Light-induced alterations of retinal pigment epithelium in black, albino, and beige mice.
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Age Factors↗
Biomedical subjects
T Kuwabara
Publications and source records attributed to T Kuwabara.
Phagocytosis by the monkey pigment epithelium.
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Animals↗
Ocular pathology induced by the suckling mouse cataract agent.
The eye disease caused by SMCA may be best characterized as an endophthalmitis, with early retinitis followed by subsequent posterior uveitis. Pathologic features of lens included: proliferation and abnormal posterior extension of lens epithelium, increased accumulation of lens capsule material, and production of aberrant lens substance. Cataractous change appears to be secondary to intraocular inflammation. In addition to the above pattern, in roughly 20 per cent of all cases, 3 weeks after inoculation, lens capsule is destroyed giving rise to a foreign body granulomatous reaction.
Animals↗
Sliding of the epithelium in experimental corneal wounds.
The corneal epithelial cell has a unique sliding capability. The epithelial cell spreads and migrates in an amebic fashion without mitotic activity when the continuity of the epithelium is broken. This movement is demonstrated both in vivo and in vitro. Prompt sliding for sealing the wound defect is apparently the first step of the wound healing of the superficial cornea. Cut edges of collagen fibers show no sign of activity towards healing the wound. The energy source of the sliding is provided mainly from stored glycogen in the epithelial cells. Sliding is inhibited by removal of glycogen from the cell or by adding glycolytic enzyme inhibitors.
Animals↗
Menkes' kinky hair disease: a light and electron microscopic study of the eye.
Light and electron microscopic studies of the ocular tissue of a case of Menkes' kinky hair disease are described. The copper deficiency responsible for this systemic and neurologic disease appears to cause a progressive degeneration of retinal ganglion cells, loss of nerve fibers, and optic atrophy. The pigment epithelium is also abnormal with only small and irregular melanin granules present among electron-dense inclusion bodies. Abnormal elastica is present in Bruch's membrane.
Brain Diseases↗
Light effect on the synaptic organ of the rat.
The photoreceptor synapses of albino rats show considerable pathologic changes following fluorescent light exposure. The changes in the synapses and in the lamellar membranes of the outer segments occur and progress simultaneously. Membranes proliferate in the paramitochondrial zone of the rod synaptic spherule and fine budding of the smooth endoplasmic reticulum occurs in the cone pedicle within one hour's exposure to the brightness of 500 foot candles. Proliferating paramitochondrial membranes have no cytochrome c oxidase activity and degenerate together with mitochondria by further exposure. The cone pedicles remain relatively intact in photically damaged retina.
Animals↗
Effect of hyperosmotic agents on the ciliary epithelium and trabecular meshwork.
Hyperosmotic agents (2 M urea or 2 M DL-lactamide), perfused into the internal carotid artery of Rhesus monkeys, produced a marked decrease in intraocular pressure and an increase in aqueous humor protein. Fenestrae of the ciliary capillaries were broken immediately following the perfusion and the nonpigmented epithelium was separated from the pigmented epithelium. The pigmented epithelium especially of the pars plana then became degenerative. As intraocular pressure began to rise slowly, three to seven days after perfusion, the nonpigmented epithelium recovered to an almost normal structure, but the pigmented epithelium did not regenerate. The surviving cells in the pars plicata formed the original apico-apical junctions. The number of vacuoles in the endothelium of Schlemm's canal decreased while the intraocular pressure was low and increased gradually with the recovery of the intraocular pressure.
Amides↗
Progressive bilateral essential iris atrophy.
A case of bilateral progressive essential iris atrophy, more advanced in one eye than the other, has been studied. Histopathologic examination of the iris from the eye with the more advanced iris atrophy failed to find any vascular abnormalities in that the vessels were patent and appeared normal except for accumulated perivascular connective tissue. Fluorescein angiographic examination of the right eye which was undergoing the earliest changes of iris atrophy failed to show any vascular abnormalities. However, tonographic examination indicated a markedly decreased outflow facility. There does not appear to be any vascular abnormality involved in the pathogenesis of this case.
Adult↗
[The epidermoid tumor of the lateral cerebral ventricle; report of a case (author's transl)].
The authors report a case of epidermoid tumor of the lateral ventricle. Epidermoid tumors are relatively uncommon intracranial lesions and the one situated in the lateral ventricle has not been reported in this country. A 42 year old house wife was admitted to Asahi Central Hospital on February 14, 1973, complaining of progressive right hemiparesis for 2 years. The patient had no headache and no other symptoms of increased intracranial pressure. Neurological examination revealed disorientation, dyscalculia, amnestic aphasia, morter dysphasia, right facial paresis (central type) and right hemiparesis. The laboratory findings, which included complete blood count, serum electrolytes, urinalysis, electrocardiogram and blood Wassermann, were normal. Initial pressure of the spinal tap was 410 mmH2O and crystal clear CSF was obtained. tplain craniogram showed no calcification and was normal. The left CAG showed clearly the signs of the temporal lobe tumor (Fig. 1, 2, 3, 4.), but showed no early veins and no tumor stains. The brain scintigram was normal. A left temporo-parietooccipital craniotomy was performed. The epidural Echogram (horizontal section-Fig. 5, coronall section-Fig. 6) revealed the clear demarcated, multicystic round tumor in the inferior horn of the left lateral ventricle. After the whitesoap like tumor was totaly removed, the all interior surface of the left inferior horn of the lateral ventricle was seen (Fig. 8). Tumor was 5.5 cm in diameter and 50 g in weight. Histological findings of the tumor showed typical epidermoid (Fig. 9, 10). The origin of the intravetricular epidermoids and the usefulness of echo-encephalorgaphy were briefly discussed.
