Identification and genotyping of feline infectious peritonitis-associated single nucleotide polymorphisms in the feline interferon-γ gene

Feline infectious peritonitis (FIP) is an immune-mediated, highly lethal disease caused by feline coronavirus (FCoV) infection. Currently, no protective vaccine or effective treatment for the disease is available. Studies have found that some cats survive the challenge of virulent FCoV isolates. Since cellular immunity is thought to be critical in preventing FIP and because diseased cats often show a significant decrease in interferon-γ (IFN-γ) production, we investigated whether single nucleotide polymorphisms (SNP) in the feline IFN-γ gene (fIFNG) are associated with the outcome of infection. A total of 82 asymptomatic and 63 FIP cats were analyzed, and 16 SNP were identified in intron 1 of fIFNG. Among these SNP, the fFING + 428 T allele was shown to be a FIP-resistant allele (p = 0.03), and the heterozygous genotypes 01C/T and +408C/T were found to be FIP-susceptible factors (p = 0.004). Furthermore, an fIFNG + 428 resistant allele also showed a clear correlation with the plasma level of IFN-γ in FIP cats. For the identification of these three FIP-related SNP, genotyping methods were established using amplification refractory mutation system PCR (ARMS-PCR) and restriction fragment length polymorphisms (RFLP), and the different genotypes could easily be identified without sequencing. The identification of additional FIP-related SNP will allow the selection of resistant cats and decrease the morbidity of the cat population to FIP.     

A population of comets in the main asteroid belt

Comets are icy bodies that sublimate and become active when close to the Sun. They are believed to originate in two cold reservoirs beyond the orbit of Neptune: the Kuiper Belt (equilibrium temperatures of approximately 40 kelvin) and the Oort Cloud (approximately 10 kelvin). We present optical data showing the existence of a population of comets originating in a third reservoir: the main asteroid belt. The main-belt comets are unlike the Kuiper Belt and Oort Cloud comets in that they likely formed where they currently reside and may be collisionally activated. The existence of the main-belt comets lends new support to the idea that main-belt objects could be a major source of terrestrial water.     

Plasma acceleration above martian magnetic anomalies

Auroras are caused by accelerated charged particles precipitating along magnetic field lines into a planetary atmosphere, the auroral brightness being roughly proportional to the precipitating particle energy flux. The Analyzer of Space Plasma and Energetic Atoms experiment on the Mars Express spacecraft has made a detailed study of acceleration processes on the nightside of Mars. We observed accelerated electrons and ions in the deep nightside high-altitude region of Mars that map geographically to interface/cleft regions associated with martian crustal magnetization regions. By integrating electron and ion acceleration energy down to the upper atmosphere, we saw energy fluxes in the range of 1 to 50 milliwatts per square meter per second. These conditions are similar to those producing bright discrete auroras above Earth. Discrete auroras at Mars are therefore expected to be associated with plasma acceleration in diverging magnetic flux tubes above crustal magnetization regions, the auroras being distributed geographically in a complex pattern by the many multipole magnetic field lines extending into space.     

Methylation of tRNAAsp by the DNA methyltransferase homolog Dnmt2

The sequence and the structure of DNA methyltransferase-2 (Dnmt2) bear close affinities to authentic DNA cytosine methyltransferases. A combined genetic and biochemical approach revealed that human DNMT2 did not methylate DNA but instead methylated a small RNA; mass spectrometry showed that this RNA is aspartic acid transfer RNA (tRNA(Asp)) and that DNMT2 specifically methylated cytosine 38 in the anticodon loop. The function of DNMT2 is highly conserved, and human DNMT2 protein restored methylation in vitro to tRNA(Asp) from Dnmt2-deficient strains of mouse, Arabidopsis thaliana, and Drosophila melanogaster in a manner that was dependent on preexisting patterns of modified nucleosides. Indirect sequence recognition is also a feature of eukaryotic DNA methyltransferases, which may have arisen from a Dnmt2-like RNA methyltransferase.     

Efficient hydrolysis of tuna oil by a surfactant-coated lipase in a two-phase system

A surfactant-coated lipase (SCL) prepared by mixing Candida rugosa lipase with emulsifier in ethanol was used to hydrolyze tuna oil in a two-phase aqueous-organic system. Both enzyme (SCL) and substrate (tuna oil) were soluble in the organic phase, and the hydrolysis could occur with water molecules from the aqueous phase. This hydrolysis could promptly proceed compared to that catalyzed by native lipases which only occurred at the interface between the two phases. Michaelis-Menten kinetics in the two-phase reactions showed that the K(m) value of the SCL was half that of the native lipase, while the maximum velocity (V(max)) was 11.5 times higher. The hydrolysis method resulted in enrichment of n-3 polyunsaturated fatty acid (n-3 PUFA) content in glyceride mixtures from 26.4% to 49.8% and DHA from 19.1% to 38.9%. The SCL acted as an efficient hydrolytic catalyst for tuna oil.     

