Objective To investigate a suspected outbreak event of Mycobacterium abscessus(Mab)infection in department of pulmonary and critical care medicine in a hospital,provide basis for the precise prevention and control of healthcare-associated infection(HAI).Methods On-site epidemiological investigation and environmental hygienic detection were carried out in patients with Mab infection following fiberbronchoscopic bronchoalveolar lavage in the department of pulmonary and critical care medicine in this hospital,and targeted intervention measures were pro-posed.Results From September 7 to October 20,2022,a total of 344 cases of bronchoalveolar lavage were per-formed for patients in fiberbronchoscopy room of department of pulmonary and critical care medicine.Mab was de-tected from bronchoalveolar lavage fluid(BALF)of 10 patients.Through on-site and follow-up investigation,the initial case was defined as community-associated infection,and the other 9 cases were due to the contamination of specimens.A total of 33 environmental hygienic specimens were collected,and no Mab was detected.The event was effectively controlled after standardizing the process of bronchoscope decontamination,strengthening the infection management of ward and bronchoscopy room,and strictly implementing the certificate system of bronchoscopy de-contamination personnel.Conclusion This pseudo-outbreak is due to the contamination of fiberbronchoscope by Mab.Timely identifying risk factors as well as taking targeted prevention and control measures can effectively con-trol the spread and prevalence of Mab infection.

In recent years, the development of host-acting antibacterial compounds has gradually become a hotspot in the field of anti-infection. Through research on the interaction mechanism between hosts and pathogenic bacteria, it has been found that the immune system is one of the key targets of host-acting antibacterial compounds. There is a communication system called the quorum sensing system in microorganisms, which mainly adjusts the structure of multi-microbial community and coordinates the group behavior. When the quorum sensing molecules secreted by microorganisms reach a threshold concentration, the quorum sensing system is activated and the overall gene expression of the microorganism is changed. In addition to regulating the density of microorganisms, quorum sensing molecules can also act as a link between pathogenic microorganisms and hosts, entering the host immune system and playing a role in affecting the morphological structure of immune cells, secreting cytokines, and inducing apoptosis, leading to host immune injury and causing host immune dysfunction.The key mechanism of 3-oxo-C12-HSL and other acyl-homoserine lactone (AHL) molecules in the innate immune system has been extensively studied. The lipid solubility allows AHLs to pass through the plasma membrane of host immune cells easily and induce dissolution of lipid domains. Then, it acts through signaling pathways such as p38MAPK and JAK-STAT, further influencing the immune cell’s defense response to bacteria and potentially leading to cell apoptosis. Additionally, the human lactonase paraoxonase 2, which can degrade3-oxo-C12-HSL, has been found in macrophage. It acts as an immune regulator that promotes macrophage phagocytosis of pathogens and is hypothesized to have the ability to reduce bacterial resistance. The mechanism of quorum sensing molecules in the adaptive immune system is less studied, the current results suggest that 3-oxo-C12-HSL is closely related to the mitochondrial pathway in host immune cells. For example, 3-oxo-C12-HSL induces apoptosis of Jurkat cells by inhibiting the expression of three mitochondrial electron transport chain proteins; it can also trigger mitochondrial dysfunction and induce mast cell apoptosis through Ca²⁺ signaling.Among the quorum sensing molecules, the AHLs have the greatest impact on plant immune system. The different effects on plant resistance depends on the chain lengths of acyl groups in bacterial-produced AHLs. Short-chain AHLs (C4-HSL and C8-HSL) induce plant resistance to pathogenic bacteria mainly through the auxin pathway and jasmonic acid pathway. Long-chain AHL (3-oxo-C14-HSL) is commonly used in hosts against fungal pathogens by inducing stomata defense responses, and the reaction process is related to salicylic acid. Diffusible signal factor molecules also interfere with the stomatal immunity caused by pathogens. It may act through the formin nanoclustering-mediated actin assembly and MPK3 pathway to inhibit the innate immunity of Arabidopsis. In summary, AHLs induced different plant pathways and affects the plant-bacteria interactions to trigger plant immunity. As a quorum sensing molecule of fungi, farnesol has similar effects on host immunity as AHLs, such as stimulating cytokine secretion and activating an inflammatory response. It also plays a unique role on dendritic cell differentiation and maturation. In addition, studies have found that farnesol has a protective effect on autoimmune encephalomyelitis, which may be related to its effect on the composition of intestinal microorganisms of the host.Therefore, targeting the host immune system and quorum sensing molecules to develop antibacterial compounds can effectively inhibit the invasion of pathogens and subserve the host to resist the influence of pathogenic bacteria. This article will review the mechanism of host immune responses triggered by important quorum sensing molecules, aiming to explore the targets of host-acting antibacterial compounds and provide new directions for the prevention or treatment of causative infectious sources and the development of related drugs.

