[Intein-Mediated Protein trans-Splicing of the Recombinant Streptavidin on Magnetosomes]

When expressing streptavidin recombinant polypeptide on magnetosomes (called bacterial magnetic nanoparticles, or BMPs), the presence of endogenous bacterial biotin might be detrimental. In the study, the streptavidin monomer fragment (S1-116) was fused with the intein N-terminal (termed precursor S1-116-IN), and S1-116-IN was expressed in E. coli (BL21). Meanwhile, the SA117-160 fragment was fused with the C-terminal intein, and then this chimeric polypeptide was expressed on magnetosomes by fusion with magnetosome membrance protein MamF. In the in vitro protein splicing system, the purified engineered magnetosomes (BMP-SA117-160-IC) and the S1-116-IN precursor were mixed. Intein-mediated trans-splicing reaction was induced to produce the functional magnetic beads BMP-SA. Our results indicate that intein-mediated protein trans-splicing may lead to efficient synthesis of the recombinant streptavidin on the magnetosomes, showing its promising potential to produce other functional magnetic nanoparticles.

[Effects of LINC00839 targeting miR-3666 on proliferation, migration and invasion of hepatocellular carcinoma cells]

Objective: To investigate the effects of lncRNA LINC00839 on the proliferation, migration and invasion of hepatocellular carcinoma cells and its mechanism. Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of LINC00839 and miR-3666 in hepatocellular carcinoma tissues and adjacent tissues. Pearson correlation was used to analyze the correlation between LINC00839 and miR-3666 expression in liver cancer tissues. Hepatocellular carcinoma cells MHCC97H were cultured in vitro and divided into si-NC group, si-LINC00839 group, miR-NC group, miR-3666 group, si-LINC00839+ anti-miR-NC group, and si-LINC00839+ anti-miR-3666 group. Methylthiazoletrazolium (MTT) method and clone formation experiment were used to detect cell proliferation. Transwell array was used to detect the cell migration and invasion. Western blot was used to detect the protein expressions of p21, E-cadherin and MMP-2. The double luciferase reporter gene experiment was used to verify the regulatory relationship between LINC00839 and miR-3666. Results: Compared with adjacent tissues, the expression level of LINC00839 in hepatocellular carcinoma tissues increased (2.82±0.27 vs. 0.96±0.10, P<0.001), but the expression level of miR-3666 decreased (0.23±0.02 vs. 1.01±0.10, P<0.001). The expression levels of LINC00839 and miR-3666 in liver cancer tissue were negatively correlated (r=-0.658, P<0.001). The survival rate of MHCC97H cells in the si-LINC00839 group [(53.91±5.41)% vs. (100.53±10.22)%], the number of clones formed (92.0±8.0 vs. 164.0±14.3), the number of migration (131.0±12.7 vs. 247.0±22.4), the number of invasion (66.0±6.4 vs. 120.0±11.6) and the protein level of MMP-2 (0.20±0.02 vs. 0.67±0.06) were lower than those in the si-NC group (P<0.001). However, the protein levels of p21 (0.76±0.07 vs. 0.25±0.02) and E-cadherin (0.78±0.08 vs. 0.14±0.01) were higher than those in the si-NC group (P<0.001). LINC00839 targeted and negatively regulated the expression of miR-3666. The survival rate of MHCC97-H cells in the miR-3666 group [(47.93±4.86)% vs. (100.11±10.21)%], the number of clone formation (78.0±7.7 vs. 166.0±15.9), the number of migration (117.0±12.1 vs. 250.0±25.0), the number of invasion (57.0±5.7 vs. 121.0±12.3) and the protein level of MMP-2 (0.16±0.01 vs. 0.69±0.07) were lower than those in the miR-NC group (all P<0.001). However, the protein levels of p21 (0.83±0.08 vs. 0.24±0.02) and E-cadherin (0.87±0.09 vs. 0.13±0.01)were higher than those in the miR-NC group (all P<0.001). The survival rate of MHCC97-H cells in the si-LINC00839+ anti-miR-3666 group [(89.94±9.05)% vs. (54.12±5.39)%], the number of clones (143.0±13.8 vs. 94.0±9.4), the number of migration (208.0±19.8 vs. 129.0±12.6), the number of invasion (108.0±10.1 vs. 65.0±6.4) and the protein level of MMP-2 (0.31±0.03 vs 0.66±0.06) were higher than those in the si-LINC00839+ anti-miR-NC group (P<0.001). However, the protein levels of p21 (0.31±0.03 vs. 0.74±0.07) and E-cadherin (0.28±0.03 vs. 0.80±0.08) were lower than those int the si-LINC00839+ anti-miR-NC group (P<0.001). Conclusion: Inhibition of LINC00839 expression may inhibit the proliferation, migration and invasion of hepatocellular carcinoma cells by targeting up-regulation of miR-3666 expression.

