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Shen XZ, Lu Q, Deng L, Yu S, Zhang H, Deng Q, Jiang M, Hu Y, Yao KH, Yang YH. Resistance of Haemophilus influenzae isolates in children under 5 years old with acute respiratory infections in China between 2000 and 2002. J Int Med Res 2007; 35:554-63. [PMID: 17697534 DOI: 10.1177/147323000703500416] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This prospective, three-centre study tested for antimicrobial susceptibility in 898 isolates of Haemophilus influenzae between 2000 and 2002 in Chinese children aged under 5 years with acute upper respiratory tract infection. The average incidence of beta-lactamase production was 12.0%. Overall, 88.0% of isolates were susceptible to ampicillin, 100.0% were susceptible to amoxicillin/clavulanic acid, ceftriaxone, cefuroxime and azithromycin, and 99.0% were susceptible to ciprofloxacin. Isolates from Beijing and Shanghai had a lower susceptibility to tetracycline (57.0% and 61.0%, respectively) compared with those from Guangzhou (81.0%), while trimethoprim/sulfamethoxazole susceptibilities in Shanghai (47.0%) and Guangzhou (54.0%) were significantly higher than in Beijing (35.0%). A total of 34.5% of all the isolates were susceptible to all eight of these antimicrobial agents and 12.8% were multi-drug resistant. Ampicillin resistance increased over the duration of the study. These findings show that beta-lactamase production and ampicillin resistance among isolates from Chinese children with upper respiratory tract infection are increasing, and highlight the strong correlation between ampicillin resistance and resistance to cefaclor, chloramphenicol and tetracycline in H. influenzae isolates.
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252
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Jiang M, Luo Y, Yang S. Stochastic convergence analysis and parameter selection of the standard particle swarm optimization algorithm. INFORM PROCESS LETT 2007. [DOI: 10.1016/j.ipl.2006.10.005] [Citation(s) in RCA: 335] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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253
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Jiang M, Sullivan SM, Walker AK, Strahler JR, Andrews PC, Maddock JR. Identification of novel Escherichia coli ribosome-associated proteins using isobaric tags and multidimensional protein identification techniques. J Bacteriol 2007; 189:3434-44. [PMID: 17337586 PMCID: PMC1855874 DOI: 10.1128/jb.00090-07] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Biogenesis of the large ribosomal subunit requires the coordinate assembly of two rRNAs and 33 ribosomal proteins. In vivo, additional ribosome assembly factors, such as helicases, GTPases, pseudouridine synthetases, and methyltransferases, are also critical for ribosome assembly. To identify novel ribosome-associated proteins, we used a proteomic approach (isotope tagging for relative and absolute quantitation) that allows for semiquantitation of proteins from complex protein mixtures. Ribosomal subunits were separated by sucrose density centrifugation, and the relevant fractions were pooled and analyzed. The utility and reproducibility of the technique were validated via a double duplex labeling method. Next, we examined proteins from 30S, 50S, and translating ribosomes isolated at both 16 degrees C and 37 degrees C. We show that the use of isobaric tags to quantify proteins from these particles is an excellent predictor of the particles with which the proteins associate. Moreover, in addition to bona fide ribosomal proteins, additional proteins that comigrated with different ribosomal particles were detected, including both known ribosomal assembly factors and unknown proteins. The ribosome association of several of these proteins, as well as others predicted to be associated with ribosomes, was verified by immunoblotting. Curiously, deletion mutants for the majority of these ribosome-associated proteins had little effect on cell growth or on the polyribosome profiles.
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Jiang M, Wang R, Wang J, Jin D. A Method of Recognizing Finger Motion Using Wavelet Transform of Surface EMG Signal. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2005:2672-4. [PMID: 17282789 DOI: 10.1109/iembs.2005.1617020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In this paper, an identification method of finger motions using the wavelet transform of multi-channel electromyography (EMG) signal is presented. The first step of this method is to analyze surface EMG signal detected from the subject's upper arm using the multi-resolution of wavelet transform, and extract features using the variance, maximum and mean absolute value of the wavelet coefficients. In this way, a new feature space is established by wavelet coefficients. The second step is to import the feature values into an Artificial Neural Network (ANN) to identify the finger motion. Based on the results of experiments, it is concluded that this method is effective in identification of finger motion. Thus, it provides an alternative approach to use the surface EMG in controlling the finger motion of a multi-fingered prosthetic hand.
