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.     

Transmission of methicillin-resistant Staphylococcus aureus in the neonatal intensive care unit from a patient with community-acquired disease.

Methicillin-resistant Staphylococcus aureus (MRSA) has traditionally been a nosocomial pathogen. However, several recent studies have noted community-acquired MRSA among young, healthy patients with no risk factors or healthcare system exposure. We report the transmission of a strain of community-acquired MRSA in our neonatal intensive care unit.     

Hypothermia differentially affects tuning curves generated by forward and by simultaneous masking.

In the gerbil maintained at euthermic (37.5 degrees C) conditions, forward masking produces a compound action potential tuning curve (CAP TC) which is less sensitive but more sharply tuned than that which is generated by simultaneous masking. These differences between forward- and simultaneously-masked CAP TCs are minimized at hypothermic (30 degrees C) conditions. The unmasking effect occurs at both temperatures, suggesting that hypothermia does not exert these changes by eliminating two-tone suppression.     

Inhibin and age in men

OBJECTIVE: Normal elderly men are reported to have decreased testicular function despite elevated gonadotrophin levels. We wished therefore to determine if changes in testicular function occur over the age range 19-60 years. DESIGN: Single fasting blood samples were obtained between 0800 and 0900 h. PATIENTS: Working men in a large industrial company between the ages of 19 and 60 years participated in the study. MEASUREMENTS: FSH, serum immunoreactive inhibin and total testosterone were measured, the latter two as measurements of Sertoli and Leydig cell function respectively. RESULTS: The mean baseline serum immunoreactive inhibin level was significantly lower in men from the older age groups, 31-40 years (479 U/l), 41-50 years (439 U/l) and 51-60 years (415 U/l) than in men from the youngest age group, 21-30 years (613 U/l) while serum FSH was higher in men from the older age groups, 41-50 years (3.7 IU/l) and 51-60 years (6.1 IU/l) than in men from the youngest age group, 21-30 years (2.6 IU/l). There appears to be a change in both FSH and inhibin production, consistent with a primary decline in testicular function. There was no significant difference in testosterone levels between the older age group, age 51-60 years and the younger age group, age 21-30 years. However, testosterone levels were significantly lower in the 41-50 year age group, when compared with the 21-30 year, this significance levelling out at about age 45 years. CONCLUSION: The data are consistent with the hypothesis that immunoreactive inhibin reflects inhibin bioactivity, and that inhibin plays a role in the feedback control of FSH secretion in men.     

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.     

Mitochondrial DNA variability detected in a single wheat regenerant involves a rare recombination event across a short repeat

The mitochondrial genome of the selfed progeny of a plant regenerated from long-term somatic tissue culture displays specific structural rearrangements characterized by the appearance of novel restriction fragments. A mitochondrial DNA library was constructed from this selfed progeny in the SalI site of cosmid pHC79 and the novel fragments were subsequently studied. They were shown to arise from reciprocal recombination events involving DNA sequences present in the parental plant. The regions of recombination were sequenced and the nucleotide sequences were aligned with those of the presumptive parental fragments. We characterized an imperfect short repeated DNA sequence, 242 bp long, within which a 7-bb DNA repeat could act as a region of recombination. The use of PCR technology allowed us to show that these fragments were present in both parental plants and tissue cultures as low-abundance sequence arrangements.