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Biomedical subjects

A Ito

Publications and source records attributed to A Ito.

At least 685 records · Page 38Linked to original sources
PubMed1989

Effect on the action potential of the low power Nd: YAG laser as irradiated directly to the nerve.

The present paper reports our studies of changes in the compound action potential after Nd: YAG laser irradiation of the rat's sciatic nerve. The nerve on one side was exposed and irradiated by Nd: YAG laser directly. The temperature of the irradiated nerve was also measured. 1) Under 100 mW irradiation the compound action potential and the temperature of the surface of the sciatic nerve did not show a detectable change. 2) Under 300 mW irradiation the compound action potential showed an increase in amplitude, and shortening in latency. A negative after-potential appeared within 30 secs of irradiation. The temperature on the sciatic nerve rose by 3 degrees C during the irradiation. 3) Under 500 mW irradiation the compound action potential decreased gradually in amplitude and ultimately disappeared. The temperature on the sciatic nerve reached more than 47 degrees C.

Action Potentials↗
PubMed1989

Two cases of simple bone cyst suspected of being odontogenic tumors.

We report here two cases of simple bone cyst suspected of odontogenic tumors. The first case, a 17-year-old female, was introduced to our department by a dental practitioner because of a large radiographic defect of the bone. The patient had no subjective symptoms. The defect extended between 3 and the ascending ramus, and had multilocular radiolucency associated with bone expansion. The Marsupialization and curettage of the defect were performed. One year after the surgery, the defect was filled with new bone. The second case, a 14-year-old male, complained of occlusal pain in the anterior mandible. Irregular and unilocular radiolucency was seen radiographically in 4 + 2. The biopsy suggested an ossifying fibroma. Extirpation and curettage of the lesion were performed. Ten months after the surgery, the bone expansion disappeared.

Adolescent↗
PubMed1989

[Pathological features and treatment of ulcerative lesions of the duodenum associated with Crohn's disease].

Among a total of 22 patients with Crohn's disease, eight patients with duodenal ulcerative lesions were investigated for pathological features and treatment. All duodenal ulcerative lesions of the eight patients were difficult to be distinguished morphologically from peptic duodenal ulcers at the beginning. But during the course of observation six of eight lesions revealed different pathological features from peptic duodenal ulcers: One showed highly edematous mucosa. Four granular mucosa, and another one longitudinal ulcers and cobblestone appearance. Gastric analysis of these patients showed 6.6 +/- 4.0 mEq/L of BAO and 21.3 +/- 3.4 mEq/L of MAO which was comparable to high acidity of peptic duodenal ulcers. Effectiveness of administration of anti-peptic ulcer drugs only and both anti-peptic ulcer drugs plus drugs against Crohn's disease were 40.0% and 57.1%, respectively. Two patients underwent distal partial gastrectomy. Recurrence was not observed. In conclusion, high acidity would be a cause of duodenal ulcerative lesions associated with Crohn's disease, and the pathological features of them would be affected by Crohn's disease itself. Anti-peptic ulcer drugs should to be administered as well as drugs against Crohn's disease. The method which has hypoacidity effect should be selected in operative therapy to such patients as to have stenosis of the duodenum.

Adolescent↗
PubMed1989

[Effect of exercise on urate excretion].

Bidirectional renal urate transport was studied in normal male subjects, aged 21-26 yr. They performed a exhaustive running on treadmill for about 10 mins, after oral intake of each medicine. The used medicines were probenecid inhibited presecretory reabsorption, pyrazinamide inhibited tubular secretion and benzbromarone inhibited postsecretory reabsorption. The results were as follows: 1) Glomerular filtration rate decreased only 3 min after exercise, compared with resting level. 2) Presecretory reabsorption rate did not change substantially after exercise, compared with resting level. 3) Tubular secretion rate markedly decreased at 30 min and 1 hour after exercise, compared with resting level. 4) Postsecretory reabsorption rate changed as well as changes in tubular secretion rates.

Adult↗
PubMed1988

Molecular cloning of a cDNA for rat liver monoamine oxidase B.

The cDNA for rat monoamine oxidase B mRNA was isolated from liver cDNA library in lambda gt11 using specific antibody and oligonucleotide probes derived from FAD-containing peptide of the enzyme. The primary structure of the protein, deduced from the nucleotide sequence, consisted of 520 amino acid residues and its molecular weight was calculated to be 58.4 kD which is in good agreement with that of the in vitro-synthesized peptide. FAD-binding site is located in the carboxy-terminal region. There is no typical structural feature common to the targeting signals for mitochondria, the periodic distribution of basic amino acids spaced by several uncharged residues, at its amino-terminal region. This region has an uninterrupted stretch of 14 hydrophobic residues.

