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Biomedical subjects

H Masuda

Publications and source records attributed to H Masuda.

At least 487 records · Page 27Linked to original sources
PubMed1987

Characterization of a cis-diamminedichloroplatinum(II)-resistant human ovarian cancer cell line and its use in evaluation of platinum analogues.

Human ovarian cancer cell lines with stable cisplatin resistance have been developed by chronic exposure of the parent cisplatin-sensitive A2780 line to increasing concentrations of cisplatin. 2780CP8 (CP8 refers to this cell line's growth in medium containing 8 microM cisplatin) has several clonal cytogenetic abnormalities but lacks homogeneously staining regions or double-minute chromosomes. It has a significantly greater monolayer growth rate, cloning efficiency in agarose, and total glutathione content compared to the A2780 line, but similar activities of several glutathione-dependent enzymes. The 2780CP8 subline is 7.3-fold resistant to cisplatin compared to the A2780 line, as well as cross-resistant to irradiation and melphalan. It is not cross-resistant to Adriamycin, but this develops with increased cisplatin resistance (14-fold) obtained by further cisplatin exposure of 2780CP8. Of the cisplatin analogues tested which are of current clinical interest, carboplatin, iproplatin, and tetraplatin, only the latter is more cytotoxic than cisplatin in the A2780 and 2780CP8 lines. The 2780CP8 subline is also cross-resistant to these analogues in the relative order carboplatin greater than iproplatin greater than tetraplatin (most to least cross-resistant). Treatment of a highly cisplatin resistant cell line (2780CP70) with either melphalan or cisplatin was associated with a significant increase in [3H]thymidine incorporation into DNA in the presence of 10 mM hydroxyurea compared with the parent sensitive cell line which showed essentially no capacity to repair DNA damage by these drugs. A2780 and its cisplatin-resistant cell lines may thus be useful in studying drug resistance mechanisms, in screening new drugs for activity (especially against drug resistant tumors), and in formulating induction and salvage therapies for ovarian cancer.

Antineoplastic Agents↗
PubMed1987

Spectrum of double outlet right ventricle induced by electrical shock at the conotruncus of the embryonic chick heart: emphasis on cellular changes and evaluation of hemodynamics using Doppler.

Administration of electrical shock to the conotruncal area of embryonic chicks at developmental stage 24-27 induced a complex malformation, namely, double outlet right ventricle (DORV) of varying degrees of severity. The device used to apply electrical current to the heart was constructed using a 9-volt battery, a push-button switch, and a 100-ohm potentiometer with calibrated dial. This allowed a short pulse of known voltage to be applied through the electrodes to a selected area of the heart. Two different methods were chosen to administer electrical shock at the conotruncal area of the heart. One method utilized longitudinal application of electrical shock, and the other used horizontal application of electrical shock directly to the conotruncus. Three distinct types of DORV were found in the longitudinal (L) and the horizontal (H) electrical shock groups: 1) DORV without a ventricular septal defect (VSD), in which the dilated sinus of Valsalva of the aortic valve extends into the right ventricle. 2) DORV with a subaortic VSD, with variable degrees of pulmonary stenosis and a hypoplastic left ventricle. 3) DORV with a subpulmonic VSD, pulmonic stenosis and a hypoplastic right ventricle. Longitudinal stimulation produced a higher incidence of cardiovascular anomalies than horizontal stimulation (p = 0.01). Histological examination showed complete disappearance of myocardial fibers, myocardial degeneration, and the aggregation of protein material or glycogen within myocardial cells. Our Doppler findings demonstrate that relative to control embryos, peak velocity initially increased 3 minutes after electrical stimulation (p less than 0.01), and subsequently decreased significantly within 30 minutes (p less than 0.01). One may hypothesize that the marked initial increase of peak velocity was induced by tissue damage, which led to a narrowing of the conotruncal outflow tract. Evidence for contruncal narrowing was also reflected in percent window data (% W), which indicates the level of turbulence within a vessel. However, the decrease of peak velocity 30 minutes after stimulation might be caused by myocardial damage resulting in a diminished cardiac output. The relationship between cell death processes in the conotruncal area and DORV spectrum induced by electrical shock is discussed.

