Cooling of isolated anthracene cations probed with photons of different wavelengths in the Mini-Ring

We report on a direct measurement of the Internal Energy Distribution (IED) shift rate of an initially hot polycyclic aromatic hydrocarbon (PAH) molecular ensemble, anthracene cations (C₁₄H₁₀⁺). The ions were produced in an electron cyclotron resonance (ECR) ion source and stored in an electrostatic ion storage ring, the Mini-Ring. Laser pulses of two wavelengths were sent successively to merge the stored ion bunch at different storage times to enhance the neutral fragment yield due to fast laser induced dissociation. Using this technique, we have been able to determine directly the energy shift rate of the IED, without involving any theoretical simulation or any assumption on dissociation rates, cooling rates, or the initial IED. Theoretical energy shift rates have been estimated from the evolution of simulated IEDs by taking into account the effects of the unimolecular dissociation and two radiative decay mechanisms: the Poincaré fluorescence and the infrared vibrational emission. The comparison between the experimental results and the model provides new evidence of the important role of the Poincaré fluorescence in the overall cooling process of anthracene cations. Although in the short time range the commonly accepted intuition says that the cooling would result mostly from the dissociation of the hottest ions (depletion cooling), we demonstrate that the Poincaré fluorescence is the dominant contribution (about 85%) to the net cooling effect.

Discovery of natural mouse serum derived HIV-1 entry inhibitor(s)

Among rationally designed human immunodeficiency virus 1 (HIV-1) inhibitors, diverse natural factors have showed as potent anti-HIV activity in human blood. We have discovered that the boiled supernatant of healthy mouse serum could suppress HIV-1 entry, and exhibited reduced inhibitory activity after trypsin digestion. Further analysis demonstrated that only the fraction containing 10-25 K proteins could inhibit HIV-1 mediated cell-cell fusion. These results suggest that the 10-25 K protein(s) is novel natural HIV-1 entry inhibitor(s). Our findings provide important information about novel natural HIV entry inhibitors in mouse serum.

Developing a genetic manipulation system for the Antarctic archaeon, Halorubrum lacusprofundi: investigating acetamidase gene function

No systems have been reported for genetic manipulation of cold-adapted Archaea. Halorubrum lacusprofundi is an important member of Deep Lake, Antarctica (~10% of the population), and is amendable to laboratory cultivation. Here we report the development of a shuttle-vector and targeted gene-knockout system for this species. To investigate the function of acetamidase/formamidase genes, a class of genes not experimentally studied in Archaea, the acetamidase gene, amd3, was disrupted. The wild-type grew on acetamide as a sole source of carbon and nitrogen, but the mutant did not. Acetamidase/formamidase genes were found to form three distinct clades within a broad distribution of Archaea and Bacteria. Genes were present within lineages characterized by aerobic growth in low nutrient environments (e.g. haloarchaea, Starkeya) but absent from lineages containing anaerobes or facultative anaerobes (e.g. methanogens, Epsilonproteobacteria) or parasites of animals and plants (e.g. Chlamydiae). While acetamide is not a well characterized natural substrate, the build-up of plastic pollutants in the environment provides a potential source of introduced acetamide. In view of the extent and pattern of distribution of acetamidase/formamidase sequences within Archaea and Bacteria, we speculate that acetamide from plastics may promote the selection of amd/fmd genes in an increasing number of environmental microorganisms.

Protection and immunological study on two tetraspanin-derived vaccine candidates against schistosomiasis japonicum

Tetraspanins (TSPs) are proteins found on the surface of helminth parasites of the genus Schistosoma and are regarded as potentially protective antigens. The large extracellular loop of Schistosoma mansoni tetraspanin-2, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund's adjuvants, has been shown to be an efficacious vaccine against murine schistosomiasis. It is well recognized that CD4(+) T-cell-dependent immunity might play an important role against schistosomes; however, the contribution of CD8(+) T cells against multicellular pathogen is still uncertain. The exogenous protein-pulsed dendritic cells (DCs) can easily activate CD4(+) T cells response, while CD8(+) T cells response was relatively difficult to be induced. In this study, we evaluated the immunogenicity of TSP2HD antigen (hydrophilic domain of the S. japonicum tetraspanin-2) and TAT (the protein transduction domain of HIV-1)-coupled TSP2HD protein. As TAT-fused protein could promote major histocompatibility complex class I-dependent antigen presentation in vitro, TAT-TSP2HD-pulsed DCs induced stronger proliferation of schistosome-specific CD8(+) T cells compared with DCs incubated with TSP2HD alone. Vaccination with TAT-TSP2HD-pulsed DCs in vivo could improve disease outcome in S. japonicum-infected mice and was slightly superior to vaccination with DCs treated with TSP2HD. In summary, these data showed that TAT fusion proteins could help activate CD8(+) cells and Th1 cells and provide part protection against schistosome.

