Histogenesis of the ferret retina.
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Animals↗
Biomedical subjects
J V Greiner
Publications and source records attributed to J V Greiner.
Ciliogenesis in photoreceptor cells of the retina.
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Aging↗
Biomicroscopy of papillae associated with hard contact lens wearing.
We studied the macrostructural characteristics of papillary changes of the upper tarsal conjunctiva associated with the wearing of polymethyl methacrylate (PMMA) contact lenses. Fifty subjects with elevated conjunctival papillae greater than 0.3 mm in diameter were studied. Macrostructural characteristics recorded were location, diameter, and number of papillae, presence or absence of staining at the apices of papillae, and degree of hyperemia of the upper tarsal conjunctiva. Patient information collected included age, duration of lens wear, average daily lens wearing time, presence or absence of itching or mucus, refractive status, and atopic history. The tarsal conjunctiva was divided into three zones of equal size. Papillae were present in various zones and combinations of zones; however, papillae were never confined exclusively to either (1) the zone adjacent to the tarsal folds or (2) the latter zone in combination with the zone adjacent to the eyelid margin without also occurring in the intervening zone. The diameter of the papillae ranged from greater than 0.3 mm to 2.0 mm. The number of papillae per eyelid ranged from two to over 100. The apices of the papillae were frequently flattened and craterlike, and often stained with fluorescein.
Adult↗
Effect of contact lens wear on the conjunctival mucous system.
Biopsy specimens from the upper tarsal conjunctiva of 20 contact lens wearers with a clinically evident increase in mucus and ten non-lens wearing subjects were examined by light microscopy and scanning and transmission electron microscopy to determine the effect of contact lens wear on the mucous cell system(s). Three types of crypts associated with mucous secretion were found in all specimens: those with intracellular openings (type I, 0.1 to 0.2 mum) associated with non-goblet mucous secretory cells; those with small intercellular openings (type II, 1 to 2 mum) usually associated with goblet cells, and those with intraepithelial and intrastromal crypts with large intercellular openings (type III, 10 to 60 mum) lined with goblet and non-goblet mucous secretory cells. Contact lens wearers had increased numbers of non-goblet cells with mucous secretory vesicles lining the surface of the conjunctiva and the epithelial infoldings of type III crypts than did the normal subjects. We conclude that increased mucous secretion in contact lens wearers is associated with an increased number of cells and number of secretory vesicles involved in the non-goblet cell mucous system.
Conjunctiva↗
Analysis of intact rat lens metabolites by P-31 NMR spectroscopy.
Using phosphorus-31 nuclear magnetic resonance (P-31 NMR) spectroscopy the rat crystalline lens was evaluated as a potential animal model for the study of lens metabolic processes relevant to the human. The P-31 NMR spectra of intact rat lenses and rat lens PCA extracts provided comparable qualitative and quantitative results concerning the tissue levels of the phosphorus-containing metabolites of intermediate metabolism. The study also establishes the feasibility of examining intact rat lens metabolism by P-31 NMR. Comparisons with reported human and rabbit lens metabolite levels revealed significant differences; consequently, metabolic information derived from rat lens studies should be extrapolated to the human with caution.
Animals↗
Organophosphates of the crystalline lens: a nuclear magnetic resonance spectroscopic study.
We quantitated the concentrations of the principal organophosphate metabolites present in the intact crystalline rabbit lens, measured the intralens pH, and evaluated dynamic changes during 24 hr incubations, using phosphorus-31 nuclear magnetic resonance (P-31 NMR) spectroscopy. Tissue perchloric acid extracts prepared from these same lenses were analyzed by this technique to verify metabolite identifications and to quantitate the concentrations of the minor lens metabolites. Values for lens organophosphate concentrations, including three groups of previously unidentified phosphorus-containing substances, were established for freshly excised lenses, 24 hr incubated lenses, and lenses incubated in glucose-deficient media. Lens metabolite levels were not adversely affected by incubation in a medium previously shown to maintain lens clarity and ion transport capabilities. Conversely, lens incubation in glucose-deficient media induced significant metabolic changes characterized by a time-dependent decline in ATP, corresponding increases in ADP, inorganic phosphate, and phosphorylated hexoses. Cataract formation was noted after incubation in this medium. These findings support the hypothesis that alterations in the organophosphate levels of the lens actually preceded changes in the Na+ and K+ concentrations and therefore may be the "initiating factor" in formation of lens cataracts.
Animals↗
Branching of microvilli in the human conjunctival epithelium.
Biopsy specimens were obtained from the upper tarsal and limbal conjunctivae of ten normal persons and from the upper tarsal conjunctivae of five asymptomatic contact lens wearers and five patients with giant papillary conjunctivitis (GPC) associated with contact lens wear. The microvillar surface of the conjunctival epithelium was studied by transmission and scanning electron microscopy. Branches often stemmed from the side of a straight tubular microvillus and formed an acute angle with the main process. Branches sprouted at various distances from the origin of the microvillus. The most common branching pattern was the bifurcated (bifid) form. Occasionally, both primary and secondary bifurcations were primary and secondary bifurcations were observed on the same microvillus. Some microvilli were branched in the normal conjunctivae, but the conjunctivae of asymptomatic contact lens wearers and patients with GPC had more branched microvilli and greater polymorphism, which correlated with the degree of alteration. This report demonstrates the presence of branched microvilli and describes the types seen in normal conjunctivae and compares the frequency with which branched microvilli are seen in altered conjunctival surfaces.
