[Elesclomol-Cu Induces Cuproptosis in Human Acute Myeloid Leukemia Cells].

OBJECTIVE: To investigate the effects of elesclomol-Cu (ES-Cu) on the proliferation and cuproptosis of human acute myeloid leukemia (AML) cells. METHODS: The effects of ES-Cu on the proliferation of AML cells and the AML cells pre-treated with ammonium tetrathiomolybdate (TTM) were examined by CCK-8 assay. The Calcein/PI kit was used to detected the changes in activity and cytotoxicity of AML cells induced by ES-Cu. Flow cytometry and Cytation3 fully automated cell imaging multifunctional detection system were used to analyze DCFH-DA fluorescence intensity, so as to determine the level of reactive oxygen species (ROS). The GSH and GSSG detection kits were used to measure the intracellular GSH content. Western blot was used to detected the expression of cuproptosis-related proteins ATP7B, FDX1, DLAT and DPYD. RESULTS: ES-Cu inhibited the proliferation of Kasumi-1 and HL-60 cells in a concentration-dependent manner (r Kasumi-1=-0.99， r HL-60=-0.98). As the concentration of ES-Cu increased, the level of intracellular ROS also increased (P <0.01-0.001). TTM could significantly reverse the inhibitory effect of ES-Cu on cell proliferation and its promoting effect on ROS. With the increase of ES-Cu concentration, the content of GSH was decreased (r =-0.98), and Western blot showed that the protein expressions of ATP7B, FDX1, DLAT and DPYD were significantly reduced (P <0.05). CONCLUSION: ES-Cu can induce cuproptosis in AML cells, which provides a new idea for the treatment of AML.

In-situ Electrochemical Transformed Cu Oxide from Cu Sulfide for Efficient Upgrading of Biomass Derived 5-Hydroxymethylfurfural in Anion Exchange Membrane Electrolyzer.

The electrochemical transformation of biomass to high value-added products is attractive. Herein, Cu sulfide-mediated in-situ synthesis of Cu oxide was achieved for efficient electro-oxidation of biomass derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). The copper foam-supported Cu sulfide (Cu-S/CF) was in-situ converted to Cu oxide during the electro-oxidation process. The in-situ formed Cu oxide presented high HMF conversion, FDCA yield, and faradaic efficiency in 1 m KOH with HMF concentration up to 100 mm. The oxidation of HMF on Cu oxide started with the formation of high-valence Cu species with the assistance of OH- , which then oxidized HMF spontaneously. An anion exchange membrane (AEM) electrolyzer with Cu-S/CF as the anode was assembled to continuously produce FDCA with H2 generation at the cathode. The AEM electrolyzer ran stably for 60 h with FDCA content higher than 85 % at a cell voltage between 1.50 and 1.60 V.

Characterization of the Clinical Features in HBV-Related Acute-on-Chronic Liver Failure.

OBJECTIVE: Acute-on-chronic liver failure (ACLF) is a type of liver failure commonly found in China, and currently the mechanism of the disease remains unknown. This study aimed to investigate the epidemiology, clinical features and prognostic factors in ACLF. METHODS: This study retrospectively included 170 patients with ACLF admitted to Beijing Friendship Hospital in Beijing, China from November 2017 to May 2019. Patients were divided into 2 groups: the improved group and the deteriorated group, according to the severity of their disease. Patients' demographic data; clinical manifestations; complications; laboratory indicators including platelets (PLT), alanine aminotransferase (ALT), aspartate amino transferase (AST), total bilirubin (TBIL), prothrombin time (PT), activated partial thromboplastin time (APTT), prothrombin activity (PTA), international normalized ratio (INR), and alkaline phosphatase (ALP) were collected. The relationship between these factors and the patients' prognosis were analyzed by logistic multivariate regression analysis. RESULTS: The highest morbidity rate was in the age group 40 to 49 years (29.41%). The age group with the second highest morbidity was between 50 and 59 years (25.29%), followed by >60 (21.18%), 30 to 39 (20.59%), 20 to 29 (2.94%) and <20 years (0.59%). A total of 53 patients (31.18%) had a family history of hepatitis B virus infection. The patients' main clinical manifestations were ascites (77.65%) and weakness (68.23%). The most common complications were hypoalbuminemia (80%), infection (67.65%) and electrolyte imbalance (44.12%). In addition, the PTA (P = .009), hepatorenal syndrome (P = .005) and hepatic encephalopathy (level IV) (P = .005) were independently related to the prognosis of ACLF. There is a significant relationship between complications and prognosis (χ2 = 8.502; P = .004). CONCLUSION: This study showed that prothrombin activity, hepatorenal syndrome and hepatic encephalopathy were independently related to the prognosis of ACLF. This outcome provided more options for reducing patient mortality in clinic.

