1.Effect of hyperbaric oxygen on plasma calcitonin gene-related peptide and beta-enderphin levels in rats with transient global brain ischemia
Rui CHEN ; Huifang FU ; Yanguo TAN
Chinese Journal of Tissue Engineering Research 2006;10(4):169-171
BACKGROUND: Prevention of tissue damage during early hours of cerebral ischemia has remained a major challenge in acute stroke management.Whether the application of hyperbaric oxygen (HBO) can protect cerebraltissue or not remains a question to be answered.OBJECTIVE: In cerebral ischemia-reperfusion rat model we studied the change on CGRP and β-endorphine levels and the therapeutic implication with hyperbaric oxygenation.DESIGN: A randomized controlled animal study.SETTING: Animal Research Department of Capital University of Medical Science.MATERIALS: The experiment was carried out at the Animal Research Department of the Capital University of Medical Science from December 2003 to February 2005. Sixty three healthy Sprague-Dewey female rats were randomly divided into 9 groups. There were 7 in the sham operation group. Four groups with 7 in each group received cerebral ischemia followed by reperfusion (IR) and blood sample taken at 6, 24, 48 and 96 hourrespectively. Another 4 groups (IR-HBO) with 7 in each received cerebral ischemia and reperfusion under hyperbaric oxgenation with blood sampling at 6, 24, 48 and 96 hours.INTERVENTIONS: With the exception of sham operation groups, animals in all the experimental groups were exposed to global cerebral is chemia of 20 minutes duration. Sham operation group and the IR groups remained under the normal atmospheric pressure. The HBO chamber was flushed with 100% oxygen for 5 minutes and raised the pressure in 5 minutes to a steady pressure at 0.2MPa. Rats in IR-HBO groups were put into the chamber with inhalation of 100% oxygen for 45 minutes and decompression was done for 15 minutes. The rats in HBO group were placed into the HBO chamber after 3-hour post reperfusion on the first day and this treatment was repeated for three consecutive days, always at the same time.Plasma was collected after 6 hours, 24 hours, 48 hours or 96 hours post cerebral reperfusion, respectively.MAIN OUTCOME MEASURES: The level of CGRP and β-EP in the plasma were measured by RIA (Radio-immunoassay).RESULTS: Sixty-three rats entered the final analysis. ① At 6-hour ischemia-repefusion: CGRP in HBO group was increased (64.12±18.16) ng/L and the onset time was earlier than that in IR group and the level was higher than those in IR group (32.62 ±11.72)ng/L and sham operation group (49.09±8.59)ng/L at the same time point (F=6.614, P < 0.001, P < 0.05). Β-EP level in 6-hour HBO group was slightly increased, but recovered at 24-hour, 48-hour, 96-hour HBO groups. ② At 24-hour and 48-hour ischemia-reperfusion: The plasma CGRP levels of the HBO group recover within 24-hours [(43.53±22.73)ng/L, F=0.390; (46.02±10.64)ng/L,F=0.969, P > 0.05]. ③ 96-hour ischemia-reperfusion: CGRP increase in the IR group (81.74±20.64)ng/L was higher than that in the sham operation group (49.09±8.59)ng/L and the HBO group (40.98±20.52)ng/L at the same time point (F=6.419, P < 0.01); and also obviously higher than those in 6-hour, 24-hour and 48-hour IR group (F=10.806, P < 0.01).The β-EP level at 96-hour HBO group was decreased to the lowest as compared with that in the sham operation group [(370.00±130.15)ng/L,(872.30±403.92)ng/L, F=3.691, P < 0.05].CONCLUSION: ① HBO in the early period of cerebral ischemia can reduce the onset of injury of cerebral tissue through increasing CGRP level and decreasing β-EP level; ②The more times treated by HBO, the better is its therapeutic effect.
