Biomedical subjects

Y Shintani

Publications and source records attributed to Y Shintani.

At least 91 records · Page 5Linked to original sources

PubMed1994

[A case of testicular cancer in which complete response was achieved with chemotherapy including cisplatin, etoposide and bleomycin, and salvage surgery].

A 27-year-old man was admitted with a complaint of induration of the left testis in August, 1992. On physical examination, he had a palpable supraclavicular mass. The clinical diagnosis was testicular cancer with metastases of lung field, cervical, mediastinal and retroperitoneal lymph node. The histological diagnosis made by inguinal orchiectomy was embryonal cell carcinoma with syncytiotrophoblastic cell. Chemotherapy with cisplatin, etoposide and bleomycin (BEP) was started on August 22, 1992. After 3 courses of chemotherapy, most of the lymph node metastases decreased in volume on CT scan with negative tumor markers. In an attempt to obtain surgical complete response, dissection including cervical, mediastinal and retroperitoneal node was performed in December, 1992. Pathological examination revealed no viable cells in all sections. He is alive with no evidence of disease on September 8, 1993.

Adult↗

PubMed1993

Effect of reconstituted basement membrane on growth and secretory function in pancreatic acinar AR42J cells.

This study investigated the influence of extracellular matrix on growth and secretory function associated with cholecystokinin (CCK) receptors in pancreatic acinar AR42J cells, using reconstituted basement membrane derived from Engelbreth-Holm-Swarm (EHS) tumor. The cells were cultured with basement membranes of two different thickness, 1 mg/ml protein equivalent (thick RBM) and 50 micrograms/ml protein equivalent (thin RBM). In cells cultured with thin RBM, the secretory function and the number of CCK receptors increased, but cell growth did not increase significantly. Cells cultured with thick RBM showed remarkable cell growth, but secretory function and the number of CCK receptors were reduced. There was little change in CCK receptor affinity. It was concluded that the extracellular matrix plays a crucial role in the proliferation and differentiation of AR42J cells and further, the quantitative difference of matrix components strongly influenced the up- and down-regulation of CCK receptor in the cells via cell-matrix interaction.

Amylases↗

PubMed1993

[Effect of KSG-504, a new synthetic cholecystokinin receptor antagonist on ethionine-induced acute pancreatitis in rats].

KSG-504, a new synthetic cholecystokinin (CCK) receptor antagonist derived from proglumide, has superior selectivity and affinity to CCK-A receptors. We have investigated the effect of KSG-504 on ethionine-induced acute pancreatitis in rats and the influence of endogenous CCK on evolution of pancreatitis and regeneration of pancreatic acinar cells. Reduction of pancreatic proteins and digestive enzyme contents was dose-dependently prevented by subcutaneous administration of KSG-504. The inhibition of evolution of pancreatitis was demonstrated histologically in KSG-504 treated rats. The effect of KSG-504 on pancreatic regeneration was evaluated by bromodeoxyuridine labeling index (B.L.I.) of acinar cells. There was no significant difference of B.L.I. between KSG-504 treated and non-treated rats. These results suggest that KSG-504 has a beneficial effect on ethionine-induced acute pancreatitis by blockade of endogenous CCK.

Acute Disease↗

PubMed1992

Serum parathyroid hormone-related protein concentrations in patients with hematologic malignancies or solid tumors.

The clinical significance of parathyroid hormone-related protein in humoral hypercalcemia of malignancy was investigated by determining the serum parathyroid hormone-related protein concentrations in 167 normal subjects, 56 patients with hematologic malignancy and 144 patients with solid tumor. Serum parathyroid hormone-related protein was measured with a radioimmunoassay kit that recognizes the C-terminal portion of the molecule. The serum parathyroid hormone-related protein concentrations were 20.2-50.8 pmol/l (mean +/- 2 SD) in normal subjects, and were elevated in 80% of the patients with malignancies with hypercalcemia, including squamous cell carcinoma and adult T cell leukemia. Moreover, two cases of B cell non-Hodgkin's lymphoma with hypercalcemia had high serum parathyroid hormone-related protein concentrations, which varied in parallel with the tumor size during the clinical course. Of 136 patients with solid tumors with normocalcemia, the serum parathyroid hormone-related protein concentration was slightly elevated in only 5.1%, all of whom were at an advanced stage. These data indicate that determination of the serum parathyroid hormone-related protein concentration is useful for differential diagnosis of humoral hypercalcemia of malignancy and prediction of its development.

