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M R Allansmith

Publications and source records attributed to M R Allansmith.

At least 55 records · Page 3Linked to original sources
PubMed1987

Late-phase reaction and tear fluid cytology in the rat ocular anaphylaxis.

Tear fluid cytology is described for the early and late phases of ocular anaphylaxis in actively immunized Sprague-Dawley rats. Tears were collected from both eyes of the rats before challenge and at 1, 2, 4, 6, 8, 10, 12, 24, and 48 h after topical challenge with di-DNP-lysine in one eye and PBS in the fellow eye. Results showed a statistically significant increase in the Aggregate Cell Rating, which represents the aggregate scores in neutrophil, eosinophil, lymphocyte, and atypical epithelial cell levels, in antigen-treated vs control eyes. This report is the first to use a cytologic study of tear film to detect the late phase of ocular anaphylaxis in the rat. Cytology of the tear film could be applied to the study of allergic conjunctivitis in both animals and humans.

Anaphylaxis↗
PubMed1987

The immune response of the lacrimal gland to antigenic exposure.

This study probed the influence of antigenic exposure on the immunological response of the lacrimal gland. We utilized the germfree rat as a model system to monitor tissue and tear immunoglobulin changes following transfer of these animals into an antigen-laden, conventional environment. The number of IgA- and IgM-containing cells in the lacrimal glands of germfree rats was 5 to 8 fold less than that of conventional controls. This reduced immunological expression in germfree animals also extended to tear IgA levels, which were significantly decreased. No effect of germfree conditions was found on the tear content of secretory component (SC). Transfer of rats from a germfree to a conventional environment resulted in a significant increase in the number of IgA- and IgM-containing cells in the lacrimal gland. By four weeks after 'conventionalization', the number of Ig-containing cells in lacrimal tissue was similar in both ex-germfree and conventional rats. In addition, 'conventionalization' led to a significant increase in the tear content of IgA: within four weeks following exposure to a conventional environment, tear IgA levels in ex-germfree rats were equivalent to those of age-matched, conventional controls. Overall, our results demonstrate that the secretory immune system of the lacrimal gland reacts to antigenic challenge with an increased immunological response.

Animals↗
PubMed1987

Hormonal influence on the secretory immune system of the eye: endocrine interactions in the control of IgA and secretory component levels in tears of rats.

Previous research from our laboratory has demonstrated that androgens regulate the ocular secretory immune system of the rat. The purpose of the present study was to determine whether other hormones might influence this androgen effect. Experiments involved the daily administration of saline or hormones to adult orchiectomized rats, the collection of tears 24 hr after the fourth hormone injection, and the measurement of free secretory component (SC), IgA and total protein levels in tears. Our first aim was to evaluate whether female sex steroids might antagonize androgen action on tear IgA and SC: orchiectomized rats were treated with combinations of saline, testosterone, oestradiol or progesterone. Testosterone induced a significant increase in the tear SC and IgA concentrations, as compared to those of saline-injected controls. This androgen effect was not inhibited by co-treatment with oestradiol or progesterone, nor duplicated by the administration of these hormones alone. Our second aim was to assess whether the absence of certain hormones might alter tear SC and IgA levels, or influence the ocular response to androgen exposure: rats underwent orchiectomies and specific endocrine organ ablations or appropriate sham-surgery. Absence of the pituitary gland, but not the thyroid, adrenal or pineal glands, resulted in a significant decrease in tear SC, IgA and total protein content. In addition, removal of the thyroid or adrenal glands did not prevent the testosterone-associated increase in tear SC and IgA, although thyroidectomy or adrenalectomy did diminish the magnitude of the androgen response. In contrast, hypophysectomy completely blocked the effect of testosterone on both tear SC and IgA. These results indicate that the hypothalamic-pituitary axis may regulate, or mediate, the action of androgens on ocular immunity in the rat.

Adrenal Glands↗
PubMed1987

Pathology and treatment of giant papillary conjunctivitis. I. The U.S. perspective.

Giant papillary conjunctivitis is a disease we are seeing more and more. I believe it can be avoided with new ways of designing the lenses and new ways of cleaning them. Meanwhile, however, we need to improve cleaning, increase our use of enzymes, irrigate the conjunctiva, change lenses often, and use cromolyn sodium to stabilize the mast cells. These measures should enable our patients to continue using their contact lenses longer.

