Impact of Liver Fibrosis and Fatty Liver on T1rho Measurements: A Prospective Study.

OBJECTIVE: To investigate the liver T1rho values for detecting fibrosis, and the potential impact of fatty liver on T1rho measurements. MATERIALS AND METHODS: This study included 18 healthy subjects, 18 patients with fatty liver, and 18 patients with liver fibrosis, who underwent T1rho MRI and mDIXON collections. Liver T1rho, proton density fat fraction (PDFF) and T2* values were measured and compared among the three groups. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the T1rho values for detecting liver fibrosis. Liver T1rho values were correlated with PDFF, T2* values and clinical data. RESULTS: Liver T1rho and PDFF values were significantly different (p < 0.001), whereas the T2* (p = 0.766) values were similar, among the three groups. Mean liver T1rho values in the fibrotic group (52.6 ± 6.8 ms) were significantly higher than those of healthy subjects (44.9 ± 2.8 ms, p < 0.001) and fatty liver group (45.0 ± 3.5 ms, p < 0.001). Mean liver T1rho values were similar between healthy subjects and fatty liver group (p = 0.999). PDFF values in the fatty liver group (16.07 ± 10.59%) were significantly higher than those of healthy subjects (1.43 ± 1.36%, p < 0.001) and fibrosis group (1.07 ± 1.06%, p < 0.001). PDFF values were similar in healthy subjects and fibrosis group (p = 0.984). Mean T1rho values performed well to detect fibrosis at a threshold of 49.5 ms (area under the ROC curve, 0.855), had a moderate correlation with liver stiffness (r = 0.671, p = 0.012), and no correlation with PDFF, T2* values, subject age, or body mass index (p > 0.05). CONCLUSION: T1rho MRI is useful for noninvasive detection of liver fibrosis, and may not be affected with the presence of fatty liver.

[Duplex real-time PCR assay for rapid detection of E. coli O157 and E. coli O104 in the legume plants and its products].

OBJECTIVE: To establish a rapid assay to detect enterohemorrhagic Escherichia coli O157 (E. coli O157) and enterohemorrhagic Escherichia coli O104 (E. coli O104) in the legume plants and its products by using the duplex real-time PCR. METHODS: Based on part fragments of E. coli O157 specific gene rfbE and E. coli O104 specific gene wzy, primers and Taq-Man probes were designed. Results DNA (Q157): DNA (O104) = 1 : 3, DNA 2 µL, Master Mix 12.5 µL, primers (10 µmol/L) 1 µL,Taq-Man probes( 10 µmol/L) 0.5 µL, ddH2O 25 µL. The two pathogens could be detected in one reaction system, the lowest limit of detection sensitivity was 10(2) CFU/mL(g). CONCLUSION: This method is rapid and convenient, with good specificity, high sensitivity. The duplex real-time PCR assay could provide a cost-effective and convenient method for detect foodborne pathogenic bacteria.

H1foo is essential for in vitro meiotic maturation of bovine oocytes.

Oocyte-specific linker histone, H1foo, is localized on the oocyte chromosomes during the process of meiotic maturation, and is essential for mouse oocyte maturation. Bovine H1foo has been identified, and its expression profile throughout oocyte maturation and early embryo development has been established. However, it has not been confirmed if H1foo is indispensable during bovine oocyte maturation. Effective siRNAs against H1foo were screened in HeLa cells, and then siRNA was microinjected into bovine oocytes to down-regulate H1foo expression. H1foo overexpression was achieved via mRNA injection. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that H1foo was up-regulated by 200% and down-regulated by 70%. Based on the first polar body extrusion (PB1E) rate, H1foo overexpression apparently promoted meiotic progression. The knockdown of H1foo significantly impaired bovine oocyte maturation compared with H1foo overexpression and control groups (H1foo overexpression = 88.7%, H1foo siRNA = 41.2%, control = 71.2%; P < 0.05). This decrease can be rescued by co-injection of a modified H1foo mRNA that has escaped from the siRNA target. However, the H1e (somatic linker histone) overexpression had no effect on PB1E rate when compared with the control group. Therefore we concluded that H1foo is essential for bovine oocyte maturation and its overexpression stimulates the process.

