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Biomedical subjects

Salvatore Grisanti

Publications and source records attributed to Salvatore Grisanti.

At least 19 recordsLinked to original sources

Hyperprogression Upon Cemiplimab Alone or With Short Course Chemotherapy in PD-L1 ≥ 50% Non-small Cell Lung Cancer: A Biomarker Guided Multicenter International Phase 2 Trial-HYPERBOLIC Study.

BACKGROUND: Immune checkpoint inhibitor (ICI) monotherapy is the standard first-line treatment for advanced non-small cell lung cancer (NSCLC) with PD-L1 ≥ 50%; however, up to 30% of patients experience early progression or death, including cases of hyperprogressive disease (HPD). High baseline levels (≥ 30.5%) of circulating CD10- low-density neutrophils (LDNs) have been associated with increased HPD occurrence. Emerging evidence suggests that combining ICI with platinum-based chemotherapy (PCT) may mitigate the risk of HPD. Currently, no prospective studies have addressed HPD prevention in this context. PATIENTS AND METHODS: HYPERBOLIC (NCT07274384) is a phase 2, randomized, open-label, multicenter, international trial evaluating whether adding 3 cycles of PCT to first-line cemiplimab reduces HPD rate in stage IV NSCLC with PD-L1 ≥ 50% and CD10- LDNs (identified by flow cytometry as CD15⁺CD11b⁺ within the PBMC fraction, with immature cells defined by loss of CD10) ≥ 30.5%. Seventy-four patients will be randomized (1:1 ratio) to receive cemiplimab alone or cemiplimab plus 3 PCT cycles, followed by cemiplimab maintenance. Randomization will be stratified by Lung Immune Prognostic Index. The first computed tomography scan at week 7 after treatment start will assess HPD occurrence, defined as RECIST v 1.1. disease progression with a delta tumor growth rate (ΔTGR) ≥ 50% and/or TGR ratio ≥ 2. The primary endpoint will be the combined rate of HPD and early death (death within 12 weeks with no radiological evaluation). Secondary endpoints will be HPD rate according to alternative definitions, overall survival, progression free survival, objective response rate, and safety. An extensive translational research platform will include spatial transcriptomics of tumor tissue, single-cell RNA sequencing of PBMCs, circulating-free DNA and plasma factors profiling, and saliva/stool microbiome genomics and metabolomics, to longitudinally explore tumor-host dynamic interactions during treatment. CONCLUSION: to our knowledge, HYPERBOLIC is the first prospective, biomarker-driven trial investigating early treatment escalation based on HPD risk in PD-L1-high NSCLC.

CD10↗

Effects of the protein tyrosine kinase inhibitor genistein and taurine on retinal function in isolated superfused retina.

BACKGROUND: Genistein has the potential to act as an intraocular antiangiogenic agent. Its therapeutical use, however, is limited by toxic side effects on the retina. This study was designed to evaluate the simultaneous use of taurine as a neuroprotective drug. METHODS: Bovine retinas were isolated and perfused with an oxygen-preincubated nutrient solution. The electroretinogram (ERG) was recorded as a transretinal electrical potential using Ag/AgCl electrodes. At stable ERG amplitudes, genistein at concentrations of 11, 37, and 150 microM was added to the nutrient solution for 45 min, in the absence or presence of taurine (3 mM). Thereafter, the retina was reperfused with the nutrient solution for another 100 min. The percentage of b-wave reduction during genistein and genistein/taurine application was calculated. RESULTS: The b-wave amplitude was reduced by a smaller amount during the application of genistein (11 and 37 microM) in the presence of taurine compared with genistein alone. For both, genistein/taurine and genistein alone the b-wave recovered completely during the wash-out of the drugs. However, during the application of the highest tested concentration of genistein (150 microM), taurine did not protect completely, leading to an irreversible b-wave reduction. CONCLUSIONS: The adjuvant use of taurine reduces the genistein-induced retinal toxicity to a certain degree. However, the protective effect of taurine is limited and there is only a narrow therapeutic index for a combined intravitreal administration of genistein in coapplication with taurine to inhibit pathological ocular neovascularization.

