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Yen HL, Forrest H, Cheung P, Wong D, Li O, Krauss S, Ferguson A, Crumpton JC, Jones J, Choy T, Ma E, Poon LLM, Smith GJ, Nicholls J, Guan Y, Webster RG, Webby R, Peiris JSM. Transmissibility of pandemic H1N1 and genetically related swine influenza viruses in ferrets. BMC Proc 2011. [PMCID: PMC3019425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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202
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Guan Y. P34-26 Autonomic nervous system manifestations and skin sympathetic response findings in Lambert-Eaton syndrome. Clin Neurophysiol 2010. [DOI: 10.1016/s1388-2457(10)61270-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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203
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Liu M, Cui L, Ding Z, Wang Y, Guan Y, Chen L. P34-14 The utility of clinical exercise test in diagnosis of hypokalaemic periodic paralysis. Clin Neurophysiol 2010. [DOI: 10.1016/s1388-2457(10)61258-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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204
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Guan Y, Ren K, Zhang D, Shan Z, Wang Y, Li Y, Guo H, Zhang Y. e0007 The effect of omeprazole on the oxidative stress and acute atrial electrical remodelling in rabbits. BRITISH HEART JOURNAL 2010. [DOI: 10.1136/hrt.2010.208967.7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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205
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Feng X, Wang X, Liu M, Cui L, Guan Y. P7-2 F-wave and nerve conduction studies in 138 patients with amyotrophic lateral sclerosis. Clin Neurophysiol 2010. [DOI: 10.1016/s1388-2457(10)60578-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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206
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Guan Y, Shen Y. A weighted estimating equation approach for inhomogeneous spatial point processes. Biometrika 2010. [DOI: 10.1093/biomet/asq043] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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207
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Huang K, Bahl J, Fan XH, Vijaykrishna D, Cheung CL, Webby RJ, Webster RG, Chen H, Smith GJD, Peiris JSM, Guan Y. Establishment of an H6N2 influenza virus lineage in domestic ducks in southern China. J Virol 2010; 84:6978-86. [PMID: 20463062 PMCID: PMC2898240 DOI: 10.1128/jvi.00256-10] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 04/30/2010] [Indexed: 11/20/2022] Open
Abstract
Multiple reassortment events between different subtypes of endemic avian influenza viruses have increased the genomic diversity of influenza viruses circulating in poultry in southern China. Gene exchange from the natural gene pool to poultry has contributed to this increase in genetic diversity. However, the role of domestic ducks as an interface between the natural gene pool and terrestrial poultry in the influenza virus ecosystem has not been fully characterized. Here we phylogenetically and antigenically analyzed 170 H6 viruses isolated from domestic ducks from 2000 to 2005 in southern China, which contains the largest population of domestic ducks in the world. Three distinct hemagglutinin lineages were identified. Group I contained the majority of isolates with a single internal gene complex and was endemic in domestic ducks in Guangdong from the late 1990s onward. Group II was derived from reassortment events in which the surface genes of group I viruses were replaced with novel H6 and N2 genes. Group III represented H6 viruses that undergo frequent reassortment with multiple virus subtypes from the natural gene pool. Surprisingly, H6 viruses endemic in domestic ducks and terrestrial poultry seldom reassort, but gene exchanges between viruses from domestic ducks and migratory ducks occurred throughout the surveillance period. These findings suggest that domestic ducks in southern China mediate the interaction of viruses between different gene pools and facilitate the generation of novel influenza virus variants circulating in poultry.
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Vijaykrishna D, Poon LLM, Ma SK, Li OTW, Cheung CL, Smith GJD, Peiris JSM, Guan Y. Reassortment of pandemic H1N1/2009 influenza A virus in swine. Science 2010; 328:1529. [PMID: 20558710 PMCID: PMC3569847 DOI: 10.1126/science.1189132] [Citation(s) in RCA: 294] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The emergence of pandemic H1N1/2009 influenza demonstrated that pandemic viruses could be generated in swine. Subsequent reintroduction of H1N1/2009 to swine has occurred in multiple countries. Through systematic surveillance of influenza viruses in swine from a Hong Kong abattoir, we characterize a reassortant progeny of H1N1/2009 with swine viruses. Swine experimentally infected with this reassortant developed mild illness and transmitted infection to contact animals. Continued reassortment of H1N1/2009 with swine influenza viruses could produce variants with transmissibility and altered virulence for humans. Global systematic surveillance of influenza viruses in swine is warranted.
