[Development of a fluorescent recombinase-aided isothermal amplification-based nucleic acid assay for detection of Leishmania]

OBJECTIVE

To develop a fluorescent recombinase-aided isothermal amplification (RAA)-based nucleic acid assay for detection of Leshimania.

METHODS

Specific primers and probes were designed targeting Leishmania internal transcribed spacer 1 (ITS1) gene for RAA assay, and a fluorescent RAA assay was developed for detection of Leishmania following screening of primer pairs and optimization of primer and probe concentrations. The sensitivity of RAA assay for detection of Leishmania was evaluated using recombinant plasmid containing Leishmania ITS1 gene sequences at different copies and Leshimania genomic DNA at different concentrations as templates, and the specificity of RAA assay for detection of Leishmania was evaluated using the genomic DNA of transfusion-transmitted parasites, including Babesia microti, Toxoplasma gondii, Plamodium vivax, P. ovale, P. falciparum, P. malariae, L. donovani and L. infantum.

RESULTS

After the optimal primer pair was screened from 9 pairs of primer combinations, the final primer and probe concentrations were optimized as 0.3 μmol/L and 0.08 μmol/L, respectively. Nucleic acid detection of Leishmania was completed by the fluorescent RAA assay at an isothermal temperature of 39 °C within 20 min. Remarkable florescent signals were seen within 5 min following RAA detection of genomic DNA of L. donovani and L. infantum, and no cross-reactions were observed with B. microti, T. gondii, P. vivax, P. ovale, P. falciparum or P. malariae. The lowest limitation of detection of the fluorescent RAA assay was 10 copies/μL recombinant plasmid containing Leishmania ITS1 gene sequences and 1 fg/μL Leishmania genomic DNA.

CONCLUSIONS

A rapid, simple, sensitive and specific fluorescent RAA assay is successfully developed for detection of L. donovani and L. infantum, which is effective for field screening of leishmaniasis.

[Establishment of a fluorescent recombinase-aided isothermal amplification assay for nucleic acid detection of Paraginiumus skrjabini and preliminary evaluation of its detection efficiency]

OBJECTIVE

To establish a nucleic acid assay for detection of Paragonimus skrjabini based on the recombinase-aided isothermal amplification (RAA) technique, and to preliminarily evaluate its detection efficiency.

METHODS

The metacercariae of P. skrjabini, P. westermani and Euparagonimus cenocopiosus were isolated from crabs, and genomic DNA was extracted for molecular characterization. The cytochrome coxidase 1 (cox1) gene sequence of P. skrjabini was selected as the target gene fragment, and the primers and probes were designed, screened and synthesized for RAA assay. The genomic DNA of P. skrjabini metacercariae from Jiyuan City and Yiyang County of Luoyang City, Henan Province were used as templates for verification of the fluorescent RAA assay. The fluorescent RAA assay was performed to detect different concentrations of plasmids containing target gene fragment and P. skrjabini metacercariae genomic DNA to determine the sensitivity. Fluorescent RAA assay was performed with recombinant plasmids containing P. skrjabini cox1 gene sequences at different concentrations and P. skrjabini genomic DNA as templates to evaluate its sensitivity, and the genomic DNA of P. westermani, E. cenocopiosus, Clonorchis sinensis and Schistosoma japonicum was detected with fluorescent RAA assay to evaluate its specificity.

RESULTS

P. skrjabini, P. westermani and E. cenocopiosus metacercariae were isolated from crabs, respectively. Molecular characterization and phylogenetic analysis confirmed their homology with the genes sequences of standard Paragonimus strains in GenBank. A fluorescent RAA assay was successfully established for nucleic acid detection of P. skrjabini, and the genomic DNA of P. skrjabini metacercariae from Jiyuan City and Yiyang County of Luoyang City, Henan Province was amplified using the fluorescent RAA assay within 5 min, while the negative control was not amplified. If the recombinant plasmid containing P. skrjabini cox1 gene sequences was used as templates, the fluorescent RAA assay showed the lowest detection limit of 10 copies/μL, and positive amplification was observed within 5 min. If genomic DNA was used as templates, the fluorescent RAA assay showed the lowest detection limit of 10 pg/μL, and all positive amplifications were found within 5 to 10 min. In addition, the fluorescent RAA assay was tested negative for P. westermani, E. cenocopiosus, C. sinensis and S. japonicum.

