P11.01 TMZ-LEV- IFN cocktail regimen significantly inhibited the growth of glioma

BACKGROUND

TMZ, is the first line chemotherapeutic drug for glioma, and drug resistance is one of the most important reasons for glioma treatment failure. Our previous studies have found that: 1) Type I interferon (IFN) could reverse the resistance of TMZ by inhibiting NF-κB activity, and down-regulating the expression of MGMT in vivo and in vitro; 2) IFN-α could significantly improve chemtherapeautic effect of TMZ for GBM patients. We aim to investigate the therapeutic effect of a cocktail chemotherapy regimen combining temozolomide (TMZ)- Levetiracetam(LEV) - interferon (IFN) on human glioma U138 and U251 subcutaneous xenograft tumor.

MATERIAL AND METHODS

30 xenograft tumors were established by subcutaneously injecting 1×106 glioma cells into the right flank of 4-week-old female BALB/C nude mice and then randomly divided into 5 groups (n=6/group): Control group; TMZ group; TMZ+IFN group; TMZ+LEV group; TMZ+LEV+IFN group. Anti-tumor efficacy of five regimens for tumor-bearing mice was tested after treatment with TMZ (50 mg/kg, i.p.), IFN (2×105 IU, s.c.), LEV (150 mg/kg, i.p.), while TMZ dose were reduced to 12.5 mg/kg for U251 tumors. All drugs are given once a day for five consecutive days. After therapy, the size of tumor was measured every day until the control tumors reached 2000 mm3. Mice bearing U138 tumors were sacrificed at 40 days after therapy, and mice bearing U251 tumors were killed at 26 days after therapy.

RESULTS

We identified that both U138 and U251 tumor growth among TMZ group, TMZ+IFN group, TMZ+LEV group and TMZ+LEV+IFN group were significantly inhibited (P<0.05), compared with the control group. Tumor weight of all treating group was lower than that of the control group (P<0.05). The tumor weight of TMZ+LEV+IFN group was the lowest and significantly lower than that of TMZ+LEV group and TMZ group (P<0.05, respectively). No significant difference was found between TMZ+LEV+IFN group and TMZ+IFN group in U251 subcutaneous xenograft tumors, although the tumor weight was lower in TMZ+LEV+IFN group (P>0.05). In the treatment of mice bearing U138 glioma, TMZ+LEV+IFN regimen was significantly superior to TMZ+IFN regimen.

CONCLUSION

Our data demonstrate that both IFN and LEV can sensitize TMZ effect on glioma. TMZ-LEV-IFN cocktail appears the best regimen.

Microbial diversity in the tick Argas japonicus (Acari: Argasidae) with a focus on Rickettsia pathogens

The soft tick Argas japonicus mainly infests birds and can cause human dermatitis; however, no pathogen has been identified from this tick species in China. In the present study, the microbiota in A. japonicus collected from an epidemic community was explored, and some putative Rickettsia pathogens were further characterized. The results obtained indicated that bacteria in A. japonicus were mainly ascribed to the phyla Proteobacteria, Firmicutes and Actinobacteria. At the genus level, the male A. japonicus harboured more diverse bacteria than the females and nymphs. The bacteria Alcaligenes, Pseudomonas, Rickettsia and Staphylococcus were common in nymphs and adults. The abundance of bacteria belonging to the Rickettsia genus in females and males was 7.27% and 10.42%, respectively. Furthermore, the 16S rRNA gene of Rickettsia was amplified and sequenced, and phylogenetic analysis revealed that 13 sequences were clustered with the spotted fever group rickettsiae (Rickettsia heilongjiangensis and Rickettsia japonica) and three were clustered with Rickettsia limoniae, which suggested that the characterized Rickettsia in A. japonicus were novel putative pathogens and also that the residents were at considerable risk for infection by tick-borne pathogens.

Effect of infectious bursal disease virus infection on energy metabolism in embryonic chicken livers

1. The purpose of this study was to investigate ATP levels and the activities of important enzymes involved in glycolysis and TCA cycle in livers of embryonated chicken eggs infected by infectious bursal disease virus (IBDV).2. Embryonated chicken eggs (9 days) were randomly divided into two groups (50 eggs per group). The first group was inoculated with a very virulent IBDV (vvIBDV) isolate into the chorioallantoic membrane. The second group was maintained as uninfected control eggs and inoculated with physiological saline. Embryo survival was assessed daily, and six embryos were sacrificed at 24, 48, 72, 96, and 120 hpi for examining livers. Viral loads in the livers were evaluated by qRT-PCR. A comparative analysis of markers associated with the regulation of energy metabolism across several functional classes (ATP, pyruvic and lactic acids, mitochondrial protein, NAD+/NADH ratios, and enolase, lactic acid dehydrogenase and the respiratory chain complex I activities) were examined in the context of IBDV infection.3. The results indicated that increases in the enzymatic activities associated with glycolytic metabolism in turn affected the synthesis and cytoplasmic concentrations of ATP at early timepoints in infected chicken embryos. Subsequently, energy metabolism was inhibited through the pathological perturbations of metabolic enzymes and mitochondrial damage, as inferred from reduced ATP generation.4. These results suggested impaired bioenergetics, which may lead to liver dysfunction consequent to IBDV infection, contributing to the disease pathogenesis.

