The coinfection of respiratory viruses and bacteria is a major cause of morbidity and mortality worldwide, despite the development of vaccines and powerful antibiotics. As a macromolecule that is difficult to absorb in the gastrointestinal tract, a homogeneous polysaccharide from Houttuynia cordata (HCPM) has been reported to exhibit anti-complement properties and alleviate influenza A virus (H1N1)-induced lung injury; however, the effects of HCPM without in vitro antiviral and antibacterial activities on more complicated pulmonary diseases resulting from viral-bacterial coinfection remains unclear. This study established a representative coinfection murine pneumonia model infected with H1N1 (0.2 LD₅₀) and methicillin-resistant Staphylococcus aureus (MRSA, 10⁷ CFU). HCPM significantly improved survival rate and weight loss, and ameliorated gut-lung damage and inflammatory cytokine production. Interestingly, the therapeutic effect of HCPM on intestinal damage preceded that in the lungs. Mechanistically, HCPM inhibited the overactivation of the intestinal complement (C3a and C5a) and suppressed the activation of the NLR family pyrin domain-containing 3 (NLRP3) pathway, which contributes to the regulation of the Treg/Th17 cell balance in the gut-lung axis. The results indicate the beneficial effects of an anti-complement polysaccharide against viral-bacterial coinfection pneumonia by modulating crosstalk between multiple immune regulatory networks.

Objective To observe the changes of potassium ion (K+), lactic acid (Lac) and glucose (Glu) in swine with traumatic hemorrhagic shock (THS) inside the dry-heat environment and to explore its possible mechanism. Methods A total of 40 local Landrace piglets were randomly(random number) divided equally into 4 groups: the normal temperature sham operation group (NS), the normal temperature traumatic hemorrhagic shock group (NTHS), the dry-heat sham operation group (DS group) and the dry-heat traumatic hemorrhagic shock group (DTHS). The experiment was carried out in the artifi cia climate cabin simulated the special environment of northwest of China. After exposed to their respective environment[dry-heat environment: (40.5±0.5), plus(10±2)% humidity; normal temperature environment: (25±0.5), plus(35±5)% humidity] for 3 h. Laparotomy were performed in swine of all groups, and then splenectomy and partial hepatectomy were performed only in NTHS and DTHS. The process of exsanguination from the external iliac artery was established to make the MAP reaching to 40-50 mmHg, and thus the traumatic hemorrhagic shock model of swine was successfully made. Blood samples were collected from external iliac artery at different intervals including the time just after exposure for 3 h and the successful establishment of traumatic hemorrhagic shock model (0 h) and then every 30 min after 0 h, serum levels of K+, Lac and Glu were detected. The features of varied serum K+, Lac and Glu were observed in each group. All data were statistically analyzed using One-way ANOVA and Pearson correlation analysis. Results After exposed , the level of serum K+inside the dry-heat environment was higher than that of swine inside the normal temperature group ( P<0.01), however the Glu level was lower in the swine inside dry-heat environment than that of swine inside the normal temperature ( P<0.01).The level of serum K+and Lac of DTHS group were rapidly increased from the establishment of the model to the death in about 3 h, while those of NTHS group were increased slowly. The level of K+and Lac were positively correlated in the two groups amd the correlation coeffi cient were rDTHS=0.927 (P<0.01) and rNTHS=0.539 (P<0.01),respectively. The level of Glu was progressively decrease in DTHS group, while in NTHS group, it was not noticeable. The level of K+and Glu were negatively correlated in the two group, the correlation coeffi cient were rDTHS=-0.804 (P<0.01) and rNTHS=0.420 (P<0.01),respectively. Conclusions The changes of serum K+, Lac and Glu occurred sooner and more obvious in traumatic hemorrhagic shock models inside dry heat environment (DTHS) group than those in NTHS group. The level of serum K+positively correlated with Lac, however, negatively correlated with Glu, which suggested that hyperkalemia and acidosis should be paid more attention to the treatment of traumatic hemorrhagic shock inside the dry heat environment, and the hypoglycemia should be treated at the same time.

A new dibenzocyclooctadiene lignan, renchangianin E (1) was isolated from the stems of Kadsura renchangiana. Its structure and stereochemistry were elucidated by spectroscopic methods, including 2D-NMR techniques.

To obtain single chain variable fragment (scFv) and bivalent single chain variable fragment (bsFv) against transferrin receptor, up-stream and down-stream primers were designed according to the complementary sequences of FR1 region of variable heavy (VH) and FR4 of variable light (VL), respectively, which contained inter-linker G4S and the restriction endonuclease SfiI, AscI and NotI. Two pieces of scFv fragments were first amplified through PCR and then inserted into plasmid pAB1, which could express scFv protein once induced by IPTG in the host bacteria. To express scFv and bsFv, E. coli TG1 was cultured in LB broth and was induced by IPTG. The restriction enzyme digestion map and DNA sequencing demonstrated that scFv and bsFv genes were successfully inserted into the expression plasmid. SDS-PAGE and Western blotting revealed the protein band at 35kD and 60kD, which were consistent with the molecular weight of scFv and bsFv respectively. Flow cytometry showed that scFv and bsFv harbored the specific binding activity with TfR expressed in various tumor cells, and the avidity of bsFv was higher than that of the parent scFv.
Base Sequence ; Cloning, Molecular ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Genetic Vectors/genetics ; Hep G2 Cells ; K562 Cells ; Molecular Sequence Data ; Receptors, Transferrin/*immunology ; Recombinant Fusion Proteins/biosynthesis ; Recombinant Fusion Proteins/genetics ; Single-Chain Antibodies/*biosynthesis ; Single-Chain Antibodies/genetics

To obtain single chain variable fragment (scFv) and bivalent single chain variable fragment (bsFv) against transferrin receptor, up-stream and down-stream primers were designed according to the complemenary sequences of FR1 region of variable heavy (VH) and FR4 of variable light (VL), respectively, which contained inter-linker G4S and the restriction endonuclease Sill, AscI and NotI. Two pieces of scFv fragments were first amplified through PCR and then inserted into plasmid pAB 1, which could express scFv protein once induced by IPTG in the host bacteria. To express scFv and bsFv, E. coli TG1 was cultured in LB broth and was induced by IPTG The restriction enzyme digestion map and DNA sequencing demonstrated that scFv and bsFv genes were successfully inserted into the expression plasmid. SDS-PAGE and Western blotting revealed the protein band at 35kD and 60kD, which were consistent with the molecular weight of scFv and bsFv respectively.Flow cytometry showed that scFv and bsFv harbored the specific binding activity with TfR expressed in various tumor cells, and the avidity of bsFv was higher than that of the parent scFv.