ABSTRACT
Organic aggregates (OA) are the important circulation hub of matter and energy in aquatic ecosystems. However, the comparison studies on OA in lakes with different nutrient levels are limited. In this study, spatio-temporal abundances of OA and OA-attached bacteria (OAB) in oligotrophic Lake Fuxian, mesotrophic Lake Tianmu, middle-eutrophic Lake Taihu, and hyper-eutrophic Lake Xingyun were investigated in different seasons during 2019-2021 using a scanning electron microscope, epi-fluorescence microscope, and flow cytometry. The results showed that:â the annual average abundances of OA in Lake Fuxian, Lake Tianmu, Lake Taihu, and Lake Xingyun were 1.4×104, 7.0×104, 27.7×104, and 16.0×104 ind·mL-1, whereas the annual average abundances of OAB in the four lakes were 0.3×106, 1.9×106, 4.9×106, and 6.2×106 cells·mL-1. The ratios of OAB:total bacteria (TB) in the four lakes were 30%, 31%, 50%, and 38%, respectively. â¡ OA abundance in summer was significantly higher than that in autumn and winter; however, the ratio of OAB:TB in summer was approximately 26%, which was significantly lower than that in the other three seasons. ⢠Lake nutrient status was the most important environmental factor that affected the abundance variations of OA and OAB, accounting for 50% and 68% of the spatio-temporal variations in OA and OAB abundances. ⣠Nutrient and organic matters were enriched in OA, especially in Lake Xingyun; the proportions of particle phosphorous, particle nitrogen, and organic matters in this lake were as high as 69%, 59%, and 79%, respectively. Under the circumstance of future climate change and the expansion of lake algal blooms, the effects of algal-originated OA in the degradation of organic matters and nutrient recycling would be increased.
Subject(s)
Ecosystem , Lakes , Seasons , Eutrophication , PhosphorusABSTRACT
Air in concentrated animal feeding operations contains antibiotic resistance genes and airborne pathogens, with potential threat to human and animal health. In this study, air was sampled in the living area, outside, and inside of a fattening pig house in a pig farm for 24 and 48 hours. Feedstuffs, drinking water additives, and feces in the pig house were collected. Three kinds of antibiotic resistance genes (macrolide, ß-lactam, and tetracycline) and seven pathogenic microorganisms (Campylobacter, Clostridium perfringens, Enterococcus, Escherichia coli, Yersinia enterocolitica, Staphylococcus spp., and Streptococcus suis) were detected by polymerase chain reaction (PCR). Six genes with high detection rates were selected, with their concentrations being determined by real-time quantitative PCR (qPCR). Results showed that three macrolide and two tetracycline resistance genes were detected in all air samples. Enterococcus, Escherichia coli, Yersinia enterocolitica, and Staphylococcus spp. were detected in air samples and drinking water additive. The concentrations of most target genes were above 104 copies·m-3. The gene concentrations near the pig house were much higher than those in the living area. Main sources of antibiotic resistance genes and pathogens in the air were pig manure and drinking water additive. Sampling time of 24 h in the pig farm met the requirements for PCR detection. Sampling time of 48 h had a higher sampling efficiency than that of 24 h in the living area of the pig farm, whereas sampling time of 24 h was more appropriate than that of 48 h in high bioaerosol concentration area such as the pig house.
Subject(s)
Animal Husbandry , Drug Resistance, Bacterial/genetics , Genes, Bacterial , Animals , Anti-Bacterial Agents , Bacteria , Enterococcus , Environmental Pollution , Escherichia coli , Feces , Manure , Swine , Tetracycline , Tetracycline ResistanceABSTRACT
To clear the kinds of trace elements which is closely related with the active ingredient, proclaim the effects of trace elements on the quality of the Glycyrrhizae Radix et Rhizoma, provide the theoretical foundation to the further quality control of cultivation, take the advantage of the HPLC to determine the contents of glycyrrhizic acid and the liquiritin according to Chinese pharmacopoeia, use the inductively coupled plasma mass spectrometry to test the contents of Cu, Zn, Mn, Pb, Se, Cd, Ni, La, Na, Cr, M, Fe, Ca, Al, K, Sr, then, use SPSS statistical software for active ingredient and trace elements Correlation Analysis. The result of correlation analysis showed that Liquiritin contents of Glycyrrhizae Radix et Rhizoma have strong a positive correlation with the Mn, Pb contents, well, have a negative correlation with the Cu, Na contents; Glycyrrhizic acid contents showed a positive correlation with Mg, Cd, La contents, however, it showed a negative correlation with K, Fe contents. Comprehensive analysis of the results of the study, a preliminary thought that the active ingredient of Glycyrrhizae Radix et Rhizoma closely related with the trace elements, but the exact conclusion still need further study concentration-response relationship analysis.
