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Biomedical subjects

R Bellucci

Publications and source records attributed to R Bellucci.

At least 19 recordsLinked to original sources

Clear lens phacoemulsification for correction of high myopia.

PURPOSE: To assess phacoemulsification and posterior chamber intraocular lens (IOL) implantation as an effective, safe, and predictable technique for the correction of high myopia. SETTING: University Eye Clinic of Verona, Verona, Italy. METHODS: A series of 25 eyes with myopia higher than -12.0 diopters (D) had clear lens extraction by phacoemulsification and IOL implantation in the capsular bag. The mean postoperative follow-up was 42.92 months +/- 3.76 (SD). RESULTS: No serious intraoperative complications occurred. Uncorrected visual acuity improved in all cases. The mean postoperative best corrected visual acuity improved by an average of 1 line. One case (4.0%) of postoperative retinal detachment (RD) occurred at 12 months. One case (4.0%) of biometric error (3.0 D) occurred. CONCLUSION: Clear lens extraction by phacoemulsification and IOL implantation in a series of highly myopic eyes was effective and had an acceptable predictability and a low rate of complications. Careful evaluation of the retinal periphery by indirect ophthalmoscopy is recommended to avoid postoperative RD.

Adult↗

Modulation of VLA-4 and L-selectin expression on normal CD34+ cells during mobilization with G-CSF.

We have evaluated the immunophenotype, functional activity and clonogenic potential of CD34+ cells from peripheral blood (PB) of normal donors before and after 4 and 6 days of G-CSF administration. The percentage and absolute number of CD34+ cells significantly increased at days 4 and 6 of G-CSF administration, compared to the steady-state level (P < 0.0001). Two-colour fluorescence analysis showed, at days 4 and 6, a lower proportion of CD34+/c-kit+ compared to the steady-state level (P < 0.0001), but a similar expression of CD13, CD33, CD38, HLA-DR and Thy-1 antigens on CD34+ cells. The expression of adhesion molecules on CD34+ cells revealed a significant reduction of CD11a (P = 0.009), CD18, CD49d and CD62L (P < 0.0001) at days 4 and 6, compared to the baseline level. Three-colour staining showed a reduction of the more immature compartment (34+/DR-/13-) and an increase of the more differentiated compartment (34+/DR+/13+). Downregulation of VLA-4 during mobilisation was seen almost exclusively on more committed cells (34+/13+); downregulation of CD62L, on the contrary, was observed on both early progenitors (34+/13-) and more committed cells (34+/13+). The expression of 34+/VLA-4+ decreased on both c-kit+ and c-kit- cells, while the expression of 34+/62L+ decreased on the c-kit+ cells only. In vivo administration of G-CSF reduced the adherence capacity of CD34+ cells to normal BM stroma; in vitro incubation with SCF or IL-3 enhanced the expression of CD49d on CD34+ cells, while GM-CSF reduced the expression of CD62L. SCF was the only cytokine able to induce a significant increase of CD34+ cell adherence to preformed stroma. Pre-incubation with the blocking beta2 integrin monoclonal antibody caused a reduction of CD34+ cell adherence. In conclusion, the decrease of CD49d expression on mobilized CD34+ cells correlates with a poor adhesion to BM stroma; CD34+ cells incubated in vitro with SCF showed, conversely, a higher expression of CD49d and a greater adherence capacity on normal preformed stroma.

Antigens, CD↗

Monitoring of CD34+ cells during leukapheresis allows a single, successful collection of hemopoietic progenitors in patients with low numbers of circulating stem cells.

We have studied a total of 188 patients with hematological malignancies, submitted to mobilization therapy with G-CSF associated or not with chemotherapy in order to: (1) establish the lower limit of circulating progenitor cells that allows the collection of 2 x 10(6) CD34+ cells/kg by a single leukapheresis, utilizing the instrument set on standard parameters; (2) evaluate whether the number and quality of CD34+ cells collected remain stable during leukapheresis; and (3) collect a sufficient number of circulating CD34+ cells by a single procedure in patients in whom such an approach would have been insufficient to reach the target with the instrument set on standard parameters. The retrospective analysis conducted in 85 patients showed that 19 circulating CD34+ cells/microl represented the cut-off number capable of discriminating between patients who will require one or more apheresis to collect 2 x 10(6) CD34+ cells/kg. The validity of this value was prospectively confirmed in 70 subsequent patients. Based on in vitro results that showed the stability in the number of CD34+ cells, the proportion of different CD34+ cell subpopulations and the clonogenic capacity of the stem cell compartment during leukapheresis both in the blood of the patients and in samples taken directly from the instrument, we have adapted the blood volume to be processed in 33 patients with <19 PB CD34+ cells/microl. Stem cell collection was monitored during the leukapheresis and the procedure was prolonged for a time period estimated to be sufficient to reach the target number of CD34+ cells with a single procedure. The median increment of the total blood volume processed, calculated from the volume set automatically by the instrument was 25.2%, with a median of 3.3-fold total blood volume processed. In all cases, a sufficient CD34+ cell collection was completed in a single procedure. After autograft, the pattern of blood reconstitution was similar to that of all the other patients.

