1
|
Liu L, Park J, Siegel DA, McCarty KF, Clark KW, Deng W, Basile L, Idrobo JC, Li AP, Gu G. Heteroepitaxial Growth of Two-Dimensional Hexagonal Boron Nitride Templated by Graphene Edges. Science 2014; 343:163-7. [DOI: 10.1126/science.1246137] [Citation(s) in RCA: 433] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
|
11 |
433 |
2
|
|
|
29 |
249 |
3
|
Huang M, Gu G, Ferguson EL, Chalfie M. A stomatin-like protein necessary for mechanosensation in C. elegans. Nature 1995; 378:292-5. [PMID: 7477350 DOI: 10.1038/378292a0] [Citation(s) in RCA: 220] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The mec-2 gene is required for the function of a set of six touch receptor neurons in the nematode Caenorhabditis elegans; mec-2 mutants, which are touch-insensitive, have touch cells that appear morphologically normal. Gene interaction studies suggest that mec-2 positively regulates the activity of the putative mechanosensory transduction channel (and the present paper), comprised in part of proteins encoded by the two degenerin genes mec-4 and mec-10 The central region of the mec-2 protein (MEC-2) is very similar to stomatin, an integral membrane protein (band 7.2b) in human red blood cells that is thought to regulate cation conductance. MEC-2-LacZ fusions are distributed along the touch receptor axons. This axonal distribution, which is mediated by the mec-2-specific amino terminus, is disrupted by mutations in mec-12, an alpha-tubulin gene needed for touch cell function. Our results indicate that MEC-2 links the mechanosensory channel and the microtubule cytoskeleton of the touch receptor neurons. Such linkage provides the basis for a mechanism of mechanosensation whereby microtubule displacement leads to channel opening.
Collapse
|
|
30 |
220 |
4
|
Wang Y, Ono S, Onose Y, Gu G, Ando Y, Tokura Y, Uchida S, Ong NP. Dependence of upper critical field and pairing strength on doping in cuprates. Science 2003; 299:86-9. [PMID: 12511645 DOI: 10.1126/science.1078422] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We have determined the upper critical field Hc2 as a function of hole concentration in bismuth-based cuprates by measuring the voltage induced by vortex flow in a driving temperature gradient (the Nernst effect), in magnetic fields up to 45 tesla. We found that Hc2 decreased steeply as doping increased, in both single and bilayer cuprates. This relationship implies that the Cooper pairing potential displays a trend opposite to that of the superfluid density versus doping. The coherence length of the pairs xi(0) closely tracks the gap measured by photoemission. We discuss implications for understanding the doping dependence of the critical temperature Tc0.
Collapse
|
|
22 |
171 |
5
|
Chen Y, Yang H, Gu G. Effect of acid and surfactant treatment on activated sludge dewatering and settling. WATER RESEARCH 2001; 35:2615-2620. [PMID: 11456159 DOI: 10.1016/s0043-1354(00)00565-0] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of pretreating activated sludge with sulfuric acid and surfactant on its exocellular polymer(ECP), dewaterability and settleability was investigated. It was observed that the centrifugal dewatering efficiency was increased with the decrease of sludge pH value, and which was further improved if the surfactant was simultaneously applied. However, to the filtration dewatering, the water content reached the minimum in the case of pH 2.5, and the additional use of surfactant was also favorable. The water content of sludge dewatered with filtration reached 73.99% when a pH 2.5 and a 0.1 g surfactant were employed, which was reduced by around 2% as compared with surfactant unused. Experimental results indicated that the sludge sedimentation rate was significantly accelerated under pH 2.5 condition, and which was increased once more by the utilization of surfactant. Further studies revealed that treating activated sludge with sulfuric acid at pH 2.5 or combined with surfactant was an effective method to remove the polymers from sludge surface and induced the decrease of ECP, which resulted in the improvement of dewaterability and settleability. This study suggested the potentiality of improving activated sludge mechanical dewaterability by the use of sulfuric acid to control its pH at 2.5 or together with a surfactant.
