Fabrication and evaluation of protein imprinted polymer based on magnetic halloysite nanotubes

A novel protein imprinted polymer, which combined the surface imprinting technology and magnetic halloysite nanotubes (MHNTs), was prepared for selective separation of a template protein.

One-pot preparation of boronic acid and PEG bi-functionalized silica particles for separation and purification of catecholamine from rat serum

A novel boronate absorbent with the ability to resist protein adsorption was synthesized by a one step method.

A novel molecularly imprinted material based on magnetic halloysite nanotubes for rapid enrichment of 2,4-dichlorophenoxyacetic acid in water

A new type of magnetic halloysite nanotubes molecularly imprinted polymer (MHNTs@MIP) based on halloysite nanotubes (HNTs) with embedded magnetic nanoparticles was introduced in this study. MHNTs@MIP was prepared through surface imprinting technology, using 2,4-dichlorophenoxyacetic acid (2,4-D) as a template, 4-vinylpyridine as the monomer, divinylbenzene as cross-linking agents, and 2,2-azodiisobutyronitrile as initiator. MHNTs@MIP was characterized by Fourier Transform Infrared Spectrometer, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. MHNTs@MIP exhibited rapid and reliable analysis with supermagnetic properties, as well as repeated use and template-specific recognition. The adsorption capacity of magnetic halloysite nanotubes non-imprinted polymer (MHNTs@NIP) and MHNTs@MIP was 10.3mg/g and 35.2mg/g, respectively. In the detailed discussion on specific selectivity, MHNTs@MIP can be applied as an adsorbent for sample pretreatment extraction and obtain high recoveries of about 85-94%. After extraction, high-performance liquid chromatography was used to detect 2,4-D residue in water.

Efficient conversion of myricetin from Ampelopsis grossedentata extracts and its purification by MIP-SPE

In this study, we developed an efficient conversion process of dihydromyricetin to myricetin from Ampelopsis grossedentata extracts. The content of myricetin increased from 2.38% to 85.57%, demonstrating the successful dehydrogenation of dihydromyricetin. Molecularly imprinted polymers (MIPs) were prepared by surface imprinting method using silica microspheres as the support matrices and myricetin as template. The MIPs were applied for the selective adsorption of myricetin. The chemical structure of the MIPs was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Static, dynamic and selective adsorption experiments showed that the MIPs exhibited good adsorption ability, rather fast template rebinding kinetics, and appreciate selectivity over structurally related compounds. Accordingly, the MIPs were applied as the selective sorbent in SPE to purify myricetin obtained through dehydrogenation, followed by HPLC-UV analysis. The recoveries of myricetin and dihydromyricetin were 92.7% and 55.6%, respectively. This study demonstrates the feasibility of using the developed MIP-SPE method to purify and enrich myricetin in the natural products.

Pharmacokinetics of a new immediate-release compound omeprazole capsule and its comparison with the enteric-coated formulation under fasting and fed conditions

The present study was conducted to describe the pharmacokinetic profile of immediate-release compound omeprazole capsule and compare it with the enteric-coated formulation under fasting and fed condition.This study was designed to phase I, open-label, randomized, 3-part clinical trial. 12 subjects in part one received single doses (20 mg and 40 mg) and repeated doses (20 mg). Different 30 subjects in part 2 (fasting condition) and part 3 (fed condition) received either compound omeprazole capsule (40 mg) or delayed-release omeprazole (40 mg) separated by 7 days.Compound omeprazole capsule showed dose non-proportionality in the range from 20 mg to 40 mg. The AUC0-t of 20 mg omeprazole is 78% higher after repeated doses. The C max was higher and T max was lower for compound omeprazole capsule than delayed-release omeprazole. 90% CIs for AUC0-t of the 2 periods (test/reference) under fasting and fed conditions were 106.3% (102.2%~109.2%) and 104.1% (93.4%~109.6%), respectively. Presence of food reduced the rate (C max) and extent (AUC0-t) of systemic exposure of the test and reference formulations from 1 462 to 777 ng · mL-1, 1 055 to 602 ng · mL-1, 2 597 to 1 852 ng · h · mL-1 and 2 454 to 1 873 ng · h · mL-1, respectively.Exposed dose of omeprazole in subjects with compound omeprazole capsule was time- and dose-dependent. Compared with delayed-release omeprazole, compound omeprazole capsule had rapid but similar degree of absorption of omeprazole.

