A novel single-chain enzyme complex with chain reaction properties rapidly producing thromboxane A2 and exhibiting powerful anti-bleeding functions.

Uncontrollable bleeding is still a worldwide killer. In this study, we aimed to investigate a novel approach to exhibit effective haemostatic properties, which could possibly save lives in various bleeding emergencies. According to the structure-based enzymatic design, we have engineered a novel single-chain hybrid enzyme complex (SCHEC), COX-1-10aa-TXAS. We linked the C-terminus of cyclooxygenase-1 (COX-1) to the N-terminus of the thromboxane A2 (TXA2 ) synthase (TXAS), through a 10-amino acid residue linker. This recombinant COX-1-10aa-TXAS can effectively pass COX-1-derived intermediate prostaglandin (PG) H2 (PGH2 ) to the active site of TXAS, resulting in an effective chain reaction property to produce the haemostatic prostanoid, TXA2 , rapidly. Advantageously, COX-1-10aa-TXAS constrains the production of other pro-bleeding prostanoids, such as prostacyclin (PGI2 ) and prostaglandin E2 (PGE2 ), through reducing the common substrate, PGH2 being passed to synthases which produce aforementioned prostanoids. Therefore, based on these multiple properties, this novel COX-1-10aa-TXAS indicated a powerful anti-bleeding ability, which could be used to treat a variety of bleeding situations and could even be useful for bleeding prone situations, including nonsteroidal anti-inflammatory drugs (NSAIDs)-resulted TXA2 -deficient and PGI2 -mediated bleeding disorders. This novel SCHEC has a great potential to be developed into a biological haemostatic agent to treat severe haemorrhage emergencies, which will prevent the complications of blood loss and save lives.

Creating a mouse model resistant to induced ischemic stroke and cardiovascular damage.

Vascular prostanoids, isomerized from an intermediate prostaglandin (PG), H2, produced by cyclooxygenase (COX), exert various effects on the vascular system, both protective and destructive. During endothelial dysfunction, vascular protector prostacyclin/prostaglandin I2 (PGI2) is decreased, while inflammatory PGE2 and thrombotic TXA2 are increased. Therefore, our research aim was to reverse the event by controlling PGH2 metabolism by generating an in vivo model via enzymatic engineering of COX-1 and prostacyclin synthase (PGIS). The COX-1 and PGIS genes were linked to a 10-residue amino acid linker to form a Single-chain Enzyme Complex (SCHEC), COX-1-10aa-PGIS. Transgenic (CP-Tg) mice in a FVB/N background were generated using the pronuclear microinjection method. We first confirmed mRNA and protein expression of COX-1-10aa-PGIS in various CP-Tg mouse tissues, as well as upregulation of circulating PGI2. We then examined the cardiovascular function of these mice. Our CP-Tg mice exhibited marked resistance to vascular assault through induced carotid arterial blockage, acute thrombotic stroke and arterial arrest, angiotensin-induced peripheral vasoconstriction, and hepatic lipid accumulation after receiving a high-fat diet. They also had a longer lifespan compared with wild-type mice. This study raises the possibility of fighting cardiovascular diseases by regulating cellular arachidonic acid-derived PGH2 metabolites using enzymatic engineering.

Hypoxia-induced lncRNA-NUTF2P3-001 contributes to tumorigenesis of pancreatic cancer by derepressing the miR-3923/KRAS pathway.

Recent studies indicate that long non-coding RNAs (lncRNAs) play crucial roles in numerous cancers, while their function in pancreatic cancer is rarely elucidated. The present study identifies a functional lncRNA and its potential role in tumorigenesis of pancreatic cancer. Microarray co-assay for lncRNAs and mRNAs demonstrates that lncRNA-NUTF2P3-001 is remarkably overexpressed in pancreatic cancer and chronic pancreatitis tissues, which positively correlates with KRAS mRNA expression. After downregulating lncRNA-NUTF2P3-001, the proliferation and invasion of pancreatic cancer cell are significantly inhibited both in vitro and vivo, accompanying with decreased KRAS expression. The dual-luciferase reporter assay further validates that lncRNA-NUTF2P3-001 and 3'UTR of KRAS mRNA competitively bind with miR-3923. Furthermore, miR-3923 overexpression simulates the inhibiting effects of lncRNA-NUTF2P3-001-siRNA on pancreatic cancer cell, which is rescued by miR-3923 inhibitor. Specifically, the present study further reveals that lncRNA-NUTF2P3-001 is upregulated in pancreatic cancer cells under hypoxia and CoCl2 treatment, which is attributed to the binding of hypoxia-inducible factor-1α (HIF-1α) to hypoxia response elements (HREs) in the upstream of KRAS promoter. Data from pancreatic cancer patients show a positive correlation between lncRNA-NUTF2P3-001 and KRAS, which is associated with advanced tumor stage and worse prognosis. Hence, our data provide a new lncRNA-mediated regulatory mechanism for the tumor oncogene KRAS and implicate that lncRNA-NUTF2P3-001 and miR-3923 can be applied as novel predictors and therapeutic targets for pancreatic cancer.

[Surveillance and forecast of schistosomiasis based on sentinel mouse technique in key water regions of Wuhan City in 2011].