Collapse
|
|
24 |
162 |
6
|
Abstract
The mec-5 and mec-9 genes encode putative extracellular proteins that allow a set of six touch receptor neurons in C. elegans to respond to gentle touch. MEC-5 is a collagen made by the epidermal cells that surround the touch cells. Mutations causing touch insensitivity affect the Gly-X-Y repeats of this collagen. mec-9 produces two transcripts, the larger of which is expressed in the touch cells and two PVD neurons. This transcript encodes a protein with 5 Kunitz-type protease inhibitor domains, 6 EGF-like repeats (2 of the Ca(2+)-binding type), and a glutamic acid-rich region. Missense mutations causing touch insensitivity affect both the EGF-like and Kunitz domains. Since mec-9 loss of function mutations dominantly enhance the touch insensitive phenotype of several mec-5 mutations, MEC-5 and MEC-9 may interact. We propose that these proteins provide an extracellular attachment point for the mechanosensory channels of the touch cells.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Caenorhabditis elegans/genetics
- Caenorhabditis elegans/physiology
- Caenorhabditis elegans Proteins
- Collagen/genetics
- Collagen/physiology
- Epistasis, Genetic
- Extracellular Matrix/physiology
- Extracellular Matrix Proteins/chemistry
- Extracellular Matrix Proteins/genetics
- Extracellular Matrix Proteins/physiology
- Fluorescent Dyes
- Genes, Helminth
- Genes, Recessive
- Genes, Reporter
- Helminth Proteins/chemistry
- Helminth Proteins/genetics
- Helminth Proteins/physiology
- Mechanoreceptors/physiology
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Neurons, Afferent/chemistry
- Neurons, Afferent/physiology
- Protein Structure, Tertiary
- Recombinant Fusion Proteins/analysis
- Repetitive Sequences, Nucleic Acid
- Sequence Alignment
- Sequence Homology, Amino Acid
- Touch/physiology
Collapse
|
Comparative Study |
29 |
110 |
7
|
Ho DD, Cao Y, Zhu T, Farthing C, Wang N, Gu G, Schooley RT, Daar ES. Idiopathic CD4+ T-lymphocytopenia--immunodeficiency without evidence of HIV infection. N Engl J Med 1993; 328:380-5. [PMID: 8093634 DOI: 10.1056/nejm199302113280602] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND The human immunodeficiency virus (HIV), the etiologic agent of the acquired immunodeficiency syndrome (AIDS), infects and depletes CD4+ T lymphocytes. Recently, patients have been described with profound CD4+ T-lymphocytopenia but without evident HIV infection, a condition now termed idiopathic CD4+ T-lymphocytopenia, and a national surveillance network has been set up to investigate such cases. METHODS We studied 12 patients with CD4+ T-lymphocytopenia who were referred to us from three U.S. cities. Blood samples were tested for HIV with specific antibody assays, viral cultures, and polymerase-chain-reaction (PCR) techniques. RESULTS The patients (10 men and 2 women) ranged in age from 30 to 69 years. Eight had risk factors for HIV infection. The clinical manifestations were heterogeneous: five patients had opportunistic infections, five had syndromes of unknown cause, and two had no symptoms. Two patients died from acute complications of their immunodeficiency. The patients' lowest CD4+ lymphocyte counts ranged from 3 to 308 per cubic millimeter (mean, 149). Three patients had complete or partial spontaneous reversal of the CD4+ T-lymphocytopenia. Concomitant CD8+ T-lymphocytopenia was noted in three patients, and abnormal immunoglobulin levels were found in five. Multiple virologic studies by serologic testing, culture, and PCR were completely negative for HIV in all patients. CONCLUSIONS Our 12 patients with idiopathic CD4+ T-lymphocytopenia appear to be epidemiologically, clinically, and immunologically heterogeneous. It is unclear whether this syndrome is new, transmissible, or acquired. Many of the clinical and immunologic features are distinct from those found in AIDS, and our extensive virologic studies found no evidence of HIV infection. The cause of this condition remains unknown.
Collapse
|
|
32 |
100 |
8
|
Gu G, Caldwell GA, Chalfie M. Genetic interactions affecting touch sensitivity in Caenorhabditis elegans. Proc Natl Acad Sci U S A 1996; 93:6577-82. [PMID: 8692859 PMCID: PMC39067 DOI: 10.1073/pnas.93.13.6577] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
At least 13 genes (mec-1, mec-2, mec-4-10, mec-12, mec-14, mec-15, and mec-18) are needed for the response to gentle touch by 6 touch receptor neurons in the nematode Caenorhabditis elegans. Several, otherwise recessive alleles of some of these genes act as dominant enhancer mutations of temperature-sensitive alleles of mec-4, mec-5, mec-6, mec-12, and mec-15. Screens for additional dominant enhancers of mec-4 and mec-5 yielded mutations in previously known genes. In addition, some mec-7 alleles showed allele-specific, dominant suppression of the mec-15 touch-insensitive (Mec) phenotype. The dominant enhancement and suppression exhibited by these mutations suggest that the products of several touch genes interact. These results are consistent with a model, supported by the known sequences of these genes, that almost all of the touch function genes contribute to the mechanosensory apparatus.
