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Biomedical subjects

Y Ohno

Publications and source records attributed to Y Ohno.

At least 415 records · Page 23Linked to original sources
PubMed1993

[Assay of erythropoietin in serum with short term enzyme linked immunosorbent assay method--the clinical significance, Part 1: Relation to anemia in renal failure and hematological disorders].

With a newly developed enzyme linked immunosorbent assay kit TOYOBO Co. in which 2 anti-EPO monoclonal antibodies were used, we assayed EPO concentration in sera from normal adults, 168 patients with renal failure and 333 patients with hematological disorders. In the patients with renal failure, serum EPO level was normal (52.9%) or reduced (42.9%), and there was no correlation to their hematocrits. However, there was an increment in EPO concentration correlated to their severity of anemia in the most patients with hematological disorders, such as iron deficiency anemia (correlation coefficient r = -0.74), aplastic anemia (r = -0.89), leukemia (r = -0.81), and MDS (r = -0.65). On the other hand, EPO concentration in sera from all the untreated patients with polycythemia vera were significantly low level. But the concentrations of EPO from the patients successfully treated, with normal hematocrit were recovered to normal level. In the patients with secondary polycythemia, there were much varieties in EPO level. Assay of EPO in blood is important not only for diagnosis of polycythemia but also for the analysis of anemia and clinical use of EPO in vivo. The method described here is accurate and technically not complicated, and could be widely induced in most laboratories.

Adolescent↗
PubMed1993

[Assay of erythropoietin in serum with short term enzyme linked immunosorbent assay method--the clinical significance: Part 2--:Relation to serum iron, UIBC and ferritin in renal failure and hematological disorders].

With a newly developed short term enzyme linked immunosorbent assay kit (TOYOBO Co.), in which 2 kinds of anti-EPO monoclonal antibodies were used, we assayed EPO concentration in sera from patients with renal failure and hematological disorders. In this report, the EPO data were analysed in relation to serum iron concentrations, with ferritin and UIBC. In the patients with renal failure, there was no significant correlation between EPO concentration and serum iron, ferritin, nor UIBC concentration. On the other hand, in the patients with hematological disorders, there were two types. One was in patients with iron deficiency anemia, whose serum EPO was negatively correlated to serum iron (r = -0.64) and ferritin (r = -0.59), but positively related to UIBC (r = 0.27). The another was the pattern in patients with aplastic anemia, leukemia and MDS, whose serum EPO positively correlated to iron and ferritin but negatively correlated to UIBC. In the patients with aplastic anemia serum EPO had good correlation to serum iron (r = 0.62), ferritin (r = 0.60) and UIBC (r = -0.46). The relationship of EPO to iron in the patients with leukemia (r = 0.54), and EPO to ferritin in the patients with MDS (r = 0.42) show significantly positive correlation coefficient.(ABSTRACT TRUNCATED AT 250 WORDS)

Enzyme-Linked Immunosorbent Assay↗
PubMed1993

[Descriptive epidemiology of malignant neoplasm of the ovary in Japan].

Descriptive-epidemiological analysis of national mortality statistics on malignant neoplasm of the ovary revealed the following major findings. 1. Crude and age-adjusted mortality rates have gradually and constantly increased from 1947 to 1990 by 8.8 times and 5.4 times, respectively. 2. This increasing mortality trend was concluded to be mainly ascribable to the increasing rate of incidence rate and more accurate diagnosis. Eight background factors are generally considered to be determinants of the mortality trend. 3. Individual effects of age, year and birth cohort on mortality were analyzed and found to be constant after 50 years of age, uniformly increasing in 1950-1990, and clearly decreasing in cohorts born after 1931-1935. 4. A high standardized mortality ratio was detected in prefectures with large cities and in the northern part of Japan, with significant geographical clustering of the low standardized mortality ratio in the southern part, particularly in Kyushu Island. 5. The incidence rate of ovarian cancer was found to be relatively low in Japan as compared to the developed countries in Europe and the U.S.A..

Adult↗
PubMed1993

[Clinical usefulness of measurement of erythropoietin in blood].

Blood erythropoietin (EPO) concentration was measured by radioimmunoassay in 513 patients with various diseases. Untreated polycythemia vera showed lower EPO concentration than normal. Aplastic anemia (AA) revealed the highest EPO level among all anemic diseases in relation to hematocrit value. EPO level of AA patients who underwent bone marrow transplantation was as low as normal subjects even when the anemia has not fully recovered. Paroxysmal nocturnal hemoglobinuria (PNH) showed unusually high EPO concentration among hemolytic anemias. In normal subjects, blood EPO concentration showed a diurnal rhythm that was higher at night than during the daytime. These findings suggest the diagnostic usefulness of measurement of EPO in blood diseases.

