Objective To introduce a kind of operative technique in repair for the prolapse of the anterior mitral valve leaflet.Methods From January 2004 to October 2010,the operation of chordal transfer based on theedge-to-edge technique was performed in 18 cases with serious mitral valve regurgitation because of prolapse of the anterior leaflet.First,the edge-to-edge suturing was performed at the free edge of the prolapsed anterior leaflet with corresponding posterior leaflet.After that,quadrangular resection was performed to transfer these segments of posterior leaflet with its attached chordae.At last,the posterior leaflet was repaired after a quadrangular resection which would be much easier for the surgeons.After the operation,echocardiography was performed in each patient before discharge and at the time of follow-up.Results All patients survived after the operation,1 case required the rnitral valve replacement because of anterior leaflet performation occurring 3 days after the operation,1 case with hemoglobinuria and 1 case with low cardiac output,who all got symptomatic treatment afterwards.All the other patients were well discharged.At the time of follow-up,all of the patients were in NYHA functional class I.In all these patients,pre-discharge and follow-up echocardiography showed neither stenosis nor significant regurgitation of the mitral valve:the cross-sectional area of the mitral valve was 2.8-4.8 (3.78 +0.52) cm2,the mean regurgitation area was (0.45 +0.22) cm２.At the same time,both dimension of left atrium and left ventricular reduced significantly [ left atrium diameter:pre-operation ( 48.26 + 11.12 ) mm,post-operation ( 37.57 ± 9.56) mm (P ＝ 0.028 );the end-diastolic diameter of the left ventricular:pre-operation(61.43 ± 8.24) mm,post-operation (42.35 ±10.79) mm (P＝0.008)].Conclusion Chordal transfer based on the edge-to-edge technique provides good results for repair of anterior leaflet prolapse.

OBJECTIVE: To investigate the classification and incidence of acid-base disturbance (ABD) in the patients with post-traumatic multiple organ dysfunction syndrome (MODS). METHODS: A total of 119 patients with MODS were examined with arterial blood gas analysis and serum electrolytes detection for 675 times in this study. RESULTS: Different types of ABD existed in 647 times out of 675 times (95.9%) of blood-gas analyses. There were 270 times (41.7%) of simple ABD, 271 times (41.9%) of double ABD and 106 times (16.4%) of triple ABD. Among which, 404 times (62.4%) were in respiratory alkalosis (RAL), 332 times (51.3%) in metabolic acidosis (MA), 227 times (35.1%) in metabolic alkalosis (MAL) and 167 times (25.8%) in respiratory acidosis (RA). In this study, 79 cases (66.4%) out of 119 cases with MODS died from these kinds of ABD. CONCLUSIONS: It suggests that in the early stage of MODS, RAL with or without hypoxemia may exist, and later on, MA or even triple ABD may occur. In order to detect and correct the primary disorders as early as possible, it is important to keep the balance of hydrolyte. The treatment of primary diseases is also important. Disorders of acid-base balance were corrected according to pH standard values, anion gap (AG) and the potential [HCO(3)(-)] were also calculated simultaneously. When pH was more than 7.50 or lower than 7.20, it is necessary to give drugs of acidity or alkalinity to the patients with ABD to maintain pH value within a normal range.

Objective:To explore the clinical effect and application value of simultaneous modulated accelerated radiotherapy (SMART) in the suspicious positive lymph nodes of head and neck.Methods:From January 2017 to February 2019, 60 patients with suspected positive lymph nodes in the head and neck in the Hanzhong Central Hospital of Shaanxi Province were divided into experimental group and control group according to different treatment plans, and 30 patients in each group were included. In the experimental group, 63.36 to 66.66 Gy patients were treated with SMART, while in the control group, 54.12 to 60.06 Gy patients were treated with conventional neck prophylactic radiation. In order to evaluate the feasibility of the method, the change of the short diameter of the largest cross section of the suspicious positive lymph nodes in the two groups were observed, and the adverse reactions in the treatment of the two groups were analyzed.Results:There was no significant difference between the two groups before treatment ( P>0.05). After treatment, the size of short diameter of lymph nodes in the two groups was smaller than that before treatment. The maximum short diameter of the largest cross section of lymph nodes in the experimental group was smaller than that before treatment: (0.43 ± 0.07) cm vs. (0.72 ± 0.10) cm, and the difference was statistically significant ( P<0.05). In the control group, the maximum short diameter of the largest cross section of lymph node decreased after treatment, and the difference was not statistically significant ( P>0.05). After treatment, the reduction of the short diameter in the experimental group was more obvious than that in the control group. The maximum short diameter of the largest cross section between the two groups: (0.43±0.07) cm vs. (0.66±0.08)cm was statistically significant ( t = 11.523, P<0.05). Before treatment, hemoglobin (HGB) levels of the two groups were in the normal physiological range, and there was no significant difference between the two groups ( P>0.05); the white blood cell (WBC) levels of the two groups at different time after treatment were compared: in the first week (7.83 ± 2.53) × 10 9/L vs. (8.26 ± 3.16) × 10 9/L, in the third week (7.14 ± 3.65) × 10 9/L vs. (7.08 ± 2.53) × 10 9/L, in the fifth week (5.47 ± 2.81) × 10 9/L vs. (6.41 ± 2.57) × 10 9/L, and in the seventh week (4.36 ± 2.59) × 10 9/L vs. (4.98 ± 1.64) × 10 9/L, and there were statistical differences ( P<0.05), which indicated that the WBC index levels of the two groups were gradually decreased during the treatment, and the decreased degree of the experimental group was higher than that of the control group. The levels of HGB and PLT were maintained in the normal physiological range before and after treatment, and there was no significant difference between the two groups ( P>0.05). The main complications in the treatment of the experimental group were xerostomia and stomatitis. The adverse reactions in the control group were pain in the target area of radiotherapy. There was no significant difference between the two groups ( P>0.05). Conclusions:The application of IMRT is an effective method for the treatment of occult lymph node metastasis, and it is also a therapeutic diagnostic method, which can provide evidence for the study of the law of lymph node metastasis in the head and neck. The safety and tissue tolerance of IMRT in the treatment of suspicious positive lymph nodes in the head and neck are good, which can be used for the suspicious lymph nodes in the head and neck. The treatment of positive lymph nodes and the evaluation of patients′ prognosis provide an effective way of clinical treatment.