Adolescent↗

Interferon-alpha and bcr-abl antisense oligodeoxynucleotides in combination enhance the antileukemic effect and the adherence of CML progenitors to preformed stroma.

We have studied the in vitro effect of IFN-alpha and bcr-abl antisense oligodeoxynucleotides (As ODN) alone and in combination with the aim of enhancing the antileukemic activity of the two single agents and evaluating whether the two agents in combination might restore the adherence capacity of chronic myeloid leukemia (CML) progenitors to preformed stroma. We have also correlated the increased adhesion found after in vitro treatment with the expression of adhesion molecules on leukemic progenitors. Incubation of the BV173 cell line with escalating doses of IFN-alpha (100-10000 U/ml) showed a colony growth inhibition between 10 and 30%. IFN-alpha and junction-specific As ODN in combination showed a greater antiproliferative effect compared to that observed with the two agents used alone. In particular, As ODN at a concentration of 40 microg/ml in combination with IFN-alpha at 100 and 1000 U/ml showed a greater inhibitory effect compared to that obtained with IFN-alpha only. Addition of As ODN to IFN-alpha at 10000 U/ml did not result in a greater BV173 inhibition. In a further set of experiments, primary cells from 16 CML patients at diagnosis were incubated with 40 microg/ml of J-spec As ODN, several control ODNs and IFN-alpha at 1000 U/ml alone and in combination. A significantly greater elimination of CML progenitors was found after treatment with the combination of IFN-alpha and J-spec As ODN, compared to any other treatment group, confirmed also by a more marked effect on p210 expression. The deficient adhesion of CML progenitors on human preformed stroma was restored at levels similar to that of normal bone marrow cells after treatment with IFN-alpha and/or J-spec As ODN, while the phenotypic analysis showed that the combined treatment increased significantly the expression of CD49b and CD62L on CML CD34+ cells. However, when the expression of adhesion molecules was blocked with specific monoclonal antibodies, only CD49d (expressed on more than 90% of CML CD34+ cells) appeared to influence the functional activity of adhesion molecules. In conclusion, IFN-alpha and bcr-abl As ODN in combination exert a marked in vitro antileukemic activity and could be a useful approach for in vitro purging of CML cells prior to autologous transplantation.

Antigens, CD34↗

Anesthesia for cataract surgery.

Developments of anesthesia for cataract surgery emerging from literature published during the scanning period include new drugs for sedation before general anesthesia and some discussion about monitoring. A few articles report on both improvements in and complications of peribulbar and retrobulbar injections. There are studies confirming the efficacy of sub-Tenon and topical anesthesia, sometimes associated with facial block. A tendency toward topical anesthesia emerged. Intraocular drug delivery was studied for toxicity both for cornea and for retina, in experimental and clinical settings.

Anesthesia, General↗

Intraocular penetration of topical lidocaine 4%.

PURPOSE: To evaluate the intraocular penetration of lidocaine 4% topically applied before phacoemulsification. SETTINGS: Institute of Ophthalmology, University of Verona, and Department of Medical Pharmacology, University of Padua, Italy. METHODS: Thirty eyes having phacoemulsification for senile cataract were anesthetized by topical application of lidocaine 4%. The drug was applied 3 times in 30 minutes in 15 eyes and 6 times in 60 minutes in 15 eyes. At the beginning of surgery, aqueous humor samples were obtained to measure the lidocaine levels. Blood samples were obtained in 6 patients 30 and 60 minutes after aqueous humor collection. The aqueous humor levels were compared with the amount of pain perceived by patients during surgery. RESULTS: Mean aqueous humor lidocaine concentration was 8.68 micrograms/mL +/- 2.43 (SD) after 3 instillations and 23.21 +/- 8.87 micrograms/mL after 6 instillations. Blood levels of lidocaine were negligible. Patients whose intraocular level was below 12 micrograms/mL perceived more pain during surgery. Only 2 eyes had these low levels after 6 instillations. CONCLUSIONS: Topically applied lidocaine 4% effectively penetrates the eye, providing analgesia for phacoemulsification. We suggest at least 6 instillations in the hour preceding surgery. In this study, pain during surgery was primarily related to poor intraocular levels of the anesthetic agent.

