51
|
Peng T, Wang Q, Liu M, Zheng J, Lin J. An optimization approach for hot compaction technology of Mg–10Gd–2Y–0.5Zr alloy during solid-state recycling. POWDER TECHNOL 2009. [DOI: 10.1016/j.powtec.2009.03.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
52
|
Guo QS, Qin SY, Zhou SF, He L, Ma D, Zhang YP, Xiong Y, Peng T, Cheng Y, Li XT. Unbalanced translocation in an adult patient with premature ovarian failure and mental retardation detected by spectral karyotyping and array-comparative genomic hybridization. Eur J Clin Invest 2009; 39:729-37. [PMID: 19515099 DOI: 10.1111/j.1365-2362.2009.02141.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND There are only three cases of unbalanced translocation (X;1) reported in childhood in the literature, while no such phenotypic information is available in adults. MATERIALS AND METHODS To delineate the phenotype-genotype relationship of unbalanced translocation (X;1) in adulthood, we reported here a 20-year-old female with an unbalanced translocation (X;1) which was determined by spectral karyotyping, array-comparative genomic hybridization and subtelomeric fluorescence in situ hybridization (FISH). RESULTS The phenotype of partial trisomy 1 and partial monosomy X of the present case was much attenuated, including premature ovarian failure, mental retardation, class I obesity, mild dysmorphism and delayed secondary sexual characteristics. The breakpoints of the unbalanced translocation were accurately located at Xq28 and 1q32.1. The large amplification on Chromosome 1 q arm was found to involve 312 genes and the deletion on Chromosome X q arm also involved 141 genes. Overall, genes associated with physiological process (47 genes), cellular process (33), development (23), response to stimulus (1) and reproduction (1) were observed in the amplification on Chromosome 1 q arm. In addition, genes related to physiological process (23 genes), cellular process (13), development (6) and response to stimulus (2) were observed in the large deletion on chromosome X q arm. Late-replication studies revealed the existence of skewed X inactivation in the derivative X chromosome. CONCLUSIONS The phenotype of partial monosomy X and partial trisomy 1q is much attenuated in case of unbalanced translocation (X;1) in adulthood probably owing to skewed X inactivation in derivative X chromosome.
Collapse
|
53
|
Li Y, Li Y, Feng Q, Arnold M, Peng T. Calpain activation contributes to hyperglycaemia-induced apoptosis in cardiomyocytes. Cardiovasc Res 2009; 84:100-10. [DOI: 10.1093/cvr/cvp189] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
54
|
O'Neill DP, Peng T, Payne SJ. A two-equation coupled system model for determination of liver tissue temperature during radio frequency ablation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2009:3893-3896. [PMID: 19963608 DOI: 10.1109/iembs.2009.5332651] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A model is presented that is an alternative approach to the bio-heat equation for use in radio frequency heating of the liver. The model comprises both a tissue subvolume and a blood subvolume. Separate bio-heat equations are determined for each subvolume, but with an additional term exchanging heat between them, thus creating a coupled system. The derivation for the two coupled differential equations is outlined and sample simulations are presented to demonstrate the importance of considering the two subvolumes separately, even when the blood subvolume is a small fraction of the tissue subvolume.