2.Optimal time window selection in hyperbaric oxygen treatment for rat transient global cerebral ischemia on the basis of neuron-specific enolase bioactivity changes
Tianhui LIU ; Rui CHEN ; Yanguo TAN
Chinese Journal of Tissue Engineering Research 2005;9(37):140-142
BACKGROUND: The level of blood neuron-specific enolase may help predict the severity of brain damage.OBJECTIVE: To define the optimal time window of hyperbaric oxygen(HBO) treatment for brain ischemia based on the dynamical changes in plasma neuron-specific enolase bioactivity.DESIGN: Factorial design.SETTING: Department of Biochemistry and Molecular Biology of Capital University of Medical Sciences.PARTICIPANTS: The experiment was conducted in the Laboratory of the Department of Hyperbaric Oxygen, Beijing Chaoyang Hospital Affiliated to Capital University of Medical Sciences in June 2002. Totally 54 adult female SD rats were randomized into 3 groups, namely sham operation group(n=6), ischemia-reperfusion (IR) group (n=24), and HBO group (n=24), the latter 2 groups further divided into 4 groups according to the reperfusion time of 6, 24, 48 and 96 hours, with 6 rats in each subgroup.METHODS: [1] Rat models of IR was prepared by occlusion of the 4 arteries for 20 minutes followed by reperfusion for different time. [2] The rats in the sham operation received the same operation without blocking the arteries. The rats in HBO group were subjected to HBO treatment (0.2 MPa,pure oxygen for 45 minutes), which was given after a 3-hour reperfusion inthe 6-hour subgroup and scheduled once daily at the same time point in the other 3 subgroups until blood sampling. The rats in IR group and sham operation group were kept under normal pressure without additional oxygen.MAIN OUTCOME MEASURES: Blood samples were collected at the specified time points in IR and HBO groups and at 24 hours of reperfusion in the sham operation group. Enzyme-linked immunosorbent assay (ELISA)was used to determine the activity of plasma neuron-specific enolase.RESULTS: Totally 54 rats enter result analysis after supplementary.Plasma neuron-specific enolase level was significantly lower in the sham operation group (1.97±0.09) μg/L than in 6 and 96-hour subgroups in the IR group [(2.80±0.26), (2.40±0.19) μg/L, respectively, P < 0.05],and was obviously lower in 6-hour HBO subgroup than the 6-hour IR group [(2.04±0.27) μg/L, P < 0.05], which was slightly increased at 24hours after HBO treatment but the difference was of no statistical significance (P > 0.05).CONCLUSION: IR injury may lead to increment of plasma neuron-specific enolase level, which occurred at 6 and 96 hours respectively in IR group, possibly due to acute neuronal necrosis during brain ischemia and subsequent delayed neuronal apoptosis. HBO treatment promotes the recovery of neuron-specific enolase level, with 6 hours of reperfusion as the optimal therapeutic time window.
3.Research progress in role of B cell immunity in primary biliary cirrhosis
Yanguo TAN ; Huiping YAN ; Zuhua GAO
Journal of Clinical Hepatology 2014;31(5):400-404
Primary biliary cirrhosis (PBC)is characterized by injury of small intrahepatic bile ducts,but its mechanism,especially the role of B cell immunity in this disease,remains unclear.The possible role of B cell immunity in the pathogenesis of PBC is reviewed from the fol-lowing aspects:distribution of B cells and plasma cells in the liver tissues of PBC patients,clearance of B cells,mechanism of abnormal in-crease in serum IgM and its sources among PBC patients,mechanism of production of antimitochondrial antibodies and their possible func-tions in bile duct injury,and typical autoantibodies in PBC.B cell immunity is considered to play a significant role in the pathogenesis of PBC,but there are still many key problems to be clarified.
4.The application evaluation of a rapid urine microalbumin screening test
Yan ZHANG ; Yanguo TAN ; Xiawu XIE
Chinese Journal of Laboratory Medicine 2012;35(7):647-649
ObjectiveTo evaluate the clinical application value of a kind of rapid urine microalbumin( mALB )screening test.Methods Six hundred and thirteen samples for urine routine detection from Affiliated Fuxing hospital,Capital Medical University were included from December 2006 to February 2007.mALB of all urine samples was detected with H-800 automated urine analyzer based on a dry chemical qualitative screening test.To validate the screening effect of the dry chemical screening test,all of the positive samples and a part of negative samples were determined by a mALB quantitative test as confirmation by lmmage-800 automated specific protein analyzer.Comparison of mALB quantitative level between screening positive group and negative group was carried out by 2 independent samples rank sum test.Comparison between enumeration data was carried out by Kappa test for consistency.Results One hundred and fourteen positive samples out of 613 were detected by screening method ( 18.6% ).Out of the 114 positive samples by screening test,seventy-one samples were confirmed positive by quantitative test (mALB > 13.3 mg/L).Out of 76 negative sample by screening test,eight samples were confirmed positive by quantitative test.The mALB level of the screening positive group and negative group was 17.70 ( 9.19 -32.90) mg/L and 4.55(2.38-7.60) mg/L,respectively,and the mALB level of the screening positive group was much higher than that of the negative group ( Z =- 8.644,P < 0.01 ).According to the quantitative test,the sensitivity and specificity of the mALB screening method were 89.9% (71/79) and 61.3% (68/111 ),respectively.ConclusionsThe mALB rapid screening test in the research has a certain screening value.But the test method should be further perfected to improve its sensitivity for its certain omission rate.
