[Effects of ppk1 deletion on the drug susceptibility of uropathogenic Escherichia coli producing ESBLs].

To investigate the effect and the mechanism of ppk1 gene deletion on the drug susceptibility of uropathogenic Escherichia coli producing extended-spectrum beta-lactamases (ESBLs-UPEC). The study was an experimental study. From March to April 2021, a strain of ESBLs-UPEC (genotype was TEM combined with CTX-M-14) named as UE210113, was isolated from urine sample of the patient with urinary tract infection in the Laboratory Department of Guangzhou Eighth People's Hospital, meanwhile its ppk1 gene knock-out strain Δpk1 and complemented strain Δpk1-C were constructed by suicide plasmid homologous recombination technique, which was used to study the effect of ppk1 gene on ESBLs-UPEC drug sensitivity and its mechanism. The drug susceptibility of UE210113, Δpk1, and Δpk1-C were measured by Vitek2 Compact System and broth microdilution method. The quantitative expression of ESBLs, outer membrane protein and multidrug efflux systems encoding genes of UE210113, Δpk1 and Δpk1-C were performed by using qRT-PCR analysis. By using two independent sample Mann-Whitney U test, the drug susceptibility results showed that, compared with UE210113 strain, the sensitivities of Δpk1 to ceftazidime, cefepime, tobramycin, minocycline and cotrimoxazole were enhanced (Z=-2.121,P<0.05;Z=-2.236,P<0.05;Z=-2.236,P<0.05;Z=-2.121,P<0.05), and the drug susceptibility of Δpk1-C restored to the same as which of UE210113 (Z=0,P>0.05). The expression levels of ESBLs-enconding genes blaTEM and blaCTX-M-14 in Δpk1 were significantly down-regulated compared with UE210113, but the expression was not restored in Δpk1-C. The expression of outer membrane protein gene omp F in Δpk1 was significantly up-regulated, while the expression of omp A and omp C were down-regulated. The results showed that the expression of multidrug efflux systems encoding genes tol C, mdt A and mdtG were down-regulated in Δpk1 compared with UE210113. The expression of all of the outer membrane protein genes and the multidrug efflux systems genes were restored in Δpk1-C. In conclusion,the lost of ppk1 gene can affect the expression of the outer membrane protein and multidrug efflux systems encoding genes of ESBLs-UPEC, which increase the sensitivity of ESBLs-UPEC to various drugs.

[Research progress on toxic effects and biomarkers of organophosphate ester flame retardant exposures].

Organophosphate ester (OPEs) has been widely used as a substitute of brominated biphenyl ethers and other brominated flame retardant (BFRs), and their health effects and environmental impacts are widely concerned. This article systematically reviews the common types, metabolites, environmental occurrences, exposure pathways, levels, toxic effects and biomarkers of OPEs, in order to explore the relationships between OPEs exposures and biomarkers, to reveal the potential mechanisms of health effects, and to provide references and scientific basis for the health effects of OPEs exposure in China.

[Molecular epidemiological analysis of Norovirus in patients with foodborne diseases in sentinel hospital, Ma'anshan City, Anhui Province].

Objective: To understand the infection status and genetic characteristics of Norovirus from foodborne diseases in sentinel hospital of Ma'anshan city. Methods: The 911 stool samples and epidemiological data of the patients with foodborne disease were collected from three hospitals of Ma'anshan city during January 2015 to June 2018. The G Ⅰ and G Ⅱ Norovirus were detected by real-time reverse transcription PCR. Some of the positive specimens were amplified by conventional reverse transcription PCR, and the PCR products were sequenced for sequence alignment and phylogenetic analysis. Results: The positive rate of Norovirus was 14.7% (134/911), in which 7 strains were G Ⅰ, 124 strains were G Ⅱ and 3 strains were mixed infection. Norovirus can be detected throughout the year, with high positive rate from December to April of the next year [24.4%(20/82)-45.3%(24/53)]. The 78 males (15.5%) and 55 females (13.7%) were positive for Norovirus (χ(2)=0.58,P=0.448). There was no significant difference in different age groups (χ(2)=9.55, P=0.089). A total of 79 strains were successfully sequenced, 4 strains were G Ⅰ group(5.1%), 75 strains were G Ⅱ group (94.9%). The predominant strains were GⅡ.17 and GⅡ.4, aud the number were 35 and 15 respectively. The predominant strains were different in different years. The main strain was GⅡ.17 in 2015 (30, 68.2%),GⅡ.4 in 2016 (5/9) and 2017 (8/16), but GⅡ.3 in 2018 (3/6). Conclusion: Norovirus diarrhea was popular in Ma'anshan city throughout the year,especially in winter and spring. The prevalent strain was GⅡ,genotypes were diversified distribution,the dominant strains were GⅡ.17 and GⅡ.4. The predominant strains were different in different years.

