826
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Huang L, Gerber M, Taylor H, Lu J, Tapaszi E, Wutkowski M, Hill M, Lewis C, Harvey A, Herndon A, Wei M, Rusa C, Tonelli A. Creation of novel polymer materials by processing with inclusion compounds. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/1521-3900(200112)176:1<129::aid-masy129>3.0.co;2-m] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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827
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Ding H, Wang G, Lei W, Wang R, Huang L, Xia Q, Wu J. Non-invasive quantitative assessment of oxidative metabolism in quadriceps muscles by near infrared spectroscopy. Br J Sports Med 2001; 35:441-4. [PMID: 11726485 PMCID: PMC1724436 DOI: 10.1136/bjsm.35.6.441] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Near infrared spectroscopy can be used in non-invasive monitoring of changes in skeletal muscle oxygenation in exercising subjects. OBJECTIVE To evaluate whether this method can be used to assess metabolic capacity of muscles. Two distinctive variables abstracted from a curve of changes in muscle oxygenation were assessed. METHODS Exercise on a cycle ergometer was performed by 18 elite male athletes and eight healthy young men. A measuring probe was placed on the skin of the quadriceps muscle to measure reflected light at two wavelengths (760 and 850 nm), so that the relative index of muscle oxygenation could be calculated. Exercise intensity was increased from 50 W in 50 W increments until the subject was exhausted. During exercise, changes in muscle oxygenation and blood lactate concentration were recorded. The following two variables for assessment of muscle oxygenation were then abstracted and analysed by plotting curves of changes in muscle oxygenation: the rate of recovery of muscle oxygen saturation (R(R)) and the relative value of the effective decrease in muscle oxygenation (D(eff)). RESULTS Data analysis showed a correlation between muscle oxygenation and blood lactate concentration at the various exercise intensities and verified the feasibility of the experiment. Data for the athletes were compared with those for the controls using the Aspin-Welch test of significance; t = 2.3 and 2.86 for R(R) and D(eff) respectively. There were significant differences (p = 0.05) between the athletes and the control group with respect to these two variables. CONCLUSION R(R) and D(eff) may be distinctive variables that can be used to characterise muscle oxidative metabolism during human body movement.
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828
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Huang L, Juneja VK. A new kinetic model for thermal inactivation of microorganisms: development and validation using Escherichia coli O157:H7 as a test organism. J Food Prot 2001; 64:2078-82. [PMID: 11770643 DOI: 10.4315/0362-028x-64.12.2078] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A new kinetic model has been proposed to simulate the nonlinear behavior of survivor curves frequently observed in thermal inactivation of microorganisms. This model incorporates a time component into the first-order inactivation kinetics and is capable of describing the linear, convex, and concave survivor curves. The model was validated using Escherichia coli O157:H7 as a test microorganism. Ground beef (93% lean) samples inoculated to 10(7) to 10(8) CFU/g of meat were subjected to immersion heating at 55, 57.5, 60, 62.5, and 65 degrees C, respectively, in a water bath. All the survivor curves in this study showed upward concavity. Linear and nonlinear regressions were used to fit the survivor curves to the linear first-order inactivation kinetics and the proposed model. Analyses showed that the new kinetic model provides a much better estimate of the thermal inactivation behavior of E. coli O157:H7 in ground beef.
