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Biomedical subjects

M Ohta

Publications and source records attributed to M Ohta.

At least 829 records · Page 46Linked to original sources
PubMed1990

Purification and characterization of a major glycoprotein in rat liver lysosomal membrane.

A major lysosomal membrane glycoprotein (LGP107) which has an apparent molecular weight (Mr) of 107 kilodaltons (kDa) was purified from rat liver by a simple method with a yield of 1 mg/87 g wet weight of liver. The purification procedures include; preparation of tritosomal membranes of triton-filled lysosomes (tritosomes), extraction of tritosomal membranes by Lubrol PX, wheat germ agglutinin (WGA)-Sepharose affinity chromatography, and monoclonal antibody-Sepharose affinity chromatography. The quantitative immunoblot analysis indicated that LGP107 represents 6.2% of the total protein of tritosomal membranes. The isoelectric point of the purified glycoprotein was 2.7, and it moved toward neutral pH after sialidase treatment, with its molecular weight decreased by about 10 kDa. LGP107 contained 52% carbohydrates, and the carbohydrate moiety was compared of Fuc, Man, Gal, GlcNAc and sialic acid in a molar ratio of 7.2:68.2:40.6:63.0:32.3, respectively, indicating that LGP107 was highly glycosylated with N-linked complex-type olgosaccharide chains. Out of the N-linked glycans released from the glycoprotein by hydrazinolysis/N-reacetylation, about 70% was sialylated. Anion exchange and reverse-phase high performance liquid chromatography analysis on the structure of N-glycans revealed that a disialyl biantennary form is a major component in the oligosaccharide chains of LGP107.

Animals↗
PubMed1990

Synthesis and bioactivity of propranolol analogues with a rigid skeleton. I.

The synthesis of two kinds of propranolol analogues, A and B, with a rigid skeleton was investigated. The compounds were designed to help identify the conformation involved in beta-adrenergic receptor-propranolol interaction. The key intermediate, 2-hydroxy.2,3-dihydronaphtho[1,8-bc]pyran (5), was obtained starting from acenaphthenone (1). On sequential dehydration, hydroboration, and oxidation, 5 gave 2,3-dihydronaphtho[1,8-bc]pyran-3-one (8), which was converted to compound A. Compound 5 was also derived to 2-formyl-2,3-dihydronaphtho[1,8-bc]pyran (13) via the 2-vinyl compound (12). Condensation of nitromethane with 13 followed by reduction and alkylation produced the desired compound B. The beta-blocking activities of A and B were examined.

Adrenergic beta-Antagonists↗
PubMed1990

Significance of ultrafast computed tomography in cardiac imaging: usefulness in assessment of myocardial characteristics and cardiac function.

The usefulness of cardiac ultrafast computed tomography (CT) is discussed in this article. Thirty-three patients with ischemic heart disease and 15 patients with hypertrophic cardiomyopathy were assessed for myocardial characteristics, while 30 patients with various heart diseases were assessed for cardiac function. Volume mode (100 msec scan) and cine mode (50 msec scan) studies were applied. As the findings of abnormal myocardial characteristics, early defect (ED) and late enhancement (LE) of the left ventricular (LV) wall were observed after injection of contrast medium. In ischemic heart disease, all 27 patients with myocardial infarction (MI) and all 16 MI sites showed LE, while 25 ED sites were well correlated with MI or significant coronary stenosis. LE was quite sensitive for MI and ED was highly predictive for ischemia. Seven of 15 HCM patients (47%) also showed LE, indicating that LE occurs in tissues with a different capillary architecture from that observed in normal myocardium. For evaluation of cardiac function, ventricular volumetry was performed by summation of a sliced area of the ventricles. End-diastolic volume and LV ejection fraction calculated by this means correlated excellently with the values obtained using left ventriculography (R = 0.97 and 0.96). The stroke volumes for both ventricles were nearly equal when calculated using ultrafast CT. Consequently, the study of cardiac volumetry using ultrafast CT was thought to be reliable and utilizable in clinical practice.

Cardiomyopathy, Hypertrophic↗
PubMed1990

Effects of novel hydantoin derivatives with aldose reductase inhibiting activity on galactose-induced cataract in rats.

