Pinus koraiensis in broad-leaved Korean pine forests of Changbai Mountain at different successional stages (secondary poplar-birch forest, secondary coniferous and broad-leaved forest and the primitive Korean pine forest) were selected in this paper as the research objects. In this research, the annual growth of net primary productivity (NPP) (1921-2006) of P. koraiensis was obtained by combining the tree-ring chronology and relative growth formulae, the correlation between NPP of P. koraiensis and climatic factors was developed, and the annual growth of NPP of P. koraiensis at different successional stages in relation to climatic variation within different climate periods were analyzed. The results showed that, in the research period, the correlations between climatic factors and NPP of P. koraiensis at different successional stages were different. With increasing the temperature, the correlations between NPP of P. koraiensis in the secondary poplar-birch forest and the minimum temperatures of previous and current growing seasons changed from being significantly negative to being significantly positive. The positive correlation between NPP of P. koraiensis in the secondary coniferous and broad-leaved forest and the minimum temperature in current spring changed into significantly positive correlation between NPP of P. koraiensis and the temperatures in previous and current growing seasons. The climatic factors had a stronger hysteresis effect on NPP of P. koraiensis in the secondary coniferous and broad-leaved forest, but NPP of P. koraiensis in the primitive Korean pine forest had weaker correlation with temperature but stronger positive correlation with the precipitation of previous growing season. The increases of minimum and mean temperatures were obvious, but no significant variations of the maximum temperature and precipitation were observed at our site. The climatic variation facilitated the increase of the NPP of P. koraiensis in the secondary poplar-birch forest at the initial successional stage and in secondary coniferous and broad-leaved forest at the intermediate successional stage, and this effect was especially obvious for the secondary coniferous and broad-leaved forest, but very small for the primitive Korean pine forest which was at the climax phase.
Plectasin, a novel antimicrobial peptide, has the potential to disrupt bacterial cell walls and alter the rumen fermentation mode, making it a superior alternative to antibiotics. However, there is limited research on the effects of plectasin on rumen microbiota. This study aimed to evaluate the effects of plectasin (0.057 μmol/L) on in vitro rumen fermentation characteristics and select groups of rumen bacterial communities in comparison with monensin (5 μmol/L), one of the most commonly used ionophores in ruminants, and as a control treatment with the basal substrate. Unlike monensin, plectasin was found to increase the molar proportions of butyrate and acetate/propionate ratio (p < 0.001) while decreasing pH and the molar proportions of propionate (p < 0.05). Principal component analysis of bacterial 16S rRNA gene amplicons clearly showed a separation between the bacteria shaped by plectasin and monensin. Comparative analysis also revealed differences in the relative abundance of certain bacteria in different taxa between plectasin and monensin. The divergent effects of plectasin and monensin on bacterial communities are likely responsible for the differences in their ability to alter rumen fermentation. Plectasin may have advantages over monensin in modulating ruminal bacterial communities and increasing the butyrate and the acetate/propionate ratio. Therefore, it may be considered as a potential additive for ruminant feed.
