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Biomedical subjects

J Findlay

Publications and source records attributed to J Findlay.

31 records · Page 2Linked to original sources
PubMed1985

Mechanisms of epileptogenesis in photosensitive epilepsy implied by the effects of moving patterns.

The triggering of epileptiform EEG discharges by pattern is thought to depend on the intensity of excitation within the visual cortex. The present study investigates the role of the synchronisation of neuronal activity by the stimulus. In 10 pattern-sensitive subjects the effects of the following patterns have been compared: (1) static gratings, (2) gratings oscillating in a direction orthogonal to the lines (which should synchronise activity in direction-sensitive cortical units), and (3) gratings drifting at the same angular velocity (which should produce little or no synchronisation, because the contours enter and leave the overlapping receptive fields of individual neurones asynchronously). The oscillating gratings were most, and the drifting least, epileptogenic. In 2 further subjects oscillating and phase-reversing patterns were more epileptogenic than drifting gratings. Although open to alternative explanations, the findings conform with predictions from the hypothesis that synchronisation of individual cortical neurones by the stimulus contributes to epileptogenesis in photosensitive subjects.

Adolescent↗
PubMed1981

Ovarian and peripheral blood inhibin concentrations increase with gonadotropin treatment in immature rats.

The effects of PMSG treatment on ovarian and circulating inhibin concentrations in immature female rats has been examined. Sixty-four hours after injection of 10, 20 or 40 IU of PMSG the animals were anesthetized with ether; ovaries, uteri and blood from the abdominal aorta were collected. Steroid-free extracts of ovary and serum samples were prepared and assayed quantitatively for inhibin activity in an in vitro bioassay system. PMSG treatment elevated (p less than 0.001) both uterine and ovarian wt, and ovarian and peripheral concentrations of inhibin. A dose-related increase occurred ovarian wt, and in peripheral and ovarian content of inhibin. Ovarian inhibin concentration increased with dose of PMSG until the highest dose, where a significant decline and luteinization were seen. Peripheral FSH levels were significantly lowered at all doses of PMSG treatment; in contrasts, LH was significantly elevated, due to cross-reaction of PMSG in the LH assay. These results show that both ovarian and circulating levels of inhibin are related to the degree of gonadotropic stimulation, supporting the view that inhibin is involved in folliculogenesis and in the feedback regulation of FSH.

Animals↗
PubMed1976

Lack of effect of alcohol on small intestinal binding of the vitamin B12 - intrinsic factor complex.

Absorption of 57Co-labelled vitamin B12 - intrinsic factor (IF) complex and its binding to mucosal precipitate and brush border fractions of rat small intestine was studied in rats pair-fed with a liquid diet containing ethanol 5 g/100 ml, 35% of calories, or isocalorically substituted sucrose. IF was obtained from rats fasted for 18 h. and for each experiment the amount of vitamin B12 added was the minimum required to achieve maximum binding to IF. Rats fed alcohol exhibited hepatic steatosis, proliferation of smooth endoplasmic reticulum, and disordered mitochondria after 6 weeks on the diet, and absorption of vitamin B12, fed with IF by stomach tube, was reduced signficantly. In contrast, binding of 57Co-labelled vitamin B12 -IF complex to mucosal precipitate and brush border fractions was never less than that of fractions from control rats at 4, 8 and 12 weeks on the alcohol diet. Furthermore, binding to the brush border was significantly greater in alcohol-fed rats at 12 weeks whether expressed per unit of beta-naphthylamidase (EC 3.4.1.1) activity or per milligram of protein. Total mucosal sucrase (EC 5.2.1.26) and beta-naphthylamidase were unchanged or slightly increased (beta-naphthylamidase at 12 weeks) on the alcohol-containing diet indicating that total brush border membrane was not reduced. Total brush border binding activity was the same in alcohol-fed and control rats at each time period. These results indicate that malabsorption of vitamin B12 in rats fed alcohol cannot be due to decreased binding of the vitamin B12 - IF complex by brush border membrane receptors, or secondary to a net decrease in membrane receptors.

Animals↗
PubMedDate not supplied

The establishment and maintenance of pregnancy using in vitro fertilization and embryo donation in a patient with primary ovarian failure.

Ovarian steroid replacement therapy in the ovariectomized ewe, given in the correct sequence to mimic endogenous steroid changes in the normal ovulatory cycle, allows the development of embryos transferred in utero. A similar type of sequential therapy was designed for steroid replacement in women with primary ovarian failure. This produces the histological changes in uterine endometrial morphology and plasma oestradiol and progesterone similar to those observed in the normal ovulatory cycle. We now report that in one of these women a donated oocyte, fertilized by her husband's spermatozoa and cultured to the two-cell stage in vitro, was transferred in utero, resulting in a normal pregnancy and the delivery of a healthy child. Oestrogen therapy was withdrawn at 12 weeks and progesterone at 19 weeks gestation. This technique allows the treatment of human infertility due to primary ovarian failure.

Embryo Transfer↗
PubMedDate not supplied

Shifting time.

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Hospital Units↗