Interstitial hyperthermia in combination with brachytherapy

Flexible coaxial cables were modified to serve as microwave antennas operating at a frequency of 915 MHz. These antennas were inserted into nylon afterloading tubes that had been implanted in tumors using conventional interstitial implantation techniques for iridium-192 seed brachytherapy. The tumor volume was heated to 42-45 degrees C within 15 minutes and heating was continued for a total of 1 hour per treatment. Immediately following a conventional brachytherapy dose and removal of the iridium seeds the tumors were heated again in a second treatment. This interstitial technique for delivering local hyperthermia should be compatible with most brachytherapy methods. The technique has proved so far to be practical and without complications. Temperature distributions obtained in tissue phantoms and a patient are described.     

Value of plasma calcium, phosphate, and alkaline phosphatase measurements in the diagnosis of histological osteomalacia

Plasma calcium and phosphate concentrations and alkaline phosphatase activities were examined retrospectively in 50 patients with histologically proven osteomalacia and 50 age- and sex-matched control subjects with normal bone histology. An abnormal plasma alkaline phosphatase activity was more useful than an abnormal plasma calcium or phosphate concentration in distinguishing between normal and osteomalacic subjects, producing a false-negative rate of 14% and a false-positive rate of 8%. False-negative and false-positive rates of 10% and 8% respectively were obtained when the presence of an abnormality in any one of the three biochemical measurements was used as a predictor of histological osteomalacia. When discriminant analysis was applied to plasma calcium, phosphate and alkaline phosphatase together a false-negative rate of 12% and a false-positive rate of 0% was obtained.     

The effects of an opiate agonist and antagonist on the human upper gastrointestinal tract

Endogenous opiates may play a role in regulating intestinal function and we have investigated this possibility in the human upper gastrointestinal tract using loperamide as a locally-acting opiate agonist and naloxone as antagonist. Loperamide (4 mg) had no effect on the fasting pattern of motor activity in the antrum, duodenum and proximal jejunum. However, naloxone (40 micrograms kg-1 h-1, i.v.) abolished interdigestive motor activity in five of ten subjects and reduced antroduodenal motility index per cycle in all subjects (antrum: 1230 +/- 120 to 130 +/- 140 mm2; duodenum: 1120 +/- 150 to 225 +/- 160 mm2; P less than 0.005). These effects were not significantly affected by loperamide. Plasma motilin exhibited cyclic variation with significantly higher concentrations during antroduodenal phase 3 than during phases 1 and 2 of the interdigestive cycle. Plasma motilin was not altered by naloxone or loperamide, and neither drug had any effect on basal gastric acid secretion, duodenal output of amylase and bile salt or duodenogastric reflux. The results suggest that endogenous opiates regulate fasting motor activity in the human gastrointestinal tract but do not influence basal secretory function of the stomach, pancreas or biliary tree.     

Physiology of sucking in the normal term infant using real-time US

Our study of 16 normal term, breast-fed infants documents real-time ultrasound as a technique for evaluating the oral portion of the sucking mechanism in infants. We also describe the mechanics of sucking used by the infants during breast-feeding.     

SELECTIVE α2 RECEPTOR BLOCKADE FACILITATES THE INSULIN RESPONSE TO ADRENALINE BUT NOT TO GLUCOSE IN MAN

The adrenergic nervous system plays an important role in the control of insulin release and animal work suggests that this is mediated by way of alpha 2 adrenoceptors. A specific alpha 2 adrenoceptor antagonist (idazoxan) is now available for use in man and we have studied its effects on insulin release in normal volunteers (a) during the infusion of adrenaline (0.05 micrograms/kg/min) and (b) after an intravenous dose of glucose (20 g). The infusion of adrenaline alone had no significant effect on insulin release while in the presence of idazoxan, insulin release was markedly stimulated by adrenaline. Despite this, adrenaline-induced hyperglycaemia was unaffected by pretreatment with idazoxan. In the second study, pretreatment with either idazoxan or a specific alpha 1 antagonist (prazosin) had no significant effect on either glucose tolerance, glucose-induced insulin release or glucose-induced suppression of glucagon. Intravenous glucose also had no significant effect on pancreatic polypeptide levels. Therefore the effect of adrenaline on insulin release is mediated by way of inhibitory alpha 2 adrenoceptors in the pancreas, while the release of insulin in response to glucose in a resting subject is independent of the alpha-adrenergic system.     

PREVALENCE OF MITRAL VALVE PROLAPSE IN HONG KONG CHINESE A CLINICAL AND AUTOPSY STUDY

The prevalence of mitral valve pro.lapse in Chinese was determined by screening 156 heal- thy subjects and by patholobic examination of 86 adult autopsies. Mitral valve prolapse was found in 7.7% in the clinical study and 5.8% in the autopsy study. A slight female preponderance was noted.