CONCLUSIONS

A rapid, sensitive and specific fluorescent RAA assay is successfully established for nucleic acid detection of P. skrjabini, which has potential values in rapid field detection and species identification in freshwater crabs in areas endemic for P. skrjabini.

Neural Burst Firing and Its Roles in Mental and Neurological Disorders

Neural firing patterns are critical for specific information coding and transmission, and abnormal firing is implicated in a series of neural pathologies. Recent studies have indicated that enhanced burst firing mediated by T-type voltage-gated calcium channels (T-VGCCs) in specific neuronal subtypes is involved in several mental or neurological disorders such as depression and epilepsy, while suppression of T-VGCCs relieve related symptoms. Burst firing consists of groups of relatively high-frequency spikes separated by quiescence. Neurons in a variety of brain areas, including the thalamus, hypothalamus, cortex, and hippocampus, display burst firing, but the ionic mechanisms that generating burst firing and the related physiological functions vary among regions. In this review, we summarize recent findings on the mechanisms underlying burst firing in various brain areas, as well as the roles of burst firing in several mental and neurological disorders. We also discuss the ion channels and receptors that may regulate burst firing directly or indirectly, with these molecules highlighted as potential intervention targets for the treatment of mental and neurological disorders.

Spotlight-based 3D Instrument Guidance for Autonomous Task in Robot-assisted Retinal Surgery

Retinal surgery is known to be a complicated and challenging task for an ophthalmologist even for retina specialists. Image guided robot-assisted intervention is among the novel and promising solutions that may enhance human capabilities during microsurgery. In this paper, a novel method is proposed for 3D navigation of a microsurgical instrument based on the projection of a spotlight during robot-assisted retinal surgery. To test the feasibility and effectiveness of the proposed method, a vessel tracking task in a phantom with a Remote Center of Motion (RCM) constraint is performed by the Steady-Hand Eye Robot (SHER). The results are compared to manual tracking, cooperative control tracking with the SHER and spotlight-based automatic tracking with SHER. The reported results are that the spotlight-based automatic tracking with SHER can reach an average tracking error of 0.013 mm and keeping distance error of 0.1 mm from the desired range demonstrating a significant improvement compared to manual or cooperative control methods alone.

High MEK/ERK signalling is a key regulator of diapause maintenance in the cotton bollworm, Helicoverpa armigera

MEK/ERK signalling has been identified as a key factor that terminates diapause in Sarcophaga crassipalpis and Bombyx mori. Paradoxically, high p-MEK/p-ERK signalling induces diapause in pupae of the moth Helicoverpa armigera; however, the regulatory mechanism is unknown. In the present study, we show that p-MEK and p-ERK are elevated in the brain of diapause-destined pupae and suppression of MEK/ERK activity terminates diapause progress. Reactive oxygen species (ROS) activate MEK/ERK signalling, causing large-scale phosphorylation of downstream proteins. The levels of ubiquitin-conjugated proteins are also significantly reduced when ROS or p-ERK level decreased. Moreover, terminated diapause progress by 20-hydroxyecdysone injection significantly decreases p-MEK, p-ERK and phospho-ribosomal S6 kinase levels, while phospho-MAPK substrates and ubiquitin-conjugated protein levels increase. Our data demonstrate that high MEK/ERK signalling mediated by ROS promotes diapause maintenance via increasing phosphorylation and degradation of downstream substrates. The results of this study may provide important information for understanding the regulatory mechanisms during insect diapause.

[Short-term effect of thoracoscopy-assisted mitral valvuloplasty in patients with mitral valve prolapse]

The data of 56 patients with mitral valve prolapse undergoing thoracoscopy-assisted mitral valvuloplasty in the Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University from May 2019 to December 2020 were retrospectively analyzed. Among them, 31 cases were male and 25 cases were female, with a mean age of (45±14) years. There was no death during perioperative period. No patient was converted to median sternotomy. The duration of cardiopulmonary bypass (CPB), aortic cross-clamp and operation was (207±58) min, (134±59) min, and (374±90) min, respectively. The intraoperative blood loss was (690±268) ml, and 5 (8.9%) patients required blood transfusion. Postoperative mechanical ventilation duration was (19±9) h, and 24-hour pleural fluid drainage volume was (460±247) ml. The length of intensive care unit (ICU) and hospital stay was (25±6) h and (13±4) d, respectively. Therefore, thoracoscopy-assisted mitral valvuloplasty has the advantages of reliable curative effect, less trauma, less complications, fast recovery and satisfactory perioperative outcomes.