Animals↗

Compound subretinal prostheses with extra-ocular parts designed for human trials: successful long-term implantation in pigs.

BACKGROUND: Subretinal implants aim to replace photoreceptor function in patients suffering from degenerative retinal disease like retinitis pigmentosa by topically applying electrical stimuli in the subretinal space. This study-as a last step before upcoming human trials-explored a newly developed surgical technique for permanent implantation of complex subretinal implants with extra-ocular parts. METHODS: The implant consisted of a microphoto-diode array (MPDA) with 1550 electrodes and a 4x4 array of gold electrodes for direct electrical stimulation; both were mounted onto a polyimide foil for transscleral placement into the subretinal space. The foil carried connection lanes to a silicone cable that was implanted under the skin and led to a stimulator box in the animal's neck. Surgery was performed in 11 domestic pigs. Improved vitreo-retinal surgical technique consisted of a 180 degrees peripheral retinotomy and use of diathermy to penetrate the choroid in order to avoid choroidal haemorrhage. Subretinal forceps were used to place the implant safely onto the retinal pigment epithelium before the retina was flattened, peripheral laser photocoagulation was applied and the eye was filled with silicon oil. The implant was stabilized by a scleral fixation patch, use of a metal clamp with bone screws on the animal's skull and a tissue ring under the animal's skin in the neck. Behaviour was observed in the freely moving animals after direct subretinal electrical stimulation and funduscopy, optical coherence tomography, fluorescein angiography and histology were performed. RESULTS: All implants were successfully placed subretinally. In three animals a proliferative vitreo-retinopathy was observed after approximately 2 weeks. Otherwise, funduscopy and OCT demonstrated complete retinal attachment and FA showed no retinal vascular abnormalities over and around the implant. The animals showed clear behavioural reactions to electrical stimulation over the whole examination period. Histological examination failed to show any voltage-induced alteration in the cellular architecture of the retina overlying the stimulation electrodes. CONCLUSIONS: This study demonstrates the feasibility of a new surgical procedure for highly safe and controlled implantation of complex subretinal devices with extra-ocular parts. The new implant design proved to be safely implantable in free-moving pigs for an observation period of 4 weeks.

Animals↗

Full macular translocation versus photodynamic therapy with verteporfin in the treatment of neovascular age-related macular degeneration: 1-year results of a prospective, controlled, randomised pilot trial (FMT-PDT).

BACKGROUND: The purpose of this study was to compare full macular translocation (FMT) with photodynamic therapy (PDT) in the treatment of neovascular age-related macular degeneration (AMD). METHODS: In a prospective, randomised, non-masked, mono-center, pilot-trial, 50 eyes of 50 patients were assigned to either FMT or PDT. Baseline and control examinations in 3-monthly intervals over a 12-month period included standardized protocol refraction, visual acuity testing and fluorescein angiography. Primary outcome measurements were made to establish the change in distant visual acuity from the baseline to the 12-month examination. The statistical analyses were carried out on the intent-to-treat principle. RESULTS: The improvement of one or more ETDRS lines was 56% (14/25) of the eyes in the FMT and 16% (4/25) of the eyes in the PDT arm (P = 0.007). Twenty eyes (80%) in the FMT and 16 eyes (64%) in the PDT group had less than three ETDRS lines of vision loss (P = 0.35). Retinal detachment (six eyes) and diplopia (five patients) were recorded in the FMT group. None of the eyes treated in the FMT group had phtysis. CONCLUSION: This pilot study showed that no statistically significant difference existed between the FMT and PDT in terms of the vision loss of less than three ETDRS lines in eyes with neovascular AMD. The chance of vision improvement was significantly higher for the patients in the FMT group. However, in the era of promising therapy with anti-vascular endothelial growth factor for neovascular AMD, FMT should not be offered as a standard primary procedure for neovascular AMD.

