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Biomedical subjects

N Yoshida

Publications and source records attributed to N Yoshida.

At least 577 records · Page 32Linked to original sources
PubMed1984

[Clinico-pathological features of intracranial germ cell tumors with dissemination or metastasis in childhood].

Recently reports of the cases with intracranial germ cell tumor associated with dissemination to the central nervous system are increased since the introduction of CT scan. The authors experienced 8 cases with the dissemination among 19 cases of intracranial germ cell tumor in childhood, and discussed their clinico-pathological features. Before the CT scan era, the authors experienced only one case with dissemination, who was a 11 years-old boy (Case 1) and revealed two cell pattern pinealoma disseminating on the subependymal layer of all ventricles and in the basal cisterns at autopsy. Since the introduction of CT scan, 4 cases were found, who showed periventricular dissemination already at the first admission. Among them three cases revealed tumors in the pineal or suprasellar region and also dissemination of tumors on the wall of the lateral ventricles. The other one (Case 3) did not reveal any tumor at pineal or suprasellar region, but disseminated tumors on the wall of the third and lateral ventricles. Histological appearances of all 4 cases were two cell pattern pinealoma by examination of surgical or CSF materials. Only one case (Case 5) was found spinal dissemination later. All 4 cases were good prognosis. The authors considered that there might be diffuse primary ependymal germ cell tumor besides diffuse metastatic one. In the CT scan era, there were three cases who showed dissemination or metastasis along their clinical courses, but had not showed at the first administration. One (Case 6) of 3 cases showed a tumor at the right thalamus at the first administration. Five years later, the tumor metastasized to the cervical cord and he died.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

[Clinical use of cefoxitin in respiratory tract infections].

Cefoxitin (CFX) was used in 9 patients who had respiratory tract infections and following results were obtained: CFX was used in 2 patients with acute pneumonia, 2 with lung abscess, 3 with a mixed infection of lung cancer, 1 with a mixed infection of pulmonary tuberculosis and 1 with empyema. The overall efficacy rate was 77.8%; results were excellent in 2, good in 5 and poor in 2. Bacteriologically, all strains except P. aeruginosa were eradicated after treatment. No side effects were observed. A slight transient elevation of transaminase was observed in 1 patient after doses of 4 approximately 8 g daily. From the above, CFX seems to be a useful and safe drug as an initial choice in the treatment of respiratory tract infections.

Adult↗
PubMed1983

Effects of superoxide dismutase and catalase on disseminated intravascular coagulation in rats.

The effects of superoxide dismutase (SOD) and catalase on endotoxin-induced experimental disseminated intravascular coagulation (DIC) were studied in rats. Experimental DIC was induced by a 4 hr sustained infusion of endotoxin at a dose of 100 mg/kg. The rats were subcutaneously injected with SOD at 0.5, 5.0 or 50.0 mg/kg, or catalase at 0.01, 0.1 or 1.0 mg/kg, followed by the continuously infusion of 100 mg/kg/4hr of endotoxin. A preventive effect against DIC was noted in all the parameters, such as fibrinogen and fibrin degradation products, fibrinogen level, prothrombin time, partial thromboplastin time, platelet count and the number of renal glomeruli with fibrin thrombi, in the rats treated with 50.0 mg/kg of SOD or 1.0 mg/kg of catalase. When 50.0 mg/kg of SOD or 1.0 mg/kg of catalase was injected subcutaneously at 1, 2 or 3 hr after the initiation of the endotoxin-infusion, the protective effect against DIC was noted in all the parameters.

Animals↗
PubMed1983

Purification of human platelet calcium-activated protease. Effect on platelet and endothelial function.

Calcium-activated protease (CAP) was purified from the cytosol fraction of homogenized human platelet concentrates using a combination of gel filtration chromatography and affinity chromatography on antipain aminohexyl-Sepharose and activated thiol-Sepharose 4B. Purified CAP is composed of two different polypeptides of Mr = 80,000 and 27,000. Half-maximal protease activity was observed at 0.52 mM Ca2+, and all activity was inhibited by antipain, leupeptin, and N-ethylmaleimide. Activated CAP showed a time-dependent inactivation in the presence of 1 mM Ca2+ with only 5% of the control protease activity remaining after a 1-h exposure to calcium. Preincubation of washed platelets with varying amounts of CAP (0.2-0.4 units) significantly interfered with thrombin-induced platelet aggregation. In addition, ristocetin-induced platelet agglutination in the presence of von Willebrand factor was completely inhibited by 0.4 units of CAP. Concomitant with these protease-induced changes in platelet function, a decrease was observed in a major glycoprotein band of Mr = 150,000 present in platelet membranes and presumed to be glycoprotein Ib. In addition to these effects on platelets, CAP inhibited thrombin-induced production of prostacyclin by cultured human endothelial cells in a dose-dependent manner when the cells were pretreated with CAP. Thus platelet CAP can modulate membrane functions in both platelets and endothelial cells and may thus contribute to the regulation of hemostasis.

