PubMed Health⌕ Search

Biomedical subjects

R Manabe

Publications and source records attributed to R Manabe.

At least 91 records · Page 5Linked to original sources
PubMed1984

Fibronectin enhancement of corneal epithelial wound healing of rabbits in vivo.

The effect of topical administration of fibronectin on corneal reepithelialization in vivo was investigated in rabbits. Rabbit plasma fibronectin was purified by affinity chromatography using gelatin-coupled agarose gel (Sepharose 4B). The concentration of purified fibronectin was adjusted to 0.75 mg/mL. Corneal epithelial cells were removed by iodine vapor in 13 rabbits (26 eyes), and the size of the epithelial defect was calculated from the printed photographs in each eye. Fibronectin or phosphate-buffered saline eye drops were instilled. Healing rate was calculated by linear regression. The mean epithelial healing rate in fibronectin-treated eyes was 1.62 +/- 0.33 sq mm/hr, whereas in the control eyes it was 1.30 +/- 0.35 sq mm/hr. This study shows that fibronectin facilitates corneal epithelial wound healing in vivo.

Administration, Topical↗
PubMed1984

Ontogeny of substance P-containing structures in the ocular tissue of the rat: an immunohistochemical analysis.

The ontogeny of the substance P-like immunoreactivity (SPI) containing system in the ocular tissue of the rat was examined by means of the indirect immunofluorescence method. SPI-containing amacrine cells first appeared at postnatal day 4 and displaced SPI-containing amacrine cells at postnatal day 5. After this time, they developed markedly reaching their maximum content and distribution at postnatal day 14. On the other hand, SPI-containing cells in the trigeminal ganglion were first seen at gestational day 17 and reached their maximum content at birth. SPI-containing fibers in the cornea and uvea were first observed at gestational days 17-19. The SPI-containing fibers in the iris reached their maximum content at birth, while those in the cornea, choroid and ciliary body were fully developed at postnatal day 3. In the adult rats, numerous SPI structures were still seen in the ocular tissue, retina, cornea and uvea. These findings suggest that SPI might play some role in the developing ocular tissue in addition to its neurotransmitter or neuromodulator role in the adult, because SPI structures appear in the retina before establishment of synaptogenesis and in the cornea and uvea during the fetal stage.

Animals↗
PubMed1984

Subretinal neovascularisation in eyes with localised inferior posterior staphylomas.

We report seven cases of subretinal neovascularisation with inferior posterior staphyloma. The upper border of the shallow staphyloma, detected by B-mode echography, invaded the macular area, and there was a neovascular net at the edge of the staphyloma. Three of the cases showed chorioretinal atrophy at the upper edge of the staphyloma in the same location as the neovascular net. Our cases were identical to those of subretinal neovascularisation in high myopic eyes in which the rupture of Bruch's membrane was related to the deformity of the scleral shell. As our cases included not-high-myopic eyes, the results suggest that the identical mechanism might be involved in the occurrence of neovascular maculopathy in the pathological high myopic eye and in the not-high-myopic eye with posterior staphyloma. Localised inferior posterior staphyloma may be an important cause of 'idiopathic' subretinal neovascularisation.

Adult↗
PubMed1984

Electrical characteristics of the isolated dog ciliary body.

Transepithelial potential difference and short-circuit current of the dog ciliary body were measured in vitro in an Ussing-type chamber using HEPES-buffered solution containing bicarbonate. Their values were -1.35 +/- 0.08 mV (mean +/- S.E.M., n = 52) and -23.6 +/- 1.7 microA/cm2, respectively. At 10(-4) M, ouabain reduced the short-circuit current upon to either side of the chamber. On the other hand, at 10(-5) M of furosemide to the aqueous side, the short-circuit current was reduced. However even at 10(-3) M, this drug had no effect when applied to the stromal side. Behavior of the dog ciliary body towards these two inhibitors was compared with that of the toad and rabbit tissues.

Animals↗
PubMed1984

Neutrophil collagenolytic activity in patients with Behçet disease.

Studies were made on neutrophil dysfunction in Behçet disease by examining collagenolytic activity in neutrophils. The collagenolytic activity of neutrophil was found to be significantly higher in patients during the attack phase of this disease than in patients during the remission phase, in patients with other forms of uveitis and in normal controls. Collagenase was present in the collagenolytic enzyme, which showed high activity in the attack phase. The molecular weight of this enzyme was similar to that of mammalian neutrophil collagenase.

Adult↗
PubMed1984

Natural killer cells kill human retinoblastoma cells.

