Aqueous nicotine solutions:PH-measurements and salting-out effects - Analysis of the effective Gibbs energies of hydration and ionic strengths of the solutions

This work is a continuation of previous studies on phase demixing - salting-out effects - in aqueous nicotine solutions. Thus, pH measurements were performed, allowing a brief analysis of the existing hydrogen bond interactions. Salting-out effects - the related experimental cloud point shifts - provoked by the addition of two inorganic salts, potassium nitrate and sodium sulfate, which have not hitherto been studied, were determined. Analysis of the current and previously reported salting-out/or salting-in phenomena in nicotine aqueous solutions was performed. In this respect, five studied salts were included: four inorganic salts (sodium chloride, potassium nitrate, sodium sulfate and trisodium phosphate (Na3PO4)), and ionic the liquid 1-ethyl-3-methylimidazolium ethyl sulfate ([C2mim][EtSO4], commercial name ECOENG212®). Based on pH measurements, the effective Gibbs energies of hydration and the ionic strengths of the respective ternary solutions were calculated and plotted against the related cloud-point shifts caused by the addition of the salts. For the studied salts, the results and diagram obtained within this work may be used to predict the cloud-points shifts, based on the related quantities of the salts added and/or the molar Gibbs energies of hydration and/or ionic strengths requested in each case

Laser-induced mouse model of chronic ocular hypertension

PURPOSE. To develop an inducible mouse model of glaucoma. METHODS. An obstruction of aqueous humor outflow in adult C57BL6/J mice was induced by combined injection of indocyanine green (ICG) dye into the anterior chamber and diode laser treatment. To evaluate intraocular pressure (IOP), tonometry was performed with a modified Goldmann tonometer. The function of the retina was evaluated with electroretinography (ERG). RESULTS. IOP was significantly elevated in surgical eyes compared with control eyes: before surgery, 15.2 Ϯ 0.6 mm Hg; 10 days after surgery, 33.6 Ϯ 1.5 mm Hg (P Ͻ 0.001); and 30 days after surgery, 27.4 Ϯ 1.2 mm Hg (P Ͻ 0.001). However, 60 days after surgery, IOP in the surgical eyes decreased to 19.5 Ϯ 0.9 mm Hg and was not significantly different compared with control eyes (control, 17.3 Ϯ 0.7 mm Hg; P ϭ 0.053). ERG amplitudes, expressed as a ratio (surgical/control), were decreased in surgical eyes. The amplitudes for b-wave were: before surgery, 107.6% Ϯ 4.6%; 28 days after surgery, 61% Ϯ 4% (P Ͻ 0.001); and 56 days after surgery, 62% Ϯ 5.6% (P Ͻ 0.001). Oscillatory potentials were the most dramatically affected: before surgery, 108.6% Ϯ 6.7%; 28 days after surgery, 57.5% Ϯ 5% (P Ͻ 0.01); and 56 days after surgery, 57% Ϯ 8.5% (P Ͻ 0.001). Amplitudes of the a-waves had relatively smaller but still significant deficits: before surgery, 105.8% Ϯ 6.9%; 28 days after surgery, 72.2% Ϯ 5.4% (P Ͻ 0.01); and 56 days after surgery, 79.8% Ϯ 11.0% (P Ͻ 0.01). Histologic analysis of the surgical eyes revealed development of anterior synechia, loss of retinal ganglion cells (RGCs), and thinning of all retinal layers. Electron microscopy of optic nerve cross sections revealed swelling and degeneration of the large diameter axons and gliosis. CONCLUSIONS. Diode laser treatment of ICG saturated episcleral veins causes a chronic elevation of IOP and sustained ERG deficits. (Invest Ophthalmol Vis Sci. 2003;44:4337-4346

Topical ocular sodium 4-phenylbutyrate rescues glaucoma in a myocilin mouse model of primary open-angle glaucoma

