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Biomedical subjects

J V Greiner

Publications and source records attributed to J V Greiner.

At least 73 records · Page 4Linked to original sources
PubMed1984

Late-phase reactions in ocular anaphylaxis in the rat.

We assessed whether anaphylactic stimulation of rat ocular tissue produces a late-phase reaction at the histologic level. Clinical changes of swelling and redness started within minutes, peaked at about 20 min, and then subsided. Neutrophils increased at 1/2 hr after stimulation, peaked at 6 hr, and subsided to normal at 24 hr. Eosinophils reached a significant increase at 6 hr. Compaction of vessel contents was present at 1/2 hr; vessels were normal thereafter. Extravasated red blood cells and debris in the tissue were prominent at 6 hr. Macrophages had accumulated significantly at 6 hr and maintained that level at 24 hr. Any effect of anaphylaxis on macrophage accumulation was masked because control-injected ocular tissue also showed an accumulation of macrophages at 24 hr. Our results demonstrate that in ocular tissue, as in skin, the early acute phase of immediate hypersensitivity is but one stage of a multiphasic reaction.

Anaphylaxis↗
PubMed1984

Histology of the ferret retina.

The retina of the adult ferret, Mustelo furo, was studied with light and transmission electron microscopy to provide an anatomical basis for use of the ferret as a model for retinal research. The pigment epithelium is a simple cuboidal layer of cells characterized by a zone of basal folds, apical microvilli, and pigment granules at various stages of maturation. The distinction between rod and cone photoreceptor cells is based on their location, morphology, heterochromatin pattern and the electron density of their inner segments. The round, light-staining cone cell nuclei occupy the layer of perikarya along the apical border of the outer nuclear layer. The remainder of the outer nuclear layer consists of oblong, deeply-stained rod cell nuclei. Ribbon type synaptic complexes involving photoreceptor cell axons, horizontal cell processes, and bipolar cell dendrites characterize the outer plexiform layer. The inner nuclear layer is comprised of horizontal, bipolar, and amacrine cell perikarya as well as the perikarya of the Müller cells. The light-staining horizontal cell nuclei are prominent along the apical border of the inner nuclear layer. The light-staining amacrine cell nuclei form a more or less continuous layer along the basal border of the inner nuclear layer. Both conventional and ribbon-type synapses characterize the inner plexiform layer. The ganglion cells form a single cell layer. The optic fiber layer contains bundles of axons surrounded by Müller cell processes. Small blood vessels and capillaries are present in the basal portion of the retina throughout the region extending from the internal limiting membrane to the outer plexiform layer. The adult one-year-old retina is compared with the retina at the time of eye opening.

Animals↗
PubMed1983

Treatment of contact lenses with papain. Increase in wearing time in keratoconic patients with papillary conjunctivitis.

In 15 Keratoconic patients with papillary conjunctivitis associated with wearing rigid polymethylmethacrylate contact lenses, the cleaning of the lenses with enzymatic contact lens cleaner (papain) increased lens wearing time in nine and diminished the symptoms of mucus and itching in 12. In 13 control, lens-wearing keratoconic subjects with papillary conjunctivitis, three had a decrease, four had an increase, and six had no change in lens wearing time and one had a diminution of symptoms. Use of the enzymatic contact lens cleaner did not, however, influence the biomicroscopic appearance of the papillary conjunctivitis. The inclusion of the enzymatic contact lens cleaner in the cleaning regimen offered an adequate improvement in wearing time and tolerance for three of four patients that previously suffered a reduction in wearing time that compromised or precluded their vocational responsibilities.

Adult↗
PubMed1983

Dynamic changes in intact crystalline lens metabolism modulated by alkaline earth metals: I. Effects of magnesium.

Dynamic changes in organophosphate levels during incubation of the intact crystalline lens in Earle's buffer containing 10 and 20 mM-MgCl2 were studied using phosphorus-31 nuclear magnetic resonance spectroscopy. Twenty-eight phosphatic metabolites of intermediary metabolism were quantitated and the utilization of these compounds was determined during a 24-hr time-course. In addition, intralenticular pH was assessed from both the resonance position of alpha-glycerophosphate and inorganic orthophosphate as measured in the intact tissue. Generally, high extracellular magnesium concentrations promote a net reduction of ATP with a concomitant production of inorganic orthophosphate; however, subtle changes occur in the metabolic processes which modulate this primary activity. The most notable difference between incubation in 10 and 20 mM-magnesium is that during 20 mM-magnesium incubations the intralenticular pH decline is proportionate to the net ATP consumption; however, in response to 10 mM-magnesium, the intralenticular pH becomes alkalotic in conjunction with the decrease in intralenticular ATP levels. The demonstration that high extracellular magnesium concentrations significantly alter lens metabolite levels is presumptive evidence that lens metabolic activity may be modulated through cellular mechanisms involving magnesium-sensitive processes.

