Sensitive detection of microRNAs using polyadenine-mediated fluorescent spherical nucleic acids and a microfluidic electrokinetic signal amplification chip / 药物分析学报

The identification of tumor-related microRNAs(miRNAs)exhibits excellent promise for the early diag-nosis of cancer and other bioanalytical applications.Therefore,we developed a sensitive and efficient biosensor using polyadenine(polyA)-mediated fluorescent spherical nucleic acid(FSNA)for miRNA analysis based on strand displacement reactions on gold nanoparticle(AuNP)surfaces and electrokinetic signal amplification(ESA)on a microfluidic chip.In this FSNA,polyA-DNA biosensor was anchored on AuNP surfaces via intrinsic affinity between adenine and Au.The upright conformational polyA-DNA recognition block hybridized with 6-carboxyfluorescein-labeled reporter-DNA,resulting in fluores-cence quenching of FSNA probes induced by AuNP-based resonance energy transfer.Reporter DNA was replaced in the presence of target miRNA,leading to the recovery of reporter-DNA fluorescence.Sub-sequently,reporter-DNAs were accumulated and detected in the front of with Nafion membrane in the microchannel by ESA.Our method showed high selectivity and sensitivity with a limit of detection of 1.3 pM.This method could also be used to detect miRNA-21 in human serum and urine samples,with re-coveries of 104.0％-113.3％and 104.9％-108.0％,respectively.Furthermore,we constructed a chip with three parallel channels for the simultaneous detection of multiple tumor-related miRNAs(miRNA-21,miRNA-141,and miRNA-375),which increased the detection efficiency.Our universal method can be applied to other DNA/RNA analyses by altering recognition sequences.

Selection and identification of salt-tolerant variants of Taraxacum officinale / 生物工程学报

In order to obtain salt-tolerant variant plants of Dandelion (Taraxacum officinale Weber), the leaf discs were excised from 20 to 30-day old seedlings to produce callus, then the induced calli were transferred to selection mediums containing 1.5% NaCl. After regenerating and rooting, these salt-tolerant calli finally developed into 12 variant plantlets. Compared with the wild-type, these regenerated plants produced more trichomes on their leaves, and had larger leaves and shorter petioles. Additionally, the dumpy roots and an approximately 2-cm bract in middle parts of the floricanes were clearly observed in these salt-tolerant plants. By RAPD (Random Amplified Polymorphic DNA) and SDS-PAGE analysis, these salt-tolerant plants showed differences from the control at DNA and protein levels. With 1.5% NaCl treatment, the antioxidant enzyme activity, proline content, and flavonoid concentration were higher in these salt-tolerant plants, whereas maloaldehyde concentration was significantly lower. Salt-tolerant lines of T. officinale showed stronger anti-oxidative activity and higher flavonoid contents.

Selection and characterization of salt-tolerant calli of Taraxacum officinale / 生物工程学报

In order to obtain salt-tolerant calli of Dandelion (Taraxacum officinale Weber), calli were induced from leaf explants of Dandelion on Murashige and Skoog's medium supplemented with 2.0 mg/L 6-benzyladenine and 0.5 mg/L 2,4-dichlorophen oxyacetic acid With 1.5% NaCl as selection pressure, most calli became brown and dead, whereas some new cell clusters appeared at the edge of the brown calli after 2 to 3 weeks. The survived cells were picked out and sub-cultured every 3 weeks onto the fresh selection medium and salt-tolerant calli were finally obtained through 4 continuous selections on the selection medium supplemented with 1.5% NaCl. Salt-tolerant calli increased steadily under a fixed NaCl stress though their relative growth rate decreased with increased NaCl concentration whereas the control calli which were sub-cultured by 4 continus selections on salt free medium ceased to grow under the same condition. This result indicated that the salt-tolerance of the selected calli is improved and this character is stable. Compared with the control, the SDS-PAGE pattern of the salt-tolerant calli had a unique 34 kD protein band. Its 30 kD and 18 kD protein bands were up-regulated. Further more, within the NaCl stress range up to 1.5%, the activities of antioxidant enzymes such as super oxidase dimutase, peroxidase and catalase, and the proline contents of the salt-tolerant calli were higher than those of the control. The results indicated that the selected calli with improved and stable salt tolerance were cell variants. The accumulation of the organic compatible solutes including proteins and the enhanced antioxidant capabilities in the salt tolerant calli are the two ways for them to regulate their osmotic homeostasis and alleviate the secondary reactive oxygen spexies damage respectively.

