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Biomedical subjects

K Misugi

Publications and source records attributed to K Misugi.

At least 37 records · Page 2Linked to original sources
PubMed1991

Nanomolar L-dopa facilitates release of dopamine via presynaptic beta-adrenoceptors: comparative studies on the actions in striatal slices from control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated C57 black mice, an animal model for Parkinson's disease.

Effects of L-DOPA (0.1-10,000 nM) on spontaneous release (Sp), evoked release (S) and tissue content (C) of dopamine (DA) were studied comparatively in superfused striatal slices from control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated C57 black mice to obtain evidence for L-DOPA-induced facilitation of S via presynaptic beta-adrenoceptors. In control slices, isoproterenol-induced concentration-dependent increases in S were propranolol-sensitive. L-DOPA at 0.1-3 nM tended to increase the S of DA with a concomitant tendency of increases in Sp. L-DOPA at 10-1 x 10(4) nM concentration-dependently increased Sp. L-DOPA at 1-10 microM tended to increase S and 10 microM increased C. In slices from MPTP-treated mice, the absolute amounts of Sp, S and C decreased by half compared to those in control slices. L-DOPA at 3 nM facilitated S without increasing Sp. This facilitation was antagonized by propranolol at 3 nM. L-DOPA at 30 nM decreased S from the peak facilitation, which contrasted with no effect in the control slices. However, 10-100 nM L-DOPA increased Sp more markedly than that in the control slices. L-DOPA at 100 nM increased S and C, which contrasted with no effect in the control slices. In conclusion, nanomolar L-DOPA facilitates the S of DA via presynaptic beta-adrenoceptors at concentrations lower than those required to induce conversion to DA even in striatal slices from the MPTP-treated mice model for Parkinson's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1991

[Study of satellite tumor nodules in renal cell carcinoma].

Topography and histological types of main tumor and satellite tumor nodules (STN) were investigated on 60 cases of renal cell carcinoma by gross and microscopic study by making whole area histological sections. 30-100 histological slides were made from the median sagittal section and multiple horizontal sections of renal cell carcinoma. STN were observed in 28 cases of the 60 cases (46.7%) and could be classified into 3 types according to their location relative to the main tumor. STN could not be observed in some cases despite the large main tumor of 10 cm or more, while STN were observed in some cases with the main tumor of only 2.5 cm or less. High grade and high stage cases showed a high incidence of STN. It is considered that, only in cases, with the tumors of low grade, low stage and has only 1 STN or less, conservative surgery on renal parenchyma is possible. When the case is of low grade and low stage and has a possibility of preserving normal renal parenchyma, conservative surgery on renal parenchyma may be justified even if the tumor is large.

Carcinoma, Renal Cell↗
PubMed1990

Evaluation of a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated C57 black mouse model for parkinsonism.

We evaluated neurochemically, behaviorally, and neuropathologically the availability of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated C57 black (BL) mice as a model for Parkinson's disease. The dopamine and 3,4-dihydroxyphenyl acetic acid content in the striatum, measured by high-performance liquid chromatography with an electrochemical detector, decreased by 70% at 10 and 20 days after the withdrawal of MPTP (30 mg/kg, i.p. twice daily for 5 days). During these days, the mice showed a decrease in locomotor activity and exhibited akinesia in both pole and traction tests. Light microscopically, 44% of the MPTP-treated mice showed neuronal degeneration in the substantia nigra 1 month after the withdrawal (damaged group), and 56% showed no change (undamaged group). Morphometric analysis revealed that the number of neurons in the substantia nigra decreased by 33% on the average in both groups. Electron microscopically, an electron-dense degeneration of most neurons was seen in the substantia nigra of the damaged group, and even in the undamaged group, loss of rough endoplasmic reticulum and mitochondrial deformity were seen in 50-70% of the neurons. Electron-dense bodies were seen in the striatum of both groups. These results show the validity of the MPTP-treated C57 BL mice as a suitable model for parkinsonism, including Parkinson's disease.

Animals↗
PubMed1990

Establishment of an epithelioid malignant schwannoma cell line (YST-1).

A novel cell line, YST-1, was established from an epithelioid malignant schwannoma (EMS) that occurred in the upper arm of an 8-year-old girl. YST-1 cells were polygonal and stellate in shape, contained abundant free ribosomes, mitochondria, lysosomes and rough-surfaced endoplasmic reticulum, and grew stably with a population doubling time of 40 h. Immunohistochemically, vimentin, S100 protein and S100 protein beta subunit were positive in the cytoplasm. The xeno-transplanted tumor in nude mice was composed of cells with an epithelioid arrangement similar to the original tumor. The borders of the tumor cells were connected intimately without desmosomal junctions, and there were abundant organelles in the cytoplasm. YST-1 cells were considered to be of value for studying the nature and histogenesis of EMS.

Animals↗
PubMed1990

[Ectopic production of human chorionic gonadotropin by poorly differentiated transitional cell carcinoma of the renal pelvis].