Mental Health, Wellbeing and Preventive Behaviors in 10 Western Pacific Countries during COVID-19

Background

COVID-19 has shown varying impacts on different populations. In the Western Pacific (WP) Region with a relatively low COVID-19 burden, the variabilities of its impact on mental health, wellbeing and preventive behaviors across countries are unclear.

Methods

We analyzed repeated national-representative, cross-sectional data of 87,787 adults collected via the Imperial College London YouGov COVID-19 behavior tracker in ten WP countries-Australia, China, Singapore, Japan, South Korea, Vietnam, Taiwan, the Philippines, Malaysia and Hong Kong during the pandemic (April-September 2020). Main outcomes were severe depression/anxiety (Patient Health Questionnaire-4 score≥9), wellbeing (Cantril Ladder Scale 0-10), worries of contracting COVID-19 and prevalence of preventive behaviors. Monthly temporal trends were examined.

Results

Percentages of severe depression/anxiety were higher in Australia (12.9%), Hong Kong (11.8%) and lowest in Vietnam (6.8%); increasing trends were noted in the Philippines (5.9% to 12.3%, p < 0.0001) and Malaysia (8.2% to 10.7%, p = 0.019). South Korea, China and Taiwan had the lowest levels of wellbeing (5.0-5.5) compared with their highest counterparts in the Philippines, Australia and Vietnam (6.2-6.5). Worries of COVID-19 remained high in Asia countries (Japan, South Korea, Malaysia, Vietnam and the Philippines: 79.2%-81.6%), compared to that in Australia (41%). 83.5%-97.2% of the Asian respondents persistently wore face masks outside home, while the mean percentages were low in Australia (32.2%) despite the increasing trend observed (24.1% to 48.6%, p < 0.000). Over half of the WP countries have significant decreasing trends (p < 0.000) for avoid going out; Taiwan showed the lowest prevalence (45.7%).

Conclusions

Psychological and behavioral responses to COVID-19 in the WP region varied widely. COVID-19-related negative impact on mental health and wellbeing was universal. A Global effort to tackle the aftermath of the pandemic is crucial.

Key messages

The psychological and behavioral responses to COVID-19 in Western Pacific countries varied widely.

Severe depression/anxiety and low levels of wellbeing were prevalent in Western Pacific Region.

Tributyrin supplementation in pasteurized waste milk: Effects on growth performance, health, and blood parameters of dairy calves

This study evaluated the effects of incremental tributyrin supplementation in pasteurized waste milk on growth performance, health, and blood metabolism of dairy calves before and after weaning. Forty-eight newborn female Holstein dairy calves (39.6 ± 2.75 kg; mean ± standard deviation) were blocked by age and randomly assigned to 3 treatments: pasteurized waste milk (1) without supplementation, (2) with 1 g/L of tributyrin products (unprotected solid powder; containing 35% tributyrin), or (3) with 2 g/L of tributyrin products. The calves were weaned on d 56 and were raised until d 77. Data were analyzed for the preweaning, postweaning, and overall periods. The results showed that starter intake and hay intake were not different among treatments in any period of the trial, but the crude protein intake tended to increase linearly with tributyrin supplementation during the overall period. Although tributyrin supplementation had no effects on body weight during preweaning and overall periods, body weight increased linearly with tributyrin supplementation postweaning. The average daily gain tended to increase linearly during postweaning and overall periods. No effects were observed on feed efficiency in any period. A positive linear relationship between body length and tributyrin supplementation was observed during the postweaning period, but no differences were found for the other body structural measurements in any period. The results of diarrhea showed that tributyrin concentration had a negative linear relationship with diarrhea frequency during preweaning and overall periods. The rectal temperature did not differ among treatments in any period, but a treatment × week effect for rectal body temperature was observed. For blood metabolism, tributyrin supplementation had no effects on insulin, growth hormone, total protein, albumin, or globulin. No differences were found in serum amyloid A concentration in any of the periods, yet haptoglobin concentration decreased linearly with increasing tributyrin concentration during postweaning and overall periods. Endothelin concentration showed a tendency to decrease linearly during preweaning and postweaning periods and decreased linearly with tributyrin supplementation during the overall period. An increasing tributyrin concentration was associated with a negative linear relationship with IL-1β concentration during the preweaning period, and no differences were found in the other periods. The concentration of IL-6 and tumor necrosis factor α were not different among treatments in any of the periods. These data suggest that increasing the concentration of tributyrin in pasteurized waste milk could increase growth performance and health of dairy calves, and incremental tributyrin supplementation could linearly reduce haptoglobin, endothelin, and IL-1β concentrations, indicating a positive effect of tributyrin on alleviating oxidative stress and inflammatory status of dairy calves. Calves fed pasteurized waste milk supplemented with tributyrin products (containing 35% tributyrin) at 2 g/L compared with 1 g/L of milk had more improved growth and health.

