Molecular dynamics simulation of condensed-phase chiral molecular propellers.

Molecular dynamics simulations were performed for an axial-chiral liquid crystalline (LC) monolayer under trans-monolayer gas flow. The rotational dynamics of the monolayer chiral LC molecule along its long-molecular axis were analyzed at the molecular level. We found a precise correspondence between the flow-driven molecular rotation direction and molecular chirality as well as between the rotation direction and the trans-monolayer flow direction. The rotational direction exactly corresponded to what was expected in the proposed chiral molecular propeller model (Tabe, Y.; Yokoyama, H. Nat. Mater. 2003, 2, 806). Among the four trans-monolayer gas species we investigated, we found argon to be the most efficient at driving the chiral molecular propeller and helium the least efficient.

An autopsy case of intravascular malignant lymphoma presenting with intracranial B-cell type malignant lymphoma.

This report concerns a 79-year-old man with intravascular malignant lymphoma who was admitted to our hospital for slight right side hemiparesis. Radiological examinations showed a mass in the left parietal lobe, and a brain biopsy revealed a B-cell type malignant lymphoma. The tumor could not be detected on magnetic resonance images following focal radiotherapy, but the patient died of acute progressive pneumonia about 3 months after the onset of symptoms. An autopsy was performed. Microscopic examinations disclosed proliferation of neoplastic cells in the small and medium-sized blood vessels of the adrenal glands, liver, spleen, pancreas, kidneys and epididymis. A diagnosis of intravascular malignant lymphoma was established on the bases of these autopsy findings.

[Chondrosarcoma of the skull base associated with fatal intratumoral hemorrhage : report of an autopsy case and review of the literature].

We report a case of intracranial chondrosarcoma of the skull base with fatal intra- and peritumoral hemorrhage. A 75-year-old woman complained of right blepharoptosis and diplopia in 1989. An initial diagnosis of Tolosa-Hunt syndrome was made, and the patient was treated with steroid hormone therapy at a local hospital. Because the symptoms had not been relieved, she was admitted to our hospital. Computed tomography (CT) scan and magnetic resonance (MR) images demonstrated a large mass extending from the right side of the clivus to the parasellar region and petrous apex. The mass was partially calcified and had destroyed the base of the middle cranial fossa. The lesion had homogeneous enhancement with contrast medium. Preoperative diagnosis was chordoma or chondroma. A biopsy of the tumor was made. The pathological diagnosis of biopsy specimen was chondroid chordoma. The patient was followed up but no palliative treatment such as radiotherapy was given. On June 25, 1991, she suffered from cerebral infarction. On June 29, 1993, she died of sudden respiratory failure. Autopsy was performed. It revealed intra- and peritumoral hematoma compressing the medulla oblongata, pons and midbrain. Histologically immature chondroid cells proliferated in a myxoid-rich extracellular matrix. The tumor cells were composed of hyperchromatic nuclei and eosinophilic cytoplasm, but there was no evidence of notochordal differentiation. Compared with biopsy findings, the tumor showed high cellular density. Immunohistochemically, the tumor cells reacted positively for S - 100 protein, vimentin and cytokeratin, but negatively for epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA). In view of these histopathological findings, the diagnosis of low-grade myxoid chondrosarcoma was established. Intratumoral hemorrhage often occurs in malignant brain tumors such as glioblastoma and metastatic brain tumor, but chondroid tumors rarely develop a fatal type of intratumoral hemorrhage. Only 8 cases have been reported in detail to date. We discuss the immunohistochemical features and spontaneous intratumoral hemorrhage of chondrosarcoma.

[Ventriculoperitoneal shunts with the use of pressure-adjustable valve in the management of hydrocephalus].

Sixteen patients with hydrocephalus of varied etiology who underwent ventriculo-peritoneal shunts utilizing pressure-adjustable valves were reviewed, and the usefulness of the pressure-adjustable valve in the management of hydrocephalus was evaluated. Before shunting all patients had CT evidence of hydrocephalus with Evans' Index greater than 30%. High-, medium- and low-pressure settings were chosen in 3, 11 and 2 patients respectively, according to the CSF pressure as measured during lumber puncture or ventricular drainage. Following the shunting procedures with programmable pressure valves, hydrocephalus was alleviated with Evans' Index being 27% on the average, as evaluated by CT scans. Such clinical symptoms as disturbed consciousness, dementia and increased intracranial pressure all subsided. There were no mortality, infection or revision during the follow-up period of 5 to 16 months. Of particular note was that, among these 16 cases, there were three illustrative cases in which programmable pressure valves were found useful in coping with newly developed subdural effusion and low-intracranial-pressure syndrome, by manually adjusting the valves to higher pressure settings.

Composed dynamic topography for spike and sharp wave.

We reported two kinds of dynamic topographies. In one, an interspike interval histogram and a computerized topography of the EEG basic activity were composed. In the other, spike and sharp wave characteristics were composed of an isopotential topography. These topographies enabled us to observe serial changes in epileptic discharge dynamically by 1 msec.

Pituitary enlargement associated with Addison's disease.

We report a case of Addison's disease with pituitary enlargement which could easily have been misinterpreted as a pituitary adenoma or other pituitary disease. Serial computed tomography following replacement therapy was essential to confirm the diagnosis.

Association of arteriovenous malformation and intracranial aneurysm in the posterior fossa.

Two cases of a saccular aneurysm of the posterior inferior cerebellar artery associated with an anatomically related arteriovenous malformation are presented. The aneurysms were clipped and the arteriovenous malformations were totally extirpated in one-stage operations in both cases. The association of arteriovenous malformation and arterial aneurysm in the posterior fossa was reviewed in the literature.