[Clinical multicenter study of carboprost methylate suppository for cervical ripening prior to diagnostic hysteroscopy].

Objective: To evaluate the effectiveness of carboprost methylate suppository for cervical ripening before diagnostic hysteroscopy in premenopausal women. Methods: From July 2014 to July 2015, 1 614 women who were undergone diagnostic hysteroscopy in 12 hospitals were randomly assigned into study group (n=1 209) and control group (n=405) . The cases in study group were given 1 mg carboprost methylate suppository in vagina before hysteroscopy, the cases in control group were given 1 mg placebo. The extent of cervical ripening, the time of dilated cervix, pain scoring, incidence of drug side reactions after 24, 48, 72 hours, satisfaction degree of operators and patients, the time of hysteroscopy, incidence of complications between the two groups were observed and compared. Results: (1) Mean cervical widths in the study and control groups were 6.11±1.11 and 5.95±1.11, and showed a significant difference (P=0.034) ; the percentage of women requiring cervical dilatation in study group was lower than the percentage in control group significantly [28.3% (342/1 209) versus 34.6% (140/405) , P=0.020]. (2) The time of dilated cervix in study group was shorter than the time in control group significantly [ (34±25) versus (52±49) s, P=0.028] for the patients whose mean cervical widths≤4. (3) There was no significant difference in pain scores between the two groups (P>0.05) . (4) The incidence of side reactions 24, 48, 72 hours after operation were no significant difference between the two groups (P>0.05) . (5) The satisfaction degree of operators and patients, the time of hysteroscopy, incidence of complications between the two groups were no singnifcant difference between the two groups (all P>0.05) . Conclusion: Application of carboprost methylate suppository by vagina before hysteroscopy is an effective and safe method of cervical ripening.

Epidemiological characteristics and influential factors of hand, foot and mouth disease (HFMD) reinfection in children in Anhui province.

Hand, foot and mouth disease (HFMD) is an acute contagious condition caused by a spectrum of human enteroviruses. HFMD reinfection is common in the absence of cross-protection from other virus subtypes. This study focused on reinfection in children in Anhui province, China between 2008 and 2013 using surveillance system data. We classified 8960 cases as reinfected, corresponding to a rate of 2·02%. The reinfection rate was higher in boys than in girls [odds ratio (OR) 1·27, 95% confidence interval (CI) 1·21-1·32, P < 0·001], children aged < 3 years (OR 3·82, 95% CI 3·58-4·07, P < 0·001), and children living in rural areas (OR 1·09, 95% CI 1·04-1·14, P = 0·001). The reinfection rate in children who were originally infected with non-enterovirus A71 (non-EVA71) enteroviruses was higher than those infected with EVA71 (OR 1·36, 95% CI 1·02-1·80, P = 0·034). Influential factors of reinfection rate included annual incidence (ß coefficient = 0·715, P = 0·002) and the proportion of EVA71 in patients with mild HFMD (ß coefficient = -0·509, P = 0·018). These results demonstrate that boys aged <3 years, especially those in rural areas or regions with a lower EVA71 proportion are more prone to reinfection, and specific health education programmes should be developed to protect these susceptible populations.

Plasma kinetics, excretion in milk of eprinomectin, and its efficacy against Hypoderma spp. following topical administration in yaks.

The plasma pharmacokinetics and mammary excretion of eprinomectin were determined in dairy yaks following topical administration at a dose of 0.5 mg/kg. The kinetics of plasma and milk concentrations were analyzed using a noncompartmental model. Plasma and milk concentrations of eprinomectin increased to reach maximal concentrations of 5.45 ± 2.84 and 2.29 ± 0.90 ng/mL at a Tmax of 1.79 ± 0.57 and 2.00 ± 0.82 days, respectively. The concentration of eprinomectin in plasma was remained >0.5 ng/mL for more than 30 days after administration. The mean residence times of eprinomectin in plasma and milk were 14.73 ± 6.22 and 9.37 ± 2.81 days, respectively. The AUC value in plasma (55.89 ± 18.16 ng day/mL) was threefold greater than that in milk (18.02 ± 6.48 ng day/mL). The AUC milk/plasma ratio was 0.33 ± 0.08. The systemic availability of eprinomectin in yaks was lower than that observed value in other domestic bovines. The low level of eprinomectin excretion in milk suggests that eprinomectin can be used in yaks with zero milk-withdrawal time. The efficacy of eprinomectin against naturally acquired larvae of Hypoderma spp. was also determined in yaks. Topically administrated eprinomectin at a dose of 0.5 mg/kg was 100% efficacious against larvae of Hypoderma bovis, H. lineatum, and H. sinense.

