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Biomedical subjects

T Manabe

Publications and source records attributed to T Manabe.

At least 19 recordsLinked to original sources
PubMed1999

Basement membrane material in ovarian clear cell carcinoma: correlation with growth pattern and nuclear grade.

Stromal hyalinization in ovarian clear cell carcinomas has been suggested to be caused by deposition of basement membrane (BM) material, but the biological and diagnostic significance of this finding remains unknown. The distribution of BM material in 17 primary ovarian clear cell carcinomas was examined semiquantitatively using hematoxylin and eosin-stained sections and immunohistochemistry with antibodies to laminin and type IV collagen. For comparison, other surface epithelial tumors, including 8 serous tumors of low malignant potential, 10 serous adenocarcinomas, 6 mucinous tumors of low malignant potential, 5 mucinous adenocarcinomas, 6 endometrioid carcinomas, 4 Brenner tumors, 1 transitional cell carcinoma, and 3 undifferentiated carcinomas, were examined. Stromal hyalinization was found in all 17 clear cell carcinomas and was immunoreactive for type IV collagen and laminin. Other types of surface epithelial tumor lacked these findings. In clear cell carcinoma, areas showing a papillary pattern tended to show abundant deposition regardless of nuclear grade, whereas in solid, tubular, or cystic areas, the deposition was more prominent in areas showing high-nuclear-grade features (grade 2 and 3) than in areas with low-nuclear-grade features (grade 1). Dense deposition of BM material recognized as stromal hyalinization on hematoxylin and eosin-stained sections in primary ovarian clear cell carcinoma is a characteristic feature that is not seen in other ovarian surface epithelial tumors. This matrix production correlates with high-nuclear-grade features and papillary growth pattern.

Adenocarcinoma, Clear Cell↗
PubMed1998

Alliinase [S-alk(en)yl-L-cysteine sulfoxide lyase] from Allium tuberosum (Chinese chive)--purification, localization, cDNA cloning and heterologous functional expression.

Alliinase [S-alk(en)yl-L-cysteine sulfoxide lyase], a pyridoxal-phosphate-(Pxy-P)-dependent enzyme, is responsible for the degradative conversion of S-alk(en)yl-L-cysteine sulfoxide to volatile odorous sulfur-containing metabolites in Allium plants. We have purified alliinase from shoots of Allium tuberosum (Chinese chive) to apparent homogeneity by SDS/polyacrylamide gel electrophoresis. A cDNA clone encoding alliinase was isolated from a cDNA library constructed from whole plants of A. tuberosum by hybridization screening with a synthetic 50-residue oligonucleotide encoding a conserved region of the alliinases from onion and garlic. The isolated cDNA encoded a protein of 476 amino acid residues with a molecular mass of 54083 Da. The deduced amino acid sequence exhibited 66-69% identities with those of reported alliinases from onion, garlic and shallot. The partial amino acid sequence, which was determined for a V8 protease-digested peptide fragment of the purified alliinase, was perfectly matched with the sequence deduced from the cDNA. An expression vector of recombinant alliinase cDNA was constructed in yeast. The catalytically active protein was in the soluble fraction of transformed yeast. Site-directed mutagenesis experiments indicated that Lys280 was essential for the catalytic activity and, thus, a possible Pxy-P-binding residue. The mRNA expression of the alliinase gene comprising a multigene family in the shoots of green plants was twofold higher than that in the roots of green plants; however, the expression in the shoots of etiolated plants was only 13% that in green shoots, although the expression in the roots was not remarkably different between in green and etiolated plants. Immunohistochemical investigation indicated that the alliinase protein is predominantly accumulated in the bundle sheath cells of shoots of A. tuberosum.

Allium↗
PubMed1998

Removal of specific protein spots on the patterns of non-denaturing two-dimensional electrophoresis using protein A agarose and antibodies.