A Novel Anastomosis Technique for Laparoscopic Pancreaticoduodenectomy: Case Series of Our Center's Experience.

Background: Laparoscopic pancreaticoduodenectomy has developed rapidly in recent years. Postoperative pancreatic fistula is still the most dangerous complication of laparoscopic pancreaticoduodenectomy. Baumgart pancreaticojejunostomy is considered one of the safest anastomosis procedures, with low rates of pancreatic fistula. We modified Blumgart pancreaticojejunostomy and applied the modified procedure during laparoscopic pancreaticoduodenectomy. The modified procedure entailed a longitudinal U-shaped suture through the pancreas for anastomosis of the pancreatic duct and the jejunal mucosa. Methods: We prospectively collected and retrospectively analyzed the data of 120 patients who underwent laparoscopic pancreaticoduodenectomy from January 2016. The total operative time, time for complete pancreaticojejunostomy, postoperative pancreatic fistula rate, postoperative delayed gastric emptying, postoperative bleeding, postoperative length of hospital stays, and mortality within 90 days after surgery were analyzed. An analysis of laparoscopic pancreaticojejunostomy compared with open pancreaticojejunostomy is also reported. Results: In the laparoscopic pancreaticojejunostomy group, the average total operative time, the average time for complete pancreaticojejunostomy, and the average intraoperative blood loss were 271 min, 35.3 min, and 184 ml, respectively. The total postoperative clinically relevant pancreatic fistula rate was 9.2% (Grade B and C fistulas). The incidence rates of postoperative delayed gastric emptying and postoperative biliary fistula were ~2.5 and 1.7%, respectively. The postoperative bleeding rate was 0.83%, and the average postoperative indwelling time of the abdominal drainage tube was 7.3 days. The postoperative length of hospital stay was 10.8 days, and the mortality rate within 90 days after surgery was 0.83%. The rates of clinically relevant postoperative clinically relevant pancreatic fistula are comparable between laparoscopic and open surgery, there were no other severe postoperative complications in either group. The mean postoperative length of hospital stay was significantly shorter in the laparoscopic pancreaticojejunostomy group. Conclusion: The modified laparoscopic-adapted Blumgart anastomosis simplifies and facilitates the creation of the pancreaticojejunostomy in laparoscopic pancreaticoduodenectomy. The rates of clinically relevant postoperative pancreatic fistula are comparable with those obtained by open surgery, and length of stay are shoter.

Species Distribution and Antifungal Susceptibility of Invasive Candidiasis: A 2016-2017 Multicenter Surveillance Study in Beijing, China.

