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Biomedical subjects

M Miyazaki

Publications and source records attributed to M Miyazaki.

At least 685 records · Page 38Linked to original sources
PubMed1990

[A case of transsphenoidal meningoencephalocele].

A 6-year-old boy was sent to us due to basal meningoencephalocele detected by MRI. He had had a past history of strabismus and morning glory syndrome since 6 months of age, as well as hypopituitary dwarfism since he was 3 years old. On admission, physical examination revealed hypertelorism and left coloboma. Laryngoscopic examination revealed a round mass covered by normal nasal mucose in the midline of the tegmen of the choana. X-ray tomogram and CT scan demonstrated an isodense mass protruding into the nasopharyngeal cavity through a bony defect of the sella turcica. Right carotid angiogram showed stenosis of the right internal carotid artery and abnormal fine vessels in the basal ganglia similar to basal Moyamoya network. There was an irregular filling of the right anterior cerebral artery. Left carotid angiogram showed an irregular filling of the left middle cerebral artery. MRI showed an anterior part of the third ventricle descending into, and the meningocele protruding into the nasopharyngeal cavity. It also showed a stalk extending from the hypothalamus into the meningocele, but the pituitary gland was not recognized. The meningocele was of the same signal intensity as CSF in both T1 and T2 weighted images. Growth hormone deficiency was confirmed by radioimmunoassay of the peripheral blood. An operation was scheduled transcranial to prevent snoring during sleep at age 9. The stalk was observed behind the chiasm during the operation, but a radical operation was not performed because of a possibility of postoperative hypothalamic-pituitary dysfunction. Transsphenoidal encephalocele is rare. So far as we could see, only 30 cases have been reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1990

[Anesthetic management for surgery of patients with metastatic brain tumors associated with lung tumors].

We had four patients who received anesthesia for metastatic brain tumors. All patients were complicated with primary lung tumors which had caused several respiratory problems. Respiratory failure and intratracheal hemorrhage from lung tumors were the severest complications during and after the operation. Two patients suffered from pneumonia at early postoperative stage and died of respiratory failure within eighty days after the operation. We consider that these preoperative findings of atelectasis and hemosputum are important signs that could predict those severe complications. To avoid postoperative respiratory complications in patients with atelectasis, the anesthetist should perform careful perioperative management such as active preoperative pulmonary physical therapy and should choose anesthetics which do not affect postoperative consciousness and respiration, and should perform intensive postoperative respiratory care. To prevent pulmonary hemorrhage, the fiberoptic bronchoscopy is useful for the diagnosis and the therapy. We also consider that the long operation aggravates postoperative complications. Planning of operation and performing operative procedure in a shortest time possible are also important.

Adult↗
PubMed1990

[The effect of craniotomy on lymphocyte subpopulations].

The effect of craniotomy on cell mediated immunity was studied by using monoclonal antibodies and flow cytometry. Twelve patients undergoing craniotomy were investigated. Six patients had malignant brain tumor, four benign tumor, one AVM and one aneurysm. Examined lymphocyte monoclonal antibodies were Leu4, Leu2a and Leu3a. In addition, two color analysis using two monoclonal antibodies, Leu3a and Leu8, or Leu2a and Leu15, was performed. This technique can classify Leu3a positive cell into helper T cell and inducer T cell and Leu2a positive cell into suppressor T cell and cytotoxic T cell. The number of Leu4 positive cell (T cell) decreased during operation. The number of Leu3a positive cell (OKT4) also decreased at 30 minutes after incision and moderately recovered during operation. Leu2a positive cell (OKT8) did not show significant change. As the result, the decline of Leu3a/Leu2a ratio (OKT4/OKT8 ratio) was found after incision and this ratio gradually returned to preoperative level during operation. By two color analysis, decrease of inducer and helper T cell in Leu3a positive cell, and increase of suppressor T cell, and decrease of cytotoxic T cell in Leu2a positive cell were observed. The results of this study show that stress of craniotomy affected the immunological state.

Adolescent↗
PubMed1990

[Disorders of vision and act in a child with spastic cerebral palsy].

A boy with spastic cerebral palsy, who had frequent apneic attacks during the neonatal period, showed developmental disorders; (1) cerebral poor eye sight, a disorder of visual directed attention, and associative visual agnosia (2) disorders of visuospatial perception and corporeal awareness, and (3) dyspraxia d'évolution (Stambak et al.). When the visual directed attention was completed at the age of 10 years, the integration of his cerebral higher functions was facilitated, except the following neuropsychological deficits; (1) visual line agnosia (apperceptive type) and (2) constructive apractognosia. These deficits were not compensated through the maturation of the central nervous system and through the contacts and interchanges with the outer world. MRI findings showed bilateral lesions of the white matter of occipital and parieto-occipital transitional regions, and the trunk and splenium of corpus callosum. Although this case is included in mental retardation, what differs is the fact that each "higher" function developed unevenly in this case unlike the ordinary mental retardation. In this report these disorders and deficits were discussed considering his developmental process of neuropsychological functions.

