经骶前轴向腰5/骶1椎间融合手术入路的影像学分析

Background  Trans-sacral axial L5/S1 interbody fusion (AxiaLIF), a novel surgical procedure, recently adopted in clinical practice, has excellent clinical outcomes. However, there is inadequate data on the feasibility of the approach in all adult patients and the optimal surgical approach is currently unclear; therefore, further studies are required. In order to enhance the surgical approach for AxiaLIF, prospective anatomical imaging optimization is necessary. The objective of this study was to investigate the ability of magnetic resonance imaging (MRI) to achieve an optimal procedural setting.

Methods  The subjects (n=40) underwent lumbosacral MRI examination. The median sagittal MRI images were analyzed and four measurement markers were defined as follows: the center of the L5/S1 disc (A), the anterior margin of the S1/2 disc space (B), the sacrococcygeal junction (C), and the coccygeal tip (D). The measurement markers were connected to each other to produce five lines (AB, AC, AD, BC, and BD), as reference lines for surgical approaches. The distance between each reference line and the anterior and posterior margins of the L5 and S1 vertebral bodies was measured to determine the safety of the respective approaches.

Results  In all patients, Lines AB and AC satisfied the imaging safety criteria. Line AB would result in a significant deviation from the median and was determined to be unsuitable for AxiaLIF. Line AD satisfied the imaging safety criteria in 39 patients. However, the anal proximity of the puncture point proved to be limiting. For lines BC and BD, the imaging safety criteria were satisfied in 70% and 45% of patients, respectively.

Conclusions  The AxiaLIF procedure is a safe technique for insertion of fusion implants in all subjects. Line AC is a favorable reference line for surgical approach and safe for all subjects, while line BC is not suitable for all subjects.

     

Minimally invasive transforaminal lumbar interbody fusion aided with computer-assisted spinal navigation system combined with electromyography monitoring

Background  Minimally invasive techniques are gaining wide-spread application in lumbar fusion surgery, because they may have advantage over conventional open surgery in approach-related morbidity. This research was aimed to evaluate the safety and accuracy of the techniques of minimally invasive transforaminal lumbar interbody fusion by using a computer-assisted spinal navigation system combined with electromyography monitoring.

Methods  Sixteen patients underwent minimally invasive transforaminal lumbar interbody fusion. A computer-assisted spinal navigation system and electromyography were used for guiding pedicle screw placement. The operative duration, blood loss, complications, and fluoroscopic time were recorded. Clinical outcome was assessed by Visual Analog Scale and Oswestry Disability Index. Radiographic images were obtained to evaluate the accuracy of pedicle screw placement and fusion rates.

Results  The Visual Analog Scale and Oswestry Disability Index scores were vastly improved postoperatively. A total of 64 pedicle screws were implanted and three were regarded as misplacement by post-operative CT scan. Three screw trajectories were adjusted according to intra-operative stimulus-evoked electromyography monitoring. The average fluoroscopy time in each patient was 31.8 seconds, which equals to 7.9 seconds per pedicle screw. No patients had instrument related neurological complications, infection, implant failure or revision. Successful fusion was found in all patients.

Conclusions  The combination of navigation system and real-time electromyography monitoring can make the minimally invasive operation more safe and accurate while decreasing radiation exposure time of the medical staff and patient and minimizing the chance and the degree of the pedicle screw misplacement.

     

Complications and clinical outcomes of minimally invasive transforaminal lumbar interbody fusion for the treatment of one- or two-level degenerative disc diseases of the lumbar spine in patients older than 65 years

Background  Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has been successfully used to treat degenerative diseases of the lumbar spine. There are few reports comparing the complications and clinical outcomes in older patients who have undergone one- or two-level MIS-TLIF with those of younger patients. The aim of this study was to investigate the clinical outcomes of MIS-TLIF in the treatment of degenerative disc disease of lumbar spine of the patients older than 65 years, with an emphasis on perioperative complications compared to the younger patients.

