Comparison of growth factor and interleukin content of adult peripheral blood and cord blood serum eye drops for cornea and ocular surface diseases

INTRODUCTION

Various blood-derived products have been proposed for the topical treatment of ocular surface diseases. The aim of the study was to compare the different content of Growth Factors (GFs) and Interleukins (ILs) in peripheral blood (PB-S) and Cord Blood (CB-S) sera.

MATERIALS AND METHODS

Sera were obtained from 105 healthy adult donors (PB-S) and 107 umbilical/placental veins at the time of delivery (CB-S). The levels of epithelial-GF (EGF), fibroblast-GF (FGF), platelet-derived-GF (PDGF), insulin-GF (IGF), transforming-GF alpha (TGF-α,) and beta 1-2-3 (TGF-β1-β2-β3), vascular endothelial-GF (VEGF), nerve-GF (NGF), Interleukin (IL)-1β,IL-4,IL-6,IL-10, and IL-13 were assessed by Bio-Plex Protein Array System (Bio-Rad Laboratories, CA, USA). The Mann-Whitney test for unpaired data was applied to compare GFs and ILs levels in the two sources. The associations among each GF/IL level and the obstetric data for CB-S and hematological characteristics for PB-S were also investigated.

RESULTS

The levels of EGF, TGF-α, TGF-β2, FGF, PDGF, VEGF, NGF, IL-1B, IL-4, IL-6, IL-10, and IL-13 were significantly higher in CB-S compared to PB-S. Conversely, the levels of IGF-1, IGF-2, and TGF-β1 were significantly higher in PB-S. The female sex and the weight of the child showed a significant association in predicting EGF and PDGF levels.

CONCLUSION

A significantly different content in those GFs and ILs was demonstrated in the two blood sources. Since each GF/IL selectively regulates different cellular processes involved in corneal healing, the use of PB-S or CB-S should be chosen on the basis of the cellular mechanism to be promoted in each clinical case.

Frequent Replacement and Conventional Daily Wear Soft Contact Lens Symptomatic Patients: Tear Film and Ocular Surface Changes

We analyzed tear film changes, ocular surface tissue alterations and inflammatory conditions in Frequent Replacement Soft (FRS) Contact Lens (CL) or Conventional Soft (CS)-CL wearers suffering from eye discomfort, by applying complementary diagnostic tests. Our data suggest the following conclusions: i) eye discomfort symptoms begin after 1–3 years of successful wear, mainly in FRS-CL wearers; ii) tear film stability is affected by CL wear, mainly in FRS-CL wearers; iii) CL wear produces a subclinical moderate inflammation based on mononuclear cell recruitment in 3 out of 4 patients of both types of lenses; iv) CL wear induces dry eye conditions, more pronounced in FRS-CL users; v) discomfort symptoms, presence of subclinical inflammation, degree of dryness are not directly related to a clinical presentation of intolerance, mainly in FRS-CL wearers; vi) CL wear-related discomfort symptoms should never be underestimated, since a hidden inflammation or dryness can be present beyond an apparently good clinical picture.

Ocular surface analysis in hematological patients before and after allogeneic hematopoietic stem cell transplantation: implication for daily clinical practice

PurposeTo evaluate ocular surface parameters before and after hematopoietic stem cell transplantation (HSCT) and to correlate them with clinical and transplant variables.MethodsThis is a retrospective analysis of data from 93 patients affected by hematological malignancies undergoing HSCT. Values from Ocular Surface Disease Index, Schirmer test, Break-up Time, ocular surface staining, and Meibomian Gland Dysfunction score obtained before HSCT and 3-6 months after were retrieved from charts. Diagnosis and staging of dry eye (DE) disease was performed according to Dry Eye WorkShop criteria. Graft-versus-host-disease (GVHD) was classified according to the NIH criteria. Odds ratios for DE onset after HSCT were estimated for demographic, ocular, hematological and transplant variables.ResultsDE was diagnosed before HSCT in 50 (53%) of the patients, mostly of hyperevaporative profile. After HSCT, all ocular parameters significantly worsened with no change in DE profile. A 51% incident cases (22 of the 43 non-DE subjects) were reported. Increasing recipient age and female sex, higher CD34+ cells infused, donor-recipient sex mismatch (males receiving from females), related donors, and peripheral blood cells as stem cell source were associated with a significant higher incidence of DE after HSCT. Systemic chronic GVHD was diagnosed in 42% while ocular GVHD in 35.5% of the patients, which decreased to 12% when taking into account only incident cases.ConclusionsHigh DE prevalence was shown already before HSCT. A pre-HSCT ocular surface assessment is recommended for early DE diagnosis and treatment. This new protocol also influences the prevalence of ocular GVHD.

