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The objective of the present study was to investigate the potential role of immunization against INH on follicular development, serum reproductive hormone (FSH, E2, and P4) concentrations, and reproductive performance in beef cattle. A total of 196 non-lactating female beef cattle (4-5 years old) with identical calving records (3 records) were immunized with 0.5, 1.0, 1.5, or 2.0 mg [(T1, n = 58), (T2, n = 46), (T3, n = 42) and (T4, n = 36), respectively] of the pcISI plasmid. The control (C) group (n = 14) was immunized with 1.0 mL 0.9% saline. At 21d after primary immunization, all beef cattle were boosted with half of the primary immunization dose. On day 10 after primary immunization, the beef cattle immunized with INH DNA vaccine evidently induced anti-INH antibody except for the T1 group. The T3 group had the greatest P/N value peak among all the groups. The anti-INH antibody positive rates in T2, T3 and T4 groups were significantly higher than that in C and T1 groups. RIA results indicated that serum FSH concentration in T2 group increased markedly on day 45 after booster immunization; the E2 amount in T3 group was significantly increased on day 10 after primary immunization, and the levels of E2 also improved in T2 and T3 groups after booster immunization; the P4 concentration in T2 group was significantly improved on day 21 after primary immunization. Ultrasonography results revealed that the follicles with different diameter sizes were increased, meanwhile, the diameter and growth speed of ovulatory follicle were significantly increased. Furthermore, the rates of estrous, ovulation, conception, and twinning rate were also significantly enhanced. These findings clearly illustrated that INH DNA vaccine was capable of promoting the follicle development, thereby improving the behavioral of estrous and ovulation, eventually leading to an augment in the conception rates and twinning rate of beef cattle.

With the increasing spread of infectious diseases worldwide, there is an urgent need for novel strategies to combat them. Cryogenic sample electron microscopy (cryo-EM) techniques, particularly electron tomography (cryo-ET), have revolutionized the field of infectious disease research by enabling multiscale observation of biological structures in a near-native state. This review highlights the recent advances in infectious disease research using cryo-ET and discusses the potential of this structural biology technique to help discover mechanisms of infection in native environments and guiding in the right direction for future drug discovery.

Objective: To optimize the extraction process of polysaccharides from Microcos paniculata, and evaluate the antioxidant, antibacterial and pancreatic lipase inhibitory activities of Microcos polysaccharide. Methods: Ultrasonic-assisted extraction method was employed to extract polysaccharides from Microcos paniculata. The single-factor experiments were combined with orthogonal experiment to optimize the parameters of the extraction process. Antioxidant activity of Microcos polysaccharide was evaluated by DPPH, ABTS+, and OH free radical scavenging assays. The pancreatic lipase test was used to study the lipid lowering activity of Microcos polysaccharide. In addition, the antibacterial activity of Microcos polysaccharide against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae were measured by the micro broth dilution method. Results: The optimum conditions of Microcos polysaccharide were as follows: Ultrasonic power was 225 W, extraction temperature was 65 ℃, solid-liquid ratio was 1:20 (g/mL), extraction time was 35 min. Under these conditions, the yield of Microcos polysaccharide was 3.76%±0.25%. Microcos polysaccharide exhibited potent scavenging activity on DPPH, ABTS+ and OH free radicals, with the half-inhibitory concentrations were 0.1430, 0.01553 and 0.1451 mg/mL, respectively. The inhibition rate of pancreatic lipase was 36.22%±1.76%, when the concentration of Microcos polysaccharide was 5 mg/mL. The minimum inhibitory concentrations of Microcos polysaccharide against P. aeruginosa was 50 mg/mL, against E. coli and K. pneumoniae were all 100 mg/mL, against A. baumannii was 200 mg/mL. Conclusion: The extraction process optimized by single factor experiments combined with orthogonal experiment could effectively extract Microcos polysaccharides. The Microcos polysaccharide revealed good antioxidant and antibacterial as well as potential pancreatic lipase inhibitory activities, which would be valuable for in-depth developmental research.