Search PubMed⌕ Search

Biomedical subjects

F Suzuki

Publications and source records attributed to F Suzuki.

At least 559 records · Page 31Linked to original sources
PubMed1981

Multiplication-stimulating activity (MSA) and cartilage-derived factor (CDF): biological actions in cultured chondrocytes.

Previously, we showed that a polypeptide isolated from fetal bovine cartilage stimulates proteoglycan synthesis, RNA synthesis, and DNA synthesis in cultured rabbit costal chondrocytes. In the present study, the effects of the cartilage-derived factor (CDF) were compared with those of multiplication-stimulating activity (MSA), which is thought to be included in somatomedins. CDF and MSA markedly increased [3H]thymidine incorporation into rabbit costal chondrocytes from 7--14 h after their additions. The incorporation of [3H]uridine was also increased within 1--2 h in the cells incubated with the peptides. These stimulations of nucleic acid syntheses were followed by cell division in serum-free culture medium. On the other hand, the peptides enhanced the synthesis of sulfated proteoglycans within 7 h. Furthermore, the extent of stimulation of proteoglycan synthesis, as measured in terms of increased incorporation of [35S]sulfate, [3H]glucosamine, or [3H]serine into material precipitated with cetylpyridinium chloride, was consistently higher than the extent of CDF or MSA stimulation of total protein synthesis, as measured in terms of increased incorporation of [3H]serine into acid-insoluble cellular material. These findings suggest that the stimulation of proteoglycan synthesis by CDF and MSA is not directly linked to the peptide-induced stimulation of cell proliferation. The present study also showed that CDF is as effective as MSA in stimulating various metabolic indices in cultured chondrocytes at their optimal concentrations.

Animals↗
PubMed1981

Experimental myocarditis induced in mice by infection with influenza A2 virus.

A mouse model was established for the study of acute myocarditis that occurs during influenza infection. Challenge with more than 10 LD50 of mouse-adapted influenza A2 virus (H2N2) induced myocarditis macroscopically discernible as white, irregularly shaped lesions which were shown by histological examination to consist of necrotic myofibers surrounded by infiltrating mononuclear inflammatory cells. After challenge with 10 LD50 of the virus, macroscopic myocarditis was found to advance in a progressive manner up to the 7th day, while the virus titer in the heart reached its peak on the 2nd day and began to decrease on the 5th day of infection. However, development of myocarditis was significantly suppressed in mice which were irradiated with 400 R of X-rays before infection. In addition, myocarditis did not develop in congenitally athymic nude mice. These data indicate that myocarditis was not brought about by viral action directly, but that it was mediated by some function of the host against viral invasion, which was abolished by X-irradiation. The data also suggest that T cells played a key role in the development of myocarditis.

Animals↗
PubMed1981

Interferon-inducing activity of an immunotherapeutic anticancer agent, SSM, prepared from Mycobacterium tuberculosis strain Aoyama B.

The interferon-inducing capacity of arabinomannan-lipid preparation (SSM) extracted from Mycobacterium tuberculosis Aoyama B in both BCG-sensitized and unsensitized mice was studied in comparison with that of purified protein derivative (PPD) prepared from the same tubercle bacillus. Although it is known that PPD cannot stimulate interferon production in BCG-unsensitized mice, interferon activity was found in sera of both groups of mice after intravenous injection of SSM at a dose of 5 mg/kg. The maximum titer was detected 5 hr after injection. The interferon induced by SSM in both groups of mice shared certain physicochemical properties with the immune interferon induced by PPD in BCG-sensitized mice. In BCG-unsensitized mice, interferon induction by SSM was markedly inhibited by pretreatment with trypan blue and carrageenan, whereas it was not depressed in BCG-sensitized mice given the same treatment or when interferon was induced by PPD. In addition, induction of interferon in BCG-sensitized mice by SSM and PPD and in unsensitized mice by SSM was completely abrogated by pretreatment with hydrocortisone acetate and whole-body x-irradiation (700 R). These results suggest that in BCG-unsensitized mice macrophages, in addition to X-ray or hydrocortisone-sensitive cells, may be required for interferon induction by SSM.

