The external defibrillator is an emergency instrument used very widely in clinics. It plays an important role in rescuing ventricle fibrillation (VF) patients. We have designed an external defibrillator using the truncated exponential biphasic waveform. The system consists of three parts: the ECG collection module, the control module and the defibrillator module. They are introduced respectively, listing the main problems and the methods to solve them. Some experiments have been done and the corresponding results are given.
Animals ; Defibrillators ; Equipment Design ; Swine ; Ventricular Fibrillation

AIMTo analyse the impurities of gatifloxacin.

METHODSThe impurity of gatifloxacin were analysized and determinated by RP-HPLC/electrospray ionization mass spectrometry with a Zorbax SB-C18(4.6 mm x 150 mm ID, 5 microns). The mobile phase was 3% acetic acid/acetonitrile-3% acetic acid/water (15:85). The two compounds were synthesized: 1-cyclopropyl-6-fluoro-1, 4-dihydro-8-methoxy-7-(1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid (DMP) and 1-cyclopropyl-6-fluoro-1, 4-dihydro-8-hydro-7-(3-methy-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid (DMO). Their liquid chromatogram, UV, MS were compared with those of the impurity of gatifloxacin.

RESULTSThe mass of the impurity was 14 less than that of gatifloxacin. It means the impurity was CH2 less than gatifloxacin. The tR (HPLC), UV and MS of DMP were the same as those of the impurity of gatifloxacin.

CONCLUSIONBased on the tR (HPLC), UV and MS, the impurity of gatifloxacin is confirmed as DMP.

Anti-Infective Agents ; analysis ; chemistry ; Chromatography, High Pressure Liquid ; Drug Contamination ; Fluoroquinolones ; analysis ; chemistry ; isolation & purification ; Molecular Structure ; Spectrometry, Mass, Electrospray Ionization

BACKGROUNDAdvances in catheter ablation procedures for the treatment of supraventricular arrhythmias have created the need to understand better the morphological and electrophysiological characteristics of the inferior nodal extension (INE) and transitional cellular band (TCB) in the atrioventricular (AV) junctional area.

METHODSFirstly, we observed the histological features of 10 rabbit AV junctional areas by serial sections under light microscopy. Then we recorded the action potentials (APs) of transitional cells (TCs) in the INE, TCBs, AV node, and ordinary right atrial myocytes from the AV junctional area of 30 rabbits using standard intracellular microeletrode techniques.

RESULTSUnder light microscopy, the INE appeared to be mostly composed of transitional cells linking upward to the AV node. Four smaller TCBs originated in the orifice of the coronary sinus, the region between the septal leaflet of the tricuspid valve and the coronary sinus, the inferior wall of the left atrium, and the superior interatrial septum, respectively, all linking to the INE or the AV node. Compared with ordinary atrial myocytes, the AP of the TCs in both the INE and the TCBs had a spontaneous phase 4 depolarization (not present in ordinary atrial myocytes), with a less negative maximum diastolic potential, a smaller amplitude, a slower maximum velocity of AP upstroke, and a longer action potential duration at 50% repolarization (APD50) and at 30% repolarization (APD30). The AP characteristics of these TCs were similar to those of the AV node, except that the velocities of the phase 4 spontaneous depolarization were slower and their action potential durations at 90% repolarization (APD90) were shorter. Moreover, APD50 and APD30 of the TCs of the TCBs were shorter than in the case of TCs of the AV node.

CONCLUSIONSThe TCs of the INE and TCBs are similar to slow response automatic cells. They provide a substrate for slow pathway conduction. In addition, repolarization heterogeneity exists in the AV junctional area.

Action Potentials ; Animals ; Atrioventricular Node ; cytology ; physiology ; Female ; Male ; Rabbits

OBJECTIVETo explore the effects of bone marrow mesenchymal stem cells (MSCs) on in vitro expansion potential, the adherent molecules expression of cord blood (CB) CD34(+) cells.

METHODSMSCs were obtained from human bone marrow and their differentiation function and phenotype were identified. CB CD34(+) cells were expanded in culture systems with or without MSC layer. Hematopoietic progenitor cells and adhesion molecules expression were assessed by semisolid culture assay and flow cytometry.

RESULTSThy-1, SH2, SB10, CD44, CD13, CD49e and CD29 were highly expressed on MSCs with no expressions of CD34, CD45, HLA-DR, CD14 and CD31. The MSCs could differentiate into adipocytes and osteoblasts under specific induction conditions. After culturing on MSCs layer with supplement of cytokines for 8 days, the absolute numbers of nuclear cells, CD34(+), CD34(+)CD38(-), CD34(+)CD62L(+) cells and CFU-Cs were increased by 145.57 +/- 17.89, 37.47 +/- 13.78, 69.78 +/- 50.07, 10.74 +/- 5.89 and 20.73 +/- 5.54-folds, respectively, being significantly higher than that cultured with cytokines alone. The expression of ALCAM, VLA-alpha4, VLA-alpha5, VLA-beta1, HCAM, PECAM and LFA-1 on CD34(+) cells remained unaffected. The expressions of ICAM-1 and L-selectin were downregulated during expansion, while the absolute numbers of CD34(+)CD62L(+) and CD34(+)CD54(+) cells were increased.

