Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An electron microscope study of lenses in 11--15 and 17 days old embryos of mice homozygous by dominant cataract-Fr (CatFr) gene has shown that ultrastructural changes in the nuclear envelope are the earliest expression of the mutant gene. The primary lens fibers of 12 days old embryos CatFr/CatFr, unlike those of the normal ones, are characterized by the decrease in the number of nuclear pores, evagination of the outer nuclear membrane, marked and unequal extension of perinuclear space which connects itself with the endoplasmic reticulum cisternae. In 14 days old embryos breaks in the outer nuclear membrane and evaginations in the inner one, fusion of nuclear membranes and breaks of the nuclear envelope are observed and resulted in the release of the nuclear contents with the nucleolus in the cytoplasm. Similar ultrastructural changes are characteristic also of the nuclei of secondary lens fibers at a comparable stage of differentiation. The destructive changes of nuclei are accompanied by the degeneration and autophagocytosis of cellular organelles and matrix.
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PMID:[Ultrastructural analysis of the effects of dominant cataract-Fr gene in mouse embryos]. 102 73

Spontaneous lymphomas from a strain of hereditary cataract (CAC-nct/+) mice were examined by light and electron microscopy and by immunohistochemical reaction for the mouse heavy and light immunoglobulin chains. Lymphomas occurred in 28 out of 45 male cataract mice and in 34 out of 52 females at 25 to 65 weeks of age. All of the lymphoma-bearing mice showed an enlargement of the spleen and mesenteric lymph nodes, and some mice also had hepatomegaly. Morphologically, all tumors were composed of a mixed population of small and large cells. Neoplastic cells had features of follicular center cell lymphomas, such as scant to moderate amounts of cytoplasm and cleaved and/or round nuclei with a large nuclear-to-cytoplasmic ratio. Large cells were often admixed with small cells, and had vesicular nuclei with prominent nucleoli juxtaposed to the nuclear membrane. Intracytoplasmic eosinophilic inclusions were observed in occasional cells, but Golgi apparatus was poorly developed and rough-surfaced endoplasmic reticulum was scant, unlike those in plasma cells. C-particles were seen in all lymphoma-bearing mice by electron microscopy. Intracisternal A-particles were detected in some mice. Immunohistochemically, neoplastic lymphoid cells were positive for the kappa light chain and the surface/cytoplasmic immunoglobulin M. These results indicate that lymphoid cell neoplasms found in hereditary cataract mice originate from follicular center B cells.
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PMID:Spontaneous follicular center cell lymphomas of B cell origin in cataract mice. 158 91

Localization of acid phosphatase activity is described in equatorial segments of four human cataractous lenses, including one lens with equatorial cortical cataract, and three lenses with no significant equatorial opacities. The lenses were removed surgically with a cryoprobe. Enzyme reaction product was confined mostly to epithelial and cortical Golgi complexes and dense bodies, and to cortical smooth endoplasmic reticulum (SER). It also was located in small cortical vacuolar cysts in the lens with equatorial cataract, and intercellularly in a single lens which was devoid of equatorial opacity. In the latter case, intercellular activity was confined mostly to areas showing minimal pathological modification. Evidence is presented that the cortical SER represented GERL. The hypothesis is made that intercellular acid hydrolase activity might play a role in the early stages of human senile cortical cataract development. However, it is recognized that confirmation of this hypothesis will require additional studies involving comparison of both cataractous and normal lenses of various ages, which have been removed by a careful procedure which minimizes the lysis of lens cells.
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PMID:Acid phosphatase localization in the equatorial region of human lenses. 648 64

The traumatic cataract was experimentally induced in the lens of a Japanese monkey and observed with the electron microscope. The purpose of this study was to shed some light on the origin of the cataract caused by various factors. The clinical examinations of the experimental animal showed the opacity of the posterior subcapsular cortex. Electronmicroscopic investigations revealed that lens fibers within the opaque region increased in number of mitochondrion, rough surfaced endoplasmic reticulum and other organelles when compared with those in the clinically normal region of the lens. Furthermore, the intercellular space in the opaque region increased to such an extent that large extracellular vacuoles were formed. Many of these lens fibers became swollen and decreased the interdigitation. Some swollen cells showed sparse arrangement of their cytoplasmic filaments. These morphological changes showed an acceleration of water absorption of the lens fibers from a relatively early stage of the traumatic contusion cataract. The increase in number of mitochondrion in such swollen (hydropic) fibers may play an important role in this process. The present experiment suggests that the appearance of so-called hydropic cells is an initial change in the cataractous lens.
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PMID:[Electron microscopic study of an experimental contusion cataract of a Japanese monkey]. 667 51

Current applications of light and electron microscopy to investigations of changes in various tissues from fish exposed to xenobiotics have been reviewed. Emphasis has been placed on two types of contaminants, petroleum hydrocarbons and chlorobiphenyls, as examples of important xenobiotics found in the marine environment. Although the data are fragmentary because of the small number of studies, they clearly contribute new and valuable information to an understanding of the impact of these contaminants on the olfactory organ, liver, lens, and intestine from several species of fish. The morphological aspects of damage to the olfactory organs of fish exposed to petroleum hydrocarbons included hyperplasia and attenuation of the chemosensory cilia. In the liver of fish exposed to chlorobiphenyls, one of the most evident cellular anomalies was whorls of smooth endoplasmic reticulum. The rough endoplasmic reticulum appeared proliferated and its cisternae were dilated. Changes in th amount of lipid stored in the hepatocytes have been observed in fish exposed to both petroleum hydrocarbons and chlorobiphenyls. Some hydrocarbons affected eye tissues. Structural alterations that occurred during hydration of lens fiber cells and cataract formation were elucidated. A synopsis of the morphological changes in the intestine of fish exposed to petroleum hydrocarbons alone, chlorobiphenyls alone, and the combined contaminants is presented. All three groups of contaminant-exposed fish have subcellular inclusions that are distinctly abnormal. Recommendations for future studies include the need for further characterization of the range of normal tissue structure, comparative studies of additional species, and multiple contaminant exposures.
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PMID:The effects of xenobiotics on fish tissues: morphological studies. 677 1