[Characteristics of magnetic resonance imaging and clinical etiology of ovarian infertility]

Objective: To analyze the characteristics of magnetic resonance imaging (MRI) and clinical etiology of ovarian infertility. Methods: The data of infertile women who underwent 3.0T MRI and magnetic resonance hysterosalpingography (MR-HSG) examination in the Affiliated Hospital of Nanjing University of Chinese Medicine from September 2017 to March 2020 were collected. The ovarian factors of infertility, as well as the abnormalities of bilateral fallopian tubes and uterus, were evaluated. Etiologies assessed by MRI were finally confirmed by hysteroscopy, laparoscopy, surgery, or a comprehensive clinical diagnosis. Results: Among 1 351 patients, 1 296 cases were eligible and included for further analysis. Evaluated by MRI and MR-HSG, 494(38.12%) cases had ovarian abnormalities, including 239(48.38%) cases of ovarian endometriosiss, 116(23.48%) cases of polycystic ovary syndrome (PCOS), 37(7.49%) cases of diminished ovarian reserve (DOR), 33(6.68%) cases of ovarian mass, 28(5.67%) cases of ovarian injury, and 41(8.30%) cases who had at least two kinds of ovarian diseases. Unilateral and bilateral ovarian abnormalities accounted for 52.02% (257/494) and 47.98%(237/494), respectively.In total, 453 of 494(91.7%) patients had only one kind of ovarian disease. Among the 494 patients, 103(20.85%) cases had abnormal ovary with normal uterus and fallopian tubes, and the other 391(79.15%) cases had abnormalities not only in ovary, but in fallopian tube and/or uterus. Conclusion: Infertility-related ovarian diseases have certain characteristics of MRI findings. 3.0T MRI is useful for comprehensive analysis of etiology in ovarian infertility. Combined with MR-HSG, it provides one-stop assessments of the pelvic factors in female infertility.

[Investigation on population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province]

OBJECTIVE

To investigate the population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province.

METHODS

Rodents were captured using the mouse trap method in pastures from Batang Township and Longbao Township of Yushu City, Qinghai Province on May, August and October, 2018. The body weight and snout-vent length of all captured rodents were measured, and the species was identified according to the rodent morphology. Genomic DNA was extracted from rodent liver specimens and lesion specimens, and the mitochondrial cox1 gene of Echinococcus was amplified using PCR assay for identification of parasite species. In addition, the tissue specimens positive for PCR assay were sampled for pathological examinations. The prevalence of Echinococcus infections was estimated in rodents, and a phylogenetic tree was created based on Echinococcus cox1 gene sequences.

RESULTS

A total of 285 small rodents were captured, including 143 Ochotona curzoniae (50.2%), 141 Lasiopodomys fuscus (49.5%), and 1 Neodon irene (0.3%), and there was a remarkable variation in habitat selection among these three rodent species. The number of L. fuscus correlated positively with vegetation coverage (r = 0.350, P = 0.264), with the greatest number seen in August, and the number of O. curzoniae negatively with vegetation coverage (r = -0.371, P = 0.235), with the highest number seen in August and the lowest number in May. The female/male ratios of O. curzoniae and voles were 1:0.96 and 0.82:1, respectively. The body weight (r = 0.519, P < 0.01) and snout-vent length (r = 0.578, P < 0.01) of O. curzoniae showed a tendency towards a rise with month, while the body weight (r = -0.401, P < 0.01) and snout-vent length (r = -0.570, P < 0.01) of voles presented a tendency towards a reduction with month. No Echinococcus infection was detected in voles, while 2.1% prevalence of E. shiquicus infection was seen in O. curzoniae. Phylogenetic analysis revealed consistent sequences of cox1 gene from E. shiquicus in Yushu City of Qinghai Province and Shiqu County, Ganzi Tibetan Autonomous Prefecture of Sichuan Province.

CONCLUSIONS

The small rodents around the human settlement in Yushu City of Qinghai Province mainly include O. curzoniae and L. fuscus, with the greatest numbers seen in May and August, respectively. Following the concerted efforts for echinococcosis control, the prevalence of Echinococcus infections is low in small rodents around the human settlement in Yushu City; however, there is still a risk of echinococcosis transmission.