Collapse
|
|
29 |
94 |
9
|
Rody WJ, King GJ, Gu G. Osteoclast recruitment to sites of compression in orthodontic tooth movement. Am J Orthod Dentofacial Orthop 2001; 120:477-89. [PMID: 11709665 DOI: 10.1067/mod.2001.118623] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although it is widely acknowledged that osteoclasts are formed by the fusion of mononuclear cells of hematopoietic origin, it has been extremely difficult to understand how they originate after appliance activation. The purpose of this study was to quantify osteoclast recruitment at compression sites as a function of time following orthodontic force application. Appliances were placed in 96 rats. At day 0, the animals were randomized to either appliance activation or sham activation followed by the injection of 5-bromo-2'-deoxyuridine (BrdU). Thus, BrdU was incorporated into the nuclei of cells in S-phase, including hematopoietic stem cells. Groups of 10 to 13 rats were killed at 1, 3, 5, and 7 days after activation/sham, and the tissue samples were prepared. The numbers of BrdU-labeled cells positively stained with tartrate-resistant acid phosphatase (TRAP) were measured in the periodontium. A significant number of BrdU-positive preosteoclasts was observed in the periodontal ligament (PDL) and bone surface at day 3. The number of osteoclastic cells in the bone marrow also peaked at day 3; however, the highest percentage of cells in this location was observed at day 1. These data suggest that osteoclasts in the PDL originate by the fusion of recently recruited preosteoclasts from the marrow instead of from local PDL cells. Furthermore, the alveolar bone marrow plays a role in the formation of osteoclasts during orthodontic tooth movement.
Collapse
|
|
24 |
89 |
10
|
Zhu HM, Qin L, Garnero P, Genant HK, Zhang G, Dai K, Yao X, Gu G, Hao Y, Li Z, Zhao Y, Li W, Yang J, Zhao X, Shi D, Fuerst T, Lu Y, Li H, Zhang X, Li C, Zhao J, Wu Q, Zhao SJ. The first multicenter and randomized clinical trial of herbal Fufang for treatment of postmenopausal osteoporosis. Osteoporos Int 2012; 23:1317-27. [PMID: 21505910 DOI: 10.1007/s00198-011-1577-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 01/22/2011] [Indexed: 10/18/2022]
Abstract
UNLABELLED This multicenter and randomized clinical trial showed that daily oral herbal formula Xian Ling Gu Bao (XLGB) was safe in postmenopausal women over a 1-year treatment. Those patients (n ∼ 50) treated with XLGB at the conventional dose demonstrated a statistically significant increase in dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) at lumbar spine at 6 months and a numerically increased BMD at 12 months. INTRODUCTION The aim of this study was to examine the safety and efficacy of a herbal formula XLGB in postmenopausal women (ChiCTR-TRC-00000347). METHODS One hundred eighty healthy postmenopausal women (≥60 years old) with BMD T-score ≤ -2.0 (lumbar spine or femoral neck) were recruited from four clinical centers to receive low-dose (conventional dose) XLGB (L-XLGB group, 3 g/day, n = 61) or high-dose XLGB (H-XLGB group, 6 g/day, n = 58) or placebo (CON group, n = 61). Women received daily calcium (500 mg) and vitamin D (200 IU) supplementation. Primary endpoints were lumbar spine BMD and safety; secondary endpoints were femoral neck BMD and bone turnover markers measured at baseline and at 6 and 12 months. RESULTS Of 180 women recruited, 148 completed the study. The compliance in each group was comparable. Prominent adverse events were not observed in either group. In the L-XLGB group at 6 months, lumbar spine BMD by DXA increased significantly from baseline (+2.11% versus CON +0.58%, p < 0.05), but femoral neck BMD did not; at 12 months, BMD in the L-XLGB group decreased from 6-month levels yet remained higher than baseline, but without difference from the CON group. There was no dose-dependent response. Bone turnover marker levels declined during the first 6 months after XLGB treatment. There was no significant difference in the overall incidence of side effects among treatment and control groups. CONCLUSION XLGB over 1-year treatment at the conventional dose demonstrated safe and only a statistically significant increase in BMD at lumbar spine at 6 months in postmenopausal women.
Collapse
|
Multicenter Study |
13 |
81 |
11
|
Gu G, Garbuzov DZ, Burrows PE, Venkatesh S, Forrest SR, Thompson ME. High-external-quantum-efficiency organic light-emitting devices. OPTICS LETTERS 1997; 22:396-398. [PMID: 18183213 DOI: 10.1364/ol.22.000396] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We study the internal and external quantum efficiencies of vacuum-deposited organic light-emitting devices (OLED's). The internal quantum efficiency of OLED's based on tris-(8-hydroxyquinoline) aluminum is calculated to be 5.7 times the observed external quantum efficiency ?(e), consistent with measurements. We demonstrate a shaped substrate that increases ?(e) by a factor of 1.9+/-0.2 over similar OLED's fabricated upon flat glass substrates and leads to a 100%-emissive aperture, i.e., the emitting area completely occupies the display area even in the presence of metal interconnects. We also discuss a substrate structure that increases ?(e) by an additional factor of 2. The high device efficiencies are promising for developing OLED-based displays with extremely low power consumption and increased operational lifetime.