Methods  One hundred and fifty-one consecutive cases of one- or two-level degenerative disc disease of lumbar spine treated with MIS-TLIF were reviewed for the radiological and clinical outcomes. They were divided into elderly group (age ≥65 years old) and younger group (age <65 years old), and were followed for at least 6 months. Radiographs were obtained before and after surgery, 3 months postoperatively, and at the final follow-up to determine the presence of fusion, hardware-related problems. The clinical outcomes were evaluated using the Oswestry Disability Index (ODI) before and after surgery, and at the final follow-up. The visual analogue scale (VAS) score of back and leg pain were evaluated as well. The intra-operative data and peri-operative complications were recorded.

Results  The mean age of these patients at operation was (57.7±14.2) years (range 26–82 years). Of 151 patients, 62 were 65 years or older. The elderly patients had more comorbidities and more porportion of lumbar canal stenosis. The overall fusion rate was 88.4% at the final follow-up, with no significant difference between younger and elderly patients. The ODI, the VAS of back pain and radicular pain of both young and elderly group were significantly improved after surgery and at the final follow-up, without significant difference between two groups. There were 16 complications with an incidence of 10.6%, including 7 major complications and 9 minor complications. There was no significant difference of the incidence of complications between two groups. The incidence of dura tear was significantly related to bilateral deompression.

Conclusions  The clinical and radiological outcomes of MIS-TLIF in the treatment of one- or two-level degenerative disc diseases of lumbar spine in the elderly patients were satisfactory. Though there are more pre-operative comorbidities, with proper patient selection, the elderly patients are not at increased risk of perioperative complications compared to younger patients. Screw malposition and dura tear, which are the most frequent complications, were more related to the surgical technique and should be avoided.     

Antimicrobial resistance and molecular epidemiological characteristics of clinical isolates of Staphylococcus aureus in Changsha area

Background  Increasing prevalence of Staphylococcus aureus (S. aureus), particularly methicillin-resistant S. aureus (MRSA) has been reported in China. In this study, we investigated the drug resistance characteristic, genetic background, and molecular epidemiological characteristic of S. aureus in Changsha.

Methods  Between January 2006 and December 2008, 293 clinical isolates of S. aureus were collected from 11 hospitals in Changsha and identified by the Vitek-2 system. All the isolates were verified as MRSA by PCR amplification of both femA and mecA genes. K-B disk method was used to test drug sensitivity of S. aureus to antibiotics. Pulsed-field gel electrophoresis (PFGE) was performed for genotypic and homologous analysis of 115 isolates randomly selected from the original 293 clinical S. aureus isolates.

Results  S. aureus was highly resistant to penicillin, ampicillin, erythromycin, and clindamycin with resistant rates of 96.6%, 96.6%, 77.1%, and 67.2% respectively. All the isolates were susceptible to tecoplanin, vancomycin, and linezolid. MRSA accounted for 64.8% (190/293) of all the S. aureus strains. The 115 S. aureus isolates were clustered into 39 PFGE types by PFGE typing, with 13 predominant patterns (designated types A to M) accounting for 89 isolates. The most prevalent PFGE type was type A (n=56, 48.7%) and 100.0% of type A strains were MRSA. PFGE type A included 13 subtypes, and the most prevalent subtype was subtype A1 (46.4%, 26/56). Strains with PFGE type A were isolated from eight hospitals (8/11), and both subtypes A1 and A4 strains were isolated in a university hospital.

Conclusions  Clinical isolates of S. aureus in Changsha were resistant to multiple traditional antibiotics. There was an outbreak of PFGE type A MRSA in this area and the A1 subtype was the predominant epidemic clone. Dissemination of the same clone was an important reason for the wide spread of MRSA.     

Immunization with HBsAg-Fc fusion protein induces a predominant production of Th1 cytokines and reduces HBsAg level in transgenic mice

Background  The Fc receptor associated pathway might improve the immune responses against hepatitis B virus (HBV) as previously described by us. In addition, the Flt3 ligand (FL) has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice.

Methods  The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 (HBsAg-Fc) and/or the Flt3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase (ALT)/AST were investigated after immunization.

Results  After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Th1 cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Flt3 ligand stimulated an alternative Th1-type immune response featured with high level productions of tumor necrosis factor α (TNF-α) and monocyte chemoabstractant protein 1 (MCP-1), causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level.

