Effects of spermine and the passive avoidance learning (PAL) following cerebral ischemia in chicks: Association with neuroprotection of pyramidal cells.

The aim of this study is to investigate the effects of spermine and the passive avoidance learning on hippocampus following transient cerebral ischemia in the chicks. The study is composed of the pure control (CG), sham (SG) and experimental groups (n=20). Experimental groups (ischemia group, IG and ischemia-spermine group, ISG) were exposed to ischemia for 20min whereas the SG was exposed to sham operation and CG group was not exposed to any operation. Passive avoidance learning (PAL) was applied to the half number of the subjects in each group. Both before and after 7days from the ischemia, operated animals were taken to PAL and then they were sacrificed. Total numbers of neurons in the hippocampus were stereologically estimated using Cresyl violet stained sections. We detected that number of neurons was increased following PAL and especially spermine treatment. According to our results, we suggested that spermine may reduce the deleterious effects of the ischemia by causing to increase in the neuronal number and so, it may be slightly supportive to the PAL.

Effects of low level electromagnetic field exposure at 2.45 GHz on rat cornea.

PURPOSE: To investigate the effects of low level electromagnetic field (low level-EMF) exposure, as frequently encountered in daily life, on the normal rat cornea using histological and stereological method. METHODS: Twenty-two adult male Wistar rats were randomly divided into two groups: Study group (n = 11) and control group (n = 11). Rats in the study group were exposed to 2.45 GHz microwave (MW) radiation (11.96 ± 0.89 V/m), 0.25 W/kg specific absorption rate (SAR) for 2 hours each day for 21 days. The corneal thickness and the anterior epithelium corneal thickness were measured using two different methods. RESULTS: Using the histological method, the mean corneal thicknesses in the control and study group were 278.9 ± 54.5 µm, and 272.4 ± 85.6 µm, respectively. There was no statistically significant difference between the groups (p > 0.05). The anterior corneal epithelium thickness was 28.1 ± 4.9 µm in the control group and 31.7 ± 5.5 µm in the study group. There were statistically differences between the groups with regard to the thickness of anterior epithelium (p < 0.05). In the measurement made by the stereological method, the percentage of the cornea occupied by anterior corneal epithelium was 15.94% in the control group and 17.9% in the study group. Despite the fact that there was a relation between increased anterior epithelial area (AEA) and radiation exposure, no statistically significant relationship in area fraction of each compartment was found between the control and study groups. CONCLUSIONS: Results of this preliminary study show that exposure to MW radiation might cause alterations in the rat cornea.

Is it really necessary to delay intranasal steroid treatment after FESS? An animal study.

OBJECTIVES: The aim of this study is to investigate the effect of early intranasal steroid administration on wound healing after sinus surgery. STUDY DESIGN: Randomized, placebo-controlled, blinded animal study. SETTING: Animal laboratory. SUBJECTS AND METHODS: Forty-two male New Zealand rabbits underwent bilateral 3-mm punch resection of the concha nasalis ventralis. The animals were divided into 3 groups: saline, late steroid, and early steroid. The saline group received saline drops, the late steroid group received saline drops for 7 days followed by intranasal mometasone furoate 50 µg/nostril/d, and the early steroid group received intranasal mometasone furoate (same dose) starting on postoperative day 1. The animals were sacrificed on postoperative days 10 and 21. Left nasal specimens were examined histopathologically with hematoxylin-eosin and matrix metalloproteinase-9 (MMP-9) stains. Right nasal specimens were examined with high-performance liquid chromatography, and hydroxyproline levels were measured as mg/g in wet tissue. RESULTS: Late steroid and early steroid groups were similar with regard to MMP-9 staining on days 10 and 21. On day 10, the early steroid group revealed significantly intense MMP-9 staining when compared with the saline group, and the late steroid and early steroid groups revealed significant fibrosis when compared with the saline group. Hydroxyproline levels were similar in all groups on day 10. The early steroid group revealed significantly higher hydroxyproline levels when compared with the late steroid group on day 21. CONCLUSION: Our findings showed that early intranasal steroid administration after sinus surgery in an animal model has no detrimental effects with regard to wound-healing parameters.

Effects of exposure to electromagnetic field (1.8/0.9 GHz) on testicular function and structure in growing rats.

The aim of our study was to evaluate the possible effects of whole-body electromagnetic field (EMF) exposure on reproduction in growing male rats. Male albino Wistar rats (2 days old) were exposed to EMF 1800 and 900 MHz for 2 h continuously per day for 90 days. Sham control was kept under similar conditions except that the field was not applied for the same period. After blood samples were collected, the animals were sacrificed 24 h after the last exposure and the tissues of interest were harvested. The mean plasma total testosterone showed similarity among the two study groups and was significantly higher than the sham control rats. The percentage of epididymal sperm motility was significantly higher in the 1800 MHz group (P<0.05). The morphologically normal spermatozoa rates were higher and the tail abnormality and total percentage abnormalities were lower in the 900 MHz group (P<0.05). Histopathologic parameters in the 1800 MHz group were significantly higher (P<0.05). In conclusion, the present study indicated that exposure to electromagnetic wave caused an increase in testosterone level, epididymal sperm motility (forward), and normal sperm morphology of rats. As a consequences, 1800 and 900 MHz EMF could be considered to be a cause of precocious puberty in growing rats.

Characterization of local immune response against lungworms in naturally infected sheep.

This study describes the immunohistochemical and histochemical phenotypes of inflammatory cells in sheep lungs infected with lungworms. A total of 20 naturally infected sheep lungs were used. Protostrongylus spp., Muellerius capillaris, Neostrongylus linearis, and Cystocaulus ocreatus were the chief organisms determined from such lesions, which were of a chronic nature. All the lungs had many developmental stages of the parasites and a similar inflammatory response, which included numerous mast cells, eosinophils, T cells, B cells, dendritic cells, and macrophages. In the bronchial and interstitial tissues, the inflammatory cells were dominated by MHCII, CD1, CD4, CD5, CD14, CD21, IgM, and CD172a positive cells, whereas CD2 and WC1 positive cells were detected less. The data provided additional evidence that subsets of inflammatory cells were included within ovine lungs infected with lungworms; however, understanding the entire immune-response process and development of resistance to lungworms in sheep remain to be clearly elucidated.