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T Hara

Publications and source records attributed to T Hara.

At least 793 records · Page 44Linked to original sources
PubMed1991

Human complement regulatory proteins expressed on mouse A9 cells containing a human chromosome 1.

The structural genes of human complement regulatory proteins are clustered on chromosome 1 at position q3.2. Human chromosome 1 was transferred into a mouse fibroblast cell line, A9 [designated as A9(neo-1)], and the surface expression of its gene products participating in complement regulation, namely C3b/C4b receptor (CR1, CD35), decay-accelerating factor (DAF, CD55), membrane co-factor protein (MCP, CD46) and C3d/EB virus receptor (CR2, CD21), were assessed using respective monoclonal antibodies by flow cytometry. CR1 became positive within 7 days of culture. MCP appeared in a small population of cells by Day 3 and, together with DAF, began to increase on Day 7. CR2 appeared on Day 14. The order of the expression was CR1 greater than DAF = MCP greater than CR2. On Day 42, however, all became negative except for MCP, which was markedly diminished. These human regulatory proteins were specifically associated with the presence of human chromosome 1, since none of them were expressed on human chromosome 12-transferred A9 cells [A9(neo-12)]. Intact A9 and A9(neo-12) cells activated human complement via the alternative pathway. The activation of this pathway was suppressed in the A9(neo-1) cells that expressed CR1, DAF and MCP. Slight protective activity was still observed in the 42-day cultured A9(neo-1) cells expressing only trace MCP. These results suggest that human complement regulators, expressed via the transferred human chromosome 1, can protect heterologous cells from complement, overcoming their ability to activate the human alternative pathway.

Animals↗
PubMed1991

[Statistical analysis of possible causes of repeated spontaneous abortions].

The possible causes of early pregnancy failure in one thousand, three hundred and seventeen women (n = 1,317) with a history of repeated reproductive wastage were analysed and the results of treatment for each etiology were evaluated. Out of 1,200 hysterosalpingographies, 188 (15.7%) congenital uterine anomalies were detected and the degree of each uterine cavity deformity was evaluated by the X/M ratio. Metroplasty was performed on 71 women with no other causes of spontaneous abortion, and more than 84% of the post-operative pregnancy were successfully maintained. One hundred and four (n = 104, 5.5%) out of 949 couples with a high incidence of reproductive failure had either a chromosomal abnormality or normal variants in the wife and/or husband. Twelve cases (n = 12, 8.1%) had a positive analysis for anticardiolipin antibody among 148 women examined. Immunotherapy utilizing the husband's lymphocytes was indicated for four hundred and seventy three (n = 473) other couples with no other abnormalities likely to induce spontaneous abortions. This treatment brought approximately 80% of pregnancies to successful termination and 199 deliveries were recorded with this immunotherapy. The present study suggests that the causes of early pregnancy failure are complex, but that most of the causes of repetitive wastage are curable after exact diagnosis and appropriate treatment.

Abortion, Habitual↗
PubMed1991

Subjective detection of visual field defects using home TV set.

The usefulness of the noise-field spontaneously generated on a home television screen for subjective perception of visual field defects was studied in 196 eyes of ocular hypertensive or normal subjects, 166 eyes with primary open angle glaucoma and 124 eyes with low-tension glaucoma. All subjects had never perceived their field defects. In 290 glaucoma eyes, including 71 eyes of early glaucoma, 265 eyes (91.4%) could perceive abnormality of the noise-field which corresponded to visual field defects confirmed by static perimetry. In 6 normal eyes abnormality of the noise-field was perceived at the blind spot. The sensitivity and specificity of the test was 91% and 97%, respectively. The time required for testing one eye was 3-5 seconds. The results indicate that the Noise-Field Test using a home television set can be an excellent method for subjective perception of visual field defects, and can also be used for glaucoma screening.

Fundus Oculi↗
PubMed1991

Synthesis of maltotriose by maltase purified from rabbit kidney.

To clarify the enzyme participates in maltotriose synthesis, we purified maltase from rabbit kidney using 2-amino-2-hydroxymethylpropane-1,3-diol (Tris) affinity column chromatography. The purified enzyme possessed specific activity of 33.7 mumol/mg/min and estimated molecular weight of 350,000 dalton, as judged by SDS-polyacrylamide gel electrophoresis, comparable with those reported from rat kidney. Moreover this enzyme possessed not only maltase (maltose----glucose) but also amylomaltase (maltose----maltotriose) activity, and both activities were inhibited by Tris in a dose-dependent manner with similar IC50 values. From these results, we concluded that maltotriose was synthesized by maltase in vitro and that kidney maltase may participate in sugar metabolism in vivo.

