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Biomedical subjects

M Ogura

Publications and source records attributed to M Ogura.

At least 19 recordsLinked to original sources
PubMed1992

Purification and characterization of NF-R1 that regulates the expression of the human multidrug resistance (MDR1) gene.

We have purified a protein, NF-R1, that specifically binds to two unrelated motifs--the ATTCAGTCA motif and the GC-box motif--on the MDR1 proximal promoter. Purified NF-R1 has been confirmed by southwestern blotting to be a 110-kDa protein. Methylation interference analysis revealed that the nucleotides were in close contact with purified NF-R1 on the ATTCAGTCA and GC-box motifs. The nucleotides were required for the binding of NF-R1, as seen by competition gel mobility shift assay using point mutated oligonucleotides. In a CAT expression assay using the corresponding point-mutated MDR1 promoter fused to a CAT gene, binding inhibition of NF-R1 to the promoter resulted in 2- to 3-fold increases of CAT activity, as compared to the intact promoter in Adriamycin-resistant K562 cells. Thus NF-R1 has a relation to the negative regulation of the MDR1 gene transcription.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Intracellular signal transduction for interleukin-1 beta-induced endothelin production in human umbilical vein endothelial cells.

The authors investigated the intracellular signal transduction for interleukin (IL)-1 beta-induced endothelin (ET) production by endothelial cells from cultured human umbilical vein (HUVEC). Cultured HUVEC released immunoreactive (iR)-ET into the media in a time-dependent manner and a significant increase of iR-ET production was observed by the addition of IL-1 beta. The stimulating effect of IL-1 beta on iR-ET production was respectively inhibited by protein kinase C (C kinase) inhibitor (H-7), Ca-calmodulin inhibitor (W-7), cyclic AMP-dependent protein kinase (A kinase) inhibitor (H-8) and tyrosine kinase inhibitor (genistain) in a dose-dependent fashion. The data suggested that intracellular signal transduction for IL-1 beta-induced iR-ET production were via such pathways as C kinase, A kinase, Ca-calmodulin and tyrosine kinase in combination or independently, though possible mediation by other pathways cannot be ruled out.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Deficiency of fibrinolytic enzyme activities in the serum of patients with Alzheimer-type dementia.

Previously we reported that there is a kallikrein deficiency in the cerebral tissue of patients with Alzheimer-type dementia. The present study was performed to investigate protease changes in the serum of these patients. The results showed that the kallikrein activity was normal, but that the activities of plasmin and urokinase were significantly low. The present findings indicate a derangement in the clotting and fibrinolytic systems in Alzheimer patients.

Aged↗
PubMed1992

Biosynthesis of cholic acid accelerated by diabetes: its mechanism and effect of vanadate administration.

[7 beta-3H]3 alpha,7 alpha-Dihydroxy-5 beta-cholestane was infused into the femoral vein of bile-fistula rats. The main metabolites in bile were cholic, chenodeoxycholic, and alpha-muricholic acids. Cholic acid accounted for only 7.5% of the total biliary [3H]bile acids in the normal rats, but 51.8% in the diabetic rats. This increased proportion of cholic acid was partially cancelled by treatment of the diabetic rats with insulin (29.8%) or vanadate (28.8%). These results clearly confirm that an alternative biosynthetic pathway of cholic acid via 3 alpha,7 alpha-dihydroxy-5 beta-cholestane is accelerated by diabetes, and indicate that vanadate has an insulin-like effect on the formation of cholic acid in an insulin-deficient state.

Animals↗
PubMed1992

Peroxidase-amplified assay of sialidase activity toward gangliosides.

Sialidase assays were carried out with the substrate, ganglioside GD1a, coated onto enzyme immunoassay plate wells. Following the incubation of GD1a with sialidase from V. cholerae, the amount of ganglioside GM1 produced was measured as follows: cholera toxin B subunit conjugated to horseradish peroxidase was added to specifically bind to GM1, and then the amount of bound peroxidase was determined in a colorimetric enzymatic assay. In the absence of detergent, linearity for the detection of GM1 was 0 to 0.5 pmol per well, and the sensitivity for sialidase detection was about 3 fmol of product formed per minute. The addition of detergent (Triton CF-54) to the assay reduced the sensitivity and increased the amount of substrate required. Application of this assay for the detection of cell-derived neutral (pH 6.5) sialidase activities in the conditioned medium of human skin fibroblasts is described.

Chromatography, Gel↗
PubMed1992

Phenotypic and genotypic characterization of 14 leukemia and lymphoma cell lines with 11q23 translocations.