Aged↗

Antipermeability and antiproliferative effects of standard and frozen bevacizumab on choroidal endothelial cells.

BACKGROUND: Bevacizumab is an antiangiogenic compound developed to target tumour vessels. Its off-label use in ophthalmology requires in vitro testing on ocular cells. AIM: To quantify the antipermeability and antiproliferative effects of bevacizumab on cultured choroidal endothelial cells (CECs). It was examined whether deep-freezing of bevacizumab attenuates its antiangiogenic activity. METHODS: Porcine CECs were cultured in permeable insert systems. Permeability of the cell monolayers was quantified by a fluorescent isothiocyanate-dextran assay after treatment with vascular endothelial growth factor (VEGF; 20-100 ng/ml) alone and in combination with bevacizumab (0.1-1 mg/ml). Proliferation of the CECs was tested using a "wound scratch" assay. The experiments were repeated with bevacizumab after freezing at -20 degrees C for 5 days. RESULTS: Bevacizumab significantly reduced VEGF-induced permeability in a dose-dependant manner. A molar ratio of 2.6:1 of bevacizumab to VEGF was required for complete blocking of VEGF-induced rise in permeability. CEC proliferation was significantly blocked by bevacizumab (0.5 mg/ml). Thawed bevacizumab after deep freezing showed a moderate, but not statistically significant loss in activity. CONCLUSION: Bevacizumab significantly reduces VEGF-induced permeability and proliferation of CECs. Freezing and thawing of bevacizumab will affect its biological activity.

Angiogenesis Inhibitors↗

Influence of different purification techniques on triamcinolone yield and particle size spectrum.

BACKGROUND: To systematically investigate the common purification techniques for commercially available triamcinolone acetonide preparations and the influence of different filter parameters on final yield, reproducibility and particle size spectrum. METHODS: Two non-filter techniques using either sedimentation or centrifugation, and two different filter techniques were tested. Filters with different characteristics were investigated with the pore size ranging from 0.1 to 5.0 microm, and the filter diameter ranging from 4 to 30 mm. Only sterile standard syringe filters with low adsorptive characteristics (hydrophilic cellulose filter membranes) for pharmaceutical use were employed. For quantification, triamcinolone acetonide was dissolved in 60% methanol and measured spectrophotometrically at 239 nm. The crystal size spectrum was determined using a particle size analyzer that combines electronic pulse area analysis and resistance measurement. RESULTS: Depending on the purification technique used the resulting triamcinolone doses differed significantly. While the centrifugation method achieved purification without relevant loss, the sedimentation method yielded only 28.7% compared to the original commercial suspension, and in addition, the predictability was low (range 8.1-17.2 mg). With filter techniques high and consistent doses with a good reproducibility were achieved, but results were highly dependent on the filter characteristics. The final triamcinolone amount inversely correlated with the filter diameter due to a uniform loss of crystalline particles. In contrast, enlarging the pore size caused a substantial shift in the particle size spectrum due to a selective loss of small crystalline particles. CONCLUSIONS: The most common purification techniques vary notably in regard to final triamcinolone doses, reproducibility and particle size spectrum. The appropriate choice of the filter parameters seems to be more important than assumed, as pore size and filter diameter substantially influence both the final TA doses and the particle size of the TA crystals.

Centrifugation↗

Effect of verteporfin photodynamic therapy on endostatin and angiogenesis in human choroidal neovascular membranes.

