Effect of aging on NADPH-diaphorase neurons in laterodorsal tegmental nucleus and striatum of mice

Age-related changes of reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d)-containing neurons were examined quantitatively in the laterodorsal tegmental nucleus (TLD) and the caudate-putamen of mice. Six 2-month-old and six 25- to 30-month-old DDD mice were studied using computer-assisted image analysis. Although no age-related changes in neuronal counts were found in the TLD, the cell size in this nucleus showed a statistically significant reduction with aging. In addition, the degree of the age-related neuronal shrinkage differed within the TLD; the most significant occurring in the rostral, less in the caudal third and no significant alteration being found in the middle third portion of TLD. In contrast, NADPH-d-positive neurons in the striatum did not show distinct age-related changes. NADPH-d-containing neurons in the TLD correspond to cholinergic cells, which project to the forebrain. Thus, the age-related shrinkage of NADPH-d neurons in the TLD may be related to the cholinergic dysfunctions seen in the forebrain of senescent mice.

The increase in local cerebral glucose utilization following fluid percussion brain injury is prevented with kynurenic acid and is associated with an increase in calcium

Immediately following a lateral fluid percussion brain injury, the cerebral cortex and hippocampus ipsilateral to the percussion show a marked accumulation of calcium and a pronounced increase in glucose metabolism. To determine if this increase in glucose metabolism was related to the indiscriminate release of the excitatory amino acid (EAA) glutamate, kynurenic acid (an EAA antagonist) was perfused into the cerebral cortex through a microdialysis probe for 30 min prior to injury. The results show that adding kynurenic acid to the extracellular space prior to trauma prevents the injury-induced increase in glucose utilization. These results indicate that calcium contributes to the ionic fluxes that are typically seen following brain injury and supports the concept of an increased energy demand upon cells to drive pumping mechanisms in order to restore membrane ionic balance.

Oedema fluid formation within contused brain tissue as a cause of medically uncontrollable elevation of intracranial pressure: the role of surgical therapy

In patients with focal cerebral contusions, medical therapies have generally been advocated unless haemorrhages significantly contributing to the elevated intracranial pressure (ICP) exist. We report here several lines of clinical evidence which indicate that (1) enormous amount of extracellular oedema fluid is formed within contused brain tissue, (2) the formation of extracellular oedema fluid within contused brain tissue alone can be a cause of medically uncontrollable elevation of ICP and (3) surgical excision of the contused brain tissue provides excellent control of the elevated ICP in such patients. The excision of contused brain tissue appears to be the only therapy currently available to alleviate the formation of extracellular oedema fluid in cerebral contusions. We believe that, if ICP is elevated primarily by extracellular oedema due to cerebral contusions and the elevated ICP is medically uncontrollable, surgical excision of contused brain tissue should be carried out without delay regardless of the size of associated haemorrhages.

A complete deletion mutant of the Escherichia coli dnaKdnaJ operon

Southern hydridization analyses of genomic DNAs from various dnaJ mutants of Escherichia coli showed that mutant K7052, which has well characterized dnaK706 and dnaJ705 double mutantions, is a deletion mutant. The deletion is about 8.0 kb long and encompasses the whole of the dnaKdnaJ operon.

[Primary torsion of the omentum--report of a case and review of the Japanese literature]

A case of primary torsion of the omentum is reported. A 37-year-old male was admitted with the chief complaint of RLQ pain of 3 day's duration on June 10, 1986. Tenderness and Blumberg's sign were found at Mc Burney's point with leucocytosis of 11,500/mm3. His body temperature was not elevated. Operation was carried out under the diagnosis of suspicion of acute appendicitis. Laparotomy revealed a dark-red omental mass of 12 X 5 X 1 cm which had been formed by torsion (7 times, clock-wise) and a little clear ascites. The omental mass was resected, and appendectomy was also performed. The postoperative course was uneventful. Eighteen cases including this case in the Japanese literature were reviewed and reported.

[Catecholaminergic systems in the amygdaloid complex of SDAT and aged controls: tyrosine hydroxylase immunohistochemistry]

Catecholaminergic systems in the amygdaloid complex in patients with senile dementia of Alzheimer type (SDAT) and aged controls have been studied with tyrosine hydroxylase (TH) immunohistochemistry. TH-immunoreactivity was found in fibers in all subnuclei of human amygdala, although varying in density in the subnuclei. The most dense catecholaminergic innervation was observed in the central, basal, and cortical nuclei of amygdala. The prominent finding in the amygdaloid complex of SDAT was that swollen and bulbous TH-immunoreactive neurites were found in association with neuritic plaques, which have not, rarely if any, been found in controls. The numerical density of neurites was mostly in parallel with that of TH-immunoreactive fibers except for the central nucleus. Thus, it is suggested that a class of populations of TH-immunoreactive neurons are selectively affected in the amygdaloid complex in SDAT.