Protein spots, such as immunoglobulin G (IgG), A (IgA) or alpha 2-macroglobulin, on the patterns of non-denaturing two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) were selectively removed by the application of protein A or antibody-conjugated protein A agarose to the first-dimension gel top at the cathode side. A protein residing at pI 5.8 and with a molecular mass of about 200 kDa was clearly detected when the IgG and IgA spots were removed from the 2-D PAGE pattern.

Antibodies↗
PubMed1998

Increased thresholds for long-term potentiation and contextual learning in mice lacking the NMDA-type glutamate receptor epsilon1 subunit.

The NMDA-type glutamate receptor (GluR) channel, composed of the GluRepsilon and GluRzeta subunits, plays a key role in synaptic plasticity in the CNS. The mutant mice lacking the GluRepsilon1 subunit exhibited a reduction in hippocampal long-term potentiation (LTP), but a stronger tetanic stimulation restored the impairment and the saturation level of LTP was unaltered. These results suggest an increase of threshold for LTP induction in the GluRepsilon1 mutant mice. After a series of backcrosses we established a GluRepsilon1 mutant mouse line with a 99.99% pure C57BL/6 genetic background. The performance of the mutant mice in tone- and context-dependent fear conditioning tests was comparable with that of the wild-type mice. However, a significant difference in the extent of contextual learning became apparent when the chamber exposure time before footshock was shortened. Furthermore, there was a significant difference in freezing responses immediately after footshock on the conditioning day between the wild-type and mutant mice, and the difference was not restored by longer chamber exposure in contrast to the contextual learning on the next day of the conditioning. These results suggest that the GluRepsilon1 subunit of the NMDA receptor channel is a determinant of thresholds for both hippocampal LTP and contextual learning and plays differential roles in two forms of contextual fear memories.

Animals↗
PubMed1998

Facilitation of long-term potentiation and memory in mice lacking nociceptin receptors.

The peptide nociceptin (also named orphanin FQ) acts in the brain to produce various pharmacological effects, including hyperalgesia and hypolocomotion. The nociceptin receptor uses guanine-nucleotide-binding proteins to mediate the inhibition of adenylyl cyclase, the activation of potassium channels and inhibition of calcium channels. It has been shown using knock-out mice that the nociceptin receptor is not required for regulation of nociceptive responses or locomotion activity, but modulates the auditory function. Here we show that mice lacking the nociceptin receptor possess greater learning ability and have better memory than control mice. Histological analysis revealed the expression of both the nociceptin precursor and the nociceptin receptor in the hippocampus, thought to take part in aspects of learning and memory. Moreover, the receptor-deficient mice showed larger long-term potentiation in the hippocampal CA1 region than control mice, without apparent changes in presynaptic or postsynaptic electrophysiological properties. These results show that the loss of the nociceptin receptor results in a gain-of-function mutation in both the memory process and the long-term potentiation mechanism in CA1, perhaps as a result of altered intracellular signal transduction systems in neurons.

Animals↗
PubMed1998

Correlation of plasma protein separation patterns obtained by two-dimensional polyacrylamide gel electrophoresis and by capillary electrophoresis.

We used three different electrophoretic techniques for the analysis of human plasma proteins: (i) two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), with sodium dodecyl sulfate (SDS) used only in slab gel electrophoresis; (ii) capillary isoelectric focusing (CIEF) with no denaturants; (iii) linear polyacrylamide (LPA)-filled capillary electrophoresis with SDS (SDS-CE). With technique (i), data on isoelectric point and molecular size of plasma proteins can be obtained. Techniques (ii) and (iii) are suited to obtain quantitative information on proteins. The separation principle used in technique (ii) is closely related to that used in the first dimension of technique (i), and that used in technique (iii) related to that in the second dimension of technique (i). Therefore, we could successfully correlate protein separation patterns obtained by 2-D PAGE and those obtained by capillary electrophoresis. The advantages of correlating data obtained by various electrophoretic techniques in the course of constructing a comprehensive database on human plasma proteins are discussed.

