Efficacy of intelligent diagnosis with a dynamic uncertain causality graph model for rare disorders of sex development / 医学前沿

Disorders of sex development (DSD) are a group of rare complex clinical syndromes with multiple etiologies. Distinguishing the various causes of DSD is quite difficult in clinical practice, even for senior general physicians because of the similar and atypical clinical manifestations of these conditions. In addition, DSD are difficult to diagnose because most primary doctors receive insufficient training for DSD. Delayed diagnoses and misdiagnoses are common for patients with DSD and lead to poor treatment and prognoses. On the basis of the principles and algorithms of dynamic uncertain causality graph (DUCG), a diagnosis model for DSD was jointly constructed by experts on DSD and engineers of artificial intelligence. "Chaining" inference algorithm and weighted logic operation mechanism were applied to guarantee the accuracy and efficiency of diagnostic reasoning under incomplete situations and uncertain information. Verification was performed using 153 selected clinical cases involving nine common DSD-related diseases and three causes other than DSD as the differential diagnosis. The model had an accuracy of 94.1%, which was significantly higher than that of interns and third-year residents. In conclusion, the DUCG model has broad application prospects as a computer-aided diagnostic tool for DSD-related diseases.

Enhanced MGMT expression contributes to temozolomide resistance in glioma stem-like cells / 癌症

O6-methylguanine DNA methyltransferase (MGMT) can remove DNA alkylation adducts, thereby repairing damaged DNA and contributing to the drug resistance of gliomas to alkylating agents. In addition, glioma stem-like cells (GSCs) have been demonstrated to be involved in the recurrence and treatment resistance of gliomas. In this study, we aimed to investigate MGMT expression and regulatory mechanisms in GSCs and the association of MGMT with temozolomide (TMZ) sensitivity. GSCs were enriched from one MGMT-positive cell line (SF-767) and 7 MGMT-negative cell lines (U251, SKMG-4, SKMG-1, SF295, U87, MGR1, and MGR2) through serum-free clone culture. GSCs from the U251G, SKMG-4G, SF295G, and SKMG-1G cell lines became MGMT-positive, but those from the U87G, MGR1G, and MGR2G cell lines remained MGMT-negative. However, all the GSCs and their parental glioma cell lines were positive for nuclear factor-κB (NF-κB). In addition, GSCs were more resistant to TMZ than their parental glioma cell lines (P < 0.05). However, there was no significant difference in the 50% inhibition concentration (IC50) of TMZ between MGMT-positive and MGMT-negative GSCs (P > 0.05). When we treated the MGMT-positive GSCs with TMZ plus MG-132 (an NF-κB inhibitor), the antitumor activity was significantly enhanced compared to that of GSCs treated with TMZ alone (P <0.05). Furthermore, we found that MGMT expression decreased through the down-regulation of NF-κB expression by MG-132. Our results show that MG-132 may inhibit NF-κB expression and further decrease MGMT expression, resulting in a synergistic effect on MGMT-positive GSCs. These results indicate that enhanced MGMT expression contributes to TMZ resistance in MGMT-positive GSCs.

The clinical report of 21 cases of occlusion of atrial septal defect through right chest small incision / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the methods and efficacy of atrial septal defect (ASD) occlusion through right chest incision.</p><p><b>METHODS</b>The clinical data of 21 patients with ASD from July 2004 to May 2005 were analyzed retrospectively. Eight patients were male and 13 patients were female, aged from 1 to 70 years old, with the median age of 21 years old. The diameter of ASD was from 8 to 40 mm. All the 21 patients were under general anaesthesia. A 2 to 3 cm incision was made in the 4th intercostals of right side of sternum. With the help of transesophageal or normal transthoracic echocardiography, the occluder was released using monotube unit.</p><p><b>RESULTS</b>All cases were occluded successfully without death. The types of the occluder were from 14 to 46 mm. None failed and had to choose extracorporeal circulation operations. No transfusion and no serious complication such as the occluder dislocated occurred. And no evident of atrial shunt was found when in review echo.</p><p><b>CONCLUSIONS</b>The ASD occlusion through right chest minimal incision is safe, credit, minimal invasive and worth to use widely.</p>

Study on chemical constituents from Opuntia dillenii / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical composition of Opuntia dillenii.</p><p><b>METHOD</b>Many kinds of chromatography methods were used in the isolation procedure, while the structures of isolated compounds were determined on the aids of NMR and MS spectral analysis.</p><p><b>RESULT</b>A new compound, together with five known compounds, was isolated form the 80% ethanolic extract of its stems.</p><p><b>CONCLUSION</b>The new compound was characterized as opuntioside. Four compounds were obtained for the first from the genus Opuntia, and they were daucosterol, p-hydroxybenzoicacid, L-(-)-malic acid, (E)-ferulic acid. Opuntiol was also separated for the first from the plant.</p>

The isolation and identification of a new alpha-pyrone from Opuntia dillenii / 药学学报

<p><b>AIM</b>To study the chemical composition of Opuntia dillenii Haw.</p><p><b>METHODS</b>Many kinds of chromatography methods were used to separate the chemical constituents. Their structures were determined by NMR and MS spectral analysis.</p><p><b>RESULTS</b>A new compound, together with five known compounds, were isolated from the 80% ethanolic extract of the stems.</p><p><b>CONCLUSION</b>The new compound was identified as 4-ethoxyl-6-hydroxymethyl-alpha-pyrone. Compounds 1, 3, 4 and 5 were obtained for the first time from the genus of Opuntia, and they were: 3-O-methyl isorhamnein, 1-heptanecanol, vanillic acid, isorhamnetin-3-O-beta-D-rutinoside. Ruin was isolated from this plant for the first time.</p>

Different gene expression during hepatocarcinogenesis in tree shrew induced by aflatoxin B1 / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To understand the molecular mechanism and find out the responsible genes for liver cancer by exploring the regulation of gene expression during hepatocarcinogenesis in tree shrew induced by aflatoxin B1 (AFB1).</p><p><b>METHODS</b>The tissues from tree shrew of different stages during the pathogenesis and development of hepatocellular carcinoma (HCC), liver cancer tissue, para-cancerous tissues, pre-cancerous liver tissues, liver tissues of the same stage from normal controls and the liver tissues taken before AFB1-treatment were analyzed for gene expression by cDNA array.</p><p><b>RESULTS</b>Four patterns of gene expression were observed during AFB1-induced hepatocarcinogenesis. They were: genes up-regulated in HCC tissue and para-cancerous tissue, especially in HCC tissues; genes with similar expressing level in both HCC tissue and para-cancerous tissue, but higher than that in pre-cancerous tissue; genes down-regulated in HCC tissue; genes up-regulated before HCC appeared but down-regulated after HCC appeared.</p><p><b>CONCLUSION</b>Dynamic observation of gene expression will be beneficial to elucidate the mechanisms of AFB1- induced hepatocarcinogenesis and locate the responsible genes.</p>