Conclusion  HBsAg-Fc is effective in eliciting both the humoral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.

     

Axial and tangential views of the acromioclavicular joint: the introduction of new projections

Background  Routine anteroposterior radiographs of the acromioclavicular (AC) joint with or without weight bearing have limitations in demonstrating the AC joint. Transarticular fixation with Kirschner wire is a treatment choice for AC dislocations. However, percutaneous fixation of the AC joint is technically demanding. The C-arm fluoroscopy can be used as routine intraoperative guidance to facilitate this procedure. The current study aims to introduce new projections, the axial and tangential views of AC joint, to help evaluate the severity of the injury and facilitate the percutaneous procedure.

Methods  Three shoulder specimens were used to find the projection directions of the axial and tangential views of the AC joint by using the digital radiography (DR) unit. The axial and tangential views were taken of 20 adult volunteers by referencing the projection directions determined in the shoulder specimens. The angles showed on the DR system and the angles between the coronal plane of the body and the vertical plane of the flat panel detector (FPD) during taking these radiographs were recorded. The C-arm fluoroscopy unit was used to take the axial and tangential views referencing the angles measured on the DR system. Routine anteroposterior radiographs of the AC joint were taken on the volunteers. The minimal distances from the distal clavicle to the acromion were measured on both tangential and anteroposterior radiographs. The data was statistically analyzed.

Results  The clear axial and tangential radiographs of AC joints of the volunteers were obtained using both DR and C-arm fluoroscopy units. The angles demonstrated on the DR window are (20.8±2.4)° for male and (18.3±2.3)° for female. During taking the axial views, the angles between the coronal plane of the body and vertical plane of FPD are (23.3±3.2)° for male and (20.1±2.4)° for female. During taking tangential views, the corresponding angles are (117.5±3.7)° for male and (113.1±3.3)° for female. On the tangential radiographs, the minimal distance from the distal clavicle to the acromion is (6.1±1.2) mm, wider than the same measurement on the anteroposterior radiographs (P <0.05). Statistical analyses showed no significant differences in the above-mentioned angles and the minimal distances between the left and right AC joints (P >0.05). There were no significant differences in the above-mentioned angles between DR and C-arm fluoroscopy units (P >0.05).

Conclusions  The axial and tangential radiographs of the AC joint can demonstrate the joint clearly and they can be easily obtained with both DR system and C-arm fluoroscopy unit in similar projection directions.

     

Efficacy and safety of the treatment: combination of benazepril/lercanidipine vs. benazepril alone in patients with mild-to-moderate hypertension

Background Combination therapy is an effective method to reduce the blood pressure (BP) for patients with hypertension. This study was performed to evaluate the efficacy and safety of benazepril/lercanidipine compared with benazepril alone in patients with mild-to-moderate hypertension.

Methods One hundred and eighty-one patients with mild-to-moderate primary hypertension were assigned in this randomized, single-blind, parallel-group study and were randomly divided into group A (benazepril 10 mg/lercanidipine 10 mg) and group B (benazepril 10 mg) for 8 weeks. At 4 weeks, the dosage of Benazepril was titrated up to 20 mg if the diastolic blood pressure (DBP) remained ≥90 mmHg. BP control and side effects were evaluated at the end of 1, 4 and 8 weeks.

Results The baseline characteristics of the two groups were similar. The BP in both groups decreased from the baseline (P <0.05). At the end of 4 and 8 weeks, Benazepril/Lercanidipine produced greater BP reduction than Benazepril alone (P <0.05). The comparison of the rate of BP control for the benazepril/lercanidipine and benazepril groups at the end of 1, 4, and 8 weeks were 41.2% vs. 37.6% (P >0.05), 67.1% vs. 44.7% (P <0.05), and 71.8% vs. 45.9% (P <0.05). There was no significant difference of side effects between the two groups.

Conclusion The benazepril/lercanidipine combination is more effective in reducing BP than benazepril alone, while it does not increase the incidence of side effects.

     

Association of serum uric acid with different levels of glucose

Background  Previous studies have demonstrated that serum uric acid (UA) is an independent predictor of incident type 2 diabetes mellitus (T2DM) in general populations. This study aimed to investigate specific characteristics of UA and its relationship between UA and blood glucose and other risk factors in the Chinese population.