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MESH Headings
- Abattoirs
- Animals
- Disease Outbreaks
- Genes, Viral
- Genotype
- Hemagglutinin Glycoproteins, Influenza Virus/genetics
- Hong Kong
- Humans
- Influenza A Virus, H1N1 Subtype/classification
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/isolation & purification
- Influenza A Virus, H1N1 Subtype/pathogenicity
- Influenza A Virus, H1N2 Subtype/classification
- Influenza A Virus, H1N2 Subtype/genetics
- Influenza A Virus, H1N2 Subtype/isolation & purification
- Influenza, Human/epidemiology
- Influenza, Human/virology
- Molecular Sequence Data
- Neuraminidase/genetics
- Orthomyxoviridae Infections/epidemiology
- Orthomyxoviridae Infections/transmission
- Orthomyxoviridae Infections/veterinary
- Orthomyxoviridae Infections/virology
- Phylogeny
- Population Surveillance
- Reassortant Viruses/classification
- Reassortant Viruses/genetics
- Reassortant Viruses/isolation & purification
- Swine/virology
- Swine Diseases/epidemiology
- Swine Diseases/transmission
- Swine Diseases/virology
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209
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Li C, Liu S, Guan Y, Qian W, du F, Hou X. Long pulse gastric electrical stimulation induces regeneration of myenteric plexus synaptic vesicles in diabetic rats. Neurogastroenterol Motil 2010; 22:453-61, e108. [PMID: 19886913 DOI: 10.1111/j.1365-2982.2009.01420.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Gastric electrical stimulation (GES) may improve delayed gastric emptying in diabetic gastroparesis, but whether enteric nervous system (ENS) is directly involved in its mechanism of improvement in gastric motility is unclear. The aims were to investigate the correlation between the changes in ENS and effects of long pulse GES on them in diabetic rats induced by streptozotocin (STZ). METHODS Electron microscopy, immunohistochemistry, RT-PCR and western blot were used to evaluate changes of myenteric plexus neurons and synaptic vesicles in different stages of the diabetic rats. The effects of GES were detected by same methods after pacing wires were implanted and then diabetes was induced and followed by long pulse GES. KEY RESULTS Since 6 weeks after STZ injection, the nerve fibres were incompact and synaptic vesicles in myenteric neurons reduced. Furthermore, the myenteric neurons showed severe damage such as partial depletion of the axon, swelling of mitochondria and seriously decreased synaptic vesicles in 12 weeks after STZ injection. The synaptophysin and PGP9.5-positive area and expressions of synaptophysin mRNA and protein decreased with the duration of diabetes. Long pulse GES could induce increase of myenteric neuronal synaptic vesicles, synaptophysin and PGP9.5-positive area and in myenteric plexus. The synaptophysin mRNA and protein expression rose after GES, whatever GES beginning early or late, short-term or long-term. CONCLUSIONS & INFERENCES The longer duration of diabetes, the more significant damages to myenteric neurons and synaptic vesicles of diabetic rats; long pulse GES could induce regeneration of myenteric plexus synaptic vesicles, thereby reform gastric motility.
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Sun L, Lv H, Wei W, Zhang D, Guan Y. Angiotensin-converting enzyme D/I and plasminogen activator inhibitor-1 4G/5G gene polymorphisms are associated with increased risk of spontaneous abortions in polycystic ovarian syndrome. J Endocrinol Invest 2010; 33:77-82. [PMID: 19636212 DOI: 10.1007/bf03346557] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Polycystic ovary syndrome (PCOS) is a main cause of infertility, particularly in high-risk settings such as spontaneous abortions (SAB). We aimed to evaluate the effect of genetic polymorphisms in ACE and plasminogen activator inhibitor-1 (PAI-1) on the occurrence of SAB in PCOS. METHODS One hundred and forty-two PCOS patients (83 women have a history of one or more unexplained SAB, 59 women have successfully live births) and 107 healthy controls matched for age and body mass index were included in the study. Levels of PAI-1, LH, FSH, testosterone, fasting glucose and insulin were measured. ACE deletion (D)/insertion (I) and PAI-1 4G/5G gene polymorphisms were performed. RESULTS The D/D and/or 4G/4G genotype frequency, the D or 4G allelic frequency, the combination of the ACE D/D and PAI-1 4G/5G, D/I and 4G/4G genotypes of PCOS patients with SAB women were statistically higher than non-SAB group (p<0.05). The 4G/4G or D/D genotype of PCOS with SAB patients had significantly higher PAI-1 levels than non-SAB women. CONCLUSIONS The ACE D/I and PAI-1 4G/5G gene polymorphisms might represent risk factor in PCOS with SAB. Homozygosity for ACE D or PAI-1 4G polymorphisms as well as compound carrier status are significant positive explanatory variable for PCOS patients with SAB, which may result in increased PAI-1 concentrations and hypofibrinolysis and contribute to early pregnancy loss.
