ABSTRACT
BACKGROUND: As a common disabling disease, irreversible neuronal death due to spinal cord injury (SCI) is the root cause of functional impairment; however, the capacity for neuronal regeneration in the developing spinal cord tissue is limited. Therefore, there is an urgent need to investigate how defective neurons can be replenished and functionally integrated by neural regeneration; the reprogramming of intrinsic cells into functional neurons may represent an ideal solution. METHODS: A mouse model of transection SCI was prepared by forceps clamping, and an adeno-associated virus (AAV) carrying the transcription factors NeuroD1 and Neurogenin-2(Ngn2) was injected in situ into the spinal cord to specifically overexpress these transcription factors in astrocytes close to the injury site. 5-bromo-2´-deoxyuridine (BrdU) was subsequently injected intraperitoneally to continuously track cell regeneration, neuroblasts and immature neurons marker expression, neuronal regeneration, and glial scar regeneration. In addition, immunoprotein blotting was used to measure the levels of transforming growth factor-ß (TGF-ß) pathway-related protein expression. We also evaluated motor function, sensory function, and the integrity of the blood-spinal cord barrier(BSCB). RESULTS: The in situ overexpression of NeuroD1 and Ngn2 in the spinal cord was achieved by specific AAV vectors. This intervention led to a significant increase in cell regeneration and the proportion of cells with neuroblasts and immature neurons cell properties at the injury site(p < 0.0001). Immunofluorescence staining identified astrocytes with neuroblasts and immature neurons cell properties at the site of injury while neuronal marker-specific staining revealed an increased number of mature astrocytes at the injury site. Behavioral assessments showed that the intervention did not improve The BMS (Basso mouse scale) score (p = 0.0726) and gait (p > 0.05), although the treated mice had more sensory sensitivity and greater voluntary motor ability in open field than the non-intervention mice. We observed significant repair of the BSCB at the center of the injury site (p < 0.0001) and a significant improvement in glial scar proliferation. Electrophysiological assessments revealed a significant improvement in spinal nerve conduction (p < 0.0001) while immunostaining revealed that the levels of TGF-ß protein at the site of injury in the intervention group were lower than control group (p = 0.0034); in addition, P70 s6 and PP2A related to the TGF-ß pathway showed ascending trend (p = 0.0036, p = 0.0152 respectively). CONCLUSIONS: The in situ overexpression of NeuroD1 and Ngn2 in the spinal cord after spinal cord injury can reprogram astrocytes into neurons and significantly enhance cell regeneration at the injury site. The reprogramming of astrocytes can lead to tissue repair, thus improving the reduced threshold and increasing voluntary movements. This strategy can also improve the integrity of the blood-spinal cord barrier and enhance nerve conduction function. However, the simple reprogramming of astrocytes cannot lead to significant improvements in the striding function of the lower limbs.
Subject(s)
Astrocytes , Basic Helix-Loop-Helix Transcription Factors , Disease Models, Animal , Nerve Tissue Proteins , Spinal Cord Injuries , Animals , Spinal Cord Injuries/therapy , Spinal Cord Injuries/physiopathology , Basic Helix-Loop-Helix Transcription Factors/metabolism , Astrocytes/physiology , Nerve Tissue Proteins/metabolism , Mice , Nerve Regeneration/physiology , Neurons , Female , Mice, Inbred C57BL , Spinal Cord/metabolismABSTRACT
The molecular mechanisms underlying seizure generation remain elusive, yet they are crucial for developing effective treatments for epilepsy. The current study shows that inhibiting c-Abl tyrosine kinase prevents apoptosis, reduces dendritic spine loss, and maintains N-methyl-d-aspartate (NMDA) receptor subunit 2B (NR2B) phosphorylated in in vitro models of excitotoxicity. Pilocarpine-induced status epilepticus (SE) in mice promotes c-Abl phosphorylation, and disrupting c-Abl activity leads to fewer seizures, increases latency toward SE, and improved animal survival. Currently, clinically used c-Abl inhibitors are non-selective and have poor brain penetration. The allosteric c-Abl inhibitor, neurotinib, used here has favorable potency, selectivity, pharmacokinetics, and vastly improved brain penetration. Neurotinib-administered mice have fewer seizures and improved survival following pilocarpine-SE induction. Our findings reveal c-Abl kinase activation as a key factor in ictogenesis and highlight the impact of its inhibition in preventing the insurgence of epileptic-like seizures in rodents and humans.