Adult↗
PubMed1993

Osteoinductive activity of composites of bone morphogenetic protein and pure titanium.

Titanium sponges were infused with bone morphogenetic protein (BMP-Ti), and the osteoinductivity of the resultant composite was measured. New bone formation occurred three weeks after implantation and was identified by soft x-ray analysis. Quantitative analysis showed no significant difference between BMP-Ti composites and control samples (BMP only). Consequently, pure titanium neither inhibited nor promoted BMP activity. Chondrocytes and new bone formation occurred in direct contact with the surfaces of the titanium. X-ray microanalysis demonstrated new bone formation inside the pores of the titanium sponges. The BMP-Ti composite has interesting properties as an osteoinductive implant and has potential practical clinical applications.

Animals↗
PubMed1993

[Ferrokinetics and bone marrow scanning in patients with myelodysplastic syndrome, hypoplastic myelodysplastic syndrome and aplastic anemia].

Ferrokinetic measurement were performed in a total of 48 patients with myelodysplastic syndrome (MDS), 13 with hypoplastic MDS and 25 with aplastic anemia (AA). Forty seven % of patients with hypoplastic MDS progressed to acute leukemia, however none of the patients with AA progressed to acute leukemia. Sixty-nine% of the patients with MDS showed increased erythron transferrin uptake (ETU) caused by ineffective erythropoiesis. On the other hand, 85% of the patients with hypoplastic MDS and all patients with AA showed decreased ETU caused by reduced erythropoiesis. Positive correlation was observed between ETU and the erythroid precursor cells in the bone marrow. Bone marrow scintigraphy utilizing 99mTc-sulphur colloid showed peripheral expansion of active marrow in MDS patients and islands-like distribution in hypoplastic MDS and AA patients. Ferrokinetics and bone marrow scintigraphy demonstrated the difference between typical MDS and hypoplastic MDS. Hypoplastic MDS appears to be a distinct clinicopathologic entity.

Anemia, Aplastic↗
PubMed1993

[Recurrence presenting as anuria at 16 years after partial nephrectomy for a pelvic tumor in a solitary kidney: a case report].

A 61-year-old male underwent right partial nephrectomy for a pelvic tumor of a solitary kidney at the former hospital on April 1975. Two years later he had a small bladder tumor and transurethral resection was performed. Since August 1985 he had been followed up in our hospital. On June 1986, the urine cytology showed class V, but neither cystoscopy nor drip infusion pyelography revealed the tumor. On January 1992, he consulted our department with macrohematuria and anuria. Serum creatinine and blood urea nitrogen level were 17.24 mg/ml and 84.1 mg/ml, respectively. Hemodialysis was administered. Retrograde pyelography revealed a defect of tumor at the pyeloureteral junction, and pyuria by ureteral catheterization showed class V cytology. Abdominal CT showed right hydronephrosis caused by the recurrence of pelvic tumor, and right nephrectomy was performed. The histopathological diagnosis was non-papillary transitional cell carcinoma, grade 3 > 2, pT3. He is in good condition with maintenance hemodialysis. In the Japanese literature there were 16 cases of pelvic tumor on the solitary or residual kidneys. In 12 of the 16 cases, kidney sparing treatment was tried and only our case has lived over 10 years. The indication of partial nephrectomy for pelvis tumor was discussed.

Anuria↗
PubMed1993

[Determination of the standard level of serum erythropoietin in relation to hemoglobin concentration].

Serum erythropoietin (EP) concentration was measured by the recombinant EP-based radioimmunoassay and was examined to standardize the hemoglobin (Hb) related level of 144 normal control and 56 patients with iron deficiency anemia and hemolytic anemia excluding paroxysmal nocturnal hemoglobinuria. The standardization was achieved by logarithmic regression of the EP titier on Hb either by the two-phase linear form or by the third degree sigmoid form at a 95% confidence limit for each regression. The third degree regression was found to be preferable from the view point of both statistics and the negative feedback mechanism. The average and scattering of the deviation from the standard level thus determined of the disease groups indicated that the EP level is: (1) 12 fold higher than the standard level in 42 aplastic anemias (the most in excess and a few in standard). (2) three fold higher than that in 27 myelodysplastic syndromes (relatively higher dispersed state). (3) 29% of the standard level in 33 anemias associated with chronic renal failure (deficient state). (4) 105% of the extrapolated standard level in 22 polycythemia veras (standard state). The standardization of Hb-related Ep titer may provide new pathophysiological approaches in a variety of hematopoietic disorders.

