Retinoschisis associated with disc coloboma.
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Adult↗
Biomedical subjects
A Hirakata
Publications and source records attributed to A Hirakata.
Japanese juvenile retinoschisis is caused by mutations of the XLRS1 gene.
We investigated the XLRS1 gene in Japanese patients with retinoschisis (RS). All exons of the XLRS1 gene were sequenced in 14 males, including a pair of monozygotic twins, from 11 individual families with RS and five of their mothers who are asymptomatic but diagnosed as carriers. Six kinds of missense mutations and a nonsense mutation, including six novel mutations, were detected in all 14 patients and carriers. Mutations in the XLRS1 gene are also responsible for RS in non-Caucasian patients. Most Japanese RS cases are caused by an XLRS1 gene defect. A novel mutation, Glu72Lys, was found in four families, suggesting a common mutation in the Japanese population. Clinical features of RS patients with both the Glu72Lys and Pro193Leu mutations indicate that a genotype-phenotype correlation is not recognized in RS.
Eye Diseases, Hereditary↗
Unusual macular retinal detachment associated with vitreomacular traction syndrome.
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Aged↗
[Characteristics of retinal detachment in eyes with choroidal colobomas].
We reviewed 6 eyes of 6 patients (1 male and 5 females) with retinal detachment associated with choroidal coloboma. Three of these 6 eyes had visible retinal breaks within or at the margin of the coloboma. In one eye, no retinal breaks were noted before or during vitreous surgery, and shallow retinal detachment was localized in the posterior fundus. One eye with bullous retinal detachment with retinal breaks within the coloboma had been having serous retinal detachment localized in the nasal area close to the optic nerve head. In all of these five eyes; vitrectomy, relaxing retinotomy inside the coloboma close to its edges, and cyanoacrylate retinopexy resulted in successful reattachment of the retina. Schisis-like separation similar to that in pit-macular syndrome was noted in the posterior retinal in one eye which had no visible retinal break. Non-rhegmatogenous retinal detachment may exist in association with choroidal colobomas.
Adolescent↗
CD44 expression in the developing human retina.
BACKGROUND: CD44, the transmembrane adhesion molecule, is expressed in the fetal brain and supposed to mediate neuroglial, interactions. We evaluated the expression and distribution of CD44 in the developing human retina. METHODS: Four developing human eyes were evaluated at 6, 10, 16, and 21 weeks of gestation, as well as the eyes of one infant and four adults. Frozen sections were immunohistochemically stained with monoclonal antibodies to three human CD44 clones (BU52, F10-44-2, and DF1485) and to vimentin, and antiserum to glial fibrillary acidic protein (GFAP). Specimens were evaluated by light and electron microscopy. RESULTS: Positive immunostaining for CD44 was first detected at 21 weeks of gestation in the longitudinal fibers that extended from the inner to the outer limiting membrane and around capillary vessels with the simultaneous expression of vimentin and GFAP. Immunoelectron microscopy demonstrated the presence of CD44 on the surface of Müller cells and astrocytes. CD44 was faintly seen in the Müller cells in the periphery and definitely present in the astrocytes in the infant and adult retinas. CONCLUSION: CD44 was expressed in Müller cells at a late stage of fetal development and in the fetal, infant, and adult astrocytes, which suggests that it is important in the morphogenesis and homeostasis of the neural retina.
Adult↗
[Proliferative vitreoretinopathy treated with daunorubicin].
Nine eyes with severe proliferative vitreoretinopathy underwent vitrectomy and infusion of Daunorubicin to prevent reproliferation. In 5 eyes (56%) the retina was reattached. In 4 eyes redetachment occurred because of reproliferation or incomplete sealing of the break. After a second vitrectomy, complete reattachment of the retina was obtained eventually in all eyes including one eye with silicone oil tamponade. As postoperative complications, conjunctival dehiscience occurred in 3 eyes. In two of the 3 eyes scleral buckling occurred, and orbital cellulitis occurred in one eye. Daunorubicin seemed to be effective to suppress reproliferation, but care should be taken to avoid postoperative complications.
