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P Vinciguerra

Publications and source records attributed to P Vinciguerra.

At least 19 recordsLinked to original sources
PubMed2001

The yeast hnRNP-Like proteins Yra1p and Yra2p participate in mRNA export through interaction with Mex67p.

Yra1p is an essential nuclear protein which belongs to the evolutionarily conserved REF (RNA and export factor binding proteins) family of hnRNP-like proteins. Yra1p contributes to mRNA export in vivo and directly interacts with RNA and the shuttling mRNP export receptor Mex67p in vitro. Here we describe a second nonessential Saccharomyces cerevisiae family member, called Yra2p, which is able to complement a YRA1 deletion when overexpressed. Like other REF proteins, Yra1p and Yra2p consist of two highly conserved N- and C-terminal boxes and a central RNP-like RNA-binding domain (RBD). These conserved regions are separated by two more variable regions, N-vr and C-vr. Surprisingly, the deletion of a single conserved box or the deletion of the RBD in Yra1p does not affect viability. Consistently, neither the conserved N and C boxes nor the RBD is required for Mex67p and RNA binding in vitro. Instead, the N-vr and C-vr regions both interact with Mex67p and RNA. We further show that Yra1 deletion mutants which poorly interact with Mex67p in vitro affect the association of Mex67p with mRNP complexes in vivo and are paralleled by poly(A)(+) RNA export defects. These observations support the idea that Yra1p promotes mRNA export by facilitating the recruitment of Mex67p to the mRNP.

Fungal Proteins↗
PubMed1998

Radial and staggered treatment patterns to correct hyperopia using noncontact holmium:YAG laser thermal keratoplasty.

PURPOSE: To compare the effects of two treatment patterns in the correction of hyperopia by noncontact holmium:YAG laser thermal keratoplasty (LTK). SETTING: Divisione Oculistica, Ospedale S. Gerardo, Monza, Italy. METHODS: Using two treatment patterns, we performed noncontact LTK in one session in 16 eyes of 8 patients with isometropic hyperopic refractive errors; mean preoperative subjective cycloplegic refraction was +4.90 diopters (D) +/- 1.17 (SD). The treatment consisted of 24 spots in three concentric rings of eight spots each; ring diameters were 6.0, 7.0, and 8.0 mm, respectively. Each spot received seven pulses of laser energy at 30 mJ/pulse. We treated one eye of each patient with a radial pattern (the spots of the three rings aligned on the eight semimeridians) and the fellow eye with a staggered pattern (the spots of the contiguous rings at 22.5 degrees from each other). Follow-up at 1, 15, 30, 90, 180, and 360 days included subjective cycloplegic refraction, uncorrected (UCVA) and spectacle-corrected visual acuity (SCVA), computerized videokeratography (CVK), and Scheimpflug camera examination. RESULTS: One year postoperatively, the mean subjective cycloplegic refraction was +2.75 +/- 1.6 D in the eyes treated with the radial pattern and +3.40 +/- 1.6 D in those treated with the staggered pattern; the mean change in subjective cycloplegic refraction was 2.15 and 1.50 D, respectively. Mean UCVA improved by five lines in the radial group and by four lines in the staggered group. Mean SCVA returned to preoperative levels by day 15 in the radial group and at 1 year in the staggered group; at 1 year, SCVA improved by one line in the radial group and remained unchanged in the staggered group. No eye lost one or more lines of SCVA. Refractive astigmatism was essentially unchanged in both groups. Scheimpflug photography and CVK indicated larger and more uniform corrected zones in the radial group. CONCLUSIONS: Radial and staggered patterns effectively corrected low hyperopia, although both were subject to a certain amount of regression. The radial pattern produced faster postoperative recovery of SCVA and demonstrated greater refractive stability.

Adult↗
PubMed1998

Long-term results of photorefractive keratectomy for hyperopia and hyperopic astigmatism.

PURPOSE: This study was conducted to determine the safety and efficacy of using the Nidek EC-5000 excimer laser for photorefractive keratectomy to correct hyperopia and hyperopic astigmatism. METHODS: We treated 67 eyes of 44 patients for hyperopia and hyperopic astigmatism with the Nidek EC-5000 excimer laser. The algorithm provided an ablation zone of 5.5 mm diameter with the addition of a tapered transition zone of 3.5 mm diameter, for a total ablation of 9 mm diameter. RESULTS: Uncorrected visual acuity (geometrical mean) changed from 0.16 to 0.37 at 12 months; corrected visual acuity (geometrical mean) changed from 0.8 to 0.89; mean sphere decreased by 2.08 D from 3.76 to 1.40 D (range, 1.70 to 1.68 D) and cylinder by 1.40 D from 2.20 to 1.00 D. Refractive results for < or = 3.00 D were reasonably accurate and stable, but for > +3.00 D, undercorrection and regression over l year were the rule. CONCLUSION: Hyperopic PRK proved to be a safe technique in regard to the risk of loss of visual acuity with no central corneal opacities and with a generally rapid recovery of baseline spectacle-corrected visual acuity, but the predictability of correction greater than +3.00 needs improvement.