Adult↗

PubMed1991

Radioimmunoassay for activin A/EDF. Method and measurement of immunoreactive activin A/EDF levels in various biological materials.

A radioimmunoassay (RIA) for the measurement of activin A, which is identical to erythroid differentiation factor (EDF), has been developed. A specific antiserum against activin A/EDF was raised in rabbits using a mixture of recombinant EDF and polyvinyl pyrrolidone. Of the compounds tested this polyclonal antibody cross-reacted only with bovine inhibin (3.2%) and human TGF-beta (4.2%). The least detectable value in this assay was 0.06 ng/tube. The within- and between-assay coefficients of variation at three different concentrations were 3.6-9.8% and 3.4-7.7%, respectively. Using this RIA, immunoreactive activin A/EDF levels in various biological fluids and tissues were examined. The dose-response curves of porcine follicular fluid and ovarian extract were parallel to the standard curve, and porcine follicular fluid contained high activin A/EDF immunoreactivity (1050 ng/ml). On gel chromatography of porcine follicular fluid, the major immunoreactivity was eluted in the same position as authentic activin A/EDF. Human placental extract and amniotic fluid had relatively high immunoreactive activin A/EDF levels (174 ng/g wet wt. and 63.9 ng/ml, respectively), but the dose-response curve of amniotic fluid was not parallel to the standard curve. Among rat tissues, the ovary showed the highest activin A/EDF immunoreactivity (163 ng/g wet wt.) much lower than that of porcine ovary (1020 ng/g wet wt.). Low immunoreactive activin A/EDF levels were detected in most parts of rat brain (8.7-14.2 ng/g wet wt.), except for the pituitary gland (70.0 ng/g wet wt.). The initial plasma half clearance time (t1/2) of exogenous activin A/EDF was 14 min in the rat and the plasma FSH concentration did not change significantly during this period. These results suggest that this RIA system has sufficient sensitivity and specificity to measure activin A/EDF concentrations in biological materials, and that the reproductive tissues are the main sources of activin A/EDF.

Activins↗

PubMed1991

Improvement in the proliferative activity of human-human hybridomas at low cell density by transfection with bFGF gene.

Highly purified recombinant basic fibroblast growth factor (rbFGF) and acidic FGF (aFGF) stimulated the proliferation of human-human (h-h) hybridomas to the extent of over four-fold from a low cell density such as 1 x 10(3) cells per ml in a serum-free medium in 24-well plates. The stimulatory effect of rbFGF was also observed in various lymphoid cell lines. Expecting that FGF could be an autocrine growth factor, we introduced bFGF gene into a h-h hybridoma using an expression plasmid induced by dexamethasone. The transformed cells thus obtained, HPO-75.11 bFGF-7, were able to grow well from a low inoculum density in a serum-free medium and antibody production was also increased when bFGF gene expression was induced. The transformed cells could grow at clonal density in a serum-free medium in 96-well plates, though the original cells could not. We also obtained a more practical transfectant, HPO-75.29-H74, using a high-shear stress adapted clone as the recipient and an expression plasmid having bFGF gene under the control of metallothionein-I promoter. The HPO-75.29-H74 cells were capable of growing and producing human monoclonal antibody against hepatitis B virus surface antigen from an inoculum density of 1 x 10(3) cells per ml in an agitation vessel without addition of an inducer.

Animals↗

PubMed1991

Comparison of culture methods for human-human hybridomas secreting anti-HBsAg human monoclonal antibodies.

