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Biomedical subjects

M Umeda

Publications and source records attributed to M Umeda.

At least 433 records · Page 24Linked to original sources
PubMed1986

[Changes in N-acetyl-beta-glucosaminidase (NAG) in prostatitis patients].

NAG was measured before and after treatment and compared in 11 acute prostatitis patients, 13 chronic prostatitis patients and 10 healthy volunteers. Urinary NAG before treatment was 34.1 +/- 18.4 U/l in the acute prostatitis patients and was significantly higher than that in the healthy volunteers, which was 5.1 +/- 1.2 U/l. It was 8.5 +/- 3.2 U/l in the chronic prostatitis patients. Urinary NAG after treatment decreased and was 7.6 +/- 4.4 U/l and 6.7 +/- 1.7 U/l in the acute and chronic prostatitis groups, respectively. These results suggest that urinary NAG is useful in evaluating the changes in the condition of prostatitis and in diagnosing prostatitis, especially acute prostatitis.

Acetylglucosaminidase↗
PubMed1985

HVJ-induced fusion of liposome to erythrocyte. Possible involvement of virus-induced activated state of erythrocyte membranes during fusion process.

HVJ-induced fusion between liposomes and erythrocytes was examined as a model of cell-cell fusion and the following results were obtained: Liposome-liposome fusion seldom occurred in the presence of HVJ. Liposomes free of receptors for viral HN protein could efficiently fuse with erythrocytes when the concentration of liposomes and erythrocytes was high. Direct interaction between HVJ and liposomes should be negligible in the present system. A distinct lag phase (10 min) was observed before the liposome-erythrocyte fusion occurred appreciably. Efficiency of the liposome-erythrocyte fusion decreased linearly up to 1 h after stopping the virus-erythrocyte fusion. The former fusion was almost negligible after 1 h but could be restored by further addition of HVJ. Efficiency of the liposome-erythrocyte fusion was suppressed significantly when erythrocytes were pretreated with N-ethylmaleimide (N-EM), a membrane-permeable sulfhydryl agent, whereas rho-chloromercuriphenylsulfonic acid (PCMBS), a membrane-impermeable sulfhydryl agent, had no appreciable effect on the fusion efficiency. The study suggests possible involvement of some HVJ-induced 'activated state' of the erythrocyte membrane during the process inducing the liposome-erythrocyte fusion. The structure including the membrane skeleton system may be responsible for producing an 'activated state' in the erythrocyte membrane. Such an 'activated state' was induced 10 min after the viral infection to erythrocytes, and thereafter decayed gradually.

Cell Fusion↗
PubMed1985

Effect of lipid composition on HVJ-mediated fusion of glycophorin liposomes to erythrocytes.

We previously reported that liposomes containing glycophorin or gangliosides, both of which were isolated from human erythrocytes, are efficiently fused to erythrocyte membranes in the presence of HVJ (Umeda, M. et al., J. Biochem. 94, 1955-1966 (1983), and Virology 133, 172-182 (1984]. In the present work, the effect of lipid composition in glycophorin liposomes on their sensitivity to fusion with erythrocytes was studied. Very little fusion occurred when glycophorin liposomes composed of dipalmitoylphosphatidylcholine-dicetylphosphate (9:1), dimyristoylphosphatidylcholine-dicetylphosphate (9:1), or egg yolk phosphatidylcholine-dicetylphosphate (9:1) were incubated with human erythrocytes in the presence of HVJ at 37 degrees C. Addition of cholesterol into these liposomal membranes greatly enhanced the sensitivity of the liposomes to fusion. The presence of phosphatidic acid and phosphatidylethanolamine in liposomes also enhanced the sensitivity, whereas the presence of lysophosphatidylcholine had no significant effect on the ability of the liposomes to fuse. The fusion efficiency of liposomes was also enhanced by the presence of glucosylceramide. Change of lipid composition in liposomes had, however, no appreciable influence on the HVJ-mediated binding of liposomes to erythrocytes, suggesting that the interaction between HANA protein of HVJ and glycophorin in liposomes was not affected by the lipid composition of the liposomes.

Calcium↗
PubMed1985

31P-NMR studies on the energy metabolism of the living rat brain using a surface coil method.

