Numerous studies of relationship between epigenomic features have focused on their strong correlation across the genome, likely because such relationship can be easily identified by many established methods for correlation analysis. However, two features with little correlation may still colocalize at many genomic sites to implement important functions. There is no bioinfor-matic tool for researchers to specifically identify such feature pairs. Here, we develop a method to identify feature pairs in which two features have maximal colocalization minimal correlation (MACMIC) across the genome. By MACMIC analysis of 3306 feature pairs in 16 human cell types, we reveal a dual role of CCCTC-binding factor (CTCF) in epigenetic regulation of cell identity genes. Although super-enhancers are associated with activation of target genes, only a subset of super-enhancers colocalized with CTCF regulate cell identity genes. At super-enhancers colocalized with CTCF, CTCF is required for the active marker H3K27ac in cell types requiring the activation, and also required for the repressive marker H3K27me3 in other cell types requiring repression. Our work demonstrates the biological utility of the MACMIC analysis and reveals a key role for CTCF in epigenetic regulation of cell identity. The code for MACMIC is available at https://github.com/bxia888/MACMIC.

Objective: To explore the safety and feasibility of transumbilical single channel laparoscopic cryptorchidopexy with conventional instruments in treatment of cryptorchidism in children. Methods: Thirty-five children with cryptorchidism were treated by transumbilical single channel laparoscopic cryptorchidopexy with conventional instruments from November 2017 to March 2018 at Department of Pediatric Surgery, the First Affiliated Hospital of Guangxi Medical University.Clinical data were recorded including the general information, operation time, intraoperative blood loss, postoperative testicular position and postoperative complications, etc. Results: All 35 patients completed the cryptorchidopexy in one operation.Among those 35 patients, 28 patients had unilateral lesions and 7 patients had bilateral lesions, with a total of 42 sides.Twenty-six patients were of groin type(33 sides), 9 patients abdominal type(9 sides). The average operation time was (40.4±8.2) min for unilateral lesion, and (62.5±15.3) min for bilateral lesions; the average intraoperative blood loss was (3.0±1.8) mL; and the average postoperative hospital stay was (6.4±2.1) h. Testis of 32 patients (40 sides) were fixed in the middle and bottoms of the scrotum, and testis of 2 patients (2 sides) were fixed on the top of the scrotum.One case had poor healing of naval incision, which was recovered in 1 week after dressing change.There were no postoperative complications such as scrotum hematoma, infection of incision, testicular epididymitis, testicular necrosis, testicular retraction or testicular atrophy, etc.No obvious visible scar was found in the abdomen review 2 weeks postoperatively, with the incidence of complications was 2.9%(1/35 cases). Conclusions Transumbilical single channel laparoscopic cryptorchidopexy with conventional instruments in treatment of cryptorchidism is characterized by small trauma, quick recovery, low complication rate and visible scar free result, which is worthy of clinical promotion, but the operation is relatively complex and the correct procedures are required.

Objective To investigate the influence of the genotype distribution of methylenetetrahydrofolate reductase (MTHFR) C677T,A1298C and methionine synthase reductase (MTRR) A66G in threatened abortion of Chinese Han gestationalage women in Sanya city,which involved in the folic acid biosynthetic pathway among.Methods One hundred and thirty-nine samples of case group and the same number of control group were recruited from Sanya region in Hainan Province.Genomic DNA was extracted from the mucosal epithelium of the subjects.The gene polyrnorphisms of MTHFR and MTRR were detected by Fluorescence quantitative PCR technology.The distribution frequencies of both case group and control group.were analyzed and compared,to investigate the effect of the gene polymorphisms on threatened abortion.Results Both the case group and the control group complied with Hardy-Weinberg law.The genotype frequency of MTHFR C677T,MTHFR A1298C and MTRR A66G were not significantly different.Conclusion This study suggests that the gene polymorphism which involved in folic metabolism was not significantly different from the group of threatened abortion and the control group,and whether the metabolism related genes are the risk factors of threatened abortion need to be further discussed.

Objective To investigate the application significance of 3.0T MR three dimensional double-echo steady state(3D-DESS) and three dimensional-true fast imaging with steady-state procession(3D-True FISP) sequences in diagnosis of wrist cartilage of rheumatoid arthritis (RA).Methods 26 patients who were clinically diagnosed with RA underwent wrist MR scans with 3D-DESS and 3D-True FISP sequences, while both sequences' scanning were achieved on 20 of them.340 articular-surface morphological conditions' were observed,which were divided into level 0, level 1 and level 2 damages according to morphological performance,and recorded on 3D-DESS and 3D-True FISP sequence respectively.The diagnostic differences in the number of lesions were compared for two sequences.Results The numbers were 79 and 50 for level 1 damage and 23 and 33 for level 2 damage on 3D-DESS and 3D-True FISP sequence respectively (P<0.05).The artifacts were showed in 14 patients on 3D-True FISP,and only two patients on 3D-DESS.Conclusion 3D-DESS sequence does better than 3D-True FISP in displaying RA wrist cartilage,which is able to provide certain help for treatment and prognosis evaluation of RA.

