The distribution of manganese-54 in fetal, young and adult rats

The distribution of 54Mn in various organs of pregnant rats and of their 19-day-old fetuses and in non-pregnant female rats of various ages has been studied 18 h after an i.v. injection of 54MnCl2. The results indicate that early neonates are more susceptible to manganese (Mn) than the growing rats. The localization of 54Mn in liver and brain of the embryo was highly significant.

Alterations in glutamate dehydrogenase of the brain of rats of various ages

The activity of glutamate dehydrogenase of the brain of 6-, 22-, 52-, and 96-week-old rats was determined. The specific activity, units per milligram DNA and units per organ, increased with growth and was highest at 22 weeks. This was probably due to a higher rate of protein synthesis during growth since the total DNA content did not change during this period. The activity declined in old age. Some biogenic amines, endogenous to nervous tissue and possibly having neurotransmitter functions, such as 5-hydroxy-tryptamine (5-HT), acetylcholine (ACh), and norepinephrine (NEp), inhibited enzyme activity; epinephrine (Ep) stimulated enzyme activity at all ages. Studies on the effects of various concentrations of the transmitters showed that the concentrations of 5-HT, ACh, NEp, and Ep producing significant regulatory effects on the enzyme may be 0.048, 0.18, 0.05, and 0.025 mg/ml, respectively.

Hydranencephaly

Hydranencephaly is a rare congenital condition where the greater portions of the cerebral hemispheres and the corpus striatum are replaced by cerebrospinal fluid and glial tissue. The meninges and the skull are well formed, which is consistent with earlier normal embryogenesis of the telencephalon. Bilateral occlusion of the internal carotid arteries in utero is a potential mechanism. Clinical features include intact brainstem reflexes without evidence of higher cortical activity. The infant's head size and the spontaneous reflexes such as sucking, swallowing, crying, and moving the arms and legs may all seem normal at birth. However, after a few weeks the infant usually becomes irritable and has increased muscle tone and after a few months of life, seizures and hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain) may develop. Other symptoms may include visual impairment, lack of growth, deafness, blindness, spastic quadriparesis (paralysis), and intellectual deficits. Since the early behaviour appears to be relatively normal, the diagnosis may be delayed for months sometimes. There is no definitive treatment for hydranencephaly. The outlook for children with hydranencephaly is generally poor, and many children with this disorder die before their first birthday. Key words: hydranencephaly; congenital anomaly; vascular disruption; thromboplastin DOI: 10.3126/kumj.v8i1.3227 Kathmandu University Medical Journal (2010), Vol. 8, No. 1, Issue 29, 83-86