ANTEROVENTRAL WALL OF THE THIRD VENTRICLE AND DORSAL LAMINA TERMINALIS: HEADQUARTERS FOR CONTROL OF BODY FLUID HOMEOSTASIS?

1. The subfornical organ, median preoptic nucleus and the organum vasculosum of the lamina terminalis (OVLT) are a series of structures situated in the anterior wall of the third ventricle and form the lamina terminalis. The OVLT and ventral part of the median preoptic nucleus are part of a region known as the anteroventral third ventricle region.
2. Data from many laboratories, using techniques ranging from lesions, electrophysiology, neuropharmacology, Fos expression, immunohistochemistry and receptor localization, indicate that the tissue in the lamina terminalis plays a major role in many aspects of body fluid and electrolyte balance.
3. The subfornical organ and OVLT lack the blood-brain barrier and detect alterations in plasma tonicity and the concentrations of circulating hormones such as angiotensin II and possibly atrial natriuretic peptide and relaxin.
4. This information is then integrated within the lamina terminalis (probably in the median preoptic nucleus) with neural signals from other brain regions. The neural output from the lamina terminalis is distributed to a number of effector sites including the paraventricular (both parvo- and magno-cellular parts) and supraoptic nuclei and influences vasopressin secretion, water drinking, salt intake, renin secretion, renal sodium excretion and cardiovascular regulation.     

The flow cytometric detection of alloantibodies in screening for renal transplantation

Flow cytometric screening of sera using pooled chronic lymphocytic leukaemia (CLL) cells has previously been reported as a quick method for detecting HLA antibodies of the IgG class. In this study we investigated the sensitivity of this method in the detection of IgG and IgM alloantibodies, and its performance in serum screening when compared to conventional microlymphocytotoxic screening. Results indicate that flow cytometric screening is more sensitive in the measurement of IgG alloantibodies by up to five doubling dilutions, whereas the converse is true for IgM. IgM autoantibodies were found not to be detectable by flow cytometry. By testing a large number of sera by both methods in parallel, we have found that a significant proportion of sera exhibiting no activity or IgM activity alone on cytotoxic screening contain IgG antibodies detectable with a pool of CLL cells on the flow cytometer.     

Cardiopulmonary bypass temperature and brain function

A debate has emerged in recently published studies about the optimum cardiopulmonary bypass temperature for good neurological outcome - warm vs. cold, i.e. normothermic vs. hypothermic. Although many comparative studies have been performed, the results of these studies are inconclusive and are difficult to interpret. Brain function has been studied in terms of neurological and neuropsychological outcome, protein S100beta levels as a marker of brain damage, and cerebral oxygenation using jugular bulb oximetry and near-infrared spectroscopy. The studies produce no conclusive proof of the superiority of warm or cold cardiopulmonary bypass. However, it appears that any degree of bypass hypothermia (< 35 degrees C) may protect the brain. On the other hand, even a slight increase in bypass temperature to > 37 degrees C may cause marked brain injury.     

Audit--using both the good and the bad news to improve patient care

Audit has become a familiar part of everyone's clinical practice.Since its introduction into mainstream clinical care, the importanceof audit in identifying the current standard of practice andendeavouring to make improvements has become clear, as one looksat an increasing number of areas. Over the years, we have learnta number of lessons from audit, some of them not entirely welcome.Given the diversity, complexity and variability within modernhealth care, one thing has become clear: audits that revealonly good news should be viewed with some suspicion. Given thesubject, it was perhaps inevitable that the first National Auditconducted by the Royal College of Anaesthetists, reported inthis issue of the British Journal of Anaesthesia,¹ would containboth the good news and the not so good. Its topic, ‘Supervisionand responsibility’, was chosen by anaesthetic audit coordinators(ACs) in hospitals throughout the United     

An open comparison between routine and self-administered postoperative pain relief

Patients receiving staff-administered analgesics after upper abdominal surgery had higher pain scores than similar patients having self-administered analgesics, but this was associated with a considerably smaller average amount of analgesic given. This survey was subject to observer and patient bias and it was necessary to use 'pethidine equivalents' to enable comparisons to be made between drugs with effects of different duration; thus the striking differences in pain scores and grades can be considered indicative only. They nevertheless support the continued investigation of on-demand systems and make a strong case for a double-blind controlled trial.