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Zhang DF, Zhang QQ, Li AH. Development of a multiplex PCR assay for rapid and simultaneous detection of four genera of fish pathogenic bacteria. Lett Appl Microbiol 2014; 59:471-8. [PMID: 25041355 DOI: 10.1111/lam.12303] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/04/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED Species of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus are the most common fish pathogenic bacteria that cause economically devastating losses in aquaculture. A multiplex polymerase chain reaction (mPCR) was developed for the simultaneous detection and differentiation of the four genera of fish pathogenic bacteria. Through the use of genus-specific primers instead of species-specific ones, the current mPCR covered much more target bacterial species compared with previously reported species-specific mPCR methods. The specificity of the four putative genus-specific primers was validated experimentally while used exclusively (uniplex PCR) or combined (mPCR) against bacterial genomic DNA templates of the target bacteria and nontarget bacteria. The PCR amplicons for the following genera were obtained as expected: Aeromonas (875 bp), Vibrio (524 bp), Edwardsiella (302 bp) and Streptococcus (197 bp), and the fragments could be separated clearly on the agarose gel electrophoresis. The mPCR did not produce nonspecific amplification products when used to amplify 21 nontarget species of bacteria. The mPCR detection limits for each target bacterial genera were 50 colony-forming units (CFU) in pure culture and 100 CFU in fish tissue samples. In conclusion, the mPCR assay was proven to be a powerful alternative to the conventional culture-based method, given its rapid, specific, sensitive and reliable detection of target pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY The fish pathogenic bacteria of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus frequently cause severe outbreaks of diseases in cultured fish, and the genus-specific multiplex PCR assay developed in this study can detect the bacteria of the four genera when present in the samples either alone or mixed. The mPCR assay is expected to identify the causative agents more efficiently than uniplex PCR or species-specific multiplex PCR for clinical diagnosis, resulting in the earlier implementation of control measures. This mPCR assay provides a rapid, specific and sensitive tool for the detection or identification of common fish pathogenic bacteria in aquaculture practice.
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Jiang T, Yu JT, Zhu XC, Zhang QQ, Tan MS, Cao L, Wang HF, Lu J, Gao Q, Zhang YD, Tan L. Angiotensin-(1-7) induces cerebral ischaemic tolerance by promoting brain angiogenesis in a Mas/eNOS-dependent pathway. Br J Pharmacol 2014; 171:4222-32. [PMID: 24824997 DOI: 10.1111/bph.12770] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 04/18/2014] [Accepted: 04/30/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE As a newer component of the renin-angiotensin system, angiotensin-(1-7) [Ang-(1-7) ] has been shown to facilitate angiogenesis and protect against ischaemic damage in peripheral tissues. However, the role of Ang-(1-7) in brain angiogenesis remains unclear. The aim of this study was to investigate whether Ang-(1-7) could promote angiogenesis in brain, thus inducing tolerance against focal cerebral ischaemia. EXPERIMENTAL APPROACH Male Sprague-Dawley rats were i.c.v. infused with Ang-(1-7), A-779 (a Mas receptor antagonist), L-NIO, a specific endothelial NOS (eNOS) inhibitor, endostatin (an anti-angiogenic compound) or vehicle, alone or simultaneously, for 1-4 weeks. Capillary density, endothelial cell proliferation and key components of eNOS pathway in the brain were evaluated. Afterwards, rats were subjected to permanent middle cerebral artery occlusion (pMCAO), and regional cerebral blood flow (rCBF), infarct volume and neurological deficits were measured 24 h later. KEY RESULTS Infusion of Ang-(1-7) for 4 weeks significantly increased brain capillary density via promoting endothelial cell proliferation, which was accompanied by eNOS activation and up-regulation of NO and VEGF in brain. These effects were abolished by A-779 or L-NIO. More importantly, Ang-(1-7) improved rCBF and decreased infarct volume and neurological deficits after pMCAO, which could be reversed by A-779, L-NIO or endostatin. CONCLUSIONS AND IMPLICATIONS This is the first evidence that Ang-(1-7) promotes brain angiogenesis via a Mas/eNOS-dependent pathway, which enhances tolerance against subsequent cerebral ischaemia. These findings highlight brain Ang-(1-7)/Mas signalling as a potential target in stroke prevention.