[Clinical characteristics of patients with odontogenic sinusitis underwent endoscopic sinus surgery]

Objective: To analyze the clinical features of patients with odontogenic sinusitis (OS) treated by endoscopic sinus surgery (ESS). Methods: A retrospective investigation was carried out in our 27 (16 males and 11 females) cases with OS aged (49.74±14.42) years old. Subjects were hospitalized between January 2018 and November 2020 from Department of Otorhinolaryngology Head and Neck Surgery, Beijing Chaoyang Hospital. The medical history, symptoms, result of nasal endoscopy and paranasal sinus computed tomography (CT) were analyzed statistically by SPSS 19.0. Results: OS mainly occured on unilateral sinuses, with a duration of (8.56±11.79) months. Seventy point four percent (19/27) of the patients had a course within six-month, only 11% was over 12 months (3/27). Symptoms mostly showed as nasal obstruction (88.9%; 24/27), runny nose (81.5%; 22/27), nasal stinks (16/19) and postnasal drip (10/10). Sixty-three percent (17/27) of the OS patients had a dental history. Nasal endoscopic examination revealed a swelling of the ostiomeatal complex (77.8%; 21/27), medial wall interhal displacement of maxillary sinus (55.6%; 15/27), white emulsion-like purulent secretion in the middle meatus (70.4%; 19/27) and nasal polyps (59.3%; 16/27). Etiology of OS included implant-related problems (14.8%; 4/27) and periodontal disease (85.2%; 23/27). Conclusions: OS is usually unilateral sinusitis with a short history. Its clinical features show nasal stinks, white emulsion-like purulent secretion in the middle meatus and imaging findings of unilateral maxillary sinusitis with tooth-related lesions.

[Expression of GATA3 and bcl-11b in peripheral T-cell lymphoma and their clinical significance]

Objective: To study the expression of GATA3 and bcl-11b in peripheral T-cell lymphoma (PTCL) and their correlation with clinicopathological features. Methods: The Oncomine and GEO databases were used for analyzing the expression levels of GATA3 and bcl-11b mRNA in PTCL. Immunohistochemistry was used to detect the expression of GATA3 and bcl-11b proteins in 127 cases of PTCL diagnosed at Shanxi Provincial Cancer Hospital from January 2010 to June 2020, as well as 40 cases of lymph node with reactive hyperplasia. Results: The data in Oncomine and GEO databases showed that the expression of GATA3 and bcl-11b mRNA in PTCL was lower than that in normal tissues (P<0.05). Immunohistochemistry showed that the positive rates of GATA3 in PTCL and lymph nodes with reactive hyperplasia were 60.6% (77/127) and 85.0% (34/40, P<0.05), respectively. The expression rates of bcl-11b in PTCL and lymph nodes with reactive hyperplasia were 55.1% (70/127) and 75.0% (30/40, P<0.05), respectively. The expression of GATA3 was related to the pathological classification of the patients with PTCL, and was inversely related to the Ann Arbor stage of the patient, while the expression of bcl-11b was inversely correlated with the IPI score of the patient (P<0.05). The expression of GATA3 and bcl-11b was related to the patients' age, gender, LDH level, and B symptoms. Other clinicopathological characteristics were irrelevant. Spearman correlation analysis shows that the expression of GATA3 protein was associated with that of bcl-11b protein in PTCL. Conclusion: GATA3 and bcl-11b are closely related to the prognosis of PTCL, and may be important factors involved in the occurrence and development of PTCL.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

[Cross sectional study of familial hypercholesterolemia in dyslipidemia patients receiving lipid-lowering therapy: DYSIS-China subgroup analysis]