Collapse
|
55
|
Peng T, Zhang T, Lu X, Feng Q. JNK1/c-fos inhibits cardiomyocyte TNF- expression via a negative crosstalk with ERK and p38 MAPK in endotoxaemia. Cardiovasc Res 2008; 81:733-41. [DOI: 10.1093/cvr/cvn336] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
56
|
Oka Y, Peng T, Takei F, Nakatani K. The reaction of cytosine with bisulfite by base flipping from the duplex. ACTA ACUST UNITED AC 2008:435-6. [DOI: 10.1093/nass/nrn221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
57
|
Peng T, Shen E, Fan J, Zhang Y, Arnold JMO, Feng Q. Disruption of phospholipase C 1 signalling attenuates cardiac tumor necrosis factor- expression and improves myocardial function during endotoxemia. Cardiovasc Res 2007; 78:90-7. [DOI: 10.1093/cvr/cvm100] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
58
|
Ferrara A, Weiss NS, Hedderson MM, Quesenberry CP, Selby JV, Ergas IJ, Peng T, Escobar GJ, Pettitt DJ, Sacks DA. Pregnancy plasma glucose levels exceeding the American Diabetes Association thresholds, but below the National Diabetes Data Group thresholds for gestational diabetes mellitus, are related to the risk of neonatal macrosomia, hypoglycaemia and hyperbilirubinaemia. Diabetologia 2007; 50:298-306. [PMID: 17103140 DOI: 10.1007/s00125-006-0517-8] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Accepted: 10/02/2006] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS Gestational diabetes mellitus (GDM) is a risk factor for perinatal complications. In several countries, the criteria for the diagnosis of GDM have been in flux, the American Diabetes Association (ADA) thresholds recommended in 2000 being lower than those of the National Diabetes Data Group (NDDG) that have been in use since 1979. We sought to determine the extent to which infants of women meeting only the ADA criteria for GDM are at increased risk of neonatal complications. MATERIALS AND METHODS In a multiethnic cohort of 45,245 women who did not meet the NDDG criteria and were not treated for GDM, we conducted nested case-control studies of three complications of GDM that occurred in their infants: macrosomia (birthweight >4,500 g, n = 494); hypoglycaemia (plasma glucose <2.2 mmo/l, n = 488); and hyperbilirubinaemia (serum bilirubin > or =342 micromol/l (20 mg/dl), n = 578). We compared prenatal glucose levels of the mothers of these infants and mothers of 884 control infants. RESULTS Women with GDM by ADA criteria only (two or more glucose values exceeding the threshold) had an increased risk of having an infant with macrosomia (odds ratio OR = 3.40, 95% CI = 1.55-7.43), hypoglycaemia (OR = 2.61, 95% CI = 0.99-6.92) or hyperbilirubinaemia (OR = 2.22, 95% CI = 0.98-5.04). Glucose levels 1 h after the 100-g glucose challenge that exceeded the ADA threshold were particularly strongly associated with each complication. CONCLUSIONS/INTERPRETATION These results lend support to the ADA recommendations and highlight the importance of the 1-h glucose measurement in a diagnostic test for GDM.
Collapse
|
59
|
Rice JC, Peng T, Kuo YF, Pendyala S, Simmons L, Boughton J, Ishihara K, Nowicki S, Nowicki BJ. Renal allograft injury is associated with urinary tract infection caused by Escherichia coli bearing adherence factors. Am J Transplant 2006; 6:2375-83. [PMID: 16869795 DOI: 10.1111/j.1600-6143.2006.01471.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Urinary tract infections are the most common infection in renal transplant patients and Escherichia coli (E. coli) is the most common clinical isolate. Although acute allograft injury (AAI) secondary to urinary tract infection (UTI) has been reported, the incidence of AAI associated with UTI, the virulence factors express by uropathic E. coli and whether virulence factors are associated with renal allograft outcome have not been described. We collected E. coli from our renal transplant patients with UTI, determined O:H serotypes, P and Dr fimbriae expression and the clinical presentation and allograft function during the UTI and post-UTI period. Pyelonephritis occurred in 40% of our patients, 82% of which had AAI (>20% increase in SCr). Sixty-two percent of E. coli isolates that expressed P fimbriae were associated with AAI, whereas only 29% that did not express P fimbriae had AAI (p = 0.03). The pattern of P fimbriae and O serotypes differed from reported isolates, as the P fimbriae PapG class II and the O25 serotype were the most common. Dr adhesin was expressed on 7 isolates, including 2 of 3 with urosepsis. We propose a unique pattern of uropathogenic serotypes and adherence factors contribute to acute allograft injury in renal transplant patients with UTI.
