Biomedical subjects

Y Masuda

Publications and source records attributed to Y Masuda.

At least 613 records · Page 34Linked to original sources

PubMed1991

[Evaluation of dopamine and dobutamine for use in circulatory depression associated with induced total spinal block].

We carried out total spinal block (T.S.B.) in adult mongrel dogs with 0.5 ml.kg-1 of 2% lidocaine, and compared the effects of dopamine (DOA) and dobutamine (DOB) to correct the circulatory depression produced by T.S.B. HR, MAP, LV dp/dt max. and CI decreased significantly by T.S.B. under continuous infusion of 2.5 mcg.kg-1.min-1 of both DOA and DOB. During DOA infusion these circulatory values decreased significantly compared with those of control period, while during DOB infusion they were unchanged. MAP, LV dp/dt max. and CI decreased significantly by T.S.B. under 5 mcg.kg-1.min-1 of DOA infusion, while influence was hardly observed by T.S.B. under DOB infusion. From the results, it is concluded that DOB is more effective than DOA to correct the circulatory depression by T.S.B., and in order to correct it more than 5 mcg.kg-1.min-1 of DOA and approx. 2.5 mcg.kg-.min-1 of DOB are necessary.

Anesthesia, Spinal↗

PubMed1991

[Intestinal T-cell lymphoma (so-called malignant histiocytosis of the intestine) complicated by multiple perforations].

We describe a case of intestinal T-cell lymphoma which was histologically diagnosed of malignant histiocytosis of the intestine. A 47-year-old man was admitted to our hospital because of fever and generalized lymphadenopathy. Mild anemia, leukocytosis, positive CRP and a high level of LDH were noted. Pathological finding of the lymph node was compatible with dermatopathic lymphadenopathy with a slight increase in atypical lymphoid cells. At the 14th day after admission, he suffered from abdominal pain and was diagnosed as having perforative peritonitis. In laparotomy, the infiltration of histiocyte-like atypical cells were found around a site of small perforation of the terminal ileum. The findings were compatible with that of malignant histiocytosis of the intestine (MHI). He had recurrent perforations of the small intestine and died of peritonitis and sepsis at the 42nd day. Southern blot analysis of the biopsied lymph node showed TCR-beta gene rearrangement. Some patients diagnosed clinically and pathologically as having MHI may have a T-cell lymphoma like our case.

Histiocytic Sarcoma↗

PubMed1991

Clinical importance of coronary calcification detected by CT.

Coronary calcifications appear in advanced atheromatous lesions therefore fluoroscopy is useful for the detection of the atherosclerotic coronary artery disease (Aldrich et al., 1979). However, the detection of coronary calcification by fluoroscopy is difficult in the case of obesity or thick chest wall and also impaired by the background structures including bone and other intrathoracic calcifications. X-ray CT is more advantageous than fluoroscopy in the detection of coronary calcification. It can eliminate the interference from background structures and clearly demonstrates calcified sites of the coronary artery. Therefore, we investigated the clinical usefulness in the detection of coronary calcification with X-ray CT.

Adult↗

PubMed1990

Solubilization of receptor for pituitary adenylate cyclase activating polypeptide from bovine brain.

A receptor for pituitary adenylate cyclase activating polypeptide (PACAP) was solubilized from bovine brain membranes with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate. Saturable binding experiments using [125I]PACAP27 revealed that the solubilized extract contained a single class of binding sites with a Kd of 200 pM and a Bmax of 0.9 pmol/mg protein. The Kd did not change significantly after the solubilization. Competitive binding experiments confirmed that the solubilized receptor retained a specificity for PACAP. Thus, the solubilization of the receptor in an active form was successfully achieved by the present procedure.

Animals↗

PubMed1990

Effects of oxygen deficiency and calcium omission on carbon tetrachloride hepatotoxicity in isolated perfused livers from phenobarbital-pretreated rats.

