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Biomedical subjects

T Awata

Publications and source records attributed to T Awata.

100 records · Page 6Linked to original sources
PubMed1984

Fibronectin synthesis by the rabbit cornea: effects of mouse epidermal growth factor and cyclic AMP analogs.

We investigated whether the cornea can synthesize fibronectin which participates in corneal wound-healing. We also examined the effects of epidermal growth factor (EGF) and cyclic AMP analogs on fibronectin synthesis by the cornea. Rabbit corneal blocks were cultured in medium without serum, and the amount of fibronectin in culture medium was determined by ELISA assay. When rabbit corneal blocks were cultured in the medium alone, fibronectin contents in the medium increased with increase in the incubation period. This increase was enhanced by the addition of EGF to the culture medium, and was inhibited by addition of a protein synthesis inhibitor, cycloheximide. The addition of cAMP analogs, 8-bromo cyclic-AMP and dibutyryl cAMP, to the culture medium also increased the rate of fibronectin production by the cornea. These results show that the cornea can synthesize fibronectin and its synthesis is stimulated by EGF and cAMP analogs.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1983

Fibronectin. A new therapy for corneal trophic ulcer.

Fibronectin, a glycoprotein, is present in plasma and extracellular matrix and is responsible for cellular adhesion. With the use of affinity chromatography, we purified plasma fibronectin from two patients with trophic corneal ulcer and persistent epithelial defect after conventional therapy was ineffective. Reepithelialization began three days after initiation of treatment with autologous purified fibronectin eyedrops, and the epithelial defects disappeared completely within three weeks. No recurrence was observed after treatment ended. By modifying the original chromatographic procedure, we were able to obtain purified fibronectin in two hours, which allowed us to treat outpatients as well as inpatients.

Adult↗
PubMed1983

Fibronectin promotes epithelial migration of cultured rabbit cornea in situ.

We investigated the effect of fibronectin on epithelial migration onto the stroma in cultured rabbit cornea. Rabbit plasma fibronectin was purified by affinity chromatography using gelatin-Sepharose 4B, and its purity was confirmed by SDS polyacrylamide slab gel electrophoresis. Antibody against rabbit plasma fibronectin raised in guinea pigs formed a single precipitin line against rabbit plasma and purified rabbit plasma fibronectin by Ouchterlony double diffusion test. When rabbit cornea was cut into small blocks and cultured in TCM-199 medium alone, corneal epithelial cells began to migrate on the cut edge of the corneal stroma. The addition of purified rabbit plasma fibronectin to the culture medium significantly enhanced epithelial migration. The degree of enhancement depended on the amount of fibronectin added. When guinea pig IgG anti-rabbit plasma fibronectin was added, epithelial migration was significantly inhibited when compared with that in control cultured corneal blocks. The results demonstrate that fibronectin promotes epithelial migration in the cornea and thus plays an important role in corneal wound healing.

Animals↗
PubMed1982

[The experimental errors in measuring the size of bones in mice].

An experiment was conducted with 236 mice (3-9 weeks of age) to determine the bias in taking soft-X-ray photograph, and systematic and random errors of the values measured with a picture analyzer. Sites measured are length of scapula (SCAL), humerus (HUML), ulna (ULNL), coxae (COXL), femur (FEML), tibia (TIBL), thoracic vertebrae (VTL), lumbar vertebrae (VLL) and sacral vertebrae (VSL), and width of scapula (SCAW) and coxae (COXW). Systematic bias peculiar to the procedure was found in the values of bones measured. The X-ray photograph caused the downward bias to the length of sacral vertebrae alone, but did not to others. The standard errors of measurements (squared root of error variance) with picture analyzer ranged between 0.12 and 0.24 mm and had no apparent relationship to the size of bone.

Animals↗
PubMed1982

Fibronectin in corneal wound healing: appearance in cultured rabbit cornea.

Fibronectin (FN) has been detected at the site of corneal wounds. To investigate whether FN is supplied by the cornea itself or by extracorneal sources, we cultured small blocks of rabbit cornea in vitro with and without autologous serum (5%). The sliding rate of epithelial cells was determined and localization of FN in the corneal block examined by indirect immunofluorescent microscopy. Epithelial cells slid more rapidly in the presence of serum and covered most of the stromal surface in about 24 hours. FN was detected at the surface edge of the cut stroma shortly after culturing began. During epithelial cell sliding, FN-specific fluorescence was noted beneath the migrating cells. The location of FN was essentially the same in cultures with and without autologous serum. These results suggest that FN might be supplied by the cornea itself and that it may play a role in epithelial cell sliding.

Animals↗
PubMed1982

Rapid preparation of purified autologous fibronectin eyedrops from patient's plasma.

Fibronectin (FN), a glycoprotein present in plasma and the extracellular matrix, has been reported to be effective on corneal trophic ulcer. This study reported a rapid method for preparing purified FN eyedrops from a patient's own plasma. Plasma FN concentration in healthy Japanese was found to be 235 +/- 62 micrograms per ml(age 21-31 years old). Men had a higher plasma FN level than women (264 +/- 62 vs. 206 +/- 44 micrograms/ml). The FN eyedrops were prepared by gelatin-coupled Sepharose 4B affinity chromatography and gel filtration by Sephadex G-25 (PD-10). Biochemical and immunochemical analyses revealed that the prepared FN eyedrops contained electrophoretically pure FN and no other plasma proteins were detected. Average FN concentration in the eyedrops was 425 micrograms per ml and recovery rate was 54%. The FN eyedrops were found to be stable at room temperature up to 10 days in biological activity as far as we examined. The total time required to prepare the FN eyedrops was within 2 hours. Thus it is possible to apply them to outpatients as well as inpatients.

Adult↗
PubMedDate not supplied

Human and rabbit corneal endothelial permeability after different chemical forms of glutathione.

This study aimed to compare the effects of reduced glutathione (GSH) with those of S-(1,2-dicarboxyethyl)glutathione (DCE-GS) (in rabbits and humans), and different concentrations of the latter (in humans), on corneal endothelial permeability when added to solutions bathing the isolated cornea. Inulin/dextran permeability was determined from stromal- to endothelial-facing surfaces of de-epithelialized corneas. The bathing solution was modified Opeguard(R)-MA (MOMA), an ocular irrigating solution, to which either GSH or another intrinsic tripeptide, DCE-GS, was added. Paired corneas were used to compare either different combinations of GSH with DCE-GS (rabbit or human) or various concentrations of DCE-GS from 0.25 to 2.0 mM (human). Endothelial cyclic AMP levels were determined in cultured rabbit cells. MOMA alone resulted in approximately the same permeability as MOMA + 0.3 mM GSH while the use of 2 mM DCE-GS significantly reduced rabbit (40% maximum, p < 0.00001) and human (30% maximum, p < 0.01) corneal permeability. Human corneal endothelial permeability remained reduced through a range of concentrations of DCE-GS from 0.25 to 2.0 mM DCE-GS. Tissue-cultured rabbit corneal endothelium showed an increase in cyclic AMP after DCE-GS or GSH. DCE-GS potentially offers a viable alternative to GSH for inclusion in ocular irrigating or corneal preservative solutions since it maintains human corneal endothelial permeability at a lower, stable value relative to non-DCE-GS-containing solutions.

Aged↗