Collapse
|
|
28 |
79 |
12
|
Gu G, Hentunen TA, Nars M, Härkönen PL, Väänänen HK. Estrogen protects primary osteocytes against glucocorticoid-induced apoptosis. Apoptosis 2005; 10:583-95. [PMID: 15909120 DOI: 10.1007/s10495-005-1893-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Glucocorticoid-induced osteoporosis may be at least in part due to the increased apoptosis of osteocytes. To study the role of osteocyte apoptosis in glucocorticoid-induced osteoporosis, we isolated primary osteocytes from murine calvaria for the analysis of the effects of dexamethasone in in vitro culture. The cells were identified by morphology, cytochemical staining, immunocytochemical staining and mRNA expression of phosphate-regulating gene with homology to endopeptidases on the X chromosome (PHEX) and sclerosteosis/van Buchem disease gene (SOST). We found that dexamethasone induced osteocyte apoptosis in a dose-dependent manner. A glucocorticoid receptor antagonist, mifepristone (RU486), suppressed dexamethasone-induced osteocyte apoptosis, suggesting that it was mediated by glucocorticoid receptor. Immunocytochemical stainings showed that glucocorticoid receptors are present in primary osteocytes, and they were translocated to nuclei after the exposure to dexamethasone. Addition of estrogen prevented glucocorticoid receptor translocation into nuclei. Corresponding antiapoptotic effects in primary osteocytes were also seen after the pretreatment of primary osteocytes with a picomolar concentration of estrogen. The pure antiestrogen ICI 182,780 inhibited estrogen effect on apoptosis induced by dexamethasone. These data suggest that glucocorticoid receptors play an important role in glucocorticoid-induced osteocyte apoptosis. Most importantly, estrogen has a protective effect against osteocyte apoptosis. To conclude, the mechanism of glucocorticoid-induced osteoporosis may be due to the apoptosis of osteocytes, which can be opposed by estrogen.
Collapse
|
Journal Article |
20 |
63 |
13
|
Polston EK, Gu G, Simerly RB. Neurons in the principal nucleus of the bed nuclei of the stria terminalis provide a sexually dimorphic GABAergic input to the anteroventral periventricular nucleus of the hypothalamus. Neuroscience 2004; 123:793-803. [PMID: 14706792 DOI: 10.1016/j.neuroscience.2003.09.034] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neurons of the principal nucleus of the bed nuclei of the stria terminalis (BSTp) process pheromonal and viscerosensory stimuli associated with reproduction and relay this information to preoptic and hypothalamic cell groups that regulate reproductive function. The anteroventral periventricular nucleus of the hypothalamus (AVPV), a nucleus involved in the regulation of gonadotropin secretory patterns, receives dense projections from BSTp neurons in males but not in females. By injecting the anterograde tracer, Phaseolus vulgaris leucoagglutinin (PHAL), into the BSTp of rats and immunohistochemically colocalizing the GABA synthetic enzyme, GAD65, to PHAL-immunoreactive fibers in the AVPV, we tested the hypothesis that these sex-specific projections arise from BSTp neurons that synthesize the inhibitory neurotransmitter GABA. Although dense GAD65-immunoreactive fiber terminals were observed in both the male and female AVPV, higher numbers of GAD65-labeled terminals were found in the male, and those localized to PHAL-immunoreactive fibers were seen almost exclusively in males. Treatment of newborn females with testosterone or neonatal orchidectomy of males reversed these sex differences, while GAD65-immunoreactivity in the AVPV was not altered in response to exogenous hormone treatments administered to peripubertal animals. Our results suggest that projections from BSTp neurons constitute a stable, sex-specific GABAergic input to the AVPV that is patterned permanently by perinatal hormone exposure.
Collapse
|
Research Support, U.S. Gov't, P.H.S. |
21 |
58 |
14
|
Gu G, Burrows PE, Venkatesh S, Forrest SR, Thompson ME. Vacuum-deposited, nonpolymeric flexible organic light-emitting devices. OPTICS LETTERS 1997; 22:172-174. [PMID: 18183139 DOI: 10.1364/ol.22.000172] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate mechanically flexible, organic light-emitting devices (OLED's) based on the nonpolymetric thin-film materials tris-(8-hydroxyquinoline) aluminum (Alq(3)) and N, N(?) -diphenyl- N, N(?) -bis(3-methylphenyl)1- 1(?) biphenyl-4, 4(?) diamine (TPD). The single heterostructure is vacuum deposited upon a transparent, lightweight, thin plastic substrate precoated with a transparent, conducting indium tin oxide thin film. The flexible OLED performance is comparable with that of conventional OLED's deposited upon glass substrates and does not deteriorate after repeated bending. The large-area (~1 - cm>(2)) devices can be bent without failure even after a permanent fold occurs if they are on the convex substrate surface or over a bend radius of ~0.5>cm if they are on the concave surface. Such devices are useful for ultralightweight, flexible, and comfortable full-color flat panel displays.
