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Albino Guinea Pigs (albino + guinea_pigs)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

N -acetylcysteine inhibits chromium hypersensitivity in coadjuvant chromium-sensitized albino guinea pigs by suppressing the effects of reactive oxygen species

EXPERIMENTAL DERMATOLOGY, Issue 8 2010
Bour-Jr Wang
Please cite this paper as: N -acetylcysteine inhibits chromium hypersensitivity in coadjuvant chromium-sensitized albino guinea pigs by suppressing the effects of reactive oxygen species. Experimental Dermatology 2010; 19: e191,e200. Abstract Background:, Chromium hypersensitivity is an important issue in occupational skin disease. When hexavalent chromium enters the cell, it can be reduced to trivalent chromium, resulting in the formation of reactive oxygen species (ROS). ROS are considered to play an important role in the progression of allergic contact dermatitis. N -acetylcysteine (NAC) could increase glutathione levels in the skin and act as an antioxidant. Aims:, We attempted to demonstrate that NAC could inhibit chromium hypersensitivity in a coadjuvant chromium-sensitized albino guinea pig model by counteracting the formation of ROS. Methods:, We utilized a coadjuvant chromium-sensitized albino guinea pig model to evaluate both the severity of the skin reaction by intradermal and epicutaneous elicitation tests and the sensitization rate of chromium hypersensitivity in NAC-treated and NAC-untreated albino guinea pigs (GP). Furthermore, three ROS parameters, including H2O2, malondialdehyde (MDA) levels in the skin and the oxygen radical absorbance capacity (ORAC) in plasma, were analyzed in NAC-treated and NAC-untreated coadjuvant chromium-sensitized albino GP. Results:, The severity of the skin reaction in the intradermal and epicutaneous elicitation test significantly diminished when the albino GP were treated with a dose of 1200 mg/kg/day of NAC. This dose also significantly decreased the sensitization rate of chromium hypersensitivity. In addition, treatment with 1200 mg/kg/day of NAC significantly reduced the H2O2 and MDA levels in the skin and significantly increased the ORAC in the plasma of albino GP. Therefore, NAC could be a potential chemopreventative agent to prevent the progression of chromium hypersensitivity. [source]

Topical Application of Calcium Channel Blockers to Reduce the Progression of Experimentally Induced Myringosclerosis and Tympanosclerosis

THE LARYNGOSCOPE, Issue 4 2008
Adin Selcuk MD
Abstract Objectives: This study aimed to evaluate the ability of topically applied calcium channel blockers (diltiazem) to reduce the progression of experimentally induced myringosclerosis and tympanosclerosis. Study Design: Animal model. Experimental prospective study. Methods: The study included 25 adult albino guinea pigs that were bilaterally myringotomized and inoculated with a suspension of Streptococcus pneumonia type 3. The right ears were treated with topical application of diltiazem, and the untreated left ears served as the control group. Otomicroscopy and remyringotomy were conducted every week. One animal was sacrificed after 1 week and the remaining at the end of 6 weeks. Temporal bones were dissected, and tympanic bullae were analyzed with light microscopy. Results: The untreated control ears showed evidence of extensive myringosclerosis on otomicroscopy, and the ears treated with calcium channel blockers did as well although to a lesser degree. Under light microscopy, the lamina propria of both tympanic membranes and middle ear mucosae of the control group exhibited thicker (P < .1 and P < .05, respectively) and larger (P < .01 and P < .01, respectively) sclerotic tissue in comparison with the treatment group. Conclusion: The results suggest that calcium channel blockers had an influence in the prevention of tympanosclerosis. [source]

REGULATION OF FIBROGENESIS DURING THE EARLY PHASE OF COMMON BILE DUCT OBSTRUCTION

ANZ JOURNAL OF SURGERY, Issue 7 2006
Atilla Engin
Background: Both nitric oxide (NO) and prostaglandins have been proposed as inhibitor substances involved in collagen deposition in the hepatic parenchyma. The possible reciprocal connections between NO and eicosanoids in the development of liver fibrosis were investigated during the initial phase of common bile duct obstructions. Methods: A total of 30 male albino guinea pigs were randomly and equally assigned to three groups. Group 1 underwent sham laparotomy. Group 2 and group 3 were subjected to permanent common bile duct ligature for 24 and 72 h , respectively. Changes in the liver prostaglandin E2 (PGE2), leukotriene C4, malondialdehyde contents and plasma nitrite plus nitrate concentrations were measured. To evaluate the extent of hepatic fibrosis, histological assessment of liver was confirmed with the equivalent hydroxyproline contents of liver. Results: Twenty-four hours after ligature, the amount of malondialdehyde and PGE2 and plasma nitrite plus nitrate concentrations increased significantly, whereas liver hydroxyproline contents did not change. However, 72 h after ligature (Group 3), lipid peroxidation and collagen deposition were significantly higher than that of the group 2 animals. The PGE2 : leukotriene C4 ratio peaked at 24 h and later decreased, whereas PGE2 : NO ratio remained unchanged in both group 2 and group 3 animals. Conclusions: The initiation of collagen synthesis occurred in portal tract as early as within the first 72 h of bile duct obstruction. The optimum function of reactive oxygen species on the stellate cell activation might be determined by the interaction between NO and PGE2. [source]