Objective To investigate the features of risk factors of minor stroke with CISS classification in Guangdong Province. Methods We retrospectively investigated the patients admitted within 3 days of the occurrence of a minor stroke, and were classified by CISS criteria as large artery atherosclerosis (LAA), cardiogenic stroke (CS), penetrating artery disease (PAD), other etiology (OE), undetermined etiology (UE). Results In this study, 303 pa-tients met the inclusion criteria of minor stroke. The highest percentage of the risk factors included hypertension (72.3%), hyperlipidemia (58.3%), and diabetes mellitus (39.9%). Among different subtypes, 41.9% were diagnosed with LAA, and 50.8% with PAD. Plasma triglyceride (TG)(1.765 ±1.18)mg/L vs.(2.19 ±1.84)mg/L,P=0.03], apolipoproteinsB (ApoB) [(0.95±0.29)mg/L vs.(1.11±0.46)mg/L,P=0.009]C-reactive protein (CRP) [(6.63±11.30) mg/L vs.(3.42 ±5.02)mg/L,P=0.042] and ApoB/ApoA1 ratio [(0.754 ±0.25)mg/L vs.(0.875 ±0.49)mg/L,P=0.019], differed significantly between group LAA and PAD. Conclusion Hypertension, hyperlipidemia and diabetes mellitus are the major risk factors of minor stroke. The most common subtypes of the minor stroke patients in Guangdong Province are LAA and PAD, and detecting their TG, apoB, CRP level and apoB/apoA1 ratio might help subclassify minor stroke according to CISS.

Objective To compare the clinical outcome of internal fixation(IF)and total hip arthroplasty (THA)for the elderly patients with displaced femoral neck fracture. Methods A total of 128 patients with dis-placed femoral neck fracture admitted from January 2010 to December 2012 were selected and divided into IF group(61 cases)and THA group(67 cases). The operation and hospitalization index were compared between the 2 groups. All patients underwent follow-ups after operation. The functional recovery scale for hip fracture (FRS) and EQ-5D index were applied to evaluate the clinical outcomes periodically. Results Compared to THA group, the intraoperative trauma ,operation time and bed days were less in IF group(P<0.05),however the incidence of complication in IF group was higher than that in THA group. All the patients were followed up more than 3 years and mortality rate between the 2 groups showed no significant difference(P>0.05). Follow-ups at all time points revealed hip function in THE group is better than that in IF group(P<0.05),while no significant difference was found in terms of life quality(P > 0.05). Within 3 years,the costs related to fracture were 41772 yuan for IF group and 61174 yuan for THA group respectively. Conclusion Both internal fixation and total hip arthroplasty can provide satisfactory outcome for elderly patients with displaced femoral neck fracture. Compared with IF ,THA causes bigger trauma and costs more ,but ends up with lower complication incidences ,and improve hip function in a shorter period.

According to the trend of the development of the quality education, it is necessary to re-form the traditional homework assignments in medical microbiology for improving the innovation ability of students. This program attempts to reform the homework on clinical medicine undergraduates. First, the teacher must master diversified knowledge, and then the student design and finish the homework combine with personal characteristic from the training requirements of experimental confirmation, theoretical cognition and social survey. The questionnaire shows the personalized homework can help students to master the pro-fessional knowledge, stimulate study interest and improve the comprehensive quality.

Objective To establish methods for the determination of doxorubicin and elacridar, and prepare PLGA nanoparticles for the co-delivery of doxorubicin and elacridar.Methods Ultraviolet spectrophotometry (UV) and high performance liquid chromatography (HPLC) were used to establish the determination method of doxorubicin and elacridar, respectively;co-delivery nanoparticles system was prepared by nanoprecipitation method, and optimizing the prescription was by adjusting the dosage ratio of the two drugs to investigate the particle size,morphology, encapsulation efficiency (EE), drug loading (DL) and in vitro release.Results The linearity of doxorubicin was better in the rang of 1 to 40 μg/ml, A=0.021C+0.002,r=0.999 5;the linearity of elacridar was better in the rang of 0.5 to 100 μg/ml,A=120 742.462 6C+1 974.570 4,r=1.000 0;the particle size was about 50 nm;transmission electron microscope (TEM) showed that nanoparticles were round in shape and had a good dispersion;EE of doxorubicin and elacridar were 56.58%、51.66%,respectively, DL of doxorubicin and elacridar were 1.48%、1.85%,respectively,the molar ratio of two drugs was about 1∶1;the nanoparticles released slowly in vitro.Conclusion The established methods of doxorubicin and elacridar were convenient and efficient, accurate and repeatable.The Co-delivery nanoparticles system was well dispersionand smaller size, which could be used for further studies.

Strokes due to atrial fibrillation (AF) are common and frequently devastating.While oral anticoagulant agents are the mainstay in the prevention of embolic events,they have several limitations and not all patients can tolerate them long term.The left atrial appendage (LAA) has been identified as the source of thrombus formation in nonvalvular AF.Several LAA closure devices have been developed,they have been successful in stroke prevention in patients with nonvalvular AF and fewer periprocedural complications.This article reviews the application of percutaneous left atrial appendage closure for stroke prevention in patients with nonvalvular AF.