[Artificial intelligence technology enables ultrasonography in precision diagnosisand treatment of liver diseases].

Liver disease is one of the major problems affecting human health. Ultrasound plays an important role in diagnosis and treatment of diffuse and focal liver diseases. However, conventional ultrasound evaluation is subjective and provides limited information. Artificial intelligence (AI) technology may supplement the disadvantages of conventional ultrasound and has been widely used in the field of ultrasound in liver diseases. To date, remarkable progress has been achieved for the use of AI technology in the diagnosis, assessment of therapeutic efficacy and prognosis prediction of liver diseases. This paper reviews the research progress of ultrasound image-based AI technology in the diagnosis and treatment of diffuse and focal liver diseases.

[Survey of Oncomelania hupensis in national schistosomiasis surveillance sites of Guangxi Zhuang Autonomous Region from 2015 to 2019].

OBJECTIVE: To investigate the distribution characteristics of Oncomelania hupensis in Guangxi Zhuang Autonomous Region, so as to provide insights into the assessment of the risk of schistosomiasis transmission and the scientific formulation of the schistosomiasis surveillance strategy. METHODS: From 2015 to 2019, a total of 19 national schistosomiasis surveillance sites were assigned in Guangxi Zhuang Autonomous Region, including 4 fixed sites and 15 mobile sites. Snail survey was performed by means of systematic sampling in combination with environmental sampling, and the infection of Schistosoma japonicum was detected by the crushing method combined with loop-mediated isothermal amplification (LAMP) assay. RESULTS: From 2015 to 2019, snail habitats were detected at areas of 17 040 to 39 527 m2, including 6 214 m2 emerging snail habitats and 16 563 m2 re-emerging snail habitats. The overall mean density of living snails was 0.019 2 snails/0.1 m2 and the occurrence of frames with snails was 1.11% in the national schistosomiasis surveillance sites; however, no S. japonicum infection was identified in snails. The area of snail habitats increased by 121.46% in the national surveillance sites in 2019 as compared to that in 2015; however, 50.34% (Z = -0.422, P > 0.05) and 42.85% (χ2 = 130.41, P < 0.01) reductions were seen in the overall means density of living snails and the occurrence of frames with snails. All snail habitats were distributed in the 4 fixed surveillance sites, and were mainly found in ditches, paddy fields and dry lands, with weeds as the primary vegetation type. CONCLUSIONS: There are still risk factors leading to re-emergent transmission of schistosomiasis in Guangxi Zhuang Autonomous Region, such as local snail spread, and the monitoring of schistosomiasis remains to be reinforced to further consolidate the achievements of schistosomiasis elimination in the region.

Specific PCR-based assays for the identification of Fasciola species: their development, evaluation and potential usefulness in prevalence surveys.

Among the helminths infecting ruminants in China are three taxa belonging to the genus Fasciola: F. hepatica, F. gigantica and the so-called 'intermediate form' that appears to lie between these two species. Based on the sequences of the second internal-transcribed spacers (ITS-2) within the parasites' nuclear ribosomal DNA (rDNA), a pair of primers (DSJf/DSJ3) specific for F. hepatica and a pair (DSJf/DSJ4) specific for F. gigantica were designed and used to develop PCR-based assays. These assays allowed the identification and differentiation of F. hepatica, F. gigantica and the 'intermediate' Fasciola, with no amplicons produced from heterologous DNA samples. The results of sequencing confirmed the species-specific identity of the amplified products. The assays showed good sensitivity, giving positive results with as little as 0.11 ng of F. hepatica DNA and 0.35 ng of F. gigantica DNA. This meant that the DNA from a single Fasciola egg or a single infected snail was sufficient for identification of the Fasciola taxon. The developed PCR assays could provide useful tools for the detection, identification and epidemiological investigation of Fasciola infection in humans, other mammals and snails.

[Work flow of clinical microbiology laboratory in the epidemic of the coronavirus disease 2019].

