OBJECTIVE: CRISPR-Cas protects bacteria from exogenous DNA invasion and is associated with bacterial biofilm formation and pathogenicity. METHODS: We analyzed the type I-F CRISPR-Cas system of Legionella pneumophila WX48, including Cas1, Cas2-Cas3, Csy1, Csy2, Csy3, and Cas6f, along with downstream CRISPR arrays. We explored the effects of the CRISPR-Cas system on the in vitro growth, biofilm-forming ability, and pathogenicity of L. pneumophila through constructing gene deletion mutants. RESULTS: The type I-F CRISPR-Cas system did not affect the in vitro growth of wild-type or mutant strains. The biofilm formation and intracellular proliferation of the mutant strains were weaker than those of the wild type owing to the regulation of type IV pili and Dot/Icm type IV secretion systems. In particular, Cas6f deletion strongly inhibited these processes. CONCLUSION The type I-F CRISPR-Cas system may reduce biofilm formation and intracellular proliferation in L. pneumophila.
Legionella pneumophila/pathogenicity* ; CRISPR-Cas Systems ; Biofilms/growth & development* ; Phenotype ; Bacterial Proteins/metabolism* ; Gene Deletion

Sleep-wake disorder is one of the most common nonmotor symptoms of Parkinson's disease (PD). Melatonin has the potential to improve sleep-wake disorder, but its mechanism of action is still unclear. Our data showed that melatonin only improved the motor and sleep-wake behavior of a zebrafish PD model when melatonin receptor 1 was present. Thus, we explored the underlying mechanisms by applying a rotenone model. After the PD zebrafish model was induced by 10 nmol/L rotenone, the motor and sleep-wake behavior were assessed. In situ hybridization and real-time quantitative PCR were used to detect the expression of melatonin receptors and lipid-metabolism-related genes. In the PD model, we found abnormal lipid metabolism, which was reversed by melatonin. This may be one of the main pathways for improving PD sleep-wake disorder.
Animals ; Zebrafish ; Melatonin/pharmacology* ; Lipid Metabolism/drug effects* ; Disease Models, Animal ; Rotenone/pharmacology* ; Sleep Wake Disorders/metabolism* ; Parkinson Disease/metabolism* ; Motor Activity/drug effects* ; Sleep/drug effects*

COVID-19 has been prevalent for three years. The virulence of SARS-CoV-2 is weaken as it mutates continuously. However, elderly patients, especially those with underlying diseases, are still at high risk of developing severe infections. With the continuous study of the molecular structure and pathogenic mechanism of SARS-CoV-2, antiviral drugs for COVID-19 have been successively marketed, and these anti-SARS-CoV-2 drugs can effectively reduce the severe rate and mortality of elderly patients. This article reviews the mechanism, clinical medication regimens, drug interactions and adverse reactions of five small molecule antiviral drugs currently approved for marketing in China, so as to provide advice for the clinical rational use of anti-SARS-CoV-2 in the elderly.

ObjectiveTo explore the guidance value of “treatment of disease in accordance with three conditions” theory in the prevention and treatment of corona virus disease 2019（COVID-19） based on the differences of syndromes and traditional Chinese medicine（TCM） treatments in COVID-19 patients from Xingtai Hospital of Chinese Medicine of Hebei province and Ruili Hospital of Chinese Medicine and Dai Medicine of Yunnan province and discuss its significance in the prevention and treatment of the unexpected acute infectious diseases. MethodDemographics data and clinical characteristics of COVID-19 patients from the two hospitals were collected retrospectively and analyzed by SPSS 18.0. The information on formulas was obtained from the hospital information system （HIS） of the two hospitals and analyzed by the big data intelligent processing and knowledge service system of Guangdong Hospital of Chinese Medicine for frequency statistics and association rules analysis. Heat map-hierarchical clustering analysis was used to explore the correlation between clinical characteristics and formulas. ResultA total of 175 patients with COVID-19 were included in this study. The 70 patients in Xingtai，dominated by young and middle-aged males，had clinical symptoms of fever， abnormal sweating，and fatigue. The main pathogenesis is stagnant cold-dampness in the exterior and impaired yin by depressed heat， with manifest cold， dampness， and deficiency syndromes. The therapeutic methods highlight relieving exterior syndrome and resolving dampness， accompanied by draining depressed heat. The core Chinese medicines used are Poria，Armeniacae Semen Amarum，Gypsum Fibrosum，Citri Reticulatae Pericarpium，and Pogostemonis Herba. By contrast，the 105 patients in Ruili， dominated by young females， had atypical clinical symptoms， and most of them were asymptomatic patients or mild cases. The main pathogenesis is dampness obstructing the lung and the stomach， with obvious dampness and heat syndromes. The therapeutic methods are mainly invigorating the spleen， resolving dampness， and dispersing Qi with light drugs. The core Chinese medicines used are Poria，Atractylodis Macrocephalae Rhizoma，Glycyrrhizae Radix et Rhizoma，Coicis Semen，Platycodonis Radix，Lonicerae Japonicae Flos， and Pogostemonis Herba. ConclusionThe differences in clinical characteristics， TCM syndromes， and medication of COVID-19 patients from the two places may result from different regions，population characteristics， and the time point of the COVID-19 outbreak. The “treatment of disease in accordance with three conditions” theory can help to understand the internal correlation and guide the treatments.