The effect of oxygen concentration and Ca2+ omission on CCl4-induced hepatotoxicity was studied in a non-recirculating and hemoglobin-free liver perfusion system using phenobarbital-pretreated rats. With 95% O2-saturated perfusate, infusion of 0.5 mM CCl4 caused an instantaneous increase of thiobarbituric acid reactive substances (TBA-RS) in the effluent perfusate, accompanied by only a slight leakage of K+ and lactate dehydrogenase (LDH). CBrCl3 produced a far greater increase in the TBA-RS level, but again with slight K+ and LDH leakage. With 20% O2-saturated perfusate, CCl4 caused a marked LDH leakage, which was preceded by an early and considerable increase in K+ leakage coupled with Na+ uptake, Ca2+ uptake was initially slight, being enhanced concurrently with the LDH leakage. The TBA-RS level changed biphasically with an initial moderate and a succeeding greater increase coupled with LDH leakage. N,N"-Diphenyl-p-phenylenediamine and promethazine suppressed the TBA-RS production, but improved neither K+ nor LDH leakage. Omission of the Ca2+ from the perfusate reduced the initial K+ leakage as well as the later TBA-RS release, and markedly delayed the LDH leakage. In retrograde perfusion under low oxygen supply with Ca2+, CCl4 produced essentially the same toxic manifestations as those observed in the anterograde perfusion. Hepatocytes of the periportal and pericentral areas were not stained with trypan blue in the antero- and retrograde perfusion systems respectively. Thus, oxygen deficiency, rather than lipid peroxidation by itself, and the essential role of extracellular Ca2+ may be important for CCl4-induced hepatic cell necrosis, in which plasma membrane permeability change may be an early and critical event.

Animals↗

PubMed1990

Production and significance of TGF-beta in AT-3 metastatic cell line established from the Dunning rat prostatic adenocarcinoma.

A colony formation assay using NRK-49F cells revealed that a metastatic cell line, AT-3, established from the Dunning prostatic carcinoma could produce TGF-beta in a latent form. TGF-beta at a concentration as low as 0.05 ng/ml either stimulated the attachment or detachment of AT-3 cells depending on the kind of culture media. Acid extracts from conditioned medium (5 micrograms/ml) showed the activity comparable to that of TGF-beta (5 ng/ml). The detached cells were able to grow in suspension. TGF-beta (0.1 ng/ml) could also stimulate the growth of MC3T3-El osteoblasts established from mouse calvaria. These results suggest that TGF-beta is a key growth factor for osteoblastic bony metastasis of prostate cancer.

Adenocarcinoma↗

PubMed1990

Affinity labelling of endothelin receptor and characterization of solubilized endothelin-endothelin-receptor complex.

Chick cardiac membranes were affinity labelled by cross-linking to membrane-bound 125I-endothelin-1 with disuccinimidyl tartarate. SDS/PAGE and autoradiographic analysis of the 125I-endothelin-1-labelled material in the presence or absence of 2-mercaptoethanol revealed one major labelled band, corresponding to a molecular mass of 53 kDa, whose appearance was dose-dependently inhibited by the addition of unlabelled endothelin-1 (1-100 nM). Subtracting the molecular mass of 125I-endothelin-1 and disuccinimidyl tartarate, the binding protein appeared to have a molecular mass of 50 kDa. To investigate further the molecular properties of endothelin receptor, the 125I-endothelin-1-endothelin-receptor complex was solubilized from chick cardiac membranes using the detergent digitonin. Sucrose gradient sedimentation of the solubilized complex indicated a sedimentation coefficient of 13 S, whereas the complex of (+)-[3H]PN200-110, a dihydropyridine derivative, and dihydropyridine-sensitive Ca2+ channels sedimented at 22 S. A monoclonal antibody raised against dihydropyridine-sensitive Ca2+ channels from the chick brain did not immunoprecipitate the 125I-endothelin-1-endothelin-receptor complex. These data suggest that endothelin receptor is clearly distinct from dihydropyridine-sensitive Ca2+ channels and endothelin has its own specific 50-kDa receptor.

Affinity Labels↗

PubMed1990

Analysis of Epstein-Barr viral genomes in lymphoid malignancy using Southern blotting, polymerase chain reaction and in situ hybridization.

109 malignant lymphomas were surveyed by Southern blot analysis and polymerase chain reaction (PCR) for Epstein-Barr virus (EBV) DNA and compared with 16 examples of non-neoplastic lymphadenopathy and 4 normal thymuses. In specimens positive by the method of Southern and PCR, in situ hybridization studies were performed on formalin-fixed, paraffin-embedded sections. By Southern blot analysis, two of seven Hodgkin's disease samples (29%) (one of mixed cellularity and the other of lymphocyte predominance type), three of 56 B-cell lymphomas (5.6%) and five of 46 T-cell lymphomas (11%) demonstrated EBV DNA. However, the 16 examples of lymphadenitis and the 4 normal thymuses showed no EBV DNA. With PCR, EBV DNA was identified in one B-cell lymphoma, nine T-cell lymphomas, ten lymphadenitis specimens and two of the normal thymus, in addition to the positive specimens determined by the Southern blotting method. These results indicate that the presence of EBV DNA is not related to lymphoid malignancy, but enhancement of the DNA is demonstrated in some neoplastic conditions. By in situ hybridization, EBV genomes were not detected in all PCR-positive cases, but only in those positive by Southern blot analysis.

