The Efficacy and Safety of Jitongning Capsule in Patients with Ankylosing Spondylitis

• 98 •Chin J Integr Med 2013 Feb;19(2):98-103ORIGINAL ARTICLEThe Efficacy and Safety of Jitongning Capsule (脊痛宁胶囊) in Patients with Ankylosing SpondylitisWANG Yan-yan (王炎焱), LU Hui (路 辉), ZHAO Zheng (赵 征), and HUANG Feng (黄 烽)ABSTRACT Objective: To confirm the efficacy and safety of Jitongning Capsule (脊痛宁胶囊) in the treatment of ankylosing spondylitis (AS)1 Methods: A total of 120 AS patients with early-intermediate were randomly and equally assigned to Jitongning Capsule group and sulfasalazine group1 Jitongning Capsule was orally taken 415 g per day and sulfasalazine was orally taken 2 g daily for 12 months1 The primary endpoint was the proportion of patients achieving the Assessment in Ankylosing Spondylitis 20 (ASAS 20), secondary end points included Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), patient's global assessment by VAS rating, spinal pain, general pain and night pain, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)1 Tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and interleukin-4 (IL-4) in the peripheral blood mononuclear cells (PBMC) of AS patients were measured1 Results: A total of 111 patients completed the study1 There were 58 patients in Jitongning group and 53 patients in sulfasalazine group1 Both drugs showed mild and occasional side effects1 After treated by Jitongning Capsule and sulfasalazine, the proportion of ASAS20 responders at 12 month was 72141% (42/58) and 67192% (36/53) respectively1 Both Jitongning Capsule and sulfasalazine treatment induced significant decrease in the proportion of CD4+T cell and CD8+T cell expressing TNF-α and IFN-γ at 12-month of treatment compared with baseline values (P <0105)1 Conclusion: Jitongning Capsule are effective in a setting close to real-life medical care with a sustained improvement in signs and symptoms of AS, and reduce cytokine levels in PBMC1 It showed comparable effects to sulfasalazine1 KEYWORDS ankylosing spondylitis, Jitongning Capsule, sulfasalazine, cytokineAnkylosing spondylitis (AS) is a chronic inflammatory disease mainly with sacroiliac joints and spine involvement1 It can also lead to extraarticular lesion including the eye, bowel, and heart1 AS is common in young populations characterized by stiffening of spine1 Among these patients, 2/3 will progress into partial or full stiffening of spine several years after onset1(1) The incidence of AS is about 013% in China1 Up to now, the treatment options for AS were limited to routine physical therapy and non-steroidal anti-inflammatory drugs (NSAIDs)1 Corticosteroids, which are quite effective in rheumatoid arthritis (RA), show only very marginal efficacy in AS1 At present, clinically used sulfasalazine, methotrexate (MTX) and leflunomide could effectively treat peripheral arthritis of AS, but failed in axial diseases1 The adverse effects of these drugs included injuries of liver and kidney, decrease of sperm, and even infertility1 Thalidomide showed good efficacy for axial AS, but had serious clinical side effects, such as fetus malformation1 Therefore, it was prohibited in female patients of child-bearing age1 In recent years, many tumor necrosis factor (TNF) inhibitors (infliximab, etanercept,adalimumab) have been available in market for their satisfied clinical efficacy1 (2) However, they are much expensive1 Moreover, these drugs can increase the risks of infection (even tuberculosis infection), lymphadenoma and solid tumor1 Therefore, some patients of child-bearing age are unwilling to take these drugs due to their adverse reactions, which results in a delay in treatment1 The development of drug for these patients is thus required1 Jitongning Capsule (脊痛宁胶囊) is a Chinese patent medicine for the treatment of AS1 It can nourish the Liver (Gan) and Kidney (Shen), expel wind-evil and remove wetness, and activate blood and resolve stasis1 Jitongning Capsule has been used clinically©The Chinese Journal of Integrated Traditional and Western