Suppression of P-gp induced multiple drug resistance in a drug resistant gastric cancer cell line by overexpression of Fas

AIM To observe the drug sensitizing effect andrelated mechanisms of fas gene transduction onhuman drug-resistant gastric cancer cellSGC7901/VCR(resistant to Vincristine).METHODS The cell cycle alteration wasobserved by FACS.The sensitivity of gastriccancer cells to apoptosis was determined by invitro apoptosis assay.The drug sensitization ofcells to several anti-tumor drugs was observedby MTT assay.Immunochemical method wasused to show expression of P-gp and Topo Ⅱ ingastric cancer cells.RESULTS Comparing to SGC7901 and pBK-SGC7901/VCR,fas-SGC7901/VCR showeddecreasing G2 cells and increasing S cells,theG2 phase fraction of pBK-SGC7901/VCR wasabout 3.0 times that of fas-SGC7901/VCR,but Sphase fraction of fas-SGC7901/VCR was about1.9 times that of pBK-SGC7901/VCR,indicatingS phase arrest of fas-SGC7901/VCR.FACS alsosuggested apoptosis of fas-SGC7901/VCR,fas-SGC7901/VCR was more sensitive to apoptosisinducing agent VM-26 than pBK-SGC7901/VCR.MTT assay showed increased sensitization offas-SGC7901/VCR to DDP,MMC and 5-FU,butsame sensitization to VCR according to pBK-SGC7901/VCR.SGC7901,pBK-SGC7901/ VCRand fas-SGC7901/VCR had positively stainedTopo Ⅱ equally.P-gp staining in pBK- SGC7901/VCR was stronger than in SG07901,but there was little staining of P-gp in fas.SGC7901/VCR.CONCLUSION fas gene transduction couldreverse the MDR of human drug-resistant gastriccancer cell SGC7901/VCR to a degree,possiblybecause of higher sensitization to apoptosis anddecreased expression of P-gp.

Protective effects of prostaglandin E1 on hepatocytes

INTRODUCTION E Numerous studies have demonstrated the protective action of prostaglandin E1(PGE1) on experimental animal models of liver injury and on patients with

Down-regulation of Hsp90 could change cell cycle distribution and increase drug sensitivity of tumor cells

AIM:To construct Hsp90 antisense RNA eukaryotic expression vector, transfect it into SGC7901 and SGC7901/VCR of MDR-type human gastric cancer cell lines, HCC7402 of human hepatic cancer and Ec109 of human esophageal cancer cell lines, and to study the cell cycle distribution of the gene transected cells and their response to chemotherapeutic drugs.METHODS:A 1.03kb cDNA sequence of Hsp90beta was obtained from the primary plasmid phHSP90 by EcoR I and BamH I nuclease digestion and was cloned to the EcoR I and BamH I site of the pcDNA by T4DNA ligase and an antisense orientation of Hsp90beta expression vector was constructed. The constructs were transfected with lipofectamine and positive clones were selected with G418. The expression of RNA was determined with dot blotting and RNase protection assay, and the expression of Hsp90 protein determined with western blot. Cell cycle distribution of the transfectants was analyzed with flow cytometry, and the drug sensitivity of the transfectants to Adriamycin (ADR), vincrinstine (VCR), mitomycin (MMC) and cyclophosphamide (CTX) with MTT and intracellular drug concentration of the transfectants was determined with flow cytometry.RESULTS:In EcoR I and BamH I restriction analysis, the size and the direction of the cloned sequence of Hsp90beta remained what had been designed and the gene constructs were named pcDNA-Hsp90.AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 cell clones all expressed Hsp90 anti-sense RNA. The expression of Hsp90 was down-regulated in AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 cell clones. Cell cycle distribution was changed differently. In AH-SGC7901/VCR and AH-Ec109 cells, G(1) phase cells were increased; S phase and G(2) phase cells were decreased as compared with their parental cell lines. In AH-SGC7901 cell, G(1)phase cells were decreased, G(2) phase cells increased and S phase cells were not changed, and in AH-HCC7402 cells G(1), S and G(2) phase cells remained unchanged as compared with their parental cell lines. The sensitivity of AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 to chemotherapeutic drugs, the sensitivity of AH-SGC7901/VCR to ADR, VCR, MMC and CTX the sensitivity of AH-HCC7402 to ADR and VCR, and the sensitivity of Ec109 to ADR, VCR and CTX all increased as compared with their parental cell lines. The mean fluorescence intensity of ADR in AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 was also significantly elevated (P 【 0.05).CONCLUSION: Down-regulation of Hsp90 could change cell cycle distribution and increase the drug sensitivity of tumor cells.

