Desulfovibrio is not always associated with adverse health effects in the Guangdong Gut Microbiome Project.

Desulfovibrio (DSV) is frequently found in the human intestine but limited knowledge is available regarding the relationship between DSV and host health. In this study, we analyzed large-scale cohort data from the Guangdong Gut Microbiome Project to study the ecology of DSV and the associations of DSV and host health parameters. Phylogenetic analysis showed that Desulfovibrio piger might be the most common and abundant DSV species in the GGMP. Predominant sub-OTUs of DSV were positively associated with bacterial community diversity. The relative abundance of DSV was positively correlated with beneficial genera, including Oscillospira, Coprococcus,Ruminococcus,Akkermansia, Roseburia,Faecalibacterium, andBacteroides, and was negatively associated with harmful genera, such as Clostridium,Escherichia,Klebsiella, and Ralstonia. Moreover, the relative abundance of DSV was negatively correlated with body mass index, waist size, triglyceride levels, and uric acid levels. This suggests that DSV is associated with healthy hosts in some human populations.

High Oscillospira abundance indicates constipation and low BMI in the Guangdong Gut Microbiome Project.

Oscillospira is a common yet rarely cultivated gut bacterial genus. Recently human gut microbiota studies have demonstrated its underlying significance for host health. However, little is known about Oscillospira-related host information and the links between Oscillospira and other members of the gut microbial community. To study the ecology of Oscillospira and gain insights into Oscillospira-related host physiological conditions, we analyzed data from the Guangdong Gut Microbiome Project, one of the largest gut microbiota database currently. Data of 6376 participants were analyzed. We studied the prevalence and relative abundance of Oscillospira as well as the profiles of associated microbial communities. We found that Oscillospira is closely related to human health because its abundance was positively correlated with microbial diversity, high density lipoprotein, and sleep time, and was inversely correlated with diastolic blood pressure, systolic blood pressure, fasting blood glucose, triglyceride, uric acid and Bristol stool type. Moreover, random forest analysis with five-fold cross validation showed Oscillospira could be a predictor of low BMI and constipation in the subset. Overall, in this study, we provide a basic understanding of Oscillospira-related microbiota profile and physiological parameters of the host. Our results indicate Oscillospira may play a role in aggravating constipation.

Differential expression of genes in HepG2 cells caused by UC001kfo RNAi as shown by RNA-seq.

The differential expression of genes in HepG2 cells caused by UC001kfo RNAi was investigated using RNA-seq. HepG2 cells were infected by Lenti-shUC001kfo lentivirus particles. The expression of UC001kfo mRNA in the HepG2-shUC001kfo cell line was detected by real-time PCR. RNA-seq technology was used to identify the difference in the expression of genes regulated by lncRNA UC001kfo in the HepG2 cell line. Gene ontology and signaling pathway analysis were performed to reveal the biological functions of the genes encoding of significantly different mRNAs. The results showed that mRNAs were differentially expressed between the HepG2-shUC001kfo cell line and the HepG2 cell line. The UC001kfo mRNA was significantly down-regulated in the stable cell line HepG2-shUC001kfo (P<0.001). Additionally, we found 19 signaling pathways or functional classifications encompassing 30 genes that played a role in cancer characteristics, cell adhesion, invasion and migration. The results also showed that the expression of many genes associated with cancer cell invasion and metastasis was decreased with the down-regulation of the lncRNA UC001kfo. LncRNA UC001kfo may play a role in regulating cancer cell invasion and metastasis. It was suggested that mRNAs were differentially expressed in the HepG2 cell line after the down-regulation of lncRNA-UC001kfo. Some took part in the extracellular matrix, cell adhesion, motility, growth, and localization. The genes encoding of differentially expressed mRNAs may participate in cell invasion and metastasis.

[Efficacy of real-time PCR for detecting Clostridium difficile infection: comparison with enzyme-linked fluorescent spectroscopy-based approaches].

