Fabrication and Characterization of π-π Stacking Peptide-Contained Double Network Hydrogels

Since the physical properties are similar to native extracellular matrices, double network (DN) hydrogels have been studied extensively in the tissue engineering. However, the double chemical crosslinked DN hydrogel is limited by poor fatigue resistance. π-π stacking is a non-covalent bonding interaction, which is essential to maintain and self-assemble the three-dimensional structure of biological proteins and nucleic acids. In this study, a robust polyethylene glycol diacrylate (PEGDA)/FFK hybrid DN hydrogel was prepared by Michael addition and π-π stacking. The hybrid DN hydrogels with π-π stacking interactions have excellent mechanical strength and fatigue resistance. The DN FFK/PEGDA hydrogels reveal great biocompatibility and hemocompatibility. The DN hydrogels containing π-π stacking have the potential to fabricate robust hybrid DN hydrogels in drug release and tissue engineering.

Prodigiosin improves acute lung injury in a rat model of rheumatoid arthritis via down-regulating the nuclear factor kappaB/nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 signaling pathway

Prodigiosin (PRO) is a natural pigment that possesses multiple activities, covering anti-tumor, anti-bacteria, and immunosuppression. This study is committed to an investigation into the underlying function and the certain mechanism of PRO in acute lung damage followed by rheumatoid arthritis (RA). Cecal ligation and puncture (CLP) method was implemented to trigger a rat lung injury model, and a rat RA model was constructed with the help of rheumatoid arthritis induced by collagen. Prodigiosin was administered to intervene in the rats' lung tissues post-treatment. The expressions of pro-inflammatory cytokines (interleukin-1beta, interleukin-6, tumor necrosis factor-alpha, and monocyte chemoattractant protein-1 were determined. Western blot was carried out to detect anti-surfactant protein A (SPA), anti-surfactant protein D (SPD), apoptosis-concerned proteins (Bax, cleaved-caspase-3, Bcl-2, and pro-caspase-3), the nuclear factor-kappaB (NF-κB)/nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3)/apoptosis-concerned speckle-like protein (ASC)/caspase-1 signaling pathway. The apoptosis of pulmonary epithelial tissues was checked via TUNEL assay, as corresponding kits were adopted to confirm the activity of lactate dehydrogenase (LDH) and the levels of oxidative stress markers malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Prodigiosin ameliorated the pathological damage of CLP rats. Prodigiosin alleviated the production of inflammatory and oxidative stress mediators. In the RA rats with acute lung injury, prodigiosin hampered apoptosis in the lung. Mechanistically, prodigiosin hinders the activation of the NF-κB/NLRP3 signaling axis. In conclusion: prodigiosin relieves acute lung injury in a rat model of rheumatoid arthritis by exerting anti-inflammatory and anti-oxidative effects through downregulating the NF-κB/NLRP3 signaling axis.

Prodigiosin improves acute lung injury in a rat model of rheumatoid arthritis via down-regulating the nuclear factor kappaB/nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 signaling pathway

Prodigiosin (PRO) is a natural pigment that possesses multiple activities, covering anti-tumor, anti-bacteria, and immunosuppression. This study is committed to an investigation into the underlying function and the certain mechanism of PRO in acute lung damage followed by rheumatoid arthritis (RA). Cecal ligation and puncture (CLP) method was implemented to trigger a rat lung injury model, and a rat RA model was constructed with the help of rheumatoid arthritis induced by collagen. Prodigiosin was administered to intervene in the rats' lung tissues post-treatment. The expressions of pro-inflammatory cytokines (interleukin-1beta, interleukin-6, tumor necrosis factor-alpha, and monocyte chemoattractant protein-1 were determined. Western blot was carried out to detect anti-surfactant protein A (SPA), anti-surfactant protein D (SPD), apoptosis-concerned proteins (Bax, cleaved-caspase-3, Bcl-2, and pro-caspase-3), the nuclear factor-kappaB (NF-κB)/nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3)/apoptosis-concerned speckle-like protein (ASC)/caspase-1 signaling pathway. The apoptosis of pulmonary epithelial tissues was checked via TUNEL assay, as corresponding kits were adopted to confirm the activity of lactate dehydrogenase (LDH) and the levels of oxidative stress markers malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Prodigiosin ameliorated the pathological damage of CLP rats. Prodigiosin alleviated the production of inflammatory and oxidative stress mediators. In the RA rats with acute lung injury, prodigiosin hampered apoptosis in the lung. Mechanistically, prodigiosin hinders the activation of the NF-κB/NLRP3 signaling axis. In conclusion: prodigiosin relieves acute lung injury in a rat model of rheumatoid arthritis by exerting anti-inflammatory and anti-oxidative effects through downregulating the NF-κB/NLRP3 signaling axis.