Anemia, Hemolytic↗
PubMed1993

[Lifestyles related to preserving 20 or more teeth at 80 years of age].

To explore lifestyle factors related to preserving 20 or more teeth at 80 years of age, a total of 114 Japanese persons aged 80 years old (70 with 20 teeth or more (mean teeth: 25.0 +/- 2.8) and 44 with 19 teeth or less (mean teeth: 5.2 +/- 6.3)) were studied. Study subjects received a dental examination and were directly interviewed, using a questionnaire, to collect such information as past episodes of tooth and gingival conditions, past attitude to dental care and several lifestyle habits. The following major findings emerged by statistical analysis. Probability of preserving 20 or more teeth at 80 years of age was significantly high with: (1) strict upbringing in childhood (p < 0.05 in males), (2) no swollen gums around 60 years old (p < 0.01 in males), (3) early visit to a dentist around 40 years old (p < 0.05 in males), and (4) not being fond of sweets in childhood (p < 0.05 in females). The following related to a high tendency toward preserving 20 or more teeth at 80 years of age: (1) graduate from primary school only (in females), (2) having a home dentist around 20 years old (in males), (3) tended to visit a dentist earlier at 20 years old (in males), (4) not eating sweet things at 60 years old (in males), and (5) have not smoked cigarettes (in males).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

A novel post-translational incorporation of tyrosine into multiple proteins in activated human neutrophils. Correlation with phagocytosis and activation of the NADPH oxidase-mediated respiratory burst.

Activation of human neutrophils by PMA causes a post-translational incorporation of 14C-labeled tyrosine into multiple neutrophil (PMN) proteins, that is distinctly different from the enzymatic tyrosinolation of tubulin in FMLP-stimulated PMN. Post-translational incorporation of other radiolabeled amino acids, including the structurally similar amino acid phenylalanine, does not occur under identical conditions of neutrophil activation, suggesting an involvement of the phenolic hydroxyl group of tyrosine in the PMA-mediated reaction. Similar to the stimulation of PMN tubulin tyrosinolation by FMLP, the PMA-induced incorporation of tyrosine into multiple PMN proteins is closely associated with activation of the NADPH oxidase-mediated respiratory burst in stimulated PMN and can be inhibited by a variety of reducing agents, inhibitors of peroxidase-mediated reactions, and intracellular scavengers of oxygen radicals. Moreover, the PMA-induced post-translational incorporation of tyrosine does not occur in PMN from patients with chronic granulomatous disease and is significantly reduced (50%) in PMN of an individual with myeloperoxidase deficiency. A similar stimulus-induced incorporation of tyrosine into multiple PMN proteins is also observed in PMN exposed to various phagocytic stimuli, and the incorporated radioactivity in cells undergoing phagocytosis is substantially enriched (40- to 50-fold) in isolated PMN phagolysosomes. Consistent with this latter observation, HPLC fractionation of stimulated PMN proteins and analysis of the incorporated radioactivity reveal that the 14C label is primarily associated with PMN membrane proteins. Furthermore, this post-translational incorporation of tyrosine, like that associated with PMA stimulation, is associated with production of oxygen radicals and the generation of protein carbonyl derivatives, which are indicative of oxidative protein modifications via mixed function oxidases. Our findings indicate that tyrosine incorporation into membrane proteins of stimulated PMN is functionally relevant to the physiologic host-defense responses of human neutrophils undergoing phagocytosis.

Blood Proteins↗
PubMed1992

Estimation of the rate constants associated with the inhibitory effect of okadaic acid on type 2A protein phosphatase by time-course analysis.

As is often the case with tightly binding inhibitors, okadaic acid produces its inhibitory effect on type 2A protein phosphatase (PP2A) in a time-dependent manner. We measured the rate constants associated with the binding of okadaic acid to PP2A by analysing the time-course of the reduction of the p-nitrophenyl phosphate (pNPP) phosphatase activity of the enzyme after application of okadaic acid. The rate constants for dissociation of okadaic acid from PP2A were also estimated from the time-course of the recovery of the activity from inhibition by okadaic acid after addition of a mouse IgG1 monoclonal antibody raised against the inhibitor. Our results show that the rate constants for the binding of okadaic acid and PP2A are of the order of 10(7) M-1.s-1, a typical value for reactions involving relatively large molecules, whereas those for their dissociation are in the range 10(-4)-10(-3) s-1. The very low values of the latter seems to be the determining factor for the exceedingly high affinity of okadaic acid for PP2A. The dissociation constants for the interaction of okadaic acid with the free enzyme and the enzyme-substrate complex, estimated as the ratio of the rate constants, are both in the range 30-40 pM, in agreement with the results of previous dose-inhibition analyses.