Medicine Press and Springer-Verlag Berlin Heidelberg 2012 11 Department of Rheumatology, Chinese PLA General Hospital, Beijing (100853), China; 21 Department of Nephrology, First Hospital Affiliated to General Hospital of PLA, Beijing (100048), China Correspondence to: Dr1 HUANG Feng, Tel: 86-10-55499013, E-mail: fhuang@301hospital1com1cn DOI: 1011007/s11655-012-121-xChin J Integr Med 2013 Feb;19(2):98-103• 99 •to treat early-intermediate AS1 The aim of the present study was to observe the therapeutic effect of the Jitongning Capsule in patients with AS, and determine its effect on cytokines, in order to provide proof for clinical application of this drug1METHODSInclusion CriteriaOne hundred and twenty eligible patients were 16 years of age or older and had AS that was diagnosed according to the modified New York classification criteria X-ray examination showed sacroiliitis level was below Ⅲ1(3) They all had partial stiffening of spine and did not receive sulfasalazine, MTX, Tripterygium wilfordii, Zhengqing Fengtongning (正清风痛宁) and steroid hormones at least one month before entering the study1and Technology Center of PLA General Hospital, 015 g/capsule) was orally administrated at dose of three capsules for each time and three times daily for 12 months1 All other drugs used by the patients were withdrawn at least one month before receive Jitongning Capsule1 NSAIDs being used were replaced by diclofenac sodium sustained release capsules (trade name: Yingtaiqing, Nantong huashan Pharmaceuticals, China, 50 mg/capsule)1 The dosage of sulfasalazine tablet (Shanghai Sunve Pharmaceuticals, 0125 g/tablet) was 110 g, twice one day, for 12 months1 The dosage of Diclofenac sodium was chosen depending on the diseases1ReagentCy-chrome-labeled anti CD3 monoclonal antibody (mouse anti-human IgG2a, k; HIT3a clone, PE-labeled anti CD8 monoclonal antibody (mouse anti-human IgG1k, RPA-T8 clone), FITC-labeled mouse IgG1, k isotype control immunoglobulin (MOPC-21clone), FITC-labeled anti interferon-γ (INF-γ) monoclonal antibody (mouse IgG1; 4S1B3 clone), FITC-labeled anti interleukin-4 (IL-4) monoclonal antibody (mouse IgG1, MP4-25D2 clone), FITC-labeled anti TNF-α monoclonal antibody (mouse IgG1; Mab11 clone) were all purchased from PharMingaen Company (USA)1Exclusion CriteriaPregnant and nursing women or women planning a pregnancy; Current symptoms of severe, progressive or uncontrolled renal, hepatic, haematologic, gastrointestinal, endocrine, pulmonary, cardiologic, neurologic or cerebral disease; Laboratory exclusions: haemoglobin level <815 mg/dL, white blood cell count <315×10 9 /L, platelet count <100×10 9/L; Creatinine level >150 µmol/L, liver enzymes >115 times the upper limit of normal or alkaline phosphatase more twice the upper limit of normal1Detection of Intracellular Cytokine by Flow CytometryFifteen patients from Jitongning group, 15 patients from sulfasalazine and 15 health subjects from age- and sex-paired normal control group were randomly selected1 IL-4, TNF-α and IFN-γ from CD3+CD8– T and CD3+CD8+ T cells were detected by triad colour flow cytometry at baseline and 12-month visit, respectively1PatientsThis study was conducted from November 2003 to January 20061 Briefly, eligible subjects aging 20–80 years old who fulfilled modified New York classification criteria in the Outpatient Department of Rheumatology Chinese PLA General Hospital were consecutively invited and considered to participate in this trial1 This study was approved by the Institutional Review Board of Chinese PLA General Hospital1 All patients provided written informed consent before enrollment1Efficacy AssessmentThe primary efficacy end point was the Assessment in Ankylosing Spondylitis 20 (ASAS20)1 Secondary efficacy end points included the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), (4) and general pain, spinal pain, patient's global assessment and night pain by VAS (0–10 mm)1 The responsiveness was defined as an improvement of 20% of at lease three among four indices of patients' global