Predisposing Factors for Person-to-Person Transmission of Severe Fever with Thrombocytopenia Syndrome Bunyavirus

Person-to-person transmission of severe fever with thrombocytopenia syndrome virus (SFTSV) is a new threat to human health. Here we report an outbreak of nosocomial person-to-person transmission of SFTS. Among eight persons with face-to-face contact distance ≤50 centimeters and/or exposure time ≥30 minutes to the index patient, six became were infected. Only one of the 17 persons with exposure distance ≥ 50 centimeters and exposure time ≤ 30 minutes was infected (75% vs. 6.25%, p <0.001). Epidemiological investigation revealed high viral load, bloody secretions and bleeding, exposure time and distance as the key factors in person-to-person transmission.

[Role of histological evaluation of periprosthetic tissue in diagnosis of periprosthetic joint infection]

Objective: To evaluate the role of histologicalpathology in the diagnosis of periprosthetic joint infection. Methods: A total of 145 cases of joint arthroplasty during October 2017 and October 2018 from Beijing Jishuitan Hospital were collected. There were 23 cases of infection, including knee joint arthroplasty (12 cases) and hip arthroplasty (11 cases). There were 17 females and 6 males. Patients' age ranged from 39 to 76 years (mean 63 years). The infection was diagnosed if there were >5 neutrophils per high power field in at least 5 high power field. The permanent sections were examined twice separately by two pathologists, and the interval time of histologic examination was at least two weeks. Sensitivity (SE), specificity (SP), positive predictivevalue (PPV), and negative predictive value (NPV) were calculated. The consistency evaluation of histologic examination of two pathologists was calculated by Kappa analysis. Results: The neutrophil cells could locate scattered or focally in the synovium tissue of periprosthetic joint infection. Somewhere, the infiltration of vessel and the perivascular distribution could also exist. Opportunity coincidence rate between two pathologists was 91.3% (Kappa=0.817). The results showed that SE was 60.9%, SP was 100.0%, NPV was 93.1%, PPV was 100.0%. Conclusions: The presence of polymorphonuclear cells in histologic examination is correlated with infection. There was high consistency between histologic examination and clinical diagnosis of joint arthroplasty.

The effect of transesophageal echocardiography in the surgical treatment of tetralogy of Fallot

OBJECTIVE

To investigate the effect of transesophageal echocardiography (TEE) in the surgical treatment of tetralogy of Fallot.

PATIENTS AND METHODS

98 patients with tetralogy of Fallot received and cured by Zhengzhou Cardiovascular Hospital (Zhengzhou No. 7 People's Hospital) from January 2015 to January 2017 were selected as the study objects. All patients were examined by TEE before surgery, and the pulmonary artery index (PAI) and pulmonary vein index (PVI) were measured, so as to analyze the effect of TEE in the surgical treatment of tetralogy of Fallot. Among the 98 patients, 12 patients were diagnosed with intensive care unit (ICU) retention, 23 patients were diagnosed with respirator assisted respiration extension, 8 patients were diagnosed with low cardiac output syndrome, and 10 patients were diagnosed with respiratory tract infection, which indicated that TEE could diagnose conditions after radical operation of tetralogy of Fallot.

RESULTS

The calculation results showed that the PAI was (171.37±58.39) mm2/m2 and the PVI was (282.46±54.37) mm2/m2. The Pearson correlation analysis showed that the correlation between them was good (r=0.821, p<0.001). TEE had good specificity and sensitivity in the diagnosis of respirator assisted respiration extension, ICU retention, and low cardiac output syndrome after radical surgery of tetralogy of Fallot.

CONCLUSIONS

TEE can predict the occurrence of respirator assisted respiration extension, ICU retention and low cardiac output syndrome of patients after radical surgery by evaluating the PAI and PVI of patients with tetralogy of Fallot.