Congenital bilateral absence of the vas deferens (CBAVD) is observed in 1%-2% of males presenting with infertility and is clearly associated with cystic fibrosis transmembrane conductance regulator (CFTR) mutations. CFTR is one of the most well-known genes related to male fertility. The frequency of CFTR mutations or impaired CFTR expression is increased in men with nonobstructive azoospermia (NOA). CFTR mutations are highly polymorphic and have established ethnic specificity. Compared with F508Del in Caucasians, the p.G970D mutation is reported to be the most frequent CFTR mutation in Chinese patients with cystic fibrosis. However, whether p.G970D participates in male infertility remains unknown. Herein, a loss-of-function CFTR p.G970D missense mutation was identified in a patient with CBAVD and NOA. Subsequent retrospective analysis of 122 Chinese patients with CBAVD showed that the mutation is a common pathogenic mutation (4.1%, 5/122), excluding polymorphic sites. Furthermore, we generated model cell lines derived from mouse testes harboring the homozygous Cftr p.G965D mutation equivalent to the CFTR variant in patients. The Cftr p.G965D mutation may be lethal in spermatogonial stem cells and spermatogonia and affect the proliferation of spermatocytes and Sertoli cells. In spermatocyte GC-2(spd)ts (GC2) Cftr p.G965D cells, RNA splicing variants were detected and CFTR expression decreased, which may contribute to the phenotypes associated with impaired spermatogenesis. Thus, this study indicated that the CFTR p.G970D missense mutation might be a pathogenic mutation for CBAVD in Chinese males and associated with impaired spermatogenesis by affecting the proliferation of germ cells.
Humans ; Animals ; Mice ; Male ; Mutation, Missense ; Retrospective Studies ; Cystic Fibrosis Transmembrane Conductance Regulator/genetics* ; Infertility, Male/genetics* ; Mutation ; Vas Deferens/abnormalities* ; Spermatogenesis/genetics*

PURPOSE: This study aims to elucidate the electrotaxis response of alveolar epithelial cells (AECs) in direct-current electric fields (EFs), explore the impact of EFs on the cell fate of AECs, and lay the foundation for future exploitation of EFs for the treatment of acute lung injury. METHODS: AECs were extracted from rat lung tissues using magnetic-activated cell sorting. To elucidate the electrotaxis responses of AECs, different voltages of EFs (0, 50, 100, and 200 mV/mm) were applied to two types of AECs, respectively. Cell migrations were recorded and trajectories were pooled to better demonstrate cellular activities through graphs. Cell directionality was calculated as the cosine value of the angle formed by the EF vector and cell migration. To further demonstrate the impact of EFs on the pulmonary tissue, the human bronchial epithelial cells transformed with Ad12-SV40 2B (BEAS-2B cells) were obtained and experimented under the same conditions as AECs. To determine the influence on cell fate, cells underwent electric stimulation were collected to perform Western blot analysis. RESULTS: The successful separation and culturing of AECs were confirmed through immunofluorescence staining. Compared with the control, AECs in EFs demonstrated a significant directionality in a voltage-dependent way. In general, type Ⅰ alveolar epithelial cells migrated faster than type Ⅱ alveolar epithelial cells, and under EFs, these two types of cells exhibited different response threshold. For type Ⅱ alveolar epithelial cells, only EFs at 200 mV/mm resulted a significant difference to the velocity, whereas for, EFs at both 100 mV/mm and 200 mV/mm gave rise to a significant difference. Western blotting suggested that EFs led to an increased expression of a AKT and myeloid leukemia 1 and a decreased expression of Bcl-2-associated X protein and Bcl-2-like protein 11. CONCLUSION EFs could guide and accelerate the directional migration of AECs and exert antiapoptotic effects, which indicated that EFs are important biophysical signals in the re-epithelialization of alveolar epithelium in lung injury.
Humans ; Rats ; Animals ; Alveolar Epithelial Cells ; Lung ; Lung Injury ; Cell Movement/physiology*