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Wei Q, Li M, Fu X, Tang R, Na Y, Jiang M, Li Y. Global analysis of differentially expressed genes in androgen-independent prostate cancer. Prostate Cancer Prostatic Dis 2007; 10:167-74. [PMID: 17199135 DOI: 10.1038/sj.pcan.4500933] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Progression to androgen independent (AI) is the main cause of death in prostate cancer, and the mechanism is still unclear. By reviewing the expression profiles of 26 prostate cancer samples in a holistic view, we found a group of genes differentially expressed in AI compared with androgen-dependent groups (P-value<0.01, t-test). Focusing on apoptosis, proliferation, hormone and angiogenesis, we found a group of genes such as thioredoxin domain containing 5 , tumor necrosis factor receptor superfamily, member 10a , ribosomal protein S19 and Janus kinase 2 upregulated in AI prostate cancer, could play important roles in the transition from AD to AI and could be biomarkers of prognosis.
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Nie X, Zhang YJ, Tian WD, Jiang M, Dong R, Chen JW, Jin Y. Improvement of peripheral nerve regeneration by a tissue-engineered nerve filled with ectomesenchymal stem cells. Int J Oral Maxillofac Surg 2007; 36:32-8. [PMID: 17169530 DOI: 10.1016/j.ijom.2006.06.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 02/27/2006] [Accepted: 06/20/2006] [Indexed: 11/28/2022]
Abstract
Ectomesenchymal stem cells (EMSCs) originate from the cranial neural crest. They are a potential source of neuronal and Schwann cells (SCs) of the peripheral nervous system (PNS) during embryonic development. The third passage of EMSCs enzymatically isolated from the mandibular processes of Sprague-Dawley rats were cultured in forskolin and bovine pituitary extract for 6 days to generate functional Schwann cell phenotypes. Next, 10-mm defects in the sciatic nerves were bridged with an autograft, tissue-engineered nerve filled with differentiated cells in collagen, or a PLGA conduit alone in 18 rats, and the nerve defects of another four rats were left untreated. The regenerated nerves were evaluated by the sciatic functional index (SFI) monthly and by histological analysis 4 months after grafting. The recovery index of the sciatic nerve improved significantly in the autograft and tissue-engineered nerve groups, both of which were superior to the PLGA group. In animals transplanted with the EMSCs, there was greater regeneration than with conduit alone during the same period of implantation. These results show that when EMSCs are transplanted to a peripheral nerve defect they differentiate into supportive cells that contribute to the promotion of axonal regeneration.
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Caquineau C, Leng G, Guan XMM, Jiang M, Van der Ploeg L, Douglas AJ. Effects of alpha-melanocyte-stimulating hormone on magnocellular oxytocin neurones and their activation at intromission in male rats. J Neuroendocrinol 2006; 18:685-91. [PMID: 16879167 DOI: 10.1111/j.1365-2826.2006.01465.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The peptides alpha-melanocyte-stimulating hormone (alpha-MSH) and oxytocin have very similar effects on several behaviours, including male sexual behaviour. Both induce penile erection and enhance copulatory behaviour when given centrally, suggesting that their central actions are not independent. Here, we used intromission as a physiological stimulus to investigate whether some central effects of alpha-MSH during male sexual behaviour are mediated by oxytocin neurones. We used the expression of the immediate-early gene product Fos to investigate oxytocin neurone activation at intromission and after intracerebroventricular (i.c.v.) administration of alpha-MSH (1 microg/5 microl) and studied the effects of i.c.v. administration of a MC4 receptor antagonist on Fos expression and on the latency of male rats to exhibit sexual behaviour in the presence of a receptive female. In rats that showed intromission, Fos was expressed in magnocellular oxytocin neurones in both the paraventricular nucleus (PVN) and the supraoptic nucleus (SON), but there was no significant activation of parvocellular oxytocin neurones of the PVN. Similarly, alpha-MSH increased Fos expression in magnocellular oxytocin neurones but had little or no effect in parvocellular oxytocin neurones. In male rats that achieved intromission, central injection of a MC4 receptor antagonist significantly attenuated the increase in Fos expression in magnocellular oxytocin neurones in both the PVN and the SON and increased mount and intromission latencies compared to vehicle-injected controls. Together, the results indicate that magnocellular oxytocin neurones are involved in the central regulation of male sexual behaviour, and that some of the central effects of alpha-MSH are likely to be mediated by magnocellular oxytocin neurones.