Adenosine Triphosphate↗
PubMed1983

Biomicroscopy of papillae associated with wearing of soft contact lenses.

We studied the topographical, macrostructural, and fluorescein staining characteristics of papillary changes of the upper tarsal conjunctiva associated with the wearing of hydrophilic (soft) contact lenses. Fifty soft contact lens wearers with elevated conjunctival papillae greater than 0.3 mm in diameter were studied. Topographic characteristics recorded were distribution and number of papillae; macrostructural characteristics recorded were diameter and morphology of papillae. The information collected included age of patient, duration of lens wear, average daily time of wearing lens, presence or absence of itching or mucus, refractive status, and atopic history. Papillae were found in most cases in the conjunctival zone adjacent to the tarsal fold and were never found in 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 4 to over 100. The apices of the papillae were frequently flattened, and these flattened surfaces frequently stained with fluorescein. The vascular supply of individual papillae was observed to radiate from a vessel occupying the central core of each papilla.

Adult↗
PubMed1983

Pericentriolar processes of photoreceptor cell basal bodies in the mammalian retina.

Pericentriolar processes (arm-like fibers) of the migrating centrioles (diplosome) in differentiating retinal photoreceptor cells were examined in six mammalian species (hamster, vole, rat, rabbit, ferret, cat). These processes emanate in a radial fashion from one end of the centrioles comprising the photoreceptor diplosome. The pericentriolar processes of the basal body are first observed as the diplosome migrates toward the apical plasmalemma, suggesting that centrioles are committed early-on to developing such processes. One pericentriolar process arises from each set of microtubular triplets comprising the centriole and are apicoexternally oriented at an angle of between 30 and 60 degrees with the centriolar axis. Prior to the arrival of one of the centrioles at the apical plasmalemma these processes connect with an electron-dense portion of a centriole-associated vacuole. The diplosome migrates to the apical plasmalemma where one centriole (the presumptive basal body) orients perpendicularly to the apical plasmalemma. The centriole-associated vacuole appears to fuse with the plasmalemma. The pericentriolar processes appear to attach to this fusion site on the plasmalemma which is a region of the membrane characterized by increased electron density (the basilar plate). Invagination of the apical membrane, which occurs at this same site, is accompanied by a lengthening of the microtubules forming a cilium and is observed as an outpouching of the plasmalemma within the aforementioned invagination. The associated vacuole apparently becomes continuous with the apical plasmalemma. These pericentriolar processes appear to be functionally involved in ciliogenesis and offer structural stability between the basal body, the plasmalemma and indirectly the cilium.

Animals↗
PubMed1983

Phosphatic metabolites of the intact cornea by phosphorus-31 nuclear magnetic resonance.

The principal low molecular weight phosphatic metabolites of the intact cornea were identified and quantitated nondestructively by phosphorus-31 nuclear magnetic resonance (P-31 NMR) spectroscopy. As part of this analytical procedure, the intracorneal pH was approximated from the resonance shift position of inorganic orthophosphate. In addition the metabolic and pH stability of incubated corneas at 37 C in MK medium was evaluated during an 8-hr time course and compared to similar dynamic analyses performed on corneas with denuded endothelium. Perchloric acid extracts prepared from these same corneas were analyzed by P-31 NMR to verify the metabolite peak assignments and to quantitate the concentrations of minor corneal metabolites. The concentrations of phosphatic metabolites of the cornea, including three previously unidentified phosphorus-containing substances, were determined for freshly excised corneas. The initial corneal spectroscopic profile was not altered by removal of the endothelium. At 37 C the MK media-incubated intact whole corneas experienced a time-dependent decline in ATP levels with a concomitant rise in inorganic orthophosphate; however, the tissue levels of the other principal phosphatic metabolites were not altered by prolonged incubation. In contrast, removal of the endothelial layer of the cornea-induced progressive metabolic deterioration of intact corneas characterized, most prominantly, by time-dependent declines in ATP and glycerol 3-phosphorylcholine levels and concomitant increases in ADP and inorganic orthophosphate levels relative to intact whole corneas. This study has established the feasibility of monitoring the metabolic status of intact rabbit corneas nondestructively and noninvasively. As such, P-31 NMR spectroscopy offers a promising method that may enable analysis of the metabolic viability of intact human donor corneas to provide a basis for selecting donor corneas for transplantation.

