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Biomedical subjects

T Masuda

Publications and source records attributed to T Masuda.

At least 487 records · Page 27Linked to original sources
PubMed1990

Karyometric and DNA content analyses of cancer cells in stage III breast cancer with reference to prognosis.

Karyometric and DNA content analyses were simultaneously performed on 32 cases of stage III invasive ductal breast cancer using an image analysis system. From the karyometric analysis, the nuclear areas (NAs; microns 2) were (mean +/- SD) 36.27 +/- 9.40 in five-year survivors (n 17) and 57.14 +/- 13.26 in non-survivors (n 15). The nuclear shape factors (NSFs; NSF = 4 pi X NA/NP2; NP, nuclear perimeter) were 0.756 +/- 0.037 in survivors and 0.716 +/- 0.040 in non-survivors. The NA was significantly larger (P less than 0.01) and the NSF significantly lower (P less than 0.01) in non-survivors than in survivors. From the DNA content analysis, the DNA content values (c; see Measurements section) were +/- 2.59 +/- 0.70 in survivors and 3.72 +/- 1.08 in non-survivors. The percentages of aneuploid cells over 4c were 7.10 +/- 9.89 in survivors and 23.07 +/- 20.19 in non-survivors. The DNA content and the percentage of aneuploid cells over 4c were significantly higher (P less than 0.01) in non-survivors than in survivors. This method may be valuable for estimating the prognosis of patients with invasive ductal carcinoma of the breast.

Adult↗
PubMed1990

[Clinical results of open heart surgery within 2 weeks after cardiogenic embolic stroke].

Fourteen patients, 5 with infective valvular disease (IVD), 7 with non-infective valvular disease (NVD) and 3 with LA myxoma, underwent open heart surgery within 2 weeks after cardiogenic embolic stroke because of uncontrolled heart failure or recurrent embolism. Fifty percent of patients experienced a second embolism within 2 weeks of the initial stroke. Preoperative brain CT revealed no hemorrhagic infarction in all patients. However, in 3 of 5 patients with IVD, who had large brain infarction, one patient died from massive brain edema and two patients from severe brain hemorrhage. The other 2 patients with IVD, who had small infarction, and the remaining 7 patients with NVD and LA myxoma, even having large or small infarction, recovered without any complications. From these results, we concluded that 1) Open heart surgery within 2 weeks after initial stroke was safe in patients with no brain infarction and small non-hemorrhagic infarction, 2) Patients with IVD should be treated surgically before embolic stroke, because mortality rate was so high even in patients with non-hemorrhagic infarction.

Adult↗
PubMed1990

[A case of intimal dissection of the left internal mammary artery grafting].

A 73-year-old man underwent reoperation using the in situ left internal mammary artery (IMA) because of the stenosis of the vein graft to the left anterior descending artery (LAD). The patient recovered free from angina but angiography performed 1 month after operation revealed the dissection of intima of the left IMA. Use of the IMA in coronary artery bypass grafting (CABG) is now generally accepted as the optimal method of myocardial revascuralization and the use of the left IMA to the LAD has become a routine procedure in our CABG surgery. However, because the IMA wall is friable and disruption occurs easily, especially in the elder, much care should be taken during mobilization of the IMA.

Aged↗
PubMed1990

[Shortest route for in situ left thoracic artery to left anterior descending coronary artery].

For coronary artery bypass grafting, the internal thoracic artery (ITA) graft carries a greater long-term patency and a decreased need for reoperation when compared with the saphenous vein graft. However, the number and length of ITAs limit their use. In an effort to extend the use of the ITA and to improve patency, we evaluated the shorter course from the left ITA (LITA) origin to the left anterior descending coronary artery (LAD). We compared the distance using the conventional route over the lung (20 patients) with that using the newly-devised route medial to the lung and through the pericardial incision (20 patients). The distance using the route medial to the lung and through the pericardial incision was 12.6 +/- 1.4 cm (mean +/- SD), which was shorter compared with 15.1 +/- 1.1 cm of the route over the lung (p less than 0.01). And also the route medial to the lung and through the pericardial incision could avoid the danger of strectching or kinking by the inflated left lung. From these results, we concluded that the use of the route medial to the lung and through the pericardial incision was better method of extending the use of the in situ LITA to LAD.

Coronary Artery Bypass↗
PubMed1989

[Presence of atrial natriuretic peptide in canine cerebrospinal fluid and its origin].

