Wellbore Stability through Novel Catechol-Chitosan Biopolymer Encapsulator-Based Drilling Mud.

The problem of wellbore stability has a marked impact on oil and gas exploration and development in the process of drilling. Marine mussel proteins can adhere and encapsulate firmly on deep-water rocks, providing inspiration for solving borehole stability problem and this ability comes from catechol groups. In this paper, a novel biopolymer was synthesized with chitosan and catechol (named "SDGB") by Schiff base-reduction reaction, was developed as an encapsulator in water-based drilling fluids (WBDF). In addition, the chemical enhancing wellbore stability performance of different encapsulators were investigated and compared. The results showed that there were aromatic ring structure, amines, and catechol groups in catechol-chitosan biopolymer molecule. The high shale recovery rate demonstrated its strong shale inhibition performance. The rock treated by catechol-chitosan biopolymer had higher tension shear strength and uniaxial compression strength than others, which indicates that it can effectively strengthen the rock and bind loose minerals in micro-pore and micro-fracture of rock samples. The rheological and filtration property of the WBDF containing catechol-chitosan biopolymer is stable before and after 130 °C/16 h hot rolling, demonstrating its good compatibility with other WBDF agents. Moreover, SDGB could chelate with metal ions, forming a stable covalent bond, which plays an important role in adhesiveness, inhibition, and blockage.

Antibiotic prophylaxis in perioperative period of percutaneous nephrolithotomy: a systematic review and meta-analysis of comparative studies.

OBJECTIVE: To explore the efficacy of antibiotic prophylaxis in perioperative period of percutaneous nephrolithotomy (PCNL) by conducting a systematic review and meta-analysis. MATERIALS AND METHODS: A systematic literature search using Pubmed, Embase, and the Chinese SinoMed, CNKI, WanFang and VIP databases was performed to find comparative studies on the efficacy of different antibiotic prophylaxis strategies in PCNL for preventing postoperative sepsis. The last search was conducted on 21 April 2019. All selected articles were reviewed independently by two, and in case of discordance, three reviewers. Summarized unadjusted odds ratios (ORs) or risk ratios (RRs) with 95% confidence intervals (CIs) were calculated to assess the efficacy of different antibiotic prophylaxis strategies. RESULTS: Thirteen independent studies comprising up to 1549 individuals were included. Compared with single dose before anesthesia, preoperative prophylactic antibiotics significantly reduced postoperative sepsis (OR 0.31, 95% CI 0.20-0.50; P < 0.00001) and fever (OR 0.26, 95% CI 0.14-0.48; P < 0.0001). But no remarkable difference in sepsis risk between patients with and without postoperative prophylactic antibiotics was detected (RR 1.19, 95% CI 0.72-1.97; P = 0.49). And patients receiving postoperative prophylactic antibiotics were at a significantly high risk of fever (OR 1.88, 95% CI 1.01-3.05; P = 0.05). Compared with single dose before anesthesia, preoperative prophylactic antibiotics significantly reduced positive pelvic urine (RR 0.22, 95% CI 0.09-0.54; P = 0.0009) and stone cultures (RR 0.40, 95% CI 0.25-0.64; P = 0.0001). CONCLUSIONS: The conclusion is drawn that preoperative prophylactic antibiotics indeed lowered the risk of postoperative sepsis and fever, whereas its postoperative use seems unnecessary. Besides, preoperative prophylactic antibiotics reduced positive pelvic urine and stone cultures significantly, which are a risk factor for sepsis. In our meta-analysis, the efficacy of different types of antibiotics and different courses of preoperative antibiotics could not be assessed. To verify the correctness of these conclusions, randomized controlled trials with a larger sample size and more rigorous study design are required.

Conditionally replicative adenovirus carrying shRNA targeting EZH2 inhibits prostate cancer growth and invasion.