Collapse
|
|
28 |
45 |
15
|
Tatarkiewicz K, Belanger P, Gu G, Parkes D, Roy D. No evidence of drug-induced pancreatitis in rats treated with exenatide for 13 weeks. Diabetes Obes Metab 2013; 15:417-26. [PMID: 23163898 PMCID: PMC3654567 DOI: 10.1111/dom.12040] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 09/29/2012] [Accepted: 11/12/2012] [Indexed: 12/18/2022]
Abstract
AIMS The potential association of glucagon-like peptide receptor agonists (GLP-1RAs) with the development of pancreatitis or pancreatic malignancies in patients with diabetes has been suggested. This study evaluated the long-term effects of the GLP-1RA exenatide on pancreatic exocrine structure and function in the Zucker diabetic fatty (ZDF) rat model of type 2 diabetes. METHODS Rats received subcutaneous twice-daily injections of 0 (control), 6, 40 and 250 µg/kg/day exenatide for 3 months. Clinical signs, body and pancreas weight, food consumption, HbA1c, fasting serum amylase, lipase, glucose and insulin concentrations were evaluated during treatment and after a 28-day off-drug period to assess the reversibility of any observed effects. Morphometric analysis of pancreatic ductal cell proliferation and apoptosis were performed. RESULTS Plasma exenatide concentrations were several-fold higher than therapeutic levels observed in humans. No exenatide-related effects were observed on clinical signs, lipase concentration, pancreatic weight, pancreatic histology, ductal cell proliferation or apoptosis. Exenatide improved animal survival, physical condition, glucose concentrations and HbA1c, decreased food intake, and increased serum insulin concentration. Total amylase concentrations, although within normal ranges, were slightly higher in exenatide-treated rats; following the off-drug period, total amylase concentrations were comparable in treated and untreated rats. Exenatide-related minimal-to-moderate islet hypertrophy was observed at doses ≥6 µg/kg/day, with dose-related increases in incidence and degree. These changes were still present after the off-drug period. CONCLUSIONS Chronic administration of exenatide in ZDF rats resulted in the expected metabolic benefits and improved animal survival, with no adverse effects noted on pancreatic exocrine structure and function.
Collapse
|
research-article |
12 |
43 |
16
|
Leng N, Gu G, Simerly RB, Spindel ER. Molecular cloning and characterization of two putative G protein-coupled receptors which are highly expressed in the central nervous system. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1999; 69:73-83. [PMID: 10350639 DOI: 10.1016/s0169-328x(99)00092-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have cloned from a rat hypothalamic cDNA library two closely related G protein-coupled receptors (GPCRs) which we have designated GPCR/CNS1 and GPCR/CNS2. The peptide sequences of these two G protein-coupled receptors shared 42% identity with each other and were next most closely related to the endothelin receptors and the bombesin-like peptide receptors (approximately 25% identity). Northern blot analysis showed that both GPCR/CNS1 and GPCR/CNS2 were very highly expressed in rat brain. In situ hybridization of rat brain demonstrated broad distribution of both receptors throughout the central nervous system. GPCR/CNS1 appeared to be expressed primarily in glial cells of the fiber tracts, while GPCR/CNS2 was expressed primarily in cells of the gray matter. The different distribution patterns of these two receptors in rat brain suggests distinct functional roles for each receptor in the central nervous system. Expression of these two receptors in Xenopus oocytes showed no response to any known endothelin and bombesin-like peptides. Therefore, the endogenous ligands and physiological significance of GPCR/CNS1 and GPCR/CNS2 remain to be elucidated, but may be related to the endothelins or bombesins. The very abundant expression in brain by these two receptors, however, suggests that they play important roles in the central nervous system.
Collapse
MESH Headings
- Animals
- Blotting, Northern
- Brain Chemistry/genetics
- Cloning, Molecular
- DNA, Complementary
- GTP-Binding Proteins/genetics
- In Situ Hybridization
- Molecular Sequence Data
- Nerve Tissue Proteins/genetics
- Oocytes/physiology
- Peptidylprolyl Isomerase/genetics
- RNA, Messenger/analysis
- RNA, Ribosomal, 18S/analysis
- RNA, Ribosomal, 28S/analysis
- Rats
- Receptor, Endothelin B
- Receptors, Bombesin/genetics
- Receptors, Cell Surface/genetics
- Receptors, Endothelin/genetics
- Receptors, G-Protein-Coupled
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Xenopus laevis
Collapse
|
|
26 |
39 |
17
|
Luo L, Cheng D, Song B, Wang LL, Vaswani C, Lozano PM, Gu G, Huang C, Kim RHJ, Liu Z, Park JM, Yao Y, Ho K, Perakis IE, Li Q, Wang J. A light-induced phononic symmetry switch and giant dissipationless topological photocurrent in ZrTe 5. NATURE MATERIALS 2021; 20:329-334. [PMID: 33462464 DOI: 10.1038/s41563-020-00882-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Dissipationless currents from topologically protected states are promising for disorder-tolerant electronics and quantum computation. Here, we photogenerate giant anisotropic terahertz nonlinear currents with vanishing scattering, driven by laser-induced coherent phonons of broken inversion symmetry in a centrosymmetric Dirac material ZrTe5. Our work suggests that this phononic terahertz symmetry switching leads to formation of Weyl points, whose chirality manifests in a transverse, helicity-dependent current, orthogonal to the dynamical inversion symmetry breaking axis, via circular photogalvanic effect. The temperature-dependent topological photocurrent exhibits several distinct features: Berry curvature dominance, particle-hole reversal near conical points and chirality protection that is responsible for an exceptional ballistic transport length of ~10 μm. These results, together with first-principles modelling, indicate two pairs of Weyl points dynamically created by B1u phonons of broken inversion symmetry. Such phononic terahertz control breaks ground for coherent manipulation of Weyl nodes and robust quantum transport without application of static electric or magnetic fields.