Effects of novel aldose reductase inhibitors, M16209 (1-(3-bromobenzo[b]furan-2-ylsulfonyl)hydantoin) and M16287 (1-(3-chlorobenzo[b]furan-2-ylsulfonyl)hydantoin), on galactose-induced cataract formation in rats were investigated. Rats fed a 30% galactose diet developed lenticular opacity in the peripheral region by the 6th day of galactose feeding and showed gradual progression of opacity from the equator to the center of lenses. Histological study on the 15th day showed apparent lens fiber swelling and vacuolation predominantly in the equatorial and anterior cortical regions. Biochemical changes such as accumulation of galactitol, depletion of myo-inositol and decrease in glutathione (GSH) content in lenses preceded the appearance of opacity. Remarkable increase in NADPH content and decrease in NADP+ content, in addition to elevation of the ratio of Na+/K+, in lenses were also observed on the 15th day. Both M16209 and M16287 (10, 30 and 100 mg/kg/day, p.o.) dose-dependently ameliorated these morphological and biochemical changes except that restoration of myo-inositol content was incomplete. These results indicate that M16209 and M16287 can prevent galactose-induced cataract formation through amelioration of metabolic disorders and thus have high potential for clinical use in the treatment of some diabetic complications.

Aldehyde Reductase↗
PubMed1990

Effects of androgen on progesterone secretion from granulosa cells obtained from antral follicles of rats.

The effects of testosterone (T) on the secretion of progesterone (P) by ovarian granulosa cells obtained from immature rats pre-treated with pregnant mare's serum gonadotropin were examined in vitro. T (10 nM-10 microM) enhanced both basal and FSH- or cAMP-stimulated secretion of P in a dose-dependent manner. Furthermore, T augmented FSH-stimulated cAMP production. The biphasic secretory pattern of P induced by continuous superfusion of granulosa cells with FSH was much exaggerated in the cultures supplemented with T. A stimulatory effect of T on secretion of P was observed only in the medium that contained serum. T affected neither the basal nor the FSH-stimulated secretion on 20 alpha-dihydroprogesterone. Androsterone, a non-aromatizable and low-potency androgen, at a similar concentration as T mimicked the effects of T on the secretion of progesterone. These results indicate that androgen stimulates mature granulosa cells to enhance the secretion of P. This androgen action extends either up- or down-stream of cAMP in the process of steroidogenesis.

20-alpha-Dihydroprogesterone↗
PubMed1990

Effects of central osmotic stimulation on vasopressin and enkephalin release into the blood and cerebrospinal fluid and blood pressure.

To assess the central effect of hypertonic NaCl on the release of vasopressin (AVP) and methionine enkephalin-like substances into the blood and cerebrospinal fluid, and on blood pressure, ventriculocisternal perfusion (0.25 ml/min, 60 min) was performed in anesthetized dogs with artificial cerebrospinal fluid (CSF), either isotonic (300 mosmol/kg) or hypertonic (600 and 1200 mosmol/kg). The effect of central administration of a V1-AVP antagonist on the central osmotic challenge was also studied. In dogs, given 600 mosmol/kg, CSF osmolality increased with a concomitant rise in mean arterial pressure and plasma AVP concentrations. Plasma osmolality, heart rate, CSF AVP and plasma and CSF methionine enkephalin-like substances showed no significant change. In dogs, given 1200 mosmol/kg, the CSF osmolality increase was accompanied by a rise in mean arterial pressure, heart rate, plasma AVP and CSF AVP. Plasma osmolality and plasma and CSF methionine-enkephalin-like substances did not change significantly. A V1-AVP antagonist given centrally attenuated the rise in mean arterial pressure induced by osmotic challenge. In dogs, given 300 mosmol/kg, no parameters changed significantly except for a gradual fall in heart rate. These results suggest that central osmotic stimulation by hypertonic NaCl increases blood pressure, heart rate and the release of AVP, but not methionine enkephalin-like substances, into the blood and CSF, and a V1-blocker given centrally attenuates the pressor response.

Animals↗
PubMed1990

Effects of intracerebroventricular administration of adrenoceptor-agonists on the regulation of renal water and electrolytes handling through endocrine, renal and hemodynamic function.

