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Liu M, Mao XA, Ye C, Nicholson JK, Lindon JC. Three-dimensional maximum-quantum correlation HMQC NMR spectroscopy (3D MAXY-HMQC). JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1997; 129:67-73. [PMID: 9405217 DOI: 10.1006/jmre.1997.1246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The extension of two-dimensional maximum-quantum correlation spectroscopy (2D MAXY NMR), which can be used to simplify complex NMR spectra, to three dimensions (3D) is described. A new pulse sequence for 3D MAXY-HMQC is presented and exemplified using the steroid drug dexamethasone. The sensitivity and coherence transfer efficiency of the MAXY NMR approach has also been assessed in relation to other HMQC- and HSQC-based 3D methods. Copyright 1997 Academic Press. Copyright 1997Academic Press
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Ding G, Hu H, Li L, Ye C. High-field (9.4 T)(1)H magnetic resonance microscopy of mouse brain. SCIENCE IN CHINA. SERIES C, LIFE SCIENCES 1997; 40:477-480. [PMID: 20229298 DOI: 10.1007/bf03183585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/1996] [Indexed: 05/28/2023]
Abstract
The FLASH and STEAM pulse sequences were used to perform the microimaging and localized spectroscopy of brain of living and dead mice, respectively. The phase-shift presaturation approach was used to suppress water NMR signal. The experimental results show that the differences in localized spectra and MR images of brain between live and dead mice can be observed by means of magnetic resonance microscopy.
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Sowell MO, Ye C, Ricupero DA, Hansen S, Quinn SJ, Vassilev PM, Mortensen RM. Targeted inactivation of alphai2 or alphai3 disrupts activation of the cardiac muscarinic K+ channel, IK+Ach, in intact cells. Proc Natl Acad Sci U S A 1997; 94:7921-6. [PMID: 9223288 PMCID: PMC21530 DOI: 10.1073/pnas.94.15.7921] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Cardiac muscarinic receptors activate an inwardly rectifying K+ channel, IK+Ach, via pertussis toxin (PT)-sensitive heterotrimeric G proteins (in heart Gi2, Gi3, or Go). We have used embryonic stem cell (ES cell)-derived cardiocytes with targeted inactivations of specific PT-sensitive alpha subunits to determine which G proteins are required for receptor-mediated regulation of IK+Ach in intact cells. The muscarinic agonist carbachol increased IK+Ach activity in ES cell-derived cardiocytes from wild-type cells, in cells lacking alphao, and in cells lacking the PT-insensitive G protein alphaq. In cells with targeted inactivation of alphai2 or alphai3, channel activation by both carbachol and adenosine was blocked. Carbachol-induced channel activation was restored in the alphai2- and alphai3-null cells by reexpressing the previously targeted gene and guanosine 5'-[gamma-thio] triphosphate was able to fully activate IK+Ach in excised membranes patches from these mutants. In contrast, negative chronotropic responses to both carbachol and adenosine were preserved in cells lacking alphai2 or alphai3. Our results show that expression of two specific PT-sensitive alpha subunits (alphai2 and alphai3 but not alphao) is required for normal agonist-dependent activation of IK+Ach and suggest that both alphai2- and alphai3-containing heterotrimeric G proteins may be involved in the signaling process. Also the generation of negative chronotropic responses to muscarinic or adenosine receptor agonists do not require activation of IK+Ach or the expression of alphai2 or alphai3.
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Chattopadhyay N, Legradi G, Bai M, Kifor O, Ye C, Vassilev PM, Brown EM, Lechan RM. Calcium-sensing receptor in the rat hippocampus: a developmental study. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1997; 100:13-21. [PMID: 9174241 DOI: 10.1016/s0165-3806(97)00009-6] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The extracellular Ca2+ (Ca2+(o))-sensing receptor (CaR) plays a key role in maintaining near constancy of Ca2+(o) in mammals through its presence in parathyroid gland and kidney. The CaR is also present in brain, and although its role(s) in the brain is not known, it is possible that small changes in Ca2+(o) modify essential physiological and pathological processes, since calcium is crucial for numerous neuronal functions. Northern analysis has revealed that the CaR mRNA is present in hippocampus and several other regions of the brain. The hippocampus is an important site for learning and memory, but the relevance of the CaR to these processes is unknown. Long-term potentiation (LTP), a putative in vitro analog of memory, can only be induced after 7-10 days postnatally in rat hippocampus. Therefore, in the present study we determined the time course for the developmental expression of the CaR in rat hippocampus to assess its relationship to the development of other important hippocampal functions, such as the capacity for induction of LTP. Northern and Western analyses showed that CaR mRNA and protein were expressed at low levels at 5 days postnatally but then increased markedly at 10 days. A high level of receptor expression, due primarily to an increase in a 7.5 kb transcript, persisted until 30 days, when it gradually decreased by 3-fold to reach the adult level of expression. In situ hybridization histochemistry and immunohistochemistry revealed CaR mRNA and protein in pyramidal cells of all the layers of hippocampus and in granule cells of the dentate gyrus. The results show that CaR expression rises at a time when LTP can first be induced in hippocampus and persists at high levels during the time when brain development is proceeding most rapidly. Further studies are needed to determine the role of the CaR in the development of important aspects of the function of hippocampus and other regions of brain, including LTP.
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Chattopadhyay N, Ye C, Singh DP, Kifor O, Vassilev PM, Shinohara T, Chylack LT, Brown EM. Expression of extracellular calcium-sensing receptor by human lens epithelial cells. Biochem Biophys Res Commun 1997; 233:801-5. [PMID: 9168937 DOI: 10.1006/bbrc.1997.6553] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The extracellular calcium-sensing receptor (CaR) confers the capacity to sense small changes in the extracellular Ca2+ concentration (Ca2+o) not only upon cells involved in maintaining systemic Ca2+ homeostasis but also upon those not directly involved in this process. Since high Ca2+o is known to affect various physiological processes in lens epithelium both in health and in disease states (e.g., the formation of cataracts in hypocalcemic states), we investigated the expression and function of the CaR in these cells. By RT-PCR and immunocytochemistry the CaR is expressed in human lens epithelial cells in culture. In addition, the open state probability of a Ca(2+)-activated potassium (K+) channel with a conductance of 82 +/- 3 pS is significantly increased by elevating Ca2+o to 3.0 mM or by application of 100 microM neomycin, both effective CaR agonists. Therefore, our data suggest that human lens-epithelial cells express the CaR, which may be functionally linked to Ca(2+)-activated K+ channels and, perhaps, to other ion channels involved in ionic homeostasis in the lens.