OBJECTIVE: Invasive candidiasis (IC), a life-threatening fungal infection prevalent among hospitalized patients, has highly variable regional epidemiology. We conducted a multicenter surveillance study to investigate recent trends in species distribution and antifungal susceptibility patterns among IC-associated Candida spp. in Beijing, China, from 2016 to 2017. MATERIALS AND METHODS: A total of 1496 non-duplicate Candida isolates, recovered from blood and other sterile body fluids of IC patients, were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry combined with ribosomal DNA internal transcribed spacer (ITS) region sequencing. Broth microdilution-based susceptibility testing using six antifungal agents was also conducted. RESULTS: Candida albicans was the most frequently isolated species (49.9%), followed by Candida tropicalis (15.5%), Candida glabrata (14.7%) and Candida parapsilosis (14.2%). No significant differences in species distribution were observed when compared with a 2012-2013 dataset. Overall, the rates of susceptibility to fluconazole and voriconazole were high among C. albicans (98% and 97.2%, respectively) and C. parapsilosis species complex (91.1% and 92%, respectively) isolates but low among C. tropicalis (81.5% and 81.1%, respectively) isolates. In addition, the rate of azole resistance among C. tropicalis isolates increased significantly (1.8-fold, P<0.05) compared with that observed in 2012-2013, while micafungin resistance rates were <5% for all tested Candida species. CONCLUSION: Our results suggest that species distribution has remained stable among IC-associated Candida isolates in Beijing. Resistance to micafungin was rare, but increased azole resistance among C. tropicalis isolates was noted. Our study provides information on local epidemiology that will be important for the selection of empirical antifungal agents and contributes to global assessments of antifungal resistance.

An improved bind-n-seq strategy to determine protein-DNA interactions validated using the bacterial transcriptional regulator YipR.

BACKGROUND: Interactions between transcription factors and DNA lie at the centre of many biological processes including DNA recombination, replication, repair and transcription. Most bacteria encode diverse proteins that act as transcription factors to regulate various traits. Several technologies for identifying protein-DNA interactions at the genomic level have been developed. Bind-n-seq is a high-throughput in vitro method first deployed to analyse DNA interactions associated with eukaryotic zinc-finger proteins. The method has three steps (i) binding protein to a randomised oligonucleotide DNA target library, (ii) deep sequencing of bound oligonucleotides, and (iii) a computational algorithm to define motifs among the sequences. The classical Bind-n-seq strategy suffers from several limitations including a lengthy wet laboratory protocol and a computational algorithm that is difficult to use. We introduce here an improved, rapid, and simplified Bind-n-seq protocol coupled with a user-friendly downstream data analysis and handling algorithm, which has been optimized for bacterial target proteins. We validate this new protocol by showing the successful characterisation of the DNA-binding specificities of YipR (YajQ interacting protein regulator), a well-known transcriptional regulator of virulence genes in the bacterial phytopathogen Xanthomonas campestris pv. campestris (Xcc). RESULTS: The improved Bind-n-seq approach identified several DNA binding motif sequences for YipR, in particular the CCCTCTC motif, which were located in the promoter regions of 1320 Xcc genes. Informatics analysis revealed that many of these genes regulate functions associated with virulence, motility, and biofilm formation and included genes previously found involved in virulence. Additionally, electromobility shift assays show that YipR binds to the promoter region of XC_2633 in a CCCTCTC motif-dependent manner. CONCLUSION: We present a new and rapid Bind-n-seq protocol that should be useful to investigate DNA-binding proteins in bacteria. The analysis of YipR DNA binding using this protocol identifies a novel DNA sequence motif in the promoter regions of target genes that define the YipR regulon.

A multiple-center clinical evaluation of a new real-time reverse transcriptase PCR diagnostic kit for SARS-CoV-2.

Aim: The outbreak of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has had serious repercussions worldwide. This study was aimed to evaluate the accuracy of a new kit for detection of SARS-CoV-2 compared with similar detection kit. Materials & methods: A total of 500 subjects were included and tested with both the new test and control kits. Clinical diagnosis results were taken as the reference standard. Results: Compared with clinical diagnosis, the sensitivity of the test kit was 82.64%, specificity was 98.45% and total coincidence rate was 90.80%. The total coincidence rate, sensitivity and specificity between control kit and clinical diagnosis were 89.20%, 78.10% and 99.61%, respectively. Conclusions: The new kit was comparable to the similar detection kit for detection of SARS-CoV-2 in sensitivity, specificity and total coincidence rate.