Subject(s)
Glycyrrhiza/chemistry , Plant Roots/chemistry , Plants, Medicinal/chemistry , Rhizome/chemistry , Trace Elements/analysis , Chromatography, High Pressure Liquid , Flavanones/analysis , Glucosides/analysis , Glycyrrhizic Acid/analysis , Mass Spectrometry/methodsABSTRACT
The MNS blood group system includes more than 40 antigens, and the M, N, S and s antigens are the most significant ones in the system. The antigenic determinants of M and N antigens lie on the top of GPA on the surface of red blood cells, while the antigenic determinants of S and s antigens lie on the top of GPB on the surface of red blood cells. The GYPA gene coding GPA and the GYPB gene coding GPB locate at the longarm of chromosome 4 and display 95% homologus sequence, meanwhile both genes locate closely to GYPE gene that did not express product. These three genes formed "GYPA-GYPB-GYPE" structure called GYP genome. This review focuses on the molecular basis of genomic GYP and the variety of GYP genome in the expression of diversity MNS blood group antigens. The molecular basis of Miltenberger hybrid glycophorin polymorphism is specifically expounded.
Subject(s)
Blood Group Antigens/genetics , Chromosomes, Human, Pair 4/genetics , MNSs Blood-Group System/genetics , Humans , MNSs Blood-Group System/immunology , Molecular Sequence Data , Sequence HomologyABSTRACT
OBJECTIVE: To study the blooming habits, pollen viability and stigma receptivity of Chrysanthemum morifolium and provide theoretical basis for its breeding. METHODS: Explored the blooming habits by dynamic observation on the process of blossom, evaluated the pollen viability by germination in vitro culture method and estimated stigma receptivity by benzidine-hydrogen peroxide method. RESULTS: About the pollen viability, there were no significant differences between the flowers which in the same round of the capitulum; Tubular flowers in the center of a capitulum were significantly higher than that on the edge; In the morning pollen vitality gradually raised, during 11: 00 - 14: 00 maintained the highest, and then gradually decreased; Tubular flower began to loose powder on the third day, during 4th - 6th day the pollen viability was highest, respectively was 35.12%, 39.89%, 38.12%, then gradually decreased, on the 15th day was only 7.41%, finally turned into wither. Regard to the stigma receptivity, the center of a capitulum were significantly higher than that on the edge, outer edge ligulate flower had no receptivity; Revealed the strongest during 13: 00 - 14:00 in one day; During the 5th - 7th day was the strongest after flowering. The regulation of the stigma secreted mucus existed great consistency with the stigma receptivity, namely the stigma receptivity usually was strong when it secreted large number mucus. CONCLUSION: Understand the blossom habits of Chrysanthemun morifolium, as well as the dynamic changes regulation of pollen viability and stigma receptivity during its blossom, which could be used to select the flowers in a capitulum which are on the more suitable period and position for artificial pollination and hybridization breeding research.
Subject(s)
Chrysanthemum/physiology , Flowers/physiology , Plants, Medicinal/physiology , Pollen/physiology , Chrysanthemum/growth & development , Flowers/growth & development , Germination , Plants, Medicinal/growth & development , Pollination/physiology , Reproduction/physiology , Time FactorsABSTRACT
A normal temperature lignocellulose-degrading microflora has been constructed by our laboratory. We researched the degradation activity and compose of the community in 28 degrees C fermentation condition. The results showed that the microbial community could degrade 39.6% of rice stew gross weight within five days.The volatile products were detected using CP-Chirasil-Dex CB capillary column by GC-MS, propionic acid, ethanol, isopropyl alcohol, 4-amino-1-butanol, butanoic acid, diethoxydimethyl-silane, lactic acid, ethanol,2,2'-oxybis-, diethyl phthalate and glycerin,more than 10 kinds of volatile products were detected. The state volatile products of changed largely along with the process of decompose, the productions gradually increase, and the content changes much with the process of decompose. Denaturing gradient gel electrophoresis (DGGE) detected the dynamic change of bacterium compose, the bacterium changes much in different period,the result of Blast from 16S rDNA sequence was found that the closest relative in community belong to Clostridium sp., Brevibacillus sp., Rhizobium sp., Bacterium sp. four genera.
