Search PubMed⌕ Search

Biomedical subjects

K Tabuchi

Publications and source records attributed to K Tabuchi.

At least 181 records · Page 10Linked to original sources
PubMed1985

[Pleomorphic xanthoastrocytoma (Kepes): a case report].

A case of tumor to be diagnosed as pleomorphic xanthoastrocytoma (Kepes) is reported. This patient was a 34-year-old female with a 6-year history of TIA. Neurological examination on admission showed no abnormalities except for bilateral choked disc. Plain CT scan revealed a well-defined low density area with a small high density region in the right temporal lobe. The small high density region and a part of peripheral portion of low density area were moderately enhanced with contrast media. At operation there was a cyst containing xanthochromic fluid at 1.5 cm depth from the cerebral surface. Temporal lobectomy and subtotal removal of tumor (5gr) were performed. The patient received postoperative radiation therapy (5960 rad). She has been doing extremely well for these 5 years following craniotomy and has no deficits except for the left upper quadrant hemianopsia which appeared immediately after surgery. There cannot be observed any symptoms or signs suggesting tumor recurrence. Histologically the tumor cells displayed marked pleomorphism. However, either necrosis or mitosis were very hard to find. The tumor cells were surrounded by a dense network of reticulin fibers. Electron-microscopically the tumor cells were occasionally filled with glial fibrils, and lipid granules were seen. Immunoperoxidase technique revealed both glial fibrillary acidic protein (GFAP) and S-100 protein in the cytoplasm of tumor cells, suggesting of neuroectodermal origin. Although this patient is older than previously reported cases (age 3 to 32), the histological findings as well as the good postoperative course indicate that this case may fulfill the criteria of pleomorphic xanthoastrocytoma first proposed by Kepes et al.

Adult↗
PubMed1984

Laminar-related projection of primary trigeminal fibers in the caudal medulla demonstrated by transganglionic transport of horseradish peroxidase.

The mode of termination of primary afferent fibers within the cat trigeminal nucleus caudalis was investigated by means of the transganglionic transport of horseradish peroxidase (HRP). Several types of laminar-related labeling were observed, depending upon the survival time after HRP application. At the earliest survival time (28-34 h) the highest density of labeling was found in laminae I and II. At 2 and 3 days survival laminae III and IV were heavily labeled, in addition to laminae I and II where the amount of labeling was greatly increased in lamina I, but not in lamina II. At 5 days survival time an abrupt drop of labeling occurred in laminae I and II, while this pattern was not predominant in laminae III and IV. In lamina V the pattern of labeling was less intense and not changeable through all survival times observed. These findings indicating a differentiation of the primary afferent terminals have good correspondence with a functional specialization of neuronal locations since the functional properties of neurons vary according to their locations.

Animals↗
PubMed1984

Reverse cellular distribution of calmodulin to S-100 protein in primate brain.

Both calmodulin and S-100 protein are Ca2+-binding proteins of the EF-hand family. Immunocytochemical study revealed that calmodulin existed mainly in the neurons, whereas S-100 protein was localized primarily in the glial cells of the cerebral and cerebellar cortices of man and monkey. The observed reverse cellular distribution of calmodulin to S-100 protein in primate brain suggests that calmodulin might be replaced in its role as a Ca2+-binding protein by S-100 protein in the glial cells.

Animals↗
PubMed1984

Detection of S-100 protein in melanocytic and neurogenic cutaneous tumors.

Quantitative determination of S-100 protein content on human melanoma tissues and in sera of melanoma patients was made possible through radioimmunoassay (RIA). Melanoma tissue extracts prepared from metastatic sites in both skin and lymph nodes contained 0.08-2.80% of S-100 out of the total extractable proteins, and it was also noticed that the tumors obtained from lymph-node metastasis possessed slightly higher levels of S-100 as compared with those obtained from the skin lesions. Serum S-100 levels of 12 melanoma patients with Stage 1 to 3 diseases were also examined by means of RIA, but only two patients showed a slight elevation of serum S-100 levels. When tissue sections prepared from a variety of cutaneous tumors, including pigmented nevus, melanoma and Schwannoma, were stained for S-100 by an immunoperoxidase technique, these tumors of neuroectodermal origin were demonstrated to contain a detectable amount of S-100, whereas other tested nonmelanocytic and non-neurogenic tumors were entirely negative for S-100. These data stress the usefulness of S-100 for the diagnosis of neurogenic and melanocytic tumors, especially melanomas, despite the difficulty of its detection in the sera of the tumor bearers, which might reflect the low tendency of S-100 to be shed from the tumor cells.