Dual RNA-seq of Xanthomonas oryzae pv. oryzicola infecting rice reveals novel insights into bacterial-plant interaction.

The Gram-negative bacterium Xanthomonas oryzae pv. oryzicola (Xoc) is the causal agent of rice bacterial leaf streak (BLS), one of the most destructive diseases of rice (Oryza sativa L.) that is the important staple crop. Xoc can invade host leaves via stomata and wounds and its type three secretion system (T3SS) is pivotal to its pathogenic lifestyle. In this study, using a novel dual RNA-seq approach, we examined transcriptomes of rice and Xoc in samples inoculated with wild type Xoc GX01 and its T3SS defective strain (T3SD), to investigate the global transcriptional changes in both organisms. Compared with T3SD strain, rice inoculated with wild type Xoc GX01 resulted in significant expression changes of a series of plant defence related genes, including ones altered in plant signalling pathway, and downregulated in phenylalanine metabolism, flavonoid and momilactone biosynthesis, suggesting repression of plant defence response and reduction in both callose deposition and phytoalexin accumulation. Also, some known transcription activator-like effector (TALE) targets were induced by Xoc GX01, e.g. OsSultr3;6 which contributes to rice susceptibility. Some cell elongation related genes, including several expansin genes, were induced by GX01 too, suggesting that Xoc may exploit this pathway to weaken cell wall strength, beneficial for bacterial infection. On the other hand, compared with wild type, the T3SD strain transcriptome in planta was characterized by downregulation of ATP, protein and polysaccharide synthesis, and upregulation of antioxidation and detoxification related genes, revealing that T3SD strain faced serious starvation and oxidation stresses in planta without a functional T3SS. In addition, comparative global transcript profiles of Xoc in planta and in medium revealed an upregulation of virulence factor synthesis and secretion in planta in favour of bacterial infection. Collectively, this study provides a comprehensive representation of cross talk between the host and bacterial pathogen, revealing insights into the Xoc-rice pathogenic dynamic and reveals novel strategies exploited by this important pathogen to cause disease.

Segmental zoster abdominal paresis mimicking an abdominal hernia: A case report and literature review.

RATIONALE: Herpes zoster infection typically involves the posterior root ganglia and most of the symptoms are sensory. Motor involvement can occur in the same distribution but is relatively uncommon. Segmental zoster paresis is a rare motor complication of Herpes zoster, mimicking an abdominal hernia, but it needs no surgery different from the real abdominal wall hernia. PATIENT CONCERNS: We present a case of a 58-year-old man with an abdominal protrusion and characteristical herpes zoster rash. DIAGNOSES: Initially, the surgeon regarded it as an abdominal hernia, while ultrasonography excluded the abdominal wall defect, and then the dermatologist diagnosed it as segmental herpes zoster abdominal paralysis. INTERVENTIONS: He received a treatment with oral acyclovir, mecobalamin, and vitamin B1. OUTCOMES: The abdominal wall bulge disappeared after 2 months, avoiding unnecessary surgery. LESSONS: Segmental zoster abdominal paresis, mimicking an abdominal hernia needs no surgery.

Large Aggressive Angiomyxoma of the Liver: A Case Report and Brief Review of the Literature.

Aggressive angiomyxoma (AAM) is an uncommon mesenchymal myxoid tumor that almost solely involves the soft tissues of the perineum and pelvis. An AAM originating from the liver is extremely rare. Herein, we present a case of a 45-year-old female with a large mass in the left lateral lobe of the liver. She underwent a left lateral lobe hepatectomy. The histopathology of the resected specimen showed features that were characteristic of AAM. Immunohistochemical analysis of the neoplastic cells showed reactions to antibodies against CD34, smooth muscle actin (SMA), and Ki67 (2%) and showed no reactions to antibodies against Estrogen receptor (ER), C-keratin (CK), and Desmin. The patient was subsequently diagnosed with a primary AAM of the liver. This is the largest AAM of the liver that has been reported. We hereby report these findings and review the current literature.