Conjunctivitis, Allergic↗
PubMed1987

Sequential development of a conjunctival basophil hypersensitivity lesion in guinea pig.

We investigated the cellular profile of inflammatory infiltrate during development of a guinea pig conjunctival basophil hypersensitivity lesion at 1, 6, 24, 48, and 72 hr following injection of keyhole limpet hemocyanin (KLH). Neutrophils reached maximal accumulation at 6 hr. Eosinophils and basophils reached maximal accumulation at 24 hr. Basophil numbers remained high at 48 hr and were lower at 72 hr. The number of stromal monocytes did not vary significantly from PBS-injected tissues at any time. Mast cell number decreased at 24 hr following antigen challenge. Morphologic evidence for intense secretory activity was seen in cells at the stromal reaction site. Secretion channels and evidence of intense degranulation was seen from electron microscopy of neutrophils, eosinophils, and basophils. Inflammatory cells migrate through the basement membrane into the conjunctival epithelium. After maximal accumulation there was a decrease in the number of inflammatory cell types in the epithelium.

Animals↗
PubMed1987

A hapten model of topically-induced ocular anaphylaxis in the rat.

A hapten (DNP) model of topically induced ocular anaphylaxis has been developed. Rats immunized with DNP-Ascaris were skin-tested with DNP-bovine serum albumin (DNP-BSA) and Evans blue and challenged topically with varying amounts of di-DNP-lysine. The degree of clinical conjunctival edema was assessed, and eye tissues were evaluated histologically. Clinical conjunctival edema and histologic mast cell degranulation increased with higher concentration of di-DNP-lysine. In general, rats with positive skin tests showed more clinical conjunctival edema and more mast cell degranulation than those with negative skin tests. Three other groups of rats with positive skin tests to the DNP-BSA were injected intravenously with 125I-BSA and challenged topically with di-DNP-lysine. Retention of 125I-BSA in ocular adnexa and in globes was higher in di-DNP-lysine- than in PBS-challenged eyes. The hapten model simulates the ocular component of human hay fever in that ocular anaphylaxis is induced in immunized rats by topical challenge with antigen alone.

Administration, Topical↗
PubMed1986

Characterization of a localized basophil hypersensitivity lesion in guinea pig conjunctiva.

Basophils accumulate in response to antigen challenge in cutaneous basophil hypersensitivity (CBH) reactions. Two ocular diseases, vernal conjunctivitis and contact-lens-associated conjunctivitis, are also characterized by this histopathology. We have refined a model previously developed in guinea pig conjunctiva by precisely defining the site of antigen injection and correlating the site with the clinical and histologic changes. Guinea pigs were primed by an intradermal injection of keyhole limpet hemocyanin (KLH) in the flank and challenged (Day 6) by injection of a small bolus of KLH just under the conjunctival epithelium. Twenty-four hours later histologic examination showed a perivascular infiltrate of inflammatory cells containing large numbers of basophils. Eosinophils, neutrophils, macrophages, and mast cells were also seen. Serial sections of the reaction site showed discrete boundaries. At all sites examined in antigen-challenged tissues, there were significantly more basophils than in control-injected conjunctiva. Insertion of a sterile needle or injection of PBS or KLH into normal conjunctiva induced a significant increase in neutrophils and some macrophages. Injection of graded doses of antigen into the conjunctiva of primed animals, resulted in a dose-dependent increase in basophils up to 50 micrograms KLH (optimal dose).

Animals↗
PubMed1986

Hormonal modulation of tear volume in the rat.

The present study examined the influence of hormones on the tear volume of male rats. The mean tear volume in a population of 2-3-month-old intact rats equaled 4.6 +/- 0.2 microliter. This volume, however, varied depending upon the hormonal environment of the animal. Orchiectomy induced a significant, 46%, increase in the mean tear volume, compared with that of intact rats. Testosterone administration to orchiectomized rats reversed this increase and caused a significant reduction in tear volume. Of interest, this androgen action was prevented if rats were also hypophysectomized. Hypophysectomy alone decrease tear volume and this response was not influenced by later castration. Other endocrine manipulations, including thyroidectomy, adrenalectomy and estrogen treatment of orchiectomized rats had no effect on tear volume. Overall, our results indicate that tear volume may be modulated by hormones from the hypothalamic-pituitary-gonadal axis.

Adrenalectomy↗
PubMed1986

Worm antigen-induced ocular anaphylaxis in rats infected with Nippostrongylus brasiliensis.