Absorption↗

BCR-ABL antisense oligodeoxynucleotide in vitro purging and autologous bone marrow transplantation for patients with chronic myelogenous leukemia in advanced phase.

BCR-ABL antisense oligodeoxynucleotides (ODN) have provided evidence of antileukemia effect when tested in vitro against Philadelphia-positive (Ph-pos) cells and in vivo when injected into leukemic mice. On the basis of the results obtained in vitro at diagnosis, eight patients with chronic myelogenous leukemia (CML) were selected and submitted to autologous bone marrow transplantation (ABMT) with bone marrow (BM) cells purged in vitro with junction-specific (J-sp) BCR-ABL antisense ODN at the time of transformation in accelerated phase or during second chronic phase. Mononuclear BM cells were treated in vitro for 24 or 72 hours with 150 micro/mL of antisense ODN yielding a median recovery of 47.6% mononuclear cells, 48.8% CD34(+) cells, and 20.3% clonogenic cells. After a conditioning regimen including busulphan and etoposide, the reinfused treated cells allowed engraftment and hematologic reconstitution in all patients. Evaluation of the antileukemic effect by standard cytogenetic analysis and fluorescence in situ hybridization showed a complete karyotypic response in two cases and a minimal or no response in the other six. The patient autografted in second chronic phase died in blast crisis 7 months after ABMT; of the seven patients autografted in transformation, three developed blast crisis 21 to 39 months after reinfusion, one died from unrelated BMT complications 30 months after ABMT, and three are in persistent second chronic phase 14 to 26 months after autograft. The low toxicity of the protocol and the hemopoietic reconstitution observed in all patients make this approach feasible; the marked karyotypic response observed in some patients and the duration of the second chronic phase show that ODN-mediated BM purging and autograft is a promising treatment for this high-risk group of CML.

Adult↗

Evaluation of marrow and blood haemopoietic progenitors in chronic lymphocytic leukaemia before and after chemotherapy.

We have evaluated the number and differentiation pattern of CD34+ cells, as well as the CFU-GM, BFU-E and CFU-GEMM progenitors from the blood (PB) and marrow (BM) of 53 chronic lymphocytic leukaemia (CLL) patients. Twenty-four patients were untreated and 29 were studied at 2 months from the last course of fludarabine or chlorambucil; 6 patients, studied after fludarabine therapy, were further evaluated after mobilization with cyclophosphamide and G-CSF. PB of untreated patients showed a median number of CD34+ cells, CFU-GM, BFU-E and CFU-GEMM/10(5) seeded cells and per litre of PB similar to those of normal controls. No differences were also found in the number of clonogenic progenitors/10(5) cells in patients studied before and after therapy, while significantly fewer BFU-E/l of PB were found after fludarabine. The number of circulating CD34+ cells/l of PB was significantly lower in patients treated with fludarabine or chlorambucil compared to untreated patients. BM growth was significantly reduced in untreated CLL patients compared to healthy donors. Treatment with fludarabine or chlorambucil restored BM progenitors at levels similar to those of normal controls; this effect did not occur for CFU-GM in patients treated with fludarabine. Three-colour fluorescence analysis demonstrated a differentiation pattern of CD34+ cells, with a greater expression of CD13 and CD33 after treatment with fludarabine compared to untreated patients and normal controls. In 4 patients previously treated with fludarabine who underwent a successful cyclophosphamide and G-CSF mobilization therapy, 4x10(6) CD34+ cells/kg were collected. These 4 patients showed a notable increase of CD34+ cells and of clonogenic cells in the PB, but a marked decrease of BM progenitor cells. The 2 patients who failed CD34+ cell mobilization had a reduced CFU-GM growth both in the PB and in the BM. Taken together, these studies indicate that residual haemopoietic progenitors are present in untreated CLL patients and that stem cell mobilization and collection can be carried out following fludarabine treatment.

Adult↗

Efficacy and safety of combined diclofenac 0.1% and gentamicin 0.3% eyedrops after phacoemulsification.