OBJECTIVE: To evaluate the diagnostic efficacy of real?time polymerase chain reaction (q?PCR) for Clostridium difficile infection (CDI) in comparison with routine culture and enzyme?linked fluorescent spectroscopy?based aprroaches. METHODS: Stool samples were collected from suspected CDI cases in General Hospital of Guangzhou Military Command of PLA between May and December in 2016. All the samples were examined with 3 methods, namely enzyme?linked fluorescent spectroscopy for detecting Clostridium difficile toxin A/B (CDAB), detection of glutamate dehydrogenase (GDH), and q?PCR for amplification of Clostridium difficile?specific gene tpi and toxin gene (tcdA/tcdB), with the results of fecal culture as the reference for evaluating the diagnostic efficacy of the 3 methods. RESULTS: Of the total of 70 fecal samples, 13 (18.57%) were found to be positive for Clostridium difficile, including toxin?producing strains in 6 (8.57%) samples. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate of q?PCR for tpi were 92.31%, 91.23%, 70.59%, 98.11% and 91.43%, respectively, which were significantly higher than those of GDH test (84.62%, 84.21%, 55.00%, 96.00%, and 84.29%, respectively; Χ2=24.881, P<0.001). The sensitivity of q?PCR for tcdA/cdB was significantly higher than that of enzyme?linked fluorescent spectroscopy for CDAB in detecting CDI (66.67% vs 33.33%; Χ2=35.918, P<0.001). CONCLUSION: Both CDAB detection and q?PCR have a high specificity in detecting CDI, but GDH detection has a good sensitivity, and all these 3 methods have a high negative predictive value. Compared with other detection methods, amplification of tpi and tcdA/tcdB using q?PCR allows more rapid, sensitive and specific detection of CDI.

Differential Expression of Genes in HepG2 Cells Caused by UC001kfo RNAi as Shown by RNA-seq / 华中科技大学学报（医学）（英德文版）

The differential expression of genes in HepG2 cells caused by UC001kfo RNAi was investigated using RNA-seq.HepG2 cells were infected by Lenti-shUC001kfo lentivirus particles.The expression of UC001kfo mRNA in the HepG2-shUC001kfo cell line was detected by real-time PCR.RNA-seq technology was used to identify the difference in the expression of genes regulated by lncRNA UC001kfo in the HepG2 cell line.Gene ontology and signaling pathway analysis were performed to reveal the biological functions of the genes encoding of significantly different mRNAs.The results showed that mRNAs were differentially expressed between the HepG2-shUC001kfo cell line and the HepG2 cell line.The UC001kfo mRNA was significantly down-regulated in the stable cell line HepG2-shUC001kfo (P＜0.001).Additionally,we found 19 signaling pathways or functional classifications encompassing 30 genes that played a role in cancer characteristics,cell adhesion,invasion and migration.The results also showed that the expression of many genes associated with cancer cell invasion and metastasis was decreased with the down-regulation of the lncRNA UC001kfo.LncRNA UC001kfo may play a role in regulating cancer cell invasion and metastasis.It was suggested that mRNAs were differentially expressed in the HepG2 cell line after the down-regulation of lncRNA-UC001kfo.Some took part in the extracellular matrix,cell adhesion,motility,growth,and localization.The genes encoding of differentially expressed mRNAs may participate in cell invasion and metastasis.

[Epidemiological survey of high-risk human papillomavirus among 2501 woman].