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Jiang T, Yu JT, Zhu XC, Zhang QQ, Tan MS, Cao L, Wang HF, Shi JQ, Gao L, Qin H, Zhang YD, Tan L. Ischemic preconditioning provides neuroprotection by induction of AMP-activated protein kinase-dependent autophagy in a rat model of ischemic stroke. Mol Neurobiol 2014; 51:220-9. [PMID: 24809692 DOI: 10.1007/s12035-014-8725-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 04/29/2014] [Indexed: 11/26/2022]
Abstract
Accumulating evidence suggests that ischemic preconditioning (IPC) increases cerebral tolerance to the subsequent ischemic exposure. However, the underlying mechanisms are still not fully understood. In the present study, we tested the hypothesis that AMP-activated protein kinase (AMPK)-dependent autophagy contributed to the neuroprotection of IPC in rats with permanent cerebral ischemia. Male Sprague-Dawley rats were pretreated with vehicle, compound C (an AMPK inhibitor), or 3-methyladenine (3-MA, an autophagy inhibitor) and then were subjected to IPC induced by a 10-min middle cerebral artery occlusion. Afterward, the brain AMPK activity and autophagy biomarkers were measured. At 24 h after IPC, permanent cerebral ischemia was induced in these rats, and infarct volume, neurological deficits as well as cell apoptosis were evaluated 24 h later. We demonstrated that IPC activated AMPK and induced autophagy in the brain, which was accompanied by a reduction of infract volume, neurological deficits, and cell apoptosis after cerebral ischemia. Meanwhile, the IPC-induced autophagy was inhibited by compound C while the neuroprotection of IPC was abolished by compound C or 3-MA. These findings suggest that AMPK-mediated autophagy contributes to the neuroprotection of IPC, highlighting AMPK as a therapeutic target for stroke prevention and treatment.
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Jiang T, Yu JT, Zhu XC, Tan MS, Wang HF, Cao L, Zhang QQ, Shi JQ, Gao L, Qin H, Zhang YD, Tan L. Temsirolimus promotes autophagic clearance of amyloid-β and provides protective effects in cellular and animal models of Alzheimer's disease. Pharmacol Res 2014; 81:54-63. [PMID: 24602800 DOI: 10.1016/j.phrs.2014.02.008] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 02/24/2014] [Accepted: 02/24/2014] [Indexed: 01/25/2023]
Abstract
Accumulation of amyloid-β peptides (Aβ) within brain is a major pathogenic hallmark of Alzheimer's disease (AD). Emerging evidence suggests that autophagy, an important intracellular catabolic process, is involved in Aβ clearance. Here, we investigated whether temsirolimus, a newly developed compound approved by Food and Drug Administration and European Medicines Agency for renal cell carcinoma treatment, would promote autophagic clearance of Aβ and thus provide protective effects in cellular and animal models of AD. HEK293 cells expressing the Swedish mutant of APP695 (HEK293-APP695) were treated with vehicle or 100nM temsirolimus for 24h in the presence or absence of 3-methyladenine (5mM) or Atg5-siRNA, and intracellular Aβ levels as well as autophagy biomarkers were measured. Meanwhile, APP/PS1 mice received intraperitoneal injection of temsirolimus (20mg/kg) every 2 days for 60 days, and brain Aβ burden, autophagy biomarkers, cellular apoptosis in hippocampus, and spatial cognitive functions were assessed. Our results showed that temsirolimus enhanced Aβ clearance in HEK293-APP695 cells and in brain of APP/PS1 mice in an autophagy-dependent manner. Meanwhile, temsirolimus attenuated cellular apoptosis in hippocampus of APP/PS1 mice, which was accompanied by an improvement in spatial learning and memory abilities. In conclusion, our study provides the first evidence that temsirolimus promotes autophagic Aβ clearance and exerts protective effects in cellular and animal models of AD, suggesting that temsirolimus administration may represent a new therapeutic strategy for AD treatment. Meanwhile, these findings emphasize the notion that many therapeutic agents possess pleiotropic actions aside from their main applications.