Base Sequence↗

PubMed1990

Reversible drug effects on the metabolic activation of polymorphonuclear leukocytes.

Polymorphonuclear leukocytes (PMNs) stimulated by the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP) were effectively inhibited by chlorpromazine (10 microM) and azelastine (20 microM) in terms of superoxide generation, and restored by the addition of dodecylbenzenesulfonic acid (DBS) in a range of concentrations from 20 to 40 microM. The stimulation of superoxide generation by DBS was also inactivated by dodecylamine (DA) but was restored by the subsequent addition of DBS. A dose dependent competitive inhibition and activation of leukocytes was observed between azelastine (10 microM) and DBS (20 microM). The release of arachidonic acid from leukocytes activated by the chemotactic peptide was decreased by DA or chlorpromazine, but could be restored by DBS. The changes in membrane potential of leukocytes as monitored by cyanine dye were also decreased by DA, chlorpromazine or azelastine. These observations indicate that some cationic drugs reversibly inhibit membrane bound enzymes or receptors. The physiological responses of these inhibited PMNs can then be restored by appropriate anionic amphiphiles.

Amines↗

PubMed1990

Behavioural and ECoG spectrum changes induced by intracerebral infusion of interferons and interleukin 2 in rats are antagonized by naloxone.

Rat interferon, alpha-interferon, interleukin 2 and recombinant interleukin-2 injected into the third cerebral ventricle produced typical behavioural sedation and/or sleep and ECoG synchronization in rats while beta-interferon produced no behavioural sleep or ECoG synchronization. A slight sedation was observed after the largest dose of beta-interferon only. During sleep induced by lymphokines, a dose-dependent increase in total voltage power as well as in the 0.5-3, 4-7 and 12-16 Hz frequent bands was observed. Much smaller doses were required to produce similar behavioural and ECoG spectrum effects after infusion of interferons and interleukin-2 into the locus coeruleus. No significant behavioural and ECoG changes were obtained after infusion of the same doses of interferons and interleukin-2 into other areas of the brain (caudate nucleus, dorsal hippocampus, substantia nigra pars compacta, ventromedial hypothalamus). The behavioural and ECoG effects of alpha-interferon, rat interferon and interleukin-2 were blocked in animals pretreated with naloxone. These results are consistent with the hypothesis that the behavioural and ECoG effects of these lymphokines are mediated at locus coeruleus level by stimulation of opiate receptors.

Animals↗

PubMed1990

Very rapid and simple assay of taurine in the brain within two minutes by high-performance liquid chromatography with electrochemical detection.

We describe a very rapid and simple method for the assay of taurine (Tau) in the brain tissue, using high-performance liquid chromatography (HPLC) with electrochemical detection in combination with precolumn o-phthalaldehyde (OPA) derivatization. The present method permits Tau assay within 2 min in one chromatographic run. Recovery for Tau was 107.4 +/- 1.3% (SD, n = 10). Within-run coefficients of variation were +/- 1.6% (n = 15). The limit of quantitative detection of the method was 0.1 pmol for Tau. The present method has been applied to the measurement of Tau levels in several discrete brain areas of the mouse.

Animals↗

PubMed1990

An introduction to Anatomical Image Digitizing System (AIDS).

We designed, constructed, and evaluated a prototype of a digital data management system for anatomical studies and education, named AIDS (Anatomical Image Digitizing System). By implementing the prototype systems, we intended to determine the technical and anatomical parameters required for such a system, and to attempt digital imaging analysis of morphology. We demonstrated that such systems can be used as a new morphological tool on a macroscopic level, particularly in mathematical image analysis, in comparative anatomy by organizing a database and by modifying images with graphic techniques, and in statistical discussions by manipulating large numbers of illustrations quickly. A 512 X 512 X 8 bit matrix is judged to be satisfactory for analyzing images mathematically and producing illustrations of bones, but higher quality tools are required to store anatomical figures with halftones in a good condition, and to prepare fine anatomical illustrations. Classifications of figures and formats of figure legends are necessary to standardize the storage of figures in the form of a database.

