Search PubMed⌕ Search

Biomedical subjects

T Miyazaki

Publications and source records attributed to T Miyazaki.

At least 883 records · Page 49Linked to original sources
PubMed1986

[Treatment of recurrent chronic subdural hematoma--setting an Ommaya tube].

The rate of postoperative recurrences of chronic subdural hematomas is high. Several methods have been advocated, but each one remains controversial. We proposed a simple method of setting an Ommaya tube after burr-hole evacuation. The reservoir was placed in the subcutaneous space, the tip of the tube was placed in the subdural space. The reservoir was punctured with a needle, thereby allowing aspiration of fluid from the subdural space. Sixty one cases of chronic subdural hematomas were operated by simple burr-hole evacuation. The Ommaya tube was used in 46 selected patients.: 1) the volume of hematoma was more than 100 ml and, or 2) older than 70 years of age. Reaccumulation of subdural effusion was detected in 10 cases. The subdural effusions were drained by percutaneously needling the reservoir of the Ommaya tube. This procedure was curative in 9 of the patients. However 1 patient required a small craniotomy. The patient had two outer membranes therefore inner hematoma could not be removed. The authors propose this technique and discuss about it.

Aged↗
PubMed1985

Three components of active membrane current in the C-neurons of rabbit cervical nodose ganglion under voltage clamp.

In the C-neurons of rabbit nodose ganglion there is a persistent slow outward current at Vm levels positive to -80 mV. This current was detectable in Na+-free Ringer and disappeared in Ca2+-free medium. Therefore it may be the Ca2+-activated K+ current. This K+ current shows a unique time and voltage dependency, suggesting that it may have a regulatory role on the excitability of C-neurons. Two other types of current also observed in C-neurons were IQ- and IA-like currents. In A-neurons, however, a Ca2+-activated K+ current was not observed at all.

Action Potentials↗
PubMed1985

Establishment and characterization of neoplastic cells from a malignant fibrous histiocytoma. A possible stem cell line.

Using the semisolid agar method, neoplastic three clones were isolated from a malignant fibrous histiocytoma. All clones represented morphologically only one type of cells having fine structure similar to that of histiocyte with multiple filopodia. The clones carrying Fc- and C3-surface receptors showed marked immunophagocytosis. They were positive for acid phosphatase, nonspecific esterase, and alpha-1-antitrypsin. These clones were able to display the potential for production of collagenous matrix. Moreover, inoculations of the each clone into nude mice resulted in productions of malignant fibrous histiocytoma with pleomorphic pattern. These tumors were composed morphologically of various types of cells such as immature, histiocyte-like, fibroblast-like, and multinucleated giant cells. These morphologic alterations of histiocytes occurred in all of the three clones in vitro. These findings suggest that the cloned cells established from the malignant fibrous histiocytoma are neoplastic histiocytes with capability to form various types of cells, a possible stem cell.

Adult↗
PubMed1985

Ectopic ventricular tachycardia sensitive to calcium antagonists in acute myocardial infarction in dogs.

The effects of antiarrhythmic agents on automatic ventricular tachycardia (VT), which emerged in the early stage of acute myocardial infarction (AMI), were examined in 30 closed-chest mongrel dogs. Antiarrhythmic agents were administered intravenously when the rate of VT became almost equal to sinus rate (5.6 +/- 1.4 hours). VT was slowed significantly by verapamil (0.15 or 0.3 mg/kg), diltiazem (0.2 or 0.4 mg/kg), propranolol (0.1 mg/kg) and amiodarone (5 mg/kg), but not by procainamide (20 mg/kg), lidocaine (2 or 4 mg/kg), nifedipine (0.01 mg/kg) and nicorandil (0.03 mg/kg). The number of ventricular premature complexes was reduced most effectively by verapamil. The significant suppressive effects of calcium antagonist drugs (verapamil and diltiazem) and propranolol indicate that an inward calcium current during diastole may play a critical role in the abnormal enhancement of ventricular automaticity in the early stage (4 to 8 hours) of AMI.

