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Biomedical subjects

Y Ohtsuka

Publications and source records attributed to Y Ohtsuka.

At least 181 records · Page 10Linked to original sources
PubMed1993

[Causes of idiopathic interstitial pneumonia (IIP): inhaled dust as environmental problem].

We have reported that patients with IIP can be roentgenologically grouped into two subtypes, typical (type-A) and atypical (type-B). The characteristic feature of X-ray findings in type-A is marked restriction of the lung, especially of the lower lobes, and in type-B is emphysematous changes in addition to the findings of type-A. In this study, to clarify the pathological findings of these two subtypes, 60 IIP patients in whom open lung biopsy and/or autopsy were performed were studied both clinically and pathologically. The following results were obtained. 1) Pathological features of type-A were alveolitis, marked restriction of the lung secondary to atelectasis and fibrosis of lung parenchyma, and honeycombing as a result of remodeling. 2) The features of type-B were intra-alveolar organization and secondary emphysema after intra-alveolar inflammation (pneumonia) overlapped the pathological changes of type-A. 3) Patients with a history of dust inhalation were much more frequently observed in type-B than in type-A (p < 0.01). These results suggest that inhaled dust may be a causative factor of IIP, especially of type-B.

Dust↗
PubMed1993

[Detection of HIV-1 proviral DNA and RNA in serum from HIV-1 sero-positive hemophiliacs by polymerase chain reaction].

We amplified HIV-1 proviral DNA and RNA in serum by DNA-PCR and RT-RCR in 20 HIV-1 seropositive hemophiliacs asymptomatic carrier (AC): 10, AIDS-related complex (ARC):8, AIDS:2). HIV-1 DNA sequences were identified in 44 (93.6%) of 47 specimens. 23 (92.0%) of 25 samples in AC, 13 (100%) of 13 in ARC, 8 (88.8%) of 9 in AIDS had detectable bands. RNA sequences were identified in 36 (85.7%) of 42 specimens. 17 (70.8%) of 24 specimens in AC, 13 (100%) of 13 in ARC, 5 (100%) of 5 in AIDS cases had detectable bands. RNA in serum was strongly positive in two asymptomatic patients with progression to AIDS who showed no changes of other markers. Patients with almost normal CD4 cell counts had trace amounts of proviral DNA and RNA in serum. RNA in serum is the parameter most predictive of progression to AIDS and is detectable earlier than other parameters. From the results of RT-PCR before and after seroconversion, the serum of one patient was shown to be positive at 5 months before seroconversion.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Improvement of ischemia/reperfusion-induced contractile dysfunction of perfused hearts by class Ic antiarrhythmic agents.

The present study was undertaken to determine whether class Ic antiarrhythmic agents, flecainide and pilsicainide, improve ischemia/reperfusion-induced cardiac contractile dysfunction. Isolated rat hearts were subjected to a 35-min global ischemia, followed by a 60-min reperfusion, and the functional and metabolic consequences were examined. Ischemia/reperfusion resulted in no recovery of contractile function and a sustained rise in left ventricular and diastolic pressure of the perfused heart during reperfusion. The ischemia/reperfusion also induced increases in tissue sodium and calcium levels, decreases in potassium and magnesium ion contents and the release of creatine kinase and purine nucleosides and bases (ATP metabolites) from the heart, suggesting a pronounced change in cardiac transmembrane flux of ions, substrates and macromolecules. Treatment of the perfused heart with either 5 to 50 microM flecainide or 10 to 100 microM pilsicainide during preischemia resulted in diminishing the postischemic contractile dysfunction; suppressing the changes in tissue sodium, potassium, calcium and magnesium contents; and attenuating the release of creatine kinase and ATP metabolites in a concentration-dependent manner. Tissue sodium accumulation and potassium loss were also observed at the end of ischemia, which was attenuated by pretreatment with these agents. These results provided evidence that class Ic antiarrhythmic agents are capable of diminishing ischemia/reperfusion-induced contractile dysfunction and tissue ionic disturbance.

Adenosine Triphosphate↗
PubMed1992

Primary and secondary bilateral synchrony in epilepsy: differentiation by estimation of interhemispheric small time differences during short spike-wave activity.