Algorithms↗

PubMed1990

Aryl hydrocarbon hydroxylase activity levels in the hepatic microsomal fraction from MC- or TCDD-treated mice: a comparison between aromatic hydrocarbon responsive and non-responsive strains.

The effects of in vivo administration of polycyclic aromatic hydrocarbons on the levels of aryl hydrocarbon hydroxylase (AHH) activity in aromatic hydrocarbon (Ah) responsive and non-responsive strains of mice were studied using the hepatic microsomal fraction. Injection of 3-methylcholanthrene (MC; 42 mg/kg body wt.) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 120 micrograms/kg body wt.) into both strains produced marked enhancement of AHH activity except for MC treatment of Ah non-responsive strains. Addition of 7,8-benzoflavone (BNF) to the microsomal AHH assay mixture prepared from mice previously injected with vehicle (olive oil) alone caused an increase in activity when the mice were responsive, while BNF lowered the activity in non-responsive strains. With regard to MC-injected mice, BNF and 3-methyl-sulphonyl-4,5,3',4'-tetrachlorobiphenyl (3-MSF-TCB) decreased microsomal AHH activity in Ah-responsive mice, whereas these drugs enhanced the activity in Ah-non-responsive strains. 3-MSF-TCB also had inhibitory potency on AHH activity, but the mechanism of inhibition seems to be somewhat different from that of BNF. It may also suggest that cytochrome P-450 isozymes inhibited by BNF are different from those inhibited by 3-MSF-TCB.

Animals↗

PubMed1990

Comparison of coronary hemodynamics in patients with internal mammary artery and saphenous vein coronary artery bypass grafts: a noninvasive approach using combined two-dimensional and Doppler echocardiography.

Blood flow in bypass grafts and recipient left anterior descending coronary arteries was evaluated with combined two-dimensional and Doppler echocardiography in 15 patients with an internal mammary artery graft and in 24 patients with a saphenous vein graft. Comparative studies of coronary hemodynamics were also performed regarding these two different grafting techniques. The graft vessel was detected in 11 (79%) of 14 patients with an internal mammary artery graft and in 20 (87%) of 23 with a saphenous vein graft. The recipient left anterior descending coronary artery was detected in 10 (67%) of the former group and 17 (71%) of the latter. The blood flow patterns obtained were generally biphasic, consisting of systolic and diastolic phases with higher velocity during diastole. The maximal diastolic flow velocity in internal mammary artery grafts was much higher than that in saphenous vein grafts. In patients with an internal mammary artery graft, the flow pattern characteristics within the recipient coronary artery were quite similar to those within the arterial graft, and flow velocities within the recipient coronary artery and the arterial graft were quantitatively almost identical. This outcome may contribute to the long-term patency seen in internal mammary artery grafts. On the other hand, the flow velocity in saphenous vein grafts was fairly low throughout the cardiac cycle. Flow velocity in the recipient coronary artery in patients with a saphenous vein graft was accelerated only in early diastole. As a result, the recipient coronary artery flow pattern and velocity differed substantially from those in the saphenous vein graft.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗

PubMed1990

Genotypic and immunophenotypic analysis of anaplastic large cell lymphoma (Ki-1 lymphoma).

Genotypic and immunological analysis was performed in 10 patients with anaplastic large cell lymphoma (Ki-1 lymphoma), 4 were male and 6 female. Immunophenotypically, 9 of these patients expressed some T cell markers; CD 2 in 9, CD 4 in 9, CD 3 in 6, CD 8 in 4, and UCHL-1 in 8. For B cell markers, 4 patients expressed B 1 and one expressed L 26; these patients also expressed T cell markers. In genotypic analysis, 9 of 10 cases displayed some incidence of T cell receptor gene (TCR) rearrangement or deletion, which was found in 3 patients for C beta 1, 7 for C beta 2, 8 for J gamma, 5 for C gamma (Hind III), 5 for C gamma (EcoRI), 3 for J delta 1 (Hind III), 3 for J delta 1 (BamHI), 3 for J delta 2, and 2 for C delta. One patient with rearrangement of TCR also showed rearrangement of immunoglobulin heavy chain. Another patient exhibited rearrangement of both TCR and immunoglobulin chain. These results indicate a common T cell lineage for this type of lymphoma.