Collapse
|
60
|
Blakeley JO, Peng T, Ye X, Grossman SA. Dose and duration of dexamethasone in patients with high grade gliomas (HGG): Relationship to steroid myopathy (SM). J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.18517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
18517 Background: Steroids are critical in the management of HGG due to their ability to control peri-tumoral edema. Myopathy is a disabling complication of steroids leading to loss of ambulation and respiratory compromise. We sought to describe the use of steroids in the first 8 months after the diagnosis of HGG and its relationship to SM. Methods: Charts of all adults with HGG diagnosed and treated at Johns Hopkins Hospital from June 2004 to May 2005 were reviewed. Patients who died in less than 8 months were excluded. Starting steroid dose, subsequent documented doses, initial date and dates of change were recorded. Only charts with the phrase “steroid myopathy” were defined as SM positive. Results: Twenty-eight patients met all inclusion criteria. The mean age was 57.2 ± 8.7 years and 19 (67.8%) were males. All patients (100%) received steroids. Dexamethasone was used exclusively. Ninety-three percent of patients received >16mg/day and 36% were on >16mg/day for at least a month. The average daily dose was 15.3 ± 7.1 mg. Mean cumulative dose was 2.8 ± 1.8 grams. The median peak dose was 40mg/day (range 16–120mg/day). Median days on steroids was 224 days (range 5–224 days) from diagnosis and 67.8% of patients were on continuous steroids for 8 months. Eleven (39% [95% CI: 22%-59%]) of the 28 patients were defined as SM. Seven of the 11 (63.6%) SM patients required wheelchairs versus two (11.8%) without SM (p = 0.004). Days on steroid was significantly longer (p = 0.012) in the SM group (214 ± 32 days) versus the non-SM group (155 ± 81days). No strong evidence supported differences between groups in total dose, average daily dose, peak dose or days on high dose steroids. Conclusions: Patients with HGG are exposed to high doses of steroids for long periods. SM was noted in 39% of our patients and most required wheelchairs within 8 months of diagnosis. These figures are likely significant underestimates given the amount of steroids administered and the retrospective nature of this study. Our data confirm prior reports of an association between duration of steroid use and SM. The findings highlight the need to prevent SM using alternate dosing schedules and agents and to develop effective treatment interventions for SM. No significant financial relationships to disclose.
Collapse
|
61
|
Liu Y, Wang Y, Wan C, Zhou W, Peng T, Liu Y, Wang Z, Li G, Cornelisson G, Halberg F. The role of mPer1 in morphine dependence in mice. Neuroscience 2005; 130:383-8. [PMID: 15664694 PMCID: PMC2656444 DOI: 10.1016/j.neuroscience.2004.09.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2004] [Indexed: 12/25/2022]
Abstract
Investigations using Drosophila melanogaster have shown that the circadian clock gene period can influence behavioral responses to cocaine, and the mouse homologues, mPer1 and mPer2, modulate cocaine sensitization and reward. In the present study, we applied DNAzyme targeting mPer1 to interfere the expression of mPer1 in CNS in mice and studied the role of mPer1 on morphine dependence. We found that the DNAzyme could attenuate the expression of mPer1 in CNS in mice. Mice treated with DNAzyme and morphine synchronously did not show preference to the morphine-trained side, whereas the control group did. In contrast, mice treated with DNAzyme after morphine showed preference to the morphine-trained side as well as the control group did. These results indicate that drug dependence seems to be influenced at least partially by mPer1, but mPer1 cannot affect morphine dependence that has been formed.
Collapse
|
62
|
Metz CN, Peng T, Saeed R, Tracey KJ. ACETYLCHOLINE INHIBITS ENDOTHELIAL CELL ACTIVATION IN VITRO. Shock 2003. [DOI: 10.1097/00024382-200306001-00237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
63
|
Li Y, Pan Z, Ji Y, Peng T, Archard LC, Zhang H. Enterovirus replication in valvular tissue from patients with chronic rheumatic heart disease. Eur Heart J 2002; 23:567-73. [PMID: 11922647 DOI: 10.1053/euhj.2001.2837] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIMS To investigate the involvement of enterovirus infection in chronic, rheumatic heart disease. METHODS AND RESULTS Formalin-fixed, paraffin-embedded, surgical samples of valve tissue were examined for the presence of enteroviral RNA and virus capsid protein VP1 by in situ hybridization and immunostaining. Of 53 cases, 33 were patients with chronic rheumatic heart disease and 20 had Marfan's syndrome or degenerative valve disease. Enterovirus RNA was detected in 8 (24.2%) of 33 patients with chronic rheumatic heart disease by in situ hybridization using strand-specific oligonucleotide probes, complementary to conserved sequences in enterovirus genomic (positive strand) RNA. The replication template (negative strand) RNA also was found in seven of these eight cases. The viral capsid protein VP1 was detected in 16 (48.5%) of 33 patients with chronic rheumatic heart disease by immunohistochemistry and correlated with viral RNA detection. Virus was localized generally to valvular tissue. Neither viral RNA nor capsid protein VP1 were found in valvular tissue from any of the 20 comparison cases. CONCLUSIONS This is the first demonstration of detection and localization of both enterovirus RNA and capsid protein in chronic rheumatic heart disease. The presence of negative strand RNA and VP1 indicates enteroviral RNA replication and protein synthesis and suggests an aetiological role of enterovirus in the pathogenesis of chronic rheumatic heart disease.
