RETARDED FETAL BRAIN DEVELOPMENT RESULTING FROM SEVERE DIETARY IODINE DEFICIENCY IN SHEEP

Potter B.J., Mano M.T., Belling G.B., Mcintosh G.H., Hua C, Cragg B.G., Marshall J., Wellby M.L. & Hetzel B.S. 1982 Neuropathology and Applied Neurobiology 8, 303–313 Retarded fetal brain development resulting from severe dietary iodine deficiency in sheep Sheep have been used to study the effect of dietary iodine deficiency on the development of the fetal brain. Severe iodine deficiency caused reduction in fetal brain and body weights and in brain DNA and protein from 70 days gestation to parturition. The lowered brain weight and brain DNA at 70 days gestation indicates a reduced number of cells, probably due to slower neuroblast multiplication which normally occurs from 40–80 days in the sheep, and the reduction in DNA and protein after 80 days implies that the development of neuroglia could be slowed also in iodine deficiency. Morphological changes were observed in both the cerebral hemispheres and the cerebellum. In the cerebral hemispheres of the iodine-deficient fetuses an increased density of neurons was apparent histologically in the motor cortex and visual cortex and in the CAI and CA4 areas of the hippocampus in comparison with controls. In the cerebellum there was delayed migration of cells from the external granular layer to the internal granular layer and increased density of Purkinje cells in the iodine-deficient fetal brains. In addition, the molecular area was increased and the medullary area reduced in comparison with controls. These changes are indicative of delayed brain maturation. Evidence of fetal hypothyroidism was provided by low fetal thyroid iodine and plasma T4 values, thyroid hyperplasia from 70 days gestation, significant reduction in body weight at the same time as the brain retardation, and absence of wool growth and delayed skeletal maturation near parturition. It is apparent from the biochemical and histological changes observed during iodine deficiency that iodine is an essential element for normal fetal brain and physical development in the sheep.     

Impact of AV Conduction Disorders on SafeR Mode Performance

Purpose: CAN-SAVE R is a Canadian multicenter study that compares the effects of a new pacing mode algorithm designed to minimize right ventricular (V) pacing versus DDD mode with a long atrioventricular (AV) delay in a general population of pacemaker (PM) recipients .
Study Participants: Patients with permanent atrial fibrillation (AF) or high-degree AV block (AVB) were excluded. We present preliminary data collected in 208 patients (mean age = 71 ± 11 years, 68% men), for the 2-month baseline period during which all PM were programmed in the new pacing mode. The pacing indications were sinus node disease (SND) without AVB in 39%, AVB without SND in 30%, SND and AVB in 16%, and miscellaneous in 15% of patients.
Results: The mean percent V pacing in the overall population was 9.5 ± 23.8% (range = 0–100%, median <1%), ranging between 0.5 ± 1.5% (median = 0) in patients without AVB and 18.7 ± 31.2% in patients (median = 1) with AVB. Adverse events potentially related to the new pacing mode were observed in two patients with AVB.
Conclusions: A new pacing mode was effective and safe in a general population of PM recipients without permanent AVB and was associated with an overall <1% median V pacing. CAN-SAVE R will compare the long-term effects of the new pacing mode with DDD with a long AV delay on clinical outcomes and cardiac function.     

Ageing reduces sympatho-suppressive response to head-out water immersion in humans

Muscle sympathetic nerve activity (MSNA) is suppressed during thermoneutral head-out water immersion (HOI) in humans. In this study, the effects of ageing on the suppressive response of MSNA to HOI were determined. MSNA was recorded microneurographically from the tibial nerve in 16 healthy men, 10 of whom were aged 19–30 years (young group) and six aged 45–67 years (older group). MSNA was suppressed in all the subjects during HOI. The suppressive response was significantly less prominent in the older group than in the young group. A significant negative correlation between age and the suppressive response of MSNA induced by HOI (r=-0.53, P<0.05) was found. We conclude that suppressive response of sympathetic nerve activity to HOI is reduced with age.     

Current management of ovarian carcinosarcoma

Ovarian carcinosarcomas (OCS), also known as malignant mixed müllerian tumors, are uncommon malignancies that carry a poor prognosis. The presentation of OCS is usually indistinguishable from that of epithelial ovarian cancer. Due to its low frequency, prospective trials have been difficult to perform, but there is evidence that OCS are sensitive to platinum-based chemotherapy. Recent studies have shown encouraging results with platinum-ifosfamide and platinum-taxane schedules, which are usually considered the treatment of choice. However, poor performance status at presentation is also a common problem, so that many patients may be unsuitable for combination chemotherapy but may still benefit from single-agent platinum or ifosfamide or, occasionally, from nonplatinum schedules such as ifosfamide plus paclitaxel. Aggressive cytoreductive surgery appears to have a positive impact on outcome and should probably be offered to most patients. However, this procedure has been associated with higher rates of complication in OCS and should only be attempted by experienced (gynecological) surgeons in centers with expertise in the management of gynecological malignancies.