Adult↗
PubMed1998

Effect of decreasing surface and interface irregularities after photorefractive keratectomy and laser in situ keratomileusis on optical and functional outcomes.

PURPOSE: To assess a new method for decreasing corneal ablated surface irregularities after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) by performing a final smoothing immediately after the treatment. METHODS: One hundred forty-seven eyes with ablation irregularities after PRK or LASIK using the Nidek ED-5000 excimer laser and examined with the Nidek EAS 1000, were randomized into two groups: 74 eyes had final smoothing and 73 eyes were patched immediately. Preoperative mean refraction for the smoothing group was -7.55 +/- 2.50 D and for the patched group, it was -7.30 +/- 1.90 D, (p = 0.04). RESULTS: AT 12 months after treatment, mean haze was 0.5 +/- 0.3 in the smoothing group and 1.2 +/- 0.4 in the patched group (p = 0.006); mean spectacle-corrected visual acuity was 1.1 +/- 0.25 in the smoothing group and 0.95 +/- 0.18 in the patched group (p = 0.02); the percentages of eyes within 1.00 D of the planned correction was 68% in the smoothing group and 33% in the patched group. CONCLUSION: Performing a final smoothing immediately after PRK or LASIK improves refractive and optical outcomes.

Adult↗
PubMed1998

A method for examining surface and interface irregularities after photorefractive keratectomy and laser in situ keratomileusis: predictor of optical and functional outcomes.

PURPOSE: To develop a system for the examination of the ablated surface after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and to correlate the surface regularity to the functional outcome. METHODS: A Nidek Eas-1000 Anterior Eye Segment Analysis System was used to examine the ablated surface or the interface regularity immediately after PRK and LASIK. Eighty eyes were evaluated and divided into three study groups; group 1; regularity (18 eyes), group 2; mild irregularity (32 eyes) group 3; severe irregularity (30 eyes). RESULTS: At 12 months postoperatively, group 1 (regularity) showed the best percentage of eyes with 0 haze (100%) and with a refraction +/- 1.00 D of plano (89%); group 2 (mild irregularity) 84% had 0 haze and 62% were +/- 1.00 D of plano; group 3 (severe irregularity) 27% had 0 haze and 47% were +/- 1.00 D of plano. CONCLUSION: The patients with no postoperative irregularity had a sharply lower incidence of haze and a better refractive outcome with respect to plano, confirming the influence of ablation regularity on the results and the importance of this analysis in clinical practice.

Cornea↗
PubMed1998

Zonal photorefractive keratectomy for presbyopia.

PURPOSE: We performed zonal excimer laser photorefractive keratectomy in three eyes of three presbyopic patients using a specially designed mask, with a minimum follow-up of 24-months. METHODS: Two females (ages 59 and 48) and one male (age 55) were included in the study. The procedure was performed with a mask designed by one of the authors (GMN), applied to the Aesculap-Meditec Mel 60 excimer laser. The mask consists of a mobile diaphragm formed by two blunt blades. The aim in all the eyes was a presbyopic correction of 3.00 D. RESULTS: After an initial regression of 1.00 D, the presbyopic correction remained stable during the 36-month follow-up. The patients read at least J3 at normal reading distance without correction. Since the ablated zone was only about 15% of the total area of a 3.0 mm pupil, all three patients were also able to read with their preoperative presbyopic correction (using the untreated 85% of the pupillary area). CONCLUSION: Although only three eyes were treated with the zonal presbyopia mask presented here, the visual and refractive outcome appears promising in view of the relatively long follow-up time.

Contrast Sensitivity↗
PubMed1992

The effect of simultaneous internal tamponade on fluid compartmentalization and its relationship to cell proliferation.

To determine whether the residual free spaces within the vitreous chamber that result after vitreoretinal surgery and internal tamponade may be avoided, and to verify whether such compartmentalization is of real importance in the recurrence of postoperative proliferative vitreoretinopathy (PVR), the use of simultaneous double filling with polydimethylsiloxane (PDMS) and fluorosilicone (FSiO) in the repair of complicated retinal detachment is evaluated in 12 selected cases. Initial retinal reattachment was achieved in all cases. PVR recurred in 10 patients (83%), 6 of whom showed partial retinal detachment. Inferior and superior postoperative residual free spaces were abolished by this procedure, but a new residual fluid space was created, lying horizontally between the bubbles and expanding in a triangular shape nasal to the optic disc and temporal to the macula. Overall, 9 of 10 eyes with PVR after surgery had proliferation involving these areas. These findings support the concept that compartmentalization is of major importance in determining postoperative cell proliferation.

Adult↗
PubMed1992

Combined silicone and fluorosilicone oil tamponade (double filling) in the management of complicated retinal detachment.