Animals↗
PubMed1985

Electron microscopic study on Langerhans cells and related cells in lymph nodes of DNCB-sensitive mice.

To understand contact hypersensitivity, it is important to know the kinetics of Langerhans cells (LC) and related cells in the lymph node (LN), as well as in the skin. For this purpose, we tried experimentally to induce increased numbers of LCs, Birbeck granule-like structure (BgS)-containing cells, and interdigitating reticulum cells (IDC) in DNCB-sensitive mice and studied them by means of electron microscopy with the following results: (1) cytologically, LC, BgS-containing cells and IDC were closely related; (2) BgS seemed to arise from rough-surfaced endoplasmic reticulum (r-ER), and BgS-containing cells were midway in nature between LC and IDC from the morphological view point. From these findings, it appears that IDC, BgS-containing cells, and LCs were simultaneously involved in the contact hypersensitivity reactions of LNs.

Animals↗
PubMed1985

Increased Langerhans cells and related cells in mesenteric lymph nodes of DNCB-sensitive mice.

We used electron microscopy to study mesenteric lymph nodes (LNs) of 2,4-dinitro-1-chlorobenzene(DNCB)-sensitive mice. It was found that Langerhans cells (LCs) and cells containing Birbeck-granule-like structures (BgSs) increased in number only after challenge with DNCB. This increase reached a peak 4 h after challenge. LCs and BgS cells were only found in the paracortical area of LNs. There were no appreciable differences in the morphology of LCs, BgS cells, and interdigitating reticulum cells (IDCs), except for the presence or absence of Bgs or BgSs. No LCs, BgS cells, or IDCs were found in the marginal sinus of mesenteric LNs or in the surroundings of afferent blood vessels. These findings were in complete agreement with those obtained in our previous study of cutaneous LNs. From our findings and the results of previously published studies, we propose the following conclusions: first, LCs and BgS cells observed in mesenteric LNs are the product of the differentiation and maturation of precursor cells pre-existing in the paracortical area of LNs caused by DNCB stimulation. Second, the activated T lymphocyte to DNCB pre-exists in the paracortical area; thus, the DNCB used for challenge stimulates this T lymphocyte to release lymphokine, which then causes some precursor cells to differentiation into LCs and/or BgS cells. Finally, morphological findings suggest that precursor cells of LCs and BgS cells are probably IDCs.

Animals↗
PubMed1985

Changes in left ventricular diastolic function after left ventriculography: a comparison with iopamidol and urografin.

Changes in left ventricular (LV) diastolic indices after left ventriculography (LVG) with iopamidol or urografin were studied in 42 subjects. Increase in heart rate and decrease in LV systolic pressure were more significant with urografin than with iopamidol (p less than 0.05 to 0.001). LV end-diastolic pressure was elevated more with urografin than with iopamidol (p less than 0.005 to 0.05) 1 to 3 minutes after LVG. LV peak negative dP/dt decreased significantly with urografin immediately (10 to 15 seconds, -511 and 30 seconds, -376 mm Hg/sec; p less than 0.0005 to 0.02), but with iopamidol it did not decrease significantly after LVG. Time constant, T, was elongated with iopamidol (10 to 15 seconds, +13 and 30 seconds, +6 msec; p less than 0.0005), but this elongation was significantly less than urografin (10 to 15 seconds, +34; 30 seconds, +25; 1 minute, +15; and 2 minutes, +10 msec; p less than 0.05 to 0.0005). We conclude that iopamidol disturbed LV diastolic function to a lesser degree than did urografin.

Adult↗
PubMed1985

A promoter for Bacillus subtilis expression vector.

A 117-bp EcoRI-PstI fragment with strong promoter activity (P1 promoter) was cloned from Bacillus subtilis chromosomal DNA and sequenced. The P1 promoter was shown to contain a putative -35 region (TTTACT) and -10 region (TAGATT), and promotes expression of cloned human interleukin-2 (IL-2) and human interferon-gamma (IFN-gamma) genes in B. subtilis.

Bacillus subtilis↗
PubMed1985

IgA . K type myeloma with severe postextraction bleeding.