DSA analysis of hepatic arteriovenous fistula concurrent with hepatic cancer and its clinical significance

INTRODUCTIONIntervention therapy has become one of the maintherapies of hepatic cancer.Theintroduction of hepatic arterial perfusion andembolization has provided opportunities for asecondary operation on patients with intermediateand advanced cancer,thus

Epidermal growth factor prevents gut atrophy and maintains intestinal integrity in rats with acute pancreatitis

INTRODUCTIONThere is abundant evidence that stressful insults suchas acute pancreatitis may significantly alter themetabolism of the gut mucosa and therefore itsbarrier integrity,resulting in an increase in mucosalpermeability and subsequent translocation of entericbacteria and their cndotoxins.The fact thatmost bacteria associated with acute pancreatic andperipancreatic infections are of enteric originimplies that the gut plays a major role in

Identification of tumor associated single-chain Fv by panning and screening antibody phage library using tumor cells

AIM:To study the feasibility of panning and screeningphage-displaying recombinant single-chain variablefragment (ScFv) of anti-tumor monoclonal antibodiesfor fixed whole cells as the carriers of mAb-bindingantigens.ME,ODS: The recombinant phage displaying librariesfor anti-colorectal tumor mAb MC3Ab, MC5Ab andanti-gastric tumor mAb MGD1 was constructed.Panning and screening were carried outby means ofmodified fixation of colorectal and gastric tumor cellsexpressed the mAb-binding antigens. Concordance ofbinding specificity to tumor cells between phageclones and parent antibodies was analyzed. Thephage of positive clones was identified withcompetitive ELISA, and infected by E.coli HB2151 toexpress soluble ScFv.RESULTS:The ratio of positive clones to MC3-ScF-MC5-ScFv and MGD1-ScFv were 60 %, 24 % and 30 %. MC3-ScFv had Mr 32 000 confirmed by Western blot. Thespecificity to antigen had no difference between 4positive recombinant phage antibodies and MC3Ab.CONCLUSION:The modified process of fixing wholetumor cells is efficient, convenient and feasible to panand screen the phage-displaying ScFv of anti-tumormonoclonal antibodies.

Treatment of hepatic cysts by B-ultrasound-guided radiofrequency ablation

BACKGROUND: The traditional therapy for hepatic cysts has limited success because of recrudescence. Radiofrequency ablation (RFA) has become popular because of its advantages including little damage, therapeutic effect and reduced suffering. This report describes the effects and reliability of RFA in the treatment of 29 patients with hepatic cysts. METHODS: B-ultrasound-guided REA was used to treat hepatic mono-cyst or multi-cysts of 29 patients (63 tumors). Ablative efficiency and complications were assessed by imaging and clinical symptoms. RESULTS: The tumors were abated completely in 34 cysts with a diameter <5 cm and no recurrence was seen after 3 months. In 21 cysts with a diameter of 5-10 cm, tumor volume was decreased by over 70%, then reduction and fiberosis were found. In 8 cysts with a diameter greater than 10 cm, tumor volume was decreased by more than 60%, and in 2 cysts it was increased more slightly than that at I month after REA. In subsequent follow-up (6 and 12 months after REA), tumors <10 cm in diameter were fully ablated. No significant discomfort and complications were found in any patient. CONCLUSION: RFA for the treatment of hepatic cysts is safe, and free from complications.