Estimation of interhemispheric small time differences (TDs) during spike-wave bursts in the EEG by coherence and phase analysis is useful for differentiation between primary bilateral synchrony (PBS) and secondary bilateral synchrony (SBS) in epilepsy. Because the previous method via Fast Fourier Transform needed long bursts for reliable analysis, a method using a 2-dimensional autoregressive model was newly developed to enable estimation of TDs even in 1.2 sec bursts, and applied to 19 epileptic patients with apparently bilaterally synchronous spike-wave bursts. At the onsets of bursts, estimated maximal TDs were 5.8 msec or less and inconsistent in leading hemispheres in 10 patients with a clinical diagnosis of idiopathic, cryptogenic or symptomatic generalized epilepsy indicating PBS, while the maximal TDs were 9.3-41.5 msec and consistent in leading in 7 patients with clinically symptomatic partial epilepsy and also in two with idiopathic and symptomatic generalized epilepsy suggesting SBS. Among 8 patients with bursts which suggested SBS and long enough for evaluation of intra-burst TD variation, TDs tended to disappear in the middle to end parts of the bursts in 5 cases, but not in the other 3, suggesting 2 different pathophysiological mechanisms in SBS.

Action Potentials↗
PubMed1992

Effect of insulin on impaired antioxidant activities in aortic endothelial cells from diabetic rabbits.

The defense system of aortic endothelial cells against oxidative stress was studied in alloxan-induced diabetic rabbits, and the effect of insulin on the antioxidant activities was estimated. Endothelial cells were prepared from 10 diabetic rabbits, 18 diabetic rabbits treated with insulin, and 10 age-matched controls after 17 days of diabetes. These cells were used for the estimation of glutathione (GSH) levels and its related enzyme activities. The antioxidant activities in these endothelial cells from diabetic rabbits were compared with those from control subjects. The concentration of GSH decreased in diabetic rabbits (1.6 +/- 0.2 nmol/mg protein [mean +/- SD] v 3.7 +/- 0.6 nmol/mg protein). Decreases in the activities of Cu, Zn-superoxide dismutase (Cu,Zn-SOD) (62.7 +/- 11.0 U/mg protein v 172.9 +/- 20.2 U/mg protein), catalase (7.6 +/- 2.1 U/mg protein v 12.3 +/- 3.2 U/mg protein), and GSH peroxidase (134.0 +/- 27.0 mU/mg protein v 179.1 +/- 26.2 mU/mg protein) were observed. The activities of other GSH-related enzymes such as GSH S-transferase or GSH reductase did not change in endothelial cells from diabetic rabbits. Most of these antioxidant activities were prevented when diabetic rabbits were treated with insulin (1 to 2 U/kg/d). These antioxidant activities were also determined in the diabetic liver and kidney. Similar decreases in the cellular defense activities and prevention of the decrease in activities by insulin were observed in the diabetic liver, while these antioxidant enzyme activities in the kidney were resistant to diabetic conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Biological activity of chemically synthesized core sugar linked lipid A analog, heptose-(alpha 1----5)-2-keto-3-deoxyoctonic acid-(alpha 2----6)-2,3-diacyloxyacylglucosamine-4-phosphate.

The mitogenicity, lethal toxicity and antitumor activity against Meth A fibrosarcoma and the induction of tumor necrosis factor (TNF) of chemically synthesized compounds designated as A-103, 2,3-diacyloxyacylglucosamine-4-phosphate (GlcN-4-P), and A-503), heptose-(alpha 1----5)-2-keto-3-deoxyoctonic acid (KDO)-linked GlcN-4-P (A-103), were determined. Compound A-103 induced significant incorporation of [3H]thymidine of C57BL/6 mice at 25-100 micrograms/ml, and A-503 showed the highest incorporation of [3H]thymidine at 100 micrograms/ml. The mitogenicity of A-503 exhibited a lower activity than of A-103. Compound A-503 showed no lethality at high doses of 25 and 50 micrograms/mouse in C57BL/6 mice loaded with D-galactosamine, whereas A-103 caused the death of one of three mice at a dose of 50 micrograms/mouse. Although, the two compounds with or without muramyl dipeptide showed weak antitumor activity against Meth A fibrosarcoma in BALB/c mice, but there were no remarkable differences between the compounds on antitumor activity. Peritoneal macrophages, stimulated with A-103 or A-503 caused no production of TNF which induces L929 cell lysis in vitro. These findings indicate that the addition of heptose and KDO to GlcN-4-P seems not to affect mitogenic activity, lethal toxicity, antitumor activity and TNF-production of the GlcN-4-P compound (A-103).

