Pachygyriclike changes: topographic appearance at MR imaging and CT and correlation with neurologic status

Studies of 23 pediatric patients with pachygyriclike changes (PLCs) examined with computed tomography (CT) and magnetic resonance (MR) imaging were reviewed to determine topographic patterns and correlate them with various clinical syndromes and degrees of neurologic impairment. Three types of topographic distributions were identified: unilateral, diffuse, and bilateral nondiffuse (of which eight of 10 showed frontotemporal predominance). PLCs were an isolated finding in seven patients, were associated with various congenital syndromes in nine patients, and were associated with congenital infection in seven patients, six of whom showed marked white matter abnormalities. Although most patients had severe developmental delay, three with nondiffuse PLCs had less severe impairment, permitting less required care.     

Bilharzial portal fibrosis: an important cause of portal hypertension

Thirty consecutive cases of portal hypertension seen in a surgical unit in Lusaka, Zambia, are reported. Of these cases 70% were due to portal fibrosis caused by Schistosoma mansoni infestation. Portacaval shunting was undertaken in most cases. Patients with portal fibrosis responded more favourably to portal decompression than did patients with cirrhosis. It is probable that the condition is more common than is generally reconigzed in areas where S. mansoni infestation is endemic.     

Prevention of mammary carcinogenesis in rats by pregnancy: effect of full-term and interrupted pregnancy

In this study, the role of parity in conferring protection of the mammary gland against chemical carcinogenesis induced by 7,12-dimethylbenz(a)anthracene (DMBA) was investigated. Experiments were also carried out to determine if an 'interrupted' pregnancy was capable of reducing the incidence of mammary tumour induction. Since it has been suggested that morphological development or the proliferative pattern of the mammary gland at the time of carcinogen administration may be involved in reducing the susceptibility of the mammary gland to chemical carcinogenesis, experiments were designed to elucidate the possible influence of these two factors. Sprague-Dawley female rats were mated and were either allowed to complete pregnancy and parturition or were subjected to Caesarian section on day 5, 10 or 15 of the pregnancy. When DMBA was administered i.v. to animals which had been allowed to complete a full-term pregnancy, only 14% developed tumours, compared to 70% in age-matched nulliparous controls. Termination of the pregnancy on days 5, 10 or 15 was as effective in reducing tumour incidence as full-term gestation and parturition, but still resulted in partial and statistically significant inhibition, compared to age-matched nulliparous controls. There was no significant difference in 3H-thymidine labelling index (LI) at the time of DMBA treatment in the parous rats compared to age-matched nulliparous controls. We also observed no significant differences in the morphological development of the mammary gland in parous and nulliparous rats of the same age. These results indicate that the protective mechanism may not lie in the mammary gland per se, but may indeed be a host factor, such as hormonal or immunological changes occurring in the host as a result of the pregnancy.     

Rise in blood pressure increases the release of endogenous catecholamines in the anterior hypothalamus of the cat

Summary In anaesthetized cats, anterior and posterior hypothalamic areas were simultaneously superfused with artificial CSF using two push-pull cannulae. The rates of release of endogenous catecholamines were determined in the superfusates which were continuously collected in periods of 10 seconds. In both areas, the rate of release of dopamine was higher than the rates of release of noradrenaline and adrenaline. Electrical stimulation of the splanchnic nerve elicited a rise in the arterial blood pressure and increased the rates of release of noradrenaline, adrenaline and dopamine in the anterior hypothalamic area. The rates of release of the catecholamines in the posterior hypothalamic area were not influenced by the pressor response to stimulation of the splanchnic nerve. Transection of the brain caudal to the hypothalamus reduced the rates of release of the catecholamines in the anterior hypothalamus and abolished the releasing effect of the stimulation of the splanchnic nerve. The results indicate that acute rise in blood pressure activates catecholamine cell bodies in the lower brain stem, which in turn stimulate the anterior hypothalamus to counteract the pressor response.     

A study of Cytomegalovirus, Epstein-Barr virus and Herpesvirus hominis (types 1 and 2) antibody in institutionalized and non-institutionalized children.

In an attempt to demonstrate differences in antibody prevalence between free-living and institutionalized children, antibodies to Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Herpesvirus hominis (HVH), types 1 and 2, were assayed in 123 children. The children comprised three groups consisting of 41 institutionalized patients with Down's syndrome (all non-disjunctive trisomy-G karyotype and equal numbers of age-, sex-, and race-matched non-mongoloid institutionalized subjects and non-institutionalized normal controls. CMV antibody titer values were statistically similar in the three groups. However, fewer mongoloids (21.9%) were seropositive than other institutionalized retardates (39.0%) and normal control subjects (43.9%). Antibody titer values to EBV were also similar; however, in comparison to the other groups, significantly more mongoloids were seropositive at younger ages. More mongoloids were seropositive to HVH-1 and had higher antibody titers than the other two groups. Antibody to HVH-2 was more prevalent in institutionalized subjects, 85.4% in mongoloids and 65.8% in other institutionalized retardates, than in normal non-institutionalized children (26.8%).