Dot immunogold filtration assay for rapid detection of anti-HAV IgM in Chinese

INTRODUCTION The hepatitis A virus specific immunoglobulin M(IgM)antibody is a specific serological marker forearly diagnosis of hepatitis A..At present,themethods used at home or abroad for detecting anti-HAV IgM are RIA,ELISA and SPHAI.The dotimmunogold combination assay that has beendeveloped since 1989 is a new technique with theproperty of simple and rapid immunologicaldetection,by using the red colloidal gold particles tolabel the antibodies as indicator,and the

Prevention of pancreatic leakage after pancreaticoduodenectomy by modified Child pancreaticojejunostomy

BACKGROUND: Pancreatic leakage after pancreaticoduodenectomy is associated with a morbidity and mortality. Different techniques have been used to make a safe anastomosis to the left pancreatic remnant. METHODS: We performed 'modified Child pancreatico jejunostomy' for 31 patients, by which end-to-end pancreaticojejunal anastomosis was made with a two-layer polypropylene continuous running suture. RESULTS: In the patients who underwent pancreaticojejunostomy, the average operative time was 14.2 minutes. There was no pancreaticoenterostomy leakage in all patients, and no deaths occurred. CONCLUSIONS: In pancreaticojejunostomy, pancreatic anastomosis is time-saving and free from complications. Thus it is an improvement of pancreaticojejunostomy.

Significance of alpha-fetoprotein mRNA level in hepatocellular carcinoma patients treated with radiofrequency ablation

BACKGROUND: Many methods are used to treat liver cancer. Among them, radiofrequency ablation (RFA) is a hot topic because of its advantages. This study was designed to determine the significance of blood alpha-fetoprotein mRNA (AFPmRNA) changes in patients with hepatocellular carcinoma (HCC) treated with RFA. METHODS: The AFPmRNA content in blood samples from HCC patients was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) before RFA and 48 hours, 72 hours, I week and 2 weeks later. RESULTS: The blood of 183 patients was negative for AFPmRNA before REA, but that of 62 of them was positive 72 hours later, then returned to negative after 2 weeks. The blood of 129 patients was positive for AFPmRNA before RFA, but that of 112 of them became negative 2 weeks later; 17 patients were still AFPmRNA positive 2 weeks after REA. CONCLUSIONS: Blood AFPmRNA, which is increased temporarily after RFA, can be used as an objective index for the persistence and recurrence of HCC after REA.

Cloning and identification of an angiostatic molecule IP-10/crg-2

AIM To obtain human and murine cDNAsencoding IFN--y inducible protein 10 (lP--10) andcytokine responsive gene--2 (Crg-2).METHODS The encoding genes of lP-10 and Crg2 were amplified by RT--PCR from Cultured humanfibroblast cells and Balb/ c mouse liver treatedby IFN-y and TNF-a, respectively, and clonedinto plasmids of PUC19 and PGEM3Zf(+ ).RESULTS The nucleotide sequences ot theamplified DNA were confirmed by endonucleasesdigestion and sequencing.CONCLUSION Recombinant lP-10/ crg--2 geneclones with 306 hp and 314 hp inserts wereestablished for further research on biologicalactivities and ligands of hiP-10/mCrg--2.

Clinical value of contrast-enhanced ultrasonography in the characterization of focal liver lesions:a prospective multicenter trial

BACKGROUND: Contrast-enhanced ultrasonography (CEUS) is increasingly accepted in clinical settings for diagnostic imaging of focal liver lesions (FLLs). This study aimed to assess the efficacy of CEUS in the characterization of FLLs in comparison with final diagnosis based on gold standard assessment. METHODS: The study was approved by the local ethics committee and participating patients provided written informed consent. A total of 148 patients with 164 FLLs were studied. Unenhanced ultrasonography (US) and CEUS were performed using fundamental and harmonic imaging, respectively. Contrast enhancement was assessed during the arterial, portal and late vascular phases after intravenous administration of contrast (SonoVue (R), Bracco, Italy). Sensitivity, specificity and diagnostic accuracy of US and CEUS were compared in identifying the lesion as benign, malignant or indeterminate and its actual tumor type. Final diagnosis was established by biopsy (129/164), MR imaging (11/164) or medical history (24/164). RESULTS: When compared to the gold standard, the number of indeterminate diagnoses was reduced from 56.7% (93/164) as assessed by fundamental imaging to 6.1% (10/164) after SonoVue (R) enhanced US examination. Sensitivity and specificity improved from 49% and 25% at baseline US to 93% and 75% with CEUS, respectively (P<0.01). Diagnostic accuracy of CEUS was 88% in contrast to 41% of baseline US. CONCLUSION: SonoVue (R) enhanced US improves the characterization of FLLs and may limit the need for further investigations.