Blood Proteins↗
PubMed1998

Size separation of sodium dodecyl sulfate complexes of human plasma proteins by capillary electrophoresis employing linear polyacrylamide as a sieving polymer.

Electrophoretic conditions to separate sodium dodecyl sulfate (SDS) complexes of human plasma proteins according to their size differences, by capillary electrophoresis employing linear polyacrylamide as a sieving matrix (LPA-CE), have been examined. Using the optimized separation conditions, SDS complexes of human plasma proteins not treated with reducing agents were separated into about 40 peaks and shoulders within 60 min. The molecular mass values of major peaks in a separation pattern were estimated from a plot of molecular mass and migration time for standard proteins and some of the major plasma proteins have been identified on the pattern. The electrophoretic conditions were successfully applied for the analysis of proteins in immunoglobulin G (IgG) myeloma sera.

Acrylic Resins↗
PubMed1998

Angiomyolipoma of the liver: case report and collective review of cases diagnosed from fine needle aspiration biopsy specimens.

We experienced a rare case of primary angiomyolipoma (AML) of the liver, preoperatively diagnosed by fine needle aspiration biopsy (FNAB). Radiographic imaging revealed characteristic features of an angiomyolipoma. The diagnosis was confirmed by the presence of epithelioid smooth muscle cells, mature fat cells and blood vessels in the biopsy tissue. Our review of the literature showed this to be the eleventh case to be diagnosed in this way. Despite this preoperative diagnosis, the lesion was resected because of its pleomorphic histological features. Histologically, the epithelioid smooth muscle component included cells with a bizarre appearance and occasional hyperchromatic nuclei, and furthermore, occasional mitotic figures were observed. In own MEDLINE search of the literature we found 11 cases of AML of the liver for which the diagnoses were established by FNAB, and the same features were present in 5 cases for which surgical excision was contemplated.

Angiomyolipoma↗
PubMed1998

Malignant fibrous histiocytoma originating from the chest wall: report of a case and collective review of cases.

Malignant fibrous histiocytomas occur principally as a mass of the extremities, abdominal cavity, or retroperitoneum in adults. However, they only rarely occur in the chest wall. A rare case of primary malignant fibrous histiocytoma originating from the chest wall is herein presented. The 36 previously reported cases are also reviewed. Of the 32 patients who underwent a resection as the initial treatment, 10 (31.3%) had a local recurrence. Of the 37 patients with this disease, 9 (25.0%) had subsequent metastases. The majority of the deaths (36.1%) from this disease occurred within the first 12 months. The patients who undergo surgical and adjuvant therapy must therefore be monitored carefully by frequent examinations.

Aged↗
PubMed1998

Oncocytic lipoadenoma of the submandibular gland.

We report a case of oncocytic lipoadenoma of the submandibular gland, previously unrecognized benign tumor of the salivary gland. The patient was a 66-year-old Japanese woman with a left submandibular mass, measuring 11 x 7.5 x 5 cm. Microscopically, the mass was completely surrounded by a thin fibrous connective tissue capsule, and was composed of an intimate admixture of mature fat cells and oncocytes. There have been no English reports of such a neoplasm in the salivary gland with the exception of one recent case report of lipoadenoma of the parotid gland without oncocytic features. We propose the diagnostic term "oncocytic lipoadenoma" for this benign tumor.

Adenoma↗
PubMed1998

Role of the carboxy-terminal region of the GluR epsilon2 subunit in synaptic localization of the NMDA receptor channel.

The synaptic localization of the N-methyl-D-aspartate (NMDA) type glutamate receptor (GluR) channel is a prerequisite for synaptic plasticity in the brain. We generated mutant mice carrying the carboxy-terminal truncated GluR epsilon2 subunit of the NMDA receptor channel. The mutant mice died neonatally and failed to form barrelette structures in the brainstem. The mutation greatly decreased the NMDA receptor-mediated component of hippocampal excitatory postsynaptic potentials and punctate immunofluorescent labelings of GluR epsilon2 protein in the neuropil regions, while GluR epsilon2 protein expression was comparable. Immunostaining of cultured cerebral neurons showed the reduced punctate staining of the truncated GluR epsilon2 protein at synapses. These results suggest that the carboxy-terminal region of the GluRepsilon2 subunit is important for efficient clustering and synaptic localization of the NMDA receptor channel.