Proton Pump Inhibitor Therapy Increases the Risk of Spontaneous Bacterial Peritonitis in Patients with HBV-Related Acute-on-Chronic Liver Failure

INTRODUCTION

Spontaneous bacterial peritonitis (SBP) is a common infection in patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF). SBP significantly increases the mortality rate and medical costs. The association between proton pump inhibitor (PPI) use and SBP remains unclear. We conducted a retrospective study to investigate the association between PPI use and SBP in patients with HBV-related ACLF and to explore the risk factors for SBP.

METHODS

We compared the SBP incidence between the PPI and non-PPI groups before and after propensity score matching and explored the association between the duration and type of PPI and SBP occurrence. Risk factors for SBP occurrence were determined by univariate and multivariate logistic regression analysis.

RESULTS

The SBP incidence was higher in the PPI group than in the non-PPI group before and after propensity score matching. The SBP incidence increased for elevated MELD scores in PPI users. There was a similar SBP incidence in both different types and durations of PPI users. MELD score, old age, male sex, and high WBC count were significant independent risk factors for SBP in PPI users with HBV-related ACLF in the hospital.

CONCLUSIONS

PPI therapy increases the risk of SBP development in patients with HBV-related ACLF. MELD score, old age, male sex, and high WBC count could serve as predictors of SBP in PPI users. Caution should be taken regarding PPI use, especially for patients with MELD scores > 30.

Automatic brain tumour diagnostic method based on a back propagation neural network and an extended set-membership filter

BACKGROUND

Diagnosing brain tumours remains a challenging task in clinical practice. Despite their questionable accuracy, magnetic resonance image (MRI) scans are presently considered the optimal facility for assessing the growth of tumours. However, the efficiency of manual diagnosis is low, and high computational cost and poor convergence restrict the application of machine learning methods. This study aims to design a method that can reliably diagnose brain tumours from MRI scans.

METHODS

First, image pre-processing (which includes background removal, size standardization, noise removal, and contrast enhancement) is utilized to normalize the images. Then, grey level co-occurrence matrix features are selected as texture features of the brain MRI scans. Finally, a method combining a back propagation neural network (BPNN) and an extended set-membership filter (ESMF) is proposed to classify features and perform image classification.

RESULTS

A total of 304 patient MRI series (247 images of brains with tumours and 57 images of normal brains) were included and assessed in this study. The results revealed that our proposed method can achieve an accuracy of 95.40% and has classification accuracies of 97.14% and 88.24% for brain tumour and normal brain, respectively.

CONCLUSION

This study proposes an automatic brain tumour detection model constructed using a combination of BPNN and ESMF. The model is found to be able to accurately classify brain MRI scans as normal or tumour images.

[Establishment of a nucleic acid dipstick test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay]

OBJECTIVE

To develop a rapid test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay (RAA) and nucleic acid dipstick test.

METHODS

The S. japonicum SjG28 gene fragment was selected as the target gene fragment, and the primers and fluorescent probe were designed and synthesized. Then, a S. japonicum nucleic acid dipstick test was established. The sensitivity of this dipstick test was evaluated by detecting different copies of recombinant plasmids containing the S. japonicum SjG28 gene fragment and different concentrations of genomic DNA from adult worms of S. japonicum, and the specificity of the dipstick test was evaluated by detecting the genomic DNA from Clonorchis sinensis, S. mansoni, Ancylostoma duodenale, S. haematobium, Babesia and Paragonimus westermani.

RESULTS

The S. japonicum nucleic acid dipstick test based on the S. japonicum SjG28 gene fragment showed the minimum detectable limit of 10 copies/μL of the recombinant plasmid containing the S. japonicum SjG28 gene fragment and the minimum detectable limit of 1 pg/μL of S. japonicum genomic DNA, and the dipstick assay tested negative for the genomic DNA from C. sinensis, S. mansoni, A. duodenale, S. haematobium, Babesia and P. westermani.