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Guan Y. Genetic characterisation of H5N1 viruses isolated from different regions of southern China. Hong Kong Med J 2010; 16:27-28. [PMID: 20864744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023] Open
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212
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Lee SMY, Gardy JL, Cheung CY, Cheung TKW, Hui KPY, Ip NY, Guan Y, Hancock REW, Peiris JSM. Systems-level comparison of host-responses elicited by avian H5N1 and seasonal H1N1 influenza viruses in primary human macrophages. PLoS One 2009; 4:e8072. [PMID: 20011590 PMCID: PMC2788213 DOI: 10.1371/journal.pone.0008072] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 11/05/2009] [Indexed: 11/25/2022] Open
Abstract
Human disease caused by highly pathogenic avian influenza (HPAI) H5N1 can lead to a rapidly progressive viral pneumonia leading to acute respiratory distress syndrome. There is increasing evidence from clinical, animal models and in vitro data, which suggests a role for virus-induced cytokine dysregulation in contributing to the pathogenesis of human H5N1 disease. The key target cells for the virus in the lung are the alveolar epithelium and alveolar macrophages, and we have shown that, compared to seasonal human influenza viruses, equivalent infecting doses of H5N1 viruses markedly up-regulate pro-inflammatory cytokines in both primary cell types in vitro. Whether this H5N1-induced dysregulation of host responses is driven by qualitative (i.e activation of unique host pathways in response to H5N1) or quantitative differences between seasonal influenza viruses is unclear. Here we used microarrays to analyze and compare the gene expression profiles in primary human macrophages at 1, 3, and 6 h after infection with H5N1 virus or low-pathogenic seasonal influenza A (H1N1) virus. We found that host responses to both viruses are qualitatively similar with the activation of nearly identical biological processes and pathways. However, in comparison to seasonal H1N1 virus, H5N1 infection elicits a quantitatively stronger host inflammatory response including type I interferon (IFN) and tumor necrosis factor (TNF)-α genes. A network-based analysis suggests that the synergy between IFN-β and TNF-α results in an enhanced and sustained IFN and pro-inflammatory cytokine response at the early stage of viral infection that may contribute to the viral pathogenesis and this is of relevance to the design of novel therapeutic strategies for H5N1 induced respiratory disease.
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213
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Guan Y, Hensen EJM. Cyanide leaching of Au/CeO2: highly active gold clusters for 1,3-butadiene hydrogenation. Phys Chem Chem Phys 2009; 11:9578-82. [PMID: 19830344 DOI: 10.1039/b909487c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ceria-supported gold catalysts before and after leaching by NaCN were investigated by X-ray absorption spectroscopy at the Au L(III) edge. After gold leaching, isolated gold cations remain in close interaction with the support. These ions form an ideal precursor to very small clusters of a few gold atoms upon reduction. The resulting gold clusters exhibit a very high intrinsic activity in the hydrogenation of 1,3-butadiene, which is at least one order of magnitude higher than that of the nanometre-sized gold particles in the non-leached parent catalyst. These findings point to a very strong structure sensitivity of the gold-catalyzed hydrogenation of dienes.