Humans↗
PubMed1984

Perchloric acid treatment and use of chromogenic substrate in the Limulus test: application to veterinary diagnosis.

The Limulus test was carried out for endotoxin determination using a synthetic chromogenic substrate after perchloric acid(PCA) treatment to remove inhibiting substances in the blood. PCA treatment completely removed non-specific amidolytic activity and other factors which interfered with the Limulus test. The recovery of added endotoxin was about 100% irrespective of animal species. Endotoxin levels in PCA-treated blood plasma of healthy domestic animals were invariably below 1 pg ml-1. Many of the cows with gangrenous mastitis, from which Gram-negative rods were isolated, showed high endotoxin levels ranging from 22.8 to 138.0 pg ml-1. Endotoxin was also detected in the blood of cows affected with salmonellosis, colibacillosis, Haemophilus somnus infection and urethritis associated with Proteus.

Animals↗
PubMed1984

[Changes of the DNA synthesis and the amount of S-100 protein associated with the morphological differentiation of cultured glioma cells].

S-100 protein is a highly acidic protein unique to the nervous system and exists predominantly in the cytoplasm of glial cells in a water-soluble form. The exact biological function is still unknown in spite of its well-known biochemical properties. Some investigators have reported that the amount of S-100 protein in developing brains increased in proportion to the brain's development and differentiation. In order to clarify the relationship between S-100 protein and differentiation of glial cells the changes of DNA synthesis and the amount of the water-soluble S-100 protein were investigated on cultured rat glioma (C-6) cells in the course of the morphological differentiation induced by dibutyryl cyclic AMP (dbc-AMP). C-6 cells were cultured in Eagle's minimum essential medium supplemented with 10% fetal calf serum and incubated in a humidified atmosphere of 5% CO2-95% room air at 37 degrees C. Dbc-AMP was added to the media at the concentration of 1 mM, and the media were changed every 48 hrs. A flow cytometric analysis of DNA histogram patterns was performed to investigate the changes of DNA synthesis using a Cytofluorograf FC 4800 A-50 (Bio/Physics). The changes of the amount of S-100 protein were examined by micro-complement fixation assay as described by Levine using rabbit antisera against bovine S-100 protein. Dbc-AMP inhibited the growth of C-6 cells remarkably and induced morphological changes resembling normal astrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Anterior inferior cerebellar artery aneurysm. Report of three cases.

Three cases of aneurysms of the anterior inferior cerebellar artery are reported. Two of the aneurysms were located in the cerebellopontine angle and one in the ventral portion of the pons. Through a suboccipital craniectomy, beck clipping was performed on one aneurysm, neck ligation on another, and coating on the third. A discussion of the surgical procedures and complications includes a review of previous reports.

Adult↗
PubMed1983

[Effect of ACNU, a water-soluble nitrosourea, on cell cycle of cultured glioma cells--flow cytometric analysis].

Cytotoxic and cytokinetic effects of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl) 3-nitrosourea hydrochloride (ACNU) on cultured rat and human glioma cells (C-6 and KC) were studied in vitro. Exponentially growing culture cells were exposed to ACNU at the final concentrations of 5 micrograms/ml, 20 micrograms/ml, and 80 micrograms/ml, respectively. The cytotoxic effect was evaluated by inhibition of cell growth and the cytokinetic effect was analyzed by DNA histogram using a flow cytometer. Inhibition of cell growth was dose-dependent in ACNU and C-6 cells were more resistant than KC cells. The growth of C-6 and KC cells were not inhibited at all by low concentrations of ACNU (5 micrograms/ml, 20 micrograms/ml), however, at these concentrations a marked accumulation of treated cells in S and G2+ M phases was evident. The accumulation in S and G2+M phases was dose-dependent and it was more prominent in KC than C-6 cells. ACNU-treated cells accumulated initially in S phase and then in G2+M phase. After maximum accumulation in G2+M phase, the cells seemed to be released into G1 or G0 phase. These results indicate that the cytokinetic effect of ACNU (5 micrograms/ml, 20 micrograms/ml) is more conspicuous than the cytotoxic effect on C-6 and KC cells.