Methods  A total of 946 subjects were included in this study. UA, glucose, insulin, fractional excretion of UA (FEua), creatinine clearance rate (Ccr), hemoglobin A1c (HbA1c), fructosamine (FA), blood pressure and lipids were studied and also reexamined after the patients underwent two weeks of combined therapeutics.

Results  UA levels were the highest in subjects with impaired glucose regulation (IGR), followed by subjects with normoglycemia (NGT) and finally by subjects with T2DM. The level of the 2-hour postprandial insulin and the area under the curve for insulin (AUCins) showed a similar tendency. The UA levels initially increased with increasing fasting blood glucose (FBG) and postprandial blood glucose (PPBG) levels, up to 7 mmol/L and 10 mmol/L, respectively, and thereafter decreased at higher FBG and PPBG levels. Compared with subjects in the lower serum UA quartile, subjects in the upper quartile of serum UA levels had higher weights, triglyceride levels, and creatinine levels as well as lower Ccr and FEua levels. Compared with women’s group, UA levels were higher, and FEua levels were lower in men’s group. Sex, body mass index (BMI), mean arterial blood pressure (MAP), serum triglycerides (TG), FA and Ccr were independent correlation factors of UA. UA decreased and FEua increased after the patients underwent a combined treatment.

Conclusions  UA increased initially and then decreased as glucose levels increased from NGT to IGR and T2DM. Compared with NGT and T2DM, IGR subjects had higher SUA levels, which related to its high levels of insulin. Under T2DM, male gender, BMI, MAP, Ccr, TG and FA are independent correlation factors of UA. Glucose-lowering, antihypertensive, lipemia-regulating combined treatments were of advantage to decline of SUA of T2DM.

     

Molecular mechanism of indirubin-3′-monoxime and Matrine in the reversal of paclitaxel resistance in NCI-H520/TAX25 cell line

Background  Multidrug resistance (MDR) is a main reason for paclitaxel (TAX) treatment failure. Indirubin-3′-monoxime (IRO) and Matrine are traditional Chinese medicines, which may reverse the resistance of tumor cells to some chemotherapy drugs, but the relationship between paclitaxel resistance and Matrine is still unclear. The aim of this study was to explore the potential molecular mechanism of IRO and Matrine in reversal of TAX resistance.

Methods  In this study, MTT assay was used to measure the non-cytotoxic dosage of IRO and Matrine on NCI-H520/TAX25 cells and determine the reversal extent of TAX resistance under non-toxic doses. In addition, RT-PCR and Western blotting were used to evaluate the mRNA expression and the protein level of survivin, Oct-4, and Sox-2 in NCI-H520/TAX25 cells using semi-quantitative methods.

Results  There was no obvious inhibition on sensitive cell strains and drug-resistant strains, when the final concentration was at lest 4 µmol/L for IRO and 100 µmol/L for Matrine. So 4 µmol/L of IRO and 100 µmol/L of Matrine were considered as the reversal dosage. When 4 µmol/L of IRO or 100 µmol/L of Matrine were used together with TAX, the sensitivity to TAX increased evidently in NCI-H520/TAX2 cells; the reversal rate of IRO and Matrine was about 1.92 (43.56/22.6 nmol/L) and 1.74 (43.56/25.0 nmol/L), respectively. The mRNA expression and the protein level of survivin, Oct-4, and Sox-2 in NCI-H520/TAX25 decreased significantly (P <0.05) after addition of IRO or Matrine in TAX treatment, compared to that of TAX treatment alone.

Conclusion  The decrease in both mRNA expression and protein level of survivin, Oct-4, and Sox-2 might be the molecular mechanism, by which IRO and Matrine mediate the reversal of TAX resistance.

     

Minimally invasive lumbar interbody fusion via MAST Quadrant retractor versus open surgery: a prospective randomized clinical trial

Background  In recent years, a variety of minimally invasive lumbar surgery techniques have achieved desirable efficacy, but some dispute remains regarding the advantages over open surgery. This study aimed to compare minimally invasive lumbar interbody fusion via MAST Quadrant retractor with open surgery in terms of perioperative factors, postoperative back muscle function, and 24-month postoperative follow-up results.