Amino Acid Sequence↗
PubMed1988

Evidence that human rheumatoid synovial matrix metalloproteinase 3 is an endogenous activator of procollagenase.

The treatment of crude culture medium from human rheumatoid synovial cells with 4-aminophenylmercuric acetate (APMA) or trypsin results in the activation of procollagenase. This process was shown to be dependent on the presence of matrix metalloproteinase 3 (MMP-3). MMP-3 can directly activate procollagenase without changing the apparent molecular weight of procollagenase. This activity was accelerated in the presence of APMA. We propose that MMP-3 plays an important role in connective tissue destruction through the activation of procollagenase in addition to its direct action on components of the extracellular matrix.

Arthritis, Rheumatoid↗
PubMed1988

Human recombinant interleukin-1 alpha-mediated stimulation of procollagenase production and suppression of biosynthesis of tissue inhibitor of metalloproteinases in rabbit uterine cervical fibroblasts.

Influence of human recombinant interleukin-1 (hrIL-1) on collagen metabolism was investigated with rabbit uterine cervical fibroblasts. Enzyme-linked immunosorbent assays for collagenase and tissue inhibitor of metalloproteinases (TIMP) indicated that hrIL-1 participates in both stimulation of procollagenase production and suppression of TIMP synthesis by uterine cervical cells. IL-1 did not modulate collagen synthesis. In addition, the sensitivity to IL-1 of uterine cervix from ovariectomized rabbits was augmented by estradiol-17 beta treatment. Thus it is proposed that IL-1 accelerates collagenolysis in the cervical tissue and its effect on uterine cervix is hormonally regulated.

Animals↗
PubMed1988

Increase of estrogen receptor level by thyroxine in estrogen dependent pituitary tumor (MtT/F84) in rats.

A rat transplantable pituitary tumor, MtT/F84, grows much faster in E2 treated rats than in normal females, but is much retarded in thyroidectomized rats. Triiodothyronine (T3) administration in a drinking water increased the tumor growth by the dose dependent manner. The tumor contained both estrogen receptor (ER) and T3 receptor. ER levels both in the nuclei and cytosols elevated 2 to 3 times by the T3 administration compared to those of control. E2 administration promotes the growth of MtT/F84 through elevation of nuclear ER level. T3 may directly elevate cellular ER level and thus it may enhance estrogenic actions including the tumor growth.

Animals↗
PubMed1988

Inhibition of cytochrome c oxidase and hemolysis caused by lysosphingolipids.

Galactosylsphingosine, glucosylsphingosine and sphingosine all inhibited cytochrome c oxidase activity in mitochondria from rat liver; more than 50% inhibition was caused by 5 microM lipid (0.1 mumol/mg mitochondrial protein). However, these lysosphingolipids did not suppress the activity of purified cytochrome c oxidase. When the enzyme was "reconstituted" with phosphatidylcholine, the lysosphingolipids clearly inhibited the activity. On the other hand, galactosylsphingosine, glucosylsphingosine and sphingosine all hemolyzed erythrocytes, indicating that lysosphingolipids can disrupt the membrane. Thus, it appears that the inhibition of cytochrome c oxidase, a membrane-bound enzyme in mitochondria, is due to perturbation of the environment of the enzyme and that the primary attacking site of the lysosphingolipids is the membrane. Because the potency to inhibit cytochrome c oxidase and to hemolyze erythrocytes did not differ among these lysosphingolipids and because galactosylceramide caused neither inhibition of cytochrome c oxidase nor hemolysis, the free amino group in the lysosphingolipids seems to be essential to give the effects. In addition, both inhibition of cytochrome c oxidase and hemolysis caused by lysosphingolipids were completely abolished by albumin, suggesting that toxic effects of lysosphingolipids may not be apparent in blood.

Animals↗
PubMed1988

Spontaneous production of interleukin-1-like factors from pregnant rabbit uterine cervix.

Uterine cervical explants in culture from pregnant rabbits at term spontaneously synthesized and secreted three species of interleukin-1-like factors in culture medium. The addition of the exogenous mitogen lipopolysaccharide to the culture system induced further release of these factors. However, these phenomena were not observed with explants from nonpregnant cervices. The molecular weights of these factors estimated by gel filtration were approximately 49, 22, and 12 kDa, respectively, and were identical to those of interleukin-1 from rabbit macrophages and polymorphonuclear leukocytes. These results indicate that interleukin-1-like factors are involved in cervical ripening and dilatation, especially in the acceleration of collagenase production, at term.

Animals↗