assessment (VAS), spinalGroup and TreatmentThe total of 120 subjects were randomly and equally assigned to Jitongning Capsule or sulfasalazine group following simple randomization procedures (computerized random numbers)1 Jitongning Capsule (consisted of Cortex Eucommiae , Radix Angelicae pubescentis , Radix Aconili , Rhizoma Corydalis , Radix Puerariae , Radix Paeoniae ruba , and Radix Glycyrrhizae ; manufactured by Science• 100 •Chin J Integr Med 2013 Feb;19(2):98-103pain (VAS), BASFI, BASDAI (the latter two items concerns morning stiffness and duration) and an improvement of at least 1 point relative to baseline on 0–10 mm scale1 Physical examination, blood and urine tests, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) measurement were performed at each visit1 All clinical evaluations were carried out by the same investigator1Twenty-three patients used to take sulfasalazine, and 8 took MTX once1 In sulfasalazine group, there were 60 patients, with 48 males and 12 females1 Fifty-seven patients had positive HLA-B27 and the remaining had negative HLA-B271 The mean age was 29150±6185 years (range: 22–60)1 The disease course ranged from 4 months to 12 years (averaged 4183±3125 years)1 Forty-four had spine involvement, among which 6 were accompanied by hip joint involvement1 Twenty had combined central axis and peripheral joints involvement1 Iritis was detected in 8 patients at the beginning of AS onset1 No complicated psoriasis, Crohn's disease and ulcerative colitis were found1 All patients used NSAIDs at least once1 Nine patients continuously took NSAID at fixed-dose during the treatment with sulfasalazine1 Eighteen patients took sulfasalazine and 5 took MTX once1 Two patients were falling off in Jitongning group and 7 patients were falling off in sulfasalazine group1Statistical AnalysisVariance test was used to compare the percentage of patients with improvement at different treatment periods1 Statistical significance was assumed at P <01051 All data were analyzed using SPSS version 1110 software for Windows1RESULTGeneral InformationEfficacy assessment was carried out at 0, 6, and 12 months of treatment1 Two out of Jitongning group and 7 out of sulfasalazine group withdrew from the study due to poor response and fear of side effects1 There were no differences between two groups1 Followup visit was planned at 6 and 12 months of treatment1 After 12 months, the drugs were withdrawn1 Jitongning group contained 60 patients, male 48 and female 121 Fifty-six patients had positive HLA-B27, and the remaining had negative HLA-B271 The mean age of these patients was 27150±8120 years (range: 16–62)1 The disease course ranged from 3 months to 14 years (averaged 5101±3156 years)1 Forty-seven patients had spine involvement, among which 8 were accompanied by hip joint involvement1 Eighteen had combined central axis and peripheral joints involvement1 Iritis was found in 10 patients at the beginning of AS onset1 No complicated psoriasis, Crohn's disease and ulcerative colitis were observed1 All patients used NSAIDs once1 Nine patients continuously used to take NSAID at fixeddose during the treatment with Jitongning Capsule1Assessment of Primary Endpoint OutcomesFifty-eight patients in the Jitongning group and 53 patients in the sulfasalazine group who completed the 1-year study1 In the Jitongning group, scores of BASDAI, BASFI, BASMI, spine pain, night pain and general pain were significantly improved (P <0105) both at 6 and 12 months of treatment compared with baseline values1 The scores of BASMI in Jitongning group were significantly improved at 12 months compared with baseline values (P <0105)1 In sulfasalazine group, scores of BASDAI, spine pain, night pain and general pain were significantly improved (P <0105) both at 6 and 12 months of treatment, the score of BASFI was significantly improved at 6 month, but there was no statistical difference at 12 month and there was no statistical difference in BASMI compared with baseline values1 There was no significant difference