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Zhang QQ, Xu H, Zu MH, Gu YM, Shen B, Wei N, Xu W, Liu HT, Wang WL, Gao ZK. Strategy and long-term outcomes of endovascular treatment for Budd-Chiari syndrome complicated by inferior vena caval thrombosis. Eur J Vasc Endovasc Surg 2014; 47:550-7. [PMID: 24560649 DOI: 10.1016/j.ejvs.2014.01.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 01/19/2014] [Indexed: 02/03/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate the strategy and long-term outcomes of endovascular treatment of Budd-Chiari syndrome (BCS) complicated by inferior vena cava (IVC) thrombosis. METHODS The treatment strategy and outcomes of BCS complicated by IVC thrombosis were retrospectively evaluated in a single-center study. The treatment was aimed at the IVC thrombus, not hepatic vein occlusion. All 133 patients with BCS complicated by IVC thrombosis from February 2003 to March 2013 underwent endovascular treatment. For the fresh thrombus group (n=75) recanalization was performed after transcatheter thrombolysis with urokinase. For the mixed thrombus group (n=19) a small balloon pre-dilation of the IVC was performed first, followed by transcatheter thrombolysis using urokinase and a large balloon dilation of the IVC. For the old thrombus group (n=39) a large balloon dilation or/and stent placement was performed directly. Pre- and post-treatment follow-ups were recorded. RESULTS The endovascular treatment was successful in 131 out of 133 patients (98.5%). Thirty seven patients had synchronous hepatic vein occlusion. The incidence of serious complications was 4.5% (6/133). Symptomatic pulmonary embolism occurred in three cases, cerebral hemorrhage in two, and cardiac tamponade in one. The cumulative 1-, 5-, and 10-year primary patency rate was 96.3%, 84.0%, and 64.6%, respectively. The cumulative 1-, 5-, and 10-year secondary patency rate was 99.0%, 96.1% and 91.3%, respectively. Segmental occlusion of the IVC and duration of anticoagulant therapy less than 6 months were independent risk factors for reocclusion. CONCLUSIONS For patients with BCS complicated by IVC thrombosis, an individualized treatment strategy based on the property of the thrombus can result in excellent long-term patency.
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Zhang QQ, Wu XJ, Tang T, Zhu SW, Yao Q, Gao BZ, Yuan XC. Quantitative analysis of rectal cancer by spectral domain optical coherence tomography. Phys Med Biol 2012; 57:5235-44. [PMID: 22850124 DOI: 10.1088/0031-9155/57/16/5235] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To quantify OCT images of rectal tissue for clinic diagnosis, the scattering coefficient of the tissue is extracted by curve fitting the OCT signals to a confocal single model. A total of 1000 measurements (half and half of normal and malignant tissues) were obtained from 16 recta. The normal rectal tissue has a larger scattering coefficient ranging from 1.09 to 5.41 mm⁻¹ with a mean value of 2.29 mm⁻¹ (std:±0.32), while the malignant group shows lower scattering property and the values ranging from 0.25 to 2.69 mm⁻¹ with a mean value of 1.41 mm⁻¹ (std:±0.18). The peri-cancer of recta has also been investigated to distinguish the difference between normal and malignant rectal tissue. The results demonstrate that the quantitative analysis of the rectal tissue can be used as a promising diagnostic criterion of early rectal cancer, which has great value for clinical medical applications.
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Zhang QQ, Wang JG, Wang MW, Bu J, Zhu SW, Wang R, Gao BZ, Yuan XC. A modified fractal zone plate with extended depth of focus in spectral domain optical coherence tomography. JOURNAL OF OPTICS (2010) 2011; 13:10.1088/2040-8978/13/5/055301. [PMID: 24353894 PMCID: PMC3864818 DOI: 10.1088/2040-8978/13/5/055301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In optical coherence tomography (OCT) systems, there is a trade-off between the depth of focus (DOF) and lateral resolution when conventional lenses are used. We propose a new method that employs a modified fractal generalized zone plate (MFraGZP) combined with a conventional lens to improve the trade-off effect, with an extended DOF of about 2.5 mm (14 times larger) while the lateral resolution is maintained at ~9.5 μm. As an example, images of the calibration microspheres are obtained and demonstrated with the extended DOF in a spectral domain OCT system.