The burn microbiology laboratory of the author's unit is a level Ⅱ biosafety laboratory, which is mainly responsible for handling clinical microbial samples from our department and other departments in the hospital. Since the outbreak of the coronavirus disease 2019, in order to ensure the normal operation of routine work and the safety of medical staff, the microbiology laboratory has actively adjusted the daily work flow. The detailed work flow is summarized as follows to provide references for the safety protection of peer in clinical microbiology laboratory.

[Analysis of distribution and drug resistance of pathogens isolated from 159 patients with catheter-related bloodstream infection in burn intensive care unit].

Objective: To analyze the distribution and drug resistance of pathogens isolated from patients with catheter-related bloodstream infection (CRBSI) in burn intensive care unit (BICU). Methods: From January 2011 to December 2018, among 2 264 patients who were peripherally inserted central venous catheter at the BICU of the First Affiliated Hospital of Army Medical University (the third Military Medical University), hereinafter referred to as the author's unit, 159 patients were diagnosed CRBSI, including 131 males and 28 females, aged 43 (1, 79) years. The pathogens primarily isolated from peripheral venous blood and central venous catheter blood/anterior central venous catheter specimen of patients with CRBSI were retrospectively analyzed. API bacteria identification kits and automatic microorganism identification instrument were used to identify pathogens. Broth micro-dilution method or Kirby-Bauer paper disk diffusion method was used to detect the drug resistance of the pathogens to 5 antifungal drugs including fluconazole and itraconazole, etc., and 37 antibacterial drugs including tigecycline and imipenem, etc. Modified Hodge test was used to further identify imipenem- and meropenem-resistant Klebsiella pneumonia. D test was used to detect erythromycin-induced clindamycin resistant Staphylococcus aureus. The WHONET 5.6 software was applied to analyze the annual incidence of CRBSI, mortality of patients with CRBSI, incidence of CRBSI cases, distribution of infection site, and duration of catheterization, detection of Gram-negative and Gram-positive bacteria, fungi, methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-sensitive Staphylococcus aureus (MSSA), and drug resistance of fungi and major Gram-negative and Gram-positive bacteria to the commonly used antibiotics in clinic. Results: (1) The incidence of CRBSI was 7.0% (159/2 264) during the eight years, which was slightly higher in 2014 and 2017 with 13.6% (30/221) and 11.1% (24/217) respectively. The mortality rate of patients with CRBSI was 7.5% (12/159). (2) The incidence of CRBSI cases was 14.9% (338/2 264); the main infection site was femoral vein, totally 271 cases (80.2%), and the duration of catheterization of this site was 9 (2, 25) d. (3) During the eight years, totally 543 strains of pathogens were isolated, including 353 (65.0%) strains of Gram-negative bacteria, 140 (25.8%) strains of Gram-positive bacteria, and 50 (9.2%) strains of fungi. The top three isolated pathogens with isolation rate from high to low were Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa, accounting for 23.2% (126/543), 17.1% (93/543), and 15.7% (85/543), respectively. Fungi were mainly Candida parapsilosis. Among the Staphylococcus aureus, the detection rate of MRSA was 98.9% (92/93), and that of MSSA was 1.1% (1/93). (4) Except for the low drug resistance rates to polymyxin B, minocycline, and tigecycline, the drug resistance rates of Acinetobacter baumannii to the other antibiotics were considerably high (80.1%-100.0%). Pseudomonas aeruginosa was not resistant to polymyxin B but highly resistant to netilmicin (88.7%) and piperacillin (92.6%), with resistance rates to the other antibiotics from 34.5% to 62.7%. Klebsiella pneumoniae was not resistant to tigecycline and lowly resistant to imipenem and meropenem (28.9%, 9 imipenem- and meropenem-resistant strains were further confirmed by modified Hodge test), with resistance rates to the other antibiotics from 40.9% to 95.2%. The resistance rates of MRSA to most antibiotics were higher than those of MSSA. MRSA was not resistant to linezolid, vancomycin, teicoplanin, sulfamethoxazole, or tigecycline. The resistance rates of MRSA to clindamycin and erythromycin were 7.9% and 62.0%, respectively, and those to the other antibiotics were higher than 91.5%. Except for the complete resistance to penicillin G and tetracycline, MSSA was not resistant to the other antibiotics. Thirty-three strains of Staphylococcus aureus showed resistance to erythromycin-induced clindamycin. Fungi was not resistant to amphotericin B, with drug resistance rates to voriconazole, itraconazole, ketoconazole, and fluconazole from 4.2% to 6.2%. Conclusions: The incidence of CRBSI and mortality of patients with CRBSI are high in BICU of the author's unit, and the main infection site is femoral vein. There are various types of pathogens in patients with CRBSI, and most of them are Gram-negative. The top three isolated pathogens are Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa, accompanying with grim drug resistance phenomenon.

