Phenotypic plasticity of locus coeruleus noradrenergic neurons after transplantation into the dopamine-depleted caudate in the rat.
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Animals↗
Biomedical subjects
T Sakurai
Publications and source records attributed to T Sakurai.
pH and microwave power effects on the electron spin resonance spectra of Rhus vernicifera laccase and Cucumis sativus ascorbate oxidase.
The present study shows that the electron spin resonance (ESR) spectral features of Rhus laccase depend considerably on the pH value of the enzyme solution and the irradiated microwave power. Because of the local protein structure change, the type 1 copper is appreciably autoreduced at alkaline pH as monitored both by the ESR and absorption spectroscopies. In addition, the ESR signal of the type 2 copper, especially its g perpendicular region, becomes prominent at alkaline pH. Protein dissociation from a water or an imidazole group coordinated to the type 2 copper is supposed to be responsible for this behavior. Besides above pH effects, the g perpendicular component of the type 2 copper ESR signal is obscured with rising microwave power level. The power saturation behavior of native laccase and its derivatives reveals that the type 2 copper is more easily saturated than the type 1 copper. Cucumis ascorbate oxidase also exhibits similar behavior upon pH variation and microwave power saturation.
Ascorbate Oxidase↗
Alteration of propranolol pharmacokinetics and pharmacodynamics by quinidine in man.
The effects of quinidine on pharmacokinetics and pharmacodynamics of propranolol were investigated in a double-blind, placebo-controlled design. Healthy subjects of group A (n = 5) and group B (n = 11) were given oral propranolol (dose: group A 10 mg, group B 20 mg) with placebo or propranolol with quinidine (dose: group A 100 mg, group B 200 mg) on separate occasions. Quinidine induced a significant rise in the plasma concentrations of propranolol, and the area under the propranolol concentration-time curves (AUC) was also increased about 3-fold in both groups, indicative of an alteration of propranolol pharmacokinetics. In order to estimate the pharmacodynamic action of the pharmacokinetic interaction, the change in the heart rate during treadmill exercise testing was studied in group A. A significant inhibition of exercise-induced tachycardia was observed after administration of propranolol alone, but in combination with quinidine an even greater suppression was evident. These results indicate that the coadministration of propranolol and quinidine provides not only the potentiation of quinidine action by propranolol, which has been reported, but also the enhancement of propranolol action by quinidine, due to an increased plasma concentration of propranolol.
Adult↗
Protective effect of DM-9384, a novel pyrrolidone derivative, against experimental cerebral anoxia.
The protective effects of DM-9384 [N-(2,6-dimethylphenyl)-2-(2-oxo- 1-pyrrolidinyl) acetamide] against cerebral anoxia were investigated using various animal models. Oral administration of DM-9384 resulted in a significant prolongation of survival time in mice and rats subjected to the normobaric hypoxia; its minimal effective doses were 30 and 10 mg/kg, respectively. A significant protection by this drug against hypobaric hypoxia, histotoxic anoxia and cerebral ischemia also occurred in mice at a dose of 100 mg/kg, p.o. Bifemelane (100-300 mg/kg, p.o.) was protective against these models except for hypobaric hypoxia, and the effects of piracetam, aniracetam and pramiracetam (1000 mg/kg, p.o.) were variable depending on the type of anoxia model used. DM-9384 (100 mg/kg and lower) attenuated the hypolocomotion and the disturbance of cerebral energy metabolism such as a decrease in ATP, an increase in lactate and lactate/pyruvate ratio induced by hypoxia in rats. The spontaneous motor activity, uptake and utilization of brain glucose in normal animals, however, were not influenced by this drug. Based on these results, DM-9384 is characterized as a broad spectrum anti-anoxic drug with negligible CNS depression, and the cerebral protective effect of this drug may be, at least in part, attributable to its ability to improve the cerebral energy metabolic disturbance.
Animals↗
A simple method for mouse embryo cryopreservation in a low toxicity vitrification solution, without appreciable loss of viability.
