Co-Expression of Pig IL-2 and Fusion Bovine Cathelicidin Gene by Recombinant Plasmids in Yeast and Their Promotion of Mouse Antibacterial Defense.

In order to develop an effective and safe immunomodulator to enhance the antimicrobial bioactivity and immunity of animals against infectious bacterial diseases, a recombinant plasmid pGAPZαA-IL2-B co-expressing pig interleukin-2 (PIL-2) and fused bovine cathelicidin (FBC) genes were constructed using the 2A self-cleavage technique. After being expressed in Pichia pastoris strain SMD1168, the recombinant yeast was administered orally to 5-week-old female ICR mice. The control mice were similarly dosed with P. pastoris with a blank plasmid or FBC recombinant plasmid alone. At 28 days post-treatment, the mice were challenged intraperitoneally with virulent strains of either E. coli or S. aureus. Compared with the control groups, the mice that received recombinant yeast co-expressing PIL-2/FBC manifested significant increases in the number of leukocytes, CD4+ and CD8+ T cells, IgG, and the gene expressions of TLRs(TLR1,4,6,9), antimicrobial peptides(CRP4 and CRAMP) and cytokines (IL-2, 4, 6, 7, 12, 15, 23, IFN-γ, and TNF-α) in the blood. Furthermore, the treated mice displayed significantly higher survival than the other two control groups after the challenge. These results suggest that the antimicrobial activity and immunity of animals can be effectively enhanced by the in vivo co-expression of IL-2 and the FBS gene, which can facilitate the development of new immunopotentiation molecules to overcome the infection of antibiotic-resistant bacteria.

Influence of algal organic matter of Microcystis aeruginosa on ferrate decay and MS2 bacteriophage inactivation.

Surface water contaminated with algae and with enteric viruses is a global problem. When surface water is used as a drinking water source, it is important to know the influence of algal organic matter on the disinfection of viruses. In this work, we studied the disinfection efficacy of ferrate and the influence of algal organic matter on the disinfection. We determined the MS2 inactivation kinetics by ferrate under three pH conditions (7, 8, and 8.7). The experimental results and pH-dependent calculation suggest that H2FeO4 and HFeO4- are 1935 and 8 times as effective as FeO42- in MS2 inactivation. We also found that intracellular algal organic matter (IAOM) had a stronger effect on MS2 inactivation kinetics than extracellular algal organic matter (EAOM) suggesting that IAOM led to higher consumption of Fe(VI) compared to EAOM. At pH 8.7, while significant consumption of FeO42- by as low as 8 mg C/L of EAOM and 2 mg C/L of IAOM was detected, MS2 inactivation was negatively influenced only when 13 mg C/L of IAOM present. This study showed that it is important to control pH and to determine the concentration of algal organic matter if ferrate is used for disinfection of surface water contaminated with algae.

Genomic Characterization and Probiotic Potency of Bacillus sp. DU-106, a Highly Effective Producer of L-Lactic Acid Isolated From Fermented Yogurt.

Bacillus sp. DU-106, a newly isolated member of Bacillus cereus group, exhibits the predominant ability to produce L-lactic acid. The probiotic potency of test strain revealed its survivability at acidic pH, bile salts and viability in simulated gastric juice in vitro. The acute oral toxicity test indicated its no toxicity to laboratory mice in vivo. We further determined the complete genome of strain DU-106 to understand genetic basis as a potential probiotic. It has a circular chromosome and three plasmids for a total genome 5,758,208 bp in size with a G + C content of 35.10%. Genes associated with lactate synthesis were found in the DU-106 genome. We also annotated various stress-related, bile salt resistance, and adhesion-related domains in this strain, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival under gastrointestinal tract. Moreover, strain DU-106 genome lacks the virulence genes encodes cereulide synthetase, enterotoxin FM, and cytotoxin K. These phenotypic and genomic probiotic potencies facilitate its potential candidate as probiotic starter in food industry.

Effects of solution chemistry on the sunlight inactivation of particles-associated viruses MS2.

The inactivation efficacy of bacteriophage MS2 by simulated sunlight irradiation was investigated to understand the effects of MS2 aggregation and adsorption to particles in solutions with different components. Kaolinite and Microcystis aeruginosa were used as model inorganic and organic particles, respectively. Lower pH and di-valent ions (Ca2+) were main factors on the aggregation and inactivation of MS2. In the presence of both particles, there was no significant impact on the MS2 inactivation efficacy by kaolinite (10-200mM) or Microcystis aeruginosa (102-105Cells/mL) in 1mM NaCl at pH 7. However at lower pH 3, MS2 aggregates formed in the particle-free and kaolinite-containing solutions, caused lower inactivation since the outer viruses of aggregation protect the inner viruses. In addition, more MS2 adsorbed on Microcystis aeruginosa at lower pH (3 and 4). Microcystis aeruginosa would act as a potential photosensitizer for ROS production to inactivate the adsorbed MS2, since extracellular organic matter (EOM) of Microcystis aeruginosa was detected in this study, which has been reported to produce ROS under solar irradiation. At pH 7, Na+ had no effect on the inactivation of MS2, because MS2 was stable and dispersed even at 200mM Na+. MS2 aggregated and adsorbed on particles even at 10mM Ca2+ and led to lower inactivation. Kaolinite cannot offer enough protection to adsorbed MS2 as aggregation and Microcystis aeruginosa acts as potential photosensitizer to produce ROS and inactivate the adsorbed MS2 at high concentration of Ca2+. In particle-free solution, SRNOM inhibited MS2 inactivation by shielding the sunlight and coating MS2 to increase its survival.