We have examined the changes of the energetic metabolic state of rat and mouse brains under hypoxic hypoxia or ischemia using a 31P-NMR spectrometer with a surface coil. The NMR spectrometer has a super-conducting magnet providing a homogeneous magnetic field of 6.3 tesla. A probe was remodelled to accommodate an experimental animal in it. The animals were anesthetized with 1.0% or 1.5% halothane throughout the experiments. The optimal measurement conditions were a 90 degrees pulse width of 20 microsecond, and a 2 sec pulse repetition time. 200 acquisitions of FIDs was required for high spatially resolved signals. The Pcr/ATP ratio of the live, anesthetized rat brains was 1.76 +/- 0.46 (n = 8) for cerebra and 1.63 +/- 0.11 (n = 4) for cerebella. That of gerbil brains was 1.23 +/- 0.09 (n = 4). The Pcr/ATP ratio did not show any significant changes under both the conditions of hypoxic hypoxia or ischemia. The value of Pcr/Pi ratio decreased in the hypoxic conditions. The level of Pcr. of rat cerebrum decreased by 76.8 +/- 10.5% at 10% oxygen and by 57.3 +/- 15.7% at 5% oxygen compared with the value of 20% oxygen. The ATP level in the rat brain also decreased according to the degree of hypoxia. Cerebral ischemia was produced in the gerbil by ligation of the common carotid artery. The levels of Pcr. and ATP were severely depressed in the ischemic hemisphere but those of the intact side remained normal.

Adenosine Triphosphate↗
PubMed1985

[Myelolipoma of the adrenal gland: a case report].

A case of myelolipoma of the adrenal gland is reported. The patient was a 50-year-old male who was obese and robust, and complained of right flank pain. Laboratory investigation of adrenal functions were within normal levels. Excretory urography showed a large radiolucent mass in the right upper quadrant, displacing the right kidney to a lower position. Angiography demonstrated a large hypovascular mass. CT scan showed a large mass with low density in the right retroperitoneal space. The tumor was surgically removed through a lumbar incision, and was 800 gm in weight and well capsulated. A pathological study of the tumor disclosed adrenal myelolipoma consisting of mature fat cells and myeloid elements. Myelolipoma of the adrenal gland is rare and 33 cases of adrenal myelolipoma from the English and Japanese literature including this case were reviewed and analyzed statistically.

Adrenal Gland Neoplasms↗
PubMed1984

Activity of human erythrocyte gangliosides as a receptor to HVJ.

Liposomes could bind and fuse efficiently to human erythrocytes in the presence of HVJ when they contained gangliosides isolated from human erythrocytes. Sialosylparagloboside, which has a terminal sequence of NeuAc alpha 2-3Gal beta 1-4GlcNAc, has a much higher receptor activity to the virus than GD1a, GD1b, GT1b, and GT1a, all of which contain the terminal sequence of NeuAc alpha 2-3Gal beta 1-3GalNAc or NeuAc alpha 2-8NeuAc alpha 2-3Gal beta 1-3GalNAc. The activity of sialosylparagloboside is comparable to that of glycophorin, a major sialoglycoprotein of human erythrocytes, when compared on the basis of the required amount (as sialic acid) of compounds. The high affinity of sialosylparagloboside to the viral HANA protein is also suggested by the finding that it showed high inhibitory activity against HVJ-mediated binding of glycophorin liposomes to erythrocytes. Sialosylparagloboside was also highly susceptible to the viral sialidase, the other biological function of HANA protein.

Chromatography, Thin Layer↗
PubMed1984

Sensitive induction of chromosome aberrations in the in vivo liver cells of rats by N-nitrosodiethylamine.

The in vivo induction of chromosome aberrations has been studied in the liver cells of rats exposed to N-nitrosodiethylamine (DEN). Rats were treated with DEN before or after partial hepatectomy. For chromosome analysis, liver cells were isolated by a collagenase digesting procedure. In both treatment schedules, DEN caused significant and dose-dependent chromosome structural aberrations at dose levels as low as 0.5-4.0 mg/kg which are comparable to the range employed in lifetime carcinogenicity tests. Repeated exposures to DEN increased the rates of aberrations. By the procedure described above, detection of clastogenic activities of other hepatocarcinogens will be possible.

Animals↗
PubMed1984

Interaction between glycophorin and ganglioside GM1 on liposomal membranes. Effect of the interaction on the susceptibility of membranes to HVJ.