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Yuan J, Lin J, Xu A, Li H, Hu B, Chen J, Yao J, Dong H, Jiang M. Antepartum immunoprophylaxis of three doses of hepatitis B immunoglobulin is not effective: a single-centre randomized study. J Viral Hepat 2006; 13:597-604. [PMID: 16907846 DOI: 10.1111/j.1365-2893.2006.00738.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
To investigate the efficacy of antepartum administration of three doses of hepatitis B immunoglobulin (HBIg), currently being used in China, 250 pregnant women who were seropositive for hepatitis B e antigen (HBeAg) were randomly divided into study (117 cases) and control groups (133 cases). Subjects in the study group received HBIg 400 IU intramuscularly once a month at the third, second and first month before delivery; subjects in the control group received no antepartum treatment. All neonates received passive-active immunization after birth. The maternal hepatitis B virus (HBV) markers, hepatitis B surface antigen (HBsAg) titres and HBV deoxyribonucleic acid (DNA) levels were measured at week 28 of gestation (before the antepartum treatment) and at labour; the neonatal serum HBV markers were detected at birth and at 12 months after birth. No side-effects were found in any of the women or their neonates. No statistical differences were seen between the maternal HBsAg and HBV DNA levels of the study and control groups at labour nor the protective efficacy rates of postnatal immunoprophylaxis at 12 months after birth (P > 0.05, respectively). To conclude, antepartum administration of three doses of HBIg for the HBeAg-positive women is inefficacious.
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Xu A, Jiang M, Narayanan N. A16. Calmodulin triggers Cardiac SR Ca2+ pump function by disrupting Ca2+-ATPase-phopholamban interaction. J Mol Cell Cardiol 2006. [DOI: 10.1016/j.yjmcc.2006.03.356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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260
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Jiang M, Xu A, Narayanan N. A12. Thyroid hormone down regulates the expression and function of CaM kinase II in the rabbit heart. J Mol Cell Cardiol 2006. [DOI: 10.1016/j.yjmcc.2006.03.326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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261
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Zhang M, Liu J, Jiang M, Wu DM, Sonawane K, Guy HR, Tseng GN. Interactions between charged residues in the transmembrane segments of the voltage-sensing domain in the hERG channel. J Membr Biol 2006; 207:169-81. [PMID: 16550488 DOI: 10.1007/s00232-005-0812-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2005] [Revised: 10/09/2005] [Indexed: 11/30/2022]
Abstract
Studies on voltage-gated K channels such as Shaker have shown that positive charges in the voltage-sensor (S4) can form salt bridges with negative charges in the surrounding transmembrane segments in a state-dependent manner, and different charge pairings can stabilize the channels in closed or open states. The goal of this study is to identify such charge interactions in the hERG channel. This knowledge can provide constraints on the spatial relationship among transmembrane segments in the channel's voltage-sensing domain, which are necessary for modeling its structure. We first study the effects of reversing S4's positive charges on channel activation. Reversing positive charges at the outer (K525D) and inner (K538D) ends of S4 markedly accelerates hERG activation, whereas reversing the 4 positive charges in between either has no effect or slows activation. We then use the 'mutant cycle analysis' to test whether D456 (outer end of S2) and D411 (inner end of S1) can pair with K525 and K538, respectively. Other positive charges predicted to be able, or unable, to interact with D456 or D411 are also included in the analysis. The results are consistent with predictions based on the distribution of these charged residues, and confirm that there is functional coupling between D456 and K525 and between D411 and K538.
