BACKGROUND: 6-minute walking test (6MWT) is a submaximal test, characterizing by easily processing and low cost, thus it is widely used in the clinic. However, how to change walking distance into maximal motor capacity needs to be further studied.OBJECTIVE: To study the correlation of 6-minute walking distance (D), work (W), peak oxygen uptake (VO_2 peak) and maximal oxygen uptake (VO_2 max) detected by Bruce.DESIGN, TIME AND SETTING: This study was performed at tshe Department of Rehabilitation Medicine, Zhongda Hospital affiliated to Southeast University from March to May 2009.PARTICIPANTS: A total of 25 healthy volunteers were enrolled, including 14 males and 11 females, with a mean age of (22.0±2.3) years.METHODS: All 25 subjects were tested with cardiopulmonary exercise testing (CPET) according to Bruce, VO_2 max and anaerobic threshold (AT) was detected respectively, then 6MWT" was adopted to detect 6-minute walking distance (D), work (W) and maximal oxygen uptake (VO_2 max) of subjects. Data of pulmonary gas exchange in breathing was detected by wireless remote sensor K4b~2 to obtain VO_2 max and VO_2 peak.MAIN OUTCOME MEASURES: ① Regularity of cardiac rate, oxygen uptake and respiratory frequency varied with time passing; ② Walking distance, work, oxygen uptake, cardiac rate and respiratory frequency were compared before and after testing; ③ Maximal oxygen uptake and anaerobic threshold with CPET were compared to peal oxygen uptake with 6MWT; ④ Correlation of distance, work between maximal oxygen uptake and peal oxygen uptake.RESULTS: There was no significant difference between AT from CPET and VO2 peak from 6MWT (P > 0.05). 6-minute walking distance was not correlated with either VO_2 peak or VO_2 max. However, 6-minute walking work was linearly correlated with both VO2 peak (r=0.779 7, P < 0.001) and VO_2 max (r=0.894 1, P < 0.001).CONCLUSION: 6-minute walking test is an exercise test at level of anaerobic threshold. 6-minute walking work can reflect both submaximal exercise capacity and maximal exercise capacity.

BACKGROUND: The lymphocyte-specific recombination-activating gene (RAG) 1 and 2 are essential for initiating V (D)J recombination events in both T and B cells. In addition to initiating V(D)J recombination, RAG-mediated transposition has also been proposed to contribute to chromosomal translocations and lymphoid malignancy, but the mechanism underlying this activity remains poorly understood.OBJECTIVE: To investigate RAG gene,DNA repair factors Ku70/Ku80 and terminal deoxynucleotidyl transferase(TdT)mRNA expression and T cell receptor(TCR) gene recombination in human leukemia and lymphoma cell lines.DESIGN: Repeated-determined experiment.SETTING: Institute of Molecular Immunology, College of Biotechnology,Southern Medical University.MATERIALS: Four human T leukemia and lymphoma cell lines (Jurkat,Molt-4, HuT-102, 6T-CEM) ,two Burkitt's lymphoma(Raji and Daudi) and two myelogenous leukemia cell lines (HL-60 , K-562) were cultured in complete growth medium (Hyclone,USA) , penicillin/streptomycin(50 U/mLand 50 mg/L) at 37 ℃ in a humidified atmosphere in 0.05 volume fraction of CO2. Jurkat and 6T-CEM were bought from SIBS,CAS(Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences). The other cell lines were conserved by Institute of Molecular Immunology, College of Biotechnology, Southern Medical University.METHODS: The experiment was carried out in Institute of Molecular Immunology, College of Biotechnology, Southern Medical University from October 2005 to January 2006.Reverse transcription-polymerase chain reaction (RT-PCR)was performed to examine the expression of RAG1,RAG2,terminal deoxynucleotidyl transferase(TdT), Ku70 and Ku80 genes,reparative factors,in pathway of non-homologous end joining (NHEJ);Nested and semi-nested PCR reactions were performed with locus-specific primer sets to determine TCR Dβ-Jβ signal joint T-cell receptor excision DNA circles (sjTRECs); Ligation-mediated PCR(LM-PCR) assay was used to detect the recombinational intermediates ds RSS breaks of TCRβ locus with primers specific for the flanking sequences of both Dβ1 and Dβ2.Thus,gene expression during initiating V (D)J recombination and generation of TCR gene recombination intermedium could be known.MAIN OUTCOME MEASURES: RAG gene,DNA repair factors Ku70/Ku80 and TdT mRNA expression and TCR gene recombination in human leukemia and lymphoma cell lines.RESULTS: Determination results by RT-PCR showed that RAG1 was expressed in four T cell lines and was not expressed in two Burkitt's lymphoma and two myelogenous leukemia cell lines. RAG2 and TdT were only expressed in Jurkat,Molt-4 and 6T-CEM, but TdT expression in 6T-CEM was very low. Except that Ku80 expression was not detectable in HL-60,Ku70 and Ku80 were expressed in all the cell lines. However, Determination results of TCR gene in T cell lines recombination intermedium showed that the TCR gene recombination process was not occuring in all the RAG-expression T cell lines. Ongoing TCR gene recombination was only found in Jurkat, which represent a mature stage of T cell development. In addition,characteristic junctional diversity of signal joints was observed in DNA isoated from Jurkat.CONCLUSION: T leukemia and lymphoma may be more likely to have a relation with RAG.The results give a clue that Jurkat can probably provide an ideal cell line modle for studying RAG and T cell lymphomagenesis.

