RESUMO
This study investigates the effects of forest aging on ectomycorrhizal (EcM) fungal community and foraging behavior and their interactions with plant-soil attributes. We explored EcM fungal communities and hyphal exploration types via rDNA sequencing and investigated their associations with plant-soil traits by comparing younger (~120 years) and older (~250 years) temperate forest stands in Northeast China. The results revealed increases in the EcM fungal richness and abundance with forest aging, paralleled by plant-soil feedback shifting from explorative to conservative nutrient use strategies. In the younger stands, Tomentella species were prevalent and showed positive correlations with nutrient availability in both the soil and leaves, alongside rapid increases in woody productivity. However, the older stands were marked by the dominance of the genera Inocybe, Hymenogaster, and Otidea which were significantly and positively correlated with soil nutrient contents and plant structural attributes such as the community-weighted mean height and standing biomass. Notably, the ratios of longer-to-shorter distance EcM fungal exploration types tended to decrease along with forest aging. Our findings underscore the integral role of EcM fungi in the aging processes of temperate forests, highlighting the EcM symbiont-mediated mechanisms adapting to nutrient scarcity and promoting sustainability in plant-soil consortia.
RESUMO
Acute promyelocytic leukemia (APL) is a subtype of acute myelocytic leukemia. Previous studies have reported a number of functions and therapeutic roles of microRNAs (miRs) in APL, and have suggested that miR-218 acts as a tumor suppressor in a number of types of human cancer; however, its role in APL remains unclear. In the present study, the expression of miR-218 and its effects on the viability and proliferation of HL-60 cells was investigated. Reverse transcription-quantitative polymerase chain reaction analysis demonstrated that miR-218 was frequently downregulated in APL marrow tissues compared with normal marrow tissues. Overexpression of miR-218 significantly inhibited cell proliferation, arrested the cell cycle in the G0/G1 phase and induced apoptosis. In addition, B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) mRNA expression was negatively associated with miR-218 expression; BMI-1 mRNA and protein expression were downregulated following transfection with miR-218 mimic. These results indicate that miR-218 functions as tumor suppressor in APL, and the miR-218/BMI-1 signaling axis may be a potential novel diagnostic marker and therapeutic target for the treatment of APL.
RESUMO
A new initiator system for polyacrylamide gel polymerization at low pH is developed. The system consists of ascorbic acid, ferrous sulfate and ammonium persulfate (AP). It is effective under acid conditions even if the concentration of the initiators is very low. To get high incorporation efficiency of acrylamide, the ratio of the AP, ascorbic acid and ferrous sulfate must be in a suitable range. The conversion efficiency has been assessed as a function of the pH of the gelling solution, in pH2.0--6.58 range. New system is able to guarantee>98% conversion in the pH 2.0--5.0 range. In contrast to the hydrogen peroxide-ascorbic acid-ferrous sulfate system widely used under acid conditions, new system gives a much higher incorporation efficiency of acrylamide, lower gel pore size at the same concentration and cross linkage and better gel mechanical property that made the gel easy handle for general purpose. The recommended concentrations of the initiators are: AP, 2.2-3.3 mmol/L, ascorbic acid, 0.91-1.82mmol/L, FeSO(4), 0.046-0.092 mmol/L.
RESUMO
AIM: To establish quantitative ELISA for soluble sB7-H3 and evaluate its clinical application. METHODS: Two mAbs of mouse anti-human sB7-H3(4H7 and 2E6)established by our lab were used. The mAb 4H7 was used as coating antibody and the 2E6 as a sandwich antibody, which recognized a different epitope and was labeled by biotin. The serum sB7-H3 levels of healthy volunteers and patients were measured by this method. RESULTS: Sandwich ELISA was established with the linear range covering from 8.192 ng/L to 2 000 ng/L. The outcomes of repeatability test, recovery test, stability test and specificity test were quite good. The increased levels of sB7-H3 were found in schistosomiasis cirrhosis, the reduced levels in severe hepatitis and the difference in both situations showed significance. CONCLUSION: A specific and sensitive sandwich ELISA is developed, the detection in liver disease indicates that the ELISA kit provides a potential tool in the clinical application.
Assuntos
Antígenos B7/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Hepatopatias/diagnóstico , Anticorpos Monoclonais/imunologia , Antígenos B7/imunologia , Humanos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Two extracellular polysaccharides, ENP1 and ENP2, were isolated from the fermentation liquid of the marine fungus Epicoccum nigrum JJY-40 by anion-exchange chromatography and gel-filtration chromatography, and their structures were investigated using chemical and spectroscopic methods including methylation analysis and NMR spectroscopy. The results demonstrated that ENP1 was composed of mannose, glucose, and galactose in the molar ratio of 5.0:2.1:1.0, and the main chain of the polysaccharide consisted of (1 â 2)-linked mannose, (1 â 3)-linked mannose, terminal mannose, (1 â 6)-linked glucose, (1 â 4)-linked glucose, and (1 â 4)-linked galactose. ENP2 was composed of mannose, galactose, glucose, and glucuronic acid in a molar ratio of 12.4:11.2:8.3:1.0, and its glycosidic linkage patterns included terminal mannose, (1 â 6)-linked glucose, (1 â 4)-linked galactose, and (1 â 3)-linked mannose. The two polysaccharides had a partially branched structure with branch point located at C-3 position of (1 â 6)-linked glucose residue. The molecular weights of ENP1 and ENP2 were 19.2 kDa and 32.7 kDa, respectively. Antioxidant properties of the two polysaccharides were evaluated with hydroxyl, superoxide, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and lipid peroxidation inhibition in vitro, and results showed that ENP2 and ENP1 had good antioxidant activities, especially ENP2. ENP2 could be effective as a potential antioxidant.
Assuntos
Antioxidantes/química , Antioxidantes/metabolismo , Ascomicetos/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Espectroscopia de Ressonância Magnética , Metilação , Espectrofotometria InfravermelhoRESUMO
Huperzine A (HupA) and huperzine B (HupB) are two medically important components of Huperzia serrata. It is difficult to obtain high yields of the separation from the plant using conventional liquid extraction and chromatography. However, this study has found that RP chromatography with cyanopropyl (CN) medium was able to separate these two analogs simultaneously from the plant extract with higher resolution. Comparison between a CN medium and a popular C18 medium demonstrated the superiority of the CN over the C18 in resolution for both analytical and preparative separation of HupA and HupB. A preparative process was developed for simultaneous purification of HupA and HupB from H. serrata. The yields on the basis of the mass of the herbal powder for HupA and HupB were 0.019 and 0.008% respectively, which were about 1.9 and 10 times of those reported in the literature.