Subject(s)
Pilocarpine , Proto-Oncogene Proteins c-abl , Seizures , Animals , Male , Mice , Apoptosis/drug effects , Mice, Inbred C57BL , Neurons/drug effects , Neurons/pathology , Neurons/metabolism , Phosphorylation/drug effects , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-abl/metabolism , Proto-Oncogene Proteins c-abl/antagonists & inhibitors , Pyrimidines/pharmacology , Pyrimidines/therapeutic use , Seizures/chemically induced , Seizures/drug therapy , Seizures/pathology , Status Epilepticus/chemically induced , Status Epilepticus/drug therapy , Status Epilepticus/pathologyABSTRACT
Swertia L. is a large genus in Swertiinae (Gentianaceae). In China, many Swertia species are used as traditional Tibetan medicines, known as "Zangyinchen" or "Dida". However, the phylogenetic relationships among Swertia medicinal plants and their wild relatives have remained unclear. In this study, we sequenced and assembled 16 complete chloroplast (cp) genomes of 10 Swertia species, mainly distributed in Qinghai Province, China. The results showed that these species have typical structures and characteristics of plant cp genomes. The sizes of Swertia cp genomes are ranging from 149,488 bp to 154,097 bp. Most Swertia cp genomes presented 134 genes, including 85 protein coding genes, eight rRNA genes, 37 tRNA genes, and four pseudogenes. Furthermore, the GC contents and boundaries of cp genomes are similar among Swertia species. The phylogenetic analyses indicated that Swertia is a complex polyphyletic group. In addition, positive selection was found in psaI and petL genes, indicating the possible adaptation of Qinghai Swertia species to the light environment of the Qinghai-Tibet plateau. These new cp genome data could be further investigated to develop DNA barcodes for Swertia medicinal plants and for additional systematic studies of Swertia and Swertiinae species.
ABSTRACT
This study aimed to explore the structural and functional characteristics of the neural network of resting-state brain activities in patients with amnestic mild cognitive impairment (aMCI) by functional magnetic resonance imaging (fMRI) technology. Resting state fMRI scanning was performed on 10 clinically diagnosed aMCI patients and 10 healthy volunteers, and the difference in the resting-state brain activities between aMCI patients and healthy volunteers was compared using the brain function network regional homogeneity (ReHo) analysis method. Results of the ReHo analysis of aMCI patients and healthy volunteers revealed that the ReHo value significantly increased in the posterior cingulate gyrus region, medial frontal lobe, medial cortex of the prefrontal lobe, and part of the parietal lobe. Compared with the normal elderlies, ReHo decreased in aMCI patients in the left temporal lobe (middle temporal gyrus and inferior temporal gyrus), left parahippocampal gyrus, occipital lobe, lingual gyrus, precuneus, and other regions while ReHo increased in regions of the right frontal lobe (inferior frontal gyrus), left superior temporal gyrus, precentral gyrus (frontal lobe), right thalamus, left fusiform gyrus, and other regions. In the resting state, there may be regional abnormalities in brain functional areas in aMCI patients, which may be associated with cognitive impairment.