OBJECTIVE: To survey the prevalence of high-risk human papillomavirus (HPV) in woman in Guangzhou during the period from 2013 to 2014. METHODS: A total of 2501 women in Guangzhou seeking medical attention in our hospital underwent high-risk HPV genotype screening of cervical specimens using real-time PCR. RESULTS: The prevalence of high-risk HPV infection among the women was 14.85% (146/983) in the year 2013, similar to the rate of 14.56% (221/1518) in 2014 (Χ(2)=0.041, P=0.839); no significant differences were found in the high-risk HPV infection rates between different age groups in either 2013 (Χ(2)=2.916, P=0.572) or 2014 (Χ(2)=6.494, P=0.165). The constituent ratio of the 13 types of high-risk HPV showed no significant difference between 2013 and 2014 (Χ(2)=11.872, P=0.452). The 13 HPV genotypes detected, listed in a descending order of the constituent ratios, included HPV-52, -16, -58, -56, -39, -51, -68, -59, -31, -35, -18, -33 and -45 in 2013, and were HPV-52, -16, -58, -68, -18, -51, -56, -39, -31, -33, -59, -35 and-45 in 2014. CONCLUSION: We report a high prevalence of high-risk HPV among women in Guangzhou, which suggests the necessity of screening for high-risk HPV-DNA among women at all ages for prevention and early detection of cervical cancer.

Application of microwave digestion/AAS in detecting crankshaft bearing knock.

The present study was carried out to detect crankshaft bearing knock using atomic absorption spectrometry (AAS) in an innovative way. Lubricating oil of MAGOTAN 2.0 with mileage of 1000-28000Km and sampling interval of 1000Km changed into atomic vapor in the heat after digesting with microwave. Hollow --cathode lamp made of the same element with metal content under test would radiate characteristic radiation with certain wavelength. A part of atomic vapor was launched with ground state atom after heating with graphite furnace. Concentration-absorbance working curve was finished with standard series sample after absorbance was measured. Finally, element content under test in oil was obtained based on the work curve. Database of primary element (Cu and Pb) content of lubricating oil in the same engine with different mileage was established. Results showed that Cu, Pb content fluctuates with different mileage in a certain range. In practical engineering applications, primary metal content in lubricating oil of engine crankshaft bearing was measured and compared with content variation trend chart. This new method not only helps automobile maintenance personnel to diagnose crankshaft bearing knock under no-disintegration situation but also is benefit for reducing the maintenance cost of automobile greatly and improving diagnostic accuracy of crankshaft bearing knock.

[Application of atomic absorption spectrometry in the engine knock detection].

Because existing human experience diagnosis method and apparatus for auxiliary diagnosis method are difficult to diagnose quickly engine knock. Atomic absorption spectrometry was used to detect the automobile engine knock in in innovative way. After having determined Fe, Al, Cu, Cr and Pb content in the 35 groups of Audi A6 engine oil whose travel course is 2 000 -70 000 kilometers and whose sampling interval is 2 000 kilometers by atomic absorption spectrometry, the database of primary metal content in the same automobile engine at different mileage was established. The research shows that the main metal content fluctuates within a certain range. In practical engineering applications, after the determination of engine oil main metal content and comparison with its database value, it can not only help to diagnose the type and location of engine knock without the disintegration and reduce vehicle maintenance costs and improve the accuracy of engine knock fault diagnosis.

[Application of ICP-AES in automotive hydraulic power steering system fault diagnosis].

The authors studied the innovative applications of the inductively coupled plasma-atomic emission spectrometry in automotive hydraulic power steering system fault diagnosis. After having determined Fe, Cu and Al content in the four groups of Buick Regal 2.4 main metal power-steering fluid whose travel course was respectively 2-9 thousand kilometers, 11-18 thousand kilometers, 22-29 thousandkilometers, and 31-40 thousand kilometers, and the database of primary metal content in the Buick Regal 2.4 different mileage power-steering fluid was established. The research discovered that the main metal content increased with increasing mileage and its normal level is between the two trend lines. Determination of the power-steering fluid main metal content and comparison with its database value can not only judge the wear condition of the automotive hydraulic power steering system and maintain timely to avoid the traffic accident, but also help the automobile detection and maintenance personnel to diagnose failure reasons without disintegration. This reduced vehicle maintenance costs, and improved service quality.

[The application of atomic absorption spectrometry in automatic transmission fault detection].

