ObjectiveTo provide technical support for the molecular surveillance of pathogenic bacteria strains carrying mobile colistin resistance-1 （mcr⁃1） gene isolate from inlet of wastewater treatment plants （WWTP）. MethodsThe Enterobacteriaceae strains carrying mcr⁃1 resistance gene isolate from inlet of WWTP during April 1 to June 30， 2023 in Shanghai were cultured on blood-rich and SS culture medium and were identified using a mass spectrometry analyzer. The mcr⁃1 gene and copy number were detected by real-time fluorescence quantitative PCR. Drug susceptibility test was performed by microbroth dilution method. The copy numbers of Escherichia coli carrying mcr⁃1 gene isolated from wastewater and human fecel were statistically analyzed by SPSS 25.0. ResultsA total of 14 strains carrying the mcr⁃1 gene were isolated from 49 WWTP samples， and the positive isolation rate was 28.6%， including 12 non-diarrheal E. coli strains and 2 Klebsiella pneumoniae strains. The drug susceptibility results showed that all 14 strains were multi-drug resistant bacteria. They were all sensitive to imipenem and tigecycline， but were ampicillin- and cefazolin-resistant. There was no significant difference in the copy number between human-sourced diarrheal E. coli and wastewater-sourced non-diarrheal E. coli （t=0.647， P>0.05）. ConclusionThe isolation and identification of strains carrying the mcr⁃1 gene from inlet of WWTP samples were firstly established in Shanghai. The multi-drug resistance among the isolated strains is severe. To effectively prevent and control the spread of colistin-resistant bacteria， more attention should be paid to the surveillance of mcr⁃1 gene.

Objective:To investigate the effects of gene silencing inducible cyclooxygenase-2 (COX-2) combined with hyperbaric oxygen (HBO) on neuronal cell edema, apoptosis, autophagy and neural functional recovery in rats with intracerebral hemorrhage.Methods:SPF-grade adult male SD rats ( n=96) were used to establish a cerebral hemorrhage model through stereotactic injection of thrombin VII into the caudate nucleus. They were randomized (random number) into 4 groups ( n=24/group): control group, hyperbaric oxygen (HBO) group, COX-2 RNAi group and combined group (COX-2 RNAi+HBO). The siRNA plasmid targeting silencing COX-2 gene expression was constructed. After group treatment, the four rats were randomly selected from each group for testing in each category. Postoperative day 1, 7, and 14 were assessed using the modified neurological severity score (mNSS) for evaluating neurofunctional deficits. On the 7th day, the water content of the brain tissue was measured using the dry/wet weight method. The blood-brain barrier permeability was assessed using the Evans method. Annexin V and TUNEL assays were employed to assess the apoptotic rate of neural cells. The mRNA expression level of COX-2 in brain tissue was determined using the RT-PCR method. The protein expression levels of Beclin-1, COX-2, aquaporin 4 (AQP-4), B cell lymphoma/lewkmia-2 (Bcl-2), caspase-3, hypoxia-inducible factor-1α (HIF-1α) and matrix metalloprotein-2/9 (MMP-2/9) were detected by Western blot (WB). SPSS software was used for data analysis. One-way ANOVA was used for inter group comparisons and LSD- t test was used for further pairwise comparison. Results:The SD rat intracerebral hemorrhage model and plasmid construction were successfully achieved. The mNSS scores were significantly decreased in COX-2 RNAi, HBO and combined groups compared with control group on the 7th day and 14th day (all P<0.01), especially in combined group ( P<0.01). The contents of Evans blue and the water content of brain tissue of all treatment groups were significantly lower than those in control group (all P<0.05), especially in combined group ( P<0.01). The apoptotic rate of neural cells decreased in all treatment groups compared with the control group (all P<0.05), and the combined group decreased the most ( P<0.01). The mRNA expression levels of COX-2 were significantly decreased in all treatment groups compared with the control group (all P<0.01), and combined group silenced COX-2 expression most obviously ( P<0.05). The results of WB showed that the protein expression levels of Beclin-1, COX-2, AQP-4, Caspase-3, HIF-1α, MMP-2/9 were significantly lower than control group (all P<0.05), while the expression of Bcl-2 was increased in all treatment groups (all P<0.01). Among them, the combined group exhibited the most pronounced trend ( P<0.01). Conclusions:Gene silencing of COX-2 in combination with hyperbaric oxygen therapy can effectively restore neurological function in rats with cerebral hemorrhage. The mechanism may be associated with reduced blood-brain barrier permeability, alleviated brain edema, and inhibition of neuronal apoptosis and autophagy.

