Objective:To investigate a method to identify Actinobacillus actinomycetemcomitans serotypes by polymerase chain reaction. Methods:18 Actinobacillus actinomycetemcomitans strains representing serotypes a to f were used in the test. 6 pairs of specific oligonucleotide primers for gene clusters involved in the biosynthesis of serotype specific polysaccharide antigens were designed. The primers were developed and evaluated in a genetic method of identifying serotypes of Actinobacillus actinomycetemcomitans strains by using a PCR assay. Results: Each pair of primers can specifically identify one serotype of Actinobacillus actinomycetemcomitans strains. No cross reaction was observed in all 18 strains. The PCR product sizes were as follows: 428 bp (serotype a), 298 bp (serotype b), 559 bp (serotype c), 690 bp (serotype d), 211 bp (serotype e) and 232 bp (serotype f). Conclusion:PCR method may be useful to identify Actinobacillus actinomycetemcomitans serotypes rapidly and directly.

Objective To explore the feasibility of inherent depressive Fawn-Hooded (FH/Wjd)rats as a comorbidity model of mental disorder and irritable bowel syndrome (IBS) by comparing visceral sensitivity of FH/Wjd rats and Sprague-Dawley (SD) rats. Methods Depression trait of FH/Wjd rats was validated through forced swimming test (FST) and sucrose preference test (SPT).Visceral sensitivity to colorectal distention (CRD) under various pressures was assessed by abdominal withdrawal reflex (AWR). The expression of 5-HT in rats' colon,c-fos expression in colon and brain areas of infralimbic cortex (IL),prelimbic cortex (PrL) and rostral anterior cingulated cortex (rACC)was tested with immunohistochemistry. Results FST indicated that the immobility time of FH/Wjd rats was significantly longer than that in SD rats (t=-8. 931,P＜0. 01). SPT showed that the ratio of sucrose water in total liquid consumed was significantly lower in FH/Wjd rats than that of SD rats(t=4. 155,P=0. 01). At each CRD pressure gradient (20,40,60 and 80 mm Hg,1 mm Hg=0. 133kPa),AWR score was all significantly higher in FH/Wjd rats than that of SD rats (t=-2. 697,-3.464,-6.822 and -3. 976,P=0. 022,0.006,0.000 and 0.003). The expression level of 5-HT in FH/Wjd rats' control group was significantly higher than that of SD rats' control group (t=-11.371,P=0. 000). Compared with their own control group,5-HT expression increased both in FH/Wjd rats dilated groups and SD rats dilated groups,and the expression level in FH/Wjd rats was higher than that of SD rats (t= -3. 364,P= 0. 007). There was no significant difference of c-fos expression in colon and prefrontal brain areas between FH/Wjd rats' control group and SD rats'control group (colon:t=-0. 129,P= 0. 900;IL:t=-1. 316,P= 0. 218;PrL:t=1. 241,P = 0. 243;rACC:t=2. 151,P = 0. 057). Compared with their own control group,the expression of c-fos in colon and prefrontal brain areas significantly increased both in FH/Wjd rats dilated groups and SD rats dilated groups,and the expression level in FH/Wjd rats was higher than that of SD rats (colon: t=- 5.864,P= 0.000;IL:t=-2. 530,P = 0. 030;PrL:t=-7. 039,P= 0. 000;rACC:t=-6. 489,P=0. 000). Conclusions Inherent depressive FH/Wjd rats present visceral hypersensitivity. Meanwhile,the expression of 5-HT in colon is high,and with hyperreactivity to visceral noxious stimuli in colon and brain IL,PrL,and rACC areas. FH/Wjd rats might be a comorbidity animal model of mental disorder and IBS.

Objective To approach the value of combination mode of different CT post-processing technique in diagnosing rib fine fracture.Methods 98 patients suspected with rib fractures underwent multislice spiral CT(MSCT) scanning,and CT features of rib fractures were observed with the combination of three different images:(A)volume rendering(VR),curved planar reformation(CPR) and axial view;(B)maximum intensity projection(MIP),CPR and sxial view;and(C) VR+MIP,CPR and axial view.The results were respectively recorded.Results 265 rib fine fractures were found among 98 patients.The detecting rate of fine fractures with C group was higher than that with A group (χ~2＝6.67,P＜0.01) and B group (χ~2＝6.75,P＜0.01).Conclusion MSCT four step observation method can improve the detecting rate of rib fine fracture,that is of important clinical value.