Animals↗
PubMed1991

"Equator ring" for maintenance of the completely circular contour of the capsular bag equator after cataract removal.

We designed an "equator ring," a flexible silicone rod with a groove on its inner surface, to maintain the circular contour of the capsular bag equator after cataract removal. After cataract extraction, the ring is inserted in the bag through a 5.0-mm circular capsulorhexis or 4.5-mm linear "dumbbell" opening. Then a conventional posterior chamber intraocular lens (PC-IOL) is inserted, with the IOL loops in the groove. The ring not only allows complete maintenance of the circular contour of the capsular bag equator for most conventional PC-IOLs, but also may prevent invasion of metamorphosed lens epithelial cells into the posterior capsule.

Cataract Extraction↗
PubMed1991

[A case of inoperable advanced gastric cancer with effective treatment by local administration of OK-432, intra-abdominal administration of CDDP, and long-term high-dose mitomycin C, and UFT].

A 61-year-old male diagnosed as Borrmann type 3 advanced gastric cancer was operated, but could not be resected because of the invasion to the pancreas and the lymph nodes metastases. So, local administration of OK-432 20 KE, intra-abdominal administration of CDDP 50 mg, and long-term intermittent intravenous administration of MMC a total amount of 1480 mg, and oral administration of UFT were performed. As the result of this therapy, the tumor was reduced in size. Three years and seven months after the operation, he feels well. Because of this combined therapy, his renal function was made worse.

Adenocarcinoma↗
PubMed1991

[The effectiveness of CDDP in metastatic adenocarcinoma with unknown origin].

A 28-year-old man with inoperable metastatic adenocarcinoma in the retroperitoneum was referred to our hospital for a further evaluation for its origin. The tumor was measured 80 x 107 mm by abd. U.S. and showed papillary adenocarcinoma, histologically. Chemotherapy with intravenous administration of CDDP at the dose of 80 mg/m2 for 6 times at 2-3 week intervals was started, and CDDP concentration of binding-form and free-form in serum and urine were measured in time course. The tumor has reduced for 29 weeks after the discontinuance of CDDP. Free-CDDP, which was thought to have an anticancerous effect, immediately went up high levels in serum and rapidly excreted to urine, while total-CDDP in serum remained in high concentration for more than 10 weeks. Thus it was suggested that anticancerous effect of CDDP could not be contributed only to free-CDDP and the mechanism of CDDP will be clarified by the elucidation of metabolism of both free and total CDDP, especially in the tumor tissue.

Adenocarcinoma↗
PubMed1990

Complement-mediated tumor cell damage induced by antibodies against membrane cofactor protein (MCP, CD46).

We have developed polyclonal and monoclonal antibodies against human membrane cofactor protein (MCP) to use as tools to investigate the functions of MCP on intact nucleated cells. Two human T cell lines, CEM and TALL, are CR1- and DAF-. Pretreatment of these cell lines with M177 and polyclonal anti-MCP, which inhibit cofactor activity almost completely, resulted in effective C3 deposition immediately following addition of these cells to Mg2+/EGTA/human sera. The deposited C3 remained expressed partly on the cell surface and most of them were gradually converted to C3bi. Some of the deposited C3 were complexed with membrane proteins, since 140- and 250-kD bands became significantly accumulated on SDS-PAGE by treatment with the antibodies. We next tested whether these C3-coated cells were damaged by complement-mediated cytolysis. p18, an inhibitor of membrane attack complex (MAC) formation, was negative in TALL but positive in CEM. TALL was lysed efficiently only by treatment with the polyclonal anti-MCP, while CEM showed only slight lysis with the same treatment. Monoclonal antibodies to MCP, including M177, caused only minimal cell destruction. Based on these results, together with the fact that decay-accelerating factor (DAF) serves as a factor for preventing C3 attack on human cells, we conclude that MCP and DAF cooperatively protect host cells from C3 targeting and, in these T cell lines, MCP is sufficient for preventing C3 deposition even without DAF. After all, human cells undergo almost no autologous complement-mediated cytolysis if they express at least one of the functionally active inhibitors, MCP, DAF, or p18.

Animals↗
PubMed1990

Cloning and nucleotide sequence of cDNA for retinochrome, retinal photoisomerase from the squid retina.

The Rhodopsin-retinochrome system is essential for the visual photoreception of molluscs. cDNA coding for retinochrome of the squid (Todarodes pacificus) was cloned and the nucleotide sequence has been determined. The sequence (2.1 kb) covers the whole coding region of 903 bp. The deduced primary sequence suggests that retinochrome contains seven transmembrane spanning domains. The homology with bovine rhodopsin and the possible retinal binding site are also discussed.

