1
|
Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, Liu L, Shan H, Lei CL, Hui DSC, Du B, Li LJ, Zeng G, Yuen KY, Chen RC, Tang CL, Wang T, Chen PY, Xiang J, Li SY, Wang JL, Liang ZJ, Peng YX, Wei L, Liu Y, Hu YH, Peng P, Wang JM, Liu JY, Chen Z, Li G, Zheng ZJ, Qiu SQ, Luo J, Ye CJ, Zhu SY, Zhong NS. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med 2020; 382:1708-1720. [PMID: 32109013 PMCID: PMC7092819 DOI: 10.1056/nejmoa2002032] [Citation(s) in RCA: 18740] [Impact Index Per Article: 3748.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Since December 2019, when coronavirus disease 2019 (Covid-19) emerged in Wuhan city and rapidly spread throughout China, data have been needed on the clinical characteristics of the affected patients. METHODS We extracted data regarding 1099 patients with laboratory-confirmed Covid-19 from 552 hospitals in 30 provinces, autonomous regions, and municipalities in mainland China through January 29, 2020. The primary composite end point was admission to an intensive care unit (ICU), the use of mechanical ventilation, or death. RESULTS The median age of the patients was 47 years; 41.9% of the patients were female. The primary composite end point occurred in 67 patients (6.1%), including 5.0% who were admitted to the ICU, 2.3% who underwent invasive mechanical ventilation, and 1.4% who died. Only 1.9% of the patients had a history of direct contact with wildlife. Among nonresidents of Wuhan, 72.3% had contact with residents of Wuhan, including 31.3% who had visited the city. The most common symptoms were fever (43.8% on admission and 88.7% during hospitalization) and cough (67.8%). Diarrhea was uncommon (3.8%). The median incubation period was 4 days (interquartile range, 2 to 7). On admission, ground-glass opacity was the most common radiologic finding on chest computed tomography (CT) (56.4%). No radiographic or CT abnormality was found in 157 of 877 patients (17.9%) with nonsevere disease and in 5 of 173 patients (2.9%) with severe disease. Lymphocytopenia was present in 83.2% of the patients on admission. CONCLUSIONS During the first 2 months of the current outbreak, Covid-19 spread rapidly throughout China and caused varying degrees of illness. Patients often presented without fever, and many did not have abnormal radiologic findings. (Funded by the National Health Commission of China and others.).
Collapse
|
research-article |
5 |
18740 |
2
|
Bak P, Tang C, Wiesenfeld K. Self-organized criticality: An explanation of the 1/f noise. PHYSICAL REVIEW LETTERS 1987; 59:381-384. [PMID: 10035754 DOI: 10.1103/physrevlett.59.381] [Citation(s) in RCA: 2207] [Impact Index Per Article: 58.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
|
|
38 |
2207 |
3
|
Guan WJ, Liang WH, Zhao Y, Liang HR, Chen ZS, Li YM, Liu XQ, Chen RC, Tang CL, Wang T, Ou CQ, Li L, Chen PY, Sang L, Wang W, Li JF, Li CC, Ou LM, Cheng B, Xiong S, Ni ZY, Xiang J, Hu Y, Liu L, Shan H, Lei CL, Peng YX, Wei L, Liu Y, Hu YH, Peng P, Wang JM, Liu JY, Chen Z, Li G, Zheng ZJ, Qiu SQ, Luo J, Ye CJ, Zhu SY, Cheng LL, Ye F, Li SY, Zheng JP, Zhang NF, Zhong NS, He JX. Comorbidity and its impact on 1590 patients with COVID-19 in China: a nationwide analysis. Eur Respir J 2020; 55:13993003.00547-2020. [PMID: 32217650 PMCID: PMC7098485 DOI: 10.1183/13993003.00547-2020] [Citation(s) in RCA: 2177] [Impact Index Per Article: 435.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 03/13/2020] [Indexed: 02/07/2023]
