Objective To investigate the feasibility with low dose contrast agent in patients undergoing peripheral magnetic resonance angiography with high spatial resolution at open-bore 3 T scanner. Methods Images of MRA were assessed separately by two radiologists. And the images of DSA were assessed by one radiologist. The degree of the two interobservers' consensus for detection of arterial stenosis was determined by calculating the Kappa coef-ficient. Spearman rank correlation coefficient was used for revealing the relationship between contrast-enhanced MR angiography and DSA,in terms of categories of stenosis. Results For the degree of vessel stenosis, Cohen' s statis-tics revealed excellent agreement between the two observers. There was a significant correlation between DSA and MRA(P<0. 05). Conclusion At this open-bore 3 T scanner, high spatial resolution peripheral magnetic reso-nance angiography is achieved with low dose contrast agent.

Objective To evaluate the value of energy spectrum CT with multimodal quantitative parameters in diagnosis of the metastatic lymph nodes of gastric adenocarcinoma compared with the conventional CT.Methods 37 patients with gastric adenocarcinoma diagnosed by gastroscopy underwent enhanced CT scan with gemstone spectral imaging mode.We positioned and marked the stomach lymph nodes on CT images and compared with postoperative pathologic results one to one.ROC was used to identify the critical quantitative index of energy spectrum CT in distinguishing the metastasis from benign lymph node,and to evaluate the diagnostic effect compared with CT features.Results The 40-80 keV single energy spectrum curve slope (λHU )and normalized iodine concentration (NIC)in metastasis group were lower than those in the benign one in the arterial phase with statistical differences (P <0.05 ),but without statistical differences in venous phase.The combination of arterialλHU and NIC showed significant advantages compared with CT features(P <0.01), with the sensitivity,specificity and accuracy of 84.3% vs 61.4 %,88.4% vs 81.3 % and 86.8% vs 73.6 %.Conclusion The energy spectrum CT can provide quantitative analysis for differential diagnosis of gastric cancer metastasis from benign lymph nodes,and significantly improve the diagnostic accuracy of lymph node metastasis of the cancer.

The present experiment applied the freeze cracking technique and scanning electron microscopy for further studies of ultrastructural changes of cancer cells after they invaded into the organ. It was found that, after two days of cultivation, there were a lot of cancer ceils which adhered on to the surface of organ fragments. The cancer cells migrated on the surface of the organ and at the same time penetrated into the organ by stretching out their pseudopodia. After 3 days of cultivation, some cancer cells had already invaded into the organ. After invasion they connected target cells of the organ by different ways, but their filopodium is the important organelle for the connection and communication with those target cells.The cancer cells caught the projecting portion of surface of target cells by branches of filopodia forming a mosaic pattern with them. Sometimes the filopodia of cancer cells fused with the opposed surface of target cells by inserting into it. Some filopodia became short and thick inside the organ due probably to the limited distance between cancer cells and target cells when they were in close contact to each other. Once the tumor cell nests were formed in the organ, the tumor cells connected each other by stretching out pseudopodia from both poles, but kept a definite space between cells. It is postulated that these inter-cellular spaces were formed probably by the repelling force of the identical electric charge of the tumor cell membranes.

Objective To study the changes of AKP activity and its cytochemistry position during liver regeneration following partial hepatectomy. Methods Using colorimetry to analyze AKP activity; using non-denatured electrophoresis technique to analyze the kinds and activity of AKP; using electron microscope cytochemistry to analyze its position. Results During liver regeneration, AKP activity had two peaks at 16*!h and 19*!h and followed by decline dramatically; Three hepatic-derived AKP isoenzymes were detected, and 180*!kD AKP appeared only in liver regeneration; AKP appeared in different part with the process of liver regeneraion.Conclusion AKP plays an important role in liver regeneration and it may involve in cell metabolism, material transportation, DNA synthesis and cell differentation.

Objective To investigate the frequent species of pathogenic bacteria causing infections in burn patients and their re‐sistance to commonly used antibacterial agents ,so as to provide references for rational use of antibacterials in clinic .Methods The distribution and drug susceptibility of pathogenic bacteria isolated from secretions of wound surfaces of 140 cases of burn patients from January 2012 to December 2014 were retrospectively analyzed .Results A total of 152 strains of pathogenic bacteria were iso‐lated .The gram‐negative bacteria accounted for 59 .2% ,in which Pseudomonas aeruginosa ,Proteus mirabilis and Acinetobacter bau‐mannii were the most common isolates ;the gram‐positive bacteria accounted for 34 .2% ,in which Staphylococcus aures ,Staphylo‐coccus haemolyticus and Enterococcus faecalis were the most common isolates ;and fungi were accounted for 6 .6% .A majority of these isolates were multiple resistant to the antibacterial agents .Conclusion Culturing ,identifing and carring out drug‐sensitivity test of pathogenic bacteria isolated from burn patients could provide basis for rational application of antibacterial agents and effec‐tive control of infection .

