Clinical Value of Pepsinogen in the Screening, Prevention, and Diagnosis of Gastric Cancer.

OBJECTIVES: To compare the levels of serum pepsinogen (PG) in patients with gastric cancer (GC), patients with atrophic gastritis (AG), and healthy donors. Also, we explored the clinical value of PG detection for the diagnosis and treatment of GC. METHODS: The PG level in peripheral blood from patients and heathy donors was determined using an Abbott automatic chemiluminescence instrument. The study included 117 patients with GC confirmed by gastroscopy and histopathology, of whom 13 patients had cancer at stage I, 47 at stage II, 41 at stage III, and 16 at stage IV. The AG group included 122 patients, and the control group had 120 healthy donors. The relationship between serum PG levels and the occurrence and development of GC, as well as the evaluation of the clinical value of diagnostic tests based on serum PG detection, were investigated by receiver operating characteristic (ROC) curve analyses. RESULTS: Pepsinogen I (PGI) levels gradually decreased from the control group, the AG group, and the GC group. PGI exhibited high diagnostic value for GC (area under the curve [AUC], 0.834; cutoff, 51.2 ng/mL, sensitivity, 81.7%; specificity, 68.4%), PGII (AUC, 0.587; cutoff value, 13.05 ng/mL; sensitivity, 65.8%; specificity, 53.8%), and PGR (AUC, 0.752; cutoff, 5.65; sensitivity, 54.2%; specificity, 87.2%). The occurrence of GC was negatively correlated with serum levels of PGI (B = -0.054; OR = 0.947; 95% confidence interval [CI], 0.925-0.970; P <.001) and PGR (B = -0.420; OR = 0.657; 95% CI, 0.499-0.864; P = .003). CONCLUSIONS: The combined detection of PGI, PGII, and PGR has important clinical value for the screening, prevention, and diagnosis of GC and could allow for earlier detection, diagnosis, and treatment of GC.

Macroevolutionary patterns in seed component mass and different evolutionary trajectories across seed desiccation responses.

Seed coat and seed reserve show substantial mass variation, play different roles in plant life strategies and are shaped by different selective forces. However, remarkably little is known about the macroevolution of the relative allocation in seed components and its influence on important ecophysiological processes. Using phylogenetic comparative methods and evolutionary modelling approaches, we modelled mass changes in seed components along individual lineages for 940 species and compared the patterns across seed desiccation responses. Seed component allocation was driven primarily by changes in reserve mass rather than coat mass, as evolutionary rates in reserve mass significantly outpaced those in coat mass. Although the scaling patterns between reserve mass and coat mass were similar across desiccation responses, desiccation-sensitive seeds allocated more and evolved faster in reserve compared to desiccation-tolerant seeds. The findings emphasize the relative importance of reserve to coat in the evolution of plant reproductive strategies, revealing potential ecological advantages gained by enlarged reserve. As the first quantification of the evolutionary tempo and mode of seed component mass, our study allows a detailed interpretation of evolutionary pathways underlying seed storage behaviours and advances the understanding of the evolution of desiccation sensitivity in seeds.

Effects of drought-stress on seed germination and growth physiology of quinclorac-resistant Echinochloa crusgalli.

Echinochloa crusgalli (L.) Beauv. (barnyard grass) is considered a noxious weed worldwide, and is the most pernicious weed decreasing rice yields in China. Recently, E. crusgalli has evolved quinclorac resistance, making it among the most serious herbicide resistant weeds in China. The present study explored differences in germination and growth between quinclorac-resistant and -susceptible E. crusgalli collected in Hunan Province. The order of the seven E. crusgalli biotypes assessed, from high to low quinclorac-resistance, was: quinclorac-resistant, Chunhua, Hanshou, Shimen, Hekou, Dingcheng, and quinclorac-susceptible. With an increased in the level of quinclorac-resistance, the germination rate, length of young shoots and roots, and fresh weight of E. crusgalli were all decreased compared with that in more susceptible biotypes. However, there were no significant differences between quinclorac-resistant and susceptible E. crusgalli biotypes without polyethylene glycol 6000 treatment. Drought had a more obvious effect on glutathione S-transferases (GST) activity, determined by spectrophotometric method, in quinclorac-resistant E. crusgalli. Higher resistance level biotypes showed greater activity, and when treated with polyethylene glycol 6000 for 3 days, all E. crusgalli biotypes showed the highest GST activity. This study demonstrated that as the level of quinclorac-resistance increased, the rate of seed germination decreased, while the growth of young buds, young roots, and fresh weight decreased. Increased quinclorac-resistance may be related to the increased metabolic activity of GST in E. crusgalli.

An allometry between seed kernel and seed coat shows greater investment in physical defense in small seeds.