Percutaneous injection of hemostatic agents for active liver hemorrhage

BACKGROUND: Active hemorrhage arising from hepatic injury can be life-threatening and require immediate attention. At present, nonoperative management of abdominal solid organ injuries has become the usual method of care. The purpose of this study was to determine whether, hemocoagulase injection alone guided by contrast-enhanced ultrasonography (CEUS) could control active bleeding in rabbit liver. METHODS: The livers of 30 rabbits were punctured with an 18-gauge semiautomatic biopsy needle to create an active bleeding liver model, which was confirmed with CEUS. The animals were randomly divided into two groups: a treatment group (n=15) and a control group (n=15). In the treatment group, hemocoagulase was injected into the bleeding site under CEUS guidance. In the control group, the active bleeding site was treated with normal saline. When these treatment procedures had been performed, lactated Ringer's solution was given to both groups to maintain the mean arterial pressure at 70 mmHg for 1 hour. The intraperitoneal blood loss, hematocrit, mean heart rate, and macroscopic and microscopic examinations were analyzed at the end of the study. RESULTS: CEUS showed hypoechoic and anechoic perfusion defects in active bleeding liver models. Macroscopic and microscopic examinations also supported the results. After the hemocoagulase injection, the former bleeding site appeared on CEUS as an area devoid of contrast. The blood loss was lower in the treatment group than in the control group (38.0+/-16.6 ml versus 107.9+/-20.8 ml; t=10.172, P<0.05). The mean hematocrit value and the heart rate were higher in the treatment group than in the control group (hematocrit: 23.9+/-3.8% versus 18.8+/-4.1%; t=3.541, P<0.05; heart rate: 250+/-18 versus 223+/-15; t=4.551, P<0.01). CONCLUSION: Hemocoagulase injection alone under the guidance of CEUS is a simple and quick method to control blood loss in active liver bleeding.

Morphology of the medullary visceral zone

Since 1990, a series of studies on rats, monkeys and human foetus showed that an arcshaped zone is present in the middle-caudal segment of medulla oblongata, running from the dorsomedial part to the ventrolateral part and passing through the reticular formation. It was named the medullary visceral zone (MVZ). The MVZ has been investigated with various techniques (Golgi method, Nissl method, immunohistochemical method, in situ hybridization method, triple labelling method, neurophysiological method, etc. ), and the morphological features as well as the physiological functions of MVZ have been preliminarily understood. It is proved that the medullary life center is located in MVZ.An introduction and some comments are given on the location of MVZ, its shape and extent, cytoarchitecture, and chemicoarchitecture, afferent and efferent fiber connections and their functions, and its important physiological functions.

多孔磷酸钙骨水泥与钛合金支架材料修复兔颅骨骨缺损的比较研究

通过采用结构可控的多孔磷酸钙骨水泥(calcium acid phosphate cement,CPC)和钛合金支架材料修复兔颅骨骨缺损,比较了两种修复材料骨环境下的成骨性能。结果显示,与多孔钛合金材料相比,多孔CPC材料表现出了更好的成骨活性。CPC材料的新生骨量、成骨速率均高于钛合金材料。而且骨吸收重建过程也早于钛合金材料。同时,三维贯通的孔隙结构有利于骨组织的长入,能够在一定程度上克服钛合金材料的应力屏蔽缺陷,使植入体在早期获得良好的固位,从而使界面骨性结合得以顺利进行。