CONCLUSIONS

A rapid, simple, and visualized assay is established for detection of S. japonicum specific gene fragments based on RAA and nucleic acid dipstick test.

[Relationship of quality and duration of sleep with hypertension among adults in Guangzhou]

Objective: To explore the relationship of sleep quality and sleep duration with hypertension among adults aged 30-79 years old in Guangzhou. Methods: According to multi-stage stratified cluster sampling, 12 747 residents aged 30-79 years old were sampled and surveyed in Guangzhou from January 2018 to March 2019. Data on general demographic characteristics, sleep quality, sleep duration and hypertension were collected through questionnaire survey, the Pittsburgh sleep quality index (PSQI) and physical examination. Multivariate logistic regression models were used to analyze the putative association between sleep quality, sleep duration and hypertension. Restrictive cubic spline curve was used to draw the dose-response relationship curve between sleep quality, sleep time and hypertension. Results: The mean age of the subjects was (52.68±12.17) years, the prevalence of hypertension was 36.6% (4 664/12 747), the average score of PSQI was (4.70±2.88), and the average sleep time was (7.00±1.32) hours. The prevalence of hypertension was positively associated with the PSQI score. Compared to the subjects with a score less than 3, OR (95%CI) of hypertension with a PSQI score of 3-5, 5-8, ≥9 were 1.14 (1.02-1.27), 1.17 (1.03-1.34), 1.41 (1.21-1.64), respectively. The relationship between sleep duration and hypertension appeared U-shaped. Compared with 6 to 8 hours sleep duration, both sleep duration<6 hours with OR(95%CI) of 1.27(1.12-1.43) or >8 hours with OR(95%CI) of 1.20(1.05-1.38) was associated with hypertension. Conclusion: Both poor sleep quality, longer or shorter sleep duration were responsible for increased risk of cognitive impairment in older Chinese.

Engineering Bacillus subtilis ATCC 6051a for the production of recombinant catalases

Catalases are a large group of enzymes that decompose hydrogen peroxide to oxygen and hydrogen, and have been applied widely in numerous areas. Bacillus subtilis ATCC 6051a is a well-known host strain for high level secretion of heterologous peptides. However, the application of 6051a was seriously hampered by insufficient transformation efficiency. In this study, D-xylose inducible comK was integrated into the genome of B. subtilis ATCC 6051a, generating 164S, a mutant owns a transformation efficiency of 1 000-fold higher than its parent strain, thus allowing gene replacement by double crossover recombination using linear dsDNAs. The efficiency of the flanking arms for homologous recombination was then analyzed. We found that 400 bp was the minimal length of homologous fragments required to initiate efficient recombination in the 164S strain. In addition, DNA cassettes encoding two mesophilic catalases (Orf 2-62 and Orf 2-63) from B. licheniformis were integrated onto 164S. The catalytic properties of recombinant Orf 2-62 and Orf 2-63 were analyzed, and were found to be predominantly secreted into the fermentation broth, although they obviously lack any known secretory signal peptide. This work demonstrated that B. subtilis 164S is an excellent cell tool, not only for its superior secretion capacity, but also for its convenience in genetic modification.

[Use of alternative pancreatic fistula risk score system for patients with clinical relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy]

