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Biomedical subjects

P Versura

Publications and source records attributed to P Versura.

At least 19 recordsLinked to original sources
PubMed2006

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.

Autoimmune Diseases↗
PubMed2006

[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.

Adolescent↗
PubMed2000

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.

Contact Lenses, Hydrophilic↗
PubMed1999

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.

Actins↗
PubMed1999

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.

Adolescent↗
PubMed1992

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.

Blood Platelets↗
PubMed1991

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.

Blood Platelets↗
PubMed1989

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.

Adult↗
PubMed1989

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.

Biopsy↗
PubMed1989

Ultrastructural and immunohistochemical study on the effect of topical cyclosporin A in the rabbit eye.

The effect of topically administered cyclosporin A (CyA) was evaluated in this experimental study by means of transmission and scanning electron microscopy, and immunohistochemistry. CyA dissolved in sterile olive oil was injected in the retrobulbar area and in the subconjunctival space, or administered as eyedrops in both non-grafted and corneal xenografted rabbit eyes. The vehicle rather than the drug was thought to be responsible for the inflammatory reaction observed in the conjunctiva of the injected eyes as well as for the surface epithelial defects developing in the cornea of the topically administered eyes. CyA was found to be effective in prolonging the survival of the xenografts after 1 month follow-up. The immunohistochemistry indirectly demonstrated the CyA effectiveness in impairing the T-cell function, and this is, to our knowledge, the first documented report on this subject. We conclude that another type of vehicle for the drug has to be introduced and that the administration of CyA as eyedrops is the best route to provide fast diffusion and to avoid adverse side effects.

Administration, Topical↗
PubMed1989

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.

Animals↗
PubMed1989

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.

Adult↗
PubMed1989

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.

Aging↗
PubMed1988

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.

Animals↗
PubMed1988

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.

Adult↗
PubMed1988

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.

Conjunctiva↗