Objective: To explore the effect of perioperative chemotherapy on the prognosis of gastric cancer patients under real-world condition. Methods: A retrospective cohort study was carried out. Real world data of gastric cancer patients receiving perioperative chemotherapy and surgery + adjuvant chemotherapy in 33 domestic hospitals from January 1, 2014 to January 31, 2016 were collected. Inclusion criteria: (1) gastric adenocarcinoma was confirmed by histopathology, and clinical stage was cT2-4aN0-3M0 (AJCC 8th edition); (2) D2 radical gastric cancer surgery was performed; (3) at least one cycle of neoadjuvant chemotherapy (NAC) was completed; (4) at least 4 cycles of adjuvant chemotherapy (AC) [SOX (S-1+oxaliplatin) or CapeOX (capecitabine + oxaliplatin)] were completed. Exclusion criteria: (1) complicated with other malignant tumors; (2) radiotherapy received; (3) patients with incomplete data. The enrolled patients who received neoadjuvant chemotherapy and adjuvant chemotherapy were included in the perioperative chemotherapy group, and those who received only postoperative adjuvant chemotherapy were included in the surgery + adjuvant chemotherapy group. Propensity score matching (PSM) method was used to control selection bias. The primary outcome were overall survival (OS) and progression-free survival (PFS) after PSM. OS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the last effective follow-up or death. PFS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the first imaging diagnosis of tumor progression or death. The Kaplan-Meier method was used to estimate the survival rate, and the Cox proportional hazards model was used to evaluate the independent effect of perioperative chemo therapy on OS and PFS. Results: 2 045 cases were included, including 1 293 cases in the surgery+adjuvant chemotherapy group and 752 cases in the perioperative chemotherapy group. After PSM, 492 pairs were included in the analysis. There were no statistically significant differences in gender, age, body mass index, tumor stage before treatment, and tumor location between the two groups (all P>0.05). Compared with the surgery + adjuvant chemotherapy group, patients in the perioperative chemotherapy group had higher proportion of total gastrectomy (χ(2)=40.526, P<0.001), smaller maximum tumor diameter (t=3.969, P<0.001), less number of metastatic lymph nodes (t=1.343, P<0.001), lower ratio of vessel invasion (χ(2)=11.897, P=0.001) and nerve invasion (χ(2)=12.338, P<0.001). In the perioperative chemotherapy group and surgery + adjuvant chemotherapy group, 24 cases (4.9%) and 17 cases (3.4%) developed postoperative complications, respectively, and no significant difference was found between two groups (χ(2)=0.815, P=0.367). The median OS of the perioperative chemotherapy group was longer than that of the surgery + adjuvant chemotherapy group (65 months vs. 45 months, HR: 0.74, 95% CI: 0.62-0.89, P=0.001); the median PFS of the perioperative chemotherapy group was also longer than that of the surgery+adjuvant chemotherapy group (56 months vs. 36 months, HR=0.72, 95% CI:0.61-0.85, P<0.001). The forest plot results of subgroup analysis showed that both men and women could benefit from perioperative chemotherapy (all P<0.05); patients over 45 years of age (P<0.05) and with normal body mass (P<0.01) could benefit significantly; patients with cTNM stage II and III presented a trend of benefit or could benefit significantly (P<0.05); patients with signet ring cell carcinoma benefited little (P>0.05); tumors in the gastric body and gastric antrum benefited more significantly (P<0.05). Conclusion: Perioperative chemotherapy can improve the prognosis of gastric cancer patients.
Chemotherapy, Adjuvant ; Female ; Gastrectomy ; Humans ; Male ; Neoadjuvant Therapy ; Neoplasm Staging ; Prognosis ; Retrospective Studies ; Stomach Neoplasms/surgery*