The present study aimed to construct conditionally replicative adenovirus (CRAds) carrying small hairpin (sh)RNA targeting enhancer of zeste homolog 2 (EZH2), in order to study its effect on inhibiting prostate cancer (PCa) cell growth and invasion. Immunohistochemical analyses of EZH2 was performed in tumor tissue samples from PCa and benign prostate hyperplasia (BPH). The human telomerase reverse transcriptase (hTERT) promoter was chosen to transcriptionally control EZH2 gene expression to obtain adenoviral replication (Ad­hTERT­EZH2shRNA) in human PCa cell lines. The inhibitory effect of Ad­hTERT­EZH2shRNA on EZH2 expression was evaluated by reverse transcription­-quantitative polymerase chain reaction and western blot analyses. Cell Counting Kit­8 assays were used to examine the effects of the Ad­hTERT­EZH2shRNA on cell proliferation. Transwell Matrigel invasion assays were used to detected cell invasion. Immunohistochemistry showed that EZH2 staining was stronger in castration­resistant prostate cancer (CRPC) samples, compared with androgen­dependent prostate cancer (ADPC) samples, and was absent in BPH. Furthermore, EZH2 expression knockdown suppressed PCa cell proliferation and invasion. In addition, it was found that Ad­hTERT­EZH2shRNA selectively replicated and significantly reduced the expression of EZH2 in PCa cells lines. The growth ability and invasion of DU145 and PC3 cells in vitro was effectively inhibited by Ad­hTERT­EZH2shRNA. Silencing the expression of EZH2 led to decreased expression of CCND1 and Ki67 and increased expression of E­cadherin, as determined by western blot analysis. Thus, it was shown that CRAds armed with EZH2 shRNA exhibited significant antitumor effects in human PCa cells. Ad­hTERT­EZH2shRNA may be developed as a treatment for hormone­refractory PCa.

Clinicopathological characteristics and survival outcomes of bladder neuroendocrine carcinomas: a population-based study.

BACKGROUND: Bladder neuroendocrine carcinomas (BNECs) are relatively a rare type of tumor. The aim of this study was to examine the clinicopathological characteristics and predictors of survival outcomes of patients with BNECs based on the analysis of the national Surveillance, Epidemiology, and End Results (SEER) database. MATERIALS AND METHODS: Kaplan-Meier analysis with log-rank test was used for survival comparisons. Multivariate Cox regression model was employed to analyze the effect of different treatments on overall survival (OS) and cancer-specific survival (CSS). RESULTS: A total of 910 patients were identified between 2004 and 2014. Overall, 648 (71.2%) patients had small cell neuroendocrine carcinoma (SCNEC), 35 (3.8%) had large cell neuroendocrine carcinoma (LCNEC), 10 (1.1%) had carcinoid tumor (well-differentiated neuroendocrine tumor), 16 (1.8%) had paraganglioma/pheochromocytoma (PGL/PHEO), 619 (68.0%) had a poorly differentiated or undifferentiated histology grade, 214 (23.5%) presented with metastatic disease, 586 (64.4%) underwent transurethral ablation/destruction for bladder tumor, and 245 (26.9%) had partial/total cystectomy. Cystectomy+chemotherapy+radiotherapy (CCR) has the highest long-term survival rate among various treatments. The 1-, 3-, and 5-years CSS of CCR were 56%, 56%, and 56%, respectively. By using multivariable Cox proportional hazard model, age, histology, N stage, SEER stage, tumor size, radiotherapy, chemotherapy, and local treatment of the primary site were identified as independent predictors for OS and CSS; all P<0.05. CONCLUSION: In BNEC, SCNEC has an absolute advantage in number. SCNEC/LCNEC tend to be older men. PGL/PHEO and carcinoid tumors have younger mean ages, earlier tumor stages, and better prognosis than SCNEC/LCNEC. Surgery, radiotherapy and chemotherapy are better than conservative treatment. However, whatever cystectomy or bladder sparing, chemotherapy should be a major component of treatment.

MiR-199b-5p targets HER2 in breast cancer cells.

HER2 (ErbB2) has been reported to be overexpressed in 20-30% of breast cancer and confers poor survival because of high proliferation and metastasis rates. MicroRNAs are small noncoding RNAs that are responsible for the post-transcriptional regulation of target genes. We found miR-199b-5p inhibited HER2 expression by direct targeting its 3'-untranslated region (3'UTR) in breast cancer cells. In addition, miR-199b-5p inhibited HER2 downstream signaling by ERK1/2 and AKT pathways in breast cancer cells. Besides, transwell migration, wound healing, and clonogenicity were obviously inhibited by overexpression of miR-199b-5p in HER2-positive breast cancer cells. We also found that miR-199b-5p could enhance the suppression of trastuzumab on cell migration and clonogenicity. These results suggest that miR-199b-5p may have the potential to be a novel important alternative therapeutic target for HER2-positive breast cancer.

Evaluation of novel saponins from Psammosilene tunicoides and their analogs as immunomodulators.