Collapse
|
64
|
Roche TE, Baker JC, Yan X, Hiromasa Y, Gong X, Peng T, Dong J, Turkan A, Kasten SA. Distinct regulatory properties of pyruvate dehydrogenase kinase and phosphatase isoforms. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2002; 70:33-75. [PMID: 11642366 DOI: 10.1016/s0079-6603(01)70013-x] [Citation(s) in RCA: 197] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mammalian pyruvate dehydrogenase complex (PDC) plays central and strategic roles in the control of the use of glucose-linked substrates as sources of oxidative energy or as precursors in the biosynthesis of fatty acids. The activity of this mitochondrial complex is regulated by the continuous operation of competing pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase phosphatase (PDP) reactions. The resulting interconversion cycle determines the fraction of active (nonphosphorylated) pyruvate dehydrogenase (E1) component. Tissue-specific and metabolic state-specific control is achieved by the selective expression and distinct regulatory properties of at least four PDK isozymes and two PDP isozymes. The PDK isoforms are members of a family of serine kinases that are not structurally related to cytoplasmic Ser/Thr/Tyr kinases. The catalytic subunits of the PDP isoforms are Mg2+-dependent members of the phosphatase 2C family that has binuclear metal-binding sites within the active site. The dihydrolipoyl acetyltransferase (E2) and the dihydrolipoyl dehydrogenase-binding protein (E3BP) are multidomain proteins that form the oligomeric core of the complex. One or more of their three lipoyl domains (two in E2) selectively bind each PDK and PDP1. These adaptive interactions predominantly influence the catalytic efficiencies and effector control of these regulatory enzymes. When fatty acids are the preferred source of acetyl-CoA and NADH, feedback inactivation of PDC is accomplished by the activity of certain kinase isoforms being stimulated upon preferentially binding a lipoyl domain containing a reductively acetylated lipoyl group. PDC activity is increased in Ca2+-sensitive tissues by elevating PDP1 activity via the Ca2+-dependent binding of PDP1 to a lipoyl domain of E2. During starvation, the irrecoverable loss of glucose carbons is restricted by minimizing PDC activity due to high kinase activity that results from the overexpression of specific kinase isoforms. Overexpression of the same PDK isoforms deleteriously hinders glucose consumption in unregulated diabetes.
Collapse
|
65
|
Czarneski J, Meyers J, Peng T, Abraham V, Mick R, Ross SR. Interleukin-4 up-regulates mouse mammary tumor virus expression yet is not required for in vivo virus spread. J Virol 2001; 75:11886-90. [PMID: 11689671 PMCID: PMC114776 DOI: 10.1128/jvi.75.23.11886-11890.2001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mouse mammary tumor virus (MMTV) superantigen induces T-cell production of cytokines, such as interleukin-4, which in turn increase MMTV transcription. However, interleukin-4 is not required for in vivo virus spread, because mice lacking interleukin-4 or the STAT6 transcription factor showed wild-type infection of lymphoid and mammary tissue. In spite of this, mammary tumor incidence was decreased in STAT6 null mice.