A proposal of new ocular items in Sjögren's syndrome classification criteria

OBJECTIVE

To verify whether ocular surface tests other than those included in primary Sjögren's syndrome (SS-I) classification criteria (Schirmer I, Break up Time, vital dye staining) may contribute to SS I diagnosis.

METHODS

Two hundred and sixty-two patients (78 SS-1, 91 non-SS autoimmune diseases, 93 Sicca syndrome) filled a validated questionnaire on symptoms and were evaluated by Schirmer test without (Schirmer I) and with (Jones test) topical anaesthesia, Break Up Time (BUT), corneal aesthesiometry, tear clearance rate, vital dye (lissamine green) staining, impression conjunctival cytology, concentration of tear lysozyme and lactoferrin. Thresholds were selected from Receiver Operating Curves; sensitivity, specificity, likelihood ratio (LR+), predictive values were calculated for each test. A logistic regression model was constructed representing the best diagnostic index for SS.

RESULTS

Data showed a poor diagnostic performance of Schirmer test I (LR+ 1.38) and BUT (LR+ 1.05); results from lissamine green staining may be unreliable due to incorporation bias. Tear lactoferrin (LR+ 4.52), Jones test (LR+ 6.24), tear lysozyme (LR+ 8.0), symptom questionnaire (LR+ 8.62), tear clearance rate (LR+ 18.73) and corneal aesthesiometry (LR+ 20.96) exhibited high diagnostic performance also taken together in the regression model.

CONCLUSION

Because many of the tests we have screened in this study can be carried out by a trained ophthalmologist in any clinical setting, we recommend that ocular surface impairment is studied with the combination of tests proved to be helpful for the SS I diagnosis.

[Astigmatism in ocular neuromuscular nystagmus]

BACKGROUND

Data on refraction of patients with congenital nystagmus are not available in the literature.

PATIENTS AND METHODS

We have analysed the refractive errors in a cohort of 224 consecutive patients with congenital nystagmus, aged 1-57 years.

RESULTS

Refractive errors, i. e., myopia, hyperopia (> 0.50 dioptres) and astigmatism (> 1.25 dioptres), were found in 179 patients (79.91 %). Of them 8 were myopic (4.46 %), 19 were hyperopic (10.61 %) and 152 were astigmatic (84.91 %). Mean astigmatism was of 2.44 dioptres for right eyes and 2.74 dioptres for left eyes.

CONCLUSIONS

Astigmatism is extremely common in congenital nystagmus. Its presence is much higher than that found in normal populations. The amount of astigmatism found in nystagmus patients is noticeable. When considering he visual difficulties of patients with nystagmus, the astigmatic component should be taken in greatest consideration. Its presence should favour early surgery for anomalous head posture. Furthermore, refractive surgery should be considered as early as possible, for improving visual potential.

Diagnostic performance of tear function tests in Sjogren's syndrome patients

OBJECTIVE

To evaluate the diagnostic performance of the tests included in primary Sjogren's syndrome (SS-I) diagnostic criteria (Schirmer I, break-up time, vital dye staining) and to compare them with other examinations related to the ocular surface status.

METHODS

Clinical and cytological data were collected from 177 patients (62 SS-1, 56 non-SS autoimmune diseases, 59 Sicca syndrome). Tear tests included: a validated questionnaire on symptoms, Schirmer I, Jones test, Ferning test, BUT, corneal aesthesiometry, tear clearance test, lissamine green staining, impression conjunctival cytology. Data were statistically evaluated and sensitivity, specificity, likelihood ratio (LR+), receiver-operating characteristics (ROC) curves were calculated for each test.

