Proteome analysis of wheat leaf under salt stress by two-dimensional difference gel electrophoresis (2D-DIGE)

Salt stress is a major abiotic stress that limits agricultural productivity in many regions of the world. To understand the molecular basis of the salt stress response in wheat (Triticum aestivum L.), a proteomic approach was used to identify the salt stress-responsive proteins in an elite Chinese wheat cultivar, Zhengmai 9023, which exhibits a high yield, superior gluten quality and better biotic resistance. Three-week-old seedlings were treated with NaCl of four different concentrations (1.0%, 1.5%, 2.0%, and 2.5%). The total proteins from the leaves of untreated and NaCl-treated plants were extracted and separated by two-dimensional difference gel electrophoresis (2D-DIGE). A total of 2358 protein spots were detected on the gels, among which 125 spots showed a significant change in protein abundance, and 83 differentially expressed spots were localised on preparative gels. Using Q-TOF mass spectrometry, 52 salt-responsive spots were identified, which were classified into six functional categories that included transport-associated proteins, detoxifying enzymes, ATP synthase, carbon metabolism, protein folding, and proteins with unknown biological functions. Of the 52 differentially expressed proteins, 26 were up-regulated, 21 were down-regulated, and five spots showed multi-expression patterns. In particular, some important proteins for salt tolerance were found to be up-regulated in Zhengmai 9023 under salt stress, such as H(+)-ATPases, glutathione S-transferase, ferritin and triosephosphate isomerase.

QSAR studies on the depuration rates of polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and polychlorinated biphenyls in mussels (Elliptio complanata)

Based on the mechanism of action, a quantitative structure-activity relationship (QSAR) model for the depuration rate constants (k(d)) of 28 PAHs, 8 PBDEs and 28 PCBs in mussels (Elliptio complanata) was constructed by partial least squares (PLS) regression, following the guidelines for development and validation of QSAR models. For the training set of the QSAR model, r² = 0.953, the cross-validated regression coefficient (Q²(CUM)) was 0.947. The predicted log k(d) values for the validation set were consistent with the observed values, with a standard error (SE) of 0.160 log units and a squared correlation coefficient (Q²(EXT)) of 0.892. Comparatively, the developed QSAR model had good robustness, predictive ability and extended applicability domain. The electrophilicity index (ω), molecular polarizability (α), the averages of the negative potentials on the molecular surface (V(s⁻)) and the balance parameter of surface potential (τ) were the key parameters governing the log k(d) values in the QSAR model, which indicated that the log k(d) value was mainly related to the partition ability, electrostatic interactions, and van der Waals interactions of compounds.

A toxicological evaluation of a claudin modulator, the C-terminal fragment of Clostridium perfringens enterotoxin, in mice

Tight junctions (TJs) maintain cellular polarity between the apical and basolateral region of epithelial cells. Claudin, a tetra-transmembrane protein, plays a pivotal role in the barrier function of TJs. We previously found that a claudin modulator, the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE), may be a promising candidate for improving the mucosal absorption of drugs. C-CPE is a fragment of enterotoxin, and putative CPE claudin receptors are highly expressed in liver and kidney. The safety and antigenicity of C-CPE must be evaluated for future clinical application. Therefore, we evaluated whether C-CPE administration in mice leads to tissue injury or production of antibodies. Intravenous administration of C-CPE at 5 mg/kg, which is a more than 25-fold higher dose than that used in a murine mucosal absorption model, did not increase biochemical markers of liver and kidney injury even after 11 injections once a week. Nasal C-CPE administration (2 mg/kg) once a week for 11 administrations also did not increase these biochemical markers, but 6 administrations of C-CPE resulted in elevation of C-CPE-specific serum IgG. These results indicate that development of a less antigenic claudin modulator will be essential for future clinical application of a C-CPE-based mucosal absorption enhancer.

