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Biomedical subjects

Y Maki

Publications and source records attributed to Y Maki.

At least 145 records · Page 8Linked to original sources
PubMed1987

Late radiation effects in the mouse brain. A quantitative study on PAS positive deposits.

Mice received whole brain irradiation (250 kV roentgen rays) with single doses ranging from 13 to 25 Gy. PAS positive deposits, microscopically observed in the dorsal part of the ventral thalamic nucleus, were quantitatively scored at different intervals between 20 and 85 weeks after irradiation. A significant dose-dependent inhibition of the formation of these deposits was observed in the irradiated brains.

Animals↗
PubMed1987

Blood pressure changes in spontaneously hypertensive and normotensive rats with neonatal streptozotocin induced type 2 diabetes.

We examined the blood pressure changes in hypertensive and normotensive rats with Type 2 diabetes induced by neonatal streptozotocin (STZ) treatment. STZ was intraperitoneally injected at 2 days of age with the dose of 25, 50 and 75 mg/kg for male spontaneously hypertensive rats (SHR) and with 75, 100, 125 and 150 mg/kg for male normotensive Wistar Kyoto rats (WKY). Blood pressure was measured by indirect tail-cuff method until 12 weeks of age. STZ-treated SHR, of which plasma glucose and glycosylated hemoglobin increased and body weight decreased with the dose of STZ, developed and maintained hypertension, same as did the vehicle-treated control SHR. On the other hand, STZ-treated WKY which developed only mild hyperglycemia lost body weight with the dose of STZ but the blood pressures rose slightly, these changes being correlated with the glycemic levels. The explanation for these differences between SHR and WKY remained to be elucidated.

Animals↗
PubMed1987

[Spontaneous occlusion of a cerebral arteriovenous malformation--report of a case].

The authors report a case of spontaneous occlusion of an arteriovenous malformation (AVM) verified by the second angiography performed 3 days after the initial one. This 65-year-old man had a sudden attack of headache, nausea, and vomiting and was admitted to our hospital next day. On admission, CT scan showed subcortical hemorrhage in the right temporo-parietal area and right CAG showed a small AVM in the same area. The main feeder was a MCA distal branch and the drainer joined Labbe's vein. Repeated angiography 3 days after initial one failed to demonstrate the AVM. Craniotomy was performed and thrombosed AVM was totally removed. Mechanism for disappearance of the malformation is assumed to be acute thrombosis due to intracranial hemorrhage and arteriosclerotic change. The literature is reviewed.

Aged↗
PubMed1987

Contribution of glycemic control to the levels of urinary N-acetyl-beta-D-glucosaminidase (NAG), total protein, beta 2-microglobulin and serum NAG in type 1 (insulin-dependent) diabetes mellitus without macroalbuminuria.

To clarify the significance of the parameters which might indicate the abnormalities in the kidney, urinary N-acetyl-beta-D-glucosaminidase (NAG), urinary total protein (TP), urinary beta 2-microglobulin (beta 2MG) and serum NAG were determined in 61 type 1 diabetics who had neither retinopathy nor macroalbuminuria (negative albuminuria by Albustix), and in 19 age, sex-matched nondiabetic subjects. Urinary NAG, urinary TP and serum NAG levels were significantly elevated in the diabetics compared with the nondiabetic subjects, even though in the diabetics, whose duration of diabetes was not longer than 2.5 years. The relationships between these parameters and glycemic indices at different periods were studied in diabetics. Urinary NAG was correlated the strongest with the mean blood glucose level over the 7 days before the collection of urine (r = 0.47) among the 5 glycemic indices. On the other hand, urinary TP and urinary beta 2MG were correlated the strongest with the urinary glucose at the time of collection of urine (r = 0.77 and r = 0.37, respectively) among the 5 glycemic indices. No correlation of urinary NAG, urinary TP or urinary beta 2MG with stable HbA1 was observed. On the multiple regression analysis, 32% of the changes in urinary NAG, 61% of urinary TP, 19% of urinary beta 2MG and 20% of serum NAG were explained merely by the blood glucose levels, respectively. No relationship was observed among each parameter and duration of diabetes, insulin dose, urinary excretion of C-peptide or lipid levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1986

Spizofurone, a new anti-ulcer agent, increases alkaline secretion in isolated bullfrog duodenal mucosa.