[Analysis of the pathogenic characteristics of fungal bloodstream infection in severe burn patients].

Objective: To retrospectively analyze the diagnosis time, pathogen distribution, and drug resistance of fungal bloodstream infection in severe burn patients. Methods: Blood samples were collected from 55 severe burn patients with fungal bloodstream infection (including 46 males and 9 females, aged 42 (1, 78) years) admitted to the intensive care unit of the Institute of Burn Research of the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from July 2011 to May 2019 for retrospective analysis. Microbial monitoring system was used to cultivate pathogens, API yeast identification kit and Candida chromogenic medium were used to identify pathogens, and Kirby-Bauer paper disk diffusion method was used to detect drug resistance of fungi to fluconazole, amphotericin B, itraconazole, ketoconazole, and voriconazole. The positive rate of blood fungal culture, mortality rate, distribution of local fungal proliferation sites, the diagnosis time distribution of fungal bloodstream infection, the distribution of fungal species, resistance to commonly-used antifungal drugs, and the use of antibiotics were assessed. The WHONET 5.6 software was applied to analyze the distribution and drug resistance of fungi. Results: (1) Totally 4 839 blood samples were collected during the 9 years, and 122 strains of fungi were isolated, with positive rate of 2.52%. The mortality rate was 14.55% (8 patients) in 55 patients. Catheter fungal proliferation ranked the first among 30 cases of local fungal proliferation. (2) The diagnosis time of fungal bloodstream infection mainly distributed in ≤1 week of hospitalization [32.73% (18/55)]. (3) Among the 55 strains of fungi detected, the detection rate of Candida parapsilosis ranked the first (21.82%, 12 strains), Candida glabrata was the second (18.18%, 10 strains), and Candida tropicalis was tied with Candida albicans in the third place (14.55%, 8 strains). All the detected fungi were sensitive to amphotericin B, and the resistance rates to voriconazole, fluconazole, itraconazole, and ketoconazole were between 4.5% and 9.1%. (4) Droad-spectrum antibiotics were used in all the 55 patients, ≥3 kinds of antibiotics were used in 44 patients, and 37 patients used antibacterial drugs ≥7 days. Conclusions: The diagnosis time of fungal bloodstream infection in the 55 severe burn patients was mainly within 1 week of hospitalization. Candida parapsilosis is the most commonly detected fungal species. Catheter fungal proliferation occurs most commonly among the 30 patients with local fungal proliferation. All the detected fungi were sensitive to amphotericin B, with low drug resistance to voriconazole, fluconazole, itraconazole, and ketoconazole. Broad-spectrum antibiotics were overused in the severe burn patients with fungal bloodstream infection.

LncRNA ANRIL knockdown ameliorates retinopathy in diabetic rats by inhibiting the NF-κB pathway.

OBJECTIVE: To evaluate the impacts of long non-coding ribonucleic acid (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) on diabetic retinopathy (DR) in rats and the underlying mechanism. MATERIALS AND METHODS: A total of 60 adult male Sprague Dawley (SD) rats were randomly divided into 3 groups: the Sham group (n=20), DR group (n=20) and DR + lncRNA ANRIL knockdown group [DR + lncRNA ANRIL small interfering RNA (siRNA) group, n=20]. DR model in rats was established by intraperitoneal injection of streptozocin (STZ; 60 mg/kg). Meanwhile, a certain dose of lncRNA ANRIL siRNA was added dropwise into rat eyes of DR + lncRNA ANRIL siRNA group during model induction to downregulate lncRNA ANRIL expression in the retina. 16 weeks later, rat retinal tissues were taken to extract total RNA and protein. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was applied to detect the expression levels of lncRNA ANRIL, interleukin-1 (IL-1), IL-6 and monocyte chemotactic protein-1 (MCP-1) in each group of the rat retina. Pathological structure of rat retinal tissues in each group was observed via hematoxylin and eosin (H&E) staining. Immunohistochemistry was adopted to measure the expression levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax) and P65 in each group of retinal tissues. In addition, the retinal vascular permeability in each group of rats was detected by fluorescent staining. Finally, Western blotting was utilized to determine the expressions of genes in the P65 signaling pathway. RESULTS: Compared with rats in the Sham group, lncRNA ANRIL was upregulated in rat retinal tissues harvested from the DR + lncRNA ANRIL siRNA group (p<0.05). After knockdown of lncRNA ANRIL in the retinal tissues of DR rats, pathologic damage was alleviated notably, and the levels of inflammatory markers (IL-1, IL-10 and MCP-1) were lowered markedly (p<0.05). The protein expressions of Bax and P65 decreased evidently, while the protein level of Bcl-2 increased markedly (p<0.05) in DR rats with ANRIL knockdown. Furthermore, Western blotting results revealed that inhibition of lncRNA ANRIL could prominently repress the phosphorylation level of P65 in the retinal tissues of DR rats (p<0.05). CONCLUSIONS: LncRNA ANRIL knockdown can significantly ameliorate the retinopathy in diabetic rats by blocking the nuclear factor-kappa B (NF-κB) signaling pathway.