Animals↗
PubMed1992

Chiba Spinal System in the operative management of scoliosis.

The Chiba Spinal System was developed for three-dimensional correction of scoliosis. The system consists of a 7-mm diameter smooth solid rod, closed and open hooks, and specially designed conical sleeves. The rod does not have ratchets or threads, thus minimizing stress concentrations. The closed and open hooks are attached to the rod using the conical sleeves. The sleeves have longitudinal slits permitting compression during insertion. The outrigger system with a torque wrench is used to correct the deformity in the frontal plane. When correcting lordosis with vertebral rotation, a sagittal correction device may be used. Fifty-two patients with idiopathic scoliosis were operated on with this system from 1986 through 1989. The average correction of the scoliosis was 58%. For the 21 patients with thoracic lordosis less than 0 degrees, the mean preoperative lordosis was -8 degrees, which was corrected to +7 degrees. The mean correction of the vertebral rotation was 24%. Two patients complained of paresthesia of the thoracic region after operation, but this disappeared within 2 weeks. In 32 patients with more than 2 years' follow-up, the mean loss of correction was 3 degrees. One case with instrumentation failure was noted.

Adolescent↗
PubMed1992

[Abnormal amino acid metabolism in diabetes mellitus].

Abnormal amino acid metabolism is sometimes observed among patients with diabetes mellitus. Of many amino acids, alanine and branched-chain amino acids such as valine, leucine, isoleucine show characteristic changes. In diabetic ketoacidosis, plasma concentration of alanine decreases and that of branched-amino acid increases and the oxidation of branched-amino acids is enhanced. Splanchnic amino acid uptake is generally higher in diabetics and this level is partially restored by exercise. Some glycosylated proteins are used to estimate the condition of diabetes mellitus. Increment of urinary glycosylated amino acid excretion is reported in diabetics. Plasma homocysteine, reactive vascular-injuring amino acid, increases in diabetics with nephropathy. Those abnormal amino acid metabolism would be restored after good glycemic control is obtained.

Amino Acids↗
PubMed1992

Naturally occurring Mycobacterium scrofulaceum infection in a laboratory mouse colony.

A contamination with Mycobacterium scrofulaceum was experienced in a colony of BALB/c-nu/nu mice. The contamination was noticed after introduction of C57BL/6 and C57BL/6. Lyt l. 1 strains into facilities that kept the colony. M. scrofulaceum seemed to be spread by oral infestation and cross-contamination of fecal excretions during handling of the mice. The organisms were shed continually or intermittently into feces of weaned nu/+ and nu/nu mice of BALB/c background, and were isolated from the mesenteric lymph nodes and spleen of some of the mice. Some of the bacillus-carrying mice developed serum antibody to M. scrofulaceum of IgG and IgA classes and gave a low degree of hypersensitivity to PPD from M. tuberculosis.

Animals↗
PubMed1991

L-carnitine protection in ammonia intoxication. Effect of aminocarnitine on carnitine-dependent metabolism and acute ammonia toxicity.