Characterization of Listeria monocytogenes isolates in import food products of China from 8 provinces between 2005 and 2007.

UNLABELLED: A total of 48 Listeria monocytogenes isolates of different import food products from 8 provinces between 2005 and 2008 were characterized. The serotype and virulence were confirmed for each strain and molecular subtyping were analyzed by multilocus sequence typing (MLST). Twenty five strains were assigned to serotype 1/2a, and 11 isolates to serotype 1/2b, serotype 4b were found in 7 isolate, and the remaining 5 strains were grouped into serotypes 1/2c, 4a, and 4e. Molecular subtyping schemes found thirty two sequence types (STs) among these isolates and the majority of L. monocytogenes strains belonged to lineage II (56%), followed by lineage I (38%), lineage III (6%). Two molecular subtype clusters, cluster A included all isolates of lineage II, while cluster B contained the isolates of lineages I and lineages III. Two L. monocytogenes strains were not grouped in either of the two clusters. Fifty three isolates were as virulent as L. monocytogenes reference strain EGD in mouse virulence assay, while the isolates 22213 and 22265 had low pathogenicity. These results provide the first molecular insight into the L. monocytogenes strains isolated from import food products of 8 provinces in China and indicate the potential risk to cause human disease if intake by contaminated foods. MLST could be used as a routine subtyping method of L. monocytogenes isolates. In China, inspection and quarantine strategies of imported foods should be strengthened. PRACTICAL APPLICATION: There is a potential risk of listeriosis in China and routine subtyping of L. monocytogenes isolates is important. It is necessary for food hygiene management to strengthen the supervision of imported foods.

A randomized, multi-central, controlled study of patients with hepatitis B e antigen-positive chronic hepatitis B treated by adefovir dipivoxil or adefovir dipivoxil plus bicyclol.

OBJECTIVE: To evaluate the efficacy and safety profiles of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) treated with adefovir dipivoxil (ADV) or ADV plus bicyclol, and to optimize the treatment strategy for CHB patients. PATIENTS AND METHODS: A total of 250 patients with HBeAg-positive CHB were randomized to ADV plus bicyclol combination group and ADV monotherapy group. The patients in the ADV plus bicyclol combination therapy group (n = 125) received ADV 10 mg orally q.d. and bicyclol 25 mg orally t.i.d. for 48 weeks, and those in the ADV monotherapy group (n = 125) were administered ADV 10 mg orally q.d. alone for 48 weeks. The serum aminotransferases (ALT/AST), HBV DNA, HBeAg/HBeAb, and liver biopsy were conducted before and after therapy. RESULTS: The serum aminotransferase levels were decreased significantly in both groups. The serum aminotransferase level in ADV plus bicyclol combination therapy group decreased greater than that in ADV monotherapy group (P < 0.01). The virological response rate in ADV plus bicyclol combination therapy group was not significantly different from that in ADV monotherapy group (P > 0.05). After treatment for 48 weeks, the Knodell necroinflammatory score of the two groups were all alleviated significantly, and the Knodell score in the combination group was significantly lower than that in the ADV monotherapy group (P < 0.05). There were no remarkable adverse events probably related to the drug in this study. CONCLUSION: Adefovir dipivoxil plus bicyclol combination therapy is a safe and superior treatment regimen for patients with HBeAg-positive CHB when compared with ADV monotherapy.

[Real-time PCR assay for rapid detection of Listeria monocytogenes in simulated milk specimens].

OBJECTIVE: To establish a real-time PCR assay for the rapid detection of Listeria monocytogenes in simulated milk specimens. METHODS: Based on part fragments of hlyO gene, a pair of primers and Taq-Man probe were designed for quantitative detection of L. monocytogenes. The specificity of the primers and probe were tested by using different L. monocytogenes strains and other common pathogenic bacteria. RESULTS: L. monocytogenes strains were positive in the detection and other tested strains were negative. The sensitivity of assay was 9 copies per PCR reaction. CONCLUSION: The specificity and sensitivity of Taq Man real-time PCR technology for detecting L. monocytogenes in simulated dairy specimens were high, and the assay could be completed within 1.5 h. This method could be used to detect other food samples contaminated by L. monocytogenes and identify the cause of food-borne Listeriosis outbreaks.