Purpose To clarify the morphological parameter and describe the distance from the insertion of the lateral ankle ligaments to the adjacent bony landmarks through precisely anatomical explore of human cadaveric ankles,so as to provide anatomical evidences for the reconstruction of lateral ankle ligaments.Methods Nineteen ankle specimens were dissected to isolate the lateral ankle ligaments and measure the morphological parameters such as length,width,thickness and the distance from the insertion of the lateral ankle ligaments to the adjacent bony landmarks.Results The average length of anterior talofibular ligaments (ATFL) was 23.1 ± 2.98 mm,among which 8 were single-banded(42.1％)and 11 were double-banded(57.9％).The average distance from the fibular origination of ATFL to the anterior tubercle of fibula(AA)was 17.1 ± 3.00 mm,to the fibular obscure tubercle(AO)was 5.1 ± 1.69 mm,to the tip of the fibula(AT)was 14.1 ± 2.86 mm.The distances from the talus insertion of ATFL to the superior and inferior talus articular surface were 11.4 ± 2.25 mm and 18.4 ± 2.30 mm respectively,to the anterior lateral talus chondral surface was 4.8 ± 1.42 mm.The average length of calcaneofibular ligament(CFL)was 31.4 ± 3.55 mm.The average distance of the fibular origination from ATFL to CFL was 6.4 ± 2.55 mm.The average angle between ATFL and CFL was 116.6 ± 12.69°.The distance from the calcaneus insertion of CFL to the peroneal tubercle(CP)was 15.4 ± 2.86 mm,to the posterior superior border of calcaneus(CC)was 13.9 ± 2.46 mm,to the subtalar joint surface was 15.2 ± 3.21 mm.The coefficient variation assessing the anatomical reliability of different bony landmarks were as follows:ATFL fibular origination AA(17.54％) ＜AT(20.28％) ＜ AO(33.14％),CFL calcaneus insertion CC(17.70％)＜CP(18.57％)＜CS(21.1％).Conclusion Certain variations exist in the morphological parameters and the distances from the insertion of the lateral ankle ligaments to the adjacent bony landmarks.It provides anatomical evidence for lateral ankle ligament reconstruction in treating chronic ankle instability.

Objective: To investigate the application of CD44 receptor-targeted nanoparticles HACDDP-DOX in the treatment of breast cancer, and to clarify its inhibitory effect on allograft breast cancer in the mice. Methods: Hyaluronic acid (HA) was used to construct a breast cancer targeted nanoparticle via green synthesis approach, and its particle size, stability and doxorubicin release profile at different pH conditions were measured. Then the breast cancer models were constructed by inoculating 4T1 cells into the mouse mammary fat pad. The model mice were randomly divided into control group, DOX/CDDP group and HACDDP-DOX group according to the tumor volumes and the body weights. PBS, free drug DOX/CDDP and HACDDP-DOX were intravenously injected into the allograft breast cancer models on the 1st, 5th and 9th days after the tumor volume reached about 80 mm5 The antitumor effect and biosafety of HACDDP-DOX were evaluated by detecting the tumor volume, mouse weight and immunohistopathology. Moreover, the biological distribution of HACDDP-DOX in the mice was studied by biofluorescence imaging. Results: The average particle size of HACDDP-DOX was (80.0 ± 17.4) nm, which was stable under pH 7.4. Under acidic condition, the particle size was increased and the DOX was effectively released. Compared with DOX/CDDP group, the body weight of the mice in HACDDP-DOX group was increased (P<0.05) and the tumor volume was decreased (P<0.05). The HE staining results showed that the liver of the mice in control group had tumor metastasis and the alveolar septum was widened. The tumor tissue of the mice in DOX/CDDP group and HACDDP-DOX group were all necrotic, while in HACDDP-DOX group the degree of necrosis was significantly higher than DOX/CDDP group. Compared with DOX/CDDP group, the activity of Caspase-3 in HACDDP-DOX group was significantly increased (P<0.01), while the Ki-67 activity was significantly decreased (P<0.01). The biofluorescence imaging showed that the nanoparticle HACDDPTXX could accumulate to the tumor site by targeting, and effectively release the drug. Conclusion: HACDDP-DOX nanoparticles can effectively target the breast cancer cells, reduce the toxicity of chemotherapy drugs, and enhance the therapeutic effect of breast cancer.