Animals↗
PubMed1987

Events on different chromosomes alter the genes for the two peptides of platelet-derived growth factor in an osteogenic sarcoma.

Platelet derived growth factor consists of dimers of partially homologous peptides (A and B) encoded by separate genes on different chromosomes. A clinically aggressive osteogenic sarcoma had both an amplified A-chain gene on chromosome #7 and a reduplication of all or part of chromosome #22 containing the B-chain (c-sis) gene. Other oncogenes on chromosomes #1, #2, #5, #6, #7, #8, #11, #12, #14, and #15 were not reduplicated or amplified. These observations are consistent with the hypothesis of autocrine stimulation of growth of some sarcomas in humans, and indicate that amplification and reduplication of related genes on different chromosomes can occur in tumors in vivo.

Chromosomes, Human, Pair 22↗
PubMed1987

Analyses of glycosaminoglycans in human lung cancer.

Studies were conducted on the total amount of glycosaminoglycans and glycosaminoglycan composition in adenocarcinoma tissue of human lung. The glycosaminoglycans were prepared by exhaustive proteinase digestion of adenocarcinoma tissue from human lungs and of lung tissue without pulmonary diseases taken at autopsy as a control. The glycosaminoglycan classes were characterized by biochemical, enzymatic, and electrophoretic methods. The presence of heparin, which has until now not been found in lung cancer tissue, was demonstrated on both carcinoma and control tissues. The levels of whole glycosaminoglycans were markedly increased in cancer tissue compared to the controls. The classes of glycosaminoglycans which increased in lung carcinoma tissue were predominantly chondroitin-4-sulfate and chondroitin-6-sulfate. Both hyaluronic acid and heparin were slightly increased in cancer tissue.

Adenocarcinoma↗
PubMed1987

Rearrangement of the p53 gene in human osteogenic sarcomas.

p53 is a 53-kDa nuclear protein that is associated with malignant transformation in several tumor model systems. In a survey of 134 human carcinomas, sarcomas, leukemias, and lymphomas obtained at surgery or from peripheral blood, we found rearrangements of the p53 gene only in osteogenic sarcomas (3 of 6 osteogenic sarcomas examined). Normal tissue from one of these patients had an unrearranged gene, indicating that the genetic abnormality in the tumor was acquired. Two of the sarcomas with rearranged genes expressed levels of p53 protein that were elevated relative to other tumors. Rearranged p53 genes were also found in human osteogenic sarcoma cell lines.

Cell Line↗
PubMed1987

Purification and properties of starch hydrolyzing enzymes in mature roots of sugar beets.

Mature roots of sugar beets, which accumulate large amounts of sucrose but not starch, nevertheless contained acid and neutral amylases, judging from their pH optima, as well as pullulanase. Acid and neutral amylases were partially purified by procedures including fractionation with ammonium sulfate, ion exchange column chromatography, and gel filtration. Acid amylase was classified as an exoamylase, since it produced only glucose from soluble starch, amylopectin. beta-limit dextrin, and rabbit liver glycogen. Neutral amylase was classified as an endoamylase, since it liberated maltose as the main product plus a small amount of glucose and oligosaccharides, and was capable of hydrolyzing beta-limit dextrin. Pullulanase was purified to apparent homogeneity by procedures including fractionation with ammonium sulfate, Diethylaminoethyl-cellulose column chromatography and affinity chromatography. Pullulanase was capable of hydrolyzing soluble starch, amylopectin, beta-limit-dextrin, and pullulan. Debranching of amylopectin was further evident by an increase in extinction coefficient, and by a shift of lambda(max) from 530 to 560 nm when the debranched amylopectin formed a complex with I(2)-KI.

Journal Article↗
PubMed1987

Classification of cardiac rupture complicated in myocardial infarction. Pathological study of 32 cases.