Age-related changes in the lenses of ddy strain mice, ranging from 4 to 24 months old, were studied histologically. The early change of aging lens was noted as a slight extension of fiber cells into the posterior capsule in the area behind the nuclear bow around 6 months of age. Those cell extensions formed villous projections reaching up to one half of the total capsule by 18 months of age. Another notable change was a decreasing cell population of the lens epithelium and the appearance of their nuclear inclusions. The latter contained rough endoplasmic reticulum, free ribosomes and filamentous matrix at the early stage and a mass of filamentous material at the later stage. This change was initiated by 12 months of age, and became profound with the increase of age. Moreover, the bow nuclei became markedly displaced posteriorly after 14 months of age. At about 18 months of age, when the pathological changes in both epithelial and bow regions became severe, the superficial cells in the posterior cortex showed swelling and atrophy, which soon led to the lens opacity due to accumulation of cell debris and fluid. These histopathological changes associated with aging appear to correspond to the incipient form of posterior subcapsular cataract which is detectable by clinical examinations.
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PMID:Morphological study of age-related changes in mouse lens. 685 9

Cataracts, inherited in an autosomal dominant manner in New Zealand Romney sheep were first detected at 1 - 2 months of age as focal anterior and posterior cortical opacities. Within a short time these coalesced to form spoke-like patterns which gradually became more diffuse. Total lens opacity developed by 10 - 11 months of age. Congenital mature cataracts occurred in two lambs believed to be homozygous for the mutant gene and in these animals lens resorption later occurred. Histology showed that new lens fibres formed normally at the equator but then underwent progressive degenerative swelling and lysis. Cytoplasmic vacuolation of anterior epithelial cells was a notable feature and occurred apparently in response to adjacent cortical degeneration. Ultrastructurally these vacuoles were interpreted as dilations of endoplasmic reticulum but there were also a number of smaller vacuoles not lined by membrane. Anterior epithelial cells also underwent metaplasia, hyperplasia, and migration beneath the posterior capsule. Analyses of lenses reflecting different stages of cataractogenesis showed a progressive increase in water, sodium and calcium ions with cataract development and a concomitant decrease in potassium and magnesium ions.
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PMID:The pathology of an inherited cataract of sheep. 718 16

Sebastian platelet syndrome is an hereditary thrombocytopenia with giant platelets and inclusion bodies in the granulocytes consisting of dispersed filaments, clusters of ribosomes and a few segments of rough and smooth endoplasmic reticulum at the ultrastructural level, similar to those observed in Fechtner syndrome (a variant of the Alport syndrome)--Sebastian platelet syndrome lacks the additional clinical features such as high frequency deafness, congenital cataract, and chronic interstitial nephritis. Here we report the fourth case worldwide and the first of an Arabian ancestry.
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PMID:The Sebastian platelet syndrome. Report of the first native Saudi Arabian patient. 756 53

Defects in the human GALK1 gene result in galactokinase deficiency and cataract formation. We have isolated this gene and established its structural organization. The gene contains 8 exons and spans approximately 7.3 kb of genomic DNA. The GALK1 promoter was localized and found to have many features in common with other housekeeping genes, including high GC content, several copies of the binding site for the Sp1 transcription factor, and the absence of TATA-box and CCAAT-box motifs typically present in eukaryotic Pol II promoters. Analysis by 5'-RACE PCR indicates that the GALK1 mRNA is heterogeneous at the 5' terminus, with transcription sites occurring at many locations between 21 and 61 bp upstream of the ATG start site of the coding region. In vitro translation experiments of the GALK1 cDNA indicate that the protein is cytosolic and not associated with the endoplasmic reticulum membrane.
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PMID:Fine structure of the human galactokinase GALK1 gene. 890 17

Ocular toxicity of acetaminophen was investigated in cytochrome P450 inducer-responsive and nonresponsive strains of mice by light and electron microscopy. Acetaminophen injected into C57BL6 mice (responsive strain) that had been pretreated with beta-naphthoflavone produced cataract. The drug did not induce cataract in C57BL6 mice without the pretreatment or in DBA2 mice (nonresponsive strain) similarly pretreated with beta-naphthoflavone. Therefore, induction of cytochrome P450 enzymes that metabolically activate acetaminophen is essential for cataractogenesis. Following acetaminophen injection, tissue damage became noticeable first in the ciliary epithelium and then spread to the iris, corneal endothelium, and lens. The neural retina, retinal pigmented epithelium, and choroid remained unaffected. A close examination of tissues revealed that mitochondria are the primary target of acetaminophen cytotoxicity in ocular tissues affected. The nucleus, endoplasmic reticulum, and other subcellular structures appeared normal. The course of propagation of tissue damage and the almost exclusive damage to mitochondria suggest that the cytotoxic metabolite of acetaminophen is secreted with the aqueous humor by the ciliary epithelium and transported to the lens and that inhibition of mitochondrial energy metabolism, together with other effects of the metabolite, contributes to acetaminophen-induced cataract.
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PMID:Histocytological study on the possible mechanism of acetaminophen cataractogenesis in mouse eye. 894 Oct 46


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