Takatoshi Tashima

Practical Methods for Chemical Inactivation of Creutzfeldt-Jakob Disease Pathogen

Chemical inactivation of pathogen of Creutzfeldt‐Jakob disease (CJD; was examined using the mouse‐adapted CJD strain. A high concentration of formic acid, guanidine compounds, trichloroacetate and phenol prevented CJD transmission. NaOH between 0.25 and 2 N lengthened the incubation periods. Sodium dodecyl sulfate (SDS) in a concentration between 1 and 3% did not alter incubation at room temperature but did completely block the transmission after boiling for 3 min in 300 SDS. This method is recommended for practical disinfection.

Tumors of the Lateral Ventricular Wall, Especially the Septum Pellucidum: Clinical Presentation and Variations in Pathological Features

The clinical and histopathological features of 19 patients with tumors involving the septum pellucidum are presented. These tumors predominantly affected young adults, and the clinical manifestations were usually the results of raised intracranial pressure related to obstructive hydrocephalus, mental abnormality, epileptic seizures, or a combination of these. Seventeen of the tumors grew mainly in the lateral and third ventricles, and the other 2 grew both into the lateral ventricle and the cerebral parenchyma. The direction of cellular differentiation of the tumor cells varied from patient to patient and consisted of 8 neurocytomas, 1 mature neuronal tumor with ganglionic and small round neuronal cells, 3 subependymomas, 3 subependymal giant cell astrocytomas, 2 pilocytic astrocytomas, 1 malignant astrocytoma, and 1 teratoma with embryonal carcinoma. These tumors were considered to have arisen from the multipotential cells in the subependymal plate or germ cell rests in the lateral ventricular wall, especially in the septum pellucidum. Because of the relatively inert biological behavior and histological features of most of these tumors, we favor the malformative theory of their origin. Either total or an extensive excision of the tumors in this series, which had developed mainly in the ventricular system, provided long-term survival in many cases.

Immunohistochemical study of ependymal neoplasms: histological subtypes and glial and epithelial characteristics

An immunohistochemical study on ependymal tumours was performed in order to determine what relationships exist between histological subtypes and epithelial or glial characteristics. Thirty-eight ependymal tumours were examined with antibodies to cytokeratin (CK), epithelial membrane antigen (EMA), transthyretin (TTR) and glial fibrillary acidic protein (GFAP) using the avidin-biotin-complex technique. They included 23 ependymomas, 13 anaplastic ependymomas, and 2 myxopapillary ependymomas. Only 3 of the 23 ependymomas were positive with EMA but 19 reacted with GFAP. None of them were positive with CK. Six of the 13 anaplastic ependymomas were positive with EMA, 3 with CK and 10 with GFAP. Five of the 6 anaplastic ependymomas which had epithelial marker proteins were either negative or weakly positive for GFAP. The present study demonstrates that most benign ependymomas exhibit GFAP positivity while the anaplastic ones tend to suppress their glial nature in favour of epithelial differrentiation. However, ependymal tumours showed few characteristics of choroid plexus cells; only one of the examined cases was positive for TTR.

Cerebral Aspergillosis after Burr-Hole Surgery for Chronic Subdural Hematoma: Case Report

We report a case of aspergillosis in the subdural space and frontal lobe in an 83-year-old man. The clinical course simulated that of a brain tumor. The source for the infection was considered to be the previous burr-hole surgery for chronic subdural hematoma, which was performed 2.5 years before the onset of symptoms. The patient was treated by removal of the abscess and granuloma. The clinical features and treatment of aspergillosis after neurosurgical procedures are discussed.

Malignant lymphoma of the scalp at the site of a previous blunt trauma: Report of two cases

We describe two cases with malignant lymphoma presented as scalp tumors. Both patients had slowly growing subcutaneous lymphoma masses in the scalp after head trauma. In the first case, the scalp lymphoma presented as a recurrent disease during complete remission of her systemic lymphoma after chemotherapy. In the second case, the tumor involved the scalp, subjacent skull, and intracranial space without systemic manifestation. These cases represent examples of a possible relationship between head trauma and the development of between head trauma and the development of tumors involving the brain and its coverings.