Abstract
Background The coronavirus disease 2019 (COVID-19) outbreak is evolving rapidly worldwide. Objective To evaluate the risk of serious adverse outcomes in patients with COVID-19 by stratifying the comorbidity status. Methods We analysed data from 1590 laboratory confirmed hospitalised patients from 575 hospitals in 31 provinces/autonomous regions/provincial municipalities across mainland China between 11 December 2019 and 31 January 2020. We analysed the composite end-points, which consisted of admission to an intensive care unit, invasive ventilation or death. The risk of reaching the composite end-points was compared according to the presence and number of comorbidities. Results The mean age was 48.9 years and 686 (42.7%) patients were female. Severe cases accounted for 16.0% of the study population. 131 (8.2%) patients reached the composite end-points. 399 (25.1%) reported having at least one comorbidity. The most prevalent comorbidity was hypertension (16.9%), followed by diabetes (8.2%). 130 (8.2%) patients reported having two or more comorbidities. After adjusting for age and smoking status, COPD (HR (95% CI) 2.681 (1.424–5.048)), diabetes (1.59 (1.03–2.45)), hypertension (1.58 (1.07–2.32)) and malignancy (3.50 (1.60–7.64)) were risk factors of reaching the composite end-points. The hazard ratio (95% CI) was 1.79 (1.16–2.77) among patients with at least one comorbidity and 2.59 (1.61–4.17) among patients with two or more comorbidities. Conclusion Among laboratory confirmed cases of COVID-19, patients with any comorbidity yielded poorer clinical outcomes than those without. A greater number of comorbidities also correlated with poorer clinical outcomes. The presence and number of comorbidities predict clinical outcomes of COVID-19http://bit.ly/3b9ibw5
Collapse
|
Research Support, Non-U.S. Gov't |
5 |
2177 |
4
|
Bak P, Tang C, Wiesenfeld K. Self-organized criticality. PHYSICAL REVIEW. A, GENERAL PHYSICS 1988; 38:364-374. [PMID: 9900174 DOI: 10.1103/physreva.38.364] [Citation(s) in RCA: 1146] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
|
37 |
1146 |
5
|
Mohammadi M, McMahon G, Sun L, Tang C, Hirth P, Yeh BK, Hubbard SR, Schlessinger J. Structures of the tyrosine kinase domain of fibroblast growth factor receptor in complex with inhibitors. Science 1997; 276:955-60. [PMID: 9139660 DOI: 10.1126/science.276.5314.955] [Citation(s) in RCA: 901] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A new class of protein tyrosine kinase inhibitors was identified that is based on an oxindole core (indolinones). Two compounds from this class inhibited the kinase activity of fibroblast growth factor receptor 1 (FGFR1) and showed differential specificity toward other receptor tyrosine kinases. Crystal structures of the tyrosine kinase domain of FGFR1 in complex with the two compounds were determined. The oxindole occupies the site in which the adenine of adenosine triphosphate binds, whereas the moieties that extend from the oxindole contact residues in the hinge region between the two kinase lobes. The more specific inhibitor of FGFR1 induces a conformational change in the nucleotide-binding loop. This structural information will facilitate the design of new inhibitors for use in the treatment of cancer and other diseases in which cell signaling by tyrosine kinases plays a crucial role in disease pathogenesis.