The authors studied the innovative applications of atomic absorption spectrometry in the automatic transmission fault detection. After the authors have determined Fe, Cu and Cr contents in the five groups of Audi A6 main metal in automatic transmission fluid whose travel course is respectively 10-15 thousand kilometers, 20-26 thousand kilometers, 32-38 thousand kilometers, 43-49 thousand kilometers, and 52-58 thousand kilometers by atomic absorption spectrometry, the authors founded the database of primary metal content in the Audi A6 different mileage automatic transmission fluid (ATF). The research discovered that the main metal content in the automatic transmission fluid increased with the vehicles mileage and its normal metal content level in the automatic transmission fluid is between the two trend lines. The authors determined the main metal content of automatic transmission fluid which had faulty symptoms and compared it with its database value. Those can not only judge the wear condition of the automatic transmission which had faulty symptoms but also help the automobile detection and maintenance personnel to diagnose automatic transmission failure reasons without disintegration. This reduced automobile maintenance costs, and improved the quality of automobile maintenance.

[Clinical evaluation of the application of gene chip for identifying pathogens in blood cultures].

OBJECTIVE: To explore the feasibility of using gene chip method to identify pathogens in blood cultures. METHODS: Clinical blood samples were obtained and cultured using an automated blood culture system. A gene chip diagnostic kit was used to detect the pathogenic bacteria in these blood cultures following the procedures of target gene extraction and amplification, hybridization and result analysis. The conventional method was also used to isolate and identify the bacteria from the clinical blood cultures, and the results of the two methods were compared. RESULTS: In the 86 clinical blood samples, 74 were positive and 12 negative according to the conventional method, while 48 were positive and 38 negative as found by the gene chip method, showing significant differences in the results (P<0.05). The two methods only had a concordance rate of 69.77%. CONCLUSION: The gene chip diagnostic kit has low concordance rate with the conventional method for detecting pathogens in clinical blood cultures and awaits further improvement.

[Variability analysis of S2 gene of SARS-CoV].

OBJECTIVE: To determine the sequence of S2 gene of SARS-associated coronavirus (SARS-CoV) GD322 and analyze the phyletic evolution of S2 gene. METHOD: S2 gene fragment was amplified from SARS-CoV GD322 genome with RT-PCR and ligated to pGEM-T vector for sequence analysis after transformation of the plasmid into E. coli DH5a. The variability of S2 genes and S2 proteins from 12 strains isolated in the early, intermediate and advanced stages of the SARS outbreak were analyzed and the phylogenetic tree was constructed with Lasergene, Clustal X, DNAman and Treeview. T cell antigen epitopes of S2 protein were predicted on the basis of Internet database. RESULT: With the epidemic spread of SARS-CoV, the S2 genes of the virus tended to become stable. Homology of S2 genes of SARS-CoV isolated in advanced stage of the outbreak reached 99.9%. Prediction of T cell antigen epitope showed that mutation at the 57th amino acid effected T cell antigen epitope. CONCLUSION: S2 gene of GD322 SARS-CoV is relatively stable during the epidemic spread of the virus, and mutation at the 57th amino acids of S2 protein may affect the T cell antigen epitope.

[Construction and identification of genomic cDNA subclones of dengue 2 virus NGC strain].

OBJECTIVE: To construct the cDNA subclones spanning the entire genome of dengue 2 virus NGC strain for further construction of full-length infectious viral cDNA clone. METHODS: Two pairs of primers were designed according to the restriction endonuclease sites in the viral genome of dengue 2 virus NGC strain. After viral RNA extraction from the brain of infected new-born mice, two parts of full-length viral cDNA were amplified by long RT-PCR and cloned into the vector pCR-XL-TOPO. The partial sequence of the recombinant plasmid was determined. RESULTS AND CONCLUSION: Sequence analysis and digestion with restriction enzymes demonstrated that the two cDNA subclones were specific for dengue 2 virus NGC strain, suggesting the successful construction of the two cDNA subclones of dengue 2 virus NGC strain.