Cell Membrane↗
Mucus secretory vesicles in conjunctival epithelial cells of wearers of contact lenses.
Biopsy specimens from the upper tarsal conjunctivae of ten patients with clinically evident contact-lens-associated giant papillary conjunctivitis (GPC) and eight asymptomatic contact lens wearers without clinically evident conjunctival changes were compared by light and transmission electron microscopy to determine the contribution of nongoblet epithelial cells to increased mucus. A control group consisted of five subjects who had never worn contact lenses. The apical cytoplasm of superficial nongoblet epithelial cells in specimens from all groups showed single-membrane-limited vesicular inclusions that stained metachromatically with toluidine blue and were positive with PAS staining, which indicated muco-protein content. Some vesicles appeared to discharge their contents into the conjunctival sac. More vesicles were found in the GPC subjects and the asymptomatic contact lens wearers than in the normal subjects. These observations, coupled with the sign of increased or excessive mucus discharge in GPC subjects and in asymptomatic lens wearers, support the premise that the superficial layers of non-goblet conjunctival epithelial cells can contribute to an increase in mucus production.
Adult↗
Histologic and immunohistologic comparison of main and accessory lacrimal tissue.
Main and accessory lacrimal tissues from autopsy and biopsy specimens were compared histologically and immunohistologically. Formaldehyde-fixed, paraffin-embedded specimens were studied by light microscopy with hematoxylinand-eosin and PAS staining. Glutaraldehyde-fixed, Epon-embedded specimens were sectioned at 1 micron, stained with alkaline Giemsa, and studied by light microscopy. Specimens fixed in a solution of alcohol and acetic acid were stained by immunofluorescence techniques for lactoferrin, lysozyme, secretory component, and the immunoglobulins IgG, IgA, IgM, IgD, and IgE. The main and the accessory lacrimal tissues were identical histologically and had identical distributions of secretory products and immunoglobulin-containing plasma cells. The finding of myoepithelial cells in 1-micron sections of accessory lacrimal tissue indicates autonomic innervation in that tissue. This finding, in conjunction with the identical immunohistology, indicates a common source for unstimulated and stimulated tears.
Aged↗
Histogenesis of the cat retina.
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Animals↗
Prevalence of conjunctival changes in wearers of hard contact lenses.
The prevalence of elevated papillae more than 0.3 mm in diameter was 10.5% in the conjunctivae of 200 subjects who had successfully worn polymethylmethacrylate hard contact lenses for eight hours or more daily for more than five years. Only three of 500 (0.6%) control subjects who had never worn contact lenses had these papillary changes. The prevalence of papillary changes for those with the so-called normal symptoms of mucus, itching, or both associated with wearing of hard contact lenses was 53% (16 of 21 subjects). The prevalence of these symptoms was 76% among subjects with polymethylmethacrylate contact lenses who had papillary changes and 8% among subjects with polymethylmethacrylate contact lenses who did not have papillary changes. We conclude that changes in the upper tarsal conjunctiva are associated with the wearing of hard contact lenses, occur in a significant percentage of patients wearing hard contact lenses for prolonged periods, and include a spectrum of papillary changes.
Conjunctival Diseases↗
Posterior subcapsular cataracts: histopathologic study of steroid-associated cataracts.
Long-term steroid therapy is associated with production of a posterior subcapsular cataract (PSC). Five steroid-associated cataractous lenses were studied, using light, scanning, and transmission electron microscopy. Anterior, equatorial, and posterior regions were examined. Findings were compared with five age-matched senile PSCs and five nuclear cataractous lenses with no cortical opacities. The posterior polar region of steroid-associated cataractous lenses consists of (1) a superficial zone of liquefaction and (2) a deep zone of segmentally swollen lens fibers. Nucleated lens fibers are present in posterior cortical regions. Cytoplasm at knob and socket junctions had become lucent and plasma membranes were disappearing, leaving empty spaces. Laminated membranous configurations were seen. Although the same basic histopathologic abnormalities were found in steroid-associated cataracts and in nonsteroid senile PSCs, it is their organization and localization that may be the distinguishing characteristics of the steroid-associated cataract.
Adrenal Cortex Hormones↗
Attachment of bacteria to soft contact lenses.
A total of 25 soft contact lenses from 17 asymptomatic contact lens wearers and eight patients with contact lens-associated giant papillary conjunctivitis were examined by scanning electron microscopy. Structures that resembled bacteria were present on the anterior surface of seven lenses. All lenses showed a coating of granular mucus-like deposits. Some bacteria were seen scattered randomly over the surface, with no apparent attachment to the lens, whereas others were attached to the coated surface by thin, flagella-like foot processes, the distal ends of which were unattached. These attached bacteria were cylindrical in shape. Several bacteria showed a constriction centrally. Some bacteria were covered by the surface coating, while others, which were round to ovoid in shape, appeared partially embedded in the coating itself. Aggregations of bacteria were seen around clumps of mucus-like debris.