Total auricular reconstruction without skin grafting

Successful ear reconstruction depends on two factors: an ear framework and the skin covering the framework. However, the relative deficiency of skin for coverage of the cartilage framework remains an issue. This new method for total auricular reconstruction is a three-stage operation and involves the use of two tissue expanders. First, two skin expanders are implanted, one underneath the scalp and the other sited behind the microtic ear. At the second stage, after lobule transposition, the two expanded skin flaps (upper and lower) and mastoid fascial flap are raised. At the same time, the autogenous rib cartilage is harvested and the framework constructed. The cartilage framework is then anchored between the upper expanded skin flap and the fascial flap with its inferior pole inserted into the rotated earlobe. The upper expanded skin flap covers the whole anterior surface of the framework and drapes over the margins of the fascial flap, which wrap the framework from beneath. The raw surface of fascial flap is covered with the lower expanded skin flap. The formation of a pseudomeatus and tragus is performed at the third stage. Deficiency of skin is the major problem encountered with the other conventional methods. Our innovations using two tissue expanders in combination with an autogenous rib cartilage framework eliminate this problem completely.

Evaluation of neutron sources for ISAGE-in-situ-NAA for a future lunar mission

For a future Moon landing, a concept for an in-situ NAA involving age determination using the (40)Ar-(39)Ar method is developed. A neutron source (252)Cf is chosen for sample irradiation on the Moon. A special sample-in-source irradiation geometry is designed to provide a homogeneous distribution of neutron flux at the irradiation position. Using reflector, the neutron flux is likely to increase by almost 200%. Sample age of 1Ga could be determined. Elemental analysis using INAA is discussed.

The amount of surface HLA-I on T lymphocytes decreases in breast infiltrating ductal carcinoma patients

Human leucocyte antigen class I (HLA-I), which includes HLA-A, -B and -C, is an essential immune factor participating in the antitumour immune response. The changes in HLA-I expression in peripheral blood T lymphocytes in cancer patients have yet to be defined. This study examined the expression of HLA-I on CD4(+) and CD8(+) T lymphocytes in female patients with stage I - IV breast infiltrating ductal carcinoma, benign breast tumour diseases (mammary intraductal papilloma or breast fibroadenoma), and in healthy controls. HLA-I was down-regulated on CD4(+) T lymphocytes from patients with stage III and IV cancer, and on CD8(+) T lymphocytes in patients with stage I - IV cancer compared with healthy controls. HLA-I expression in T lymphocytes may contribute towards immune-balance disorders in tumour patients.

Colitogenic role of tumour necrosis factor (TNF) receptors in trinitrobenzene sulphonic acid colitis: TNF-R1 ablation does not affect systemic inflammatory response

Tumour necrosis factor (TNF)-α plays a critical role in the pathogenesis of T helper type 1-mediated colitis such as Crohn's disease. However, the roles of its two receptors in mediating pathology remain largely unknown. In this study, trinitrobenzene sulphonic acid (TNBS) was used to induce colitis in TNF-receptor single or double knock-out (DKO) BALB/c mice and in wild-type counterparts. TNF-R1(-/-) mice had significantly less weight loss, reduced mortality, colon shortening and oedema, colon histological damage and lower levels of colon myeloperoxidase compared with wild-type (WT) BALB/c mice. A similar manifestation was also observed in TNF-R2(-/-) and TNF-R1(-/-) TNF-R2(-/-) (TNF-R DKO) mice. Strikingly, systemic inflammatory response (including splenomegaly and monocyte expansion) was found in WT and TNF-R1(-/-) mice after TNBS, instead of TNF-R2(-/-) and TNF-R DKO mice. Attenuated pathology of colitis in TNF-R1(-/-) or TNF-R2(-/-) mice correlated with lower amounts of interleukin (IL)-6, IL-1β, monocyte chemotactic protein (MCP)-1, IL-12p70 and interferon (IFN)-γ production in the colons. Importantly, ablation of TNF-R1 or TNF-R2 reduced the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL)-positive apoptotic epithelial cells in the affected colons compared with WT TNBS-instilled controls, which might be due to the heightened ratio of Bcl-2/Bax and reduced activity of nuclear factor (NF)-κB. These findings suggest that either TNF-R1 or TNF-R2 plays a pathogenic role in the pathology of colitis and TNF signalling via TNF-R1 or TNF-R2 alone is not sufficient for inducing mucosal damage.