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Jiang M, Wei Q, Wang J, Du Q, Yu J, Zhang L, Dong Z. Regulation of PUMA-alpha by p53 in cisplatin-induced renal cell apoptosis. Oncogene 2006; 25:4056-66. [PMID: 16491117 DOI: 10.1038/sj.onc.1209440] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nephrotoxicity is a major side effect of cisplatin, a widely used cancer therapy drug. Depending on its concentration, cisplatin induces necrosis or apoptosis of tubular cells in the kidneys, whereas the underlying injury mechanism is unclear. Our recent work has suggested a critical role for p53 in cisplatin-induced tubular cell apoptosis; nevertheless, the apoptotic events triggered by p53 remain elusive. The current study has examined Bcl-2 family proteins, critical regulators of apoptosis that may be subjected to p53 regulation. Following cisplatin treatment, the expression of Bcl-xL, an antiapoptotic molecule, was suppressed, while the expression of Bak, a proapoptotic molecule, increased slightly. Of interest, PUMA-alpha, a newly identified p53-responsive proapoptotic Bcl-2 family protein, was drastically induced by cisplatin. PUMA-alpha induction preceded or paralleled the development of apoptosis. Induced PUMA-alpha was localized in mitochondria and appeared to antagonize Bcl-xL via molecular interaction. PUMA-alpha induction during cisplatin treatment was attenuated by pifithrin-alpha, a pharmacological inhibitor of p53, which was accompanied by the amelioration of Bax activation, cytochrome c release and apoptosis. Moreover, PUMA-alpha induction was suppressed by dominant-negative p53. Importantly, cisplatin-induced apoptosis was ameliorated in PUMA-alpha knockout cells. In vivo, cisplatin induced PUMA-alpha in the kidneys, and the inductive response was abrogated in p53-deficient animals. Together, this study has demonstrated the first compelling evidence for the involvement of PUMA-alpha in p53-mediated renal cell apoptosis during cisplatin nephrotoxicity.
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Hesketh T, Li L, Ye X, Wang H, Jiang M, Tomkins A. HIV and syphilis in migrant workers in eastern China. Sex Transm Infect 2006; 82:11-4. [PMID: 16461594 PMCID: PMC2563835 DOI: 10.1136/sti.2004.014043] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2005] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE To measure the prevalence of HIV and syphilis in migrant and urban workers in eastern China, and to determine their knowledge and attitudes towards HIV. METHODS A cross sectional survey involving dried blood spot testing and self completion questionnaires. Migrants and urban workers in 39 work units in two districts of Hangzhou, Zhejiang Province, were recruited. Respondents completed a questionnaire about knowledge and attitudes towards HIV. Testing for antibodies to HIV-1 and syphilis was carried out on dried blood spots using a gelatin particle agglutination technique. RESULTS Data were obtained from 4148 migrants and 2197 urban workers. There were no HIV infections detected in either the migrant or urban populations. Syphilis was detected, but the prevalence was not significantly different between urban workers (0.68%, 95% CI: 0.35 to 1.02) and migrant workers (0.48%, 95% CI 0.26 to 0.66, p = 0.07). 36% of the migrants had migrated with a partner, and 7% had also migrated with children. Urban workers were consistently more knowledgeable than migrants about HIV, but knowledge of the major modes of transmission was good in both groups. Traditional attitudes to sexual behaviour were still pervasive in both groups and attitudes towards individuals with HIV were generally intolerant. The use of sex workers appears rare and no more common in migrants than urban workers. CONCLUSION At present HIV is probably not spreading in the internal migrant population in eastern China. Syphilis is a problem in both the migrant and urban populations. The tendency to migrate with partners makes migrants relatively low risk for engaging in casual sex.
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Ellis DE, Terra J, Warschkow O, Jiang M, González GB, Okasinski JS, Bedzyk MJ, Rossi AM, Eon JG. A theoretical and experimental study of lead substitution in calcium hydroxyapatite. Phys Chem Chem Phys 2006; 8:967-76. [PMID: 16482339 DOI: 10.1039/b509254j] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Characterization of lead substitution for calcium in hydroxyapatite (CaHA) is carried out, using experimental techniques and Density Functional theoretical (DFT) analyses. Theoretical modeling is used to obtain information of the Pb chemical environment for occupancy at either Ca(I) or Ca(II) sites of CaHA. Effects of the larger ionic radius of Pb(+2) compared to Ca(+2) are apparent in embedded cluster calculations of local chemical bonding properties. DFT periodic planewave pseudopotential studies are used to provide first-principles predictions of local structural relaxation and site preference for Pb(x)Ca(10-x)HA over the composition range x< or = 6. General characteristics of the polycrystalline material are verified by X-ray diffraction and FTIR analysis, showing the presence of a single phase of CaHA structure. A short range structure around lead is proposed in order to interpret the Pb L-edge EXAFS spectrum of the solid solution Ca(6.6)Pb(3.4)HA. In this concentration we observe that lead mainly occupies Ca(II) sites; the EXAFS fit slightly favors Pb clustering, while theory indicates the importance of Pb-Pb avoidance on site (II).
