Akihiro Ijichi

Pineoblastoma with neuronal differentiation--immunohistochemical and immunocytochemical studies.

SummaryImmunohistochemical and immunocytochemical studies were performed on a specimen obtained at operation from a 4 year-old female with intracranially spread pineal tumor in the right temporal lobe.Microscopically, it was a highly cellular tumor, and the cells contained chromatin-rich round or oval nuclei and scanty cytoplasms. There were numerous mitotic figures. Rossetes were not detected. Both immunohistochemical staining of paraffin-embedded sections and immunocytochemical staining of short-term cultured cells disclosed a subgroups of cell positive for NSE and 68K-NF (neurofilament). No cells were positive for GFAP, S-100 protein or HCG.From these findings, the tumor was thought to be pineoblastoma, which is an undifferentiated tumor that rarely shows divergent differentiating potential. This is the first report of pineoblastoma with the differentiation only toward the neuronal line confirmed by the analysis of immunohistochemistry and immunocytochemistry.

Antitumor Effects of Human Monoclonal Antibodies on Human Malignant Glioma Xenografts and Their Clinical Application

Human anaplastic gliomas still have a poor prognosis despite current aggressive therapies such as microsurgery, advanced radiation therapy, combined chemotherapy and/or immuno-therapy. It has been widely reported that a major limitation of these treatments is the lack of tumor specificity. Hybridoma technology has made it possible to generate large quantities of monoclonal antibodies (MAB) which are highly specific to human malignant tumors. Such tumor-associated MABs are potentially powerful tools in the diagnosis and treatment of human malignant tumors. A large number of monoclonal antibodies has been produced by hybridomas from mouse × mouse or mouse × human cells, and those antibodies were used in the diagnosis and the treatment of human cancers [1–3].

Clinical Evaluation of Sophisticated Mental Tests and 123I-IMP SPECT in Normal Pressure Hydrocephalus (NPH) Patients

We examined the mental functions and intelligence, as well as the dynamics of cerebrospinal fluid and cerebral blood flow pre- and post-shunting in NPH patients.

Intracranial Arachnoid Cysts: A quantitative analysis of fluid dynamics and continuous intracystic pressure monitoring —A new concept of “localized hydrocephalus”—

The natural history and pathophysiology of intracranial arachnoid cysts are still obscure. The purpose of this paper is to analyze the characteristics of the fluid dynamics of arachnoid cysts by utilizing the quantitative analysis method of metrizamide CT cisternography (CTCG). These results are then compared with those of intracystic pressure dynamics. We discuss the pathophysiology of and the operative indication for intracranial arachnoid cysts.

Post-Shunt Isolated Compartments in Hydrocephalus: Proposal for a New Classification and Experimental Proof of the Pathophysiology

The clinical features and pathophysiology of specific forms of postshunt isolated compartments were analyzed. The possible pathogenesis of the individual clinical entity was discussed on the basis of various experimental studies, which included morphological evaluation and pressure monitoring in a canine slit-ventricle model a silicon ventricular system simulation model for post-shunt ICP dynamics analysis, and so forth. A clinically applicable classification was used to evaluate the progression of hydrocephalus (Stage I–IV), and to define the compartment isolation after shunting in previously communicating cerebral ventricles and the central canal of the spinal cord (Type I–IV).

Infantile Subdural Effusion: A phenomenon of “regional destruction of major CSF pathways—Pathophysiological studies with quantitative relativity analysis of CSF dynamics and dynamic analysis of intracranical pressure gradients—

The pathophysiology of subdural effusions were prospectively evaluated with quantitative relatively analysis of CSF dynamics and dynamic analysis of intracranial pressure gradients. The results revealed that there are various forms of intracranial pressure gradients as transmantle pressure and the communicating pattern of CSF dynamics.

CSF Dynamics in Children: A quantitative analysis of the relativity of major and minor pathways of cerebro-spinal fluid dynamics

Cerebrospinal fluid (CSF) dynamics in infants and children is still obscure. This paper aims to analyze the characteristics of CSF dynamics in the younger age group and to clarify the changes both in the acute/chronic hydrocephalic status and in the post-shunt condition on the basis of our experience with 118 cases of metrizamide CT cisternography. In order to pursue the CSF passive movements, the exact regional CT numbers were obtained by means of the ROI method in each case at 3, 6, and 24 hours after metrizamide injection. The results revealed that, in the normal CSF dynamics in both the major and minor pathways in children, it took more than 24 hours until the regional metrizamide was completely cleared up.