Biomedical subjects

R Caramazza

Publications and source records attributed to R Caramazza.

At least 19 recordsLinked to original sources

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↗

PubMed1998

Inhibition of bacterial adherence to a high-water-content polymer by a water-soluble, nonsteroidal, anti-inflammatory drug.

Deposition and aggregation of lachrymal proteins on the contact lens surface can promote bacterial adherence. Lysozyme is the major tear protein and is also mainly responsible for the formation of protein deposits on contact lenses. Nonsteroidal anti-inflammatory drugs (NSAID) prevent protein aggregation. The effect of a water-soluble NSAID drug on bacterial adherence to high-water-content/ionic disposable contact lenses was examined in a radiolabeling study. Dose-related inhibition of adherence of Staphylococcus aureus, S. epidermidis, and Pseudomonas aeruginosa on both pretreated lenses and after adding the drug to the medium was investigated. When the drug was added to the media, maximal inhibition of S. aureus adherence was observed in trypticase soy broth (59-98% at the lower and higher drug concentrations, respectively); inhibition progressively decreased in calf aqueous humor (48-75%), lysozyme (34-63%), and saline (12-20%) solutions. Inhibition of adherence varied with the three bacterial species; it was maximal with S. aureus, intermediate with S. epidermidis, and minimal with P. aeruginosa. When lenses were pretreated with the drug, consistent, and even higher, inhibitory effects were observed. The results suggest that water-soluble NSAIDs could be used in preventive treatments for conjunctivae and corneal infections in contact lens wearers, and may provide a clue as to which compounds might inhibit protein interaction and bacterial adhesion.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1998

Applications of Raman spectroscopy to ophthalmology: spectroscopic characterization of disposable soft contact lenses.

Disposable soft contact lenses based on HEMA-MAA hydrogels are examined using Raman and ATR/FTIR vibrational spectroscopies and thermal analysis. The main factors dealing with physical, chemical, and biological biocompatibility are evaluated in relation to those of long-wear soft contact lenses with the aim of individuating the most biocompatible lens. The Raman spectra of HEMA-MAA lenses show that some biocompatibility factors are affected by environmental conditions and, in particular, by changes in pH and ionic strength values.

Biocompatible Materials↗

PubMed1998

Fatty acid use in glaucomatous optic neuropathy treatment.

The authors have studied the efficacy of an association of DHA, vitamin E and vitamin B complex (TROFINERV) in glaucomatous patients. The parameters evaluated were computerized visual field (CVF) and retinal contrast sensitivity (RCS). Thirty chronic simple glaucoma patients in good tensional compensation with local therapy were given TROFINERV oral therapy. The results show significant differences after 90 days of treatment both in the perimetric indices (MD, SF, CPSD; p < 0.05) and in the RCS frequency values (p < 0.05). In the light of the results obtained, the authors consider the use of such association to be a useful support in glaucomatous patient therapy for preventing or delaying the progress of damage.

Administration, Oral↗

PubMed1997

Color Doppler imaging and plasma levels of endothelin-1 in low-tension glaucoma.

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelin cells There are reports in the literature that ET-1 plasma levels are raised in low tension glaucoma (LTG). ET-1 plasma concentration and Color Doppler Imaging (CDI) evaluation in ophthalmic and posterior ciliary arteries were measured in 15 LTG patients and in 15 healthy subjects. The blood flow index recorded for the ophthalmic artery in normal subjects was a PSV of 36.646 +/- 6.611 cm/sec with RI of 0.717 +/- 0.019 while in the LTG patients it was 32.961 +/- 3.045 cm/sec (p < 0.003) with RI of 0.789 +/- 0.018 (p < 0.001). For the posterior ciliary arteries in the same two groups, we obtained a PSV of 13.878 +/- 4.149 cm/sec vs 8.720 +/- 1.645 cm/sec (p < 0.001) and an RI of 0.679 +/- 0.039 vs 0.722 +/- 0.024 (p < 0.001). The plasma ET-1 level in normal subjects was 1.720 +/- 0.174 pg while in LTG patients it was 2.947 +/- 0.217 pg (p < 0.001). On the basis of our experience, we think that GON and the visual field damage found in LTG can be attributed to an alteration in the endothelial self-regulating sections and consequent vascular insufficiency, particularly pronounced in the posterior ciliary arteries which, since it is these that provide the blood supply to the optic nerve head, leads to irreversible functional damage.

