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Biomedical subjects

H Hamada

Publications and source records attributed to H Hamada.

At least 469 records · Page 26Linked to original sources
PubMed1988

Urokinase-like plasminogen activator increased in plasma after alcohol drinking.

After taking the local Japanese spirit 'Shochu', 'Sake' and beer, increased plasma fibrinolysis was confirmed in normal persons at about 1 hr after for both the pyro-Glu-Gly-Arg-pNA amidolytic and Glu-plasminogen activating activities in eluates from [N alpha-(epsilon-aminocaproyl)-DL-homoarginine hexylester;)]-Sepharose affinity column. The activity was highest in the Shochu group, followed by the Sake and beer groups with an approximately 2.1-, 1.7- and 1.5-fold increase in fibrinolytic activity, respectively, compared to the control. The enzyme could be further purified using urokinase-IgG-Sepharose immunoadsorbent column from the Shochu group and it reacted with and was inhibited by urokinase specific antibody. The main molecular weight of the active enzyme was about 30,000, and those of minor components were about 50,000 and 100,000, as determined by zymography. These findings suggest that some of the enzymes appearing in the plasma after drinking are related to 'urokinase-like plasminogen activator', being endogenously produced.

Adult↗
PubMed1988

[Limb salvage surgery for pelvic malignancies followed by reconstruction with hip endoprosthesis].

Between 1983 and 1987, nine patients with pelvic malignancy were treated with limb salvage surgery and preoperative chemotherapy. They were 6 males and 3 females, ranging in age from 13 to 73. There were 4 chondrosarcomas, 3 osteosarcomas and 2 Ewing's sarcomas. Seven patients received preoperative chemotherapy mainly consisting of adriamycin and cis-platinum. The remaining 2 patients with Ewing's sarcoma received T-11 protocol by Rosen. Surgical margins were wide but partially marginal in 6 patients and intra-lesional in 3 patients. Reconstruction with hip endoprosthesis fixed with screws and bone cement in the sacrum was performed after whole involved iliac bone was resected. Local recurrence was detected in one patient with osteosarcoma treated by marginal resection and 2 patients treated by intralesional resection. Complications occurred in 5 patients. Dislocation was observed in the first patient in this series. Other complications were infection in one patient, sciatic nerve palsy in one patient and leg length shortening in 2 patients. One patient walks without crutches, 5 patients with them. One patient uses a wheelchair and 2 patients are on bed rest. Four patients survived with no evidence of disease for 8-51 months (average 25 months). Two patients have survived with disease for 11-16 months (average 14 months). Three patients died from metastasis a 6-10 months (average 9 months).

Adolescent↗
PubMed1988

[A case of gastric carcinoma remarkably responding to etoposide, adriamycin and cisplatin (EAP) therapy].

A 47-year-old male was diagnosed as having gastric cancer with metastases to liver, para-aorta node and Virchow node. He was treated with EAP (Etoposide, Adriamycin, Cisplatin) therapy, as a result of which a partial response was obtained according to the criteria of the Jpn. Soc. Cancer. Ther. The response was disappearance of subjective symptoms and Virchow's metastasis and reduction of chief tumor and liver metastases. However, this therapy was accompanied by severe side effects such as leucopenia and thrombocytopenia, but in this case, these side effects improved within 20 days.

Adenocarcinoma↗
PubMed1988

Desmoplastic fibroma of the axis. A case report.

Desmoplastic fibroma of the bone appears in a wide variety of bones but rarely involves the spine. A 24-year-old male with desmoplastic fibroma of the axis treated by complete resection and posterior spinal fusion is reported. There was no recurrence of the tumor three years after surgery. Complete resection and reconstructive surgery for spinal instability are recommended for this benign spinal tumor.

Adult↗
PubMed1987

A novel fibrinolytic enzyme (nattokinase) in the vegetable cheese Natto; a typical and popular soybean food in the Japanese diet.

A strong fibrinolytic activity was demonstrated in the vegetable cheese Natto, which is a typical soybean food eaten in Japan. The average activity was calculated at about 40 CU (plasmin units)/g wet weight. This novel fibrinolytic enzyme, named nattokinase, was easily extracted with saline. The mol. wt and pI were about 20,000 and 8.6, respectively. Nattokinase not only digested fibrin but also the plasmin substrate H-D-Val-Leu-Lys-pNA (S-2251), which was more sensitive to the enzyme than other substrates tried. Diisopropyl fluorophosphate and 2,2,2-trichloro-1-hydroxyethyl-o,o-dimethylphosphate strongly inhibited this fibrinolytic enzyme.

Chromatography, Gel↗
PubMed1987

Enhancement of voltage-gated Na+ channel current associated with multidrug resistance in human leukemia cells.