Adolescent↗

PubMed1990

The effects of phosphatidylserine on the decreased cardiovascular response to clonidine microinfused into the nucleus tractus solitarii of old rats.

1. The cardiovascular effects of direct microinfusions of clonidine into the nucleus tractus solitarii (NTS) in rats of different ages were studied. 2. Clonidine microinfused into the NTS produced a dose-dependent hypotensive and bradycardic response, which was reduced by previous microinfusion of yohimbine but not of propranolol or prazosin. 3. Unilateral microinfusion of clonidine into the NTS produced a significantly smaller hypotensive and bradycardic response in 16 month old rats than in 3 month old rats, whereas in older animals (24 month old) the same doses of clonidine were ineffective. In 16 month old rats, yohimbine given into the NTS produced a smaller pressor and tachycardic response than in 3 month old rats whereas in 24 month old animals yohimbine, at the same doses, was unable to change blood pressure and heart rate. 4. Oral administration of phosphatidylserine (50 mg kg-1 day-1 for 30 consecutive days) enhanced the hypotensive and bradycardic response to clonidine microinfused into the NTS in 16 month old rats. The same schedule of treatment with phosphatidylserine did not affect the cardiovascular response to clonidine in young (3 month old) rats and did not restore responsiveness to clonidine in older rats (24 month old). 5. Methoxamine and phentolamine, given intravenously, produced similar pressor and depressor responses, respectively in 3, 16 and 24 month old rats, suggesting that the decreased sensitivity to clonidine in old rats was not due to peripheral cardiovascular changes. 6. In conclusion, the present results indicate that, during aging, there is a decreased sensitivity of alpha 2-adrenoceptors in the brain. Such an alteration can be reversed by chronic treatment with phosphatidylserine during the initial but not the later stages of aging.

Aging↗

PubMed1990

In vitro effects of methylsulfonyl polychlorinated biphenyls and 7,8-benzoflavone on aryl hydrocarbon hydroxylase activity in human lymphoblastoid cells.

The effects of 11 isomers of methylsulfonyl polychlorinated biphenyls (MSF-PCBs) on the aryl hydrocarbon hydroxylase (AHH) activity were examined at a fixed dose of 1.5 micrograms/ml by using cultured lymphoblastoid cells. One of the isomers 3-MSF-3',4,4',5-tetraCB, as well as 4-MSF-3,3',4',5-tetraCB and 4-MSF-3,3',4',5,5'-pentaCB, effectively reduced the AHH activity when added to the culture medium, especially that previously treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to induce the AHH activity. However, the inhibitory potencies exerted by the above three MSF-PCB compounds were smaller than that by 7,8-benzoflavone (BNF). When added to the culture medium simultaneously with TCDD or 3-methylcholanthrene (MC), 3-MSF-3',4,4',5-tetraCB blocked the enhancement of the AHH activity by TCDD but did not that by MC. This is in contrast to BNF which blocked the increases due to both TCDD and MC. On the other hand, 3-MSF-3',4,4',5-tetraCB added directly to the reaction mixture for the TCDD-induced AHH activity showed little influence, while BNF decreased the same activity. These results imply that the effect of 3-MSF-3',4,4',5-tetraCB on the AHH activity is different from that of BNF.

Aryl Hydrocarbon Hydroxylases↗

PubMed1990

[Five cases of listeriosis in the elderly].

We reported five cases of listeriosis (sepsis and meningitis) in the elderly in our hospital during the last 4 years, where no cases of listeriosis had been found. These 5 cases had diabetes mellitus, lung cancer, chronic respiratory failure, gastric ulcer and aplastic anemia respectively as their underlying diseases. At the onset of listeriosis, 3 cases received corticosteroid and 3 cases received H2-blocker. 2 patients were cured and 3 patients died. Three autopsy cases had meningitis or meningoencephalitis and 2 cases of these autopsy cases had granulomatous changes in these spleens. In serotypes of Listeria monocytogenes (L. monocytogenes), 4 cases were 4b and 1 cases was 1b. All 5 strains were resistant to 3rd generation cephems. Wide uses of 3rd generation cephems and H2-blocker may be one of the reasons for the recent increase of listeriosis. Ingestion of contaminated food is the pathogenetic mechanism for initiating L. monocytogenes infections. And following the change of eating habits and the increase of imported foods, food-born listeriosis may increase. We suppose the increase of L. monocytogenes infections and must give attention to L. monocytogenes infections.

Age Factors↗