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Biomedical subjects

M Miyamoto

Publications and source records attributed to M Miyamoto.

At least 523 records · Page 29Linked to original sources
PubMed1986

Observation of electro-kinetic phenomena by imposing oscillating pressure and voltage gradients across some epithelial membranes.

When hydrostatic pressure across epithelia fixed between a Ussing-type chamber was oscillated mechanically, the membrane potential was found to oscillate synchronously. When the transepithelial potential was oscillated artificially, the hydrostatic pressure difference also oscillated synchronously. Under such oscillating gradient conditions, concentration changes in the unstirred layer can be minimized. Accordingly, the method using such oscillatory gradients seem to be appropriate for observation of the true streaming potential and electro-osmosis, respectively.

Animals↗
PubMed1986

Measurement of extra-cellular fluid change in salivary gland using an impedance method.

The method of electrical impedance measurement was tested for its usefulness in monitoring of extra-cellular fluid (ECF) in the dog submandibular gland during salivary secretion. Measurements were performed during rest and stimulated state with or without blood supply. During stimulation with blood supply, the conductivities of the gland decreased to some extent. During stimulation without blood supply, the decrease in conductivities was markedly enhanced. The decrease of ECF compartment during stimulation without blood supply was ascertained by the stereological measurement. Coincidence of conductivity decrease and histologically observed decrease of ECF compartment supports the usefulness of impedance measurement for monitoring of ECF during secretory activity of gland tissue. The present study also shows that the interlobular space decreased mainly during stimulation when blood supply is absent. This indicates that, among ECF space, the interlobular space plays an important role as a fluid reservoir in the salivary gland.

Animals↗
PubMed1986

A practical evaluation of accuracy with the standard deviation index (SDI) chart method. Second report. Report covering the period from April 1980 to March 1983.

To evaluate the accuracy of laboratory data for 18 items determined with an Technicon SMAC (Sequential Multiple Analyzer Computer), the SDI chart method was used in investigating the data according to five kinds of control survey programs from April 1980 to March 1983. The results can be summarized as follows: Inorganic phosphorus showed a gradual downward shift, arriving at the minus side of SDI in all control surveys. Potassium showed a particularly large fluctuation as was the case in the previous evaluation. The other items were relatively stable (i.e., showed less fluctuation), although many of them showed an upward shift. Some of the control survey programs yielded biased evaluation results. Thus, the SDI chart method proved to allow, as one of the external quality control techniques, observation of long-term, slight changes without necessitating any complicated calculation. Furthermore, it was confirmed that this is a practically useful method of accuracy evaluation because it allows overall evaluation of the data from various control survey programs on the same graph.

Alkaline Phosphatase↗
PubMed1986

Delta check system for detection and further management of laboratory errors. First report. Graphical presentation of results.

The delta check system is effective for detecting errors that may occur during the whole course of tests, from the time a laboratory test is ordered until it is interpreted. This system detects errors that exceed the preestablished values by comparing present data with the most adjacent ones in all items for each case. Graphical presentation of delta-checked data led to easier judgment as to whether such a difference is due to erroneous testing or changes in the patient's condition on the basis of whether a difference in values is limited to a particular item or is common to pathologically associated multiple ones. Furthermore, since test items were classified by analytical instruments, it became easier for us to determine at which process of the testing an error occurred. This report gives the present status of utilization of delta check system in our laboratory.

Blood Chemical Analysis↗
PubMed1986

Delta check system for detection and further management of laboratory errors. Second report. Computer program to identify laboratory errors.

A delta-check system has been introduced for routine work in our laboratory to detect laboratory errors in blood chemistry. All pairs of data that exceed allowable limits were displayed for each item. To easily understand the details, these data were displayed on a graph divided for each analyzer. Looking at this graph the responsible causes were inferred from the number or type of analyzers and from the number of items in which errors were detected. Following this first report, the algorithm involved in the last processes was programmed. When all data derived from analyzers were put into the personal computer, 1) the details of errors were shown separately for each analyzer and item, and 2) presumed causes to be identified finally from the results of confirmative tests were displayed graphically at the same time according to our program. By this system, most of the errors that may happen during the whole course of tests, from the time a laboratory test was ordered until it was interpreted, were detected more rapidly, thoroughly and objectively inside the laboratory before the data were reported to the clinical ward. This system is also regarded as an indispensable base for the development of an accurate interpretation of laboratory data.

