Tatsuro Takahashi

Morphological studies on cerebral cortical lesions induced by transient ischemia in Mongolian gerbil —Diffuse and peripheral pallor of the neuronal perikarya

SummaryUnilateral transient cerebral ischemia was produced in Mongolian gerbils by clipping the left common carotid artery for 1h. About 60% of the gerbils with neurological symptoms had post-ischemic seizures. The majority of those that had seizures died within a few days, and sections of their cerebral cortices contained many dark and shrunken neurons. However, the gerbils that did not have seizures survived without any severe complications. In the cerebral cortex of the latter, the neurons with diffuse or peripheral pallor of the perikarya were seen along with a small number of dark and shrunken neurons. Diffuse pallor occurred within a few hours following ischemia in layers III, V and VI, and disappeared 1 or 2 days after recirculation. Electron microscopically, these neurons showed dispersion of ribosomes, simple and elongated profiles of rough endoplasmic reticulum (r-ER), clustered vacuoles, and mild to moderate mitochondrial swelling. Occasional net-like tubulomembranous structures, probably derived from r-ER, were observed. On the other hand, peripheral pallor became apparent after 5 days following ischemia, usually involving layer II first and gradually extending to the deeper layers. Concomitantly, the amount of neuropil decreased and the dendrites exhibited tortuosity and irregularity in layer II. Electron microscopically, these neurons showed marked swelling of peripheral perikarya and polyribosomes and organelles were located peripherally to the nuclei. In addition, numerous degenerated axon terminals and distended dendrites were observed around the neurons. These observations indicate that diffuse pallor represents damage directly induced by ischemia and subsequent recirculation, while peripheral pallor is the delayed and remote effect of ischemia, probably due to degeneration of neuronal processes.

Congenital cerebellar neuroepithelial tumor with multiple divergent differentiations

SummaryA case of congenital cerebellar tumor is reported. The tumor is composed of a few incomplete tubular structures analogous to the neural tube, and of neuroblastic, mature ganglionic, astrocytic, ependymal and undetermined neuroepithelial cells. A tentative diagnosis of congenital cerebellar neuroepithelial tumor with multiple divergent differentiations is made: the histogenesis is discussed. From a histogenetic point of view this tumor is given the provisional name of matrix cell tumor.

PLASMA CELL GRANULOMA OF THE LUNG WITH EXTRAPULMONAL EXTENSION

A rare case of plasma cell granuloma of the lung in a 5‐year‐old girl showing extrapulmonal extension to the adjoining thoracic wall was reported. Intrapulmonal and thoracic wall granulomas revealed the same histopathologic features; proliferation of plasma cells and fibrous connective tissue. Although slightly atypical plasma cells were observed among many mature ones, immunohistochemical examination revealed polyclonal proliferation, confirming their inflammatory nature. Cellular components of fibrous connective tissue were identified as fibroblastic cells and myofibroblasts by electron microscopy. The present case and literature suggested the importance of the fact that “infiltrative” plasma cell granuloma had a tendency to occur in children. ACTA PATHOL. JPN. 35: 933–944, 1985.

Congenital Anaplastic Ependymoma: A Case Report of Familial Glioma

A congenital anaplastic infratentorial ependymoma, occurring in a female infant whose sister also died of brain tumor, is described. The tumor, located in the cerebellum and the fourth ventricle, is characterized by predominantly undifferentiated neuroepithelial cells associated with numerous mitoses, and partially of the cells demonstrating differentiation into ependymal cells and astrocytes. Of special interest is the fact that the elder sister of the patient had also died of a congenital glioma located in the cerebellum and the fourth ventricle, which leads to the discussion about the influences of genetic factors in the development of the familial gliomas as well as about the histogenesis of the tumor examined.

Redistribution of glutamate and GABA in the cerebral neocortex and hippocampus of the Mongolian gerbil after transient ischemia : an immunocytochemical study

The redistribution of glutamate and GABA in postischemic brains was examined immunocytochemically using the gerbil model of unilateral 1 h cerebral ischemia. In the cerebral neocortex, the majority of neurons underwent recovery processes after 5 h of recirculation, while neurons in the hippocampus were irreversibly damaged. Glutamate-like immunoreactivity (LI) was highly increased in the degenerating hippocampal CA3 pyramidal cells after recirculation, while in the neocortex and the hippocampal CA1 sector, the pyramidal cells showed only slightly increased glutamate-LI. GABA-LI-positive punctae in the neuropil, corresponding to neuronal processes of GABAergic neurons, were accentuated after recirculation both in the cerebral neocortex and the hippocampus. Although the astrocytes on the nonischemic side showed neither glutamate-LI nor GABA-LI, the swollen astrocytes and their foot processes, which were observed after recirculation, often showed strong glutamate-LI and GABA-LI. These data suggest (1) the accumulation of glutamate or glutamate-like substances, especially in the CA3 pyramidal cells, (2) the excitation of the GABAergic neurons and their subsequent uptake of GABA, and (3) the sequestration of the extracellular neurotransmitters by astrocytes in the postischemic period.