Objective: To examine the application value of alternative pancreatic fistula risk score system(a-FRS) for patients with clinically relevant postoperative pancreatic fistula(CR-POPF) after laparoscopic pancreaticoduodenectomy(LPD). Methods: Clinical data of 400 patients who underwent LPD at Department of Hepatobiliary and Pancreatic Surgery,Jilin University First Hospital,from April 2015 to August 2019 were retrospectively analyzed.There were 217 males and 183 females, with age of (M(Q_R)) 58 (53) years (range:26 to 93 years) and body mass index of (23.0±2.7) kg/m² (range:19.4 to 27.1 kg/m²).Preoperative CA19-9 was (171.6±212.7) U/ml (range:32.1 to 762.6 U/ml), and preoperative CA125 was (18.6±22.9) U/ml (range:9.0 to 112.3 U/ml).Univariate analysis and multivariate Logistic regression analysis were implemented to find independent risk factors in CR-POPF.According to 3 indicators of a-FRS system(pancreatic texture,main pancreatic duct diameter,and body mass index),receiver operator characteristic curve was used to prospectively analyze the clinical value of CR-POPF. Results: CR-POPF occurred in 60 patients(15.0%) among the 400 LPD patients,including 54 patients(13.5%) with grade B pancreatic fistula and 6 patients(1.5%) with grade C pancreatic fistula.Univariate and multivariate Logistic regression analysis results showed that soft pancreas,diameter of main pancreatic duct ≤3 mm,and body mass index>23 kg/m² were the independent risk factors for CR-POPF after LPD.The incidence of CR-POPF was 1.9% in the group with low pancreatic fistula risk(0 to 5%),5.9% with moderate pancreatic fistula risk(>5% to 20%),and 80.7% with high pancreatic fistula risk(>20%).a-FRS prospectively predicted the sensitivity and specificity of CR-POPF after LPD was 76.7% and 96.8%,positive predictive value was 80.7%,negative predictive value was 95.9%,positive likelihood ratio was 23.66,negative likelihood ratio was 0.24,and area under the curve was 0.735(95%CI:0.668-0.799). Conclusion: a-FRS system has great clinical application value in predicting CR-POPF after LPD,which can provide basis for early risk prediction of CR-POPF and timely related clinical intervention.

[Short- and mid-term outcomes of percutaneous balloon mitral valvuloplasty under the guidance of ultrasound]

Objective: To evaluate the safety, short- and mid-term outcomes of percutaneous balloon mitral valvuloplasty (PBMV) guided by the ultrasound. Methods: In this retrospective study, medical data of 15 patients [9 males and 6 females, with an age of (53±13) years] with PBMV under the guidance of ultrasound in Heart Center of Henan Provincial People's Hospital between December 2016 and January 2019 were collected and reviewed. The short-and mid-term outcomes were analyzed. Results: PBMV was successfully performed in all the patients. One patient underwent surgical valve replacement due to severe mitral regurgitation, and the other 14 patients were all followed up successfully. The average follow-up time was (13.8±4.6) months. Comparisons of preoperative and postoperative data showed significant differences in valve area [(1.84±0.43) cm² vs (0.89±0.24) cm²], left atrial pressure [(11.9±4.5) mmHg (1 mmHg=0.133 kPa) vs (21.9±6.0) mmHg] and mean mitral valve pressure gradient [(10.9±3.2) mmHg vs (20.1±3.6) mmHg](all P<0.01), with no significant differences in mitral regurgitation area (P=0.67). Postoperative follow-up showed that there were no significant differences in mitral valve area, regurgitation area and N-terminal pro-B-type natriuretic peptide (NT-proBNP) between short-and mid-term postoperatively (all P>0.05). There was no secondary operation due to mitral stenosis in 14 patients, and 3 patients with moderate or severe tricuspid regurgitation showed significant improvement, with gradually recovered cardiac function, and there were no deaths in these patients. Conclusion: PBMV guided by the ultrasound is feasible and effective, and exhibits favorable short-and mid-term outcomes.

[The tuberculosis sanitariums during era of the Republic of China]

The quarantine and treatment plays an important role in prevention and control of respiratory infectious diseases. It has been nearly 200 years since sanatorium model was adopted to isolate and treat patients with tuberculosis(TB). The era of the Republic of China was an important period for the model to sprout and expand. TB sanatorium was established in the early 20th century in China, and flourished in the 1930s. Establishment and changes of TB sanatoriums in Peking, Shanghai and Hangzhou during the era of the Republic of China, has great significance for sorting out the clues of China's anti-TB history, exploring historical trends of TB in China, and most important of all, summing up valuable lessons.

Unusually thick shear-softening surface of micrometer-size metallic glasses

The surface of glass is crucial for understanding many fundamental processes in glassy solids. A common notion is that a glass surface is a thin layer with liquid-like atomic dynamics and a thickness of a few tens of nanometers. Here, we measured the shear modulus at the surface of both millimeter-size and micrometer-size metallic glasses (MGs) through high-sensitivity torsion techniques. We found a pronounced shear-modulus softening at the surface of MGs. Compared with the bulk, the maximum decrease in the surface shear modulus (G) for the micro-scale MGs reaches ~27%, which is close to the decrease in the G upon glass transition, yet it still behaves solid-like. Strikingly, the surface thickness estimated from the shear-modulus softening is at least 400 nm, which is approximately one order of magnitude larger than that revealed from the glass dynamics. The unusually thick surface is also confirmed by measurements using X-ray nano-computed tomography, and this may account for the brittle-to-ductile transition of the MGs with size reductions. The unique and unusual properties at the surface of the micrometer-size MGs are physically related to the negative pressure effect during the thermoplastic formation process, which can dramatically reduce the density of the proximate surface region in the supercooled liquid state.