A case of multiple myeloma detected by the first symptom of severe postextraction bleeding was presented. Although laboratory data showed severe anemia, rouleaux formation of erythrocytes, abnormal hemostatic parameters, elevated erythrocyte sedimentation rate and hyperglobulinemia, no involvement of bones such as the jaws, skull, ribs or sternum was demonstrated roentgenologically. Final diagnosis obtained by immunoelectrophoresis was Ig A . K type myeloma. During a therapeutic period with melphalan and predonine, bleeding from the extracted wound was repeated. 2 months after the onset of the first symptoms, the patient died of systemic bleeding. Autopsy findings revealed many hemorrhagic sites in the lungs, stomach, kidney and bladder and the existence of plasma cell-like tumor cells in the bone marrow of lumber vertebra and sternum.

Electrophoresis↗
PubMed1985

Diagnostic significance of endoscopy of the eustachian tube.

The significance of introducing endoscopic examination to evaluate Eustachian tube dysfunction including the newly developed pneumatic endoscopic procedure is discussed. The pneumatic endoscopic procedure at the three selected portions; the pharyngeal adjacent tubal area, the pharyngeal tubal orifice, and the lumen of the cartilaginous portion, is useful to detect topographic pathology, and its diagnostic significance may be attributed to visual detection of the morphological pathology.

Endoscopy↗
PubMed1985

Intractable heart failure, conduction disturbances and myocardial infarction by massive myocardial invasion of malignant lymphoma.

A patient with malignant lymphoma who developed congestive heart failure, conduction disturbances and myocardial infarction is presented. Two-dimensional echocardiography revealed marked thickening of the left ventricular wall, where the gallium scan correspondingly showed an abnormal accumulation. Irradiation to the mediastinum resulted in a dramatic decrease in ventricular wall thickness and disappearance of the gallium accumulation. Postmortem examination confirmed previous lymphomatous involvement of the myocardium. Combined techniques, including echocardiography and gallium scan, can be valuable for noninvasive detection and follow-up of myocardial involvement in patients with malignant lymphoma.

Aged↗
PubMed1985

Deranged metabolism of cyclic nucleotides in liver diseases.

To clarify the factor(s) responsible for changes in the plasma cyclic GMP concentration in liver diseases, we measured the plasma levels of cyclic GMP, along with cyclic AMP, in various clinical stages of chronic liver diseases and acute hepatitis. The level of cyclic GMP was found to increase significantly in the early stage of acute hepatitis, in the decompensated stage of liver cirrhosis, and in malignant diseases. In the former two states, it is postulated that decreased hepatic mass is responsible for the changes in the plasma cyclic GMP concentration. The retention rate of indocyanin green (ICGR15) was highly correlated with the plasma cyclic GMP level. The result suggests that the determination of plasma cyclic GMP is useful as an index of the reserve function of the liver in disease states.

Carcinoma, Hepatocellular↗
PubMed1985

Peculiar cytoplasmic inclusions in acute lymphoblastic leukemia: cytochemical and electron microscopic observations.

In acute lymphoblastic leukemia (ALL) of a 19-year-old woman, blast cells in the blood and bone marrow contained peculiar large cytoplasmic inclusions. The inclusions, measuring 0.5-3.5 micron in diameter, were stained with methylene blue, toluidin blue, pyronin, and periodic acid-Schiff. Activities for acid phosphatase and alpha naphthyl butyrate esterase were not detected in the inclusions. The cytochemical findings indicated that the inclusions contained basophilic material and polysaccharides and that they were not lysosomal in nature. In electron microscopy, the inclusions were membrane bound and contained densely packed microvesicles, measuring 40-70 nm in diameter; amorphous electron-dense material; and whorled membranous figures. The microvesicles often had a nucleoid-like core and resembled viruses in size and structure.

Adult↗
PubMed1985

Direct implication of surface mannosyl residues in cell adhesion of Dictyostelium discoideum.