Objectives: To analyze the incidence, blood lipid levels and cardiovascular disease of familial hypercholesterolemia (FH) in dyslipidemia patients receiving lipid-lowing therapy from the DYSIS-China. Methods: Dyslipidemia International Study-China (DYSIS-China) database was re-analyzed according to the criteria of "Chinese guidelines for prevention and treatment of dyslipidemia in adults-2016 version". DYSIS-China database included 25 317 dyslipidemia out-patients who received at least one lipid-lowering drug for at least three months. All the patients were divided into three groups: unlikely HF, possible FH and definite FH according to the Dutch Lipid Clinic Network diagnostic criteria. Age, gender, lipids levels, drug use and complications were compared among the three groups. Factors were compared between Possible FH group and definite FH group in terms of age stratification. Results: A total of 23 973 patients with dyslipidemia were included. The average age was (64.8±9.9) years, 11 757 patients were females (49.0%). The proportion of unlikely FH in the total population was 20 561 (85.7%), possible FH was 3294 (13.7%), and the definite FH was 118(0.5%). Patients in the definite FH group (58.3±8.5 years) was younger than in unlikely HF(65.3±9.8 years) and possible FH(61.8±9.9 years) group. LDL-C ((5.6±1.9) mmol/L) levels were significantly higher in definite FH group than in unlikely HF ((2.5±0.9) mmol/L) and possible FH ((4.3±1.0) mmol/L) group. TC ((7.4±1.8) mmol/L) levels were also significantly higher in definite FH group than in unlikely HF ((4.3±1.0) mmol/L) and possible FH ((6.0±1.0) mmol/L) group. Percent of female sex, sedentary lifestyle and systolic blood pressure value were significantly higher in definite FH group than in other two groups (all P<0.05). Statin use was similar among the 3 groups. Prevalence of ischemic cardiomyopathy (70(59.3%)) was significantly higher in the definite FH group than in unlikely FH group7519 (36.6%) and possible FH group1149 (34.9%). The rate of hypertension (82 (69.5%)) was also significantly higher in the definite FH group than in unlikely FH group (2 063 (62.6%) and in possible FH group (13 928 (67.7%)). The possible FH group had the highest proportion of patients aged 55-64 years (1 146 (34.8%)), and the prevalence of hypertension 358 (76.8%), diabetes 189 (40.6%), ischemic heart disease 186 (39.9%), cerebrovascular disease 149 (32.0%) and heart failure 28 (6.0%) was the highest in patients over 75 years old. The definite FH group had the highest proportion of patients aged 55-64 years (49 (41.52%)), and the prevalence of ischemic heart disease (70 (59.3%)) was the highest in patients aged 45-54 years old group, there was no significant difference in the prevalence of diabetes,hypertension,heart failure,peripheral artery disease and cerebrovascular disease among different age groups. Conclusion: The detection rate of FH in Chinese patients with dyslipidemia is not low, the blood lipid level is poorly controlled, and the risk of cardiovascular disease is high in Chinses FH patients.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

[Preparation of paclitaxel-loaded and folic acid-modified poly (lactic-co-glycolic acid) nano-micelles and in vitro anticancer effect on cervical cancer HeLa cells]

The paclitaxel-loaded and folic acid-modified poly(lactic-co-glycolic acid) nano-micelles(PTX@FA-PLGA-NMs) were prepared by the emulsion solvent evaporation method, and the parameters of paclitaxel-loaded nano-micelles were optimized with the particle size and PDI as evaluation indexes. The morphology of the nano-micelles was observed by transmission electron microscopy(TEM), and the stability, drug loading and encapsulation efficiency were systematically investigated. In vitro experiments were performed to study the cytotoxic effects of nano-micelles, apoptosis, and cellular uptake. Under the optimal parameters, the nano-micelles showed the particle size of(125.3±1.2) nm, the PDI of 0.086±0.026, the zeta potential of(-20.0±3.8) mV, the drug loading of 7.2%±0.75%, and the encapsulation efficiency of 50.7%±1.0%. The nano-micelles were in regular spherical shape as observed by TEM. The blank FA-PLGA-NMs exhibited almost no inhibitory effect on the proliferation and growth of tumor cells, while the drug-loaded nano-micelles and free PTX exhibited significant inhibitory effects. The IC_(50) of PTX@FA-PLGA-NMs and PTX was 0.56 μg·mL~(-1) and 0.66 μg·mL~(-1), respectively. The paclitaxel-loaded nano-micelles were potent in inhibiting cell migration as assessed by the scratch assay. PTX@FA-PLGA-NMs had good pro-apoptotic effect on cervical cancer HeLa cells and significantly promoted the uptake of HeLa cells. The results of in vitro experiments suggested that PTX@FA-PLGA-NMs could target and treat cervical cancer HeLa cells. Therefore, as nanodrug carriers, PTX@FA-PLGA-NMs with anti-cancer activity are a promising nano-system for improving the-rapeutic effects on tumors.

Bacillus velezensis WLYS23 strain possesses antagonistic activity against hybrid snakehead bacterial pathogens

AIM

The aims of this study were to screen an antagonistic probiotic for the prevention and control of bacterial diseases in snakehead fish and to evaluate the antimicrobial activities, biosafety and biocontrol effect of the antagonistic strain.

