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Biomedical subjects

F Suzuki

Publications and source records attributed to F Suzuki.

At least 541 records · Page 30Linked to original sources
PubMed1982

Effect of bone-derived growth factor on DNA, RNA, and proteoglycan synthesis in cultures of rabbit costal chondrocytes.

Calvariae and chondrocytes in culture have been reported to release growth factors which stimulate bone and cartilage growth respectively. In the present studies, we examined the effects of bone-derived growth factor (BDGF) on DNA, RNA and proteoglycan synthesis in cultured rabbit chondrocytes. Two partially purified fractions of BDGF were tested, one with an approximate molecular weight (MW) of 20-30,000 and with greater activity on calvarial DNA labeling (BDGF I) and another with an approximate MW 6-13,000 and greater activity on bone collagen labeling (BDGF II). Both fractions had a similar effect and increased the incorporation of -3H-uridine into acid insoluble residues in chondrocytes and the incorporation of 35SO4(2-), 3H-glucosamine and 3H-serine into proteoglycans. However, BDGF II had a greater stimulatory effect on the incorporation of 3H-thymidine than BDGF I. These findings suggest that factor(s) released by bone cells are capable of stimulating cartilage metabolism and growth.

Animals↗
PubMed1982

Peripheral distribution of nervous system-specific S-100 protein in rat.

S-100 protein, a nervous system-specific protein, was determined in a soluble extract of various rat tissues with a sensitive enzyme immunoassay method, which consisted of a solid-phase with immobilized anti-S-100 antibody and the antibody labeled with beta-D-galactosidase from Escherichia coli. The minimum detectable amount of S-100 protein was 3 pg/assay. Central nervous tissues (cerebrum, cerebellum, and brain stem) contained 1.4 to 2.8 micrograms S-100 protein/mg protein, whereas most of the peripheral tissues contained less than 0.05 microgram/ml of the specific protein. However, the level of S-100 protein was high in adipose tissue (0.5--1.1 micrograms/mg) and in trachea (about 0.5 microgram/mg), which involves cartilage. The S-100 protein levels in several tissues were significantly higher in female rats than in males at ages of 5 to 6 weeks.

Animals↗
PubMed1982

Characterization of cells infiltrating the lungs of x-irradiated and nude mice after influenza virus infection.

After X-irradiated and nonirradiated mice (C3H/He) as well as athymic nude mice and haired littermates (BALB/c) were infected with influenza A virus (Kumamoto strain, H2N2), they were examined for survival period, the development of consolidation in the lungs and the characteristics of the cells infiltrating the lung tissues. In two different T-cell deficient groups, there was a definite delay in the development of consolidation compared with their respective controls and this was reflected in prolonged survival periods: 5 days longer for irradiated mice and 6 days longer for nude mice. In both T-cell deficient and normal groups, about 70% of the cells obtained from consolidated lung tissues after virus infection were found to be small lymphoid cells and there were no morphological differences between the T-cell deficient and normal groups. None of these small lymphoid cells from the peripheral blood or the spleen of T-cell deficient mice responded to concanavalin A. In the lungs of both X-irradiated mice and nude mice, however, a definite increase in cells having natural killer activity was found at the late stages of the influenza infection, suggesting their participation in the development of consolidation.

Animals↗
PubMed1982

Alterations of interferon production in a mouse model of thermal injury.

The effect of thermal injury on the response of interferon (IFN) production in vivo and in vitro after stimulation with eight representative inducers was investigated in a mouse model. The response of mice to immune IFN (IFN-gamma) inducers, staphylococcal enterotoxin A, concanavalin A, and a specific antigen for BCG-sensitized lymphocytes (purified protein derivative) was impaired after a 30% total body surface area third-degree burn. Suppression of IFN-gamma production was observed at day 2 and persisted until day 7 after burn. Decreased IFN-gamma production correlated closely with the percentage of total body surface area burned. When virus type IFN (IFN-alpha/beta) inducers, Newcastle disease virus, polyriboinosinic-polyribocytidylic acid, 10-carboxymethyl-9-acridanone, and E. coli endotoxin, were administered to mice, no change in IFN response was observed after thermal injury. Similar results were obtained when spleen cells obtained from thermally injured mice were stimulated with IFN-gamma inducers in vitro. These studies suggest that although the capacity for IFN-alpha/beta production remains intact in thermally injured mice, IFN-gamma production may be selectively decreased in burned animals and in their spleen cells.

Animals↗
PubMed1982

[Induction of interferon and activation of NK cells and macrophages in mice by oral administration of Ge-132, an organic germanium compound].

