Effect of Lignin Structure Characteristics on the Performance of Lignin Based Phenol Formaldehyde Adhesives.

As the second most abundant biopolymer, lignin remains underutilized in various industrial applications. Various forms of lignin generated from different methods affect its physical and chemical properties to a certain extent. To promote the broader commercial utilization of currently available industrial lignins, lignin sulfonate (SL), kraft lignin (KL), and organosolv lignin (OL) are utilized to partially replace phenol in the synthesis of phenol formaldehyde (PF) adhesives. The impact of lignin production process on the effectiveness of lignin-based phenolic (LPF) adhesives is examined based on the structural analysis of the selected industrial lignin. The results show that OL has more phenolic hydroxyl groups, lower molecular weight, and greater number of reactive sites than the other two types of lignins. The maximum replacement rate of phenol by OL reaches 70% w/w, resulting in organosolv lignin phenolic (OLPF) adhesives with a viscosity of 960 mPa·s, a minimal free formaldehyde content of 0.157%, and a shear strength of 1.84 MPa. It exhibits better performance compared with the other two types of lignin-based adhesives and meets the requirements of national standards.

EM-2, a natural sesquiterpene lactone from Elephantopus mollis H.B.K., enhanced the sensitivity of breast cancer cells to epirubicin by blocking protective autophagy.

BACKGROUND: EM-2, a natural sesquiterpene lactone isolated from Elephantopus mollis H.B.K., showed a good anti-breast cancer effect when combined with epirubicin (EPI). However, its synergistic sensitization mechanism remains unclear. PURPOSE: This study aimed to determine the therapeutic effect and possible synergistic mechanism of EM-2 with EPI in vivo and in vitro and to provide an experimental basis for the treatment of human breast cancer. METHODS: Cell proliferation was measured with MTT and colony formation assays. Apoptosis and reactive oxygen species (ROS) levels were examined through flow cytometry, and the expression levels of proteins related to apoptosis, autophagy, endoplasmic reticulum stress, and DNA damage were detected through Western blot analysis. Moreover, the caspase inhibitor Z-VAD-FMK, autophagy inhibitors bafilomycin A1 and chloroquine, ER stress inhibitor 4-phenylbutyric acid, and ROS scavenger N-acetyl cysteine were applied to verify signaling pathways. Breast cancer cell lines were used to evaluate the antitumor functions of EM-2 and EPI in vitro and in vivo. RESULTS: We demonstrated that in MDA-MB-231 and SKBR3 cells, the IC50 of EPI combined with EM-2 (IC20) was 37.909 and 33.889 times lower than that of EPI alone, respectively. Further study verified that in EPI-resistant lines (MDA-MB-231/EPI), the IC50 of EPI combined with EM-2 (IC20) was 26.305 times lower than that of EPI alone. Mechanistically, EM-2 could reverse the protective effect of EPI against autophagy in SKBR3 and MDA-MB-231 cells. EM-2 and EPI could trigger ER stress. When EM-2 and EPI were used in combination, ER stress was continuously activated, and ER stress-mediated apoptosis was induced. Meanwhile, EM-2 combined with EPI promoted DNA damage then induced apoptosis. In vivo, the volume of breast cancer xenografts in the combination group was smaller than that in the control, EM-2, and EPI groups. Immunohistochemical experiments demonstrated that the combination of EM-2 and EPI could block autophagy and promote ER stress in vivo. CONCLUSION: EM-2 enhances the sensitivity of MDA-MB-231, SKBR3, and EPI-resistant cells to EPI.

Knockdown of the SELENOK gene induces ferroptosis in cervical cancer cells.

Selenoprotein K (SELENOK) is one of the endoplasmic reticulum (ER) proteins that mainly functions in the regulation of ER stress, calcium flux, and antioxidant defense. Reactive oxygen species (ROS) is one of the key indicators of ferroptosis, and SELENOK inhibition could disrupt ROS balance, and consequently might cause ferroptosis. However, there are no previous studies about the mechanism of SELENOK in ferroptosis by regulating ROS. In this study, we report the effect of SELENOK inhibition on cell proliferation, viability, iron recycling-associated proteins, ROS, antioxidant enzymes, and lipid peroxidation of cervical cancer cells (HeLa cells). The results showed that ROS levels and iron-dependent lipid peroxidation were significantly enhanced, whereas cell viability and proliferation were significantly downregulated, and resulted in marked reductions in tumor size after SELENOK knockdown. SELENOK knockdown also caused steep decreases in glutathione peroxidase 4/glutathione levels and deterioration in ROS scavenging ability, and exacerbated ferroptosis in HeLa cells. Our findings elucidated that SELENOK knockdown could shrink tumor size by regulating ferroptosis, which might provide a theoretical basis for treating cervical cancer.