BACKGROUND:Recent studies have found that long non-coding RNAs (lncRNAs) can regulate stem cel proliferation and differentiation. But it is unclear that how lncRNA NR_033474 regulate stem cel proliferation and cel cycle. OBJECTIVE:To investigate the effect of lncRNA NR_033474 on the proliferation and cel cycle regulation in C3H10T1/2 mesenchymal stem cel s after the NR_033474 overexpressed by lentivirus, and to study the possible regulation mechanism of NR_033474 on mesenchymal stem cel s. METHODS:LncRNA NR_033474 was cloned into a lentivirus vector. Lentivirus particles were infected into C3H10T1/2 cel s to upregulate the expression of NR_033474. The NR_033474 expression level was detected by real-time PCR. Compared with the empty lentivirus vector, the proliferation of C3H10T1/2 cel s which overexpressed NR_033474 was detected by cel counting assay and cel cycle was detected using flow cytometry. The expression of cel cycle-associated proteins such as CDK1, Cyclin B1, Cyclin D1 and P53 were detected by western blot assay. RESULTS AND CONCLUSION:Compared with the control group, lncRNA NR_033474 in C3H10T1/2 cel s which overexpressed NR_033474 was increased by about 100 times (P<0.01), and the proliferation of C3H10T1/2 cel s was significantly inhibited after NR_033474 overexpression by lentivirus (P<0.05). In addition, flow cytometry showed that C3H10T1/2 cel s overexpressing NR_033474 were arrested in G2/M phase compared to the control group. Western blot showed that the expression levels of CDK1 and Cyclin B1 were downregulated, while there were no changes in Cyclin D1 and P53 expression. To conclude, these findings suggest that the NR_033474 overexpression significantly inhibits the cel growth of C3H10T1/2 cel s, at least in part, through induction of cel cycle arrest at G2/M phase.

Objective To discuss the treatment strategy of medial collateral ligament and combined injury in the terrible triad of elbow.Methods The data of 21 patients with terrible triad of elbow who received treatment from February 2010 to April 2012 was retrospectively analyized.There are 17 males and 4females with12 cases left and 9 right elbows.The average age of them was 37.6 years (16-57).MRI examination was performed routinely,and used as guidance of treatment strategy of medial collateral ligament and combined injury.For the patients without or with partial damage of anterior bundle of medial collateral ligament(AMCL) injury while the continuity of ligament remains complete in MRI image,exploration and repair of the medial collateral ligament is not conventional.For the patients with MRI image showing AMCL avulsion or body disruption,we routinely used antero-medial approach to explore and repair,suture-anchors were used for suture the bony avulsion of the medial collateral ligament,body disruption of ligament and combined flexor-pronator teres complex injury were also be suture repaired.None of the patients used hinged external fixator during operation.A hinged brace was applied after operation.Results All patients were followed up for an average of 12.4 months (6-26).At the last follow-up,the average range of motion of the elbow was 135.2 ±10.2 degrees,average straight limited degrees,6.7±2.2 degrees,an average of 142±11.0 degrees of flexion.Mayo elbow performance score was 92 points (85-100).17 cases were excellent and 4 were good.Complications included:a transient ulnar nerve palsy in 3 cases,heterotopic ossification in 2 cases,tardive ulnar neuritis in 1 case,no elbow residual instability,dislocation,elbow stiffness and other complications.Conclusion Anterior bundle of medial collateral ligament avulsion or body disruption should be routinely suture repaired,which is in favor of restoring elbow immediate stability favoring restore elbow immediate stability.

Traditional right ventricular pacing is non-physiological pacing, can lead to ventricular electrical and mechanical dyssynchmnization, which increases the risk of heart failure and atrial fibrillation. His-Purkinje system pacing is the hot research of physiological pacing method. The high thresholds and difficult implantation of his bundle pacing limits its application and popularization. In recent years, domestic scholars have proposed left bundle branch area pacing. Many studies have confirmed the safety and feasibility of left bundle branch area pacing. Left bundle branch pacing transmit down the conduction system, which can effectively achieve ventricular electrical and mechanical synchrony, At the same time, it also has many others advantages, such as good and stable electrical parameters, significantly improved cardiac function, and pacing across blocked parts. It will become the main development direction of physiological pacing in the future. This article aims to review the origin, standard and classification, advantages and limitations of left bundle branch area pacing.

BACKGROUND:Recent studies have found that stem cellpluripotency and differentiation is regulated by many long non-coding RNAs (LncRNAs). The expression and effect of LncRNA AK089560 during differentiation of stem cells is unclear. OBJECTIVE:To investigate the expression of LncRNA AK089560 in mesenchymal stem cells C3H10T1/2 undergoing osteogenic and adipogenic differentiation. METHODS:Osteogenic differentiation of mesenchymal stem cells C3H10T1/2 was induced by recombinant human bone morphogenetic protein-2 and evaluated using alkaline phosphatase staining. The adipogenic differentiation of mesenchymal stem cells C3H10T1/2 was induced by three factors (dexamethasone, indomethacin and insulin) and evaluated by oil red O staining. The dynamical expression of LncRNA AK089560 was detected by qRT-PCR assay. The AK089560 secondary structure was predicted using RNAfold software. The relationship between AK089560 and neighboring protein-coding genes was analyzed using UCSC genome browser and visualized by fancyGENE online software. RESULTS AND CONCLUSION:Over 70%of C3H10T1/2 cells were positive for alkaline phosphatase after osteogenic induction and more than 80%of the cells positive for oil red O staining after adipogenic induction. qRT-PCR results showed that the expression of LncRNA AK089560 at days 2, 4, 6 of both osteogenic and adipogenic differentiation was significantly decreased compared with the control group (P<0.05). Bioinformatics analysis showed that there was a stem-loop structure for AK089560 and sense overlap relationship between AK089560 and protein-encoding gene Sema3a. These findings indicate that LncRNA AK089560 expression is reduced during osteogenic differentiation and adipogenic differentiation, showing that AK089560 may be involved in regulating the multi-directional differentiation of stem cells.