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The shear modulus and thickness of metallic glass (MG) surface is determined through torsion testing on micrometer-size wires

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The surface region of MG wires has a significant shear-modulus softening close to the supercooled liquid, yet still behaves solid-like

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The thickness of the soft surface of MG wires is at least 400 nm, which is about one order of magnitude larger than those revealed from surface dynamics

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The unusually thick surface accounts for the brittle-to-ductile transition of the MGs with size reduction

[Performance of a recombinase - aided amplification assay for detection of Schistosoma japonicum infections in Oncomelania hupensis]

OBJECTIVE

To evaluate the efficiency of a recombinase-aided amplification (RAA) assay for the detection of Schistosoma japonicum infections in Oncomelania hupensis snails.

METHODS

A group test was employed. Fifty Oncomelania snails were collected as a detection sample. The detection samples without infected snails were designated as negative specimens, while the detection samples that contained different numbers of infected snails were designated as positive specimens. A total of 10 negative specimens, 10 positive specimens containing 1 infected snail, 20 positive specimens containing 2 infected snails and 10 positive specimens containing 3 infected snails were assigned. Following random grouping, 40 specimens were subject to the florescent RAA assay using a blind method. The miradium shedding method served as a gold standard, and the sensitivity, specificity, Youden's index and coincidence rate of the florescent RAA assay were estimated. In addition, 20 samples consisted of 5 negative specimens and 15 positive specimens with 1, 2 and 3 infected snails respectively were grouped randomly. The same specimens were detected using the crushing method and fluorescent RAA assay with the blind method in a paired-design manner. Then, the test results were compared and analyzed.

RESULTS

Florescent RAA assay detected 29 positives in the 30 specimens containing different numbers of infected snails, with a sensitivity of 96.67%, and 8 negatives in the 10 detection specimens without infected snails, with a specificity of 80.00%, showing a Youden's index of 0.77. The coincidence rate was 100% among 10 repeated assays for a detection specimen. In addition, there was no significant difference in the detection of infected snails between the florescent RAA assay and the crushing method (χ² = 0, P > 0.05), and the actual coincidence rates of the florescent RAA assay and crushing method were 95.00% (19/20) and 90.00% (18/20) with the real results, respectively.

CONCLUSION

Fluorescent RAA assay has a favorable efficiency for the detection of S. japonicum infections in Oncomelania snails, which shows a potential in screening of S. japonicum-infected Oncomelania snails.

Development and Validation of a Clinical Predictive Model for Bacterial Infection in Hepatitis B Virus-Related Acute-on-Chronic Liver Failure

INTRODUCTION

Bacterial infection is one of the most frequent complications in hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF), which leads to high mortality. However, a predictive model for bacterial infection in HBV-ACLF has not been well established. This study aimed to establish and validate a predictive model for bacterial infection in two independent patient cohorts.

METHODS

Admission data from a prospective cohort of patients with HBV-ACLF without bacterial infection on admission was used for derivation. Bacterial infection development from day 3 to 7 of admission was captured. Independent predictors of bacterial infection development on multivariate logistic regression were used to develop the predictive model. External validation was performed on a separate retrospective cohort.

RESULTS

A total of 377 patients were enrolled into the derivation cohort, including 88 patients (23.3%) who developed bacterial infection from day 3 to 7 of admission. On multivariate regression analysis, admission serum globulin (OR 0.862, 95% CI 0.822-0.904; P < 0.001), interleukin-6 (OR 1.023, 95% CI 1.006-1.040; P = 0.009), and C-reactive protein (OR 1.123, 95% CI 1.081-1.166; P < 0.001) levels were independent predictors for the bacterial infection development, which were adopted as parameters of the predictive model (GIC). In the derivation cohort, the area under the curve (AUC) of GIC was 0.861 (95% CI 0.821-0.902). A total of 230 patients were enrolled into the validation cohort, including 57 patients (24.8%) who developed bacterial infection from day 3 to 7 of admission, and the AUC of GIC was 0.836 (95% CI 0.782-0.881). The Hosmer-Lemeshow test showed a good calibration performance of the predictive model in the two cohorts (P = 0.199, P = 0.746). Decision curve analysis confirmed the clinical utility of the predictive model.