Aged↗

PubMed1997

The use of flunarizine in the management of low-tension glaucoma: a color Doppler study.

The authors assess the efficacy of flunarizine in improving blood flow and perimetric indices in low-tension glaucoma (LTG). A group of 20 patients with LTG well-compensated by medical treatment underwent Color Doppler Imaging (CDI) of the ophthalmic artery and posterior ciliary arteries with peak systolic velocity (PSV) and Purcelot's index (PI) evaluation. Computerized perimetry was also performed to assess MD, SF and CPSD. The parameters were measured before and after three months' therapy with flunarizine. Data before and after flunarizine treatment were: Ophthalmic artery- PSV 33.261 +/- 1.628 cm/sec vs 35.746 +/- 0.800 cm/sec (p < 0.001); PI 0.697 +/- 0.017 vs 0.627 +/- 0.031 (p < 0.001); Posterior ciliary arteries- PSV 9.385 +/- 0.751 cm/sec vs 10.738 +/- 1.566 cm/sec (p < 0.005); PI 0.673 +/- 0.056 vs 0.589 +/- 0.023 (p < 0.001). The perimetric indices were modified as follows: MD -11.002 +/- 6.574 vs -6.604 +/- 6.426 (p < 0.006); SF 5.05 +/- 5.717 vs 2.937 +/- 1.780 (p < 0.193); CPSD 10.198 +/- 13.392 vs 3.445 +/- 2.709 (p < 0.093). Oral administration of flunarizine, a calcium channel-blocker which acts at a vascular and neuronal level, improves the blood flow indices for the optic nerve, improving thereby the perimetric indices in LTG.

Administration, Oral↗

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

Corneal endothelium cell adhesion on intraocular lenses in vitro.

An in vitro evaluation was conducted of the adhesion capabilities of rabbit corneal endothelial cells on intraocular lenses (IOLs) made of heparin-coated polymethylmethacrylate (HSM-PMMA). The concave endothelial surfaces of albino rabbit corneas were placed in contact in vitro with the convex surfaces of the optical side of HSM-PMMA IOLs in 4-day cultures. PMMA IOLs served as controls. After an incubation period, the preparations were examined via phase-contrast microscopy and via inverted microscopy after staining with vital dye (neutral red), both with and without the cornea in place. After fixation and staining with Giemsa, the cells adherent on the lens were counted on five different microscopic fields. It was observed that the corneal endothelial cells adhered equally to heparin-coated and untreated PMMA IOLs.

Animals↗

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

Raman spectroscopy in the study of biocompatibility.

This review deals with the application of Raman spectroscopy to the study of the biocompatibility of orthopaedic and ophthalmological materials and includes an introduction, a brief theory on the fundamental concepts of the technique, a description of the method and of the traditional and non-traditional instrumentation and a brief treatment of the surface properties of the different classes of materials. In the orthopaedic field, Raman studies on the structures of glasses, ceramic materials, carbon fibres and polymers before and after implantation are reviewed, particularly as far as structural modifications at the biomaterial-tissues interface are concerned. In the ophthalmological field, the chemical biocompatibility of hydrophobic and hydrophilic polymers for intraocular and intrastromal implants and for soft contact lenses is considered with respect to the presence of monomeric reactive centres in hydrophobic materials and the water amount in hydrophilic ones. The progress of the multichannel Raman technique for 'in-vivo' measurements is also described.

Biocompatible Materials↗

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↗