11q23 translocation is the most popular chromosomal abnormality in infant leukemia. In adults, it is often encountered in non-Hodgkin's lymphoma (NHL). In this study, we analyzed the phenotypic and genotypic characteristics of 9 acute leukemic cell lines with 11q23 translocations and one with deletion of the 11q23 locus, nine of which were established by researchers in this group, together with 4 NHL cell lines with 11q23 translocations. All lines were considered to belong to the B-cell lineage at different stages. All 10 leukemic lines showed clonal rearrangement of the immunoglobulin heavy chain (IgH) gene: two corresponded to the B-precursor stage (CD19+, cytoplasmic mu-), while the other 8 corresponded to the pre-B stage (cytoplasmic mu+). All 4 NHL lines showed rearrangements of both the IgH and Ig kappa genes with three expressing surface Ig; specifically, mature B-cell phenotype. As for myelocytic-monocytic markers, at least one out of 4 antigens examined were positive in 8 of the 10 leukemic cell lines, while only one of the 4 NHL lines was reactive. There were essentially no clear phenotypic or genotypic differences between t(4;11) and t(11;19) cell lines, supporting the view that both diseases have similar clinicopathological characteristics. These cell lines are also valuable for cloning genes at the chromosomal breakpoints.

Acute Disease↗
PubMed1992

Is injectable collagen truly safe?

Most patients have no response to injectable collagen or silicone, but some cases may have positive or 'undersea' (= clinically negative but immunologically positive) response to collagen. From the results of the Macrophage migration inhibition test, the relative immunogenicity was augmented most when we used implants with the following combination. The first immunization was collagen and the second one was collagen with silicone. The augmented antigenicity might be enough to cause an allergic reaction to the patients who had no response to each implant alone.

Adjuvants, Immunologic↗
PubMed1992

Phenotypic and genotypic lineage switch of a lymphoma with shared chromosome translocation and T-cell receptor gamma gene rearrangement.

A case of non-Hodgkin's lymphoma showed a phenotypic and genotypic cell lineage switch twice during nine years of his clinical history; first, T-cell type, pleomorphic small cell lymphoma developed, followed by B-cell type, diffuse centroblastic/centrocytic lymphoma, and finally T-zone lymphoma without follicles again developed, from which AST-1 cultured cell line was established. Karyotype analysis demonstrated a shared abnormal chromosome, der(1)t(1;?)(p36;?), among the first relapsed B-cell tumor, the second relapsed T-cell tumor and AST-1 cell line. Furthermore, T-cell receptor (TCR) gamma gene rearrangement bands of the same size were observed in the first relapsed B-cell tumor and the second relapsed T-cell tumor as well as AST-1 cell line. These results suggested that both relapsed tumors of different cell lineages are derived from a common malignant clone, presumably a committed lymphoid stem cell. A unique translocation, t(2;14)(q37;q11.2), which may involve TCR delta/alpha gene complex, was observed in the second relapsed tumor and AST-1 cells. To attempt to isolate the breakpoint of this translocation, the configuration of TCR delta/alpha gene complex was studied. The result showed that two rearrangements of TCR alpha gene detected with J alpha probes were the products of the normal TCR rearrangement process, and were not involved in the translocation at this region. This patient, together with the AST-1 cell line, provided us a unique opportunity to study the development and clonal evolution of malignant lymphoma.

Amino Acid Sequence↗
PubMed1992

Postauricular response in motor paresis with intracranial lesions.

The clinical usefulness of the postauricular response (PAR) in the evaluation of motor paresis was studied in 105 patients with intracranial lesions and 25 normal volunteers. Click stimuli at 90 dB hearing level were delivered in each ear, and PARs recorded from bilateral posterior auricular muscles with reference to the vertex (Cz). No volunteer demonstrated PAR in the relaxed posture, but in tensed postures increasing muscle tone PARs were elicited with a latency of 11.5 +/- 0.7 msec and an amplitude of 6.2 +/- 2.8 muV. Sixty-two patients (59%) had high-amplitude PARs in the relaxed posture. PARs were enhanced more frequently in paretic patients than in non-paretic patients (p less than 0.01). In subcortical lesions, the PAR latency had a significant correlation with the degree of motor paresis (p less than 0.005). In patients, the enhanced PAR amplitude suggested the presence of motor paresis associated with deep-seated mass lesions. The enhanced response is thought to be associated with dysfunction of the pyramidal and extrapyramidal tracts.

Brain Diseases↗
PubMed1992

[Serum alpha 1-antichymotrypsin in senile dementia].