Subject(s)
Brevibacterium/metabolism , Clostridium/metabolism , Lignin/metabolism , Plant Stems/chemistry , Rhizobium/metabolism , Biodegradation, Environmental , Brevibacterium/isolation & purification , Clostridium/isolation & purification , Oryza/chemistry , Refuse Disposal/methods , Rhizobium/isolation & purification , TemperatureABSTRACT
The NSC-7 microbial community could decompose cellulose and lindan with high efficiency. In order to determine the bacterial composition of the community, 11 isolate strains were detected by plate isolation, while a community reset by the 11 isolate strains lost the capacity of degrading cellulose. The capacity of degrading of the filter paper in double deck plate and monolayer plate were determined, only the filter paper in double deck plate were degraded, that means the main or key microbe are anaerobic. The denaturing gradient gel electrophoresis (DGGE) and construction of 16S rDNA clone library were used to identify the composition diversity of NSC-7 community. 195 clones and 25 strains were detected in clone library, and about 60% closest relative among them was known the detailed information which were belonged to Clostridium, Petrobacter, Bacteria, Paenibacillus, Proteobacterium. Furthermore, there were 40% closest relative belonged to uncultured bacterium clone.
Subject(s)
Bacteria, Anaerobic/isolation & purification , Bacteria/classification , Cellulose/metabolism , Clostridium/isolation & purification , Proteobacteria/isolation & purification , Biodiversity , Electrophoresis, Polyacrylamide Gel/methods , Fermentation , Hexachlorocyclohexane/metabolism , Paenibacillus/isolation & purification , RNA, Ribosomal, 16S/geneticsABSTRACT
The EIAgen HCV test (Adaltis Inc., Montreal, Canada) is an enzyme immunoassay (EIA) for the detection of anti-hepatitis C virus (HCV) antibodies. This study compared the performance of this test side-by-side with the current Ortho HCV 3.0 Anti-HCV assay (Ortho-Clinical Diagnostics Inc., Johnson & Johnson Company, Raritan, NY, USA). Among 2559 specimens examined, 178 were true positives, 2376 were true negatives and 5 were indeterminate. The sensitivity of the EIAgen HCV test was 100%, versus 98.3% for the Ortho HCV test, while their respective specificities were 98.1% and 98.2%. The EIAgen HCV test gave a positive predictive value of 79.8% and a negative predictive value of 100%. Overall, the concordance of this test with the Ortho HCV test was 98.2%. Specimens from potentially interfering substances, such as sera from pregnant women, sera from patients with acute non-C hepatitis, autoimmune diseases, lipidemia, or from patients undergoing hemolysis, showed no interference with either EIA. An EIAgen HCV test signal-to-cut-off ratio of >5.9 would be highly predictive of a true-positive finding in these specimens. The EIAgen HCV test is well suited for screening blood and blood products in antibodies to HCV.
Subject(s)
Hepacivirus/immunology , Hepatitis C Antibodies/blood , Hepatitis C/diagnosis , Immunoenzyme Techniques/methods , Reagent Kits, Diagnostic , False Positive Reactions , Female , Hepatitis C/immunology , Hepatitis C/virology , Humans , Predictive Value of Tests , Pregnancy , Sensitivity and SpecificityABSTRACT
Limitations of polyacrylamide gel or agarose gel electrophoretic methods in genotyping research affect the interpreting of detection results. In order to develop a simple and reliable method for appraising results of ABO genotyping detection, the microfluidic chip analysis system was established by using microfluidic chip to replace the gel electrophoresis and combining with multiplex-PCR-RFLP technique. 150 blood samples were tested by this microfluidic chip analysis system with multiplex-PCR-RFLP technique to evaluate its stability and accuracy. The results showed that all the testing results were consistent with serologic ABO genotyping results and 1 blood sample with decrease of B antigen caused by CML was identified. In conclusion, the established microfluidic chip analysis system is stable and reliable technique. Application of this technique enables the ABO genotyping results to be more objective and accurate.