Adenosine Triphosphate↗
PubMed1982

Interspecies variations in mammalian lens metabolites as detected by phosphorus-31 nuclear magnetic resonance.

Multiple interspecies differences were detected between humans and seven other mammals in 15 of the 24 metabolites measured in the intact crystalline lens and lens perchloric acid extracts. Generally, the number of statistically significant metabolite differences among the various species, relative to the human, increase in the following order: cat or approximately dog greater than pig greater than rat greater than sheep greater than rabbit greater than cow.

Adenine Nucleotides↗
PubMed1982

Human ocular mucus. Scanning electron microscopic study.

Twenty biopsy specimens of the human conjunctival epithelial surface with its associated mucus from normal subjects and contact lens wearers with biomicroscopic evidence of excess mucus were studied by scanning electron microscopy. Mucus existed in strands, sheets, and granules; each morphologic type of mucus was observed in all samples. No qualitative difference in morphologic features of mucus was found between normal subjects and those with excess mucus. Mucous forms observed by scanning electron microscopy closely resembled structures previously shown by biomicroscopic and light microscopic techniques, providing evidence that careful scanning electron microscopic preparation of biopsy specimens containing mucus may not greatly alter in situ morphologic characteristics of mucus.

Conjunctiva↗
PubMed1982

Langerhans cells of the ocular surface.

Recent evidence has been collected by several investigators defining a distinct population of dendritic cells (Langerhans cells) of mesenchymal origin residing in the epidermal surfaces of many mammalian species. These cells play a dominant role in the processing of antigens presented through cutaneous surfaces and carry a Class II histocompatability antigen felt to be of central importance in the afferent arm of allograft rejection. They also possess many of the characteristics of macrophages active in the efferent arm of immunologic responses. An equivalent subset of dendritic cells (Langerhans cells) in ocular surface epithelium of the human, mouse rat, and guinea pig has been identified by enzyme histochemistry, immunofluorescence, and electron microscopy. Ocular surface Langerhans cells proliferate in the setting of corneal inflammation (remote and recent) and are depleted by topical and systemic corticosteroids. Ocular surface Langerhans cells may play a central role in ocular contact hypersensitivity, corneal allograft rejection, and ocular surface immune surveillance.

Adolescent↗
PubMed1982

Dynamic changes in the organophosphate profile of the experimental galactose-induced cataract.

Dynamic changes in lens organophosphate metabolites during 24 hr incubation in 30 mM galactose media were measured with phosphorus-31 nuclear magnetic resonance spectroscopy. The following phosphates were quantitated from the intact crystalline lens: adenosine triphosphate (ATP), adenosine diphosphate (ADP), inorganic orthophosphate, alpha-glycerophosphate, phosphorylated hexoses and trioses, nicotinamide adenine dinucleotide, uridine diphosphoglucose and uridine diphosphogalactose, glycerol-3-phosphorylethanolamine and 3-phosphorylcholine, and an unidentified phosphorus-containing molecule. The temporal sequences of metabolic events that define the dynamic rates of accumulation or depletion of lens organophosphates reveal that the first event in the decline of the tissue upon galactose incubation is a net consumption of ATP, which occurs as a sigmoidal function with time and which is typified by a characteristic half-life of 18 hr. Alpha-glycerophosphate accumulated at an increasing rate with time, whereas ADP, inorganic orthophosphate, and the other organophosphates were essentially unchanged. Cataract formation in the subcapsular and superficial cortical regions was visible after 16 hr incubation in the experimental buffer. These findings support the hypothesis that alterations in the organophosphate levels of the lens are contributing factors to the initial formation of the experimental galactose cataract.

Adenosine Diphosphate↗
PubMed1982

Dynamic changes in the organophosphate profile upon treatment of the crystalline lens with dexamethasone.

