Low-Toxicity and High-Efficiency Streptomyces Genome Editing Tool Based on the Miniature Type V-F CRISPR/Cas Nuclease AsCas12f1.

Genome editing tools based on SpCas9 and FnCpf1 have facilitated strain improvements for natural product production and novel drug discovery in Streptomyces. However, due to high toxicity, their editing requires high DNA transformation efficiency, which is unavailable in most streptomycetes. The transformation efficiency of an all-in-one editing tool based on miniature Cas nuclease AsCas12f1 was significantly higher than those of SpCas9 and FnCpf1 in tested streptomycetes, which is due to its small size and weak DNA cleavage activity. Using this tool, in Streptomyces coelicolor, we achieved 100% efficiency for single gene or gene cluster deletion and 46.7 and 40% efficiency for simultaneous deletion of two genes and two gene clusters, respectively. AsCas12f1 was successfully extended to Streptomyces hygroscopicus SIPI-054 for efficient genome editing, in which SpCas9/FnCpf1 does not work well. Collectively, this work offers a low-toxicity, high-efficiency genome editing tool for streptomycetes, particularly those with low DNA transformation efficiency.

Poor sleep quality association with higher lung cancer risk: a nested case-control study.

Background: Little is known about the relationship between sleep quality and lung cancer incidence. Thus, this study was conducted to investigate the potential connection between sleep quality and lung cancer incidence. Methods: We performed and selected a nested case-control study that included 150 lung cancer cases and 150 matched controls based on the Lianyungang cohort. Univariate and multivariate logistic regression was utilized to investigate the connection between potential risk factors and lung cancer incidence risk. Results: In this study, the average age of participants was 66.5 ± 9.1 years, with 58.7% being male, and 52.7% reportedly experiencing sleep quality problems. The results of multivariate logistic regression showed that poor sleep quality was connected to an increased lung cancer incidence risk (P = 0.033, odds ratio = 1.83, 95% confidence interval = [1.05-3.19]) compared with those with good sleep quality. The stratified analyses showed a significantly positive connection between poor sleep quality (vs. good sleep quality) and cancer risk in smokers (vs. non-smoker, P for interaction = 0.085). The combined effect analysis indicated that smokers with poor sleep quality suffered from a 2.79-fold increase in cancer incidence rates when compared with non-smokers with good sleep quality. Conclusions: Poor sleep quality was positively connected to an increased lung cancer incidence risk. In addition, among those individuals with poor sleep quality, smoking increased the lung cancer incidence risk.

[Remote Sensing Classification of Urban Black-odor Water Based on Decision Tree].

Remote sensing monitoring of black-odor water is an important method for understanding the current status of urban water quality, and comprehensively evaluating the effect of urban water environment treatment. A total of 171 samples were collected in Nanjing, Changzhou, Wuxi, and Yangzhou cities and water quality parameters and optical parameters were measured simultaneously. Based on the analysis of the water color and optical characteristics of the black-odor water and non-black-odor water (denoted as general water), a decision tree was constructed to identify the severe, mild black-odor water, and general water as green and yellow water. The results found that:①According to the water color, the water bodies can be divided into six types. Among them, type 1 to 4 water bodies are black-odor water, which are gray black, dark gray, gray, and light gray water, respectively, and type 5 and 6 water bodies are general water, which are green and yellow water, respectively; ②Type 1 water body contains high contents of non-pigmented particulate matter and colored dissolved organic matter(CDOM), however, the absorption of pigmented particulate matter is not dominant. Type 2 and 5 water bodies are dominated by pigmented particulate matter. Type 3, 4, and 6 water bodies are dominated by non-pigmented particulate matter; ③After water color classification, and according to the differences of the reflection spectrums of the six types of water bodies, the difference of black-odorous water index (DBWI), green-red-nir area water index (G-R-NIR AWI), the green band reflectance and the normalized difference black-odorous water index (NDBWI) were used to construct a decision tree to identify the severe, mild black-odor water, and general water; ④The decision tree was applied to the PlanetScope satellite image of Yangzhou City on April 9, 2019, and 10 synchronous sampling points were used for verification. The overall recognition accuracy reached 80.00%, and the K value reached 0.67. The urban water classification model, after water color classification, can be applied to other similar water bodies, and provides a technical method for the supervision of black-odor water bodies.

[Synthesis and biological evaluation of 3-aromatic Shiff base-5-fluoroindol-2-one derivatives].

Based on the structure of 5-fluoroindol-2-one and fragments from thirteen multi-target tyrosine kinase inhibitors which have been marketed or in the phase of clinical research, eleven 3-aromatic Shiff base-5-fluoroindol-2-one derivatives were designed and synthesized. Their structures were identified by 1H NMR, MS and elemental analysis. In vitro antitumor bioactivities evaluation was done by MTT method. It was shown that most of synthesized compounds had antitumor activities and compounds 1b, 1g, 1i and 1h were better than or equal to the antitumor activity of positive control.

Effects of wuwei dilong decoction on inflammatory cells and cytokines in asthma model guinea pigs.