Collapse
|
|
4 |
38 |
18
|
Nelson MN, White-Traut RC, Vasan U, Silvestri J, Comiskey E, Meleedy-Rey P, Littau S, Gu G, Patel M. One-year outcome of auditory-tactile-visual-vestibular intervention in the neonatal intensive care unit: effects of severe prematurity and central nervous system injury. J Child Neurol 2001; 16:493-8. [PMID: 11453445 DOI: 10.1177/088307380101600706] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thirty-seven infants with severe central nervous system injury or extreme prematurity were randomly assigned to a multisensory (auditory-tactile-visual-vestibular) intervention or control group. Intervention began in the hospital at 33 weeks' postconceptional age and continued twice daily in the home until 2 months' corrected age. Mother-infant interactions during feedings were videotaped, and the Bayley Scales of Infant Development were administered. Control mothers stimulated their infants more during feeding, but these significant differences dissipated by 4 months. The presence of periventricular leukomalacia was associated with significantly poorer mental development, regardless of group assignment. Experimental infants tended to exhibit better motor and mental performance and had 23% fewer cerebral palsy diagnoses at 1 year, but these trends were not statistically significant. The type of brain injury was more important in determining 1-year developmental outcome than type of postnatal experience, suggesting that periventricular leukomalacia presents a major challenge for infant development.
Collapse
|
Clinical Trial |
24 |
38 |
19
|
Gelsomino L, Panza S, Giordano C, Barone I, Gu G, Spina E, Catalano S, Fuqua S, Andò S. Mutations in the estrogen receptor alpha hormone binding domain promote stem cell phenotype through notch activation in breast cancer cell lines. Cancer Lett 2018; 428:12-20. [DOI: 10.1016/j.canlet.2018.04.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 04/17/2018] [Accepted: 04/19/2018] [Indexed: 12/21/2022]
|
|
7 |
37 |
20
|
Gu G, Zhang W, Li M, Ni J, Wang P. Transplantation of NSC-derived cholinergic neuron-like cells improves cognitive function in APP/PS1 transgenic mice. Neuroscience 2015; 291:81-92. [PMID: 25681520 DOI: 10.1016/j.neuroscience.2015.01.073] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 01/30/2015] [Accepted: 01/30/2015] [Indexed: 01/10/2023]
Abstract
The ability to selectively control the differentiation of neural stem cells (NSCs) into cholinergic neurons in vivo would be an important step toward cell replacement therapy. First, green fluorescent protein (GFP)-NSCs were induced to differentiate into cholinergic neuron-like cells (CNLs) with retinoic acid (RA) pre-induction followed by nerve growth factor (NGF) induction. Then, these CNLs were transplanted into bilateral hippocampus of APP/PS1 transgenic mice. Behavioral parameters showed by Morris water maze (MWM) tests and the percentages of GFP-labeled cholinergic neurons of CNL transplanted mice were compared with those of controls. Brain levels of choline acetyltransferase (ChAT) mRNA and proteins were analyzed by quantitative real-time PCR and Western blotting, ChAT activity and acetylcholine (ACh) concentration were also evaluated by ChAT activity and ACh concentration assay kits. Immunofluorescence analysis showed that 80.3±1.5% NSCs differentiated into CNLs after RA pre-induction followed by NGF induction in vitro. Three months after transplantation, 82.4±6.3% CNLs differentiated into cholinergic neurons in vivo. APP/PS1 mice transplanted with CNLs showed a significant improvement in learning and memory ability compared with control groups at different time points. Furthermore, CNLs transplantation dramatically increased in the expressions of ChAT mRNA and protein, as well ChAT activity and ACh concentration in APP/PS1 mice. Our findings support the prospect of using NSC-derived CNLs in developing therapies for Alzheimer's disease (AD).
