The hypothalamus and photoperiodic control of FSH secretion by melatonin in the male Syrian hamster.

In the photoinhibited castrated male Syrian hamster, removal of the pineal gland or transfer to long photoperiods was followed by a rapid increase in the serum concentration of FSH. Levels were significantly above those of controls within 10 days. Central passive immunization of pineal-intact photoinhibited castrated animals against melatonin had a stimulatory effect on serum FSH levels, comparable with that observed following pinealectomy or transfer to short days. The effects of pinealectomy were blocked by programmed s.c. infusions of melatonin in a time-dependent manner. Serum FSH levels remained low in animals receiving 100 ng melatonin delivered over 10 h but the same mass of melatonin delivered over 4 h had no effect on the response to pinealectomy. Lesions of the anterior hypothalamus had no effect on the pinealectomy-induced increase of serum FSH in animals receiving saline infusions. However, in lesioned animals, programmed infusions of melatonin were no longer able to suppress the rise in FSH following pinealectomy. These results demonstrated that pineal melatonin is the mediator of central photoperiodic control of FSH secretion. The duration of the melatonin signal determines its effectiveness and an intact anterior hypothalamus is necessary for the signal to be read and/or the appropriate neuroendocrine response expressed.

Bone density: is it affected by orchidectomy and radiotherapy given for stage I seminoma of the testis?

A cross-sectional study of bone density involving 30 patients who had undergone orchidectomy and para-aortic radiotherapy for Stage I seminoma of the testis, has been performed. Bone density measurements were made of the whole body, lumbar spine and hips, including all irradiated areas. Comparison was made with previously obtained standard sex and age matched control data. The 30 patients treated for seminoma had a significantly increased mean bone density compared with age matched normal values. No significant differences were demonstrated between the mean bone densities of the irradiated and non-irradiated hips. There was no significant relationship between bone density measurement and time since orchidectomy or radiotherapy. These results suggest that nodal irradiation for seminoma has little long term effect on bone density.

The radiological appearances of invasive cribriform carcinoma of the breast. Nottingham Breast Team.

Invasive cribriform carcinoma (ICC) of the breast is characterized by a cribriform histological architecture. It is rare, accounting for 0.6% of breast cancers in Nottingham and has an excellent prognosis. Its radiological features have not been previously described. Preoperative mammograms were available in eight cases (6 symptomatic, 2 screen-detected) and preoperative ultrasound examinations in four. The tumour was mammographically occult in four (50%) cases. The four tumours which were visible on mammography all showed as a large (20-35 mm) spiculated mass and two contained a few flecks of punctate calcification. The ultrasound appearances were not entirely typical of breast carcinoma. Three of four showed an ill-defined, inhomogeneous solid mass, but without the distal acoustic attenuation found in 60-97% of other forms of breast carcinoma. We conclude that ICC has imaging characteristics distinct from tubular carcinoma, which is its closest histological analogue.