OBJECTIVE: To explore the effects and the mechanism of Wuwei Dilong Decoction (Schisandra Fruit and Earthworm Decoction) for treatment of asthma. METHODS: The asthma guinea pig model was established with spray of ovalbumin (OVA). Fifteen days later, the guinea pigs were administered by intra-gastric perfusion of Wuwei Dilong Decoction once a day for 8 consecutive days. Blood samples were taken for testing the total leucocytes, eosinophil (EOS), lymphocytes, interferon-gamma (IFN-gamma) and leukotriene B4 (LTB4). RESULTS: In the asthma model group, the total leucocytes, EOS and lymphocytes were all increased, with significant differences as compared with the different dosage Wuwei Dilong Decoction groups (P < 0.01 or P < 0.05). The serum LTB4 in the asthma model group was significantly increased and IFN-gamma decreased. After administration of Wuwei Dilong Decoction of the large, medium and small dosages, LTB4 decreased, while IFN-gamma increased (P < 0.05 or P < 0.01). CONCLUSION: Wuwei Dilong Decoction can inhibit infiltration and diffusion of the inflammatory cells in the asthma model guinea pigs, and regulate LTB4 and IFN-gamma, which is probably one of the important mechanisms of Wuwei Dilong Decoction for relieving asthma.

[Expression of hepatocyte growth factor and its receptor in gastric cancer].

OBJECTIVE: To investigate the role of expression of hepatocyte growth factor (HGF) and its receptor (c-Met) in gastric cancer. METHODS: The expression of HGF and c-Met was detected with SABC immunohistochemistry in 44 specimens of gastric cancer, 20 chronic superficial gastritis, 10 chronic atrophic gastritis and 16 gastric ulcer tissues. RESULTS: No positive expression of HGF/c-Met was found in the chronic superficial gastritis specimens. The positivity rates of HGF in the gastric cancer was 72.7% (32/44), significantly higher than that in chronic atrophic gastritis [20% (2/10), P<0.005] and gastric ulcer [37.5% (6/16). P<0.025]. The positivity rates of c-Met in gastric cancer [77.3% (34/44)] was also significantly higher than that in chronic atrophic gastritis [40% (4/10), P<0.05] and gastric ulcer [37.5% (6/16), P<0.025]. CONCLUSION: Co-expression of HGF and c-Met in gastric cancer may promote the progression of the malignancy, and also opens a new pathway for the therapy of gastric cancer.

[Effect of earthworm decoction on airway inflammation of bronchial asthma in guinea pigs].

OBJECTIVE: To investigate the effect of Earthworm decoction on the airway inflammation of experimental bronchial asthma in guinea pigs and inquire into the mechanism in the decoction. METHOD: Forty-eight guinea pigs were randomly divided into six groups: the control group, the model group, the dexamethasone group, the Xiaoqinglong decoction group, the earthworm decoction large dosage group and the Earthworm decoction low dosage group, 8 guinea pigs in each group. Except the control group, the other groups were sensitized with ovalbumin (OVA) by a combination of intraperitional injection and repeated intranasal challenges to establish the guinea pigs asthma model. However, in the control group, normal saline was used. The morphological changes of bronchial tube, the lung tectology and the inflammation germ cell quantity of eosinophils (Eos), lymphocytes (Ly), neutrophils (Neu) and total blood cells in the blood and bronchoalveolar lavaga fluid (BALF) were examinated in each group respectively. RESULT: The levels of Eos, Ly, Neu and total cell quantity in the blood and BALF after the earthworm decoction treatment in the large dosage group were significantly lower than those in the model group (P <0.01), and in the low dosage group were lower too (P <0.05). The Earthworm decoction large dosage could obviously improve the bronchial tube epidermis damage, the mucous membrane gland proliferation and hydrops, asthma pathology change and basilar membrane accumulation. Eos apoptosis was obsered in the bronchoalveolar, blood and BALF. The Earthworm decoction small dosage had a similar effect but slightly to the large dosage. CONCLUSION: The Earthworm decoction can lighten the airway inflammation in asthmatic guinea pigs, its mechanism is related with the inhibition of Eos infiltration, acceleration of Eos apoptosis and improvement of the bronchial tube and the lung tectology changes. The effect of the decoction is dose-dependent.

Electroenterogram manifestations and significance in hypokalemia.

OBJECTIVE: To study the electroenterogram manifestations and their significance in patients with hypokalemia. METHODS: Electroenterogram was recorded in 20 normal control subjects and 24 patients with hypokalemia using computerized electrogastroenterography. RESULTS: The frequencies and amplitudes of the electroenterogram in patients with hypokalemia were significantly lower than those in the normal control subjects (P<0.05), and the frequencies, amplitudes and their coefficients of variation varied significantly in patients with hypokalemia before / after treatment (P<0.001). CONCLUSION: Electroenterogram may serve as an objective means for evaluating the therapeutic effect and estimating intestinal motility of patients with hypokalemia, with also important value in predicting and diagnosing hypokalemic intestinal paralysis.