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Wu SX, Guo NR, Li XF, Liao WQ, Chen M, Zhang QQ, Li CY, Li RY, Bulmer GS, Li DM, Xi LY, Lu S, Liu B, Zheng YC, Ran YP, Kuan YZ. Human pathogenic fungi in China--emerging trends from ongoing national survey for 1986, 1996, and 2006. Mycopathologia 2011; 171:387-93. [PMID: 21509517 DOI: 10.1007/s11046-011-9398-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 02/08/2011] [Indexed: 12/27/2022]
Abstract
This epidemiological survey was a retrospective study on three nodes during the past three decades on fungal infections representing the China, including Taiwan. Owing to rare publications reporting on dynamic epidemiological trends in the pathogen epidemiology in China, we surveyed the isolation rates and pathogenic fungi from 8 representative districts in China using uniform identification with uniform methodology. The pathogenic fungi isolation rates and species obtained from 1986 (n=9,096), 1996 (n=19,009), and 2006 (n=33,022) suggested that Trichophyton rubrum was the commonest organism cultured in 1980s (45.4%) and 1990s (34.5%), but Candida albicans increased significantly and reaching to its peak (26.9%) in 2006s' survey, and has become the most common isolate of fungal infections in China currently. In addition, Candida glabrata became the most common non-albicans species of Candida in 2006s' survey. At the same time, the incidence of molds also gradually increased. According to comparative analysis of the results of these three surveys, we found apparent differences in the isolation rates of different pathogenic fungi and the forefront 10 species in China varied significantly, and the dermatophytes decreased markedly, while yeasts, especially the Candida species and the molds, increased gradually during the past three decades. Less dermatophytic infections may suggest better access to healthcare or increase in Candida species indicated higher incidence of hospital acquired infections.
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Shi JQ, Shen W, Chen J, Wang BR, Zhong LL, Zhu YW, Zhu HQ, Zhang QQ, Zhang YD, Xu J. Anti-TNF-α reduces amyloid plaques and tau phosphorylation and induces CD11c-positive dendritic-like cell in the APP/PS1 transgenic mouse brains. Brain Res 2010; 1368:239-47. [PMID: 20971085 DOI: 10.1016/j.brainres.2010.10.053] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Revised: 10/08/2010] [Accepted: 10/14/2010] [Indexed: 01/08/2023]
Abstract
Inflammation plays an important role in the pathogenesis of Alzheimer's disease (AD). Overexpression of tumor necrosis factor-α (TNF-α) occurs in the AD brain. Recent clinical studies have shown that the anti-TNF-α therapy improves cognition function of AD patients rapidly. However, the underlying mechanism remains elusive. The present study investigates the effects of intracerebroventricular injection of the monoclonal TNF-α antibody, Infliximab, on the pathological features of AD in the APP/PS1 double transgenic mice. We found that Infliximab administration reduced the levels of TNF-α, amyloid plaques, and tau phosphorylation as early as three days after daily injection of 150 μg Infliximab for three days. The number of CD11c-positive dendritic-like cells and the expression of CD11c were found to be increased concurrently after Infliximab injection. These data suggested that the CD11c-positive dendritic-like cells might contribute to the Infliximab-induced reduction of AD-like pathology. Furthermore, our results support the use of anti-TNF-α for the treatment of AD.
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Sun LP, Wang S, Zhang ZW, Wang XY, Zhang QQ. Biological evaluation of collagen-chitosan scaffolds for dermis tissue engineering. Biomed Mater 2009; 4:055008. [PMID: 19779250 DOI: 10.1088/1748-6041/4/5/055008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Three-dimensional collagen-chitosan scaffolds were fabricated with type I collagen and chitosan through freeze drying and glutaraldehyde cross-linking. Dermal fibroblasts were isolated from neonatal Sprague-Dawley rat skin by dispase II/collagenase I digestion. The fibroblasts were then seeded into the scaffolds to construct tissue-engineered dermis. The microstructure of the scaffolds as well as the fibroblasts' proliferation, cytokine secretion and cell cycle were investigated. Flow cytometry analysis indicated that cells in the scaffolds proliferated steadily. IL-6 concentration measurement by the ELISA test suggested that the scaffolds could promote secretion of the fibroblasts' cytokine. These results show that the fibroblasts and the scaffolds interact well with each other, and the fibroblasts have better proliferation ability and biological activity in the scaffolds than in monolayer culture. The scaffolds are a promising candidate for tissue repair and regeneration with enhanced biostability and good cytocompatibility.