Effects of AIF-1 inflammatory factors on the regulation of proliferation of breast cancer cells

The purpose of this study was to explore the effect of Allograft Inflammatory Factor 1 (AIF-1) on the regulation of proliferation of breast cancer cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), cell culture and counting, and mass spectrometry were performed. The biologically active high-purity recombinant protein rhAIF-1 was obtained by optimizing the rhAIF-1 protein purification system, and MDA-MB-231 and MDA-MB-361 breast cancer cell lines were used. After adding to the culture medium, rhAIF-1 was found to promote cell proliferation in dose-dependent and time-dependent manners. The purified protein rhAIF-1 was marked with rhodamine and incubated with the cells. Confocal imaging analysis revealed that the foreign protein was localized in the cytoplasm, and rhAIF-1 was unevenly distributed in the cytoplasm. Although AIF-1 accumulates around the nucleus, it can not enter the nucleus, suggesting that other factors might be involved in the regulation of cell proliferation. In order to find the possible interacting protein of rhAIF-1, protein immunoprecipitation technique and mass spectrometry were employed, and it was indicated that ADAM28m was the possible interacting protein of rhAIF-1. The interaction between rhAIF-1 and ADAM28m was validated by immunoprecipitation along with Western blotting. It was found that rhAIF-1 could precipitate ADAM28m protein by immunoprecipitation. The results indicated that IF-1 participates in the development of breast cancer by interacting with ADAM28m and activating downstream signaling pathways. It was concluded that AIF-1 provides a new idea for the molecular mechanism of breast cancer cell proliferation and acts as a new target for the prevention and treatment of breast cancer in the future.

Removal of Fluoride and Arsenic by a Hybrid Constructed Wetland System

A pilot-scale hybrid wetland system was constructed for the removal of fluoride and arsenic from synthetic wastewater. After five months of operation, the fluoride and arsenic removal rate were at the value of 65 % and 90 %, respectively. Through calculation, the accumulation of fluoride in plants only accounted for 1.63 % of the accumulation in substrates, and the accumulation of arsenic in plants accounted for 3.3 % of that in substrates. Both the accumulation of fluoride and arsenic in plants were much higher in roots than that in leaves. And for substrates, the accumulation in the first layer was higher than the second layer. The changes of microbial community in the substrate of the wetland during the operation were also analyzed to investigate the effects of operating condition on the microbial community and to study the role of microorganism on the removal of fluoride and arsenic. The results showed that the relative abundance of Firmicutes reduced, while the relative abundance of Proteobacteria increased, indicating that the fluoride and arsenic in solution had a great influence on the microbial community. Findings of this study suggest that the hybrid constructed wetland system may be a promising process for the removal of fluoride and arsenic from synthetic wastewater.

Ferric citrate, nitrate, saponin and their combinations affect in vitro ruminal fermentation, production of sulphide and methane and abundance of select microbial populations

AIMS

This study investigated the effects of ferric citrate, nitrate and saponin, both individually and in combination, on sulphidogenesis, methanogenesis, rumen fermentation and abundances of select microbial populations using in vitro rumen cultures.

METHODS AND RESULTS

Ferric citrate (50 mg l^-1 ), Quillaja saponin (0·6 g l^-1 ) and sodium nitrate (5 mmol l^-1 ) were used in in vitro ruminal fermentation. Ferric citrate alone, its combination with saponin and/or nitrate lowered the aqueous sulphide concentration and total sulphide production. Methane production was suppressed by nitrate alone (by up to 32·92%), its combination with saponin (25·04%) and with both saponins with nitrate (25·92%). None of the treatments adversely affected feed digestion or rumen fermentation. The population of sulphate-reducing bacteria was increased by nitrate and saponin individually, while that of total Archaea was decreased by nitrate alone and the combination of the three inhibitors.

CONCLUSIONS

Nitrate and its combination with saponin or both ferric citrate and saponin substantially decreased methane production. Most importantly, the decreased methane production was not at the expense of feed digestion or fermentation. Sulphidogenesis from the sulphate present in the high-sulphur diets can be suppressed competitively by ferric citrate, although it was elevated by saponin and nitrate.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study demonstrated that combinations of certain methane inhibitors, which have different mechanisms of antimethanogenic actions or inhibit different guilds of microbes involved in methane production and sulphate reduction, can be more effective and practical than individual inhibitors, not only in mitigating enteric methane emission but also in lowering the risk of sulphur-associated polioencephalomalacia in feedlot cattle fed high sulphur diets.

