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Biomedical subjects

Emilio C Campos

Publications and source records attributed to Emilio C Campos.

7 recordsLinked to original sources
PubMed2006

Medical treatment of amblyopia: present state and perspectives.

A brief review is provided on the role of experimental modulation of the visual system during its plastic period. The importance of several substances has been demonstrated. Potential clinical applications of available studies on the treatment of amblyopia are summarized. The role of the dopaminergic system and particularly of dopamine in amblyopia are also discussed. The results of the use of cytidine-5'-diphosphocholine (citicoline) in amblyopia are evaluated in detail. The advantages of and indications for an association of citicoline with part-time occlusion are also discussed. Finally, new administration modalities of citicoline, more detailed evaluation of its efficacy, and the use of new substances are briefly analyzed.

Amblyopia↗
PubMed2006

Effects of endothelin-1 and flunarizine on human trabecular meshwork cell contraction.

Trabecular meshwork (TM) cells are now considered to play an active role in the aqueous outflow mechanism because they exhibit smooth muscle-like contractile properties. Endothelin-1 (ET-1), a potent vasoconstrictor peptide, has been proposed to play a role in the local regulation of aqueous outflow and intraocular pressure (IOP) control. We propose an in vitro culture model as a method for the study of ET-1-induced human TM (HTM) cell contractility and for the study of whether pre-incubation with flunarizine, a calcium-channel blocker, can inhibit the action of ET-1. Experiments were performed on semiconfluent HTM cells (primary cultures established from normotensive human donor eyes) at the second passage, with phosphate-buffered saline (PBS) as a control. The contractile status of the cells was evaluated by a morphometric analysis of cell area, assuming that HTM cells in culture are able to reduce their area as a consequence of cytoskeletal contraction, rather than regulatory volume decrease. After incubation with 10 microM ET-1 for 5 mins, we observed a reduction of HTM cell area with respect to PBS-treated cells: 2425 +/- 876 microm2 versus 3125 +/- 987 microm2 (P < 0.001); and cells exhibited a retraction in shape and a reduction in number of indented profiles. Administration of ET-1 at progressively lower doses produced a corresponding lower reduction of HTM cell area, suggesting a dose-response effect of ET-1. Pre-incubation with 10 microM flunarizine strongly inhibited the ET-1 effect on HTM cell contraction: 2806 +/- 865 microm2 versus 2910 +/- 846 microm2 (P = not significant). Our data indicate that ET-1 induced a statistically significant reduction in the area of HTM cells versus controls, and that ET-1 can directly influence the aqueous outflow. Moreover, we observed that flunarizine inhibited the effect of ET-1 on the HTM cells.

Cells, Cultured↗
PubMed2005

Isometric force measured in human horizontal eye muscles attached to or detached from the globe.

BACKGROUND: Human eye muscle tension has been measured directly only in detached condition. The purpose of this study is to compare force development in single, horizontal human eye muscle during saccadic eye movements, first when the muscle was still attached and later when it was detached from the globe. METHODS: Eleven horizontal muscles of eight patients were examined during surgery under topical anesthesia for concomitant strabismus. None of the muscles examined had been operated before. Isometric muscle tension was recorded with a strain gauge system, to which the muscle tendon was attached by a silk suture. The subjects made saccadic eye movements with the non-recorded eye by fixating light-emitting diodes in the center and at 10, 20, and 30 degrees horizontally to each side. Continuous and stepwise saccades were produced. In the tension signals, peak tension (Fp), steady tension (Fs), and the ratio Fp/Fs were measured. Statistical analysis was done with multivariate analysis of variance. RESULTS: The values of Fp, Fs, and Fp/Fs at different amplitudes of the saccadic eye movements were compared in the attached and the detached muscle. There were no consistent statistical differences between the values obtained in the two conditions. CONCLUSIONS: The muscle force development, measured at the tendon, was the same in muscles attached to the globe and in muscles free from the globe. Thus isometric muscle tension can be adequately recorded in muscles still attached to the globe, which increases the possibilities for studying contractile properties of various eye muscles during ophthalmic surgery procedures performed under topical anesthesia.

Adult↗
PubMed2005

Menopause and dry eye. A possible relationship.