Adult↗
Homologous retinal outer segment immunization in primates. A clinical and histopathological study.
Immune intraocular inflammation was induced in primates with homologous retinal outer segments. Perivascular retinitis, uveitis, and edema of the optic nerve head were the prominent acute clinical features. Acute and chronic inflammation was seen in the central and peripheral retinal vessels and granulomatous infiltration was present in the choroid of the uvea. Selective degeneration of the outer segments of the photoreceptor cells of the retina with sparing of the inner segments and of the adjacent pigment epithelium was confirmed by light and electron microscopy. This study strongly suggests that photoreceptor outer segments are highly and specifically immunogenic. The inciting antigen has yet to be identified. Implication of rhodopsin will have to await further studies since it exists as the essential protein in the outer segment.
Animals↗
Structure of the muscles of the upper eyelid.
The human and monkey orbicularis muscle has fibers that are more uniform in size and structure than those of rectus muscles. They have distinct myofibrils, a moderate number of mitochondria, and a well-developed transverse T-tube system. The levator muscle also has relatively uniform fibers, but the myofibrils are less distinct than those of the orbicularis. Especially noteworthy is the unusual arrangement whereby Muller muscle arises directly from the undersurface of the levator muscle, causing an intimate intermingling of smooth and striated fibers. Muller muscle then inserts on the tarsus, whereas the levator muscle extends by an aponeurosis into the septa of the orbicularis muscle. In surgical specimens from patients with ptosis, the levator fibers show varying degrees of abnormality, whereas Muller fibers are normal.
Adolescent↗
The histopathology of pigmentary dispersion syndrome with glaucoma.
Iris tissue and trabecular meshwork, obtained at time of trabeculectomy, was studied using the light and electron microscope in a 54-year-old woman with pigmentary dispersion syndrome with glaucoma. The specific defect was a loss of the outer epithelial cells of the iris with marked thinning of the remaining outer layers so that the two-cell architecture of the iris epithelium was maintained. In addition, the radial muscle layer was increased in both number and size of muscle fiber. It would appear that the pigmentary dispersion syndrome may represent a congenital or developmental abnormality of the iris epithelium, or both, and that the glaucoma which occasionally occurs in conjunction with this syndrome is of the usual open-angle type.
Atrophy↗
The effects of laser photocoagulation in the retinal capillaries.
Using ruby and argon lasers, we produced multiple lesions on normal rhesus monkey retinas. The clinically used energy levels of both lasers produced identical cellular changes in the retina. Neither laser directly produced obliteration of capillaries. However, after the cellular damage in each burn lesion was repaired, we observed delayed degeneration of capillaries in a small segment at the burned areas. The marked reduction of active retinal cells that reduce vascular activity may beneficially affect laser treatment of diabetic retinopathy. The retinal tissue appears to have excessive photoreceptor cells and the horizontal connection of other cells seems to compensate for visual function after loss of many photoreceptor cells. We demonstrated severe damage in the ganglion cells by argon laser when it was aimed at the thick blood films in the vitreous cavity. Certain precautions must be taken when peripapillary neovascularization is treated by laser beam.
Animals↗
The histopathology of Peters' anomaly.
Corneal, iris, and trabecular meshwork tissue in a 23-month-old boy with Peters' anomaly were studied with light and electron microscopy. In the cornea, both Descemet's membrane and endothelium were present beneath the area of the corneal opacity except at the point of iris adhesion. However, Descemet's membrane was thin and embryonal in nature, and the endothelium markedly attenuated. The trabecular meshwork demonstrated changes characteristic of old age such as wide-banded collagen and the presence of phagocytosed pigment granules in the endothelium. The iris appeared normal except for anterior synechiae to the corneal opacity. Developmentally, the primary fault appeared to be a failure in the normal differentiation of endothelial cells of the cornea and trabecular meshwork.
Cornea↗
The maturation of the lens cell: a morphologic study.
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Animals↗
Ultrastructural changes in rat optic nerve associated with hyperphenylalaninemia induced by para-chlorophenylalanine and phenylalanine.
The morphologic effects of hyperphenylalaninemia induced by treatment with para-chlorophenylalanine (PCP) plus phenylalanine on optic nerve were studied in developing F344 rats. PCP and phenylalanine were infected daily between days 5 and 20 days of life. At 20 days optic nerve of treated animals, as compared with saline-injected controls, showed enhanced neuroglial activity with broad astrocytic septae and debris-laden oligodendrocytes. In specimens obtained long after treatment with PCP and phenylalanine, continuing gliosis with evidence of focally abnormal myelination and axonal degeneration were observed. The results are consistent with a metabolic insult sustained in early development by astrocytes and oligodendrocytes, and are considered in relation to other work in experimental hyperphenylalaninemia and to human phenylketonuria.
Animals↗
Epidermoid tumor in the lateral ventricle. Significance of echo-encephalography.
The authors report on a case of epidermoid tumor in the lateral cerebral ventricle. Epidermoid tumors are relatively uncommon intracranial lesions and were first described by Esmarch. Till now about 300 cases have been reported. In Japan this tumor was first described by Yamamura, and since then many cases have been reported. But the one situated in the lateral ventricle has not been reported yet in this country. The significance of echo-encephalography is discussed because this procedure was very useful in determining the location and the nature of the tumor of this case.
Adult↗