The laryngeal mask airway in children

Clinical and fibreoptic assessment of the positioning of the laryngeal mask airway was performed in 100 children. Clinical observation indicated a patent airway in 98% and severe airway obstruction in 2% of cases. Perfect positioning, as judged by fibreoptic laryngoscopy, was found in 49% and the epiglottis was within the mask in 49%. Fibreoptic evidence of partial airway obstruction in 17% was not detected clinically.     

Frontoethmoidal meningoencephaloceles

Frontoethmoidal meningoencephaloceles constitute a well-defined clinical entity with remarkable epidemiologic peculiarities, being very prevalent in Southeast and Southern Asia, but relatively rare in Western Europe, Japan, Australia, and North America. They do not show an increased risk of recurrence in siblings and offspring, unlike other cephaloceles and neural tube defects generally, from which they should be distinguished. Combined craniofacial and neurosurgical operative treatment permits one-stage correction of the whole deformity, the associated hypertelorism being reduced by selective orbital translocation and the nasal deformity by rhinoplasty. In planning these procedures, three-dimensional CT scanning is very helpful. Although our experience is chiefly with cases referred in childhood, we have some experience with operations done in infancy and believe this to be the ideal age.     

The influence of enalapril or spironolactone on experimental cyclosporin nephrotoxicity

Adult Sprague-Dawley rats treated daily for 14 days with 50 mg/kg cyclosporin A (CsA) exhibited nephrotoxicity, characterized by reduced glomerular filtration rate, decreased urinary sodium and potassium flow, tubular enzymuria and proximal tubular structural damage. Elevations in plasma renin activity (PRA) were observed on day 4, but returned to normal within 7 days. Co-treatment of animals for the 14 day period with enalapril (8 mg/kg/day), a potent inhibitor of angiotensin converting enzyme (ACE), or spironolactone (25 mg/kg/day), the distal tubular antagonist of aldosterone, reduced the nephrotoxicity, although PRA remained elevated. Neither enalapril nor spironolactone affected circulating CsA levels. These data suggest that the action of aldosterone on the distal tubule may be important in the pathogenesis of CsA nephrotoxicity.     

Effect of exercise on met-enkephalin in unfit and superfit individuals

Summary Twenty-four unfit volunteers and twenty-three superfit athletes were subjected to a progressive intensity treadmill exercise to total exhaustion in order to study the plasma met-enkephalin response to exercise. Blood samples were collected before and 5 min post-exercise.The basal met-enkephalin levels were significantly higher in the superfit individuals (180 fmol·ml^–1) than in the unfit individuals (126 fmol·ml^–1). Post-exercise the increase from basal levels of plasma met-enkephalin was significantly higher in the superfit athletes (180–278 fmol·ml^–1) than in the unfit individuals (126–157 fmol·ml^–1).The magnitude of the met-enkephalin responses to exercise therefore appears to be dependent on the amount of work performed and the degree of previous physical training. Peripherally circulating opioid peptides may, therefore, possibly play a role in the body's adaptation to exercise training.     

Role of tumor necrosis factor in sepsis and acute lung injury

TNF is a small protein secreted by activated monocytes and macrophages that mediates the in vivo effects of endotoxin. When injected into experimental animals, TNF reproduces the picture of septic or endotoxin shock. In addition, antibodies to TNF protect animals against the deleterious effects of IV injections of either LPS or live bacteria. Specifically, the available evidence suggests that TNF may be necessary for the organ injury and failure seen in sepsis. However, TNF probably is not the final common pathway to shock and tissue injury. Inhibition of cyclooxygenase is protective from the lethal effects of both LPS and TNF infusion, suggesting that prostanoids play an important, and perhaps more proximal role in the generation of tissue injury. In addition, TNF is produced and cleared from the blood-stream within a short period of time after an LPS stimulus, suggesting that TNF sets into motion a chain of events that may be self-perpetuating even in the absence of further TNF stimulus. In the near future, the treatment of sepsis may involve the administration of antibodies both to TNF and to LPS. Cyclooxygenase inhibitors should also begin to play a role in the therapy of sepsis. In the more distant future it is likely that we will be able to manipulate the state of activation of genes that code for TNF to exert some control over its production and secretion. It is perhaps within our grasp to finally reduce the morbidity and mortality of this lethal condition.     

New method for the chelation of indium-111 to monoclonal antibodies: biodistribution and imaging of athymic mice bearing human colon carcinoma xenografts

B72.3, a murine monoclonal antibody (MAb) that reacts with 85% of human colon carcinomas as well as other epithelial neoplasias, was labeled with 111In using four chelating agents: 1-(p-isothiocyanatobenzyl)-DTPA (SCN-Bz-DTPA), isobutylcarboxycarbonic anhydride (MA-DTPA), cyclic anhydride (CA-DTPA), and 1-(p-isothiocyanatobenzyl)-ethylenediaminetetraacetic acid (SCN-Bz-EDTA). Comparative biodistribution and imaging studies were performed in athymic mice bearing human colon carcinoma xenografts (LS-174T). Tumor uptake of radiolabel was very similar between the chelates (30% ID/g) and tumors were identified in scintigraphic images with all the chelate-antibody complexes. The uptake by normal organs, especially the liver, was greater for MA-DTPA, CA-DTPA, and SCN-Bz-EDTA chelate-B72.3 IgG (1.3:1 to 2.5:1) in comparison to that found with the B72.3-SCN-Bz-DTPA (approximately 5:1) and abdominal organ, and uptake was very prominent on imaging with these chelate-MAb complexes but was virtually absent in the mice injected with B72.3-SCN-Bz-DTPA. Purification of the MAb-chelate complex by Sephadex G-50 chromatography followed by HPLC using a TSK-3000 column provided better subsequent biodistribution and also resulted in clearer images as compared to MAb chelate complexes purified by less rigorous purification protocols. We conclude that the 111In-SCN-Bz-DTPA complex is superior, at least when bound to MAb B72.3, to other chelate-complexes currently in use.