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Vassilev PM, Ho-Pao CL, Kanazirska MP, Ye C, Hong K, Seidman CE, Seidman JG, Brown EM. Cao-sensing receptor (CaR)-mediated activation of K+ channels is blunted in CaR gene-deficient mouse neurons. Neuroreport 1997; 8:1411-6. [PMID: 9172145 DOI: 10.1097/00001756-199704140-00018] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The extracellular Ca2+ (Cao)-sensing receptor (CaR) is expressed in hippocampus and other brain regions, suggesting that it could mediate some of the well recognized but poorly understood direct actions of Cao on neuronal function. This study presents evidence that the CaR is functionally coupled to Ca(2+)-activated K+ channels. The effects of CaR agonists on these channels in neurons from wild type (WT) and CaR-deficient (CaR -/-) mice were compared. Neomycin (100 mM) and elevation of Cao from 0.5 to 3 mM significantly increased the probability of channel opening (Po) in neurons from WT but not in those from CaR -/- mice. Thus the CaR activates neuronal K+ channels and could potentially inhibit neuronal excitability and neurotransmission via membrane repolarization.
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Hu JZ, Zhou J, Yang B, Li L, Qiu J, Ye C, Solum MS, Wind RA, Pugmire RJ, Grant DM. Dynamic nuclear polarization of nitrogen-15 in benzamide. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1997; 8:129-137. [PMID: 9203286 DOI: 10.1016/s0926-2040(96)01263-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A 15N dynamic nuclear polarization (DNP) experiment is reported in which a 15N DNP enhancement factor of approximately 2.6 x 10(2) is obtained on free radical doped samples of 99% 15N labeled benzamide. The free radicals BDPA (1:1 complex of alpha, gamma-bisdiphenylene-beta-phenylallyl with benzene) and DPPH (2,2-Di(4-tert-octylphenyl)-1-picrylhydrazyl) are used as dopants and the spin relaxation effects of adding these dopants are studied by means of changes in proton and nitrogen T1 values of the samples. The combination in solids of a very low natural abundance, 0.37%, a small gyromagnetic ratio, and a long spin-lattice relaxation time for 15N nuclei create severe sensitivity problems that, in large part, are ameliorated by the signal enhancement observed in the 15N DNP experiment on samples containing free electrons.
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Wang PY, Ye C, Pang YZ, Su JY, Tang CS. [Changes of calcium transport in rat liver nuclei during sepsis]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1997; 49:191-6. [PMID: 9812856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Calcium transport changes in rat liver nuclei were observed on the model of early sepsis (9 h after operation of cecal ligation and puncture). Calcium content in hepatocytes and nuclei were significantly increased by 20% and 36% respectively (P < 0.05) during sepsis. The activity of Ca(2+)-ATPase in hepatocytic nuclei was increased by 94% (P < 0.01) and 45Ca2+ transport accelerated by 32% (P < 0.01). There was a positive correlation between nuclear 45Ca2+ transport and nuclear Ca(2+)-ATPase activity (r = 0.914, P < 0.01). Calmodulin stimulated the activity of nuclear Ca(2+)-ATPase and 45Ca2+ transport; while calmodulin inhibitor trifluoperazine exerted an opposite effect. The above results suggest that liver nuclear calcium transport is strengthened during early sepsis as a result of changes of Ca(2+)-ATPase activity.
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Ye C, Ho-Pao CL, Kanazirska M, Quinn S, Rogers K, Seidman CE, Seidman JG, Brown EM, Vassilev PM. Amyloid-beta proteins activate Ca(2+)-permeable channels through calcium-sensing receptors. J Neurosci Res 1997; 47:547-54. [PMID: 9067864 DOI: 10.1002/(sici)1097-4547(19970301)47:5<547::aid-jnr10>3.0.co;2-v] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The amyloid-beta peptides (A beta) are produced in excess in Alzheimer's disease (AD) and may contribute to neuronal dysfunction and degeneration. This study provides strong evidence for a novel cellular target for the actions of A beta, the phospholipase C-coupled, extracellular Ca(2+)-sensing receptor (CaR). We demonstrate that A beta(s) produce a CaR-mediated activation of a Ca(2+)-permeable, nonselective cation channel (NCC), probably via elevation in cytosolic Ca2+ (Cai), in cultured hippocampal pyramidal neurons from normal rats and from wild type mice but not those from mice with targeted disruption of the CaR gene (CaR -/-). A beta(s) also activate NCC in CaR-transfected but not in nontransfected human embryonic kidney (HEK293) cells. Thus aggregates of A beta deposited on hippocampal neurons in AD could appropriately activate the CaR, stimulating Ca(2+)-permeable channels and causing sustained elevation of Cai with resultant neuronal dysfunction.
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Deng F, Wang G, Du Y, Ye C, Kong Y, Li X. 1H MAS and 1H[23Na] double resonance NMR studies on the modification of surface hydroxyl groups of gamma-alumina by sodium. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1997; 7:281-290. [PMID: 9176933 DOI: 10.1016/s0926-2040(96)01281-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The modification of surface hydroxyl groups with sodium in a series of Na2CO3-gamma-Al2O3 catalysts was investigated as a function of both the Na2CO3 loading and the calcination temperature by means of 1H magic angle spinning (MAS) and 1H(23Na) spin-echo double resonance NMR techniques. The 1H NMR experiments revealed that sodium ions are homogeneously distributed over the alumina surface and closely coordinated with the surface hydroxyl groups. In the catalysts calcined at 250 degrees C, the acidic hydroxyl groups (with a chemical shift of 2.0 ppm) are preferentially associated with sodium ions at low Na2CO3 coverages (5 and 10%), while both the acidic and the basic (0 ppm) hydroxyl groups are accessible for sodium ions at high coverages (15 and 20%). The coordination causes a low-field shift of about 2 ppm in the 1H MAS spectra, and a broad signal at 4.5 ppm appears. It is interesting that the 4.5 ppm signal is completely suppressed in the 1H(23Na) MAS experiments, providing direct evidence that a strong interaction exists between adsorbed sodium ions and the surface hydroxyl groups. Increasing the calcination temperature to 450 degrees C results in preferential removal of the acidic hydroxyl groups, and only the most basic hydroxyl groups remain when the calcination temperature is raised to 600 degrees C. This is attributed to the formation of the coordinated species. [formula: see text] which enhances the acidity of the surface hydroxyl groups and prompts their dehydroxylation, especially at high calcination temperature. Correlation of the 1H MAS NMR results and catalytic activity measurements indicates that the basic hydroxyl groups are essential for the carbonyl sulfide hydrolysis reaction.