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829
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Huang L, Mivechi NF, Moskophidis D. Insights into regulation and function of the major stress-induced hsp70 molecular chaperone in vivo: analysis of mice with targeted gene disruption of the hsp70.1 or hsp70.3 gene. Mol Cell Biol 2001; 21:8575-91. [PMID: 11713291 PMCID: PMC100019 DOI: 10.1128/mcb.21.24.8575-8591.2001] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The murine hsp70 gene family includes the evolutionarily conserved hsp70.1 and hsp70.3 genes, which are the major proteins induced by heat and other stress stimuli. hsp70.1 and hsp70.3 encode identical proteins which protect cells and facilitate their recovery from stress-induced damage. While the hsp70 gene family has been widely studied and the roles of the proteins it encodes as molecular chaperones in a range of human pathologies are appreciated, little is known about the developmental regulation of hsp70.1 and hsp70.3 expression and the in vivo biological function of their products. To directly study the physiological role of these proteins in vivo, we have generated mice deficient in heat shock protein 70 (hsp70) by replacing the hsp70.1 or hsp70.3 gene with an in-frame beta-galactosidase sequence. We report here that the expression of hsp70.1 and hsp70.3 is developmentally regulated at the transcriptional level, and an overlapping expression pattern for both genes is observed during embryo development and in the tissues of adult mice. hsp70.1-/- or hsp70.3-/- mice are viable and fertile, with no obvious morphological abnormalities. In late embryonic stage and adult mice, both genes are expressed constitutively in tissues exposed directly to the environment (the epidermis and cornea) and in certain internal organs (the epithelium of the tongue, esophagus, and forestomach, and the kidney, bladder, and hippocampus). Exposure of mice to thermal stress results in the rapid induction and expression of hsp70, especially in organs not constitutively expressing hsp70 (the liver, pancreas, heart, lung, adrenal cortex, and intestine). Despite functional compensation in the single-gene-deficient mice by the intact homologous gene (i.e., hsp70.3 in hsp70.1-/- mice and vice versa), a marked reduction in hsp70 protein expression was observed in tissues under both normal and heat stress conditions. At the cellular level, inactivation of hsp70.1 or hsp70.3 resulted in deficient maintenance of acquired thermotolerance and increased sensitivity to heat stress-induced apoptosis. The additive or synergistic effects exhibited by coexpression of both hsp70 genes, and the evolutionary significance of the presence of both hsp70 genes, is hence underlined.
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830
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Jiang T, Liu S, Tan M, Huang F, Sun Y, Dong X, Guan W, Huang L, Zhou F. The phase-shift mutation in the glucocorticoid receptor gene: potential etiologic significance of neuroendocrine mechanisms in lupus nephritis. Clin Chim Acta 2001; 313:113-7. [PMID: 11694247 DOI: 10.1016/s0009-8981(01)00661-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Glucocorticoid (GC), a mediator of the hypothalamo-pituitary-adrenal axis, has been found to play an important role in maintaining the stability of immune endo-environment of the body. The pathogenesis of lupus nephritis, an autoimmune disease, is thought to be related to the intrinsic hyposensitivity to GC secreted by adrenal gland, and impairs the regulation of the immuno-neuro-endocrine axis. METHODS To test this hypothesis, we examined the response of 39 clinic patients with lupus nephritis to GC and analyzed the molecular structure and function of the GC receptor (GR) on peripheral blood mononuclear cells. RESULTS There was no difference in the level of ACTH, GC and ligand affinity of GR between the patients and the controls. The GR number on mononuclear cells of lupus patients was lower than that of the controls. There was no difference in GR number between the patients with heterogeneous response, i.e. sensitive, dependent and resistance, to GC. The analysis of exon 9 of the GC receptor with PCR-amplified single strand conformation polymorphism (PCR-SSCP) method showed the polymorphism in exon 9 of GC receptor in 8 of the 39 lupus nephritis patients. DNA sequence analysis revealed an adenine insertion at the 2439 base pair of the GC receptor gene. This phase-shift mutation caused an additional 20 amino acids being translated into protein of GC receptor. CONCLUSION The decreased number of GC receptor and the molecular variation of GR on mononuclear cells could explain the phenomenon of GC resistance, potentially to endogenous GC, which suggested an etiological significance of neuro-endocrine-immune mechanism in lupus nephritis. This may be useful in the design of lupus nephritis therapy.
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831
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Huang L, Apkarian RP, Chaikof EL. High-resolution analysis of engineered type I collagen nanofibers by electron microscopy. SCANNING 2001; 23:372-375. [PMID: 11770932 DOI: 10.1002/sca.4950230603] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Collagen nanofibers were generated at ambient temperature and pressure by electrospinning a 1 wt% solution of type I collagen and polyethylene oxide. Products were imaged with high-resolution scanning electron microscopy (HRSEM) at medium (approximately 30,000 x) and high magnifications (approximately 100,000 x) and with transmission electron microscopy (TEM). The capacity to produce collagen nanofibers may lead to the generation of extracellular matrix-based fabrics with applications in the fields of wound healing and tissue engineering.