[Efficacy of the Sentinel Mouse Method in Monitoring Schistosoma japonicum Infection in Key #br# Water Areas of Hanchuan City].

Objective: To understand the water infectivity of schistosomes in key water areas of Hanchuan City, and explore the use of sentinel mice in surveillance and forecast of schistosomiasis. Methods: Surveillance and forecast sites were set up in North Han River, Diaocha Lake, and Miaowu Ditch in 2014. Sentinel mice （male Kunming mice, n=20 in each site） were placed there within the first ten-day period of June and September, respectively. Field detections lasted 4 h each, for a total of 2 days. The loss and death rates of mice were recorded. Humans and livestocks with activities in these sites were also examined for schistosome infection. The sentinel mice recovered were raised in laboratory for 35 days, dissected, and examined for liver granulomas and adult worm counting. The distribution of sites with positive detections and their infection status were analyzed. Emergency measures were taken in the positive sites. Results: A total of 13（5 sites in North Han River, 5 in Diaocha Lake, and 3 in Miaowu Ditch） surveillance and forecast sites were set up. No infected snail was detected in any of these sites in spring 2014. The detection rate of living snails in North Han River （18.7%, 224/1 201) was significantly higher than that in Diaocha Lake（12.8%, 852/6 644） and in Miaowu Ditch （6.4%, 202/3 147）（P<0.01）. Of the 520 mice placed, 6 were lost, and 514 were recovered, among which 4 mice died during laboratory raising. The remaining 510 sentinel mice were then dissected, revealing infection in 4 mice, with a positive rate of 0.8%. Twenty-seven Schistosoma japonicum worms were collected, and the mean worm burden of positive mice was 6.8 worms per mouse. Three sites (Sansi village, Kangjia village and Doubu village) were found to be positive sites of infection in September, with the detailed number of 2, 1 and 0 in North Han River, Diaocha Lake, and Miaowu Ditch respectively, with a positive rate of 1.5% （3/197）, 0.5% （1/195） and 0 （0/118） in sentinel mice （P>0.05）. In addition, among the 22 cattle found in the 13 sites, 2 were infected with schistosomes; and among the 62 fishermen and boatmen, 2 were infected. Emergency measures were taken in the three positive sites, and no high endemicity occurred. Conclusion: The monitoring of sentinel mice infections can improve the sensitivity of the surveillance and forecast system of schistosomiasis. The infected fishermen and cattle remain the major source of schistosomiasis transmission in Hanchuan City.

[Influence of SGHWJN particles on mediators of inflammation in esophageal tissues of rat with reflux esophagitis].

OBJECTIVE: To study the influence of SGHWJN particles on inflammation and the mediators of inflammation in esophageal tissues of rat with reflux esophagitis. METHOD: Fifty SD rats were randomly divided into 5 groups, namely, a control group, a sham-operated group, a model group, a SGHWJN particles group and a PPI group. Reflux esophagitis was induced by adopting partial pyloric ligation plus cardiomyotomy. One week later, the rats were orally administered twice daily for 28 days. Pathological changes of esophagus mucous membrane were evaluated by using HE staining and Harry S. Cooper's method in every groups. MDA and SOD contents in esophageal tissues were measured by colorimetric method. Expression of TNF-alpha in esophageal tissues were examined by real-time fluorescent quantitative reverse transcriptase polymerase chain reaction (RT-FQ-PCR) with SYBR Green. RESULT: Model group, esophageal inflammation scores, expression of TNF-alpha in esophageal tissues and MDA contents compared with the normal group and sham operation group were significantly higher (P < 0.05). SOD contents in the esophageal tissues of the model group was significantly lower than that of control group and sham-operated group (P < 0.05). SGHWJN particles group and PPI group of esophageal tissue inflammation scores, expression of TNF-a in esophageal tissues and MDA levels than those in model group decreased significantly (P < 0.05). SOD content was significantly higher than that of model group (P < 0.05), SGHWJN particles group and PPI group showed no statistically significant difference between the above-mentioned indicators. The above-mentioned indicators showed no statistically significant difference between the normal group and sham-operated group. MDA content and expression of TNF-alpha in esophageal tissue was positively correlated with inflammatory scores of model group (r = 0.813). Model group esophageal tissue SOD content and inflammation scores were negatively correlated (r = -0.847). Esophageal tissue SOD levels were negatively correlated with MDA levels (r = -0.863). CONCLUSION: SGHWJN particles can effectively inhibit inflammation in rat with reflux esophagitis through regulating TNF-alpha, SOD and MDA.