Alpha-picolinic acid,a fungal toxin and mammal apoptosis-inducing agent,elicits hypersensitive-like response and enhances disease resistance in rice

Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistant mutants. Here,we report that PA is an efficient apoptosis agent triggering cell death of hypersensitive-like response in planta. Confirmed by Fluorescence Activated Cell Sorter (FACS),rice suspension cells and leaves exhibited programmed cell death induced by PA. The PA-induced cell death was associated with the accumulation of reactive oxygen species that could be blocked by diphenylene iodonium chloride,indicating that the generation of reactive oxygen species was NADPHoxidase dependent. We also demonstrated the induction of rice defense-related genes and subsequent resistant enhancement by PA against the rice blast fungus Magnaporthe grisea. Hence,it was concluded that the PA-stimulated defense response likely involves the onset of the hypersensitive response in rice,which also provides a simple eliciting tool for studying apoptosis in the plant cell.

Levels of plasma des-γ-carboxy protein C and prothrombin in patients with liver diseases

AIM: To study the plasma des-γ-carboxy protein C activity, antigen and prothrombin levels in patients with liver diseases and their clinical significance. METHODS: Plasma protein C activity (PC:C) was detected by chromogenic assay and antigen (PC:Ag) and des-γ-carboxy protein C (DCPC) were detected by ELISA. Total prothrombin and unabsorbed prothrombin in plasma were detected by ecarin chromogenic assay. RESULTS: Compared with the control, the levels of PC:C and PC:Ag in patients with hepatocellular carcinoma (HCC) and liver cirrhosis (LC) were lower (PCC: 104.65±23.0%,62.50±24.89%, 56.75±20.14%, PC:Ag: 5.31±1.63 μg/mL, 2.28±1.15 μg/mL, 2.43±0.79 μg/mL, P<0.05). The levels of PC:Ag in patients with acute viral hepatitis (AVH) also was lower (2.98±0.91 μg/mL, P<0.01), but PC:C was close to the control (93.76±30.49%, P>0.05). The levels of DCPC in patients with HCC were remarkably higher (0.69±0.29 μg/mL,1.18±0.63 μg/mL, 0.45±0.21 μg/mL, P<0.05) and its averagewas up to 50% of total PC:Ag. But those of DCPC in patients with AVH were not significantly different from the control. The levels of total prothrombin were lower in patients with LC, but higher in patients with HCC. The levels of unabsorbed prothrombin were predominantly higher than those of other groups. CONCLUSION: PC:C and PC:Ag in patients with liverdiseases (except PC:C in AVH) were lower. The total prothrombin was lower in patients with LC. The higher level of unabsorbed prothrombin may be used as a scanning marker for HCC. DCPC may be used as a complementary marker in the diagnosis of HCC.

PEG10 Activation by Co-Stimulation of CXCR5 and CCR7 Essentially Contributes to Resistance to Apoptosis in CD19^(+)CD34^(+) B Cells from Patients with B Cell Lineage Acute and Chronic Lymphocytic Leukemia

We investigated CD19^+CD34^+ and CD19^+CD34 B cells from cord blood (CB) and typical patients with B cell lineage acute and chronic lymphocytic leukemia (B-ALL and B-CLL) in terms of expression and functions of CXCR5/CXCL13 and CCR7/CCL19.CXCR5 and CCR7 were selectively frequent expressed on B-ALL,B-CLL and CB CD19^+CD34^+ B cells,but not on CD19^+CD34 B cells.Instead of induction of impressive chemotactic responsiveness,CXCL13 and CCL19 together induced significant resistance to TNF-α-mediated apoptosis in B-ALL and B-CLL but not CB CD19^+CD34^+ B cells.B-ALL and B-CLL CD19^+CD34^+ B cells expressed elevated level of Paternally Expressed Gene 10 (PEG10),and CXCL13 and CCL19 together significantly up-regulated PEG10 expression in the cells.We found that CXCL13 and CCL19 together by means of activation of CXCR5 and CCR7 up-regulated PEG10 expression and function,subsequent stabilized caspase-3 and caspase-8 in B-ALL and B-CLL CD19^+CD34^+ B cells,and rescued the cells from TNF-α-mediated apoptosis.We suggested that normal lymphocytes,especially naive B and T cells,utilized CXCR5/CXCL13 and CCR7/CCL19 for migration,homing,maturation,and cell homeostasis as well as secondary lymphoid tissues organogenesis. Meanwhile certain malignant cells took advantages of CXCR5/CXCL13 and CCR7/CCL19 for infiltration, resistance to apoptosis,and inappropriate proliferation.Cellular & Molecular Immunology.2004;1(4):280-294.

Attribute Mathematical Model for Comprehensive Index System＇ Quality Evaluation for Natural Science Academic Journals

Journal evaluation is a compliated engineering system, how to evaluate academic journals more scientifically in scientific methods have becomes a problem of great concerns. This paper presents attribute mathematical model for comprehensive index system' quality evaluation for natural science academic journals, aiming to make comprehensive index system' quality evaluation for academic journals more objective and reasonable compared with other quantitative evaluation ways.