Primary clear cell adenocarcinoma of the pancreas: a case report and literature update.

Primary clear cell carcinoma of pancreas is extremely rare. We present a case of a 64-year-old male with a mass in the distal body and tail of the pancreas. He underwent a distal pancreatectomy. The histopathology of tumor cells showed features with abundant clear cytoplasm and prominent cell boundaries. Immunohistochemical analysis of neoplastic cells showed reactions to antibodies against cytokeratin-7 and showed no reactions to antibodies against hepatocyte nuclear factor-1ß, carbonic anhydrase 9, synaptophysin, and chromogranin A. The patient was subsequently diagnosed with a primary clear cell carcinoma of the pancreas. This is the first time we have encountered it. We report this rare case and update the current literature of this tumor.

A Retrospective Study of Culture-confirmed Mycobacterial Infection among Hospitalized HIV-infected Patients in Beijing, China.

A retrospective analysis was performed in two major HIV/AIDS referral hospitals in Beijing to evaluate the prevalence of Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterial (NTM) infections in HIV-infected patients. A total of 627 patients' data were reviewed, and 102 (16.3%) patients were diagnosed with culture-confirmed mycobacterial infection, including 84 with MTB, 16 with NTM, and 2 with both MTB and NTM. The most frequent clinical complication by mycobacterial infection was pulmonary infection (48/102, 47.1%). The overall rates of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) were 11.9% and 3.4%, respectively. This study underlines the urgent need to intensify screening for mycobacteria coinfection with HIV and to prevent the spread of drug-resistant TB among HIV-infected patients.

Epidemiology and antifungal susceptibilities of yeast isolates causing invasive infections across urban Beijing, China.

AIM: To investigate the species distribution and antifungal susceptibility profiles of yeast isolates causing invasive infections across Beijing. MATERIALS & METHODS: A total of 1201 yeast isolates recovered from blood and other sterile body fluids were correctly identified by matrix-assisted laser desorption/ionization TOF MS supplemented by DNA sequencing. Antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute broth microdilution method. RESULTS: Candida (95.5%) remained the most common yeast species isolated; Candida albicans (38.8%) and Candida parapsilosis (22.6%) were the leading species of candidemia. Azole resistances were mainly observed in Candida glabrata and Candida tropicalis isolates. CONCLUSION: This study outlined the epidemiologic data of invasive yeast infections and highlighted the need for continuous monitoring of azole resistances among C. glabrata and C. tropicalis isolates in Beijing.

Rapid and efficient genome-wide characterization of Xanthomonas TAL effector genes.

Xanthomonas TALE transcriptional activators act as virulence or avirulence factors by activating host disease susceptibility or resistance genes. Their specificity is determined by a tandem repeat domain. Some Xanthomonas pathogens contain 10-30 TALEs per strain. Although TALEs play critical roles in pathogenesis, their studies have so far been limited to a few examples, due to their highly repetitive gene structure and extreme similarity among different members, which constrict sequencing and assembling. To facilitate TALE studies, we developed an efficient and rapid pipeline for genome-wide cloning of tal genes as many as possible from a strain. Here, we report the pipeline and its use to identify all 18 tal genes from a newly isolated strain of the rice pathogen Xathomonas oryzae. Target prediction revealed a number of potential rice targets including several notable genes such as genes encoding SWEET, WRKY, Hen1, and BAK1 proteins, which provide candidates for further experimental functional analysis of the TALEs.

Molecular Characteristics and Drug Susceptibility of Mycobacterium tuberculosis Isolates from Patients Co-infected with Human Immunodeficiency Virus in Beijing, China.

