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Biomedical subjects

C D Matthews

Publications and source records attributed to C D Matthews.

At least 109 records · Page 6Linked to original sources
PubMed1981

Human luteal phase function following oocyte aspiration from the immediately preovular graafian follicle of spontaneous ovular cycles.

Human luteal phase function as evaluated by peripheral venous blood steroid levels does not appear to be impaired following the aspiration of follicular fluid together with a cumulus enclosed oocyte and a number of granulosal cells from the immediate preovular follicle in women having otherwise spontaneous ovular cycles. The day to day levels of luteinising hormone, oestradiol-17 beta, 17 alpha-hydroxy-progesterone, progesterone and basal temperatures in 14 women who had their preovular follicle aspirated were compared with a control group of 28 spontaneously ovulating women. It was concluded that a carefully performed single aspiration of the contents of a preovular follicle, for the purpose of extra-corporeal fertilisation of the mature oocyte, did not lead to impaired steroid function of the subsequent corpus luteum, although the prolactin levels were increased due to the effects of the relaxant anaesthetic and/or the laparoscopic procedure. A safe and simple laparoscopic procedure is also described, which is particularly suitable for women with a likelihood of extensive pelvic adhesions.

Adult↗
PubMed1981

The role of the pineal gland in seasonality.

The life time reproductive performance of 2 flocks of Merino crossbred ewes pinealectomized at 7-60 days of age, and maintained in South Australia did not differ from that of sham-operated control animals kept in the same flocks. The pineal gland is therefore not a major determinant of reproductive success, but a role for the pineal in adjusting breeding activity to season is not excluded. It was confirmed that pineal denervation of adult ewes by cranial sympathectomy could have disruptive effects and evidence of a seasonal change in pineal function was obtained from studies of plasma levels of melatonin, a putative pineal hormone, and a pineal peptide with gonadotrophin releasing activity. That melatonin stems mainly, but not exclusively, from the pineal gland was confirmed by studies of urinary excretion values. Adult Merino ewes produced 39-90 micrograms melatonin/day, mostly (80%) during the dark period, whereas pinealectomized animals produced less than one-fifth this amount. A link was provided between the pineal gland and diet. Melatonin and other 5-methoxyindoles influenced the activity of alpha-chymotrypsin and may regulate the availability of precursor substances required for the synthesis of neurotransmitters important in reproduction.

Animals↗
PubMed1980

Predicting the luteinizing hormone surge: relationship between the duration of the follicular and luteal phases and the length of the human menstrual cycle.

Determination of blood serum levels of luteinizing hormone (LH) are used to detect the day of the midcycle surge. This information, collected over several menstrual cycles of numerous women, is used to derive mathematical expressions relating the day of the surge to the length of the cycle. The equations are subsequently employed to predict the most likely day of the LH surge, and hence the time of ovulation, solely from knowledge of the average length and variability of a woman's cycles, without the need for determinations of LH. A convenient table is provided for making this prediction.

Adult↗
PubMed1980

Concentrations of melatonin in the plasma of the rhesus monkey (Macaca mulatta).

A radioimmunoassay for the determination of concentrations of melatonin in the plasma of rhesus monkeys has been developed. Antiserum for the assay was raised against N-acetyl serotonin and there was a 100% cross-reaction with melatonin. Cross-reactivity with closely related indoles, precursors and metabolites was less than or equal to 1%. The lower of sensitivity of the assay was 4 pg/tube. The assay has been used for the investigation of diurnal variations and cyclical changes in melatonin concentrations in peripheral plasma of the rhesus monkey. The concentrations of melatonin ranged between 26.6 and 85.3 pg/ml during sampling for 24 hr. There was a distinct diurnal variation in the concentration of melatonin in plasma. The concentration during darkness (61.0+/-7.1 (S.E.M.) pg/ml) was greater (P less than 0.01) than that during illumination (40.1+/-6.1 pg/ml). There were no significant differences in the concentration of melatonin in plasma at any time during the 28 day menstrual cycle of the rhesus monkey.

Animals↗
PubMed1980

Optimal features of basal body temperature recordings associated with conceptional cycles.