Human peripheral blood lymphocytes were obtained from healthy individuals and their cytotoxicity against retinoblastoma cells was measured using 51Cr-release assay. The lysis of two human retinoblastoma cell lines, Y-79 and WERI-Rb 1, varied greatly from blood donor to donor, but the lysis of K-562 was very similar among the donors. Furthermore, the lysis of Y-79 was markedly inhibited by the addition of K-562, a natural killer (NK) cell-sensitive target, but not by Raji, an NK-resistant target, suggesting that both Y-79 and K-562 shared a common NK-directed antigen. The major cytotoxic activity was associated with nonphagocytic and nonadherent cells, and it was finally recovered in the low-density fraction which was enriched with large granular lymphocytes. These lines of evidence indicate that natural killer cells (NK cells) in the peripheral blood killed retinoblastoma cell lines. On the other hand, three kinds of retinoblastoma cells freshly isolated from patients were resistant to the lysis by the lymphocytes obtained from the donors with high NK activity. However, these tumor cells displayed an enhanced susceptibility when the effectors from the same donors were treated with interferon. The study of NK cells and the interferon system may shed light on the treatment of retinoblastoma.

Cell Line↗
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↗
PubMed1984

Overall distribution of substance P nerves in the rat cornea and their three-dimensional profiles.

The overall distribution of substance P-like immunoreactive (SPI) fibers, examined by using whole-mounts of the rat cornea, was investigated by means of indirect immunofluorescence. SPI fibers entered the cornea from two levels; one from the middle layer of the sclera and the other from the episclera. From the sclera, a thick SPI fiber trunk, extending to the central part, subdivided into smaller SPI fiber bundles and approached the epithelium. The SPI fiber bundles from the episclera were smaller than those from the sclera. However, both fiber bundles formed a dense fiber network in the uppermost part of the stroma. This fiber plexus dissociated into SPI fibers extending to the superficial part of the epithelium where they formed an abundant arborization of fine SPI fibers. The results suggest that these fibers originate from SPI neurons in the trigeminal ganglion.

Animals↗
PubMed1984

Superoxide dismutase activity in diabetic rat retina.

We investigated the changes in superoxide dismutase activity in the retina, cornea, lens, blood, liver and kidney of streptozotocin-induced diabetic rats. Superoxide dismutase activity decreased in the retina; however, no changes were found in the cornea, lens, blood, liver and kidney. Electrophoretic studies showed no qualitative alteration of the enzyme protein in the diabetic rat retina. The present results show that superoxide dismutase activity decreased in the diabetic rat retina, and that superoxide reacted with unsaturated fatty acids of the retinal cells resulting in an increase of lipid peroxide contents. Superoxide dismutase may play a regulatory role in diabetic retinopathy.

Animals↗
PubMed1984

Measurement of retinal permeability to sodium fluorescein in vitro.

Fluorescein permeabilities of isolated dog retinal pigment epithelium (RPE)-choroid and sensory retina were measured individually. Retina to choroid (outward) permeability of sodium fluorescein was significantly larger than choroid to retina (inward) permeability at RPE-choroid under both open- and short-circuit conditions. Outward permeability was decreased by the addition of 10(-3) M KCN and of 10(-4) M probeneside but was not affected by 10(-6) M ouabain. These drugs decreased transepithelial potential and short-circuit current. No directional difference of fluorescein permeability for sensory retina was found. Active transport of fluorescein across RPE from retina to choroid is suggested. Fluorescein permeability of sensory retina was larger than inward but less than outward permeability of RPE-choroid. The result indicates that the sensory retina acts as a diffusion barrier for sodium fluorescein.

Animals↗
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

Incidence of cystoid macular edema after retinal detachment surgery and the use of topical indomethacin.

We conducted a prospective, double-masked, controlled study to determine the effects of indomethacin in preventing the development of cystoid macular edema after retinal detachment surgery. In addition to routine medication, topical indomethacin was applied to 63 eyes (52 with intact lenses and 11 aphakic) and a placebo was applied to 61 eyes (51 with intact lenses and ten aphakic) that underwent retinal detachment surgery. Indomethacin drops or placebo were instilled once an hour for five hours preoperatively and three times daily for four weeks postoperatively. Fluorescein angiography, done before surgery and four to six weeks after surgery to detect cystoid macular edema, showed that cystoid macular edema developed in 11 of 63 eyes (13%) in the indomethacin-treated group and in 20 of 61 eyes (33%) in the placebo group (P less than .01). Five of 28 eyes (18%) with cystoid macular edema in both groups and 38 of 96 eyes (40%) without cystoid macular edema in both groups had visual acuities of 20/40 or better (P less than .05).

Administration, Topical↗
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↗