Collapse
MESH Headings
- 3T3 Cells
- Adenosine Triphosphate/metabolism
- Amino Acid Sequence
- Animals
- Crystallography, X-Ray
- Enzyme Inhibitors/chemistry
- Enzyme Inhibitors/metabolism
- Enzyme Inhibitors/pharmacology
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/metabolism
- Hydrogen Bonding
- Mice
- Models, Molecular
- Phosphorylation
- Phosphotyrosine/metabolism
- Piperazines/chemistry
- Piperazines/metabolism
- Piperazines/pharmacology
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Protein-Tyrosine Kinases/chemistry
- Protein-Tyrosine Kinases/metabolism
- Pyrroles/chemistry
- Pyrroles/metabolism
- Pyrroles/pharmacology
- Receptor Protein-Tyrosine Kinases
- Receptor, Fibroblast Growth Factor, Type 1
- Receptor, Insulin/antagonists & inhibitors
- Receptor, Insulin/metabolism
- Receptors, Fibroblast Growth Factor/antagonists & inhibitors
- Receptors, Fibroblast Growth Factor/chemistry
- Receptors, Fibroblast Growth Factor/metabolism
- Receptors, Platelet-Derived Growth Factor/antagonists & inhibitors
- Receptors, Platelet-Derived Growth Factor/metabolism
Collapse
|
|
28 |
901 |
6
|
Jones KA, Borowsky B, Tamm JA, Craig DA, Durkin MM, Dai M, Yao WJ, Johnson M, Gunwaldsen C, Huang LY, Tang C, Shen Q, Salon JA, Morse K, Laz T, Smith KE, Nagarathnam D, Noble SA, Branchek TA, Gerald C. GABA(B) receptors function as a heteromeric assembly of the subunits GABA(B)R1 and GABA(B)R2. Nature 1998; 396:674-9. [PMID: 9872315 DOI: 10.1038/25348] [Citation(s) in RCA: 781] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The principal inhibitory neurotransmitter GABA (gamma-aminobutyric acid) exerts its effects through two ligand-gated channels, GABA(A) and GABA(C) receptors, and a third receptor, GABA(B) , which acts through G proteins to regulate potassium and calcium channels. Cells heterologously expressing the cloned DNA encoding the GABA(B)R1 protein exhibit high-affinity antagonist-binding sites, but they produce little of the functional activity expected from studies of endogenous GABA(B) receptors in the brain. Here we describe a new member of the GABA(B) polypeptide family, GABA(B)R2, that shows sequence homology to GABA(B)R1. Neither GABA(B)R1 nor GABA(B)R2, when expressed individually, activates GIRK-type potassium channels; however, the combination of GABA(B)R1 and GABA(B)R2 confers robust stimulation of channel activity. Both genes are co-expressed in individual neurons, and both proteins co-localize in transfected cells. Moreover, immunoprecipitation experiments indicate that the two polypeptides associate with each other, probably as heterodimers. Several G-protein-coupled receptors (GPCRs) exist as high-molecular-weight species, consistent with the formation of dimers by these receptors, but the relevance of these species for the functioning of GPCRs has not been established. We have now shown that co-expression of two GPCR structures, GABA(B)R1 and GABA(B)R2, belonging to the same subfamily is essential for signal transduction by GABA(B) receptors.
Collapse
|
|
27 |
781 |
7
|
Cahill L, Haier RJ, Fallon J, Alkire MT, Tang C, Keator D, Wu J, McGaugh JL. Amygdala activity at encoding correlated with long-term, free recall of emotional information. Proc Natl Acad Sci U S A 1996; 93:8016-21. [PMID: 8755595 PMCID: PMC38867 DOI: 10.1073/pnas.93.15.8016] [Citation(s) in RCA: 551] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Positron emission tomography of cerebral glucose metabolism in adult human subjects was used to investigate amygdaloid complex (AC) activity associated with the storage of long-term memory for emotionally arousing events. Subjects viewed two videos (one in each of two separate positron emission tomography sessions, separated by 3-7 days) consisting either of 12 emotionally arousing film clips ("E" film session) or of 12 relatively emotionally neutral film clips ("N" film session), and rated their emotional reaction to each film clip immediately after viewing it. Three weeks after the second session, memory for the videos was assessed in a free recall test. As expected, the subjects' average emotional reaction to the E films was higher than that for the N films. In addition, the subjects recalled significantly more E films than N films. Glucose metabolic rate of the right AC while viewing the E films was highly correlated with the number of E films recalled. AC activity was not significantly correlated with the number of N films recalled. The findings support the view derived from both animal and human investigations that the AC is selectively involved with the formation of enhanced long-term memory associated with emotionally arousing events.