Subject(s)
ABO Blood-Group System/genetics , Blood Grouping and Crossmatching/methods , Microfluidic Analytical Techniques , DNA Primers/genetics , Genotype , Humans , Microfluidics , Oligonucleotide Array Sequence AnalysisABSTRACT
OBJECTIVE: To study the geographical variation of morphologic and germination characteristic of different Glycyrrhiza uralensis provenance seeds, approach the geographical variation mode and ecology mechanism, and laid theoretical foundation for districting and allocating of G. uralensis seeds. METHOD: Field investigation and laboratory analysis were applied. Seed shape and kilosseed weight were sampled randomly, germination rate germination force by general methods. RESULT: The morphologic characteristic of G. uralensis seeds showed roughly longitude variation tendency that the seeds increased gradually from west to east. While the germination characteristic showed roughly altitude variation tendency that the seeds germination rate and germination force increased with the increase of the altitude, and the average germination rate was the same with the seeds morphologic characteristic. The results of analysis correlated with the climatic factors show that the morphologic characteristic of G. uralensis was positive correlated with annual rain-fall of the habitat, and the germination rate was quickened by drought, high temperature and strong sunshine. CONCLUSION: The morphologic and germination characteristic and of G. uralensis seeds present distinguished geographical variation, and the formation of the variation was related to the ecological environment in which the seed provenance adapted.
Subject(s)
Geography , Germination , Glycyrrhiza uralensis/anatomy & histology , Glycyrrhiza uralensis/growth & development , Seeds/anatomy & histology , Seeds/growth & development , Altitude , Drugs, Chinese Herbal , Glycyrrhiza uralensis/classification , RainABSTRACT
The aim of this study was to establish a diagnostic method for ABO genotyping and to investigate the distribution of ABO genotype in Beijing Han population so as to understand the distribution characteristics and regularity of ABO genotype. An ABO genotyping method was established by using multiplex-PCR-RFLP and PCR-SSP techniques, and the ABO allele frequency in Beijing Han population was investigated. The results showed that A102, O1 and B allele were more common genes in Beijing Han individuals. And A102 allele was predominant in the phenotype A group in this population. Three O2 alleles were found and no A201 allele was found while gene frequency investigation was performed. No A101A101, A101O2, A102O2, BO2 and O2O2 in this population were discovered. It is concluded that the primary regularity of ABO allele distribution in Beijing Han population is found through this study. It provides basic reference for further study of ABO types.
Subject(s)
ABO Blood-Group System/genetics , Asian People/genetics , Polymorphism, Genetic , Adult , Alleles , China/ethnology , Female , Gene Frequency , Genotype , Humans , Male , Middle Aged , Polymerase Chain Reaction/methods , Young AdultABSTRACT
To detect the metabolic characteristic of rice straw degradation by composite microbial system WSC-6, we cultured WSC-6 in the media used rice straw as the limiting carbon source. The rice straw was added in the style of different quantity once or the same quantity at the different time intervals during 90 days culture. The systems were cultivated under static condition at 50 degrees C. The degradation ratio, absolute degradation quantity,products from degradation and dynamics of pH value of fermentation system were all investigated. The results showed: when 1% rice straw was added once, the pH of fermentation system decreased from initial 7.8 to 6.0 within the first three days inoculation, and after six-day cultivation, it increased to 8.0 and was stable. For dissolved oxygen concentration (DO), the value was maintained at range of 0.01 to 0.12 mg x L(-1) of microaerobic condition. During the rice straw degradation, more than ten kinds of products including ethanol, acetic acid, lactic acid and glycerol and so on were detected using GC-MS. Especially, the highest concentration of lactic acid among all products was 7.381 g x L(-1) at 24 h after inoculation. During 90-day cultivation, for the addition treatments of the different quantity once, the more rice straw added, the quicker and lower the pH decreased, and the longer time intervals returned the pHs were. Especially for 5.0% addition, when 5.0% of rice straw was added once, pH did not increase again after it decreased. Among the addition of the same quantity at the different time intervals, the trend of decrease-increase in pH at 12-day and 15-day intervals could be repeated and high degradation activity well maintained. After 90-day of inoculation, the highest degradation ratio occurred in the treatment at 15-day interval, which was 86.7%. The highest absolute quantity occurred in the treatment at 6-day interval, which was 32.4 g. The trend of pH changes can indicate the activity of lignocellulose degradation and degradation process of the WSC-6.