Influence of lncRNA-MALAT1 on neuronal apoptosis in rats with cerebral infarction through regulating the ERK/MAPK signaling pathway.

OBJECTIVE: To investigate the regulatory effect of long non-coding ribonucleic acid (lncRNA)-metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling pathway, and to explore its influence on neuronal apoptosis in rats with cerebral infarction. MATERIALS AND METHODS: A total of 45 adult male Sprague-Dawley rats were randomly divided into sham group (n=15), model group (n=15) and MALAT1 low-expression group (n=15). The model of cerebral infarction was successfully established in the model group and MALAT1 low-expression group via middle cerebral artery occlusion (MCAO). After 3 d, the nerve injury in each group was evaluated using Zea-Longa score. Meanwhile, the area of cerebral infarction in each group was detected via 2,3,5-triphenyl tetrazolium chloride (TTC) staining. After the cortical tissues were separated, the expression level of lncRNA-MALAT1 was detected via quantitative Polymerase Chain Reaction (qPCR). The apoptotic level of neurons in each group was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. The expression levels of inflammatory factors were detected using enzyme-linked immunosorbent assay (ELISA) kits. Furthermore, the expression levels of apoptosis-related proteins and ERK/MAPK signaling pathway-related proteins were detected via Western blotting. RESULTS: Compared with the sham group, the behavioral score and area of cerebral infarction in the model group were significantly increased (p<0.01). The low expression of MALAT1 could effectively reduce the behavioral score and area of cerebral infarction in the model group (p<0.01). The expression level of lncRNA-MALAT1 in cortical tissues of the model group was markedly higher than that of the sham group and MALAT1 low-expression group (p<0.01). Compared with the sham group, the content of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cortical tissues was significantly increased (p<0.01). However, the content of IL-10 was remarkably decreased in the model group (p<0.01). Low expressed MALAT1 could markedly reduce the content of TNF-α and IL-6 and increase the content of IL-10 in cortical tissues (p<0.01). The level of apoptosis in cortical tissues was increased in the model group when compared with that of the sham group (p<0.01). Meanwhile, low expression of MALAT1 could effectively reduce the apoptosis level in cortical tissues in model group (p<0.01). In the model group, the expression levels of B-cell lymphoma-2/Bcl-2 associated X protein (Bcl-2/Bax), p-ERK and matrix metalloproteinase-2 (MMP-2) in cortical tissues were significantly declined than the sham group (p<0.01). However, the protein expression level of cleaved caspase-3 was markedly increased (p<0.01). Furthermore, the low expression of MALAT1 could remarkably increase the expressions of Bcl-2/Bax, p-ERK and MMP-2 (p<0.01), as well as decrease the expression of cleaved caspase-3 (p<0.01). CONCLUSIONS: LncRNA-MALAT1 may increase the release of inflammatory cytokines by inhibiting the ERK/MAPK signaling pathway, thereby up-regulating the level of neuronal apoptosis and aggravating the cerebral injury in rats with cerebral infarction.

IL-10 gene polymorphism in diabetic retinopathy.

INTRODUCTION: To investigate the relationship between the interleukin-10 (IL-10) gene polymorphism and the pathogenesis of diabetic retinopathy (DR). PATIENTS AND METHODS: According to the fundus examination report, 420 patients with diabetes were divided into the non-DR group (n=200) and the DR group (n=220). The single nucleotide polymorphisms rs1145612 and rs11567245 in the promoter region of the IL-10 gene were classified by the conformational differential gel electrophoresis. RESULTS: No correlation was found between the polymorphism rs1145612 and the clinical information of DR patients. The polymorphism rs11567245 had correlations with multiple clinical indicators of DR patients, including body mass index (BMI), systolic blood pressure (SBP), blood urea nitrogen (BUN), fasting blood glucose (FBG), and 2-h postprandial blood glucose (2hBG) (p<0.05). CONCLUSIONS: The IL-10 gene promoter rs1145612 is not related to the occurrence and development of DR, but a relationship exists between the polymorphism rs11567245 and the occurrence and development of DR.