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Ohwaki K, Bujo H, Jiang M, Yamazaki H, Saito Y. Tu-P7:277 Secreted soluble form of LR11, and LDL receptor gene family member, is a potent regulator of macrophage adhesion and smooth muscle cell migration. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)80980-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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266
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Jiang M, Bujo H, Yamazaki H, Kanaki T, Schneider W, Saito Y. Th-W57:7 Pitavastatin inhibits intimal thickness through the attenuation of LR11/UPA receptor-mediated migration of vascular smooth muscle cells. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)81928-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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267
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Jiang M, Swann JW. A role for L-type calcium channels in the maturation of parvalbumin-containing hippocampal interneurons. Neuroscience 2005; 135:839-50. [PMID: 16154277 DOI: 10.1016/j.neuroscience.2005.06.073] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 06/09/2005] [Accepted: 06/16/2005] [Indexed: 10/25/2022]
Abstract
While inhibitory interneurons are well recognized to play critical roles in the brain, relatively little is know about the molecular events that regulate their growth and differentiation. Calcium ions are thought to be important in neuronal development and L-type voltage gated Ca(+2) channels have been implicated in activity-dependent mechanisms of early-life. However, few studies have examined the role of these channels in the maturation of interneurons. The studies reported here were conducted in hippocampal slice cultures and indicate that the L-type Ca(+2) channel agonists and antagonists accelerate and suppress respectively the growth of parvalbumin-containing interneurons. The effects of channel blockade were reversible suggesting they are not the result of interneuronal cell death. Results from immunoblotting showed that these drugs have similar effects on the expression of the GABA synthetic enzymes, glutamic acid decarboxylase65, glutamic acid decarboxylase67 and the vesicular GABA transporter. This suggests that L-type Ca(+2) channels regulate not only parvalbumin expression but also interneuron development. These effects are likely mediated by actions on the interneurons themselves since the alpha subunits of L-type channels, voltage-gated calcium channel subunit 1.2 and voltage-gated calcium channel subunit 1.3 were found to be highly expressed in neonatal mouse hippocampus and co-localized with parvalbumin in interneurons. Results also showed that while these interneurons can contain either subunit, voltage-gated calcium channel subunit 1.3 was more widely expressed. Taken together results suggest that an important subset of developing interneurons expresses L-type Ca(+2) channels alpha subunits, voltage-gated calcium channel subunit 1.2 and especially voltage-gated calcium channel subunit 1.3 and that these channels likely regulate the development of these interneurons in an activity-dependent manner.
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O’Keefe W, Jiang M, Ng F, Rempel G. Liquid phase kinetics for the selective hydrogenation of mesityl oxide to methyl isobutyl ketone in acetone over a Pd/Al2O3 catalyst. Chem Eng Sci 2005. [DOI: 10.1016/j.ces.2005.02.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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269
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Metzger D, Imai T, Jiang M, Takukawa R, Desvergne B, Wahli W, Chambon P. Functional role of RXRs and PPARgamma in mature adipocytes. Prostaglandins Leukot Essent Fatty Acids 2005; 73:51-8. [PMID: 15936932 DOI: 10.1016/j.plefa.2005.04.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The peroxisome proliferator-activated receptor gamma (PPARgamma) is abundantly expressed in adipocytes, and plays an important role in adipocyte differentiation and fat accretion. It is a heterodimeric partner of the retinoid X receptors alpha, beta and gamma, which are also expressed in the adipose tissue. As lethality of PPARgamma(-/-) and RXRalpha(-/-) mouse fetuses precluded the analysis of PPARgamma and RXRalpha functions in mature adipocytes, we generated RXRalpha(ad-/-) and PPARgamma(ad-/-) mice, in which RXRalpha and PPARgamma are selectively ablated in adult adipocytes, respectively. Even though the adiposity of RXRalpha(ad-/-) mice is similar to that of control mice when fed a regular diet, they are resistant to chemically and dietary-induced obesity. However, mature adipocytes lacking either both RXRalpha and RXRgamma or PPARgamma die, and are replaced by newly formed adipocytes. Thus, in adipocytes, RXRalpha is essential for lipogenesis, but RXRgamma can functionally replace RXRalpha for the adipocyte vital functions exerted by PPARgamma/RXR heterodimers.
