Pietro Russo

Comparison of Hypotonic and Isotonic Solutions Containing Sodium Hyaluronate on the Symptomatic Treatment of Dry Eye Patients

This study was designed to compare the efficacy of two artificial tears both containing hyaluronic acid but differing in their osmolarity. A multicentric double-masked, crossover clinical trial was performed in which 158 subjects were randomized to receive either hypotonic or isotonic artificial tears up to 6 times a day. Both treatments were effective in improving signs and symptoms to a similar extent. No adverse events were reported. It was concluded that hypotonic and isotonic eye drops are comparable for the symptomatic treatment of patients suffering from dry eye syndrome.

Topical naproxen sodium for inhibition of miosis during cataract surgery. Prospective, randomized clinical trials

Purpose To assess corneal penetration of naproxen sodium and its efficacy in maintaining intraoperative mydriasis during cataract surgery.Methods Two double blind studies have been performed comparing the efficacy of naproxen ophthalmic solution to that of placebo or diclofenac in inhibiting pre-operative miosis. Study No. 1 was a placebo-controlled study and involved 194 patients undergoing extracapsular cataract extraction. Study No. 2 was an active-controlled study (vs diclofenac) concerning 214 patients undergoing phacoemulsification. In both studies treatment started the day before surgery. A balanced salt solution containing adrenaline was used in all patients. Pupil size was measured prior to the corneal section and at the end of surgery. An aqueous humor sample was taken immediately before corneal incision in a subset of 20 patients to measure naproxen aqueous concentration.Results In both studies the pupillary diameter decreased during surgery within each treatment group in a statistically significant manner (P < 0.001). Naproxen was more effective than placebo (P < 0.01) and as effective as diclofenac in controlling pupil diameter regression during cataract. Mean concentration level of naproxen in the aqueous humor was 372.3 ng/ml.Conclusions Naproxen sodium ophthalmic solution penetrates the cornea and it is effective in maintaining intraoperative mydriasis.

Effect of ofloxacin and netilmicin on human corneal and conjunctival cells in vitro.

The purpose of this study was to compare the cytotoxic effects of the fluoroquinolone ofloxacin with that of the aminoglycoside netilmicin. Human corneal epithelial cells (HCE-T) and human conjunctival epithelial cells (Wong-Kilbourne derivative of Chang conjunctiva) were exposed to antibiotics (0.08-5.0 mg/mL) for 4 or 24 hours. Cell proliferation and viability were assessed with the MTT assay, neutral red uptake, and bromo deoxy uridine incorporation. In both cell lines, ofloxacin inhibited cell proliferation and viability. These effects were time and dose dependent. Concentrations of ofloxacin ranging from 0.4 to 2.4 mg/mL (0.04% to 0.24%) produced a 50% inhibition of proliferation and viability. In contrast, netilmicin induced no toxic effect. The differences between ofloxacin and netilmicin were highly statistically significant (p < 0.001). This finding is particularly relevant in deciding the optimal antibiotic to be applied in clinical situations in which the epithelium is compromised.

In vitro effects of fluoroquinolone and aminoglycoside antibiotics on human keratocytes.

Purpose: The purpose of this study was to assess the cytotoxic effects of the fluoquinolone ofloxacin and the aminoglycoside netilmicin on stromal human keratocytes in vitro. Methods: Cultured human keratocytes were exposed to various concentrations of ofloxacin or netilmicin (0.16-5.0 mg/mL). Both cell proliferation (MTT assay) and cell morphology (phase-contrast microscopy) were evaluated after 1, 4, 12, and 24 hours of incubation. Measurement of annexin V binding performed in association with the dye exclusion test using propidium iodide (PI) was also performed by FACS analysis after 4 hours of exposure. Results: Both antimicrobials induced dose- and time-dependent morphologic changes in keratocytes, yet the effects of netilmicin were minimal. After 24 hours of exposure, both drugs induced a dose-dependent inhibition of cell proliferation; however, ofloxacin demonstrated significantly more toxic effects than netilmicin (t test for ED50 values, P < 0.0001). Statistical differences between 2 antibiotics start at concentrations above 1.25 mg/mL (ANOVA with post-hoc test, P < 0.01). Expression of the apoptotic marker annexin V was unaffected by antibiotic exposure, whereas the uptake of the necrotic marker PI was increased by ofloxacin (5 mg/mL) but not by netilmicin (ofloxacin versus netilmicin, ANOVA, P < 0.05). Conclusions: Relative effects of aminoglycosides and fluoroquinolones on stromal keratocytes appear to be different: netilmicin was shown to be significantly less toxic than ofloxacin. This finding is particularly relevant in deciding the optimal antibiotic to be applied in clinical situations in which the epithelium is absent or compromised, as after photorefractive keratectomy, alkali burns, or ulcerative keratitis.

Insulin receptor content in tissues of normal and diabetic rats measured by radioimmunoassay

Insulin receptor (IR) content in different tissues has been quantitatively evaluated by means of steady state binding studies with radiolabeled insulin. The information provided by this approach, however, does not give a direct measurement of the receptor protein. Rather, it depends on the binding function of the IR, evaluated on the basis of curvilinear plots derived by Scatchard analysis of the experimental data. In the present report we employed a sensitive and specific radioimmunoassay (RIA) that allows a direct measurement of IR in solubilized cells or tissues. By this method we studied: a) IR distribution in several tissues of the rat, the animal model most frequently used in studies of insulin action; b) IR regulation in streptozotocin-treated, diabetic insulin deficient rats. Tissues from male Wistar rats (11 controls and 6 streptozotocin-treated diabetic animals) were homogenized, solubilized with Triton X-100 in the presence of protease inhibitors and stored at −80 C. IR content in the solubilized material was then measured by RIA. IR were detectable in all 11 tissues tested. Liver, kidney and brain neocortex had the highest IR content. (24.7±1.0, 20.5±1.1, 25.9±1.6 ng/mg protein, m ± SE, respectively). As expected, circulating insulin levels were lower in diabetic rats than in control rats. In diabetic, insulin deficient rats, liver, kidney and skeletal muscle contained more IR than in control rats (p = 0.001; p = 0.018; p = 0.003, respectively), whereas IR content in neocortex was similar in the two groups. The IR RIA may represent a useful tool for the study of IR regulation and pathophysiology. Our data provide a comparative direct measurement of IR distribution in a variety of rat tissues. IR content in diabetic rats is increased in typical target organs for insulin action, as a consequence of up-regulation due to the reduced insulin levels. This is not the case for metabolically insulin-dependent tissues, like brain.

Efficacy of Sodium Hyaluronate Eye Drops of Different Osmolarities in the Symptomatic Treatment of Dry Eye Patients

Our research program concerns the pathogenesis of bacterial corneal infection. We are studying the early events occurring when bacteria interact with the corneal surface, since it is these events that determine whether infection ensues or if the cornea can resist disease. Our long-term goals are two-fold: (1) to understand why certain factors, such as contact lens wear or preexisting trauma/disease, promote infection, and (2) to develop new approaches for prevention and therapeutics. How our research goals relate to tear film homeostasis is the subject of this paper.

Nachweis von Insulin-Rezeptoren (IR) in Ovarialkarzinomgewebe

Der Tumormarker CA-125, ein hochmolekulares Glykoprotein, hat sich als verlaslicher Parameter von Ovarialkarzinomen erwiesen.