Blood Platelets↗
PubMed1983

B cell growth factors and B cell differentiation factor from human T hybridomas. Two distinct kinds of B cell growth factor and their synergism in B cell proliferation.

Human T hybridomas secreting B cell growth factors (BCGF) and B cell differentiation factor (BCDF) have been established. Hybrid clones 77-A, 94-C, and 98-F secreted BCGF that induced proliferation of anti-IgM-stimulated normal B cells. The culture supernatant from 77-A cells could also maintain continuous proliferation of colony-forming B cells, but the factor from 94-C could not. The addition of the supernatant from 94-C cells to that from 77-A cells, however, synergistically augmented the proliferation of colony-forming B cells, demonstrating the existence of two distinct kinds of BCGF and the synergism between them. These supernatants, however, showed no interleukin 2 (IL-2) or BCDF activity. A hybrid clone, 90-E, secreted BCDF. The culture supernatant induced Ig production in Cowan I-stimulated normal B cells or in a transformed B cell line, CESS. However, the supernatant had no BCGF or IL-2 activity. Anti-Ig-stimulated B cells, but not IL-2-dependent T cells, absorbed BCGF activity and CESS cells absorbed BCDF activity but not BCGF activity in the culture supernatants from T hybridomas. Taken collectively, the results demonstrated that IL-2, BCGF, and BCDF were different molecules and acceptors specific for the each molecule are present on the each target cell.

Absorption↗
PubMed1983

Staphylococci adherence to trypanosomes exposed to immune sera as a method for the diagnosis of Chagas' disease.

A new method, the staphylococci adherence test (SAT), for the serological diagnosis of Chagas' disease is described; it is based on the affinity of staphylococcal Protein A for IgG globulins and uses epimastigotes of Trypanosoma cruzi which are fixed on to glass slides and incubated stepwise with probing sera and a Staphylococcus aureus A suspension. After Giemsa staining, epimastigote preparations which have been incubated with positive sera appear covered by cocci. Results using indirect immunofluorescence, complement fixation and SAT were in agreement in 98.37% of 860 human sera. A slightly modified SAT (SAT') may also be utilized for the diagnosis of acute Chagas' disease. The simplicity of the method may allow its adaptation for field work. Other possible uses were investigated.

Animals↗
PubMed1983

Isotype switching in murine pre-B cell lines.

Isotype switching at the pre-B cell stage was studied by employing A-MuLV-transformed cell lines. Two gamma 2b-producing cell lines that did not have other cytoplasmic heavy chains or light chains were established from A-MuLV-transformed cell lines. One clone (SL2-1-52) arose spontaneously from a non-Ig-producing cell line (SL2-1) during in vitro culture. Another clone (AT11-2-24-6-99) underwent isotype switching from a mu-producing cell line (AT11-2-24-6), which had been derived from another non-Ig-producing line (AT11-2). Southern blot analysis of two gamma 2b-producing clones was performed in comparison to that of their respective parent clones. The results showed that isotype switching can operate at the stage of pre-B cells by a CH gene deletion mechanism without utilizing the switch region. In addition, the possibility is presented that deletion of the intervening CH genes could occur prior to the formation of the functional V region-coding DNA segment. This indicates that the prior expression of mu chains is not obligatory for the expression of other isotypes and that isotype commitment could occur in pre-B cells.

Abelson murine leukemia virus↗
PubMed1983

Interaction between trypsin-like enzyme from Streptomyces erythraeus and Japanese quail ovomucoid.

We examined the interaction between a trypsin-like enzyme from Streptomyces erythraeus (TLE-Se) and Japanese quail ovomucoid (QO) as a model of the interaction between a serine protease and a Kazal-type inhibitor. Both the second domain (Domain II) and the third domain (Domain III) of QO inhibited TLE-Se. But there was a great difference in the apparent association rate constant (kappa a) between Domain II and Domain III at pH 8.0 (the optimum pH of the enzymatic activity), and Domain III associated with TLE-Se about 10(5) times faster than Domain II. The pH dependency of kappa a for Domain III and TLE-Se was maximum around pH 8, but in the case of Domain II and TLE-Se the maximum was around pH 4. This suggested that some acidic amino acid residues had some influence upon the association of Domain II with TLE-Se. When we examined the interaction between TLE-Se and amidated Domain II in which most of the aspartic and glutamic acids were amidated for conversion into asparagine and glutamine with NH4Cl and carbodiimide, the pH dependence of kappa a greatly differed from that obtained for TLE-Se and native Domain II, and an almost constant kappa a value (10(3)-10(5) times higher than that of native Domain II) was exhibited between pH 5 and 8. At the same time, the dissociation constant at pH 8.0 became about 10(-2) times smaller, and thus the affinity between TLE-Se and amidated Domain II became stronger. These observations suggest that the electrostatic effect derived from the repulsion between the minus charges which are located at contact area sites of both molecules control the reactivity in the interaction between protease and a protein protease inhibitor.