A-to-I RNA editing: A new mechanism of genomic information modification

A-to-I RNA editing, the important event of gene modification, which takes place at post-transcriptional level, was firstly reported in 1991. The molecular mechanism of A-to-I RNA editing involves site-selective deamination of adenosine to inosine in pre-mRNA, which leads to altering translation codons and splicing in nuclear transcripts, thereby functionally distinct proteins can be produced from a single gene. The mammalian editing enzymes ADARs (adenosine deaminases acting on RNA) are widely expressed in brain and other tissues, however, up to date their sub-strates are mainly found in the central nervous system. It has recently been noticed that imperfect editing of these RNA substrates play critical roles in corresponding diseases, indi-cating that A-to-I RNA editing may be quite important in physiological or pathophysiological processes. Finding more new substrates of ADARs, especially in peripheral tissues, and performing functional research on new genes will be helpful to elucidate the biological significance of A-to-I RNA editing.

Profile of Dr.Xu Zhang

Dr.Xu Zhang was conferred the Bachelor's degree of Medicine from Fourth Military Medical University in 1985.From 1990 to 1994,he carried out his Ph.D.study at the Department of Neuroscience,Karolinska Institute in Sweden.Then,he was appointed as lecturer,associate professor and professor successively at the Institute of Neuroscience,Fourth Military Medical University.In 1999,he was recruited as a principal investigator by the Institute of Neuroscience,Chinese Academy of Science.He received the outstanding young investigator award of National Natural Science Foundation of China in 1995.He was elected as Academician of Chinese Academy of Sciences in 2015.

The Chinese Expert Consensus on Evaluation of Coma after Cardiopulmonary Resuscitation

INTRODUCTIONThe prognosis of patients who suffer from coma after cardiopulmonary resuscitation （CPR） may be poor （defined as cerebral performance categories scores from 3 to 5） Thus, an accurate prediction of their neurological outcomes is an essential component of post-cardiac arrest evaluation, especially for decisions to limit or withdraw life-sustaining care. Since the 1960s, a series of domestic and foreign studies began to focus on the evaluation of coma patients after CPR, and considerable progress has been achieved in this field.

Microscopic and ultramicroscopic localizations and quantitative analysis of 5-HT receptors in human placentas

The localizations of 5-hydroxytryptamine receptor (5-HTR) at light and electron microscopic levels and its quantitative analysis in human placentas were studied by using immunohistochemistry and in situ hybridization. Both syncytiotrophoblast and cytotrophoblast in placental villi and fetal white blood cells in villose capillary cavity showed 5-HT receptor immunoreactivity, with 5-HT 1A receptor mRNA hybridized signal detected in cytoplasm. But the stromal cells and capillary endothelium in placental villi showed 5-HT receptor immunoreactivity in cytoplasm, without 5_HT\-1A receptor mRNA hybridized signal detected. This suggested that two layers of trophoblast cells may produce 5-HT 1 and 5-HT 2 receptors, that the stromal cells and capillary endothelium in placental villi may only produce 5-HT 2 receptor. By immunohistochemistry at electron microscopic level, the small flattened vesicles and large dense cored vesicle within trophoblast cells showed 5-HT receptor immunoreactivity. This suggested that it may be the result of 5-HT receptors internalization and transportion. Using a quantitative immunohistochemical method, the contents of 5-HT receptor in placenta were higher during the 6th week of gestation, and decreased in 7th and 8th, reoccurred the second peak in the 9th, reduced gradually during the 10th, 20th and 40th of the gestation period. These changes paralleled the contents of 5-HT in the authors’ studies, reflecting that 5-HT may be one of the most important bioactive substances in placental self-regulation.

Localization and quantitative analysis of interleukin-6 in human placenta

The localization of IL6 at light microscopic levels and its quantitative analysis in human placentas were studied by using immunohistochemistry. Both syncytiotrophoblast and cytotrophoblast in placental villi, white blood cells in villose capillary cavity stromal cells and capillary endothelium present IL6 immunoreactivity in cytoplasm. Using a quantitative immunohistochemical method, the amounts of IL6 in placenta were low at the 6th week of gestation, increased saliently and peaked at the 7th, then reduced gradually during the rest of the gestation period and maintained the same level as that in the 6th week of gestation. This changing trend was paralleled with that of GnRH in our previous studies. These results revealed that IL6 could be produced by the human placenta and may take part in the regulation of placental hormone releasing.