Biomedical subjects
Publications and source records attributed to S Akiya.
We report 2 cases of lattice corneal dystrophy type III and gelatinous drop-like corneal dystrophy predominantly manifested in one eye. These 2 corneal dystrophies are found frequently in Japan. The case of lattice corneal dystrophy type III is the second, and the case of gelatinous drop-like corneal dystrophy is the first report at this time.
We have analyzed cellular DNA sequences at the viral genome integration site in a human fibroblast cell line VA13 immortalized by simian virus 40 (SV40). The computer analysis of the junctional cellular DNA sequences did not show any homology to the DNA sequences previously reported. This suggests that immortalization by SV40 was not induced by the destruction of any known oncogene or anti-oncogene at the integration site. We did not find the precise substantial sequence homology at the junctional site between the cellular DNA and SV40 DNA, indicating that the recombination mechanism involved does not require precise sequence homology and therefore, SV40 genome was probably not integrated by homologous recombination. Short direct and inverted repeats of 5 to 29 nucleotides were found in the junctional cellular and SV40 DNA. Cellular DNA abutting SV40 DNA was found by the Northern blot analysis to be expressed in diploid human fibroblasts and SV40-transformed cells. The nature of this RNA is now under study.
Changes in the distribution of hyaluronic acid in the developing human retina were investigated histochemically with alcian blue staining and the Streptomyces hyaluronidase digestion method using 56 human embryos and fetuses ranging from 5 to 41 weeks of gestational age. Hyaluronic acid was first detected in the inner layer of the retina at 12 weeks. The site of accumulation extended towards the outer layer by 20 weeks. At the neonatal stage, longitudinal fibers, possibly the processes of Müller cells, were proved to contain hyaluronic acid. These findings suggest that Müller cells produce hyaluronic acid transiently from 12 weeks' gestation to the neonatal stage.
A cornea with gelatinous drop-like corneal dystrophy was examined by histochemical and immunohistochemical techniques. Pretreatment of the sections with potassium permanganate did not decrease the staining with Congo red dye. Immunohistochemically, amyloid deposits in the cornea with this disease almost did not stain with antibodies to amyloid protein AA and AA-3. However, the corneal epithelium reacted distinctly with antibodies to amyloid protein AA and AA-3. Cross-reactivity with antibodies to protein AA and serum precursor of protein AA has been reported and protein AA-3 is the synthesized peptide corresponding to the amino acid sequence 37-47 of the human amyloid protein AA molecule. The present study suggests at least that corneal epithelial cells with gelatinous drop-like corneal dystrophy may produce a precursor of amyloid related to protein AA-3.
Our previous reports described the formation processes of epiretinal membranes composed of retinal glial cells in the experimental vitreous hemorrhage. This report presents the pathological changes of retinal glial cells, inner limiting membranes and vitreous body in the early stage of experimental vitreous hemorrhage. Using an operating microscope, 0.3 ml of autologous whole blood was injected through the pars plana into the vitreous cavity of albino rabbits. The eyes were enucleated at 3, 7, 10, 14 and 28 days after injection. Three days after injection, normal vitreous structure disappeared and vitreous fibers condensed. Seven days after injection, red blood cells were found on the retinal surface. The inner limiting membrane, composed of lamina rara and lamina densa, had a normal appearance. Where the red blood cell were present on the retinal surface, the lamina rara of the inner limiting membrane became thin. Fourteen days after injection, where glial cells showed upheaval, lamina rara disappeared and lamina densa became thin. Afterward, glial cells extruded their cytoplasmic processes onto the retinal surface. Twenty-eight days after injection, the inner limiting membranes were normal in appearance except for the area of glial cells penetrating the inner limiting membranes. The results suggested that, in vitreous hemorrhage, glial cell proliferation onto the retinal surface is an active reaction in order to engulf the debris of the red blood cells.
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We examined five patients with an undescribed type of lattice corneal dystrophy. All patients were in the seventh to ninth decades of life and had developed decreasing vision late in life. None of the patients had suffered from recurrent epithelial erosions, there was no overt evidence of systemic amyloidosis, and the lattice lines were much thicker than those usually observed in lattice corneal dystrophy types I and II. Available pedigree data from two families of three patients indicated that the corneal disorder affected several siblings but not the parents or offspring. Two patients had no affected family members. There was no known consanguinity in any of the four families.