RESULTS

Data showed a poor diagnostic performance of Schirmer test I (sensitivity 0.42; specificity 0.76; LR+1.75) and BUT (sensitivity 0.92; specificity 0.17; LR+1.11) (area under the curve in ROC analysis <0.58). Validated subjective symptoms questionnaire (sensitivity 0.89; specificity 0.72; LR+3.18), Jones test (sensitivity 0.60; specificity 0.88; LR+5), corneal aesthesiometry (sensitivity 0.80; specificity 0.67; LR+2.42), and tear clearance test (sensitivity 0.63; specificity 0.84; LR+3.93), all exhibited a high diagnostic performance (area under the curve in the ROC analysis always >0.70). Lissamine green staining exhibited the best performance (sensitivity 0.63; specificity 0.89; LR+5.72) but the result could be distorted by an incorporation bias.

CONCLUSIONS

Our data suggest to implement the items for ocular signs and symptoms contained in many SS-I diagnostic criteria with the use of a validated questionnaire, performance of Jones test, corneal aesthesiometry measurement, and tear clearance rate evaluation.

[Ocular surface analysis in patients affected with rheumatic diseases]

OBJECTIVE

The international criteria for primary Sjögren's Syndrome (SS I) diagnosis (Vitali et al. 2002) include the Schirmer test I and vital dye staining as tests for ocular surface involvement, but diagnosis can be reached also when the item for ocular signs is not satisfied. The purpose of our study was to evaluate the ocular surface in patients with Sjögren's Syndrome, non-Sjögren's autoimmune diseases and Sicca Syndrome, to understand whether the SS I diagnosis can be targeted also on other tests related to the ocular surface status.

METHODS

Clinical and cytological data were collected from 122 patients: 40 patients had diagnosis of Primary Sjögren's Syndrome, 51 a non Sjögren's autoimmune disease and 31 had symptoms of dry eye. A validated questionnaire on symptoms was filled by each patient; clinical tests included: Schirmer test I, Jones test, Ferning test, Break Up Time, corneal aesthesiometry, tear clearance test, vital dye staining of the ocular surface, scraping and impression conjunctival cytology. Data were statistically evaluated by using SPSS software and Mann-Whitney analysis on unpaired data.

RESULTS

Data show that the subjective symptoms score, tear production, tear turnover, corneal sensitivity and ocular surface integrity are affected in SS I patients, with a statistically significant difference when matched to the other two groups.

CONCLUSIONS

Our results suggest to enlarge the spectrum of ocular surface analysis, to support and orient a differential diagnosis among the autoimmune diseases.

Dryness symptoms, diagnostic protocol and therapeutic management: a report on 1,200 patients

PURPOSE

To report the diagnostic and therapeutic data obtained from 1,200 patients suffering from dry eye symptoms not due to Sjögren's syndrome or other auto-immune diseases.

METHODS

Schirmer test I, ferning test, breakup time, vital dye staining, brush and imprint cytology were performed; data were grouped into diagnostic profiles, and the therapy was prescribed according to these.

RESULTS

Eight diagnostic profiles were identified. Dry eye was diagnosed in 57.1% of patients; the remaining 42.9% were found to suffer from eye discomfort or conjunctivitis of different aetiologies.

CONCLUSIONS

Subjective symptoms of dryness can hide diseases other than dry eye; combined clinical and laboratory tests are requested to make a diagnosis. Our experience indicates that a therapy prescribed on the basis of diagnostic profiles provides relief in 79.1% of cases.

The biocompatibility of silicone, fluorosilicone and perfluorocarbon liquids as vitreous tamponades. an ultrastructural and immunohistochemical study

PURPOSE

To investigate the interactions occurring at the interface between some currently used vitreous tamponading substances and the ocular tissues, in an early follow-up after surgery.

METHODS

Adult albino rabbit eyes underwent vitrectomy and were injected intravitreally with silicone oils at 1,000 or 3,000 cSt, fluorosilicone oil and perfluorodecalin. Different morphological techniques (light microscopy, scanning and electron microscopy, immunohistochemistry) were applied.