In the cell adhesion of aggregation-competent Dictyostelium cells, the requirement for the carbohydrate moiety of the glycoprotein appeared to be indirect in that it acts to protect the protein moiety from proteolytic degradation; however, the effect was limited to the tunicamycin (TM)-sensitive carbohydrate moiety (Hirano, T., et al. (1983) J. Biochem. 93, 1249-1257). In the present study, we showed that the EDTA-stable adhesion of aggregation-competent Dictyostelium cells was abolished by the treatment of intact cells with jack bean alpha-mannosidase, whereas neuraminidase, beta-galactosidase, beta-N-acetylhexosaminidase, or alpha-L-fucosidase had no effect. The EDTA-stable cohesiveness of TM-treated cells in the presence of leupeptin (TM/LP cells) was also abolished by the treatment of the cells with alpha-mannosidase. The effect of alpha-mannosidase was not prevented in the presence of LP. The N-glycoside-deficient contact site A (an adhesion-mediating glycoprotein) was obtained from TM/LP cells and was shown to have a molecular weight of 70,000. This protein (p 70) was shown to still have carbohydrates as detected by polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS) and subsequent staining of the gel with periodic acid-silver stain. Moreover, p 70 reacted with anti-gp 68, which has a specificity against alpha-mannosyl residues of carbohydrate chains. However, p 70 treated with alpha-mannosidase showed decreased reactivity with anti-gp 68. The monovalent antibody fragment of anti-contact site A or anti-p 70 inhibited EDTA-stable cell adhesion of both control and TM/LP cells. These results indicated that TM-resistant mannosyl residues of contact site A are directly involved in EDTA-stable adhesion of aggregation-competent cells. This is the first report of the direct involvement of the carbohydrate moiety in cell adhesion of aggregation-competent Dictyostelium cells. A schematic model is presented of the role of the carbohydrate moiety in EDTA-stable cell adhesion, including the direct effect of carbohydrates.

Antibodies↗
PubMed1985

Dissociation of bovine cytochrome c1 subcomplex and the status of cysteine residues in the subunits.

Purified bovine heart two-band cytochrome c1 subcomplex was dissociated by treatment with p-chloromercuribenzoic acid (pCMB) into its heme subunit and a colorless subunit called hinge protein, which is essential for the formation of cytochrome c1-c complex. The subcomplex was found by titration to react with 4 mol of pCMB per mol of cytochrome c1. The contents of mercury of the dissociated heme subunit and the hinge protein were 3 and 1 mol per mol of polypeptide, respectively. These results, together with the sequence analysis, indicated that the three cysteine residues in cytochrome c1 heme subunit not involved in heme-binding existed in free thiol form. One of the five cysteine residues in the hinge protein was in free form and four in two disulfide bonds. The dissociated hinge protein was digested with staphylococcal protease and the cysteine-containing peptides were separated by reversed-phase high-performance liquid chromatography (HPLC). The content of mercury and the result of performic acid oxidation of cystine peptides revealed that Cys-30 existed in free thiol form and two disulfide bridges were formed between Cys-24 and Cys-68 and between Cys-40 and Cys-54. The conformation of the hinge protein was predicted to be composed largely of either two-alpha-helical or four-alpha-helical conformation with the amino (N)-terminal 20 residues being in a random structure.

Amino Acid Sequence↗
PubMed1985

Production of monoclonal antibodies against Legionella pneumophila serogroup 1.

Four monoclonal antibodies to Legionella pneumophila Philadelphia 1 were produced by the fusion of immunized BALB/c lymphocytes to a murine myeloma cell line. Two (Lp1-1 and Lp1-3) of the four monoclonal antibodies reacted with 14 L. pneumophila serogroup 1 strains, and the other (Lp1-2 and Lp1-4) reacted with only three out of 20 strains tested. These four monoclonal antibodies did not bind to any strains of L. pneumophila serogroup 2-7 and other Legionella species. In addition, it has been shown that these monoclonal antibodies may be useful not only for subserotyping of L. pneumophila but also for retrospective diagnosis using immunopathological methods.

Antibodies, Monoclonal↗