The Association between Diabetic Retinopathy and Levels of Ischemia-Modified Albumin, Total Thiol, Total Antioxidant Capacity, and Total Oxidative Stress in Serum and Aqueous Humor.

Purpose. To investigate the oxidant and antioxidant status of patients with type 2 diabetes mellitus and nonproliferative diabetic retinopathy (DRP). Methods. Forty-four patients who had cataract surgery were enrolled in the study. We included 22 patients with DRP in one group and 22 patients in the control group. Samples of aqueous humor and serum were taken from all patients. Serum and aqueous ischemia-modified albumin (IMA), total thiol, total antioxidant capacity (TAC), and total oxidative stress (TOS) levels were compared in two groups. Results. Median serum IMA levels were 44.80 absorbance units in the DRP group and 40.15 absorbance units in the control group (P = 0.031). Median serum total thiol levels in the DRP group were significantly less than those in the control group (3051.13 and 3910.12, resp., P = 0.004). Mean TOS levels in the serum were 2.93 ± 0.19 in the DRP group and 2.61 ± 0.26 in the control group (P = 0.039). The differences in mean total thiol, TAC, and TOS levels in the aqueous humor and mean TAC levels in the serum were not statistically significant. Conclusion. IMA, total thiol, and TOS levels in the serum might be useful markers in monitoring the risk of DRP development.

In vitro amoebicidal activity of propolis on Acanthamoeba castellanii.

PURPOSE: The aim of this study was to investigate the in vitro effects of an ethanolic extract of propolis on the growth and adherence of Acanthamoeba castellanii trophozoites and cysts. METHODS: The effect of propolis with concentrations of 8.0, 6.0, 5.0, 4.0, 3.0, and 2.0 mg/mL on the proliferation of A. castellanii trophozoites, and with a concentration of 62.25, 31.25, 15.62, 7.81, 3.90, 1.95, and 0.97 mg/mL on the proliferation of A. castellanii cysts, at 1, 3, 6, 12, 24, 48, and 72 h were examined in vitro. RESULTS: After 1-72 h, incubation in concentrations between 2.0 and 6.0 mg/mL, its effect was amoebistatic; at concentrations of 8.0 mg/mL and higher, its effect was amoebicidal. After 48 h or longer incubation times at 15.62 mg/mL and at higher concentrations, the propolis extract was cysticidal. At concentrations of 1.97 mg/mL or lower, there was no observable effect at any time point. CONCLUSIONS: These findings indicate that ethanolic extract of propolis has amoebicidal, as well as cysticidal, properties for Acanthamoeba trophozoites and cysts. Propolis alone, or in combination with other amoebicidal agents, may be used in clinical practice after further investigations.

Relaxant effects of beta-adrenoceptor agonist formoterol and BRL 37344 on bovine iris sphincter and ciliary muscle.

We investigated the relaxant effect of beta2-adrenoceptor agonist formoterol and beta3-adrenoceptor agonist BRL 37344 on bovine iris sphincter and ciliary muscle and measured cAMP and cGMP levels. Iris sphincter (n = 16) and ciliary muscle (n = 16) strips were mounted in organ baths and tested for changes in isometric tension in response to formoterol and BRL 37344. Their relaxant effects on serotonin-induced contractions in the presence or absence of metoprolol, ICI 118.551 and SR 59230A (beta1-, beta2-, beta3-adrenoceptor antagonist, respectively) were investigated. Their effects on cAMP and cGMP levels in iris sphincter (n = 12) and ciliary muscle (n = 12) were evaluated. Formoterol (10(-11)-10(-5) M) and BRL 37344 (10(-10)-10(-5) M) decreased the serotonine-induced contractions in a concentration-dependent manner. Emax values of formoterol were significantly higher than those of BRL 37344 in iris sphincter and ciliary muscle, with no significant change in pD2 values. The relaxation responses by formoterol and BRL 37344 were antagonized with ICI 118.551 (10(-6) M) and SR 59230A (10(-6) M). cAMP levels of formoterol- and BRL 37344-treated tissues were significantly higher than those of the control tissues. cGMP levels of BRL 37344-treated tissues were significantly higher than those of control tissues, but this effect of BRL 37344 was less significant than its effect on cAMP levels. beta-adrenoceptor relaxation responses in bovine iris sphincter and ciliary muscle are mediated by a mixed population of beta2- and beta3-adrenoceptor subtypes, with a predominant contribution of cAMP. Potency of formoterol and BRL 37344 was similar, but efficacy of formoterol was better than BRL 37344.