RESULTS

All the tested materials, although non-toxic, penetrate the ocular tissues also at the anterior segment level, and in the long-term follow-up this can yield functional impairment. No massive inflammation has been detected in the zones in contact with the materials, but immunoglobulins and complement fractions are anyway present in the stroma of various tissues and around the droplets of emulsified materials, suggesting a local immune reaction.

CONCLUSIONS

Data from this study confirmed that a permanent vitreous substitute, showing a perfect biocompatibility, still does not exist. The indication to remove the tamponading substance within 2 months after the surgery emerges from this investigation, confirming previous studies. Despite some negative features, silicone oil still appears the most biocompatible material for vitreous replacement.

Frequent replacement and conventional daily wear soft contact lens symptomatic patients: tear film and ocular surface changes

We analyzed tear film changes, ocular surface tissue alterations and inflammatory conditions in Frequent Replacement Soft (FRS) Contact Lens (CL) or Conventional Soft (CS)-CL wearers suffering from eye discomfort, by applying complementary diagnostic tests. Our data suggest the following conclusions: i) eye discomfort symptoms begin after 1-3 years of successful wear, mainly in FRS-CL wearers; ii) tear film stability is affected by CL wear, mainly in FRS-CL wearers; iii) CL wear produces a subclinical moderate inflammation based on mononuclear cell recruitment in 3 out of 4 patients of both types of lenses; iv) CL wear induces dry eye conditions, more pronounced in FRS-CL users; v) discomfort symptoms, presence of subclinical inflammation, degree of dryness are not directly related to a clinical presentation of intolerance, mainly in FRS-CL wearers; vi) CL wear-related discomfort symptoms should never be underestimated, since a hidden inflammation or dryness can be present beyond an apparently good clinical picture.

Eye discomfort and air pollution

Discomfort eye syndrome (DES) comprises a series of 'minor' subjective symptoms in patients where no relevant clinical signs are observed suggesting ocular disease. Our study includes 100 DES patients, excluding video terminal users, selected from the First Aid Service of our Department over two peak periods in both winter and summer time. The Schirmer test I, ferning test, breakup time and conjunctival cytology (scraping and imprint) were performed and data were related to sex, age and air pollution indexes, recorded in the patients' living zones. Our results demonstrate that: (i) the ocular surface cytology and the analysis of tear film changes provide significant information in those patients where no other clinical signs are evident; (ii) DES symptoms are more frequent in women than in men (ratio about 2:1), both with ages over 51 years; (iii) DES is significantly associated with ocular surface inflammation, as detected by cytological methods, and (iv) ocular surface subclinical inflammation and ocular dryness are related to high concentrations of atmospheric polluters, in both sexes.

Adhesion mechanisms of human lens epithelial cells on 4 intraocular lens materials

PURPOSE

To evaluate lens epithelial cell (LEC) adhesion on different intraocular lens (IOL) materials with particular attention to the distribution of proteins located in the focal contacts.

SETTING

Center of Biotechnological and Clinical Research in Ophthalmology, University of Bologna, Italy.

METHODS

The IOL materials tested were poly(methyl methacrylate) (PMMA), heparin-surface-modified PMMA (HSM PMMA), polyHEMA, and silicone. Primary cultures of human LECs were established from human anterior capsules obtained during cataract surgery. The mean number of cells attached per square millimeter was calculated for each material after 24 and 72 hours. Transmission electron microscopy and immunocytochemical analysis were performed to detect the proteins actin, vinculin, and talin.

RESULTS

Mean adhesiveness of human LECs increased over time with PMMA and decreased with the other materials. At 72 hours, mean LECs ranged from 54.8 cells/mm2 +/- 12.8 (SD) on PMMA to 2.1 +/- 0.7 cells/mm2 on silicone. The means for HSM PMMA and polyHEMA fell in between. The cytoskeletal proteins were arranged to produce focal contacts in only the LECs cultured on PMMA. The LECs cultured on polyHEMA, HSM PMMA, and silicone attached but failed to develop focal contacts or stress fibers.

