Lateral Organ Boundaries Domain 19 (LBD19) negative regulate callus formation in Arabidopsis

Plant Cell, Tissue and Organ Culture (PCTOC) - Callus is a remarkable regeneration tissue. The genes correlated with root development can be involved in regulating callus development in higher...     

Pulmonary hemodynamic reaction to foreign blood in goats and rabbits.

We have found that the goat is extraordinarily sensitive to very small quantities of rabbit or rat blood. As little as 0.004 ml/kg induces transient pulmonary hypertension [maximal rise in pulmonary arterial pressure 32 +/- 10 (SD) cmH2O] in goats. We hypothesized that this reaction may be related to the presence of the resident population of intravascular macrophages that reside in the pulmonary capillaries of goats. If that is so, then rabbits or rats, which have few or no intravascular macrophages, should not be reactive to foreign blood. We compared pulmonary hemodynamics and changes in blood thromboxane B2 concentrations among goats, rabbits, and rats in response to graded doses of foreign blood. The pulmonary reaction to foreign blood was much greater in goats than in rabbits or rats, even though we injected up to 10- or 60-fold larger amounts into the latter species. In goats the pulmonary vascular pressure response to rabbit blood was dose dependent in goats and correlated well with changes in systemic arterial thromboxane B2 concentrations [change in pulmonary arterial pressure = 0.07 (thromboxane B2) + 8.3, r = 0.79]. We also tested the prostaglandin H2 endoperoxide analogue (U-46619) and found that the goats are somewhat more reactive than rabbits. We conclude that the pulmonary hemodynamic reaction to foreign blood is consistent with the concept that the foreign erythrocytes are reacting with the pulmonary intravascular macrophages in goats. The lower reactivity of the rabbit pulmonary circulation to thromboxane may also have a role.     

High level soluble expression and one-step purification of IBDV VP2 protein in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Objectives

To improve the expression of soluble IBDV VP2 protein by using different tagged vectors in Escherichia coli.

Results

Fusion tags, Grifin, MBP, SUMO, thioredoxin, γ-crystallin, ArsC and PpiB, enhanced the expression and solubility of VP2 protein. The fusion proteins were purified by Ni–NTA chromatography, MBP-VP2 showed the highest purity about 90 %. After removing the MBP tag, VP2 self-assembled into virus-like particles, ~25 nm diam. Results from AGP suggested the recombinant IBDV VP2 protein identified by reference serum like IBDV.

Conclusion

All the seven tags enhanced the expression and solubility of IBDV VP2 protein. The recombinant protein self-assembly into virus like particles and possess antigenicity as reference IBDV.

     

Nitidine chloride inhibited the expression of S phase kinase-associated protein 2 in ovarian cancer cells

Nitidine chloride (NC) has been reported to exert its anti-tumor activity in various types of human cancers. However, the molecular mechanism of NC-mediated tumor suppressive function is largely unclear. In the current study, we used several approaches such as MTT, FACS, RT-PCR, Western blotting analysis, invasion assay, transfection, to explore the molecular basis of NC-triggered anti-cancer activity. We found that NC inhibited cell growth, induced cell apoptosis, caused cell cycle arrest in ovarian cancer cells. Emerging evidence has demonstrated that Skp2 plays an important oncogenic role in ovarian cancer. Therefore, we also explored whether NC exerts its biologic function via downregulation of Skp2 in ovarian cancer cells. We observed that NC significantly inhibited the expression of Skp2 in ovarian cancer cells. Notably, overexpression of Skp2 abrogated the anti-cancer activity induced by NC in ovarian cancer cells. Consistently, downregulation of Skp2 expression enhanced the sensitivity of ovarian cancer cells to NC treatment. Thus, inactivation of Skp2 by NC could be a novel strategy for the treatment of human ovarian cancer.     