Human-human hybridomas which secrete a human monoclonal antibody (h-MoAb) against hepatitis B virus surface antigen showed growth associated production kinetics. The rate of h-MoAb production rapidly decreased after cell growth was arrested in a perfusion culture, even if the perfusion rate was increased. A continuous suspended-perfusion culture, in which both culture broth and culture supernatant are continuously harvested and the same volume of fresh medium is continuously fed into the reactor, was developed to maintain continuous growing conditions during cultivation. In this culture system, the production of h-MoAb continued for more than 50 days with an average productivity of 5.0 mg/l of working volume/day. A semicontinuous immobilized-perfusion culture in which parts of the cells are repeatedly removed from the immobilized reactor was another useful technique for the long term cultivation of these h-h hybridomas. As an average h-MoAb production rate, 62 mg/l of immobilized-bed volume/day was achieved for 65 days of cultivation using a ceramic matrix reactor, and 327 mg/l/day was achieved over 47 days of cultivation using a hollow fiber reactor equipped with Cultureflo M. Thus, the antibody productivity per reactor volume per day by the semicontinuous immobilized-perfusion culture was much higher than that of the continuous perfusion culture in an agitation reactor.

Antibodies, Monoclonal↗

PubMed1991

Effect of the third-strand length on the formation of DNA triple helix.

The triple-helix formation of octadeoxyribonucleotides, (dA)8 and (dT)8, and a shorter oligonucleotide, (dT)n (n; 4, 5, 6, or 7) has been studied by UV and CD measurements. The results showed that the third strand, (dT)5, (dT)6, or (dT)7 can bind to the double helix of (dA)8.(dT)8 at 50 mmol dm-3 MgCl2 though (dT)4 can not bind at the same concentration of the salt.

Circular Dichroism↗

PubMed1990

Improvement in the antibody productivity of human-human hybridomas by transfection with Tac gene.

The presence of a highly purified recombinant interleukin-2 (rIL-2) increased the production of immunoglobulin (IgM or IgG) by human-human hybridomas to 1.5-2.0 times the production by untreated cells. However, these cells did not react with anti-Tac (IL-2 receptor alpha) antibody. To enhance the response of the hybridoma cells to rIL-2, Tac gene was introduced by co-transfection with Tac gene expression plasmid pTB459 and G418 resistant gene expression plasmid pRSVneo. Tac cDNA transfected hybridoma (HBW-4.16.459-6-126) was induced to produce 6 times as much IgG by rIL-2 as was the control. This antibody production promoting phenomenon mediated by rIL-2 was depressed by anti-Tac antibody.

Antibodies, Monoclonal↗

PubMed1989

Inhibition of fibrin monomer polymerization by Bence Jones protein in a patient with primary amyloidosis.

The mechanism of inhibition of fibrin monomer polymerization was studied in a patient with primary amyloidosis. Thrombin and reptilase times of the patient's purified fibrinogen (Fbg) were remarkably prolonged, and polymerization of the patient's fibrin monomer was disturbed. Fbg-Bence Jones protein (BJP) complex was demonstrated by immunoelectrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis on the patient's purified Fbg. The patient's BJP not only prolonged the thrombin time of normal Fbg but also inhibited the polymerization of normal fibrin monomer. These results suggested that in this patient fibrin monomer polymerization was inhibited by binding of BJP to Fbg.

Aged↗

PubMed1988

Effective production of a human monoclonal antibody against tetanus toxoid by selection of high productivity clones of a heterohybridoma.

A mouse.human-human heterohybridoma, N12-16.63, has been described which produces an anti-tetanus toxoid human monoclonal antibody (MoAb). A clone, N12-16.63.49.19, which produces eight times as much MoAb as that produced by the original cell line, was selected by repeating the recloning and selection twice. Two clones, N12-16.63.49.19.69 and N12-16.63.49.19.127, further selected from this clone produced almost 20 times more than that produced by the original cell line. Though the production of MoAb by these clones gradually decreased with repeating transfers, they still produced a large amount of human MoAb even after 3 months of transfer. Human MoAb (IgM) was isolated from the culture supernatants of the original and high productivity clones and the products were confirmed to be identical. Human MoAb was effectively produced by batch culture on the 20 liter scale or a perfusion culture on the 1 liter scale using these high productivity clones.

Animals↗

PubMed1988