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Chen K, Zhang J, Ye C. [Metallothionein involvement in the delayed protection after ischemic or anoxic preconditioning in myocardium or cultured cardiomyocytes]. ZHONGHUA YI XUE ZA ZHI 1997; 77:106-10. [PMID: 9596940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To study whether metallothionein (MT) is an OH scavenger and plays a protective role in cardiac ischemic/reperfusion injury. MT involves in the delayed protection 24 hr after preconditioning (PC). METHODS MT contents in myocardium or cultured cardiomyocytes are assayed at the 0 hr, 12 hr, and 24 hr after PC on the model of rabbit heart in situ or that of the cultured cardiomyocytes. The myocardial infarct size, LDH release, cell viability, and the content of cellular MDA were measured with or without the intervention of PD098059, the inhibitor of mitogen-activated protein kinase in the models before PC and different time intervals after PC. RESULTS The MT contents were increased significantly at 2 hr (1406.2 +/- 112.2 vs 129.9 +/- 10.4 pmol/mg Pr., P < 0.01, in cardiomyocytes) and 24 hr (1032.7 +/- 199.1 vs 129.9 +/- 10.4 pmol/mg Pr., P < 0.01, in cardiomyocytes; 62.1 +/- 12.6 vs 27.2 +/- 3.7 pmol/mg Pr., P < 0.01, in myocardium) after PC compared with those in normal group. The infarct sizes (13.2 +/- 3.6% vs 32.3 +/- 5.7%, P < 0.05) and the rise of LDH release in plasma (1944 +/- 256 vs 2826 +/- 239 IU/L, P < 0.05) were greatly decreased in preconditioned myocardium after a long time ischemia-reperfusion than those in the unpreconditioned. Compared with the cardiomyocytes unconditioned, the number of viable cell (71.0 +/- 1.6 vs 48.2 +/- 2.2%, P < 0.01) was greatly increased, the cellular MDA contents (33.5 +/- 12.8 vs 103.5 +/- 15.0 nmol/mg Pr., P < 0.01) and the LDH release (850.0 +/- 139.1 vs 1552.0 +/- 102.6 IU/L, P < 0.01) were dramatically decreased in preconditioned ones. All the delayed protection at 24 hr after PC were completely disappeared with the inhibition of MT's production with PD098059 (P > 0.05). CONCLUSION The myocardium or cardiomyocytes at 24 hr after PC are offered more capacity to tolerate the I/R damage, and MT involves in the delayed protection.
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Zhou J, Fu R, Hu JZ, Li L, Ye C. Measurement of spin-lattice relaxation times of 13C in organic solids. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1997; 7:291-299. [PMID: 9176934 DOI: 10.1016/s0926-2040(96)01283-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A transient nuclear Overhauser effect (NOE) makes measurements of the 13C spin-lattice relaxation times in organic solids complicated. Extended Solomon equations are applied in order to describe 13C spin-lattice relaxation with 1H r.f. field irradiation. Spin-lattice relaxation under r.f. irradiation is shown to be generally a triple-exponential process, but it can be reduced to be single-exponential under stronger r.f. field irradiation as well as in the absence of 1H initial magnetizations. Based on numerical calculations, the difference between spin-lattice relaxation curves obeying T1C < T1H and those obeying T1C > T1H is clearly indicated. The methyl group resonances in solid-state L-valine are examined, and the experimental results agree well with the theoretical results.
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163
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Vassilev PM, Kanazirska MP, Ye C, Francis J, Hong K, Brown EM. A flickery block of a K+ channel mediated by extracellular Ca2+ and other agonists of the Ca2+-sensing receptors in dispersed bovine parathyroid cells. Biochem Biophys Res Commun 1997; 230:616-23. [PMID: 9015373 DOI: 10.1006/bbrc.1996.6017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Single K+ channel activities in parathyroid cells were studied using the patch-clamp technique. A K+ channel modulated by external Ca2+ (Ca2+o) was identified. This channel had a unitary conductance of 109pS at 150 mM K+o in the pipette solution. An increase in Ca2+o from 0.5-0.75 to 2-3 mM induced a flickery partial block of the channel over a wide voltage range. The mechanism of channel blockade included a significant increase in the number of closings per burst and a reduction of the mean open times. Addition of other divalent and polyvalent agonists of the Ca2+-sensing receptor (CaR) induced a similar channel blockade. With its typical characteristics and flickery block by CaR agonists, this channel differs from previously described types of K+ channels. It is probably strongly coupled to the CaR and may contribute to the depolarization of parathyroid cells which is known to occur at elevated levels of Ca2+o.
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164
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Xie X, Ye C. [Clinical analysis of 120 patients with fibromyalgia]. HUNAN YI KE DA XUE XUE BAO = HUNAN YIKE DAXUE XUEBAO = BULLETIN OF HUNAN MEDICAL UNIVERSITY 1997; 22:167-70. [PMID: 9868064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
The clinical characteristics of 120 patients with fibromyalgia is reported. Most of the patients were 21-50 years old. More than 56% patients had three chief symptoms: generalized myalgia, abnormal sensations and easily fatigue. 49.2% of the patients complained multiple arthralgia; 29% with sleep disorder and 23% with local myospasm of lower limbs. The trigger point was regarded as an important physical sign. The etiology and differential diagnosis for fibromyalgia were discussed.
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Ye C, Ho-Pao CL, Kanazirska M, Quinn S, Seidman CE, Seidman JG, Brown EM, Vassilev PM. Deficient cation channel regulation in neurons from mice with targeted disruption of the extracellular Ca2+-sensing receptor gene. Brain Res Bull 1997; 44:75-84. [PMID: 9288833 DOI: 10.1016/s0361-9230(97)00088-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study presents evidence that a receptor sensitive to the concentration of extracellular Ca2+ (Ca[2+]o) (CaR) is functionally coupled to ion channels involved in modulation of neuronal excitability. This receptor is expressed in hippocampus and other brain regions, suggesting that it could mediate some of the well-recognized but poorly understood direct actions of extracellular Ca2+ (Ca[2+]o) on neuronal function. The effects of polycationic CaR agonists on the activity of a nonselective cation channel (NCC) in cultured hippocampal neurons from wild-type mice and from mice homozygous for targeted disruption of the CaR gene (CaR -/-) were compared in this study. The CaR agonists, neomycin (100 microM), spermine (300 microM), and elevation of Ca(2+)o from 0.75 to 3 mM, significantly increased the probability of channel opening (Po) in wild-type neurons. None of these agents, however, produced any effect on Po in neurons from mice lacking the CaR. The same NCC, however, could be activated by thapsigargin in neurons from both wild-type mice and CaR-deficient mice, most likely through an associated increase in the cytosolic free calcium concentration (Ca[i]). Thus the CaR regulates the activity of Ca2+-permeable NCC in hippocampal neurons and could potentially modulate key neuronal functions, including neurotransmission and neuronal excitability, via membrane depolarization.
