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Biomedical subjects

R Caramazza

Publications and source records attributed to R Caramazza.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Preparation and activity of metal complexes with heteroatomic organic ligands. Preliminary note].

Various coordination compounds were prepared between transition metals (in particular copper, zinc, silver and cobalt) and benzotriazole 5-methylbenzotriazole, 2-methylbenzotriazole and 2-methylbenzimidazole. Compounds of this type present a significant herbicidal capacity both on monocotyledons and dicotyledons and some of them also present an antimicrobic activity. The method of preparation, the principal chemical characteristics and the analyses to determine the formulae are reported. It was observed that metal can coordinate with benzotriazole and its derivatives either as a neutral molecule (BTAH) or as a deprotonated anion (BTA-), or as a combination of both (BTAH and BTA-).

Anti-Infective Agents↗
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↗
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

Scanning electron microscopy, X-ray microanalysis and immunohistochemistry on worn soft contact lenses.

The deposits accumulated on the surfaces of soft contact lenses are a cause of problems for the wearer of these lenses, as the deposits are never completely removed by the available washing solutions. Therefore it appears of interest to investigate the composition of these deposits. In this paper we review the major findings in the literature and, in addition, present our personal experience. We have studied new, continuously and daily worn soft contact lenses by scanning electron microscopy (SEM), X-ray microanalysis and immunohistochemistry. We have carefully evaluated preparative methods, and we can conclude that SEM and X-ray microanalysis are best carried out on unfixed, air-dried lenses. The deposits present consist mainly of mucus, especially on the tarsal side of the lenses. Chloride and potassium, coming from the tear fluid, as well as sulfur, derived from proteins, were found. Calcium was very rarely detected. IgG, IgA, IgE and C3c complement fractions were found only on the outer surfaces and not within the lens. We believe that the best characterization of the deposits is achieved by means of correlative techniques on the same lens. In fact, this approach integrates morphology and composition.

Contact Lenses, Hydrophilic↗
PubMed1987

Photic maculopathy by arc welding. A case report.

The authors report the case of a photic maculopathy that developed in an arc welder after 5 to 10 minutes of exposure to the bright light of an electric arc, even though the young worker was wearing protective eye glasses. Pigmented foveal changes and a small central scotoma in both eyes without anomalies on fluorescein angiography characterized this maculopathy, that had a favorable course with corticosteroid therapy. Aetiopathogenetic aspects are discussed.

Adult↗
PubMed1987

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.

Adult↗
PubMed1986

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.

Carbohydrate Metabolism↗
PubMed1986

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.

Carbohydrate Metabolism↗
PubMed1986

Characterization of mucus glycoconjugates in normal human conjunctiva by lectins in light microscopy, transmission and scanning electron microscopy.

Maintenance of tear film in normal conditions is dependent on mucus layer integrity and the presence and distribution of conjunctival epithelial cell microvilli. In the present work a new methodology has been developed to gain correlative information about microprojection assessment and mucus composition, from the same specimen, by Light Microscopy (LM), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). We have characterized the glycosidic residues secreted by goblet cells in normal human conjunctiva, by means of four lectins (WGA, ConA, PNA and SBA), conjugated with FITC for LM and with colloidal gold for TEM and SEM. The cytochemical reactions were performed on histological sections of paraffin-embedded material and on semithin and ultrathin sections of both Epon embedded material directly processed for TEM and of blocks recovered from SEM and reprocessed for TEM. WGA, ConA, PNA and SBA receptors were found to be constituents of the mucus produced by goblet cells in human conjunctiva. The granules of the so-called "second mucus system" (SMS) cells were labelled mainly by WGA. A difference in the quality of glycoconjugates between goblet cells and SMS cells has been also demonstrated. Our results provide an improved method to evaluate alterations of tear film that occur in many conjunctival diseases.

Carbohydrates↗
PubMed1985

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.

Cornea↗
PubMed1985

Scanning electron microscopy study of human cornea and conjunctiva in normal and various pathological conditions.

Relatively few morphological studies on human cornea have been performed due to the difficulty in obtaining material. The specimens may be obtained either by superficial scraping-off, limited to the epithelial layer, or from corneal buttons obtained at keratoplasty. Conjunctiva, on the other hand, may be obtained by painless biopsy. We have studied the three-dimensional ultrastructure of the normal cornea and conjunctiva and in the course of various diseases where the application of scanning electron microscopy (SEM) seemed to be useful. In the cornea, we studied Fuchs' endo-epithelial dystrophy. In the conjunctiva, we analysed the ultrastructural characteristics of adenovirus follicular conjunctivitis, hay fever conjunctivitis and keratoconjunctivitis sicca. We also considered the problem of contact lens wearing, studying by SEM both the conjunctival tissue and the discarded lenses. On the basis of our results we conclude that SEM supplies useful information which integrates that obtained by biomicroscopy, used by clinicians to interpret the lesions at microscopic level. It is, however, indispensable to carry out, in addition to SEM, an examination on sections to completely investigate the disease.

Conjunctiva↗
PubMedDate not supplied

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.

Animals↗