Animals↗
PubMed1992

Musk xylene is a novel specific inducer of cytochrome P-450IA2.

The effect of musk xylene on contents of both cytochrome P-450IA1 and cytochrome P-450IA2 in rat liver was investigated using Western blotting analysis. Rats were treated i.p. for five consecutive days with either 50, 100 or 200 mg musk xylene/kg body weight. Musk xylene increased both total cytochrome P-450 and cytochrome b5 contents in rat liver microsomes. Musk xylene induced cytochrome P-450IA2 (384 pmol/mg protein) strongly and preferentially and the ratio of cytochrome P450IA2/P-450IA1 was about 12 at the lowest dose tested. Musk xylene also induced the cytochrome P-450IA1 dose-dependently, but these extents were very small (32-174 pmol/mg protein). These results suggest that musk xylene may be a more specific inducer for cytochrome P-450IA2 than any other inducers reported.

Animals↗
PubMed1992

[A case of significant, non-neoplastic, ovarian hypertestosteronism].

A 24-year-old female with significant ovarian hypertestosteronism, who responded well both to gonadotropin releasing hormone (GnRH) agonist and cyclic administration of estrogen and gestagens in terms of suppressing circulating testosterone levels is reported. The patient's menstrual periods had been regular since menarche at the age of 12 until she became amenorrheic at the age of 20. She visited our facility in November 1988 after receiving three cycles of estrogen and gestagen replacement therapy from a previous physician which caused withdrawal bleeding. Clomiphen citrate reportedly failed to induce apparent ovulation. On her first visit with us, she was 160 cm tall weighing 47 kg with apparent hoarseness but not with hirsutism. Pelvic examination revealed significant clitoromegaly but otherwise normal external and internal genitalia. Laparoscopic examination disclosed that her uterus appeared to be normal with bilateral ovaries relatively small (4 x 4 x 3 cm) without tumorous or polycystic appearance. Histological examination of her ovaries obtained at laparoscopy showed several primary follicles with mild infiltration of the stromal cells. No thickened tunica albuginea or cystic formation were observed. These findings did not support either polycystic ovary or hyperthecosis. Serum testosterone (T) levels were extremely high (7.1 ng/ml), while serum androstenedione levels were only slightly above normal range (3.1 ng/ml). Urine 17-KS excretion was slightly increased (6.1 mg/day), while 17-OHCS output was within normal range (4.0 mg/day). Basal serum LH and FSH levels were within normal range and LH pulse frequency was reduced to 1 in 4 hours. Administration of dexamethasone 1 mg/day for 2 days did not suppress circulating T and free T levels but lowered serum cortisol concentration and urine excretion of 17-OHCS. Blood glucose and insulin levels were within normal limits and their responses to oral glucose administration were normal. Abdominal and pelvic ultrasonography and computed tomography as well as adrenal scintigraphy did not reveal any tumorous lesions in bilateral adrenals and ovaries. Administration of GnRH agonist, Buserelin 900 micrograms/day, suppressed circulating T concentrations to 0.7 ng/ml in 8 days, while it had no significant effects on DHEA and DHEA-S levels. After 16 weeks of Buserelin administration, ovulation was successfully induced by hMG administration. Cyclic estrogen and gestagen replacement therapy by Kaufmann's schedule for 2 cycles also suppressed serum T levels to normal, female range. Thus, the present case represents non-neoplastic, non-PCO, ovarian hypertestosteronism which responded well both to GnRH agonist and estrogen and gestagen replacement therapy in terms of lowering circulating T levels.

Adult↗
PubMed1992

Effect of tetrakis-mu-3,5-diisopropylsalicylatodiaquodicopper(II) on the status of reduced glutathione in freshly isolated hepatocytes.

Effects of different concentrations of tetrakis-mu-3,5-diisopropylsalicylatodiaquodicopper(II) (Cu(II)2(3,5-DIPS)4(H2O2)2) on the reduced status of glutathione (GSH), the major nonprotein thiol in tissues, were investigated using freshly isolated hepatocytes. Cu(II)2(3,5-DIPS)4 below 100 microM did not have any significant effects on either the GSH content or viability of the hepatocytes, but at 150-250 microM it decreased both parameters after 1 h of incubation. The decrease in cellular GSH was not followed by an increase in the oxidized form of GSH (GSSG) in the cell suspension. The addition of deferoxamine with Cu(II)2(3,5-DIPS)4 to the hepatocyte suspension prevented depletion in GSH content and loss of cell viability by Cu(II)2(3,5-DIPS)4. Both GSH depletion and loss of cell viability were found to be Cu(II)2(3,5-DIPS)4 dose dependent. From these results, it appears that Cu(II)2(3,5-DIPS)4 penetrated the cell membrane and acted by decreasing the GSH level by forming a copper-glutathione complex.

