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Biomedical subjects

R J Morgan

Publications and source records attributed to R J Morgan.

At least 253 records · Page 14Linked to original sources
PubMedDate not supplied

Slow wave field potentials in the rat brain during the estrous cycle.

Twenty-one rats were implanted with chronic electrodes in the amygdala, preoptic area, and arcuate nucleus-median eminence region in an effort to learn more about electrical activity in the limbic system and the relationship to the estrous cycle. Slow wave field potentials from these three areas were recorded for ten minutes of each half-hour between 10:00 a.m. and 3:30 p.m. each day of the four-day estrous cycle. These recordings were analyzed for amount of correlation and direction of conduction between pairs of electrodes and for conduction times between pairs of sites. Slow wave field potential conduction from the amygdala to the preoptic area during the "critical period" on the day of proestrus lasts longer and takes longer en route than at other times of the cycle. This is statistically significant at p < 0.002 and implies a change in the conducting pathway during this time.

Action Potentials↗
PubMedDate not supplied

Uterine effects of tamoxifen: a prospective study.

The purpose of the study was to evaluate tamoxifen-associated changes in the vagina and uterus in postmenopausal breast cancer patients. Between June 1994 and December 1998, 45 patients enrolled in a prospective study before commencing tamoxifen therapy. Patients with endometrial thickness >5 mm or neoplasia were excluded. Transvaginal ultrasonography, vaginal maturation indexes (VMI), and endometrial biopsy were performed at baseline and repeated at 6 months (n= 42), 1 year (n= 39), 2 years (n= 32), 3 years (n= 26), 4 years (n= 19), and 5 years (n= 15). For the 39 patients followed for 1 year, VMI (% parabasal/intermediate/superficial) was 21/71/8 at baseline compared with 1/90/9 at 1 year (P value = 0.0008/0.001/0.78). At baseline, mean endometrial thickness and uterine volume were 2.6 mm and 64 cm(3), respectively, compared with 5.8 mm and 84 cm(3) at 1 year (P= 0.0002, 0.002). At baseline, 80% of patients had atrophic endometrium and 9% proliferative endometrium compared with 61% and 26% at 1 year, respectively (P= 0.04). No cases of endometrial hyperplasia or adenocarcinoma were detected. Findings observed at 6 months persisted through 5 years of follow-up. Tamoxifen exerts a weak estrogenic effect on the vagina and uterus in highly prescreened postmenopausal women without preexisting endometrial pathology.

Adult↗
PubMedDate not supplied

Mg deficiency in chronic inflammatory bowel disease and requirements during intravenous nutrition.

Assessment of magnesium (Mg) status by serum and 24-hr urine estimations has been used to study a group of 17 patients with severe Crohn's disease, 10 of whom have required intravenous (IV) nutrition. Mg depletion was present in 15 (88%) and severe enough to cause symptoms in two. Urine levels were low in most patients and would appear to be a more sensitive indication of Mg depletion than serum levels alone. Serum Mg levels were significantly lower in the Crohn's group than in a group of hospital controls; 5-10 mmol of IV Mg were required daily to prevent Mg depletion during IV nutrition and some patients required higher intakes. Three patients with particularly severe malabsorption required oral Mg supplements in the long-term. The rationale for using our method of assessing Mg status, and the importance of recognizing and treating chronic Mg deficiency are presented.

Adolescent↗