Schwannoma of the lateral ventricle: eight-year follow-up and literature review.

Intracerebral and intramedullary schwannomas are uncommon; but, in general, spinal intramedullary schwannomas are more frequent than intracerebral schwanomas. We present a case of right lateral ventricle schwannoma in a 21-year-old man and review the associated literature. The 21-year-old right-handed man presented with loss of the left-eye vision approximately 8 months before referral to an ophthalmologist. The patient was immediately subjected to computed tomography (CT) scan, which showed an enhanced lesion with cystic component in the right occipital horn of the lateral ventricle. And consecutively, he was admitted to our department. The tumor was evacuated via craniotomy with marked improvement in his clinical state. The postoperative course was uneventful and postoperative CT control showed no residue. On MRI control no recurrence was noted after a follow-up period of 8 years. Intracerebral schwannoma is a rare, benign neoplasm. It is usually located superficially or adjacent to a ventricle. Characteristic imaging features include cyst formation, calcification, and evidence of peritumoral edema or gliosis. The recognition of this benign and potentially curable neoplasm and its differentiation from other neoplasms, some of which have less favourable outcomes, is of obvious importance.     

Positive autoradiographic findings in brains of four MS patients

Autoradiography of brain slices from 4 multiple sclerosis (MS) and 9 control patients was performed. After 6 weeks of exposure the exact picture of the white matter appeared on the X-ray films in all cases with MS, but only in one of the controls. The high level of autoradiographic signal from MS white matter suggests that an abnormal accumulation of radioactive trace elements takes place within the brains of MS victims.     

The cholinergic innervation of the rat fascia dentata: identification of target structures on granule cells by combining choline acetyltransferase immunocytochemistry and Golgi impregnation

A monoclonal antibody against choline acetyltransferase (ChAT), the acetylcholine-synthesizing enzyme, was used to study cholinergic synapses on identified (Golgi stained) granule cells in the rat fascia dentata. Choline acetyltransferase immunocytochemistry was applied to 40-microns Vibratome sections cut perpendicular to the longitudinal axis of the hippocampus. Light microscopy revealed fine varicose ChAT-immunoreactive axons in all layers of the fascia dentata, i.e., in the stratum moleculare, the stratum granulosum, and the subgranular polymorph zone. Most fibers were observed in the vicinity of granule cell bodies where they ran mainly parallel to the granular layer. Next, the immunostained Vibratome sections were sandwiched between small pieces of Parafilm and piled to form a block that was covered with agar and Golgi stained. After that, the sections were separated by cutting away the agar and removing the Parafilm. Sections containing well-impregnated granule cells were gold-toned (Fairén et al., '77), embedded in Araldite, and subjected to ultrathin sectioning for electron microscopy. A total of 14 gold-toned granule cells were examined in the electron microscope for synaptic contacts with cholinergic afferents. Choline acetyltransferase-immunoreactive axon terminals were observed that established symmetric synaptic contacts with the cell bodies and dendritic shafts of the gold-toned identified granule cells. Two types of contact were observed on spines arising from gold-toned granule cell dendrites. Immunoreactive terminals established asymmetric synaptic contacts with the head of small spines and symmetric contacts with the stalk of large, complex spines. The boutons forming asymmetric synaptic contacts with the cup-shaped spine head of the complex spines were not found to be immunoreactive. Our results demonstrate that cholinergic fibers to the rat fascia dentata establish characteristic types of synaptic contact with different postsynaptic elements of granule cells, suggesting a complex function of this afferent system.     

Exercise-induced muscle protein leakage in the rat. Effects of hormonal manipulation

Differences in exercise-induced muscle damage between males and females were studied in an animal model by measuring the serum activities of specific muscle enzymes (creatine kinase and aspartate aminotransferase). It was found that rats showed muscle damage, comparable to that observed in humans after long-term exercise: males were much more affected than females. For example, the CK activity in male rats immediately after exercise was 335% of the resting value, but remained unchanged in females. To test the hypothesis that oestrogens may protect the female muscle membrane, female rats were ovariectomized at different stages of sexual maturity and exercised. A clear effect of this hormonal manipulation was observed: operated animals showed post-exercise CK elevations, depending of the age at the time of ovariectomy. Rats, ovariectomized before reaching sexual maturity, showed more damage than those ovariectomized after reaching sexual maturity.     

A case of juvenile chronic myeloid leukemia with XX/XXX mosaicism.

Cytogenetic abnormalities are rarely found in patients with juvenile chronic myelogenous leukemia (JCML). In patients with chromosomal abnormalities, chromosomes 7 and 8 are usually involved. A case of JCML with 47 XXX and a 46 XX karyotype is described and the literature is reviewed. To our knowledge, this is the first case ever to have been reported.     

The mitochondrial K(ATP) channel opener BMS-191095 reduces neuronal damage after transient focal cerebral ischemia in rats.

Activation of mitochondrial ATP-sensitive potassium (mitoK(ATP)) channels protects the brain against ischemic or chemical challenge. Unfortunately, the prototype mitoK(ATP) channel opener, diazoxide, has mitoK(ATP) channel-independent actions. We examined the effects of BMS-191095, a novel selective mitoK(ATP) channel opener, on transient ischemia induced by middle cerebral artery occlusion (MCAO) in rats. Male Wister rats were subjected to 90 mins of MCAO. BMS-191095 (25 microg; estimated brain concentration of 40 micromol/L) or vehicle was infused intraventricularly before the onset of ischemia. In addition, the effects of BMS-191095 on plasma and mitochondrial membrane potentials and reactive oxygen species (ROS) production in cultured neurons were examined. Finally, we determined the effects of BMS-191095 on cerebral blood flow (CBF) and potassium currents in cerebrovascular myocytes. Treatment with BMS-191095 24 h before the onset of ischemia reduced total infarct volume by 32% and cortical infarct volume by 38%. However, BMS-191095 administered 30 or 60 mins before MCAO had no effect. The protective effects of BMS-191095 were prevented by co-treatment with 5-hydroxydecanoate (5-HD), a mitoK(ATP) channel antagonist. In cultured neurons, BMS-191095 (40 micromol/L) depolarized the mitochondria without affecting ROS levels, and this effect was inhibited by 5-HD. BMS-191095, similar to the vehicle, caused an unexplained but modest reduction in the CBF. Importantly, BMS-191095 did not affect either the potassium currents in cerebrovascular myocytes or the plasma membrane potential of neurons. Thus, BMS-191095 afforded protection against cerebral ischemia by delayed preconditioning via selective opening of mitoK(ATP) channels and without ROS generation.