Oral basal body temperature (BBT) recordings of 46 women that conceived by donor insemination and who had midcycle monitoring of luteinising hormone (LH) were analysed to establish features associated with an optimal cycle. All cycles exhibited a biphasic temperature shift associated with the follicular (mean + SD, 36.5 degrees C +/- 0.22) and luteal phases (36.8 degrees C +/- 0.19). Whilst a mean body temperature rise occurred on Day +1 when all cycles were analysed, individual patterns were seen at ovulation including no change or a decrease in BBT between Day 0 and Day +1. The BBT of the postovulatory phase was stable and only 4.5% of the 644 observations made showed a change of more than 0.2 degrees C from day to day. It was concluded that the BBT charting has limitations when used to recognize the day of ovulation, and that some variable patterns of the early luteal phase are consistent with conception. Finally, optimal luteal phases demonstrated remarkable stability.

Body Temperature↗
PubMed1979

The pineal gland as an APUD organ: supporting evidence and implications.

It is only in recent years that the pineal gland has emerged from being thought of as non-functional and unimportant. The rise from obscurity has been the result of the interest of investigators of multidisplinary origins; such approaches, whilst clearly advancing understanding, also tend to leave knowledge fragmentary. In the last decade, a new neuroendocrine axis known as the APUD system has been delineated and scientifically accepted. The essence of the concept has been to link a physically widely dispersed and apparently unconnected series of glandular structures by a common embryological derivation and their secretion of closely similar functional products. The present proposal collates evidence for the inclusion of the pineal gland within the APUD system. In addition, because of the proven connections and response of the pineal gland to environmental changes, it is hypothesised that pineal products may provide the link between the environment and other members of the widely dispersed APUD system and thereby temper body homeostasis.

APUD Cells↗
PubMed1979

The influence of insemination timing and semen characteristics on the efficiency of a donor insemination program.

The analysis of accumulated data from conceptional and nonconceptional ovulatory menstrual cycles of patients undertaking artificial donor insemination has allowed some observations to be made on the practical aspects which may influence the efficiency of the program. The evidence suggests that with the use of preserved semen, accurate timing of insemination is essential, and that days 0 and +1 with respect to the luteinizing hormone surge appear to be advantageous as compared with closely related days. When the numbers of motile spermatozoa which were inseminated over a critical 4-day interval were analyzed, the results also suggested that improved conception rates occurred when larger numbers of active spermatozoa were used. A comparison was made between those patients who had been inseminated on a single occasion and those inseminated on more than one occasion during the periovulatory period. The results obtained from those cycles inseminated on a single occasion were inferior to those obtained from cycles inseminated more than once. Finally, some limited comparison is drawn between the established insemination programs of bovine husbandry and the relatively inefficient human experience. One explanation may lie in the wider spectrum of donor semen desirable for the human programs.

Cell Count↗
PubMed1979

Plasma melatonin, luteinizing hormone, follicle-stimulating hormone, prolactin, and corticoids in two patients with pinealoma.

Plasma melatonin, LH, FSH, PRL, and corticoids were measured in two patients with pineal tumors. Plasma melatonin was not detectable (less than 7 pg/ml) in either patient while gonadotropin and cortisol levels were within the normal range. One patient exhibited low PRL levels and the other patient, a prepubertal boy, had elevated levels. The clinical value of the measurement of melatonin as a potential marker for all pineal tumors must be questioned.

Adolescent↗
PubMed1977

Assessment and treatment of female urinary incontinence by cystometrogram and bladder retraining programs.

One hundred female patients complaining of urinary incontinence without evidence of associated disease or urinary infection were assessed by clinical appraisal and by simple cystometrogram. Discrepancies were apparent between the two methods of patients assessment. Treatment was primarily based on cystometrogram patterns, and included the surgical correction of the urethrovesical defect, the institution of a program of micturition retraining, or a combination of both methods. Based on a short follow-up assessment period, of those 68 patients chosen for surgery, 78% were cured and 91% were markedly improved. Bladder retraining programs alone were instituted for 32 patients, and a marked (72%) improvement rate was demonstrated. It is suggested that the cystometrogram has an integral and essential place in the assessment of female urinary incontinence and may be easily integrated into practice. Bladder retraining programs may be most usefully employed for some patients found to have bladder dysfunction.

Female↗