The effect of spizofurone, a new anti-ulcer agent, on alkaline secretion was studied in an isolated sheet of bullfrog (10(-4)-10(-3) M) as well as prostaglandin E2 (PGE2, 10(-8)-10(-5) M) added to the nutrient solution increased alkaline secretion, transmucosal potential difference (PD) and short-circuit current (Isc), in a concentration-dependent manner. The maximum increases in alkaline secretion stimulated by spizofurone and PGE2 were much the same. Spizofurone also showed this effect when added to the secretory solution while PGE2 did not. Treatment with indomethacin partly but significantly inhibited the effect of spizofurone, but did not affect that of PGE2. These results indicate that the increase in alkaline secretion in bullfrog duodenal mucosa seen in the presence of spizofurone is mediated, at least in part, by stimulation of endogenous PGs synthesis.

1-Methyl-3-isobutylxanthine↗
PubMed1986

Electroencephalography in minor head injury in children.

EEG and CT scans of 280 cases of minor head injury in children under 15 years of age were studied. Abnormality on initial EEG was shown in 42.5%. Those who lost consciousness had a higher incidence of abnormality than those who did not, and it was higher between 4 and 13 years of age. The sleep state has much influence on the finding. The patients should be awake or in a light sleep stage. The most frequent abnormality was slow waves, seen predominantly in the occipital regions, and which tended to disappear more easily than the paroxysmal ones. The EEGs became or remained normal in 95%, excluding incompletely followed-up cases. There was no case of post-traumatic epilepsy in our series, but 4 cases of post-traumatic early convulsions, in which the EEGs were variable. CT scan disclosed abnormality in 6%.

Adolescent↗
PubMed1986

A new model of type 2 (non-insulin-dependent) diabetes mellitus in spontaneously hypertensive rats: diabetes induced by neonatal streptozotocin treatment.

This study was designed to develop an animal model of Type 2 (non-insulin-dependent) diabetes with persistent hypertension. Male spontaneously hypertensive rats were treated with 25.0, 37.5, 50.0, 62.5 or 75.0 mg/kg of streptozotocin given intraperitoneally at 2 days of age and maintained for 12 weeks. In the rats which received 50.0 mg/kg or more streptozotocin, overt hyperglycaemia gradually and consistently developed following incomplete recovery from an initial hyperglycaemia. Compared to vehicle-treated controls, body weight gain in these animals did not differ for the first 8 weeks; thereafter, it was slightly but significantly (p less than 0.05) reduced. The animals treated with 25.0 or 37.5 mg/kg streptozotocin developed mild to moderate hyperglycaemia, but their body weight gain was similar to controls. The relationships between streptozotocin dose and metabolic responses (plasma glucose, glycosylated haemoglobin, urinary glucose, food intake, etc.) were clearly demonstrated. Systolic blood pressure rose with progressing age in both controls and streptozotocin-treated rats, irrespective of dosage or metabolic response. This new rat model of Type 2 diabetes associated with persistent hypertension may be useful in studying these combined effects on small and large vessels.

Animals↗
PubMed1986

Quantitative histology of peritumoural low density area associated with glioma on CT; image analyzing study of peritumoural low density area after steroid-osmotherapy.

In this study, an invasive site of the tumour cells was quantitatively investigated in the low density area (LDA) on computerized tomography (CT) after steroid and osmotic drug therapy (SOT) by using a texture image analyzing computer system (TAS). Twenty six patients with gliomas (10 benign, 16 malignant) were applied in this study. According to the effect to reduce the volume of LDA, patients were classified into three groups as follows; good, poor, and failed. The reduction effect of the low density volume was not significantly different between the benign and malignant gliomas. Cells including those with a large nucleus with 6.8-9.1 microns in diameter were not observed in the control group, but they were observed in the adjacent and distant parts from the centre of the enhanced tumour element in the peritumoural LDA with 0.87-0.99 percent of all cells in both the poor and failed groups. But in the good group they were significantly rarely observed in the peritumoural LDA after SOT (p less than 0.05). Furthermore, they were significantly frequently observed in the adjacent part from the centre of the enhanced tumour element in the peritumoural LDA with 0.9 percent of all cells after SOT in the malignant gliomas in comparison with the benign gliomas (p less than 0.05). Conclusively it was suggested that the treatment of glioma with peritumoural LDA on CT must be extended to the adjacent and distant part from the centre of the enhanced tumour element in the peritumoural LDA as well as the treatment of the enhanced tumour mass on CT in the poor and failed groups.