Amides↗
PubMed1983

Surface antigens of metacyclic trypomastigotes of Trypanosoma cruzi.

The surface antigen makeup of metacyclic trypomastigote forms of strain G of Trypanosoma cruzi, which produce a subpatent infection in mice, differed from those of the virulent strains Y and CL. A 100,000-molecular-weight protein, barely detectable on the Y or CL cell surface, appeared as the main surface antigen of the G metacyclic trypomastigotes. In addition, the G metacyclic forms differed from those of the virulent strains in their susceptibility to complement-mediated immunolysis.

Animals↗
PubMed1983

Treatment of DIC with antithrombin III concentrates.

We administered AT III concentrates to 21 patients with DIC who failed to respond initially to heparin therapy. About 60% of these 21 patients were effectively treated with AT III concentrates by enhancing the effect of heparin and alleviating the burden of excessive plasma transfusions on the cardiovascular system.

Adult↗
PubMed1983

Natural and antibody-dependent cellular cytotoxicity of polymorphonuclear leukocytes.

Cytotoxic activity of polymorphonuclear leukocytes (PMN) in the peripheral blood of patients with various diseases was demonstrated to K562 cells (natural cytotoxicity, NC) and the antibody-coated P815 cells (antibody-dependent cellular cytotoxicity, ADCC), using a 51Cr-release method. The NC values of normal PMN were lower than those of normal lymphocytes with mean values of 5.0% and 30%, respectively. The NC values of patients' PMN were also lower in malignancy, chronic hepatitis and connective tissue diseases. The ADCC values of normal PMN were moderately high with a mean value of 16.0%, which was almost a half of normal lymphocytes. Higher ADCC values of PMN were found in patients with chronic hepatitis, SLE and Behcet's disease, and in these cases the ADCC values of their lymphocytes were extremely low. The supernatants of PMN mix-cultured with unlabeled K562 or the antibody-coated P815 cells were fairly cytotoxic to both cells, though the similar supernatants of lymphocytes were cytotoxic only to K562 cells, but not to the antibody-coated P815 cells.

Animals↗
PubMed1983

New antibiotics, carbazomycins A and B. III. Taxonomy and biosynthesis.

The carbazomycin-producing microorganism, strain H 1051-MY 10, was determined to a strain of Streptoverticillium ehimense. Biosynthesis of carbazomycin B was studied using 14C-labeled and 13C-enriched precursors in combination with 13C NMR spectroscopy. The C-2 carbon of [2-13C]trytophan was shown to be involved at the C-3 carbon in carbazomycin B and both carbons of [1,2-13C]acetate at the C-1 and C-10 moiety of the antibiotic. [CH3-13C]Methionine was involved at the methoxyl group but not at the methyl group on the C-2 carbon of the antibiotic. Neither of the labeled carbons, [1-14C]tryptophan nor [2,3-13C]propionic acid, was detected in the antibiotic, and a progenitor of the C-2 and C-11 moiety of the antibiotic has not been determined.

Anti-Bacterial Agents↗
PubMed1983

[Clinical studies of long-acting amoxicillin granules].

The long-acting amoxicillin granules (L-AMPC) was administered to 12 patients with respiratory tract infections and the following results were obtained. 1. L-AMPC was administered to 6 cases of acute upper respiratory tract infection, 2 of lower respiratory infection with lung cancer, 2 of bronchiectasis, 1 of lower respiratory infection with diffuse interstitial fibrous pneumonia and 1 of chronic bronchitis, and the overall efficacy rate was 83.3% (10/12), excellent in 2, good in 8, fair in 1 and poor in 1. 2. Bacteriologically, H. influenzae (5 strains), S. aureus (3 strains), S. pneumoniae (1 strain) and S. faecalis (1 strain) were eradicated and each 2 strains of K. pneumoniae and C. diversus appeared after treatment. 3. No side effect was observed and a slightly transient elevation of GPT was observed in only 1 case. From the above, L-AMPC seems to be a useful and safety drug in respiratory tract infections.

Adult↗