MicroRNA-185 inhibits cell proliferation and epithelial-mesenchymal transition in hepatocellular carcinoma by targeting Six2

OBJECTIVE

Epithelial-mesenchymal transition (EMT) plays an important role in the malignant transformation of cancer. MicroRNAs are a group of small non-coding RNA molecules that down-regulate the expression of genes involved in tumorigenesis. Although microRNA-185 (miR-185) participates in the pathogenesis of several types of cancer, its relationship with EMT in human hepatocellular carcinoma (HCC) has not been investigated. The present study aims to elucidate the regulatory effects of miR-185 on EMT in HCC cells.

MATERIALS AND METHODS

MTT and an in vitro wound-healing assay were performed to determine cell growth and metastasis potential, respectively. Real-time PCR was used to measure the mRNA expression of miR-185 and Six2. In addition, protein expression levels of Six2 and EMT-related markers were determined by western blot.

RESULTS

Our study showed that miR-185 was significantly down-regulated in HCC cells. Also, a luciferase reporter gene assay confirmed Six2 as a direct target of miR-185. Functional analyses indicated that miR-185 up-regulation remarkably suppressed cell growth and the metastatic potential of HCC cells. We also found that ectopic expression of miR-185 reversed EMT via the up-regulation of E-cadherin and down-regulation of vimentin in epithelial and mesenchymal HCC cells.

CONCLUSIONS

miR-185 suppresses cell growth and EMT progression by targeting Six2, providing a novel target for the molecular treatment of liver malignancies.

Quantification and antioxidant and anti-HCV activities of the constituents from the inflorescences of Scabiosa comosa and S. tschilliensis

To investigate the bioactive constituents of the inflorescences of Scabiosa comosa and S. tschilliensis, which are used traditionally for liver diseases, we tested the antioxidant activity using 2,2'-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), ferric reducing antioxidant potential (FRAP), and DPPH-ultra high performance liquid chromatography-mass spectrometer (UPLC-MS) assay. In addition, cell-based anti-HCV activity of the major compounds were evaluated. The plant extracts showed strong antioxidant activity. For the first time, 3,4-dicaffeoylquinic acid (DCQA), 3,5-DCQA and 4,5-DCQA were identified from genus Scabiosa. A UPLC-MS method in multiple reaction monitoring (MRM) mode was established to quantify 18 constituents in the inflorescences of Scabiosa. The 3,5-DCQA, chlorogenic acid and some glycosides of luteolin or apigenin were found to be the most abundant constituents. Chlorogenic acid and 3,5-DCQA showed excellent radical scavenging activity and demonstrated anti-HCV activity. These findings provided scientific evidences for the clinic use of this herbal medicine for liver diseases.

An adaptive genetic algorithm for crystal structure prediction

We present a genetic algorithm (GA) for structural search that combines the speed of structure exploration by classical potentials with the accuracy of density functional theory (DFT) calculations in an adaptive and iterative way. This strategy increases the efficiency of the DFT-based GA by several orders of magnitude. This gain allows a considerable increase in the size and complexity of systems that can be studied by first principles. The performance of the method is illustrated by successful structure identifications of complex binary and ternary intermetallic compounds with 36 and 54 atoms per cell, respectively. The discovery of a multi-TPa Mg-silicate phase with unit cell containing up to 56 atoms is also reported. Such a phase is likely to be an essential component of terrestrial exoplanetary mantles.

Effects of different antihypertensive drugs on blood pressure variability in patients with ischemic stroke

OBJECTIVE

Blood pressure variation is one of the factors that affects the risk of stroke recurrence and prognosis. This study investigates the effects of calcium channel blockers and beta-blockers on blood pressure variability in severe ischemic stroke patients.

PATIENTS AND METHODS

The clinical data of 24 patients with ischemic stroke in our intensive care unit were analyzed, and received amlodipine or metoprolol for more than 14 days with 24-hour ambulatory blood pressure monitoring. All patients aged 61-90 years, with GCS score ≤ 8 or associated with other organ dysfunction.

RESULTS

Among these 24 ischemic stroke patients, 12 received amlodipine and 12 received metoprolol. The observation period was divided into two phases: 1-6 days and 7-14 days. The decrease in blood pressure was faster in the metoprolol group than in the amlodipine group, while the average standard deviation was significantly greater and the smoothness index was less.

CONCLUSIONS

Metoprolol has faster onset than amlodipine and less blood pressure variability than metoprolol.

Chemokines fluctuate in the progression of primary breast cancer

BACKGROUND

Many studies have demonstrated that chemokines and their receptors play important roles in breast cancer. However, few of them focus on the concentration change of chemokines along breast cancer evolvement, especially for primary breast cancer.

PURPOSE OF THE STUDY

To investigate the effects of chemokines and their receptors on different stage of primary breast cancer, and to find correlationships between chemokines, between different clinico-pathological characters of patients or between chemokines and different clinico-pathological characters of patients.