In order to assess the roles of central adrenoceptors in the release of atrial natriuretic peptide (ANP), aldosterone (ALD), vasopressin (AVP) and renin as well as in the regulation of renal and cardiovascular functions, either norepinephrine (NE; 0.07 microgram/kg/min), guanabenz (GB; alpha 2-agonist; 0.4 microgram/kg/min), methoxamine (MET; alpha 1-agonist; 0.4 microgram/kg/min), or isoproterenol (ISO; beta-agonist; 0.07 microgram/kg/min), dissolved in the artificial cerebrospinal fluid (ACSF), was intracerebroventricularly (i.c.v.) administered at a rate of 10 microliters/min for 30 min in anesthetized dogs. In the control study, the drugs were omitted. NE decreased mean arterial pressure (MAP), urinary osmolality (Uosm) and plasma ALD and AVP concentrations, and increased urine flow (UF). GB increased UF and urinary K excretion without any changes in urinary Na excretion, but decreased plasma ALD and AVP, heart rate, and Uosm without changes in MAP. ISO decreased MAP and plasma ALD, and increased Na and K output, renal plasma flow and UF with decreased Uosm. MET and ACSF failed to affect any of these parameters. Glomerular filtration rate, plasma ANP concentration and renin activity did not change in any of the studies. The present results suggest that central alpha 2- and beta-adrenoceptors may attenuate ALD and/or AVP release without changes in ANP and renin release, and decrease blood pressure, thereby causing a diuresis and natriuresis.

Adrenergic alpha-Agonists↗
PubMed1990

Multiple oligodendroglioma--case report.

A 32-year-old male was hospitalized with headache and disturbance of consciousness. Computed tomography (CT) revealed a tumor and an intracranial hematoma in the right frontal lobe. The tumor was totally removed, and postoperative radiation therapy was administrated locally at 50 Gy. Five years later, he experienced sudden onset of headache and vertigo. CT demonstrated a mass lesion with a hematoma in the cerebellar vermis. The tumor was subtotally removed and he underwent postoperative local irradiation at 50 Gy as well as ventriculoperitoneal shunting. Four years later, he complained of visual and gait disturbances, and CT disclosed a tumor in the suprasellar region. Following partial removal of the tumor, local brain irradiation was given at 40 Gy. Histological examination proved all three tumors to be oligodendrogliomas with no evidence of malignant change.

Adult↗
PubMed1990

[Studies on the quality of enzyme preparations (XI)--Kallidinogenase preparations].

Qualitative tests of 22 kinds of commercially available kallidinogenase preparations were carried out by the enzymological method. These preparations consisted of 16 kinds of tablets, 5 kinds of capsules and 1 kind of ampoule. One sample of tablet showed kallidinogenase activity less than 80% of the labeled amount by spectrophotometry, pH stat and kinin-liberating methods. All other preparations were found to have 90-120% 120% of the labeled amount by spectrophotometry using S-2266 as the substrate. Other enzymes, i.e. kininase, trypsin and chymotrypsin were found as impurities, but the cntants were very low.

Dosage Forms↗
PubMed1990

Carcinosarcoma and spindle cell carcinoma of the lung. Clinicopathologic and immunohistochemical studies.

We examined pulmonary carcinomas with prominent sarcoma-like lesions both clinicopathologically and immunohistochemically. Grossly, two tumors had predominantly endobronchial growths, four bulky parenchymal growths, and two endobronchial, parenchymally mixed growths. In these eight patients, six tumors were completely resected, one patient was given irradiation only, and one patient died in the early postoperative period. On the basis of specific differentiation of the sarcoma-like lesions, the tumors were separated into three groups: two with "true" sarcoma differentiated into soft tissues such as striated muscle or osteoid tissue; three with a fibromatous sarcoma resembling atypical pseudosarcomatous stroma; and three with spindle cell carcinoma with evidence of epithelial differentiation. The prognosis was poor, and tumors with specific differentiation into rhabdomyosarcoma, chondrosarcoma, or spindle cell carcinoma progressed more rapidly than did those with a fibromatous sarcoma. Because the fibromatous sarcoma-like lesions were found to relate to a longer survival time for the patients, we wish to emphasize that a distinction of sarcomatous components should be made with regard to assessing the prognosis of pulmonary carcinoma with sarcoma-like lesions.

Aged↗
PubMed1990

[Antibody response to P-fimbriae of Escherichia coli in patients with genitourinary infections].