Methods  From September 2006 to June 2008, patients with single-level degenerative lumbar spine disease who were not responsive to conservative treatment were enrolled in this study. Patients were randomized to undergo either minimally invasive surgery (MIS, transforaminal lumbar interbody fusion via MAST Quadrant retractor, 41 cases) or open surgery (improved transforaminal lumbar interbody fusion, 38 cases).

Results  The MIS group had longer intraoperative fluoroscopy time than the open surgery group, and the open surgery group had significantly increased postoperative drainage volume and significantly prolonged postoperative recovery time compared with the MIS group (P <0.05 for all). MRI scanning showed that the T2 relaxation time in the multifidus muscle was significantly shorter in the MIS group than in the open surgery group at 3 months after surgery (P <0.01). Surface electromyography of the sacrospinalis muscle showed that the average discharge amplitude and frequency were significantly higher in the MIS group than in the open surgery group (P <0.01). The Oswestry disability index and visual analog scale scores were better at 3, 6, 12 and 24 months postoperatively than preoperatively in both groups. Both groups of patients met the imaging convergence criteria at the last follow-up.

Conclusions  MIS can effectively reduce sacrospinalis muscle injury compared with open surgery, which is conducive to early functional recovery. In the short term, MIS is superior to open surgery, but in the long term there is no significant difference between the two procedures.

     

Gene delivery in peritoneal dialysis related peritoneal fibrosis research

Objective  To summarize the development of gene delivery vectors in peritoneal fibrosis research and discuss the feasibility and superiority of lentiviral vectors.

Data sources  The data in this article were collected from PubMed database with relevant English articles published from 1995 to 2011.

Study selection  Articles regarding the gene therapy in peritoneal fibrosis research using non-viral vectors, adenoviral vectors, retroviral vectors, and lentiviral vectors were selected. Data were mainly extracted from 60 articles, which are listed in the reference section of this review.

Results  Non-viral vector-mediated gene delivery (including naked DNA for ex vivo, oligonucleotides, ultrasound- contrast agent mediated naked gene delivery, etc.) and viral vector-mediated gene delivery (including adenovirus, helper-dependant adenovirus, and retrovirus vectors) have been successfully applied both in the mechanistic investigation and the potential prevention and treatment of peritoneal fibrosis.

Conclusions  Peritoneal fibrosis is a major complication of peritoneal dialysis (PD). Recently, the wide use of the gene delivery technique made it possible to access and further research peritoneal fibrosis. The use of lentiviral vector is expected to be widely used in PD research in the future due to its advantages in gene delivery.

     

Somatosensory disinhibition in patients with paroxysmal kinesigenic dyskinesia

Background  Paroxysmal kinesigenic dyskinesia (PKD) is characterized by recurrent brief episodes of chorea and dystonia induced by sudden movement. Whether the central nervous system is hyper- or hypoexcitable in PKD remains undetermined. The aim of our study was to compare the somatosensory evoked potential (SEP) recovery cycle, a marker of somatosensory system excitability, in PKD patients and controls.

Methods  Twenty-four PKD patients (mean age of (20.0±5.3) years; 21 males, 3 females) and 18 control age-matched subjects (mean age of (22.0±5.0) years; 17 males, 1 female) were studied. The stimuli were delivered to the median nerve in the affected dominant arm in patients and in the dominant arm in controls. The change in SEP amplitude was measured after paired electrical stimulation at interstimulus intervals (ISIs) of 5, 20, and 40 ms. The SEPs evoked by S2 (test stimulus) were calculated by subtracting the response to S1 (the conditioning stimulus) from the response to a pair of stimuli (S1 + S2), and their amplitudes were compared with those of the control response (S1) at each ISI. Analysis of variance (ANOVA) or equivalent was used for non-parametric data.

Results  In patients, the P27 amplitude after the single stimulus (S1) was significantly larger than that after the control stimulus. The (S2/S1)×100 ratio for P14 and N30 SEPs did not differ significantly between PKD patients and normal subjects at ISI of 5 ms but were significantly higher in patients at ISIs of 20 and 40 ms (P <0.05).