Objective:To evaluate the effects of neuromuscular blocking agents (NMBA) on oxygenation and respiratory conditions in patients with acute respiratory distress syndrome(ARDS).Methods:English databases such as MEDLINE, Embase and Web of Science were searched online, as well as Chinese databases such as China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database and Wanfang Database. Randomized controlled trials (RCTs) of NMBA therapy for ARDS with publication date up to May 2020 were retrieved. Literature was screened according to inclusion and exclusion criteria, and the main analysis indicators were oxygenation index.Results:A total of 5 RCTs were included, and 1 462 ARDS patients were enrolled. Compared with the control group, the ratio of partial arterial oxygen pressure to fraction of inspired (PaO 2)/(FiO 2) significantly improved in the intervention group after 72 hours MD=14.39, (95 %CI 6.40-22.38, P=0.000 4) and 96 hours of NMBA, but there was no difference between PaO 2/FiO 2 at 24 and 48 hours ( P>0.05).Positive end expiratory pressure (PEEP) significantly decreased at 72 hours ( MD=-0.45, 95 %CI -0.87--0.03, P=0.04) and 96 hours ( MD=-0.82, 95 %CI -1.39--0.26, P=0.004) treatment with NMBA, while there was no significant difference in PEEP between 24 and 48 hours after treatment ( P>0.05). At 96 h, plateau pressure (Pplat) in the intervention group was significantly lower ( MD=-1.69, 95 %CI -2.64--0.75, P=0.000 4), and there was no significant difference in Pplat between 24, 48 and 72 h after treatment ( P>0.05). Conclusion:The early use of NMBA within 48 hours has a delayed improvement effect on oxygenation and ventilator conditions in ARDS patients.

OBJECTIVES: To investigate the incidence of extrauterine growth retardation (EUGR) and its risk factors in very preterm infants (VPIs) during hospitalization in China. METHODS: A prospective multicenter study was performed on the medical data of 2 514 VPIs who were hospitalized in the department of neonatology in 28 hospitals from 7 areas of China between September 2019 and December 2020. According to the presence or absence of EUGR based on the evaluation of body weight at the corrected gestational age of 36 weeks or at discharge, the VPIs were classified to two groups: EUGR group (n=1 189) and non-EUGR (n=1 325). The clinical features were compared between the two groups, and the incidence of EUGR and risk factors for EUGR were examined. RESULTS: The incidence of EUGR was 47.30% (1 189/2 514) evaluated by weight. The multivariate logistic regression analysis showed that higher weight growth velocity after regaining birth weight and higher cumulative calorie intake during the first week of hospitalization were protective factors against EUGR (P<0.05), while small-for-gestational-age birth, prolonged time to the initiation of total enteral feeding, prolonged cumulative fasting time, lower breast milk intake before starting human milk fortifiers, prolonged time to the initiation of full fortified feeding, and moderate-to-severe bronchopulmonary dysplasia were risk factors for EUGR (P<0.05). CONCLUSIONS It is crucial to reduce the incidence of EUGR by achieving total enteral feeding as early as possible, strengthening breastfeeding, increasing calorie intake in the first week after birth, improving the velocity of weight gain, and preventing moderate-severe bronchopulmonary dysplasia in VPIs.
Female ; Fetal Growth Retardation ; Gestational Age ; Hospitalization ; Humans ; Incidence ; Infant ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Prospective Studies ; Risk Factors