Adolescent↗
[Posterior segment complications after macular hole surgery].
Fifty-three patients with stage III or stage IV idiopathic macular holes who underwent vitrectomy were reviewed. Posterior segment complications were noted in 20 (38%) of patients. These included peripheral retinal breaks (21%), peripheral visual field loss of unknown etiology (8%), rhegmatogenous retinal detachment caused by peripheral retinal break (6%), late reopening of the hole (4%), and retinal pigment epithelium loss under the hole (4%). The final visual acuity was two lines or more worse than preoperative visual acuity in 10% of these complicated eyes and in 9% of eyes without posterior segment complications. Patients with peripheral retinal breaks or retinal detachment had significantly shorter duration of macular hole symptoms (p < 0.01) than those without these complications. Posterior segment complications after vitrectomy for macular hole appear to be more common than expected, but the effect of such complications on final visual outcome was not significant.
Aged↗
[Elucidation of the mechanism of retinal degeneration and regeneration and the prospects for its clinical application].
In order to obtain the basic knowledge necessary to develop therapeutical intervention for blindness due to the damaged retina and optic nerve, the mechanism of retinal degeneration and regeneration in an amphibian model, Cynops pyrrhogaster, was studied. In the retinal degenerative process following enucleation and reimplantation of the eye ball, evidence was found for active cell death of neural retinal cells. As the degeneration proceeded, Musashi, an ribonucleic acid (RNA)-binding protein, started its expression in the daughter cells of proliferating retinal pigment epithelium (RPE) cells, messenger RNA (mRNA) expression of proneural genes with basic helix-loop-helix motif was then detected in the newly developing retina. These results suggest that transdifferentiation of RPE cells to neural retina involves at least partial cascade, if not entirely, of neural induction from uncommitted ectodermal tissue. Search for genes that are required for transdifferentiation of RPE cells to neural retinal cells, in addition to those mentioned above, will provide the basic knowledge for successful retinal transplantation and retinal regeneration in higher vertebrates.
Amphibians↗
[Vitrectomy in Coats' disease].
Four eyes of four patients with Coats' disease underwent vitrectomy because of exudative or tractional detachments involving the macula or premacular fibrosis. All cases had gelatinous vitreous and had no complete posterior vitreous detachment. The exudates decreased and the retina reattached after removing vitreous traction and coagulating abnormal vessels with endodiathermy and not removing subretinal fluid in 3 eyes with retinal detachment. In one eye with tractional detachment, retinal breaks were found beneath the proliferative membrane during the initial vitrectomy procedure. This eye needed multiple operations because of recurrent traction by the remaining peripheral vitreous. Exudation into the vitreous and vitreous traction may cause mutual progression in these eyes, and vitrectomy is an effective treatment, although there are difficulties in removing vitreous traction completely.
Adolescent↗
Binding, coupling, and mRNA subtype heterogeneity of alpha 1-adrenergic receptors in cultured human RPE.
In retinal pigment epithelium, apically applied epinephrine changes the conductance of specific ions which subsequently affects the membrane voltage and stimulates transepithelial fluid transport. In this investigation, myo-[3H]inositol radiotracer studies, radioligand binding with [125I]HEAT, and ribonuclease protection assays were performed to examine the coupling of this receptor to phosphoinositide hydrolysis and the specific mRNA subtypes expressed in cultured human retinal pigment epithelial cells. After labeling second to sixth passage cells with 3-muCi myo-[3H]inositol for 24 hr, epinephrine caused a dose- and time-dependent increase in [3H]inositol phosphate products (EC50 of 0.7 microM). This stimulation was antagonized by prazosin but not by propranolol. The effect of epinephrine was potentiated by the presence of the monoamine oxidase inhibitor, pargyline (10 microM). Pertussis toxin (1 microgram per well) attenuated the stimulatory effect of epinephrine. In the radioligand binding assays, [125I]HEAT binding sites varied among different cell lines, with a range of 44 to 200 fmol (mg protein)-1. Using a ribonuclease protection assay, alpha 1D and alpha 1B, but not alpha 1C, adrenergic mRNA subtypes were detected in cultured human cells. Collectively, these results show that the catecholamines act on a potentially heterogeneous population of alpha 1-adrenergic receptors coupled to phospholipase C by a pertussis toxin-sensitive G protein.