Intraperitoneal administration of L-carnitine (16 mmol/kg) was reported by O'Connor et al. (FEBS Lett 166: 331-334, 1984) to fully protect mice from ammonium acetate given at a dose that kills 100% of untreated controls. Other investigators either have failed to observe protection by L-carnitine or have attributed the increased survival to a nonspecific "osmoprotective effect" of quaternary ammonium compounds. In the present studies we have confirmed the protective effect of L-carnitine in acute ammonia intoxication and have shown that D-carnitine and deoxycarnitine, close structural analogs of L-carnitine, are without protective effect. Although D-carnitine and deoxycarnitine do not support L-carnitine-dependent metabolisms, they are transported into tissues and their solutions are osmotically identical to those of L-carnitine; lack of protection by D-carnitine and deoxycarnitine suggests that metabolic rather than nonspecific osmotic effects account for L-carnitine-mediated protection. Further supporting the importance of L-carnitine-dependent metabolisms, we found that mice exhibited increased sensitivity to ammonium acetate when pretreated with DL-aminocarnitine, acetyl-DL-aminocarnitine or palmitoyl-DL-aminocarnitine, potent inhibitors of the carnitine acyltransferases. Interestingly, intraperitoneal injection of hyperosmotic solutions of sodium chloride or sucrose did afford significant protection against subsequently administered ammonium acetate. This phenomenon, which may be due to interference with ammonium acetate uptake from the peritoneal cavity or to reduction of cerebral edema by increased plasma osmolarity, apparently does not play a major role in L-carnitine-mediated protection since, as noted, hyperosmotic D-carnitine and deoxycarnitine solutions were not protective.

Acetates↗
PubMed1991

Adrenoleukodystrophy: a correlation between saturated very long-chain fatty acids in mononuclear cells and phenotype.

Saturated very long-chain fatty acids in erythrocyte membranes, blood plasma, and mononuclear cells were studied in 4 patients with childhood-adolescent adrenoleukodystrophy and 4 patients with adult adrenoleukodystrophy and 19 normal control subjects by using high-performance liquid chromatography. Ratios of C26:0 to C22:0 in mononuclear cells, erythrocyte membranes, and blood plasma in patients with childhood-adolescent and adult adrenoleukodystrophy were significantly higher than in normal control subjects. Furthermore, ratios of C26:0 to C22:0 in mononuclear cells were significantly higher in patients with childhood-adolescent adrenoleukodystrophy than in patients with adult adrenoleukodystrophy, whereas there was no significant difference in the ratios in erythrocyte membranes and blood plasma between the two groups of patients with adrenoleukodystrophy. These results suggest that there is a correlation between phenotype and ratio of C26:0 to C22:0 within mononuclear cells in patients with adrenoleukodystrophy.

Adolescent↗
PubMed1991

Combined effects of synthetic lipid A analogs and muramyl dipeptide on antitumor activity against Meth A fibrosarcoma in mice.

Combined effects of chemically synthesized lipid A analogs, the compound A-171 (acylglucosamine-4-phosphate with (R)-3-hydroxytetradecanoyl and (R)-3-hydroxytetradecanoyloxy]tetradecanoyl group at the C-2 and C-3 positions), or the compound A-172 (with (R)-3-hydroxytetradecanoyloxy]tetradecanoyl and (R)-3-tetradecanoyloxytetradecanoyl group at the C-2 and C-3 positions), and muramyl dipeptide (MDP) on antitumor activity against Meth A fibrosarcoma, were examined. Meth A fibrosarcoma cells (5 X 10(5)) were inoculated intradermally into BALB/c mice on day 0, compound A-172 and/or MDP were administered intravenously (i.v.) on day 7. Although the antitumor activity by single i.v. injection of A-172 (50 micrograms/mouse) with MDP (10 micrograms) was weaker than that of 50 micrograms of synthetic lipid A analogs (506), or 10 micrograms of bacterial lipopolysaccharide (LPS) with MDP, A-172 alone and with MDP exhibited tumor inhibition rates of 49.0 and 70.6%, respectively. When A-171 (50 micrograms) with MDP (10 micrograms) was administered i.v. twice (days 7 and 10) into mice inoculated Meth A fibrosarcoma, two of five mice caused complete tumor regression. Furthermore, L929 cell lysis by the combination of A-171, A-172 with MDP was higher than that by the analogs or MDP alone, suggesting that the lipid A analogs of monosaccharide type as well as LPS are able to enhance the production of tumor necrosis factor in the presence of MDP.

Acetylmuramyl-Alanyl-Isoglutamine↗