Two original oleanane-type triterpenoid saponins, tunicosaponin A (TSA) and tunicosaponin E (TSE) were isolated from the roots of Psammosilene tunicoides. Four semi-synthetic saponin derivatives, TSA1, TSA2, TSA3, and TSA4, were synthesized from TSA; two derivatives TSE1 and TSE2 were prepared from TSE. Through comparing their hemolytic activity and effects on ovalbumin (OVA)-induced IgG response with those of Quil A, TSA2 was selected as a lead candidate to evaluate acute and hepatotoxic toxicities and adjuvant potentials on the cellular and humoral immune responses of ICR mice against OVA. TSA2 had lower hemolytic activity than Quil A and TSA (P<0.001). Furthermore, TSA2 did not cause any mortality and side effects when mice were administered subcutaneously at a dose up to 1.6 mg. Moreover, no significant hepatotoxic effect was observed in TSA2 groups in doses ranging from 0.05 mg to 0.8 mg. The Con A-, LPS-, and OVA-induced splenocyte proliferation, OVA-specific antibody levels (IgG, IgG1, IgG2a and IgG2b) and IFN-γ, TNF-α, IL-2, IL-4 and IL-5 in serum were significantly enhanced by TSA2 (25 µg/mouse). The present study of structure-activity relationship indicates that the hydrophobicity of the ester/amide chains bonds to the carboxyl group of the glucuronic acid residue at position C-3 of the triterpene aglycone and the type of sugar chain at C-28 position of saponin could affect the potential of toxicity and adjuvant. Our findings demonstrate that TSA2 possesses higher adjuvant activities with less adverse effects and should be further explored as an immunomodulator for immune responses.

Mimic peptides bonding specifically with the first and second extracellular loops of the CC chemokine receptor 5 derived from a phage display peptide library are potent inhibitors of experimental autoimmune encephalomyelitis.

PURPOSE: To obtain mimic peptides that specifically bind with the first and second extracellular loops (ECL1, ECL2) of the CC chemokine receptor 5 (CCR5) and to study their treatment effects on experimental autoimmune encephalomyelitis (EAE) mice. METHODS: A phage display peptide library was applied to screen peptides that bond with ECL1 and ECL2. ELISA and DNA sequence analysis were used to identify positive clones. EAE mice were treated with synthesized peptides by intraperitoneal injection. RESULTS: Eighteen positive clones were obtained and four peptides with sequences STFTTTL, TPIPQLL, SLPLPKP and QTSSAAL were identified. These peptides could significantly protect against and reduce the severity of EAE. The infiltration of monocytes and lymphocytes into the spinal cord decreased significantly in treated mice, while abundant inflammatory cells and demyelination were observed in spinal cords of EAE mice. CONCLUSION: CCR5 mimic peptides provided a significant protective effect to EAE mice. These potent inhibitory mimic peptides could be useful in the clinical treatment of multiple sclerosis.

Camptothecin-induced cell proliferation inhibition and apoptosis enhanced by DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine.

Camptothecin (CPT) reversibly binds and stabilizes cleavable complexes formed between DNA and topoisomerase I (Top1), thereby activating many downstream signaling pathways. Although several pathways induced by CPT have been elucidated, there are additional proteins that represent targets of CPT pharmacological mechanisms and remain uncharacterized. Using two-dimensional electrophoresis analysis and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF)-MS/MS identification, we investigated the hepatocellular carcinoma cell line SMMC-7721 for changes of protein expression following CPT treatment. Proteomic results showed that CPT treatment caused decreased expression of galectin-1 in SMMC-7721 cells. Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis confirmed mRNA expression changes in galectin-1. Protein expression levels of DNA methyltransferases (DNMTs) were downregulated in response to CPT. The DNMT inhibitor 5-aza-2'-deoxycytidine (DAC) sensitized SMMC-7721 cells to the cytotoxic effect of CPT. Our results indicate that inhibition of DNMT activity by CPT may play a role in CPT-induced cell proliferation inhibition and apoptosis.

Induction of copper/zinc-superoxide dismutase by CCL5/CCR5 activation causes tumour necrosis factor-alpha and reactive oxygen species production in macrophages.

Using two-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis, we found that copper/zinc superoxide dismutase (Cu/Zn-SOD, SOD-1) was induced in constructed CCR5 stably transfected HEK 293 cells, but not in mock cells, treated with CCL5. CCL5-induced SOD-1 expression was also confirmed in HEK 293-CCR5 cells and CCR5-positive granulocyte-macrophage colony-stimulating factor-induced human macrophages and murine macrophage RAW264.7 cells. CCL5 and CCR5 interaction induced SOD-1 expression mainly via MEK-ERK activation. In addition, we provided evidence that upregulation of SOD-1 by CCL5/CCR5 activation occurred in parallel with the increased release of tumour necrosis factor-alpha and nitric oxide and production of intracellular reactive oxygen species as well as enhanced nuclear factor-kappaB transcriptional activity in CCR5-positive RAW264.7 cells. Conversely, the MEK1/2 inhibitor PD98059 significantly inhibited SOD-1 expression with the decrease of these biological responses. More importantly, inhibition of SOD-1 activity by disulfiram also strongly inhibited the CCL5-induced biological effects. These data suggest that SOD-1 mediates CCR5 activation by CCL5 and that pharmacological modulation of SOD-1 may be beneficial to CCR5-associated diseases.

