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Biomedical subjects

T Sakaguchi

Publications and source records attributed to T Sakaguchi.

At least 307 records · Page 17Linked to original sources
PubMed1986

Changes in glycolytic intermediates in rat erythrocytes during exposure to simulated high altitude.

Regulatory mechanisms of erythrocyte glycolysis and 2,3-diphosphoglycerate (2,3DPG) metabolism under hypoxia were studied in rats exposed to a simulated altitude of 18,000 ft (5,486 m) for 5 d. Changes in erythrocyte glycolytic intermediates were determined by enzymatic analysis. Marked alterations of glycolytic intermediates were found during 1 d of exposure which were quite different from those observed during exposure for 2, 3, and 5 d. Alterations of intermediates seem to be highly correlated with blood pH changes; however, pH alone cannot explain the overall changes in intermediates. Results suggested that overall intermediate changes are the results of the combined effect of alterations of cellular pH and hemoglobin desaturation. Increased 2,3DPG at initial stages of exposure (within 1 d) may be caused mainly by the increased cellular pH; sustained elevation of 2,3DPG at later stages could be attributed to the relief of product inhibition of diphosphoglycerate mutase by deoxygenation.

2,3-Diphosphoglycerate↗
PubMed1985

Inhibition of gastric motility induced by activation of the hypothalamic paraventricular nucleus.

Electrical stimulation of the paraventricular nucleus depressed the intragastric pressure of adrenalectomized male rats of which gastric movement had been induced by insulin-hypoglycemia. Electrical stimulation to the pituitary stalk produced a similar response in the pressure, but the response was abolished by bilateral lesion of the paraventricular nucleus. These findings allow us to speculate that the paraventricular nucleus is capable of modulating gastric motility, and suggest that the nucleus has a neural connection between the neurohypophysis and the system relevant to visceral function.

Animals↗
PubMed1985

D-glucose anomers in the nucleus of the vagus nerve can depress gastric motility of rats.

The infusion of alpha-,beta-, or equilibrated (alpha: 36%; beta: 64%) D-glucose solution in the vicinity of the nucleus of the vagus nerve decreased gastric motility caused by insulin in rats with bilateral adrenalectomy. This effect was not reproduced after vagotomy at the cervical level. Of the 3 forms of D-glucose solution the effect of beta-D-glucose was greatest. The infusion of isotonic NaCl, however, produced no change in the motility. These results suggest that blood beta-D-glucose may predominantly activate a brain mechanism which vagally controls gastric motility at the medullary level.

Animals↗
PubMed1985

Total hemiatrophy. Association with localized scleroderma, Schönlein-Henoch nephritis, and paroxysmal nocturnal hemoglobinuria.

In the clinical course of a patient with progressive facial hemiatrophy associated with ipsilateral body atrophy (total hemiatrophy), signs and symptoms of localized scleroderma were noted. The patient subsequently was found to have Schönlein-Henoch purpura with renal involvement and, later, paroxysmal nocturnal hemoglobinuria. To our knowledge, such an association has not been reported before.

Adult↗
PubMed1985

[Effects of pentoxifylline on 5-hydroxytryptamine in the mouse brain].

Effects of combined administration of pentoxifylline (PTX) and precursors of 5-hydroxytryptamine (5-HT) on behavior and cerebral contents of 5-hydroxytryptophan (5-HTP), 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) were examined in mice. The intraperitoneal administration of PTX at 100 mg/kg to mice pretreated with pargyline (100 mg/kg, i.p.) significantly increased the frequency of head twitches induced by 5-HTP (25 mg/kg, i.p.), and the effect of PTX was approximately 2 times more potent than that of other methylxanthines. In these mice, the cerebral contents of 5-HTP, 5-HT and 5-HIAA were also elevated significantly. However, PTX itself had no effect to induce head twitch response or to increase the contents of the indoles in mice. When administered in combination with tryptophan (100 mg/kg, i.v.) to pargyline-pretreated mice, PTX (100 mg/kg, i.p.) did not affect the contents of the indoles in the brain. These results suggest that PTX may have an effect to promote transport of exogenous 5-HTP into the neurons, besides the 5-HT turnover-increasing effect common to methylxanthine derivatives.

5-Hydroxytryptophan↗
PubMed1985

[Serum levels and clinical evaluation of CA 19-9 in various diseases].

We evaluated the clinical significance of serum CA 19-9 in various cancers, benign diseases and healthy controls. The percentage of positive cases for CA 19-9 (higher than 37 U/ml) was 83% in pancreas cancer, 78% in biliary tract cancer and 75% in urinary tract cancer. Benign diseases showed a low frequency of positive cases for CA 19-9, and their serum levels of CA 19-9 were low. Benign diseases with high serum levels of CA 19-9 were rarely seen, but they were easy to differentiate from malignant tumors by simultaneous examination of other tumor markers. In cancer patients with high serum levels of CA 19-9, CA 19-9 showed a weak positive correlation to CEA and ferritin.

