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Biomedical subjects

R Nuzzi

Publications and source records attributed to R Nuzzi.

At least 19 recordsLinked to original sources
PubMed2005

Quantitative spatial analysis of the distribution of NADPH-diaphorase-positive neurons in the developing and mature rat retina.

NADPH-diaphorase (NADPH-d) histochemistry labels a subpopulation of nitric oxide-synthesizing amacrine cells in the inner nuclear layer of the rat retina. We have studied their morphology and distribution in postnatal and adult rats in whole-mounted retinae. NAPDH-d-positive neurons are detected as early as postnatal day (P)5, especially in the peripheral retina; intense labeling of somata and long lengths of dendrites is obtained between P10 and P18, after which only the somata exhibit NADPH-d activity. The density and number of these cells increase progressively from P7 to P14, with a significantly higher density in the central retina as compared to the periphery. The sociology of these cells was analyzed quantitatively studying the Voronoi domains: a polygon area can be drawn that delineates the territory of the map that is closer to the cell than to any other cell of the map. In addition, we calculated the conformity ratio of Cook, i.e., the mean nearest neighbor distance/standard deviation of all the nearest neighbor distances, in order to reveal whether or not these cells are regularly distributed through the retina. We find that the distribution of the NADPH-d-positive cells tends to be regular throughout the retina: the local coefficient of variation (obtained by comparing the size of each Voronoi polygon area to those of its neighbors) tends to regularity at P14 and remains unaltered through maturity. Therefore, as other cell types, NADPH-d-positive amacrine cells are almost regularly distributed from the time of eye opening and nitric oxide may play a role in the development of retinal circuitry and in the regulation of retinal blood flow.

Age Factors↗
PubMed2001

Brown tides and mariculture in Saldanha Bay, South Africa.

In 1997, the brown tide organism, Aureococcus anophageffens, was detected for the first time in Saldanha Bay, South Africa. Its presence was limited to an isolated, tidal dam that was similarly impacted during the late summer of the following two years but not in 2000. Bloom concentrations are typically of the order of 10(-9) cells l-1. This is one of the few reported occurrences of these nuisance blooms outside the north-eastern United States. A small oyster grow-out facility based in the dam has been severely affected by the reduced growth of oysters during these blooms. Reduced flushing of this culture site is a possible explanation for bloom initiation and persistence. However, Aureococcus blooms can be considerably more extensive as was evident during 1998 when the whole of the bay system, including Langebaan Lagoon, was affected for 6-8 weeks during late summer.

Animals↗
PubMed1998

Adverse effects of topical antiglaucomatous medications on the conjunctiva and the lachrymal (Brit. Engl) response.

BACKGROUND: Increasing evidence indicates that long-term use of topically administered medication can induce changes in the conjunctiva and lachrymal function. METHODS: In order to evaluate changes in the conjunctiva and lachrymal response after prolonged use of topically administered antiglaucoma medications and preservatives found in antiglaucomatous medication solutions (benzalkonium chloride), we tested lachrymal function (Schirmer I., Jones, BUT, Ferning tests) and used the conjunctival impression cytology technique. MATERIALS: A group of patients with primary open angle glaucoma (POAG) receiving topical antiglaucomatous medication were recruited. A second group received only preservative instillations while a control group was formed of similarly aged subjects with no eye disease and was given topical or systemic medical therapy. Excluded from the trial were patients with a history of external eye disease or who had received conjunctival surgery. RESULTS: Tear secretion was reduced against that of the control group in those subjects who received protracted administration of antiglaucomatous eyedrops (timolol and/or pilocarpine). A statistically significant degree of conjunctival metaplasia was associated with long-term use of topical medication. The subjective symptoms reported by those patients receiving chronic topical antiglaucomatous therapy and the objective observations on them were found to be proportional to the observed tearing response. Changes were more pronounced in subjects who received only benzalkonium chloride. CONCLUSION: Our study results suggest that long-term use of antiglaucoma medication induces changes in both tear film and conjunctival surface. Such changes may be related to the medication or the duration of treatment, but may also be due to the preservatives used in the commercial product.