The purposes of the present study are to demonstrate the presence of atrial natriuretic peptide (ANP) in canine cerebrospinal fluid (CSF) and to determine its origin as either the brain or atrium. Fifty-seven mongrel canines weighing from 7.5 to 23.0kg (male: 28, female: 29) were anesthetized with sodium pentobarbital (30mg/mg, iv) and were ventilated with a Harvard respirator. 16 canines (11.5 to 16.0kg) were used to examine the effect of endogenously increased plasma ANP level on the ANP concentration of the CSF in acute heart failure induced by experimental aortic regurgitation. Subsequently to examine the effect of exogenously increased plasma ANP level on the ANP concentration of the CSF, physiological and pharmacological doses of synthetic human alpha-ANP were continuously infused into the right ventricle (25ng/kg/min. and 250ng/kg/min., respectively) for 32 min. in 15 canines (8.0 to 23.0kg), only physiological dose (25ng/kg/min.) was infused for 180 min. in 8 canines (12.5 to 23.0kg). The concentrations of ANP in canine CSF and plasma were measured by our highly sensitive and specific radioimmunoassay (RIA). The molecular forms in the plasma, CSF and the atrium and hypothalamus tissues were determined by gel permeation chromatography (GPC). The ANP concentration in CSF was 2.8 +/- 1.2pg/ml (mean +/- SD), lower than that in the plasma which was 51.5 +/- 19.9pg/ml, and no correlation was found between them (r = 0.16, p = ns). Plasma ANP concentrations increased from 46.5 +/- 13.0pg/ml to 94.6 +/- 27.7pg/ml according to a rise of the left atrial pressure by experimental aortic regurgitation. However, no significant change was noted from 3.7 +/- 0.7pg/ml to 3.8 +/- 1.0pg/ml in CSF ANP concentrations during the aortic regurgitation. The ANP concentration in the CSF did not change significantly while the plasma ANP concentration greatly increased following each intravenous infusion of the synthetic alpha-ANP. Only a single peak corresponding to a low molecular weight form of ANP in the position of authentic alpha-ANP in the canine CSF was observed by GPC, while there were peaks for both low and high molecular forms of ANP in the canine plasma. Furthermore, both low and high molecular weight peaks were observed for the right atrium and hypothalamus tissue extracts by GPC, and those tissues of the right atrium and hypothalamus contained ANP concentrations of 1.97ng/mg wet tissue and 2.6pg/ml wet tissue, respectively. These results indicate the presence of ANP in canine CSF and that it does not come from blood that has seeped across the blood-CSF barriers but may originate in the brain.

Animals↗
PubMed1989

[The concentration of atrial natriuretic peptide (ANP) in plasma and atrial tissue of canines with acute heart failure induced by reversible aortic or mitral regurgitation].

We have established an easily reversible acute heart failure model in beagle canines by reversible aortic or mitral regurgitation (AR or MR). To cause reversible AR, a basket catheter was inserted into the left ventricle from the apex and fixed at the aortic valve in 10 canines. To cause MR, a basket catheter was inserted into the left atrium via the pulmonary vein and fixed at the mitral valve in 10 canines. The regurgitation by AR or MR was caused by extending the tip basket wire, and the recovery from the regurgitation was immediately possible by closing it. Left atrial pressure (LAP), right atrial pressure (RAP) and pulmonary artery pressure (PAP) were increased significantly during AR or MR, and decreased to the normal level after the release of AR or MR. Using these reversible acute heart failure models, the effects of both advancing and restoring acute heart failure by the secretion of ANP were examined by observing the changes of ANP concentration and its molecular forms in the plasma and left atrial tissue in the same canine. Plasma ANP concentration showed a reversible change. In group analysis, plasma ANP concentration did not correlate with LAP or RAP, but in each canine it showed high correlations with LAP (r = 0.70 approximately 0.94, 0.82 +/- 0.07) and RAP (r = 0.60 approximately 0.93, 0.79 +/- 0.08), having a different slope in each regression line. The ANP concentration in the atrial tissue was decreased during AR or MR, but the low level was maintained after AR or MR. The main molecular form of ANP in the plasma was alpha-ANP and that in the tissue was gamma-ANP. In summary, the tissue storage of ANP was decreased because the ANP secretion caused by stimulation of acute heart failure exceeded its production. The ANP secretion was decreased by the subsequent elimination of heart failure, but the production was not stimulated rapidly, because the tissue content remained unchanged.

Acute Disease↗
PubMed1989

Immunological characterization and clinical implication of cobalamin binding protein in human gastric cancer.