Subject(s)
Brain/physiology , Cognitive Dysfunction/physiopathology , Aged , Brain/diagnostic imaging , Brain Mapping , Cognitive Dysfunction/diagnostic imaging , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Neural Pathways/physiopathologyABSTRACT
High frequency ultrasound can enhance olive oil extractability industrially. However, the ultrasound attenuation phenomena and their implications on extractability, are not well understood. This work aims at evaluating the ultrasound attenuation effects on the oil extraction efficiency, while providing deeper insights into the physics behind the ultrasound extraction in a heterogeneous medium. Olives were collected and processed both in Italy and Uruguay during their respective harvest seasons. Sound pressure distribution was characterized in a high frequency ultrasound reactor, carrying 3â¯kg of water or paste, by using an indirect contact hydrophone device at 0.4â¯MHz or 2â¯MHz. A through-transmission ultrasonic technique was applied to determine attenuation profiles and coefficients in paste at the central frequency of each transducer, with various paste to water ratios and reactor sizes. Other ultrasound improvements on extractability were evaluated including reduction of malaxation time (10, 30â¯min), sonication time (2.5, 5â¯min) and power level (174, 280â¯W) without water addition and in a reactor with a 14.5â¯cm transducer to wall distance. However, no sound pressure levels in paste were detectable beyond 9â¯cm from the transducer at both frequencies. Among the various effects evaluated, an emission frequency of 0.4â¯MHz better improved extractability compared to 2â¯MHz. The attenuation profiles corroborated these findings with attenuation coefficients of 3.9 and 5.3â¯dB/cm measured near the respective frequencies. Improvements in oil extractability due to increasing sonication time and power level were significant (pâ¯<â¯0.05) also when sonicating beyond 14.5â¯cm and without water addition. Oil extractability improvements were observed even when sound pressure was undetectable beyond 9â¯cm from the transducer, suggesting that the standing wave oil trapping effect is not the governing mechanism for separation in high attenuation media for large scale systems.
ABSTRACT
Tagetes erecta is an important ornamental and medicinal plant indigenous to Mexico and Guatemala. The complete chloroplast genome of T. erecta was newly sequenced in this study. The total chloropalst genome size of T. erecta was 152,055 bp. In total, 123 genes were indetified, including 79 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. Twelve genes are containing introns (ycf3 and clpP contained two introns). The overall GC content of this genome was 37.4%. A further phylogenomic analysis of Asteraceae, including 23 taxa, was conducted for the placement of genus Tagetes. The complete plastome of T. erecta will provide a valuable resource for further genetic conservation, evolution, and molecular breading studies in Asteraceae.
ABSTRACT
This study aimed to explore the structural and functional characteristics of the neural network of resting-state brain activities in patients with amnestic mild cognitive impairment (aMCI) by functional magnetic resonance imaging (fMRI) technology. Resting state fMRI scanning was performed on 10 clinically diagnosed aMCI patients and 10 healthy volunteers, and the difference in the resting-state brain activities between aMCI patients and healthy volunteers was compared using the brain function network regional homogeneity (ReHo) analysis method. Results of the ReHo analysis of aMCI patients and healthy volunteers revealed that the ReHo value significantly increased in the posterior cingulate gyrus region, medial frontal lobe, medial cortex of the prefrontal lobe, and part of the parietal lobe. Compared with the normal elderlies, ReHo decreased in aMCI patients in the left temporal lobe (middle temporal gyrus and inferior temporal gyrus), left parahippocampal gyrus, occipital lobe, lingual gyrus, precuneus, and other regions while ReHo increased in regions of the right frontal lobe (inferior frontal gyrus), left superior temporal gyrus, precentral gyrus (frontal lobe), right thalamus, left fusiform gyrus, and other regions. In the resting state, there may be regional abnormalities in brain functional areas in aMCI patients, which may be associated with cognitive impairment.
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Brain/physiology , Cognitive Dysfunction/physiopathology , Image Processing, Computer-Assisted , Brain/diagnostic imaging , Brain Mapping , Magnetic Resonance Imaging , Cognitive Dysfunction/diagnostic imaging , Neural Pathways/physiopathologyABSTRACT
Abstract This study aimed to determine the association between the polymorphisms and haplotypes in the xeroderma pigmentosum group D (XPD) gene and the risk of pancreatic cancer in the Chinese Han population. SNaPshot was used for genotyping six SNP sites of the XPD gene. Comparisons of the correlations between different genotypes in combination with smoking and the susceptibility to pancreatic cancer were performed. Individual pancreatic cancer risk in patients who carry mutant C alleles (AC, CC, and AC+CC) at rs13181 increased (p < 0.05). Taking non-smoking individuals who carry the AA genotype as a reference, and non-smoking individuals who carry mutant allele C (AC+CC), the risk of pancreatic cancer increased by 3.343 times in individuals who smoked ≥ 20 cigarettes daily, 3.309 times in individuals who smoked ≥ 14 packs per year, 5.011 times in individuals who smoked ≥ 24 packs per year, and 4.013 times in the individuals who smoked ≥ 37 packs per year (P < 0.05). In addition, haplotype analysis revealed that haplotype AGG, which comprised rs13181, rs3916874 and rs238415, was associated with a 1.401-fold increase in pancreatic cancer risk (p < 0.05). We conclude that the polymorphism of XPD Lys751Gln (rs13181) in combination with smoking contributes to increased risk of pancreatic cancer in the Chinese Han population. Haplotype AGG might be a susceptibility haplotype for pancreatic cancer.