betweenTable 1. Changes of Primary Endpoints of AS Patients Relative to Baseline (Score, ±s )Group Jitongning Case 58 Time 0-month 6-month 12-month Sulfasalazine 53 0-month 6-month 12-month BASDAI 3153±1165 2130±1123 2103±1115 3176±1128 2173±1134 2119±1150 BASFI 1150±1123 0171±0178 0176±1107 1174±2101 0171±1135 0191±1139 BASMI 1159±1140 1115±1148 0181±1113 1187±1164 1155±1184 1130±1171 Patients' global Spinal pain assessment 4175±1153 3186±2104 2181±1135 2172±1158 5138±1135 4100±2122 3125±2122 2133±1157 2154±1190 4156±2132 3105±2101 2180±2111 General pain 3167±2135 1187±1153 1142±1175 4123±2127 3140±2134 2150±1182 Night pain 3197±2108 2109±1170 0198±1166 4102±2116 2165±2139 1180±2109Notes: P <0105, P <0101, compared with the same group at 0 monthChin J Integr Med 2013 Feb;19(2):98-103• 101 •two groups at 6 and 12 months1Lab ExaminationLevels of ESR and CRP in both Jitongning and sulfasalazine groups were obviously decreased relative to baseline values1 At 12 month, ESR in Jitongning group was significantly decreased compared with index at 0 month, but have no similar in CRP1 At 12 month, CRP and ESR in sulfasalazine group were significantly decreased compared with index at 0 month (Table 2)1Table 2.Group Jitongning(56160%) in sulfasalazine group achieving ASAS20 response at 6-month and 36 (67192%) in sulfasalazine group achieving ASAS20 response at 12-month1 There was no significant difference between the two groups1Detection of IL-4, TNF-α and IFN-γ Secreted by CD4+T Cell and CD8+T Cell in Peripheral Blood of AS Patients at BaselineTo observe the change of CD3+/CD8–(CD4) and CD3+/CD8+(CD8) T lymphocyte subsets by three colour flow cytometry, the results are as follows (Figure 1)1Changes of ESR and CRP of AS Patients Relative to Baseline ( ±s )Case 58 Time 0-month 6-month ESR (mm/h) 23174±21179 18151±19144 21147±21189 13190±20127 CRP (mg/dL) 1111±1159 1102±1124 0157±0142 1148±2156 0192±1107 0151±013612-month 15172±14156 Sulfasalazine 53 0-month 6-month12-month 12132±18130Note: P <0105, compared with the same group at 0 monthResponse to TreatmentBased on an observed analysis among patients with 6 or 12 months exposure, 38 cases (65151%) in Jitongning group achieving ASAS20 response at 6-month and 42 cases (72141%) in Jitongning group achieving ASAS20 response at 12-month1 Thirty cases1000TNF-α, IFN-γ and IL-4 were secreted by CD4+ or CD8+ T cell1 The proportion of CD4+ and CD8+ cells expressing TNF-α and IFN-γ both decreased in peripheral bloods of patients at baseline of Jitongning and sulfasalazine groups compared with normal control1 There was statistical difference in proportion of CD4+T cells expressing TNF-α and IFN-γ between treatment groups and normal control group (P <0105)1 No significant difference in percentage of CD4+T and CD8+T cells expressing IL-4 was observed between AS patients and normal populations (Figure 2)1Effects on Proportion of CD4+ T Cells Expressing IL-4, TNF-α and IFN-γJitongning and sulfasalazine treatments both resulted in significant decrease in the proportion800 1000 200 400 600AData1001BSSC-H800200400SSC-H600R2 100 101 E 1000 102 FL2-H 103 104R1 0 0 200 400 FSC-H 600 D 800 1000 1000 0 800C8001000600600SSC-HSSC-HSSC-H R5 101 102 FL1-H 103 104400400200R4 100 101 102 FL2-HR3 103 104200200400600800R6 100 101 102 FL1-H 103 1040Notes: A: lymphocytes; B: CD3+ lymphocyte; C: CD4+ and CD8+ lymphocytes stained with CD8–PE; D: intracellular cytokines produced by CD4+; E: intracellular cytokines produced by CD8+Figure 1. Detection of Cytokines Produced by CD4+ and CD8+ Cells in Peripheral Blood of AS Patients by Three Color Flow Cytometry01000• 102 •Chin J Integr Med 2013 Feb;19(2):98-103Jitongning Sulfasalazine Healthy control6050 40 30 20 10 0IL-4TNF-α CD4+IFN-γIL-4TNF-α CD8+IFN-γFigure 2. Comparison of Proportion of CD4+T and CD8+T Cells Expressing IL-4, TNF-α and IFN-γ in Peripheral Blood in Subjects among Three GroupsNote: P <0105, compare with the healthy control groupof CD4 +T cells expressing TNF-α and IFN-γ at 12-month of treatment relative