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214
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Xiong GX, Guan Y, Hong Y, Zhang JW, Guan H. Motor unit number estimation may be a useful method to evaluate motor function recovery after spinal cord transection in rats. Spinal Cord 2009; 48:363-6. [PMID: 19884895 DOI: 10.1038/sc.2009.141] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN Experimental rat study. OBJECTIVE To investigate changes in motor unit number estimation (MUNE) value of the medial gastrocnemius (MG) muscle after thoracic spinal cord transection in rats and to correlate the MUNE with hindlimb motor function recovery. SETTING China Rehabilitation Research Center, Beijing, China. METHODS Twelve rats were subjected to spinal cord transection or sham surgery and then evaluated by MUNE and the Basso, Beattie and Bresnahan (BBB) behavioral scale 56 days after the surgery. RESULTS The MUNE values of the MG muscle were significantly decreased from baseline at 14-49 days after surgery. However, they returned to near pre-injury levels after 56 days. Rats recovered progressively from the severely impaired hindlimb motor function induced by spinal cord injury, as indicated by a gradual increase in BBB score during days 3-49 after surgery. However, this behavioral recovery was only partial and reached a plateau on day 49. Finally, there was a U-shape-like correlation between changes in MUNE values and BBB scores after thoracic spinal cord transection. CONCLUSIONS Time-dependent changes in the functional motor unit number may occur in spinal segments caudal to the transection level, and MUNE could be a useful method to evaluate motor function recovery.
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215
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Guan Y, Xiao Z, Shou J, Xiao Z, Tian J, Wang D, Bi X, Guan K, Ma J, Li C. MP-14.02: Clinical Characteristics of Renal Cell Carcinoma in Young Adult. Urology 2009. [DOI: 10.1016/j.urology.2009.07.853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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216
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Alba M, Sheng D, Guan Y, Williams-Herman D, Larson P, Sachs JR, Thornberry N, Herman G, Kaufman KD, Goldstein BJ. Sitagliptin 100 mg daily effect on DPP-4 inhibition and compound-specific glycemic improvement. Curr Med Res Opin 2009; 25:2507-14. [PMID: 19691426 DOI: 10.1185/03007990903209514] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE In clinical trials, the degree of glucose lowering with sitagliptin has been correlated with the magnitude of dipeptidyl peptidase-4 (DPP-4) inhibition over 24 h. Previous studies evaluating sitagliptin doses ranging from 25 to 200 mg/day demonstrated that the daily dose of 100 mg provided maximal glucose-lowering efficacy for this compound in patients with type 2 diabetes. However, sitagliptin 200 mg once daily provided numerically greater percent plasma DPP-4 inhibition compared with 100 mg once daily. The purpose of this study was to evaluate whether sitagliptin 200 mg once daily provides greater improvement in glycemic efficacy as assessed by weighted mean glucose (WMG) over 24 h relative to sitagliptin 100 mg once daily and to relate the percent DPP-4 inhibition achieved with these doses to any between-treatment differences in glycemic efficacy. METHODS In a double-blind crossover study, patients with type 2 diabetes (fasting plasma glucose [FPG] 130-250 mg/dL) were randomized to one of six treatment sequences over three treatment periods (placebo, sitagliptin 100 mg once daily, or sitagliptin 200 mg once daily). Each of the treatment periods was 7 days in duration, with 28-day washout periods between treatments. After each treatment period, patients underwent blood sampling at various time points over 24 h to determine 24-h WMG. Plasma DPP-4 activity was assessed at trough, 24 h following dosing on day 7; percent DPP-4 inhibition was corrected for sample assay dilution. RESULTS The 103 randomized patients had a baseline mean FPG of 172 mg/dL. Following a planned interim analysis, the study was stopped because the 24-h WMG values were not different between the sitagliptin doses. Furthermore, a significant carryover effect across periods was observed for FPG; thus, efficacy results from period 1 are presented herein. The 24-h WMG values were significantly (p < 0.01) lower with sitagliptin relative to placebo, but the difference between sitagliptin doses was not significant (p = 0.365). Corrected percent plasma DPP-4 inhibition at trough was not significantly (p = 0.791) different with sitagliptin 200 mg (LS mean [95% CI] 96.9% [90.0, 100.0]) compared with sitagliptin 100 mg (95.6% [88.4, 100.0]). The early termination and the carryover effect described above are limitations to this study. CONCLUSION Across sitagliptin doses in this study, the similarity of the 24-h WMG concentrations and the similarity of the corrected DPP-4 inhibition values support prior findings that the maximal glucose-lowering efficacy of sitagliptin is achieved with once-daily dosing of 100 mg. Clinicaltrials.gov: NCT00541229.