Mouse morulae were exposed to solutions containing 30-50% of permeable agents (ethylene glycol, glycerol, propylene glycol) in modified phosphate-buffered saline (PB1 medium) at 20 degrees C for 20 min. A high percentage of them developed to expanded blastocysts in culture, after exposure to 30% and 40% ethylene glycol (98 and 84%, respectively), or 30% glycerol (88%). Ethylene glycol and glycerol were diluted to 30 and 40% with PB1 medium or with PB1 containing 30% Ficoll or 30% Ficoll + 0.5 M-sucrose, immersed in liquid nitrogen in straws and warmed in 20 degrees C water. Solutions containing 40% of a permeable agent with Ficoll did not crystallize during cooling or warming. Mouse morulae were exposed to 40% ethylene glycol in PB1 medium containing 30% Ficoll (EF) or PB1 medium + 30% Ficoll + 0.5 M-sucrose (EFS) for 5-20 min at 20 degrees C. EFS solution was non-toxic to the embryos during 5 min of exposure. When embryos, equilibrated in EFS solution for 2 or 5 min at 20 degrees C, were vitrified at -196 degrees C and were warmed rapidly, nearly all embryos developed in culture (97-98%), and 51% developed to live young at term after transfer. This method, which results in virtually no decrease in embryonic viability, may be of practical use for embryo preservation.
Animals↗
Arteriovenous malformation associated with moyamoya disease--case report.
The authors report a case of moyamoya disease accompanied by arteriovenous malformation (AVM). Angiography demonstrated typical moyamoya vessels on the right and early changes of moyamoya disease on the left. A small AVM in the left frontal lobe supplied by a distal branch of the middle cerebral artery (MCA) was also revealed. The AVM was surgically resected simultaneously with contralateral encephaloaponeurotic synangiosis for the moyamoya vessels. One month after surgery, left MCA occlusion at the origin occurred probably due to hemodynamic changes after the resection of the AVM.
Adult↗
Suspected vibration magnitude on the body of chain saw users among National Forest workers in Kyusyu, from 1956 to 1984.
Chain saws were first used in Kyusyu in 1956 for cutting down trees and sawing timber in the national forests. In 1961, some workers complained of symptoms due to the vibrations, but countermeasures were not taken until later. The working system and payment system in those times were different from the systems, today. The magnitudes of the chain saw vibrations were very large and the chain saws were operated for many hours, each day. Workers with VWF (vibration induced white finger) had to continue to operate the chain saws without restriction. Vibration disease is related primarily to the vibration of the tools, but also to the transmission of the vibration to the workers. From the official data on chain saws used in national forests, vibration transmission to the body was determined for workers from 1956 to 1984 by comparing the vibration magnitude on the body during work with modern chain saws and during vibration loading tests with an electrodynamic shaker in the laboratory. The vibrations transmitted to the body in some rule in the observation. If the working posture of chain saw operator was the same as today, the vibration transmission was determined from the tool vibration, tool weight, joint fixation and orientation of the hands and the hands and the arms to the handle (joint elasticity). Older chain saws had 20 to 30 times larger vibration magnitudes than modern chain saws, and were also 2 to 3 times heavier. The vibrations transmitted to the foreheads of earlier workers were approximately the same magnitude as the vibrations at the back of the hands of present workers. Also the daily and annual hours of chain saw use were very long, and there were not sufficient measures to protect from the cold. The vibration in the former days led to more symptoms and lesions than in present times.
Elasticity↗
[Effect of green tea on iron absorption in elderly patients with iron deficiency anemia].
The effect of green tea on iron absorption from tablets containing sodium ferrous citrate was investigated in four elderly patients with iron deficiency anemia and in eleven normal elderly subjects. In both groups, the serum iron level reached a maximum value from 2 to 4 hours after taking iron tablets and returned to the baseline value after 24 hours. No inhibitory effect of green tea on iron absorption was recognized.
Aged↗
Pro-opiomelanocortin gene expression in silent corticotroph-cell adenoma and Cushing's disease.
The silent corticotroph-cell adenoma (SCCA) is characterized by the presence of immunoreactive adrenocorticotropic hormone (ACTH) in the tumor tissue in patients without symptoms of Cushing's disease. To elucidate the pathophysiology of SCCA, the expression of pro-opiomelanocortin (a ACTH precursor) genes was studied in a patient with SCCA and in three patients with Cushing's disease. Pro-opiomelanocortin messenger ribonucleic acid (mRNA) was found in the SCCA tissue to a greater degree than in the adenomas of the patients with Cushing's disease. Northern blot analysis revealed that the size of pro-opiomelanocortin mRNA present in the SCCA tissue was indistinguishable from that in the adenomas associated with Cushing's disease. A ribonuclease mapping study indicated that there were no point mutations in the coding sequence of pro-opiomelanocortin mRNA present in the SCCA tissue. Because of the presence of pro-opiomelanocortin mRNA and immunoreactive ACTH in the adenoma tissue, it is proposed that translation of the mRNA and subsequent accumulation of ACTH precursor occurred in the SCCA. Thus, the absence of Cushing's disease symptoms in this SCCA could not be caused by abnormality in the coding sequence of the pro-opiomelanocortin gene or in ribonucleic acid processing. The occurrence of abnormality at or after the translational steps was strongly suggested.