Objective To approach the application value of diffusion weighted imaging with background suppression (DWIBS) combined with routine MR sequence in differentiating benign and malignant lymph nodes,and assessing therapeutic effect of lympho-genic tumors.Methods 48 patients with cervical lymph node enlargement who were confirmed by pathology and follow up under-went DWIBS and routine MRI examination,malignant lymph nodes were 83,benign lymph nodes were 79.16 patients with malig-nant lymph nodes were rechecked after radiotherapy and chemotherapy,Apparent diffusion coefficient (ADC)values of the solid part for lymph nodes were compared.Results More lymph nodes can be detected in DWIBS than conventional sequence.ADC values of the solid part for malignant lymph node(0.898±0.111)×10-3 mm2/s were lower than that of benign lymph node(1.043±0.106)× 10-3 mm2/s,there was significant difference between them (P<0.05).ADC values of all malignant lymph nodes after treatment (1.205±0.121)×10-3 mm2/s were significantly higher than that of pretherapy (0.883±0.090)×10-3 mm2/s (P<0.05).Conclu-sion DWIBS could more sensitively detect lymph node than conventional MR sequence.ADC value could provide some reference values for differentiating benign and malignant lymph nodes and assessing therapeutic effect.

Objective To investigate the application value of diffusion-weighted imaging with background suppression (DWIBS) in lymph node metastasis of rectal cancer.Methods 30 patients with rectal cancer diagnosed by colonoscopy underwent routine MRI and DWIBS examinations.Metastatic and non-metastatic lymph nodes were confirmed by postoperative pathology.Apparent diffu-sion coefficient (ADC)values of the solid part of metastatic and non-metastatic lymph nodes were measured and compared.ROC curve analysis was used to define the threshold between the metastatic and non-metastatic lymph nodes.Results In all 73 lymph nodes,there were 52 metastatic lymph nodes and the other 21 were non-metastatic.ADC values of the solid part of metastatic and non-metastatic lymph nodes were (0.881 ± 0.094)× 10 -3 mm2/s and (1.072 ± 0.108)×10 -3 mm2/s respectively,the difference was statistically significant (P <0.05).With the threshold ADC value of 0.957×10 -3 mm2/s,the sensitivity and specificity for dif-ferentiating metastatic from non-metastatic lymph nodes were 90.5% and 80.8% respectively.The diagnostic value was excellent (Az value = 0.91 9,P <0.05).Conclusion ADC values may be used to differentiate lymph node metastasis of rectal cancer,and DWIBS has higher application value in assessing lymph node metastasis of rectal cancer.

AIM:To analyze the alterations of angiotensin Ⅱ (Ang Ⅱ), connexin 43 (Cx43), angiotenisinⅡreceptor type 1 (AT1) and signaling molecules in the TGF-β1/Smad pathway in different regions of the left ventricular heart tissue for exploring whether Ang Ⅱregulates Cx43 expression via the TGF-β1/Smad signaling pathway in myocardial infarction ( MI) rats.METHODS:MI was induced in 20 male Sprague-Dawley rats by the left anterior descending coronary artery ligation.The rats were then randomized into 2 groups.In the losartan group, 20 mg· kg-1· d-1 of losartan were ad-ministered for 2 weeks.Heart functions were assessed after surgery and 2 weeks later again following the above treatments . All the rats were sacrificed and relevant molecules , including Ang Ⅱ, AT1, and Cx43 were determined thereafter in diffe-rent areas of the left ventricle .TGF-β1 and its downstream signaling molecules , including Smad 2, Smad 3 and Smad 7, were also detected .RESULTS:In losartan group , both left ventricular internal dimension diastole ( LVIDd) and left ven-tricular internal dimension systole (LVIDs) were smaller, with diminished interventricular septal thickness (IVSd) and left ventricular posterior wall depth ( LVPWd ) and distinct improvement of left ventricular ejection fraction ( LVEF ) ( P<0.05 ) .Losartan therapy exhibited a reduction of Ang Ⅱin the infarct zone and the border zone in the cardiac tissues .AT1 was obviously attenuated in the infarct zone with an enhanced expression of Cx 43, which was also elevated in the border zone and none infarct zone .TGF-β1, Smad 2 and Smad 3 were decreased in different zones of the left ventricle , while Smad 7, in contrary to the above factors , presented a converse alteration .CONCLUSION:The activation of Ang Ⅱpro-vokes downregulation of Cx 43 through TGF-β1/Smad signaling pathway in MI rats .