Shugoshin-1 (SGOLl) is one of the human homologues of yeast Shugoshin that locates in the centromeric region. It prevents premature division of the eentromerie cohesin complex and maintaining chromosome stability. Very recently, the role of SGOLl in tumors has emerged, but its role in lung cancer is unclear. In this study, we identify that SGOLl was upregulated in lung cancer samples from the TCGA database (n=529, P< 0.00001), which was correlated to the overall survival time of lung cancer patients (P = 0.0049). Detected by qRT-PCR and Western blotting, we demonstrate that SGOLl was consistently upregulated in lung cancer cell lines than normal epithelial cell line. Regulatory effects of SGOLl on cell viability, clonality, migration and invasion of lung cancer cells A549 and NCI-H2405 were examined by Cell Counting Kit-8 (CCK8), Colony formation, Scratch and Transwell assays, respectively. Compared with the control group, knockdown of SGOLl significantly inhibited proliferation, migration and invasion in A549 and NCI-H2405 cells (P<0. 05). A positive correlation was identified between expression levels of pyruvate kinase muscle isoenzyme 2 (PKM2) and SGOLl in the TCGA data-base (r=0. 38, P = 0). Western blotting results showed that knockdown of SGOLl in A549 and NCI-H2405 cells down-regulated PKM2 as well. In addition, co-interventions of SGOLl and PKM2 were performed in A549 and NCI-H2405 cells to clarify the interaction mechanism between them. The results showed that overexpression of PKM2 in lung cancer cells could partially reverse the regulatory effects of SGOLl knockdown on proliferation, migration and invasion (P<0. 05). Therefore, our study showed that SGOLl promoted the proliferation, migration and invasion of lung cancer cells by regulating PKM2. This study provided a theoretical basis for the mechanism of SGOLl in lung cancer.

In the original publication of the article, the representative EEG of female rat pups with FS in Figure 1 C and D was incorrectly intercepted from that of male rat pups. This correction does not affect the conclusions of the paper. Figure 1 has been corrected on the online PDF version and displayed below.

BACKGROUNDFew studies have focused on peripheral nerve conduction during exposure to microgravity. The -6° head-down tilt (HDT) comprises an experimental model used to simulate the space flight environment. This study investigated nerve conduction characteristics of rhesus monkeys before and after prolonged exposure to HDT.

METHODSSix rhesus monkeys (3-4 years old) were tilted backward 6° from the horizontal. Nerve conduction studies (NCSs) were performed on the median, ulnar, tibial, and fibular motor nerves. Analysis of variance with a randomized block design was conducted to compare the differences in the NCS before and 7, 21, and 42 days after the -6° HDT.

RESULTSThe proximal amplitude of the CMAP of the median nerve was significantly decreased at 21 and 42 days of HDT compared with the amplitude before HDT (4.38 ± 2.83 vs. 8.40 ± 2.66 mV, F = 4.85, P = 0.013 and 3.30 ± 2.70 vs. 8.40 ± 2.66 mV, F = 5.93, P = 0.004, respectively). The distal amplitude of the CMAP of the median nerve was significantly decreased at 7, 21, and 42 days of HDT compared with the amplitude before HDT (7.28 ± 1.27 vs. 10.25 ± 3.40 mV, F = 4.03, P = 0.039; 5.05 ± 2.01 vs. 10.25 ± 3.40 mV, F = 6.25, P = 0.04; and 3.95 ± 2.79 vs. 10.25 ± 3.40 mV, F = 7.35, P = 0.01; respectively). The proximal amplitude of the CMAP of the tibial nerve was significantly decreased at 42 days of HDT compared with the amplitude before HDT (6.14 ± 1.94 vs. 11.87 ± 3.19 mV, F = 5.02, P = 0.039).

CONCLUSIONSThis study demonstrates that the compound muscle action potential amplitudes of nerves are decreased under simulated microgravity in rhesus monkeys. Moreover, rhesus monkeys exposed to HDT might be served as an experimental model for the study of NCS under microgravity.

Action Potentials ; physiology ; Animals ; Female ; Head-Down Tilt ; physiology ; Macaca mulatta ; Male ; Neural Conduction ; physiology ; Weightlessness Simulation

This study was designed to investigate triterpenoids from the roots of Rosa laevigata Michx. The silica gel column chromatography was used to separate the chemical constituents from the roots of Rosa laevigata Michx. HPLC was used to analyze its purity and chemical constitution. Spectroscopy methods were used to determine their structures. Five constituents were isolated and identified as19α-OH-3β-E-feruloyl corosolic acid (1), 23-hydroxy-tormentic acid (2), 2α, 3β, 19α, 23-tetrahydroxy-12-en-28-oleanolic acid (3), 2α, 3α, 20β-trihydroxyurs-13 (18)-en-28-oic-acid (4), 2α, 3β, 20β-trihydroxyurs-13 (18)-en-28-oic-acid (5). Compound 1 was assigned as a new compound, compounds 4, 5 were obtained from the genus Rosa for the first time.