Molecular cloning and functional identification of invertase isozymes from green bamboo Bambusa oldhamii

Three Bo beta fruct cDNAs encoding acid invertases were cloned from shoots of the green bamboo Bambusa oldhamii. On the basis of the amino acid sequences of their products and phylogenetic analyses, Bo beta fruct1 and Bo beta fruct2 were determined to encode cell wall invertases, whereas Bo beta fruct3encodes a vacuolar invertase. The recombinant proteins encoded by Bo beta fruct2 and Bo beta fruct3 were produced in Pichia pastoris and purified to near homogeneity using ammonium sulfate fractionation and immobilized metal affinity chromatography. The pH optima, pI values, and substrate specificities of the isolated enzymes were consistent with those of plant cell wall or vacuolar invertases. The growth-dependent expression of Bo beta fruct1 and Bo beta fruct2 in the base regions of shoots underscores their roles in sucrose unloading and providing substrates for shoot growth. Its high sucrose affinity suggests that the Bo beta fruct2-encoded enzyme is important for maintaining the sucrose gradient between source and sink organs, while the predominant expression of Bo beta fruct3 in regions of active cell differentiation and expansion suggests functions in osmoregulation and cell enlargement.     

Production of ascorbyl palmitate by surfactant-coated lipase in organic media

The surface of a lipase from Burkholderia cepacia was coated with a nonionic surfactant, propylene glycol monostearate, and was used as a biocatalyst in the production of ascorbic acid in tert-butyl alcohol. The influence of various factors such as the type of surfactant, the pH of the buffer used for coating, the amount of surfactant in the coating, the organic solvent, and the temperature and molar ratio of the substrates used in the reaction on the conversion of ascorbyl palmitate were studied. After 24 h of reaction at 50 degrees C, a conversion of 47% was obtained using an ascorbic acid to palmitic acid molar ratio of 1:6. The native lipase showed only 6% conversion.     

Induction of autophagy and apoptosis by the extract of Solanum nigrum Linn in HepG2 cells

Solanum nigrum L. (SN) has been used in traditional folk medicine to treat different cancers. It is also used as a hepatoprotective and anti-inflammatory agent. In this study, we demonstrated that the extract of SN (SNE) induced a strong cytotoxic effect toward HepG2 cells but much less to Chang liver and WRL-68 cells. The mechanisms of the cytotoxic effect were concentration-dependent. High doses of SNE (2 and 5 mg/mL) induced apoptotic cell death in HepG2 cells, as evidenced by increases in the expressions of p-JNK and Bax, mitochodrial release of cytochrome c, and caspase activation. On the other hand, cells treated with low concentrations of SNE (50-1000 microg/mL) revealed morphological and ultrastructural changes of autophagocytic death under electron microscopic observation. Furthermore, these cells showed increased levels of autophagic vacuoles and LC3-I and LC3-II proteins, specific markers of autophagy. The levels of Bcl-2 and Akt that have been implicated in the down-regulation of autophagy were decreased upon SNE treatment. Taken together, these findings indicate that SNE induced cell death in hepatoma cells via two distinct antineoplastic activities of SNE, the ability to induce apoptosis and autophagocytosis, therefore suggesting that it may provide leverage to treat liver cancer.     

Heat-killed cells of lactobacilli skew the immune response toward T helper 1 polarization in mouse splenocytes and dendritic cell-treated T cells

It is believed that probiotics play an important role for the health of the host, including modulation of immune responses. Most studies have focused on the immunomodulatory effects of viable cells of lactic acid bacteria; however, we investigated those of heat-killed cells of lactic acid bacteria in this study. We first observed the effects on immune functions via stimulating splenocytes with three heat-killed Lactobacillus strains. Furthermore, we also investigated the effect of mouse dendritic cells (DCs) treated with these heat-killed Lactobacillus strains on T cell responses. The results showed that these Lactobacillus strains were able to stimulate cell proliferation and interleukin (IL)-10, IL-12 p70, and interferon (IFN)-gamma production but not transforming growth factor (TGF)-beta in splenocytes. In addition, these heat-killed Lactobacillus strains also stimulated high-level secretion of IL-12 p70 in DCs and switched T cells to T helper (Th) 1 immune responses, as evidenced by the elevated secretion of IFN-gamma but not IL-5, IL-13, and TGF-beta. These results showed that lactobacilli play a potentially important role in modulating immune responses and allergic reactions.