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Biomedical subjects

J Findlay

Publications and source records attributed to J Findlay.

35 records · Page 2Linked to original sources
PubMed1986

Relative levels of thecal blood flow in atretic and non-atretic ovarian follicles of the conscious sheep.

The relative level of blood flow through thecal capillaries (RTF) in individual atretic and non-atretic follicles greater than 1 mm was measured in conscious ewes by injecting 15 micron radioactive microspheres into the aorta near the origin of the ovarian artery, and determining the ratio of radioactivity per mg protein in theca of individual follicles to that in the non-luteal portion (stroma plus follicles less than 1 mm diameter) of the corresponding ovary. In follicles greater than 1 mm diameter, RTF in those showing advanced stages of atresia (stages IV and V) was significantly less than that in non-atretic (stage I) follicles. RTF values in non-atretic (stage I), early atretic (stage II) and moderately atretic (stage III) follicles did not differ significantly. There was no effect of follicular diameter (P greater than 0.05) on the relative level of blood flow within individual thecae or of atresia on thecal protein content. These data indicate that reduced thecal blood flow is associated with advanced atresia of antral follicles and are in accordance with the findings of previous histological studies. Whether thecal ischaemia is a factor involved in the onset of atresia, or occurs as a consequence of the degenerative process, remains uncertain.

Animals↗
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

A new system for sternal intraosseous infusion in adults.

BACKGROUND: Intraosseous (IO) infusion provides an alternative route for the administration of fluids and medications when difficulty with peripheral or central lines is encountered during resuscitation of critically ill and injured patients. OBJECTIVE: To report the first 50 uses of a new system for emergency IO infusion into the sternum in adults, the Pyng F.A.S.T.1 IO infusion system. METHODS: Six emergency departments and five prehospital emergency medical services (EMS) sites in Canada and the United States provided clinical and/or research data on their use of the IO system in a pilot study of success rates, insertion times, and complications. Indications for use included adult patient, urgent need for fluids or medications, and unacceptable delay or inability to achieve standard vascular access. A basic data set was standardized for all sites, and some sites collected additional data. RESULTS: The overall success rate for achieving vascular access with the system was 84%. Success rates were 74% for first-time users, and 95% for experienced users. Failure to achieve vascular access occurred most frequently in patients (5 of 9) described subjectively by the user as "very obese," in whom there was a thick layer of tissue overlying the sternum. Mean time to achieve vascular access was 77 seconds. Flow rates of up to 80 mL/min were reported for gravity drip, and more than 150 mL/min by syringe bolus. Pressure cuffs were also used successfully, although fluid rate was controlled by clamping the line. Further research on flow rates is needed. No complications or complaints were reported at two-month follow-up. CONCLUSION: These early data indicate that sternal IO infusion using the new F.A.S.T.1 IO system may provide rapid, safe vascular access and may be a useful technique for reducing unacceptable delays in the provision of emergency treatment.

Adolescent↗
PubMedDate not supplied

Shifting time.

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Hospital Units↗