ObjectiveTo explore whether miR-375 regulates the malignant characteristics of osteosarcoma (OS) by influencing the expression of MMP13. MethodsPlasmid DNAs and miRNAs were transfected into OS cells and HEK293 cells using Lipofectamine 3000 reagent. Real-time quantitative polymerase chain reaction was performed to measure the expression of miR-375 and MMP13 in OS patients and OS cells. Western blot was performed to analyze the MMP13 protein in the patients with OS and OS cells. The targeting relationship between miR-375 and MMP13 was analyzed by luciferase assay. Migration and invasion were analysed by heal wound and transwell assays, respectively. ResultsmiR-375 expression in OS tissues was lower than that in normal tissues. The expression of MMP13 was upregulated in OS tissues. MMP13 expression was negatively correlated withmiR-375 expression in patients with OS. Migration and invasion were significantly inhibited in OS cells with the miR-375 mimic compared with OS cells with the miRNA control. MMP13 partially reversed the inhibition of migration and invasion induced by miR-375 in the OS cells. ConclusionmiR-375 attenuates migration and invasion by downregulating the expression of MMP13 in OS cells.

ObjectiveGastric cancer (GC) seriously affects human health and life, and research has shown that it is closely related to the serine/glycine metabolism. The proliferation ability of tumor cells is greatly influenced by the metabolism of serine and glycine. The aim of this study was to investigate the molecular mechanism of serine/glycine metabolism can affect the proliferation of gastric cancer cells. MethodsIn this work, a stable metabolic dynamic model of gastric cancer cells was established via a large-scale metabolic network dynamic modeling method in terms of a potential landscape description of stochastic and non-gradient systems. Based on the regulation of the model, a quantitative analysis was conducted to investigate the dynamic mechanism of serine/glycine metabolism affecting the proliferation of gastric cancer cells. We introduced random noise to the kinetic equations of the general metabolic network, and applied stochastic kinetic decomposition to obtain the Lyapunov function of the metabolic network parameter space. A stable metabolic network was achieved by further reducing the change in the Lyapunov function tied to the stochastic fluctuations. ResultsDespite the unavailability of a large number of dynamic parameters, we were able to successfully construct a dynamic model for the metabolic network in gastric cancer cells. When extracellular serine is available, the model preferentially consumes serine. In addition, when the conversion rate of glycine to serine increases, the model significantly upregulates the steady-state fluxes of S-adenosylmethionine (SAM) and S-adenosyl homocysteine (SAH). ConclusionIn this paper, we provide evidence supporting the preferential uptake of serine by gastric cancer cells and the important role of serine/glycine conversion rate in SAM generation, which may affect the proliferation ability of gastric cancer cells by regulating the cellular methylation process. This provides a new idea and direction for targeted cancer therapy based on serine/glycine metabolism.

Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

Microsporidia is a group of intracellular parasitic eukaryotic microorganisms that pose threats to livestock fish production and human health, but there is no special chemo-therapeutic drug available for the treatment of microsporidia currently. In this study, sulfonamide derivatives of spectinomycin were designed by taking into consideration the low toxicity of spectinomycin and the favorable pharmaceutical properties of sulfonamides. Through the exploration of reaction conditions, a total of 21 target molecules were synthesized with a yield of 52%-74% and their chemical structures were confirmed by ¹H NMR, ¹³C NMR, and high resolution mass spectrometry (HR MS). By screening in vitro, the host cell cytotoxicity and biological activity of target molecules to Encephalitozoon hellem, a representative of vertebrates infecting microsporidia, were studied. It was found that four target molecules each could inhibit or promote the proliferation of E. hellem. In this study, the synthesis method of sulfonamide derivatives of spectinomycin was established, and new compounds effective against E. hellem were discovered, which provided a new idea for the further derivatization of spectinomycin and the development of therapeutic drugs targeting microsporidia.

