Responses of leaf morphology, NSCs contents and C:N:P stoichiometry of Cunninghamia lanceolata and Schima superba to shading.

BACKGROUND: The non-structural carbohydrates (NSCs), carbon (C), nitrogen (N), and phosphorus (P) are important energy source or nutrients for all plant growth and metabolism. To persist in shaded understory, saplings have to maintain the dynamic balance of carbon and nutrients, such as leaf NSCs, C, N and P. To improve understanding of the nutrient utilization strategies between shade-tolerant and shade-intolerant species, we therefore compared the leaf NSCs, C, N, P in response to shade between seedlings of shade-tolerant Schima superba and shade-intolerant Cunninghamia lanceolate. Shading treatments were created with five levels (0, 40, 60, 85, 95% shading degree) to determine the effect of shade on leaf NSCs contents and C:N:P stoichiometry characteristics. RESULTS: Mean leaf area was significantly larger under 60% shading degree for C. lanceolata while maximum mean leaf area was observed under 85% shading degree for S. superba seedlings, whereas leaf mass per area decreased consistently with increasing shading degree in both species. In general, both species showed decreasing NSC, soluble sugar and starch contents with increasing shading degree. However shade-tolerant S. superba seedlings exhibited higher NSC, soluble sugar and starch content than shade-intolerant C. lanceolate. The soluble sugar/starch ratio of C. lanceolate decreased with increasing shading degree, whereas that of S. superb remained stable. Leaf C:N ratio decreased while N:P ratio increased with increasing shading degree; leaf C:P ratio was highest in 60% shading degree for C. lanceolata and in 40% shading degree for S. superba. CONCLUSION: S. superba is better adapted to low light condition than C. lanceolata through enlarged leaf area and increased carbohydrate reserves that allow the plant to cope with low light stress. From mixed plantation viewpoint, it would be advisable to plant S. superba later once the canopy of C. lanceolata is well developed but allowing enough sunlight.

Better performance of PIVKA-II for detecting hepatocellular carcinoma in patients with chronic liver disease with normal total bilirubin.

BACKGROUND: Serum protein induced by vitamin K absence or antagonist-II (PIVKA-II) is a promising biomarker for hepatocellular carcinoma (HCC) surveillance. AIM: To identify the contributing factors related to the abnormal elevation of PIVKA-II level and assess their potential influence on the performance of PIVKA-II in detecting HCC. METHODS: This study retrospectively enrolled in 784 chronic liver disease (CLD) patients and 267 HCC patients in Mengchao Hepatobiliary Hospital of Fujian Medical University from April 2016 to December 2019. Logistic regression and the area under the receiver operating characteristic curve (AUC) were used to evaluate the influencing factors and diagnostic performance of PIVKA-II for HCC, respectively. RESULTS: Elevated PIVKA-II levels were independently positively associated with alcohol-related liver disease, serum alkaline phosphatase (ALP), and total bilirubin (TBIL) for CLD patients and aspartate aminotransferase (AST) and tumor size for HCC patients (all P < 0.05). Serum PIVKA-II were significantly lower in patients with viral etiology, ALP ≤ 1 × upper limit of normal (ULN), TBIL ≤ 1 × ULN, and AST ≤ 1 × ULN than in those with nonviral disease and abnormal ALP, TBIL, or AST (all P < 0.05), but the differences disappeared in patients with early-stage HCC. For patients with TBIL ≤ 1 × ULN, the AUC of PIVKA-II was significantly higher compared to that in patients with TBIL > 1 × ULN (0.817 vs 0.669, P = 0.015), while the difference between ALP ≤ 1 × ULN and ALP > 1 × ULN was not statistically significant (0.783 vs 0.729, P = 0.398). These trends were then more prominently perceived in subgroups of patients with viral etiology and HBV alone. CONCLUSION: Serum PIVKA-II has better performance in detecting HCC at an early stage for CLD patients with normal serum TBIL.

[Variation characteristics of soil seed bank during vegetation restoration in red soil erosion area]. / 红壤侵蚀区植被恢复过程中土壤种子库变化特征.

As a natural disturbance agent, soil erosion could affect secondary distribution and species composition of soil seed bank. The composition, storage and distribution pattern of the soil seed banks in five different vegetation recovery areas, including bare ground (1), pine forest land (2-4) and secondary forest (5) in the typical red soil erosion area, were studied to explore the effects of soil erosion on soil seed bank during vegetation restoration. The results showed that a total of 21 species were recorded in the soil seed bank. Species richness was low, and dominated by herbaceous species. The density of soil seed bank varied from 56.7 to 793.3 seeds·m-2 and differed significantly among the sampling plots. Further, the density of soil seed bank decreased obviously with the increasing soil erosion intensity. The seed bank density of 0-2 cm soil layer increased along uphill, middle slope, and downhill. The soil seed banks of severely eroded and strongly eroded plots were mainly distributed in the 5-10 cm soil layer, with almost no seeds in 0-2 cm soil layer on the middle slope and uphill. Soil erosion made the distribution of soil seed bank to deeper soil layer, the accumulation of which will need a long time after vegetation restoration.

[IgM to recombinant antigen E2 of HEV envelope protein is a sensitive and specific serological marker in diagnosis of acute hepatitis E].

OBJECTIVES: To evaluate the sensitivity and specificity of IgM to recombinant antigen E2 of HEV envelope protein in the diagnosis of acute sporadic hepatitis E. METHODS: anti-E2 IgM was detected in sera samples from 176 cases of acute sporadic hepatitis E and 191 cases of acute non A-E hepatitis by ELISA and was compared with HEV IgM detected by some domestic and Genelabs (GL) kits. HEV RNA was also detected in sera positive for anti-E2 IgM. Logistic regression was used to analyze factors associated with the detection of anti-E2 IgM and HEV RNA. RESULTS: Anti-E2 IgM was found in 68.75% of the serum samples from the 176 patients of acute hepatitis E and the positive rate of HEV IgM detection by domestic kits was 56.25% (chi2 IgM = 6.49, P < 0.05). There were 37 (19.37%) anti-E2 IgM positive cases in those 191 sera of the acute non A-E hepatitis, out of which 11 cases were also detected as positive by the GL kit. Of the 158 anti-E2 IgM positive sera, HEV RNA was found in 81 (51.27%), among which 57.02% was positive in acute hepatitis E and 32.43% in acute non A-E hepatitis. No HEV RNA was found in the anti-E2 IgM negative sera from the cases of acute hepatitis E. By logistic regression analysis, no variance relative to the detection of anti-E2 IgM was found with the time interval from onset to hospitalization, age, levels of bilirubin, ALT and AST of the serum. Only the level of serum ALT was found being significantly associated with the detection of HEV RNA (P = 0.024). CONCLUSIONS: (1) anti-E2 IgM is a sensitive and specific serological maker for diagnosing an acute infection of HEV. (2) HEV is still the pathogen of some cases diagnosed clinically as non-A-E hepatitis. (3) Persistent HEV viremia is possibly an important factor influencing the severity of acute hepatitis E.