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Hu F, Wu W, Ye X, Xu X, Zhu D. The molecular characteristics of cefepime-susceptible Escherichia coli and Klebsiella spp. isolates with a positive β-lactamase screening test result but negative confirmation. Eur J Clin Microbiol Infect Dis 2010; 29:1297-9. [PMID: 20549530 DOI: 10.1007/s10096-010-0987-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2010] [Accepted: 05/29/2010] [Indexed: 10/19/2022]
Abstract
A negative extended-spectrum β-lactamase (ESBL) phenotypic confirmation test result obtained after a positive ESBL screening test result but which was cefepime-susceptible (NCPSCS) using the Clinical and Laboratory Standards Institute (CLSI) methods has been observed among isolates of Escherichia coli and Klebsiella spp. in the antimicrobial surveillance program in Shanghai, China. Among isolates collected from Huashan Hospital in 2005, NCPSCS strains were observed in 2.5% of 433 E. coli isolates and in 1.2% of 562 Klebsiella spp. isolates. We then selected 11 E. coli isolates and seven Klebsiella spp. NCPSCS isolates. Transmission electron microscopy (TEM), SHV, plasmid-borne AmpC, and CTX-M type ESBL genes were detected by the polymerase chain reaction (PCR) method. We found that all except two K. pneumoniae strains of NCPSCS isolates producing ESBL and AmpC harbored a plasmid-borne CMY-2 or DHA-1 type AmpC enzyme. The majority of NCPSCS E. coli and K. pneumoniae strains from Shanghai harbor plasmid-borne AmpC enzyme, and we recommend that, when NCPSCS strains are identified, further work such as the PCR detection of ESBL genes is necessary to determine whether they will produce ESBLs. The ESBL-positive strains should be reported as resistant to cefepime according to the CLSI guidelines.
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Zhu D, Qing Z, Ji B, Zude M. ANALYZING THE BROWNING OF APPLE JUICE BY FLUORESCENCE SPECTROSCOPY. ACTA ACUST UNITED AC 2010. [DOI: 10.17660/actahortic.2010.858.64] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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253
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Haeberlen M, Zhu D, McAleese C, Kappers MJ, Humphreys CJ. Dislocation reduction in MOVPE grown GaN layers on (111)Si using SiNxand AlGaN layers. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/209/1/012017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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254
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Rao DVS, Beanland R, Kappers MJ, Zhu D, Humphreys CJ. Lattice distortions in GaN thin films on (0001) sapphire. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/209/1/012022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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255
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Wang Y, Liang D, Wang S, Qiu Z, Chu X, Chen S, Li L, Nie X, Zhang R, Wang Z, Zhu D. Role of the G-protein and tyrosine kinase--Rho/ROK pathways in 15-hydroxyeicosatetraenoic acid induced pulmonary vasoconstriction in hypoxic rats. J Biochem 2010; 147:751-64. [DOI: 10.1093/jb/mvq010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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256
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Zhu D, Jarmin S, Ribeiro A, Prin F, Xie SQ, Sullivan K, Briscoe J, Gould AP, Marelli-Berg FM, Gu Y. Applying an adaptive watershed to the tissue cell quantification during T-cell migration and embryonic development. Methods Mol Biol 2010; 616:207-228. [PMID: 20379878 DOI: 10.1007/978-1-60761-461-6_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Cell and particle quantification is one of the frequently used techniques in biology and clinical study. Variations of cell/particle population and/or protein expression level can provide information on many biological processes. In this chapter, we propose an image-based automatic quantification approach that can be applied to images from both fluorescence and electron microscopy. The algorithm uses local maxima to identify labelling targets and uses watershed segmentation to define their boundaries. The method is able to provide information on size, intensity centroids and average intensity within the labelling partitions. Further developed from this method, we demonstrated its applications in four different research projects, including recruitment enumeration of circulating T cell in non-lymphoid tissues, cell clustering in the early development of the chick embryo, gold particle localization and clustering in electron microscopy, and registration/co-localization of transcription factors in neural tube development of early chick embryo. The advantages and limitations of the method are also discussed.