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832
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Liu F, Huang L. Improving plasmid DNA-mediated liver gene transfer by prolonging its retention in the hepatic vasculature. J Gene Med 2001; 3:569-76. [PMID: 11778903 DOI: 10.1002/jgm.222] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Naked DNA is the simplest and safest method to deliver genes to the liver. In this study, we demonstrate that significant gene expression could be achieved in the liver by transiently restricting blood flow through the liver immediately following peripheral intravenous injection of plasmid DNA. METHODS Mice were intravenously (tail vein) injected with plasmid DNA in 100 microl of saline (0.9% NaCl) immediately followed by 8 s of occlusion of blood flow through the liver. The occlusion of blood flow was performed by using a clip at either the vena cava (VC) or at the portal vein and hepatic artery (PV+HA). Alternatively, the VC was clamped for 4 s followed by clamping the PV+HA for 4 s (VC and PV+HA). RESULTS Gene transfer to the liver was completed after blood flow through the liver was blocked for as short as 1 s. Up to 560 pg of luciferase protein per mg of extracted protein was observed from the liver after a single injection of 80 microg of plasmid DNA. Gene expression was increased more than 50-fold by the combination of clamping and electroporation. CONCLUSION This is the first demonstration of gene transfer to the liver via systemic administration without using any carrier system or physical force. Also, the technique provides new insights into the mechanism of hepatic gene transfer.
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833
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Mu L, Yan Y, Li S, Li Y, Huang L, Ling Y. Transparent morphology of the thoracoabdominal wall. J Reconstr Microsurg 2001; 17:611-4. [PMID: 11740657 DOI: 10.1055/s-2001-18816] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The transverse rectus abdominis myocutaneous (TRAM) flap has become the gold standard for autologous breast reconstruction in the last decade. The deep inferior epigastric perforator (DIEP) flap is a refinement of the conventional myocutaneous flap, which is based on anatomic studies of the abdominal wall. These authors have performed a transparent morphologic study of the abdominothoracic wall, in order to visualize the vessel architecture and relationships. The methodology of specimen processing, the anatomic findings, and modifications of surgical incisions are illustrated and discussed.
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834
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Polli JW, Wring SA, Humphreys JE, Huang L, Morgan JB, Webster LO, Serabjit-Singh CS. Rational use of in vitro P-glycoprotein assays in drug discovery. J Pharmacol Exp Ther 2001; 299:620-8. [PMID: 11602674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
P-glycoprotein (Pgp) affects the absorption, distribution, and clearance of a variety of compounds. Thus, identification of compounds that are Pgp substrates can aid drug candidate selection and optimization. Our goal was to evaluate three assays used to determine whether compounds are Pgp substrates. Sixty-six compounds were tested in monolayer efflux, ATPase, and calcein-AM assays. Assay results yielded two categories of compounds. Category I (n = 35) exhibited concordance across the assays. Category II (n = 31) revealed differences among the assays that related to the apparent permeability (P(app)) of the compounds. Within category II, two groups were discerned based on the absence (group IIA, n = 10, nontransported substrates) or presence (group IIB, n = 21, transported substrates) of monolayer efflux. Detection of efflux (group IIB) was associated with compounds having low/moderate P(app) values (mean = 16.6 nm/s), whereas inability to detect efflux (group IIA) was associated with compounds having high P(app) values (mean = 535 nm/s). The calcein-AM and ATPase assays revealed Pgp interactions for highly permeable group IIA compounds but were less responsive than monolayer efflux for low/moderate P(app) compounds of group IIB. All assays detected substrates across a broad range of P(app), but the efflux assay was more prone to fail at high P(app), whereas the calcein-AM and ATPase assays were more prone to fail at low P(app). When P(app) is low, efflux is a greater factor in the disposition of Pgp substrates. The efflux assay is more reliable at low/moderate P(app) and is the method of choice for evaluating drug candidates despite low throughput and reliance on liquid chromatography with tandem mass spectrometry.