Dynamic changes in organophosphate metabolites during incubations of the intact crystalline lens in a medium containing 2 X 10(-3) M dexamethasone were studied using phosphorus-31 nuclear magnetic resonance intact-tissue spectroscopy. ATP, ADP, inorganic orthophosphate, alpha-glycerophosphate, nicotinamide adenine dinucleotides, uridine diphosphorylglucose and diphosphorylgalactose, glycerol 3-phosphorylethanolamine and -phosphorylcholine, and an unidentified phosphorus-containing molecule at 6 ppm were quantitated. Time-dependent changes in lens metabolism involving these compounds were examined during a 24-hr incubation period with dexamethasone. The first event in the decline of the tissue after steroid incubation was the consumption of ATP, which was linear with time until the ATP was reduced to 10% of its initial value. The sugar phosphates, inorganic orthophosphate, and the nucleoside diphosphorylsugars increased linearly with time, whereas the dinucleotides decreased. The ADP concentration was unaffected by the steroid treatment, as was that of the other organophosphates in the intact tissue profile. The steroid-induced alterations in lens phosphate metabolite levels follow a distinctive pattern that differs substantially from that observed in response to experimental hypoglycistic or hyperglycistic conditions. These findings suggest that pharmacologic steroid doses may directly alter lens metabolism through a complex mechanism involving, at least in part, a steroid-mediated antagonism of lens glucose uptake and/or utilization.

Adenosine Diphosphate↗
PubMed1982

Cell surface variations of the human upper tarsal conjunctiva.

Fifteen specimens of the upper tarsal conjunctiva were obtained from subjects with biomicroscopically normal conjunctivae. Ten specimens were examined by scanning electron microscopy and five by transmission electron microscopy. This examination was performed to examine cells with variant surface morphologic appearance that may be signs of the initial changes typical of those seen in the diseased conjunctiva. Although most specimens had cells with a characteristic uniform distribution of microvilli, seven specimens had cells with nonuniform microvillar patterns. In these seven specimens, less than 5% of the cells showed these changes. Cell surface variations marked by reduced cell diameters and alterations in the microvillar distribution were categorized into two groups: cells with microvilli that were grouped together to form tufts of varying height and number, and cells with a single, centralized group of microvilli. These variations were seen with increased frequency in disease, and it is postulated that the microvillar changes described in this study represent a continuum of adaptive responses of cells to insult and disease.

Conjunctiva↗
PubMed1981

Immunohistochemical localization of human tear lysozyme.

Possible local sources of human tear lysozyme were investigated using an indirect immunofluorescence technique. Lysozyme was identified in 20% to 50% of acinar and ductular epithelial cells of both main and accessory lacrimal glands. The staining was granular in character and confined to the apices of the cells. Cells that stained positive tended to be grouped. Interstitial tissues of main and accessory lacrimal tissues did not stain. Conjunctiva and all other ocular tissues examined were unstained by antilysozyme antisera. Our findings are compatible with lysozyme either being produced in lacrimal tissue or being concentrated from plasma. The absence of any other lysozyme-specific fluorescence in the interstitial elements of the lacrimal tissues supports the notion of local synthesis by acinar lacrimal tissue.

Aged↗
PubMed1981

Density of goblet cells in vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis.

Using light microscopy, the density of goblet epithelial cells was determined in the conjunctival epithelium of ten patients with vernal conjunctivitis, ten patients with contact lens-associated giant papillary conjunctivitis, and ten normal subjects. The median density was 13,000/cu mm for vernal conjunctivitis, 11,000/cu mm for giant papillary conjunctivitis, and 11,000/cu mm for normal subjects, a statistically insignificant difference. Increased mucus in vernal conjunctivitis and contact mucus in vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis is not accounted for by an increased density of goblet cells per cubic millimeter. It is probably caused by the greater surface area and thickness of epithelium, with a concomitant increase in the total number of goblet cells and increased mucus from nongoblet epithelial cells.

Adolescent↗
PubMed1981

Goblet cells of the human conjunctiva.

We correlated histologic findings concerning conjunctival goblet cells with findings concerning the mucous membrane surfaces of the conjunctiva. Ten biopsy specimens were obtained from the upper tarsal conjunctiva and ten from the perilimbal bulbar conjunctiva. Changes in goblet cells just before and during secretion included changes in surface cell diameter, evagination of the apical surface of the cell membrane, decrease in the number of microvilli, and alteration in the arrangement and morphologic characteristics of microvilli. Changes seen by light and transmission electron microscopy correlated with those observed by scanning electron microscopy. Goblet cells were often associated with crypt openings; some crypts served as conduits for the secretion of mucus from underlying goblet cells. This study supports the hypothesis that crypts in the conjunctiva seen by scanning electron microscopy are often associated with goblet cells and their mucus secretion.

Adult↗