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257
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Yang C, He YL, Zhang L, Xu L, Yi Z, Wang Y, Li N, Zhu D. GLS/IL-12-modified Mycobacterium smegmatis as a novel anti-tuberculosis immunotherapeutic vaccine. Int J Tuberc Lung Dis 2009; 13:1360-1366. [PMID: 19861007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
OBJECTIVE To study the effects and mechanisms of recombinant Mycobacterium smegmatis (rMS) carrying pZM03 (a co-expression plasmid encoding human granulysin [GLS] and murine interleukin 12 [IL-12]) on murine M. tuberculosis infection. DESIGN BALB/c mice infected with M. tuberculosis were treated with normal saline, M. smegmatis, pZM03 or rMS. The number of viable bacteria in the lungs and spleens were counted to observe the therapeutic effects. The levels of IL-12 and interferon-gamma (IFN-gamma) in serum, and IFN-gamma and tumour necrosis factor-alpha (TNF-alpha) released from spleen lymphocytes were detected to observe the T-helper 1 (Th1) response. Secretory IgA (SIgA) in bronchoalveolar lavage fluid was measured to observe the mucosal immunity. The lungs and spleens were prepared for pathological analysis. RESULTS The rMS group showed a significantly reduced number of colony-forming units compared to the other groups. The expression of GLS in the tissue, and increased levels of IL-12, IFN-gamma, TNF-alpha and SIgA, were found in the rMS group. The pathological changes in the lungs of the rMS group were localised, while those in the control group were extensive. CONCLUSION rMS had immunotherapeutic effects associated with a switch to the Th1 response and the antibacterial activity of GLS.
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MESH Headings
- Animals
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/immunology
- Bronchoalveolar Lavage Fluid/immunology
- Cells, Cultured
- Disease Models, Animal
- Female
- Humans
- Immunoglobulin A, Secretory/metabolism
- Interferon-gamma/blood
- Interleukin-12/blood
- Interleukin-12/genetics
- Interleukin-12/immunology
- Lung/immunology
- Lung/microbiology
- Mice
- Mice, Inbred BALB C
- Mycobacterium smegmatis/genetics
- Mycobacterium smegmatis/immunology
- Mycobacterium tuberculosis/pathogenicity
- Spleen/immunology
- Spleen/microbiology
- Th1 Cells/immunology
- Tuberculosis Vaccines/genetics
- Tuberculosis Vaccines/immunology
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/microbiology
- Tuberculosis, Pulmonary/pathology
- Tuberculosis, Pulmonary/therapy
- Tuberculosis, Splenic/immunology
- Tuberculosis, Splenic/microbiology
- Tuberculosis, Splenic/pathology
- Tuberculosis, Splenic/therapy
- Tumor Necrosis Factor-alpha/metabolism
- Vaccines, Synthetic/immunology
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258
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Zheng XF, Liu L, Zhou J, Miao MY, Zhou JR, Zhu D, Xia ZF, Jiang CL. Biphasic effects of dexamethasone on glycogen metabolism in primary cultured rat hepatocytes. J Endocrinol Invest 2009; 32:756-8. [PMID: 20009502 DOI: 10.1007/bf03346532] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Glucocorticoids (GC), the basic function of which is modulating carbohydrates metabolism, play a critical role in stress response by enhancing the organism's resistance. It is widely believed that they could promote glycogen synthesis. However, it is doubtful whether GC can still stimulate glycogen deposition in stress response, as it is known that glucose is imperatively needed at that time. Here, we used primary cultured rat hepatocytes to investigate the effects of GC on glycogen metabolism in vitro to exclude other influences in stress. The results showed that dexamethasone (Dex) played biphasic effects on hepatocytes glycogen metabolism depending on its dosage and the duration of stimulation. Dex could decrease glycogen content of hepatocytes in the higher concentration within a relatively shorter period of time, which could not be blocked by cycloheximide. Therefore, dual roles in hepatic glycogen metabolism played by GC were demonstrated, and a non-genomic mechanism might be involved in the glycogenolytic action of GC. We postulated that the biphasic effects of GC on hepatic glycogen metabolism might be of important significance in stress response.
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259
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Li Q, Wang Z, Zhu D, Xu M, Chen X, Peng D, Iwata Y, Xie P. Detection and analysis of Borna disease virus in Chinese patients with neurological disorders. Eur J Neurol 2009; 16:399-403. [PMID: 19364367 DOI: 10.1111/j.1468-1331.2008.02516.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE Borna disease virus (BDV) is a neurotropic RNA virus that is known to cause neurological disturbances in various animal species, potentially even humans. However, the association between BDV infection and human neurological disorders remains unclear. METHODS Between August 2005 and March 2006, 65 patients with neurological disorders were enrolled into our study. The presence of BDV p24 RNA from peripheral blood mononuclear cells (PBMCs) was investigated by using nested reverse transcriptase PCR (RT-PCR) assay. RESULTS Borna disease virus p24 RNA was detected from PBMCs in six patients with viral encephalitis by using nested RT-PCR assay. However, BDV p24 RNA was not detected in patients with multiple sclerosis or peripheral nerve diseases. CONCLUSION There might be possible associations between BDV infection and human viral encephalitis.