Collapse
|
Research Support, Non-U.S. Gov't |
10 |
37 |
21
|
Nazarian A, Gu G, Gracias NG, Wilkinson K, Hua XY, Vasko MR, Yaksh TL. Spinal N-methyl-D-aspartate receptors and nociception-evoked release of primary afferent substance P. Neuroscience 2008; 152:119-27. [PMID: 18222611 DOI: 10.1016/j.neuroscience.2007.11.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 11/13/2007] [Accepted: 11/28/2007] [Indexed: 11/26/2022]
Abstract
Dorsal horn N-methyl-D-aspartate (NMDA) receptors contribute significantly to spinal nociceptive processing through an effect postsynaptic to non-primary glutamatergic axons, and perhaps presynaptic to the primary afferent terminals. The present study sought to examine the regulatory effects of NMDA receptors on primary afferent release of substance P (SP), as measured by neurokinin 1 receptor (NK1r) internalization in the spinal dorsal horn of rats. The effects of intrathecal NMDA alone or in combination with D-serine (a glycine site agonist) were initially examined on basal levels of NK1r internalization. NMDA alone or when co-administered with D-serine failed to induce NK1r internalization, whereas activation of spinal TRPV1 receptors by capsaicin resulted in a notable NK1r internalization. To determine whether NMDA receptor activation could potentiate NK1r internalization or pain behavior induced by a peripheral noxious stimulus, intrathecal NMDA was given prior to an intraplantar injection of formalin. NMDA did not alter the formalin-induced NK1r internalization nor did it enhance the formalin paw flinching behavior. To further characterize the effects of presynaptic NMDA receptors, the NMDA antagonists DL-2-amino-5-phosphonopentanoic acid (AP-5) and MK-801 were intrathecally administered to assess their regulatory effects on formalin-induced NK1r internalization and pain behavior. AP-5 had no effect on formalin-induced NK1r internalization, whereas MK-801 produced only a modest reduction. Both antagonists, however, reduced the formalin paw flinching behavior. In subsequent in vitro experiments, perfusion of NMDA in spinal cord slice preparations did not evoke basal release of SP or calcitonin gene-related peptide (CGRP). Likewise, perfusion of NMDA did not enhance capsaicin-evoked release of the two peptides. These results suggest that presynaptic NMDA receptors in the spinal cord play little if any role on the primary afferent release of SP.
Collapse
|
Research Support, N.I.H., Extramural |
17 |
35 |
22
|
Noxon SJ, King GJ, Gu G, Huang G. Osteoclast clearance from periodontal tissues during orthodontic tooth movement. Am J Orthod Dentofacial Orthop 2001; 120:466-76. [PMID: 11709664 DOI: 10.1067/mod.2001.117912] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The presence of osteoclasts at locations of alveolar bone remodeling is antecedent to orthodontic tooth movement. Cell recruitment and clearance are the mechanisms by which osteoclast populations are regulated. Research in other tissues has revealed that many cells die after their functional lives are past by a process called apoptosis, or programmed cell death. The purpose of this study was to examine the role of apoptosis in osteoclast clearance at orthodontically treated sites as a function of time and location. Orthodontic appliances were placed on 96 rats of the Sprague-Dawley strain. The rats were assigned to either treatment or sham (control) groups and killed 1, 3, 5, and 7 days after appliance placement. Tissue samples were prepared for histochemical evaluation and quantification of morphologic features. Tartrate-resistant acid phosphatase (TRAP) and ApopTag (TdT-mediated dUTP-biotin nick 3' end labeling) stains were used to identify osteoclasts and committed preosteoclasts and to discriminate between apoptotic and nonapoptotic nuclei. Pyknotic nuclei and apoptotic bodies were also counted as a morphologic assessment of apoptosis. The percentages of TRAP/ApopTag-positive nuclei were measured in 4 different periodontal regions. There was a highly significant difference in the overall percentage of TRAP/ApopTag-positive nuclei between the control and the treatment groups at 3, 5, and 7 days (P <.001). Morphologic criteria were also statistically different at days 5 and 7 (P <.05). These data strongly suggested that osteoclasts recruited for orthodontic tooth movement are, at least in part, cleared by apoptosis.