Abstract P4-08-10: Systematic expression analysis of the genes related to drug-resistance in isogenic docetaxel- and adriamycin-resistance breast cancer cell lines

Background: Docetaxel (Doc) and Adriamycin (Adr) are two of the most effective chemotherapeutic agents in the treatment of breast cancer. However, their efficacy is often limited by the emergence of multidrug resistance (MDR). The purpose of this study was to investigate MDR mechanisms through analyzing systematically the expression changes of genes related to MDR in the induction process of isogenic drug resistant MCF-7 cell lines.

Material and Methods: Isogenic resistant sublines selected at 100 and 200nM docetaxel (MCF-7/100nM Doc and MCF-7/200nM Doc) or at 500 and 1500 nM adriamycin (MCF-7/500nM Adr and MCF-7/1500nM) were developed from human breast cancer parental cell line MCF-7/S, by exposing MCF-7/S to gradually increasing concentrations of docetaxel or adriamycin in vitro. Flow cytometry, MTT cytotoxicity assay and cell growth curves were preformed to demonstrate the MDR characteristics developed in sublines. Some key genes on the pathways related to drug resistance (including drug-transporters: MDR1, MRP1 and BCRP; drug metabolizing-enzymes: CYP3A4 and GST pi; target gene: Topo IIα and β-tubulin III; apoptosis genes: Bcl-2 and Bax) were analyzed at RNA and protein expression levels by real time RT-qPCR and western blot, respectively.

Results: MCF-7/100nM Doc and MCF-7/200nM Doc was 22- and 37-fold resistant to docetaxel, and 18- and 32-fold to adriamycin, respectively. MCF-7/500nM Adr and MCF-7/1500nM Adr was 61- and 274-fold resistant to adriamycin, and 3- and 12-fold to docetaxel, respectively. Meantime, they also showed cross-resistance to the other anticancer drugs in different degree. Compared to sensitive MCF-7/S, RT-qPCR and Western blot results revealed that the expression of MDR1, MRP1, BCRP, Bcl-2 were elevated in both MCF-7/Doc and MCF-7/Adr, and Topo IIα, Bax were down-regulated in both the sublines, while CYP3A4 and β-tubulin III were increased only in MCF-7/Doc and GST pi was increased only in MCF-7/Adr. Furthermore, these changes above were dose-dependent, i.e. acquirement of MDR is dependent on docetaxel or adriamycin concentrations in breast carcer model resistant MCF-7 cells.

Conclusions: The established MCF-7/Doc or MCF-7/Adr has the typical MDR characteristics, which can be used as the models for resistance mechanism study. The acquired process of MCF-7/S resistance to docetaxel or adriamycin is gradual, and is also complicated with the various pathways involved in. There are some common mechanisms as well as drug-special mechanisms between MCF-7/Doc and MCF-7/Adr.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-08-10.

Stable knockdown of clusterin by vectorbased RNA interference in a human breast cancer cell line inhibits tumour cell invasion and metastasis

OBJECTIVE

Overexpression of the clusterin (CLU) gene occurs in breast cancer and is associated with lymph node metastasis. The present study explored the effect of CLU silencing on invasion and metastasis, and the relationship between CLU expression and the extracellular signal-regulated kinase (ERK) / matrix metalloproteinase-9 (MMP) signalling pathway in human breast cancer cells.

METHODS

A pcDNA3.1-based RNA interference approach was used to knockdown the CLU gene in MDA-231 cells (MDA-231-CLUi); control MDA-231 cells were transfected with an empty vector (MDA-231-Vec). Reverse transcription-polymerase chain reaction was used to assess CLU and MMP-9 mRNA levels, and Western blotting was used to analyse CLU, MMP-9 and ERK protein levels. Metastatic potential was evaluated using in vitro and in vivo models of invasion and metastasis.

RESULTS

Compared with MDA-231-Vec cells, the MDA-231-CLUi cells demonstrated reduced migration and invasion in vitro and decreased metastatic potential in vivo. Reintroduction and reexpression of the CLU gene into the MDA-231-CLUi cells restored the invasive phenotype. MMP-9 mRNA and protein levels were reduced in MDA-231-CLUi cells, and there was a correlation between activated ERK and CLU and MMP-9 protein levels.

CONCLUSION

CLU may regulate the aggressive behaviour of human breast cancer cells through modulation of ERK signalling and MMP9 expression.