Objective To study the function of gene 0955 in Streptococcus suis type 2 98HAH33. Methods Growth condition of wild-type, mutant and complemented strains of Streptococcus suis type 2 98HAH33 was compared at different stages. Differences in adhesion ability to host cells and anti-phagocyto-sis among these strains were compared by using bacterial adhesion test and analyzing their survival rates in blood. Mouse and piglet models were used to evaluate their virulence. Results The growth of the mutant and the complemented strains was slightly slower than that of the wild type strains in logarithmic growth phase, but no significant difference was found in plateau phase. Bacterial adhesion test showed that gene 0955 might encode a new adhesion factor of Streptococcus suis type 2 98HAH33. Blood bactericidal test sug-gested that gene 0955 was not associated with anti-phygocytosis. Animal experiments showed that gene 0955 might be a novel virulence gene of Streptococcus suis type 2 98HAH33. Conclusion Gene 0955 might en-code a novel adhesion factor and virulence factor of Streptococcus suis type 2 98HAH33.

Objective To study the mechanism of carboxypeptidase E ( CPE ) in promoting the migration of lymphocytes and their subsets through vascular endothelial cells. Methods CRISPR/Cas9 technology was used to prepare cpe gene-knockout MS1 (Cpe-/-MS1) cells. Adhesion ability of lymphocytes to MS1 and Cpe-/-MS1 cells was analyzed with adhesion assay. Expression of adhesion molecules on these cells were detected by RT-PCR and flow cytometry. Transwell model was used to compare the difference in the transmigration of lymphocytes and their subsets through MS1 and Cpe-/-MS1 cells. Results Cpe-/-MS1 cells were successfully obtained. Under the stimulation of TNF-α, the adhesion ability of lymphocytes to MS1 cells was much better than that of Cpe-/-MS1 cells. Moreover, adhesion molecules expressed on MS1 cells were significantly more than those on Cpe-/-MS1 cells. The percentages of lymphocytes and their sub-sets that transmigrated through MS1 cells were significantly higher than those through Cpe-/-MS1 cells. Con-clusion CPE involved in the adhesion of lymphocytes to vascular endothelial cells and the transmigration of them through vascular endothelial cells, which was of great significance for understanding the migration of lymphocytes across vascular endothelial cells to peripheral lymph nodes.

Objective:To construct four retroviral plasmids for differential expression of green fluorescent protein (GFP) based on different terminal sequences of internal ribosome entry site (IRES) and provide reference for subsequent flow analysis or imaging.Methods:Based on the fact that the transcription efficiency of encephalomyocarditis virus IRES depends on its terminal sequence, IRES and enhanced GFP (EGFP) were fused into four fragments with different connection modes by overlapping PCR, and then cloned into retroviral plasmid pMSCV-NGFR. NGFR fragment was amplified by PCR and inserted in front of the retroviral plasmids pMSCV-IRES(1-4)-EGFP. These retrovirus plasmids pMSCV-NGFR-IRES(1-4)-EGFP were transfected into 293T cells. The expression ratio and mean fluorescence intensity (MFI) of EGFP were analyzed, and the expression of NGFR was also detected.Results:Four retroviral plasmids pMSCV-NGFR-IRES(1-4)-EGFP were successfully constructed. No significant difference in the expression efficiency of EGFP at 24 or 48 h was observed in 293T cells transfected with the four different retroviral plasmids, but there was significant difference in fluorescence intensity. Moreover, the expression of NGFR was not significantly different, indicating that the addition of different nucleotide sequences between IRES and EGFP would make a significant difference in the fluorescence intensity of EGFP.Conclusions:The expression intensity of EGFP was affected by the sequence between IRES and EGFP. Retroviral plasmids expressing EGFP of different intensity could meet different experimental requirements.