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835
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Donohue KD, Huang L, Burks T, Forsberg F, Piccoli CW. Tissue classification with generalized spectrum parameters. ULTRASOUND IN MEDICINE & BIOLOGY 2001; 27:1505-1514. [PMID: 11750750 DOI: 10.1016/s0301-5629(01)00468-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This paper presents performance comparisons between breast tumor classifiers based on parameters from a conventional texture analysis (CTA) and the generalized spectrum (GS). The computations of GS-based parameters from radiofrequency (RF) ultrasonic scans and their relationship to underlying scatterer properties are described. Clinical experiments demonstrate classifier performances using 22 benign and 24 malignant breast mass regions taken from 40 patients. Linear classifiers based on parameters from the front edge, back edge and interior tumor regions are examined. Results show significantly better performances for GS-based classifiers, with improvements in empirical receiver operating characteristic (ROC) areas of greater than 10%. The ROC curves show GS-based classifiers achieving a 90% sensitivity level at 50% specificity when applied to the back-edge tumor regions, an 80% sensitivity level at 65% specificity when applied to the front-edge tumor regions, and a 100% sensitivity level at 45% specificity when applied to the interior tumor regions.
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836
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Huang L. [The origin of channel syndromes]. ZHONGHUA YI SHI ZA ZHI (BEIJING, CHINA : 1980) 2001; 24:219-22. [PMID: 11613257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Originally, "Shi Dong" disease, one of the Channel Syndromes, first appeared in Moxibustion Canon of Eleven-channels of Yin-yang System is a manifestation in pulse diagnosis. The two pulse-syncope (mai jue) syndromes in On Syncope of Plain Question are also the summary from different scholars far pulse manifestation. On the other hand, the "Suo Sheng" disease is the summary of ancient scholar on the lesions at the superficial running courses of channels and the disease condition of its underlying viscera, which would also be changed with the changes of channels and viscera.
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Chesnoy S, Durand D, Doucet J, Stolz DB, Huang L. Improved DNA/emulsion complex stabilized by poly(ethylene glycol) conjugated phospholipid. Pharm Res 2001; 18:1480-4. [PMID: 11697477 DOI: 10.1023/a:1012221310136] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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838
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Denning D, Mykytka B, Allen NP, Huang L, Rexach M. The nucleoporin Nup60p functions as a Gsp1p-GTP-sensitive tether for Nup2p at the nuclear pore complex. J Cell Biol 2001; 154:937-50. [PMID: 11535617 PMCID: PMC2196189 DOI: 10.1083/jcb.200101007] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The nucleoporins Nup60p, Nup2p, and Nup1p form part of the nuclear basket structure of the Saccharomyces cerevisiae nuclear pore complex (NPC). Here, we show that these necleoporins can be isolated from yeast extracts by affinity chromatography on karyopherin Kap95p-coated beads. To characterize Nup60p further, Nup60p-coated beads were used to capture its interacting proteins from extracts. We find that Nup60p binds to Nup2p and serves as a docking site for Kap95p-Kap60p heterodimers and Kap123p. Nup60p also binds Gsp1p-GTP and its guanine nucleotide exchange factor Prp20p, and functions as a Gsp1p guanine nucleotide dissociation inhibitor by reducing the activity of Prp20p. Yeast lacking Nup60p exhibit minor defects in nuclear export of Kap60p, nuclear import of Kap95p-Kap60p-dependent cargoes, and diffusion of small proteins across the NPC. Yeast lacking Nup60p also fail to anchor Nup2p at the NPC, resulting in the mislocalization of Nup2p to the nucleoplasm and cytoplasm. Purified Nup60p and Nup2p bind each other directly, but the stability of the complex is compromised when Kap60p binds Nup2p. Gsp1p-GTP enhances by 10-fold the affinity between Nup60p and Nup2p, and restores binding of Nup2p-Kap60p complexes to Nup60p. The results suggest a dynamic interaction, controlled by the nucleoplasmic concentration of Gsp1p-GTP, between Nup60p and Nup2p at the NPC.