Subject(s)
Bacteria/metabolism , Lactic Acid/metabolism , Lignin/metabolism , Oryza/metabolism , Plant Stems/metabolism , Acetic Acid/analysis , Acetic Acid/metabolism , Bacteria/cytology , Biodegradation, Environmental , Culture Media , Fermentation , Gas Chromatography-Mass Spectrometry , Glycerol/analysis , Glycerol/metabolism , Hydrogen-Ion Concentration , Lactic Acid/analysis , Lignin/analysisABSTRACT
This paper described a rare case of adenomyoma of common bile duct. The case is a 51-year-old man who was hospitalized for yellow color skin and sclera and itching for 2 mo without abdominal pain. Nothing special was found in physical examination except yellowish skin and sclera. The clinical presentation and Computerized Tomography (CT), Magnetic resonance cholangiopancreatography (MRCP), and ultrasonography suspected a tumor of the distal bile duct. The patient was treated successfully by pancreaticoduodenectomy. Histologically, the lesion consisted of adenoid and myofibrous tissue and moderate atypia. The immunophenotype of the epithelial component was cytokeratin 7+/cytokeratin 20-. The patient has been well without any evidence of recurrence for 12 mo since his operation.
Subject(s)
Adenomyoma/pathology , Common Bile Duct Neoplasms/pathology , Common Bile Duct/pathology , Adenomyoma/diagnostic imaging , Adenomyoma/surgery , Common Bile Duct/diagnostic imaging , Common Bile Duct/surgery , Common Bile Duct Neoplasms/diagnostic imaging , Common Bile Duct Neoplasms/surgery , Humans , Male , Middle Aged , Pancreaticoduodenectomy , UltrasonographyABSTRACT
In this paper, the acute toxicity of glyphosate and acetochlor on Dugesia japonica and the impact of these two chemicals on the ingestion and regeneration of D. japonica were studied. The results showed that the 24 h and 48 h LC50 of glyphosate and acetochlor on D. japonica was 41.78 and 12.22 mg x L(-1), and 35.48 and 8.41 mg x L(-1), respectively. Glyphosate at the concentration of >6.20 mg x L(-1) and acetochlor at the concentration >1.0 mg x L(-1) impact the regeneration of D. japonica (P<0.05) significantly, but the impact decreased gradually with exposure time. If taking 84 hours after operation as a standard, D. japonica could regenerate well in glyphosate and acetochlor solutions at most of test concentrations except at 1.40 mg x L(-1) and 2.00 mg x L(-1) of acetochlor. It was indicated that comparing with glyphosate, acetochlor had stronger acute toxicity and stronger impact on D. japonica and its ingestion and regeneration, and D. japonica could be used as a bio-indicator to monitor glyphosate and acetochlor contamination.
Subject(s)
Environmental Monitoring/methods , Feeding Behavior/drug effects , Glycine/analogs & derivatives , Planarians/physiology , Toluidines/toxicity , Animals , Glycine/toxicity , Herbicides/toxicity , Planarians/drug effects , Regeneration/drug effects , Toxicity Tests, Acute , GlyphosateABSTRACT
BACKGROUND: A multi-blood center study was conducted to evaluate a human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) multiplex nucleic acid testing (NAT) donor screening test and to determine the residual risk for HIV-1 and HCV infection. STUDY DESIGN AND METHODS: A commercially available HIV-1 and HCV assay (Procleix, Chiron Corp.) was used for simultaneous detection of HIV-1 RNA and HCV RNA on 89,647 unlinked donor samples. NAT was performed with pools of 16 samples that had passed all routine screening tests. Single-donor NAT was performed for samples that had been disqualified by any reactive screening test result(s). Anti-HCV (Ortho third-generation HCV enzyme immunoassay [EIA]), alanine aminotransferase, and HCV NAT (Roche COBAS Amplicor HCV test) confirmatory tests were used for HCV EIA-nonreactive, HCV NAT-reactive samples. RESULTS: Three HCV NAT yield cases and no HIV-1 yield cases were detected. The yield rate for HCV NAT was 3.4 per 10(5) (95 percent confidence interval [CI], 0.7-9.8). The estimated incidence rate for HCV is 24.2 per 100,000 person-years (95% CI, 3.4-88.0). If minipool NAT is added to routine donor screening, the residual risk for HCV is estimated to be reduced to 1 in 20.4x10(4) (95% CI, 1 in 5.2x10(4)-1 in 165.5x10(4)). CONCLUSION: The residual risk for transfusion-transmitted HCV infection is still relatively high in China. Incorporating NAT technology into blood donor screening would be estimated to reduce the residual risk of HCV infections eightfold over current EIA screening.