Animals↗
PubMed1992

N-nitrosodialkylamine dealkylation in reconstituted systems containing cytochrome P-450 purified from phenobarbital- and beta-naphthoflavone-treated rats.

Five cytochrome P-450 forms were purified from livers of rats pretreated with phenobarbital (PB) or beta-naphthoflavone (BNF), and the oxidative dealkylation of N-nitrosodialkylamines by the reconstituted cytochrome P-450 systems was measured. PB-II (P450IIB1) showed very high N-nitrosomethybutylamine (NMBA) debutylase activity, high NMBA demethylase activity and high N-nitrosomethyl-benzylamine (NMBeA) debenzylase activity, suggesting that the increase following PB treatment in hepatic microsomal NMBA debutylation and NMBeA debenzylation was due to the induction of PB-II. BNF-H (P450IA2) showed very high NMBA debutylase and high NMBeA debenzylase activities, and BNF-L (P450IA1) showed NMBA debutylase and high NMBeA debenzylase activities. These results suggested that the increase by BNF pretreatment in hepatic microsomal NMBA debutylation was due mainly to the induction of BNF-H and in some part to that of BNF-L. PB-II also showed very high dealkylation activity of lipophilic N-nitrosodialkylamines with long alkyl moieties. On the other hand, BNF-H dealkylated N-nitrosodipropylamine (NDPA), N-nitrosomethylbutylamine (NMBA) and N-nitrosoethylbutylamine (NEBA) at higher rates than N-nitrosodibutylamine (NDBA). BNF-L dealkylated NEBA at higher rates than NMBeA and NDBA. These results reveal that substrate specificity of each cytochrome P-450 form in N-nitrosodialkylamine metabolism is different from each other and several forms of cytochrome P-450 support each N-nitrosamine dealkylase activity in mammalians.

Animals↗
PubMed1992

Indium inhibits gap junctional communication between rat hepatocytes in primary culture.

The effect of indium on gap junctional communication was investigated in primary cultured rat hepatocytes. Treatment of hepatocytes with indium chloride at concentrations of 100 microM to 1 mM for 2 h resulted in dose-dependent inhibition of gap junctional communication between hepatocytes. The effect of indium on hepatocytes was also evaluated using two indices for cell viability: lactate dehydrogenase (LDH) leakage and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction. Indium did not cause any increase in LDH leakage from hepatocytes at the above concentrations, but inhibition of MTT reduction was observed at concentrations above 500 microM. These results suggest that the gap junctions between hepatocytes may be vulnerable sites to indium toxicity.

Animals↗
PubMed1992

Generation of active oxygen species in vitro by the interaction of potassium bromate with rat kidney cell.

Active oxygen species derived from the interaction of potassium bromate (KBrO3), a rat renal carcinogen, with cells from rat kidney and other organs were examined by electron spin resonance spectrometry using the spin trapping agents 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and 2,2,6,6-tetramethylpiperidine (TEMP). DMPO-OH, an indicator of hydroxyl radical production, was generated from KBrO3 by kidney cells or homogenate, but not by liver preparations and to only a limited extent by heart and brain homogenates, suggesting relative kidney specificity. To assess what chemical components are responsible for production of DMPO-OH, several physiologically related materials were examined. Glucose, saccharose, albumin and methyl linolate were found not to be involved in the KBrO3 reaction, but reduced glutathione and also ferric ions participated to produce DMPO-OH. In addition, DMPO-OH production derived from the reaction of KBrO3 with kidney homogenate was not affected by superoxide dismutase, catalase or hydroxyl radical scavengers such as DMSO or ethanol, but was effectively inhibited by singlet oxygen scavengers such as histidine and NaN3, implying singlet oxygen production. To assess this possibility, TEMP was used as a trapping agent, and TEMPO, derived from singlet oxygen, was found to be produced by the reaction of KBrO3 with homogenates of kidney, but not of liver. Furthermore, singlet oxygen production was confirmed by studies of chemiluminescence using 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2a]pyrazine-3-one. As a control, DMPO-OH was also demonstrated to be produced by a known singlet oxygen source, toluidine blue plus light. The results thus indicate that singlet oxygen is a very probably candidate for the active oxygen species generated in the specific interaction of KBrO3 with rat kidney cells in vitro. This raises the question of its concern with renal carcinogenicity in vivo.

Animals↗