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Biomedical subjects

J V Greiner

Publications and source records attributed to J V Greiner.

15 recordsLinked to original sources
PubMed1979

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↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1978

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↗
PubMed1978

Number of inflammatory cells in the normal conjunctiva.

We counted inflammatory cells per cubic millimeter in both the epithelium and the substantia propria of samples from upper tarsal conjunctiva of 15 normal subjects and from lower forniceal conjunctiva of ten normal subjects. The upper limit of normal for number of cells was nearly 500,000/mm3. Lymphocytes accounted for about 70% of the inflammatory cells. Neutrophils and lymphocytes were almost always present in both the epithelium and the substantia propria. Plasma cells and mast cells were present in the substantia propria of all subjects, but never in the epithelium. Neither eosinophils nor basophils were found in any specimen. We concluded that conjunctiva of the white and quiet eye usually contains heavy infiltrates of inflammatory cells.

Adolescent↗
PubMed1978

Giant papillary conjunctivitis induced by hard or soft contact lens wear: quantitative histology.

Both hard and soft lens wearers develop a syndrome of decreased tolerance, increased mucus, mild itching, and giant papillary excrescences in the upper tarsal conjunctiva that resemble a varnal conjunctivitis. In the fully developed syndrome, the upper tarsal plate has an increase in stringy mucus and is covered by large papillae crowded together. The syndrome develops after months to years of otherwise successful lens wear and occurs in users of all types of soft and hard lenses. Histologic examination of tissues from 55 patients with well-developed giant papillary conjunctivitis compared with tissue from 15 normal people showed three findings characteristic of the syndrome: (1) mast cells in the epithelium, (2) eosinophils in the epithelium and substantia propria, and (3) basophils in the epithelium and substantia propria. Plasma cells and lymphocytes per cubic millimeter were not increased in detailed counts of 15 patients and 15 normal individuals. It is proposed that the number of plasma cells and lymphocytes cannot increase much beyond the level already present in normal conjuctiva and further influx of mononuclear inflammatory cells is the impetus for growth of the papillae. It is proposed that giant papillary conjunctivitis is a generalized response of the upper tarsal conjunctiva.

Adolescent↗
PubMed1978

Development of the hamster retina: a morphologic study.

Hamster retinas were examined by light and electron microscopy during the first 15 postnatal days and at the adult stage. At birth, these retinas were more primitive than those of other rodents, but eventually they became very similar. Initial postnatal growth and development were more rapid than in other rodents of comparable ages. Mitotic figures were present throughout the first 9 days. The primitive inner plexiform layer formed during days 2 to 4; on day 7, several developmental changes became apparent: outer segment disks of the photoreceptor cells formed from flattened, smooth vesicles, horizontal cells became readily identifiable, the outer plexiform layer appeared, and ribbon synapses formed in the receptor cell axon terminals. By day 11, there were numerous conventional synapses in the inner plexiform layer, and ribbon synapses were beginning to appear in the terminal portions of the bipolar axons. The retinal tissue was progressively invaded by developing vasculature. The first photoreceptor outer segment disks formed from smooth membranous vesicles flattening radially around the ends of the connecting cilium. After the outer segment assumed a more mature appearance, with a stacked disk arrangement, further disk formation occurred by plasma membrane infoldings at the outer segment base. The adult hamster retinas were similar to those of other rodents.

Animals↗
PubMed1977

Giant papillary conjunctivitis in contact lens wearers.

A syndrome that occurred in both hard and soft contact lens wearers was characterized by increased mucus, itching, decreased lens tolerance, and giant papillae in the upper tarsal conjunctiva. It developed in as few as three weeks with soft lens wearers but also occurred after months or even years of successful wear. The histology was characterized by basophils, eosinophils, and mast cells in the epithelium, and these cells as well as increased numbers of lymphocytes, plasma cells, and polymorphonuclear leukocytes in the stroma. The syndrome may be immunologic in origin with deposits on the lenses as the antigen, and the syndrome may be a major cause of difficulty in wearing contact lenses once they have been successfully fit.

Antigens↗
PubMed1977

Phacocryolysis and phacoemulsification.

The effect of rapid freezing and thawing was tested in vitro on 100 human hard nuclear cataracts before ultrasonic emulsification. After phacocryolysis the interspace between lens fibers increased, and the normally closely packed fibers appeared to loosen. This seemed to soften the hard cataract, thereby facilitating ultrasonic emulsification.

Cataract Extraction↗