Subject(s)
Blood Donors , HIV Infections/diagnosis , Hepatitis C/diagnosis , Nucleic Acid Amplification Techniques , China , HIV/isolation & purification , HIV Infections/prevention & control , HIV Infections/transmission , Hepacivirus/isolation & purification , Hepatitis C/prevention & control , Hepatitis C/transmission , Humans , Risk , Transfusion ReactionABSTRACT
In vitro shoot regeneration is a developmental process that multiple genes and their interactions are involved in. Initiation of somatic cells stimulated by cytokinin, division of the initiated somatic cells and succeeding shoot meristem development are three key steps in the process. Therefore, exploration of gene expression and their interactions involved in these steps will shed light on our understanding of the molecular mechanism for regulation of plant in vitro shoot regeneration. Here we reviewed the research results of molecular regulation process involved in these steps.
Subject(s)
Plant Shoots/physiology , Regeneration , Cell Division , Cyclins/metabolism , Cytokines/metabolism , Gene Expression Regulation, Plant , Plant Shoots/cytology , Plant Shoots/genetics , Plant Shoots/metabolismABSTRACT
Microbial dynamics of microbial community during the composting process was investigated with the methods of denaturing gradient gel electrophoresis (DGGE) and plating. The results showed that the most of microorganism count was bacterium, the second was actinomycete and the least was fungi. At the same time, the count of the thermophilic microorganism was always less than that of the mesophilic during the composting process. The count of mesophilic microorganism at later stage was less than that at the initial stage. However, the count of thermophilic antinomycete and fungi at later stage were more than that at initial stage, and the count of thermophilic bacterium was stable throughout the composting process. The bands pattern of DGGE and 16S rDNA analyses indicated that bacterial succession was presented during the composting process. The genera of Bdellovibrio, Clostridia bacterium and Bacillus were dominant species at initial stage (before the first 15 days), and Beta proteobacterium, Petrobacter succinimandens, Nitrospirae bacterium and Paenibacillus were dominant species at middle and later stage. Moreover, Clostridium was found throughout the process.
Subject(s)
Bacteria/isolation & purification , Fertilizers/microbiology , Fungi/isolation & purification , Refuse Disposal , Actinobacteria/genetics , Actinobacteria/isolation & purification , Bacteria/classification , Bacteria/genetics , Clostridium/genetics , Clostridium/isolation & purification , DNA, Bacterial/analysis , Electrophoresis, Polyacrylamide Gel , Population Dynamics , RNA, Ribosomal, 16S/analysisABSTRACT
The study was purposed to investigate whether processing and storage conditions might influence the stability of the HCV RNA in whole blood or in plasma. The samples obtained from seven patients known to be positive for HCV RNA were kept in different storage conditions with different anticoagulants, and at the end of processing the plasma samples were frozen at -80 degrees C until fluorescent quantitative PCR testing. The results showed that there was no significant loss of HCV RNA titers in whole blood anticoagulated with CPDA or ACD or EDTA or none (P > 0.05), while differences in comparison of the EDTA-anticoagulant storage condition with three other anticoagulants storage conditions at 4 degrees C after 48 hours were significant (P < 0.05). The HCV RNA level decreased to 53.8%, 72.5% and 29.8% after 48 hours of storage of whole blood anticoagulated with ACD at 4 degrees C, 25 degrees C and 37 degrees C respectively. The HCV RNA level of plasma samples stored at 4 degrees C and at 25 degrees C (room temperature) after 7 days decreased to 70.9% and 25.1% respectively. After four freeze-thaw cycles the HCV RNA level decreased 38.9% in plasma samples. It is concluded that the HCV RNA is stable relatively. The HCV RNA is resistant to degradation under routine laboratory handling and storage conditions or blood collection, transport and processing conditions. The influence of different anticoagulants on the stability of HCV RNA is different. Blood samples would better be stored at 4 degrees C after collection and plasma separated within 48 hours. And it is important for the stability of HCV RNA undergoing asepsis blood collection process. HCV RNA remains stable at 4 degrees C for at least 7 days or at room temperature for 3 days, allowing greater flexibility in samples collection and transport in transfusion practice nowadays. HCV RNA in plasma samples subject to up to three short-term freeze-thaw cycles is still stable.