Adenoma↗
Prolactin gene expression in human growth hormone-secreting pituitary adenomas.
To elucidate the mechanism of hyperprolactinemia often observed in patients with growth hormone (GH)-secreting pituitary adenomas, the presence of immunoreactive prolactin (ir-PRL) and prolactin (PRL) messenger ribonucleic acid (mRNA) in the tumor tissue was examined by immunohistochemistry and cytoplasmic dot hybridization. Hyperprolactinemia was observed in three of 18 patients with GH-secreting adenoma. The tumor tissue was demonstrated to contain ir-PRL in nine patients and PRL mRNA in 13. The presence of ir-PRL in the tumor tissue was always associated with positive PRL mRNA, indicating production of PRL in GH-secreting tumors. Among the three patients with hyperprolactinemia, both ir-PRL and PRL mRNA was revealed in the tumor tissue of one, PRL mRNA but not ir-PRL was detected in the adenoma tissue of another, and neither PRL mRNA nor ir-PRL was found in the tumor tissue of the third. The association of hyperprolactinemia with the presence of both ir-PRL and PRL mRNA or PRL mRNA alone is indicative of PRL production and secretion. However, the absence of ir-PRL and PRL mRNA in the tumor tissue may indicate that hyperprolactinemia is caused by the suppression of PRL inhibitory factor due to hypothalamic dysfunction by the tumor mass. Thus, the study of PRL gene expression and immunohistochemistry in GH-secreting adenomas is valuable to understanding the pathophysiology of pituitary tumors.
Adenoma↗
[Holistic and analytic modes in classification learning of young children].
To examine the factors underlying children's categorization modes (holistic vs. analytic) and ease of classification learning, 5-6 year-olds were given a classification task of schematic faces with two values in each of five dimensions. The tasks varied on the similarity between sample and learning exemplars (high vs. low) and the number of categories to be classified (one vs. two), and could classify either by holistic or analytic mode. The subjects were trained on one of the four tasks and tested the categorization modes after reaching each of three learning criteria (4/4, 8/8, and 8/8 + 8 correct). The results showed that (a) with increasing training trials, the number of subjects who used the analytic mode increased while that who used the holistic mode decreased, (b) the number of subjects who used the analytic mode was greater for the low-similarity than the high-similarity tasks, and (c) the task with two categories was learned faster than that with one category.
Child↗
[Clinical and histological observation of HBV glomerulonephritis treated with interferon-beta].
Hepatitis B virus carriers, a 30-year-old man (case 1) and a 31-year-old man (case 2), associated with nephrotic syndrome were treated with interferon-beta. The nephrotic syndrome did not respond to corticosteroid therapy. Their HBs-Ag, HBe-Ag and HBc-Ab were positive. Renal biopsies revealed membranous glomerulonephritis in case 1 and mixed membranous and proliferative glomerulonephritis in case 2. Direct immunofluorescence studies showed strong granular staining of the GBM with IgG and using sandwich technique with anti-HBe antiserum, granular deposits were seen throughout the GBM. Patients were administrated mainly 3-6 x 10(6) IU/day interferon-beta intravenously for four weeks. After transitory elevation of serum transaminase, HBe-Ag and DNA-polymerase have disappeared with development of HBe-Ab (seroconversion) about six months after the end of interferon-beta administration. Then nephrotic syndrome has recovered in incomplete remission after a year and a half follow-up. The secondary renal biopsy in case 1 showed less intense deposits of HBe-Ag along GBM. These facts suggest that the improvement of proteinuria is associated with the decrease in HBV replication due to interferon therapy.
Adult↗
[Magnetic resonance angiography using a magnetic resonance flow tagging technique].