70 clinical Mycobacterium tuberculosis strains isolated from AIDS patients in two HIV/AIDS referral hospitals in Beijing were used in this study. M. tuberculosis and non-tuberculosis mycobacterium (NTM) were identified by using multi-locus PCR. M. tuberculosis was genotyped by using 15-locus MIRU-VNTR technique and spoligotyping afterwards. Meanwhile, the drug susceptibilities of the strains to the four first-line anti TB drugs (rifampin, isoniazid, streptomycin, and ethambutol) and the four second-line anti-TB drugs (capreomycin, kanamycin, ofloxacin, and ethionanide) were tested with proportional method. In this study, M. tuberculosis and NTM strains isolated from AIDS patients with TB-like symptoms were identified and genotyping analysis indicated that Beijing genotype was the predominant genotype. In addition, the prevalence of drug-resistant TB, especially the prevalence of XDR-TB, was higher than that in TB patients without HIV infection.

Transcriptome profiling of Xanthomonas campestris pv. campestris grown in minimal medium MMX and rich medium NYG.

Xanthomonas campestris pathovar campestris (Xcc) is the causal agent of black rot disease in cruciferous plants worldwide. Although the complete genomes of several Xcc strains have been determined, the gene expression and regulation mechanisms in this pathogen are far from clear. In this work, transcriptome profiling of Xcc 8004 grown in MMX medium (minimal medium for Xanthomonas campestris) and NYG medium (peptone yeast glycerol medium) were investigated by RNA-Seq. Using the Illumina HiSeq 2000 platform, a total of 26,514,630 reads (90 nt in average) were generated, of which 15,708,478 reads mapped uniquely to coding regions of Xcc 8004 genome. Of the 4273 annotated protein-coding genes of Xcc 8004, 629 were found differentially expressed in Xcc grown in MMX and NYG. Of the differentially expressed genes, 495 were up-regulated and 134 were down-regulated in MMX. The MMX-induced genes are mainly involved in amino acid metabolism, transport systems, atypical condition adaptation and pathogenicity, especially the type III secretion system, while the MMX-repressed genes are mainly involved in chemotaxis and degradation of small molecules. The global transcriptome analyzes of Xcc 8004 grown in MMX and NYG might facilitate the gene functional characterization of this phytopathogenic bacterium.

Molecular and pathogenic characterization of new Xanthomonas oryzae pv. oryzae strains from the coastline region of Fangchenggang city in China.

Virulence assays and DNA polymorphism analyses were used to characterize 33 Xanthomonas oryzae pv. oryzae (Xoo) strains collected from the coastline region of Fangchenggang city in China. Two new pathogenic races (FXP1 and FXP2), were determined by leaf-clipping inoculation of 12 near-isogenic International Rice-Bacterial Blight (IRBB) rice lines, each containing a single resistance gene. Race FXP1 consisted of twenty-eight strains that were incompatible on IRBB5 and IRBB7, while race FXP2 included five strains that were incompatible on IRBB5 and IRBB7 and moderately virulent on IRBB8 containing the xa8 gene. Restriction fragment length polymorphism (RFLP) analysis revealed that each probe of avrXa10 and IS1112 resolved two haplotypes. In a dendrogram generated from the combined RFLP data, the 33 Xoo strains were resolved into two clusters. There was a weak correlation (r = 0.53) between race and haplotype. All of the rice cultivars planted in the coastline region of Fangchenggang city were susceptible to the representative Xoo strains tested above. However, we found that four rice cultivars used as breeding materials in the laboratory could fully resist infection by the Xoo strains, suggesting that the isolated Xoo strains could be used to detect resistant rice cultivars suitable for planting in the local rice field.

Performance of serological tests for syphilis in sexually transmitted diseases clinics in Guangxi Autonomous Region, China: implications for syphilis surveillance and control.

