[Significance of soluble PD-L1 in patients with chronic hepatitis B and hepatitis C].

Objective: The programmed death receptor 1/programmed death ligand 1 (PD-1/PD-L1) pathway can negatively regulate the immune response of the body, and serum soluble PD-L1 (sPD-L1) can reflect the expression level of PD-L1. This study aims to compare the expressional differences of sPD-L1 in serum between patients with chronic hepatitis B (CHB) and C (CHC) and further explore the factors influencing the clinical cure of CHB. Methods: 60 cases with CHB, 40 cases with CHC, and 60 healthy controls were selected. Serum levels of sPD-L1 were detected using an ELISA kit. The relationship between sPD-L1 levels and viral load, liver injury indicators, and others was analyzed in CHB and CHC patients. According to the distribution type of the data, a one-way ANOVA or Kruskal Wallis test as well as Pearson's correlation or Spearman's rank correlation analysis were performed. A difference of P<0.05 was considered statistically significant. Results: The serum sPD-L1 levels were significantly higher in CHB patients (414.6 ± 214.9) pg/ml than those in CHC patients (58.9 ± 122.1) pg/ml and the healthy control group (66.27 ± 24.43) pg/ml, and there was no statistically significant difference in serum sPD-L1 between CHC patients and the healthy control group. Further grouping and correlation analysis showed that the level of serum sPD-L1 was positively correlated with the content of HBsAg in CHB patients but not with HBV DNA, alanine transaminase, albumin, and other liver injury indicators. Additionally, there was no correlation between serum sPD-L1 levels, HCV RNA, and liver injury indicators in CHC patients. Conclusion: The serum sPD-L1 levels are significantly higher in CHB patients than those in the healthy control group and the CHC group, and there is a positive correlation between sPD-L1 levels and HBsAg. The persistent presence of HBsAg is an important mechanism for the activity of the PD-1/PD-L1 pathway, indicating that the activity of the PD-1/PD-L1 pathway may be an important factor that cannot be clinically cured in CHB as in CHC.

Effects of an inducible aiiA gene on disease resistance in Eucalyptus urophylla × Eucalyptus grandis.

N-acyl-homoserine lactones (AHLs) are metabolites of mostly gram-negative bacteria and are critical signaling molecules in bacterial quorum-sensing systems. At threshold concentrations, AHLs can activate the expression of pathogenic genes and induce diseases. Therefore, reducing AHL concentrations is a key point of disease control in plants. AHL-lactonase, which is expressed by aiiA, is widespread in Bacillus sp and can hydrolyze AHLs. In the present study, we cloned aiiA from Bacillus subtilis by PCR. A plant expression vector of aiiA was constructed and name Pcam-PPP3-aiiA, in which expression of aiiA was controlled by the pathogen-inducible plant promoter PPP3. The recombinant plasmid was transferred into Eucalyptus × urophylla × E. grandis by an Agrobacterium-mediated transformation. PCR and Southern blotting showed that aiiA was successfully integrated into the E. urophylla × E. grandis genome and its expression was induced by Ralstonia solanacearum 12 h after inoculation, as shown by reverse transcription-PCR. The transcription efficacy of aiiA increased 43.88-, 30.65-, and 18.95-fold after inoculation with R. solanacearum, Erwinia carotovora ssp. zeae (Sabet) and Cylindrocladium quinqueseptatum, respectively as shown by RT-real-time PCR. Transgenic E.urophylla × E.grandis expressing the AIIA protein exhibited significantly enhanced disease resistance compared to non-transgenic plants by delaying the onset of wilting and reducing the disease index.

Genetic analysis of grain shape and weight after cutting rice husk.

