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Biomedical subjects

Y Yoshitake

Publications and source records attributed to Y Yoshitake.

At least 55 records · Page 3Linked to original sources
PubMed1992

Distribution of fibroblast growth factors in cultured tumor cells and their transplants.

The distributions of acidic fibroblast growth factor (aFGF) and basic FGF (bFGF) in extracts of various cultured mammalian cells were determined from their elution profiles on heparin-affinity chromatography, and assay of activity as ability to stimulate DNA synthesis in BALB/c3T3 cells. Only aFGF was found in extracts of mouse melanoma B 16 cell and rat Morris hepatoma cell (MH1C1) lines. Other tumor cell lines established from solid tumors and some normal cells contained bFGF as a main component, but blood tumor cell lines contained no aFGF or bFGF. The FGFs in extracts of solid tumor tissues derived by transplantations of these cultured tumor cells and various normal tissues of mice were also examined. Tumors formed by all cell lines, regardless of whether they produced aFGF, bFGF, or neither, contained bFGF that was probably derived from host cells including capillary endothelial cells, in addition to the tumor-derived aFGF or bFGF, if produced. The content of bFGF, possibly derived from the host, in these tumor tissues was comparable to those of various mouse organs other than thymus, lung, spleen, and testis, which have higher bFGF contents. Tumor tissues derived from cultured cells producing bFGF had relatively higher bFGF contents. Like bFGF, aFGF was distributed almost ubiquitously in normal mouse tissues.

Animals↗
PubMed1992

Roles of various growth factors in growth of human osteosarcoma cells which can grow in protein-free medium.

The human osteosarcoma cell line (OST-1-PF) can grow in protein-free Coon's modified Ham's F12 medium. Growth of the cells in protein-free medium was partially density-dependent and partially depressed by medium change. An extract and conditioned medium of OST-1-PF cells contained high mitogenic activity for BALB/c3T3 cells. The growth factor in the cells was purified and identified as a basic fibroblast growth factor (bFGF)--like factor on the basis of its elution profile on heparin-affinity chromatography and the result of immunoblotting. An unidentified factor in a conditioned medium eliciting most of the DNA synthesis-stimulating activity showed a weak affinity for heparin. Various additions, including serum and growth factors, stimulated the growth of OST-1-PF cells in protein-free medium. Of these factors, epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), acidic fibroblast growth factor (aFGF) and bFGF were the most potent mitogens. High-affinity receptors of EGF and FGF were found on the surface of these cells. These results indicate that autonomous growth of OST-1-PF cells in protein-free medium is mainly controlled by an intracellular mechanism.

Cell Division↗
PubMed1991

Immunohistochemical localization of basic fibroblast growth factor in A431 human epidermoid carcinoma cells.

The intracellular location of basic fibroblast growth factor (bFGF) was determined in A431 human epidermoid carcinoma cells both on immunofluorescence and on immunoelectron microscopy using a monoclonal anti-bFGF antibody. The immunofluorescence was located in the cytoplasm in quiescent cells. Following the addition of FCS to the culture medium of quiescent sparse cells the growth factor was translocated to and accumulated in the nucleolus. Immunogold particles were dense near the ribosomes, but were not recognized in the cytoplasmic structures concerned with the usual secretory pathway such as the rough endoplasmic reticulum, the Golgi apparatus, and secretory granules. These results suggest that endogenous bFGF undergoes intracellular sorting and enters the nucleoli in A431 cells according to an extracellular growth signal.

Carcinoma, Squamous Cell↗
PubMed1991

[Serum-free culture of tumor cells--recent problems in autocrine hypothesis].

Tumor cell lines in culture that can grow in protein-free medium are suitable for studying the mechanism of autonomous growth of tumor cells. We have studied the mechanism of autonomous growth of three cell lines which were established from human solid tumors. These cell lines produce basic fibroblast growth factor (bFGF), but it does not seem to act as an autocrine growth factor. bFGF produced by these cells is accumulated in the nuclei and may act as an autointrafactor for autonomous growth of these cells.

Adenoma, Bile Duct↗
PubMed1990

Production of basic fibroblast growth factor-like factor by cultured human cholangiocellular carcinoma cells.

An extract of cultured human cholangiocellular carcinoma cells (HuCC-T1) was found to contain high mitogenic activity for BALB/c3T3 cells. The growth factor eliciting most of the mitogenic activity was purified and concluded to be identical with basic fibroblast growth factor (bFGF)-like factor on the basis of its molecular weight and heparin-Sepharose elution profile, and the results of immunoblotting and radioimmunoassay. HuCC-T1 cells also secreted bFGF-like factor into serum-free medium. A combination of insulin and transferrin or bovine serum albumin stimulated the growth of HuCC-T1 cells in serum-free medium. However, bFGF did not stimulate their growth in the presence and absence of these supplements. Neutralizing monoclonal antibody against bFGF did not inhibit growth. These results indicate that bFGF-like factor is not a growth factor for this cell line.