Cerebral Palsy↗
PubMed1990

[Transcatheter embolization of splenic artery aneurysm; a case report].

A 76-year old woman with splenic artery aneurysm was treated by nonsurgical treatment. Surgical treatment has been recommended for the treatment of visceral aneurysms because these aneurysms may rupture and lead to fatal hemorrhage. This report describes the successful interventional coil and Gelfoam occlusion of splenic aneurysm.

Aged↗
PubMed1989

Determination of amphetamine-related compounds by high-performance liquid chromatography with chemiluminescence and fluorescence detections.

High-performance liquid chromatography with chemiluminescence detection has been established for the determination of trace levels of amphetamine-related compounds (APs) after fluorigenic derivatization. Bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide in acetonitrile was used as a post-column chemilumigenic reagent. As derivatization reagents, dansyl chloride (Dns-Cl), 4-fluoro-7-nitrobenzoxadiazole (NBD-F) and naphtalene-2,3-dicarbaldehyde (NDA) were compared. Dns-Cl was the most suitable of the three for the simultaneous determination of both primary and secondary amino APs. The on-column detection limits for Dns-derivatives were 3.10(-15) - 4.10(-15) mol. NDA gave the most sensitive derivatives (cyanobenz[f]isoindole, CBI derivatives) with only primary amino APs. The detection limits for CBI derivatives were as low as 2.10(-16) mol. The present method was applied to the determination of methamphetamine in human urine. Only diethyl ether extraction was necessary as a clean-up treatment before Dns derivatization, because diethyl ether extracted methamphetamine quantitatively from urine at strong alkaline pH and the extract showed few interfering peaks around the retention time of methamphetamine after the derivatization. Methamphetamine concentrations as low as 1.10(-7) M in urine were determined after the above treatments.

Amphetamine↗
PubMed1989

Comparative distribution of three opioid systems in the lower brainstem of the monkey (Macaca fuscata).

The regional distribution of the three opioid peptide neuronal systems--proopiomelanocortin (POMC), proenkephalin A, and proenkephalin B--was investigated in the lower brainstem of Japanese monkeys (Macaca fuscata) by immunocytochemical techniques. Antiserum to beta-endorphin/beta-lipotropin, [Met]-enkephalin-Arg6-Gly7-Leu8, and human leumorphin were used to identify the POMC and the proenkephalin A and B systems, respectively. POMC-related immunoreactive material was not found in the neuronal perikarya in the lower brainstem; reactive fibers and apparent terminals were distributed in the substantia nigra, lemniscus lateralis, midbrain central gray, the nucleus raphes, nucleus parabrachialis lateralis, ventral area of the spinal trigeminal nerve, nucleus tractus solitarii, and in the reticular formation throughout the lower brainstem. Proenkephalin A-related immunoreactive neuronal perikarya were detected in the central gray, reticular formation, nucleus raphes, trapezoid body, nucleus parabrachialis lateralis and medialis, nucleus spinalis nervi trigemini, nucleus dorsalis nervi vagi, and in the nucleus tractus solitarii. Densely packed immunoreactive fibers were widely distributed in the substantia nigra, nucleus interpeduncularis, nucleus raphes, superior colliculus, periaqueductal central gray, nucleus parabrachialis lateralis and medialis, locus coeruleus, trapezoid body, nuclei cochleares, nucleus spinalis nervi trigemini, tractus spinalis nervi trigemini, nucleus tractus solitarii, nucleus dorsalis nervi vagi, nucleus gracilis, nucleus cuneatus, nucleus cuneatus accessorius, and in the reticular formation throughout the lower brainstem. Neuronal perikarya containing immunoreactive material related to proenkephalin B were found in the periaqueductal central gray, nucleus parabrachialis lateralis and medialis, nucleus tractus solitarii, and nucleus spinalis nervi trigemini. In addition, immunoreactive fibers were detected in the ventral tegmental area, substantia nigra, nucleus parabrachialis lateralis and medialis, nucleus vestibularis lateralis and medialis, and in some areas of the reticular formation. These anatomical findings demonstrate that these three opioid peptide neuronal systems are widely but uniquely distributed in the lower brainstem of the monkey.

Animals↗
PubMed1989

HPLC determination of cis-diamminedichloroplatinum(II) in plasma and urine with UV detection and column-switching.