PREMISE OF THE STUDY: Numerous studies have treated the mass of a whole seed as an integrated unit, although the components seed kernel and seed coat play different roles and are subject to different evolutionary selection pressures. In this study, we provided the first global-scale quantification of the relative biomass investments in seed coats and seed kernels. We tested the following hypotheses: there is a negative allometry between seed kernel mass and seed coat mass, and therefore, seed coat ratio (SCR) is negatively correlated with seed mass. METHODS: We compiled a global-scale data set from the published literature, including 680 plant species from 420 genera and 108 families. The relationships between seed components were quantified using standardized major axis regression, ordinary least squares regression, and phylogenetic independent analyses. KEY RESULTS: We found a weak but significantly negative allometry between seed kernel mass and seed coat mass, which resulted in a negative relationship between seed mass and SCR. Similar results were found after accounting for the phylogeny. CONCLUSIONS: The finding that smaller seeds invest more in protective tissues but less in stored reserves may explain the general prediction that larger seeds suffer greater predation than smaller seeds. Furthermore, this weak allometry may also explain, at least in part, why so many studies failed to identify a clear pattern of the effect of seed mass on many ecological processes. Our study suggests that the allometry between the two seed components must be considered when evaluating the ecological significance and evolutionary history of seed mass.

[Overexpression of Toxoplasam gondii ROP18 by Tet-on Lentivirus Expression System].

OBJECTIVE: To construct a 293T mutant cell line over-expressing ROP18 of Toxoplasma gondii by Tet-on lentivirus expression system. METHODS: Rop18 gene of T. gondii was amplified by PCR, and inserted into a lentiviral vector pLVCT-tTR-KRAB. The recombinant plasmid pLVCT-tTR-KRAB-ROP18 (6 µg) and 293T human embryonic kidney cells were co-transfected with psPAX2 (4 µg) and pMD2.G (2 µg) for the packaging. The result of co-transfection was evaluated by fluorescence microscopy. At 48 h and 72 h after co-transfection, the supernatant of the packaging lentivirus was collected for the 293T cell infection. The doxycycline (DOX) was added into the medium to induce the ROP18 expression in 293T cells. The ROP18 fusion expression was observed under fluorescence microscope and detected by RT-PCR after induction. RESULTS: PCR product of the gene fragment encoding ROP18 was 960 bp. The recombinant plasmid pLVCT-tTR-KRAB-ROP18 was identified by PCR and restriction enzyme digestion. Green fluorescence was observed in 293T cells at 48 h post-transfection. Bright green fluorescence was observed in 293T cells at 24 h after DOX induction. RT-PCR results showed that a 960 bp specific band (ROP18 gene) was detectable in 293T cells. CONCLUSION: 293T cell line stably expressing ROP18 is established with Tet-on lentivirus expression system.

[Construction of beta-hydroxyacyl-acyl carrier protein dehydratase mutant of Toxoplasma gondii by tetracycline inducible expression system].

OBJECTIVE: To construct a beta-hydroxyacyl-acyl carrier protein dehydratase (FABZ) mutant of Toxoplasma gondii with tetracycline inducible expression system. METHODS: The fabz gene was amplified from T. gondii genomic DNA, and then used to construct the tetracycline inducible expression vector pTetO7-Sag1-FABZ-Ty-DHFR. The vector was transfected into TATi strain by electroporation. The FABZ defective mutant was selected by pyrimethamine and limitting dilution assay. The expression of Ty-tagged mutant was detected by Western blotting. 5 x 10(5) tachyzoites of FABZ defective mutant were cultured in HFF in the presence of anhydrotetracycline (ATc, 1 microg/ml) for 24 h and 48 h, respectively. The expression of Ty-tagged FABZ protein in the mutant was detected by Western blotting. RESULTS: The mutant could express the transit peptide (t-FABZ) and mature FABZ (m-FABZ) with the Ty-epitope tag. After ATc added in culture medium for 24 h and 48 h, the expression of t-FABZ in the mutant decreased significantly (P<0.05). CONCLUSION: The FABZ mutant is constructed with a tetracycline inducible expression system.

Copper(II) complexes of salicylaldehyde hydrazones: synthesis, structure, and DNA interaction.

Three hydrazone ligands, H2L1-H2L3, made from salicylaldehyde and ibuprofen- or naproxen-derived hydrazides, were prepared and transformed into the corresponding copper(II) complexes [Cu(II)L1] x H2O, [Cu(II)L2], and [(Cu(II))2(L3)2] x H2O x DMF (Scheme). The X-ray crystal structure of the last-mentioned complex was solved (Fig. 1), showing a square-planar complexation geometry, and the single units were found to form a one-dimensional chain structure (Fig. 2). The interactions of these complexes with CT-DNA were studied by different techniques, indicating that they all bind to DNA by classical and/or non-classical intercalation modes.