Adenoma, Bile Duct↗
PubMed1990

[Effects of endurance training on blood lactate, plasma noradrenaline, heart rate, and systolic blood pressure at submaximal exercise].

The purpose of this study was to investigate the effects of low-intensity endurance training on the lactate threshold (LT) and the onset of blood lactate accumulation (OBLA), as well as the relationship among blood lactate, heart rate, systolic blood pressure and the plasma noradrenaline (NA) concentration during submaximal exercise before and after training. Seven middle-aged women aged 33-57 years performed endurance training on a bicycle ergometer for 60 min 3 days a week for 6 weeks at an intensity corresponding to 50% of their maximum oxygen uptake. The results were summarized as follows: 1) LT and OBLA increased significantly by 32% (p less than 0.05) and 16% (p less than 0.05), respectively, after the training. 2) The increase rate of OBLA correlated negatively to its initial level (p less than 0.05) but the increase rate of LT did not. 3) Heart rate, systolic blood pressure and the pressure rate product (systolic blood pressure x heart rate x 10(-2] at LT and OBLA did not change significantly after the training. 4) A significant linear correlation between blood lactate and NA was observed during the submaximal exercise before (p less than 0.05) and after (p less than 0.05) the training, but the slopes of the two regression lines did not differ significantly. It was concluded that low-intensity training results in a significant improvement in LT and OBLA for middle-aged women. It was further suggested that, after the training, diminished responses of the cardiovascular and sympathetic nervous system are in parallel with the decrease in the blood lactate concentration during submaximal exercise.

Adult↗
PubMed1990

[Fenestrated basilar artery with ruptured cerebral aneurysms: case report].

Two cases of aneurysms with basilar artery fenestration are presented. A 45 year-old lady had a saccular aneurysm associated with a fenestrated basilar artery. The fenestration was located in the proximal third of the basilar artery. The aneurysm arose from the proximal end of the fenestration, projecting antero-inferiorly. Via a left retromastoid craniectomy, the aneurysm was successfully obliterated through the space between the eighth cranial nerve and the lower cranial nerve complexes. Postoperative deficit in the lower cranial nerves was minimal and transient. The other patient, a 63 year-old lady, had multiple aneurysms arising from the anterior circulation associated with a basilar artery fenestration. These aneurysms were clipped uneventfully. Surgical approach to an aneurysm arising from the basilar artery fenestration is discussed with other related literature. Full study of posterior circulation with multiple projection is mandatory to detect basilar artery fenestration, and the possible presence of saccular aneurysm at the site of the anomaly.

Basilar Artery↗
PubMed1989

Monoclonal antibodies against heparin-binding growth factor II/basic fibroblast growth factor that block its biological activity: invalidity of the antibodies for tumor angiogenesis.

Two monoclonal antibodies (mAbs) against bovine heparin-binding growth factor II (HBGF-II)/basic fibroblast growth factor (bFGF) were obtained from mouse hybridoma cell lines. They were highly specific for bFGF from bovine, human, and mouse sources and did not cross-react with bovine heparin-binding growth factor I (HBGF-I)/acidic fibroblast growth factor (aFGF). The immunoglobulin class and subclass of these mAbs were IgG1, K. The apparent dissociation constant (Kd) for bFGF of these mAbs ranged from 10(-9) to 10(-10) M. One mAb (bFM-2) also cross-reacted with heat-inactivated bFGF, while the other mAb (bFM-1) did not, suggesting that bFM-1 recognized the conformation of the bFGF molecule necessary for its biological activity. These mAbs inhibited growth of cultured bovine capillary endothelial cells in both the presence and absence of exogenous bFGF, indicating the autocrine action of this growth factor in in vitro growth of these cells. On the other hand, injection of these hybridoma cell lines s.c. into the backs of athymic mice resulted in development of highly vascularized solid tumors and a sustained high level of anti-bFGF activity in the blood of the tumor-bearing mice. These findings suggest that bFGF is not essential as an autocrine or paracrine growth factor for angiogenesis in vivo. These mAbs should be useful in further studies on the physiological role and the conformation-function relationship of bFGF because they block its biological activity.

Animals↗
PubMed1989

Identification of a family of insulin-like growth factor II secreted by cultured rat epithelial-like cell line 18,54-SF: application of a monoclonal antibody.

