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Biomedical subjects

J Simpson

Publications and source records attributed to J Simpson.

At least 307 records · Page 17Linked to original sources
PubMed1982

Effect of heparin on plasma free fatty acid concentrations after acute myocardial infarction.

Free fatty acid concentrations in plasma measured after in vivo heparinisation are often overestimated because of ex vivo lipolysis of variable degrees. A new method has been developed using immediate extraction of blood which obviates this and shows that the true rise in plasma free fatty acid concentration after heparin in ambulant ward patients and in patients with acute myocardial infarction is less than previously reported. The small rise in plasma free fatty acid concentration after heparin is unlikely to have adverse metabolic effects in most patients during acute myocardial infarction.

Adult↗
PubMed1981

Choline uptake in patients with Alzheimer pre-senile dementia.

Serum and CSF choline levels were measured in 12 patients with pre-senile Alzheimer's disease before and 1 hour after administration of 1.5 g choline chloride or 25 g lecithin granules. Serum choline levels were increased threefold and CSF choline levels by 72%. CSF choline levels in the untreated Alzheimer patients did not differ significantly from age-matched controls. In 35 neurological controls, CSF choline levels increased with age (R = 0.64, p less than 0.001). Choline influx into erythrocytes from 10 male and 10 female Alzheimer patients did not differ significantly from 40 male and 43 female controls. Choline influx into erythrocytes was not related to age or sex, although the range of values was greater (p less than 0.05) in females than in males. Our results indicate that there is no impairment of choline transport into CSF or erythrocytes in patients with pre-senile Alzheimer's disease.

Adolescent↗
PubMed1981

The interaction of dithiothreitol and acetyl coenzyme A in a radiochemical assay for rat brain ATP:citrate oxaloacetate lyase.

[14C]Acetyl-CoA was found to react spontaneously with dithiothreitol to give a relatively apolar product which was readily extractable into a butanol-toluene scintillant. This technique was used in rapid, reproducible assay for rat brain ATP:citrate lyase using [1,5-14C]citrate as substrate. The tissue extract, a 14,000 g supernatant, exhibited a lyase activity of approximately 7 nmol acetyl-CoA produced/min per mg supernatant protein, and was inhibited greater than or equal to 79% by alpha-ketoglutaric acid (10 mM), Cu2+ (1 mM) and Zn2+ (1 mM). [14C]Oxaloacetate, [14C]malate and endogenous citrate synthase were found not to interfere significantly with lyase estimations, but NADH was required in the reaction mixture to inhibit acetyl-CoA hydrolase activity.

ATP Citrate (pro-S)-Lyase↗
PubMed1980

Neurochemical observations in a case of Pick's disease.

Neurochemical markers of the activities of the cholinergic, gabaergic and dopaminergic systems were measured in post-mortem brain from a case of Pick's disease. No marked changes were found in the activities of choline acetyltransferase, acetylcholinesterase, L-glutamic acid decarboxylase and the concentration of dopamine. In areas of brain showing no histological changes, muscarinic receptor binding was within the normal range. In the cerebral cortex, which exhibited the neuropathological features of Pick's disease, the number of muscarinic cholinergic binding sites was much reduced, suggesting that the cortical neurones which are lost in Pick's disease are cholinoceptive.

Acetylcholinesterase↗
PubMed1980

The Doppler assessment of varicoceles and internal spermatic vein reflux in infertile men.

The Doppler technique has been used to evaluate venous reflux in the spermatic cord. Valsalva-induced reflux occurred on the left side in 83% and on the right side in 59% of 118 patients without clinical varicoceles and there was no difference in incidence between fertile and infertile men. The significance of Valsalva-induced reflux should be questioned. Greater importance should be attributed to the spontaneous venous reflux that occurred during quiet respiration in the majority of patients with varicoceles. Seven velocity waveform patterns are described and these are thought to represent increasing degrees of internal spermatic vein reflux and provide a basis on which it is possible to grade varicoceles. The Doppler grades correlated with the size of the varicocele, and with the internal spermatic vein diameter and testosterone concentrations.

Humans↗
PubMed1980

A new treatment for congenital nystagmus.

Congenital nystagmus is a disorder of eye movement with an associated reduction in visual acuity. The latter is mainly due to the intensity of the nystagmus (amplitude times frequency) allowing the object of regard to spend only a short time on the fovea. Training patients by an auditory feedback technique to control the nystagmus enables visual sensitivity to improve. This method is compared with present alternatives, and further studies are suggested.

Adult↗
PubMed1980

Urinary testosterone-17 beta-glucuronide as an indicator of androgen output in mice.

The androgenic status of female mice was assessed by measuring the concentration of testosterone-17 beta-glucuronide in serial samples of unextracted urine. The subcutaneous administration of testosterone (50 micrograms in lauric acid ethyl ester) resulted in a significant increase (P < 0.01) of the mean +/- s.d. concentration of urinary testosterone-17 beta-glucuronide (25.9 +/- 6.5 to 71.7 +/- 12.9 ng/ml) within 2 h. The 2-h values after the administration of 50 micrograms androstenedione or 50 micrograms dehydroepiandrosterone were 22.8 +/- 4.4 to 81.8 +/- 7.8 ng/ml (P < 0.001) and 23.4 +/- 2.7 to 121.8 +/- 20.3 ng/ml (P < 0.001) respectively. The values decreased progressively over the next 24 h. After the induction of superovulation with PMSG and hCG, the values for testosterone-17 beta-glucuronide increased significantly (P < 0.01) during the periovulatory period (5--24 h after hCG injection). The mean +/- s.d. value in pregnancy was higher (61.8 +/- 11.6 ng/ml; P < 0.001) than that in non-pregnant animals (30.7 +/- 12.3 ng/ml) and remained relatively constant between Days 1 and 16.

Androstenedione↗
PubMed1980

Ultrasound scanning of ovaries to detect ovulation in women.

Healthy volunteers with regular ovarian function, women taking oral contraceptives, and infertile patients being treated with clomiphene were studied longitudinally from day 7 of the cycle to menstruation. The main objective was to determine whether ovulation or failure to ovulate could be detected accurately by the use of ultrasound. The ovaries were scanned with a Kretz Combison 100 sector scanner every 1 to 3 days for morphologic changes consistent with follicle development, ovulation, and development of the corpus luteum. The morphologic changes were correlated with daily urinary hormone profiles. The estimated times of ovulation according to ultrasound and luteinizing hormone peak overlapped by 24 hours in 19 of 23 normal cycles and in 5 of 6 cycles of patients treated with clomiphene. Both techniques indicated that three of three women taking oral contraceptives did not ovulate. The ultrasound studies indicated a wide range in the diameter of the preovulatory follicle, which precludes follicular diameter as a single index for prediction of ovulation. However, by measuring the maximal diameter of the follicle and observing the morphologic changes within the ovary from follicle to corpus luteum, it was possible to detect ovulation in more than 80% of cycles studied. This technique was found to be quick, inexpensive, and efficient.

Clomiphene↗
PubMed1980

Sporadic Duchenne muscular dystrophy in females; genetic counseling of women with pelvifemoral muscular dystrophy.

The first two cases of sporadic Duchenne muscular dystrophy (DMD) in females without a family history of DMD are reported. Both females had normal chromosomes and were identified as DMD by in vitro studies of protein synthesis by muscle ribosomes and by carrier studies of the mother of the proband. These observations are important for the genetic counselor. The possible diagnosis X-linked DMD has to be considered for every female with sporadic pelvifemoral MD, and carrier studies have to be requested for the proband's mother and possibly other maternal female relatives.

Adult↗