To evaluate the clinical significance of serum alpha 1-Antichymotrypsin (ACT) as an early diagnostic marker of senile dementia of Alzheimer type (SDAT), we measured 333 healthy and not demented elderly subjects, 27 cases SDAT and 25 cases of vascular dementia (VD). For the measurement, a new high-sensitivity method, double antibody radioimmunoassay method was developed. In healthy elderly subjects, the mean value of serum ACT was 0.229 mg/ml. A tendency towards increase of ACT with aging was noted but was not significant. The serum level of ACT in the SDAT patients was significantly higher (0.309 mg/ml) compared with the healthy elderly subjects and the VD patients (0.226 mg/ml) (p < 0.01). We concluded that in the patients with SDAT, there was an overproduction of ACT and the serum value of ACT was markedly elevated. The measurement of serum ACT is very useful (sensitivity = 88.9%, specificity = 68.7%; cut-off value = 0.250 mg/ml) for the early differential diagnosis of senile dementia.

Aged↗
PubMed1992

[Clinical effects of six-month short time biofiltration].

The clinical effects of six-month short time biofiltration (SBF) were evaluated using a B-A-B' study (B, B': conventional bicarbonate hemodialysis; CBHD, A:SBF) in ten patients maintained on CBHD three times a week. An F80 hemodiafilter (1.9 m2, polysulfone, Fresenius) was used. In addition to routine clinical parameters for a patient on regular dialysis treatment, plasma von Willebrand factor antigen (vWF) (an index of stimulation of vascular endothelium), and the methylguanidine/creatinine ratio (MG/Cr) and malondialdehide (MDA) (indices of the levels of oxygen radicals), were evaluated. Nine patients completed the study, one patient dropping out at the 12th week of A because of muscle cramps during SBF. The treatment time was 2 hours in six cases and 2.5 hours in three cases. The mean blood flow rate was 280 +/- 42 (SD) minutes. Using the urea kinetics model, the mean KT/V was 1.26 +/- 0.28, and the mean protein catabolic rate was 1.22 +/- 0.18 g/kg body weight/day at the end of A. No change in ultrafiltration, blood pressure, cardiac function (assessed by echocardiography), CTR, human atrial natriuretic peptide, total protein, albumin, uric acid, serum creatinine, sodium, calcium, inorganic phosphorus, vWF, or MDA was found between each period. Blood urea nitrogen, c-PTH, and MG/Cr increased during the A period. Serum magnesium and beta-2 microglobulin decreased during the A period. Blood gas results, on the whole, did not change. In a patients, however, acidosis gradually developed. An increase in substitution fluid from 5 L/session to 7.5 L/session improved the acid-base balance in that patient. In conclusion, SBF is as effective as CBHD in removing small molecules and maintaining cardiocirculatory status, and is superior to CBHD in removing beta 2-microglobulin and is less stimulative to the endothelium than CBHD.

Adult↗
PubMed1992

Mediastinal diffuse large cell lymphoma of B-cell type with azurophilic granules.

A case of diffuse large cell lymphoma of B-cell type with unusual azurophilic granules is reported. Lymphoma occurred primary in the upper anterior mediastinum and was suggested to be of thymic origin. Histologically, lymphoma cells showed diffuse proliferation and were large in size, frequently with multilobulated nuclei. In imprint preparations stained by May-Giemsa, most lymphoma cells had basophilic cytoplasm with azurophilic granules. Cytochemical studies showed the granules to be negative for PAS, peroxidase, acid phosphatase, and beta-glucuronidase. Electron-dense granules and electron-lucent granules were found on ultrastructural analysis. The cells were characterized as B-cell type by immunophenotypes of L26+, CD20+, CD21-, CD22+, and PCA1+, the possession of surface monotypic IgA kappa immunoglobulin, and a genotype of immunoglobulin heavy and kappa light chain gene rearrangements.

Adult↗
PubMed1992

[Sensitivity test for anti-tumor agents-3. MTT assay and its clinical effect].

MTT assay, a sensitivity test of anti-tumor agents was performed, and its clinical usefulness, was discussed. In 15 surgical specimens, the cell suspensions were prepared aseptically, and divided into three processing; namely, Papanicolaou (Pap) smears to confirm the malignant cells, MTT assay, and cell cultures in chamber slides. MTT assay was evaluated only when tumor cells in the chamber slide were observed 50% or more by Pap staining. Drugs judged to be effective were applied for patients, resulting in 64.2% of predictive accuracy in the sensitivity. Conclusions; 1) MTT assay was developed for sensitivity test of anti-tumor agents, 2) Strict assessment was carried out by the confirmation of cancer cells using chamber slides, 3) On clinical usefulness, predictability for the sensitivity was 64.2%, that for resistance was 100%, and over all predictability was 66.7% 4) MTT assay was useful for the determination of effective and for elimination of ineffective drugs.