Blood Chemical Analysis↗
PubMed1986

[A case of alveolar soft-part sarcoma with recurrent cerebral metastasis--operative management of the cerebral metastasis].

A female patient noticed a painless swelling at the right thigh at the age of 12. Two years later, she had total removal for the tumor and irradiation. The diagnosis of the tumor was alveolar soft-part sarcoma. At the age of 16 she had left pneumonectomy for its metastasis. The next year the metastatic tumor is detected in the right lung. At 21 she was admitted to our service with a diagnosis of cerebral metastasis. Her chief complaints were headache, nausea and visual disturbance. Neurological examination revealed advanced choked disc and left homonimous hemianopsia. CT scan revealed a large vascular tumor in the right occipital lobe and chest film showed multiple metastatic shadows in right lung. A large bloody tumor was removed totally through right occipital craniotomy. She was discharged with a marked improvement of neurological symptom. Since then she had had 8 times of surgical removal for 10 cerebral metastatic tumors. Several chemotherapy was attempted for three times. At first adriamycin was administered after the first removal of cerebral metastasis. Methyl-CCNU and Picibanil was administered after the second removal. Soon after the chemotherapy, metastatic tumor recurred. Cisplatin was administered for the ninth metastasis. None of these chemotherapy had seemed to be benefit in the management. At 27 she had removal of metastatic tumor on chest wall. She died of respiratory embarrassment in thorax at 30. At autopsy she had metastatic tumors in right frontal lobe, right lung, mediastinum, heart, chest wall, and intestine. During her illness, she graduated from high school and college, and got a good job as a secretary.

Adult↗
PubMed1985

Determination of captopril and its mixed disulphides in plasma and urine by high-performance liquid chromatography.

A high-performance liquid chromatographic method has been developed which enables sensitive determination of captopril and its mixed disulphides in plasma and urine after oral administration of a new antihypertensive agent, 1-(D-3-acetylthio-2-methylpropanoyl)-L-prolyl-L-phenylalanine (DU-1219, I). Captopril is derivatized with a new reagent, N-(4-benzoylphenyl)maleimide and the derivative is extracted with chloroform and assayed using a liquid chromatograph equipped with an ultraviolet detector at 254 nm. Mixed disulphides of captopril with thiol compounds such as cysteine, glutathione and plasma proteins are reduced with tributylphosphine to form captopril, followed by derivatization with N-(4-benzoylphenyl)maleimide. Accurate determinations are possible over a concentration range of 10-500 ng/ml captopril in plasma, and 100-2500 ng/ml captopril in urine. The coefficients of variation of captopril in plasma (200 ng/ml) and urine (500 ng/ml) are 3.7% and 2.6%, respectively, and those of mixed disulphides of captopril are similar to those of captopril. Plasma levels and urinary excretion of captopril and its mixed disulphides in healthy volunteers following single oral administration of I (50 mg) have also been determined.

Captopril↗
PubMed1985

Lesioning of the rat basal forebrain leads to memory impairments in passive and active avoidance tasks.

Effects of the bilateral electrolytic lesioning of the basal forebrain (BF), including the ventral globus pallidus, on passive or active avoidance tasks, were studied in male Wistar rats. A severe deficit in acquisition of passive avoidance response was produced by the lesioning in the posterior level of BF. The retention of the passive avoidance response was markedly disrupted with post-training lesioning. Time-dependent but only slight recovery from the memory impairments was observed in the passive avoidance task given 4, 8 or 16 weeks after BF lesions. The acquisition of active avoidance response using a two-way shuttle box was also disturbed by BF lesioning. Retention of active avoidance response was clearly impaired by post-training lesions of the BF. The BF lesioned rats gradually acquired the passive avoidance performance when trained repeatedly at 24- or 48-h intervals, by giving a foot shock in case of avoidance failure. Extinction of the acquired passive avoidance response rapidly occurred in the BF lesioned rats. Furthermore, neurotoxic lesions of BF with kainic acid produced a significant impairment in acquisition of passive avoidance response. These results suggest that bilateral BF lesions impair the acquisition and retention of passive or active avoidance response, and that these impaired rats may be useful as an experimental model for Alzheimer's disease and senile dementia.