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Arena DA, Ding Y, Vescovo E, Zohar S, Guan Y, Bailey WE. A compact apparatus for studies of element and phase-resolved ferromagnetic resonance. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:083903. [PMID: 19725663 DOI: 10.1063/1.3190402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present a compact sample holder equipped with electromagnets and high frequency transmission lines; the sample holder is intended for combined x-ray magnetic circular dichroism (XMCD) and ferromagnetic resonance measurements (FMR). Time-resolved measurements of resonant x-ray detected FMR during forced precession are enabled by use of a rf excitation that is phase-locked to the storage ring bunch clock. Several applications of the combined XMCD+FMR technique are presented, demonstrating the flexibility of the experimental design.
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Poon LLM, Chan KH, Smith GJ, Leung CSW, Guan Y, Yuen KY, Peiris JSM. Molecular detection of a novel human influenza (H1N1) of pandemic potential by conventional and real-time quantitative RT-PCR assays. Clin Chem 2009; 55:1555-8. [PMID: 19439731 PMCID: PMC7108475 DOI: 10.1373/clinchem.2009.130229] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Influenza A viruses are medically important viral pathogens that cause significant mortality and morbidity throughout the world. The recent emergence of a novel human influenza A virus (H1N1) poses a serious health threat. Molecular tests for rapid detection of this virus are urgently needed. METHODS We developed a conventional 1-step RT-PCR assay and a 1-step quantitative real-time RT-PCR assay to detect the novel H1N1 virus, but not the seasonal H1N1 viruses. We also developed an additional real-time RT-PCR that can discriminate the novel H1N1 from other swine and human H1 subtype viruses. RESULTS All of the assays had detection limits for the positive control in the range of 1.0 x 10(-4) to 2.0 x 10(-3) of the median tissue culture infective dose. Assay specificities were high, and for the conventional and real-time assays, all negative control samples were negative, including 7 human seasonal H1N1 viruses, 1 human H2N2 virus, 2 human seasonal H3N2 viruses, 1 human H5N1 virus, 7 avian influenza viruses (HA subtypes 4, 5, 7, 8, 9, and 10), and 48 nasopharyngeal aspirates (NPAs) from patients with noninfluenza respiratory diseases; for the assay that discriminates the novel H1N1 from other swine and human H1 subtype viruses, all negative controls were also negative, including 20 control NPAs, 2 seasonal human H1N1 viruses, 2 seasonal human H3N2 viruses, and 2 human H5N1 viruses. CONCLUSIONS These assays appear useful for the rapid diagnosis of cases with the novel H1N1 virus, thereby allowing better pandemic preparedness.
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MESH Headings
- Animals
- Base Sequence
- DNA, Viral/analysis
- DNA, Viral/genetics
- Humans
- Influenza A Virus, H1N1 Subtype/classification
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/isolation & purification
- Influenza A Virus, H2N2 Subtype/classification
- Influenza A Virus, H2N2 Subtype/genetics
- Influenza A Virus, H2N2 Subtype/isolation & purification
- Influenza A Virus, H3N2 Subtype/classification
- Influenza A Virus, H3N2 Subtype/genetics
- Influenza A Virus, H3N2 Subtype/isolation & purification
- Influenza A Virus, H5N1 Subtype/classification
- Influenza A Virus, H5N1 Subtype/genetics
- Influenza A Virus, H5N1 Subtype/isolation & purification
- Influenza, Human/diagnosis
- Influenza, Human/virology
- Molecular Diagnostic Techniques/economics
- Molecular Diagnostic Techniques/methods
- Orthomyxoviridae Infections/diagnosis
- Orthomyxoviridae Infections/virology
- RNA, Viral/analysis
- RNA, Viral/genetics
- RNA, Viral/isolation & purification
- Reverse Transcriptase Polymerase Chain Reaction/economics
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Sensitivity and Specificity
- Swine/virology
- Time Factors
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219
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Zhou ZX, Wei DF, Guan Y, Zheng AN, Zhong JJ. Damage of Escherichia coli membrane by bactericidal agent polyhexamethylene guanidine hydrochloride: micrographic evidences. J Appl Microbiol 2009; 108:898-907. [PMID: 19709338 DOI: 10.1111/j.1365-2672.2009.04482.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS The purpose of this study was to provide micrographic evidences for the damaged membrane structure and intracellular structure change of Escherichia coli strain 8099, induced by polyhexamethylene guanidine hydrochloride (PHMG). METHODS AND RESULTS The bactericidal effect of PHMG on E. coli was investigated based on beta-galactosidase activity assay, fluorescein-5-isothiocyanate confocal laser scanning microscopy, field emission scanning electron microscopy and transmission electron microscopy. The results revealed that a low dose (13 microg ml(-1)) of PHMG slightly damaged the outer membrane structure of the treated bacteria and increased the permeability of the cytoplasmic membrane, while no significant damage was observed to the morphological structure of the cells. A high dose (23 microg ml(-1)) of PHMG collapsed the outer membrane structure, led to the formation of a local membrane pore across the membrane and badly damaged the internal structure of the cells. Subsequently, intracellular components were leaked followed by cell inactivation. CONCLUSIONS Dose-dependent membrane disruption was the main bactericidal mechanism of PHMG. The formation of the local membrane pores was probable after exposure to a high dose (23 microg ml(-1)) of PHMG. Micrographic evidences were provided about the damaged membrane structure and intracellular structure change of E. coli. SIGNIFICANCE AND IMPACT OF THE STUDY The presented information helps understand the bactericidal mechanism of PHMG by membrane damage.