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Otto IC, Ito K, Ye C, Hibi K, Kasai Y, Akiyama S, Takagi H. Causes of rectal incontinence after sphincter-preserving operations for rectal cancer. Dis Colon Rectum 1996; 39:1423-7. [PMID: 8969670 DOI: 10.1007/bf02054533] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE Low anterior resection (LAR) is the treatment of choice for middle and high rectal tumors. Even though the rectal sphincter is preserved, some patients show a postoperative loss of rectal continence that may be recovered during follow-up. The purpose of this study was to collect clinical and manometric data before and after LAR to find possible explanations for incontinence. METHODS Seventeen continent patients with rectal tumors located 10 cm above the anal verge were selected. Manometry was performed before and three months after surgery and when stable frequency of bowel movement was achieved (mean, 7 months). RESULTS Immediately after the operations, 14 of 17 patients showed a certain degree of incontinence but recovered during follow-up; at the end of the study, only two patients reported minor soiling. Resting and squeeze pressures were moderately reduced after surgery and increased during the following six months without regaining preoperative levels. Rectoanal inhibitory reflex was present in 94.4 percent of patients before the operations and in 25 percent of them after surgery, but it was not associated with incontinence. Rectal sensation was significantly reduced, and its recovery was well correlated with decrease in the frequency of bowel movements. CONCLUSIONS After LAR, there is a reduction in rectal pressures, suggesting damage to sphincter muscle fibers or innervation. There is also a reduction in rectal sensation related to loss in reservoir capacity, all of which may contribute to incontinence.
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Chen S, Lin Z, Ye C, Xu E. Long-term results of intravesical N-CWS therapy for preventing bladder cancer recurrence after operation. Chin Med J (Engl) 1996; 109:890-1. [PMID: 9275378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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168
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Ye C, Rogers K, Bai M, Quinn SJ, Brown EM, Vassilev PM. Agonists of the Ca(2+)-sensing receptor (CaR) activate nonselective cation channels in HEK293 cells stably transfected with the human CaR. Biochem Biophys Res Commun 1996; 226:572-9. [PMID: 8806675 DOI: 10.1006/bbrc.1996.1396] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Calcium (Ca2+) ions serve multiple roles both intra- and extracellularly. We recently cloned a cell surface, Cao(2+)-sensing receptor (CaR) that plays a central role in Cao2+ homeostasis by enabling direct regulation by Cao2+ of parathyroid hormone (PTH) secretion and the function of other tissues involved in mineral ion homeostasis. In parathyroid cells, the CaR activates phospholipase C, thereby raising the levels of inositol trisphosphate (IP3) and releasing Ca2+ from intracellular stores. High Cao2+ also activates Ca2+ influx into parathyroid cells through poorly defined mechanisms that may involve Ca(2+)-permeable, nonselective cation channels (NCC). We now show that human embryonic kidney (HEK293) cells also have NCC and, furthermore, that these channels are regulated by the CaR. We have utilized the cell-attached configuration of the patch clamp technique to characterize the properties of these channels as well as their regulation by various CaR agonists added to the external bath solution. The polycationic CaR agonist, neomycin (100 microM), as well as an elevated concentration of Cao2+ (3 mM), both of which activate the cloned CaR, significantly increased the probability of channel opening (Po) in HEK cells stably transfected with the CaR but not in nontransfected HEK cells which do not contain the receptor. Thus, the activation of the CaR enhances the activity of Ca(2+)-permeable NCC in these cells, which could contribute to the sustained increase in Cai2+ in parathyroid cells which is observed in response to elevated Cao2+. The CaR may also regulate the membrane functions of other CaR-expressing cells (e.g., those in the brain), at least in part, by modulating similar channels.
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Ye C, Kanazirska M, Quinn S, Brown EM, Vassilev PM. Modulation by polycationic Ca(2+)-sensing receptor agonists of nonselective cation channels in rat hippocampal neurons. Biochem Biophys Res Commun 1996; 224:271-80. [PMID: 8694826 DOI: 10.1006/bbrc.1996.1019] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We recently cloned an extracellular calcium (Ca2+0)-sensing receptor (CaR) from bovine parathyroid. The CaR is also expressed in various regions of brain, suggesting that it could potentially mediate some of the well-known but poorly understood effects of Ca2+0 on neuronal function. We have now examined the effects of polycationic CaR agonists on the activity of nonselective cation channels (NCC) in cultured rat hippocampal neurons, using the cell-attached configuration of the patch clamp technique and applying CaR active agents to the external bath solution. The polycationic CaR agonist, neomycin (100 microM), as well as an elevated concentration of Ca2+0 (3 mM), which is known to activate the cloned CaR, significantly increased the probability of channel opening (Po). The polyamine, spermine (300 microM), which also mimics the actions of Ca2+0 on the cloned CaR, produced similar changes in Po in rat hippocampal neurons. Elevation of Ca2+0 also increased Po for a similar NCC in HEK293 cells transfected with the cloned human CaR but not in nontransfected HEK cells. Thus the CaR can regulate the activity of Ca(2+)-permeable NCC in hippocampal neurons and could potentially modulate key functions of these cells, including neurotransmission and neuronal excitability.
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Zhou J, Yang B, Hu J, Hu H, Li L, Qiu J, Zeng F, Ye C. Investigation of a naphthalene pitch by high-resolution solid-state dynamic nuclear polarization. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1996; 6:127-133. [PMID: 8784951 DOI: 10.1016/0926-2040(95)01218-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The possibility of applying the dynamic nuclear polarization (DNP) technique to a study of char is explored with a naphthalene-derived pitch. It is shown that a 13C DNP enhancement factor of about 10(2) is obtained when the polarization is directly transferred from the unpaired electrons to the 13C nuclei. An undistorted spectrum with an enhancement factor of 8 is obtained by the DNP cross-polarization magic-angle spinning nuclear magnetic resonance (DNP-CP-MAS NMR) method. With such a high increase in S/N, it is possible to measure the 13C polarization time (Tp) and the spin-lattice relaxation time (T1) of the system in a reasonable experimental time. The resultant values are Tp = 19 s and T1 = 38 s, respectively. Based on the DNP enhancement as a function of the microwave frequency, it is found that the predominant DNP mechanism in the pitch is the solid-state effect.