PATIENTS AND METHODS

We evaluated and compared the concentration of 10 chemokines and receptors in serum of patients diagnosed as breast benign change, epithelial proliferation (present only or with atypia), in situ carcinoma and invasive carcinoma.

RESULTS

Our oneway ANOVA analysis results showed that in all cases from benign diseases to invasive carcinoma, the concentration of CXCL8, CXCR4 and CXCL12 was significantly different; in benign subgroups (benign change, benign change with proliferation, atypia), the concentration of CCL2 and CCR5 was significantly different; in invasive carcinoma cases, DARC concentration was significantly correlated with the relapse risk of patients.

CONCLUSIONS

The correlation analysis indicated the great crosstalk between chemokines and receptors in the course of primary breast cancer; Ki67 expression was associated with CXCL5 and CXCL7 concentration; tumor size was associated with CXCL8 concentration; and the correlation analysis between clinico-pathological characters of patients showed that pathological diagnosis was correlated with tumor size, relapse risk and Ki67 expression; nuclear grades was correlated with LN metastasis, ER status, PR status and the breast cancer genotype; LN metastasis was correlated with relapse risk. Our findings clearly indicated for the first time that the fluctuations of chemokines and receptors contributed to the evolving of primary breast cancer.

Fast radiative cooling of anthracene observed in a compact electrostatic storage ring

Fast radiative cooling of anthracene was observed in a compact electrostatic storage ring by probing the evolution of the internal energy distribution of a stored (C(14)H(10))(+) molecular ensemble via laser excitation. We have measured the mean radiative decay rate to be about 120 to 250 s(-1) for internal energies in the range from 6.6 to 6.8 eV. Such a high decay rate is 2 orders of magnitude larger than the infrared emission cooling rate expected for vibrational transitions. It is attributed to fluorescence from thermally excited electrons. This fast cooling mechanism may have important implications in astrophysics concerning the lifetime and the critical size of polycyclic aromatic hydrocarbons in interstellar conditions.

Performance and microbial characteristics of integrated fixed-film activated sludge system treating industrial wastewater

Integrated fixed-film activated sludge (IFAS) is a modification of conventional activated sludge processes used for wastewater treatment consisting of biofilm attachment surfaces added to suspended-growth reactors, thereby creating hybrid suspended attached-growth systems. In this work, an IFAS system, with a total working volume of 560.7 L, was employed to investigate the performance of pollutants removal in industrial effluent. Microbial communities of suspended-growth and attached-growth biomass were investigated by a combination of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and fluorescence in situ hybridization (FISH). In the system, suspended-growth and attached-growth biomass worked together to maintain a stable COD, NH₄(+)-N and TN removal efficiency of 74, 93 and 76%, respectively. PCR-DGGE results showed that Proteobacteria was the dominant genera of bacteria in both the suspended and attached growth sludge. Some of the bacterial species (Firmicutes and Pseudomonas) may play an important role in the organic degradation of this water. Denitrifying bacteria were found to be accumulated in the biofilms. FISH results showed that there were more nitrifying bacteria in the suspended-growth biomass than the attached-growth biomass but fewer denitrifying bacteria in the former biomass.

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<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.

The miRNA-17∼92 cluster mediates chemoresistance and enhances tumor growth in mantle cell lymphoma via PI3K/AKT pathway activation

The median survival of patients with mantle cell lymphoma (MCL) ranges from 3 to 5 years with current chemotherapeutic regimens. A common secondary genomic alteration detected in MCL is chromosome 13q31-q32 gain/amplification, which targets a microRNA (miRNA) cluster, miR-17∼92. On the basis of gene expression profiling, we found that high level expression of C13orf25, the primary transcript from which these miRNAs are processed, was associated with poorer survival in patients with MCL (P=0.021). We demonstrated that the protein phosphatase PHLPP2, an important negative regulator of the PI3K/AKT pathway, was a direct target of miR-17∼92 miRNAs, in addition to PTEN and BIM. These proteins were down-modulated in MCL cells with overexpression of the miR-17∼92 cluster. Overexpression of miR-17∼92 activated the PI3K/AKT pathway and inhibited chemotherapy-induced apoptosis in MCL cell lines. Conversely, inhibition of miR-17∼92 expression suppressed the PI3K/AKT pathway and inhibited tumor growth in a xenograft MCL mouse model. Targeting the miR-17∼92 cluster may therefore provide a novel therapeutic approach for patients with MCL.

Deficiency in TLR2 but not in TLR4 impairs dendritic cells derived IL-10 responses to schistosome antigens

The purpose of this study was to observe the diverse functions of Toll-like receptors (TLRs) in responses to specific schistosome antigens. Bone marrow-derived dendritic cells (BMDCs) from TLR2-deficient (TLR2(-/-)) or TLR4-deficient (TLR4(-/-)) mice were activated with soluble schistosomule antigen (SSA) or soluble egg antigen (SEA). TLR2 mRNA expression was significantly increased in B6 BMDCs following SEA stimulation. TLR2-deficient BMDCs showed enhanced MHCII expression following SSA and SEA stimulation. TLR2-deficient but not TLR4-deficient BMDC failed to produce IL-12p70 and IL-10 in response to schistosome antigens. TLR2-deficient BMDCs induced a stronger CD4(+) T cell proliferative response. IL-4 and IL-10 expression was inhibited in CD4(+) T cells primed with TLR2-deficient BMDCs, while enhanced in TLR4-deficient BMDCs-primed CD4(+) T cells. These results suggest that TLR2 is essential for the establishment of the DC production of IL-12p70 and IL-10.