Conclusions  Somatosensory system disinhibition takes place in PKD. The finding of reduced suppression of different SEPs, each thought to have a different origin, suggests an abnormality of intracortical and subcortical inhibitory circuits.

     

Lung function after growing rod surgery for progressive early-onset scoliosis: a preliminary study

Background  Pulmonary problems often occur in patients with early-onset scoliosis (EOS). However, lung function in patients with EOS after growing rod surgery has not been documented. The aim of this study was to investigate lung function after the treatment for EOS with growing rod and its possible correlative factors.

Methods  Eight patients with EOS were treated with growing rod surgery at Peking Union Medical College Hospital from September 2002 to September 2009. Four patients had finished the final fusion surgery (group 1), and the other 4 (group 2) were in the process of periodic lengthening. Preoperative forced vital capacity (FVC), ratio of FVC to predicted FVC, forced expiratory volume in 1 second (FEV1), ratio of FEV1 to predicted FEV1, and radiographic measurements of Cobb’s angle and C7–S1 distance were recorded. Lung function changes and correlations between lung function changes and radiographic changes (Cobb’s angle and C7–S1 distance) were analyzed.

Results  In group 1, FVC and FEV1 both increased. FVC showed a significant difference (P=0.01), but FEV1 did not (P =0.05). In group 2, FVC and FEV1 also increased, and both showed a significant difference (P=0.04 and P=0.02, respectively). Ratio of FVC to predicted FVC and ratio of FEV1 to predicted FEV1 changed similarly and did not show statistical differences in the 2 groups. There were no significant correlations between lung function changes and radiographic changes (Cobb’s angle and C7–S1 distance) (P=0.10 and P=0.41, respectively).

Conclusions  Lung function increases after growing rod surgery in patients with EOS. Lung function changes do not correlate with Cobb’s angle changes or C7–S1 distance changes.

     

Imageological measurement of the sternoclavicular joint and its clinical application

Background  Dislocation of the sternoclavicular joint is rare. However, posterior dislocation compressing important structures in the mediastinum may be fatal. Early diagnosis and prompt therapy of sternoclavicular joint dislocation are important. Computed tomography (CT) is an optimal means to investigate sternoclavicular joint anatomy; however, there are few reports on the imageological anatomical features of the sternoclavicular joint. The study investigated imageological anatomical features, and a new plate was devised according to these data to treat sternoclavicular joint dislocation.

Methods  Fifty-three healthy Chinese volunteers examined with chest CT were included in the study. The coronal, sagittal, and axial images of the sternoclavicular region were reconstructed. The sternal head diameter in the inferolateral-to-superomedial direction, length of the clavicular notch, and angle between the clavicular notch and sternum were measured on coronal images. The angle between the presternum and trunk was measured on sagittal images. The following dimensions were measured on axial images: anteroposterior dimensions of the sternal head, clavicular notch, and presternum; width of the sternoclavicular joint; distance between bilateral clavicles; and minimal distance from the presternum to the underlying structures in the thoracic cavity. A new plate was designed according to the above data and was used to repair six sternoclavicular joint dislocations. All cases were followed up with a range of 9 to 12 months.

Results  The proximal clavicle is higher than the presternum in a horizontal position. On axial images, the anteroposterior dimension of the sternal head was longer than the presternum, and the center region of the presternum was thinner than the edges. The left sternoclavicular joint space was (0.82±0.21) cm, and the right was (0.87±0.22) cm. Among the structures behind the sternum, the left bilateral innominate vein ran nearest to the presternum. The distance from the anterior cortex of the sterna to the left bilateral innominate vein was (2.38±0.61) cm. The dislocated joints were reduced anatomically and fixed with the new plate. All cases obtained satisfactory outcomes in follow-up visits.

Conclusions  Normal sternoclavicular joint parameters were measured on CT images, which can facilitate treatment of sternoclavicular joint dislocation or subluxation. This newly designed plate can be used to treat sternoclavicular joint dislocation effectively and safely.