Molecular Characterization of Fusarium Head Blight Pathogens Sampled from a Naturally Infected Disease Nursery Used for Wheat Breeding Programs in China

Fusarium head blight (FHB) is an important disease of wheat and barley worldwide. The disease is primarily caused by members of the Fusarium graminearum species complex, consisting of at least 14 phylogenetically distinct species. To determine the population structure of the FHB pathogens in a naturally infected disease nursery located at Jianyang, Fujian province, China, 160 isolates of the F. graminearum complex were recovered from symptomatic wheat spike samples collected in two consecutive years (2008 and 2009) and characterized using species- and chemotype-specific polymerase chain reaction as well as variable number tandem repeat (VNTR) markers. All isolates analyzed were identified as F. asiaticum except for one isolate, which was identified as F. avenaceum. Among the 159 F. asiaticum isolates, 126 (79%) isolates were of the nivalenol (NIV) type while 29 (18%) isolates were of the 15-acetyl deoxynivalenol type and only 4 (3%) isolates were of the 3-acetyl deoxynivalenol type. The 10 VNTR markers revealed 124 distinct haplotypes and 76 polymorphic alleles across the whole population. The two subpopulations (FA-08 and FA-09) grouped based on the year of collection exhibited low genetic differentiation (F_st = 0.032) and high gene flow (N_m = 15.13). However, a significant genetic differentiation was found within the NIV-type isolates as revealed by the Structure software. The pairwise linkage disequilibrium tests did not support the hypothesis of random mating in the population because half (48.8%) of the locus pairs showed a linkage disequilibrium (P > 0.05). Our results suggest that FHB in this nursery was caused by a genetically homogenous and non-random mating population of F. asiaticum in 2008 and 2009, which consisted of all three trichothecene types with various levels of aggressiveness.

Virulence profile and genetic structure of a North Dakota population of Pyrenophora teres f. teres, the causal agent of net form net blotch of barley

A Pyrenophora teres f. teres population in North Dakota was analyzed for virulence variation and genetic diversity using 75 monospore isolates that were collected across a 4-year period (2004 to 2007) from two North Dakota State University agricultural experiment stations at Fargo and Langdon. Pathogenicity tests by inoculation onto 22 barley differential lines at seedling stage revealed 49 pathotypes, indicating a wide range of pathogenic diversity. Two-way analysis of variance of disease ratings revealed a significant difference in the virulence among isolates and in the resistance among barley lines, as well as in the interactions between the two. 'CI5791', 'Algerian', and 'Heartland' were three barley lines showing a high level of seedling resistance to all North Dakota isolates tested; however, many previously reported resistance genes have been overcome. Forty multilocus genotypes were identified from this set of isolates by genotyping at 13 simple-sequence repeat loci. High percentages of clonal cultures were detected in the samplings from 2005 and 2007 in Fargo and 2005 in Langdon. Using a clone-corrected sample set, the mean gene diversity (h) was estimated to be 0.58, approximately the same for both locations. The calculated Wright's F(ST) value is small (0.11) but was significantly >0, indicating a significant differentiation between the Fargo and Langdon populations. In the gametic disequilibrium test, only 3 of 78 possible pairwise comparisons over all isolates showed significant (P < 0.05) nonrandom association, suggesting a random mating mode. Our results suggest that the populations from the two locations are derived from a common source and undergo frequent recombination. This research provides important information for barley breeders regarding development and deployment of cultivars with resistance to net form net blotch in this region.

P5-13-14: Drug-Metabolizing Enzyme Polymorphisms and Clinical Outcome of Anthracycline-Based Chemotherapy in Chinese Han Breast Cancer Patients

Background

Anthracycline is one of the most effective drugs in the treatment of breast cancer and many of our most effective treatment regimens include anthracycline. Its efficacy can be influenced by cellular detoxification mechanisms involving drug metabolism and transport pathways. This study aimed to assess whether the functional polymorphisms in drug-metabolizing enzymes (MnSOD, CAT and GSTs) and transporter MDR1 may predict anthracycline treatment-related outcomes in Chinese Han breast cancer patients.

Material and methods: Genotyping was performed by allele-specific oligonucleotide ligation reaction (MnSOD T47C, CAT C-262T, GSTP1 A313G), multiplex PCR (GSTM1 null, GSTT1 null), and PCR-RFLP (MDR1 C3435T, G2677T/A and C1236T). Based on 153 evaluable patients received anthracycline-based neoadjuvant chemotherapy for breast cancer, the associations of these genotypes or their haplotypes with clinical response and recurrence-free survival (RFS) were analyzed.