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Jiang M, Deng L, Chen G. High Ca(2+)-phosphate transfection efficiency enables single neuron gene analysis. Gene Ther 2004; 11:1303-11. [PMID: 15229630 DOI: 10.1038/sj.gt.3302305] [Citation(s) in RCA: 55] [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
Introducing exogenous genes into cells is one of the most important molecular techniques to study gene functions. Comparing to other type of cells, neurons are more difficult to transfect with cDNAs because they are very sensitive to microenvironmental changes. Among various gene transfer techniques, the Ca(2+)-phosphate transfection method is one of the most popular tools in neuroscience research because of its low cell toxicity and easiness to use. However, it is well known that the Ca(2+)-phosphate transfection efficiency in neurons is very low, typically in the range of 1-5%, which has limited its applications in gene functional analyses. Here we report a novel Ca(2+)-phosphate transfection protocol that dramatically increased the transfection efficiency by 10-fold, up to 60%, while maintaining low cell toxicity. The critical factors are the formation of homogenous snow-like precipitate with particle size about 1-3 microm and the subsequent removal of the precipitate. Using this new transfection protocol, we were able to routinely transfect single autaptic neurons in hippocampal microisland cultures and combine it with electrophysiology and fluorescent imaging methods to study gene functions. This high efficiency, low toxicity, and simple to use gene transfer method will have a broad application in gene research at the single cell level.
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Jiang M, Xu A, Jones DL, Narayanan N. Coordinate downregulation of CaM kinase II and phospholamban accompanies contractile phenotype transition in the hyperthyroid rabbit soleus. Am J Physiol Cell Physiol 2004; 287:C622-32. [PMID: 15115706 DOI: 10.1152/ajpcell.00352.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study investigated the effects of l-thyroxine-induced hyperthyroidism on Ca2+/calmodulin (CaM)-dependent protein kinase (CaM kinase II)-mediated sarcoplasmic reticulum (SR) protein phosphorylation, SR Ca2+pump (Ca2+-ATPase) activity, and contraction duration in slow-twitch soleus muscle of the rabbit. Phosphorylation of Ca2+-ATPase and phospholamban (PLN) by endogenous CaM kinase II was found to be significantly lower (30–50%) in soleus of the hyperthyroid compared with euthyroid rabbit. Western blotting analysis revealed higher levels of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) 1 (∼150%) Ca2+pump isoform, unaltered levels of SERCA2 Ca2+pump isoform, and lower levels of PLN (∼50%) and δ-, β-, and γ-CaM kinase II (40 ∼ 70%) in soleus of the hyperthyroid rabbit. SR vesicles from hyperthyroid rabbit soleus displayed approximately twofold higher ATP-energized Ca2+uptake and Ca2+-stimulated ATPase activities compared with that from euthyroid control. The Vmaxof Ca2+uptake (in nmol Ca2+·mg SR protein−1·min−1: euthyroid, 818 ± 73; hyperthyroid, 1,649 ± 90) but not the apparent affinity of the Ca2+-ATPase for Ca2+(euthyroid, 0.97 ± 0.02 μM, hyperthyroid, 1.09 ± 0.04 μM) differed significantly between the two groups. CaM kinase II-mediated stimulation of Ca2+uptake by soleus muscle SR was ∼60% lower in the hyperthyroid compared with euthyroid. Isometric twitch force of soleus measured in situ was significantly greater (∼36%), and the time to peak force and relaxation time were significantly lower (∼30–40%), in the hyperthyroid. These results demonstrate that thyroid hormone-induced transition in contractile properties of the rabbit soleus is associated with coordinate downregulation of the expression and function of PLN and CaM kinase II and selective upregulation of the expression and function of SERCA1, but not SERCA2, isoform of the SR Ca2+pump.
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Jiang M, Han D. Auxiliary liver-heart transplantation in the rat: a new microsurgical model inducing tolerance. Transplant Proc 2004; 36:1607-9. [PMID: 15251395 DOI: 10.1016/j.transproceed.2004.04.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To establish a model of immunological tolerance induced by simultaneous auxiliary liver transplantation and heterotopic heart transplantations using PVG and DA rats as donors and recipients respectively, to provide a new method for the research of liver transplantation. METHODS The recipient's whole portal vein blood was transfered to the auxiliary liver allograft. The donor's heart was transplanted to the recipient's abdominal cavity by end-to-side anastomosis of the donor aorta and pulmonary artery to the recipient aorta and vena cava, respectively. RESULTS In the syngeneic control group and the test group the recipient rats and their transplanted hearts both survived more than 100 days, while the hearts of alloheart control group only survived 6 days. The weight of the liver graft increased slowly. CONCLUSIONS In the presence of recipient liver, the auxiliary liver graft functioned well to induce tolerance. At 100 days, the auxiliary liver graft had increased in volume and weight with maintenance of its tolerance-inducing effects.