ABSTRACT
OBJECTIVES: Information on the impact of health insurance on smoking and quit attempts at the state level is limited. We examined the state-specific prevalence of cigarette smoking and past-year quit attempts among adults aged 18-64 by health insurance and other individual- and state-level factors. METHODS: We used data from 41 states, the District of Columbia, and Puerto Rico, the jurisdictions that administered the Health Care Access module of the 2014 Behavioral Risk Factor Surveillance System. Data on quit attempts included current smokers with a past-year quit attempt and former smokers who quit during the past year. RESULTS: Overall, smoking prevalence ranged from 14.6% among those with private insurance to 34.7% among Medicaid enrollees, and past-year quit-attempt prevalence ranged from 66.4% among the uninsured to 71.5% among Medicaid enrollees. By insurance group, differences in the prevalence of state-specific past-year quit attempts ranged from 15 to 26 percentage points. Regardless of insurance type, people who were non-Hispanic white and had lower education levels were less likely to attempt quitting than were Hispanic people, non-Hispanic black people, and adults with more than a high school education. CONCLUSIONS: We found disparities in smoking and quit attempts by insurance status and state. Opportunities exist to increase access to cessation treatments through comprehensive state tobacco control programs and improved cessation insurance coverage, coupled with promotion of covered cessation treatments.
Subject(s)
Ethnicity/psychology , Ethnicity/statistics & numerical data , Health Behavior , Smoking Cessation/psychology , Smoking Cessation/statistics & numerical data , Smoking/epidemiology , Smoking/psychology , Adolescent , Adult , Black or African American/psychology , Black or African American/statistics & numerical data , Behavioral Risk Factor Surveillance System , District of Columbia/epidemiology , Female , Hispanic or Latino/psychology , Hispanic or Latino/statistics & numerical data , Humans , Insurance Coverage/statistics & numerical data , Male , Medicaid/statistics & numerical data , Middle Aged , Prevalence , Puerto Rico/epidemiology , United States/epidemiology , White People/psychology , White People/statistics & numerical data , Young AdultABSTRACT
Ultrasound treatment is known to increase the oil extractability in olive and palm oil processes. This work examined the effect of ultrasound conditioning of avocado puree on oil extractability and quality, at low (18+40kHz) and high (2MHz) frequencies, at litre-scale. Other ultrasound parameters evaluated included high frequency effect (0.4, 0.6, and 2MHz; 5min; 90kJ/kg) and sonication time (2.5-10min at 2MHz), without malaxation. Finally, a megasonic post-malaxation intervention was assessed at selected malaxation times (15, 30, and 60min). Both low and high frequency ultrasound treatments of the non-malaxed avocado puree improved extractability by 15-24% additional oil recovery, with the highest extractability achieved after 2MHz treatments, depending on the fruit maturity and oil content. There was no preferential improvement on oil extractability observed across high frequencies, even though extractability increased with sonication time. Ultrasound treatment also showed a positive effect after puree malaxation. Oils obtained from sonicated purees showed peroxide and free fatty acid values below the industrial specification levels and an increase in total phenolic compounds after 2MHz treatment. High frequency ultrasound conditioning of avocado puree can enhance oil separation and potentially decrease the malaxation time in industrial processes without impacting on oil quality.