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260
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Rick R, Scherz A, Schlotter WF, Zhu D, Lüning J, Stöhr J. Optimal signal-to-noise ratios for soft x-ray lensless imaging. OPTICS LETTERS 2009; 34:650-652. [PMID: 19252581 DOI: 10.1364/ol.34.000650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We propose and demonstrate a method to gauge and optimize the signal-to-noise ratios (SNRs) in lensless imaging using partially coherent sources. Through spatial filtering we tuned the coherence width of an incoherent soft x-ray undulator source, and we deduce that there exists an optimal spatial filter setting for imaging micrometer-sized objects, while high-resolution imaging is best executed without spatial filtering. Our SNR analysis, given spatial coherence, allows for an estimation of the required exposure time at synchrotron sources and pulse fluence at x-ray laser sources.
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261
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Xu J, Mar A, Lu J, Jin X, Zhu D, Zhu Y, Weber R. 83. Assessment of C7 nerve distribution with sensory nerve action potential after total C7 nerve transection. Clin Neurophysiol 2009. [DOI: 10.1016/j.clinph.2008.10.101] [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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262
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Zhu D, Zhu Y, Chen X, Miro J, Xu L, Jin X, Alcuri R, Zhu Q, Lu J, Weber R, Xu J. 37. Vibration reduces human digital sensory nerve action potential amplitude. Clin Neurophysiol 2009. [DOI: 10.1016/j.clinph.2008.10.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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263
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Lu M, Zhu D, Lu Y, Hou Y, Tan B, Zhong G. Organocatalytic asymmetric alpha-aminoxylation/aza-Michael reactions for the synthesis of functionalized tetrahydro-1,2-oxazines. Angew Chem Int Ed Engl 2008; 47:10013. [PMID: 19072787 DOI: 10.1002/anie.200890274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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264
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Austerlitz C, Mota HC, Sempau J, Benhabib SM, Campos D, Allison R, deAlmeida CE, Zhu D, Sibata CH. Determination of absorbed dose in water at the reference point D(r0,θ0) for an Ir192 HDR brachytherapy source using a Fricke system. Med Phys 2008; 35:5360-5. [DOI: 10.1118/1.2996178] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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265
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Zhang L, Hu C, Ye W, Zhu D, Yu Z, Zhuo R, Sun M. The copper-resistant bacterium ACU isolated from the rhizosphere ofEichhornia crassipes(Mart.) increased the endurance ofPotamogeton crispusL. to copper toxicity. J Appl Microbiol 2008; 105:1034-43. [DOI: 10.1111/j.1365-2672.2008.03835.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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266
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Scherz A, Zhu D, Rick R, Schlotter WF, Roy S, Lüning J, Stöhr J. Nanoscale imaging with resonant coherent X rays: extension of multiple-wavelength anomalous diffraction to nonperiodic structures. PHYSICAL REVIEW LETTERS 2008; 101:076101. [PMID: 18764556 DOI: 10.1103/physrevlett.101.076101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2008] [Indexed: 05/12/2023]
Abstract
The methodology of multiple-wavelength anomalous diffraction, widely used for macromolecular structure determination, is extended to the imaging of nonperiodic nanostructures. We demonstrate the solution of the phase problem by a combination of two resonantly recorded coherent scattering patterns at the carbon K edge (285 eV). Our approach merges iterative phase retrieval and x-ray holography approaches, yielding unique and rapid reconstructions. The element, chemical, and magnetic state specificity of our method further renders it widely applicable to a broad range of nanostructures, providing a spatial resolution that is limited, in principle, by wavelength only.