Abstract Enteric methane (CH4) emissions are not only an important source of greenhouse gases but also a loss of dietary energy in livestock. Corn oil (CO) is rich in unsaturated fatty acid with >50% PUFA, which may enhance ruminal biohydrogenation of unsaturated fatty acids, leading to changes in ruminal H2 metabolism and methanogenesis. The objective of this study was to investigate the effect of CO supplementation of a diet on CH4 emissions, nutrient digestibility, ruminal dissolved gases, fermentation, and microbiota in goats. Six female goats were used in a crossover design with two dietary treatments, which included control and CO supplementation (30 g/kg DM basis). CO supplementation did not alter total-tract organic matter digestibility or populations of predominant ruminal fibrolytic microorganisms (protozoa, fungi, Ruminococcus albus, Ruminococcus flavefaciens, and Fibrobacter succinogenes), but reduced enteric CH4 emissions (g/kg DMI, −15.1%, P = 0.003). CO supplementation decreased ruminal dissolved hydrogen (dH2, P < 0.001) and dissolved CH4 (P < 0.001) concentrations, proportions of total unsaturated fatty acids (P < 0.001) and propionate (P = 0.015), and increased proportions of total SFAs (P < 0.001) and acetate (P < 0.001), and acetate to propionate ratio (P = 0.038) in rumen fluid. CO supplementation decreased relative abundance of family Bacteroidales_BS11_gut_group (P = 0.032), increased relative abundance of family Rikenellaceae (P = 0.021) and Lachnospiraceae (P = 0.025), and tended to increase relative abundance of genus Butyrivibrio_2 (P = 0.06). Relative abundance (P = 0.09) and 16S rRNA gene copies (P = 0.043) of order Methanomicrobiales, and relative abundance of genus Methanomicrobium (P = 0.09) also decreased with CO supplementation, but relative abundance (P = 0.012) and 16S rRNA gene copies (P = 0.08) of genus Methanobrevibacter increased. In summary, CO supplementation increased rumen biohydrogenatation by facilitating growth of biohydrogenating bacteria of family Lachnospiraceae and genus Butyrivibrio_2 and may have enhanced reductive acetogenesis by facilitating growth of family Lachnospiraceae. In conclusion, dietary supplementation of CO led to a shift of fermentation pathways that enhanced acetate production and decreased rumen dH2 concentration and CH4 emissions.
Abstract Ruminants are important for global food security but are major sources of the greenhouse gas methane. Methane yield is controlled by the cycling of molecular hydrogen (H 2 ), which is produced during carbohydrate fermentation and consumed by methanogenic, acetogenic, and respiratory microorganisms. However, we lack a holistic understanding of the mediators and pathways of H 2 metabolism, and how this varies between ruminants with different methane-emitting phenotypes. Here we used metagenomic, metatranscriptomic, metabolomics, and biochemical approaches to compare H 2 cycling and reductant disposal pathways between low-methane-yield Holstein and high-methane-yield Jersey dairy cattle. The microbiota of Holstein cattle disposed of reductant via propionate and amino acid production and expressed uptake [NiFe]-hydrogenases to use H 2 to support sulfate and nitrate respiration. In contrast, Jersey microbiota primarily disposed of H2 through methanogenesis via methanogenic [NiFe]-hydrogenases and acetogenesis via [FeFe]-hydrogenases, resulting in enhanced methane and acetate production. These findings were supported by two in vitro measurements of microbiota activities and metabolites, as well as public global rumen microbiome data from sheep and beef cattle. Overall, this study highlights the importance of promoting alternative H2 consumption and reductant disposal pathways for the synthesis of host-beneficial metabolites and the reduction of methane production in ruminants.
Objective
To investigate the expression of liver kinase B1 (LKB1) and phosphatase and tensin homology deleted on chromosome ten (PTEN) in hepatocellular carcinoma (HCC) and their relationship with pathological characteristics and prognosis of HCC.
Methods
Immunohistochemistry was used to detect expression of LKB1 and PTEN in 115 HCC cases . The relationship between clinicopathologic factors and the expressions was analyzed.
Results
The positive expression rate of LKB1 and PTEN was 10.4% (12/115) and 28.7% (33/115) respectively. The coexpression ratio of LKB1 and PTEN was 5.2% (6/115). LKB1 and PTEN double deletion rate was 66.1%, with the latter most often found in those ≥50 years of age group (χ2=7.968, P=0.001), middle low differentiation HCC group (χ2=11.297, P=0.025) and vascular tumor thrombus group (χ2=6.797, P=0.011). The 5 year survival rates of LKB1 and PTEN protein coexpression and double deletion patients were 100% and 36.5% (χ2=10.969, P=0.004), respectively. Multivariate COX regression analysis showed that vascular tumor thrombus, PTEN deletion and LKB1/PTEN double deletion were independent risk factors for the prognosis of HCC.
Conclusions
Double deletion of LKB1/PTEN protein is one of the independent factors that affect the survival time of HCC patients.