Cobalamin (vitamin B12) binding protein was purified from gastric cancer extracts and from serum-free culture medium of cancer cell line KATOH-III. The molecular weight, determined by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was 70,000 and the pI was 2.8 to 3.2. From biochemical and immunological properties, this cobalamin binding protein was considered to be an isoprotein of cobalamin R binder. Monoclonal antibodies were produced against saliva R and cobalamin binding protein in culture medium to study their antigenic determinants. Monoclonal antibody 55-D reacted to an epitope of peptide in both binders, whereas WK-1 and H-12 reacted to determinants of a carbohydrate moiety, including sialic acid, in cancer cell-derived binder. In addition, we carried out an enzyme-linked immunoassay and examined plasma levels of immunoreactive R binder in patients with gastric cancer (n = 72), benign gastrointestinal disease (n = 30), and healthy individuals (n = 40). Even in patients without liver metastasis, the level of immunoreactive R binder detected by monoclonal antibody H-12 was elevated in some patients and decreased after excision of the tumor. R binder was also elevated in cancer tissue extract. Immunoreactive binder was histochemically detected in the cytosol of cancer cells and metaplastic cells of the gastric mucosa. The present findings suggest that cobalamin R binder is de novo synthesized in gastric cancer cells and that its plasma level increases in some patients. This binding protein may be a useful diagnostic and therapeutic parameter.

Adult↗
PubMed1989

Electric charge distribution in proteins and ionic strength dependence of reaction rate.

The ionic strength dependence of the reaction rate between protein and dichloride anion radical has been investigated by flash photolysis of aqueous chloride-containing lysozyme, ribonuclease A, or insulin. The rate constant for the reaction of lysozyme or ribonuclease A with dichloride anion radicals decreases with increasing ionic strength, while it increases for insulin. The dependence was found to obey an equation derived from the theory of Debye and Hückel or the equation of Wherland and Gray for lysozyme within experimental errors. For ribonuclease A, however, it deviates largely from these equations. In the case of insulin a moderate deviation was observed. The different behavior in the ionic strength dependence is discussed in terms of the electric charge distribution in the protein molecules.

Amino Acid Sequence↗
PubMed1989

Cloning and sequence analysis of cDNA for luciferase of a Japanese firefly, Luciola cruciata.

Luciferases of Japanese and North American fireflies act on a common substrate (luciferin) but the resulting lights emitted are of different colors. As a step toward an understanding of the molecular mechanism of the luciferase reaction, a cDNA clone (pGLf1) was isolated from a cDNA library of lantern poly(A)+RNA of the Japanese firefly, Luciola cruciata ('Genji-botaru' in Japanese), using a cDNA of North American firefly luciferase. The isolated 2-kb cDNA sequence was able to direct the synthesis of active luciferase in Escherichia coli under the control of the lac promoter. The primary structure of Genji firefly luciferase deduced from the nucleotide sequence was shown to consist of 548 amino acids (aa) with an Mr of 60,024. Homology between the amino acid sequences of the Genji and North American firefly luciferases was 67%, but a number of amino acid changes were found in the first 200 aa from the N terminus.

Amino Acid Sequence↗
PubMed1989

Emergence of large plaque-producing clones of human immunodeficiency virus (HIV) in vitro.

Large plaque-inducing clones were obtained from small plaque-inducing parental clones of human immunodeficiency virus (HIV) by the plaque-cloning method. The cloned HIVs that formed large and small plaques were studied as follows: 1) infectivity was determined by the ratio of plaque-forming units (PFU) to reverse transcriptase (RT) activity; 2) viral growth was assessed by the amount (RT activity) of virus after infection; and 3) HIV long terminal repeat (LTR)-linked gene expression of the viruses was measured by chloramphenicol acetyltransferase (CAT) assay using persistently infected MOLT-4 cells. Results showed that clones producing large plaques showed similar or slightly lower infectivity but higher virus production, faster viral growth, and higher gene expression activity than clones producing small plaques. These analyses revealed that clones producing large plaques could replicate more rapidly than those producing small plaques. Restriction enzyme map analysis of these cloned viruses showed that they were also genetically different. These results suggest that the changes in the biological features observed here might be due to mutation during the cloning procedure.

DNA, Viral↗
PubMed1989

A long-term follow-up study of total hip replacement with bone graft. Correlations between roentgenographic measurement and hip mobility.

