Antitumor and antiangiogenic activities of anti-vascular endothelial growth factor hairpin ribozyme in human hepatocellular carcinoma cell cultures and xenografts

AIM: To study the effectiveness and mechanisms of anti-human vascular endothelial growth factor (hVEGF) hairpin ribozyme on angiogenesis,oncogenicity and tumor growth in a hepatocarcinoma cell line and a xenografted model. METHODS: The artificial anti-hVEGF hairpin ribozyme was transfected into hepatocarcinoma cell line SMMC-7721 and,subsequently,polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) were performed to confirm the ribozyme gene integration and transcription. To determine the effects of ribozyme ,VEGF expression was detected by semiquantitative RT-PCR and enzyme liked immunosorbent assay (ELISA). MTT assay was carried out to measure the cell proliferation. Furthermore,the transfected and control cells were inoculated into nude mice respectively,the growth of cells in nude mice and angiogenesis were observed. RESULTS: VEGF expression was down-regulated sharply by ribozyme in transfected SMMC-7721 cells and xenografted tumor. Compared to the control group,the transfected cells grew slower in cell cultures and xenografts,and the xenograft formation was delayed as well. In addition,the microvessel density of the xenografted tumor was obviously declined in the transfected group. As demonstratedby microscopy,reduction of VEGF production induced by ribozyme resulted in a significantly higher cell differentiation and less proliferation vigor in xenografted tumor. CONCLUSION: Anti-hVEGF hairpin ribozyme can effectively inhibit VEGF expression and growth of hepatocarcinoma in vitro and in vivo. VEGF is functionally related to cell proliferation,differentiation and tumori-genesis in hepatocarcinoma.

Effectiveness and safety of over-the-scope clip in closing perforations after duodenal surgery

BACKGROUND Endoscopic resection of duodenal subepithelial lesions(SELs)is a difficult procedure with a high risk of perforation.At present,dealing with perforation after endoscopic resection of duodenal SELs is still considered a great challenge.AIM To evaluate the effectiveness and safety of an over-the-scope clip(OTSC)in the treatment of perforation post-endoscopic resection of duodenal SELs.METHODS From May 2015 to November 2019,18 patients with perforation following endoscopic resection of duodenal SELs were treated with OTSCs.Data comprising the rate of complete resection,closure of intraprocedural perforation,delayed bleeding,delayed perforation,and postoperative infection were extracted.RESULTS The rate of complete removal of duodenal SELs and successful closure of the perforation was 100%.The median perforation size was 1 cm in diameter.Seventeen patients had minor intraoperative bleeding,while the remaining 1 patient had considerable amount of bleeding during the procedure.Seven patients had postoperative abdominal infections,of which 1 patient developed an abscess in the right iliac fossa and another patient developed septic shock.All 18 patients recovered and were discharged.No delayed bleeding or perforation was reported.The mean time taken to resume normal diet after the procedure was 6.5 d.The mean postoperative hospital stay was 9.5 d.No residual or recurrent lesions were detected during the follow-up period(15-66 mo).CONCLUSION Closing a perforation after endoscopic resection of duodenal SELs with OTSCs seems to be an effective and reasonably safe therapeutic method.

Design of an energetic particle radiation diagnostic spectroscopy system based on national core chips and Qt on Linux in EAST

Energetic particle radiation diagnoses mainly detect the particles(such as neutrons,gamma rays,hard X-rays,and escaping electrons)that are radiated in the discharge process of the experimental advanced superconducting tokamak device to characterize the operating state of the plasma in real time.The upgrading of these diagnoses requires new instruments based on national(here,“national”means developed and produced by a Chinese company)core chips and open-source software with advanced digitization,a high sampling rate,and a high time resolution.The new spectroscopy system designed in this study adopts the national field-programmable gate array(FPGA)and an analog-to-digital converter as the core chip,and it is developed using Qt on Linux.The communication between the FPGA and embedded controller occurs via a high-speed peripheral component interconnect eXtension for instrument express protocol with a direct memory access mode.On this basis,the time resolution of the system is improved from 2 to 1 ms,the maximum channel address is increased to 4096,and the sampling rate is increased from 10 to 80 Msps.Calibration experiments of the spectroscopy system with 152Eu and 137Cs sources demonstrate that the best energy resolution is 0.27%and the measurement error is less than±0.5 keV.

Microstructure evolution and passivation quality of hydrogenated amorphous silicon oxide(a-SiOx:H) on〈100〉- and 〈111〉-orientated c-Si wafers

Hydrogenated amorphous silicon oxide(a-SiOx:H) is an attractive passivation material to suppress epitaxial growth and reduce the parasitic absorption loss in silicon heterojunction(SHJ) solar cells. In this paper, a-SiOx:H layers on different orientated c-Si substrates are fabricated. An optimal effective lifetime(τ(eff)) of 4743 μs and corresponding implied opencircuit voltage(iV(oc)) of 724 mV are obtained on〈100〉-orientated c-Si wafers. While τ(eff) of 2429 μs and iV_(oc) of 699 mV are achieved on 111-orientated substrate. The FTIR and XPS results indicate that the a-SiOx:H network consists of SiOx(Si-rich), Si–OH, Si–O–SiHx, SiO2 ≡ Si–Si, and O3 ≡ Si–Si. A passivation evolution mechanism is proposed to explain the different passivation results on different c-Si wafers. By modulating the a-SiOx:H layer, the planar silicon heterojunction solar cell can achieve an efficiency of 18.15%.

Combined use of extracorporeal membrane oxygenation with interventional surgery for acute pancreatitis with pulmonary embolism: A case report

BACKGROUND Acute pancreatitis(AP) is an acute inflammatory process of the pancreas characterized by self-digestion of pancreatic tissue, which can trigger a systemic inflammatory response. Venous thrombosis, resulting from a hypercoagulable state, is a vascular complication of AP. AP complicated by pulmonary embolism(PE) is very rare, and the combined use of extracorporeal membrane oxygenation(ECMO) with a vascular interventional procedure for AP complicated by PE is even rarer.CASE SUMMARY A 32-year-old man with a history of obesity developed rapidly worsening AP secondary to hypertriglyceridemia. During treatment, the patient developed chest tightness, shortness of breath, and cardiac arrest. Computed tomography(CT) scans of his upper abdomen were consistent with pancreatitis. PE was identified by chest CT angiography involving the right main pulmonary artery and multiple lobar pulmonary arteries. The patient’s D-dime level was significantly elevated(> 20 mg/L). The patient received high-frequency oxygen inhalation, continuous renal replacement therapies, anti-infective therapy, inhibition of pancreatic secretion, emergent endotracheal intubation, and advanced cardiac life support with cardiopulmonary resuscitation. Following both ECMO and a vascular interventional procedure, the patient recovered and was discharged.CONCLUSION PE is a rare but potentially lethal complication of AP. The early diagnosis of PE is important because an accurate diagnosis and timely interventional procedures can reduce mortality. The combined use of ECMO with a vascular interventional procedure for AP complicated by PE can be considered a feasible treatment method. A collaborative effort between multiple teams is also vital.