Increased expression of CCR5 in experimental autoimmune myocarditis and reduced severity induced by anti-CCR5 monoclonal antibody.

Experimental autoimmune myocarditis (EAM) is a T-cell-mediated autoimmune disease. CCR5, which is expressed mostly on activated T cells and monocytes/macrophages, are potent chemotactic factors for autoimmune myocarditis. We investigated the role of CCR5 in the formation of experimental autoimmune myocarditis. Expression of CCR5 and its cognate ligands was assessed by RT-PCR and immunohistochemical analysis. Single-cell suspension of splenocytes and whole blood specimens from EAM mice were subjected to flow-cytometry analysis. We investigated the critical role of CCR5 in EAM mice by adoptively transferring CCR5-positive/negative T cells to mice and by neutralizing CCR5 with monoclonal antibody to observe the influence on the severity and prevalence of myocarditis. In this report, we found that CCR5-positive cells predominate in infiltrated inflammatory cells in cardiac tissue of EAM mice and CCR5-positive T cells in peripheral blood increased markedly in EAM mice compared with controls. Moreover, we demonstrated that the severity of myocarditis was significantly reduced when CCR5-negative T cells from EAM mice were adoptively transferred. When administrated with CCR5-positive T cells, the myocarditis was significantly aggravated. We also demonstrated that blockade of CCR5 with monoclonal antibodies significantly reduced severity of myocarditis in EAM mice. Overall, these findings indicate that CCR5 is important in the induction of EAM and inhibition of CCR5 with monoclonal antibody significantly reduces the severity of myocarditis. CCR5 may have the potential to become a new therapy target against autoimmune myocarditis.

The zinc finger transcription factor 191 is required for early embryonic development and cell proliferation.

Human zinc finger protein 191 (ZNF191/ZNF24) was cloned and characterized as a SCAN family member, which shows 94% identity to its mouse homologue zinc finger protein 191 (Zfp191). ZNF191 can specifically interact with an intronic polymorphic TCAT repeat (HUMTH01) in the tyrosine hydroxylase (TH) gene. Allelic variations of HUMTH01 have been stated to have a quantitative silencing effect on TH gene expression and to correlate with quantitative and qualitative changes in the binding by ZNF191. Zfp191 is widely expressed during embryonic development and in multiple tissues and organs in adult. To investigate the functions of Zfp191 in vivo, we have used homologous recombination to generate mice that are deficient in Zfp191. Heterozygous Zfp191(+/-) mice are normal and fertile. Homozygous Zfp191(-/-) embryos are severely retarded in development and die at approximately 7.5 days post-fertilization. Unexpectedly, in Zfp191(-/-) and Zfp191(+/-) embryos, TH gene expression is not affected. Blastocyst outgrowth experiments and the RNA interference-mediated knockdown of ZNF191 in cultured cells revealed an essential role for Zfp191 in cell proliferation. In further agreement with this function, no viable Zfp191(-/-) cell lines were obtained by derivation of embryonic stem (ES) cells from blastocysts of Zfp191(+/-) intercrosses or by forced homogenotization of heterozygous ES cells at high concentrations of G418. These data show that Zfp191 is indispensable for early embryonic development and cell proliferation.

Profiling of differentially expressed chemotactic-related genes in MCP-1 treated macrophage cell line using human cDNA arrays.

AIM: To study the global gene expression of chemotactic genes in macrophage line U937 treated with human monocyte chemoattractant protein-1 (MCP-1) through the use of ExpreeChipHO2 cDNA array. METHODS: Total RNA was extracted from MCP-1 treated macrophage line U937 and normal U937 cells, reversely transcribed to cDNA, and then screened in parallel with HO2 human cDNA array chip. The scanned result was additionally validated using RT-PCR. RESULTS: The result of cDNA array showed that one chemotactic-related gene was up-regulated more than two-fold (RANTES) and seven chemotactic-related genes were down-regulated more than two-fold (CCR1, CCR5, ccl16, GRObeta, GROgamma, IL-8 and granulocyte chemotactic protein 2) in MCP-1 treated U937 cells at mRNA level. RT-PCR analysis of four of these differentially expressed genes gave results consistent with cDNA array findings. CONCLUSION: MCP-1 could influence some chemokine and receptor expressions in macrophages in vitro. MCP-1 mainly down-regulates the expression of chemotactic genes influencing neutrophilic granulocyte expression (GRObeta, GROgamma, IL-8 and granulocyte chemotactic protein 2), and the mRNA level of CCR5, which plays a critical role in many disorders and illnesses.