Membrane currents were examined in a drug-sensitive human leukemia cell line (K562) and its multidrug-resistant cell line (K562/ADM) under the whole-cell variation of the patch electrode voltage clamp technique. Most K562 cells showed only the outward current, which was completely suppressed by internal Cs+ ions and 20 mM ethyleneglycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. In contrast to K562 cells, most K562/ADM cells showed tetrodotoxin-sensitive, voltage-gated Na+ channel current in addition to the outward current. Na+ current was observed in four of 29 K562 cells examined, while it was observed in 29 of 33 K562/ADM cells. Two revertant cell lines (R1-3, R1-5) did not show Na+ current. It was concluded that the amplitude of voltage-gated Na+ current increases in association with multidrug resistance in human leukemia cells.

Antineoplastic Agents↗
PubMed1987

Phosphorylation of the Mr 170,000 to 180,000 glycoprotein specific to multidrug-resistant tumor cells: effects of verapamil, trifluoperazine, and phorbol esters.

An overexpression of plasma membrane glycoprotein with a relative molecular mass (Mr) of 170,000-180,000 is consistently found in different multidrug-resistant human and animal cell lines, although the functional role of the protein in multidrug resistance is not fully understood. It has been reported previously that the Mr 170,000-180,000 glycoprotein is involved, directly or indirectly, in the drug transport mechanism and the proliferation of multidrug-resistant tumor cells. In an attempt to clarify further the function of the Mr 170,000-180,000 glycoprotein, we have studied the phosphorylation state of the protein in intact K562/ADM cells and found that: the protein is phosphorylated in the basal state; verapamil and trifluoperazine, which inhibit the active drug efflux and restore drug sensitivity in resistant cells, caused an increase in the phosphorylation of the Mr 170,000-180,000 glycoprotein; 4 beta-phorbol 12 beta-myristate 13 alpha-acetate and 1-oleoyl 2-acetylglycerol enhanced phosphorylation of the protein; the protein was phosphorylated at serine residues; tryptic phosphopeptide mapping of the Mr 170,000-180,000 glycoprotein showed that 4 beta-phorbol 12 beta-myristate 13 alpha-acetate treatment induced an increase in phosphorylation at different sites of the protein from those induced by verapamil or trifluoperazine treatment, suggesting that the protein is phosphorylated by an array of complex regulation mechanisms. Phosphorylation of the Mr 170,000-180,000 glycoprotein might play a role in the regulation of processes affecting cellular function in multidrug resistance.

Antibodies, Monoclonal↗
PubMed1987

Determination of membrane antigens by a covalent crosslinking method with monoclonal antibodies.

Monoclonal antibodies that recognize cell surface proteins may serve as very useful tools for the study of the biological functions of membrane proteins. However, solubilization of the antigens with detergents may lead to major conformational changes of the protein, making their determination with monoclonal antibodies by immune blot or ordinary immunoprecipitation methods difficult. This is especially evident when the monoclonal antibodies recognize tertiary structures of the proteins in the membrane. We have generated two monoclonal antibodies which are specific for the cell surface antigens of multidrug-resistant human cell lines. However, the antigens of both monoclonal antibodies were difficult to detect by either immune blot or ordinary immunoprecipitation methods. We used a cleavable crosslinking reagent dithiobis(succinimidyl propionate) to covalently link the monoclonal antibody with its antigenic determinant in the membrane of intact cells. By this method, we were able to detect the antigens for these two monoclonal antibodies following solubilization, immunoprecipitation, and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This method should have wide applicability in determination of membrane antigens recognized by monoclonal antibodies when immune blot or ordinary immunoprecipitation methods are not successful.

Antibodies, Monoclonal↗
PubMed1987

Characterization of a cell type-specific enhancer found in the human papilloma virus type 18 genome.

We have previously isolated long-range acting enhancer elements from the HeLa genome by functional selection. In this report, the structural and functional characteristics of one (GA1) of the enhancers are reported. By cloning various restriction fragments and by deletion mutagenesis, the activity of GA1 was located in a 230-bp region. The nucleotide sequence of GA1 and genomic Southern blot analysis indicated that GA1 is derived from human papilloma virus (HPV) 18 DNA that had been integrated into the HeLa genome. The enhancer is located in the non-coding region of the HPV 18 genome. The HPV 18 enhancer consists of two functional domains, both of which have full enhancer activity in HeLa cells. The enhancer does not contain enhancer core sequences but contains several blocks of potential Z-DNA sequence. Like SV40 and polyoma virus enhancers, the activity of the HPV 18 enhancer was repressed by adenovirus E1a products. The HPV 18 enhancer shows a narrow cell type specificity: it is active in some cervical carcinoma cell lines, but inactive in all non-cervical cells except for one neuroblastoma cell line. These results suggest that the HPV 18 enhancer plays an important role in regulation of the viral genes.