     

Cytotoxic effects of mono-（2-ethylhexyl） phthalate on human embryonic stem cells

Background  Mono-(2-ethylhexyl) phthalate (MEHP), the metabolite of di-(2-ethylhexyl) phthalate (DEHP), was suspected to be toxic to human embryos. This study contributes to investigating its toxic effects by an embryonic stem cell test (EST) based on two human embryonic stem cell (hESCs) lines.

Methods  CH1 established in our own lab and H1, a federally registered cell line were two human embryonic stem cell lines used in this test. Four endpoint measurements were performed consisting of cell viability, proliferation ability, apoptosis as well as changes of gene expression patterns after spontaneous differentiation were determined. For measuring effects on the first three endpoints, the cells were treated with various concentrations of MEHP dissolved in dimethyl sulfoxide (DMSO) and only with DMSO which served as control and harvested after 5 days. For measuring effects during spontaneous differentiation, the RNA of embryoid bodies (EBs) formed after 8 days’ MEHP exposure was collected and changes in differentiation specific gene expression patterns were analyzed by quantitative real time RT-PCR.

Results  As a result the viability and proliferation ability of both cell lines decreased significantly at 1000 µmol/L MEHP, while there was no effect on apoptosis or cell morphology. In addition MEHP also changed the gene expression pattern in the EBs of both cell lines.

Conclusion  MEHP in a high dose was cytotoxic and affected the development of hESCs, which indicates its embryo toxicity in human embryos.

     

Deformation of the left and right ventricular longitudinal myocardium in fetuses with umbilical cord around neck

Background  Umbilical cord around neck, a common obstetric complication, affects fetal hemodynamics. Does it influence fetal cardiac functions? The purpose of this study was to investigate the left and right ventricular systolic and diastolic functions of fetuses with umbilical cord around neck in the third trimester by applying velocity vector imaging (VVI).

Methods  Thirty-five cases of fetuses with umbilical cord around neck whose gestational ages from 35 to 40 weeks were selected, including 20 cases of umbilical artery ratio of the highest systolic velocity (S) to the lowest diastolic velocity (D) (S/D) <3.0 and 15 cases of umbilical artery S/D ≥3.0, while 20 cases of normal fetuses of 35–40 gestational weeks were selected as the control group. The changes in longitudinal velocity, strain, and strain rate of fetal left and right ventricle in systole and diastole in two groups, and the changes in fetal cardiac function under the situation of umbilical cord around neck were analyzed.

Results  Longitudinal strain and strain rate overall of fetal left and right ventricle in systole and diastole were less in fetuses with umbilical artery S/D ³3.0 and umbilical cord around neck than those in fetuses with umbilical artery S/D <3.0 and those in control group (P <0.05); there was no significant difference (P >0.05) in longitudinal strain and strain rate overall of fetal left and right ventricle in systole and diastole between fetuses with umbilical artery S/D <3.0 and those in control group.

Conclusions  Left and right ventricular systolic and diastolic dysfunction was detected in fetuses with umbilical cord around neck and umbilical artery S/D ³3.0. VVI could sensitively respond to cardiac function changes in fetuses with umbilical cord around neck, which provides another valuable method in the evaluation of fetal cardiac function.

     

Identification of Max binding protein as a novel binding protein of Nck1 and characterization of its role in inhibiting human liver cancer SK-HEP-1 cells

Background  The tendency of tumor cells to disperse throughout the liver is a distinct feature of hepatocellular carcinoma (HCC). Nck family adaptor proteins function to regulate actin cytoskeletal reorganization that leads to cell motility. We previously found that Max binding protein (MNT) was differentially expressed in HCC, and interacted with Nck1 by 2-DE. MNT is a protein member of the Myc/Max/Mad network which plays roles in cell proliferation, differentiation, and death. We investigated the effects of MNT on migration of human liver cancer SK-HEP-1 cells to study the migration regulatory role of MNT in HCC cells.

Methods  Interaction between MNT and Nck1 was further validated in hepatoma cells by GST-pull down assay and immunoprecipitation. siRNAs specific to MNT (MNT siRNA) were used to knockdown MNT expression. Western blotting, transwell assay were used to determine the migration potential of cells. 