Herein we report a case of ectopic production of hCG by poorly differentiated transitional cell tumor of the renal pelvis. The patient was a 55-year-old male who had been diagnosed at another hospital as having giant hydronephrosis and renal stones and was referred to our hospital. The plain abdominal CT showed a low-density mass at the lower pole of the right kidney. His serum hCG level was as high as 120 mIU/ml. Transperitoneal nephrectomy was performed on July 7, 1987. Histopathological examinations showed the presence of squamous metaplasia within a high-grade transitional cell carcinoma, and immunohistochemical studies revealed the presence of chorionic gonadotropin in some giant cells. Two courses of combination chemotherapy with methotrexate, vinblastine, adriamycin and cisplatin (M-VAC regimen) were given to him from the third week after the operation. However, he died of debility with distant metastasis 6 months after the operation. As far as we know, this is the third reported case in Japan.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Establishment and characterization of an immature epithelial cell line (ENU-T-1) derived from a rat nephroblastoma.

A new cell line designated ENU-T-1 has been established from a xenotransplanted experimental rat nephroblastoma. The cultured cells are spindle-shaped or polygonal and are arranged in a wavy fashion morphologically similar to cultured embryonal renal epithelial cells. The cells exhibit a number of epithelial characteristics. Enzyme histochemistry gives positive reactions for gamma-glutamyltranspeptidase and alkaline phosphatase, both of which are present in renal tubular epithelial cells. Immunofluorescence studies show positive reactions for vimentin and cytokeratin. When inoculated into athymic nude mice, the cultured cells form tumors composed of sheets of epithelial cells with focal tubular formation. This cell line may be of value in studying differentiation of nephroblastoma, and possibly normal nephrogenesis.

Animals↗
PubMed1989

"Grumose degeneration" of Trétiakoff.

We reviewed Trétiakoff's "grumose degeneration (GD)" which described pathologic cellular change in the substantia nigra (SN). This term has been occasionally used up to the mid-1960s by Greenfield et al.; it has rarely been used after the 1970s. This study emphasises the following: (1) after the 1970s, GD has sometimes been signalled in the SN under various names, such as "spheroid with foamy appearance", "granular spheroid", "saccular structure", or "foamy spheroid body"; (2) the ultrastructure of GD is unknown, being entirely different from that of typical axonal swellings (so-called "spheroids"); (3) more attention should be paid to GD in the SN because its nature has remained unclarified since the original description; and (4) "GD" in the cerebellar dentate nucleus is essentially different from Trétiakoff's GD.

Cerebellar Nuclei↗
PubMed1988

Foamy spheroid bodies in the substantia nigra. Report of an unusual case with recurrent attacks of peculiar twilight state.

An unusual case of recurrent attacks of peculiar twilight state persisting for 41 years is the subject of this clinicopathological report. During the attacks the patient had depersonalization, showing a stiff face, and the electroencephalogram showed constant 5 Hz diffuse theta waves. The unique and characteristic neuropathological finding were many foamy spheroid bodies (FSB) in the substantia nigra which sometimes contained varying numbers of fine or coarse eosinophilic granules. Ultrastructurally, the FSB contained various small electron-dense granules and/or membranous structures quite different from so-called spheroids (axonal swellings). Bodian staining demonstrated that some FSB were situated within the bundles of the neuronal processes, suggesting that the FSB has originated from the degeneration of the axon and/or dendrites in the substantia nigra.

Aged↗
PubMed1988

A case of renal angiomyolipomas associated with multiple and various hamartomatous microlesions.

A case of 50-year-old woman who demonstrated large intrarenal and externally protruding angiomyolipomas (AMLomas), unusual intraglomerular lesions and multiple hamartomatous microlesions of various types within the kidney is reported. This type of intraglomerular lesion has been briefly described only twice previously in patients with tuberous sclerosis (TS), and is unique in its location and histological appearance. The lesions are mainly composed of proliferating mesangial cells and are hamartomatous in nature. Although no stigmata of TS other than renal AMLomas are apparent in this case, the presence of many renal hamartomatous lesions suggests the possibility of a forme fruste of TS.

Female↗
PubMed1988

An ovarian Sertoli-Leydig cell tumor with heterologous mucinous gland and NSE-immunoreactive-cell.

A rare case of ovarian Sertoli-Leydig cell tumor with heterologous mucinous glands and tiny carcinoid-like foci in a 33-year-old female is reported. In addition to these heterologous elements, peculiar cells, which were oval, eosinophilic and neuron-specific enolase (NSE)-positive, were also observed and had not been described previously. These NSE-immuno-reactive cells were different from argentaffin cells observed in mucinous glands and carcinoid-like foci, and seemed to play a significant role in the appearance of the heterologous mucinous gland. The nature of this peculiar NSE-immunoreactive cell is discussed.

Adult↗
PubMed1988

Three categories of the degenerative appearance of the human cerebellar dentate nucleus. A morphometric and morphological study.