to baseline values (P <0105, Table 3)1Table 3. Changes of Proportion of CD4+T Cell Expressing IL-4, TNF-α and IFN-γ in Peripheral Blood of AS Patients in Two Groups ( ±s )Group Jitongning Case 15 Time CD4 T cell (%) IL-4 TNF-α IFN-γ+of treatment, and no one stopped for side effects1 The major side effects were slight dizziness in 3 cases, rash in 1 and back hot in 11 Two of above symptoms spontaneously resolved after another 1 week of treatment1 A slight increase of liver enzymes (less than 2-fold of normal value) was observed in one patient, which returned to normality after hepatoprotective treatment for one week1 In sulfasalazine group, no patients withdrew from the study because of adverse effects1 However, 7 cases quitted for poor response and fear of side effects1 The major side effects included rash in 2 and vulvar ulcer in 1, both of which spontaneously regressed after another 1 week of therapy1 Three patients had a mild increase of liver enzymes (less than 2-fold of normal value)1 Values returned to normality after one week of hepatoprotective treatment1Percentage of cell populationDISCUSSIONIn this study, we investigated the effectiveness of Jitongning Capsule to treat ankylosing spondylitis1 Jitongning Capsule, with the main ingredients of eucommia ulmoides oliv, radix aconiti preparata, and heracleum etc1, is a Chinese patent medicine developed by our hospital for the treatment of AS with symptoms of Kidney (Shen) deficiency, cold dampness and blood stasis1 It could nourish the Liver (Gan) and Kidney, expel wind-evil and remove wetness, and activate blood and resolve stasis1 We evaluated the effects of Jitongning Capsule on inflammatory reaction, efficacy data (ASAS20 and changes in BASDAI, BASFI, spine pain, general pain, patients' global assessment and night pain) are also presented by actual treatment received Jitongning capsule and sulfasalazine1 ESR and CRP of AS patients by comparing with sulfasalazine, a commonly clinically used drug for the treatment of AS1 Jitongning Capsule has been shown to be effective for improving the signs and symptoms of early-intermediate AS1 At 12-month of treatment, indeics of BASDAI, BADFI, BASMI, spine pain, general pain, patients' global assessment at night pain were all significantly improved relative to baseline values1 ESR and CRP levels were both decreased, either1 Sulfasalazine group has been shown to be effective for improving the sign and symptoms too1 At 12-month of treatment, indexes of BASDAI, spine pain, general pain, patients' global assessment at night pain were all significantly improved relative to baseline values1 ESR and CRP0-month 1126±0181 17169±6174 15150±8158 12-month 1120±1109 13118±4169 10110±5145Sulfasalazine150-month 1131±0173 16174±9152 15136±6195 12-month 1114±0182 10104±3104 10114±3143Note: P <0105, compared with 0 monthEffects on Proportion of CD8+ T Cell Expressing IL-4, TNF-α and IFN-γBoth Jitongning and sulfasalazine treatment induced significant decrease in the proportion of CD8+T cell expressing TNF-α and IFN-γ at 12-month of treatment compared with baseline values (P <0105, Table 4)1Table 4. Changes of Proportion of CD8+ T Cell Expressing IL-4, TNF-α and IFN-γ in Peripheral Blood of AS Patients in Two Groups ( ±s )Group Jitongning Case 15 Time CD8+T cell (%) IL-4 TNF-α IFN-γ0-month 1117±0156 21103±10197 28100±9125 12-month 1113±0188 13145±8137 19124±13129Sulfasalazine 150-month 1100±0168 21119±10122 28164±11151 12-month 1128±1109 13116±5142 19103±8108Note: P <0105 compared with 0 monthAdverse ReactionsTwo patients withdrew from the study of Jitongning group for poor response after 1-monthChin J Integr Med 2013 Feb;19(2):98-103• 103 •levels were both decreased1 But the indices of BASFI and BASMI have no statistical difference compared with baseline value1 No statistical difference in all these indicators was observed between Jitongning group and sulfasalazine group1 In this study, we observed the change of intracellular cytokines IFN-γ, TNF-α and IL-41 Research indicated that Th1 