Animals↗
PubMed1981

Highly sensitive immunoassays for three forms of rat brain enolase.

Highly sensitive enzyme immunoassay systems for three forms (alpha alpha, alpha gamma, and gamma gamma) of rat brain enolase were prepared by use of specific antisera to two distinct subunits (alpha and gamma) of the isozymes and beta-D-galactosidase from Escherichia coli as label. Less than fmol-levels of the homologous dimer forms (alpha alpha and gamma gamma) could be determined with the corresponding antibody F(ab')2-bound solid-phase and the antibody Fab'-beta-D-galactosidase complex. The hybrid form (alpha gamma) could also be assayed specifically by use of the antibody to one subunit as solid-phase, and the antibody to another subunit as labelled complex with a minimum detectable sensitivity of 1 fmol.

Animals↗
PubMed1981

Determination of brain enolase isozymes with an enzyme immunoassay at the level of single neurons.

Ultrasensitive enzyme immunoassay systems for the assay of rat brain enolase isozymes (alpha alpha, alpha gamma, and gamma gamma forms) were prepared by use of beta-D-galactosidase from Escherichia coli as label and the purified rabbit antibodies to alpha alpha and gamma gamma enolases. The antibodies were purified from the immunoglobulin G (IgG) fractions of antisera by immunoaffinity chromatography with a column of the corresponding antigen-coupled Sepharose. Sandwich-type immunoassay systems with the galactosidase-labeled antibody Fab' fragments and the antibody F(ab')2-immobilized polystyrene beads could determine amounts as small as 1 amol (10(-18) mol) of each isozyme. Purkinje cell bodies picked up from the bulk-separated fraction by means of a nylon loop were subjected to the assay at the level of single cells. In contrast to previous report, this neuron contained not only the gamma gamma but also the alpha gamma and alpha alpha enolases at a level of amol per cell body, although the concentration of gamma gamma was the highest. Immunohistochemical experiments on te cerebellum with the peroxidase-labeled antirabbit IgG antibody and the unlabeled antibody method confirmed the above results, and indicated that both alpha and gamma subunits of hte enolase were stained intensely in axons.

Animals↗
PubMed1981

Cartilage of I-cell disease.

Biochemical analysis and morphologic observation of the iliac crest cartilage from 8-year-old girl with I-cell disease were performed. Instead of hypertrophic change of chondrocytes in the zone of cartilage-bone junction, there were small atrophic cells having many inclusion bodies accumulated with lamellar materials. Another characteristic finding in this zone was numerous cellular debris in the cartilage matrix. Significantly, a large amount of unsulfated chondroitin (21%) occurred in the cartilage with I-cell disease, and compensatory decrease of chondroitin 4-sulfate (14%) was observed. The percentage of chondroitin and chondroitin 4-sulfate on the control averaged 8.5 and 43%, respectively. The sedimentation profile of the proteoglycans closely resembled that of the normal cartilage.

Cartilage↗
PubMed1981

Current status and future direction of clinical electrocardiography: His bundle electrogram.

Recordings of His bundle electrogram combined with stimulation method are very useful to diagnose the locations of conduction disturbance, to understand the mechanisms of arrhythmias and to evaluate the electrophysiologic properties of the A-V conducting system. However, there remain some unsolved problems regarding the electrophysiologic interpretations and prognostic implications based on His bundle electrograms. In this panel discussion, some aspects with regard to the usefulness and limitations of His bundle electrogram will be discussed from our data obtained in 300 patients.

Adolescent↗
PubMed1981

Electrophysiologic studies of Jervell, Lange-Nielsen syndrome.

Electrophysiologic studies were performed in two sibling with Jervell, Lange-Nielsen syndrome. Electrophysiologic parameters were all within normal limits except for prolongation of effective refractory period of the ventricular myocardium. This finding may suggest one of electrophysiologic mechanisms underlying QT prolongation, that is, delayed ventricular repolarization.