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839
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Huang L, Bitner-Glindzicz M, Tranebjaerg L, Tinker A. A spectrum of functional effects for disease causing mutations in the Jervell and Lange-Nielsen syndrome. Cardiovasc Res 2001; 51:670-80. [PMID: 11530100 DOI: 10.1016/s0008-6363(01)00350-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE Jervell and Lange-Nielsen syndrome (JLNS) is a recessively inherited long QT syndrome (LQTS) characterised by profound sensorineural deafness and predisposition to syncope and sudden cardiac death. Mutation analysis has established the presence of mutations in affected individuals in the genes KCNQ1 and KCNE1: the potassium channel complex responsible for the cardiac I(Ks) current involved in repolarisation of the ventricular action potential. Our objective was to determine the functional effects of disease causing mutations in JLNS. METHODS In this study we have investigated the electrophysiological effects of eight distinct JLNS mutations after expression of cRNA in Xenopus laevis oocytes. RESULTS KCNE1 mutant T59P/L60P showed no dominant negative effect and was a pure loss of function mutation. KCNQ1 mutant E261D showed a strong dominant-negative effect. KCNQ1 mutant R243H produced a moderate dominant-negative effect, right shifted the steady-state activation curve and led to an increased deactivation rate. The behaviour of KCNQ1 mutants 572-576del, 1008delC, R518X, Q530X, R594Q depended on the relative quantities of mutant and wild-type proteins (with a weak dominant-negative effect present at 1:3 but not 1:1 injection ratios). These data indicate the presence of an additional assembly domain before S2-S3 and the importance of the S4-S5 region in channel function and gating. CONCLUSIONS Our data suggest a spectrum of behaviour for disease causing mutations from simple loss of function through to prominent dominant negative behaviour.
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840
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Jolly PE, Huang L, Chen S. Neutralization/enhancement of macrophage-tropic SIVmac infection by plasma from macaques infected with macrophage-tropic or lymphocyte-tropic SIVmac. Cell Mol Biol (Noisy-le-grand) 2001; 47:997-1008. [PMID: 11785666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Plasma from macaques inoculated with macrophage-tropic SIVmac were tested for neutralization/enhancement of macrophage-tropic SIVmac239-17EBR in normal rhesus macrophages. The plasma of a macaque (R71) that developed a highly virulent neuro-tropic (macrophage-tropic) strain of SIVmac in neuro-adaptation studies significantly enhanced infection of SIVmac239-17EBR as well as infection of dual-tropic SIVmac251. Plasma from other macaques that were inoculated with macrophage-tropic virus, neutralized SIVmac239-17EBR. Also, plasma from macaques infected with lymphocyte-tropic SIVmac239 or dual-tropic SIVmac251 neutralized SIVmac251 infection. When the effect of R71 plasma on the early stages of the SIV life cycle was investigated, this plasma significantly increased binding of 35S-methionine labeled SIVmac239-17EBR and increased binding of 35S-SIVmac251 to primary macrophages, unlike plasma from other macaques infected with either macrophage-tropic or lymphocyte-tropic SIV. A single-cycle infection assay showed higher percentages of positive cells and more intense fluorescence in cultures treated with R71 plasma compared with control plasma. By in situ hybridization, SIV RNA transcripts were detected earlier (12 hr post-infection) and in higher percentages, in cultures treated with R71 plasma than in cultures treated with control plasma (18 hr post-infection). These results indicate that enhancing activity in infected macaque plasma may be associated with severe infection by highly virulent macrophage-tropic (neuro-tropic) SIV. The enhancing effect occurs early in infection and results in increased transcription of SIV RNA.
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841
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Ou R, Zhou S, Huang L, Moskophidis D. Critical role for alpha/beta and gamma interferons in persistence of lymphocytic choriomeningitis virus by clonal exhaustion of cytotoxic T cells. J Virol 2001; 75:8407-23. [PMID: 11507186 PMCID: PMC115086 DOI: 10.1128/jvi.75.18.8407-8423.2001] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2001] [Accepted: 06/11/2001] [Indexed: 01/12/2023] Open
Abstract
Under conditions of high antigenic load during infection with invasive lymphocytic choriomeningitis virus (LCMV) strains, virus can persist by selective clonal exhaustion of antigen-specific CD8(+) T cells. In this work we studied the down-regulation of the virus-specific CD8(+)-T-cell response during a persistent infection of adult mice, with particular emphasis on the contribution of the interferon response in promoting host defense. Studies were conducted by infecting mice deficient in receptors for type I (alpha/beta interferon [IFN-alpha/beta]), type II (IFN-gamma), and both type I and II IFNs with LCMV isolates that vary in their capacity to induce T-cell exhaustion. The main conclusions of this study are as follows. (i) IFNs play a critical role in LCMV infection by reducing viral loads in the initial stages of infection and thus modifying both the extent of CD8(+)-T-cell exhaustion and the course of infection. The importance of IFNs in this context varies with the biological properties of the LCMV strain. (ii) An inverse correlation exists between antigen persistence and responsiveness of virus-specific CD8(+) T cells. This results in distinct programs of activation or tolerance (functional unresponsiveness and/or physical elimination of antigen-specific cells) during acute and chronic virus infections, respectively. (iii) A successful immune response associated with definitive viral clearance requires an appropriate balance between cellular and humoral components of the immune system. We discuss the role of IFNs in influencing virus-specific T cells that determine the outcome of persistent infections.