Effects of dynamical grouping on cooperation in N-person evolutionary snowdrift game

A population typically consists of agents that continually distribute themselves into different groups at different times. This dynamic grouping has recently been shown to be essential in explaining many features observed in human activities including social, economic, and military activities. We study the effects of dynamic grouping on the level of cooperation in a modified evolutionary N-person snowdrift game. Due to the formation of dynamical groups, the competition takes place in groups of different sizes at different times and players of different strategies are mixed by the grouping dynamics. It is found that the level of cooperation is greatly enhanced by the dynamic grouping of agents, when compared with a static population of the same size. As a parameter β, which characterizes the relative importance of the reward and cost, increases, the fraction of cooperative players f(C) increases and it is possible to achieve a fully cooperative state. Analytically, we present a dynamical equation that incorporates the effects of the competing game and group size distribution. The distribution of cooperators in different groups is assumed to be a binomial distribution, which is confirmed by simulations. Results from the analytic equation are in good agreement with numerical results from simulations. We also present detailed simulation results of f(C) over the parameter space spanned by the probabilities of group coalescence ν(m) and group fragmentation ν(p) in the grouping dynamics. A high ν(m) and low ν(p) promotes cooperation, and a favorable reward characterized by a high β would lead to a fully cooperative state.

Ex vivo expansion of natural killer cells with high cytotoxicity by K562 cells modified to co-express major histocompatibility complex class I chain-related protein A, 4-1BB ligand, and interleukin-15

A large number of natural killer (NK) cells with high function are expected to generate especially in tumor adoptive immunotherapy. Here K562 cells were genetically modified to co-express major histocompatibility complex class I chain-related protein A (MICA), 4-1BB ligand, and IL-15, called K562-MICA-4-1BBL-IL-15. The modified K562 cells not only promoted activation, proliferation, and survival of NK cells, but also enhanced NK cell cytotoxicity. In long-term culture tests, K562-MICA-4-1BBL-IL-15 cells stimulated NK cell to expand mean 550 folds in 24-day culture and to cover from 14.8% of total peripheral blood monoclonal lymphocytes on day 1 to 86.7% on day 24. Prevalent NK cells after expansion enhanced the ability of killing targets and producing interferon gamma (IFN-γ), and kept high expression of activating receptors. The results indicated that K562-MICA-4-1BBL-IL-15 cells would be developed for expansion of NK cells ex vivo and may have important implications for clinical immunotherapy.

A first-principles divide-and-conquer approach for electronic structure of large systems and its application to graphene nanoribbons

We demonstrate an efficient and accurate first-principles method to calculate the electronic structure of a large system using a divide-and-conquer strategy based on localized quasi-atomic minimal basis set orbitals recently developed. Tight-binding Hamiltonian and overlap matrices of a large system can be constructed by extracting the matrix elements for a given pair of atoms from first-principles calculations of smaller systems that represent the local bonding environment of the particular atom pair. The approach is successfully applied to the studies of electronic structure in graphene nanoribbons. This provides a promising way to do the electronic simulation for large systems directly from first principles.

Screening of nasopharyngeal carcinoma by serology and nasopharyngoscopy and treatment outcome in endemic region

6029

Background: To study the incidence and treatment outcome of nasopharyngeal carcinoma (NPC) detected by serology and nasopharyngoscopy in endemic region. Methods: A prospective screening program for NPC using Epstein-Barr virus-specific viral capsid antigen IgA antibody level and nasopharyngoscopy was carried out in Southern China from 1996 to 2002. Subjects without NPC at the time of enrollment were followed-up annually by serology and clinical examination irrespective of their serology status. Subjects diagnosed to have NPC at the time of enrollment or during follow-up received conventional radiotherapy using megavoltage photon. Results: A total of 42,048 adults in Zhongshan city of China were enrolled into the screening program. About 7.4% had elevated IgA titre at the time of enrollment. NPC was diagnosed at first screening in 40 subjects and during follow-up in 131 subjects. Among the 171 NPC patients, 74 were asymptomatic and the disease was detected by the screening procedures, whereas the disease was detected in 97 following onset of symptoms. Stage distribution in those diagnosed by screening program was 59.5% stage I, 8.1% stage II, 21.6% stage III, and 10.8% stage IV. The corresponding stage distribution in subjects diagnosed after onset of symptoms was 7.2%, 12.4%, 39.2%, and 41.2%. In all NPC patients the IgA titre was found elevated and there was a serologic window in which the raised titre preceded the diagnosis of NPC for a period of up to 10 years. The median interval of this serologic window was 29 months in patients with stage I NPC and 39 months in those with stage II-IV disease. The 5-year disease-specific survival rate was 90% for stage I disease, 56% for stage II, 48% for stage III, and 52% for stage IV. Conclusions: Screening by serology and nasopharyngoscopy leads to the early diagnosis of NPC in endemic region with a high survival rate after treatment for stage I disease. In view of the rapid transition of disease from stage I to more advanced stage, a screening interval shorter than 10 months is recommended for subjects entering the serologic window.