Results  Interaction between MNT and Nck1 was validated in hepatoma cells. MNT knockdown promoted the migration of human liver cancer SK-HEP-1 cells (P <0.01).

Conclusion  The results suggest that MNT, via interaction with Nck1, inhibits hepatoma cell migration.

     

Serological and molecular capsular typing, antibiotic susceptibility and multilocus sequence typing of Streptococcus pneumoniae isolates from invasive and non-invasive infections

Background Streptococcus pneumoniae (S. pneumoniae) is a major causative agent of severe infections, including sepsis, pneumonia, meningitis, and otitis media, and has become a major public health concern. We report the pneumococcal serotype and sequence type (ST) distribution, and antimicrobial resistance of 39 S. pneumoniae strains from seven hospitals in China.

Methods Blood/cerebrospinal fluid (CSF) and sputum isolates from patients were analyzed to determine S. pneumoniae serotypes by polymerase chain reaction (PCR) and the Neufeld Quellung reaction, the multilocus sequence types (MLST) by PCR and sequencing, and susceptibility to antimicrobial agents by the VITEK Gram Positive Susceptibility Card.

Results A total of 39 isolates were collected including 21 blood/CSF and 18 sputum isolates. Conventional serotyping by the Quellung reaction required 749 reactions. In contrast, PCR based typing needed only 106 PCR reactions. The most frequent serotypes from the blood/CSF isolates were 14 (38.1%), 19A (14.3%), 23F (9.5%), and 18C (9.5%). In the sputum isolates the most frequent serotypes were 19F (33.3%), 23F (16.7%), 19A (11.1%), and 3 (11.1%). The incidence of penicillin resistance in the blood/CSF and sputum isolates was 66.7% and 55.6%, respectively. Statistical analysis showed that patients ≤5 years old had a higher resistance to penicillin when they compared with the patients ≥65 years old (P=0.011). Serotypes 14, 19A and 19F were significantly associated with penicillin resistance (P <0.001). ST320, ST271, and ST876 isolates showed high resistant rates to several antibiotics including penicillin (P=0.006). All of the isolates of serotype 19A were resistant to both penicillin and erythromycin, and they were all multi-drug resistant (MDR) isolates.

Conclusions The specificity and sensitivity of multiplex-PCR are good, and this method represents a substantial savings of time and money, and can be widely used in the laboratory and clinical practice. Data from this research showed an extremely high prevalence of penicillin resistance and an increasing prevalence of multi-drug resistant (MDR) rate in S. pneumoniae. A distinctive emergence of serotype 19A was observed which was also associated with the increasing prevalence of antimicrobial resistance. Therefore, nationwide surveillance of pneumococcal resistance and serotypes is strongly warranted.

     

中国北方人群恒齿中变形链球菌和细菌总数的定量检测

Background  Streptococcus mutans (S. mutans) is the prime pathogen of dental caries. There are few reports that studied the relationship between S. mutans, bacteria and dental caries in permanent teeth when compared to those in primary teeth. This study aimed to detect S. mutans and bacteria of dental caries and non-caries groups in permanent teeth from a north China population by real-time polymerase chain reaction (PCR) and compare the relationship between the number of these bacteria and the prevalence of dental caries in permanent teeth.

Methods  Human saliva samples were collected from 142 subjects with permanent teeth. According to their dental tooth (DT), 142 subjects were divided into a dental caries group (DT ³1) and a non-caries group (DT=0). With specific primers for S. mutans and 16S rRNA, the total number of S. mutans and total bacteria of 142 saliva samples were detected by real-time PCR and statistically analyzed.

Results  There was no significant difference between the detection rates of S. mutans (P=0.118) and medians of S. mutans (P=0.115). The ratio of S. mutans to total bacteria in people with dental caries was significantly higher than in those without caries (P <0.001), but the total number of bacteria in people with dental caries was significantly lower than in those without caries (P <0.001).

Conclusions  S. mutans had different effects on caries in the permanent teeth of several individuals from a north China population. The ratios of S. mutans to total bacteria in saliva detected by real-time PCR with Sm479F/R and 16S RNA primers were closely associated with the prevalence of dental caries in the same population. These assays may be useful for the assessment of an individual’s risk of dental caries.