Child↗
PubMed1981

Role of polyamines in expression of the differentiated phenotype of chondrocytes in culture.

Addition of putrescine to cultures of rabbit costal chondrocytes during the log-phase stimulated expression of their differentiated phenotype, as judged by increase in the synthesis of glycosaminoglycans and of metachromasia with toluidine blue staining. Putrescine stimulated glycosaminoglycan synthesis maximally at a concentration of 10(-7) M, and spermidine and spermine were also effective at similar concentration. These polyamines had little effect on DNA synthesis, RNA synthesis, DNA accumulation, or protein accumulation. These findings suggest that polyamines may be important in the expression of the differentiated phenotype of chondrocytes in culture.

Animals↗
PubMed1981

A rapid and large-scale isolation of renin from mouse submaxillary gland by pepstatin-aminohexyl-agarose affinity chromatography.

A pressor enzyme, renin, was purified about 60-fold by chromatography on an affinity column including pepstatin-aminohexyl-agarose with a high yield of 83% from the homogenate of adult mouse submaxillary glands. The renin obtained by the one-step purification was electrophoretically homogenous on SDS-polyacrylamide gel and was as active as an absolutely pure renin. The renin purified by the affinity column could be separated into five active components by chromatography on CM-cellulose. Each of these renins gave a symmetrical elution profile on the CM-cellulose column and a discrete protein band on polyacrylamide gel electrophoresis at pH 8.6. Administration of nanogram quantities of each of the two major renin fractions to nephrectomized rats caused a sustained rise of blood pressure and decrease in sensitivity of the animal to angiotensin II. This rapid and large-scale purification method using pepstatin-aminohexyl-agarose eliminates all four fractionation steps reported previously for the isolation of mouse submaxillary gland renin.

Animals↗
PubMed1981

Spectral dependencies of killing, mutation, and transformation in mammalian cells and their relevance to hazards caused by solar ultraviolet radiation.

Using germicidal lamps and Westinghouse sunlamps with and without filtration, the effectiveness of ultraviolet and near-ultraviolet light in inducing molecular and cellular changes was measured. Cell survival and the induction of resistance to 6-thioguanine or to ouabain were measured with V79 Chinese hamster cells, cell survival and neoplastic transformation were measured with C3H mouse 10 T 1/2 cells, and the induction of pyrimidine dimers containing thymine was measured in both cell lines. The short-wavelength cutoff of the sunlamp emission was shifted from approximately 290 nm (unfiltered) to approximately 300 and approximately 310 nm by appropriate filters. Although it was found that the efficiency with which all end points were induced progressively decreased as the short-wavelength cutoff was shifted to longer wavelengths, the rates of decrease differed appreciably. For example, doses of near-ultraviolet light longer than approximately 300 nm that were effective in mutating or in transforming cells were ineffective in killing them. In respect to pyrimidine dimer induction, several but not all cellular end points were induced by dose ratios of sunlamp light (short-wavelength cutoff, approximately 290 nm) to germicidal lamp light (254 nm) in fairly close accord with the doses required to produce equivalent proportions of dimers. However, for near-ultraviolet light having cutoffs at longer wavelengths, the biological action observed was appreciably greater than what would be predicted from the proportion of dimers induced. From the latter observation, it is inferred that increasing intensities of short-wavelength ultraviolet light, as would be expected from reductions in stratospheric ozone around the earth, would result in smaller increases in biological action, e.g., skin cancer, compared to current levels of action than would be predicted from an action spectrum completely corresponding to that of a pyrimidine dimer induction spectrum in DNA.

Animals↗
PubMed1980

Improved reaction buffers for solid-phase enzyme immunoassay without interference by serum factors.

A gelatin moderately digested by a protease, was as effective as original gelatin to remove the interference by serum factors with a sandwich immunoassay for insulin. Digestion of gelatin resulted in decrease in the viscosity, and the buffer containing the digested gelatin did not show gelation at 4 degrees C. Therefore the buffer involving the digested gelatin might be widely useful for the immunoassay without interference by serum factors.

Buffers↗