Effects of sugar cane extract on pseudorabies virus challenge of pigs

This experiment aimed to evaluate the efficacy of sugar cane extract (SCE) on the modulation of porcine immunity against pseudorabies virus (PrV) infection. Twelve-week-old experimental pigs were fed with SCE (500 mg/kg of body weight per day) for 3 days and challenged with PrV (2 x 10(5) TCID(50)) on the second day. Pigs that were only challenged with PrV and without SCE-treatment served as controls. The leukocyte functional assays were performed on the 7th and 14th day post-PrV challenge. Our results showed a significant enhancement (P<0.05) of natural killer cytotoxicity, lymphocyte proliferation, phagocytic function of monocytes, and interferon-gamma (IFN-gamma) production of CD4(+) and gammadelta T cells in the SCE-treated pigs compared with the controls. In addition, SCE administration reduced the severity of clinical signs and brain lesion in the course of disease in PrV-challenged pigs. SCE-treated pigs showed a 12% growth enhancement compared with untreated controls. SCE administration had an immunostimulating effect on porcine immunity that may subsequently enhance protective activities against PrV infection which may be extensively applied in field for the prevention of infections.     

Virus antigen expression and alterations in peripheral blood mononuclear cell subpopulations after classical swine fever virus infection.

Depletion in the number of lymphocytes and viral persistence are thought to be the most important outcomes of classical swine fever virus (CSFV) infection. To define the change in peripheral blood mononuclear cells (PBMC) and virus replication in leukocytes after CSFV infection, 8-week old pigs were infected with the LPC vaccine strain or virulent CSFV (HCV-YL strain). Changes in the relative number of PBMCs were analyzed by flow cytometry. The results showed a significant increase in the relative percentage of monocytes in PBMCs during acute CSFV infection of naive pigs (p < 0.05). Monocyte frequencies were not changed in LPC-vaccinated pigs and control pigs. There was also a significant decrease in the number of IgM+ cells (p < 0.05) and a slight decrease in the number of CD4+ lymphocytes after 5 days of infection. There was no change in the frequency of CD8+ lymphocytes in PBMCs after infection. To define which subpopulation of PBMCs was the target for CSFV infection, PBMC populations from CSFV infected pigs were separated and stained for virus antigen expression. Alveolar macrophages (AM) were also studied. The results showed that CSFV replicated in all PBMC subpopulations: CD4+, CD8+, and IgM+ lymphocytes, and monocytes as well as AMs. However, virus antigen expression was more intense in monocytes and AMs. The infection of lymphocytes may, therefore, contribute to the depletion in their numbers after infection and lead to defective antibody production during virulent CSFV infection.     

Characterization of humic substances derived from swine manure-based compost and correlation of their characteristics with reactivities with heavy metals

Various composts contain a significant amount of humic substances including humic acid (HA) and fulvic acids (FAs). The FA fraction in soils is considered to be sensitive to agronomic and environmental factors. In this study, three fractions of humic substances, HA (MW > 1000 Da), FA (MW > 1000 Da), and FA (MW < 1000 Da) were extracted from swine manure-based compost and characterized, and then, their reactivities were correlated with heavy metals. Compositions of the three fractions of humic substances were characterized by elemental and total acidity analyses and electron spin resonance (ESR), Fourier transform infrared (FTIR), and 13C nuclear magnetic resonance with cross-polarization and magic-angle spinning spectroscopic techniques. Elemental analyses indicated that HA has higher contents of C, H, N, and S than those of FAs. However, FA (MW > 1000) and especially FA (MW < 1000) have higher contents of O than that of HA (MW > 1000). The g values of the ESR spectra of the three fractions showed that the organic free radical characteristics and the widths of the spectra and free radical concentrations of the three fractions are significantly different. The FTIR spectra indicated that HA (MW > 1000) is abundant in C=C bonds while FA (MW > 1000), especially FA (MW < 1000), are abundant in C=O bonds. In addition, 13C NMR spectra indicate that carboxyl contents of FA (MW > 1000), especially FA (MW < 1000), are higher than that of HA (MW > 1000). The sequence of the reactivity in terms of acidic functional groups was FA (MW < 1000) > FA (MW > 1000) > HA (MW > 1000). Elemental and functional group compositions of the three fractions significantly correlated with reported reactivities with heavy metals. The application of swine manure-based compost containing HA and FAs fractions to soil and associated environments may thus significantly affect the concerned reactions with organic and inorganic compounds including pollutants.     