Objective To discuss the clinical application of homemade airway exchange catheter on the extubation of patients with difficult tracheal intubation in intensive care unit(ICU). Methods Sixty-two patients with difficult tracheal intubation who failed their initial extubation trial were randomly divided into conventional group (31 cases)and observation group(31 cases). The patients in the conventional group received routine extubation process,while the patients in the observation group were extubated under the guidance over a homemade airway exchange catheter. The changes in heart rate(HR),blood pressure,respiratory rate(RR)and pulse blood oxygen saturation(SpO2)were compared at 12 hours after extubation,so as the re-intubation rate,intubation success rate at first attempt and re-intubation time in two groups,and the tolerance and complications after extubation were observed. Results After extubation,the HR,blood pressure and RR were increased significantly(all P<0.05), and the SpO2 was much lower in conventional group(P<0.05),while those parameters were changed little and basically in the normal ranges in the observation group. At 12 hours after extubation,the re-intubation rate was much lower(6.45%vs. 25.81%,P<0.05)in the observation group,with shorter re-intubation time(seconds:27±14 vs. 49±28,P<0.01),higher intubation success rate at first attempt(90.32%vs. 54.84%,P<0.01)and better tolerance (77.4% vs. 61.3%,P<0.05)compared with those in the conventional group. There was no severe complication in the observation group,and there were 1 cases of glottic edema with cricothyroid membrane puncture,2 cases of broncheal mucous membrane bleeding and 2 cases of bucking in the conventional group. Conclusion Compared with conventional extubation process,the extubation over homemade airway exchange catheter can increase the rate of extubation,reduce re-intubation rate and the re-intubation time,with favorable tolerance and no occurrence of serious complications,and is one of the safe and effective extubation strategies in patients with difficult tracheal intubation in ICU.

AIM:To explore the ability of different group B streptococci ( GBS) strains on inducing platelet activation.METHODS:Six strains of GBS, separated from the septic patients with thrombocytopenia, were used as the inducers.Light transmission aggregometry was used to measure platelet aggregation.Scanning electron microscopy ( SEM) was performed to investigate the interaction of platelets with bacteria.The expression of platelet CD62P, Toll-like receptor 2 ( TLR2) and TLR4 was determined by flow cytometry and Western blotting.Furthermore, the activity of platelet TLR2 (or TLR4) was blocked by anti-TLR2 (or anti-TLR4) monoclonal antibody, and the platelet aggregation induced by GBS was detected.RESULTS:Only 3 of 6 GBS strains isolated from the septic patients induced platelet aggregation and up-regulated the expression of CD62P and TLR2 in the platelets (P<0.05), but not TLR4.Incubation with anti-TLR2 anti-body, but not anti-TLR4 antibody, significantly blocked platelet aggregation induced by GBS.CONCLUSION:Some GBS strains from the patients are able to trigger platelet activation in vitro, and platelet TLR2 may play an important role in the interaction between GBS and platelets.

[Objective] To explore the risk factors for mortality of bloodstream infections in the patients with hematologic diseases,so as to provide evidence for reasonable and effective application of treatments.[Methods] The clinical data of 242 cases of bloodstream infections who were hospitalized from Jan 2012 to Jun 2016 were analyzed retrospectively,then the analysis was performed for risk factors.The statistical analysis was processed by SPSS 19.0.[Results] A total of 266 strains of pathogens were isolated,including 99 strains of gram-positive bacteria,accounting for 37.2％,and 164 strains of gram-negative bacteria,accounting for 61.7％.Multivariate analysis showed that the significant independent risk factors for mortality were active states of hematologic diseases (P =0.007,OR =5.622,95％ CI 1.586 ～ 19.924),presentation with septic shock(P =0.007,OR =4.978,95％ CI 1.560 ～15.884),cardiac insufficiency (P =0.001,OR =11.878,95％ CI 2.760 ～ 51.120),level of albumin less than 35 g/L (P =0.036,OR =3.468,95％ CI 1.087 ～ 11.066),polymicrobial infection (P =0.010,OR =6.024,95％ CI 1.540 ～ 23.563),and Staphylococcus haemolyticus (P =0.001,OR =19.308,95％ CI 3.392 ～ 109.888)/Enterococcus (P =0.002,OR =15.266,95％ CI 2.817 ～82.728) infection.The survival curves show that the inappropriate initial antimicrobial therapy group or presentation with any one of the independent risk factors had a lower probability of survival than the control group.[Conclusions] Bloodstream infections in patients may cause high mortality rate,so it is necessary that we use antibiotic reasonably and spare no effort to reduce the mortality rate by appropriate application of antimicrobial therapy and effective intervention of the risk factors.