[Typing of Listeria monocytogenes in import and export foods with PFGE].

OBJECTIVE: To investigate the molecular type and genetic correlation of Listeria monocytogenes (LMO) isolated from imported and exported foods. METHODS: Pulsed-field gel electrophoresis (PFGE) standard method recommended by american PulseNet for typing LMO was applied. The chromosomal DNA of L. monocytogenes was digested by restriction enzyme Asc I and analyzed by PFGE. The PFGE patterns of L. monocytogenes strains isolated from different areas were compared by using BioNumberics software to analyze the similarity between strains. RESULTS: Twenty-four L. monocytogenes strains were grouped into 20 PFGE subtypes by the similarity of PFGE pattern ranged from 44.45% to 100%. Particularly, it was identified that there were three subtype strain groups, each group sharing with the same PFGE pattern, and the similarity reaching 100%: the first group including LMO16 from Canada, LMO18 from America and LMO13 from Denmark, the second group including LMO7 from Denmark and LMO22 from Shunde, and the third group including LMO21 from Guangzhou and LMO8 from Shanxi. CONCLUSION: Generally, much genetic diversity was shown in Listeria monocytogenes isolated from import and export foods, but the correlations among strains are existed to some extent.

[Taxonomy of Enterobacter sakazakii and the biological characteristics of the new species and genus].

Enterobacter sakazakii, one of the major pathogens affecting the safety of infant formula powder was defined as a species in 1980. However, the new names and new combinations about Enterobacter sakazakii notified in volume 58, part 6, of the International Journal of Systematic and Evolutionary Microbiology (IJSB). The taxonomic relationship of strains described as E. sakazakii, biological characteristics of its new genus and species, the development related to its isolation and identification were reviewed in this paper, in order to facilitate the related personnel to keep in touch with the latest developments on E. sakazakii. It's also conducive to unify and standardize the Chinese name for E. sakazakii.

[Isolation and characterization of bacteriophages of Enterobacter sakazakii].

OBJECTIVE: To isolate bacteriophage of Enterobacter sakazaki from sewage using reference and isolated strains as indicators, and to observe the biological characteristics of the bacteriophage. METHODS: Bacteriophages were isolated from sewage with double layer agar. Specificity and host ranges of the bacteriophages were determined by reference bacterium from same genus and family. Phage particles were observed by electron microscope and its molecular character was analyzed by Random amplified polymorphic DNA. RESULTS: Five bacteriophages of E. sakazakii were isolated from sewage and showed relatively narrow host ranges, only E. sakazakii could be lysised. The phage SK2 isolated from ATCC 51329 could form plaques on 24 of all 27 E. sakazakii strains (89%). All five phage particles had the hexagonal heads and tails after observing with negatively stained method by electron microscope. Random amplified polymorphic DNA analysis showed the polymorphism of the five phages. CONCLUSION: E. sakazakii phages isolated from sewage were only sensitive to E. sakazakii, and had potential usage in typing, preventing, treating E. sakazakii and entironment protection.

[The relationship between HBV genotypes and the efficacy of antiviral therapies in hepatitis B e antigen- positive patients].