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842
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Huang L, Pallas SL. NMDA antagonists in the superior colliculus prevent developmental plasticity but not visual transmission or map compression. J Neurophysiol 2001; 86:1179-94. [PMID: 11535668 PMCID: PMC4963030 DOI: 10.1152/jn.2001.86.3.1179] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Partial ablation of the superior colliculus (SC) at birth in hamsters compresses the retinocollicular map, increasing the amount of visual field represented at each SC location. Receptive field sizes of single SC neurons are maintained, however, preserving receptive field properties in the prelesion condition. The mechanism that allows single SC neurons to restrict the number of convergent retinal inputs and thus compensate for induced brain damage is unknown. In this study, we examined the role of N-methyl-D-aspartate (NMDA) receptors in controlling retinocollicular convergence. We found that chronic 2-amino-5-phosphonovaleric acid (APV) blockade of NMDA receptors from birth in normal hamsters resulted in enlarged single-unit receptive fields in SC neurons from normal maps and further enlargement in lesioned animals with compressed maps. The effect was linearly related to lesion size. These results suggest that NMDA receptors are necessary to control afferent/target convergence in the normal SC and to compensate for excess retinal afferents in lesioned animals. Despite the alteration in receptive field size in the APV-treated animals, a complete visual map was present in both normal and lesioned hamsters. Visual responsiveness in the treated SC was normal; thus the loss of compensatory plasticity was not due to reduced visual responsiveness. Our results argue that NMDA receptors are essential for map refinement, construction of receptive fields, and compensation for damage but not overall map compression. The results are consistent with a role for the NMDA receptor as a coincidence detector with a threshold, providing visual neurons with the ability to calculate the amount of visual space represented by competing retinal inputs through the absolute amount of coincidence in their firing patterns. This mechanism of population matching is likely to be of general importance during nervous system development.
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843
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Huang L, Zhang E, Cheng J. [The complexity measure and its application to EEG analysis]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2001; 18:488-90. [PMID: 11605523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
In this paper are reviewed the conceptions, characteristics and application of the complexity measure in studying EEG. The reviewers expound the advantages and problems of using complexity measure in the analysis of EEG in different physiological states and deem it a new way to study and understand the human brain function.
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844
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Navin TR, Beard CB, Huang L, del Rio C, Lee S, Pieniazek NJ, Carter JL, Le T, Hightower A, Rimland D. Effect of mutations in Pneumocystis carinii dihydropteroate synthase gene on outcome of P carinii pneumonia in patients with HIV-1: a prospective study. Lancet 2001; 358:545-9. [PMID: 11520525 DOI: 10.1016/s0140-6736(01)05705-1] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND Investigators have reported that patients infected with Pneumocystis carinii containing mutations in the DHPS (dihydropteroate synthase) gene have a worse outcome than those infected with P carinii containing wild-type DHPS. We investigated patients with HIV-1 infection and P carinii pneumonia to determine if DHPS mutations were associated with poor outcomes in these patients. METHODS We compared presence of mutations at the DHPS locus with survival and response of patients to co-trimoxazole or other drugs. FINDINGS For patients initially given co-trimoxazole, nine (14%) of 66 with DHPS mutant died, compared with nine (25%) of 36 with wild type (risk ratio50.55 [95% CI=0.24-1.25]; p=0.15). Ten (15%) of 66 patients with a DHPS mutant did not respond to treatment, compared with 13 (36%) of 36 patients with the wild type (0.42 [0.20-0.86]; p=0.02). For patients aged 40 years or older, four (14%) of 29 with the mutant and nine (56%) of 16 with the wild type died (0.25 [0.09-0.67]; p=0.005). INTERPRETATION These results, by contrast with those of previous studies, suggest that patients with wild-type P carinii do not have a better outcome than patients with the mutant when given co-trimoxazole. Our results suggest that presence of a DHPS mutation should be only one of several criteria guiding the choice of initial drug treatment of P carinii pneumonia in patients with HIV-1 infection.
