PubMed Health⌕ Search

Biomedical subjects

K I Shibata

Publications and source records attributed to K I Shibata.

8 recordsLinked to original sources
PubMed1998

Vascular endothelium of human dental pulp expresses diverse adhesion molecules for leukocyte emigration.

The expression of adhesion molecules on the vascular endothelium of healthy and inflamed human dental pulp was studied immunohistochemically using antibodies for selectin family and immunoglobulin super-family members. In healthy dental pulp, some vessels reacted very weakly with major histocompatibility complex (MHC) class II, and E- and P-selectin, and many vessels reacted with platelet-endothelial cell adhesion molecule-1 (PECAM-1), but no vessels reacted with intercellular adhesion molecule-1 (ICAM-1), ICAM-3 and vascular cell adhesion molecule-1 (VCAM-1). In inflamed pulp, a large number of vessels reacted strongly with MHC class II, E- and P-selectin, PECAM-1, ICAM-1, ICAM-3, and VCAM-1. This indicates that the vascular endothelium of the inflamed human dental pulp expresses diverse adhesion molecules for leukocyte emigration from the blood stream into tissue. Dental pulp is surrounded by dentin and isolated from other tissue, like an in vitro system, so dental pulp is an attractive model for studying the roles of adhesion molecules on the vascular endothelium in transendothelial migration of leukocytes.

Adolescent↗
PubMed1996

Protection of isolated lung from reperfusion injuries by rinsing with high colloidal osmotic solution with deferoaxmine.

We examined the efficacy of rinsing isolated lungs subjected to prolonged hypothermic storage with a high colloidal osmotic pressure solution prior to ex vivo blood reperfusion in order to preserve physiologic functions, suppress peroxidation of mitochondrial membranes, and inhibit infiltration of neutrophils. Isolated rabbit lungs were flushed with a Rinse-1 solution (289 mOsm/kg H2O) to remove remaining blood and immersed in physiologic saline at 8 degrees C for 24 hr. The control group received blood reperfusion immediately after storage; the Rinse-1 group was rinsed with Rinse-1 solution before blood reperfusion and the Rinse-2 group with Rinse-2 solution (312 mOsm/kg H20) including deferoxamine. Reperfused blood was passed through an artificial membranous lung to reduce oxygen tension (PO2) to the venous level, and time-dependent changes in airway pressure (AWP), pulmonary artery pressure (PAP), and PO2, as a measure of gas-exchange capability were examined. We estimated the lipid peroxide level in mitochondrial membranes as thiobarbituric acid-reactive substances (TBARS), i.e., malonedialdehyde, and neutrophil infiltration into lung tissue by measuring myeloperoxidase activity after 60 min of blood reperfusion. The PO2 was significantly higher in both rinsed groups compared with the control, while neither AWP nor PAP was significantly different in the three treatment groups. Both mitochondrial TBARS and myeloperoxidase activity were significantly higher in the control group compared with either rinsed group. These results indicate that rinsing stored lungs with a solution of high colloidal osmotic pressure prior to blood reperfusion was effective in preserving physiologic function and inhibiting neutrophil infiltration. Addition of deferoxamine was markedly effective in reducing TBARS formation and lessening reperfusion injury of stored lungs.

Animals↗
PubMed1990

Mutagenicity of cadmium, platinum and rhodium compounds in cultured mammalian cells.

The induction of mutation by cadmium chloride (CdCl2), platinum tetrachloride (PtCl4), and rhodium trichloride (RhCl3.3H2O) was measured utilizing the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus in V-79 cells. Cadmium chloride at a concentration of 0.05 microM induced ford mutation in V-79 cells 4 times that of their control mutation frequency. Platinum tetrachloride at a concentration of 15 microM and 300 microM rhodium trichloride also induced ford mutation in V-79 cells at rates of around 7 and 4 times control rates, respectively. Platinum is often, and rhodium sometimes added to dental metallic alloys to improve their metallurgic characteristics and cadmium has been mingled in such alloys as well. Moreover, metallic dental drugs such as K2PtCl4 are used a dentine desensitizers. Thus, the genetic hazards of metal ions including cadmium, platinum, and rhodium that dissolve from dental materials and drugs must be investigated and caution exercised for their safe use in dental clinics.

Animals↗
PubMed1990

Cytotoxicity of oxide anodized titanium alloy evaluated by cell and organic culture study.

The cytotoxic effects of an oxide-anodized titanium alloy were investigated by cell and organic culture studies. Toxicity was estimated based on cell survival and growth rates compared with those of control materials (glass) after cultivation of cells (L 929) and chicken embryonic femurs expose to alloy plates. The oxide-anodized titanium alloy showed no cytotoxicity with respect to survival or growth rates in either cells or chicken embryonic femurs. Furthermore, the oxide-anodized titanium alloy was more acid and alkali resistant than intact titanium alloys. The results suggest that oxide-anodized titanium has greater stability and its metallic ions may be leachedless under various conditions following dental implantations. Therefore, this alloy should be suitable for use as a dental implant material.

Aluminum↗
PubMed1990

Investigation of DNA reactivity of endodontic agents by rec-assay.

Eight endodontic agents were tested for their reactivity with DNA by the rec-assay system. Employing 2 strains of Bacillus subtilis with different recombination capacities, the assay suggested that DNA damage is produced by agents for root canal cleaning containing sodium hypochloride. Other endodontic drugs, including disinfectants for caries cavities, sedatives for pulp, root canal disinfectants, and pulp devitalizing agents containing phenol, camphor, tricresol, formalin, and paraformaldehyde were also positive by rec-assay and would seem to potentially of damage cellular DNA in Bacillus subtilis. Though no clear evidence exists that drugs showing positive results by rec-assay induce malignant tumors in the oral region, these agents should be used carefully since they would seem to possibly cause genetic toxicity in mammalian cells.

Camphor↗