AIM: To evaluate the effect of verteporfin photodynamic therapy (PDT) on endostatin with regard to expression of vascular endothelial growth factor (VEGF) in human choroidal neovascular membranes (CNVs) secondary to age-related macular degeneration. METHODS: A retrospective review of an interventional case series of 68 patients who underwent removal of CNV. 29 patients were treated with PDT 3-655 days before surgery. 39 CNVs without previous treatment were used as controls. CNVs were stained for CD34, CD105, Ki-67, cytokeratin 18, endostatin, E-selectin and VEGF. "Predominance score of VEGF over endostatin" (mean) was defined as the difference between VEGF and endostatin staining scores. RESULTS: In four CNVs treated by PDT 3 days previously, PS was significantly higher in the retinal pigment epithelium (mean = 2.5, p = 0.006) and stroma (mean = 2, p = 0.015) than in the control group (mean = 0). At longer post-PDT intervals, PS was significantly decreased in the retinal pigment epithelium (mean = 0, p = 0.019) and stroma (mean = 0, p = 0.015). Proliferative activity was high (p = 0.023), but mostly related to inflammatory cells. PDT did not influence E-selectin expression significantly. CONCLUSIONS: VEGF predominance over endostatin early after PDT might contribute to enhanced angiogenic activity associated with recurrences. Strategies upregulating or replacing endostatin early after PDT might increase the effectiveness of PDT.

Aged↗

Differential toxic effect of dissolved triamcinolone and its crystalline deposits on cultured human retinal pigment epithelium (ARPE19) cells.

The aim of the study was to evaluate the antiproliferative and cytotoxic properties of triamcinolone acetonide (TA) on human retinal pigment epithelium cells (ARPE19) and the role of epicellular crystalline deposits. Monolayer cultures of ARPE19 cells were used. Purified or unpurified crystalline TA suspension (0.01-1.0 mg/ml) or the vehicle alone (benzyl alcohol, 0.025%-0.00025%), diluted in culture medium, were added to the cells that were either grown on cell culture dishes covered by a protecting membrane filter insert or without a filter. After 1, 3, 5 and 7 days mitochondrial activity was measured using the MTT assay and the morphology assessed microscopically. Cellular proliferative activity was monitored by BrdU-incorporation into cellular DNA. For cytotoxicity assays ARPE19 cells were grown to confluence and then cultured in a serum-deficient medium to ensure a static milieu. Annexin V-FITC and propidium iodide co-staining was performed and analyzed by flow cytometry. Exposure to TA without direct cellular contact showed a moderate antiproliferative activity resulting in a dose-dependent suppression of DNA synthesis (maximum 42.7%), but not a cytotoxic effect. In contrast, adherent deposits of crystalline TA particles on top of the cell layer caused a rapid-progressive and dose-dependent cell death preceded by an early phosphatidylserine externalization to the outer leaflet of the plasma membrane. Within a healthy, confluent cell layer the number of viable cells decreased by 14.2, 20.8 and 68.8%, respectively, after one day of direct exposure. Exposure to the vehicle alone caused only a slight growth inhibitory effect in a proliferating cell layer, but early signs of cell death were detected even at the lowest concentration tested. In conclusion, the effect of the vehicle is less pronounced than formerly assumed, but not negligible, thus indicating a beneficial effect of purification. While non-adherent TA, if purified, appears to be safe in clinically used concentrations, direct physical contact with crystalline particles might cause a local, rapid-progressive cytotoxicity that involves the induction of the apoptotic cascade. Therefore, epiretinal deposits after intravitreal TA administration might be critical in terms of long-term biocompatibility.

Anti-Inflammatory Agents↗

Expression of endostatin in human choroidal neovascular membranes secondary to age-related macular degeneration.