Animals↗
PubMed1985

Renal cell carcinoma with intracaval tumor thrombus extending to the diaphragm: ultrasonography and surgical management.

We describe the successful management of a patient with intracaval extension of renal cell carcinoma to the level of the diaphragm. Ultrasonography delineated clearly the upper extent of the tumor thrombus and revealed no invasion of the vena caval wall at or above the entrance of the main hepatic veins. To prevent severe hypotension caused by intrapericardial control of the inferior vena cava, the aorta was clamped temporarily just above the celiac axis. The tumor was removed completely en bloc with the thrombus. Blood loss was minimal and the patient recovered promptly.

Aged↗
PubMed1985

[TRH and its analog (DN-1417). Effects on central dopaminergic system-dependent behaviors in rats and mice].

Effects of TRH and its analog, gamma-butyrolactone-gamma-carbonyl-histidyl-prolinamide citrate (DN-1417), on circling, stereotyped or climbing behavior were investigated in rats and mice. High doses of TRH (100 mg/kg, i.p.) and DN-1417 (20-50 mg/kg, i.p.) produced a significant ipsilateral circling behavior in rats with the lesions of the unilateral dopamine (DA) pathway by 6-hydroxydopamine. In intact mice, stereotyped sniffing accompanying hyperactivity was caused at low doses of TRH or DN-1417 (1-20 mg/kg, i.p.), and stereotyped licking behavior was observed at high doses of TRH or DN-1417 (20-200 mg/kg, i.p.). Furthermore, TRH, DN-1417 or methamphetamine caused a dose-related climbing behavior in mice pretreated with L-DOPA and Ro 4-4602. Circling behavior, stereotyped sniffing or licking behavior induced by TRH or DN-1417 was markedly suppressed by pretreatment with pimozide or alpha-methyltyrosine. However, atropine and scopolamine potentiated the circling inducing action of TRH or DN-1417, in contrast with suppression of the licking behavior. These results suggest that TRH and DN-1417 produce circling, sniffing, licking and climbing behaviors via activation of the central DA system, and that cholinergic mechanisms may be also involved in licking behavior induced by TRH or DN-1417.

Animals↗
PubMed1985

[A TRH analog (DN-1417). Effects on the levels of monoamines and the metabolites in the various brain regions in rats].

The effects of a TRH (thyrotropin-releasing hormone) analog, DN-1417 (gamma-butyrolactone-gamma-carbonyl-L-histidyl-L-prolinamide citrate), on the levels of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and the metabolites in the various brain regions of rats were determined by means of high performance liquid chromatography with electrochemical detection. DN-1417 (20 mg/kg, i.p.) produced marked decreases in the levels of NE, DA and 5-HT, especially in the nucleus accumbens, striatum and hypothalamus. The maximum effect was observed at 15 min after the administration. DA metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, increased significantly in the nucleus accumbens, striatum and hypothalamus, whereas 3-methoxy-4-hydroxyphenylglycol and 5-hydroxyindoleacetic acid remained unchanged. 3-Methoxytyramine increased significantly in the nucleus accumbens and striatum. Two week chronic administration of DN-1417 (20 mg/kg, i.p.) increased the levels of DA and NE in the nucleus accumbens and DA in the striatum. These results suggest that DN-1417 stimulates the turnover of the cerebral monoamines, especially the release of DA from the nucleus accumbens and striatum in the mesolimbic and nigro-striatal DAergic systems.

Animals↗