PubMed Health⌕ Search

Biomedical subjects

A Reibaldi

Publications and source records attributed to A Reibaldi.

At least 37 records · Page 2Linked to original sources
PubMed1991

Effects of Nd-Yag laser vitreolysis on lens and vitreous prostaglandins in the rabbit eye.

This study concerns the quantitative modifications of the prostaglandins, PGF alpha e PGE2, in the vitreous and in the lens following the application of Nd-Yag Laser. Five minutes after the Yag-laser treatment, an increase of PGF1 alpha concentration of PGE2 decreased in the lens and increased in the vitreous. These changes, similar to those occurring in the aqueous humor, may be related to the activation of specific enzymatic pathways of prostaglandin synthesis.

Analysis of Variance↗
PubMed1990

Retinopathy of prematurity (ROP): optimal timing of clinical evaluation and standard procedures.

The authors present the protocol currently used in their institution for initial and follow-up evaluation of infants at high risk for developing retinopathy of prematurity (ROP). After topical anesthesia and lid speculum insertion, the examination is carried out using an indirect binocular ophthalmoscope with a +20 or +28-diopter lens. Mydriasis is achieved by instilling one drop of 1% tropicamide, followed by one drop of 0.5% tropicamide + 2.5% phenylephrine 15 minutes later and after an additional 15 minute interval, another drop of 1% tropicamide. If mydriasis is insufficient after one hour, one drop of a 0.5% tropicamide-5.0% phenylephrine solution may be instilled. The initial examination is performed between the third and fourth weeks of life. If any areas of retinal immaturity are found, the examination is repeated every other week and, later, every three to four weeks, until vascularization has reached the ora serrata. Should any sign of ROP be present during the first examination, the patient is examined weekly or every other week depending on the severity of clinical findings.

Clinical Protocols↗
PubMed1990

Effects of hyaluronic acid fractions in the rabbit eye.

Two fractions of hyaluronic acid with different molecular weight (Ial, molecular weight 500,000-730,000 and Healon, molecular weight 750,000) were injected intracamerally or intravitreously in the rabbit eye. Although the fraction with higher molecular weight caused an increase in intraocular pressure, no change of this parameter was found after administration of the fraction with the lower molecular weight. Furthermore, various inflammatory reactions in ocular tissues were observed during slit-lamp biomicroscopy after administration of Healon but not of Ial. No inflammatory reaction was found after subchronic instillation of the compounds.

Animals↗
PubMed1990

Fifteen years of experience in retinal surgery.

We report our experiences with retinal surgery. The importance of vitrectomy and the use of silicone oil are mentioned although the latter can be responsible for iatrogenic proliferative vitreoretinopathy.

Humans↗
PubMed1987

Effects of dapiprazole on contractile responses of guinea pig isolated ileum.

The effects of dapiprazole, a relatively new alpha 1-adrenolytic agent, on contractile responses and on spontaneous mechanical activity were studied in guinea pig isolated ileum. Dapiprazole (10(-10) to 10(-4) M) produced a concentration-dependent inhibition of high K+ (80 mM) -induced contractions. These inhibitory effects were observed with dapiprazole added either before or after the induced contractions. The Ca2+-induced contractions of K+-depolarized ileum were also inhibited by dapiprazole. Dapiprazole inhibited in a non competitive manner the responses of the ileum to: carbachol, histamine, 5-hydroxytryptamine, pentagastrin, angiotensin II and cholecystokinin. In order to analize whether dapiprazole exerts an intracellular effect on Ca2+-store, skinned preparations were used. The results suggest that dapiprazole might inhibit Ca2+ entry through both voltage-and receptor-operated channels of the smooth muscle membrane.

Animals↗
PubMed1986

Receptor-responses in fresh human ciliary muscle.

The physiological and pharmacological properties of ciliary muscle isolated from fresh human eyes were investigated. The muscle exhibited no spontaneous activity. Concentration-dependent contractions in response to carbachol were competitively antagonized by atropine (pA2 = 8.95). The muscle, precontracted by carbachol (2.7 X 10(-4)M), responded to the application of isoprenaline by concentration-dependent relaxation blocked by propranolol (3.5 X 10(-9)M to 3.5 X 10(-8)M; pA2 = 9.15). Angiotensin-evoked contractions were antagonized by 8-Ala-angiotensin II (4.5 X 10(-8)M) in a competitive manner, but were not inhibited by phentolamine or propranolol. Contractions generated by electrical stimulation of the muscle (30 ms, 20 Hz, 60 pulses) were antagonized by atropine (10(-7) M) and tetrodotoxin (6.3 X 10(-7) M). Phentolamine and propranolol did not influence these responses. An increase of the external potassium concentration ([K+]o) from 5.4 to 158.8 mM produced a mechanical response, antagonized by atropine, but not influenced by tetrodotoxin, phentolamine or propranolol. The human ciliary muscle appears to carry muscarinic and angiotensin receptors and beta 2-adrenoceptors. The estimate of Katropine for muscarinic receptors mediating carbachol-induced contractions agrees with estimates of Katropine reported for human and rabbit iris.

