Evidence that the earliest generated cells of the murine cerebral cortex form a transient population in the subplate and marginal zone.

We used bromodeoxyuridine to label the earliest generated cells of the murine cerebral cortex while they were dividing, and then observed their distributions at several instances later in development. Shortly before birth, many of the labelled cells were either above the cortical plate, in the marginal zone, or below it, in the region known as the subplate in other species. These cells had disappeared by postnatal day 21.     

Which way for housing and human settlements?

In order to clarify the housing and settlements component of the European health-for-all programme and to identify perceived priorities with a view to the preparation of training materials, members of WHO's Rural and Urban Development and Housing Network were invited to complete a questionnaire. The results are reported below. The questionnaire can be used in identifying local development priorities, comparing attitudes, and studying perceived needs. Intended as a tool for policy-makers, course organizers and public health professionals, it is available from the authors of the present article.     

The experiential impact of head injury on adolescents: individual perspectives on long term outcome

Thirty one young people, who were experiencing chronic sequelae of a head injury sustained at least 1 year previously, were interviewed in depth about the impact head injury had had on their lives. Their functioning was also assessed using the Offer Self Image Questionnaire OSIQ R . The main theme raised by subjects was that they had not received adequate explanation of the emotional problems associated with head injury and relevant support in coming to terms with their condition. Head injury had had a devastating effect on their lives, causing limitations in day to day activities, employment, education and relationships, and they scored significantly below norms on the OSIQ R scale of Self Confidence. However, these young people had a predominantly positive attitude towards life, which appeared to be related to their appreciation of how fortunate they had been to survive. They scored significantly above norms on the OSIQ R scale of Social Functioning. Markers of poor functioning were identified and, in clinical practice, could be used as a method of highlighting those head injured young people who potentially are most in need of support. The findings have implications for future research directions, service delivery and planning, in that particular weaknesses of current provision are demonstrated and recommendations made for improvements.     

The effect of cimetidine on anesthetic metabolism and toxicity

Because the H2-receptor antagonist cimetidine has been shown to inhibit drug metabolism, the effects of cimetidine on anesthetic metabolism and toxicity were investigated in a rat model. Cimetidine decreased inorganic plasma fluoride production after methoxyflurane administration both in 21% oxygen (P less than 0.001) and in 100% oxygen (P less than 0.001). Phenobarbital produces an increased fluoride formation after methoxyflurane anesthesia, and this fluoride formation is also reduced by cimetidine (P less than 0.005). There was no significant difference between the plasma fluoride levels in rats anesthetized with halothane or enflurane. Although cimetidine inhibited the in vivo defluorination of methoxyflurane, fluoride levels were still within the nephrotoxic range, and cimetidine is not likely to play a role as part of a preanesthetic regimen that would permit the increased clinical use of methoxyflurane. Cimetidine also inhibited the oxidative metabolism of halothane; cimetidine decreased (P less than 0.05) trifluoroacetic acid concentrations after halothane anesthesia in 21% oxygen and in 100% oxygen and decreased (P less than 0.05) bromide concentrations after halothane anesthesia in 100% oxygen. Trifluoroacetic acid levels were less (P less than 0.02) after halothane anesthesia in 14% oxygen as compared with 100% oxygen, indicating a reduction in oxidative metabolism under hypoxic conditions. However, bromide concentrations were maximal after halothane anesthesia in 21% oxygen, and significantly (P less than 0.001) less after halothane anesthesia in 14% and 100% oxygen. Bromide production, therefore, seems to be inhibited by both hypoxia and hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance

Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy.     

Randomized, double-blind, controlled trial of long-term diuretic therapy for bronchopulmonary dysplasia

The effects of continuous therapy with hydrochlorothiazide and spironolactone on pulmonary function in 34 premature infants with severe bronchopulmonary dysplasia were assessed in a randomized double-blind controlled trial. Subjects were greater than or equal to 30 days old, were supported by mechanical ventilation in greater than or equal to 30% oxygen, and had radiographic evidence of bronchopulmonary dysplasia. The treatment group (n = 19) and the placebo group (n = 15) were similar in all respects except for distribution of gender. Anthropometrics, ventilatory measurements, and the results of pulmonary function tests were evaluated at study entry and at 1, 4, and 8 weeks into therapy. Poststudy chest radiographs were compared with those obtained before the study. The proportion of infants alive at discharge was significantly increased (84%) in the treatment group compared with the placebo group (47%) (p = 0.05). There were no statistically significant differences in total hospital days or in total ventilator days. Total respiratory system compliance at 4 weeks was higher in the treatment group (0.61 +/- 0.18) than in the placebo group (0.45 +/- 0.13) (p = 0.016). No difference in outcome was detected between male and female infants in the treatment group. These results suggest that long-term diuretic therapy improves outcome in infants with bronchopulmonary dysplasia.