PURPOSE: To study the efficacy of combined diclofenac 0.1% and gentamicin 0.3% (Digen) eyedrops to treat postoperative inflammation and prevent ocular infection in eyes having phacoemulsification. SETTING: Department of Ophthalmology, University of Milan, San Paolo Hospital, Milan; Eye Clinic, University of Verona; and Department of Ophthalmology, University of Palermo, Italy. METHODS: This double-masked, randomized, clinical trial comprised 90 patients; 45 received Digen and 45, gentamicin 0.3% eyedrops. The main outcome measure of the study was the reduction in signs and symptoms of inflammation, graded on a four-point scale. Also assessed were the presence of bacteria in the conjunctival swab and the proportion of patients requiring additional medication. RESULTS: Digen was more effective in reducing postoperative inflammation than gentamicin alone (P < .01). No statistically significant between-group difference was found regarding antibacterial activity. Both treatments were well tolerated throughout the study. CONCLUSION: Digen seemed to maintain the properties and activities of each individual drug, making it a promising treatment for reducing inflammation after phacoemulsification.

Administration, Topical↗

Secondary implantation of angle-supported anterior chamber and scleral-fixated posterior chamber intraocular lenses.

PURPOSE: To compare the results of secondary implantation of angle-supported anterior chamber intraocular lenses (IOLs) and scleral-fixated posterior chamber lenses. SETTING: Eye Clinic, University of Verona, Italy. METHODS: This study of 68 eyes of 60 patients comprised two groups. In Group A (n = 35), an angle-supported anterior chamber IOL was implanted and in Group B (n = 33), a scleral-fixated posterior chamber IOL. Follow-up was from 12 to 45 months. RESULTS: In Group A, one eye developed a retinal detachment and another, pseudophakic bullous keratopathy. In Group B, one eye had a major intraoperative choroidal hemorrhage and two developed a retinal detachment postoperatively. All other complications were minor. CONCLUSIONS: Although the rate of sight-threatening complications was about 6% for both groups, scleral-fixated posterior chamber IOLs were associated with more intraoperative and postoperative complications than angle-fixated anterior chamber IOLs, and surgery took longer. Thus, anterior chamber IOL implantation should be considered for older patients with relatively good endothelial cell counts.

Aged↗

HPR perimetry and Humphrey perimetry in glaucomatous children.

Fifteen children aged less than 11 years, affected by congenital glaucoma, underwent visual field testing using two different methods: conventional computerized perimetry (24-2 Humphrey program) and High Pass Resolution perimetry (Ring test). The aim of the study was to discover which of the two perimetric techniques was more suitable for younger patient. Results showed that HPR perimetry is more suitable to children. Reasons include the short duration of the test (5 min), and the appearance like a pleasant game to 80% of the subjects tested. In addition it proved to be better than Humphrey test because of the minimal possibilities of memorisation with a reproducibility factor of 68% in our sample and because of the reliable results and satisfactory evaluation in 76% of the eyes examined.

Child↗

Cataract surgery in eyes with early cataracts.

This prospective study assessed visual results and subjective rehabilitation after cataract surgery in eyes with a preoperative acuity of 0.4 (20/40) or better. Fifty eyes (50 patients) were entered in the study. Corrected and uncorrected visual acuity, lens opacity, glare disability, and contrast sensitivity were measured before surgery and four months after surgery. Patient satisfaction was also measured. Best corrected visual acuity was 0.54 +/- 0.12 before surgery and 0.95 +/- 0.15 four months after surgery. Uncorrected visual acuity was 0.24 +/- 0.18 before and 0.58 +/- 0.27 after surgery. Impairment of corrected visual acuity from glare decreased from 0.12 +/- 0.09 before surgery to 0.04 +/- 0.08 four months after surgery. Contrast sensitivity at 6 cycles/degree increased from 2.71 +/- 0.94 units to 4.73 +/- 1.09 units. After surgery, 62% of patients judged their vision to be greatly improved, 32% judged it improved, 6% judged it unchanged. The patient's satisfaction was partially related to the improvement in uncorrected visual acuity. We conclude that cataract surgery can benefit eyes with limited visual impairment if the surgery is uncomplicated and IOL power is calculated correctly.

Aged↗

Apraclonidine protection of the blood-aqueous barrier from traumatic break-down.