Collapse
|
|
24 |
34 |
23
|
Zhang J, Montine TJ, Smith MA, Siedlak SL, Gu G, Robertson D, Perry G. The mitochondrial common deletion in Parkinson's disease and related movement disorders. Parkinsonism Relat Disord 2002; 8:165-70. [PMID: 12039426 DOI: 10.1016/s1353-8020(01)00041-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mitochondrial 4977-bp common deletion has been reported in some studies to occur exclusively or with increased frequency in the midbrain of patients with Parkinson's disease (PD). Other studies could not confirm these results; rather, it was suggested that the mitochondrial common deletion is associated with aging in the midbrain and not PD. One possible explanation for these conflicting results is the difficulty in quantifying mitochondrial DNA deletions or mutations in the whole midbrain or substantia nigra (SN) while only a subset of midbrain neurons degenerate in PD. In addition, none of the studies has addressed the cell types with the common deletion within the midbrain. In this study we used in situ hybridization to detect the common deletion in sections of midbrain from patients with PD, multiple system atrophy-parkinsonian type (MSA-P), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB), age-matched controls, and individuals of different ages. The results demonstrated that the mitochondrial common deletion accumulated primarily in neurons but not glia in both the SN and other midbrain regions. There was no significant difference in the number or distribution of neurons with the common deletion or the average of the mean densities (AMD) of staining with the common deletion in nigral neurons among patients with PD, MSA-P, PSP, DLB, or age-matched controls. In addition, there was no difference in the number or distribution of neurons with the common deletion in nigral neurons between any age group, although there was a tendency for the common deletion to increase in the non-nigral neurons in older patients. These data indicate that accumulation of the 4977-bp common deletion in mitochondrial DNA in midbrain occurred primarily in neurons, and by this cytological approach, it was not associated with nigral neurodegeneration in the common movement disorders or aging.
Collapse
|
|
23 |
25 |
24
|
Wu Y, Ren J, Zhou B, Ding C, Chen J, Wang G, Gu G, Wu X, Liu S, Hu D, Li J. Gene silencing of non-obese diabetic receptor family (NLRP3) protects against the sepsis-induced hyper-bile acidaemia in a rat model. Clin Exp Immunol 2015; 179:277-93. [PMID: 25228381 DOI: 10.1111/cei.12457] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2014] [Indexed: 01/08/2023] Open
Abstract
The role of NOD-like receptor family (NLRP3) has been confirmed in various inflammatory diseases. The association between NLRP3 and hyper-bileacidaemia during the sepsis remains unclear. We aimed to investigate whether NLRP3 silencing protects against the sepsis-induced hyper-bileacidaemia. Sepsis was induced by caecum ligation and puncture (CLP). Gene silencing of NLRP3 was performed by injecting rats with NLRP3 short hairpin RNA plasmids (NLRP3 shRNA) 48 h before surgery. Rats were divided into four groups: group 1: sham; group 2: sepsis; group 3: NLRP3 shRNA + sepsis (called the 'NLRP3 shRNA' group); and group 4: scrambled shRNA + sepsis (called the 'scrambled shRNA' group). The serum levels of bile acids, hepatic expression of hepatocyte membrane transporters, hepatic cytokine levels and behaviours of immune cells were compared among the groups. Hepatic NLRP3 expression was increased dramatically during the sepsis, but was suppressed by pretreatment with NLRP3 shRNA. Compared with rats in the sepsis and the scrambled shRNA groups, rats in the NLRP3 shRNA group exhibited significantly decreased serum levels of glycine and taurine conjugated-bile acids, with rehabilitated expression of hepatocyte transporters, suppressed hepatic cytokine levels, decreased hepatic neutrophils infiltration and attenuated macrophages pyroptosis. Gene silencing of NLRP3 ameliorates sepsis-induced hyper-bileacidaemia by rehabilitating hepatocyte transporter expression, reducing hepatic cytokine levels, neutrophil infiltration and macrophages pyroptosis. NLRP3 may be a pivotal target for sepsis management.
Collapse
|
Research Support, Non-U.S. Gov't |
10 |
25 |
25
|
Yu S, Lu ML, Gu G, Zhou W, He L, Wang S. Musculoskeletal symptoms and associated risk factors in a large sample of Chinese workers in Henan province of China. Am J Ind Med 2012; 55:281-93. [PMID: 22125090 DOI: 10.1002/ajim.21037] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2011] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To investigate the one-year prevalence of musculoskeletal symptoms and associated risk factors in a large sample of Chinese workers in various industrial settings. METHODS A total of 5,338 (3,632 males and 1,706 females) workers from 13 companies participated in this study. Musculoskeletal symptoms in different body regions in the previous year and their risk factors were assessed by a self-reported questionnaire. Logistic regression analyses were performed to estimate the individual, work-related physical and psychosocial risk factors for the musculoskeletal symptoms. RESULTS The most commonly affected body regions among the workers were lower back (59.7%), neck (48.6%), shoulders (38.8%), and wrists (33.5%). Female workers had greater prevalence of musculoskeletal symptoms in the neck, shoulders, and wrists than male workers. Results of multivariate analyses indicated that individual, work-related physical and psychosocial factors were associated with the musculoskeletal symptoms. CONCLUSION The results suggest that interventions aimed at reducing musculoskeletal symptoms in the Chinese working population should take into account multiple risk areas including individual, physical job characteristics and work-related psychosocial factors.
Collapse
|
Research Support, Non-U.S. Gov't |
13 |
24 |