[Epidemiology investigation of carbapenems-resistant Klebsiella pneumoniae in burn care unit].

Objective: To explore the resistance mechanism and gene type of carbapenems-resistant Klebsiella pneumoniae (CRKP) in burn care unit. Methods: A total of 27 CRKP strains were primarily isolated from 22 patients [20 males, 2 females, aged (42±16) years] admitted to burn care unit of Institute of Burn Research of the First Affiliated Hospital of Army Medical University (the Third Military Medical University, hereinafter referred to as our department) from January to December 2017. After identification of bacteria, the months of detection and distribution of sample source were analyzed. Drug resistance tests of 15 antibiotics were conducted. Polymerase chain reaction was used to detect the drug resistant genes. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were used to analyze the gene type of strains. Results: (1) During the whole year of 2017, CRKP strains were mostly detected in August (8 strains), September (6 strains), and October (5 strains), with no CRKP in January, March, June, November, and December. Five strains from bed units were detected in August (2 strains), September (1 strain), and October (2 strains). (2) Twenty-seven CRKP strains were derived from blood samples (40.7%, 11/27), wound exudate samples (18.5%, 5/27), deep vein catheter samples (11.1%, 3/27), sputum samples (7.4%, 2/27), urine samples (3.7%, 1/27), and bed unit samples (18.5%, 5/27). (3) The 27 CRKP strains were detected with drug-resistance rates of 100.0% to 7 antibiotics including cefoperazone/sulbactam, piperacillin/tazobactam, cefazolin, ceftriaxone, cefepime, ertapenem, and compound sulfamethoxazole, no drug-resistance to tigecycline, with drug-resistance rates higher than 81.0% to the rest 7 antibiotics. (4) Detection rates for resistance gene bla(CTX-M-10), bla(SHV), bla(TEM), bla(CTX-M-14), bla(ACT), and bla(KPC) were all above 92.5%. (5) According to PFGE, the 27 CRKP strains had 6 types (A, A(1), A(2), B, C, and D). Strains of type A were mainly detected in February, May, and September, with detection rate of 37.0% (10/27). Strains of type C were mainly detected in July, August, and October, with detection rate of 48.1% (13/27). Strains of types A(1), A(2), B, and D were scatteredly detected, with detection rate of 3.7% (1/27) respectively. According to MLST, the 27 CRKP strains had 6 STs. ST11 was the most frequent type, accounting for 74.1% (20/27), which was detected in August to October. The detection rate of ST395, ST2230, ST215, ST260, and STnew ranged from 3.7%(1/27) to 7.4%(2/27), and the strains were scatteredly detected. Conclusions: The main source of CRKP from burn care unit of our department was bloodstream. All the CRKP strains showed high drug-resistance rate and complicated resistance mechanism. There were small scale outbreaks caused by CRKP of type A, type C, and ST11, which should be paid more attention to in clinical treatment and infection control.

[Effects of vitamin D3 on intestinal mucosal barrier of mice with severe burns].