ABSTRACT
This study aimed to determine the association between the polymorphisms and haplotypes in the xeroderma pigmentosum group D (XPD) gene and the risk of pancreatic cancer in the Chinese Han population. SNaPshot was used for genotyping six SNP sites of the XPD gene. Comparisons of the correlations between different genotypes in combination with smoking and the susceptibility to pancreatic cancer were performed. Individual pancreatic cancer risk in patients who carry mutant C alleles (AC, CC, and AC+CC) at rs13181 increased (p < 0.05). Taking non-smoking individuals who carry the AA genotype as a reference, and non-smoking individuals who carry mutant allele C (AC+CC), the risk of pancreatic cancer increased by 3.343 times in individuals who smoked ≥ 20 cigarettes daily, 3.309 times in individuals who smoked ≥ 14 packs per year, 5.011 times in individuals who smoked ≥ 24 packs per year, and 4.013 times in the individuals who smoked ≥ 37 packs per year (P < 0.05). In addition, haplotype analysis revealed that haplotype AGG, which comprised rs13181, rs3916874 and rs238415, was associated with a 1.401-fold increase in pancreatic cancer risk (p < 0.05). We conclude that the polymorphism of XPD Lys751Gln (rs13181) in combination with smoking contributes to increased risk of pancreatic cancer in the Chinese Han population. Haplotype AGG might be a susceptibility haplotype for pancreatic cancer.
ABSTRACT
Deinococcus radiodurans (DR) is an extremophile that is well known for its resistance to radiation, oxidants and desiccation. The gene dr1790 of D. radiodurans was predicted to encode a yellow-related protein. The primary objective of the present study was to characterize the biological function of the DR1790 protein, which is a member of the ancient yellow/major royal jelly (MRJ) protein family, in prokaryotes. Fluorescence labeling demonstrated that the yellow-related protein encoded by dr1790 is a membrane protein. The deletion of the dr1790 gene decreased the cell growth rate and sensitivity to hydrogen peroxide and radiation and increased the membrane permeability of D. radiodurans. Transcript profiling by microarray and RT-PCR analyses of the dr1790 deletion mutant suggested that some genes that are involved in protein secretion and transport were strongly suppressed, while other genes that are involved in protein quality control, such as chaperones and proteases, were induced. In addition, the expression of genes with predicted functions that are involved in antioxidant systems, electron transport, and energy metabolism was significantly altered through the disruption of dr1790. Moreover, the results of proteomic analyses using 2-DE and MS also demonstrated that DR1790 contributed to D. radiodurans survival. Taken together, these results indicate that the DR1790 protein from the ancient yellow protein family plays a pleiotropic role in the survival of prokaryotic cells and contributes to the extraordinary resistance of D. radiodurans against oxidative and radiation stresses.
Subject(s)
Deinococcus/genetics , Genes, Bacterial , Genetic Pleiotropy , Mutagenesis, Insertional , Bacterial Proteins/genetics , Cell Membrane/physiology , Deinococcus/drug effects , Deinococcus/growth & development , Deinococcus/radiation effects , Gene Deletion , Gene Expression Profiling , Genetic Complementation Test , Hydrogen Peroxide/toxicity , Membrane Proteins/genetics , Microarray Analysis , Microbial Viability/drug effects , Microbial Viability/radiation effects , Permeability , Radiation, Ionizing , Real-Time Polymerase Chain ReactionABSTRACT
Deinococcus radiodurans (DR) is an extremophile that is well known for its resistance to radiation, oxidants and desiccation. The gene dr1790 of D. radiodurans was predicted to encode a yellow-related protein. The primary objective of the present study was to characterize the biological function of the DR1790 protein, which is a member of the ancient yellow/major royal jelly (MRJ) protein family, in prokaryotes. Fluorescence labeling demonstrated that the yellow-related protein encoded by dr1790 is a membrane protein. The deletion of the dr1790 gene decreased the cell growth rate and sensitivity to hydrogen peroxide and radiation and increased the membrane permeability of D. radiodurans. Transcript profiling by microarray and RT-PCR analyses of the dr1790 deletion mutant suggested that some genes that are involved in protein secretion and transport were strongly suppressed, while other genes that are involved in protein quality control, such as chaperones and proteases, were induced. In addition, the expression of genes with predicted functions that are involved in antioxidant systems, electron transport, and energy metabolism was significantly altered through the disruption of dr1790. Moreover, the results of proteomic analyses using 2-DE and MS also demonstrated that DR1790 contributed to D. radiodurans survival. Taken together, these results indicate that the DR1790 protein from the ancient yellow protein family plays a pleiotropic role in the survival of prokaryotic cells and contributes to the extraordinary resistance of D. radiodurans against oxidative and radiation stresses.