Reduced nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry in the pontomesencephalic region of the human brainstem

Reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-diaphorase), which is specifically localized in neurons, has been histochemically demonstrated in human brain by using a perfusion-fixation procedure. With such fixed human brainstem, it was possible to study the topographic organization of NADPH-diaphorase-containing neurons that were visualized in fine detail for the first time. In the pontomesencephalic region, positive neurons were observed in nuclei around the decussation and arm of the superior cerebellar peduncle. These nuclei included the pedunculopontine tegmental, lateral parabrachial and oral pontine reticular nuclei. The positive somata were mainly multipolar in shape and medium to large in size. The positive neurons appeared to correspond to cholinergic neurons, at least partly in the brainstem, in terms of both the patterns of distribution and the cellular morphology.

[Ossified choroid plexus papilloma--case report]

While the calcification has been documented radiologically in 4 - 25 percent of the cases with choroid plexus papilloma, the ossification of choroid plexus papilloma has been reported only in 3 cases on literature. In this paper, we present a case of large ossified choroid plexus papilloma in the right lateral ventricle. A 35-year-old man was admitted with left hemiparesis and headache. Skull X-rays showed an abnormal calcified mass (25 mm x 23 mm x 14 mm) in the right temporal region. CT scan revealed an abnormal high density area protruding into the right lateral ventricle, and a low density area at the right corona radiata. Operation was carried out with a right temporal craniotomy. The mass was yellowish-elastic hard and protruded into the right inferior horn of the lateral ventricle. The histological examination of surgical specimen showed an ossified choroid plexus papilloma with some bone marrow formation and numerous calcification. Calcification of choroid plexus papilloma is found frequently, but ossification is a very rare neuropathological abnormality. Bone and/or cartilage formation in neuroepithelial neoplasms is an unusual event histopathologically. Several mechanisms have been proposed, such as (1) metaplasia of connective tissue, (2) transformation of neuroepithelial cells to mesenchymal tissue, (3) teratomatous nature, (4) heteroplasia, (5) mixed mesenchymal-neuroepithelial nature, and (6) ossification as an end stage of mucoid degeneration. In our case, it was considered that the bone formation resulted from metaplasia of connective tissue of choroid plexus papilloma.

Impaired hippocampal plasticity in experimental chronic hydrocephalus

Schaffer collateral responses recorded from CA1 pyramidal cell layers in the hippocampus were analysed in kaolin-induced hydrocephalic rats. Other features of this rat model of chronic hydrocephalus were evaluated from measurements of the intracranial pressure, Na-fluorescein migration from the ventricle to the cerebral parenchyma, and behavioural changes. The results indicated that: (1) the conduction velocity of the Schaffer collaterals was unchanged; (2) the threshold to elicit population spikes was decreased; (3) the paired-pulse facilitation of EPSP tended to increase; (4) the paired-pulse inhibition of population spikes was unchanged; and (5) the long-term potentiation of population spikes was clearly attenuated in the hydrocephalic rats. The changes seen in the long-term potentiation were less pronounced in rats which underwent kaolin injection but did not develop hydrocephalus. The above findings suggest that disturbance in the postsynaptic integration processes, rather than axonal conduction or synaptic transmission, are more important for the production of the neurological deficits seen in chronic hydrocephalus. Electron microscopic observations supporting this inference are also briefly described.

Periodic acid-Schiff (PAS)-positive, granular structures increase in the brain of senescence accelerated mouse (SAM)

Abnormal granular structures, which stained positively with periodic acid-Schiff (PAS-positive granular structures; PGS), were observed in the brain of senescence accelerated mouse (SAM). They were small, round to ovoid, homogeneous structures measuring up to 5 microns in diameter and usually grouped in clusters. PGS were localized in the hippocampus, piriform cortices, olfactory tubercle, nucleus of the trapezoid body, and cerebellar cortices. Quantitative analysis revealed that PGS remarkably increased in the hippocampus of SAM-P/8, a substrain of SAM, with advancing age, although a few PGS also appeared in the aged control mice, SAM-R/1 and DDD. Their histochemical nature, morphological features and distribution pattern were different from those of corpora amylacea and other similar bodies. A close anatomical relationship between PGS and glial fibrillary acidic protein-positive astrocytes was inferred from immunohistochemical studies. PGS is considered to be one of the morphological manifestations of senescence in mice brains, and are found to occur more numerously in the brains of learning or memory deficit mice, SAM-P/8.