Fifty total hip replacement treating the acetabular deficiency with autologous bone graft from the femoral head were performed on 44 patients with congenital dislocation of the hip. The average age was 55 years. The average follow-up period was 5 years and 2 months, ranging from 3 years, 8 months to 6 years, 11 months. Solid union was demonstrated in all acetabular grafting. No loosening of either acetabular or femoral components occurred. Roentgenological measurements used as a parameter of good results showed that better results were obtained using the true acetabulum (ideal position) with appropriate bony coverage.

Acetabulum↗
PubMed1989

Parietal cell autoantigens involved in neonatal thymectomy-induced murine autoimmune gastritis. Studies using monoclonal autoantibodies.

Autoimmune gastritis accompanied by autoantibodies to parietal cells was induced in BALB/c nu/+ mice by neonatal thymectomy 2-4 days after birth. Three monoclonal autoantibodies, designated as 2B6 (IgG1), 2G10 (IgG2b), and 1H9 (IgG1), were obtained from one of these mice. All three reacted specifically with parietal cells, 2G10 recognizing species-specific antigenic determinants and 2B6 and 1H9 recognizing interspecies-specific antigenic determinants. All three recognized antigens on the membrane of intracellular secretory canaliculi and the cytoplasmic tubulovesicular system of parietal cells. At least two different molecular groups were recognized by these antibodies; 2B6 recognizing a 65,000-79,000-mol wt group and 1H9 recognizing a 92,000-120,000-mol wt group. Sera of most mice with autoimmune gastritis reacted with either or both groups. Both groups were consistently coprecipitated by any of the three antibodies when solubilized in NP-40. Sera, from patients with pernicious anemia, containing anti-parietal cell antibodies could also precipitate these two groups of antigens. Competition assay and physicochemical studies showed that the epitopes recognized by the three monoclonal antibodies are different.

Anemia, Pernicious↗
PubMed1989

Characterization of a CD4(L3T4)-positive cytotoxic T cell clone that is restricted by class I major histocompatibility complex antigen on FBL-3 tumor cell.

An L3T4(CD4)+ CTL clone specific for Friend virus-induced tumor FBL-3 was isolated, characterized and compared with a conventional Lyt-2(CD8)+ CTL clone. This clone L3.1 was obtained from the limiting dilution culture of splenic MLTC cells from a CB6F1 mouse whose CD8+ T cells had been suppressed by an in vivo injection of anti-Lyt-2.2 mAb. The phenotype of clone L3.1 was sIg-, Thy-1.2+, L3T4(CD4)+, Lyt-2 (CD8)-, and Ia- as determined by flow-cytometry. Northern blot analysis also confirmed that mRNA for L3T4(CD4), but not for Lyt-2 (CD8) was present in the total RNA of L3.1. The FBL-3-specific killing activity of L3.1 was inhibited by anti-H-2D6 mAb, and the tumor cells did not express class II MHC antigen, indicating that the recognition of tumor antigen by this CD4+ CTL clone was restricted by the class I MHC molecule on the tumor cells. Furthermore, the finding that anti-L3T4(CD4) mAb GK1.5 inhibited the specific and lectin-dependent non-specific cytotoxicity of L3.1 suggested that CD4 molecules on this CTL clone are not ligand (MHC class II)-binding proteins, but are involved in signal transduction.

Animals↗
PubMed1989

Ultrastructure of secretory ameloblasts in the house musk shrew, Suncus murinus, Insectivora.

Tooth germs from neonatal house musk shrews, Suncus murinus, were used for the study. The tooth morphogenesis was compared electron microscopically to that of Primates. In the tooth germ at the bell stage, the ameloblast was 3 x 50 microns in size, columnar in shape and had several tubular-type Golgi apparatus which were at the distal end of the cell. Most mitochondria were noted at the proximal end of ameloblasts. Tomes' processes were 1 micron in width, protruded 10 microns from the ameloblast and had many dense bodies and two kinds of vesicles. They were morphologically different from human ameloblasts and enamel rods.

Ameloblasts↗
PubMed1989

Prolonged degeneration of muscle spindles in the masseter muscle after treatment of developing mice with the local anesthetic lidocaine hydrochloride.

The effect of lidocaine-HCl on muscle spindles in the masseter muscle of developing mice was investigated. Repeated injections of mice with anesthetic in the short term decreased the diameters of primary endings, intrafusal muscle fibers and outer capsules in the equatorial regions of muscle spindles, and caused a drop in the succinic dehydrogenase activity in intrafusal muscle fibers of the muscle spindles. In addition, the diameters did not recover to the control value even after about 10 weeks following cessation of anesthetic treatment. Thus, the present results suggest that repeated use of lidocaine-HCl in developing animals may cause dysfunction of the skeletal muscles.

Animals↗