Subject(s)
Deinococcus/genetics , Genes, Bacterial , Genetic Pleiotropy , Mutagenesis, Insertional , Bacterial Proteins/genetics , Cell Membrane/physiology , Deinococcus/drug effects , Deinococcus/growth & development , Deinococcus/radiation effects , Gene Deletion , Gene Expression Profiling , Genetic Complementation Test , Hydrogen Peroxide/toxicity , Microarray Analysis , Membrane Proteins/genetics , Microbial Viability/drug effects , Microbial Viability/radiation effects , Permeability , Radiation, Ionizing , Real-Time Polymerase Chain ReactionABSTRACT
Deinococcus radiodurans (DR) is an extremophile that is well known for its resistance to radiation, oxidants and desiccation. The gene dr1790 of D. radiodurans was predicted to encode a yellow-related protein. The primary objective of the present study was to characterize the biological function of the DR1790 protein, which is a member of the ancient yellow/major royal jelly (MRJ) protein family, in prokaryotes. Fluorescence labeling demonstrated that the yellow-related protein encoded by dr1790 is a membrane protein. The deletion of the dr1790 gene decreased the cell growth rate and sensitivity to hydrogen peroxide and radiation and increased the membrane permeability of D. radiodurans. Transcript profiling by microarray and RT-PCR analyses of the dr1790 deletion mutant suggested that some genes that are involved in protein secretion and transport were strongly suppressed, while other genes that are involved in protein quality control, such as chaperones and proteases, were induced. In addition, the expression of genes with predicted functions that are involved in antioxidant systems, electron transport, and energy metabolism was significantly altered through the disruption of dr1790. Moreover, the results of proteomic analyses using 2-DE and MS also demonstrated that DR1790 contributed to D. radiodurans survival. Taken together, these results indicate that the DR1790 protein from the ancient yellow protein family plays a pleiotropic role in the survival of prokaryotic cells and contributes to the extraordinary resistance of D. radiodurans against oxidative and radiation stresses.(AU)
Subject(s)
Deinococcus/genetics , Genes, Bacterial , Genetic Pleiotropy , Mutagenesis, Insertional , Bacterial Proteins/genetics , Cell Membrane/physiology , Deinococcus , Deinococcus/growth & development , Deinococcus/radiation effects , Gene Deletion , Gene Expression Profiling , Genetic Complementation Test , Hydrogen Peroxide/toxicity , Membrane Proteins/genetics , Microarray Analysis , Microbial Viability , Microbial Viability/radiation effects , Permeability , Radiation, Ionizing , Real-Time Polymerase Chain ReactionABSTRACT
An estimated 11.6% of the world cigarette market is illicit, representing more than 650 billion cigarettes a year and $40.5 billion in lost revenue. Illicit tobacco trade refers to any practice related to distributing, selling, or buying tobacco products that is prohibited by law, including tax evasion (sale of tobacco products without payment of applicable taxes), counterfeiting, disguising the origin of products, and smuggling. Illicit trade undermines tobacco prevention and control initiatives by increasing the accessibility and affordability of tobacco products, and reduces government tax revenue streams. The World Health Organization (WHO) Protocol to Eliminate Illicit Trade in Tobacco Products, signed by 54 countries, provides tools for addressing illicit trade through a package of regulatory and governing principles. As of May 2015, only eight countries had ratified or acceded to the illicit trade protocol, with an additional 32 needed for it to become international law (i.e., legally binding). Data from multiple international sources were analyzed to evaluate the 10 most commonly used approaches for addressing illicit trade and to summarize differences in implementation across select countries and the European Union (EU). Although the WHO illicit trade protocol defines shared global standards for addressing illicit trade, countries are guided by their own legal and enforcement frameworks, leading to a diversity of approaches employed across countries. Continued adoption of the methods outlined in the WHO illicit trade protocol might improve the global capacity to reduce illicit trade in tobacco products.