[Protective effect of 2,4-dihydroxybenzophenone on cocaine-induced hepatotoxicity and neurotoxicity in mice].

OBJECTIVE: To investigate the protective effect of 2,4-dihydroxybenzophenone(BP-1) on acute hepatotoxicity and neurotoxicity induced by cocaine in mice, and its possible mechanism. METHODS: Male ICR mice were pretreated with BP-1(100,200,400 mg/kg, ig, 4 d), cocaine(75 mg/kg) was injected 30 minutes after BP-1 administration on day 4.Twenty-four hours after the injection of cocaine, the serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were assayed by HITACHI-7170A automatic analyzer. The content of malondialdehyde (MDA) and the content of reduced glutathione (GSH) and oxidized glutathione (GSSG) were examined, and the ratio of GSH/GSSG was calculated, and histopathological analyses were also made. Male ICR mice were pretreated with BP-1(100,200,400 mg/kg, ig, 3 d), cocaine(20 mg/kg) was injected 30 minutes after BP-1 administration on day 3.The locomotor activity during 0-180 minutes of mice was recorded individually for each animal immediately after cocaine injection. RESULTS: After the administration of cocaine, compared with corresponding solvent group, the activities of ALT [(1 571±1 161) IU/L vs. (30±16) IU/L, P<0.05], AST [(408±226) IU/L vs. (101±12) IU/L, P<0.05] and LDH [(3 963±1 431) IU/L vs. (1 935±287) IU/L, P<0.05] were significantly increased; the ratio of GSH/GSSG [(5.11±0.63) vs. (6.88±1.13),P<0.05] was decreased and the content of MDA [(1.97±1.36) µ mol/g vs. (0.07±0.06) µmol/g, P<0.01] was significantly increased. With the pretreatment of BP-1, compared with cocaine treatment group, the serum ALT [(112±96 )IU/L, (54±20) IU/L, (35±15) IU/L, P<0.05],AST [(130±33) IU/L,(107±5) IU/L, (99±9) IU/L, P<0.05] and LDH [(1 667±564) IU/L, (1 507±365) IU/L, (1 249±349) IU/L, P<0.01] were significantly decreased, the ratios of GSH/GSSG [(7.33±1.84), (9.28±0.67), (10.5±1.20), P<0.05] were increased and the contents of MDA [(1.82±1.19)µmol/g, (0.49±0.31)µmol/g, (0.35±0.30) µmol/g, P<0.05] were decreased. Significant amelioration in liver histopathology was also presented in the BP-1 treatment groups. The BP-1 pretreated mice showed significant reduction in activity counts evoked by cocaine (20 mg/kg), and shorten the time for activity counts to become normal. CONCLUSION: BP-1 has protective effect on acute hepatotoxicity and neurotoxicity of mice induced by cocaine. Its mechanisms might be associated with its antioxidant activity.

[Study of the appearance difference of lower complete denture between functional and anatomic impression techniques].

PURPOSE: To compare the difference in oblique external ridge, oblique internal ridge and alveolar process crest of lower complete denture base made through functional impression and anatomic impression techniques. METHODS: Fifteen patients were chosen to treat with two kinds of complete dentures through functional impression and anatomic impression technique respectively. 3D laser scanner was used to scan the three-dimensional model of the denture base and the differences of the surface structural between two techniques in alveolar process crest, external and internal oblique ridges were analyzed, using paired t test with SPSS 12.0 software package. RESULTS: Between the two techniques, there were significant differences in the areas of internal and external oblique ridge(P<0.01); there was no significant difference in the main support areas(P>0.05). CONCLUSIONS: The results explain why there is less tenderness when functional impression technique is applied. The differences measured also indicate that sufficient buffering should be made in external and internal oblique ridge areas in clinic.

[Clinical evaluation of unanatomic and long centric occlusal complete dentures].

PURPOSE: To compare and analyze the effect of unanatomic and long centric complete occlusal denture on the satisfaction of edentulous patients and mastication. METHODS: Sixty edentulous patients with severe resorption of residual ridge were treated with unanatomic occlusal and long centric occlusal complete dentures. One month and three months after wearing dentures, the satisfaction evaluation from edentulous patients for the different complete dentures was analyzed, and the masticatory stroke was tested, the masticatory efficiency of the two complete dentures was detected by light absorption method. SPSS 11.0 software package was used for data analysis. RESULTS: Compared with unanatomic occlusal dentures, appearance, pronunciation and comfort of long centric occlusal denture wearers were not significantly different for one and three months (P>0.05). But the masticatory function of long centric occlusal denture wearers was significantly better than anatomic occlusal denture wearers (P<0.05). CONCLUSIONS: Modified occlusion is feasible for restoration of masticatory efficiency of edentulous patients using long centric occlusal complete dentures, and they are more acceptable by edentulous patients with severe resorption of residual ridge.