Paul Belchetz - Academia.edu (original) (raw)

Papers by Paul Belchetz

Ceylon Medical Journal, 2014

The syndrome has vast epidemiological, socioeconomic and health care delivery implications for so... more The syndrome has vast epidemiological, socioeconomic and health care delivery implications for south Asia Hirsutism Frontal balding Acne Hydradenitis suppurativa Resulting complications Anovular infertility Risk stratification Increased risk Acyclic oestrogen excess

Endocrinology, Diabetes & Metabolism Case Reports, 2017

Summary A male patient presented at the age of 30 with classic clinical features of acromegaly an... more Summary A male patient presented at the age of 30 with classic clinical features of acromegaly and was found to have elevated growth hormone levels, not suppressing during an oral glucose tolerance test. His acromegaly was originally considered to be of pituitary origin, based on a CT scan, which was interpreted as showing a pituitary macroadenoma. Despite two trans-sphenoidal surgeries, cranial radiotherapy and periods of treatment with bromocriptine and octreotide, his acromegaly remained active clinically and biochemically. A lung mass was discovered incidentally on a chest X-ray performed as part of a routine pre-assessment for spinal surgery 5 years following the initial presentation. This was confirmed to be a bronchial carcinoid tumour, which was strongly positive for growth hormone-releasing hormone (GHRH) and somatostatin receptor type 2 by immunohistochemistry. The re-examination of the pituitary specimens asserted the diagnosis of pituitary GH hyperplasia. Complete resolu...

Archives of Gynecology, 1981

Ohne Zusammenfassung

Obstet Gynecol Surv, 1979

In rhesus monkeys with hypothalamic lesions that abolish gonadotropic hormone release by the pitu... more In rhesus monkeys with hypothalamic lesions that abolish gonadotropic hormone release by the pituitary gland, the constant infusion of exogenous gonadotropin-releasing hormone (GnRH) fails to restore sustained gonadotropin secretion. In marked contrast, intermittent administration of the synthetic decapeptide once per hour, the physiological frequency of gonadotropin release in the monkey, reestablishes pituitary gonadotropin secretion. This phenomenon is attributable to the

Endocrinology, 1978

Pulsatile LH secretion was re-established in ovariectomized monkeys bearing hypothalamic lesions ... more Pulsatile LH secretion was re-established in ovariectomized monkeys bearing hypothalamic lesions by an intermittent infusion of LHRH. The administration of estradiol to such animals resulted in a prompt cessation of these pulsatile discharges of LH and a resultant decline in the mean plasma concentration of the gonadotropin. The time course of this inhibition of LH secretion was indistinguishable from that observed after estrogen administration to ovariectomized animals with intact nervous systems. In contrast, phentolamine did not interrupt the pulsatile LH discharges occasioned by the hourly administration of exogenous LHRH to the lesioned animals. These results are consistent with the conclusion that the acute negative feedback action of estradiol on circhoral LH release in the monkey is at the level of the pituitary gland, whereas the inhibitory action of phentolamine on this mode of LH secretion is at a neural site.

Endocrinology, 1981

In adult ovariectomized rhesus monkeys bearing hypothalamic lesions which reduced circulating LH ... more In adult ovariectomized rhesus monkeys bearing hypothalamic lesions which reduced circulating LH and FSH to undetectable levels, sustained elevated gonadotropin concentrations were reestablished by the intermittent administration of gonadotropin-releasing hormone (GnRH) at the rate of 1 microgram/min for 6 min once every hour. The effects of varying either the frequency or the amplitude of these GnRH pulses on gonadotropin secretion were examined in such animals. Increasing the frequency of GnRH administration from the physiological one pulse per h to two, three, or five pulses h while maintaining a constant infusion rate and pulse duration resulted in gradual declines in plasma gonadotropin concentrations. These declines were most profound at the highest frequencies and the consequence of reduced pituitary responses to individual GnRH pulses. Decreasing the frequency of GnRH pulses from one per h to one every 3 h led to variable declines in plasma LH levels, but circulating FSH invariably rose. Reducing the GnRH infusion rate from 1 to 0.1 mg/min while maintaining constant frequency and pulse duration resulted in abrupt declines in plasma LH and FSH to immeasurable levels, although pulsatile increments in circulating GnRH concentrations without a concomitant reduction in plasma LH concentrations, which remained unchanged. An infusion rate of 0.5 microgram/min resulted in unstable plasma LH and FSH levels. These results demonstrate that changes in the frequency or amplitude of hypophysiotropic stimulation have profound effects on plasma gonadotropin levels as well as on FSH to LH ratios in the circulation. The physiological implications of these observations are discussed.

Clinical Radiology, Jun 1, 1986

Pulmonary function tests and a radiological assessment of the larynx and cervical trachea were pe... more Pulmonary function tests and a radiological assessment of the larynx and cervical trachea were performed in 26 patients with acromegaly. Pulmonary function tests demonstrated six out of 26 patients to have upper-airways obstruction, while laryngeal tomography demonstrated 14 cases with marked narrowing of the true and false cords. The tracheal dimensions were normal. The thickness of both the true and the false cords showed a statistically significant increase, using the Mann-Whitney U-test, in both male and female patients compared with controls. The transverse tracheal diameter was significantly decreased in male but not female patients. These findings suggest that pulmonary function tests and radiological assessment are of value in indicating those patients with acromegaly who may be at increased risk when undergoing general anaesthesia.

Life Sciences, 1986

The sexually mature mammal secretes luteinizing hormone in a pulsatile fashion. This is presumed ... more The sexually mature mammal secretes luteinizing hormone in a pulsatile fashion. This is presumed to depend on the intermittent release of hypothalamic gonadotropin-releasing hormone (GnRH). The isolated guinea pig hypothalamus has been studied because, in this species, as in primates, the pulse generator appears to reside within the medial basal hypothalamus. The basal 2 ..~of guinea pig hypothalami were rapidly removed and perifused at 37 C wlth KreDs-Ringer solution containing 20 mM bacitracin gassed with 95% 09, 5% CO 2. The eluates were sampled at 15 and 5 min intervals ~ and pulsatile patterns of GnRH were consistently observed for periods up to 72h.

Proceedings of the Royal Society of Medicine

British medical journal (Clinical research ed.)

N Engl J Med, 1994

Review Article from The New England Journal of Medicine Hormonal Treatment of Postmenopausal Wo... more Review Article from The New England Journal of Medicine Hormonal Treatment of Postmenopausal Women.

The American Journal of Gastroenterology

Gastrointestinal symptoms are a common feature of Addison's disease, but the diagnosis ma... more Gastrointestinal symptoms are a common feature of Addison's disease, but the diagnosis may be delayed because of the nonspecific nature of the symptoms. This report describes nine patients with Addison's disease who presented to our unit over the past 3 yr. Eight had severe or unusual gastrointestinal symptoms at presentation. One, already known to have Addison's disease, required several admissions to the hospital because of unexplained abdominal pain and vomiting before inadequate glucocorticoid replacement was diagnosed. All but one had previously attended the hospital, but the diagnosis of Addison's disease had been overlooked. Five eventually presented in crisis. It is important to exclude Addison's disease in all patients with unexplained abdominal symptoms.