Adolescent↗
PubMed1986

Role of leukotrienes in rat reversed passive Arthus pleurisy and the effect of AA-861, a 5-lipoxygenase inhibitor.

In studies of the role of leukotrienes in inflammatory reactions, the induction of rat reversed passive Arthus pleurisy (a type III allergic reaction) was employed. Increases of exudate volume, vascular permeability, and migration of inflammatory cells in the pleural cavity were observed. The vascular permeability was enhanced biphasically during 0-30 min (early response) and during 3-6 h (late response) after induction of the pleurisy. The infiltration of inflammatory cells, mainly polymorphonuclear leukocytes, into the cavity increased and reached a maximum 6 h after the pleurisy was induced. Leukotriene B4 (LTB4), 5-monohydroxyeicosatetraenoic acid (5-HETE), and slow-reacting substance of anaphylaxis (SRS-A), consisting of LTC4, LTD4 and LTE4, were detected in the exudate by reversed-phase high-performance liquid chromatography during the early response. The contents of LTC4 reached a maximum 10 min after the challenge, followed by a rapid decrease within 1 h. The rise and decay of LTC4 correlated with the increase in vascular permeability during the early phase. AA-861, a 5-lipoxygenase inhibitor, given intrapleurally inhibited the increase in vascular permeability, cell migration, and generation of leukotrienes during the early phase of the pleurisy. These results indicate that products of the 5-lipoxygenase pathway, such as LTC4 and LTB4, may play an important role as chemical mediators in the inflammatory reaction.

Animals↗
PubMed1986

The antiallergic agent amoxanox suppresses SRS-A generation by inhibiting lipoxygenase.

Amoxanox has potent antiallergic activity because it inhibits the release of chemical mediators such as histamine and leukotrienes. We studied the in vitro effect of amoxanox on arachidonic acid metabolism, including the lipoxygenase and cyclooxygenase pathways. Amoxanox inhibited calcium ionophore A23187-induced formation of 5-HETE, LTB4, SRS-A (LTC4, LTD4 and LTE4), and 12-HETE in rat peritoneal resident monocytes. These results indicate that amoxanox inhibits 5- and 12-lipoxygenases. The compound, however, did not affect the formation of TXB2 or 6-keto-PGF1 alpha in guinea pig lung fragments and PGE2 or PGF2 alpha in bovine seminal vesicles, suggesting that it did not inhibit cyclooxygenase. These results show that the antiallergic action of amoxanox is associated, at least in part, with the reduction of leukotrienes due to the inhibition of lipoxygenases.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1986

Regrowth patterns of supratentorial gliomas: estimation from computed tomographic scans.

To clarify the regrowth patterns of benign and malignant gliomas, we chose 27 intervals (between two operations or between an operation and autopsy) from 21 patients with pathologically verified recurrent supratentorial gliomas. Serial computed tomographic (CT) scans of these cases were analyzed to determine the doubling time (Td) calculated from the change in volume of enhanced and low density areas, the enhancement effect graded from 0 to 4 according to the Hounsfield number, and the presence of dissemination and contralateral extension. We studied 5 benign gliomas (including 1 case of radiation necrosis), 8 malignant astrocytomas, and 8 glioblastomas. The Td's of enhanced areas on CT scans of benign gliomas, malignant astrocytomas, and glioblastomas were 937 +/- 66.5 days, 65.1 +/- 29.4 days, and 48.1 +/- 20.9 days, respectively. The Td's of low density areas were 895 +/- 130.6 days, 70.8 +/- 22.2 days, and 50.5 +/- 14.7 days. There was a significant correlation between the Td's of the enhanced and low density areas (0.97). The enhancement effect increased at recurrence in 55% of the cases, with an average increase of 1.1 grades. The increase in enhancement effect at recurrence showed a tendency to become smaller as the tumor's degree of anaplasia increased. Radiotherapy was effective in significantly retarding the growth rate of malignant gliomas, whose Td's were doubled. Although the Td's of both enhanced and low density areas of benign gliomas were significantly longer than those of malignant gliomas, there was no significant difference in the Td's of enhanced areas between malignant astrocytomas and glioblastomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

[Inhibition of the slow-reacting substance of anaphylaxis generation by ubiquinone derivatives].