METHODS AND RESULTS

In this study, the WLYS23 strain exhibiting the most effective antagonistic properties against several fish pathogens was selected from the intestine of healthy snakehead fish. The strain was identified as Bacillus velezensis based on morphological, physiological and biochemical characteristics, and phylogenetic analysis. This strain showed amylase, cellulase, protease and lipase activities according to extracellular enzyme activity assays. Moreover, the cell-free extract of the WLYS23 strain exhibited strong antibacterial activity, with MICs of ≤64 μg ml^-1 for most fish pathogens. Additionally, the cell-free extract was heat and pH stable, and resistant to protease, whereas their antimicrobial activities were significantly influenced by metal ions at high concentration. The WLYS23 strain and its cell-free extract were safe for snakehead and zebrafish. The disease resistance of snakehead fish was significantly increased following administration of the WLYS23 strain and its cell-free extract respectively. The complete genome of the WLYS23 strain was sequenced and found to harbour seven gene clusters encoding secondary metabolites with antimicrobial activity.

CONCLUSION

The WLYS23 strain possesses great potential as a biocontrol agent, which can be commercially developed to improve disease control in freshwater aquaculture.

SIGNIFICANCE AND IMPACT OF THE STUDY

Snakehead fish are important commercially farmed fish worldwide. However, the bacterial diseases caused by Aeromonas sp. and Nocardia seriolae in farmed snakehead fish lead to huge economic losses. Safe, economical and efficient probiotics are limited to prevent and control these diseases. Here, we provide a promising biocontrol agent with antagonistic activity against bacterial diseases of snakehead.

[Coronavirus and the risk of ocular transmission]

Coronaviruses are a common class of respiratory viruses that can cause human infections. 2019 novel coronavirus(2019-nCoV), a new coronavirus that has recently caused a pandemic, has affected millions of people and put tremendous pressure on the health systems of almost every country in the world. Coronaviruses are known to spread from person to person through droplets or contact. The 2019-nCoV has also been found in the conjunctival secretions and tears of some clinically diagnosed patients. To assess whether the eye is one of the transmission routes of the virus, we review literature, and summarize the anatomy of the eye-nose pathway, the expression of the virus receptor in the eye, the preclinical animal studies, and the clinical data. We analyze the possibility of eyes as a means of transmission and propose some suggestions of ocular protection. (Chin J Ophthalmol, 2021, 57: 305-310).

Anatomical correlation between left atrium pulmonary vein ablation targets of atrial fibrillation and adjacent bronchi and pulmonary arteries by MSCT

BACKGROUND

The ablation targets of atrial fibrillation (AF) are adjacent to bronchi and pulmonary arteries (PAs). We used computed tomography (CT) to evaluate the anatomical correlation between left atrium (LA)-pulmonary vein (PV) and adjacent structures.

METHODS

Data were collected from 126 consecutive patients using coronary artery CT angiography. The LA roof was divided into three layers and nine points. The minimal spatial distances from the nine points and four PV orifices to the adjacent bronchi and PAs were measured. The distances from the PV orifices to the nearest contact points of the PVs, bronchi, and PAs were measured.

RESULTS

The anterior points of the LA roof were farther to the bronchi than the middle or posterior points. The distances from the nine points to the PAs were shorter than those to the bronchi (5.19 ± 3.33 mm vs 8.62 ± 3.07 mm; P < .001). The bilateral superior PV orifices, especially the right superior PV orifices were closer to the PAs than the inferior PV orifices (left superior PV: 7.59 ± 4.14 mm; right superior PV: 4.43 ± 2.51 mm; left inferior PV: 24.74 ± 5.26 mm; right inferior PV: 22.33 ± 4.75 mm) (P < .001).

CONCLUSIONS

The right superior PV orifices were closer to the bronchi and PAs than other PV orifices. The ablation at the mid-posterior LA roof had a higher possibility to damage bronchi. CT is a feasible method to assess the anatomical adjacency in vivo, which might provide guidance for AF ablation.

[Clinical study on preserving right gastroepiploic vein during laparoscopic right hemicolectomy]