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Hu JZ, Wu X, Yang N, Li L, Ye C, Qin K. Spectral editing in 13C CP/MAS experiments at high magnetic field. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1996; 6:187-196. [PMID: 8784957 DOI: 10.1016/0926-2040(95)01203-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We show that the spinning side-bands of protonated and non-protonated carbon atoms can be well separated by means of the standard SCP and LCPD experiments at a relatively slow sample spinning rate or at high magnetic field. These experiments offer a promising way of measuring the principal values of chemical shift anisotropies via spinning side-band analysis in a moderately complex system. General spectral editing in 13C cross-polarization magic-angle spinning (CP/MAS) experiments at high field is achieved by incorporating the total side-band suppression (TOSS) pulse sequence into the standard series of spectral editing pulse sequences. It is confirmed that the relative signal intensity for a certain kind of functional group obtained at different polarization, polarization-inversion and depolarization times is about the same as that obtained at low magnetic field, and that the signal intensity distortion introduced by the TOSS sequence for resonances having different chemical shift anisotropies does not interfere with the spectral editing process. However, quantitative results can only be expected in those cases where full restoration of the intensity of the central band can be achieved by the TOSS sequence. This new strategy at high field is demonstrated by using fumaric acid monoethyl ester as a model compound. A typical application to a Chinese resin is presented, where the relative ratio of each functional group in the aliphatic portion to the total number of aliphatic carbon atoms is determined from only three experimental spectra.
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172
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Hu JZ, Zhou J, Deng F, Feng H, Yang N, Li L, Ye C. High resolution 1H spectra of powdered solids observed by Hahn echo pulse sequence with magic-angle spinning. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1996; 6:85-94. [PMID: 8925269 DOI: 10.1016/0926-2040(95)01212-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The 1H magic-angle spinning (MAS) spectrum for a typical powdered solid is composed of a high resolution component and a broadline component. The high resolution component can be well isolated from the broadline component by the Hahn echo sequence with a long echo time. Compared with CRAMPS experiment, which measures the proton system as a whole, the high resolution echo-MAS method measures only a fraction of the solid, which is usually small at room temperature and quite different from the majority of the solid in both molecular motion and chemical environment. It is shown that for a sample of fumaric acid monoethyl ester, the chemical shifts of the high resolution component are apparently distinguishable from the isotropic chemical shifts of the broadline component in the CRAMPS spectrum as the temperature approaches the melting point. In addition, for a sample of malonic acid, the echo-MAS spectrum is sensitive to moisture and temperature, while its corresponding CRAMPS spectrum is not. It is suggested that the molecules which produce the high resolution component are related to the lattice defects in a solid, including the surface disorder of the polycrystallites, while the molecules that generate the broadline component are located on the rigid lattice of the solid.
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173
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Wang Y, Xu G, Ye C, Zhao J, Zhou S, Liu Y. Observation of transparency and population trapping due to atomic coherent effects. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 53:1160-1163. [PMID: 9912995 DOI: 10.1103/physreva.53.1160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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174
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Gerstein BC, Hu JZ, Zhou J, Ye C, Solum M, Pugmire R, Grant DM. The use of differential transverse relaxation to detect mobile species in solids. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1996; 6:63-71. [PMID: 8925267 DOI: 10.1016/0926-2040(95)01211-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Delayed acquisition of the proton NMR in selected organic molecular solids (L-alanine, durene, ethyl fumarate, and p-hydroxybenzoic acid) is shown to allow the observation of mobile species in the presence of relatively rigid bulk molecules. The mobility is found to be thermally activated. The combination of the thermally activated motion and magic-angle spinning leads to a fraction of these species moving nearly isotropically on the time scale of the inverse of the homonuclear dipolar splitting. In the case of ethyl fumarate and alanine, there exist populations with differing values of T1 and T1 row. This indicates the co-existence of relatively rigid and relatively mobile molecules in the same sample. The intensities under delayed acquisition cannot always be trusted to yield quantitative information. Comparison of spectra taken under delayed acquisition and under the CRAMPS (B.C. Gerstein, R.G. Pembleton, R.C. Wilson and L.M. Ryan, J. Chem. Phys., 66 (1977)361) technique is made.
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175
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Yue X, Ye C, Zhao P, Gou D. Long-term survival of heterotopic heart transplants in allogenic rats without using anti-rejection drugs after inducing immune tolerance. Chin Med J (Engl) 1995; 108:887-91. [PMID: 8728937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Graft rejection is a baffling problem in organ transplantation which has so far no successful resolution. Present antirejection therapy is expensive, toxic, susceptible to infection, oncogenesis and atherosclerosis. With the use of 2 extremely histoincompatible strains of rats as model, it was found that when six donor splenocytes preconditioned by an extract from the culture medium of streptomyces caespitosus were injected into the host, after 2 weeks immune tolerance heterotopic transplanted donor hearts could survive normally more than 100 days without using any anti-rejection drug. Their mean survival time was 141.4 +/- 2.56 days, while that in the control group was only 11.7 +/- 3.48 days (P < 0.005). Thus, the present research offers some bright prospects in the area of organ transplantation.
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176
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Zhou J, Ye C. A novel disentangling technique for the propagator describing cross-polarization dynamics. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1995; 5:213-216. [PMID: 9053111 DOI: 10.1016/0926-2040(95)00029-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The heteronuclear cross-polarization dynamics is described by the rotation operator approach proposed recently. The established theory is suitable for an isolated two-spin system. It is shown that the propagator can be disentangled into a cascade of six exponential operators and the polarization transfer concerned can be evaluated by the usual procedure.
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177
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Xia Y, Deng F, Ye C. Off-resonance effects on 2D NMR nutation spectra of I = 3/2 quadrupolar nuclei in static samples. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1995; 5:227-232. [PMID: 9053113 DOI: 10.1016/0926-2040(95)01185-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The off-resonance effects on 2D NMR nutation of I = 3/2 quadrupolar nuclei are demonstrated with perturbation theory and numerical calculation in static samples. The off-resonant (delta omega) rf field (omega 1) enlarges a nutation frequency and consequently increases the measurement range of nuclear quadrupolar interaction parameters. When omega e > omega Qmax, and arctg(omega 1/delta omega) = +/- 54.7 degrees (magic angle), the satellite lines (produced by coherence transfers) in a nutation spectrum are superimposed with the line of central transition, and hence the nutation spectrum is simplified and its sensitivity is enhanced. The nuclear quadrupolar interaction parameters of 23Na nuclei in Na omega molecular sieve are obtained using 2D NMR nutation.
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178
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Kiriyama K, Ye C. [E-selectin expression in serum and tissue correlates with distant metastasis of colorectal cancer]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1995; 53:1760-4. [PMID: 7543166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
E-selectin is an adhesion molecule of endothelial cells that binds to cancer cells mediated by sialyl Lewis A (sLea) or sialyl Lewis X (sLex). It is suspected to be involved in hematogenous metastasis of tumors. Therefore, it is worth examining E-selectin expression in human colorectal cancer and its hepatic metastasis. In the present study, E-selectin was clearly revealed on the endothelial cells of small vessels adjacent to cancer nests in both primary and metastatic nests in immunohistochemistry. In these tissues, E-selectin was observed on the endothelial cells lining the lumen of small vessels. Its expression adjacent to cancer nests appears to be induced through some stimuli by cancer cells, since its degree of expression is inversely correlated to the distance of the blood vessels from the cancer nests (P < 0.001). Endothelial cells adjacent to the metastatic lesion expressed E-selectin more extensively than those adjacent to the primary foci. This is also in line with the finding on serum E-selectin levels which were significantly elevated in the metastatic group compared to the non-metastatic group. The serum E-selectin level may provide useful information in the diagnosis for hepatic metastasis of colorectal cancer, although the results are still very preliminary.