Objective:To analyze the risk factors of bronchopulmonary dysplasia(BPD)in very preterm infants(VPI), and to provide scientific basis for the prevention and treatment of BPD in VPI.Methods:A prospective multicenter study was designed to collect the clinical data of VPI in department of neonatology of 28 hospitals in 7 regions from September 2019 to December 2020.According to the continuous oxygen dependence at 28 days after birth, VPI were divided into non BPD group and BPD group, and the risk factors of BPD in VPI were analyzed.Results:A total of 2 514 cases of VPI including 1 364 cases without BPD and 1 150 cases with BPD were enrolled.The incidence of BPD was 45.7%.The smaller the gestational age and weight, the higher the incidence of BPD( P<0.001). Compared with non BPD group, the average birth age, weight and cesarean section rate in BPD group were lower, and the incidence of male infants, small for gestational age and 5-minute apgar score≤7 were higher( P<0.01). In BPD group, the incidences of neonatal respiratory distress syndrome(NRDS), hemodynamically significant patent ductus arteriosus, retinopathy of prematurity, feeding intolerance, extrauterine growth restriction, grade Ⅲ~Ⅳ intracranial hemorrhage, anemia, early-onset and late-onset sepsis, nosocomial infection, parenteral nutrition-associated cholestasis were higher( P<0.05), the use of pulmonary surfactant(PS), postnatal hormone exposure, anemia and blood transfusion were also higher, and the time of invasive and non-invasive mechanical ventilation, oxygen use and total hospital stay were longer( P<0.001). The time of starting enteral nutrition, cumulative fasting days, days of reaching total enteral nutrition, days of continuous parenteral nutrition, days of reaching 110 kcal/(kg·d) total calorie, days of reaching 110 kcal/(kg·d) oral calorie were longer and the breastfeeding rate was lower in BPD group than those in non BPD group( P<0.001). The cumulative doses of amino acid and fat emulsion during the first week of hospitalization were higher in BPD group( P<0.001). Multivariate Logistic regression analysis showed that NRDS, invasive mechanical ventilation, age of reaching total enteral nutrition, anemia and blood transfusion were the independent risk factors for BPD in VPI, and older gestational age was the protective factor for BPD. Conclusion:Strengthening perinatal management, avoiding premature delivery and severe NRDS, shortening the time of invasive mechanical ventilation, paying attention to enteral nutrition management, reaching whole intestinal feeding as soon as possible, and strictly mastering the indications of blood transfusion are very important to reduce the incidence of BPD in VPI.

OBJECTIVE: To analyze the experience of diagnosis and treatment of a case of brodifacoum poisoning. METHODS: The clinical data of a case of unexplained brodifacoum poisoning was retrospectively analyzed. RESULTS: The patient went to the doctor for unexplained bleeding. The bleeding symptoms included nasal o blood ozing, blood in saliva and skin ecchymosis. Blood anticoagulative rodenticide test showed positive with brodifacoum. The results of coagulative function tests showed that the indexes of partial prothrombin time, prothrombin time and fibrinogen were increased. The patient was diagnosed as brodifacoum poisoning based on the clinical symptoms and laboratory test results. The combined use of 40 mg/d of vitamin K_1 and frozen plasma improved the clotting time and quickly alleviated the bleeding symptoms of the patient. However, the patient′s bleeding symptoms recurred when vitamin K_1 was discontinued. The patient was hospitalized for 62 days and then discharged. With follow-up one month after discharge, the patient showed no bleeding symptoms, but brodifacoum could still be detected in the blood. CONCLUSION: The symptoms of brodifacoum poisoning may relapse and the treatment course is long. Vitamin K_1 could be used as the first-choice medicine for the treatment of brodifacoum poisoning, but its usage needs to be optimized.