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Zhang QQ, Djuth FT, Zhou QF, Hu CH, Cha JH, Shung KK. High frequency broadband PZT thick film ultrasonic transducers for medical imaging applications. ULTRASONICS 2006; 44 Suppl 1:e711-5. [PMID: 16793087 DOI: 10.1016/j.ultras.2006.05.130] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A modified sol-gel method is used to prepare PZT thick film on Pt-coated silicon substrate. A new method of vacuum filling sol-gel precursor solution is introduced to improve film quality. The effects of the filling on PZT thick film structure and ferroelectric properties are discussed. The fabrication of a high frequency transducer with the PZT film as the actuating layer is described. The performance of the transducer is measured and results show that the transducer backed by E-Solder without a matching layer has a center frequency of 103 MHz and a bandwidth of 70%. Beam profile measurements show that the transducer has an axial resolution of 9.2 microm and a lateral resolution of 33 microm.
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Zhang LH, Zhang QQ. [Study on the osteoblast and the growth factors of bone tissue engineering]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 2001; 23:631-7. [PMID: 12901113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
To build artificial bone with osteoblast and growth factors is one of popular studies on current bone tissue engineering. This paper has reviewed current studies on the function of the growth factors and the resource, isolation and culture of the osteoblast. It also introduces the interaction of the growth factors, and the development in the transgenosis of the relative growth factors.
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Zhang QQ, Chan HL, Ploss B, Choy CL. PCLT/P (VDF-TrFE) nanocomposite pyroelectric sensors. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2001; 48:154-160. [PMID: 11367782 DOI: 10.1109/58.895925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Thin composite films consisting of 12 vol% of nanosized lanthanum and calcium-modified lead titanate (PCLT) powder embedded in a vinylidene fluoride-trifluoroethylene copolymer [P(VDF-TrFE)] matrix were deposited on silicon (Si) substrates to form pyroelectric sensors with three different configurations. The influences of a thermal buffer layer and back etching of the silicon substrate on the current and voltage responsivities of the sensors were investigated theoretically and experimentally. The specific detectivity of the sensors was also calculated from the measured voltage responsivity and noise.
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Taylor JK, Zhang QQ, Wyatt JR, Dean NM. Induction of endogenous Bcl-xS through the control of Bcl-x pre-mRNA splicing by antisense oligonucleotides. Nat Biotechnol 1999; 17:1097-100. [PMID: 10545916 DOI: 10.1038/15079] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Resistance to apoptosis, which plays an important role in tumors that are refractory to chemotherapy, is regulated by the ratio of antiapoptotic to proapoptotic proteins. By manipulating levels of these proteins, cells can become sensitized to undergo apoptosis in response to chemotherapeutic agents. Alternative splicing of the bcl-x gene gives rise to two proteins with antagonistic functions: Bcl-xL, a well-characterized antiapoptotic protein, and Bcl-xS, a proapoptotic protein. We show here that altering the ratio of Bcl-xL to Bcl-xS in the cell using an antisense oligonucleotide permitted cells to be sensitized to undergo apoptosis in response to ultraviolet B radiation and chemotherapeutic drug treatment. These results demonstrate the ability of a chemically modified oligonucleotide to alter splice site selection in an endogenous gene and illustrate a powerful tool to regulate cell survival.
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Taylor JK, Zhang QQ, Monia BP, Marcusson EG, Dean NM. Inhibition of Bcl-xL expression sensitizes normal human keratinocytes and epithelial cells to apoptotic stimuli. Oncogene 1999; 18:4495-504. [PMID: 10442640 DOI: 10.1038/sj.onc.1202836] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The epidermis is continually exposed to harmful mutagens that have the potential to cause DNA damage. To protect the skin from accumulating mutated cells, keratinocytes have developed a highly regulated mechanism of eliminating damaged cells through apoptosis. Bcl-xL is a well-described cell survival protein that when overexpressed in skin can protect keratinocytes from UV radiation-induced apoptosis. To begin to unravel the complex mechanisms that keratinocytes use to survive, we wanted to characterize the role of endogenous Bcl-xL in protecting cells from death. In this study, we describe the development and characterization of an antisense inhibitor to Bcl-xL. We show that this inhibitor reduces Bcl-xL RNA and protein in a concentration-dependent, sequence-specific manner. Furthermore, treatment of keratinocytes and epithelial cells with this inhibitor sensitizes these cells to UV-B radiation and cisplatinum treatment-induced apoptosis. Thus, these results offer direct evidence that Bcl-xL is critical in the protection of skin and epithelial cells from apoptosis and provide a basis for the role of Bcl-xL in keratinocyte and epithelial cell survival.
