Protein-protein interaction and SNP analysis in intraductal papillary mucinous neoplasm.

Intraductal papillary mucinous neoplasm (IPMN) is a type of tumor that grows within the pancreatic ducts. It is a progress from hyperplasia to intraductal adenoma (IPMA), to noninvasive carcinoma, and ultimately to invasive carcinoma (IPMC). The objective of this study was to explore the molecular mechanism of the progression from IPMA to IPMC. By using the GSE19650 affymetrix microarray data accessible from Gene Expression Omnibus (GEO) database, we first identified the differentially expressed genes (DEGs) between IPMA and IPMC, followed by the protein-protein interaction and single-nucleotide polymorphism (SNP) analysis of the DEGs. Our study identified thousands of DEGs which involved regulation of cell cycle and apoptosis in this progression from IPMA to IPMC. Protein-protein interaction network construction found that MYC, IL6ST, NR3C1, CREBBP, GATA1 and LRP1 might play an important role in the progression. Furthermore, the SNP analysis confirmed the association between BRAC1 and pancreas cancer. In conclusion, our data provide a comprehensive bioinformatics analysis of genes and pathways which may be involved in the progression of IPMN from IPMA to IPMC.

[The effect on the pro-inflammatory role of N9 microglia exposured to hyperoxia after preconditioning with lipopolysaccharide in vitro].

AIM: To observe the time-dapendcrt expression of TLR4 and TNF-α of N9 microglia exposured to normobaric hyperoxia after preconditioning with lipopolysaccharide in vitro and to explore the role of hyperoxia on the pro-flammation response of microglia and mechanism. METHODS: N9 microglia cell line cultured in vitro was randomly divided into six groups(n=3): normoxia group, sLPS group(100 ng/mL), hLPS group(1 mg/L), hyperoxia group, hyperoxia+sLPS group(100 ng/mL), hyperoxia+hLPS group(1 mg/L). Each of the last two groups, 30 min after pretreatment with different level of LPS, was subjected to 900 mL/L hyperoxia for various times (2 h, 6 h, 12 h, 24 h and 48 h). The remanent groups was cultured in ambient O(2); in which sLPS group and hLPS group respectively was treated with 100 ng/mL and 1 mg/mL LPS in the cell supernatant. After treatment, at each time point, the cells of each group was harvested and TLR4 gene expression were observed by RT-PCR. TLR4 protein expression at 12 h was observed by Western blotting. TNF-α concentrations in the supernatant of cultured microglia N9 cells at different time points were tested with ELISA. RESULTS: After 6 h in hLPS group and 16 h in sLPS group, the expression of TLR4 mRNA was gradually increased(P<0.05), following with increasing time and concentration of LPS, which reached to the maximum at 24 h in hLPS group. Compared with hLPS group, hyperoxia+hLPS group showed downregulation of TLR4 mRNA at each time point after 6 h(P<0.05), especially at 16 h and 24 h. At 12 h, the level of TLR4 protein of hyperoxia+sLPS group and hyperoxia+hLPS group respectively was lower than the corresponding concentration of LPS group. The result of ELISA show that at each time point, compared with the corresponding concentration of LPS group respectively, the expression of TNF-α of hyperoxia+sLPS group and hyperoxia+hLPS significantly increased(P<0.05). CONCLUSION: Hyperoxia enhance the pro-flammation response of N9 microglia triggered by LPS and TLR4 may be the important negative-control target molecule.

[Expression of cTnT in rabbit hearts during myocardial ischemia and its postmortem stability].

OBJECTIVE: To study the postmortem stability of cTnT as well as its expression alteration, and to evaluate it in the diagnosis of early myocardial ischemia in forensic practice. METHODS: Animal model of early myocardial ischemia was established by rabbit coronary artery ligation. The expression of cTnT in myocardium at different postmortem intervals was detected using immunohistochemistry and analyzed using imaging technique and statistics. The results were then compared between the experimental and control groups. RESULTS: In ischemic myocardium, the expression of cTnT showed prominent focal or flaky depletion in myocardial cytoplasm with no expression detected in interstitium. The expression level showed a linear decrease with prolonged postmortem interval, and disappeared completely on day 14 after death while stored at 4 degrees C. However, there were significant differences in the expression levels of cTnT between experimental and control groups from day 1 to day 7 after death. CONCLUSION: Immunohistochemical detection of cTnT for diagnosis of early myocardial ischemia in corpses stored at 4 degrees C must be performed within 7 days after death.

[The expression of ubiquitin in the healing process of incised wounds of rat's skin and its significance to forensic medicine].

OBJECTIVE: To evaluate the changes of ubiquitin expression in incised wounds of the rat skin. METHODS: The testing rat groups were subjected to incised skin wounds, with normal rat skin used as control. The expression level of ubiquitin was assessed using immunohistochemistry and imaging analysis technique on skin samples taken at 1, 3, 6, 12h, and on day 1, 3, 6, 10, and 14d after injury. RESULTS: The expression level of ubiquitin was low in the skin of normal control group. Increased level of ubiquitin expression could be observed 1 h after injury. The expression level of ubiquitin reached its peak on day 6 and started to decline on day 10, and then returned to its normal level on day 14 d after injury. CONCLUSION: Ubiquitin may serve as a potentially useful marker for forensic determination of the skin wound age.

[Recent advancement in relationship between DNA degradation and postmortem interval].

Determination of postmortem interval (PMI) is one of the most valuable subjects in forensic practice. It, however, is often very difficult to accurately determine the PMI in daily practice. Forensic DNA technology has recently been used to estimate the PMI. It has certain advantage to traditional methods. This article reviews this technology with respect to its invention, development, advantage, disadvantage, and potential future applications with emphasis on correlation of DNA degradation and PMI.