Results: Of the 153 cases, the patients with GSTP1 313AA genotype had inferior response rates relative to those with AG or GG genotype (58.4% vs 77.8% or 100.0%; χ2=4.922, P=0.027). Moreover, the response rate of the combination of GSTP1 AA with both GSTT1 present and GSTM1 present was 44%, which was also lower comparing with the other groups (70.3%; χ2=6.454, P=0.011). A similar result was noticed for MDR1 3435 TT genotype, which had a significantly worse chemotherapy response compared with wild-type C allele carrier (33.3% vs 71.2%; χ2=11.586, P=0.001). Further, the response rate of the patients with 3435T-2677T, 3435T-1236T or 3435T-2677T-1236T haplotypes was lower than that of the patients with the other corresponding haplotypes (P=0.018, 0.011 and 0.019, respectively), too. Of note, the patients with both the adverse genotypes of GSTP1 314AA and MDR 3435TT shown the worst treatment efficacy in all (14.3%;χ2=26.33, P=0.000). Mean follow-up time of the 149 patients (4 patients lost) was 51 months. The recurrence rate in the patients with GSTP1 313AA or/and MDR 3435TT in the first three years was 39.0% (41/105), higher significantly than those with no adverse genotype [15.9% (7/44); OR=0.725, 95%Cl: 0.594−0.885, P=0.006]. Kaplan-Meier survival analysis showed that the patients with no adverse genotype were associated with reduced hazard of relapse (long-rank test, P&lt;0.01), compared to those with 1 or 2 adverse genotypes.

Conclusion: Polymorphisms in GSTs and MDR1 genes may help to predict clinical response and RFS of anthracycline-based chemotherapy in breast cancer, but further validation is required. These results provide support for a polygenic pathway approach for assessing the predictive potential of polymorphisms in treatment outcomes.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-14.

Complement inhibition enables renal allograft accommodation and long-term engraftment in presensitized nonhuman primates

Protection against humoral injury mediated by donor-specific antibodies (DSA), also known as accommodation, may allow for long-term allograft survival in presensitized recipients. In the present study, we determined the role of complement in renal allograft accommodation in donor skin-presensitized nonhuman primates under conventional immunosuppression. Donor skin allografts were transplanted to presensitized recipients 14 days prior to renal transplantation. Renal allografts not receiving any immunosuppressive treatment developed accelerated rejection with predominantly humoral injury, which was not prevented using conventional cyclosporine (CsA) triple therapy. Inhibition of complement activation with the Yunnan-cobra venom factor (Y-CVF) successfully prevented accelerated antibody-mediated rejection and resulted in successful accommodation and long-term renal allograft survival in most presensitized recipients. Accommodation in this model was associated with the prevention of the early antibody responses induced against donor antigens by complement inhibition. Some antiapoptotic proteins and complement regulatory proteins, including Bcl-2, CD59, CD46 and clusterin, were upregulated in the surviving renal allografts. These results suggest that the complement inhibition-based strategy may be valuable alternative in future clinical cross-match positive or ABO-incompatible transplantation.

Sequence variation and genetic diversity in the giant panda

About 336-444 bp mitochondrial D-loop region and tRNA gene were sequenced for 40 individuals of the giant panda which were collected from Mabian, Meigu, Yuexi, Baoxing, Pingwu, Qingchuan, Nanping and Baishuijiang, respectively. 9 haplotypes were found in 21 founders. The results showed that the giant panda has low genetic variations, and that there is no notable genetic isolation among geographical populations. The ancestor of the living giant panda population perhaps appeared in the late Pleistocene, and unfortunately, might have suffered bottleneck attacks. Afterwards, its genetic diversity seemed to recover to some extent.

Climatology of persistent deep stable layers in Utah's Salt Lake Valley, USA

Abstract. The characteristics of winter season persistent deep stable layers (PDSLs) over Utah's Salt Lake Valley are examined using 30-year twice daily rawinsonde soundings. The results highlight the basic climatological characteristics of the PDSLs, including the strengths of the inversion, the frequency of the occurrence, and the duration of the events. The data analyses also reveal linear trend, interannual variability, as well as the relationship between the interannual variability of PDSLs and the variability of large-scale circulations. Finally, the study investigates the large-scale atmosphere conditions accompanying the formation and destruction of the PDSL episodes.