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Wang L, Jiang M, Wang E, Duan L, Hao N, Lan Y, Xu L, Li Z. Preparation and characterization of the nanoporous ultrathin multilayer films based on molybdenum polyoxometalate (Mo38)n. J SOLID STATE CHEM 2003. [DOI: 10.1016/s0022-4596(03)00277-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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274
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Jiang M, Zhang J. Cross-talk between calcium and reactive oxygen species originated from NADPH oxidase in abscisic acid-induced antioxidant defence in leaves of maize seedlings. PLANT, CELL & ENVIRONMENT 2003; 26:929-939. [PMID: 12803620 DOI: 10.1046/j.1365-3040.2003.01025.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The signal interactions between calcium (Ca2+) and reactive oxygen species (ROS) originated from plasma membrane NADPH oxidase in abscisic acid (ABA)-induced antioxidant defence were investigated in leaves of maize (Zea mays L.) seedlings. Treatment with ABA led to significant increases in the activity of plasma membrane NADPH oxidase, the production of leaf O2-, and the activities of several antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR). However, such increases were blocked by the pretreatment with Ca2+ chelator EGTA or Ca2+ channel blockers La3+ and verapamil, and NADPH oxidase inhibitors such as diphenylene iodonium (DPI), imidazole and pyridine. Treatment with Ca2+ also significantly induced the increases in NADPH oxidase activity, O2- production and the activities of antioxidant enzymes, and the increases were arrested by pretreatment with the NADPH oxidase inhibitors. Treatment with oxidative stress induced by paraquat, which generates O2-, led to the induction of antioxidant defence enzymes, and the up-regulation was suppressed by the pretreatment of Ca2+ chelator and Ca2+ channel blockers. Our data suggest that a cross-talk between Ca2+ and ROS originated from plasma membrane-bound NADPH oxidase is involved in the ABA signal transduction pathway leading to the induction of antioxidant enzyme activity, and Ca2+ functions upstream as well as downstream of ROS production in the signal transduction event in plants.
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275
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Wan XW, Jiang M, Cao HF, He YQ, Liu SQ, Qiu XH, Wu MC, Wang HY. The alteration of PTEN tumor suppressor expression and its association with the histopathological features of human primary hepatocellular carcinoma. J Cancer Res Clin Oncol 2003; 129:100-6. [PMID: 12669234 DOI: 10.1007/s00432-002-0410-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2002] [Accepted: 12/02/2002] [Indexed: 10/25/2022]
Abstract
PURPOSE Although deletions or inactivating mutations of the tumor suppressor gene PTEN (phosphatase and tensin homolog deleted on chromosome 10) are involved in the development of a variety of tumors including glioblastoma, melanoma, prostate cancer, breast cancer, endometrial cancers etc., the role of PTEN expression in human primary hepatocellular carcinoma (HCC) has not yet been clarified. The aim of this study is to investigate the involvement of PTEN mRNA and protein expression in HCC. METHODS The level of PTEN mRNA expression in HCC specimens was analyzed by Northern blot. PTEN poly-clonal antibody was raised by immunizing New Zealand white rabbit with (His)(6)-tagged PTEN fusion protein and characterized by Western blot. The level of PTEN protein expression was determined by immunohistochemistry. The significance of PTEN in HCC was analyzed by comparing its expression level with the clinicopathological parameters of HCC patients. RESULTS Four transcripts of PTEN mRNA at 5.5 kb, 4.4 kb, 2.4 kb, and 1.8 kb were detected in most para-carcinoma liver tissues, and the expression level of PTEN mRNA in carcinoma liver tissues was found to decrease significantly. The poly-clonal antibody raised against histidine-tagged fusion PTEN protein showed specific immuno-reactivity to PTEN protein. Using the specific poly-clonal antibody prepared and characterized by ourselves, we found that PTEN protein was significantly down-regulated in HCC tissues compared with paired para-carcinoma tissues. The protein expression of PTEN is negatively associated with the pathological grading and presence of cancer thrombus of HCC. CONCLUSIONS Down-regulation of PTEN expression may play an important role in the development of HCC and the level of PTEN expression may be a potential adjuvant parameter in forecasting the progression and prognosis of HCC patients.
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