Objective: To explore the effects of vitamin D3 on intestinal mucosal barrier of mice with severe burns. Methods: Forty-two C57BL/6C male mice aged eight to twelve weeks were divided into vitamin D3 vehicle+ sham injury group of seven mice, vitamin D3 vehicle+ burn injury group of fourteen mice, vitamin D3+ sham injury group of seven mice, and vitamin D3+ burn injury group of fourteen mice according to random number table. Mice in vitamin D3 vehicle+ sham injury group and vitamin D3 vehicle+ burn injury group were injected with vehicle of vitamin D3 at a dose of 0.1 mL intraperitoneally at 1, 24, and 48 h before burn experiment. Mice in vitamin D3+ sham injury group and vitamin D3+ burn injury group were injected with vitamin D3 at a dose of 100 ng/kg dissolved in 0.1 mL vehicle intraperitoneally at the same time points. Mice in vitamin D3 vehicle+ burn injury group and vitamin D3+ burn injury group were inflicted with 30% total body surface area full-thickness dermal scald (hereinafter referred to as burn) on the back by 98 ℃ hot water for 3 to 4 seconds. And mice in vitamin D3 vehicle+ sham injury group and vitamin D3+ sham injury were treated with 37 ℃ water on the back for 3 to 4 seconds to simulate injury. Seven mice in vitamin D3 vehicle+ sham injury group and seven mice in vitamin D3+ sham injury group at post injury hour (PIH) 24, and seven mice in vitamin D3 vehicle+ burn injury group and seven mice in vitamin D3+ burn injury group at PIH 6 and 24 were sacrificed respectively to collect mesentery lymph nodes, spleens, livers, and intestinal tissue. The mesentery lymph nodes, spleens, and livers of mice in each group were collected to observe growth of bacteria, and number of bacteria was counted. Intestinal tissue of mice in each group was collected to detect protein expressions of zonal occludin 1 (ZO-1) and occludin by immunohistochemistry staining method, distribution of ZO-1 by immunofluorescence staining method, and expression of occludin by Western blotting. Data were processed with Kruskal-Wallis H test, Nemenyi test, one-way analysis of variance, t test, and Bonferroni correction. Results: (1) At PIH 6 and 24, bacterial counts of mesentery lymph nodes, livers, and spleens of mice in vitamin D3 vehicle+ burn injury group were significantly higher than those of mice in vitamin D3 vehicle+ sham injury group (P<0.05). At PIH 6, bacterial counts of livers and spleens of mice in vitamin D3+ burn injury group were significantly lower than those of mice in vitamin D3 vehicle+ burn injury group (P<0.05). At PIH 24, bacterial counts of mesentery lymph nodes and livers of mice in vitamin D3+ burn injury group were significantly lower than those of mice in vitamin D3 vehicle+ burn injury group (P<0.05). (2) At PIH 6 and 24, expressions of ZO-1 and occludin of intestinal tissue of mice in vitamin D3 vehicle+ burn injury group were significantly lower than those of mice in vitamin D3 vehicle+ sham injury group, and expressions of ZO-1 and occludin of intestinal tissue of mice in vitamin D3+ burn injury group were close to those of mice in vitamin D3+ sham injury group. At PIH 6 and 24, expressions of ZO-1 and occludin of intestinal tissue of mice in vitamin D3+ burn injury group were significantly higher than those of mice in vitamin D3 vehicle+ burn injury group. (3) At PIH 6 and 24, compared with that of mice in vitamin D3 vehicle+ sham injury group, distribution of ZO-1 of intestinal mucosal epithelium of mice in vitamin D3 vehicle+ burn injury group was discontinuous. Distribution of ZO-1 of intestinal mucosal epithelium of mice in vitamin D3+ sham injury group was normal, and the distribution of ZO-1 of intestinal mucosal epithelium of mice in vitamin D3+ burn injury group was with good continuity. (4) At PIH 6 and 24, expressions of occludin of intestinal tissue of mice in vitamin D3 vehicle+ burn injury group were 0.720±0.003, 0.638±0.052 respectively, significantly lower than 0.918±0.003 of mice in vitamin D3 vehicle+ sham injury group (t=57.33, 5.36, P<0.05). At PIH 6 and 24, expressions of occludin of intestinal tissue of mice in vitamin D3+ burn injury group were 0.994±0.058, 1.064±0.060, close to 0.938±0.023 of mice in vitamin D3+ sham injury group (t=0.91, 1.96, P>0.05). At PIH 6 and 24, expressions of occludin of intestinal tissue of mice in vitamin D3 vehicle+ burn injury group were significantly lower than those of mice in vitamin D3+ burn injury group (t=4.75, 5.35, P<0.05). Conclusions: Intestinal bacterial translocation can occur in the early stage of severe burn. And vitamin D3 plays a protective role in the intestinal mucosal barrier post severe burn to reduce the bacterial translocation by protecting tight junction proteins of intestinal epithelium.

Search for new half-metallic ferromagnets in zinc blende CaSi and CaGe by first-principles calculations.

We present an investigation on the electronic structure and ferromagnetism for the hypothetical zinc blende (ZB) CaSi and CaGe by using first-principles full-potential linearized augmented plane-wave (FP-LAPW) calculations. It is found that ZB CaSi and CaGe are half-metallic (HM) ferromagnets without any transition-metal component; they have a magnetic moment of 2.000 µ(B) per formula unit. Analysis of the density of states and magnetic moment indicates that their magnetism mainly originates from the spin polarization of anion p states and the hybridization between the anion p states and the Ca d states. We also find that the half-metallicity can be maintained even when the lattice constant of ZB CaSi and CaGe is compressed up to 8% and 5%, respectively. The absence of the transition-metal atoms makes ZB CaSi and CaGe attractive not only as materials for possible spintronics devices but also as model objects for the study of new mechanisms of the formation of half-metallic ferromagnetism in s-p electron systems.