The slow-reacting substance of anaphylaxis (SRS-A) is generated in lung fragments of the actively sensitized guinea pig by an antigen-antibody reaction. The SRS-A generation in lung fragments was inhibited by its quinonyl acid (QS), and quinonyl-alcohol (QSA) derivatives of ubiquinone from a concentration as low as 10(-7) M. It was of interest that the C10 and C13 side chain length in the 6-position of ubiquinone provided the highest activity. These compounds showed no antagonistic activity towards the contractile response of guinea pig ileum to SRS-A, indicating that the compounds inhibit the biosynthesis of SRS-A.

Anaphylaxis↗
PubMed1986

[Effects of ipriflavone (TC-80, an anti-osteoporotic drug) on acute and chronic pain].

The effects of TC-80 on acute and chronic pain in rats and mice were examined. Single oral administration of TC-80 at 50-300 mg/kg was not analgesic in the phenylquinone writhing, acetic acid writhing, and hot plate tests in mice or the tail flick test in rats. Three-weeks administration of TC-80 in a dose of 100 mg/kg/day, p.o., to rats had no analgesic action in the acetic acid writhing and tail flick tests. When TC-80 was given orally in a dose of 100 mg/kg/day for 3 weeks to rats with adjuvant arthritic chronic pain, analgesic effects were observed 2 weeks after the start of administration in males and in ovariectomized estrone-supplemented females; the effect seen in the females was statistically significant. Changes in the bones of the hind paws were examined radiologically, and synovitis, periosteal new bone formation and bone destruction were examined histopathologically in the females. These variables were improved by treatment with TC-80 for 3 weeks. It is concluded that TC-80 has no analgesic effect, but may inhibit chronic pain by anti-osteoporotic action on bone disease.

Administration, Oral↗
PubMed1986

Estimation of growth fraction with bromodeoxyuridine in human central nervous system tumors.

Twenty-five patients with tumors of the central nervous system received bromodeoxyuridine (BUdR), 200 mg/sq m, by intravenous infusion every 8 hours for 3 days before surgery. Excised tumor specimens were fixed in chilled 70% ethanol, embedded in paraffin, and cut into 6-micron sections. Each section was reacted with monoclonal antibodies against BUdR and stained with immunoperoxidase to identify nuclei that had incorporated BUdR. The growth fraction of each tumor was estimated by calculating the ratio of BUdR-positive nuclei to the total number of tumor cells in three to six microscopic fields in viable areas of the tumor. In seven cases, the tumor doubling time was measured from the serial computerized tomography scans and an attempt was made to estimate the cell cycle time. The growth fractions ranged from 9.1% to 46.5% in malignant gliomas, 2.0% to 6.7% in low-grade gliomas, 11.2% to 43.2% in metastatic brain tumors, 0.8% to 1.9% in pituitary adenomas, 3.9% to 4.6% in acoustic neurinomas, and 6.2% to 8.2% in meningiomas and cerebellar hemangioblastomas. The estimated cell cycle time was 5 to 12 days in most malignant gliomas and brain metastases; however, the actual cell cycle time should be substantially shorter because cell loss was not considered in the calculation. Although the growth fraction appeared to correlate with the biological malignancy of each tumor, the tumor doubling time did not reflect growth potential. It is possible that unpredictable cell loss plays an important role in tumor growth at certain sizes. Therefore, the cell cycle times calculated in this study are considerably overestimated and should be interpreted with caution.

Bromodeoxyuridine↗
PubMed1986

Two new retroviral onc genes, sea and jun.

Avian leukemia virus S13 induces erythroblastosis, granulocytic leukemia, fibrosarcoma, anemia, and endothelial neoplasia. It transforms chick embryo fibroblasts and primitive erythroid cells in culture and is defective in replication. Its onc gene, sea, is expressed as transformation specific env-sea fusion glycoprotein of 155 kDa. Gp155 is proteolytically processed into gp85env and gp70env-sea. The latter shows tyrosine specific protein kinase activity. Avian sarcoma virus 17 induces fibrosarcoma and transforms chick embryo fibroblasts in culture. Its cell derived onc gene, jun, is not related to known onc genes and appears to be expressed as a gag-jun fusion protein of 55 kDa. The amino acid sequence of jun shows homology in its C-terminal region to the C-terminal DNA binding region of the yeast regulatory protein GCN4, suggesting that the jun protein may bind to DNA.

Amino Acid Sequence↗