Enhanced thermostability of a Rhizopus chinensis lipase by in vivo recombination in Pichia pastoris

ABSTRACT: BACKGROUND: Lipase from Rhizopus chinensis is a versatile biocatalyst for various bioconversions and has been expressed at high-level in Pichia pastoris. However, the use of R. chinensis lipase in industrial applications is restricted by its low thermostability. Directed evolution has been proven to be a powerful and efficient protein engineering tool for improvement of biocatalysts. The present work describes improvement of the thermostability of R. chinensis lipase by directed evolution using P. pastoris as the host. RESULTS: An efficient, fast and highly simplified method was developed to create a mutant gene library in P. pastoris based on in vivo recombination, whose recombination efficiency could reach 2.3 x 105 /mug DNA. The thermostability of r27RCL was improved significantly by two rounds of error-prone PCR and two rounds of DNA shuffling in P. pastoris. The S4-3 variant was found to be the most thermostable lipase, under the conditions tested. Compared with the parent, the optimum temperature of S4-3 was two degrees higher, Tm was 22 degrees higher and half-lives at 60degreesC and 65degreesC were 46- and 23- times longer. Moreover, the catalytic efficiency kcat/Km of S4-3 was comparable to the parent. Stabilizing mutations probably increased thermostability by increasing the hydrophilicity and polarity of the protein surface and creating hydrophobic contacts inside the protein. CONCLUSIONS: P. pastoris was shown to be a valuable cell factory to improve thermostability of enzymes by directed evolution and it also could be used for improving other properties of enzymes. In this study, by using P. pastoris as a host to build mutant pool, we succeeded in obtaining a thermostable variant S4-3 without compromising enzyme activity and making it a highly promising candidate for future applications at high temperatures.     

Metabolic flux modeling of detoxification of acetic acid by Ralstonia eutropha at slightly alkaline pH levels

Ralstonia eutropha grows on and produces polyhydroxyalkanoates (PHAs) from fermentation acids. Acetic acid, one major organic acid from acidogenesis of organic wastes, has an inhibitory effect on the bacterium at slightly alkaline pH (6 g HAc/L at pH 8). The tolerance of R. eutropha to acetate, however, was increased significantly up to 15 g/L at the slightly alkaline pH level with high cell mass concentration. A metabolic cell model with five fluxes is proposed to depict the detoxification mechanism including mass transfer and acetyl-CoA formation of acetic acid and the formation of three final metabolic products, polyhydroxybutyrate (PHB), active biomass, and CO(2). The fluxes were measured under different conditions such as cell mass concentration, acetic acid concentration, and medium composition. The experimental results indicate that the acetate detoxification by high cell mass concentration is attributed to the increased fluxes at high extracellular acetate concentrations. The fluxes could be doubled to reduce and hence detoxify the accumulated intracellular acetate anions.     

Multifocal Langerhans cell sarcoma involving epidermis:a case report and review

ABSTRACT: OBJECTIVE: To study the clinico-pathological characteristics of Langerhans cell sarcoma (LCS) which involving epidermis. METHODS: A case of primary multifocal LCS was analyzed in histopathology and immunophenotype. RESULTS: A 41-year-old man with multifocal cutaneous LCS involving the inguina and waist was reported. Clinical and pathology data were available. Neoplastic cells with markedly malignant cytological features were observed. Tumor cells exhibited irregular shape with abundant and eosinophilic red staining cytoplasm; large, irregular-shaped, showing lobulated or dented nucleus and some cells with a longitudinal nuclear groove and prominent nucleoli. The tumor cells expressed CD1a, Langerin (CD207), S-100 protein, CD68 and vimentin, and did not express pan-T or B cell markers and epithelial markers. The patient died less than 1 year after diagnosis due to local recurrence and metastasis to the lung, despite the administration of local radiation and chemotherapy. CONCLUSIONS: LCS is a tumor with markedly malignant cytological features that originates from Langerhans cells. Primary multifocal neoplasms involving epidermis is even rare. Accurate diagnosis is based on the histopathological and immunohistochemical of the tumor cells.Virtual slideThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1182345104754765.