Somatomedin/insulin-like growth factor (IGF)-like polypeptides (designated SMP) were purified from the serum-free conditioned medium of cultured rat epithelial-like cells, 18,54-SF. A monoclonal antibody (MAb) was produced against partially purified SMP. The antibody was immunoglobulin G1 relatively specific for multiplication-stimulating activity III-2 (rat IGF-II), with a Kd value of 5.6 X 10(-9) M. The antibody showed 100% cross-reactivity with human IGF-II and 10% cross-reactivity with human IGF-I, but did not cross-react with insulin. For purification of SMP, therefore, immunoaffinity chromatography on Sepharose coupled with the MAb was used besides a procedure including ion exchange chromatography, gel filtration, and reverse phase HPLC. The purified SMP (at least five polypeptides) each gave a single peak on reverse phase HPLC and appeared as a single band with an apparent mol wt of 5000-8000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major components of SMP (designated HP1-SMP and HP3-SMP), which were purified about 100-fold from conditioned medium, stimulated DNA synthesis in human fibroblasts in culture and sulfation in chick embryonic cartilage in culture. These polypeptides showed almost the same cross-reactivity as multiplication-stimulating activity III-2 on RIA with the MAb. The partial amino acid sequences of HP1- and HP3-SMP were determined, and these polypeptides were identified with rat IGF-II.

Animals↗
PubMed1988

Growth control of A431 cells in protein-free medium: secretory products do not affect cell growth.

A431 cells grew at similar rates in protein-free Coon's modified Ham's F12 medium (PF-C-F12) with and without added bovine calf serum. The cells secreted a heparin-binding growth factor and a type-beta transforming growth factor, but their growth in PF-C-F12 was not affected by these factors, or by DNA synthesis factor from Rhodamine fibrosarcoma, basic fibroblast growth factor, insulin, human transferrin, bovine serum albumin, and their combinations. Growth of A431 cells in PF-C-F12 was not density dependent and was not affected by either addition of conditioned medium or replacement of conditioned medium by fresh medium. These results indicate that A431 cells have an intracellular mechanism for autonomous growth, and that their growth is not affected by factors that they secrete or by exogenous growth factors.

Cell Division↗
PubMed1988

Stabilization of fibroblast growth factors by a non-cytotoxic zwitterionic detergent, 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS).

The potential usefulness of a zwitterionic detergent, 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHPAS), in the stabilization of acidic and basic fibroblast growth factors (FGFs) was examined. Among several detergents, CHAPS was found to be not only non-cytotoxic but also most useful in handling the diluted preparations of FGFs. The advantages are as follows: 1) at lower concentrations than 0.01% CHAPS did not affect growth factor activity of calf serum (CS) and the growth rate of BALB/c 3T3 cells. The primary culture of rat prostate epithelium and colony formation of NRK-49F cells were hardly influenced by CHAPS lower than 0.003%; 2) the loss of FGFs that usually occurs due to their adherence to the surface of storage containers was effectively prevented by inclusion of 0.1% CHAPS; 3) the recovery of FGFs after storage or dialysis was significantly enhanced by inclusion of 0.1% CHAPS; 4) CHAPS at lower concentrations than 0.1% does not interfere with amino acid analysis, except that Thr may be misled only when the ratio of protein/CHAPS is low; 5) amino acid sequence analysis was hardly disturbed by CHAPS up to 0.5%. These results indicate that CHAPS is useful as a stabilizing agent for various kinds of polypeptides capable of showing biological activity at a low concentration.

Amino Acids↗
PubMed1988

Production of monoclonal antibodies with specificity for different epitopes on the human epidermal growth factor molecule.

Four different monoclonal antibodies (MAbs) to human epidermal growth factor (hEGF) were obtained from mouse hybridoma cell lines. They were highly specific for hEGF and did not cross-react appreciably with mouse EGF. The immunoglobulin class of these MAbs was IgG1 or IgG2a. The apparent Kd values for hEGF of these MAbs ranged from 10(-10) to 10(-9) M. These MAbs all inhibited DNA synthesis in BALB/c3T3 cells stimulated by hEGF and 125I-labeled hEGF binding to the receptor of the cells. Reduction of hEGF with dithiothreitol decreased its reactivity with these MAbs, suggesting that they recognized the conformation of the hEGF molecule maintained by the three disulfide bonds. By competitive binding experiments with hEGF, these four MAbs were classified into three groups: two binding to an A domain of hEGF, one to a B domain, and one to a C domain and preventing the bindings of the other MAbs at the A and B domains. When a methionyl residue of hEGF was removed by its treatment with CNBr, the immunological reactivity of the C domain, but not the A or B domain, was destroyed in association with a decrease in the biological activity of the growth factor. These MAbs should be useful in studies on the structure-function relationship of hEGF.

Animals↗
PubMed1987

Secretion of DNA synthesis factor (DSF) by A431 cells that can grow in protein-free medium.

A431 cells grew in protein-free Coon's modified Ham's F12 medium at a similar rate to that in medium supplemented with calf serum and secreted a growth factor capable of stimulating DNA synthesis in BALB/c3T3 cells. This factor had strong affinity for heparin and was partially purified from the conditioned medium by heparin-Sepharose affinity chromatography and molecular sieving on Bio-Gel P-60. The apparent molecular weight of the factor was 20-30K. Its activity was inhibited by heparin at concentrations of above 0.03 microgram/ml.

Carcinoma, Squamous Cell↗