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Biomedical subjects

R Caramazza

Publications and source records attributed to R Caramazza.

At least 19 recordsLinked to original sources
PubMed1996

Colour Doppler analysis of the choroidal circulation in chronic open-angle glaucoma.

PURPOSE: To assess any alteration of the blood flow in the ophthalmic artery, in the posterior ciliary arteries and in the choroid of the glaucomatous eye. METHODS: We studied 15 patients, 11 males and 4 females (mean age 62.4 years), with chronic open-angle glaucoma in good tonometric control by medical therapy. All patients underwent colour Doppler examination of the ophthalmic artery, posterior ciliary artery and choroid. The data for peak systolic velocity (Pv) and resistance index (RI) were compared with those of healthy control subjects. RESULTS: The Pv in the ophthalmic artery of glaucomatous patients was 32.961 +/- 3.045 cm/s (p < 0.033) and RI 0.789 +/- 0.018 (p < 0.001). The Pv of posterior ciliary arteries was 8.720 +/- 1.645 cm/s (p < 0.001) and RI 0.722 +/- 0.024 (p < 0.005). In the choroid the Pv was 10.637 +/- 1.401 cm/s (p < 0.001) and RI 0.643 +/- 0.051 (p < 0.022). CONCLUSIONS: Our data indicate that in a chronic open-angle glaucoma there is an alteration in the eye blood flow especially in the posterior ciliary arteries and the choroid.

Blood Flow Velocity↗
PubMed1995

Seven surgical silicones retain Staphylococcus aureus differently in vitro.

In an in vitro study, we have quantitatively evaluated the capability of seven different types of silicone to retain a Staphylococcus aureus strain, isolated from a surgical wound. All the silicone specimens were taken from prostheses already used in plastic or ophthalmological surgery. Two polymers were used as controls: polystyrene, because of its known capability to favour in vitro bacterial recovery, and nylon, for its bacterial repellence. The results show that all silicones are suitable substrata for Staphylococcus aureus. However, there are some differences among silicone types. The amounts of bacteria retained from silicone oils are greater than or equal to those obtained from the positive control material.

Biocompatible Materials↗
PubMed1994

In vitro adhesion of Staphylococcus epidermidis on heparin-surface-modified intraocular lenses.

This quantitative study assessed the in vitro adhesion of Staphylococcus epidermidis on two types of intraocular lenses: conventional poly(methyl methacrylate) (PMMA) and heparin-surface-modified PMMA. Level adhesion was measured by microbiological turbidimetry. We also measured modifications in the bacterium's structural fatty acids after adhesion using gas chromatography.

Bacterial Adhesion↗
PubMed1993

Retinitis pigmentosa, ataxia, and mental retardation associated with mitochondrial DNA mutation in an Italian family.

An Italian pedigree including two sisters and their mother affected by a neuro-ophthalmic disease characterised by retinitis pigmentosa, ataxia, and psychomotor retardation is reported. Molecular analysis of mitochondrial DNA showed the presence of heteroplasmic 8993 point mutation in the subunit 6 of the ATPase gene. The clinical features and genetic findings in this family were comparable with those recently described in an English family. The mitochondrial DNA analysis of the family showed a correlation between the amount of mutated DNA and the disease severity in the probands, and indicated the presence of a threshold amount of mutated genome inducing ophthalmic defects. Moreover, the comparative analysis of blood, hairs, muscle, and urinary tract epithelia of two probands revealed an essentially similar distribution of mutated and wild type mitochondrial genomes. Our results suggest that the 8993 mitochondrial DNA mutation characterises a disease with similar clinical features in different populations.

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↗
PubMed1992

Mitochondrial DNA analysis in Leber's hereditary optic neuropathy.

A mitochondrial DNA (mtDNA) mutation at nucleotide 11778 has been reported as the genetic defect associated with Leber's hereditary optic neuropathy (LHON), but some pedigrees failed to reveal this mutation. The authors present the genetic analysis of a large Italian LHON family with three probands and 16 asymptomatic maternal relatives. The 11778 mtDNA mutation was present in this family and absent in 52 Italian healthy controls, confirming the association between this genetic defect and LHON. In addition, they found a variable proportion of mutated and wild-type mtDNA (heteroplasmy) in every maternally related family member, including the probands. Different patterns of heteroplasmy were present in the pedigree and lower levels of wild-type mtDNA seemed to correlate with the disease status. Moreover, the authors evaluated the mitotic segregation of mt genomes in blood, hair and urinary tract epithelia of the three patients and they found a similar level of heteroplasmy in these tissues.

Base Sequence↗
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↗
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↗