The serum antibody response to P-fimbriae of Escherichia coli in patients with genitourinary infections was investigated with enzyme linked immunosorbent assay (ELISA) for P-fimbriae-specific IgG antibody. 1) Female patients with acute pyelonephritis had a significantly (P less than 0.01) higher titer of serum IgG antibody by ELISA, compared with patients with acute cystitis or control subjects. The prevalence of positive serum IgG antibody response was 65% in patients with acute pyelonephritis. 2) Patients with epididymitis with high fever had a significantly (P less than 0.01) higher titer of serum IgG antibody by ELISA, compared with patients with epididymitis without fever or control subjects. The prevalence of positive serum IgG antibody response was 60% in patients with epididymitis with high fever. Therefore, 65% of female patients with acute pyelonephritis and 60% of patients with epididymitis with high fever are infected with P-fimbriated E. coli. The measurement of serum antibody response to P-fimbriae must be helpful for the diagnosis and the antibiotic therapy of epididymitis.

Acute Disease↗
PubMed1990

A case of GM1-gangliosidosis type I: glycosphingolipid profiles of urine and transformed lymphocytes and beta-D-galactosidase activities in peripheral lymphocytes, cultured skin fibroblasts and transformed lymphocytes.

A female infant with early-onset GM1-gangliosidosis type I was investigated. The lymphocytes, transformed lymphocytes and cultured skin fibroblasts of the patient were demonstrated to have severe beta-D-galactosidase deficiency. The beta-D-galactosidase activities of these cells from the patient's father and mother were at the lower limit of the normal range. The oligosaccharide accumulation in urine of the patient showed the typical type I GM1-gangliosidosis pattern, but no GM1 ganglioside was detected in the patient's urine or transformed lymphocytes. The clinical features were compatible with infantile GM1-gangliosidosis. The mixture of homogenates from the cultured fibroblasts or transformed lymphocytes of the patient and controls showed no complementation of beta-D-galactosidase activity against the controls.

Cells, Cultured↗
PubMed1990

[Clinical evaluation of recurrent patterns of gastric cancer after intraperitoneal hyperthermic perfusion].

The patterns of recurrence and the prognosis of 24 gastric cancer patients with peritoneal seeding and/or serosal invasion, who underwent gastrectomy followed by intraperitoneal hyperthermic perfusion (IPHP), were studied in comparison with 23 gastric cancer patients given surgery alone (controls). With respect to 22 patients with peritoneal seeding, all of 8 patients in the control group died of re-accumulation of ascitic effusion, whereas of 14 patients in the IPHP group, 3 died of peritoneal recurrence, 2 of intraperitoneal tumors, 1 from pleural metastasis, and 1 of liver metastasis. The remaining 7 cases are alive without a sign of recurrence. Again, with respect to 25 patients with large serosal penetration of cancer, 7 of 15 patients in the controls died of peritoneal recurrence, whereas this was never observed in the IPHP group. As to the relation of histology and prognosis, while the poorly differentiated adenocarcinoma and signet ring cell carcinoma had poor prognosis in the controls, the same patterns in the IPHP group proved not to be so unfavorable. Since a few given IPHP resulted in hepatic metastasis and/or nodal involvement, adjuvant treatment will be required. The survival rate for the IPHP group was significantly better at p = 3.43 x 10(-2) than in controls.

Aged↗
PubMed1990

[Clinical effect of intraperitoneal hyperthermochemotherapy on the survival rate for advanced gastric cancer patients].

Intraperitoneal hyperthermic perfusion (IPHP) was performed right after surgery for 31 advanced gastric cancer patients with serosal invasion and/or peritoneal dissemination. The survival rate in the IPHP group, was compared with that in the control group, 30 patients who underwent surgery alone within the same period of time. The 1-year survival rates for IPHP group and control group were 81.9% and 40.3%, respectively. The 2-year survival rates were 52.1% and 11.8%, and the 3-year survival rates were 26.1% and 0%, respectively. The survival rate for IPHP group was better than that for control group, with p = 1.46 x 10(-4). IPHP and control group with peritoneal dissemination included 21 and 9 patients respectively, and 50% survival rates were 18 months and 4.2 months, respectively. IPHP and control group with serosal invasion included 10 and 21 patients, respectively, and 8 out of 10 patients survived in the IPHP group, while 17 out of 21 patients died in the control group. These results suggest that IPHP is effective for gastric cancer patients with peritoneal dissemination and/or serosal invasion.

Aged↗