Objective To develop a prefilled portable intelligent intravenous transfusion pump to facilitate fast and convenient fluid pumping during emergency treatment and casualty transport.Methods The prefilled portable intelligent venous transfusion pump was composed of a driver module,a pump module,a human-machine interface,a prefilled sterile infusion bag and a pump catheter.The driver module adopted integrated design and applied a high-voltage DC-AC converter to driving the piezoelectric pump used as the power source of the pump module;the human-machine interface consisted of several keys for on/off,rate adjustment,switching and confirmation;the prefilled sterile infusion bag was made of medical-grade polypropylene,and the pump catheter was made of medical silicone rubber.Results The transfusion pump developed could be worn on the casualty limb and did not require height difference for intravenous infusion,which enhanced intravenous drug delivery in portability,reliability and intelligence.Conclusion The transfusion pump developed gains advantages in low size,weight and easy operation,and thus is worthy promoting for venous transfusion in battlefield conditions and field emergency environments.[Chinese Medical Equipment Journal,2024,45(5):111-114]

Objective:To observe the changes in the nutritional status of pediatric patients after allogeneic hematopoietic stem cell transplantation(allo-HSCT)for one year,and to analyze the risk factors.Methods:We collected data from 88 pediatric patients who underwent allo-HSCT at the Department of Hematology and Oncology in Children's Hospital of Nanjing Medical University between May 2018 and November 2022.All pediatric patients underwent nutritional status analysis before transplantation,at enrollment,3 months,6 months and 1 year after allo-HSCT.Linear regression model was used to analyze the risk factors for growth rate.Results:The body mass index Z score(BMI-Z)before allo-HSCT was(0.096±1.349),and decreased to(-0.258±1.438)、(-0.715±1.432)、(-0.584±1.444)at enrollment,3 months,6 months after allo-HSCT,and(-0.130±1.317)at 1 year after allo-HSCT(P<0.001).There was no significant change in BMI-Z between pre-transplantation and 1 year after transplantation(P=1.000).Height for age Z score(HAZ)before transplantation was(0.137±1.305)and decreased to(-0.083±1.267)、(-0.221±1.299)、(-0.269±1.282)in 3 months,6 months and 1 year after allo-HSCT(P<0.001).Multivariate linear regression showed that age≥10 years old(P=0.015)and chronic graft-versus-host disease(cGVHD)(P=0.005)were independent risk factors for change in HAZ.Conclusion:The BMI-Z of pediatric patients treated with allo-HSCT returned to the pre-transplantation level after one year,while HAZ continued to decrease.Allo-HSCT may cause impaired growth rate in pediatric patients.Attention should be paid to HAZ changes in pediatric patients before and after allo-HSCT,especially in pediatric patients≥10 years old of age and those with cGVHD.Effective nutritional intervention should be provided in time.

Lasers are widely utilized in ion sources for mass spectrometry.They can be employed to desorb and ionize samples directly or enhance the ionization efficiency of neutral molecules through post-ionization.To investigate the ionization characteristics of the single photon ionization technique,in this work,a femtosecond laser with a wavelength of 515 nm was utilized for desorption,and a nanosecond laser with a wavelength of 118 nm for post-ionization.A laboratory-built laser desorption/laser post-ionization time-of-flight mass spectrometer(LDPI-TOFMS)was used to analyze three types of organic substances including acridines,phenothiazines,and metal porphyrins.The results demonstrated that the single photon ionization method effectively reduced the fragment generation,safeguarded the molecular ions against fragmentation,and achieved soft ionization as indicated by the adductive and characteristic molecular ions.Furthermore,a 266-nm nanosecond laser was employed as a multiphoton post-ionization source for comparison.The outcomes indicated that molecules were significantly fragmented,and more fragmented ions were generated due to the multiphoton ionization technique,which complicated the spectral analysis.The comparison further demonstrated that the single-photon post-ionization technology could be utilized to analyze a variety of organic compounds via soft ionization.LDPI-TOFMS procedure was straightforward,and did not require intricate sample preparations.The laser desorption with single photon post-ionization mass spectrometry showed potential to offer a high level of sensitivity and specificity for surfaces,thin layers,and complicated sample analysis.