CONCLUSION

This study confirms the multifactorial pathogenesis of posterior capsule opacification and suggests its incidence will be reduced by improving surgical techniques and using IOL surfaces that discourage cell adhesion.

Ultrastructure of cells cultured onto various intraocular lens materials

The response of three cell types (human fibroblasts, monocytes, and platelets), cultured or seeded onto different intraocular lens materials, was analyzed by ultrastructural examination. The materials considered were poly(methyl methacrylate) (PMMA), heparin surface-modified PMMA, plasma-treated PMMA, and hydrogel. Significant differences in density and distribution of the cultured cells were demonstrated among these materials. The ultrastructure of the cells appeared to be normal, except in one case. Disorganization of the points of focal contact and of the cytoskeletal elements was found in the fibroblasts cultured onto all materials except PMMA. Morphological evidence of cell activation was observed for some materials, but this requires confirmation by more specific immunocytochemical tests.

Ultrastructural investigation demonstrating reduced cell adhesion on heparin-surface-modified intraocular lenses

A major attention is focused at present to the surface characteristics of intraocular lenses (IOLs), which determine the biological response to the prostheses. There is now an overwhelming information on the fact that some cell types adhere to a lesser extent onto heparin-surface-modified (HSM) polymethylmethacrylate (PMMA) IOLs, either in vitro and in vivo. The present work aimed at sheding new insights by applying ultrastructural techniques of analysis. Our results basically confirm that human fibroblasts, platelets and monocytes are less in number when cultured onto HSM PMMA IOLs as compared to untreated PMMA IOLs. In addition: (1) the submicroscopic morphology of the cells cultured onto HSM PMMA IOLs appears to be normal, thus confirming the noncytotoxicity of the material; (2) fibroblasts grown onto PMMA IOLs are confluent and multilayered; they appear to be in a state of intense activity; the cytoskeletal elements are regularly arranged, and several points of contact at the interface are found; the rare cells present on HSM IOLs do not show at all any of these features; (3) the basic forms of resting and activated platelets are seen onto PMMA IOLs while no sign of activation is observed onto HSM IOLs, and (4) the ultrastructural morphology of monocytes does not differ significantly between the different IOLs. However, other studies are still in progress in order to localize and quantitate the specific receptors responsible for the eventual activation of these cells.

Mucus alteration and eye dryness. A possible relationship

From a very early phase we studied 15 patients suffering from a dry-eye condition ant associated to systemic diseases. Conjunctival biopsies were studied in Transmission (TEM) and Scanning (SEM) electron microscopy. Moreover, the lectin-gold cytochemistry at ultrastructural level was applied to investigate the distribution of some glycosidic receptors produced by both the goblet cells and the vesicles belonging to the Second Mucus System (SMS). No evidence of epithelial stratification and only a decrease in the goblet cell population was observed. The SMS vesicles and the superficial cell microvilli did not appear greatly reduced in number. A difference in the mucus composition in terms of content of glycosidic residues was detected in dry-eye patients compared to the normal subjects. The role of the mucus produced by both the goblet cells and the SMS vesicles in debated. A possible correlation between the alteration of the mucus content and the failure of the tear film stability is proposed. On the basis of these data, a new therapeutic approach for eye dryness is suggested.

The lectin-gold technique: an overview of applications to pathological problems

Lectins are proteins, mainly of vegetal origin, which recognize glycosidic residues with high specificity; for this property they have been used for many studies of molecular biology. The colloidal gold represents at present the most popular electron dense marker employed in immunocytochemistry, since it offers intrinsic and unique characteristics which are superior to those displayed by the other markers. The cytochemical method which utilizes the gold-labelled lectins takes advantages from both the two systems, in order to optimize the localization of the glycoconjugates. The present paper reviews both the technical aspects of the preparation of the lectin-gold complex and its application to some selected pathological problems. In particular, the papers concerning the eye and ear tissues, the urinary, reproductive, nervous and digestive systems and the blood cells are quoted.