PURPOSE. Mutations in the myocilin gene (MYOC) are the most common known genetic cause of primary open-angle glaucoma (POAG). The purpose of this study was to determine whether topical ocular sodium 4-phenylbutyrate (PBA) treatment rescues glaucoma phenotypes in a mouse model of myocilin-associated glaucoma (Tg-MYOC Y437H mice). METHODS. Tg-MYOC Y437H mice were treated with PBA eye drops (n ϭ 10) or sterile PBS (n ϭ 8) twice daily for 5 months. Long-term safety and effectiveness of topical PBA (0.2%) on glaucoma phenotypes were examined by measuring intraocular pressure (IOP) and pattern ERG (PERG), performing slit lamp evaluation of the anterior chamber, analyzing histologic sections of the anterior segment, and comparing myocilin levels in the aqueous humor and trabecular meshwork of Tg-MYOC Y437H mice. Sci. 2012;53: 1557-1565 RESULTS. Tg-MYO

Solutions of ionic liquids with diverse aliphatic and aromatic solutes – Phase behavior and potentials for applications:A review article

This article principally reviews our research related to liquid–liquid and solid–liquid phase behavior of imidazolium- and phosphonium-based ionic liquids, mainly having bistriflamide ([NTf2]−) or triflate ([OTf]−) anions, with several aliphatic and aromatic solutes (target molecules). The latter include: (i) diols and triols: 1,2-propanediol, 1,3-propanediol and glycerol; (ii) polymer poly(ethylene glycol) (PEG): average molecular mass 200, 400 and 2050 – PEG200 (liquid), PEG400 (liquid) and PEG2050 (solid), respectively; (iii) polar aromatic compounds: nicotine, aniline, phenolic acids (vanillic, ferulic and caffeic acid,), thymol and caffeine and (iv) non-polar aromatic compounds (benzene, toluene, p-xylene). In these studies, the effects of the cation and anion, cation alkyl chain and PEG chain lengths on the observed phase behaviors were scrutinized. Thus, one of the major observations is that the anion – bistriflamide/triflate – selection usually had strong, sometimes really remarkable effects on the solvent abilities of the studied ionic liquids. Namely, in the case of the hydrogen-bonding solutes, the ionic liquids with the triflate anion generally exhibited substantially higher solubility than those having the bistriflamide anion. Nevertheless, with the aromatic compounds the situation was the opposite – in most of the cases it was the bistriflamide anion that favoured solubility. Moreover, our other studies confirmed the ability of PEG to dissolve both polar and non-polar aromatic compounds. Therefore, two general possibilities of application of alternative, environmentally acceptable, solvents of tuneable solvent properties appeared. One is to use homogeneous mixtures of two ionic liquids having [NTf2]− and [OTf]− anions as mixed solvents. The other, however, envisages the application of homogeneous and heterogeneous (PEG + ionic liquid) solutions as tuneable solvents for aromatic solutes. Such mixed solvents have potential applications in separation of the aforesaid target molecules from their aqueous solutions or in extraction from original matrices. From the fundamental point of view the phase equilibrium studies reviewed herein and the diversity of the pure compounds – ionic liquids and target molecules – represent a good base for the discussion of interactions between the molecules that exist in the studied solutions

2003b. Functional characterization of retina and optic nerve after acute ocular ischemia in rats