Objective To explore the role of Fas and FasL system in the pathogenesis of adult primary immune thrombocyto‐penic purpura (ITP) .Methods The peripheral anticoagulant venous blood samples were collected from the patients with newly di‐agnosed ITP and healthy adults .The expression rates of Fas and FasL in Th/Tc ,Th1/Th2 ,Tc1/Tc2 cells and their expression rates at platelet surface were detected by flow cytometry .Results The Fas and FasL expression rates on the surface of Th ,Th1 ,Th2 , Tc ,Tc1 and Tc2 in the ITP group were increased compared with the healthy control group(P<0 .05) .,meanwhile the FasL expres‐sion on the platelet surface was significantly increased (P<0 .05) ,but the expression of FasL on the platelet surface had no obvious change(P>0 .05) .Conclusion The Fas and FasL expression on T cell subsets and platelet surface in ITP patients is abnormal , which may be related with the pathogenesis of ITP .

Objective To investigate the clinical characteristics,treatment,and prognostic factors for Langerhans cell histiocytosis (LCH) in children.Methods A retrospective review of patients diagnosed as LCH was carried out between January 2007 and December 2012 in Beijing Children's Hospital,Capital Medical University.Target patients were divided into multi-organ high-risk groups (Group Ⅰ),multi-organ low-risk groups (Group Ⅱ),single-organ groups (GroupⅢ),and the corresponding intensity of chemotherapy was given.SPSS 17.0 statistical software was used to analyze the findings.The correlations among the affected organ,the early treatment response and the prognosis were analyzed.Results A total of 217 patients were analyzed including 127 boys and 90 girls with ratio of 1.4 ∶ 1.0 and a median age of 36 months (ranged from 2 months to 14 years) on the diagnosis of LCH,and there were 132 cases (60.8％) in group Ⅰ,33 cases (15.3％) in group Ⅱ and 52 cases (23.9％) in group Ⅲ.The median age on diagnosis was 20 months in group Ⅰ,42 months in group Ⅱ and 72 months in group Ⅲ.The most frequently affected organ was the bone (176 cases,81.2％).Among 217 patients,55 cases (25.3％) had recurrence and 12 cases died.The rate of 3-year overall survival was expected to be 90.78％.The rate of 3-year event free survival was expected to be 76.5％.Myelosuppression,liver function damage and infection were the most common side effects due to chemotherapy with the percentages of 48.4％ (105 cases),24.0％ (52 cases) and 12.4％ (27 cases).Risk organs involvement and no-response to initial therapy (after 6 weeks) indicated a worse prognosis (x2 =10.60,12.84,P =0.017,0.001).Conclusions Incidence of LCH in boys is slightly higher than girls in children.Peak age at onset of LCH in children is 1-3 years old.Bone is the most frequent involved organ.Involvement of risk organs and no-response to initial therapy are key factors in determining worse prognosis.A rescue therapy should be introduced earlier in these patients.

Objective To investigate the clinical characteristics,treatment and prognosis of single-system Langerhans cell histiocytosis (LCH) in children.Methods A retrospective analysis was performed in single-system LCH patients registered between January 2006 and December 2012 in Beijing Children＇s Hospital Affiliated to Capital Medical University.The patients were divided into 2 groups:the bone involvement group and the other organ involvement group.The patients were assessed at 5 weeks,11 weeks,25 weeks,3 months,6 months,1 year and 3 years.The data were analyzed by using SPSS 17.0 software.Results A total of 112 patients (66 boys and 4,6 girls) with a median age of 5 years at diagnosis of LCH were analyzed.The most frequently affected organ was the bones(91 cases,81.3％),followed by skin(15 cases,13.4％).Few patients (27.6％) had acentral nervous system risk lesion,who were younger than those with other bone lesion(2.5 years vs 6.6 years).Patients with bone lesions were diagnosed at a significantly older age than other patients(5.6 years vs 1.5 years) (P ＜ 0.01).All patients received chemotherapy that included Prednisone and Vinblastine for 25 weeks.Twenty-five patients (22.3 ％) showed reactivation.Of these,4 patients exhibited reactivation in the pituitary.Three-year overall survival rate was expected to reach 100％,and no-event survival was expected at (73.22 ± 4.47) ％.Age of less than 2 years old was the factor of reactivation (P =0.033);sex,organ involvement and member of bone involved were not related with reactivation (P =0.679,0.142,0.639).Conclusions The bones were the frequent involvement organ in single-system LCH patients.These patients have a good prognosis.The rate of reactivation of single system-LCH can be decreased by chemotherapy.