Distribution of diffusible ions in the aging rat lens. An X-ray microanalytical investigation

The elemental content of the anterior and posterior cortex and of the nucleus of the rat eye lens, and the changes occurring as a function of age, were investigated by energy-dispersive X-ray microanalysis of cryostat sections. In contrast to most other cells investigated by this technique, the main element detectable in the lens was sulfur, not phosphorus. This is likely to be due to the lack of cell organelles and of nucleic acids in the lens cells. Up to 19 months of age, the concentrations of Na, Cl and K are much lower in the nucleus than in the cortex, whereas the concentration of S is highest in the cortex. At 25 months the differences in elemental content between nucleus and cortex, while still present, are less pronounced. The age-related changes in ion content are rather complex and appear to be different for different parts of the lens. In general, the ion content of the lens increases with age. In the nucleus, the concentration of K increases gradually with age, whereas the Na concentration only appears to increase after 19 months. The Na/K ratio in the lens nucleus is lower in the oldest groups. The Ca concentration increases with age in the nucleus and the posterior cortex, but not in the anterior cortex.

Scanning electron microscopy in the study of Campylobacter pylori associated gastritis

The close association between Campylobacter pylori (CP), gastritis and peptic ulcer is now well established. Moreover increasing evidence has been collected of a major etiological role of CP in type B chronic gastritis. For this reason, searching for CP is essential in all patients with upper gastrointestinal symptoms. Scanning electron microscopy (SEM) is a most reliable technique for studying the distribution of microorganisms and their relationship to the gastric mucosal surface. The aim of this paper is to compare SEM to other routine methods of detection for CP, such as Giemsa staining on histological sections and Urease Microtiter Test (MT) on fresh tissue and to investigate the surface morphology of gastric mucosa colonized by CP and to correlate it with the histopathological picture. Thirty-seven biopsies taken from the gastric body and the antrum of 22 patients were used for each type of determination. The different parameters were graded semiquantitatively. Histology showed a normal mucosa in 4 cases, chronic superficial gastritis in 12 and chronic atrophic gastritis in 21 cases. SEM was more sensitive than histology and Urease MT in detecting Campylobacter pylori. This is due to the patchy distribution of this bacterium on gastric mucosa. For this reason SEM should always be performed when routine tests are negative. The presence of CP correlated significantly (p less than 0.001, Spearman Rank Correlation Test) with the neutrophilic infiltrate, thus with the "activity" of the gastritis. The CP associated gastritis has no distinctive surface features other than the presence of the bacterium. SEM morphology of surface gastric mucous cells suggests that CP does not damage the lining epithelium directly. Neutrophils and inflammatory mediators could be involved in the production of the mucosal lesions.

Dry eye before and after therapy with hydroxypropyl methylcellulose. Ultrastructural and cytochemical study in 20 patients

We have utilized hydroxypropyl methylcellulose in the therapy of 20 patients suffering from dry eye in the initial stage. The effects of the substance have been evaluated both from a clinical and a morphological standpoint. In particular, transmission and scanning electron microscopy were applied to investigate the ultrastructural features of the conjunctival epithelium before and after treatment. In addition, lectin cytochemistry was carried out to analyse semiquantitatively the presence of glycoconjugates in the conjunctival mucus produced by goblet and non-goblet epithelial cells. Hydroxypropyl methylcellulose did not improve the tear film stability as demonstrated by the clinical tests. The normal surface of the conjunctival epithelium did not appear recovered as well. Only a minimal increase in the density of the second mucus system vesicles was observed. From a cytochemical point of view, the content of glycosidic residues appeared altered in dry-eye patients both before and after treatment. This alteration can lead to changes in the physical and functional properties of the mucus, impairing its role as a surfactant. We conclude that the common treatment by means of lubrificant-like substances palliates the dryness condition. The search for a drug which reintegrates the correct composition of the conjunctival mucus should be seriously considered as a valid alternative.