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Zhang QQ, Song RT, Xu ZK. [Cleavage activity of ribozymes on a target RNA of tobacco mosaic virus in E. coli]. SHI YAN SHENG WU XUE BAO 1998; 31:333-9. [PMID: 12016955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
A target cDNA fragment from TMV RNA was inserted to a reporter gene CAT immediately to the 3' end of the translation initiation codon ATG resulting in the formation of a chimeric CAT gene in an in vivo transcription and expression vector. The in vivo activities of various ribozymes on the target sequence were observed by determining the changes of the CAT activities of the chimeric CAT gene expressed in E. coli. The CAT activity was reduced by up to 30% when a specific ribozyme RZ1, RZ1A or RZ1B was transcribed, no change in CAT activity was observed when a non-specific ribozyme RZ3 was expressed. The protein electrophoresis and primer extension experiments indicated that this reduction in CAT activity was due to the specific cleavage of the ribozymes to the chimeric CAT mRNA at the target region hence the decrease in CAT protein synthesis.
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Zhang QQ, Ren L, Wang C, Liu LR, Wen XJ, Liu YH, Zhang XD. Porous hydroxyapatite reinforced with collagen protein. ARTIFICIAL CELLS, BLOOD SUBSTITUTES, AND IMMOBILIZATION BIOTECHNOLOGY 1996; 24:693-702. [PMID: 8922236 DOI: 10.3109/10731199609118892] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Porous hydroxyapatite (HAP) with certain porosity and pore size was prepared, and incorporated with bovine collagen protein. The composition and structure of the HAP was confirmed by X-Ray Diffraction (XRD) and ICP. Scanning Electron Microscopy (SEM), mechanical tests and in vitro degradation were performed. Collagen protein with low antigenicity was obtained from bovine tendon by enzyme digestion, and was then forced to fill in the HAP matrix to form composites. Scanning Electron Microscopy (SEM), Mechanical tests and in vitro degradation were performed. The test results show that first, HAP thus made has specific pore size and directions; second, mechanical properties of the composites have been markedly improved; third, the in vitro degradation rate of the composite is almost the same as and mainly controlled by the degradation rate of collagen.
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Olsen HS, Cepeda MA, Zhang QQ, Rosen CA, Vozzolo BL, Wagner GF. Human stanniocalcin: a possible hormonal regulator of mineral metabolism. Proc Natl Acad Sci U S A 1996; 93:1792-6. [PMID: 8700837 PMCID: PMC39860 DOI: 10.1073/pnas.93.5.1792] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We have isolated a human cDNA clone encoding the mammalian homolog of stanniocalcin (STC), a calcium- and phosphate-regulating hormone that was first described in fishes where it functions in preventing hypercalcemia. STC has a unique amino acid sequence and, until now, has remained one of the few polypeptide hormones never described in higher vertebrates. Human STC (hSTC) was found to be 247 amino acids long and to share 73% amino acid sequence similarity with fish STC. Polyclonal antibodies to recombinant hSTC localized to a distinct cell type in the nephron tubule, suggesting kidney as a possible site of synthesis. Recombinant hSTC inhibited the gill transport of calcium when administered to fish and stimulated renal phosphate reabsorption in the rat. The evidence suggests that mammalian STC, like its piscine counterpart, is a regulator of mineral homeostasis.