Collapse
|
|
29 |
551 |
8
|
Chen R, Liang W, Jiang M, Guan W, Zhan C, Wang T, Tang C, Sang L, Liu J, Ni Z, Hu Y, Liu L, Shan H, Lei C, Peng Y, Wei L, Liu Y, Hu Y, Peng P, Wang J, Liu J, Chen Z, Li G, Zheng Z, Qiu S, Luo J, Ye C, Zhu S, Liu X, Cheng L, Ye F, Zheng J, Zhang N, Li Y, He J, Li S, Zhong N. Risk Factors of Fatal Outcome in Hospitalized Subjects With Coronavirus Disease 2019 From a Nationwide Analysis in China. Chest 2020; 158:97-105. [PMID: 32304772 PMCID: PMC7158802 DOI: 10.1016/j.chest.2020.04.010] [Citation(s) in RCA: 408] [Impact Index Per Article: 81.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/10/2020] [Accepted: 04/11/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The novel coronavirus disease 2019 (COVID-19) has become a global health emergency. The cumulative number of new confirmed cases and deaths are still increasing out of China. Independent predicted factors associated with fatal outcomes remain uncertain. RESEARCH QUESTION The goal of the current study was to investigate the potential risk factors associated with fatal outcomes from COVID-19 through a multivariate Cox regression analysis and a nomogram model. STUDY DESIGN AND METHODS A retrospective cohort of 1,590 hospitalized patients with COVID-19 throughout China was established. The prognostic effects of variables, including clinical features and laboratory findings, were analyzed by using Kaplan-Meier methods and a Cox proportional hazards model. A prognostic nomogram was formulated to predict the survival of patients with COVID-19. RESULTS In this nationwide cohort, nonsurvivors included a higher incidence of elderly people and subjects with coexisting chronic illness, dyspnea, and laboratory abnormalities on admission compared with survivors. Multivariate Cox regression analysis showed that age ≥ 75 years (hazard ratio [HR], 7.86; 95% CI, 2.44-25.35), age between 65 and 74 years (HR, 3.43; 95% CI, 1.24-9.5), coronary heart disease (HR, 4.28; 95% CI, 1.14-16.13), cerebrovascular disease (HR, 3.1; 95% CI, 1.07-8.94), dyspnea (HR, 3.96; 95% CI, 1.42-11), procalcitonin level > 0.5 ng/mL (HR, 8.72; 95% CI, 3.42-22.28), and aspartate aminotransferase level > 40 U/L (HR, 2.2; 95% CI, 1.1-6.73) were independent risk factors associated with fatal outcome. A nomogram was established based on the results of multivariate analysis. The internal bootstrap resampling approach suggested the nomogram has sufficient discriminatory power with a C-index of 0.91 (95% CI, 0.85-0.97). The calibration plots also showed good consistency between the prediction and the observation. INTERPRETATION The proposed nomogram accurately predicted clinical outcomes of patients with COVID-19 based on individual characteristics. Earlier identification, more intensive surveillance, and appropriate therapy should be considered in patients at high risk.
Collapse
|
research-article |
5 |
408 |
9
|
Li H, Helling R, Tang C, Wingreen N. Emergence of preferred structures in a simple model of protein folding. Science 1996; 273:666-9. [PMID: 8662562 DOI: 10.1126/science.273.5275.666] [Citation(s) in RCA: 389] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Protein structures in nature often exhibit a high degree of regularity (for example, secondary structure and tertiary symmetries) that is absent from random compact conformations. With the use of a simple lattice model of protein folding, it was demonstrated that structural regularities are related to high "designability" and evolutionary stability. The designability of each compact structure is measured by the number of sequences that can design the structure-that is, sequences that possess the structure as their nondegenerate ground state. Compact structures differ markedly in terms of their designability; highly designable structures emerge with a number of associated sequences much larger than the average. These highly designable structures possess "proteinlike" secondary structure and even tertiary symmetries. In addition, they are thermodynamically more stable than other structures. These results suggest that protein structures are selected in nature because they are readily designed and stable against mutations, and that such a selection simultaneously leads to thermodynamic stability.