Adenovirus Early Proteins↗
PubMed1987

DNA polymerase activities in human placenta.

Activities of DNA polymerase alpha and beta were assayed in crude extracts prepared from human placenta. Polymerase alpha activity was high in early pregnancy but low during the 2nd trimester. Polymerase beta activity did not change significantly with gestational weeks. The increase in polymerase alpha activity in early pregnancy may be closely related to mitosis at the time of placental formation; there might also be some type of accelerating factor for polymerase in early pregnancy.

Centrifugation, Density Gradient↗
PubMed1987

A monoclonal antibody-Pseudomonas toxin conjugate that specifically kills multidrug-resistant cells.

One form of multidrug resistance is due to the expression of a 170-kDa energy-dependent drug efflux pump called P-glycoprotein in the plasma membranes of human cancer cells. We have prepared conjugates of Pseudomonas toxin with the anti-P-glycoprotein monoclonal antibody MRK-16. These anti-P-glycoprotein-toxin conjugates specifically kill multidrug-resistant human KB cells. Similar conjugates could be useful in cancer therapy to reduce or eliminate multidrug-resistant tumor populations in tumors intrinsically resistant to chemotherapy or in populations that become resistant during combination chemotherapy.

ADP Ribose Transferases↗
PubMed1987

Cellular localization of the multidrug-resistance gene product P-glycoprotein in normal human tissues.

Monoclonal antibody MRK16 was used to determine the location of P-glycoprotein, the product of the multidrug-resistance gene (MDR1), in normal human tissues. The protein was found to be concentrated in a small number of specific sites. Most tissues examined revealed very little P-glycoprotein. However, certain cell types in liver, pancreas, kidney, colon, and jejunum showed specific localization of P-glycoprotein. In liver, P-glycoprotein was found exclusively on the biliary canalicular front of hepatocytes and on the apical surface of epithelial cells in small biliary ductules. In pancreas, P-glycoprotein was found on the apical surface of the epithelial cells of small ductules but not larger pancreatic ducts. In kidney, P-glycoprotein was found concentrated on the apical surface of epithelial cells of the proximal tubules. Colon and jejunum both showed high levels of P-glycoprotein on the apical surfaces of superficial columnar epithelial cells. Adrenal gland showed high levels of P-glycoprotein diffusely distributed on the surface of cells in both the cortex and medulla. These results suggest that the protein has a role in the normal secretion of metabolites and certain anti-cancer drugs into bile, urine, and directly into the lumen of the gastrointestinal tract.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1987

Monophasic and biphasic synovial sarcoma. An immunohistochemical study.

Seven cases of synovial sarcoma (SS), two with biphasic and five with monophasic histology, were studied immunohistochemically using monoclonal antibodies to intermediate filaments, keratin, and vimentin. Slender spindle cells and plump cells were constant components of all the tumors. Epithelioid cells were present only in biphasic SS. Epithelioid cells and plump cells were positively stained by both keratin and vimentin. Slender spindle cells were stained positive for vimentin and negative for keratin. Staining manner of each cell type was similar irrespective of monophasic or biphasic pattern. Present immunohistochemical studies suggested that monophasic or biphasic patterns in SS should be regarded as a different expression of the same disease. In addition, immunohistochemistry proved to be a useful tool to detect plump cells which were difficult to find on routine staining.

Adolescent↗
PubMed1987

Trinitrophenyl-derivative of urinary trypsin inhibitor: a strong antifibrinolytic agent.

A trinitrophenyl derivative of urinary trypsin inhibitor (TNP-UTI) was found to demonstrate approximately 50 times stronger antiplasmin fibrinolysis than the intact UTI. Almost no change in antitrypsin or antichymotrypsin activity occurred as a result of the UTI modification. TNP-UTI was also shown to be a strong inhibitor of nonplasmin mediated fibrinolysis.

Antifibrinolytic Agents↗
PubMed1987

Immunocytochemical localization of P170 at the plasma membrane of multidrug-resistant human cells.

P170 (P-glycoprotein) is a membrane protein found in high levels in multidrug-resistant cultured cell lines. We have localized this protein using monoclonal antibody MRK16 by immunofluorescence and electron microscopy in the multidrug-resistant human carcinoma cell line KB-C4. The P170 determinant recognized by antibody MRK16 was found on drug-resistant KB-C4 cells, but not on parental drug-sensitive KB-3-1 cells. The determinant was present on the external surface of the plasma membrane and on the luminal side of Golgi stack membranes. P170 was excluded from coated pits at the plasma membrane and absent from endocytic vesicles and lysosomes. This determinant was detected only in small amounts in the endoplasmic reticulum. The high protein concentration of P170 in the plasma membrane is consistent with a role of this protein as a drug efflux pump at the cell surface.

ATP Binding Cassette Transporter, Subfamily B, Mem↗