Antigens, Neoplasm↗
PubMed1985

[Percutaneous puncture with a robot].

The great advances of microelectronics and mechatoronics are gradually being applied into medicine. In percutaneous nephrostomy, it is possible to calculate the depth and direction of the needle by using a computer if one point on the surface of the skin and another point in the dilated renal pelvis are determined. When a robot is moved according to the computed results, a percutaneous operation is performed fast and exactly. We established a system through which a percutaneous operation is automatically performed. The following technical difficulties of this system were overcome. The coordinates of the two points for a percutaneous operation were input into a computer through a CRT display. Machine language of the Z-80 CPU was used for the programming. A program package enabling fast calculation was developed. The shape of the robot was calculated and shown on the CRT display before it showed any movements.

Automation↗
PubMed1984

Changes in projection from locus coeruleus to lateral geniculate nucleus following ablation of visual cortex in adult rats.

The visual cortex of adult rats was unilaterally ablated. A histofluorescence study revealed an increase of noradrenergic terminals in the lateral geniculate nucleus (LGN) ipsilateral to the decortication, confirming the previous report. Corresponding to this, the frequency for encountering neurons in the locus coeruleus (LC) activated antidromically from the LGN was increased. We suggest that LC neurons whose axon terminals were damaged by ablation of the visual cortex formed new axons or axon collaterals (pruning effect) in the LGN, thus contributing, at least partly, to the increase of noradrenergic terminals therein.

Animals↗
PubMed1984

Increased projection from the locus coeruleus to the lateral geniculate nucleus and visual cortex in young adult rats following unilateral enucleation.

Rats of 30 and 60 days of age were subjected to removal of one eye, and electrophysiological experiments were carried out to see if the density of the projection from the locus coeruleus to the visual centers such as the lateral geniculate nucleus and visual cortex increased. In rats with an eye removed at 30 days, the projection of locus coeruleus neurons increased in the lateral geniculate nucleus contralateral and visual cortex ipsilateral to the removed eye, whereas rats with an eye removed at 60 days did not show any notable change in the density of the projection.

Age Factors↗
PubMed1984

Different effects of D-glucose anomers on enhanced secretion of gastric acid in rat.

The injection of alpha-, beta-, or equilibrated (alpha: 36%, beta: 64%) D-glucose solution into the cranial side of the carotid artery decreased gastric acid output caused by insulin in rats with bilateral adrenalectomy. This effect was not reproduced after vagotomy at the cervical level. Of the 3 forms of D-glucose solution the effect of beta-D-glucose was greatest. The injection of isotonic NaCl solution, however, produced no change in acid output. These results suggest that blood beta-D-glucose may play a predominant role in activating a brain mechanism which controls gastric acid secretion via the vagus nerve.

Adrenalectomy↗
PubMed1984

Fluorometric high-performance liquid chromatography of 9-aminophenanthrene-derivatized free fatty acids.

The application of 9-aminophenanthrene (9-AP), a fluorescence-labeling reagent for free fatty acids (FFA), was examined. 9-AP dissolved in benzene was added to a benzene solution of FFA chlorides derived from FFA and oxalyl chloride. The mixture was allowed to react for 45 min at 70 degrees C. By the method, 9-AP-tagged FFA with a strong fluorescence was formed. The materials thus obtained have a lambda max at around 303 nm for excitation and 376 nm for emission. By using this derivatization method, recoveries were measured for seven kinds of FFA added to 0.5 ml of healthy human serum. Significant recoveries ranging from 96 to 107% (coefficient of variation 1.4-5.0%) were obtained for each FFA. The proposed method was clinically applied to the determination of FFA in 0.5 ml of healthy human serum, and almost satisfactory results were obtained. Detection limits of FFA by this derivatization method were 10 pmol for C14:0, C16:0, C16:1, C18:1 and C18:2, and 15 pmol for C18:0 and C20:4. As a quantitative measurement of FFA, gas chromatography and high-performance liquid chromatography with fluorescence detection, which have been routinely used, were chosen for comparison with the present method.

Chromatography, High Pressure Liquid↗
PubMed1984

Inhibition of gastric acid secretion elicited by D-glucose anomers in man.

Acid outputs from the stomach were measured after venous administration of D-glucose and its optical anomers in men with insulin hypoglycemia. A significant decrease in gastric acid output was noted after the administration of 277 mM alpha-D-glucose, 277 mM optically equilibrated D-glucose consisting of 36% alpha-anomer and 64% beta-anomer, or 277 mM beta-D-glucose. The effect of beta-D-glucose was most potent in the three forms of D-glucose. NaCl solution, however, produced no appreciable change in the acid outputs. Our findings suggested that, in humans, beta-D-glucose in the blood may play an important role in the activation of glucose-sensitive mechanisms controlling vagally mediated secretion of gastric acid.

Adult↗