No significant financial relationships to disclose.

A directional passive air sampler for monitoring polycyclic aromatic hydrocarbons (PAHs) in air mass

A passive air sampler was developed for collecting polycyclic aromatic hydrocarbons (PAHs) in air mass from various directions. The airflow velocity within the sampler was assessed for its responses to ambient wind speed and direction. The sampler was examined for trapped particles, evaluated quantitatively for influence of airflow velocity and temperature on PAH uptake, examined for PAH uptake kinetics, calibrated against active sampling, and finally tested in the field. The airflow volume passing the sampler was linearly proportional to ambient wind speed and sensitive to wind direction. The uptake rate for an individual PAH was a function of airflow velocity, temperature and the octanol-air partitioning coefficient of the PAH. For all PAHs with more than two rings, the passive sampler operated in a linear uptake phase for three weeks. Different PAH concentrations were obtained in air masses from different directions in the field test.

Anaerobic uptake of phosphate in an anaerobic-aerobic granular sludge sequencing batch reactor

An unusual phenomenon of anaerobic phosphate uptake under alternating anaerobic/aerobic condition was observed in a granular sludge sequencing batch reactor, fed with acetate as sole organic substrate. Anaerobic phosphate uptake efficiencies remained at 50-70% as the influent P/COD was increased from 2/100 to 4/100, and results showed that anaerobic uptake of phosphate was correlated with anaerobic absorption of acetate. Excluding the main possibility of chemical phosphate removal, it appeared that phosphate uptake during the anaerobic phase was associated with organisms enriched in the reactor. Moreover, results indicated that intracellular glycogen was used as the main energy source of organics anaerobic absorption and intracellular polymers storage. Measuring and analysing the variation of phosphate, organic substrate, intracellular glycogen and pH in the anaerobic phase, a preliminary explanation was developed that anaerobic uptake of phosphate was the demand of intracellular glycogen degradation, and extracellular phosphate was transported to intracellular by pH gradient-sensitive phosphate carrier protein.

Stereoselective metabolism of silybin diastereoisomers in the glucuronidation process

A separation method for the hepatoprotective drug silybin and its metabolites by RP-HPLC was described. Based on this separation, the stereoselectivity of the metabolism of silybin was investigated by incubation of the drug and its two diastereoisomers with bovine liver microsomes. Information about the structures of these metabolites was obtained, using UV, HPLC/MS and NMR spectra. Four major metabolites (M(1), M(4) of silybin A and M(2), M(5) of silybin B), were prepared by preparative HPLC, and their configurations were accomplished by NMR spectra. A HPLC method was used to quantify the metabolites. The results showed that silybin was extensively metabolized and the major sites for glucuronidation were the C-20, C-7, at phenolic OH groups. Furthermore, the results obtained reveal that there was significant stereoselectivity in the glucuronidation process of silybin. Silybin B was glucuronidated at a more efficient rate than its diastereoisomer, and glucuronidation of silybin B was much preferred at the 20 position, while that of silybin A was similar at both 7 and 20 position.

Synergistic interaction between cyclophosphamide or paclitaxel and the bioreductive compound NLCPQ-1, in vivo

The antitumor effect of cyclophosphamide (CPM) and paclitaxel was investigated in BALB/c mice bearing EMT6 tumors, in combination with the bioreductive compound NLCPQ-1 by using the in vivo/in vitro assay as the endpoint. An optimum administration schedule for a synergistic interaction between NLCPQ-1 and CPM/paclitaxel was determined and dose modification factors (DMF) were calculated for antitumor effect and bone marrow toxicity. All drugs were given by IP injection; NLCPQ-1 at 15 mg/kg, which is much less than its maximally tolerated dose (MTD greater than 50 mg/kg), paclitaxel up to 25 mg/kg, and CPM up to 200 mg/kg. Bone marrow toxicity studies were performed in parallel by using a modified CFU-GM assay. A schedule-dependent synergistic interaction was observed for both chemotherapeutic agents combined with NLCPQ-1 but with entirely different patterns, as has been previously seen with the analog NLCQ-1. The optimal degree of potentiation, P (percentage of tumor cells that were killed due to clear potentiation), was 31 and 33 when NLCPQ-1 was administered 2 h before CPM and 3-3.5 h after paclitaxel, respectively. At the above time schedules, NLCPQ-1 modified the dose of CPM and paclitaxel, for 60% tumor cell killing, by a factor of 1.8 and 2.1, respectively. Bone marrow toxicity was not enhanced by combining either chemotherapeutic agent with NLCPQ-1. Comparison with results from previous similar studies with NLCQ-1 revealed that, on a molar basis, NLCPQ-1 was a less potent chemosensitizer than NLCQ-1. However, the results still suggest a potential clinical use of NLCPQ-1 as an adjuvant to CPM or paclitaxel therapy against solid tumors.

