Corrosive injury of the oesophagus in childhood

A 10-year retrospective review of 73 children who had ingested a corrosive agent was performed. Presentation, management, and eventual outcome were assessed, and comparisons were made between those who received early medical treatment and those who did not. Results suggested that immediate proper assessment of the oesophagus and institution of appropriate therapy may reduce the incidence of complications associated with treatment of subsequent stricture formation. The importance of oesophagoscopy in the direct visualization of the oesophagus within 24-48 h of the burn is stressed.     

Differential effects of CO2 and hypoxia on bronchomotor tone in the newborn dog

We compared the effects of hypoxia and hypercapnia on pulmonary mechanics in the newborn dog. Animals were anesthetized with a mixture of chloralose/urethane, paralyzed and ventilated with the chest open. Following an inflation to control volume history, mean inspiratory resistance (RLi) and dynamic compliance (CLdyn) were measured on a breath-by-breath basis during ventilation with control (FIO2 = 0.4), hypoxic (FIO2 = 0.1) and hypercapnic (FICO2 = 0.05) gas mixtures. Hypercapnia increased RLi 63% (n = 9) while hypoxia increased RLi in only 1/9 animals. Neither gas mixture changed CLdyn compared to control. The response to hypercapnia and the lone hypoxic response were eliminated by denervation of the airways by atropine administration or vagotomy. Following airway denervation hypoxia caused a small but statistically significant fall in CLdyn compared to the denervated control. These findings demonstrate that the newborn dog is capable of reflexly increasing bronchomotor tone and that vagal efferent innervation to the airways is functional at birth. Our data also suggest that in the newborn, central chemoreceptors are more effective than peripheral chemoreceptors in altering vagal tone to airway smooth muscle. Increased bronchomotor tone with hypercapnia may help to prevent dynamic compression of the airways.     

Clinical dosimetry for implementation of a multileaf collimator.

In order to initiate the use of a multileaf collimator (MLC) in the clinic, a set of technical procedures needs to be available sufficient to create MLC leaf settings and to deliver an accurate dose of radiation through the MLC-shaped field. Dosimetry data for clinical use of the MLC were measured. Dosimetric characteristics included central axis percent depth dose, output factors, and penumbra. In this paper, it has been concluded that a dose control monitor unit calculation procedure that has been applied to the use of conventional secondary field-shaping blocks can be applied to the multileaf collimator dosimetry. The multileaf collimator penumbra (20% to 80%) is only slightly wider (1-3 mm) than the penumbra of the conventional collimator jaws. Beam's-eye-view comparisons made between the isodose curves in fields shaped by conventional Cerrobend blocks and isodose curves in fields shaped by the multileaf collimator demonstrated that the 50% isodose line at 10-cm depth exhibited the discrete steps of the multileaf collimator leaves, but that the 90% and 10% isodose curves of the multileaf were close to those shaped by Cerrobend blocks.     

Prevalence and distribution of osteoarthritis in a population from Georgian and early Victorian London.

The prevalence of osteoarthritis was calculated in adult skeletons excavated from the crypt of Christ Church, Spitalfields in east London, which was used for burial between 1729 and 1869. Age and sex specific prevalences were also calculated for a subsample of the group for whom age and sex were accurately known from surviving coffin plates. Prevalences were slightly higher in men than in women, except for generalised osteoarthritis. The principal sites affected were the acromioclavicular joints, the facet joints of the spine, and the hands. Osteoarthritis of the large joints was relatively uncommon; osteoarthritis of the hip occurred in 4/360 (1.1%) of men and 10/346 (2.9%) of women and of the knee in 3/360 (0.8%) of men and 18/346 (5.2%) of women. This last difference was statistically significant. A comparison with modern data suggests that the prevalence of osteoarthritis at Spitalfields was lower than in the contemporary population, and some explanations for this apparent difference are considered.