Liposomes could bind and fuse efficiently to human erythrocytes in the presence of HVJ when they contained glycophorin isolated from human erythrocytes (Umeda, M., et al. (1983) J. Biochem. 94, 1955). In the present work we demonstrated that HVJ-induced fusion between liposomes containing glycophorin and erythrocytes was suppressed when GM1 coexisted with glycophorin in the same liposomal membranes. Asialo-GM1 and other gangliosides such as GM3 and sialosylparagloboside did not affect the fusion between the liposomes and erythrocytes. An intermolecular interaction between glycophorin and GM1 was suggested by the ESR spectrum obtained from liposomes containing glycophorin and a ganglioside GM1 analog carrying a nitroxyl spin label in the fatty acyl chains (5SL-gangliosidoide). The overall splitting value (2A parallel) observed in the ESR spectrum of liposomes containing 5SL-gangliosidoide increased with increase of the amount of glycophorin, whereas 2A parallel of spin-labeled phosphatidylcholine was not changed. The increase of 2A parallel of 5SL-gangliosidoide suggests that the mobility of the fatty acyl chain of the gangliosidoide was restricted by the interaction with glycophorin. It can be concluded that GM1 located near glycophorin, a receptor of the virus, interferes with the activity of viral F protein, inhibiting the fusion of liposome to erythrocyte.

Electron Spin Resonance Spectroscopy↗
PubMed1984

Transforming growth factor activity in human colostrum.

When human milk was examined for the presence of transforming growth factor (TGF) activity, high levels of the activity were found in milk collected in the early days after delivery. Fractionation of an acid-ethanol extract of colostrum by Bio-Gel P-60 column chromatography revealed that the activity was found in two molecular weight ranges; over 45,000 and from 10,000 to 20,000 daltons. The activity of the milk TGF did not compete with epidermal growth factor (EGF) for EGF receptor and was potentiated by the addition of EGF when assayed using normal rat kidney (NRK) cells.

Animals↗
PubMed1984

Urinary tract infection and blood P1 antigen: preliminary report.

A clinical study was made on the relationship between the blood type P1 antigen and urinary tract infection (UTI). The blood type P1 antigen could be detected in 3 out of 11 healthy Japanese volunteers (27.2%), and in 54% of the UTI patients as a whole. Classified by the type of infection, it could be detected in 3 out of 4 patients with upper UTI (75%) and in 11 out of 22 patients with lower UTI (50%). These incidences were higher than that of healthy volunteers, the difference being statistically significant. The relationship between the annual frequency of UTI and the positive detection of P1 antigen was examined. The patients who had been exposed to UTI twice or more a year proved to have a higher detection rate (61%), than the other group of patients, the difference being statistically significant. Two of the patients with E. coli detected as a clinical isolate proved to have the P1 antigen.

Blood Group Antigens↗
PubMed1984

Activities of transforming growth factors on cell lines and their modification by other growth factors.

Soft agar colony-forming activity of transforming growth factors (TGFs) was examined by a simplified method of soft agar micro-assay using nontransformed mouse BALB/3T3 and normal rat kidney (NRK) cells. Bio-Gel P-60 chromatography of acid-ethanol extracts from a human placenta, a human tumor, and hamster embryos gave similar patterns of colony-forming activity towards BALB/3T3 cells and epidermal growth factor (EGF)-potentiated NRK cells, although the molecular weight ranges of the active fractions were different among the three sources. In the soft agar assay using BALB/3T3 cells, colony-forming activity of a TGF preparation from human placenta was markedly enhanced by insulin, but not by EGF. In contrast, the activity was enhanced by EGF, but not by insulin, when NRK cells were used. Fibroblast growth factor and platelet-derived growth factor induced colonies of both BALB/3T3 and NRK cells, and the induction was suppressed by the TGF preparation. TGF preparations could not induce soft agar colonies of C3H/10T1/2 cells or human foreskin diploid fibroblasts, although they increased the saturation densities of these cell types in monolayer cultures.

Agar↗
PubMed1983

Effects of thiol protease inhibitors on intracellular degradation of exogenous beta-galactosidase in cultured human skin fibroblasts.

The effects of low molecular weight (LMW) protease inhibitors of microbial origin were evaluated on the intracellular degradation of beta-galactosidase purified from Aspergillus oryzae and taken up by cultured human skin fibroblasts with beta-galactosidase deficiency. Only thiol protease inhibitors showed an effect to increase the enzyme activity. E-64, a specific inhibitor of thiol proteases, prolonged 3-fold a half life of the exogenous beta-galactosidase and when the enzyme was supplied as liposomes, the half life was prolonged 9-fold in these cells. The role of thiol proteases in the degradation of enzyme molecules was discussed.

Biological Transport↗