Cells, Cultured↗
Histochemical and immunohistochemical studies on keratan sulfate in the anterior segment of the developing human eye.
Changes in the distribution of keratan sulfate in the anterior segment of developing ocular tissue were investigated histochemically and immunohistochemically using human eyes from 5 weeks gestation to 2 years after birth. Enzyme digestion methods with streptomyces hyaluronidase, chondroitinase and keratanase showed that the main component of glycosaminoglycans in the cornea was hyaluronic acid at the early stage and chondroitin sulfate from the middle stage to the neonatal stage. Keratan sulfate was found at the neonatal stage. Immunohistochemical staining, however, showed that keratan sulfate was present from 6 weeks around mesenchymal cells which migrated into the anterior portion. The stroma and endothelial cells of the cornea, trabecular tissue, iris, choroidal tissue of the ciliary body and anterior tunica vasculosa lentis were the next tissues to show positive for immunostaining. Keratan sulfate became limited to the cornea and lumbus and mostly disappeared from the other anterior segment tissues after birth. These findings suggest that tissues which seem to originate from mesenchymal cells and surround the chamber space contain keratan sulfate during the developmental stage.
Adolescent↗
Effect of inhibitors of arachidonic acid metabolism on corneal reepithelialization in the rat.
We examined the ability of inhibitors of arachidonic acid metabolism to influence the rate of healing of organ-cultured rat corneas with 3-mm diameter central epithelial abrasions. In control corneas, and in the presence of the cyclooxygenase inhibitors indomethacin (1 microM), or flurbiprofen (1 microM), the defect was completely reepithelialized by 25 hr. In contrast, corneas cultured with the lipoxygenase inhibitors quercetin (100 microM), esculetin (100 microM), or baicalein (10 microM) or the dual cyclooxygenase/lipoxygenase inhibitors BW 775C (100 microM) or BW A540C (100 microM) had significantly delayed epithelial healing rates when compared with the controls; complete healing of the epithelial defects required 32.5-40 hr. Dose-response studies with esculetin and BW 755C demonstrated that the concentrations for 50% inhibition of reepithelialization (65.3 microM for esculetin, 39.6 microM for BW 755 C) were significantly greater than those for inhibition of 12-lipoxygenase activity (16.6 microM for esculetin, 21.1 microM for BW 755C), the major lipoxygenase activity in normal rat cornea. Addition of 12(S)-5,8,10,14- hydroxyeicosatetraenoic acid [12(S)-HETE, 0.01-10 microM], the main 12-lipoxygenase metabolite of arachidonic acid in normal rat cornea, to the organ cultures did not influence the rate of epithelial wound healing in the absence of presence of 100 microM esculetin. Our results suggest that lipoxygenase activity is an important factor in regulating corneal epithelial wound healing in the rat, presumably by influencing epithelial cell migration. The lipoxygenase enzyme and metabolite(s) responsible for regulating reepithelialization, and the mechanism of action, remain to be determined.
Animals↗
The effect of angiostatic steroids and beta-cyclodextrin tetradecasulfate on corneal neovascularization in the rat.