CONCLUSIONSMSCs layer improves expansion of CB CD34(+) cells while inhibiting their differentiation and retaining their homing ability.

Antigens, CD34 ; Cell Adhesion Molecules ; metabolism ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; metabolism ; Humans ; Mesenchymal Stromal Cells

OBJECTIVETo determine the protective effect of monosialoganglionside (GM1) and evaluate the influence of GM1 on expression of N-methyl-D-aspartate receptor subunit 1 (NMDAR1) in Sprague-Dawley (SD) rats with focal cerebral ischemia-reperfusion (I/R).

METHODSLeft middle cerebral artery (MCA) was occluded by an intraluminal suture for 1 h and the brain was reperfused for 72 h in SD rats when infarct volume was measured, GM1 (10 mg/kg) was given ip (intraperitoneally) at 5 min (group A), 1 h (group B) and 2 h (group C) after MCA occlusion (MCAo). Expression of NMDAR1 was detected by Western blot at various time after reperfusion (4 h, 6 h, 24 h, 48 h and 72 h) in ischemic hemispheres of the rats with or without GM1 administered.

RESULTS(1) Adjusted relative infarct volumes of groups A and B were significantly smaller than that of group C and the control group (P<0.01 and P<0.05, respectively). (2) Expression level of NMDAR1 was temporally high at 6 h after reperfusion, and dipped below the normal level at 72 h after reperfusion. GM1 at 5 min after MCAo significantly suppressed the expression of NMDAR1 at 6 h after reperfusion (P<0.05 vs the control). At 72 h after reperfusion, the NMDAR1 expression level of rats treated with GM1 administered (at 5 min or 2 h after MCAo) was significantly higher than that of the control (P<0.05).

CONCLUSIONGM1 can time-dependently reduce infarct volume in rats with focal cerebral I/R partly through stabilizing the expression of NMDAR1.

Animals ; Brain Ischemia ; metabolism ; pathology ; prevention & control ; G(M1) Ganglioside ; pharmacology ; therapeutic use ; Gene Expression Regulation ; drug effects ; Male ; Middle Cerebral Artery ; surgery ; Neurons ; drug effects ; physiology ; Protein Subunits ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Reperfusion Injury ; metabolism ; pathology ; prevention & control ; Treatment Outcome

Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.

A simple, sensitive and reliable method was developed for simultaneous determination of ten banned drugs residues including zeranols(ZALs),chloroamphenicol,pentachlorophenol,etc. in swine urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The urine samples were pretreated using lyophilization and QuEChERS procedures, respectively. Acetonitrile and ammonium acetate (5 mmol/L) were chosen as mobile phases. Target compounds were separated well in ZorbaxSB-C18by following the optimized gradient elution program and determined by LC-MS/MS in negative electrospray ionization mode. The linearity of the matrix-matched standard curve of ten analytes in two methods was good in the range of the experimental concentration with correlation coefficients more than 0.99. The recoveries of ten drugs were in the range of 80.7%-107.7% and 73.5%-103.3% at the spiked levels of 5,10 and 20 μg/L by lyophilization and QuEChERS methods,respectively. The coefficients of variation were less than 15%. The limits of detection (LOD) and the limits of quantification (LOQ) from lyophilization and QuEChERS method were 0.1 to 2.0 μg/L and 0.2 to 5.0 μg/L,respectively.

This study was purposed to evaluate the outcome of patients with acute myeloid leukemia (AML) who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) in complete remission, and to study the prognostic factors. 75 cases of AML in complete remission receiving allo-HSCT from January 2000 to December 2007 were retrospectively analyzed. Major end points of study included overall survival (OS), disease free survival (DFS), relapse rate and transplantation related mortality (TRM). The results showed that 3-year OS and DFS of the study population reached to 58.4% and 53.9% respectively, and the relapse rate and TRM leaded to 16.9% and 29.9% respectively. Incidence of acute GVHD was 59.6%, with 18.7% II-IV aGVHD. Different prognosis was observed between HSCT recipients of alternative donor and HLA-matched related donor (MRD) (3-year DFS was 34.3% vs 60.0%, p = 0.019), between patients of refractory leukemia and the control (3-year DFS was 35.7% vs 58.2%, p = 0.048), between recipients with and without severe aGVHD (3-year DFS was 35.7% vs 54.4%, p = 0.059). Further analysis revealed significantly high TRM in recipients receiving allo-HSCT of alternative donor (p = 0.033) and high rate of severe aGVHD (p = 0.010). Multivariate analysis revealed three negative prognostic factors: donor availability (alternative vs MRD) (p = 0.049, RR = 2.09, 95%CI 1.01 - 4.36), refractory leukemia (p = 0.038, RR = 2.33, 95%CI 1.05 - 5.20) and severe aGVHD (p = 0.040, RR = 2.33, 95%CI 1.04 - 5.20). It is concluded that allo-HSCT is a choice for the AML case at complete remission and TRM is the major cause of the transplantation failure. Donor availability, refractory leukemia and severe aGVHD are confirmed as risk factors of poor prognosis for allo-HSCT patients with AML in CR.
Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Graft vs Host Disease ; etiology ; Hematopoietic Stem Cell Transplantation ; adverse effects ; methods ; Humans ; Leukemia, Myeloid, Acute ; mortality ; surgery ; Male ; Middle Aged ; Prognosis ; Recurrence ; Risk Factors ; Treatment Outcome ; Young Adult