A direct bolus imaging method, which was developed for flow quantitation, was applied to the cervical regions of four normal volunteers to perform magnetic resonance angiography. A transverse section of 10 mm thickness was selectively excited to tag blood flow in the supraclavicular region and a projected image of the tagged bolus viewed in terms of anteroposterior direction was obtained after the echo time (TE). Like cine magnetic resonance imaging, multiple images representing four to 16 cardiac phases were obtained with repeated excitations. With a relatively long TE, ranging from 50 to 200 msec, we advanced tagged blood farther downstream, so as to elongate the visualized bolus along the vessel. Within the visualized bolus, the outer layer close to the vessel wall, where the blood flow velocity was slow, stretched like long tails behind the central part of the bolus producing arrow-head shapes, and the tails were assumed to represent the vascular structure. Bilateral common carotid and vertebral arteries were visualized in each image size approximately 5 cm obtained at the systolic phase. Since prolonged TE yielded less signal intensity, the bolus was not clearly visualized when TE was longer than 100 msec. The cine display of images with multiple cardiac phases produced good evaluations of dynamic changes of pulsatile flow, and this method is expected to be a useful diagnostic tool which combines the capability of flow quantitation with non-invasive angiography. The accuracy of this method in delineating a stenotic lesion was also evaluated using phantom with steady flow, since it is one of the most important capabilities of a clinically used angiographic method.(ABSTRACT TRUNCATED AT 250 WORDS)
Angiography↗
[Comment on the application of medical decision making].
There are three features in decision making in medicine. Decisions must be made on uncertain diagnostic and therapeutic information, a selected course of action may have an unwanted outcome, and finally, actions can not be retried from the beginning. We often assume that, by ordering a test, we can obtain more information to assist better decision making. It should be pointed out, however, that the test itself may be harmful and/or costly, may cause delay of treatment, and may misguide the decision by giving a false result. The benefit/risk ratio of choosing a test depends on the prior probability of disease, sensitivity and specificity of the test, and the outcome (utilities) of the correct and incorrect diagnosis. By drawing decision trees and making a sensitivity analysis, decision analysis helps to make the balance explicit.
Clinical Laboratory Techniques↗
[Renal pelvic tumor in chronic renal failure: report of a case].
A 44-year-old female was admitted because of gross hematuria six years after beginning hemodialysis for chronic renal failure. There was a past history of hematuria one year before admission. Retrograde pyelography, computed tomographic scan and angiography had been performed, and a probable malignant tumor of left renal pelvis had been found in 1986. We recommended surgery at the time, but she refused treatment and was followed up. On June 22, 1987, the patient had a second attack of gross hematuria resulting in bladder tamponade, and hematuria from the left ureteric orifice was confirmed at cystoscopy. Ultrasound showed left obstructive nephropathy. Left nephrectomy was performed because of the presumptive diagnosis of malignant tumor. The histological diagnosis was transitional cell carcinoma of the left renal pelvis. Two courses of M-VAC (methotiexate, vinblastine, adriamycin and cisplatin) chemotherapy were accordingly given postoperatively. The incidence of renal pelvic tumor and its chemotherapy in patients with chronic renal failure are discussed.
Adult↗
[Essential thrombocythemia transformed to acute myeloblastic leukemia].
A 48-year-old woman was referred to Tohoku University Hospital in November 1981 because of leukocytosis pointed out in a group examination. At that time white blood cell count was 26.8 x 10(3)/microliters with no blasts, platelet count 268.0 x 10(4)/microliters and hemoglobin 11.4 g/dl. Bone marrow aspirates showed marked increase of megakaryocytes (15,900/microliters). Bone marrow chromosome analysis revealed 46, XX, -18, +mar without Ph1 chromosome, and DNA analysis showed no bcr rearrangement. She was diagnosed as having essential thrombocythemia and was treated with busulfan. On November 1986, she developed remarkable leukocytosis with leukemic blasts. White blood cells reached 153 x 10(3)/microliters with 33% blasts. Her blasts were positive for peroxidase staining, but negative for platelet peroxidase on electron microscopic study and platelet specific glycoproteins. A diagnosis of acute myeloblastic leukemia (M2) was made. The patient received various combination chemotherapy, which was ineffective, and she died due to pneumonia on June, 1989. In Japan, there has been reported only 8 cases of essential thrombocythemia transformed to acute leukemia. The clinical pictures of these 9 cases were discussed.
Cell Transformation, Neoplastic↗
[Radiographic diagnosis of benign colonic tumors excluding adenoma].
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Adult↗
[Management of coronary artery bypass grafting surgery by continuous ambulatory peritoneal dialysis in a patient with chronic renal failure under hemodialysis].
A 64-year-old patient with chronic renal failure underwent coronary artery bypass grafting (CABG) because of the frequent severe angina during hemodialysis. Intraoperative hemodialysis and extra-corporeal ultrafiltration method (ECUM) was used during cardiopulmonary bypass. Postoperative management was successfully performed by continuous ambulatory peritoneal dialysis (CAPD), which made hemodynamics stable and prevented postoperative bleeding, providing with adequate fluid removal and satisfactory control of serum chemistry.
Coronary Artery Bypass↗