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Chan KH, Lai ST, Poon LLM, Guan Y, Yuen KY, Peiris JSM. Analytical sensitivity of rapid influenza antigen detection tests for swine-origin influenza virus (H1N1). J Clin Virol 2009; 45:205-7. [PMID: 19539521 DOI: 10.1016/j.jcv.2009.05.034] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 05/22/2009] [Indexed: 11/27/2022]
Abstract
BACKGROUND A novel swine origin influenza virus (S-OIV) (H1N1) is spreading worldwide and threatens to become pandemic. OBJECTIVES Determine analytical sensitivity of selected commercially available rapid influenza antigen detection tests in detecting S-OIV H1N1. STUDY DESIGN Serial dilutions of two S-OIV isolates, one seasonal influenza A (H1N1) isolate and a nasopharyngeal aspirate from a patient with S-OIV disease were tested in five commercially available influenza antigen detection tests and by virus isolation in cell culture. Viral M gene copy number was determined by quantitative PCR methods. RESULTS The analytical sensitivity of the five influenza antigen detection tests for S-OIV (tissue culture infectious dose 50 (TCID(50)) log(10)3.3-4.7 was comparable with that of seasonal influenza (TCID(50) log(10)4.0-4.5). CONCLUSION The analytical sensitivity of the selected influenza A antigen detection tests for detection of S-IOV was comparable with that of seasonal influenza H1N1.
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Nicholls JM, Peiris JSM, Guan Y. Sialic acid and receptor expression on the respiratory tract in normal subjects and H5N1 and non-avian influenza patients. Hong Kong Med J 2009; 15:16-20. [PMID: 19509432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
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223
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Peiris JSM, Poon LM, Nicholls JM, Guan Y. The role of influenza virus gene constellation and viral morphology on cytokine induction, pathogenesis, and viral virulence. Hong Kong Med J 2009; 15:21-23. [PMID: 19509433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
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224
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You Q, Tong X, Guan Y, Zhang D, Huang M, Zhang Y, Zheng J. The biological characteristics of human third trimester amniotic fluid stem cells. J Int Med Res 2009; 37:105-12. [PMID: 19215679 DOI: 10.1177/147323000903700112] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Third trimester amniotic fluid (AF)-derived human mesenchymal stem cells (MSCs) can be greatly expanded in vitro and induced to differentiate into multiple mesenchymal cell types. This study aimed to investigate the biological characteristics of MSCs from third trimester AF as a new source of therapeutic stem cells. Forty third trimester AF samples were obtained from healthy women who underwent elective caesarean section for breech presentation. A simple culture protocol for MSCs was used. A cell growth curve was drawn, and cell surface antigens and cytokines were analysed by immunofluorescent staining, reverse transcription-polymerase chain reaction and flow cytometry. MSCs from third-trimester AF were successfully isolated, cultured and enriched. MSCs expanded extensively without feeders, they were not tumourigenic and were induced to differentiate into osteocytes. Surface antigens were analysed and found to express the pluripotency marker Oct-4. Considering the great feasibility of biomedical engineering using MSCs, third trimester AF may provide a rich source for investigation of human MSCs.
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