Collapse
|
66
|
Hartlapp I, Abe R, Saeed RW, Peng T, Voelter W, Bucala R, Metz CN. Fibrocytes induce an angiogenic phenotype in cultured endothelial cells and promote angiogenesis in vivo. FASEB J 2001; 15:2215-24. [PMID: 11641248 DOI: 10.1096/fj.01-0049com] [Citation(s) in RCA: 194] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Angiogenesis is an ordered process requiring the inter-play of numerous cellular and humoral factors. Studies over the past 20 years have identified several growth factors, cytokines, and enzymes that promote blood vessel formation. Most have revealed how individual factors promote an angiogenic phenotype in endothelial cells in vitro or contribute to blood vessel formation in vivo. However, the fundamental question that remains unanswered is how the cellular microenvironment contributes to angiogenesis. Fibrocytes are a recently characterized mesenchymal cell type isolated from peripheral blood that rapidly enter subcutaneously implanted wound chambers and sites of tissue injury. Here we describe the induction of an angiogenic phenotype in microvascular endothelial cells in vitro and promotion of angiogenesis in vivo by cultured fibrocytes. Fibrocytes constitutively secrete extracellular matrix-degrading enzymes, primarily matrix metalloproteinase 9, which promotes endothelial cell invasion. In addition, fibrocytes secrete several proangiogenic factors including VEGF, bFGF, IL-8, PDGF, and hematopoietic growth factors that promote endothelial cell migration, proliferation, and/or tube formation. By contrast, they do not produce representative antiangiogenic factors. Finally, both autologous fibrocytes and fibrocyte-conditioned media were found to induce blood vessel formation in vivo using the Matrigel angiogenesis model.
Collapse
|
67
|
Bagnasco SM, Peng T, Janech MG, Karakashian A, Sands JM. Cloning and characterization of the human urea transporter UT-A1 and mapping of the human Slc14a2 gene. Am J Physiol Renal Physiol 2001; 281:F400-6. [PMID: 11502588 DOI: 10.1152/ajprenal.2001.281.3.f400] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have isolated and characterized the human homolog of the rat largest urea transporter of the UT-A family (hUT-A1). The 4.2-kb hUT-A1 cDNA encodes a 920-amino acid peptide, which is 89% identical to the rat UT-A1 protein. By Northern hybridization, hUT-A1 expression is detected in the human inner medulla as a approximately 4.4-kb mRNA transcript. By Western analysis, hUT-A1 is identified as a approximately 100-kDa protein in the human inner medulla. By immunohistochemistry, hUT-A1 expression is localized to the inner medullary collecting duct (IMCD). When transfected into HEK-293 cells hUT-A1 cDNA is translated into a approximately 98-kDa protein. Expression of hUT-A1 in Xenopus oocytes results in phloretin-inhibitable uptake of (14)C-urea, which shows only modest stimulation by cAMP, suggesting that in the human IMCD vasopressin may have a limited role in the short-term regulation of hUT-A1-mediated urea transport. We determined the organization of the human Slc14a2 gene and identified 20 exons distributed over approximately 67.5 kb on chromosome 18, from which hUT-A1 and the other human urea transporter, hUT-A2, are transcribed.
Collapse
|
68
|
Wu Y, Hu B, Peng T, Jiang Z. In-situ separation of chromium(III) and chromium(VI) and sequential ETV-ICP-AES determination using acetylacetone and PTFE as chemical modifiers. FRESENIUS' JOURNAL OF ANALYTICAL CHEMISTRY 2001; 370:904-8. [PMID: 11569873 DOI: 10.1007/s002160100806] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-ES) has been used for the sequential determination of Cr(III) and Cr(VI). The method is based on the difference between the chelate reactions of the two Cr species and acetylacetone. Cr(III) chelate was separated from Cr(VI) and determined with use of acetylacetone as chemical modifier. The retained Cr(VI) in graphite tube was analyzed subsequently, after addition of polytetrafluoroethylene (PTFE) as chemical modifier. The different factors affecting the vaporization behavior of Cr(III) acetylacetonate were investigated in detail. The detection limits for Cr (III) and Cr(VI) were 0.56 and 1.4 ng mL(-1), respectively, and relative standard deviations for 0.1 microg mL(-1) Cr(III) and 0.1 microg mL(-1) Cr(VI) were 2.5% (n = 6) and 4.8% (n = 6), respectively. The linear ranges of the calibration curve for both Cr(IIl) and Cr(VI) covered three orders of magnitude. The proposed method was used to analyze water samples with satisfactory results.