A method for determining cis-diamminedichloroplatinum(II) (CDDP), an anticancer drug, in plasma and urine by HPLC with UV detection and column-switching has been developed. Typical conditions were as follows. An apparatus was composed of two columns, two pumps, a UV detector, a sample injector with a 100 microL loop, a switching valve, a column oven and a recorder. A Rheodyne model 7125 sample injector was used as the switching valve. A precolumn (4.6 mm ID x 25 cm) was packed with MCI GEL CK10S (a strong cation exchanger), and an analytical column (4.6 mm ID x 5 cm) was packed with MCI GEL CDR10 (a strong anion exchanger). Both columns were connected in series via the switching valve. The CDDP-containing fraction of the effluent from the precolumn was loaded to the analytical column by column-switching and the effluent from the analytical column was monitored at 210 nm. An eluent of 0.3 M sodium dihydrogen phosphate was pumped at a flow rate of 1 mL/min and the columns were maintained at 40 degrees C. CDDP was eluted at about 11 min and the identity of the peak of CDDP on the chromatogram was confirmed by its 3-dimensional chromatogram and analysis of platinum in the column effluent. Under the conditions described above, a linear relationship was obtained between peak height and concentration of CDDP up to 100 microM. Correlation efficients were 0.998 for plasma and 0.999 for urine. The detection limit was 0.1 microM for CDDP in both plasma and urine (S/N = 3,0.005 AUFS). The reproducibility was within 3% for 10 determinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromatography, High Pressure Liquid↗
PubMed1989

Detection of anionic sites and immunoglobulin A deposits in the glomerular capillary walls from patients with IgA nephropathy.

A study of anionic sites in the glomerular basement membrane (GBM) from patients with immunoglobulin A (IgA) nephropathy is described. The relationship between the deposition of IgA and the detection of glomerular extracellular components, i.e., noncollagenous (NC-1) domain of Type IV collagen, in the glomerular capillary walls was examined by double immunofluorescence. Renal biopsy specimens from patients with IgA nephropathy were immersed in polyethyleneimine (PEI) as a cationic probe and then examined by electron microscopy. Renal specimens were also incubated with mouse monoclonal anti-NC-1 domain of Type IV collagen and then stained with fluorescein isothiocyanate (FITC)-labelled goat antimouse Ig antiserum. After these reactions, sections were stained with rhodamine-labelled rabbit antihuman IgA antiserum. GBM subepithelial anionic sites marked by PEI were altered by the deposition of electron-dense deposits (EDD) in patients with IgA nephropathy and there was a significant correlation between the levels of proteinuria and the incidence of EDD in the GBM in such patients. Marked proteinuria was observed in patients who showed loss of anionic sites in the GBM by electron microscopy. By double immunofluorescence, IgA was shown to be focally deposited outside the NC-1 domain of Type IV collagen-detected regions in the same patients. The authors concluded that high levels of proteinuria might be due to alterations of the size barrier and/or anionic sites of GBM in the moderate stage of IgA nephropathy.

Basement Membrane↗
PubMed1989

Two distinct cell lines derived from a human osteosarcoma.

Two cell lines were established from a human osteosarcoma transplanted into athymic nude mice after the second (O9N2) and fifth passages (HuO9). Both cell lines expressed 1,25(OH)2D3-responsive alkaline phosphatase activity and produced tumors in the dorsum of nude mice that were histologically similar to the original tumor. However, the morphological and growth characteristics of the two cell lines differed. O9N2 cells were large and polygonal, whereas HuO9 cells showed spindle shapes. HuO9 cells had a higher growth rate and saturation density than O9N2 cells. The c-myc oncogene was amplified 4- to 8-fold in HuO9 cells but not in O9N2 cells. Both cell lines had a homozygous internal deletion, lacking the 7.4-kb HindIII fragment in the Rb gene. The results suggest the importance of the c-myc oncogene in the growth and morphological control of human osteosarcoma cells and of the Rb gene in the pathogenesis of the tumor.

Adolescent↗
PubMed1989

In vivo and in vitro test for growth potential of liver cells from rats during early stage of hepatocarcinogenesis by 3'-methyl-4-dimethylaminoazobenzene.

