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Biomedical subjects

H Watabe

Publications and source records attributed to H Watabe.

At least 73 records · Page 4Linked to original sources
PubMed1993

Specific targeting and killing activities of anti-P-glycoprotein monoclonal antibody MRK16 directed against intrinsically multidrug-resistant human colorectal carcinoma cell lines in the nude mouse model.

Anti-P-glycoprotein (P-gp) monoclonal antibody, MRK16, and its F(ab')2 fragment were evaluated for its therapeutic efficacy to P-gp-mediated multidrug resistant human colorectal carcinoma cell lines in a nude mouse model. In a blood clearance experiment, 125I-labeled MRK16 had a half-life (16 h) 7 times longer than its F(ab')2 fragment (half-life of 1.8 h) in circulation in nude mice, and approximately 16 and 5% of MRK16 were retained on days 10 and 20 after injection, respectively. In biodistribution experiments using nude mice bearing HCT-15, an intrinsically resistant cell line, 125I-labeled MRK16 accumulated at the tumor site significantly higher than its F(ab')2 fragment as revealed by the percentage of injected dose/g of tissue values (7.4 versus 0.6%) on day 3 after injection. In contrast, the tissue to blood ratio at the tumor site of the MRK16 was significantly lower than that of its F(ab')2 fragment (1.2 versus 10.5). Specific targeting of the MRK16 F(ab')2 fragment to the P-gp-positive tumor (HCT-15) but not to the P-gp-negative tumor (COLO 205) was observed in the nude mice bearing both tumors. In the therapeutic efficacy tests, when administered i.v. 3 times on days 1, 4, and 7 after tumor s.c. inoculation, MRK16 alone showed the significant inhibition of tumor growth of P-gp-positive cell lines, HCT-15, DLD-1, SW480, and SW1417 in contrast to cases of P-gp-negative cell lines, COLO 205 and KM20L2. This inhibitory effect of MRK16 was enhanced in combination with Adriamycin, which alone hardly inhibited the tumor growth. However, MRK16 F(ab')2 fragment alone, even at 1 mg/mouse, had little inhibitory effect on the growth of HCT-15 in the same treatment schedule. When administered at early palpable stage, the degree of HCT-15 tumor growth suppression depended on the number of MRK16 injections. At more progressed stages, treatment with MRK16 alone showed little antitumor activity but when combined with Adriamycin resulted in significant suppression of tumor growth. The present results suggest that MRK16 may be useful for in vivo immunoscintigraphy and immunotherapy of multidrug-resistant colorectal carcinoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Characterization of recombinant human neuron-specific enolase and its application to enzyme immunoassay.

Human gamma-enolase cDNA prepared by reverse transcriptase-polymerase chain reaction was cloned into the Escherichia coli expression vector pKK223-3. The resulting plasmid, pHTK503, expressed human gamma-enolase as a 46-kDa protein in SDS-PAGE, and in the cells as the active gamma gamma form (designated as recombinant human NSE; R-NSE). R-NSE was purified from E. coli by several chromatographic elutions. Finally, 6.0 mg of R-NSE from 8.1 g cells was purified with a specific activity of 86 units/mg protein. The structural properties of R-NSE were compared with the NSE purified from human brain tissue (B-NSE). The biochemical and enzymatic characteristics were essentially the same, except for the isoelectric point (4.5 for B-NSE and 4.7 for R-NSE). In an NSE immunoassay system, R-NSE and standard NSE were almost equal in reactivity to the anti-NSE antibody. These results indicate that R-NSE can be used as standard assay material.

Amino Acid Sequence↗
PubMed1993

Pitting scars in progressive systemic sclerosis.

The digital pitting scar is a common clinical feature in patients with progressive systemic sclerosis (PSS). Its pathogenesis is unclear, but it may result in small ulcerations. The clinical and histological features of these lesions are poorly understood. Eighty-seven patients with PSS were examined at least once per year. Pitting scars were defined as pinhole-sized digital concave depressions with hyperkeratosis. They were seen in 34 cases (39%) and were located not only on the tips of the fingers, but also on the sides, especially on the radial border of the index and middle finger and the ulnar side of the thumb, where they had a linear arrangement. Additional pitting scars were noticed on the dorsal surface of the proximal interphalangeal and metacarpophalangeal joints. Pitting was closely associated with several signs of PSS, e.g. Raynaud's phenomenon, skin thickening or articular involvement (e.g. stiffness, swelling, pain). There was no relationship between the number of pitting scars and the duration of PSS. Biopsy samples were taken of the lesions on the lateral sides of fingers in 3 patients. Histologically, there was a plug-like hyperkeratosis with parakeratosis, homogenized collagen fibers and slight perivascular mononuclear cell infiltration. Calcification and altered collagen fibers were observed in the deep dermis. Although pitting scars of the fingertips may be different from those of the lateral sides of the fingers, both histologically and pathogenetically, they were similar clinically. The scar locations on the fingertips and finger joints (proximal interphalangeal and metacarpophalangeal) suggest that exogenous trauma, vibration injury and/or cold exposure may play a role in their pathogenesis.