After oral administration of an organic germanium compound, Ge-132 (300 mg/kg), a significant level of interferon (IFN) activity was detected in the sera of mice at 20 hr and it reached a maximum of 320 U/ml at 24 hr. This IFN activity was lost after heat- or acid-treatment, suggesting that the induced IFN is of gamma nature. The molecular weight of this IFN was estimated to be 19,000 daltons by gel filtration. After the oral administration of Ge-132, NK activity of spleen cells had increased at 24 hr and cytotoxic macrophages were induced in the peritoneal cavity at 48 hr. In mice, receiving intraperitoneal (i.p.) injections of trypan blue or carrageenan 2 days before oral administration of Ge-132, neither induction of IFN nor augmentation of NK activity followed. X ray irradiation of mice also rendered the mice incapable of producing IFN, all suggesting that both macrophages and lymphocytes are required for this IFN induction. After i.p. administration of induced IFN, both NK and cytotoxic macrophage activities appeared at 48 hr with as little as 20 U/ml titered IFN. These facts may indicate that the augmentation of NK and activation of macrophages in mice after oral administration of Ge-132 is mediated by induced IFN.

Administration, Oral↗
PubMed1982

Mechanism for the suppression of gamma-interferon responsiveness in mice after thermal injury.

As reported previously, gamma-interferon production was decreased after the administration of inducers to thermally injured mice as compared with noninjured controls. Similarly, spleen cells from injured mice had decreased ability to produce interferon in vitro after stimulation with inducers. The present study demonstrated that the decrease in interferon production was associated with the presence of suppressor cells in the spleen of burned mice that were capable of inhibiting interferon production by normal splenic lymphocytes in vitro. Passive transfer of spleen cells containing suppressor cell activity derived from injured mice induced suppression in normal mice, and the time of the appearance of suppressor cell activity in injured mouse spleens closely approximated the time of the appearance of the suppression of interferon production observed in mice after thermal injury. The suppressor cells were characterized as a population of macrophages by the following: they adhered to plastic surface and could be removed from spleen cells by carbonyl-iron treatment; treatment of plastic-adherent cells with anti-Thy-1.2 and anti-mouse immunoglobulin antisera followed by complement failed to abrogate the suppression produced by these cells.

Animals↗
PubMed1982

Antitumor and interferon-inducing activities of TH69, a whole bacterial preparation of Streptococcus faecalis, in mice.

The antitumor effect of TH69, a lyophilized whole cell preparation of Streptococcus faecalis, was examined in mice using four experimental tumors: Ehrlich carcinoma and sarcoma-180 in DDI mice, MCA tumor in syngeneic C3H mice and Meth-A tumor in syngeneic BALB/c mice. Consecutive intraperitoneal injections of TH69 started one day after the tumor implantation markedly inhibited the growth of the two allogeneic ascites tumors and two syngeneic solid tumors. However, even with the most sensitive Ehrlich ascites tumor, TH69 was ineffective when the tumor cell inoculum was more than 2 X 10(6) cells per mouse. Neither oral nor subcutaneous administrations of TH69 produced significant antitumor effects. After a single intraperitoneal administration of TH69 (300 mg/kg) to mice, interferon was induced in the serum with a titer of 220 U/ml at 14 hr after administration. As TH69 has no direct cytotoxic activity against Ehrlich tumor cells, the antitumor effect of TH69 in mice must be ascribed to some immunopotentiating activity including interferon induction.

Animals↗
PubMed1981

Regulation of neuron-specific enolase in NG108-15 hybrid cells and C6BU-1 glioma cells.

Distribution of three isoenzymes of brain enolase (2-phospho-D-glycerate hydro-lyase, EC 4.2.1.11) (alpha alpha, alpha gamma and gamma gamma forms) in clonal cell lines of neuroblastoma (NS20Y and N18TG-2), glioma (C6BU-1), and hybrid cells NG108-15, NCB20, Nbr10A, Nbr20A, N4G-B-a and N4G-C-a) was examined with a sensitive enzyme immunoassay system, that uses a rabbit antibody to rat brain enolase alpha alpha or gamma gamma. All cell lines tested were found to possess the enolase which contains gamma subunit (a neuron-specific protein), although the alpha alpha enolase (non-neuronal enolase) was the dominant from in these cells. A clonal rat glioma (C6BU-1) cell contained about 40, 1 and 0.07 microgram/mg protein of alpha alpha, alpha gamma and gamma gamma enolases, respectively, at the confluent stage. Inclusion of 1 mM dibutyryl cyclic AMP or 10 micrometers prostaglandin E1 plus 1 mM theophylline in the culture medium of a hybrid cell (NG108-15, mouse neuroblastoma x rat glioma) resulted in a more than 2-fold increase in the concentrations of alpha gamma and gamma gamma in the cell within a few days, with little change in the alpha alpha enolase concentration. A similar increase in the concentration of gamma subunit by the nucleotide (but not by prostaglandin E1 plus theophylline) was also observed in the glioma cell (C6BU-1) line. The results suggest that the gamma subunit or the neuron-specific protein can be regulated in NG108-15 and C6BU-1 cells in a cyclic AMP-dependent fashion.

Animals↗
PubMed1981

Changes in intramembranous particle distribution epididymal spermatozoa of the boar.