A rapid increase in the fraction of small liver cells was observed in the liver of rats during the early stage of hepatocarcinogenesis by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). The change in cell population was represented by the decrease in glucose-6-phosphatase activity and by the increase in number of gamma-glutamyltranspeptidase-positive cells. When DNA synthesis of liver cells from rats fed 3'-Me-DAB was measured by autoradiography in primary culture, it began to increase 2 weeks after the start of the carcinogen feeding, reaching a plateau level after 3 weeks. Liver cells from rats fed 3'-Me-DAB for 2 weeks or over demonstrated a remarkable resistance to the cytotoxic effect of the carcinogen (0.24 mM) in primary culture. Furthermore, liver cells from rats fed 3'-Me-DAB for 3 weeks or over proliferated in the presence of the carcinogen in primary culture. When liver cells from 3'-Me-DAB-fed and control rats were transplanted into syngeneic rat spleens, the former cells proliferated more vigorously than did the latter. The growth potential of liver cells from 3'-Me-DAB-fed rats tended to be enhanced with time in the carcinogen feeding. Hepatocellular carcinomas developed in the host spleens implanted with liver cells from a rat fed 3'-Me-DAB for 8 weeks. As described above, liver cells from rats fed 3'-Me-DAB demonstrated much greater proliferative ability than normal control cells in vivo and in vitro.

Animals↗
PubMed1989

Undifferentiated gliomas of the brain stem.

Undifferentiated gliomas of the brain stem were confirmed surgically in two young children. The patients were treated by aggressive irradiation of the entire neuraxis, similar to that administered for medulloblastoma. Therapy resulted in a good prognosis and there was no tumor recurrence.

Brain Neoplasms↗
PubMed1989

Improved maintenance of adult rat hepatocytes in a new serum-free medium in the presence or absence of barbiturates.

For serum-free primary culture of adult rat hepatocytes, a synthetic medium DM-160 and rat-tail collagen were selected for the basal medium and for the culture substratum, respectively. Barbiturates, such as phenobarbital and 1-ethyl-5-isobutylbarbiturate, efficiently supported survival of hepatocytes and maintained their morphologic features at lower concentrations under the serum-free conditions than under the serum-supplemented conditions. However, the hepatocyte survival rates under the serum-free conditions were lower than those under the serum-supplemented conditions in the presence or absence of barbiturates. Supplementation of the basal medium with a combination of five groups of factors (5Fs), such as eight amino acids (Ala, Arg, Gly, Ile, Met, Phe, Pro, and Trp), two unsaturated fatty acids (linoleate and oleate), a protease inhibitor (aprotinin), three vitamins (A, C, and E), and five trace elements (Mn, Fe, Cu, Zn, and Se), improved the hepatocyte survival under the serum-free conditions in the presence or absence of barbiturates. In other words, the serum could be completely substituted by the 5Fs. Hepatocyte cultures maintained in the 5Fs-supplemented basal medium showed excellent induction of tyrosine aminotransferase activity in response to dexamethasone in the presence or absence of barbiturates. The efficiency of the 5Fs-supplemented basal medium for maintaining hepatocytes was not inferior to those of other media in common use with hepatocytes, such as Williams' medium E and Waymouth's medium MB-752/1. In conclusion, maintenance of functional hepatocytes in serum-free primary culture could be improved by use of the new medium preparation (the 5Fs-supplemented DM-160) in the presence of barbiturates.

Animals↗
PubMed1989

Mechanisms responsible for long-term survival of adult rat hepatocytes in the presence of phenobarbital in primary culture.

The mechanisms, by which phenobarbital (PB) supports the survival of adult rat hepatocytes in primary culture, were investigated. PB altered the shape of rat erythrocytes to produce cup-formed cells and protected them from hypotonic hemolysis. Anesthetics (ketamine, lidocaine, mepivacaine, and bupivacaine) and an anti-inflammatory agent (indomethacin), which are also known to protect erythrocytes from hypotonic hemolysis by stabilizing their membranes, efficiently supported the survival of hepatocytes in primary culture. Furthermore, the well-known biological membrane stabilizers, such as cholesterol and vitamin E, also showed the maintenance effect on primary cultured hepatocytes. PB effectively reduced the leakage of lactate dehydrogenase from hepatocytes caused by chenodeoxycholic acid in primary culture. Rotenone and amobarbital, which act repressively on the PB-sensitive site in the respiratory chain and are known to inhibit the mitochondrial formation of active oxygen species with NAD-linked substances, effectively prolonged the hepatocyte survival in primary culture. Elevation of oxygen tension in primary culture remarkably decreased the hepatocyte survival rate, which was preserved by addition of antioxidant substances, such as vitamin C, vitamin E, bifemelane, selenite, and superoxide dismutase. On the other hand, in the presence of PB, the hepatocyte survival rate hardly changed with the elevation of oxygen tension. From these findings, it seems that PB stabilizes the hepatocyte membranes and reduces the mitochondrial formation of active oxygen species and that the stabilized functions of membrane and the reduction of oxidative stress result in the prolonged survival of hepatocytes in primary culture.

Amobarbital↗