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267
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Marini AM, Banaudha K, McCall S, Zhu D, Lipsky R. α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-mediated neuroprotection requires TRKB receptor activation. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.81.s1.11_6.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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268
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Zhu D, Austerlitz C, Mota H, Benhabib S, Gay H, Allison R, Campos D, Sibata C. SU-GG-T-381: Attenuation Due to Bronchial Stents in Photodynamic Therapy. Med Phys 2008. [DOI: 10.1118/1.2962133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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269
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Benhabib SM, Zhu D, Austerlitz C, Mota H, Sempau J, Allison R, Sibata C. SU-GG-T-03: Dosimetric Study of HDR 192Ir and LDR 125I Brachytherapy Sources Using the Penelope Monte Carlo Code. Med Phys 2008. [DOI: 10.1118/1.2961753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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270
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Nicholson GA, Magdelaine C, Zhu D, Grew S, Ryan MM, Sturtz F, Vallat JM, Ouvrier RA. Severe early-onset axonal neuropathy with homozygous and compound heterozygous MFN2 mutations. Neurology 2008; 70:1678-81. [DOI: 10.1212/01.wnl.0000311275.89032.22] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective: Severe early-onset axonal neuropathy (SEOAN) is a heterogeneous phenotype first delineated by Ouvrier et al., characterized by progressive axonal degeneration with gait problems often progressing to wheelchair requirement and later respiratory involvement. Most cases are sporadic single cases. Some have heterozygous mitofusin 2 (MFN2) mutations, many of which are de novo dominant mutations. The aim of this study was to investigate the mode of inheritance in three individuals with severe early-onset axonal neuropathy and homozygous or compound heterozygous MFN2 mutations.Methods: The clinical and molecular findings in the parents of three individuals with SEOAN with homozygous or compound heterozygous MFN2 mutations were examined.Results: All parents were asymptomatic or mildly symptomatic with some signs of peripheral neuropathy indicating a minimal phenotype. Two had hearing problems. All parents carried the relevant single base (heterozygous) MFN2 variations.Conclusion: Severe early-onset axonal neuropathy due to MFN2 mutations can present as an apparently recessively inherited neuropathy but the minimal phenotype in the parents suggests a semi-dominant mechanism.
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271
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Wang H, Gao J, Kou J, Zhu D, Yu B. Anti-inflammatory activities of triterpenoid saponins from Polygala japonica. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2008; 15:321-326. [PMID: 17951039 DOI: 10.1016/j.phymed.2007.09.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Bioassay-guided investigation was performed to identify the active constituents from a methanol extract of Polygala japonica, a folk medicinal plant widely used in China to treat inflammatory diseases. The n-BuOH and EtOAc fractions of the P. japonica methanol extract, which show significant anti-inflammatory activity in in vivo test, were further subjected to column chromatography to afford six triterpene glycosides, marked here as saponins 1-6. All compounds were evaluated for their anti-inflammatory activity in the carageenan-induced mouse paw edema test, and saponins 1, 4 and 5 showed significantly anti-inflammatory effects on both phases of carageenan-induced acute paw edema in mice. Saponin 5 was also found to significantly inhibit the production of inflammatory mediators - nitric oxide (NO) in LPS-stimulated RAW264.7 macrophages, with no obvious effects on macrophage viability.
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272
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de Bono S, Laskey MA, Shaw CN, Zhu D, Laskey PJ, Prentice A. Could image analysis of pQCT scans provide additional information about bone strength? JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2008; 8:23. [PMID: 18398257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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273
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Schwab P, Zhu D, Banks MK. Heavy metal leaching from mine tailings as affected by organic amendments. BIORESOURCE TECHNOLOGY 2007; 98:2935-41. [PMID: 17157002 DOI: 10.1016/j.biortech.2006.10.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 10/02/2006] [Accepted: 10/03/2006] [Indexed: 05/12/2023]
Abstract
A column experiment was conducted to investigate Zn, Cd, and Pb leaching from mine tailings as affected by the addition of organic amendments. Composted yard waste, composted cattle manure, and cattle manure aged for one month increased heavy metal leaching from mine tailings when compared to an unamended control. Aged cattle manure and composted cattle manure significantly increased Zn concentration in the leachate. The maximum Zn concentration in leachate from the manure-amended treatments was as high as 3.7 mg/L, whereas Zn concentrations from the control were less than 0.7 mg/L. All organic amendments increased Cd leachate concentrations. The presence of aged cattle manure greatly increased Pb concentrations in the leachate from less than 10 microg/L for the control treatment to higher than 60 microg/L. Lead concentration in leachate was positively correlated with inorganic carbon, total organic carbon, total carbon and bicarbonate. Although organic amendments increased Zn, Cd, and Pb leaching when compared with the control treatment, Zn concentrations were lower than the 5 mg/L secondary drinking water standard, and Pb concentrations were only minimally higher than the 15 microg/L drinking water standard. Cadmium concentrations from manure treatments exceeded the 5 microg/L drinking water standard but only during the first 15 days. Organic amendments may encourage establishment of vegetation in mining areas that may minimize heavy metal contamination through runoff and erosion. However, increased risk due to heavy metal leaching in the presence of organic amendments should be carefully considered.