Endostatin is an endogenous angiogenesis inhibitor which requires E-selectin for its antiangiogenic activity. The aim of this study was to investigate the expression of endostatin in human choroidal neovascular membranes (CNV) secondary to age-related macular degeneration (AMD) with regard to vascularization and proliferative activity. An interventional case series of 36 patients who underwent removal of CNV were retrospectively investigated. Thirty-six CNV were analyzed by light microscopic immunohistochemistry for the expression of CD34 (endothelial cells, EC), CD105 (activated EC), Ki-67 (cell proliferation), Cytokeratin 18 (epithelial cells), VEGF (vascular endothelial growth factor), E-selectin and endostatin. Donor eyes (n=7) including one with AMD were used as controls. Endostatin immunoreactivity was present in choroidal vessels of five as well as in the retinal pigment epithelium (RPE)-Bruch's membrane complex of two donor eyes without AMD. In one eye with AMD, endostatin was detected in RPE, Bruch's membrane and choroidal vessels. Ninety-two percent (33/36) of CNV disclosed endostatin staining. RPE-Bruch's membrane complex, choroidal vessels and stroma were positive in 50% (18/36), 72% (26/36), and 78% (28/36) of the membranes, respectively. Both control eyes and CNV expressed all the investigated markers except E-selectin being positive only in membranes. Endostatin, an endogenous angiogenesis inhibitor, is expressed in CNV and its therapeutic up-regulation may be a new strategy in the treatment of neovascular AMD.

Adult↗

Analysis of neovasculature in uveal melanoma by targeting the TGFbeta-binding receptor endoglin: is there prognostic relevance of proliferating endothelium?

BACKGROUND: Endoglin/CD105 is a transmembrane regulatory receptor for transforming growth factor-beta (TGF-beta) that is predominantly expressed on proliferating endothelial cells (ECs) in culture and on angiogenic blood vessels in vivo. Endoglin has been associated with angiogenesis and prognosis in several malignancies. Although microvascular structure has been characterized by a variety of different other endothelial markers so far, there is no consensus on the prognostic value of microvessel quantification in uveal melanoma due to differences in tissue pretreatment, variability in the reactivity of endothelial cell markers, blood vessel counting methods, and vasculogenic mimicry by melanoma cells expressing endothelial cell markers. The aim of this study was to investigate the expression pattern of endoglin and to evaluate whether proliferative activity of ECs determines the clinical prognosis of uveal melanoma. METHODS: Paraffin sections from 35 clinicopathologically well-characterized cases of primary uveal melanomas were stained for Ki-67, von Willebrand factor (vWF) and endoglin. In 16 cases, metastatic disease led to death. The mean follow-up of the nonmetastasized cases was 10.6 (9-13) years. The immunohistological specimens were evaluated by three independent observers who were masked to the follow-up of patients. Statistical analyzes included Kaplan-Meier survival curves and the fitting of log-rank and Wilcoxon test models. RESULTS: Immunohistochemistry with vWF confirmed that all examined specimens were vascularized. Expression of Ki-67 could be found in 26 (74%) of the samples. Moderate to high expression of endoglin was found in 13 cases (37%). Kaplan-Meier analysis showed a significant association (p<0.001) between an enhanced endoglin expression and death due to metastatic uveal melanoma. CONCLUSIONS: The study demonstrates for the first time that the expression of endoglin can be used as a specific marker for angiogenesis in uveal melanomas. Thus, differentiation between the quiescent and proliferating ECs enables the location and characterization of hot spots of angiogenesis in melanomas. The data suggest not only a prognostic relevance in individual patients but promise applications in assessing the efficacy of antiangiogenic agents.

Adult↗

Consequences of verteporfin photodynamic therapy on choroidal neovascular membranes.

OBJECTIVE: To examine the impact of photodynamic therapy (PDT) on angiogenesis in human choroidal neovascular membranes with respect to vascular endothelial growth factor (VEGF) expression, proliferation, and vascularization. METHODS: Retrospective review of an interventional case series of 50 patients (50 eyes) who underwent removal of choroidal neovascular membranes. Choroidal neovascularization was secondary to age-related macular degeneration. Twenty patients were treated with PDT 3 to 655 days before surgery. Choroidal neovascular membranes were stained for CD34, CD105, Ki-67, cytokeratin 18, and VEGF. Thirty choroidal neovascular membranes secondary to age-related macular degeneration without previous treatment were used as controls. RESULTS: Specimens without pretreatment disclosed varying degrees of vascularization, proliferative activity, and VEGF expression by different cells. Specimens treated with PDT 3 days earlier showed mostly occluded vessels, damaged endothelial cells, and low proliferative activity. In contrast, specimens excised at later time points after PDT were highly vascularized and proliferating. This chronology was associated with an impressive VEGF immunoreactivity unique to retinal pigment epithelial cells shortly after PDT that also shifted to other cells at later time points. CONCLUSIONS: Photodynamic therapy induces selective vascular damage in choroidal neovascular membranes. The effectiveness and selectivity of this treatment, however, seem to be jeopardized by a rebound effect initiated by enhanced VEGF expression in retinal pigment epithelial cells.