OBJECTIVETo explore the impact of IFN-γ + 874 polymorphisms on the outcome in HLA matched sibling HSCT.

METHODSWe used PCR-sequence-specific primer analysis (PCR-SSP) to analyze the polymorphisms of IFN-γ + 874 T/A in 80 recipient and donor pairs from October 2005 to March 2008.

RESULTSRecipients having donors who possessed IFN-γ + 874 A/A genotype had significantly earlier neutrophil recovery compared with those having donors with non-A/A genotype (15 (11 - 27) days vs 18 (12 - 30) days, P = 0.029). And IFN-γ + 874 A/A in both recipients and donors further facilitated neutrophil recovery compared with others (13 (11 - 25) days and 19 (12 - 31) days, P = 0.019). Besides, IFN-γ + 874 A/A in recipients increased the probability of grade II-IV acute graft versus disease (aGVHD) and cytomegalovirus viraemia compared with IFN-γ + 874 T/A or T/T genotype (20% vs 4% P = 0.041, 43.6% vs 16.0% P = 0.032), which lead to increased 5-year transplant-related mortality (TRM) (33.7% ± 6.8% vs 12.0% ± 6.5%, P = 0.050) and decreased 5-year event free survival (EFS) \[(58.2 ± 6.7)% vs (84.0 ± 7.3)%, P = 0.032\] compared with the latter. IFN-γ + 874 A/A in both recipients and donors also significantly increased the probability of grade II-IV aGVHD and cytomegalovirus viraemia compared with the other (21.7% vs 5.9%, P = 0.050; 45.7% vs 20.6%, P = 0.020), which caused increased 5-year TRM \[(31.6 ± 7.5)% vs (13.6 ± 6.5)%, P = 0.048\] and decreased 5-year EFS \[(56.8 ± 7.3)% vs (79.4 ± 6.9)%, P = 0.037\] compared with the other.

CONCLUSIONIn HLA-matched sibling HSCT setting, the presence of IFN-γ + 874 T allele in recipients or in both recipients and donors significantly decreased the risk of grade II-IV aGVHD and CMV infection and increased EFS. While IFN-γ + 874 A/A in donors or in both recipients and donors was associated with shorter duration to neutrophil recovery.

Adolescent ; Adult ; Alleles ; Child ; Child, Preschool ; Female ; Genotype ; HLA Antigens ; immunology ; Hematologic Diseases ; genetics ; therapy ; Hematopoietic Stem Cell Transplantation ; Humans ; Interferon-gamma ; genetics ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Siblings ; Tissue Donors ; Transplantation, Homologous ; Treatment Outcome ; Young Adult

Chronic myeloid leukemia (CML) at advanced and blastic phase is a disease with poor prognosis, for which allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only treatment choice with curative potential. This study was purposed to investigate the therapeutic efficacy of allo-HSCT and prognosis of advanced CML patients. The 28 cases of CML in accelerated phase or blast crisis received allo-HSCT were analysed retrospectively in terms curative efficacy, basic characteristics before transplant and prognosis, therapeutic strategy before transplant and prognosis, events after transplant and prognosis. The results indicated that 10 out of 28 patients were in complete remission, showing a 3-year overall survival and disease-free survival rate of 34.9% and 35.7% respectively; 18 patients died. Univariate analysis revealed that the clonal evolution and blast amount are baseline risk factor of poor prognosis, and combination of them can be used to predict the outcome of patients; application of imatinib before transplant and achievement of complete hematologic remission could not improve the prognosis; severe aGVHD among post-transplant events was proven to be a negative prognostic factor. It is concluded that for advanced CML patients received allo-HSCT, clonal evolution and blast percentage are prognostic factors, and the pre-transplant use of imatinib did not influence the outcome.
Adolescent ; Adult ; Benzamides ; Child ; Child, Preschool ; Female ; Hematopoietic Stem Cell Transplantation ; methods ; Humans ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; drug therapy ; surgery ; therapy ; Male ; Middle Aged ; Piperazines ; therapeutic use ; Prognosis ; Pyrimidines ; therapeutic use ; Retrospective Studies ; Young Adult