MINUTE CARCINOID TUMOR OF THE UTERINE CERVIX ASSOCIATED WITH MICROINVASIVE ADENOCARCINOMA, WITH REFERENCE TO ITS HISTOGENESIS

A rare case of carcinoid tumor of the uterine cervix associated with adenocarcinoma was reported. The carcinoid tumor was composed of round to polygonal cells showing solid or trabecular proliferation. Most of these cells and a small number of isolated cells wedged in neoplastic glands were positive with either Grimelius or Fontana‐Masson stains, and also positive for serotonin by immunostain (PAP method). Positively stained cells were thus considered to have the same histochemical nature as enterochromaffln cell. The carcinoid tumor was minute, about 2×2 mm and the adenocarcinoma was a microinvasive one. In some parts, smooth transition between both tumor components was observed. From these findings, it is suggested that both the carcinoid tumor and the adenocarcinoma in the present case were derived from a primitive precursor cell of common mesodermal origin. ACTA PATHOL. JPN. 37:1183–1198, 1987.

Primary dissociated cell culture of fetal rat central nervous tissue. II. Immunocytochemical and ultrastructural studies of myelinogenesis

It is generally considered that the dissociated cell culture is a type of monolayer culture, and when this method is used with the central nervous system (CNS) cells, synapses may be formed but myelin is either not formed at all or formed in very small quantities. So we tried to establish a dissociated cell culture of the CNS which contains many myelinated axons. Cerebra from 18-day-old fetal rat were dissociated into single cells and plated onto poly-D-lysine-precoated coverslips at high cell density. With the progress of cell maturation, neuronal and non-neuronal cell processes intermingled and piled up on each other, forming 3-dimensional structures. We were able to observe not only many mature neurons and remarkable synapses but also many myelinated axons. Moreover direct connections of oligodendrocyte (ODC) somas to myelin sheaths were demonstrated either immunocytochemically or ultrastructurally. The formation of the 3-dimensional structure is considered to provide a favorable microenvironment for the intimate interaction of neurons and ODCs leading to the formation of many myelinated axons. So this culture system may provide a useful model for the investigation of the details in myelinogenesis under physiological conditions and demyelination or remyelination under pathological conditions such as multiple sclerosis and allied diseases.

Unilateral conjunctival infiltration of Adult T-cell leukemia/lymphoma. Case report and literature review

Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell lymphoma caused by human T-cell leukemia virus type 1 infection. Although conjunctival lymphoma is commonly reported with B-cell lymphoma, it rarely occurs in cases of ATLL. A 73-year-old Japanese female patient was admitted to our institution with evidence of abnormal lymphocytes, lymphadenopathy, and lung nodular lesions. Acute type ATLL was diagnosed, and therapy following the mLSG15 protocol was initiated. At the end of the second course, new bone lesions were detected. A modified treatment regimen was scheduled, but was postponed due to the appearance of gastrointestinal symptoms. Close observation resulted in a diagnosis of cytomegalovirus enteritis. One month after the diagnosis, the patient developed pain and discomfort in her left eye, which was determined to be due to a bulbar conjunctival tumor. Pathological findings revealed conjunctival infiltration of ATLL. Mogamulizumab treatment was initiated and was successful in eradicating the conjunctival lesions after the first course. However, at the end of the third course of therapy, pancytopenia was noted. Therefore, mogamulizumab therapy was discontinued, and the patient was on follow-up observation. Although there was no relapse of the conjunctival lesions, the patient died 1 year after the initial diagnosis, following therapy resistance.

Importance of T1-MRI enhanced pyramidal tracts in differential diagnosis as to paraneoplastic encephalomyelitis.

Department of Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan Department of Neurology, Kushiro Rosai Hospital, Kushiro, Japan Department of Neurology, Brain Science Center, Sapporo City General Hospital, Sapporo, Japan Department of Clinical Research, Hokkaido Medical Center, Sapporo, Japan Department of Pathology, Kushiro Rosai Hospital, Kushiro, Japan Department of Neurology, Kanazawa Medical University, Uchinada, Japan