5.Changes of brain gangliosides in rats transient global cerebral ischemia/reperfusion models after hyperbaric oxygen treatment
Yanguo TAN ; Rui CHEN ; Yanzhi HOU ; Lin SUN ; Peilan YU ; Hua LIU
Chinese Journal of Tissue Engineering Research 2006;10(16):171-174,封三
BACKGROUND: Ganglioside (Gls) is a kind of N-acetylneuraminatecontaining glycosphingolipid, which is abundant in neural tissues and exerts neuroprotective roles, and has been found its changes in content and composition pattern after cerebral ischemia or hypoxia diseases.OBJECTIVE: To investigate the effect of hyperbaric oxygen on brain gangliosides after cerebral ischemia/reperfusion and explore the possible mechanism of hyperbaric oxygen treatment to ameliorate cerebral ischemia/reperfusion damage.DESIGN: Randomized-control observation.SETTING: Department of Hyperbaric Oxygen, Chaoyang Hospital Affiliated to Capital University of Medical Sciences and Department of Biochemistry and Molecular Biology, Basic College, Capital University of Medical Sciences.MATERIALS: Animal models were established at Department of Hyperbaric Oxygen, Chaoyang Hospital Affiliated to Capital University of Medical Sciences (Key Laboratory of Beijing) from March to April 2002. All indexes were determined at the Department of Biochemistry and Molecular Biology, Basic College, Capital University of Medical Sciences. A total of 54 SD male rats were selected and randomly divided into 9 groups: shamoperated group; ischemia/reperfusion 6, 24, 48 and 96 hours group; and hyperbaric oxygen 6, 24, 48 and 96 hours group with 6 rats in each group.METHODS: Animal models with cerebral ischemic/reperfusion were established in the other 8 groups, except the sham-operation group. Global cerebral ischemia was induced by a four-vessel occlusion and reperfusion allowed after 20-minute ischemia. The rats in sham-operation group were operated in the same way except of arterial occlusion. The rats in the HBO group were placed in experimental animal chamber. After 5-minute wash by pure oxygen, the pressure of oxygen cabins was increased to 0.1 MPa in 5 minutes and kept stable for 45 minutes, then decreased to ambient level within 10 minutes. The rats in the HBO groups were treated once by hyperbaric oxygen at reperfusion 3, 24, 48 and 96 hours respectively; while the rats in the ischemia/reperfusion group and sham-operation group were placed in normal atmospheric environment. The rats of HBO and ischemia/reperfusion groups were killed by decapitation at the 6th, 24th, 48th and 96th hours respectively, and the brains removed quickly. Gls and its percentage content in each group were detected with high performance thin-layer chromatography plate.MAIN OUTCOME MEASURES: Total content of gangliosde in the whole brain tissue of rats and its percentage content.RESULTS: Totally 54 rats were involved in the result analysis without drop out. ①The contents of Gangliosides in HBO groups at 24 and 48 hours was significantly higher than those in sham-operation group and ischemia/reperfusion group at corresponding time phase (F=12.730,122.246,P < 0.01), but there was no significant difference between ischemia/reperfusion and sham-operation groups (P > 0.05). ② N-acetylneuraminosylgalactosyl-N-acetylgalactosaminyl- (N-acetylneuraminosylα2→8- N-acetylneuraminosyl) -galactosylglucosylceramide (GT1b) proportion in the ischemia/reperfusion 24 hours group was lower markedly than that in the S-O (F=13.575,P < 0.01); Both galactosyl-N-acetylgalactosaminyl- (N-acetylneuraminosyl- α2→8-N-acetylneuraminosyl) - galactosylglucosylceramide (GD1b) and galactosyl- N-acetylgalactosaminyl-(N-acetylneuraminosyl)galactosylglucosylceramide (GM1) in the reperfusion 48 hours group were lower than those in the sham-operation group (F= 4.015,3.979,P < 0.05); (N-acetylneuraminosyl)galactosylglucosylceramide (GM3)in ischemia/reperfusion 24 hours group was much higher than that in sham-operation and any other ischemia/reperfusion groups (F=21.450,P< 0.01 ); An unknown increase of GM3 was found again at the 96th hour;③GM1and GM3 proportion in the hyperbaric oxygen group was higher than that of sham-operation group at the 24th hour (F=3.970,21.450,P< 0.05, < 0.01), and all of GD1a, GD1b and GT1b were lower than that in the sham-operation group at the same times (F= 13.575,5.745,8.783, P< 0.05-0.01), but GT1b was remarkably higher than that in ischemia/reperfusion group (F=8.783 ,P < 0.05).CONCLUSION: The pattern of brain gangliosides changed after transient whole cerebral ischemia/reperfusion. The new mechanism of neuron damage after transient whole cerebral ischemia/reperfusion might be the decreasing of GT1b, GD1b and GM1 with increasing of GM3 proportion. The hyperbaric oxygen treatment could ameliorate cerebral ischemia/reperfusion damage by increasing total gangliosides content and GM1 proportion and accelerating GT1b restoration to normal level. It is unknown that the effect of percentage content of GD1a and GD1b decreased.