Aged↗

Intraoperative breakage of 20-gauge Tano forceps.

PURPOSE: To report three cases with breakage of a 20-gauge kryptonite forceps during vitreoretinal surgery. DESIGN: Interventional case report. METHODS: Pars plana vitrectomy that included a membrane peeling was performed in three patients through standard ports with 20-gauge vitrectomy systems. The peeling procedure was attempted with the end-gripping kryptonite forceps. RESULTS: Intraoperatively, the branch/tip broke and dropped onto the posterior pole. Removal of the broken part was uncomplicated, and the subsequent clinical course was unremarkable. In one case, the handle and branch/tip part were exchanged inadvertently. In the other two cases, neither an exchange nor a maladaptation of the parts was noted. CONCLUSION: An exchange of the hand piece and gripping end may increase the risk of breakage and retinal damage. The delicate gripping tips, however, may break because of inadequate maintenance and/or aging of the material. Intraoperative visual and functional examination is recommended before intraocular use.

Epiretinal Membrane↗

Expression of VEGF and PEDF in choroidal neovascular membranes following verteporfin photodynamic therapy.

PURPOSE: To examine the impact of photodynamic therapy (PDT) on pigment epithelium derived factor (PEDF) expression in human choroidal neovascularization (CNV) membranes with regard to vascular endothelial growth factor (VEGF) expression. DESIGN: Interventional case series. METHODS: Retrospective review of interventional case series of 42 patients (42 eyes) who underwent removal of CNV. CNV was secondary to age-related macular degeneration (AMD) in all cases. Fifteen patients were treated with PDT, 3 to 246 days before surgery. CNV were stained for CD34, CD105, cytokeratin 18, VEGF, and PEDF. Twenty-seven CNV without previous treatment were used as control. RESULTS: Specimens without pretreatment disclosed varying degrees of vascularization, VEGF, and PEDF expression by different cells. Specimens treated by PDT, three days previously showed mostly occluded vessels lined with damaged endothelial cells (EC). In contrast, specimens excised at later time points after PDT were highly vascularized with healthy EC. This chronology was associated with an impressive VEGF immunoreactivity increased considerably in retinal pigment epithelial cells as well as significantly reduced PEDF expression in EC and stroma. CONCLUSIONS: PDT induces a selective vascular damage in CNV. The effectiveness of PDT, however, seems to be jeopardized by a rebound effect initiated by an enhanced VEGF and reduced PEDF expression in CNV.

Aged↗

Intracameral bevacizumab for iris rubeosis.

PURPOSE: To determine whether intracameral bevacizumab decreases vascular leakage from iris rubeosis in patients with neovascular glaucoma. DESIGN: Interventional case series. METHODS: The study included six eyes of three patients with secondary neovascular glaucoma due to proliferative diabetic retinopathy (n = 2) or ischemic central retinal vein occlusion (n = 1). All patients received an intracameral injection of 1.0 mg bevacizumab. Morphologic changes and vascular leakage were investigated prospectively by iris fluorescein angiography. RESULTS: Decrease in leakage was detected as early as one day after injection. No inflammation was observed. No relapse was seen within the follow-up of four weeks. CONCLUSION: Intraocular injection of bevacizumab may provide an additional strategy for the treatment of iris rubeosis in neovascular glaucoma.