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179
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Ye C, Kiriyama K, Mistuoka C, Kannagi R, Ito K, Watanabe T, Kondo K, Akiyama S, Takagi H. Expression of E-selectin on endothelial cells of small veins in human colorectal cancer. Int J Cancer 1995; 61:455-60. [PMID: 7538975 DOI: 10.1002/ijc.2910610404] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
E-selectin is an adhesion molecule of endothelial cells that binds to cancer cells mediated by sialyl Lewis A (sLea) or sialyl Lewis X (sLe(x)). It is suspected to be involved in hematogenous metastasis of tumors. Therefore, it is worth examining E-selectin expression in human colorectal cancer and its hepatic metastasis. In the present study, E-selectin was clearly revealed on the endothelial cells of small vessels adjacent to cancer nests both in primary and in metastatic nests in immunohistochemistry. In these tissues, E-selectin was observed on the endothelial cells lining the lumen of small vessels. Its expression adjacent to cancer nests appears to be induced through some stimuli by cancer cells, since its degree of expression is inversely correlated to the distance of the blood vessels from the cancer nests (p < 0.001). Endothelial cells adjacent to the metastatic lesion expressed E-selectin more extensively than those adjacent to the primary foci. This is also in line with the finding on serum E-selectin levels which were significantly elevated in the metastatic group as compared with the non-metastatic group. The serum E-selectin level may provide useful information in the diagnosis for hepatic metastasis of colorectal cancer, although the results are still tentative.
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180
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Wu D, Sun B, Sun L, Chai K, Ye C. Effects of the clearing-heat and nourishing-stomach method in the treatment of chronic gastritis with positive Campylobacter pylori. J TRADIT CHIN MED 1995; 15:28-30. [PMID: 7783456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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181
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Wang BG, Ye C, Zhong WZ, Yin ZW. Growth of o-Dicyanovinyl Anisole (DIVA) Crystal in Organic Solvents and its Characterization. CRYSTAL RESEARCH AND TECHNOLOGY 1995. [DOI: 10.1002/crat.2170300628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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182
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Zhou J, Li L, Hu H, Yang B, Dan Z, Qiu J, Guo J, Chen F, Ye C. Study of natural diamonds by dynamic nuclear polarization-enhanced 13C nuclear magnetic resonance spectroscopy. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1994; 3:339-351. [PMID: 7842279 DOI: 10.1016/0926-2040(94)90018-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The results of a study of two types of natural-diamond crystals by dynamic nuclear polarization (DNP)-enhanced high-resolution solid-state 13C nuclear magnetic resonance (NMR) are reported. The home-built DNP magic-angle spinning (MAS) 13C NMR spectrometer operates at 54 GHz for electrons and 20.2 MHz for carbons. The power of the microwave source was about 30 W and the highest DNP enhancement factor came near to 10(3). It was shown that in the MAS spectra the 13C NMR linewidths of the Ib-type diamond were broader than those of IaB3-type diamond. From the hyperfine structure of the DNP enhancement as a function of frequency, four kinds of nitrogen-centred and one kind of carbon-centred free radicals could be identified in the Ib-type diamond. The hyperfine structures of the DNP enhancement curve that originated from the anisotropic hyperfine interaction between electron and nuclei could be partially averaged out by MAS. The 13C polarization time of DNP was rather long, i.e. 1500 s, and the spin-lattice relaxation time (without microwave irradiation) was about 300 s, which was somewhat shorter than anticipated. Discussions on these experimental results have been made in this report.
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183
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Ye C, Sundström MO, Remes K. Microscopic transmission ellipsometry: measurement of the fibril angle and the relative phase retardation of single, intact wood pulp fibers. APPLIED OPTICS 1994; 33:6626-6637. [PMID: 20941203 DOI: 10.1364/ao.33.006626] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A new technique based on transmission intensity-quotient ellipsometry has been developed for determining the fibril angle and the relative phase retardation of single, intact pulp fibers. The method uses a polarizing microscope in conjunction with a microscope video camera or CCD camera. Requiring no sample pretreatment, the new method is simple, fast, more accurate than existing methods, and nondestructive of the fiber material. To test the new method, we employed the multiwavelength measurement principle. It is based on the fact that the fibril angle is independent of wavelength, while the relative retardation is inversely proportional to the wavelength used. Measurements were carried out with single pulp fibers as samples under the illumination of different light wavelengths. The measurements and some results are described and presented.
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184
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Zhou J, Ye C. Density operator formalism for the description of coherence evolution of a homonuclear two-spin system in rotating solids. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1994; 3:287-292. [PMID: 7804786 DOI: 10.1016/0926-2040(94)90004-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Based on a simple disentangling technique of the propagator, a density operator formalism is developed to describe the behavior of a homonuclear two-spin system in rotating solids. It is shown that the coherence evolutions can be characterized in terms of quaternions or a rotation matrix in a three-dimensional space; the coherence transfers between two different spins can thus be analysed well.