OBJECTIVES: To study the relationship between HBV genotypes and the efficacy of antiviral therapies. METHODS: HBV genotypes of 90 hepatitis B e antigen positive patients with chronic hepatitis B (CHB) were determined by PCR sandwich hybridization-ELISA technique. Forty-one patients with CHB were treated with lamivudine (100 mg/day) for 48 weeks and 49 patients with CHB were given alpha-interferon (3 MU/QOD) therapy for 48 weeks. The serological, biochemical and virological symbols were measured before, during and after treatment for all the patients. RESULTS: Of the 90 patients, genotype B HBV was found in 16 and C in 74. There was no difference in the rate of response to lamivudine treatment between patients with genotype B or C HBV (33.3% vs. 20.0%) after 48 weeks treatment with lamivudine in the 41 patients. Of the 49 HBeAg positive CHB patients treated with alpha-interferon for 48 weeks, in HBV genotype B and C patients the rates of normalization of ALT were 60.0% and 20.5%; the rate of HBeAg turning to negativity was 50.0% and 17.9%; and the rate of HBV DNA undetectability was 50.0% and 17.9%. The rate of response to the interferon treatment was significantly higher in patients with HBV genotype B compared to those with genotype C. CONCLUSIONS: Our study shows that there is no influence on the lamivudine treatment effects for the HBV genotype B and C CHB patients, but the alpha-interferon treatment for HBV genotype B CHB patients is more effective than that for the genotype C ones.

[Liver pathological changes and clinical features of patients with chronic hepatitis B virus infection in their immune tolerant phase and non-active status].

OBJECTIVE: To investigate the liver pathological changes and the clinical features of patients with hepatitis B virus (HBV) infection in their immune tolerant phase and non-active status. METHODS: Fifty-four patients with chronic HBV infection in their immune tolerant stage and another 47 patients with the same infection but in non-active status were involved in this study. Statistical analysis including the ages and sex of the patients, their serum levels of HBV DNA, hepatocytic expression of HBsAg and HBcAg and their liver pathology were studied and statistically analyzed. Histological grading of inflammation and staging of fibrosis in the livers were also compared and analysed in patients with different levels of serum ALT. RESULTS: The sex ratio of the two groups was of no significant difference. The average age of the patients in the non-active status [(28.11+/-8.60) years.] was older than that of the patients in the immune tolerant stage [(24.93+/-7.21) years], showing a significant difference (P < 0.05). The serum levels of HBV DNA of the patients in the immune tolerant stage were high and 94% of them had a HBV DNA higher than 106 copies/ml. In the non-active status group, 89% of the patients were HBV DNA negative. Between the two groups of patients there were no significant differences in the histological grades of liver inflammation or in the hepatocytic expressions of HBsAg and HBcAg. The stage of fibrosis was higher in the non-active status group than in the immune tolerant stage group, showing a significant difference between these two groups (u = 2.004, P < 0.05). The fibrosis stages of the livers of patients of a higher but within normal ALT level were markedly higher than those of a lower but within normal ALT level patients (u = 3.274, P less than 0.01). CONCLUSION: Patients infected with HBV in non-active status may have experienced some occult courses of immune active stages; they are older in age and have higher levels of fibrosis. ALT sustained at a high level but within the normal range may indicate a higher degree of fibrosis, therefore liver pathological studies should be recommended for this kind of patient.

[Relationship between the quantities of peripheral dendritic cells and of serum HBV DNA and the inflammatory reaction levels in the liver].

OBJECTIVES: To investigate the relationship between the quantity of peripheral dendritic cell (DC) and of serum HBV DNA and the inflammatory level in chronic hepatitis B (CHB). METHODS: The myeloid DC (DC1) and plasmacytoid DC (DC2) in fresh peripheral blood were enumerated by using three-color flow cytometry in chronic hepatitis B patients and healthy donors. The hepatic inflammatory levels were evaluated by percutaneous liver biopsy. The serum HBV DNA levels were determined by real-time PCR. RESULTS: CHB patients with serum HBV DNA < or = 10(6) copies/ml exhibited a significant increase in the percentage of circulating DC2 in comparison with those of CHB patients with serum HBV DNA > or = 10(6) and with healthy donors (P < 0.05). The two latter groups showed no significant differences between each other. There was also no significant difference in the relative quantity of peripheral blood DC1 among the three groups mentioned above (P = 0.162). No evidence was found to support that the relative quantity of peripheral blood DC2 was associated with the clinical severity of the disease or the inflammatory level in the liver (P > 0.05). CONCLUSION: The relative quantity of peripheral blood DC2 is associated with HBV DNA level. It is suggested that DC2 may play a pivotal role in inhibiting HBV replication in CHB patients. There was no relationship found between relative quantities of DCs and the inflammatory level in the liver.