Thyroid artery embolization for hyperthyroidism / 中华放射学杂志

Objective To evaluate the method and result of thyroid artery embolization as a new therapy for hyperthyroidism. Methods Twenty two patients with hyperthyroidism underwent selective thyroid artery embolization. Totally 52 thyroid arteries were embolized with microspheres. The indications to this therapy were following: hyperthyroid patients having indications to surgical and 131 I therapy, clinically being difficult to complete the preparation for subtotal thyroidectomy and having high risk for surgical process because of their huge thyroid gland. Results Serum level of thyroid hormones dropped significantly [median T3 from 8 8 nmol/L(4 3～ 43 0 nmol/L) to 4 0 nmol/L(1 1～9 2 nmol/L), median T4 from 206 4 nmol/L(77 4～748 2 nmol/L) to 144 5 nmol/L(25 8～279 9 nmol/L), P

Treatment of severe complications after pancreatoduodenectomy under fiber choledochoscope through a subcutaneous jejunal blind loop: A report of 10 cases / 中国微创外科杂志

Objective To discuss the value of choledochoscopy via subcutaneous jejunal blind loop in the diagnosis and treatment of severe complications after pancreatoduodenectomy. Methods A fiber choledochoscope (FCC) was introduced through a subcutaneous jejunal blind loop. Under direct vision, the pancreatojejunal or choledochojejunal anastomotic leakages were coated with biological glue, or the anastomotic bleedings were stopped with hemostatic drugs. Results Five cases of intestinal leakage, 3 cases of biliary leakage and 2 cases of anastomotic bleeding were all cured. Follow-up for 1～3 years in the 10 cases found no recurrence of tumors. Choledochojejunal anastomotic stricture occurred in 1 case 1 year after the surgery and was cured by dilatation under fiber choledochoscope. In the remaining 9 cases, the pancreatic juice and bile fluid were excreted normally. Conclusions Application of FCC through the subcutaneous jejunal blind loop can be employed in the diagnosis and treatment of complications after pancreatoduodenectomy and in the long-term follow-up of pancreatojejunal or choledochojejunal anastomotic stoma under direct vision.

The use of subcutaneous jejunum blind loop in pancreatoduodenectomy / 中国普通外科杂志

Objective To improve the technique of pancreatoduodenectomy in order to facilitate the(management) of complications and direct observation on follow up.Methods Pancreatoduodenectomy and Child′s method of digestive tract reconstruction was performed in 42 paltents.A blind loop of jejunum 5 to 6 cm in length was constructed beyond the pancreatojejular anastomosis and it was fixed to the subcutaneous(tissue) of the adjacent abdominal wall.Results Thirty-two cases recovered uneventfully,and 10 cases had complications induding pancreatic and biliary leakage and hemorrhage.These complications were successfully treated under direct vision by choledochoscope passed into the blind jejunal loop.This method of observation was used for long-time follow up in 22 cases,and revealed ercurrent tumor(n=5),bile duct stricture(n=4) and bile duct ascariasis(n=1).Conclusions This operative method did not cause new(complications) and it can be combined with the traditional operation.Postoperatively,direct observation and management of leakage of pancreatojejular anastomosis and biliointestinal anastomosis and hemorrhage can be accomplished,and the anastomoses and pancreatic stump can be directly observed at followup.

Autologous leukocyte′s labeling for the diagnosis of patients with suspected intraabdominal infection / 中国普通外科杂志

Objective To evaluate the effectiveness of scanning with labeled autologous leukocytes for the detection of abdominal inflammation in equivocal patients. Methods From July 1998 to April 2000 sixteen patients with equivocal abdominal inflammation were recruited into this study. ResultsThere were 10 cases with positive scanning. The diagnosis of intraabdominal infection was consequently confirned by laparotomy and or good response to antibiotic therapy.The 6 cases with negative result were eventualy proven to have no intraabdominal infection. The average radioactivity of imaging and paired non imaging district was determined ( P