Therapeutic advantage from combining 5-fluorouracil with the hypoxia-selective cytotoxin NLCQ-1 in vivo; comparison with tirapazamine

PURPOSE

The antitumor effect and bone marrow toxicity of 5-fluorouracil (5FU) in combination with the hypoxia-selective cytotoxins NLCQ-1 or tirapazamine (TPZ) were investigated in vivo.

METHODS

Using appropriate intraperitoneal administration schedules for optimal synergistic interactions, the antitumor effect and the bone marrow toxicity of combinations of NLCQ-1 or TPZ and 5FU were determined in EMT6/BALB/c and SCCVII/C3H models in terms of dose modification factors (DMF) using the in vivo-in vitro clonogenic assay as endpoint. Bone marrow toxicity studies were performed in parallel using a modified CFU-GM assay. The antitumor efficacies of each combination treatment under optimal administration conditions were evaluated in the SCCVII/C3H model using also the tumor regrowth assay as endpoint.

RESULTS

A schedule-dependent and tumor-specific synergistic interaction was observed for NLCQ-1 plus 5FU and DMFs of 2.0-2.3 and 1.0 were obtained for the antitumor effect and bone marrow toxicity, respectively, in both tumor models. The antitumor effect of 5FU was slightly potentiated (DMF 1.2) by TPZ in the EMT6/BALB/c model but not in the SCCVII/C3H model when the in vivo-in vitro assay was used as the endpoint. Significant additional tumor regrowth delays (about 11 and 6 days for NLCQ-1 and TPZ, respectively) were observed, compared to the effect of 5FU alone, when an equitoxic dose of NLCQ-1 (10 mg/kg) or TPZ (23 mg/kg) was administered 1 h before 5FU (50 mg/kg) twice a day at 4-h intervals on days 0 and 9.

CONCLUSIONS

These results corroborate the therapeutic advantage of combining hypoxia-selective cytotoxins such as NLCQ-1 and TPZ with chemotherapy.

4-[3-(2-Nitro-1-imidazolyl)propylamino]-7-chloroquinoline hydrochloride (NLCQ-1), a novel bioreductive agent as radiosensitizer in vitro and in vivo: comparison with tirapazamine

The novel hypoxia-selective cytotoxin NLCQ-1, which is a weak DNA intercalator, was studied in conjunction with radiation against V79 cultured cells and EMT6 or SCCVII tumors in their syngeneic mice and compared with tirapazamine (TPZ). NLCQ-1 was a very potent and efficient radiosensitizer of hypoxic V79 cells, providing SER values of 2.27-2.56 at 20-80 microM concentration (measured at 10% survival level). Its C1.6 (concentration for an SER of 1.6 to be obtained) was 7.2+/-0.2 microM. Its in vitro therapeutic index (ThI, defined as CT50(Air),/C1.6) varied by the exposure time from 57 (1-h exposure) to 145 (4.5-h exposure). The corresponding C1.6 value for TPZ was 16.9 microM whereas its in vitro therapeutic index was 49 (3-h exposure). A schedule-dependent synergistic interaction was observed between NLCQ-1 or TPZ and 20 Gy of radiation in both tumor models examined, by using the in vivo-in vitro assay as endpoint. Optimal synergism (> 1 log) was observed in EMT6 tumors when each bioreductive drug was given between 45 and 60 min before irradiation. NLCQ-1 alone had no significant antitumor activity at 10 mg/kg (28% of its single LD50), whereas a 0.4 surviving fraction was obtained by TPZ at 30 mg/kg (38% of its single LD50). SER values of 1.52 and 1.25 were obtained with 10 mg/kg NLCQ-1 and 30 mg/kg TPZ, respectively, in EMT6 tumors. An SER value of 1.58 was obtained for both hypoxia-selective cytotoxins, at equitoxic doses, in SCCVII tumors, by using a fractionated regimen. These results suggest a possible use of NLCQ-1 or TPZ as adjuvants to radiotherapy.

Selective oxidation of allylic sulfides by hydrogen peroxide with the trirutile-type solid oxide catalyst LiNbMoO(6)

Chemoselective sulfur oxidation of allylic sulfides containing double bonds of high electron density due to multiple alkyl substituents or extended conjugation was developed using the composite metal oxide catalyst, LiNbMoO(6), without any epoxidation of the electron-rich double bond(s). Selective oxidation to either the corresponding sulfoxides or the sulfones was realized by controlling the stoichiometry of the quantitative oxidant, H(2)O(2). This new oxidant system had general applicability for chemoselective oxidation of various allylic, benzylic, or propargylic sulfides containing unsaturated carbon-carbon bonds with different electron properties. Various functional groups including hydroxy, formyl, and ethers of THP or TBDMS are compatible under this mild oxidation reaction condition.