Thirty of 32 cases with cardiac rupture (CR) complications in the myocardial infarction were found out of a total of 91 cases of acute myocardial infarction (AMI). The mean age of the ruptured group in females was significantly younger than that of the non-ruptured group. Twenty-one cases showed free wall rupture of the left ventricle, six perforation of ventricular septum and three double rupture. All cardiac ruptures occurred in cases of transmural infarction. The age of AMI was histologically estimated. Nine cases complicated within the first 24 hours of AMI showed rupture of the left anterior wall. CR in the periphery within the infarct occurred at any time during the first week after onset, and cases of the central rupture were increased in number after the 3rd day of AMI. Pathologic findings indicated that elevated wall tension was considered to be most closely related to the cause of CR. Thirty two cases of CR were classified into three types: (1) blowout type, (2) hemorrhagic dissecting type, and (3) thinning-with-rupture type. Hemorrhagic dissecting type was characterized by multiple endocardial ulcers and fissure canals extending from the ulcer with hemorrhage in the surrounding myocardium. Complex fissure was seen in two cases of this type.

Aged↗
PubMed1987

Immature cerebellar astrocytoma in an infant.

A case of immature cerebellar astrocytoma in a 1 year and 4 months-old girl was described. The tumor consisted mainly of closely packed relatively uniform round cells with prominent intervening capillaries. Although tumor cells showed negative GFA (glial fibrillary acidic protein) immunoreactivity, demonstration of occasional bundles of 10 nm intermediate filaments (glial filaments) in cytoplasm on electron microscopy confirmed the diagnosis of astrocytoma. Differential diagnosis to hemangioblastoma, astroblastoma, and primitive neuroectodermal tumor was discussed.

Astrocytoma↗
PubMed1987

Flow loaded canine carotid artery. II. Ultrastructural changes in the subendothelial layer.

To study the subendothelial layer of the flow loaded arteries, blood flow changes were produced by constructing an arterio-venous shunt between the common carotid artery and the external jugular vein using eleven adult beagle dogs. One week after operation, the subendothelial layer of the flow loaded canine carotid arteries was observed with a transmission electron microscope. In the arteries loaded by highly elevated blood flow, the subendothelial layer showed thick subendothelial space (300 to 500 nm) with multilayered basement membrane. The microfilaments and microfibrils increased significantly. There were no collagen fibers. Spindle to cylindrical elastic fibers appeared in the luminal margin of the internal elastic lamina. On the other hand, in the control arteries, the subendothelial layer was thin (about 50 nm) with scanty basement-membrane-like material. There were a few microfilaments and microfibrils, but no collagen fibers. The luminal margin of the internal elastic lamina was smooth. It is suggested that these are the wall shear stress dependent subendothelial changes, which would be partly due to the increased protein synthesis by the endothelial cells stimulated by the wall shear stress and be partly due to the wall shear dependent mechanical stress transmitted from the endothelial surface.

Animals↗
PubMed1987

The roles of haemolymphatic lipoproteins in the oogenesis of Rhodnius prolixus.

The fates of purified 32P-vitellin and 32P-lipophorin were followed in vitellogenic females of Rhodnius prolixus. While the radioactivity from 32P-vitellin 6 hours after injection was found almost exclusively in the ovary, the radioactivity from injected 32P-lipophorin was found distributed among several organs. In the ovary, the radioactivity from 32P-vitellin was associated with the contents of the yolk granules. 32P-lipophorin delivered a great amount of radioactive phospholipids to the ovary with no accumulation of its protein moiety, as observed after its iodination with 131I. The delivery of phospholipids was inhibited at 0 degrees C and by the metabolic inhibitors, sodium azide and sodium fluoride. Comparison of the radioactivity incorporation from 32P-lipophorin with that of 14C-inulin suggests that the 32P-phospholipids from lipophorin are not taken up by fluid phase endocytosis. The data presented here are compatible with the concept of lipophorin as a carrier of lipids in insects and provide evidence that lipophorin transports phospholipids as shown previously for other classes of lipids. The utilization by the oocytes of the phospholipids transported by lipophorin is discussed.

Animals↗
PubMed1987

Localization of hepatitis B core antigens in chronic active hepatitis using immunoperoxidase and chromotrope aniline blue staining.