Collapse
|
|
29 |
389 |
10
|
Sun L, Tran N, Tang F, App H, Hirth P, McMahon G, Tang C. Synthesis and biological evaluations of 3-substituted indolin-2-ones: a novel class of tyrosine kinase inhibitors that exhibit selectivity toward particular receptor tyrosine kinases. J Med Chem 1998; 41:2588-603. [PMID: 9651163 DOI: 10.1021/jm980123i] [Citation(s) in RCA: 382] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
3-Substituted indolin-2-ones have been designed and synthesized as a novel class of tyrosine kinase inhibitors which exhibit selectivity toward different receptor tyrosine kinases (RTKs). These compounds have been evaluated for their relative inhibitory properties against a panel of RTKs in intact cells. By modifying the 3-substituted indolin-2-ones, we have identified compounds which showed selective inhibition of the ligand-dependent autophosphorylation of various RTKs at submicromolar levels in cells. Structure-activity analysis for these compounds and their relative potency and selectivity to inhibit particular RTKs has determined that (1) 3-[(five-membered heteroaryl ring)methylidenyl]indolin-2-ones are highly specific against the VEGF (Flk-1) RTK activity, (2) 3-(substituted benzylidenyl)indolin-2-ones containing bulky group(s) in the phenyl ring at the C-3 position of indolin-2-ones showed high selectivity toward the EGF and Her-2 RTKs, and (3) the compound containing an extended side chain at the C-3 position of the indolin-2-one (16) exhibited high potency and selectivity when tested against the PDGF and VEGF (Flk-1) RTKs. Recent published crystallographic data for two of these 3-substituted indolin-2-ones provides a rationale to suggest that these compounds may bind in the ATP binding pocket of RTKs. The structure-activity analysis supports the use of subsets of these compounds as specific chemical leads for the development of RTK-specific drugs with broad application for the treatment of human diseases.
Collapse
|
|
27 |
382 |
11
|
Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, Liu L, Shan H, Lei CL, Hui DSC, Du B, Li LJ, Zeng G, Yuen KY, Chen RC, Tang CL, Wang T, Chen PY, Xiang J, Li SY, Wang JL, Liang ZJ, Peng YX, Wei L, Liu Y, Hu YH, Peng P, Wang JM, Liu JY, Chen Z, Li G, Zheng ZJ, Qiu SQ, Luo J, Ye CJ, Zhu SY, Zhong NS. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med 2020; 382:1708-1720. [PMID: 32109013 DOI: 10.1101/2020.02.06.20020974] [Citation(s) in RCA: 348] [Impact Index Per Article: 69.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
BACKGROUND Since December 2019, when coronavirus disease 2019 (Covid-19) emerged in Wuhan city and rapidly spread throughout China, data have been needed on the clinical characteristics of the affected patients. METHODS We extracted data regarding 1099 patients with laboratory-confirmed Covid-19 from 552 hospitals in 30 provinces, autonomous regions, and municipalities in mainland China through January 29, 2020. The primary composite end point was admission to an intensive care unit (ICU), the use of mechanical ventilation, or death. RESULTS The median age of the patients was 47 years; 41.9% of the patients were female. The primary composite end point occurred in 67 patients (6.1%), including 5.0% who were admitted to the ICU, 2.3% who underwent invasive mechanical ventilation, and 1.4% who died. Only 1.9% of the patients had a history of direct contact with wildlife. Among nonresidents of Wuhan, 72.3% had contact with residents of Wuhan, including 31.3% who had visited the city. The most common symptoms were fever (43.8% on admission and 88.7% during hospitalization) and cough (67.8%). Diarrhea was uncommon (3.8%). The median incubation period was 4 days (interquartile range, 2 to 7). On admission, ground-glass opacity was the most common radiologic finding on chest computed tomography (CT) (56.4%). No radiographic or CT abnormality was found in 157 of 877 patients (17.9%) with nonsevere disease and in 5 of 173 patients (2.9%) with severe disease. Lymphocytopenia was present in 83.2% of the patients on admission. CONCLUSIONS During the first 2 months of the current outbreak, Covid-19 spread rapidly throughout China and caused varying degrees of illness. Patients often presented without fever, and many did not have abnormal radiologic findings. (Funded by the National Health Commission of China and others.).