Antineoplastic Agents↗
PubMed1992

[Pitfalls in cortical localization by intraoperative recording of cortical somatosensory evoked potentials].

Cortical somatosensory evoked potential (SEP) recordings were made in 11 patients who had lesions located in or near the somatosensory or motor gyri to localize the central sulcus and sensorimotor cortex during neurosurgical operations. Cortical localization was successful in 7 of the 11 patients by recording phase reversal waveforms of N20 and P20 at electrode sites in the hand area on opposite sides of the central sulcus. There were 4 cases in which the cortical localization failed. Locations of craniotomy were far distant from the central sulcus retrospectively in 2 of the 4 patients. Cortical SEPs couldn't be recorded despite probable exposure of the hand area and apparently adequate stimulation and recording conditions in 2 patients who had showed no or low amplitude scalp SEP preoperatively. In one of these 2 patients only low amplitude negative waves were recorded at the cortex which was thought far field potentials originated from subcortical structures. In 2 patients cortical SEP was monitored during the removal of the tumors and was useful to estimate the effects of the operative procedures on the sensorimotor cortex. It is concluded that the localization of cortical functions using cortical SEP is useful for reducing risk associated with intracranial surgery. However, we must be aware that there are some pitfalls in this method.

Adolescent↗
PubMed1992

[Three dimensional display of cerebral vessels using a personal computer].

A new method for a 3-D reconstruction of angiographic cerebral vessels was developed. This system was constructed from inexpensive equipment such as a personal computer, a video camera, a video display, and a digitizer. The input of the vessel images on anteroposterior and lateral angiograms was performed using a video camera with a personal computer and an image processing program (FDM 98-4; Fotoron Co.). These processed images were modified with our original editorial method. This can contribute a lot to the erasing of "non-vessel" images such as skull bone and other noise. It also adds concerning vessels which cannot be clearly taken from angiograms with the video camera. The most beneficial point of the editorial method was to reduce the time consumed in the reconstruction. The spatial points of X-ray discharging boxes against the AP and lateral films were calculated from the length and width of the radiated images of metal bars. These bars were attached to the 3 planes of the lucent box in which the patient's head was inserted to take the angiograms. The 3-D points of the vessels were calculated as follows; one point of a vessel on the lateral image and the spatial point of the X-ray discharging box against the image were linked by a line on which a point moved within a Z range. When the extended line which linked the point and the position of the X-ray discharging box against the AP view crossed the AP image, the Z value of the point was adopted and X and Y values were gained.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Angiography↗
PubMed1991

Characterization of prostaglandin and thromboxane receptors expressed on a megakaryoblastic leukemia cell line, MEG-01s.

MEG-01s, an established human megakaryoblastic leukemia cell line, exhibited specific high-affinity binding sites for [3H]iloprost, a stable prostaglandin (PG) I2 analogue, for [3H]SQ-29548, a stable thromboxane (TX) A2 antagonist and, for [3H]PGE2/PGE1, but not for [3H]PGD2. In the MEG-01s cells, iloprost/PGI2, or PGE1 stimulated cAMP production with ED50 values practically identical to the IC50 values for the [3H] iloprost binding. STA2 and U46619, TXA2/PGH2 agonists, PGE2/PGE1, iloprost/PGI2, and thrombin elevated the intracellular concentrations of Ca2+ ([Ca2+]i), as determined by Fura-2 fluorescence signals. Elevation of [Ca2+]i by PGE2/PGE1 and iloprost, but not that by TX-agonists or thrombin, was totally dependent on the presence of extracellular Ca2+. This effect by PGE2/PGE1 was partially inhibited by prior treatment of the cells with islet-activating protein (IAP), while that by TX-agonists or by PGI2/iloprost was not affected. We tentatively conclude from these results that: (1) MEG-01s cells express (a) PGI2/PGE1 receptor(s) coupled to adenylate cyclase and Ca2+ influx, a TXA2/PGH2 receptor coupled to the phosphatidylinositol-turnover-Ca2+ system, and the PGE2/PGE1 receptor coupled to Ca2+ influx; (2) the receptors for TXA2/PGH2 and iloprost and those for PGE2/PGE1 and thrombin are coupled to IAP-insensitive and IAP-sensitive GTP-binding proteins, respectively, and function in a different manner to elevate [Ca2+]i. Thus, the MEG-01s cell line is a pertinent model for studying eicosanoid receptor-mediated signal transduction in platelet/megakaryocyte systems.

Adenylate Cyclase Toxin↗