We evaluated the use of simultaneous double filling with polydimethylsiloxane (PDMS) and fluorosilicone (FSiO) in the repair of complicated retinal detachment in 12 selected cases. Initial retinal reattachment was achieved in all cases. Proliferative vitreoretinopathy (PVR) recurred in 10 patients (83%), 6 of which showed partial retinal detachment. Inferior and superior postoperative residual free spaces were abolished by this procedure, but a new residual fluid space was created, lying horizontally between the bubbles and expanding in a triangular shape nasally to the optic disk and temporally to the macula. Overall, 9 of 10 eyes with postoperative PVR had proliferation involving these areas. These findings support the concept that 'compartmentalization' is of major importance in determining postoperative cell proliferation.

Adult↗
PubMed1985

Posterior polymorphous dystrophy of the cornea. An ultrastructural study.

A corneal button excised from a 2-month-old infant with congenital posterior polymorphous dystrophy of the cornea, a rare disease affecting Descemet's membrane and endothelium, was examined by electron microscopy. We observed irregularly arranged, sometimes multilayered cells with marked epithelial features, lining the posterior surface of the cornea in place of the endothelium, and Descemet's membrane with focal alterations sometimes involving all of its layers. We interpreted these abnormal cells as epithelial-like cells. As these findings were in a very young patient, which is unusual, we concluded that the onset of the disease may take place in the early period of intrauterine life, corresponding to the beginning of Descemet's membrane production.

Cornea↗
PubMedDate not supplied

Excimer laser photorefractive keratectomy for presbyopia: 24-month follow-up in three eyes.

BACKGROUND: For some patients, standard optical correction for presbyopia is not satisfactory. Using a specially designed mask, we developed a procedure for correcting presbyopia with excimer laser photorefractive keratectomy (PRK). METHODS: A mask consisting of a mobile diaphragm formed by two blunt blades was used to ablate a 10 to 17 microm deep semilunar-shaped zone immediately below the pupillary center, steepening the corneal curvature in that area. Three eyes of three presbyopic patients were treated, aiming at a near addition of +3.00 D. Follow-up time was 24 months. RESULTS: After an initial regression of 1.00 D during the first 6 months, the presbyopic correction remained stable for the duration of the follow-up period, enabling uncorrected near vision of J3 in all three eyes. Uncorrected distance visual acuity was not altered. Contrast sensitivity (Regan) was slightly decreased only at the 11% level. Videokeratography confirmed corneal steepening in the ablated area. CONCLUSION: The visual and refractive outcome of excimer laser PRK for presbyopia with the Aesculap-Meditec MEL 60 is promising, especially in view of the 2-year follow-up.

Cornea↗
PubMedDate not supplied

Photorefractive keratectomy to correct myopic or hyperopic astigmatism with a cross-cylinder ablation.

PURPOSE: To assess the efficacy and safety of a combined ablation of the steep and flat meridian to correct astigmatism with the excimer laser. METHODS: Twenty-two eyes with myopic, mixed, or hyperopic astigmatism (mean preoperative spherical equivalent refraction -4.30 +/- 4.70 D [range, -12.50 to +1.50 D] and mean preoperative cylinder magnitude -3.40 +/- 1.40 D [range, -1.50 to -6.00 D]) underwent PRK with the Nidek EC-5000 excimer laser. The surgical strategy involved ablating half the amount of the cylinder (in diopters) along steepest meridian, the other half in a subsequent step along the flattest meridian; thereafter, the spherical equivalent was corrected. RESULTS: Six months postoperatively, mean spherical equivalent refraction was -0.07 +/- 0.87 D and mean cylinder was -0.44 +/- 0.36 D. Mean spectacle-corrected visual acuity was 0.86 +/- 0.13 compared to 0.75 +/- 0.22 preoperatively. Mean corneal haze was 0.67 +/- 0.31. No patient lost 2 or more lines of spectacle-corrected visual acuity and there were no complaints about night halos or glare. CONCLUSIONS: Unlike other ablation strategies, the cross-cylinder method creates a smooth transition (low dioptric gradient) between the treated and untreated cornea. This is achieved by first treating the cylinder and making the corneal surface spherical and then ablating the spherical component of the refractive error.

Adult↗
PubMedDate not supplied

Algorithm to correct hyperopic astigmatism with the Nidek EC-5000 excimer laser.

BACKGROUND: The efficacy of a new ablation algorithm for the correction of hyperopic astigmatism with the Nidek EC-5000 excimer laser was evaluated. METHODS: Twenty-five eyes with mean preoperative hyperopia of +3.76 +/- 1.70 D and a mean hyperopic cylinder of 2.20 +/- 0.80 D underwent photorefractive keratectomy (PRK) using a new algorithm with the Nidek EC-5000 excimer laser (software version 3.0). The new algorithm differed from previous algorithms in that less tissue was removed for the same amount of diopters, and there was less of a dioptric gradient between the optical zone and the transition zone. Mean preoperative spectacle-corrected visual acuity was 0.8 +/- 0.09. Minimum follow-up was 6 months. RESULTS: Mean postoperative spectacle corrected visual acuity (geometric mean) increased significantly to 0.89 +/- 0.1. The mean sphere decreased by 3.08 D and the mean cylinder by 1.60 D. CONCLUSION: Hyperopic PRK using the Nidek EC-5000 excimer laser with this new algorithm for hyperopic astigmatism appears to be safe and effective.

Adult↗