Collapse
|
|
5 |
348 |
12
|
Tan WS, Tang CL, Shi L, Eu KW. Meta-analysis of defunctioning stomas in low anterior resection for rectal cancer. Br J Surg 2009; 96:462-72. [PMID: 19358171 DOI: 10.1002/bjs.6594] [Citation(s) in RCA: 327] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND A defunctioning stoma is frequently created to minimize the impact of any subsequent anastomotic leak after a low rectal anastomosis. This review evaluates the need for routine stoma formation. METHODS A meta-analysis was performed of randomized controlled trials (RCTs) and non-randomized studies with an interventional group evaluating the need for a defunctioning stoma after low anterior resection for rectal cancer. Primary outcomes analysed included clinical anastomotic leak rate, reoperation rate and mortality related to leak. RESULTS Four RCTs and 21 non-randomized studies, with 11,429 patients in total, were analysed. Meta-analysis of the RCTs showed a lower clinical anastomotic leak rate (risk ratio (RR) 0.39 (95 per cent c.i. 0.23 to 0.66); P < 0.001) and a lower reoperation rate (RR 0.29 (0.16 to 0.53); P < 0.001) in the stoma group. Meta-analysis of the non-randomized studies showed a lower clinical anastomotic leak rate (RR 0.74 (0.67 to 0.83); P < 0.001), lower reoperation rate (RR 0.28 (0.23 to 0.35); P < 0.001) and lower mortality rate (RR 0.42 (0.28 to 0.61); P < 0.001) in the stoma group. CONCLUSION A defunctioning stoma decreases clinical anastomotic leak rate and reoperation rate. It is recommended after low anterior resection for rectal cancer.
Collapse
|
Review |
16 |
327 |
13
|
Bustamante C, Vesenka J, Tang CL, Rees W, Guthold M, Keller R. Circular DNA molecules imaged in air by scanning force microscopy. Biochemistry 1992; 31:22-6. [PMID: 1310032 DOI: 10.1021/bi00116a005] [Citation(s) in RCA: 283] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Routine and reproducible imaging of DNA molecules in air with the scanning force microscope (SFM) has been accomplished. Circular molecules of plasmid DNA were deposited onto red mica and imaged under various relative humidities. In related experiments, the first images of the Escherichia coli RNA polymerase-DNA complex have also been obtained. This has been possible by (1) the use of specially modified SFM tips with a consistent radius of curvature of 10 nm or less, to minimize the amount of image distortion introduced by the finite dimensions of commercially available tips, (2) the optimization of a method to deposit and bind DNA molecules to the mica surface in a stable fashion, and (3) careful control of the sample humidity, to prevent solvation of the molecules and detachment from the surface by the scanning tip or stylus. Contact forces in the range of a few nanonewtons are routinely possible in air and in the presence of residual humidity. The spatial resolution of the images appears determined by the radius of curvature of the modified styli, which can be estimated directly from the apparent widths of the DNA molecules in the images.
Collapse
|
|
33 |
283 |
14
|
Kennedy BP, Payette P, Mudgett J, Vadas P, Pruzanski W, Kwan M, Tang C, Rancourt DE, Cromlish WA. A natural disruption of the secretory group II phospholipase A2 gene in inbred mouse strains. J Biol Chem 1995; 270:22378-85. [PMID: 7673223 DOI: 10.1074/jbc.270.38.22378] [Citation(s) in RCA: 274] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The synovial fluid or group II secretory phospholipase A2 (sPLA2) has been implicated as an important agent involved in a number of inflammatory processes. In an attempt to determine the role of sPLA2 in inflammation, we set out to generate sPLA2-deficient mice. During this investigation, we observed that in a number of inbred mouse strains, the sPLA2 gene was already disrupted by a frameshift mutation in exon 3. This mutation, a T insertion at position 166 from the ATG of the cDNA, terminates out of frame in exon 4, resulting in the disruption of the calcium binding domain in exon 3 and loss of both activity domains coded by exons 4 and 5. The mouse strains C57BL/6, 129/Sv, and B10.RIII were found to be homozygous for the defective sPLA2 gene, whereas outbred CD-1:SW mice had variable genotype at this locus. BALB/c, C3H/HE, DBA/1, DBA/2, NZB/BIN, and MRL lpr/lpr mice had a normal sPLA2 genotype. The sPLA2 mRNA was expressed at very high levels in the BALB/c mouse small intestine, whereas in the small intestine of the sPLA2 mutant mouse strains, sPLA2 mRNA was undetectable. In addition, PLA2 activity in acid extracts of the small intestine were approximately 40 times higher in BALB/c than in the mutant mice. Transcription of the mutant sPLA2 gene resulted in multiple transcripts due to exon skipping. None of the resulting mutant mRNAs encoded an active product. The identification of this mutation should not only help define the physiological role of sPLA2 but also has important implications in mouse inflammatory models developed by targeted mutagenesis.