Collapse
|
69
|
Feng Z, Li Y, Qiu Z, Li Y, Peng T, Guan X. Preliminary study on immunotoxin for the prevention of Schistosomiasis japonica. Chin Med J (Engl) 2001; 114:772. [PMID: 11780349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
|
70
|
Abe R, Donnelly SC, Peng T, Bucala R, Metz CN. Peripheral blood fibrocytes: differentiation pathway and migration to wound sites. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:7556-62. [PMID: 11390511 DOI: 10.4049/jimmunol.166.12.7556] [Citation(s) in RCA: 786] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Fibrocytes are a distinct population of blood-borne cells that display a unique cell surface phenotype (collagen I+/CD11b+/CD13+/CD34+/CD45RO+/MHC class II+/CD86+) and exhibit potent immunostimulatory activities. Circulating fibrocytes rapidly enter sites of tissue injury, suggesting an important role for these cells in wound repair. However, the regulatory processes that govern the differentiation of blood-borne fibrocytes and the mechanisms that underlie the migration of these cells to wound sites are currently not known. We report herein that ex vivo cultured fibrocytes can differentiate from a CD14+-enriched mononuclear cell population and that this process requires contact with T cells. Furthermore, we demonstrate that TGF-beta1 (1-10 ng/ml), an important fibrogenic and growth-regulating cytokine involved in wound healing, increases the differentiation and functional activity of cultured fibrocytes. Because fibrocytes home to sites of tissue injury, we examined the role of chemokine/chemokine receptor interactions in fibrocyte trafficking. We show that secondary lymphoid chemokine, a ligand of the CCR7 chemokine receptor, acts as a potent stimulus for fibrocyte chemotaxis in vitro and for the homing of injected fibrocytes to sites of cutaneous tissue injury in vivo. Finally, we demonstrate that differentiated, cultured fibrocytes express alpha smooth muscle actin and contract collagen gels in vitro, two characteristic features of wound-healing myofibroblasts. These data provide important insight into the control of fibrocyte differentiation and trafficking during tissue repair and significantly expand their potential role during wound healing.
Collapse
|
71
|
Du J, Brink M, Peng T, Mottironi B, Delafontaine P. Thrombin regulates insulin-like growth factor-1 receptor transcription in vascular smooth muscle: characterization of the signaling pathway. Circ Res 2001; 88:1044-52. [PMID: 11375274 DOI: 10.1161/hh1001.090840] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have previously demonstrated that thrombin upregulation of insulin-like growth factor-1 receptor (IGF-1R) is essential for thrombin-induced mitogenic signaling. To characterize the mechanisms involved, we studied transcription of the IGF-1R gene in rat aortic smooth muscle cells. Thrombin markedly increased IGF-1R mRNA levels, peaking at 3 hours (112+/-7% above control). This effect was mimicked by the hexapeptide SFFLRN (that functions as a tethered ligand) and was blocked by the thrombin inhibitor hirudin. Nuclear run-on assays indicated that thrombin stimulated IGF-1R gene transcription by 2.1-fold, and this was confirmed with the use of actinomycin D. Thrombin-mediated upregulation of IGF-1R mRNA and protein levels was protein kinase C independent but was completely inhibited by the protein tyrosine kinase inhibitor genistein and by the antioxidants N-acetyl-L-cysteine and pyrrolidinedithiocarbamate, suggesting the involvement of reactive oxygen species. The thrombin-induced increase in IGF-1R mRNA was inhibitable by diphenyleneiodonium chloride but not by other inhibitors of cellular oxidase systems, suggesting that NAD(P)H oxidase was necessary for the increase. Furthermore, inhibitors of the epidermal growth factor receptor kinase, Janus kinase-2 kinase, and Src kinase did not block the effect. Thus, thrombin transcriptionally regulates the IGF-1R gene via a redox-sensitive protein tyrosine kinase-dependent pathway that does not require protein kinase C activation. In view of our prior data indicating that IGF-1R density is a critical determinant of vascular smooth muscle cell growth, our findings have particular relevance to understanding mechanisms whereby growth factors such as thrombin regulate vascular proliferation in vivo.