Bacteria↗
The human limbus. A scanning electron microscopic study.
Fourteen human limbal biopsy specimens were obtained from seven normal subjects. The epithelial surface was examined by scanning electron microscopy. Epithelial cell surfaces varied greatly in shape and size, and mosaics of three- to six-sided irregular polygons were formed. Microvillar borders of cells were distinct. Cell sizes ranged from 3 to 20 micron across. Light and dark cells were present and randomly distributed. A few cells were covered with microplicae; the remainder of the cells were covered with microvilli. Intercellular crypt openings measuring 1 to 10 micron in diameter were distributed randomly over all specimens. These openings were believed to be related to goblet cells. Many openings were plugged with what appeared to be mucus. Many surface-level intercellular structures were present; they corresponded in diameter to the surface openings. The human limbal epithelium varies from both the upper tarsal conjunctiva and the cornea.
Adult↗
Number of type of inflammatory cells in conjunctiva of asymptomatic contact lens wearers.
Biopsy specimens were taken from the upper tarsal conjunctiva of eight asymptomatic contact lens wearers and quantitative histology was determined and compared to histology from 15 normals and 55 patients with contact lens-induced giant papillary conjunctivitis. No abnormalities were detected in the asymptomatic contact lens wearers. One or more of the three tissue characteristics of giant papillary conjunctivitis--(1) mast cells in the epithelium, (2) eosinophils in epithelium or substantia propria, and (3) basophils in epithelium or substantia propria--was found in all patients with this syndrome, but none was present in any of the eight asymptomatic lens wearers. Trauma occurring over months or even years does not induce histologic alteration in the upper tarsal conjunctiva; the surface changes seen previously by scanning electron microscopy in asymptomatic lens wearers are secondary to trauma, not early aspects of the giant papillary conjunctivitis syndrome.
Adult↗
Vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis compared and contrasted.
We compared quantitative histologic counts of ten subjects with vernal conjunctivitis to counts of 15 subjects with contact lens-associated giant papillary conjunctivitis and to counts of 15 normal subjects. Both vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis subjects had abnormalities of mast cells in the epithelium, and eosinophils and basophils in epithelium and substantia propria. No normal individuals had these abnormalities. An additional 28 subjects with ocular inflammatory conditions had tissue evaluation for abnormalities of mast cells, eosinophils, and basophils. A few eosinophils were found in four subjects. The histologic abnormalities of vernal conjunctivitis are shared by contact lens-associated giant papillary conjunctivitis but not by conjunctival inflammation in general. Vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis may represent different subtypes of a general category of conjunctival abnormality characterized by giant papillae.
Adolescent↗
Soft contact lenses from patients with giant papillary conjunctivitis.
We used scanning electron microscopy to study the surfaces of five coated soft contact lenses from subjects with giant papillary conjunctivitis. Findings were compared to the surfaces of five coated lenses from normal, asymptomatic wearers and five new, nerver-worn lenses. Lenses were from various manufacturers. All worn contact lenses differed strikingly from new, never-worn lenses. The anterior surface of worn lenses was covered with apparently adherent deposits. In only a few areas was the surface similar to new, never-worn lenses. Thick coatings on lenses from patients with giant papillary conjunctivitis and asymptomatic wearers were similar. High magnification of the coatings revealed a trabeculated morphology. Also seen was debris that resembled mucus-like material in both strand and particulate forms. On some lenses bacterial-shaped structures were scattered randomly over the surface. Smooth structures resembling cells were also seen. The posterior lens surface of all worn lenses was smoother than the anterior lens surface. The findings support our idea that the capacity to develop giant papillary conjunctivitis is influenced by individual differences more than by differences in lens deposits.
Adult↗
Conjunctiva in asymptomatic contact lens wearers.
Biopsy specimens of the upper tarsal conjunctiva from 11 asymptomatic, biomicroscopically normal contact lens wearers (five hard and six soft) were studied by scanning electron microscopy. The conjunctiva in lens wearers showed areas of normal epithelial cell surfaces interspersed among areas of altered cells. The altered cell surfaces were characterized by centralized clumped microvilli and baring of that portion of plasma membrane around the cell periphery. The degree of centralization of microvilli varied widely, from a mild tendency to centralize accompanied by slight reduction in cell diameter, to an exteme centralization and dramatic diameter reduction. In some cells, the centralized microvillar structure had a unique mucuslike covering. Numerous altered cells were present in all 11 specimens from asymptomatic contact lens wearers. The number of these cells found by conjunctival biopsy of the hard contact lens wearers and the number in the soft contact lens wearers apparently did not differ. The upper tarsal conjunctiva in these asymptomatic contact lens wearers has an altered epithelial surface, different from that observed in normal subjects without contact lens-wearing experience and from subjects with contact lens-associated giant papillary conjunctivitis.
Adult↗