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Qiu YH, Peng YP, Zhang QQ, Wang JH. [Effect of acetylcholine on the proliferation of T lymphocyte of rat spleen]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1995; 47:275-80. [PMID: 7570114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Experiments were performed to determine the effect of various concentrations of acetylcholine (ACh) (10(-10) to 10(-4) mol/L) on the proliferation of spleen cells of rat to concanavalin (Con A). ACh at 10(-9) mol/L to 10(-4) mol/L range significantly enhanced the proliferation of T cells, reaching a maximum at 10(-7) and 10(-6) mol/L. The proliferation of lymphocytes first stimulated by various concentrations of ACh (10(-9), 10(-7) or 10(-5) mol/L) for one hour and incubated with Con A for 72 h still showed increase. When ACh was washed off for one hour, the proliferative enhancement of lymphocytes to Con A remained to occur. However, ACh did not enhance the proliferation of T cells which were once stimulated with Con A for 6 h. Atropine at 10(-7) or 10(-6) mol/L abolished completely the effect of ACh at 10(-9) or 10(-5) mol/L. The action of ACh at 10(-7) mol/L could be blocked by 10(-6) mol/L atropine. These data suggest that ACh at a wide range of concentrations can enhance cellular immunity, an effect occurring either before or after T cells are activated through muscarinic cholinergic receptors.
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Jing HL, Shang HS, Zhang QQ, Xu ZK. [Cloning and expression of an antifreeze peptide gene of winter flounder in E. coli]. SHI YAN SHENG WU XUE BAO 1995; 28:77-83. [PMID: 7597872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Antifreeze peptide (AFP) produced in some animals is able to lower freezing temperature to prevent serum from freezing. There is a great potential to apply AFP in various circumstances wherever tolerance to cold environment is required. cDNA copies of AFP and proAFP coding sequence were synthesized according to the published sequence from a winter flounder (Pseudopleuronectes americanus). Expression of AFP or proAFP cDNA was initially tested in E. coli using a procaryotic expression vector. Level of the expression was essentially low indicated by SDS-PAGE and protein staining procedures. In order to detect the low level expression, the AFP (or proAFP) cDNA was fused, in frame, to the 5'-end of the CAT reporter gene resulting in a chimeric AFP/CAT (or proAFP/CAT) cDNA. The product translated from such a chimeric mRNA must contain a N'-terminal AFP (or proAFP) portion and C'-terminal CAT portion. Thus, low level of expression of AFP (or proAFP) in the fused form may be detected indirectly by sensitive CAT assay as long as the chimeric CAT still remains the activity. As expected, CAT activity has been clearly detected in protein extract from induced E. coli indicating that AFP (or proAFP) cDNA clones be expressed in E. coli.
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Wu X, Huang WQ, Zhang QQ, Yu ZM. Effects of histamine on electrophysiological properties and triggered activity in guinea pig papillary muscles. METHODS AND FINDINGS IN EXPERIMENTAL AND CLINICAL PHARMACOLOGY 1994; 16:583-587. [PMID: 7760583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The effects of histamine on action potentials (APs) and on early afterdepolarizations (EADs) were studied with standard microelectrode and computer in guinea pig papillary muscles. Experiments offer evidence that histamine (6.0 mumol/l) results in a significant diminution in action potential duration at 50% repolarization (APD50) and 90% repolarization (APD90) (data taken from no abnormal automaticity and oscillatory potential cells, 10 out of 19 preparations). Particularly, histamine can induce EADs (about 58%), oscillatory potentials and triggered activity. EADs frequently occur at low stimulation rates of 0.2-1.0 Hz and with prolongation of the action potential duration. EAD-induced triggered activity may exhibit fast spontaneous APs. Cimetidine (10 mumol/l, n = 6), an H2-receptor antagonist, antagonizes the effects of histamine. In the presence of cimetidine no EADs are observed by perfusing histamine. An H1-receptor antagonist, chlorpheniramine (10 mumol/l, n = 9), has no effect on the alterations of APs induced by histamine in ventricular myocardium. The results suggest that the mechanisms of histamine-induced shortness of AP duration, EADs and triggered activity may be related to the H2 receptor-mediated enhancement of the slow inward calcium current.