Inhibitory Effect of Dihydroaustrasulfone Alcohol on the Migration of Human Non-Small Cell Lung Carcinoma A549 Cells and the Antitumor Effect on a Lewis Lung Carcinoma-Bearing Tumor Model in C57BL/6J Mice

There are many major causes of cancer death, including metastasis of cancer. Dihydroaustrasulfone alcohol, which is isolated from marine coral, has shown antioxidant activity, but has not been reported to have an anti-cancer effect. We first discovered that dihydroaustrasulfone alcohol provided a concentration-dependent inhibitory effect on the migration and motility of human non-small cell lung carcinoma (NSCLC) A549 cells by trans-well and wound healing assays. The results of a zymography assay and Western blot showed that dihydroaustrasulfone alcohol suppressed the activities and protein expression of matrix metalloproteinase (MMP)-2 and MMP-9. Further investigation revealed that dihydroaustrasulfone alcohol suppressed the phosphorylation of ERK1/2, p38, and JNK1/2. Dihydroaustrasulfone alcohol also suppressed the expression of PI3K and the phosphorylation of Akt. Furthermore, dihydroaustrasulfone alcohol markedly inhibited tumor growth in Lewis lung cancer (LLC)-bearing mice. We concluded that dihydroaustrasulfone alcohol is a new pure compound with anti-migration and anti-tumor growth activity in lung cancer and might be applied to clinical treatment in the future.     

Flow Characteristics of Human Erythrocytes through Polycarbonate Sieves

We used polycarbonate sieves with uniform cylindrical pores (2.4 to 6.8 microns in diameter) to filter suspensions of human erythrocytes (mean major diameter is 7.2 microns) in Eagle-albumin solution. With 6.8-micron sieves the pressure-flow curves are convexed to the pressure-axis at low pressures and become linear with high pressures. With 4.5-micron sieves, however, the pressure-flow relationship is linear throughout the range of study. In both types of sieves, flow rate is reduced progressively with increasing concentration of red blood cells (RBC) over a range of 0.5 to 95 percent. The resistance to flow of RBC suspensions is higher in 4.5-micron than in 6.8-micron pores. With filter pore diameters of 3.0 microns or more, the RBC concentration in the filtrate was 100 percent of that in the solution being filtered, but only 70 percent with 2.4-micron pores. The observed critical pore diameter for 100 percent cell transmission agrees with theoretical calculation based on the assumption that the RBC membrane is deformable but nonextensible. The importance of cell deformation in the passage of RBC's through small pores is shown by the inability of RBC hardened in acetaldehyde to pass pores with 6.8-micron diameter.     

Crystal structure of a gammadelta T cell receptor ligand T22: a truncated MHC-like fold

Murine T10 and T22 are highly related nonclassical major histocompatibility complex (MHC) class Ib proteins that bind to certain gammadelta T cell receptors (TCRs) in the absence of other components. The crystal structure of T22b at 3.1 angstroms reveals similarities to MHC class I molecules, but one side of the normal peptide-binding groove is severely truncated, which allows direct access to the beta-sheet floor. Potential gammadelta TCR-binding sites can be inferred from functional mapping of T10 and T22 point mutants and allelic variants. Thus, T22 represents an unusual variant of the MHC-like fold and indicates that gammadelta and alphabeta TCRs interact differently with their respective MHC ligands.     

Structure of a gammadelta T cell receptor in complex with the nonclassical MHC T22

Gammadelta T cell receptors (TCRs), alphabeta TCRs, and antibodies are the three lineages of somatically recombined antigen receptors. The structural basis for ligand recognition is well defined for alphabeta TCR and antibodies but is lacking for gammadelta TCRs. We present the 3.4 A structure of the murine gammadelta TCR G8 bound to its major histocompatibility complex (MHC) class Ib ligand, T22. G8 predominantly uses germline-encoded residues of its delta chain complementarity-determining region 3 (CDR3) loop to bind T22 in an orientation substantially different from that seen in alphabeta TCR/peptide-MHC. That junctionally encoded G8 residues play an ancillary role in binding suggests a fusion of innate and adaptive recognition strategies.