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OBJECTIVE@#To observe the expression of corticotropin-releasing factor-1 receptor in hippocampus of rats model of salicylate induced tinnitus.@*METHOD@#Twenty-four rats were randomly divided into three groups, eight for each group. For Group A and Group B, 10% salicylic sodium solution was intraperitoneal injected each day at the dose of 350 mg/kg for 21 days in Group A and 14 days in Group B. Group C received intraperitoneal injection with the same amount of saline solution each day for 14 days. ABR were tested 2 days before, and 2 hours after the first administration and after the last injection. Immunohistochemical test and Western Blot were utilized to detect the expression of CRF1R in hippocampus for each group.@*RESULT@#ABR thresholds tested 2 days before the first administration of the 3 groups showed no statistically significant difference (P > 0.05). At the time point of 2 hours after the first injection, the ABR thresholds of Group A and Group B rose by 25.90 dB SPL and 25.03 dB SPL compared with that before the administration, respectively (P 0.05). Immunohistochemical test and Western Blot revealed that the expression level of CRF1R in the hippocampus was A > B > C (P < 0.05).@*CONCLUSION@#The expression of CRF1R in the hippocampus of salicylate induced tinnitus rat increased with the injection time, illustrating that CRF1R may participate in the mechanism of tinnitus involving the limbic system.
Subject(s)
Animals , Rats , Auditory Threshold , Disease Models, Animal , Hippocampus , Metabolism , Injections, Intraperitoneal , Receptors, Corticotropin-Releasing Hormone , Metabolism , Salicylates , Tinnitus , MetabolismABSTRACT
Objective To observe the expression of the IGF-1 on the auditory cortex as well as the hippo-campus of rats which underwent longterm exposure to white noise to explore its effects for the repairment of the noise induced damage in the central nervous system.Methods 16 healthy Wistar rats were randomly grouped as chronic noise exposure group(group A)which underwent the longterm noise exposure(100 dB SPL white noise,4 hours per day for 28 days)and control group(group B).The expression of IGF-1 both on the auditory cortex and hippocampus was measured and the ABR waveforms were recorded.ResuIts Compared with the group A,the num-ber of IGF-1 positive neurons as well as the expression of IGF-1 both in the auditory cortex and the hippocampus of the group B increased(P<0.05),the ABR threshold was significantly higher(P<0.05 )after long-term noise exposure.ConcIusion Chronic noise exposure induced the changes of the IGF-1 system which may play a part in the protection for the noise-induced damage of the central nervous system.
ABSTRACT
To establish a refolding process for the protein fused with 12-peptide of hirudin and reteplase (HV12p-rPA), we developed an anion-exchange chromatography assisted method to form correct disulfide bonds. After evaluating various parameters by orthogonal experiments with Q Sepharose XL as refolding medium, we found that urea gradient, sample loading size and L-Arg concentration were three major factors to affect the refolding outcomes, and urea gradient was critical to the recovery yield. Meanwhile, enzymatic activity of the refolded protein was decreased by the increase of sample loading size, and the optimal concentration of L-Arg in the eluting buffer was 1 mol/L. Thus, a dual-gradient of urea and pH on the anion-exchange chromatography resulted in remarkable increase of specific fibrinolytic and anti-coagulative activities of the refolded protein. Compared with the dilution method for refolding HV12p-rPA, the present approach was more effective and advantageous.
Subject(s)
Chromatography, Ion Exchange , Methods , Disulfides , Chemistry , Fibrinolytic Agents , Chemistry , Hirudins , Chemistry , Protein Refolding , Recombinant Fusion Proteins , Chemistry , Recombinant Proteins , Chemistry , Tissue Plasminogen Activator , ChemistryABSTRACT
Objective: To analyze the mid long term results of prosthetic valves replacement. Methods: 2?141 patients underwent prosthetic valve replacement from 1978 to 2001, and 1?681 patients were followed up by completion of 78.5%, cumulate of 8?021.1 patient years and averages of 4.77 patient years each. The data were analyzed by multi factor regression and T test. Results: 92 patients died after operation. The 5 year and 10 year survival rates were (92.3?2.2)% and (90.1?2.7)%, respectively. The main complications were thromboembolism, valve mechanical malfunction, peri prosthetic leak, hemolysis and SBE. The heart function (NYHA) was significantly improved after valve replacement. Conclusion: The mid long term results of prosthetic valve replacement are rather satisfactory with low mortality and morbidity. Subvalvular structure preservation and tricuspid annuloplasty contribute can greatly improved heart function. Satisfactory myocardial protection during CPB is the key of successful operation.