Aged↗

Sutureless amniotic membrane fixation using fibrin glue for ocular surface reconstruction in a rabbit model.

PURPOSE: Amniotic membrane transplantation has become an important treatment option for corneal surface reconstruction. However, suture fixation of the transplant has various disadvantages like corneal irritation, scarring, graft loss due to membrane shrinkage, and the need for subsequent suture removal. Replacement of sutures by bioadhesives might be an advantageous alternative. This controlled study was designed to evaluate a new sutureless technique for amniotic membrane fixation onto the corneal surface by using fibrin glue. METHODS: Standardized disks of cryopreserved amniotic membranes were transplanted onto the deepithelialized cornea of 12 rabbits using either conventional suture fixation or a new fibrin glue technique. The rabbits were followed-up with slit-lamp examination and fluorescein staining until epithelialization was completed. Consecutively, the rabbits were killed and the eyes processed for histology and immunohistochemistry for cytokeratin-3. RESULTS: All membranes of both groups stayed in place throughout the follow-up time and showed a progressive graft epithelialization that was completed after 12 days. Whereas suture-fixated membranes showed progressive tissue shrinkage, fibrin-glued sheets remained unaltered. In the bioadhesive group, histology revealed a smooth fibrin layer in the graft-host interface and a continuous, stratified layer of cytokeratin-3 expressing corneal epithelial cells on the membrane surface. In contrast, suture-fixated membranes showed contracted and prominent membrane edges with epithelial ingrowth into the submembrane interface. CONCLUSION: Our results demonstrate the general feasibility of reproducible and reliable sutureless amniotic membrane fixation onto the corneal surface in rabbits. Stable adherence is maintained until epithelialization is completed. The sutureless technique gives sufficient manipulation time for the sheet before the final cross-linking process is completed. Furthermore, several advantageous characteristics could be demonstrated as increased biocompatibility, better epithelialization pattern and the lack of membrane shrinkage.

Amnion↗

Ultrastructural changes after artificial retinal detachment with modified retinal adhesion.

PURPOSE: Artificial retinal detachment is increasingly used in submacular surgery. However, overcoming physiological retinal adhesiveness by subretinal fluid injection is suspected to cause cellular damage and thus to limit visual rehabilitation. This experimental study was designed to examine the ultrastructural changes induced by retinal detachment under vitrectomy conditions and to evaluate factors that reduce adhesiveness and minimize cellular damage. METHODS: Twenty-one pigmented rabbits underwent vitrectomy, and the vitreous cavity was perfused for 10 minutes with various solutions. These included variations in osmolarity (314 and 500 mOsM), Ca(2+) ion concentration (Ca(2+)-supplemented, low Ca(2+), active Ca(2+) deprivation via 1 mM EDTA), temperature (19 degrees C and 34 degrees C), and ischemia (5 minutes). Nonvitrectomized eyes served as the control. Consecutively, an artificial bleb detachment was created underneath the visual streak by injecting 1 mL of buffered saline solution subretinally. Eyes were enucleated within 3 minutes, fixed with 2% glutaraldehyde/0.1 M cacodylate buffer (pH 7.4) containing 100 mM sucrose and processed for transmission electron microscopy and scanning electron microscopy. RESULTS: If a Ca(2+)-containing standard solution was used during vitrectomy, retinal adhesiveness was strong, and a forced bleb detachment caused substantial cellular damage characterized by swollen and fragmented photoreceptor outer segments and disruption of retinal pigment epithelial cells. Use of a Ca(2+)-free solution moderately reduced the adhesive strength with consequently less ultrastructural damage. Active Ca(2+)-deprivation further reduced the retinal adhesion, but may have induced damage as suggested by intracellular vacuolization. Hyperosmolarity and ischemic conditions had toxic effects on both the photoreceptors and RPE cells. In contrast, the use of a preheated Ca(2+)-free solution (34 degrees C) substantially reduced retinal adhesiveness under vitrectomy conditions and hence ultrastructural damage. CONCLUSIONS: Artificial retinal detachment causes substantial ultrastructural damage in eyes with physiological retinal adhesiveness if performed under vitrectomy conditions similar to surgery in humans. The use of a preheated Ca(2+)-free physiologic saline solution seems to be suitable to reduce retinal adhesion sufficiently, without causing significant cellular damage.