cells predominated among peripheral blood lymphocyte of AS patients, IFN-γ and TNF-α are main secreted by Th1 cell1(5-8) TNF-α has been shown to play an important role in the inflammatory response observed in AS1 It has been found at increased levels in the serum and synovium of patients with AS1(9,10) In the AS patients, that have increased expression by CD4+ T cells of IFN-γ in 5516% of patients and of TNF-α in 5218% of patients1 In the controls, only 3614% of subjects demonstrated an IFN-γ response and 3614% demonstrated TNFαresponse1 With respect to CD8+ T-cell responses, versican stimulation enhanced IFN-γexpression in 4414% of AS patients and 3914% of controls, and enhanced TNF-αresponse in 5010% of AS patients and 3914% of controls1(11) Our study showed that TNF-α, IFN-γ and IL-4 were secreted by CD4+ or CD8+ T cell1 Th1 and Tc1 were represented by the cell group of IFN-γ, Th2 and Tc2 were represented by the cell group of IL-41 There were no difference of IL-4 and TNF-α that were secreted by CD4 +cell and CD8 +cell1 So, our study suggested Th1/ Tc1 cells prevailed in AS patients1 Jitongning and sulfasalazine treatment for 12 months both resulted in a significant decrease in percentages of CD4 + and CD8 + cells expressing TNF-α and IFN-γ when compared with baseline values (P <0105)1 However, no change of proportion of CD4 + and CD8+ cells expressing IL-4 was observed during the treatment period1 There were no difference between Jitongning group and sulfasalazine group1 In conclusion, our study showed that Jitongning Capsule not only improved clinical symptoms of AS but also decreased levels of inflammatory reaction, which may be associated with its inhibition of inflammatory cytokines1 The efficacy of JitongningCapsule treatment was similar to that of sulfasalazine treatment1REFERENCES11 Yang CH, Huang F1 Immunogenetics and pathogenesis of ankylosing spondylitis1 Curr Immunol 2007;27:265-2681 21 Wang LS, Huang F1 Biologic agent in inflammatory arthritis1 Chin J New Drug (Chin) 2007;16:1149-11531 31 Van der linden S, Valkenburg HA, Cats A, et al1 Evaluation of diagnostic criteria for ankylosing spondylitis1 A propsposal for modification of the New York criteria1 Arthritis Rheum 1984,27:361-3681 41 Calin A, Garrett S, Whitelock H,Kennedy LG, O'Hea J, Mallorie P, et al1A new approach to defining disease status in ankylosing spondylitis: the Bath Ankylosing Spondylitis Disease Activity Index1 J Rheumatol 1994;21:2286-22911 51 Takatori H, Kanno Y, Chen Z, O'Shea JJ1 New complexities in helper T cell fate determination and the implications for autoimmune diseases1 Mod Rheumatol 2008;18:533-5411 61 Zhu J, Liu XY, Huang F1 Th1/Th2 balance and ankylosing spondylitis1 Chin J Rheumatol (Chin) 2000;4:202-2051 71 Szántó S, Aleksza M, Mihály E, Lakos G, Szabó Z, Végvári A, et al1 Intracytoplasmic cytokine expression and T cell subset distribution in the peripheral blood of patients with ankylosing spondylitis1 J Rheumatol 2008;35:2372-23751 81 Cañete JD, Martínez SE, Farrés J, Sanmartí R, Blay M, Gómez A, et al1 Differential Th1/Th2 cytokine patterns in chronic arthritis: interferon gamma is highly expressed in synovium of rheumatoid arthritis compared with seronegative spondyloarthropathies1 Ann Rheum Dis 2000;59:263-2681 91 Braun J, Bollow M, Neure L, Seipelt E, Seyrekbasan F, Herbst H, et al1 Use of immunohistologic and in situ hybridization techniques in the examination of sacroiliac joint biopsy specimens from patients with ankylosing spondylitis1 Arthritis Rheum 1995;38:499-5051 101 François RJ, Neure L, Sieper J, Braun J1 Immunohistological examination of open sacroiliac biopsies of patients with ankylosing spondylitis: detection of tumor necrosis factor α in two patients with early disease and transforming growth factor β in three more advanced cases1 Ann Rheum Dis 2006;65:713-7201 111 Kim TJ, Kim TH, Lee HJ, Lee B, Robin Poole A, Inman RD1 T-cell responses to versican in ankylosing spondylitis1 Rheumatol Int 2011;31:191-1951 (Received April 3, 2011) Edited by ZHANG Wen。