Objective:To evaluate the short-term precision and accuracy of bone mineral density (BMD) measured with quantitative CT (QCT) and dual-energy X-ray absorptiometry (DXA) in multi-centre clinical research with a European spine phantom (ESP).Methods:From January 2016 to April 2020, totally 40 CT scanners (12 Siemens from Germany, 12 Philips from Netherlands, 9 GE from US, 5 Toshiba from Japan, 2 United Imaging from China) and 53 DXA instruments (34 GE Lunar from US, 14 Hologic from US, 5 Medlink from France) used in multi-centre in China were enrolled. The CT equipment came from 31 centers and DXA equipment from 32 centers.Using Mindways QCT software, the ESP was scanned 10 times on each instrument with repositioning using standardized spine protocols with QCT and DXA. The BMD value of the three lumbar vertebrae with low, medium, high density and the mean BMD value were measured. Accuracy was assessed by comparing BMD values measured on each device with the actual value of the phantom. Short-term precision was calculated as the root-mean-square standard deviation (RMS-SD) and root-mean-square standard deviation coefficient of variation (RMS-%CV) for the repeated measurements. The repeated measures variance analysis was used to compare the differences in BMD between different devices.Results:The differences in BMD values were statistically significant among different CT and DXA devices.The ranges of the accuracy measured by different QCT devices were 1.20% to 7.60% for Siemens, -1.83% to 0.20% for Philips, 1.18% to 13.20% for GE, -0.12% to 3.55% for Toshiba, -1.65% to 6.32% for United Imaging, 6.59% to 21.34% for GE Lunar, -6.65% to 5.45% for Hologic, and -6.97% to -0.68% for Medlink, respectively. The RMS-%CV of all vertebral BMD values measured by QCT and DXA ranged from 0.38% to 3.85%. The RMS-SD of QCT was 0.54 to 2.45 mg/cm 3, of DXA was 0.009 to 0.037 g/cm 2. The RMS-%CV values of each vertebral body measured by different QCT and DXA devices decreased with the increase of BMD, while the RMS-SD values showed the opposite tendency. Conclusions:Based on ESP, the QCT and DXA devices have significant differences in lumbar spine BMD measurement. Comparing the measurement results among different devices requires cross-calibration. Overall, the accuracy and short-term precision are within a reasonable range, which can be used for clinical follow-up observation. The short-term precision error and accuracy error range of QCT in evaluating the density of ESP were slightly smaller than those of DXA.

OBJECTIVETo observe the serological features of hepatitis G virus (HGV or GBV) in selected population of Shaanxi, Qinghai and Xinjiang Provinces (region).

METHODSEnzyme-linked immunosorbent assay (ELISA) was used to determine IgG antibody against GBV (anti-GBV IgG) in serum specimens of 1469 individuals from the 3 provinces (region).

RESULTSThe positivity rate of serum GBV-IgG antibody in ethnic minorities (4.11% in Tibetan, 5.36% in Mongolian, 4.55% in Uigur, 4.00% in Hui population) was slightly higher than that in Han population (1.36%-1.73%), but the differences were not significant (P>0.05). The positivity rate of serum GBV-IgG antibody in drug abusers (11.30%, 34/301) was remarkably higher than that of the normal population (2.44%,18/736) (P<0.01). The positivity rate of serum GBV-IgG antibody in blood donors was 1.02%-7.68%.

CONCLUSIONSThe positivity rates of serum GBV-IgG antibody among ethnic groups in the 3 provinces (region) had no significant differences; blood-borne transmission seemed to be an important transmission route of GBV, therefore supervision of blood donors and drug abusers should be intensified.

Antibodies, Viral ; blood ; Blood Donors ; China ; epidemiology ; Enzyme-Linked Immunosorbent Assay ; Flaviviridae Infections ; epidemiology ; transmission ; GB virus C ; immunology ; Hepatitis, Viral, Human ; epidemiology ; transmission ; Humans ; Immunoglobulin G ; blood ; Seroepidemiologic Studies ; Substance-Related Disorders ; virology

Histone lysine methyltransferases (HKMTs) deposit methyl groups onto lysine residues on histones and play important roles in regulating chromatin structure and gene expression. The structures and functions of HKMTs have been extensively investigated in recent decades, significantly advancing our understanding of the dynamic regulation of histone methylation. Here, we review the recent progress in structural studies of representative HKMTs in complex with nucleosomes (H3K4, H3K27, H3K36, H3K79, and H4K20 methyltransferases), with emphasis on the molecular mechanisms of nucleosome recognition and trans-histone crosstalk by these HKMTs. These structural studies inform HKMTs' roles in tumorigenesis and provide the foundations for developing new therapeutic approaches targeting HKMTs in cancers.
Nucleosomes ; Histones/metabolism* ; Histone-Lysine N-Methyltransferase/metabolism* ; Lysine/metabolism* ; Methyltransferases/metabolism* ; Methylation