Assessment of microbial communities on freshly killed wild boar meat by MALDI-TOF MS and 16S rRNA amplicon sequencing

Wild boars (Sus scrofa) are the most widely distributed large mammals and recent increase in consumption of wild boar meat urges the need of microbiological quality criteria. The aim of the study was to characterize the initial bacterial contamination on freshly-killed wild boar meat using a culture-dependent approach with ISO-methods combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry identification and 16S rRNA amplicon sequencing. Moreover, the presence of foodborne pathogens was examined using Real-Time-PCR and confirmed by classical isolation. Analysing 22 unrelated wild boar meat samples showed a higher bacterial contamination level compared to pork, with Salmonella present in almost one third of the samples. A great variability of the microbial contamination between the samples was recorded, as well as complementary results between culturing and 16S rRNA amplicon sequencing as frequently isolated genera were not always detected, and vice versa. Furthermore, the foodborne pathogen Salmonella was never detected with 16S rRNA amplicon sequencing, demonstrating the necessity for a cautious approach in the implementation of new analysis techniques in food safety. The present work determines that attention should be paid to the trade of non-inspected meat directly to retail or consumers.

Invited review: Nitrogen in ruminant nutrition: A review of measurement techniques

Nitrogen is a component of essential nutrients critical for the productivity of ruminants. If excreted in excess, N is also an important environmental pollutant contributing to acid deposition, eutrophication, human respiratory problems, and climate change. The complex microbial metabolic activity in the rumen and the effect on subsequent processes in the intestines and body tissues make the study of N metabolism in ruminants challenging compared with nonruminants. Therefore, using accurate and precise measurement techniques is imperative for obtaining reliable experimental results on N utilization by ruminants and evaluating the environmental impacts of N emission mitigation techniques. Changeover design experiments are as suitable as continuous ones for studying protein metabolism in ruminant animals, except when changes in body weight or carryover effects due to treatment are expected. Adaptation following a dietary change should be allowed for at least 2 (preferably 3) wk, and extended adaptation periods may be required if body pools can temporarily supply the nutrients studied. Dietary protein degradability in the rumen and intestines are feed characteristics determining the primary AA available to the host animal. They can be estimated using in situ, in vitro, or in vivo techniques with each having inherent advantages and disadvantages. Accurate, precise, and inexpensive laboratory assays for feed protein availability are still needed. Techniques used for direct determination of rumen microbial protein synthesis are laborious and expensive, and data variability can be unacceptably large; indirect approaches have not shown the level of accuracy required for widespread adoption. Techniques for studying postruminal digestion and absorption of nitrogenous compounds, urea recycling, and mammary AA metabolism are also laborious, expensive (especially the methods that use isotopes), and results can be variable, especially the methods based on measurements of digesta or blood flow. Volatile loss of N from feces and particularly urine can be substantial during collection, processing, and analysis of excreta, compromising the accuracy of measurements of total-tract N digestion and body N balance. In studying ruminant N metabolism, nutritionists should consider the longer term fate of manure N as well. Various techniques used to determine the effects of animal nutrition on total N, ammonia- or nitrous oxide-emitting potentials, as well as plant fertilizer value, of manure are available. Overall, methods to study ruminant N metabolism have been developed over 150 yr of animal nutrition research, but many of them are laborious and impractical for application on a large number of animals. The increasing environmental concerns associated with livestock production systems necessitate more accurate and reliable methods to determine manure N emissions in the context of feed composition and ruminant N metabolism.

Mycobacterial metabolic characteristics in a water meter biofilm revealed by metagenomics and metatranscriptomics

Mycobacteria represent one of the most persistent bacterial populations in drinking water distribution system (DWDS) biofilm communities; however, mycobacterial in situ metabolic profiles are largely unknown. In this study, the metabolic characteristics of mycobacteria in a household water meter biofilm were unveiled using a coupled metagenomic/metatranscriptomic approach. The water meter biofilm appeared to express nitrogenase genes (nifDKH) and a full complement of genes coding for several carbon-fixation pathways, especially the Calvin cycle, suggesting the CO₂ sequestration and dinitrogen fixation potential of the biofilm. These findings indicate that it may be difficult to prevent the formation of DWDS biofilms simply by controlling the availability of organic carbon or nitrogen. The composite genome of mycobacteria (CG-M) was reconstructed based on the obtained omics data. CG-M shared similar genome phylogeny and virulence-factor profiles with Mycobacterium avium complex, suggesting that population CG-M might represent a member of mycobacteria with pathogenicity. According to the gene expression patterns, population CG-M showed the metabolic potential to assimilate CO₂ via the Calvin cycle and/or anaplerotic reactions, and even to grow autotrophically with CO as the sole carbon and energy source. This suggests that organic carbon may not be a limiting factor for mycobacterial growth in DWDSs. Moreover, our results suggest that mycobacterial aromatic degradation is primarily achieved through the catechol meta-cleavage pathway, and biofilm mycobacteria could prefer phosphate as the phosphorus source.