Adult↗
PubMed1993

Detection of tetracycline resistance protein encoded by Bacillus subtilis plasmid pNS1.

Tetracycline resistance protein (TET) of Bacillus subtilis plasmid pNS1 was detected by immunoblot analysis using a specific antibody to TET-chloramphenicol acetyltransferase (CAT) fusion protein. In two-dimensional electrophoresis, one major spot which seemed to be the pNS1-encoded TET (pNS1-TET), was detected by immunostaining. Its molecular weight and isoelectric point were approximately 52 kDa and 6.2, respectively. Judging from the nucleotide sequence, the pNS1-TET is a very hydrophobic, 50 kDa protein. Therefore, the 52 kDa protein is thought to be an intact form of the pNS1-TET produced by B. subtilis cells.

Antibodies, Monoclonal↗
PubMed1993

[Two cases of acute alcoholic myopathy associated with rhabdomyolysis].

We reported two cases of acute alcoholic myopathy associated with rhabdomyolysis. The first case was 62 year-old man, who had been drinking every day for 40 years. Following diarrhea, he had psychic symptoms, and was admitted to our hospital. He was in a state of delirium. Tremor in extremities, dysarthria and weakness of lower extremities were observed. Neither swelling nor grasping pain were seen in any muscles. Laboratory data showed severe hypokalemia and high levels of serum muscle enzymes and myoglobin. An increase of lactate and pyruvate was not seen in ischemic exercise test performed at the acute or the recovery phase. It was suggested that glycolysis in muscles was suppressed in this case. The second case was 43 year-old man, who had been drinking every day for 27 years. Rapidly progressive weakness of both lower extremities was seen, and he was admitted to our hospital. Grasping pain of both legs and proximal muscle weakness of extremities were observed. Laboratory date showed normokalemia and high levels of serum muscle enzymes and myoglobin. Muscle biopsy showed no abnormal findings in histology and electron microscopy. Although the pathogenesis of acute alcoholic myopathy is unknown, suppression of muscle glycolysis enzyme caused by ethanol may play an important role in the first case.

Adult↗
PubMed1992

Purification and characterization of gamma-enolase from various mammals.

The gamma subunit of enolase (gamma-enolase) was purified from the brain tissues of cow, dog, goat, pig, rabbit, and rat. The purification was achieved in only three steps: ammonium sulfate-precipitation, DE 53 cellulose ion-exchange chromatography, and polyacrylamide gel electrophoresis (PAGE) in a preparative mode. The purification procedure was comparatively more simple than previously reported methods, and the yield of gamma-enolase was sufficient for subsequent structural and immunological analyses. In all mammals, the purified gamma-enolase migrated in sodium dodecyl sulfate-PAGE (SDS-PAGE) with a molecular mass of 46 kilodaltons (kDa), and the immunological cross-reactivity between those gamma-enolases was very strong. The structural homology of these gamma-enolases was examined by peptide mapping using cyanogen bromide cleavage and subsequent two-dimensional electrophoresis. The resulting peptide patterns were highly similar and in cow, dog, and goat, the patterns were almost identical. These results indicate that structural homology, that is, the species non-specificity of gamma-enolase, appears to be very high.

Animals↗
PubMed1992

Development of radioimmunoassay of intact laminin and its clinical evaluation as a tumor marker.

The concentration of laminin including laminin variants in serum samples was measured by a double-antibody radioimmunoassay using intact laminin. The mean level in 92 normal subjects (47 men and 45 women) was defined as 1 unit (U)/ml, and the cut-off value (2 S.D. above the mean) was 1.37 U/ml. Mean laminin level in 391 patients with various malignancies was 1.50 +/- 0.86 U/ml. Laminin levels were elevated in various cancer patients, and in 45.0% (176/391) the values exceeded the cut-off level; in patients with cancer of the stomach or pancreas, positivity rate exceeded 60%. Mean laminin concentration for 130 pregnant women (2.06 +/- 0.65 U/ml) was also significantly higher than that of normal controls, but concentrations for patients with various benign diseases were within a low range (0.55 +/- 0.29-1.10 +/- 0.29 U/ml). In the stomach or pancreas cancer patients, a positive correlation between laminin level and tumor progression or course of the disease was observed. These findings indicate that serum laminin level is potentially useful in the diagnosis and monitoring of certain cancers.

Adult↗
PubMed1992

A new tetracycline antibiotic with antitumor activity. I. Taxonomy and fermentation of the producing strain, isolation and characterization of SF2575.