Afferent Pathways↗
PubMed1998

Selective scarcity of NMDA receptor channel subunits in the stratum lucidum (mossy fibre-recipient layer) of the mouse hippocampal CA3 subfield.

Hippocampal synapses express two distinct forms of the long-term potentiation (LTP), i.e. NMDA receptor-dependent and -independent LTPs. To understand its molecular-anatomical basis, we produced affinity-purified antibodies against the GluRepsilon1 (NR2A), GluRepsilon2 (NR2B), and GluRzeta1 (NR1) subunits of the N-methyl-D-aspartate (NMDA) receptor channel, and determined their distributions in the mouse hippocampus. Using NMDA receptor subunit-deficient mice as the specificity controls, section pretreatment with proteases (pepsin and proteinase K) was found to be very effective to detect authentic NMDA receptor subunits. As the result of modified immunohistochemistry, all three subunits were detected at the highest level in the strata oriens and radiatum of the CA1 subfield, and high levels were also seen in most other neuropil layers of the CA1 and CA3 subfields and of the dentate gyrus. However, the stratum lucidum, a mossy fibre-recipient layer of the CA3 subfield, contained low levels of the GluRepsilon1 and GluRzeta1 subunits and almost excluded the GluRepsilon2 subunit. Double immunofluorescence with the AMPA receptor GluRalpha1 (GluR1 or GluR-A) subunit further demonstrated that the GluRepsilon1 subunit was colocalized in a subset, not all, of GluRalpha1-immunopositive structures in the stratum lucidum. Therefore, the selective scarcity of these NMDA receptor subunits in the stratum lucidum suggests that a different synaptic targeting mechanism exerts within a single CA3 pyramidal neurone in vivo, which would explain contrasting significance of the NMDA receptor channel in LTP induction mechanisms between the mossy fibre-CA3 synapse and other hippocampal synapses.

Animals↗
PubMed1998

Epstein-Barr virus-associated Hodgkin's disease in HTLV-I seropositive patients: a report of two cases.

Diagnosis of Hodgkin's disease (HD) is quite difficult in the patient with seropositivity for human T cell lymphotropic virus I (HTLV-I). Herein, two cases of Epstein-Barr virus (EBV)-associated HD, which occurred in males with seropositivity for anti-HTLV-I, are reported. One patient is alive and was diagnosed as having interfollicular HD with CD20+CD15-CD30-CD3-CD4-CD8-CD45RO-Read-Sternberg (R-S) cells. Positivity for EBV-encoded RNA 1 (EBER-1) and latent membrane protein 1 (LMP-1) was shown on follicular germinal center cells and R-S cells. In that case, neither T cell receptor (TCR) beta chain rearrangement nor integration of the HTLV-I provirus was demonstrated in the lymph nodes, although atyical lymphocytes (2%) were found in the peripheral blood. The other case pursued an aggressive clinical course and the patient was diagnosed as having an adult T cell leukemia/lymphoma (ATLL) because of the presence of anti-HTLV-I antibody, lymph node swelling, and the appearance of flower-like cells in the peripheral blood. However, an autopsy revealed no obvious ATLL cell infiltration in any of the organs examined. Multiple granulomatous lesions were found in the bone marrow, liver, kidneys, spleen, and lymph nodes. Reassessment of lymph node lesions in biopsies and granulomatous lesions in autopsy samples demonstrated that both lesions contained CD15+CD30+CD3-CD4-CD8-CD20-CD45RO-EBER-1+L MP-1+R-S cells, and they were considered to be a composite lymphoma of HD and ATLL. These two cases therefore suggest that EBV-associated HD can develop in patients with seropositivity for HTLV-I.

Antigens, CD↗