The role of scanning electron microscopy in ophthalmic science

The eyeglobe is one of the classical domains of Scanning Electron Microscopy (SEM) in biology as it exposes several inner and outer surfaces. Both corneal and conjunctival epithelia towards the tear film as well as the corneal endothelial cells facing the anterior chamber may be accurately evaluated. The architecture of the angle and particularly the morphology of the Schlemm's canal inner wall are clarified by SEM more than by TEM serial reconstruction. The surfaces of the iris and ciliary body, the zonula and the choroidal vessel arrangement are described in great detail. Three distinct types of membrane anchoring devices are demonstrated among the lens fibers. SEM impressively describes the retina, but it has not yet added any new information as to previous observations in a more conventional way. SEM plays a fundamental role in teaching ocular anatomy and physiology as it makes more comprehensive the interrelationships among different structures. In addition, it represents a proper structural approach of the clinician who is familiar with the three-dimensional observations obtained by means of biomicroscopy, ophthalmoscopy and fluorescein angiography. Therefore, SEM application should be further spread and possibly joined to immunocytochemistry, in order to obtain a more dynamic and functional analysis of the eye.

Immunocytochemical analysis of contact lens surface deposits in transmission electron microscopy

We studied 8 soft contact lenses from asymptomatic wearers by means of an immunocytochemical method, in transmission electron microscopy. In particular, the presence of IgA, IgG, IgE, Clq complement fraction within the surface deposits was analyzed. All the lenses were found positive for the immunoglobulins and the Clq, being the tarsal side more heavily coated than the corneal one. IgA was the predominant Ig, followed by IgG, IgE, and Clq in this descending order. New, never worn lenses were found completely negative for any of the proteins under investigation. We conclude that the Igs come from the tear fluid and speculate about the Clq as a possible sign of involvement of the host immuno-defense mechanism against the prosthesis.

Changes in glycoconjugates in rat submandibular gland after chronic treatment with reserpine and isoproterenol

Chronic treatment of rats with reserpine, isoproterenol, or a combination of these two agents has been suggested as a means to produce an experimental animal model for the chronic exocrinopathy cystic fibrosis. The effect of these treatments on glycoconjugate distribution in rat submandibular gland acinar cells was investigated by quantitative lectin cytochemistry. Significant changes in wheat-germ agglutinin (WGA), soy bean agglutinin (SBA) and concanavalin A (Con A) binding sites in the mucus granules were observed, but peanut agglutinin (PNA) binding was not significantly affected. The quantitative changes in glycoconjugates in the acinar cells of the submandibular gland could be a possible explanation for the increased binding of calcium by the intracellular mucus noted in previous studies on these animal models.

Detection of mucus glycoconjugates in human conjunctiva by using the lectin-colloidal gold technique in TEM. III. A quantitative study in asymptomatic contact lens wearers

We characterized the mucus glycoconjugates produced by goblet and non-goblet epithelial cells in asymptomatic contact lens (CL) wearers. We employed four lectins (proteins of vegetal origin which specifically recognize glycosidic residues: WGA, PNA, SBA and ConA) conjugated with colloidal gold as ultrastructural marker, at Transmission Electron Microscopy. A computerized quantitative analysis was carried out in order to compare the results from the CL wearers to those from the control patients. Goblet cells produce different amount of glycosidic residues, in particular, a significant decrease in the distribution of sialic acid, N-acetylglucosamine, N-acetylgalactosamine, galactose-N-acetylgalactosamine and mannose was observed. The content of glycosidic residues in the mucus vesicles of the non-goblet epithelial cells appeared unchanged as to the normal situation. We speculate that the CL could possibly contribute to the failure of the tear film stability by altering the production of mucus.

Scanning electron microscopy application in clinical research

Our personal experience on the application of scanning electron microscopy in cardiology, gastroenterology and ophthalmology is reviewed. SEM has not yet significantly contributed to myocardium pathology. However, in the near future, SEM could be a reliable technique to complete the information available from other sources. As to atherosclerosis, SEM allowed us to improve our knowledge of the early stages of the disease; some pathological features, not always detected by conventional morphological examinations, can be documented. An important contribution to gastrointestinal pathology was made by SEM investigations both in the staging of some important diseases (i.e., coeliac disease, peptic ulcer, Crohn's disease, ulcerative colitis) and in the follow-up of mucosal changes during therapy. In the ophthalmological field, SEM provided three-dimensional new information to clinicians, who are familiar with the biomicroscopic images. Our experience in hematology is still limited. However, in the last few years SEM joined to immunocytochemistry allowed us to characterize cell populations in several blood diseases. Some procedures of particular interest in the management of human bioptic specimens are stressed in order to get to a complete correlative microscopy. We conclude that continuous and simultaneous correlations have to be carried out between SEM and other methods and instruments available for morphological investigation.

