Effect and Mechanism of Arbuscular Mycorrhizal Fungi in Herbs / 中国实验方剂学杂志

Arbuscular mycorrhizal fungi （AMF） can establish mycorrhizal symbiosis system with most terrestrial plants，and play important roles in their growth and development. However，there is no systematic analysis and summarization of their roles in the growth, biosynthesis and accumulation of active substances of herbs，as well as stress-resistance mechanism. First，the main research methods of AMF were summarized in the paper，including the separation of AMF spores，morphological identification，chemical staining and molecular identification. The main morphological structures of some AMF were detailed in the table. In terms of growth promotion，AMF promoted the growth by prolonging mycelium，enhancing phosphatase secretion，organic acid，activation of soil and increasing absorption efficiency. In the aspect of biosynthesis and accumulation of flavonoids，terpenoids and other active substances in herbs，AMF improved the contents by regulating activities of signal substances and key enzymes involved in the metabolism of secondary products. In addition，AMF could alleviate a series of stresses caused by drought，heavy metal，high salt，high or low temperature by improving the activity of antioxidant enzymes，enhancing the ability of plants to scavenge free radicals，complexing toxic heavy metals，diluting high salt concentration，or inducing the expressions of key genes. Finally，the application prospects and in-depth study of AMF in the ecological planting of herbs were discussed, in order to provide reference for promoting relevant research.

Biosynthesis of Steroidal Saponins in Herbs / 中国实验方剂学杂志

Steroidal saponins are efficacious substances wildly existed in the herbs，and consist of glycosyl and steroid sapogenin. The biosynthesis pathways of steroidal saponins mainly include the cytosolic mevalonate （MVA） pathway and the plastidial methylerythritol 4-phosphate （MEP） pathway，with the MVA pathway as the main pathway. The key enzymes are involved in the biosynthetic pathway, including 3-hydroxy-3-methyl glutaryl coenzyme A reductase（HMGR），1-deoxy-D-xylulose 5-phosphate synthase（DXS），1-deoxy-D-xylulose-5-phosphatereduetoisomerase（DXR），farnesyl pyrophosphate synthase（FPS），squalene synthase（SS），squalene epoxidase（SE），cycloartenol synthase（CAS），cytochrome P450（CYP450），and steroidalglycosyltransferase（SGTase）. In the paper，the biosynthesis roadmap of steroidal saponins was optimized based on previous studies. According to a comprehensive analysis on studies of key enzymes for the past five years, genes, like HMGR，SS，CYP450 and UGT，were studied more，while other genes，like FPS，SE，CAS，were known less. In conclusion， current studies still focus on the primary stage，but lack direct evidence for the roles of key enzymes. This paper would provide a reference and theoretical support for subsequent studies.

Comparison between Gd-DTPA-enhanced MRI and USPIO-enhanced MRI in diagnosing benign and metastatic cervical lymph nodes in rabbit models / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To compare the diagnostic value of gadolinium diethylenetriaminepenta-acetic acid (Gd-DTPA)-enhanced MRI with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced MRI in differentiating reactive hyperplastic lymph nodes from metastatic lymph nodes in rabbit models.</p><p><b>METHODS</b>Reactive hyperplastic cervical lymph node model was established in 18 rabbits as hyperplasia group, and tumor-bearing lymph node model was established in another 18 rabbits as tumor group. For Gd-DTPA-enhanced MRI, T1WI and T2WI were performed on 9 animals of each model, and T1WI was acquired 80 seconds after administration of Gd-DTPA. For USPIO-enhanced MRI, T1WI, T2WI and T2*WI were performed on another 9 animals of each model before and 24 hours after administration of USPIO. MRI images were analyzed and correlated with surgical specimens and pathological results.</p><p><b>RESULTS</b>In the tumor group, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Gd-DTPA-enhanced MRI were 62.5%, 91.3%, 88.2%, 70.0% and 76.6%, respectively. The corresponding values of USPIO-enhanced MRI were 95.0%, 90.9%, 90.5%, 95.2% and 92.9%, respectively. The sensitivity and accuracy of USPIO-enhanced MRI differ significantly from those of Gd-DTPA-enhanced MRI. In the hyperplasia group, the accuracy of Gd-DTPA-enhanced MRI was 74.2%, while 87.1% for USPIO-enhanced MRI.</p><p><b>CONCLUSION</b>USPIO-enhanced MRI has higher accuracy in diagnosing metastatic lymph nodes than Gd-DTPA-enhanced MRI.</p>