Grain shape and weight are the most important components of rice yield and are controlled by quantitative trait loci (QTLs). In this study, a double-haploid population, derived from the cross of japonica CJ06 and indica TN1, was used to analyze QTLs for grain shape and weight under two conditions: normal growth with unbroken husk and removing partial husk after flowering. Correlation analysis revealed that these traits, except grain weight, had a connection between the two conditions. Twenty-nine QTLs for grain shape and weight were detected on chromosomes 1 to 3; 6; 8 to 10; and 12, with the likelihood of odds value ranging from 2.38 to 5.36, including 10 different intervals. Some intervals were specifically detected after removing partial husk. The results contribute to the understanding of the genetic basis of grain filling and growth regulation, and provide us some assistance for improving grain plumpness in rice breeding.

Identification and validation of a new grain weight QTL in rice.

The genetic control of grain weight (GW) remains poorly understood. Quantitative trait loci (QTLs) determining the GW of rice were identified using a natural GW mutant, sgw. Using a segregating population derived from sgw (low GW) and cultivar 9311 ('9311'; indica, high GW), the chromosome segment associated with GW was detected on the short arm of chromosome 7. To validate and further refine the locus, QTL analysis based on F2 and F3 populations was conducted, and a single major QTL (designated as qsgw7) affecting the 1000-grain weight of paddy rice was identified on the short arm region of rice chromosome 7 between simple sequence repeat (SSR) markers RM21997 and RM22015, where 4 bacterial artificial chromosome clones, OJ1339_F05, P0506F02, P0011H09, and P0519E12, were present. Analysis of the near isogenic line for qsgw7 (NILqsgw7) showed that the grain length, width, and volume of paddy rice in NILqsgw7 were significantly lower than those in '9311' and that the 1000-grain weight, grain length, width, volume, and chalkiness of brown rice in NILqsgw7 were significantly lower than those in '9311'. These results suggested that the qsgw7 gene, which was identified in this study, may be a new GW-related QTL that could affect GW and grain shape, especially grain plumpness.

Protein phosphorylation stimulates the rate of malate uptake across the peribacteroid membrane of soybean nodules.

Incubation of intact isolated symbiosomes with [gamma-32P]ATP, followed by isolation of the peribacteroid membrane and polypeptide analysis, showed that a single major polypeptide at 26 kDa was labelled. Antibodies raised against nodulin 26 reacted with a similar sized polypeptide. Incubation of the symbiosomes with alkaline phosphatase removed the label from this polypeptide. Pre-incubation with ATP stimulated malate accumulation by isolated symbiosomes, but only slightly (10-30%). Pre-treatment of symbiosomes with alkaline phosphatase inhibited malate uptake substantially and this inhibition was completely relieved by addition of ATP. The ATP stimulation of malate uptake was not affected by ATPase inhibitors. It is suggested that the rate of malate uptake across the peribacteroid membrane is controlled by phosphorylation of nodulin 26.

Antidiabetic effect of a newly identified component of Opuntia dillenii polysaccharides.

The aim of this study was to determine the most effective hypoglycemic component of polysaccharides from Opuntia dillenii Haw. by preliminary screening and to specifically study the antidiabetic effects of O. dillenii polysaccharide (ODP)-Ia in mice with streptozotocin (STZ)-induced diabetes. Three kinds of ODPs - ODP-Ia, ODP-Ib, and ODP-II' - were isolated by using an ultrasonic extraction method and diethylaminoethyl (DEAE)-Sepharose fast-flow column chromatography. The mice were administered ODPs for 3 weeks. Gavage administration of ODP-Ia significantly decreased (P<0.05) their intake of food and water; the fasting levels of blood glucose (BG), total cholesterol (TC), triglycerides (TGs), plasma urea nitrogen (PUN), and malondialdehyde (MDA); and the activity of glucose-6-phosphatase (G-6-Pase). In contrast, it significantly increased (P<0.05) the body weights, hepatic glycogen (HG) levels, high-density lipoprotein cholesterol (HDL-C) levels, and the hepatic superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in diabetic mice. However, ODP-Ia did not significantly increase insulin levels in the mice with STZ-induced diabetes. We propose that ODP-Ia exerts its antihyperglycemic effect by protecting the liver from peroxidation damage and by maintaining tissue function, thereby improving the sensitivity and response of target cells in diabetic mice to insulin.