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185
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Zhu L, Wigle D, Hinek A, Kobayashi J, Ye C, Zuker M, Dodo H, Keeley FW, Rabinovitch M. The endogenous vascular elastase that governs development and progression of monocrotaline-induced pulmonary hypertension in rats is a novel enzyme related to the serine proteinase adipsin. J Clin Invest 1994; 94:1163-71. [PMID: 8083356 PMCID: PMC295188 DOI: 10.1172/jci117432] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We showed previously a cause and effect relationship between increased activity of an endogenous vascular elastase (EVE) and experimentally induced pulmonary hypertension in rats. We now report the isolation and characterization of EVE. Degenerate oligonucleotides synthesized to homologous sequences in serine elastases were used in a PCR with rat pulmonary artery (PA) cDNA. The PCR product hybridized to a 1.2-kb mRNA and the intensity of hybridization was threefold increased in RNA from rat hypertensive PA at a timepoint when EVE activity was increased. The PCR product was used to screen a cDNA library and sequences obtained encoded rat adipsin. We then used immunoaffinity to purify EVE. An antibody to the elastin-binding protein was used to remove this competitor of elastase from the PA extract and the elastolytic activity increased 100-fold. The enzyme was purified using an antibody that recognizes NH2-terminal sequences of serine proteinases and the eluate was further purified using an antibody raised against recombinant adipsin. A single band at 20 kD immunoreactive with the adipsin antibody was resolved as an active enzyme on an elastin substrate gel. Immunogold labeling with an antibody to an adipsin peptide sequence localized EVE to PA smooth muscle cells. This is the first isolation of EVE; it appears to be a novel enzyme related to the serine proteinase adipsin originally found in adipose tissue.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Binding Sites
- Blotting, Western
- Cattle
- Complement Factor D
- DNA Primers
- Gene Expression
- Humans
- Hypertension, Pulmonary/chemically induced
- Hypertension, Pulmonary/enzymology
- Hypertension, Pulmonary/physiopathology
- Microscopy, Immunoelectron
- Molecular Sequence Data
- Monocrotaline
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Pancreatic Elastase/biosynthesis
- Pancreatic Elastase/chemistry
- Polymerase Chain Reaction
- Pulmonary Artery/drug effects
- Pulmonary Artery/enzymology
- Pulmonary Artery/pathology
- RNA, Messenger/biosynthesis
- Rats
- Rats, Sprague-Dawley
- Sequence Homology, Amino Acid
- Serine Endopeptidases/biosynthesis
- Serine Endopeptidases/chemistry
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186
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Hu JZ, Orendt AM, Alderman DW, Pugmire RJ, Ye C, Grant DM. Measurement of 13C chemical shift tensor principal values with a magic-angle turning experiment. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1994; 3:181-197. [PMID: 7834318 DOI: 10.1016/0926-2040(94)90039-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The magic-angle turning (MAT) experiment introduced by Gan is developed into a powerful and routine method for measuring the principal values of 13C chemical shift tensors in powdered solids. A large-volume MAT probe with stable rotation frequencies down to 22 Hz is described. A triple-echo MAT pulse sequence is introduced to improve the quality of the two-dimensional baseplane. It is shown that measurements of the principal values of chemical shift tensors in complex compounds can be enhanced by using either short contact times or dipolar dephasing pulse sequences to isolate the powder patterns from protonated or non-protonated carbons, respectively. A model compound, 1,2,3-trimethoxybenzene, is used to demonstrate these techniques, and the 13C principal values in 2,3-dimethylnaphthalene and Pocahontas coal are reported as typical examples.
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187
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Zhou J, Ye C. Rotation-operator approach and spin dynamics in a time-varying magnetic field. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1994; 50:1903-1905. [PMID: 9911085 DOI: 10.1103/physreva.50.1903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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188
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Buzdar A, Hortobagyi G, Frye D, Ho D, Booser D, Valero V, Holmes F, Birmingham B, Bui K, Ye C. Bioequivalence of 20-mg Once-Daily Tamoxifen Relative to 10-mg Twice-Daily Tamoxifen Regimens for Breast Cancer. J Clin Oncol 1994. [DOI: 10.1200/jco.1994.12.6.1337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Table 2 in the report entitled "Bioequivalence of 20-mg Once-Daily Tamoxifen Relative to 10-mg Twice-Daily Tamoxifen Regimens for Breast Cancer" by Buzdar et al contained an error in two column headings. It is reprinted here correctly in its entirety. Please see the PDF for Table.
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189
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Mao XA, Zhao X, Ye C, Wang S. The first solid-state 171Yb nuclear magnetic resonance spectra. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1994; 3:107-110. [PMID: 7834311 DOI: 10.1016/0926-2040(94)90029-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The first powder and magic-angle spinning (MAS) experiments on 171Yb are reported. The divalent ytterbium compound RbYbI3 was studied by solid-state 171Yb nuclear magnetic resonance (NMR) and a powder spectrum of axial symmetry was obtained. The principal components of the chemical shielding tensor were determined as sigma 11 = sigma 22 = -62 ppm and sigma 33 = 124 ppm. An inversion-recovery experiment showed an anisotropic relaxation behavior with the parallel component relaxing faster than the perpendicular component (T1 perpendicular = 426 ms, T1 parallel = 298 ma). The natural line width of 800 Hz, which corresponds to an effective T2 of 0.4 ms, was obtained from the MAS spectrum.
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190
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Ye C, Ito K, Komatsu Y, Takagi H. Extremely high levels of CA19-9 and CA125 antigen in benign mucinous ovarian cystadenoma. Gynecol Oncol 1994; 52:267-71. [PMID: 7508878 DOI: 10.1006/gyno.1994.1044] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A Japanese woman had a mucinous cystadenoma of the left ovary associated with very high serum levels of CA19-9 (3170 u/ml) and CA125 (1705 u/ml). Such high levels of both antigens have not been reported previously in patients with benign ovarian mucinous cystadenoma. Immunostaining demonstrated CA19-9 and CA125 in the tumor, and different patterns of expression were noted depending on the differentiation of the epithelium. The postoperative tumor marker profile suggested that no residual tumor was left after the operation.
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191
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Deng F, Du Y, Ye C, Kong Y. Adsorption of Na+ onto gamma-alumina studied by solid-state 23Na and 27Al nuclear magnetic resonance spectroscopy. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1993; 2:317-324. [PMID: 7812756 DOI: 10.1016/0926-2040(83)90003-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The adsorption of Na+ on gamma-alumina surfaces at four coverages of Na2CO3[5, 10, 15 and 20% w/w)] was characterized by solid-state 23Na and 27Al nuclear magnetic resonance (NMR) spectroscopy. The experimental results suggest that two distinct adsorbed species are present on the alumina surface: surface species and surface salts. At the lower coverages of Na2CO3 (5 and 10%), the surface species is predominant, in which the Na+ cations are associated with the oxygen atoms of gamma-alumina. Increasing the loading level to 15% results in the appearance of a second adsorbed species that is attributed to the surface salt, Na2CO3, deposited on the solid surface. Further adsorption of Na2CO3 leads to an increase in the amount of surface salt while the amount of surface species remains unchanged. 1H-27Al Cross-polarization magic angle spinning (CP-MAS) experiments give the evidence that some Na+ cations in the form of surface species are coordinated with the Brönsted acid sites of gamma-alumina. This may be the main driving force that improves appreciably the catalytic efficiency of an Na2CO3-Al2O3 catalyst.
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192
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Hu JZ, Orendt AM, Alderman DW, Ye C, Pugmire RJ, Grant DM. Improvements to the magic angle hopping experiment. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1993; 2:235-243. [PMID: 7804775 DOI: 10.1016/0926-2040(93)90003-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Several improvements to the magic angle hopping experiment first introduced by Bax et al. [J. Magn. Reson., 52 (1983) 147] are presented. A dc servo motor driven sample hopping mechanism which requires less than 60 ms to accomplish a 120 degrees sample rotation is described. Modifications to the data acquisition process, including starting the acquisition period immediately after the second hop and acquiring a hypercomplex data set, are also presented. Principal values of the 13C chemical shielding tensor are measured for 1,2,3-trimethoxybenzene and 2,6-dimethoxynaphthalene.