PURPOSE. To functionally characterize the status of the rat retina and optic nerve after acute elevation of intraocular pressure (IOP) and to determine the dynamics of the pathologic changes in the ischemic retina and optic nerve. METHODS. Retinal ischemia was induced in rats by acutely increasing the IOP (110 mm Hg/60 minutes). Direct and indirect pupil light reflexes (PLRs) were recorded from the noninjured eye, and electroretinograms (flash and flicker ERG) were recorded from the injured and control eyes before and after surgery. Amplitudes and latencies were calculated for each recording session. RESULTS. Preoperative PLR ratio s (indirect/direct PLR) were 76.7 Ϯ 2.6 (mean Ϯ SEM). Twenty-four hours after surgery the PLR ratio was 15.2 Ϯ 12.8, 10 days after surgery, 11.6 Ϯ 9.8; 20 days after surgery, 26.5 Ϯ 8.0; and 28 days after surgery, 33.27 Ϯ 9.3. However, at day 35, the PLR had significantly recovered (41.1 Ϯ 7.3) when compared with the 24-hour postoperative ratios (P Ͻ 0.01, repeated-measures ANOVA). Forty-two days after surgery, the PLR ratio started to decrease once again in the injured eyes (28.7 Ϯ 5.9). Electroretinographic amplitudes (full-field flash ERG) followed a similar pattern. Cone responses (flicker ERG) were measured 42 days after surgery and revealed defects in injured eyes (control eyes: 46.6 Ϯ 2.9 V, injured eyes: 3.4 Ϯ 1.7 V). Histologic analysis revealed ischemic damage to all retinal layers, with the primary defects localized to the central retina. CONCLUSIONS. Acute ocular ischemia causes a significant decrease in retinal function, as measured by PLR and ERG, although over time the rat retina and optic nerve show partial regain of function. (Invest Ophthalmol Vis Sci. 2003;44: 2597-2605) DOI:10.1167/iovs.02-0600 I schemic insults to the retina and optic nerve are frequently observed in glaucoma, acute ocular hypertension, diabetic retinopathy, hypertension, and vascular occlusion, and giant cell arteritis and can lead to serious perturbation of neuronal and glial retinal elements and can ultimately lead to blindness. Traditionally, retinal damage due to ischemia has been considered a potentially incurable condition in humans and animals because of the mammalian central nervous system has no regenerative capacity. Few reports have described the recovery of visual function in patients who have severe retinal ischemia after central retinal artery occlusion, 1,2 whereas more reports have confirmed that severe ischemic events are followed by almost complete and irreversible loss of visual function. 10,11 However, quantitative analysis of the damage has been achieved only by end-stage counting of the cells in the different retinal layers 12 or retrograde fluorescent labeling of retinal ganglion cells (RGCs). 13 Relatively few studies have included a functional analysis of the retina after ischemia-reperfusion injury using electroretinography (ERG) for a prolonged period, 14 -16 and, to our knowledge, there is only one published study that actually documents function of the retina and optic nerve in rats after ischemia-reperfusion injury (Clarke RJ, Gamlin PDR, ARVO Abstract 4593, 1998). Although morphologic studies provide important information about the number of surviving cells, only electrophysiological studies offer precise information about the functional status of the retina and the dynamics of ischemic injury. MATERIALS AND METHODS Induction of Retinal Ischemia by Elevated IOP All animal studies were conducted in accordance with the ARVO Statement for Use of Animals in Ophthalmic and Vision Research, and procedures were approved by the Iowa State University Committee on Animal Care. A previously published procedure to generate an ischemia-reperfusion insult in rats was used, with slight modification

Antiproliferative effects of Tanaceti partheni, Hypericum perforatum and propolis on HeLa cells

Tanaceti partheni, Hypericum perforatum and propolis have been widely used for centuries and are well-documented medicinal plants and natural product. In this study, we investigated the antiproliferative effects of water extracts of ethanolic dry extracts of two different medicinal plants (Tanaceti partheni and Hypericum perforatum) and propolis on HeLa cells. The Tanaceti partheni extract exhibited mild cytotoxic activity. The IC50 was 153.71 μg/mL. The extract of Hypericum perforatum did not show active cytotoxic activity against HeLa cells (IC50 >200 μg/mL). Regarding the antiproliferative effects of Hypericum perforatum, our results are not in correlation with the results of other authors, probably because different Hypericum species and different human cancer cell lines were used. The extract of propolis did not show active cytotoxic activity against HeLa cells (IC50 = 1.08 ± 0.01 mg/mL). The weak antiproliferative effect of propolis on HeLa cells is either due to the use of a low concentration of propolis extracted in weakly polar solvents, or the use of propolis collected in the autumn. [Projekat Ministarstva nauke Republike Srbije, br. 34021 i br. 175011