facial nerve injury remains uncertain. The mechanism of delayed facial palsy is not yet clear, and there is still debate about the value of tests for early evidence of denervation. Recent literature has been reviewed.

Adolescent↗
PubMed1976

The effects of dietary fatty acids and cholesterol on the milk lipids of lactating women and the plasma cholesterol of breast-fed infants.

The plasma cholesterol concentration and the composition of the plasma fatty acids was altered by dietary means in 10 lactating women. The effects of these changes in the plasma on the lipid constituents of mature human milk were studied over periods of several weeks. In eight infants who were being breast-fed, the changes in the plasma cholesterol concentration were correlated with the changes that were induced in the milk lipids. Significant alteration in the women's plasma cholesterol levels did not change the cholesterol concentration in milk. The cholesterol content of milk was closely correlated with the concentrations of the other milk lipids, supporting a functional role for the cholesterol in the secretion of milk fat. In the maternal milk consumed by the eight infants the linoleate content rose from 9.4% to 15.5% of total fatty acids as a result of a moderate increase in dietary polyunsaturated fat. This led to a fall in the infants' plasma cholesterol levels, from an average of 185 to 157 mg/100 ml.

Adult↗
PubMed1976

Greater bile acid excretion with soy bean than with cow milk in infants.

The excretion of fecal sterols and bile acids was measured in five infants from the 1st week of life to 2 or 3 months of age as the composition of their diet was changed from cow milk to soy bean milk. Bile acid excretion, adjusted for body weight, was initially lower during the 1st than during the 3rd week, when it reached adult values. The average excretion of bile acids was 6.8 mg/kg per day with soy bean milk and 3.6 mg/kg per day with cow milk. Net sterol excretion (total sterol output minus cholesterol intake) was also twice as high with soy bean milk and probably reflected enhancement of cholesterol re-excretion as well as of synthesis since the cholesterol content of soy beans is nil. However, net sterol excretion remained higher with soy bean than with cow milk even when egg yolk cholesterol was added to the soy bean milk. It is concluded that the substitution of soy bean milk for cow milk, which lowered the plasma cholesterol in all infants (even in the presence of dietary cholesterol) leads to an increase in bile acids and probably also in cholesterol excretion in young infants.

Animals↗
PubMed1976

Comparison of plasma lipids at birth and in second year of life.

The value of measuring plasma lipids at birth as a guide to hyperlipidaemia in the future has been studied in 230 infants. There was a weak overall correlation between the cholesterol concentration at birth and during the second year of life (r = +0-215, P less than 0-05). There was no such relationship for triglyceride concentration. Not one of seven infants showing hypercholesterolaemia at birth had a raised level at follow-up. By contrast, all seven infants whose cholesterol levels exceeded two standard deviations at follow-up had normal values at birth. This discrepancy may reflect the influence of diet on plasma lipids. The mean plasma cholesterol and triglyceride concentrations during the second year were significantly lower in those infants being fed diets that contained increased amounts of unsaturated fat. The likelihood of hyperlipidaemia being found during the second year of life therefore depended more on the nature of the infant's food than on the presence of hyperlipidaemia at birth. The added influence of genetic components was suggested by the finding of a greater prevalence of early cardiovascular events in the families of infants showing hyperlipidaemia at one to two years of age.

Cholesterol↗
PubMed1975

Pupillary constriction and ptosis following caudal epidural analgesia.

This study reports pupillary changes occurring in seventeen of twenty pregnant women at term who received caudal analgesia for the relief of pain in the first and second stages of labour. It is suggested that 10 ml or more of analgesic solution, injected into the sacral epidural space, reaches high enough (probably to T1) to cause meiosis and/or ptosis.

Anesthesia, Caudal↗