A model of topically induced conjunctival anaphylaxis has been developed. Male Sprague-Dawley rats were immunized by infection with 3000 Nippostrongylus brasiliensis larvae and challenged topically on the eye 4 weeks later. Application of worm antigen alone did not induce clinical (conjunctival edema) or histologic (mast-cell degranulation) signs of anaphylaxis. Topical challenge with antigen 15 min after topical application of dithiothreitol (DTT), a mucolytic agent, elicited conjunctival edema and mast-cell degranulation within the first hour after challenge. At 6 and 24 hr, no clinical change was evident and conjunctival mast cells had again become granulated. At none of the three intervals (1, 6 and 24 hr) was there a significant increase in neutrophils, lymphocytes, eosinophils or macrophages in tissues from DTT-pretreated, antigen-eyes. The present model of ocular anaphylaxis resembles the ocular component of human hay fever in that sensitization prior to challenge is essential, the antigen is presented topically to the ocular tissues, conjunctival edema is the clinical manifestation and mast cell degranulation characterizes the histologic changes.

Anaphylaxis↗
PubMed1986

Conjunctival basophil hypersensitivity in the guinea pig.

We have induced a basophil hypersensitivity reaction in the upper tarsal conjunctiva of the guinea pig by methods that induce a comparable basophil hypersensitivity reaction in the flank. The inflammatory cell infiltrate in this reaction contained large numbers of basophils and eosinophils with accompanying neutrophils and monocytes. Ocular tissue can serve as a priming site for systemic immunization and also for elicitation of a secondary flare after challenge with antigen. Very few inflammatory cells were observed in the cutaneous epithelium of either primary or secondary flares. In contrast, the mucosal stroma and epithelium contained large numbers of inflammatory cells (basophils, eosinophils, and neutrophils), suggesting directed cellular movement onto the ocular surface. The lesion of ocular basophil hypersensitivity in the guinea pig has features in common with two human eye diseases, vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis. We hypothesize that the acute basophil hypersensitivity reactions of the conjunctiva are transformed into chronic inflammatory and proliferative states in vernal conjunctivitis and giant papillary conjunctivitis.

Animals↗
PubMed1986

Naturally occurring IgA antibodies to ocular and oral microorganisms in tears saliva and colostrum: evidence for a common mucosal immune system and local immune response.

In this study, levels of naturally occurring secretory IgA (sIgA) antibodies to bacterial isolates representative of the microflora of the human eye (Staphylococcus epidermidis and a Corynebacterium species) and the oral cavity (Streptococcus mutans serotypes c and d) were assessed in three different human external secretions. Tears and parotid saliva samples collected at the same time from 22 healthy subjects and colostrum from 11 healthy women (1-14 days post partum) were assessed for sIgA anti-bacterial antibody levels by an enzyme-linked immunosorbent assay. Significantly higher levels (P less than 0.001) of IgA antibodies to Staphylococcus epidermidis and the Corynebacterium sp. were found in tears than in parotid saliva. Furthermore, higher levels of sIgA antibodies to Streptococcus mutans serotype d occurred in parotid saliva than in tears of these subjects. Although levels of salivary sIgA antibodies to S. mutans serotype c were lower than those seen to serotype d, they were not significantly different from those in tears. However, absolute sIgA anti-serotype c antibodies per mg IgA were higher in saliva than in tears. When sIgA antibody levels to the four bacterial strains were assessed in colostrum, the proportion of sIgA antibodies per mg IgA were much lower than seen in tears or saliva. These results suggest that natural sIgA antibodies which occur in human external secretions are induced by antigen ingestion and stimulation of the common mucosal immune system. However, the local presence of antigen at a mucosal site induces greater clonal expression and results in higher levels of sIgA antibodies than at mucosal sites not exposed to local antigenic stimulation.

Adolescent↗
PubMed1986

Topically induced ocular anaphylaxis in rats immunized with egg albumin.

A model of topically induced ocular anaphylaxis was developed. Male Sprague-Dawley rats were immunized by intraperitoneal injections of egg albumin (EA) and alum and topically challenged with EA. Application of EA induced clinical (conjunctival edema) and histologic (mast cell degranulation) signs of anaphylaxis, when the antigen was preceded by topical application of dithiothreitol (DTT), a mucolytic agent. Rats challenged by four EA applications did not differ significantly in clinical edema or mast cell degranulation from those challenged by one EA application at the same (0.1 M DTT) pretreatment level, but there was significantly greater histologically assessed edema in the eyes challenged four times.