Adhesiveness↗

An alternating regimen of irinotecan/ 5-fluorouracil/folinic acid and oxaliplatin/ 5-fluorouracil/folinic acid in metastatic colorectal cancer: a Phase II trial.

OBJECTIVE: To assess the feasibility and activity of a combination schedule with irinotecan (CPT-11), oxaliplatin (L-OHP), brief infusional fluorouracil (5-FU) and folinic acid (FA) as first-line treatment in metastatic colorectal cancer (MCC) patients. METHODS: Fifty consecutive patients were treated with CPT-11 125 mg/m2 as a 90-min intravenous infusion, followed by FA 20 mg/m2 as an intravenous bolus, and 5-FU 500 mg/m2 over a 2-hour intravenous infusion on days 1 and 8. L-OHP was administered at 85 mg/m2 over 2 h on day 15, in combination with a FA 60 mg/m2 intravenous bolus and 5-FU 600 mg/m2 as a 2-hour intravenous infusion on days 15-16. The treatment was repeated every 4 weeks for a maximum of 9 cycles. RESULTS: Twenty-five of 50 assessable patients achieved a complete (n=5) or partial (n=20) response, leading to a response rate of 50% (95% CI 35-64%). Eighteen (36%) patients showed stable disease. The median time to tumor progression was 10.3 months (95% CI 9.6-10.9 months). After a median follow-up of 16.4 months, the median survival was not reached. Grade 3 neutropenia (8%), grade 3 nausea/vomiting (6%) and grade 3 diarrhea (2%) were the major adverse events. CONCLUSION: This alternating three-drug regimen is very well tolerated, manageable and effective in terms of activity and time to progression.

Adult↗

Gemcitabine plus celecoxib (GECO) in advanced pancreatic cancer: a phase II trial.

INTRODUCTION: Single agent gemcitabine (GEM) is the standard treatment of pancreatic adenocarcinoma. Celecoxib is a selective cyclooxygenase-2 (COX-2) inhibitor. Recent studies in human pancreatic tumor cell lines suggest an involvement of COX-2 in tumor-dependent angiogenesis and provide the rational for inhibition of the COX pathway as an effective therapeutic approach. The aim of this study is to evaluate the toxicity and activity of gemcitabine plus celecoxib. PATIENTS AND METHODS: Forty-two consecutive patients with histologically or cytologically confirmed pancreatic adenocarcinoma entered the trial. Twenty-six patients (pts) were metastatic, 16 pts had locally advanced disease. The schedule consisted of GEM 1,000 mg/m2 (as a 30 min iv infusion) on days 1, 8 every 3 weeks and celecoxib 400 mg bid. RESULTS: Four pts (9%) achieved a partial response and 26 (62%) had stable disease, gaining a total disease control in 30 pts (71% [95% CI, 58-84%]). Overall clinical benefit response was experienced by 23 pts (54.7% [95%CI, 38.6-70.1%]). Neither grade 4 neutropenia nor grade 3-4 thrombocytopenia was observed. Grade 3 neutropenia was detected in 19% of pts. Grade 3 non-hematological toxicity was as follows: hepatic toxicity 7%, nausea 2.3%. Three pts (7%) and 5 pts (12%) had respectively a minimum creatinine increase and edema. Median survival was 9.1 months (95% CI, 7.5-10.6 months). CONCLUSION: GEM in combination with celecoxib showed low toxicity, good clinical benefit rate and good disease control. Further clinical investigation is warranted.

Adenocarcinoma↗