Nrl and Sp nuclear proteins mediate transcription of rod-specific cGMP-phosphodiesterase beta-subunit gene: involvement of multiple response elements

cGMP-phosphodiesterase (PDE) is the key effector in rod photoreceptor signal transduction. Mutations in the gene encoding its catalytic beta-subunit (beta-PDE) cause retinal degenerations leading to blindness. We report that the short -93 to +53 sequence in the upstream region of this gene is sufficient for beta-PDE transcription in both Y79 human retinoblastoma cells and Xenopus embryo heads maintained ex vivo. This sequence also functions as a minimal rod-specific promoter in transgenic Xenopus tadpoles. The Nrl transcription factor binds in vitro to the betaAp1/NRE regulatory element located within this region and transactivates it when overexpressed in nonretinal 293 embryonic kidney cells. We also found a G/C-rich activator element, beta/GC, important for promoter activity in Y79 retinoblastoma cells and Xenopus embryos. Both the ubiquitous Sp1 and the central nervous system-specific Sp4 transcription factors are expressed in retina and interact with this element in vitro. Electrophoretic mobilities of beta/GC-Y79 nuclear protein complexes are altered by antibodies against Sp1 and Sp4. Thus, our results implicate Nrl, Sp1, and Sp4 in transcriptional regulation of the rod-specific minimal beta-PDE promoter. We also conclude that Xenopus laevis is an efficient system for analyzing the human beta-PDE promoter and may be used to study other human retinal genes ex vivo and in vivo.

4-[3-(2-Nitro-1-imidazolyl)propylamino]-7-chloroquinoline hydrochloride (NLCQ-1), a novel bioreductive compound as a hypoxia-selective cytotoxin

A novel weakly DNA-intercalative bioreductive compound. 4-[3-(2-nitro-1-imidazolyl)-propylamino]-7-chloroquinoline hydrochloride (NLCQ-1). has been synthesized and studied as a hypoxia-selective cytotoxin in vitro. NLCQ-1, which shares a similar structure with the DNA-intercalative antimalarial drug chloroquine, bound more strongly to DNA than the nonchlorinated analog NLQ-1 (4-[3-(2-nitro-1-imidazolyl)propylamino]-quinaldine hydrochloride). Thus, NLCQ-1 exhibited a C50 [concentration for 50% displacement of the ethidium bromide (EB) from a DNA-EB complex] of 44 microM, whereas a C50 value could not be reached for NLQ-1 up to 225 microM. NLCQ-1 demonstrated significant hypoxic selectivity in several rodent (V79, EMT6, SCCVII) or human (A549, OVCAR-3) tumor cell lines. Its potency as a hypoxic cytotoxin (expressed as the product of exposure time and concentration for 50% survival) ranged between 10 and 136 microM x h, for the cell lines tested, at 30 microM input concentration. Because uptake in all cell lines was similar, the differences in potency may reflect differences in the enzymatic profile or damage repair processes among the cell lines. In addition, however, the most striking feature of NLCQ-1 was that hypoxic selectivity increased with exposure time, a common feature normally found in only bis-bioreductive agents carrying two moieties with different redox potentials. Thus, hypoxic selectivity of NLCQ-1 in V79 cells at 50% survival was increased from fivefold up to 388-fold by increasing exposure time from 1 to 4.5 h, as the result of a concomitant increase and decrease in its hypoxic and aerobic potency, respectively, over time. Because the nonchlorinated analog NLQ-1 did not demonstrate similar behavior, we hypothesized that the C-7 chlorine of NLCQ-1 might play a significant role in this phenomenon.

In vitro evaluation of 4-[3-(2-nitro-1-imidazolyl)-propylamino]-7-trifluoromethylquinoline hydrochloride (NLTQ-1), a new bioreductive agent as a hypoxia marker by 19F-magnetic resonance spectroscopy (19F-MRS)

19F-labeled bioreductive drugs bound to hypoxic cells in tumors could be detected by nuclear magnetic resonance, provided that they do not lose 19F during their metabolism. NLTQ-1, a 2-nitroimidazole-linked 7-trifluoromethylquinoline, has been synthesized to furnish this aim. NLTQ-1 demonstrated hypoxic selectivities of 7-10 in various cell-lines, in vitro. Uptake studies in V79 cells showed a 5 to 6 fold greater intracellular than extracellular concentration at a range of 100-300 microM input concentrations. A strong sharp peak, which was identified as the parent compound, was observed in the 19F-NMR spectrum of 90% MeCN extracts of V79 cells aerobically exposed to NLTQ-1, indicating that NLTQ-1 was not metabolized under aerobic conditions. Similarly, 19F NMR efflux studies in intact cells showed that the NLTQ-1 was bound to the cells predominantly under hypoxic conditions. 19F-NMR spectra of intact cells, exposed under hypoxic conditions to NLTQ-1, and of their lysates, after precipitation of various cellular components, indicated that possible covalent binding of NLTQ-1 had occurred with macromolecules such as proteins and nucleic acids. Therefore, NLTQ-1 might be suitable as a 19F-MRS/MRI hypoxia probe, although further in vivo work is necessary to verify this matter.