Subject(s)
Blood Preservation/methods , Hepacivirus/genetics , RNA, Viral/blood , Specimen Handling/standards , Blood Donors , Hepatitis C/virology , Humans , RNA, Viral/drug effects , Temperature , Time FactorsABSTRACT
BACKGROUND: The correlation between signal-to-cutoff (S/CO) ratios of a second-generation hepatitis C virus (HCV) enzyme immunoassay (EIA; Abbott) and a third-generation HCV enzyme-linked immunosorbent assay (ELISA; Ortho) and confirmed HCV infection has been reported. The utility of the values for the Chinese anti-HCV EIA kits, however, has not been studied in evaluating test results in Chinese blood donors. STUDY DESIGN AND METHODS: A total of 156 donor samples repeat reactive for anti-HCV at routine screening from five representative regions of China were retested for anti-HCV by the Ortho third-generation HCV ELISA and six Chinese EIA kits and for HCV RNA by a human immunodeficiency virus-1 and HCV assay (Procleix, Chiron Corp.). The HCV RNA-nonreactive samples were further tested for anti-HCV by a third-generation recombinant immunoblot assay RIBA (Chiron Corp.). The positive result by either nucleic acid amplification test or RIBA was interpreted as confirmed HCV infection. RESULTS: The confirmed HCV prevalence rate in donors in five representative regions obtained in this study was 0.20 percent (77/37,900) in 2004. All seven anti-HCV EIA kits had a significant correlation between S/CO ratios and confirmed HCV infection. The threshold S/CO ratios, which predicted more than 95 percent of confirmed HCV infections for the Ortho, SABC, BGI-GBI, InTec, GWK, KHB, and WANTAI kits, were 3.8, 6.0, 7.0, 8.6, 10.0, 10.0, and 14.0, respectively. CONCLUSIONS: Anti-HCV EIA kits commonly used in Chinese donors screening demonstrate good correlation between S/CO ratios and the confirmed infection. For the Ortho third-generation HCV ELISA, the S/CO ratio of 3.8 determined by the US Centers for Disease Control and Prevention is applicable to Chinese blood donors. The Chinese domestic EIA kits evaluated show a diverse range of threshold S/CO ratios.
Subject(s)
Blood Donors , Hepatitis C Antibodies/blood , Immunoenzyme Techniques , Mass Screening , China/epidemiology , Enzyme-Linked Immunosorbent Assay , Hepatitis C/diagnosis , Hepatitis C/epidemiology , Humans , Predictive Value of Tests , Prevalence , Reagent Kits, Diagnostic , Seroepidemiologic StudiesABSTRACT
OBJECTIVES: To evaluate the correlation between signal/cutoff (S/CO) ratios of anti-HCV EIA and their true positivity for determining the predictive value of S/CO ratios. METHODS: One hundred and fifty-nine samples of blood from donors positive for anti-HCV at the initial screening were collected from Beijing, Guangzhou, Hangzhou, Kunming and Urumchi. All the samples were retested by Ortho and 6 Chinese domestic anti-HCV EIA kits in duplicate, and detected for HCV RNA (NAT) using Chiron Procleix HIV/HCV system (transcription mediated amplification, TMA). The HCV RNA negative samples were further tested for anti-HCV by Chiron RIBA 3.0. Either NAT or RIBA positive samples were interpreted as the true positive. RESULTS: All 7 anti-HCV EIA kits had a significant correlation between S/CO ratios and true positivity. The S/CO ratio of Ortho > or = 3.8 predicted the true positivity in 96.1% of the samples tested. The S/CO ratios of BGI-GBI, GWK, SABC, KHB, InTec, and Wantai were > or = 7.0, > or = 10.0, > or = 6.0, > or = 10.0, > or = 8.6, > or = 14.0 and predicted 96.1%, 96.1%, 97.3%, 96.0%, 96.1%, 96.0% of the true positivity, respectively. CONCLUSIONS: The S/CO ratios of anti-HCV EIA kits are associated with the true positivity. S/CO ratios of Ortho, BGI-GBI, GWK, SABC, KHB, InTec and Wantai predicting > or = 95% true positivity are > or = 3.8, > or = 7.0, > or = 10.0, > or = 6.0, > or = 1 0.0, > or = 8.6 and > or = 14.0, respectively.