Objective: The operative approach and steps of laparoscopic right hemicolon cancer radical resection have been standardlized and professional consensus has been reached. However, some detailed issues such as the handling of Henle's trunk and whether to preserve the right gastroepiploic vein (RGEV) still remain controversial. This study investigates the safety, feasibility, short- and long-term outcomes of preserving RGEV during laparoscopic right hemicolectomy. Methods: A retrospective cohort study was carried out. Clinical data of 92 patients undergoing laparoscopic right hemicolectomy in Taizhou People's Hospital from March 2016 to May 2018 were retrospectively analyzed. All the patients were treated with complete mesocolon resection (CME) and had complete postoperative pathological data and follow-up data. Based on the tumor location, 49 patients preserved RGEV (preservation group) and 43 did not (non-preservation group). Pathological data, postoperative complications, short- and long-term outcomes were compared between the two groups. Results: There were no significant differences in baseline data between the two groups (all P>0.05). No significant differences were found in operation time, intraoperative blood loss, unplanned reoperation, anastomotic leak, number of harvested lymph nodes, number of metastatic lymph node, and time to food intake after surgery between two groups (all P>0.05). Compared with non-preservation group, the preservation group had faster recovery of anal gas passage after operation [(3.1±1.0) days vs. (4.0±1.7) days, t=-2.787, P=0.007], shorter length of hospitalization [(11.5±1.5) days vs. (15.0±7.9) days, t=-2.823, P=0.007], and reduced the hospitalization expenses [(46 000±5000) yuan to (57 000±33 000) yuan, t=-2.076, P=0.044]. No postoperative gastroparesis (PGS) occurred in the preservation group, while 6 cases in the non-preservation group developed gastroparesis during perioperative period (P<0.05). The median time of follow-up time was 31.8 (5.2-43.7) months. The overall survival time of the preservation group and non-preservation group was (35.4±1.8) months and (37.6±1.7) months, respectively without significant difference (P=0.336); the disease-free survival was (32.0±2.2) months and (35.5±2.0) months, respectively without significant difference as well (P=0.201). Conclusions: Dissection of the Henle's truck and preservation of RGEV is safe and feasible during laparoscopic right hemicolectomy, which can significantly reduce the incidence of postoperative gastroparesis, shorten the recovery time of postoperative intestinal function and hospitalization, and decrease the cost of hospitalization. The efficacy of RGEV preservation is similar to non-preservation of RGEV.

[Antibiotic analysis and whole genome sequencing of two nocardia farcinica strains causing joint infection]

Objective: To analyze the molecular characteristics and antibiotic susceptibility of two strains of Nocardia farcinica isolated from patients with joint infection using whole genome sequencing. Methods: Two strains of Nocardia farcinica causing knee-joint infections in two elderly patients were collected in January 2020. Whole genome sequencing was used to determine the nocardia species. Drug sensitivity test was performed using the micro-broth dilution and E-test method according to CLSI M24 guideline. ABRicate was used to analyze drug resistance and virulence genes. Snippy and other bioinformatic tools were used for genomic comparison, and to construct SNP homologous tree. Results: The clinical isolates in this study were both Nocardia farcinica. Antimicrobial susceptibility test showed the isolates were resistant to ceftriaxone, cefepime, cefotaxime and trimethoprim/sulfamethoxazole (TMP/SMX). Imipenem, linezolid and amoxicillin-clavulanic acid showed good activity. Four antibiotic resistance genes including class A β-lactamase gene far-1, RNA polymerase binding protein gene RbpA, multi-drug resistance efflux pump transcription activator gene MtrA and regulatory transcription factor gene vanR-O were identified in the Nocardia farcinica genomes, which conferred resistance to beta-lactams, rifampicin, macrolides and vancomycin respectively. No acquired TMP/SMX resistance genes were identified. There are multiple missense mutations in the dihydrofolate reductase family genes. Four virulence genes of icl, mbtH, phoP, and relA that are homologous to Mycobacterium tuberculosis were found. SNP homologous tree analysis showed the two Nocardia strains were closely related, and there were only ten SNP sites, six compound substitutions and one deletion mutation between them. Conclusions: Whole genome sequencing technology is helpful to explore the molecular characteristics and resistance mechanisms of Nocardia species. Nocardia farcinica has a trend of spreading in China. Resistance to TMP/SMX is worthy of attention. The mutation of genes involved in the metabolic pathway of dihydrofolate might be one of multiple TMP/SMX resistance mechanisms.

[Expression and pathological role of galectin-10 in different types of nasal polyps]