Folkman and coworkers have described angiostatic steroids that markedly inhibit neovascularization of the rabbit cornea when given topically with beta-cyclodextrin tetradecasulfate (beta-CD), yet have minimal or no glucocorticoid or mineralocorticoid activity. Our objective was to extend these observations to another species, the rat. We induced neovascularization by cauterizing rat corneas with silver nitrate/potassium nitrate; drugs were applied topically four times per day for 4 days in most experiments. Submicron sized emulsions of lipid-soluble dexamethasone and the angiostatic steroids 17 alpha-hydroxyprogesterone (1 or 10 mg ml-1) and cortexolone (1 or 10 mg ml-1) were prepared by lecithin encapsulation of drug microcrystals. The vehicle for water-soluble hydrocortisone 21-phosphate (HCP) +/- beta-CD (Molecusol; Pharmatec, Inc) was 10% Tween 20 in Tris-buffered 0.9% saline. Angiogenesis was significantly inhibited only by 1 mg ml-1 dexamethasone (-63.2% when compared with controls), 0.5 mg ml-1 HCP + 1 mg ml-1 beta-CD (-33.4%), and 1 mg ml-1 HCP (-40.2%). HCP (0.5 mg ml-1) or beta-CD (1 or 2 mg ml-1) alone had no significant effect on neovascularization; the inhibition by 1.0 mg ml-1 HCP was not potentiated by 2 mg ml-1 beta-CD. We also tested HCP and tetrahydro-S (TH-S) using 1.5% hydroxypropyl methylcellulose vehicle and beta-CD from Takeda Chemical Industries, Ltd., to simulate the procedure of Folkman and coworkers.(ABSTRACT TRUNCATED AT 250 WORDS)
17-alpha-Hydroxyprogesterone↗
Effect of protein kinase C inhibitors and activators on corneal re-epithelialization in the rat.
PURPOSE: To examine the ability of protein kinase C (PKC) inhibitors and activators to influence the rate of corneal re-epithelialization in the rat. METHOD: Rat corneas with 3 mm diameter central epithelial abrasions were organ-cultured in control medium or in medium with inhibitors or activators of PKC. RESULTS: In control corneas, the defect was completely re-epithelialized by 25 hr. In the presence of the PKC inhibitors staurosporine (100 nM), sphinganine (50 mumol/l), or H-7 (100 mumol/l) there were significantly larger epithelial defects than in controls after 5-25 hr of incubation. Re-epithelialization rates were similar to control corneas when the incubation medium contained HA1004 (100 mumol/l), an analogue of H-7 that is a potent inhibitor of cyclic adenosine monophosphate- and cyclic guanosine monophosphate-dependent protein kinases and a weak inhibitor of PKC. Two PKC activators, 1-oleoyl-2-acetyl-sn-glycerol (OAG) and phorbol 12-myristate 13-acetate (PMA), were unable to enhance the rate of epithelial wound healing. CONCLUSIONS: Our results suggest that PKC activity is an important factor in regulating corneal epithelial wound healing, presumably by influencing cell migration. Moreover, the results with OAG and PMA suggest that PKC is maximally activated during re-epithelialization in this organ-culture assay.
Animals↗
Inhibition of corneal neovascularization in the rat by SK&F 86002, a dual inhibitor of arachidonic acid metabolism.
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Animals↗
Analysis of 80 cases of childhood asthma provoked by mold allergens.
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Adolescent↗
The management of retinal detachments associated with choroidal colobomas by vitrectomy with cyanoacrylate retinopexy.
The techniques used and the outcome in eyes treated for retinal detachment associated with choroidal coloboma are described. We reviewed the medical reports on five eyes of five patients with retinal detachment associated with choroidal coloboma who underwent vitrectomy. Retinal breaks were identified at the margin of or within the coloboma and the retina was successfully reattached by vitrectomy and cyanoacrylate retinopexy in four of the five eyes. The remaining one eye, with no visible retinal break both before and during surgery, also underwent cyanoacrylate retinopexy at regions suspected of retinal break, and was successfully reattached. In four eyes (80%) the vision showed improvement and had a visual acuity of 20/100 or better after surgery. None of the eyes required silicone oil tamponade or endophotocoagulation around the disc or at the papillomacular bundle. For the management of retinal detachment associated with choroidal coloboma, cyanoacrylate retinopexy is the method of choice, providing adequate chorioretinal adhesion and satisfactory visual outcome.
Adolescent↗