Collapse
MESH Headings
- Animals
- Antioxidants/pharmacology
- Aorta
- Cells, Cultured
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation/drug effects
- Genistein/pharmacology
- Hirudins/pharmacology
- Janus Kinase 2
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- NADH, NADPH Oxidoreductases/antagonists & inhibitors
- NADPH Oxidases
- Onium Compounds/pharmacology
- Protein Kinase C/antagonists & inhibitors
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Proto-Oncogene Proteins
- RNA, Messenger/metabolism
- Rats
- Reactive Oxygen Species/metabolism
- Receptor, IGF Type 1/genetics
- Receptor, IGF Type 1/metabolism
- Receptor, PAR-1
- Receptors, Thrombin/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Thrombin/antagonists & inhibitors
- Thrombin/metabolism
- Thrombin/pharmacology
- Up-Regulation/drug effects
- src-Family Kinases/antagonists & inhibitors
Collapse
|
72
|
Wang X, Sun B, Zhou F, Hu J, Yu X, Peng T. Vitamin D receptor and PCNA expression in severe parathyroid hyperplasia of uremic patients. Chin Med J (Engl) 2001; 114:410-4. [PMID: 11780466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To clarify the role of vitamin D receptor (VDR) expression in parathyroid proliferation and resistance of parathyroid glands to 1,25(OH)2D3 with secondary hyperparathyroidism (SHPT). METHODS This study used archive parathyroid with 7 uremic patients. The expression of proliferation cell nuclear antigen (PCNA) and VDR was evaluated in nineteen-surgically excised parathyroid tissues, including 11 diffuse hyperplasia (DH-type) and 8 nodular hyperplasia (NH-type) of parathyroid glands, by immunohistochemistry (avidin-biotin complex method). RESULTS The weight of parathyroid in SHPT was remarkably increased by 16.1 times. The numbers of parathyroid cells were increased by 1.86 times. The rate of PCNA was remarkably increased in parathyroid hyperplasia with SHPT compared with that in control group [(6.35 +/- 3.36)@1000 vs (1.73 +/- 1.31)@1000, P < 0.001]. The number of PCNA in DH-type was lower than that in NH-type (P < 0.001). The density of VDR in the parathyroid with SHPT was significantly decreased [(40.28 +/- 13.13)% vs (83.79 +/- 3.77)%, P < 0.001], VDR immunoreactivity expression in NH-type was lower than that in DH-type [(27.14 +/- 4.12)% vs (49.84 +/- 7.33)%, P < 0.001]. A significantly negative correlation was found between VDR density and the weight of the parathyroid (r = -0.46, P < 0.05), the same as VDR and PCNA (r = -0.75, P < 0.001). CONCLUSION VDR density was significantly decreased in parathyroid tissue of uremic patients showing nodular hyperplasia compared with that in diffuse hyperplasia and there was significantly negative correlation between VDR density and the weight of the parathyroid, and this may contribute to the progression of SHPT. Furthermore, VDR deficiency may cause the resistance of parathyroid cells to 1,25(OH)2D3, in part.
Collapse
|
73
|
Peng T, Sadusky T, Li Y, Coulton GR, Zhang H, Archard LC. Altered expression of Bag-1 in Coxsackievirus B3 infected mouse heart. Cardiovasc Res 2001; 50:46-55. [PMID: 11282077 DOI: 10.1016/s0008-6363(00)00323-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVE The mechanisms by which Coxsackie B viruses cause myocarditis or dilated cardiomyopathy are not well understood. This study examined changes in the expression of cardiac genes resulting from Coxsackievirus B3 (CVB3) infection of mice. METHODS Mice (five per group) were experimentally infected with CVB3 or mock-infected with diluent. Altered expression of genes was initially identified by cDNA array, and confirmed by semiquantitative RT-PCR, western blot and immunohistochemistry. RESULTS Forty-two up-regulated or down-regulated genes were observed in cDNA arrays carrying 588 known mouse genes. Among these, one down-regulated gene, Bag-1, known to be involved in inhibition of apoptosis and modulation of chaperone activity, was investigated further. Semiquantitative RT-PCR showed that Bag-1 expression was down-regulated by up to 30% in virus-infected mouse heart on day 7 compared to the mock-infected. Cell fractionation and western blot analysis confirmed that Bag-1 isoform p32 was predominant in the cytoplasm of mouse myocardium and down-regulated at 4 days or 7 days after CVB3 infection. In contrast, Bag-1 isoform p50 appeared to increase in the nuclear fraction of mouse heart at 7 days after infection. Down regulated expression and distribution of Bag-1 protein or evidence of apoptosis in the infected mouse heart was demonstrated by immunostaining or histochemistry (TUNEL assay), respectively. CONCLUSION CVB3 infection induced differential expression of Bag-1 in cytoplasmic and nuclear fractions of mouse heart and apoptosis. This may be important in the pathogenesis of enterovirus heart muscle disease.