This study investigated the effects of apraclonidine hydrochloride 1% eye drops on blood-aqueous barrier in 108 pigmented rabbits. The effects of pretreatment with dapiprazole and yohimbine, and a comparison with clonidine 0.125% eye drops are also reported. The disruption of blood-aqueous barrier was obtained by argon laser burning of the iris. The degree of permeability of the barrier was deduced by the amount of proteins in aqueous humor 60 min after laser application. Intraocular pressure and pupil diameter were also studied. Protein content in aqueous humor was 0.72 +/- 0.26 g/l in control rabbits that did not receive any treatment; 5.98 +/- 4.23 g/l in rabbits instilled with placebo eye drops and treated by laser burning of iris; 0.43 +/- 0.25 g/l in rabbits that received apraclonidine eye drops prior to laser burning; 2.19 +/- 1.3 g/l in rabbits that received apraclonidine eye drops immediately after laser application; 0.35 +/- 0.08 g/l in rabbits that received apraclonidine 1% eye drops both before and after laser application. Rabbits treated with clonidine 0.125% had a protein content in aqueous humor of 5.45 +/- 2.08 g/l after laser application. Dapiprazole 0.5% eye drops prior to apraclonidine led to a protein content in aqueous humor of 1.93 +/- 2.13 g/l; yohimbine 0.3% eye drops prior to apraclonidine led to a protein content of 0.70 +/- 0.40 g/l. Protein content in aqueous humor was 0.93 +/- 0.36 g/l, 0.82 +/- 0.899 g/l and 1.68 +/- 1.39 g/l in rabbits treated with yohimbine 0.3, 0.6 and 1.2 mg/kg i.v. and then with apraclonidine 1% eye drops. In one group of rabbits, the penetration into the aqueous humor of Evans blue injected intravenously was also studied. Evans blue content in aqueous humor was 0.03 +/- 0.08 mg/100 ml in control rabbits; 0.92 +/- 0.53 mg/100 ml in placebo rabbits treated by laser; and 0.28 +/- 0.19 mg/100 ml in apraclonidine rabbits treated by laser. Apraclonidine eye drops led to a decrease in IOP and prevented IOP rise following argon laser application. Placebo treated rabbits had a 20% increase in IOP following laser application. Apraclonidine-treated eyes showed mydriasis and blanching of the conjunctiva. These effects were not affected by pretreatment with dapiprazole or yohimbine. In these experiments, the treatment with apraclonidine 1% eye drops completely protected the blood aqueous barrier from the disruption caused by laser burning of the iris. The protection was less effective when apraclonidine was applied after laser burnings.

Adrenergic alpha-Agonists↗

Nucleus viscoexpression compared with other techniques of nucleus removal in extracapsular cataract extraction with capsulorhexis.

We compared three nucleus delivery procedures used during extracapsular cataract extraction (ECCE) after capsulorhexis in 142 eyes. In 25 eyes, the nucleus was expressed through a capsulorhexis 7 mm or wider. In 40 eyes, the nucleus was broken into two pieces and removed through a capsulorhexis 6 mm or less. In 77 eyes, viscoexpression was used to remove the nucleus from the capsular bag through a capsulorhexis 6 mm or less. Nucleus expression after a wide capsulorhexis was successful in 68% of the eyes in which it was attempted. Nucleus fragmentation was successful in 90%. Postoperative inflammation was high in both of these groups. Nucleus viscoexpression was successful in 93%, with low postoperative inflammation. Although it requires a 7- to 8-millimeter corneoscleral incision, based on our study, viscoexpression would appear to be the best nuclear delivery technique when ECCE, rather than phacoemulsification, is being performed.

Aged↗

Pseudoaccommodation with the 3M diffractive multifocal intraocular lens: a refraction study of 52 subjects.

A refraction study was performed of 52 pseudophakic subjects implanted with a 3M diffractive intraocular lens (IOL). Twenty patients implanted with conventional monofocal IOLs from 3M were used as controls. The refraction for distance and near was determined, corresponding to the refractive (distance vision) and diffractive (near vision) foci. Pseudoaccommodation amplitude was measured relative to the variation of visual acuity as a function of "fogging" obtained with plus and minus lenses over any required spherical cylindrical power. Results showed that the 3M diffractive IOL acted as a bifocal lens in all subjects except those whose IOLs had decentered markedly. The dioptric range allowing good vision for distance and near is much wider with the diffractive IOL than it is with a monofocal IOL. Almost perfect vision, and the satisfaction of the patients, was achieved when the distance refraction was near to emmetropia and astigmatism was minimal. However, hyperopic biometric inaccuracies were less disturbing than myopic inaccuracies.

Accommodation, Ocular↗