The hormonal status and in particular sex steroids play a role in the ocular surface homeostasis and function, during the whole life and in both sexes, accomplished by estrogenic and androgenic receptors located on corneal and conjunctival epithelia and Meibomian gland. The ocular surface is an integrated unit and any dysfunction results in a scarce or unstable preocular tear film which produces dry eye, a chronic inflammatory condition with increasing incidence as people get older but always more frequent among females. In post-menopausal women endocrine changes join the aging effects in the pathogenesis of dry eye, but still it remains controversial whether estrogen or androgen deficiency or their imbalance impair ocular surface function. Another questionable issue concerns the efficacy of hormonal replacement therapy in the amelioration of dry eye symptoms and recovery of tear function, since the scientific literature stands in between a therapeutic or a promoting effect of eye dryness. Therapy of dry eye is usually based upon topical administration of tear substitutes; estrogen or androgen-based eye drops represents a promising innovative treatment based upon important scientific rationale.

Dry Eye Syndromes↗
PubMed2004

Effects of endothelin-1 on human trabecular meshwork cell contraction. an in vitro cell culture model.

Trabecular meshwork (TM) cells are now considered to play an active role in the aqueous outflow mechanism, since they exhibit smooth muscle-like contractile properties. Endothelin-1 (ET-1), a potent vasoconstrictor peptide, has been proposed to play a role in the local regulation of aqueous outflow and intra-ocular pressure control. We propose an in vitro culture model as a method in the study of ET-1-induced human trabecular meshwork (HTM) cell contractility. Experiments were performed on semi-confluent HTM cells (primary cultures established from normotensive human donor eyes) at the 2nd passage with PBS as control, ET-1, sarafotoxin 6c (a selective endothelin B receptor agonist) and Y-27632 (a selective inhibitor of rho-associated kinase). The contractile status of the cells was evaluated by a morphometric analysis of the cell area, assuming that HTM cells in culture are able to reduce their area as a consequence of cytoskeletal contraction rather than regulatory volume decrease. Our data indicate that image analysis of the HTM cell area can be a reliable method in the study of TM cell contractility, since it utilizes human cells and offers versatile opportunities for the pharmacological evaluation of drugs controlling HTM cell status.

Adult↗
PubMed2002

Selective lesions of rabbit extraocular muscles injected with the anti-AChR immunotoxin saporin-mAb 73.

PURPOSE: To evaluate the effects on extraocular muscles of a skeletal muscle-specific immunotoxin, saporin-mAb 73, as an alternative to botulinum toxin to induce a permanent correction of oculo-facial dystonias or some forms of ocular motility disorders. METHODS: An immunotoxin was prepared with a monoclonal antibody (mAb 73) against acetylcholine receptors of skeletal muscle, linked to saporin, a type 1 ribosome-inactivating protein (RIP) from Saponaria officinalis. Sixteen New Zealand white rabbits were treated with a single injection of immunotoxin directly into the medial rectus muscle of one eye. Four different dosages of 2, 5, 20, or 50 ng saporin-mAb 73 were used. The rabbits were sacrificed at two, 7 and 14 days post-injection. The medial rectus muscle and the retractor bulbi muscle of both the injected and the fellow eyes were taken and serial sections were examined by light microscopy in a blinded manner. RESULTS: Saporin-mAb 73, even at the dosage of 2 ng, brought about focal damage in the extraocular muscles of rabbits without histological changes in adjacent muscles. The histological examination revealed necrotic/apoptotic lesions restricted to the sites of inoculation and largely infiltrated by macrophages. No evident inflammatory reaction was detected at any time and neutrophils were substantially absent. At 14 days after injection, necrosis/apoptosis was still evident and the sclerotic reaction was minimal. CONCLUSIONS: The immunotoxin saporin-mAb 73 injections into the extraocular muscles of rabbits caused focal damage to the muscles. There was no significant inflammatory reaction and muscle fiber loss was present even at the lower doses. Although the lesions were followed for only 14 days, our results suggest that saporin-mAb 73 has potential to cause safe focal muscle damage but longer-term follow-up are needed to investigate the persistence of muscle weakness.

Animals↗