673 research outputs found
In VIVO anti-tumor activities of gelatin
Aim: As reported previously, porcine skin gelatin exerted direct anti-tumor effect in vitro and induced anti-tumor peritoneal macrophages in vitro. The present study investigated whether or not the gelatin exerted anti-tumor effect in vivo. Methods: In vitro anti-tumor activities of peritoneal macrophages and the gelatin were evaluated with tritium thymidine uptake by target tumor cells. In vivo anti-tumor activity was evaluated with the survival of tumor-bearing animals and the size of the tumor. Results: Intraperitoneal daily administration of 12.5 mg of the gelatin prolonged the survival of mice which had been intraperitoneally inoculated with MH134 (hepatic cell carcinoma cell line) or Colon 26 (colon carcinoma cell line) tumor cells, and there were no tumors in case of MH134 cells inoculation. Intraperitoneal daily administration of 12.5 mg of the gelatin did not affect growth of subcutaneous MH134 tumor. The gelatin administered subcutaneously did not affect the survival of mice with intraperitoneal MH134 tumor. On the other hand, bovine skin gelatin administered subcutaneously achieved statistically significant prolongation of the survival. The contact of MH134 cells with porcine skin gelatin for 5 min was required for the gelatin to exert its anti-tumor activity in vitro. Porcine skin gelatin of 12.5 mg injected intraperitoneally was detected as protein in the peritoneal cavity 5 min after the injection. Peritoneal macrophages elicited by intraperitoneal injection with porcine skin gelatin suppressed tritium thymidine uptake by MH134 cells more strongly than those elicited by thioglycollate injection. Conclusion: Porcine skin gelatin administered intraperitoneally prolonged the survival of tumor-bearing mice via activation of peritoneal macrophages and involvement of direct anti-tumor activity of porcine skin gelatin. Key Words: porcine skin, gelatin, dissemination
Serum factors that suppress cytotoxic effect of methotrexate
To study the phenomenon that human erythroid leukemia K-562 cells are more sensitive to cytotoxic effect of antimetabolites when cultured in a serum-free medium than in a conventional medium containing fetal calf serum (FCS). Methods: Cytotoxic effects of methotrexate, azaserine and 5-fluorouracil were estimated by accessing the lactate dehydrogenase (LDH) activity of viable tumor cells. Proteins of FCS were separated using two-dimensional electrophoresis followed by mass spectrometry analysis. Results: Addition of 10% FCS attenuated anti-tumor activity of methotrexate and azaserine against K-562 cells compared with serum-free medium. Such an activity of FCS was different for each serum lot. Comparison of the proteins in active serum lot with those in not active one using two-dimensional electrophoresis showed that in the active serum there were proteins 150 kDa, which were absent in the not active serum lot. Mass spectrometry indicated that all those proteins had the amino acid sequence of albumin. Sera of one healthy volunteer and two patients with thyroid cancer also attenuated the activity of the agent. Conclusion: Several lots of FCS and human serum demonstrated the ability to attenuate the cytotoxic effect of methotrexate in vitro, possibly due to the formation of albumin dimers/MTX complexes
Observation of the onset of strong scattering on high frequency acoustic phonons in densified silica glass
The linewidth of longitudinal acoustic waves in densified silica glass is
obtained by inelastic x-ray scattering. It increases with a high power alpha of
the frequency up to a crossover where the waves experience strong scattering.
We find that \alpha is at least 4, and probably larger. Resonance and
hybridization of acoustic waves with the boson-peak modes seems to be a more
likely explanation for these findings than Rayleigh scattering from disorder.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Letter
Proton Microprobe and Particle Induced X-Ray Emission (PIXE) Analysis for Studies of Pathological Brain Tissue
Particle Indiced X-ray Emission and proton microprobe analyses have been applied for the investigation of regional elemental distributions in connection with various pathological states in the brain. Malignant brain tumours and adjacent histologically intact tissue removed during surgery were analysed with PIXE. Systematic elemental variations, e.g., for calcium and selenium, were observed in the tumour front. The proton microprobe was applied to study the Ca and K concentrations in various cell strata in hippocampus following transient ischaemia in rat brain. Significant increases in the Ca level occurred in selectively vulnerable cells within 48 h after the ischaemia
A New Possibility of Dynamical Study on Solid State Ionic Materials by Inelastic Neutron Scattering
A new technique of inelastic neutron scattering measurement utilizing the multiple incident energies is applied to the dynamical study of vitreous silica. A wide variety of extracted information from a series of two-dimensional maps of dynamical structure factor with multiple different incident energies are greatly valuable. The applicability and its expected contribution of new experimental technique into the further progress of scientific activities in solid state ionic materials are discussed.Received: 30 September 2010; Revised: 25 October 2010; Accepted: 26 October 201
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