OBJECTIVE: To understand the water infectivity of schistosome in key water regions of Wuhan City and explore the role of a sentinel mouse technique on surveillance and forecast system for schistosomiasis. METHODS: Schistosome-endemic areas of the Yangtze River, the Dongjing-Tongshun River system, the Fu-Lun River system and the Jinshui River of Wuhan City were chosen as the surveillance and forecast sites. The Oncomelania snail distribution and infection were surveyed before the flood season. The water infectivity was detected by using the sentinel mouse technique during the flood season. The infection status of people in the villages around the surveillance sites and the activities of human beings and domestic animals were surveyed. The correlation between the infection rate of sentinel mice and snail status was tested by the rank correlation method. The emergency response mechanism was initiated when the areas with schistosomes were detected in water. RESULTS: Among the 18 surveillance sites, 15 sites with infected sentinel mice were found, accounting for 83.33%. A total of 554 sentinel mice were placed and 540 recovered, with a recovery rate of 97.47%. All the recovered mice were dissected and 75 infected, with a total infection rate of 13.89%. Totally 172 adult worms were collected, with mean worm burden of 2.29 +/- 0.71 worms per mouse. The infection rates of sentinel mice in 4 water systems were 8.33%, 24.53%, 10.85% and 6.56%, respectively, and the mean worm burdens of infected sentinel mice were 2.33 +/- 0.71, 2.28 +/- 0.76, 2.22 +/- 0.60 and 2.75 +/- 0.96 worms per mouse, respectively. The infection rates of sentinel mice in 4 water systems had a statistically significant difference (chi2 = 19.131, P = 0.000). The mean worm burdens of the infected sentinel mice in 4 water systems had no statistically significant difference (F = 0.638, P = 0.593). The correlation coefficient among the infection rate of sentinel mice, snail area, the average density of living snails and infected snail rate had no statistical significance. Among the 15 sites with infected sentinel mice, 8 sites with fisherman activities, 8 sites with anglers or planters, 10 sites with cattle keepings and 4 of which with infected cattle. All the 15 sites with cercariae-infected water bodies started the emergency response and no epidemic situation happened. CONCLUSIONS: The water infectivity of schistosome in key water regions of Wuhan City was relatively high. Detecting water infectivity based on a sentinel mouse technique is an important part of surveillance and forecast system for schistosomiasis.

[Analysis of 1006 cases with selective salpingography and fallopian tube recanalization].

OBJECTIVE: To retrospectively analysis of selective salpingography (SSG) and fallopian tube recanalization (FTR) in 1006 infertile women with tube obstruction, to summarize their clinical effect and practical value, to analyze the related factors which can improve treatment effect and pregnancy rate, and give suggestions of their indication and contraindication. METHODS: SSG and FTR using self-made coaxial catheter were carried out in 1006 infertile cases with tube obstruction of various portions and extents confirmed by hysterosalpingography (HSG). The one-year cumulative pregnancy rate and the effective rate by HSG reexamination were calculated, in combination with dynamic observation of preoperative HSG and intraoperative tube imaging. RESULTS: In the complete tubal occlusion group of 601 tubes in 315 cases, the recanalization rate was 87.9% (528/601), among which, 35.4% was only treated by SSG and 64.6% by FTR. Postoperative pregnancy rate and ectopic pregnancy rate were 39.9% and 2.7% respectively, and tubal reocclusion was 1.8% in one-year's follow up. In those failure to recanalization, tubal tuberculosis was in 4 cases, salpingitis isthmica nodosum was in 3 cases, isthmic occlusion was in 9 cases with club-changed terminal, ampullar or fimbrial occlusion was in 6 cases, and tubal fibrosis in 10 cases. In the incomplete tubal occlusion group of 1314 tubes in 691 cases, catheterized hydrotubation was carried out. Fimbrial adhesion diagnosed by HSG was found false positive or negative in 65 cases. The pregnancy rate was 53.6%, 45.7% and 26.8% in the mildly, moderately and severely occluded cases respectively. The ectopic pregnancy rate was 1.4%. The patent rate confirmed by HSG reexamination was 86.9% one year later. Sixteen cases with obvious fimbrial adhesion or enwrapped adnexa in both groups were treated by laparoscopy, with a coincidence rate of 97.1%. CONCLUSIONS: Selective salpingography and fallopian tube recanalization have both effects of diagnosis and treatment on tubal infertility. The techniques are simple, safe, and credible, and worth to be applied clinically. Knowing the shapes of fallopian tube confirmed by preoperative HSG can increase the rates of recanalization.

[Effects of genistein and zearalenone on proliferation of PEO4].

OBJECTIVE: The objective of this study was to investigate the estrogenic activity of genistein and zearalenone through their effects on the proliferative capacity of human ovarian PEO4. METHODS: Estrogen receptor-positive PEO4 cell was grown in DMEM medium containing 10% bovine serum. Five days before the addition of the test compounds, the cells were washed in phosphate-buffered saline, and the medium was substituted with a phenol red-free DMEM medium containing 5% dextran charcoal-stripped FBS. The respective test compound was added in fresh medium and the control cell received only the vehicle (ethanol). Cell proliferation was detected respectively by MTT assay, (3)H-TdR incorporation and flow cytometry. RESULTS: Compared with vehicle control, 96 x 10(-6) mol/L GS significantly inhibited PEO4 cell proliferation and DNA synthesis as measured by MTT and (3)H-TdR incorporation after treatment for 24 h. Alao, 32 x 10(-6) mol/L GS could exert inhibition on PEO4 cell growth as time extension to 48 h. 32 x 10(-6) mol/L approximately 96 x 10(-6) mol/L GS induced G(2)/M arrest. At low dose (< 8 x 10(-6) mol/L=, GS promoted proliferation in PEO4 cells. ZEA enhanced proliferation, promoted DNA synthesis and increased the S phase population in PEO4 cells. CONCLUSIONS: Genistein possess estrogenic activity and zearalenone have anti-estrogenic activity. They play different effects on the proliferation of human ovarian cancer cell. Genistein enhanced the proliferation of PEO4. Zearalenone inhibited its the proliferation. These results implied that genistein and zearalenone elicit different signal-transduction channel.