Animals↗
PubMed1983

[Evaluation of left ventricular asynergy by two-dimensional echocardiography: comparison between fixed external axis system and floating axis system].

Detection and quantitative estimation of segmental asynergy in the infarcted area has been impeded by the rotation and anterior movement of the heart during systole. In the present communication, we compared the two measurements determined by the floating and fixed external axis systems. The former takes into account of the effect of cardiac movement. Furthermore, we assessed which system is superior by the left ventriculographic and coronary arteriographic analyses. The materials consisted of 24 cases of myocardial infarction. There was no significant difference between the two systems in the estimation of the number of asynergic segments or between echocardiographic and ventriculographic findings. The floating axis system had a tendency to underestimate asynergy, so that the number of hypokinetic segment estimated by the floating system was greater than that by the fixed external axis system. Therefore, the fixed external axis system was superior to the floating axis system in determining the causative coronary artery.

Adult↗
PubMed1982

Characteristics of a brain lymphoma cell line derived from primary intracranial lymphoma.

A brain lymphoma cell line, designated TK, was established from biopsy material of a patient with primary intracranial lymphoma. The TK cell line grew in suspension with clumps of cells and consisted of primitive lymphoid cells. TK cells and original lymphoma cells from which the cell line was derived bore surface immunoglobulin and lacked Epstein-Barr virus-determined nuclear antigen. Transplantation of the TK cells into immunosuppressed newborn hamsters gave rise to invasive growth of tumors with metastasis to the brain and eyes. These findings provide definitive evidence for a B-cell origin of the brain lymphoma in this case.

Adult↗
PubMed1982

Repair of experimental bone defect with a collagen block containing synthesized apatite.

Collagen solution extracted from the adult steer hide was mixed with the synthesized hydroxyapatite and after cross linking lyophilized. Small blocks of this sample were filled in bone defects of rabbit fibula. Two control groups were made, of which one was filled with the collagen block contained no apatite and the other group left as a sham operation. The experimental group showed more active bone formation than control groups.

Animals↗
PubMed1982

S-100 protein in human glial tumours. Qualitative and quantitative studies.

The authors studied a total of 48 human glial tumours for S-100 protein, an extremely acidic, protein specific to the nervous system, by immunohistochemistry and by micro-complement fixation assay in order to evaluate S-100 protein as an index for malignancy of glial tumours. All of 48 glial tumours analyzed in the present study demonstrated variable amounts of S-100 protein which might serve as a biochemical cell marker for glial tumours. The mean value of S-100 protein content in 3 ependymomas is higher than those of 19 low-grade (grades I, II) astrocytomas and 26 high-grade (grades III, IV) astrocytomas, being lowest in the latter. A statistically significant (P less than 0.001) difference in S-100 protein levels between low- and high-grade astrocytomas is observed, but not for ependymoma. At present, however, no correlation can be found between S-100 protein content of a tumor and the patient's survival time. Immunoperoxidase staining for S-100 protein in high-grade astrocytomas is generally weak in intensity and heterogeneous throughout the section, whereas that in low-grade astrocytomas and ependymomas is relatively strong and homogeneous, indicating that high-grade astrocytomas consist of a more heterogeneous population of tumour cells in terms of S-100 protein. These results show that the investigation of S-100 protein in a glial tumor is valuable to a certain extent in assessing the degree of differentiation or malignancy of the tumour.

Adolescent↗
PubMed1982

Effects of cyclic AMP on S-100 protein level in C-6 glioma cells.

Dibutyryl cyclic AMP (dbcAMP) markedly elevated S-100 protein level in C-6 glioma cells in vitro. Quantitative analysis by two-dimensional polyacrylamide gel electrophoresis revealed that the elevation was caused by a combination of increased synthesis and reduced degradation of S-100 protein in C-6 cells exposed to dbcAMP. These results suggest that dbcAMP affects both the synthesis and the degradation of S-100 protein in C-6 cells.

Animals↗