A neuronal representation of the location of nearby sounds

Humans can accurately perceive the location of a sound source-not only the direction, but also the distance. Sounds near the head, within ducking or reaching distance, have a special saliency. However, little is known about this perception of auditory distance. The direction to a sound source can be determined by interaural differences, and the mechanisms of direction perception have been studied intensively; but except for studies on echolocation in the bat, little is known about how neurons encode information on auditory distance. Here we describe neurons in the brain of macaque monkeys (Macaca fascicularis) that represent the auditory space surrounding the head, within roughly 30 cm. These neurons, which are located in the ventral premotor cortex, have spatial receptive fields that extend a limited distance outward from the head.     

Mortality in patients with congenital adrenal hyperplasia: a cohort study

OBJECTIVE: To determine mortality in patients with congenital adrenal hyperplasia (CAH) compared with that in the general population. DESIGN: We identified 333 children with CAH, treated at several pediatric endocrinology departments in the United Kingdom since 1964, and monitored their mortality to mid 1996. Standardized mortality ratios were calculated, comparing mortality in the cohort with that in the general population, adjusted for sex, age, and calendar period. RESULTS: All-cause mortality in the cohort was 3 times that expected. Mortality was significantly increased at ages 1 to 4 years (standardized mortality ratio = 18.3) but not at older ages and was significantly increased in patients of Indian-subcontinent ethnicity (standardized mortality ratio = 20.4), particularly in girls. From case notes and death certificates, it appears that most deaths were caused by adrenal crisis, often after infection. CONCLUSIONS: Although survival of patients with CAH has greatly improved since steroid therapy has been used, this disease can still have fatal consequences. The high mortality rate in Indian ethnic girls may well reflect lack of parental acceptance and understanding of the disease, as well as of the action required when their child becomes acutely ill. Better communication with and education of parents of children with CAH, especially those from immigrant ethnic minorities, is important.     

The dystrophinopathies: an alternative to the structural hypothesis

Two studies with college students were conducted to further explore the reliability and construct validity of fear of emotion, as assessed by the Affective Control Scale (ACS), a measure of fear of anxiety, depressed mood, anger, and strong positive emotion. The ACS fared well in tests of internal consistency and of convergent and divergent validity. In an analogue study of panic onset with college students with no history of panic, the predictive and incremental validity of the ACS was demonstrated: the ACS predicted students' fear of induced panic-like bodily sensations even once trait and state anxiety were statistically controlled. A second aspect of the investigation was an analogue test of the hypothesis that stress from interpersonal conflict (induced via remembrance of conflictual interactions with an important person) would moderate the ACS's effects on anxiety and fear of induced bodily sensations. This hypothesis was not confirmed.     

Epithelial and surfactant changes in influenzal pulmonary lesions

Pulmonary epithelial cell destruction in mice infected with PR8-A influenza virus has been studied with light and electron microscopy and enzyme histochemistry, and correlated with pulmonary surfactant activity. All epithelial cell types were infected by the virus, resulting in destruction, pneumonitis, and atelectasis by seven to ten days. Pulmonary surfactant activity decreased progressively following onset of infection, and was minimal by seven to ten days. Before types 1 and 2 alveolar pneumocytes regenerated, the regenerating bronchial cells grew peripherally into some of the denuded alveolar ducts and alveoli to form epithelial nodules. Eventually the types 1 and 2 pneumocytes regenerated to cover the alveolar surfaces that were not invaded by bronchial epithelium. This regeneration was associated with increased surfactant activity in the postinfluenzal lesions, suggesting that the type 2 pneumocytes are a source of surfactant.     

Articulated radial head replacement and elbow release for post head-injury heterotopic ossification

We observed an interstitial deletion of the long arm of chromosome 6 occurring as the sole anomaly in a benign fibrocystic disease of the breast, confirming its nonrandom occurrence in this type of condition, and we discuss the possible meaning of this observation.     

Biventricular assist for severe acute rheumatic pancarditis

Severe heart failure in acute rheumatic myocarditis is rare. It may be rapidly reversible with treatment, so maximal medical treatment and, if necessary, mechanical support should be given before heart transplantation is considered.