Removal of slowly biodegradable COD in combined thermophilic UASB and MBBR systems

Starch, cellulose and polyvinyl alcohol (PVA) are common substrates of the slowly biodegradable COD (SBCOD) in industrial wastewaters. Removal of the individual and mixed SbCOD substrates was investigated in a combined system of thermophilic upflow anaerobic sludge blanket (TUASB) reactor (55 degrees C) and aerobic moving bed biofilm reactor (MBBR). The removal mechanisms of the three SBCOD substrates were quite different. Starch-COD was almost equally utilized and removed in the two reactors. Cellulose-COD was completely (97-98%) removed from water in the TUASB reactor by microbial entrapment and sedimentation of the cellulose fibers. PVA alone was hardly biodegraded and removed by the combined reactors. However, PVA-COD could be removed to some extent in a binary solution of starch (77%) plus PVA (23%). The PVA macromolecules in the binary solution actually affected the microbial activity in the TUASB reactor resulting accumulation of volatile fatty acids, which shifted the overall COD removal from the TUASB to the MBBR reactor where SBCOD including PVA-COD was removed. Since the three SBCOD substrates were removed by different mechanisms, the combined reactors showed a better and more stable performance than individual reactors.

Schedule-dependent potentiation of chemotherapeutic drugs by the bioreductive compounds NLCQ-1 and tirapazamine against EMT6 tumors in mice

PURPOSE

Comparisons of schedule-dependent interactions between the hypoxic cytotoxins NLCQ-1/ tirapazamine (TPZ) and various chemotherapeutic drugs in BALB/c mice bearing EMT6 tumors.

METHODS

The antitumor effects of the single or combined drugs were assessed with various administration time intervals using the in vivo-in vitro clonogenic assay as the endpoint. The chemotherapeutic drugs tested were cisplatin (cisDDP), melphalan (L-PAM), cyclophosphamide (CPM), 5-fluorouracil (5-FU), doxorubicin (Doxo), etoposide (VP-16) and Taxol at doses of 8, 5, 100, 150, 12, 35 and 20 mg/kg, respectively. NLCQ-1 was given at 10 mg/kg (28% of its single LD50 value) and TPZ was given at 30 mg/kg (38% of its single LD50 value). All drugs were given by i.p. injection in saline or as commercially available pharmaceutical solutions.

RESULTS

Schedule-dependent synergistic interactions with different patterns for each bioreductive drug were observed with almost all of the chemotherapeutic agents examined. Potentiation accounting for more than 25% of the total tumor cell killing was observed with NLCQ-1/TPZ and cisDDP, L-PAM, CPM, 5-FU and Taxol at the optimal administration intervals. Potentiation accounting for 70% of the total tumor cell killing was found with NLCQ-1 and CPM.

CONCLUSIONS

These results suggest a potential clinical use of NLCQ-1/TPZ as adjuvants to certain chemotherapeutic agents.

[The XPS of complexes of zinc salts with alpha-amino acids]

The XPS of solid complexes of ZnCl2/ZnSO4/ZnOAc2 with alpha-Met/His have been investigated. The results indicate that Zn2+ coordinate with O atom of carboxyl group and N atom of alpha-amino. The N atom of imidazolyl also participates the coordination. While the S atom of methylthio does not coordinate with Zn2+. This results are consistent with IR analyses. The structures of those complexes are presumed.

Computer-aided design, synthesis and biological assay of p-methylsulfonamido phenylethylamine analogues

Class III antiarrhythmic agents selectively delay the effective refractory period (ERP) and increase the transmembrance action potential duration (APD). Based on our previous studies, a set of 17 methylsulfonamido phenylethylamine analogues were investigated by 3D-QSAR techniques of CoMFA and CoMSIA. The 3D-QSAR models proved a good predictive ability, and could describe the steric, electrostatic and hydrophobic requirements for recognition forces of the receptor site. According to the clues provided by this 3D-QSAR analysis, we designed and synthesized a series of new analogues of methanesulfonamido phenylethylamine (VIa-i). Pharmacological assay indicated that the effective concentrations of delaying the functional refractory period (FRP) 10ms of these new compounds have a good correlation with the 3D-QSAR predicted values. It is remarkable that the maximal percent change of delaying FRP in microM of compound VIc is much higher than that of dofetilide. The results showed that the 3D-QSAR models are reliable.