Administration, Topical↗
PubMed1986

Production and utilization of a mouse monoclonal antibody to rat IgA: identification of gender-related differences in the secretory immune system.

The present study was designed: to produce a mouse monoclonal antibody to rat IgA; and to examine, by using the monoclonal antibody, possible gender-related differences in the secretory immune system. Hybridomas were prepared that secreted mouse monoclonal antibodies directed specifically against rat IgA. These antibodies were identified as IgG1 and kappa chain positive and could be used to purify rat IgA by affinity chromatography, detect tissue IgA by immunofluorescence and measure IgA levels in external secretions by radioimmunoassay. In utilizing these antibodies, we found that a distinct, gender-related difference exists in the number of IgA-containing cells in the rat lacrimal gland. Lacrimal tissue from male rats had a significantly higher content of IgA-positive cells than did that from female rats. This difference correlated well with our previous observations on the sexual dimorphism in tear IgA levels. We also observed in the present study that gender-associated variations in IgA content occur in respiratory secretions. In contrast to the eye, however, females had significantly greater IgA concentrations than did males. No effect of gender was found on IgA levels in small intestinal secretions, saliva or serum. Overall, our results indicate that gender may play a role in the immune response of specific mucosal tissues.

Animals↗
PubMed1986

Conjunctival basophil hypersensitivity lesions in guinea pigs. Analysis of upper tarsal epithelium.

The upper tarsal conjunctival epithelium was analyzed for inflammatory cell profile and accompanying morphological changes in a guinea pig system with histopathology resembling two human ocular diseases: vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis (GPC). Female Hartley strain guinea pigs were immunized intradermally on day 0 with 200 micrograms keyhole limpet hemocyanin (KLH) and challenged on day 6 with varying doses of KLH by injection beneath the conjunctival epithelium of one lid and phosphate-buffered saline in the contralateral lid. Tissues containing the reaction site were examined by light microscopy. The 50 micrograms dose of KLH elicited the maximal accumulation of basophils and eosinophils. These values were significantly higher than in the PBS-injected control. Injection of KLH, PBS, or insertion of a sterile needle into unsensitized animals, and uninjected tissue served as additional controls. Neutrophils were significantly higher in the epithelium of the traumatized tissue (repeated needle insertions) than in the uninjected control. Basophils and mast cells were rarely found in the epithelium of unsensitized animals. Epithelial thickening, quantified by a Zeiss Videoplan2 Image Analysis system (Zeiss, West Germany), was greatest in the traumatized tissue, followed by the KLH-challenged tissue of sensitized animals. These values were significantly greater than that of the PBS-injected lid or of naive animals, uninjected or KLH-injected. These results indicate that epithelial changes can be induced by both antigen and trauma. Such epithelial changes may have a role in both vernal conjunctivitis and giant papillary conjunctivitis.

Animals↗
PubMed1985

Effects of eye rubbing on the conjunctiva as a model of ocular inflammation.

We assessed the effects of eye rubbing on the histologic characteristics and inflammatory cell infiltrate of the conjunctiva. The upper eyelids of 20 adult rats were rubbed during a five-minute period, and then the animals were killed immediately, or at four, eight, or 24 hours after trauma. One eye of each animal was rubbed; the unrubbed contralateral eye served as a control. Counts of mast cells, degranulated mast cells, and inflammatory cells (neutrophils, eosinophils, lymphocytes, plasma cells, and macrophages) were recorded from conjunctival samples from the upper eyelid. Immediately after eye rubbing the conjunctival epithelium was histologically disrupted and 50% of the mast cells showed evidence of degranulation. At four hours after trauma the increase in the number of neutrophils was more than 2,300%. Neutrophils were in the margins in the conjunctival vessels, had migrated into the substantia propria, and were aligned subjacent to the epithelial basement membrane; large numbers of neutrophils populated the epithelium. The four-hour stage was the most dramatic phase of inflammation that occurred from the eye rubbing. At 24 hours there was a significant increase in the number of macrophages. The numbers of lymphocytes, plasma cells, and eosinophils were not significantly changed throughout the study. Our findings demonstrate that eye rubbing histologically disrupts the epithelium and induces significant alteration in the inflammatory cell infiltrate of the conjunctiva. These changes may influence the course of ocular disease.

Animals↗