Hepatitis B (HB) core particle, in biopsied liver specimens from patients with chronic active hepatitis (type B) were stained with immunoperoxidase and chromotrope aniline blue (a non-immunological method) and the following results were obtained. HB core particles were more clearly stained with chromotrope aniline blue than with immunoperoxidase. Numerous HB core particles were seen not only in the nuclei of hepatocytes but also in the cytoplasm in HBeAg seropositive patients with severe chronic active hepatitis. DNAase digestion indicated that the HB core particles which stained with immunoperoxidase and chromotrope aniline blue contained DNA. Small amounts of HB core particles were seen in both the nuclei and cytoplasm of all anti-HBe seropositive patients with either moderate or severe chronic active hepatitis.

Adolescent↗
PubMed1987

Double-layered stick-type formulation of bleomycin for treatment of uterine cervical cancer.

The possibility of continuous release over one week of drugs applied topically was investigated using new stick-type formulations of Brilliant Blue (BB) or bleomycin hydrochloride (BLM). Double-layered sticks of BB or BLM able to adhere to mucosa were prepared by direct compression of the drug, hydroxypropylcellulose-H (HPC) and a carboxyvinyl polymer (Carbopol 934). Drug release in vitro from the sticks was delayed by increasing the weight of the outer layer or the amount of HPC in the outer layer. The sustained release achieved with a double-layered stick having a core coated with an acrylate copolymer (MPM) suggests the possibility of once-a-week treatment of uterine cervical cancer.

Benzenesulfonates↗
PubMed1987

The effects in the excess administration of prostaglandin E1 on the indicator enzymes of organella membrane in gastric mucosa.

Administration of excess vitamin A to rats causes gastric ulceration. In this study the effects on the gastric mucosa of excess vitamin A and excess prostaglandin E1, alone and in combination, were studied. Prostaglandin E1 protected against ulceration by vitamin A. Vitamin A labilized marker enzymes from four different membrane systems, namely those of the lysosomes, mitochondria, endoplasmic reticulum and plasma membrane, whereas only the effect on lysosomes was prevented by prostaglandin E1. Indeed, the prostaglandin alone labilized the enzymes from plasma membrane and endoplasmic reticulum and also damaged mitochondrial membranes. Both vitamin A and prostaglandin E1 caused a reduction in the total number and an increase in irregularly-shaped mitochondria in the parietal cells and produced dilation of the endoplasmic reticulum in both parietal and chief cells. It is noteworthy that prostaglandin E1 effectively prevents ulceration by vitamin A despite the extent to which it damages these membrane systems. These findings lend support to the hypothesis that vitamin A ulceration of the gastric mucosa is mediated via release of lysosomal enzymes, following damage to the lysosomal membranes.

5'-Nucleotidase↗
PubMed1987

[Chemosensitivity testing for 5-FU and 5-FU derivatives using subrenal capsule assay].

An evaluation was made, using in vivo subrenal capsule (SRC) assay, of the chemosensitivity of 12 human neoplastic tissues including 7 gastric cancers, 2 colo-rectal cancers, 2 lung cancers and 1 breast cancer, exposed to 5-fluorouracil (5-FU) and the 5-FU derivatives: tegafur (FT), UFT and hexylcarbamoyl-5-FU (HCFU). The relative variation of tumor size (delta TS/TS0) was calculated as follows: delta TS/TS0 = (TS6-TS0)/TS0 X 100 (%), where TS6 was the tumor size on day 6 and TS0 that on day 0, and more than a 10% decrease of delta TS/TS0 in the treated group was considered as positive for chemosensitivity. Delta TS/TS0 was decreased to -10.9 +/- 11.3% (mean +/- standard deviation) for 5-FU, -13.0 +/- 16.4% for FT, -19.8 +/- 18.2% for UFT and -18.8 +/- 15.1% for HCFU, and the inhibition of tumor growth following exposure to 5-FU correlated well with that following exposure to 5-FU derivatives (5-FU vs. FT, r = 0.659; 5-FU vs. UFT, r = 0.864; 5-FU vs. HCFU, r = 0.729). However, the sensitivity of each tumor varied; for example, the chemosensitivity was positive for 5-FU derivatives, but negative for 5-FU, in some tissues. The SRC assay appears to be useful for selecting sensitive drugs from 5-FU and 5-FU derivatives for individual cancer patients.

Antineoplastic Combined Chemotherapy Protocols↗