CONCLUSION

GIC was established and validated for the prediction of bacterial infection development in HBV-ACLF, which may provide a potential auxiliary solution for the primary complication of HBV-ACLF.

[Molecular-related epidemic characteristics of influenza A (H3N2) viruses in Guangzhou, 2019]

Objective: To isolate the influenza A (H3N2) viruses from different sources in Guangzhou in 2019 and analyze these viruses' evolution and variation characteristics. Methods: The hemagglutinin (HA) and neuraminidase (NA) genes of H3N2 isolates from outpatient monitoring, influenza outbreaks, and inpatient severe cases in Guangzhou in 2019 were sequenced. Bioinformatics software analyzed the variations and evolution characteristics of HA and NA genes. Results: The epidemic peaks of influenza A (H3N2) viruses were made up of period Ⅰ (from January to August) and period Ⅱ (from November to December). The positive rate of influenza A (H3N2) in males was 13.46% (703/5 221), which was higher than that in females (11.50%, 510/4 435) (χ²=8.43,P=0.00). The group's positive rate of 10-20 years old was the highest (25.18%,665/2 641). The isolates from different sources were highly homologous and closely related to 3C.2a.1 branches, which could be further divided into three small groups of Group 1-3. Gene recombination was observed between different branches. The mutations of HA antigen sites gradually appeared from Group 1 to Group 3, leading to new antigen drift. Variations of HA antigenic sites mainly occurred in the region of A and B. The mutations of receptor binding sites of Group 1 and Group 3 viruses occurred in the anterior and posterior walls. There were two glycosylation sites lacked on region A of HA antigen observed in the isolates of Group 2-3. Conclusions: Genetic variations of H3N2 influenza viruses in Guangzhou included gene mutations and gene recombination. Under the pressure of the vaccine, the evolution of viruses was rapid. Therefore, the monitoring of molecular-related epidemic characteristics of the H3N2 influenza virus was necessary.

Glioma glycolipid metabolism: MSI2-SNORD12B-FIP1L1-ZBTB4 feedback loop as a potential treatment target

Abnormal energy metabolism, including enhanced aerobic glycolysis and lipid synthesis, is a well-established feature of glioblastoma (GBM) cells. Thus, targeting the cellular glycolipid metabolism can be a feasible therapeutic strategy for GBM. This study aimed to evaluate the roles of MSI2, SNORD12B, and ZBTB4 in regulating the glycolipid metabolism and proliferation of GBM cells. MSI2 and SNORD12B expression was significantly upregulated and ZBTB4 expression was significantly low in GBM tissues and cells. Knockdown of MSI2 or SNORD12B or overexpression of ZBTB4 inhibited GBM cell glycolipid metabolism and proliferation. MSI2 may improve SNORD12B expression by increasing its stability. Importantly, SNORD12B increased utilization of the ZBTB4 mRNA transcript distal polyadenylation signal in alternative polyadenylation processing by competitively combining with FIP1L1, which decreased ZBTB4 expression because of the increased proportion of the 3' untranslated region long transcript. ZBTB4 transcriptionally suppressed the expression of HK2 and ACLY by binding directly to the promoter regions. Additionally, ZBTB4 bound the MSI promoter region to transcriptionally suppress MSI2 expression, thereby forming an MSI2/SNORD12B/FIP1L1/ZBTB4 feedback loop to regulate the glycolipid metabolism and proliferation of GBM cells. In conclusion, MSI2 increased the stability of SNORD12B, which regulated ZBTB4 alternative polyadenylation processing by competitively binding to FIP1L1. Thus, the MSI2/SNORD12B/FIP1L1/ZBTB4 positive feedback loop plays a crucial role in regulating the glycolipid metabolism of GBM cells and provides a potential drug target for glioma treatment.