Incidence and characterization of age related amyloid deposits in the human anterior pituitary gland

To identify amyloid deposits in the anterior pituitary gland, we have immunohistochemical, histochemical and alkaline Congo red staining. The anti-human P component reacted positively with these amyloid deposits, while antisera against prealbumin, AA type amyloid fibril protein and various anterior pituitary hormones were negative. A combination of Congo red and anti-human P component staining was most sensitive and reliable for detection of amyloid in the anterior pituitary glands of 300 randomly autopsied patients. Amyloid deposits increased in parallel with the age of the patients, however, they appeared earlier and more frequently than heretofore reported. Deposition of amyloid was seen initially in the 3rd decade and the positivity rate of amyloid deposits was 73% in the 5th decade. The histochemical characteristics of these pituitary amyloid deposits differed from those of cerebral and systemic deposits, particularly those found in the amyloid of senile systemic amyloidosis.

Delayed cerebral radionecrosis with a high uptake of 11C-methionine on positron emission tomography and 201Tl-chloride on single-photon emission computed tomography

Abstract A 47-year-old woman, who 2.5 years previously had undergone resection of a malignant astrocytoma of the left temporal lobe followed by radiotherapy, was found to have a mass in the left frontal lobe. This showed high uptake of thallium-201 (201Tl) on single-photon emission computed tomography and 11C-methionine on positron-emission tomography, suggesting recurrent tumour. Histological examination of the resected lesion, however, revealed it to be radionecrosis. This case thus illustrates a diagnostic pitfall in the use of these investigations for distinguishing radionecrosis from recurrent malignant glioma.

Radiation-induced meningiomas and their proliferative activity : cytokinetic study using bromodeoxyuridine

SummaryTwo cases of meningiomas, which are considered to have been caused by the preceding irradiation, are reported. In both cases, the cytokinetic study of the tumour using bromodeoxyuridine (BrdU) was performed. The percent of the tumour cells in the S phase of the cell cycle was less than 1% in both cases. The low labelling indices might suggest a relatively slow growing potential of these tumours, though the radiation-induced meningiomas were reported as being rapidly growing and malignant.

Selective enhancement of intratumoural blood flow in malignant gliomas: experimental study in rats by intracarotid administration of adenosine or adenosine triphosphate.

SummaryWe studied the effect of intravenous and intracarotid infusion of adenosine and adenosine triphosphate (ATP) on the regional blood flow of intracerebrally transplanted RG-C 6 tumours in rats, using the hydrogen clearance method. The intracarotid administration of adenosine or ATP selectively increased blood flow in the tumour, but did not produce any significant change either in the regional cerebral blood flow of the extratumoural ipsilateral hemisphere or in the ipsilateral hemisphere without tumour. The intracarotid administration of ATP at a dose of 10 Μg/kg/min produced the most effective increase in the tumour blood flow (+51.5± 16.8%). In contrast, both the intravenous administration of adenosine and that of ATP failed to increase tumour blood flow. These results may possibly indicate that intracarotid administration of the adenosine or ATP might contribute in selectively enhancing the delivery of anti-cancer agents to malignant brain tumours.

Pineal and Third Ventricle Tumours in the CT and MR Eras

We have experienced 29 cases of tumour in the pineal region and posterior third ventricle in the CT and MR eras (from 1976 to 1989). An aggressive surgical removal was performed except for germinomas and suspected germinomas. The aggressive surgical cases were 5 teratomas including one inclusion foetus, one yolk sac tumour, 3 astrocytomas, one neurocytoma, one cavernous haemangioma and one telangiectasia. The surgery was performed by either the infratentorial supracerebellar approach or the occipital transtentorial approach. There was no surgical death and the quality of postoperative survival was good in patients with benign tumours. The cases of a typical teratoma, teratoma with an arterio-venous shunt, inclusion foetus, haemorrhagic nodule of telangiectasia etc. are briefly presented. A remarkable progress in the diagnosis and surgical treatment of tumours in the pineal region in the CT and MR eras is noted in our results.