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845
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Soumelis V, Scott I, Gheyas F, Bouhour D, Cozon G, Cotte L, Huang L, Levy JA, Liu YJ. Depletion of circulating natural type 1 interferon-producing cells in HIV-infected AIDS patients. Blood 2001; 98:906-12. [PMID: 11493432 DOI: 10.1182/blood.v98.4.906] [Citation(s) in RCA: 288] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Natural interferon-alpha producing cells (IPCs) are a newly characterized blood cell type, which is the major source of type I interferons in antiviral innate immune responses. The relationship between the number of circulating IPCs, HIV disease progression, and the occurrence of HIV-related complications was investigated. The study of 25 healthy donors and 54 HIV-infected subjects demonstrated a direct correlation between blood IPC number, interferon-alpha production, and clinical state of HIV-infected subjects. Asymptomatic long-term survivors had increased IPC number and function relative to uninfected controls and infected individuals with progressive disease. IPC numbers were markedly reduced in AIDS patients developing opportunistic infections and cancer. A negative correlation was found between the IPC number in the blood and the HIV viral load, suggesting that IPCs are important in controlling HIV replication. This study provides the first evidence that IPCs are being affected during the course of HIV infection and suggests that these cells can play a vital role in the protection against opportunistic pathogens and cancer. (Blood. 2001;98:906-912)
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846
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Chang C, Kuo S, Lin Y, Wang J, Huang L. Benzyloxybenzaldehyde analogues as novel adenylyl cyclase activators. Bioorg Med Chem Lett 2001; 11:1971-4. [PMID: 11454460 DOI: 10.1016/s0960-894x(01)00353-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Several benzyloxybenzaldehyde analogues were prepared and found to have significant inhibitory activity toward neutrophil superoxide formation. Consequently, these compounds were evaluated for cAMP-elevating capability. Among them, benzyloxybenzaldehyde (7), exhibiting activity equivalent to forskolin, was determined as an adenylyl cyclase activator since it elevates cAMP levels by activation of adenylyl cyclase but not by inhibition of phosphodiesterase. Having a chemical structure very different from known adenylyl cyclase activators, compound 7 is recommended by us for use as a new lead compound in the future development of adenylyl cyclase activators.
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847
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Allen NP, Huang L, Burlingame A, Rexach M. Proteomic analysis of nucleoporin interacting proteins. J Biol Chem 2001; 276:29268-74. [PMID: 11387327 DOI: 10.1074/jbc.m102629200] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Saccharomyces cerevisiae nuclear pore complex is a supramolecular assembly of 30 nucleoporins that cooperatively facilitate nucleocytoplasmic transport. Thirteen nucleoporins that contain FG peptide repeats (FG Nups) are proposed to function as stepping stones in karyopherin-mediated transport pathways. Here, protein interactions that occur at individual FG Nups were sampled using immobilized nucleoporins and yeast extracts. We find that many proteins bind to FG Nups in highly reproducible patterns. Among 135 proteins identified by mass spectrometry, most were karyopherins and nucleoporins. The PSFG nucleoporin Nup42p and the GLFG nucleoporins Nup49p, Nup57p, Nup100p, and Nup116p exhibited generic interactions with karyopherins; each bound 6--10 different karyopherin betas, including importins as well as exportins. Unexpectedly, the same Nups also captured the hexameric Nup84p complex and Nup2p. In contrast, the FXFG nucleoporins Nup1p, Nup2p, and Nup60p were more selective and captured mostly the Kap95p.Kap60p heterodimer. When the concentration of Gsp1p-GTP was elevated in the extracts to mimic the nucleoplasmic environment, the patterns of interacting proteins changed; exportins exhibited enhanced binding to FG Nups, and importins exhibited reduced binding. The results demonstrate a global role for Gsp1p-GTP on karyopherin-nucleoporin interactions and provide a rudimentary map of the routes that karyopherins take as they cross the nuclear pore complex.