Subject(s)
Commerce/legislation & jurisprudence , Law Enforcement/methods , Tobacco Products , Brazil , Canada , European Union , Health Education , Humans , Hungary , Interinstitutional Relations , Italy , Licensure , Malaysia , Records , Romania , Spain , Taxes , Tobacco Industry , Tobacco Products/economics , Turkey , United Kingdom , World Health OrganizationABSTRACT
OBJECTIVE: To study the role of hepatitis B virus with A1762T/G1764A double mutation in liver cirrhosis and hepatocellular carcinoma, and create a sensitive, fast, accurate assay for detection of A1762T/G1764A double mutation. METHODS: We developed an accurate and fast real-time amplification refractory mutation system to detect A1762T/G1764A double mutation. Cloned hepatitis B virus genome was used as a control. Assay sensitivity was determined by serial dilution and mixed template experiments. Specificity was determined by cross experiments with wild and mutant hepatitis B virus. Fifty clinical samples were tested by the real-time amplification refractory mutation system and the results were compared with sequencing. RESULTS: The real-time amplification refractory mutation system had a sensitivity of 100 copies of virus with these mutations, and 0.1% weak population virus with double mutation could be found in mixtures. A total of 50 randomly collected clinical samples were detected by real-time amplification refractory mutation system, and the results were consistent with those by DNA sequencing. Hepatitis B virus genotype C was more prevalent in 39 of 50 samples than genotype B (11 samples), and about 75% of genotype C carried a double mutation compared to 45% of genotype B. However, the percentage of A1762T/G1764A double mutation in hepatitis B e antigen-negative (58.3%) samples was almost the same as in hepatitis B e antigen-positive (61%) samples. CONCLUSION: The real-time amplification refractory mutation system is sensitive and specific for detection of hepatitis B virus double mutation. .
Subject(s)
Humans , Carcinoma, Hepatocellular/virology , DNA, Viral/genetics , Hepatitis B virus/genetics , Liver Cirrhosis/virology , Liver Neoplasms/virology , Mutation/genetics , Base Sequence , Genotype , Real-Time Polymerase Chain Reaction/methods , Sensitivity and Specificity , Sequence Analysis, DNAABSTRACT
OBJECTIVE: To study the role of hepatitis B virus with A1762T/G1764A double mutation in liver cirrhosis and hepatocellular carcinoma, and create a sensitive, fast, accurate assay for detection of A1762T/G1764A double mutation. METHODS: We developed an accurate and fast real-time amplification refractory mutation system to detect A1762T/G1764A double mutation. Cloned hepatitis B virus genome was used as a control. Assay sensitivity was determined by serial dilution and mixed template experiments. Specificity was determined by cross experiments with wild and mutant hepatitis B virus. Fifty clinical samples were tested by the real-time amplification refractory mutation system and the results were compared with sequencing. RESULTS: The real-time amplification refractory mutation system had a sensitivity of 100 copies of virus with these mutations, and 0.1% weak population virus with double mutation could be found in mixtures. A total of 50 randomly collected clinical samples were detected by real-time amplification refractory mutation system, and the results were consistent with those by DNA sequencing. Hepatitis B virus genotype C was more prevalent in 39 of 50 samples than genotype B (11 samples), and about 75% of genotype C carried a double mutation compared to 45% of genotype B. However, the percentage of A1762T/G1764A double mutation in hepatitis B e antigen-negative (58.3%) samples was almost the same as in hepatitis B e antigen-positive (61%) samples. CONCLUSION: The real-time amplification refractory mutation system is sensitive and specific for detection of hepatitis B virus double mutation.