Membranes of boar spermatozoa from different regions of the epididymis and after ejaculation were studied by the freeze-fracture replica technique. The ordered pattern of the intramembranous particles of spermatozoan plasma membranes was different in the five arbitrary zones of the epididymis and in the semen. A distinctive ordered pattern was absent in zone 1, which is the proximal segment of the epididymis. In zone 2, paired parallel rows of the particles were present in the plasma membrane over the acrosomal region. This parallel arrangement was not present in zone 3 spermatozoa. Anterior to the posterior ring, cords formed by packed particles were apparent in zone 2 spermatozoa and reached their maximum prominence in zone 3, and persisted in zones 4 and 5 and in the semen. The plasma membrane over the marginal ridge of the acrosome had a hexagonal array of particles only in zones 4 and 5 spermatozoa. A similar pattern appeared on the post-acrosomal region of spermatozoa in zone 5 and in the semen. The plasma membrane of the middle piece had a rectilinear arrangement of the particles in zone 2 spermatozoa in which the migration of the cytoplasmic droplet was complete. Rudiments of the rectilinear arrangement persisted in spermatozoa in zones 4 and 5 and in the semen. These changes are discussed in relation to sperm maturation in the epididymis. The acrosomal membrane had a hexagonal arrangement of particles in the equatorial segment. The marginal ridge of the outer acrosomal membrane had parallel rows of intramembranous particles. The organization of the acrosomal membrane particles did not change during the epididymal passage of boar spermatozoa.

Acrosome↗
PubMed1981

Effects of parathyroid hormone and cyclic AMP analogues on the activity of ornithine decarboxylase and expression of the differentiated phenotype of chondrocytes in culture.

Parathyroid hormone (PTH) greatly increased the level of adenosine 3', 5' cyclic monophosphate (cAMP) in rabbit costal chondrocytes in culture 2 minutes after its addition. PTH, as well as N6 O2' dibutyryl adenosine 3', 5' cyclic monophosphate (DBcAMP) and 8 Bromo adenosine 3', 5' cyclic monophosphate (8 Br-cAMP) induced ornithine decarboxylase (ODC; L-ornithine carboxylyase; EC 4.1.1.17), which reached a maximum 4 hours after their addition. Neither cAMP, N6 O2' dibutyryl guanosine 3', 5' cyclic monophosphate (DBcGMP), nor sodium butyrate increased the activity of the enzyme. PTH had no effect on DNA synthesis, while DBcAMP and 8 Br-cAMP decreased DNA synthesis. Expression of the differentiated phenotype of chondrocytes in culture was also induced by PTH, DBcAMP, and 8 Br-cAMP, but not by cAMP, DBcGMP, or sodium butyrate, as judged by morphological change. Glycosaminoglycan synthesis, a characteristic of the cartilage phenotype, began to increase 8 hours after addition of PTH or DBcAMP, reaching a plateau 32 hours after their addition. These findings suggest that PTH induces increase of ODC activity and expression of the differentiated phenotype of chondrocytes through increase of cAMP and that induction of OCD is closely related to expression of the differentiated phenotype of chondrocytes.

Animals↗
PubMed1981

Somatomedin-like peptide(s) isolated from fetal bovine cartilage (cartilage-derived factor): isolation and some properties.

Fetal bovine cartilage contains a polypeptide(s) that has somatomedin-like effects on rat and rabbit costal chondrocytes in culture. This factor, named the cartilage-derived factor, was extracted from fetal bovine cartilage, fractionated with acetone, and purified by gel filtration on Toyopearl HW 55-F in 4 M guanidine hydrochloride, preparative isoelectric focusing, and subsequent gel filtration on Toyopearl HW 55-F in 1 M formic acid. The resulting preparation, which focused in the neutral pH region and eluted from a Toyopearl column in a fraction with apparent Mr 10,000--11,000, appeared homogenous by NaDodSO4 gel electrophoresis. The purified preparation markedly enhanced not only proteoglycan synthesis but also DNA synthesis in rabbit costal chondrocytes and, on a protein basis, it was 1000 times more active than insulin and 1,000,000 times more active than fetal calf serum in stimulating proteoglycan synthesis.

Animals↗
PubMed1981

Simulation of the initial stage of endochondral ossification: in vitro sequential culture of growth cartilage cells and bone marrow cells.

Growth cartilage cells were isolated from the ribs of young rats and cultured at high cell density in Ham's F-12 medium supplemented with 10% fetal calf serum. During 7 days, glycosaminoglycans and proteoglycans were actively synthesized and secreted, forming a metachromatic matrix. When cultured together with growth cartilage cells precultured and biosynthetically prelabeled with 35SO4(2-) in their glycosaminoglycans, bone marrow cells caused release of 35S-labeled material into the culture medium. Glycosaminoglycan was also released by addition of conditioned medium obtained from cultures of bone marrow cells or peritoneal macrophages to the growth cartilage cell cultures. Electron microscopic studies of the extracellular matrix of growth cartilage cells cocultured with bone marrow cells showed that needles of apatite mineral were deposited within and in close apposition to the surfaces of matrix vesicles. These findings suggest that enzymes released from bone marrow cells or macrophages removed glycosaminoglycan or proteoglycans, which may be inhibitors of mineral growth, and consequently mineralization was initiated. From these findings, sequential culture of growth cartilage cells and bone marrow cells is promising as an experimental system for investigating the mechanism of the initial stage of endochondral ossification.

Animals↗