Key words:
Carcinoma, hepatocellular; Gene expression; Liver kinase B1; Phosphatase and tensin homology deleted on chromosome ten
Abstract Background: The advent of monitoring system can automatically collect the quantitative data of the feeding behavior and feed intake of individual cattle, and the immediate response system always records many non-eating visits. Increasing response time of trigger helps to decrease recording non-eating visits, but may also miss some small periods of recording feed intake. This study was to evaluate the effect of response time in monitoring system on the accuracy of recording individual feeding behavior and feed intake in dairy cows. The first experiment was to investigate the distribution of 10-h feeding behaviors of 8 Holstein dairy cows after morning feeding by using infra-red camera. The second experiment was to investigate accuracy of feed intake recorded by the monitoring system with different response times (0.3, 3, 6, 12 and 24 s) in comparison with direct weighting. The third experiment was to investigate effect of excluding the data of time interval after response time on feed intake and visiting behaviors recorded by the monitoring system, when responding time was set as 0.3 s. Results: The results showed that the most of eating and non-eating visits had duration larger than 24 s (99.0%) and less than 24 s (65.3%), respectively. Comparing with actual feed intake obtained by direct weighting, increasing response time greatly increased the recorded feed intake, with the greatest difference occurring at 6 s of response time ( P = 0.001). Although increasing time interval after response time linearly increased mean, median feed intake per visit and 10-h feed intake ( P < 0.01), it had little influence on 10-h feed intake (< 0.1%) and eating visit (< 5%). Conclusions: Setting immediate response (0.3 s) in monitoring system helps to get actual feed intake, but can obtain a lot of non-eating visits. Increasing response time helps to decrease the recording of non-eating visits, but can overestimate feed intake.
The physiological function of the reticulorumen plays an essential role in ruminant nutrition, and detailed knowledge of rumen motility can further advance understanding of ruminant nutrition and physiology. Rumen motility was simulated by setting different stirrer rotation speeds in a rumen simulation technique (RUSITEC) system. The aim of this study was to investigate the effects of rotation speeds on rumen fermentation, saturation factor of dissolved gases, hydrogen (H2) and methane (CH4) emissions, microbial protein synthesis, and selected microbial population using RUSITEC. The experiment was performed according to a balanced 3 × 3 Latin square design, and each period included 7 d for adaptation and 3 d for sampling. Three motility treatments included 5, 15, and 25 rpm rotation speeds. Daily total gas and H2 and CH4 emissions had quadratic responses to the increasing rotation speed and were highest at 15 rpm. Quadratic and linear responses (highest at 5 rpm) to increasing rotation speed were observed for saturation factors of H2 and CH4, liquid-dissolved H2 and CH4 concentrations, and headspace concentration of H2 in the gas phase, whereas increasing rotation speed linearly decreased saturation factors of CO2 and liquid-dissolved CO2 concentration. Quadratic and linear responses to increasing rotation speed were observed for molar percentages of acetate, ammonia, and microbial protein concentration, whereas increasing rotation speed quadratically increased pH and decreased total volatile fatty acid concentration and acetate-to-propionate ratio. The 15-rpm rotation speed had the highest values of total volatile fatty acids, acetate molar percentage, and microbial protein concentration. Quadratic and linear responses to increasing rotation speed were observed for copy numbers of solid-associated fungi and fluid-associated bacteria, fungi, and protozoa, while increasing rotation speed linearly increased copy numbers of solid-associated protozoa. Rotation at 15 rpm increased populations of fungi and protozoa in the solid rumen contents and the population of bacteria and fungi in the liquid rumen contents. In summary, this study provides insights on the biofunction of proper rumen motility (i.e., at a rotation speed of 15 rpm), such as improving feed fermentation, increasing gas emissions with decreased dissolved gas concentrations and saturation factors, and promoting microbial colonization and microbial protein synthesis, although further increase in rotation speed (i.e., to 25 rpm) decreases feed fermentation and microbial protein synthesis.
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