Objective: To investigate the different expression of galectin-10 in nasal polyps with different degrees of eosinophil infiltration, and to explore whether galectin-10 can be used as a new biomarker of eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) and its possible role in the pathogenesis of ECRSwNP. Methods: A total of 36 patients (20 males, 16 females, aged from 14 to 74 years old) who underwent functional endoscopic sinus surgery at the Second Affiliated Hospital of Nanchang University from November 2018 to April 2019 were enrolled into the retrospective study, including 11 cases of ECRSwNP, 15 cases of non-ECRSwNP and 10 cases in control group (deviation of nasal septum). The patients were divided into allergic rhinitis and non-allergic rhinitis groups, atopy and non-atopy groups according to whether patients in the experimental group and control group had allergic rhinitis and atopy. HE staining was performed for histological assessment of CRSwNP which was classfied as ECRSwNP and non-ECRSwNP. Immunohistochemistry (IHC) was used to determine the positive localization and semi-quantitative expression level of galectin-10 protein in ERSwNP, non-ECRSwNP and control groups. The expression levels of galectin-10 protein in three groups were determined by Western Blot. The expression levels of galectin-10 mRNA in three groups were determined using real-time quantitative polymerase chain reaction (qRT-PCR). Analyzing the correlation between the expression of galectin-10 and clinical factors including the allergic rhinitis and atopy, SPSS 19.0 software and Graphpad prism 7.0 were used for statistical analysis and mapping. Results: By using IHC method, it was found that galectin-10 was mainly localized in eosinophils in the polyp tissues. The semi-quantitative expression of the galectin-10 in the ECRSwNP group (0.051±0.003) was significantly higher than that of non-ECRSwNP (0.028±0.004) and control groups (0.025±0.004, t value was 3.862 and 5.137, both P<0.01). There was no significant difference between the control and non-ECRSwNP groups (t=0.560, P>0.05). The expression of galectin-10 in the ECRSwNP group was significantly higher than that of non-ECRSwNP and control groups (t value was 25.351 and 27.376, both P<0.01). However, there was no significant difference between the non-ECRSwNP and control groups (t=1.071, P>0.05). Compared with the non-ECRSwNP (1.188±0.054) and control groups (1.020±0.142), the expression of galectin-10 mRNA was higher in the ECRSwNP group (2.413±0.303), the differences were significant (t value was 3.973 and 4.156, both P<0.05). There was no significant difference between the non-ECRSwNP and control groups (t=1.110, P>0.05). There was no significant difference in the expression of galectin-10 between the allergic rhinitis group and the non-allergic rhinitis group (all P>0.05), so as to the atopy group and non-atopy group(all P>0.05). Conclusion: The expression level of galectin-10 is elevated in ECRSwNP, and not influenced by allergic status, suggesting that galectin-10 may be a new biomarker for ECRSwNP and play an important role in the pathogenesis of ECRSwNP.

[Exploration on endovascular treatment for symptomatic occlusion of the intracranial vertebral arteries in early non-acute stage]

Objective: To examine the clinical efficacy of endovascular treatment on symptomatic occlusion of intracranial vertebral artery (ICVA) in early non-acute stage. Methods: Nine consecutive patients who presented with aggressive ischemic events in the early non-acute stage of ICVA occlusion from January 2014 to December 2019 and received endovascular treatment at Department of Neurosurgery, Peking University First Hospital were retrospectively reviewed.There were 7 males and 2 females, aged 63.4 years old(range: 52 to 72 years).The average preoperative modified Rankin scale(mRS) was 4.3(range: 4 to 5), the National Institute of Health stroke scale(NIHSS) was 12.3(range: 8 to 18). Among them, 2 patients received a single stage endovascular treatment, and the other 7 patients received staged endovascular treatment.The strategy of staged treatment was as follows: firstly, the occlusion part was passed through by a micro-guidewire and dilated with balloons to maintain the blood flow above Thrombolysis In Cerebral Infarction grade 2b. Then, the intravascular large load thrombus was eliminated by the fibrinolytic system and strengthened antiplatelet drugs. After that, a second stage of angioplasty with stenting was performed on the severe residual stenosis part.The complications and the recanalization rate were collected, and the National NIHSS and mRS after endovascular treatment and in follow-up period were recorded. Results: In the 2 cases received single stage endovascular treatment, although revascularization was achieved lastly, one patient suffered embolus translocation and the other suffered re-occlusion after mechanical thrombectomy during the operation, respectively.Technical success was achieved in 6 of the 7 patients received staged endovascular treatment.On discharge, the average NIHSS scores was 5.7(range: 3 to 4) of the patients. Three months after operation,the average mRS was 1.6(range:0 to 3) and it was 0.9(range: 0 to 2) at the latest follow-up, which were better than preoperative status. Conclusions: Staged endovascular treatment might be a safe, efficient, viable option in carefully selected patients with symptomatic ICVA occlusion in early non-acute stage. It needs to be confirmed by further investigation, preferably in a large controlled setting.

Topologically protected beam splitters and logic gates based on two-dimensional silicon photonic crystal slabs

The beam splitters are essential optical components that are widely used in various optical instruments. The robustness of beam splitters is very necessary to all-optical networks. Here we report the design of the topologically protected beam splitter, whose splitting ratio can change flexibly to an arbitrary ratio, such as 50:50, 33:67, 25:75, based on the two-dimensional silicon photonic crystal slab. By using the 50:50 beam splitter, all major logic gates (OR, AND, NOT, XOR, NAND, XNOR, and NOR) are suitably designed with the linear interference approach. Additionally, these devices exhibit robustness even though some disorders exist. It is expected that these robust and compact devices are potentially applicable in optical computing and signal processing.