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274
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Jiang H, Qu J, He L, Pan J, Chen X, Li L, Zhu D, Cao Y. Airway hyperresponsiveness induced by repetitive intraperitoneal injection of lipopolysacharide and the involvement of inflammation and nitric oxide in guinea pigs. Inflamm Res 2006; 55:286-92. [PMID: 16955391 DOI: 10.1007/s00011-006-0085-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE Airway hyperresponsiveness (AHR) is involved in bronchial asthma and chronic obstructive pulmonary disease (COPD) and produces respiratory symptoms. Lipopolysaccharide (LPS) has been found to be significantly related to the severity of asthma. However, its clinical mechanism still remains controversial. This study investigated the in vivo effect of repetitive intraperitoneal administration of lipopolysaccharide (LPS) on airway hyperresponsiveness (AHR) in guinea pigs and the possible involvement of inflammation, nitric oxide (NO) and nitric oxide synthase (NOS). METHODS There were two exposure groups for intraperitoneal LPS injection: (1) LPS was given at a dose of 1 mg x kg(-1), followed by sterile saline (NS) 1 ml x kg(-1) 8 h later every 24 h; (2) LPS was given at a dose of 0.5 mg x kg(-1) two times with an interval of 8 h every 24 h. Each exposure regime was repeated 4 times. Control animals were given NS and 6 naive guinea pigs were used as baseline control. Determinations were made 24 h after each exposure. RESULTS Persistent AHR occurred 24 h after the third and fourth exposures to LPS in the first exposure group (at one dose), but occurred earlier after the exposures to LPS in the second exposure group (at divided doses). The numbers of total cells and neutrophils were elevated initially but subsided subsequently in LPS-treated groups. No evidence of morphological changes in the small airways was found 24 h after any of the exposures. The Ca(2+)-dependent and Ca(2+)-independent NOS activities (mainly produced by iNOS) in the BALF, as well as the production of NO, were significantly elevated 24 h after any of third and fourth exposures in LPS-treated groups. CONCLUSIONS Our results demonstrate that repetitive intraperitoneal LPS can induce persistent AHR which occurs earlier when the frequency of injection increase, and an elevation of NO production and iNOS activity may be involved in is systemic-LPS-induced AHR.
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275
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Wang MD, Rahman M, Zhu D, Bäckström T. Pregnenolone sulphate and Zn2+ inhibit recombinant rat GABA(A) receptor through different channel property. Acta Physiol (Oxf) 2006; 188:153-62. [PMID: 17054655 DOI: 10.1111/j.1748-1716.2006.01617.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
AIMS We compared the antagonistic effects of state-dependent gamma-aminobutyric acid A (GABA(A)) receptor blockers picrotoxin, Zn(2+) and pregnenolone sulphate (PS) on GABA- and pentobarbital-activated currents in recombinant rat GABA(A) receptors in Xenopus oocytes. METHODS Experiments were performed with wild type rat alpha1 beta2 gamma2L and alpha1beta2 receptors, mutants alpha1V256S beta2 gamma2L and alpha1beta2A252Sgamma2L receptors by the two-electrode voltage-clamp technique. RESULTS In contrast to respective 3840- and 56-fold increases in Zn(2+) potencies to inhibit GABA- and pentobarbital-activated currents in the alpha1beta2 receptor, the corresponding potencies of PS remained unchanged in comparison with the alpha1 beta2 gamma2L receptor. A homologous mutation of the residue at 2' position closest to the cytoplasmic end of the M(2) helix to serine on both alpha1 and beta2 subunit, alpha1V256S and beta2A252S, abolished the inhibition of GABA(A) receptor by PS. In comparison with the wild type alpha1beta2gamma2L receptor, mutants alpha1V256S beta2 gamma2L and alpha1beta2 A252S gamma2L receptors did not affect the Zn(2+) inhibition. Furthermore, a significant increase in GABA potency was observed in the mutant alpha1V256S beta2 gamma2L receptor (P < 0.05), but not the mutant alpha1beta2 A252S gamma2L receptor compared with the wild type receptor. CONCLUSIONS Pregnenolone sulphate was a gamma2-subunit independent inhibitor in the GABA(A) receptor, whereas the Zn(2+) antagonism was profoundly influenced by the gamma2-subunit. It is likely that the 2' residue closest to the N-terminus of the protein at M(2) helix on both alpha1 and beta2 subunit are critical to the inhibitory actions of PS and the function of Cl(-) channels. These results are consistent with the hypothesis that PS behaves as a Cl(-) channel blocker that does not share with Zn(2+), the coincident channel property in the GABA(A) receptors.
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