Establishment of transgenic mice carrying gene encoding human zinc finger protein 191.

AIM: Human zinc finger protein 191 (ZNF191) was cloned and characterized as a Kruppel-like transcription factor, which might be relevant to many diseases such as liver cancer, neuropsychiatric and cardiovascular diseases. Although progress has been made recently, the biological function of ZNF191 remains largely unidentified. The aim of this study was to establish a ZNF 191 transgenic mouse model, which would promote the functional study of ZNF191. METHODS: Transgene fragments were microinjected into fertilized eggs of mice. The manipulated embryos were transferred into the oviducts of pseudo-pregnant female mice. The offsprings were identified by PCR and Southern blot analysis. ZNF 191 gene expression was analyzed by RT-PCR. Transgenic founder mice were used to establish transgenic mouse lineages. The first generation (F1) and the second generation (F2) mice were identified by PCR analysis. Ten-week transgenic mice were used for pathological examination. RESULTS: Four mice were identified as carrying copies of ZNF191 gene. The results of RT-PCR showed that ZNF 191 gene was expressed in the liver, testis and brain in one of the transgenic mouse lineages. Genetic analysis of transgenic mice demonstrated that ZNF 191 gene was integrated into the chromosome at a single site and could be transmitted stably. Pathological analysis showed that the expression of ZNF 191 did not cause obvious pathological changes in multiple tissues of transgenic mice. CONCLUSION: ZNF 191 transgenic mouse model would facilitate the investigation of biological functions of ZNF191 in vivo.

[Effect of recombinant prothymosin alpha on secretion of IFN-gamma, IFN-alpha and TNF-alpha in vitro].

AIM: To study the effect of prothymosin alpha (Pro T alpha) as a fusion protein on secretion of IFN-gamma, IFN-alpha and TNF-alpha in vitro. METHODS: The in vitro study was carried out on the culture of splenocytes, splenic and peritoneal macrophages isolated from Balb/c mice. Splenocytes were incubated with various concentrations of Pro T alpha (1 x 10(-7)-1 x 10(-10) mol.L-1) with or without Con A (5 micrograms.mL-1) for 72 h. Splenic and peritoneal macrophages were respectively treated with Pro T alpha (1 x 10(-7)-1 x 10(-10) mol.L-1) in the presence of LPS (10 micrograms.mL-1) for 24 h. Then IFN-gamma, IFN-alpha and TNF-alpha levels in the supernatant were detected by ELISA. RESULTS: Pro T alpha (1 x 10(-7) mol.L-1) was found to obviously increase IFN-gamma level (P < 0.05) in the supernatant of splenocytes compared with the control group. Moreover, Pro T alpha (1 x 10(-7) mol.L-1) significantly induced the secretion of IFN-alpha (P < 0.01) and TNF-alpha (P < 0.01) in splenic and peritoneal macrophages. CONCLUSION: In vitro, Pro T alpha could increase the secretion of IFN-gamma, IFN-alpha and TNF-alpha.

CCR5 gene expression in fulminant hepatitis and DTH in mice.

AIM:To isolate mouse CCR5 cDNA (muCCR5) and study its expression in vivo.METHODS: Marathon PCR was used to isolate muCCR5 cDNA and two animal models were designed to investigate the gene expression in vivo, one was mouse fulminant hepatitis induced by Propionibacterium acnes (P.acnes) and the other was that with delayed type hypersensitivity reaction (DTH). A specific GST-NH2-terminus of muCCR5 fusion protein antibody F(ab')(2) was prepared and clarified. RT-PCR and immunohistochemical analysis were used to observe the expression level of CCR5 gene in mice.RESULTS: A positive reaction of mouse macrophage was found in DTH but not expressed in P.acnes induced fulminant hepatitis by RT-PCR and immunohistochemical analysis.CONCLUSION: This muCCR5 expression may be involved in an allergic processmediated by cellular immunity but not acute inflammatory reaction induced by P.acnes.