Adrenergic beta-Antagonists↗
PubMed1998

Is videopupillography useful in the diagnosis of Alzheimer's disease?

Patients with Alzheimer's disease (AD) reportedly exhibit greater pupillary dilation than healthy subjects in response to tropicamide. By means of videopupillography, we have found that the average basal pupillary diameter was greater in AD patients than in normal controls and that there is an inverse relationship between the average pupillary diameter and the maximal dilation obtained following tropicamide application in both groups. Pupillary response to tropicamide and videopupillography do not distinguish between Alzheimer's patients and controls.

Aged↗
PubMed1997

The relationship between pupil diameter and decentration in myopia.

Since optical zone centration is of such importance in refractive surgery, we have studied, with a computer-aided videopupillograph, the problem of identifying it in myopes. The findings of pupil centre shift as a function of pupil diameter and degree of myopia are reported in two groups of myopes (low and medium) and a control group. Results indicate that the amount and direction of decentration vary according to pupil diameter and degree of myopia. No generally valid instructions can be laid down and each case must be treated on its merits.

Adolescent↗
PubMed1997

Glaucoma, lighting and color vision. An investigation into their interrelationship.

The results of a study on color vision capacity performed with a view to further analyzing glaucomatous dyschromatopsia are reported. The Farnsworth-Munsell 100-hue test was used in a population of 52 subjects (104 eyes) with daylight fluorescent lighting and low-tension halogen lighting. Photocolorimetric observations with each type of lighting were made. It was found that halogen lighting increased the glaucomatous subjects' mean score, the number of dyschromatopsia and the number of blue-yellow dyschromatopsia axes. The authors conclude that halogen lighting is preferable for the Farnsworth-Munsell 100-hue test in glaucoma and confirm the predominance of blue-yellow dyschromatopsia axes in glaucoma.

Chronic Disease↗
PubMed1996

[Changes in adrenergic innervation of the choroid during aging].

BACKGROUND: Aging causes loss of neurons and adrenergic nerve termination in various human organism systems and apparatus. The aim of this work is the observation of qualitative and quantitative differences in the orientation and density of the human choroid adrenergic innervation in relation to age. METHODS: The choroid specimens were taken from the corresponding sectors of the eyeballs of four patients aged between 70 and 75 years and patients aged between 40 and 45 years. The glyoxilic method of Furness and Costa (1975) was used. RESULTS: The location and orientation of the adrenergic fibres was similar in the adult and aged patients. However, the fibres are clearly fewer in number, less rich in varicosity and have reduced fluorescence. In the suprachoroid lamina thickness and in the vascular layer, the adrenergic synaptic contacts with the melanocytes are fewer in number, as are also the SIF-cells (small intensely fluorescent cells). CONCLUSIONS: With age there is a significant reduction of the orthosympathetic innervation of the human choroid. This fact could explain some physiopathological aspects of the choroid circulation and blood flow and, therefore, play a part in ocular pression variations.

Adrenergic Fibers↗
PubMed1995

Conjunctiva and subconjunctival tissue in primary open-angle glaucoma after long-term topical treatment: an immunohistochemical and ultrastructural study.

BACKGROUND: Primary open-angle glaucoma is commonly treated with long-term hypotensive medical therapy. When this approach becomes inadequate, therapy proceeds with surgery. The present study investigates morphological changes in the conjunctival and subconjunctival tissues induced by short- and long-term topical medical therapy of primary open-angle glaucoma. METHODS: Comparisons were made between biopsy specimens from glaucomatous patients, who received specific eyedrop therapy (timolol and pilocarpine) for various periods of time, and control patients with no conjunctival pathology or topical treatment. Histological, immunohistochemical and ultrastructural parameters were investigated. RESULTS: The morphometric analysis of histological sections and immunohistochemistry (anti-fibronectin antibody) in medium- and long-term therapy patients showed: (a) significant increases in the thickness and number of epithelial cell layers; (b) significant increases in the fibroblast density in both subepithelial and deep connective tissue; and (c) a more compact connective tissue, richer in collagen fibers arranged in whirls, with some inflammatory elements. These findings were confirmed by the ultrastructural analysis. In the same patients, the other immunohistochemical parameters investigated (anti-HLA-DR, anti-CD1a, anti-CD4, anti-CD8, anti-IL2 and C3b antibodies) revealed a tendency to chronic inflammation. Following specific surgery, this tendency manifested itself in a diffuse immune response, especially in those patients who underwent medium- and long-term medical therapy. CONCLUSION: According to these results, antiglaucomatous surgery should be rehabilitated and considered as an alternative to long-term medical therapy in the first-instance treatment of primary open-angle glaucoma.