We examined seven corneas from five patients with a new form of lattice corneal dystrophy (designated lattice corneal dystrophy type III) by light and electron microscopy. Numerous amyloid deposits were scattered throughout the corneal stroma, some of which were much larger than those usually observed in either lattice corneal dystrophy type I or II; these were located predominantly midway between the epithelium and the endothelium. Image analysis disclosed that the cross-sectional size of the large stromal amyloid deposits was significantly greater than those in age-matched patients with lattice corneal dystrophy type I. All patients had a discontinuous band of amyloid (15 to 25 micron wide) in the superficial stroma beneath Bowman's layer, which usually had only one or two small disruptions. Descemet's membrane and the endothelium were normal. The stromal deposits, which were composed of 10-nm diameter fibrils typical of amyloid, stained positively with Congo red after the histologic sections were pretreated with dilute potassium permanganate. Immunohistochemical studies on formalin-fixed, paraffin-embedded tissue indicated that only some deposits reacted weakly with antibodies to amyloid protein AA. The deposits stained positively with antibodies to protein AP and negatively with antibodies to kappa and lambda immunoglobulin light chains.
Eight families with lattice corneal dystrophy are reported. The symptoms and signs are almost identical with the typical lattice corneal dystrophy type 1 in western countries. Lattice corneal dystrophy has been considered to be a rare disease until recently, but it might be a more common disorder. This is the first report of a large series of lattice corneal dystrophy in Japan.
Three cases of primary band-shaped spheroidal degeneration of the cornea from two consanguineous families are reported. In all cases vision deteriorated slowly, the deterioration beginning in childhood. Photophobia in childhood was also a common symptom, and two patients suffered from intermittent painful sensations. The occupational and environmental histories had no bearing on the cases. Histochemical study of the yellow, oily appearing deposits suggested that this material has a complex composition, with staining characteristics of both protein and acid-fast lipid.
We examined 15 Japanese patients who had gyrate atrophy of the choroid and retina with hyperornithinaemia. Their visual acuities fell to 0.2 or worse in the second or third decade of life. Myopia developed late in the first decade, and the refractions decreased to -10 or -15 dioptres at age 20. Tunnel vision developed at approximately age 20. Our results suggested that the visual functions of Japanese patients were worse in the third decade or later than similarly affected Finnish patients.
Vitreous fibrils, and collagen fibrils in other ocular tissues, were observed in 5-, 6- and 7-weeks human embryos. The vitreous fibrils in 7-weeks embryos were distinctly different from the fibrils of other ocular tissues. The vitreous fibrils near the rim of the optic cup were similar to the fibrils in the anterior cavity of the lens vesicle in the 6-week embryo. Broad fibrils were demonstrated with a diameter of 30-40 nm and a striated banding pattern of about 60 nm periodicity.
Corneal endothelial conditions in two children with posterior polymorphous endothelial dystrophy were studied by specular microscopy. The localized vesicular lesions seen by slit lamp formed demarcated blackout areas where two distinct populations of cells were adjacent. Focal areas of highly pleomorphic cells with increased reflective highlights, which may represent epithelial-like cells, were surrounded by enlarged and pleomorphic endothelial cells (background cells). The average background endothelial cell area was three to four times larger than the control area. The composite cells which appeared to coalesce were also observed among the enlarged background cells.
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The human primary vitreous fibrils were similar to the secondary vitreous fibrils on electron microscopic observation. On the other hand, the intravitreal strand in a persistent hyperplastic primary vitreous (PHPV) contained large numbers of collagenous fibrils with 40-50 nm diameters and about 65 nm cross-striation periodicity. Besides these, other types of noncross-striated fibrils, ranging in diameter from 10 to 30 nm were observed in the circumferential region of the intravitreal strand. Moreover, there was complete morphological continuation between the intravitreal strand and the optic disc. Their histochemical properties were very likely collagenous and in part glial. Although the results are based only on 1 case of PHPV, present observations showed that components of the intravitreal strand of PHPV considerably differed from the primary vitreous.