A new antitumor antibiotic SF2575 has been isolated from a culture filtrate of Streptomyces sp. SF2575. The molecular formula was determined to be C40H43NO15 by elemental analysis, mass and 13C NMR spectral analyses. The spectral data revealed SF2575 to be a new tetracycline antibiotic. It was active against Gram-positive bacteria and exhibited antitumor activity against P388 leukemia in mice.

Animals↗
PubMed1991

Expression of a restricted fragment of staphylococcal tetracycline resistance determinant as a fused product in Escherichia coli.

Tetracycline resistance (TcR) plasmid pNS1, a deletion derivative constructed from staphylococcal plasmid pTP5, carries a tet determinant which specifies a TcR protein (TET) with a molecular weight of 50 kilodaltons (kDa). In order to express the pNS1-encoded TET as a fused product, a 0.8 kilobase pairs fragment containing 57.1% of tet determinant was inserted into a chloramphenicol resistance determinant. From the nucleotide sequence, it is deduced that the fusion protein (designated CAT'-TET') is a 53 kDa protein composed of 472 amino acids in which the 199 and 262 amino acids are derived from CAT and TET, respectively. Although the molecular weight of CAT'-TET' obtained from the result of sodium dodecyl sulfate polyacrylamide gel electrophoresis (42 kDa) was not in agreement with its predicted weight (53 kDa), the ratio of TET' segment to the fusion protein (22 kDa/42 kDa) corresponded almost exactly to that deduced from the nucleotide sequence (29 kDa/53 kDa). The expression of CAT'-TET' in Escherichia coli caused a rapid decrease in growth rate and in the number of viable cells. This result is thought to be due to the toxic effect of CAT'-TET' on the cell membrane.

Escherichia coli↗
PubMed1991

Absorbed dose estimates in positron emission tomography studies based on the administration of 18F-labeled radiopharmaceuticals.

Absorbed doses were estimated after intravenous administration of 18F-labeled radiopharmaceuticals in Positron Emission Tomography (PET) studies. These radiopharmaceuticals, [18F]-2-Fluoro-2-Deoxy-D-Glucose (FDG), 6-[18F]Fluoro-L-Dopa (FDOPA) and 18F-5-Fluorodeoxyuridine (FdUR), are used in clinical research at the Cyclotron and Radioisotope Center of Tohoku University. Radiopharmaceutical biokinetic values were measured in humans or extrapolated from animal experiments. Selective organ uptake and rapid clearance of activity from the blood were observed. High activity in the bladder contents of humans was found. Calculations were made by the MIRD method, modified to account for the differences in physique and organ mass between the Caucasian Reference Man and the Japanese one. The bladder wall receives the highest dose (more than 1.23 x 10(-1) mGy/MBq) when any of these compounds are administered. Other organs receiving high doses are the heart, brain and kidneys from FDG; the kidneys and pancreas from FDOPA, and the kidneys and small intestine from FdUR. These organs received absorbed doses of more than 2.7 x 10(-2) mGy/MBq. Effective dose equivalents of 2.4 x 10(-2), 2.6 x 10(-2) and 3.3 x 10(-2) mSv/MBq were estimated in the intravenous administration of 18F-FDG, 18F-FDOPA and 18F-FdUR, respectively.

Adult↗
PubMed1991

[Establishment of cell lines of human germinal tumors].

Human germinal tumor cells have been studied in cancer research because of their characteristics of the multi-potentiality and the ability to produce marker proteins such as AFP and SP1. Although human germinal tumor cell colonies had usually been maintained by serial transplantation into nude mice, we established in vitro culture method of cells derived from human malignant germ cell tumors. Thirty-two cell lines were established in vitro, and AFP and SP1 produced in culture medium of those cell line were demonstrated immunochemically.

Animals↗
PubMed1990

SF2487, a new polyether antibiotic produced by Actinomadura.

A new antibiotic SF2487 has been isolated from the culture broth of Actinomadura sp. SF2487. The structure of antibiotic SF2487 was determined by spectroscopic analyses of the sodium salt and X-ray diffraction analysis of the silver salt. The antibiotic represents a new member of polyether group antibiotics known as the acyltetronic acid type 4. The antibiotic is weakly active against Gram-positive bacteria and exhibits antiviral activity against influenza virus in vitro.

Animals↗
PubMed1990

[Purification and chemical characterization of pregnancy-specific beta 1-glycoprotein (SP1)].

A pregnancy-specific beta 1-glycoprotein (SP1) was purified from human placenta using either an ion-exchange column [method I] or an anti-SP1 antibody immunoadsorbent column [method II]. The yields were 5.2% with a total of 1.2 mg per placenta [method I], and 9. 4% with a total of 2.2 mg per placenta [method II], respectively. The physicochemical properties (molecular weight, sedimentation coefficient, amino acid composition etc.) of SP1 purified from human placenta by these methods are essentially the same as those of typical SP1. It is thus apparent from the present results that these SP1 from pregnant serum and human placenta cannot be distinguished immunologically and biochemically.

Amino Acids↗