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193
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Yang D, Ye C. One-dimensional double-quantum magic-angle-spinning NMR of deuterated solids. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1993; 2:147-150. [PMID: 7827966 DOI: 10.1016/0926-2040(93)90020-n] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
An approach to double-quantum magic-angle spinning (2Q-MAS) of spin I = 1 with a time-share irradiation, resulting in a one-dimensional (1D) MQ spectrum, is demonstrated in this paper. The experiment was carried out with perdeuterated dimethoxybenzene and showed that the 2Q transitions were insensitive to the spinning axis deviation from the magic angle. The 1D-2Q-MAS scheme may also be applied to nitrogen-containing solids.
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194
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Ding S, Ye C. Corrections to the cross-polarization dynamics in solids. The effect of nonsecular terms of heteronuclear dipolar interaction on cross-relaxation. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1993; 1:321-328. [PMID: 7834307 DOI: 10.1016/0926-2040(93)90014-e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The dynamic theory of cross-polarization in solids is modified by considering the contribution of the nonsecular terms of the heteronuclear dipolar interaction Hamiltonian in the laboratory frame to cross-relaxation. This contribution is evaluated numerically and confirmed experimentally. It is shown that these nonsecular terms may play a considerable role in cross-relaxation in many systems, especially in those with fast internal molecular motion. The complication in the cross-polarization process is further revealed.
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195
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Bashir J, Butt NM, Nasir Khan M, Khan QH, Zhang B, Yang J, Ding Y, Ye C. Determination of the Debye-Waller factor of molybdenum by powder neutron diffraction. J Appl Crystallogr 1992. [DOI: 10.1107/s0021889892007416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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196
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Todorovich-Hunter L, Dodo H, Ye C, McCready L, Keeley FW, Rabinovitch M. Increased pulmonary artery elastolytic activity in adult rats with monocrotaline-induced progressive hypertensive pulmonary vascular disease compared with infant rats with nonprogressive disease. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1992; 146:213-23. [PMID: 1626806 DOI: 10.1164/ajrccm/146.1.213] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In a rat model of pulmonary hypertension induced by monocrotaline, medial hypertrophy of the pulmonary arteries is associated with enhanced production (synthesis) of insoluble elastin relative to accumulation and an increased number of elastin fragments, features suggestive of an elastolytic process. In the present study, we measured and characterized pulmonary artery (PA) elastolytic activity at time points before as well as coincident with the progression of medial hypertrophy in monocrotaline-injected adult male Sprague-Dawley rats. We also determined whether medial hypertrophy is preceded by ultrastructural changes in elastin. Since medial hypertrophy develops but fails to progress in rats injected with monocrotaline at 8 days of age, we assessed whether, compared with adult rats, there were also structural and biochemical differences in elastin and elastolytic activity. A twofold increase in elastolytic activity per milligram tissue was observed 2 days after monocrotaline injection in adult rats (p less than 0.01), and there was an increased number of breaks in the internal elastic lamina (IEL) at 4 days (p less than 0.05) (i.e., before the development of medial hypertrophy). Associated with the progression of medial hypertrophy between 16 and 28 days after monocrotaline injection, there was a further threefold increase in elastolytic activity per milligram tissue by 28 days (p less than 0.01). Susceptibility of the elastolytic activity to specific inhibitors suggested that one or more serine elastases is involved. In infant rats in which medial and right ventricular hypertrophy fail to progress in severity between 16 and 28 days after monocrotaline injection, we did not measure an increase in elastolytic activity, nor was there evidence of an increase in the number of breaks in the IEL at 4 days, suggesting a lack of increased elastolytic activity at an earlier time point. The total content of PA elastin in infant rats, although increased compared with control rats (p less than 0.01), was not associated with heightened production and appeared ultrastructurally as thicker laminae (p less than 0.05) rather than as fragments previously reported in adult rats.
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Ye C, Rabinovitch M. New developments in the pulmonary circulation in children. Curr Opin Cardiol 1992; 7:124-33. [PMID: 10149847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
This article reviews new advances in the diagnosis, treatment, and pathophysiology of pulmonary hypertension. In diagnosis, Doppler echocardiography has been refined and its accuracy increased, and magnetic resonance imaging is being developed as a new tool. Prostacyclin and calcium channel blockers remain mainstays of short-term therapy, and single-lung transplantation has become a new therapeutic option. Newer pharmacotherapeutics are largely directed at reversing acute vasoconstriction and include approaches related to ATP and endothelial-derived relaxing factor. In pathophysiology, recent studies have shown the role of elastase in mediating the initiation and progression of pulmonary hypertension, the regulation of gene expression of collagen, elastin, endothelin, and growth factors including transforming growth factor-B and insulinlike growth factor-I, and mechanisms of signal transduction of smooth muscle cell proliferation. The migratory smooth muscle cell phenotype has been studied in terms of altered expression of endothelial and smooth muscle extracellular matrix components, including hyaluronan and fibronectin, respectively.
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Ye C. [Pharmacological study on an irreversible ligand of opioid receptors, A-alpha-CAM, and its reaction with the sulfhydryl group]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1991; 13:39-45. [PMID: 1652379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A-alpha-CAM is an irreversible partial agonist of opiate receptors. Its binding to opioid receptors from P2 membrane preparations of rat brain and its effect on isolated tissues (GPI, MVD, RVD and RbVD) could not be washed away, indicating the irreversible nature of its binding. A-alpha-CAM inhibited the electrically elicited contraction of GPI, a pure agonist, with an IC50 of 2.6 mumol/L, and this effect could not be antagonized by Nx. A-alpha-CAM acted as a partial agonist on MVD with an IC50 of 0.153 mumol/L. With RVD and RbVD, A-alpha-CAM acted as an antagonist with PA2 values of 7.4 and 7.7 respectively. Possibly, covalent binding of A-alpha-CAM with the sulfhydryl groups of opioid receptors is the biochemical mechanisms responsible for its irreversible action.
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Suto M, Ye C, Lee LC. Photoabsorption and fluorescence spectroscopy of BF3 in the extreme-vacuum-ultraviolet region. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 42:424-431. [PMID: 9903819 DOI: 10.1103/physreva.42.424] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Zhang B, Yang J, Jin L, Ye C, Bashir J, Butt NM, Siddique M, Arshed M, Khan QH. Temperature factor of silicon by powder neutron diffraction. Acta Crystallogr A 1990. [DOI: 10.1107/s0108767389013401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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