BACKGROUND: China is experiencing a growing syphilis epidemic. Individuals are currently screened and cases are confirmed using traditional serological testing methods. METHODS: A total of 11 558 serum specimens from patients at 14 sexually transmitted diseases (STD) clinics at provincial, prefecture and county levels in Guangxi Autonomous Region were tested at local clinics using the toluidine red unheated serum test (TRUST) and the SD Bioline Syphilis 3.0 Treponema Pallidum (SD-TP) test and then transported to the National STD Reference Laboratory for TRUST and confirmatory Treponema pallidum particle assay (TPPA) testing. RESULTS: In local clinics, 13.2% of specimens were TRUST positive and 12.8% were TRUST and SD-TP positive. At the Reference Laboratory, 15.4% of specimens were TRUST positive and 11.8% were TRUST and TPPA positive. Local clinics showed a significantly higher prevalence of active syphilis compared with results from the Reference Laboratory (12.8 v. 11.8%, chi(2) = 4.59, P = 0.03). The local TRUST tests had consistent results with Reference Laboratory tests qualitatively among 96.2% of the specimens and quantitatively among 95.5% of the specimens. The algorithm of TRUST screening and then SD-TP confirmation among positive TRUST specimens at local STD clinics had 96.6% sensitivity and 99.3% specificity in diagnosing active syphilis compared with the 'gold standard' based on TRUST and TPPA positivity at the Reference Laboratory (positive predictive value 95.1% and negative predictive value 99.5%). CONCLUSION: The TRUST screening and SD-TP confirmation in combination can be used at local STD clinics for the efficient diagnosis of serologically active syphilis. However, continuing capacity building and quality assurance remain critical in ensuring the quality of syphilis diagnosis at local clinics.

Heavy metal contamination in soil alongside mountain railway in Sichuan, China.

Heavy metal concentration in soil was investigated at three sites with different topography (cut slope, flat and embankment) within the vicinity of Chengdu-Kunming railway in Sichuan, China. Surface soil was sampled at certain distances from the track at each site and was analyzed for Cu, Mn, Pb, Zn, Cd by atomic absorption spectrometry. Cu, Cd and Zn concentrations in some soil exceeded the thresholds for non-polluted soil following the soil quality standard set by the State Environmental Protection Agency of China. Compared to local background values, the highest enrichment factor values of Cu, Mn, Zn and Cd were 2.7, 3.4, 3.7 and 7.7, respectively, indicating a moderate or significant enrichment of these metals in soil closest to the railway. Pb showed little accumulation with the EF values generally nearer 1 at the chosen sites. Topography profile was found to influence metal levels and distribution in soil alongside railway. At the cut slope site, Mn, Zn, Cd showed the highest concentrations and the smallest dispersion distance of 2 m, while Cu showed further dispersion distance of 25 m due to a main Cu emission source, the head-over traction cable, being located higher than any other metal emission source (wheels and tracks). Heavy metal concentrations decreased conversely as compared to distance from the track, peak values occurring at locations closest to the tracks, whilst embankment site soil Cd concentrations peaked at distances of 25 m. Significant correlation was found amongst Mn, Cu, Zn and Cd, which indicates that these metals have the same anthropogenic origin there. Organic matter content had no significant correlation to the elements Mn, Cu and Zn, which implies relatively high mobility to those metals.

[Analysis of SCCmec genotyping and antimicrobial susceptibility tests in methicillin resistant Staphylococcus aureus].

OBJECTIVE: To investigate the SCCmec genotyping, subtype and antimicrobial susceptibility tests in methicillin resistant staphylococcus aureus to guide the clinical treatment and provide the proof for molecular epidemiology. METHODS: To detect mecA gene and SCCmec genetyping and subtype in 50 MRSA by PCR. According to CLSI's guideline, antimicrobial susceptibility tests were performed with disk diffusion. RESULTS: All 50 MRSA had mecA genes. 45 strains were SCCmec III types; 3 strains were SCCmec III A types; 2 strains were SCCmec II types. There were no SCCmec I and SCCmec IV types. SCCmec II, SCCmec III and SCCmec III A type strains were all multiresistant. CONCLUSION: 50 MRSA are all multiresistant. SCCmec III are the main types.