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72
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Leung BS, Stout L, Zhou L, Ji HJ, Zhang QQ, Leung HT. Evidence of an EGF/TGE-alpha--independent pathway for estrogen-regulated cell proliferation. J Cell Biochem 1991; 46:125-33. [PMID: 1918178 DOI: 10.1002/jcb.240460206] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To elucidate the relationship between epidermal growth factor (EGF)/transforming growth factor (TGF-alpha) and estradiol-17 beta (E) in cell proliferation, we examined their effects on the breast cancer cell line, CAMA-1. While E was able to consistently induce cell proliferation under a variety of experimental conditions, EGF/TGF-alpha was without effect. Despite the presence of the receptor (EGFR) gene, mature EGFR protein and mRNA were not detected by radioreceptor assay, 35S Met-labelling, and the Intron Differential RNA/PCR method under conditions in which cells remain responsive to E. Furthermore, TGF-alpha is not an autocrine factor in CAMA-1 cells. We demonstrated unequivocally that EGF/TGF-alpha interaction with EGFR is not an obligatory event in mediating estrogen-stimulated cell proliferation.
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73
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Molitor TW, Oraveerakul K, Zhang QQ, Choi CS, Ludemann LR. Polymerase chain reaction (PCR) amplification for the detection of porcine parvovirus. J Virol Methods 1991; 32:201-11. [PMID: 1874916 DOI: 10.1016/0166-0934(91)90051-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A polymerase chain reaction (PCR) amplification method was developed and evaluated to detect porcine parvovirus (PPV). A pair of 20-base primers and an oligonucleotide probe were derived from the DNA sequences common to two isolates of PPV, NADL-8 and NADL-2. The primers flanked 118-bp nucleotides within the region coding for the major structural protein VP2. After DNA amplification of PPV replicative form (RF), a 158-bp fragment was detected in agarose gels. This amplified fragment was shown to be specific for PPV DNA after Southern transfer and hybridization to a 20-base internal probe. The amplified fragment also contained a single EcoRI cleavage site. Various conditions, such as number of cycles and annealing temperature, were examined to optimize the conditions for detecting viral DNAs from infected cell cultures and swine fetal tissues. Four different isolates of PPV, NADL-8, NADL-2, KBSH and Kresse, and two other viruses, canine parvovirus (CPV) and pseudorabies virus (PRV), were included to determine specificity of amplification. Slot blot hybridization with a radiolabeled probe was used to evaluate the sensitivity of PCR amplification. The optimized protocol was specific for PPV detecting equally all four strains of PPV, but failing to amplify CPV or PRV sequences. The PCR method could detect at least 100 fg of viral replicative form (RF) DNA or the equivalent of 1 PFU of infectious virus. The applications of this method include routine detection of PPV in clinical samples and as a contaminant in mammalian cell lines.
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74
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Ji HJ, Zhang QQ, Leung BS. Survey of oncogene and growth factor/receptor gene expression in cancer cells by intron-differential RNA/PCR. Biochem Biophys Res Commun 1990; 170:569-75. [PMID: 1696473 DOI: 10.1016/0006-291x(90)92129-n] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To elucidate the possible roles of proto-oncogenes and growth factors in estrogen-regulated cell proliferation of human breast and gynecologic cancers, we have determined the gene expressions of c-myc, transforming growth factor-alpha and beta 1 (TGF-alpha, beta 1) and epidermal growth factor receptor (EGFR) in a number of these cancer cell lines by using an intron-Differential (ID) RNA/PCR method, which differentially identifies the amplified cDNA from PCR products of genomic DNA contaminants. With this method, we demonstrated the expression of these genes, except EGFR, in an estrogen-dependent breast cancer cell line (CAMA-1). Our results show that TGF-alpha/EGF does not function as an autocrine factor in this cell line. Accordingly, it is unlikely that the TGF-alpha/EGFR system participates as a mediator in the estrogen-induced cell proliferation of CAMA-1 cells. The ID RNA/PCR method is a rapid, sensitive and specific technique for mRNA phenotyping and will have great clinical utility.
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Jin SY, Zhang QQ, Zhuang J. [Effects of reserpine on the protective function of diazepam against hyperbaric oxygen-induced convulsions]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1987; 8:403-5. [PMID: 3450174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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76
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Zhou HG, Kang XZ, Zhang QQ. Homologous 14q14q Robertsonian translocation in man. Chin Med J (Engl) 1983; 96:625-33. [PMID: 6416763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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