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AIM: To investigate the effects of hypobaric hypoxia in plateau on tear indexes and related anatomical structures in rabbits.METHODS: A total of 18 healthy New Zealand rabbits were selected and randomly divided into plateau group and control group, with 9 rabbits(18 eyes)in each group. The plateau group was housed in the Simulated Climate Cabin for Special Environment of Northwest of China, simulating hypobaric hypoxia at an altitude of 6 000 m. The control group was housed in a clean animal room with atmospheric pressure and oxygen. Changes in the tear meniscus height and non-invasive tear break-up time were detected by using RHCT-1 corneal topographer dry eye comprehensive analysis system, changes in tear secretion was measured by Schirmer Ⅰ test, before intervention and on the 3, 7 d, 2 and 4 wk. Meanwhile, the changes in tear composition before and after intervention in the plateau environment were analyzed using Raman Spectroscopy. The histopathological changes of the lower lid conjunctiva, cornea, lacrimal gland, and Hardarian gland were observed by hematoxylin-eosin(HE)staining after 4 wk of intervention, and the expression of mucin 5AC(MUC5AC)in conjunctiva was detected by immunohistochemistry.RESULTS: Compared with the control group, Schirmer Ⅰ test, tear meniscus height, first and average non-invasive tear break-up time in the plateau group decreased significantly since 3 d, and the difference was significant with the extension of observation time(P<0.05). The above indexes increased from 2 wk. After 4 wk of intervention, the protein and lipid content of the tear composition of rabbits in the plateau group increased, and the nucleic acid content decreased compared with the pre-intervention period. Compared with the control group, rabbits in the plateau group showed thickening of corneal stromal edema, an increase in the number of conjunctival cup cells, increase in the level of expression of MUC5AC, an increase in the level of expression of MUC5AC, an atrophy and flattening of cytoplasm in lacrimal epithelial cells, an enlargement of glandular lumen, and no obvious destructive changes in the Hardarian glands.CONCLUSION: Acute plateau environment can destroy the homeostasis of rabbit ocular surface, so that the tear secretion and the tear film stability decreases, but within a certain period of time, rabbits undergo compensation with the habituation to the hypobaric hypoxia environment, which can increase the tear secretion to a certain extent and restore the tear film stability.
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Objective Recent studies have indicated that early brain injury is the leading cause of death in patients with subarachnoid hemorrhage ( SAH) .Our study investigated the role of aminoguanidine ( AG) in early brain injury after SAH . Methods Sixty-eight male SD rats were equally randomized into four groups of equal number :control, sham, SAH, and AG.The animals in the sham group were injected with isotonic saline solution , while those of the latter two groups with femoral artery blood ( FAB) and FAB+AG, respectively, into the pre-chiasmatic cistern to induce SAH. At 24 hours after modeling , all the rats were killed for HE staining , obtainment of behavioral neurological assessment ( BNA ) scores by Garcia, measurement of the apoptosis of neurons by TUNEL , and de-termination of the expressions of the iNOS and NSE proteins by West-ern blot. Results The results of HE staining showed the presence of more red blood cells in the subarachnoid cavity of the rats in the SAH group, with a significantly decreased BNA score ( 14.47 ± 0.62) as compared with those in the control (17.94 ±0.24), sham (17.59 ±0.51), and AG group (15.71 ±0.47) (P<0.05). The rate of positive cells was remarkably higher in the SAH group ([42.38 ±2.38]%) than in the control ([6.35 ±0.94]%), sham ([6.85 ±0.69]%), and AG group ([30.48 ±2.89]%) ( P<0.01), with significant differences among the latter three groups (P<0.05).The expressions of iNOS and NSE were markedly higher in the SAH group ([3.86 ±0.07] and [1.59 ±0.06]) than in the control (0 and[0.35 ±0.09]), sham ([2.96 ±0.34] and [0.38 ±0.08]), and AG group ([3.41 ±0.04] and [0.70 ±0.12]) ( P<0.05).Both the expression levels of iNOS and NSE were positively correlated with the rate of positive cells (r=0 .879 and 0.935, P<0.01). Conclusion AG can alleviate early brain injury after SAH in SD rats by improving the neuro-ethologic function , suppressing the apoptosis of neurons , and reducing the expressions of iNOS and NSE .
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Objective: To determine Vitexin, Vitexin 2″ O Rhamonside, Hyperoside, Rutin in Shanzha powder. Method: HPLC method was used. Chromatographic conditions included Hypersil C 18 colum and mobile phase consists of methanol and 1% acetic acid (30∶70). The detection wavelength was 359nm.Conclusion: This method was simple, quick and accurate for determination of the four favonoids in Shanzha Powder.