An improved processing method for electron microscopy investigation of conjunctival biopsies

A new schedule in the processing of conjunctival biopsies for ultrastructural investigations is proposed. The specimens are first examined in Scanning Electron Microscopy (SEM), briefly rehydrated and secondly processed for observation in Transmission Electron Microscopy (TEM). The rehydration counterbalances the shrinkage due to the previous processing steps applied for SEM examination and allows a good TEM morphology of the recovered specimens to be achieved. The correlative SEM/TEM study on the same conjunctival biopsy provides complete informations on both the surface and the inner structure of the tissue. This appears of value in the investigation of conjunctival biopsy from eyes affected by tear film quantitative and/or qualitative alterations.

Detection of mucus glycoconjugates in human conjunctiva by using the lectin-colloidal gold technique in TEM. II. A quantitative study in dry-eye patients

The mucus glycoconjugates produced by conjunctival goblet cells in dry-eye patients were studied by a specific cytochemical reaction in Transmission Electron Microscopy (TEM). Four lectins, proteins of vegetal origin which specifically bind glycosidic residues, (WGA, PNA, SBA and ConA) were used conjugated with colloidal gold as ultrastructural marker. We performed a quantitative analysis by counting the colloidal gold particles present on mucus granules. The results were compared with normal conditions. We found a decrease in sialic acid, N-acetyl-glucosamine, N-acetyl-galactosamine and galactose-N-acetyl-galactosamine and an increase in mannose. The different content of glycoconjugates in goblet cells may reflect in the change of physical and functional properties of mucus. We think these data may be useful in the search for a therapeutic mucomimetic drug.

Detection of mucus glycoconjugates in human conjunctiva by using the lectin colloidal gold technique in TEM. I. A quantitative study in normal subjects

We applied a specific cytochemical reaction to characterize the glycoconjugates produced by goblet and non-goblet epithelial cells of normal human conjunctiva. For this purpose we utilized the lectins, proteins of vegetal origin, which are extremely sensitive in binding glycosidic residues. In particular, we used WGA, PNA, SBA and ConA conjugated with colloidal gold as ultrastructural marker for Transmission Electron Microscopy. This technique allowed us also to perform a quantitative analysis, by counting colloidal gold particles present on mucus granules. In this way we analyzed the content both of goblet and non-goblet epithelial cells. In the former, WGA, PNA, SBA and ConA receptors, here reported in decreasing density, were present. In the latter WGA was always positive, SBA and PNA sometimes were negative, ConA was always negative. We speculate the different contribution to mucus production by these two sources may be important in evaluating tear film stability alterations occurring in those diseases in which non-goblet epithelial cell vesicles increase.

Scanning electron microscopy of normal human corneal epithelium obtained by scraping-off in vivo

The surface of normal human corneal epithelium was examined by scanning electron microscopy (SEM). The study was carried out on specimens obtained by scraping-off in vivo, and immediately fixed. Four different types of microprojections were observed on the epithelial surface: microridges, microvilli, tufted microvilli and knobs. Detailed high magnification of surface microprojections showed that they consist of subunits. Our data suggest a correlation between surface morphology and maturity of the corneal epithelial cell. An evolutive sequence is proposed, from the youngest cell, provided with microridges, to the oldest exfoliating one, with knobs.

Ultrastructural localization of ConA and WGA receptors on human corneal endothelium

Corneal endothelial cell plasma membrane plays an important role in maintaining normal thickness and transparency of the cornea. We investigated the molecular organization of endothelial cell membrane using lectins labeled with colloidal gold as ultrastructural probes. We detected the presence of Concanavalin A and Wheat Germ Agglutinin which recognize specific carbohydrate residues of membrane glycoconjugates. We think that this fine cytochemical approach may be useful to better understand the transport mechanisms between aqueous humor and corneal endothelium and to study adaptation and aging of corneal endothelial cells.