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848
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Ogushi F, Tani K, Endo T, Tada H, Kawano T, Asano T, Huang L, Ohmoto Y, Muraguchi M, Moriguchi H, Sone S. Autoantibodies to IL-1 alpha in sera from rapidly progressive idiopathic pulmonary fibrosis. THE JOURNAL OF MEDICAL INVESTIGATION 2001; 48:181-9. [PMID: 11694958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
To clarify the clinical significance of autoantibodies to interleukin-1 alpha (IL-1 alpha autoantibodies) in rapidly progressive idiopathic pulmonary fibrosis (IPF), we measured the level of IL-1 alpha autoantibodies in serum of 11 patients on the first hospital day, when patients were admitted due to severe symptoms, and on the 21st hospital day. IL-1 alpha autoantibodies in serum were measured using radioimmunoassay, and the limitation of this assay for IL-1 alpha autoantibodies was 5 ng/ml. These antibodies were detected in 5 of 11 patients on the first hospital day. On the 21st hospital day, these antibodies were detected in all patients, and its level was increased compared with that on the first hospital day. IL-1 alpha autoantibodies that appeared in patients corresponded to that of IgG. The half life of exogenous autoantibodies was investigated following administration of autoantibody rich plasma obtained from healthy blood donors to 6 control patients (CP) and 6 progressive IPF patients. These autoantibody levels in their serum were less than 5 ng/ml before administration. Serum was obtained at the indicated time after administration of IL-1 alpha autoantibodies and the level of these autoantibodies in serum was measured, then the half life was calculated. Half life of exogenous IL-1 alpha autoantibodies in progressive IPF patients was significantly shorter than that in CP (71.3 +/- 31.8 hr vs 352.0 +/- 98.3 hr, p < 0.01). These findings suggested that IL-1 alpha autoantibodies were generated in response to the inflammatory process of rapidly progressive IPF and may act as a regulatory factor for IL-1 alpha.
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849
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Huang L, Bell RW, Dell B. Boron supply into wheat (Triticum aestivum L. cv. Wilgoyne) ears whilst still enclosed within leaf sheaths. JOURNAL OF EXPERIMENTAL BOTANY 2001. [PMID: 11479339 DOI: 10.1093/jexbot/52.361.1731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The present study investigates whether there is significant remobilization of (10)B previously loaded in the flag and penultimate leaves into the young, actively growing ear enclosed within the sheaths of flag and penultimate leaves. It also explores whether B transport into the enclosed ear declines when air humidity in the shoot canopy increases. After 5 d (10)B labelling during the period from early to full emergence of the flag leaf, the plants were transferred into nutrient solutions containing either 10 microM (11)B or no added B for 3 d. Regardless of the subsequent B supply levels to the roots, (10)B contents in the ear continued to increase by up to 5-fold 3 d after the end of (10)B supply in the nutrient solution. During these 3 d, the ear experienced a rapid increase in biomass. However, the majority of B in the ear during the 3 d treatment period was from the newly acquired (11)B from root uptake, rather than retranslocation of (10)B previously deposited in the leaves. By comparing the relative distribution of (10)B, Rb (xylem-to-phloem transfer marker) and Sr (xylem-marker) in the ear and the flag leaf, the distribution of (10)B resembled that of Rb more than Sr. Canopy cover treatment greatly suppressed leaf transpiration and decreased the amount of newly acquired (10)B in the flag leaf and the ear, but not in the upper stem segments. The results suggest that whilst the young ear was still fully enclosed within the leaf sheaths without any significant transpiration activity, B transport into the ear is predominantly dependent on the long-distance B transport in the xylem driven by leaf transpiration and, therefore, on concurrent B uptake from the roots.
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850
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Liu F, Liang KW, Huang L. Systemic administration of naked DNA: gene transfer to skeletal muscle. Mol Interv 2001; 1:168-72. [PMID: 14993350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Skeletal muscle is a promising target tissue for the gene therapy of both muscle and non-muscle disorders. Gene transfer into muscle tissue can produce a variety of physiologically active proteins and may ultimately be applied to the treatment of many diseases. A variety of methods have been studied to transfer genes into skeletal muscle, including viral and non-viral vectors. In this review, we discuss recent developments in the non-viral delivery of genes to muscles.
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