This morphometric and morphological study demonstrates 3 categories (types A, B and C) of degenerative feature in the cerebellar dentate nucleus. Type A is characterized by neuronal loss, astrocytosis and granular and/or amorphous argyrophilic change around the neurons and neuronal processes, and this type was thought to be synonymous with the so-called grumose degeneration of the DN. Type B is characterized by extensive neuronal loss and astrocytosis without argyrophilic change, and it was considered that many diverse factors were responsible for type B. Type C features marked swelling of the neurons without neuronal loss, astrocytosis or argyrophilic change. The Purkinje cells were not involved in type A and C, but severely damaged in type B. Clinically, type A was observed in progressive supranuclear palsy and dentatorubropallidoluysian atrophy, type B extensively in many diseases including anoxic, toxic and infectious disorders, and type C in tardive dyskinesia manifesting with oral hyperkinesia. Types A and C may be more or less specific signs of degeneration of the dentate nucleus, whereas type B appears to be non-specific.

Adult↗
PubMed1988

Pulmonary hypertension associated with portal hypertension in childhood. Case report of a 6-year-old child and review of the literature.

Pulmonary hypertension is a rare complication of portal hypertension. Reports of childhood cases especially rare. This report describes an autopsy case of a 6-year-old boy with congenital biliary atresia followed by liver cirrhosis in whom severe hypertensive pulmonary arterial changes, including medial hypertrophy, intimal fibrosis and plexiform lesions were demonstrated. Fresh and organizing fibrin-platelet thrombi as well as probable organized thrombi with recanalization were occasionally found in the pulmonary vasculature, but it was thought that they had probably been formed locally as a late complication rather than being of thromboembolic origin. Retrospectively, the chest roentgenograms had revealed abnormalities suggestive of pulmonary hypertension since infancy, but the patient showed no apparent symptoms of it during life. Previously reported childhood cases of pulmonary hypertension associated with portal hypertension were briefly reviewed. Although the mechanism is presently not known, it is suggested that patients with portal hypertension, even in early childhood, are at risk of developing this unusual complication.

Biliary Atresia↗
PubMed1987

Tardive dyskinesia with inflated neurons of the cerebellar dentate nucleus. Case reports and morphometric study.

Four autopsied cases of tardive dyskinesia manifesting oral hyperkinesia revealed markedly inflated neurons in the cerebellar dentate nucleus (DN), which had not been described previously. The inflation of the neurons was proved to be statistically significant (P less than 0.01) by morphometric study. The nuclei were usually situated in the central portion of the cytoplasm. This inflated change was different from both central chromatolysis and grumose degeneration of the DN, typically observed in progressive supranuclear palsy and dentatorubropallidolysian atrophy, and seemed to be easy to miss without careful observation, since neuronal loss and gliosis were very mild in the DN. Among a few autopsied cases of tardive dyskinesia reported previously, degeneration of the DN was described in only two. It is believed, however, that the inflated neurons of the DN may not be so rare and may be related to the occurrence of some involuntary hyperkinesia, especially oral hyperkinesia following some neurotoxic disorders and/or neuroleptic medications.

Aged↗
PubMed1987

Induction of suppressor T cells by intravenous administration of monoclonal anti-I-A antibody.

Intravenously administered monoclonal anti-I-A antibodies successfully induced suppressor T (Ts) cells specific for alloantigen-specific delayed-type hypersensitivity (DTH) responses in mice. These Ts cells exerted their effects in the effector phase and had no H-2 restrictions. Phenotypic analysis revealed L3T4 antigens on their cell surface but failed to reveal Lyt-2 antigen. Ts cell activity was abrogated by a 30-min incubation with the anti-I-A antibodies used for Ts cell induction. Incubation in the anti-I-A-antibody-coated plate also abrogated the Ts cell activity. Since anti-I-A antibody is idiotypic for the I-A antigen, it is suggested that these Ts cells might express antiidiotypic receptors for I-A antigens. These findings are considered to be consistent with previous observations of hapten-specific systems, in which antiidiotypic Ts cells are inducible by idiotypic antibodies.

Animals↗
PubMed1987

Immunohistochemical study of pancreatoblastoma.

Three cases of pancreatoblastoma in children were examined immunohistochemically and the results were compared with those of pancreatic duct carcinoma in adults. The pancreatoblastoma demonstrated positive reactions to alpha-fetoprotein (AFP) (67%: 2/3), alpha-1-antitrypsin (AAT) (100%: 3/3), carcinoembryonic antigen (CEA) (67%: 2/3) and keratin (33%: 1/3), although CEA was only weakly positive in both cases. On the other hand, adult pancreatic duct carcinoma showed positive reactions as follows; AFP: 3% (1/29), AAT: 21% (6/29), CEA: 97% (28/29) and keratin: 93% (27/29). Also, endocrine substances including insulin, glucagon and somatostatin were all negative in the pancreatoblastomas. Two cases of pancreatoblastoma which were immunohistochemically positive for AFP also showed elevation of the serum AFP level clinically. The different expressive pattern of oncofetal antigens in pancreatoblastoma as compared with pancreatic duct carcinoma in adults may provide further supporting evidence for the embryonic nature of pancreatoblastoma, and suggests that such a pattern might be used as a tumor marker for pancreatoblastoma.

Adult↗