Collapse
|
74
|
Nakayama Y, Naruse M, Karakashian A, Peng T, Sands JM, Bagnasco SM. Cloning of the rat Slc14a2 gene and genomic organization of the UT-A urea transporter. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1518:19-26. [PMID: 11267655 DOI: 10.1016/s0167-4781(00)00311-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We cloned the Slc14a2 gene and determined the genomic organization of the rat urea transporter UT-A. Slc14a2, the gene encoding the rat UT-A transporter, extends for more that 300 kb. The four known rat mRNA isoforms: UT-A1, UT-A2, UT-A3, and UT-A4 are transcribed from 24 exons. The Slc14a2 genomic map also accounts for 3'-untranslated sequences expressed alternatively in UT-A1, UT-A2, and UT-A3. We previously identified a TATA-less, tonicity-responsive promoter controlling the transcription of UT-A1, UT-A3, and UT-A4 from a single initiation site in the 5'-flanking region of the gene. Here, we describe a second, internal promoter in intron 12, which controls the transcription of UT-A2 starting from exon 13. This region contains a TATA motif upstream from the UT-A2 transcription start site, and shows consensus sequences for the cAMP response element (CRE) and for the tonicity enhancer (TonE) motif. Stimulation by cAMP induces UT-A2 mRNA expression in mIMCD3 cells, and luciferase activity in mIMCD3 cells transfected with those pGL3 constructs including the CRE sequences. Although long-term exposure to hypertonicity induces UT-A2 expression in mIMCD3 cells, hypertonicity does not induce significantly the activity of the promoter in intron 12. In summary, we describe the genomic structure of the rat UT-A urea transporter, encoded by the Slc14a2 gene. Our findings suggest that two promoters regulate transcription of the four UT-A isoforms, and that stimulation of transcription by vasopressin, mediated by cAMP and CRE sequences, and controlled by an intronic promoter, may contribute to the increase in UT-A2 expression during water deprivation.
Collapse
|
75
|
Peng T, Chang G, Wang L, Jiang Z, Hu B. Slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry for the direct determination of metal impurities in aluminium oxide ceramic powders. FRESENIUS' JOURNAL OF ANALYTICAL CHEMISTRY 2001; 369:461-5. [PMID: 11270230 DOI: 10.1007/s002160000664] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A new analytical procedure for the direct determination of metal impurities (Cr, Cu, Fe and V) in aluminium oxide ceramic powders by slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-AES) is reported. A polytetrafluoroethylene (PTFE) emulsion was used as a fluorinating reagent to promote the vaporization of impurity elements in aluminium oxide ceramic powders from the graphite tube. A vaporization stage with a long ramp time and a short hold time provided the possibility of temporal analyte-matrix separation. The experimental results indicated that a 10 microL 1% m/v slurry of aluminium oxide could be destroyed and vaporized completely with 600 micrograms PTFE under the selected conditions. Two aluminium oxide ceramic powder samples were used without any additional pretreatment. Analytical results obtained by using standard addition method with aqueous standard solution were checked by comparison of the results with pneumatic nebulization (PN)-ICP-AES based on the wet-chemical decomposition and analyte-matrix separation. The limits of detection (LODs) between 0.30 microgram g-1 (Fe) and 0.08 microgram g-1 (Cu) were achieved, and, the repeatability of measurements was mainly better than 10%.
Collapse
|