Objective:This study aims to evaluate the clinical effect of Changyanqing mixture combined with mesalazine enteric-coated tablets in the maintenance treatment of ulcerative colitis（UC） in remission period. Method:The 140 patients with UC in remission period were randomly divided into control group （70 cases） and observation group （70 cases）. The 61 patients in control group completed the therapy （6 cases lost or lost to follow-up and 3 were eliminated）， 63 patients in observation group completed the therapy （5 cases lost or lost to follow-up and 2 were eliminated）. Both groups′ patients got treatment of lifestyle adjustment， and they also took mesalazine enteric-coated tablets orally， 0.5 g/time， 3 times/day. Patients in observation group took Changyanqing mixture orally for a month in the morning and evening every day， 150 mL/time， and then changed to 150 mL/time， 1 time/day， for 3 consecutive months， finally changed to once every other day for 8 months. Patients in control group took simulated medicine of Changyanqing mixture orally in the same way as observation group. The treatment was continued for 12 months. When UC recurred during the treatment， patients took mesalazine enteric-coated tablets orally at 1 g/time， 3 times/day until remission， when the above intervention plan was continued to be adopted. The recurrence rate， first recurrence time within 12 months （duration from remission to Mayo≥3） and the degree of disease activity at recurrence were recorded. Scores of traditional Chinese medicine（TCM）syndrome and inflammatory bowel disease questionnaire （IBDQ） were evaluated once every 2 months. Before treatment， and at the 6^th and 12^th month after treatment， colonoscopy and mucosal histology were performed once， enteroscopic mucosal scores， Geboes index of mucosal histology were evaluated， and fecal calprotectin（FC） levels were detected. Also， safety evaluation was conducted. Result:During 12 months， the recurrence rate in observation group was 20.63% （13/63）， lower than 39.34% （24/61） in control group（P<0.05）， the frequency of recurrence and the first recurrence duration in observation group were all less than those in control group（P<0.01）. All these meant the disease activity of patients in observation group was lighter than that in control group （χ2=5.947， P<0.05）. After repeated measurements of variance analysis， scores of TCM syndrome， enteroscopic mucosal scores， Geboes index and FC levels in two groups gradually increased（P<0.05）， and scores of IBDQ gradually decreased （P<0.05） during the 12-month period. At the second， fourth， sixth， eighth， tenth and twelfth month， scores of TCM syndromes in observation group were lower than those in control group （P<0.01）， and scores of IBDQ were higher than those in control group （P<0.01）. At the sixth and twelfth month after treatment， intestinal endoscopic mucosal scores， Geboes index and FC levels in observation group were all lower than those in control group （P<0.01）. And there were no adverse reactions related to Changyanqing mixture. Conclusion:Changyanqing mixture combined with mesalazine enteric-coated tablets in the maintenance treatment of patients with UC in remission can control the FC level， further reduce the recurrence rate， delay the recrudescence-time， reduce the frequency of UC and the disease activity， maintain the good remission state of UC， stabilize the quality of life of patients， and ensure the safety of clinical use.

Abstract： Objective To analyze the first epidemic spread of the novel coronavirus Delta variant in China based on public security forensic perspective, investigate its transmission characteristics, contributing factors, and epidemiologic research experience, and provide a reference for the prevention and control of the epidemic caused by the novel coronavirus variant. Methods Based on the information that public security forensic experts obtained from front-line epidemiologic research, the gender, age, place of residence, transmission route and infectivity of the coronavirus disease 2019 （COVID-19） confirmed cases, asymptomatic infected persons and their close contacts in Guangzhou caused by the novel coronavirus Delta variant were analyzed. The basic reproduction number （R₀） during this epidemic in Guangzhou was calculated. Results Among the 153 cases infected with novel coronavirus Delta variant in the epidemic, 63 cases were male and 90 cases were female, their age ranging from 1 to 92 years, with a median age of 49 years. The main route of transmission was close contact, including dining together, co-living, and close contact in the same residential building. There were 31 cases of family clusters, 25 of which were in Liwan District. The epidemic lasted from May 26 to May 29, and the R₀ remained above 4.0. After May 30, R₀ began to decline and remained below 1.0 from June 7. Conclusion The novel coronavirus Delta variant is highly infectious, the crowd is generally susceptible to infection and family cluster cases are easy to occur. So, it is necessary to precisely prevent and control this strain. Public security forensic experts have both medical literacy and criminal investigation capabilities, they can play a more professional role in epidemic prevention and control.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; COVID-19 ; Child ; Child, Preschool ; China/epidemiology* ; Epidemics ; Female ; Humans ; Infant ; Male ; Middle Aged ; SARS-CoV-2 ; Young Adult