Repeated Intraperitoneal Administration of Low-Concentration Methylcellulose Leads to Systemic Histologic Lesions Without Loss of Preclinical Phenotype.

Methylcellulose (MC; 0.5% concentration) is commonly used when evaluating investigational agents for efficacy in preclinical models of disease. When administered by the oral (PO) route, MC is considered a Food and Drug Administration "generally recognized as safe" compound. Yet, there is limited data pertaining to the tolerability and impact on model fidelity of repeated intraperitoneal administration of 0.5% MC. Chronic administration of high-concentration MC (2%-2.5%) has been used to induce anemia, splenomegaly, and lesions in multiple organ systems in several preclinical species. Histopathological findings from a diagnostic pathologic analysis of a single mouse from our laboratory with experimentally induced chronic seizures that had received repeated intraperitoneal administration of antiseizure drugs delivered in MC revealed similar widespread lesions. This study thus tested the hypothesis that chronic administration of intraperitoneal, but not PO, MC incites histologic lesions without effects on preclinical phenotype. Male CF-1 mice (n = 2-14/group) were randomized to receive either 6 weeks of twice weekly 0.5% MC or saline (intraperitoneal or PO) following induction of chronic seizures. Histology of a subset of mice revealed lesions in kidney, liver, mediastinal lymph nodes, mesentery, aorta, and choroid plexus only in intraperitoneal MC-treated mice (n = 7/7). Kindled mice that received MC PO (n = 5) or saline (intraperitoneal n = 6, PO n = 3) had no lesions. There were no effects of intraperitoneal MC treatment on body weight, appearance, seizure stability, or behavior. Nonetheless, our findings suggest that repeated intraperitoneal, but not PO, MC elicits systemic organ damage without impacting the model phenotype, which may confound interpretation of investigational drug-induced histologic lesions. SIGNIFICANCE STATEMENT: Methylcellulose (0.5% concentration) is commonly used when evaluating investigational agents for efficacy in preclinical models of disease. Herein, we demonstrate that repeated administration of 0.5% methylcellulose by the intraperitoneal, but not oral, route results in systemic inflammation and presence of foam-laden macrophages but does not impact the behavioral phenotype of a rodent model of neurological disease.

Effect on tomato plant and fruit of the application of biopolymer-oregano essential oil coatings.

BACKGROUND: Oregano essential oil (EO) was incorporated into film-forming dispersions (FFDs) based on biopolymers (chitosan and/or methylcellulose) at two different concentrations. The effect of the application of the FFDs was evaluated on tomato plants (cultivar Micro-Tom) at three different stages of development, and on pre-harvest and postharvest applications on tomato fruit. RESULTS: The application of the FFDs at '3 Leaves' stage caused phytotoxic problems, which were lethal when the EO was applied without biopolymers. Even though plant growth and development were delayed, the total biomass and the crop yield were not affected by biopolymer-EO treatments. When the FFDs were applied in the 'Fruit' stage the pre-harvest application of FFDs had no negative effects. All FFDs containing EO significantly reduced the respiration rate of tomato fruit and diminished weight loss during storage. Moreover, biopolymer-EO FFDs led to a decrease in the fungal decay of tomato fruit inoculated with Rhizopus stolonifer spores, as compared with non-treated tomato fruit and those coated with FFDs without EO. CONCLUSION: The application of biopolymer-oregano essential oil coatings has been proven to be an effective treatment to control R. stolonifer in tomato fruit. © 2016 Society of Chemical Industry.

Change in intraocular pressure within 1 week of phacoemulsification and intraocular lens implantation using Adatocel.

PURPOSE: To examine the change in intraocular pressure (IOP) within 1 week of phacoemulsification and foldable posterior chamber intraocular lens (PC IOL) implantation using Adatocel (hydroxypropyl methylcellulose 2% [HPMC]). SETTING: Department of Ophthalmology, University of Sciences, Faculty of Medicine, Pécs, Hungary. METHODS: In this prospective study, the IOP in 118 eyes of 118 patients (57 men, 61 women, mean age 68 years +/- 7.8 [SD]) with no history of glaucoma was assessed by Goldmann applanation tonometry 2 to 3, 6 to 8, and 22 to 24 hours and 1 week after uneventful phacoemulsification and PC IOL implantation. The effect of the removal of Adatocel ("partial removal" from the anterior chamber [AC] only versus "complete removal" from behind of the IOL as well), the lens type (Medicontur 601 HP versus Bausch & Lomb Hydroview), and the type of anesthesia (topical versus parabulbar) were compared. Statistical analysis was performed using the Student t test, and P< or =.05 was considered statistically significant. RESULTS: The mean preoperative IOP was 13.83 +/- 2.5 mmHg. There were no significant differences at any time in postoperative IOP measurements between the 2 IOL types and the 2 modes of anesthesia. At 2 to 3 hours, 6 to 8 hours, and 22 to 24 hours, the IOP was significantly higher in the 30 eyes in which the Adatocel was partially removed (from the AC only) than in the 88 eyes in which it was completely removed (from behind the PC IOL as well) (P< or =.05, P< or =.01, and P< or =.001, respectively). CONCLUSION: Severe postoperative IOP spikes in nonglaucomatous patients after uneventful phacoemulsification cataract surgery are rare. The type of implanted PC IOL and the mode of anesthesia had no significant effect on postoperative IOP. Total removal of the ophthalmic viscosurgical device, even when using HPMCs such as Adatocel, is necessary to prevent postoperative IOP spikes.

An animal model based on the Sprague Dawley rat for the evaluation of ototoxicity.

Various methodological approaches that can be used to detect ototoxic effects caused by the administration of various substances are presented, using the Sprague-Dawley rat as an animal model. Electrophysiological data are also presented to show how the model behaves with potentially ototoxic (hyaluronic acid) and initially inert (hydroxy-propyl-methyl-cellulose) substances.