Amino Acid Sequence↗
PubMed1990

Dissolution of emboli in rats with experimental cerebral thromboembolism by recombinant human tissue plasminogen activator (TD-2061).

Tissue plasminogen activator (t-PA) is frequently administered clinically as thrombolytic therapy. We injected recombinant t-PA into rats with cerebral 125I-labeled blood clot emboli to evaluate the dissolutive effect of recombinant human single-chain t-PA (rt-PA; TD-2061) on such emboli and to examine the possibility of improving neurological damage in patients with cerebral thrombosis. When rt-PA was given intravenously at a dose of 350,000 IU/kg 2 minutes before embolization, radioactivity in the affected cerebral hemisphere decreased to 20% of that in the vehicle control 2 hours after embolization. A significant decrease in radioactivity in the cerebral hemisphere was also found on the administration of 700,000 IU/kg of rt-PA 30 or 60 minutes after embolization, but not when rt-PA was administered 2 minutes after embolization. Marked inhibition of abnormal behavior such as hemiplegia was seen on treatment with rt-PA 2 minutes before embolization, but not at all when rt-PA treatment was given 30 or 60 minutes after embolization. The findings suggest that rt-PA can dissolve blood clot emboli in cerebral vessels and that prompt thrombolytic therapy is important to minimize neurological dysfunction in cases of cerebral thromboembolism.

Animals↗
PubMed1990

Quantitative analysis of membrane cofactor protein (MCP) of complement. High expression of MCP on human leukemia cell lines, which is down-regulated during cell differentiation.

Membrane cofactor protein (MCP) is a cell-associated regulatory molecule for C system with C3b/C4b binding and factor I-dependent cofactor activity. mAb were raised against MCP and amounts and distribution examined on normal human cells and cell lines. The mean quantity of MCP was 3000 to 7000 copies/cell in normal blood cells, except for E which have no MCP. Of note, PMN did not fully reveal all MCP sites until incubated for greater than 30 min at 37 degrees C. In most tumor cell lines, except for B cell lineages, expression of MCP increased by 2- to 8-fold in comparison with the normal cell counterparts. Strikingly, recombinant granulocyte CSF treatment of myeloid cell lines and hemin treatment of an erythroblastoid cell line, K562, led to a decrease of MCP to near normal levels. In contrast, C3b/C4b receptor (CR1) tended to increase with granulocyte-CSF treatment in several cell lines. We simultaneously determined levels of decay-accelerating factor (DAF) and CR1 in these tumor cells, and tested susceptibility to C3 deposition via activation of the alternative C pathway. Of 21 cell lines we examined, 14 lacked CR1 and two lacked DAF; none, however, lacked MCP. A slight amount of C3 deposition was observed in some myeloid cell lines and EBV-infected B cell lines. However, C3 deposition did not reflect a defect in the regulatory proteins. Tumor cells bearing MCP, lacking CR1 or DAF, and undergoing no C3 deposition, may escape C attack due to the compensatory effect of MCP in the absence of the other regulatory proteins. High expression of MCP provides a convenient means for tumor cells to block C attack and survive in blood stream. We favor the interpretation that MCP is up-regulated in association with certain malignant disorders, and that cell differentiation results in a switch from an MCP-dominant state to a CR1-dominant state.

Antibodies, Monoclonal↗
PubMed1990

Cytotoxic T lymphocyte triggering via CD16 is regulated by CD3 and CD8 antigens. Studies with T cell receptor (TCR)-alpha beta+/CD3+16+ and TCR-gamma delta+/CD3+16+ granular lymphocytes.

The role of CD3 and CD8 Ag in CD16-mediated CTL triggering was studied in TCR-alpha beta+ and TCR-gamma delta+ granular lymphocytes (GL). In TCR-alpha beta+/CD3+4-8+16+ GL obtained from patients with GL-proliferative disorders, antibody-dependent cellular cytotoxicity was inhibited by anti-CD3 and anti-CD8 mAb. Anti-CD3 mAb also inhibited antibody-dependent cellular cytotoxicity activity of TCR-gamma delta+/CD3+4-8-16+ GL from a patient and that of TCR-gamma delta+/CD3+4-8+/-16+ T cell clones established from patients with proliferating TCR-gamma delta+ GL. In TCR-gamma delta+ T cell clones, cytotoxicity against Fc gamma R+ targets was induced by stimulation of CD16 Ag with anti-CD16 mAb, and such cytotoxicity was also inhibited by anti-CD3 mAb. These results indicate that CD3 and CD8 molecules play a regulatory role in CD16-mediated CTL triggering.

Antibody-Dependent Cell Cytotoxicity↗