E1A gene transfection of human undifferentiated thyroid cancer cell line HTC/3 by nanoparticles / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To prepare nanoparticles containing E1A gene and observe the efficiency and feasibility of transfecting E1A gene into human undifferentiated thyroid cancer cell line HTC/3. To examine the sensitivity of transgene cells to X-ray and X-ray-induced apoptosis in those cells.</p><p><b>METHODS</b>Nanoparticle-DNA complex was prepared with PLGA coating adenoviral early expression gene E1A, and the package efficiency, release progress in vitro, and size of the complex were determined. The nanoparticle-DNA was transfected into the HTC/3 cells. Lipofectamine was used to transfect E1A gene as a control. RT-PCR was used to examine E1A gene mRNA expression in the transfected cells. The survival ratio of HTC/3-E1A and control cells, and the growth inhibition ratio induced by different doses of X-ray in HTC/3-E1A cells were examined by MTT assay. The apoptosis in HTC/3-E1A cells induced by 2 Gy X-ray iradiation was examined by flow cytometry and DNA electrophoresis.</p><p><b>RESULTS</b>The package efficiency, release progress in vitro, and size of the nanoparticle-DNA complex were 0.78%, 18 days, and 150-280 nm, respectively when transfected the plasmid at the same level, the nanoparticle group got more positive transgene cell clones than that in lipofectamine group, with a statistically significant difference (P < 0.05). RT-PCR showed that transgenic cells from both nanoparticle-DNA and lipofectamine groups had E1A gene mRNA expression. The HTC/3-E1A cells grew slowly, and their doubling time was prolongated (1.44 times in comparison with that in parental cells). According to IC50, the sensitivity of HTC/3-E1A cells to X-ray was improved 2.9 and 2.8 times, respectively, in comparison with that in HTC/3-Vect and HTC/3 cells. The ratio of subG0/G1 phase of HTC/3-E1A cells was significantly higher than that in HTC/3-Vect and HTC/3 cells (P < 0.01). The ratio of S phase of HTC/3-E1A cells was significantly lower than that in HTC/3-Vect and HTC/3 cells (P < 0.01). A typical DNA ladder pattern of apoptosis in HTC/3-E1A cells was observed by electrophoresis, but not found in HTC/3-Vect and HTC/3 cells.</p><p><b>CONCLUSION</b>A nanoparticle-DNA complex has been successfully prepared, and it may carry a foreign gene into cells. The sensitivity of HTC/3-E1A cells to X-ray is significantly improved. Moreover, apoptosis is induced by x-ray in the E1A gene-transfected cells.</p>

Fistula in ano:assessment of the fistulography of multi-slice spiral CT / 中华放射学杂志

Objective To evaluate the clinical application of the fistulography of multi-slice spiral CT(MSCT)in the diagnosis of anal fistula.Methods A total of 28 patients who were verified operatively of fistula in ano underwent preoperative fistulography of MSCT.The multi-planar reformation(MPR)and surface shadow display(SSD)images were generated and analyzed retrorespectively.Results There were 8 cases with perianal abscess and 20 cases with anal fistula in 28 patients.Complex fistula was diagnosed in 16 cases,and simple inter-sphincteric fistula was found in 4 cases;the inner orificiums of anal fistulas were revealed accurately with MPR images in 18 cases.Conclusion The fistulography of MSCT is valuable for preoperative assessment of anal fistula,in particular for investigation of the inner orificiums of anal fistulas with MPR.