Administration, Topical↗
PubMed1995

Epidemiological aspects, development and management of prevention in ophthalmology in relation to different ages.

In the ophthalmological field, it is not always easy to adopt a primary prevention. Much more useful would be a secondary prevention program towards the affections at birth or those later developed that, if diagnosed and treated early, grant a normal visual development. Differentiated prevention can be carried out, according to various ages: at the tender age congenital glaucoma and cataract, strabism, ametropia, anisometropia (possible cause of amblyopia) have to be considered; in the adult-senile age must be prevented damages due to hypertension, diabetes, thrombosis, as well as cataract, glaucoma, uveitis, kerato-conjunctivitis and retinal detachment.

Adolescent↗
PubMed1993

Geriatric ophthalmology.

The authors examined the numerous physiological alterations in the eye due to ocular tissue aging, and the main pathologies of the eye which may occur in old age so as to give guidelines to geriatric specialists on the diagnostic and therapeutic course to follow for each individual disease.

Aged↗
PubMed1992

Laser treatment of glaucoma.

The authors review the literature published between October 1990 and September 1991 on laser treatment of glaucoma. In particular, they assess their experience and that of other authors regarding both the various types of laser (argon, neodymium:yttrium-aluminum-garnet, diode, pulsed dye, and excimer) and the application techniques (iridotomy, goniotomy, gonioplasty, trabeculoplasty, trabeculopuncture, transpupillary cyclophotocoagulation, transscleral cyclophotocoagulation, sclerostomy, suture lysis, and trabecular ablation) for the parasurgical treatment of glaucoma.

Glaucoma↗
PubMed1992

[Uveitis and systemic diseases].

The uveal tract, although comprising three anatomic sections such as the iris, the ciliary body and the choroid, may be regarded as a single functional unit, and is easily affected by several pathogenic agents that may act on either infectious, toxic and immune basis. Since such inflammatory stimuli do not usually locate primarily in the eye but rather elsewhere in the body, uveitis is often associated with systemic diseases. The Authors deal with several diseases frequently associated with anterior or posterior uveal inflammation, such as Behçet's disease, Vogt-Koyanagi-Harada's syndrome, Reiter's syndrome, juvenile rheumatoid arthritis, ankylosing spondylitis, sarcoidosis, Sjogren's syndrome, ulcerative colitis, psoriasis, tuberculosis and syphilis.

Adult↗
PubMed1991

[The eye and pregnancy].

The principal effects of pregnancy on the eye are reviewed, these effects being subdivided into three main sections: paraphysiological changes, pathological conditions developing in pregnancy and related to it, pre-existing pathological conditions that are to some extent altered by pregnancy. On the basis of the data supplied, a continuous, increasingly assiduous clinico-experimental give-and-take between oculist and gynaecologist is recommended to prevent possible eye complications.

Eye↗
PubMed1984

[Blood coagulation changes and pathogenesis of diabetic retinopathy. Recent advances].

In this review the most recent advances in blood coagulation and chronic complications of diabetes mellitus are discussed. Numerous research workers have reported abnormalities in the mechanisms of platelet activation, endothelial cell function, plasma coagulation and fibrinolysis. However, the data available today cannot as yet be interpreted in terms of pathogenesis of retinopathy or any other chronic manifestation of the disease. Consequently, there is at present no rationale for pharmacological prevention or treatment.

Anticoagulants↗