Angiotensin II↗
PubMed1985

Laser and glaucoma: our experience.

The authors present some guidelines on laser therapy (Argon and/or Yag) application on the different types of glaucomatous pathology. These therapeutic guidelines are the result of a 3-year experience of constant laser therapy application on glaucoma. The case reports include 196 A-laser trabeculoplasties, 34 A-laser iridotomies, 158 Yag-laser iridotomies, 31 gonioplasties, plus numberless combined treatments (iridotomy-trabeculoplasty, gonio-trabeculoplasty, gonioplasty-ciliary body photocoagulation, and so on). The authors conclude by reaffirming the considerable reliability of these techniques, given a prolonged follow-up; they also advance some new therapeutic hypotheses on laser operation in glaucomas.

Glaucoma↗
PubMed1984

Iris receptors of fresh human eyes.

There are many reports describing the receptorial distribution in animal eyes but only a few reports concerned with human eyes. Because of this, we have studied five fresh human eyes, in vitro, by a very sensitive method. We have proved the existence of alpha exciting and beta 2 relaxing receptors on the iridial dilatator muscle and the absence of cholinergic, serotoninergic, dopaminergic, histaminergic receptors. On the contrary, on the circular muscle we have found muscarin cholinergic receptors without adrenergic ones.

Adrenergic beta-Antagonists↗
PubMed1982

[The effect of antiglaucoma drugs on the depth of the anterior chamber (I)].

The Authors have taken into account the most common effect of antiglaucomatous drugs on the depth of the anterior chamber. The modifications of the anterior chamber have been evaluated utilizing a Jaeger Pachymeter. The values were obtained before the drug instillation and an hour afterwards. The results are presented as the mean and standard deviation. Among the examined drugs, only miotics have brought about a notable decrease, whereas the others have shown no significant effects.

Adult↗
PubMed1982

[Preliminary study of the topical use of thymoxamine].

In this work the Authors have tried to show the efficacy of TMX, as a miotic drug, and to find out the lowest concentration which can give the best results with the minor complications. Seven patients, in whom TMX was instilled in both eyes at 0.50%, 1%, 2% concentrations, were studied. A mydriatic was instilled before in the right eye, in order to obtain mydriasis whereas the left eye served as control. The 0.5% concentration was as efficacious as 1% and 2% ones, but had less side-effects.

Administration, Topical↗
PubMed1981

[Histopathological observations of the human retina treated with argon-laser].

The Authors were able to observe histologically the lesions induced by Argon-laser on the retina and choroid of two eyeballs that afterwards were enucleated because they developed choroid melanoma. The observations have been respectively made 10, 20 and 40 days after the beginning of the treatment and a progressive structural overturning of the retina and the choroid due to the obstruction of choriocapillary vessels, to the tendency to fusion of the various nuclear layers as well as to the connection of the layer of nerve fibres, has been observed.

Argon↗
PubMed1980

[Preliminary study of acidification of the pH of the aqueous humor in rats treated with timolol maleate].

The Authors have studied in a homogeneous group of rabbits the variations of intraocular pressure and of aqueous humour pH caused by instillation of timolol maleate at different concentrations. In the animals treated with drug concentration of 0,25% and 0,5% a constant reduction of IOP has been observed in comparison with controls, associated to acidification of aqueous humour: no evidence of this correlation it seems to be at low doses of timolol. Further studies are in course to indicate an eventual action of intermediate substances in the mechanism of IOP depression caused by timolol.

Acid-Base Equilibrium↗
PubMed1980

[Prevention of retinal detachment in massive endovitreous hemorrhage 1a].

We have made a prophylaxis of retinal detachment resulting from massive endovitreous hemorrage by applying a silicone encirclement on rabbit eyeballs in which we have previously injected autologous blood. Because of the opacity of the means echography has shown us the moment of intervening. Retinal detachment has taken place in the 64,28% of cases, against the 91,3% of a previous experience of ours in which we made no prophylactic.

Animals↗