Collapse
|
Comparative Study |
30 |
274 |
15
|
Wang T, Chen R, Liu C, Liang W, Guan W, Tang R, Tang C, Zhang N, Zhong N, Li S. Attention should be paid to venous thromboembolism prophylaxis in the management of COVID-19. Lancet Haematol 2020; 7:e362-e363. [PMID: 32278361 PMCID: PMC7158946 DOI: 10.1016/s2352-3026(20)30109-5] [Citation(s) in RCA: 272] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 12/14/2022]
|
discussion |
5 |
272 |
16
|
Vesenka J, Guthold M, Tang CL, Keller D, Delaine E, Bustamante C. Substrate preparation for reliable imaging of DNA molecules with the scanning force microscope. Ultramicroscopy 1992; 42-44 ( Pt B):1243-9. [PMID: 1413262 DOI: 10.1016/0304-3991(92)90430-r] [Citation(s) in RCA: 226] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A simple method of substrate preparation for imaging circular DNA molecules with the scanning force microscope (SFM) is presented. These biomolecules are adsorbed onto mica that has been soaked in magnesium acetate, sonicated and glow-discharged. The stylus-sample forces that may be endured before sample damage occurs depends on the ambient relative humidity. Images of circular DNA molecules have been obtained routinely using tips specially modified by an electron beam with a radius of curvature, Rc, of about 10 nm [D. Keller and C. Chih-Chung, Surf. Sci. 268 (1992) 333]. The resolution of these adsorbed biomolecules is determined by the Rc. At higher forces individual circular DNA molecules can be manipulated with the SFM stylus. Strategies to develop still sharper probes will be discussed.
Collapse
|
|
33 |
226 |
17
|
Tang C, Blatter DD, Parker DL. Accuracy of phase-contrast flow measurements in the presence of partial-volume effects. J Magn Reson Imaging 1993; 3:377-85. [PMID: 8448400 DOI: 10.1002/jmri.1880030213] [Citation(s) in RCA: 223] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The accuracy of volume flow rate measurements obtained with phase-contrast methods was assessed by means of computer simulation and in vitro experiments. Factors studied include (a) the partial-volume effect due to voxel dimensions relative to vessel dimensions and orientation and (b) intravoxel phase dispersion. It is shown that limited resolution (partial-volume effect) is the major obstacle to accurate flow measurement for both laminar and plug flow. The results show that at least 16 voxels must cover the cross section of the vessel lumen to obtain a measurement accuracy to within 10%. Measurement accuracy also greatly depends on the relative signal intensity of stationary tissue and is better for laminar flow than plug flow.
Collapse
|
|
32 |
223 |
18
|
Liang WH, Guan WJ, Li CC, Li YM, Liang HR, Zhao Y, Liu XQ, Sang L, Chen RC, Tang CL, Wang T, Wang W, He QH, Chen ZS, Wong SS, Zanin M, Liu J, Xu X, Huang J, Li JF, Ou LM, Cheng B, Xiong S, Xie ZH, Ni ZY, Hu Y, Liu L, Shan H, Lei CL, Peng YX, Wei L, Liu Y, Hu YH, Peng P, Wang JM, Liu JY, Chen Z, Li G, Zheng ZJ, Qiu SQ, Luo J, Ye CJ, Zhu SY, Cheng LL, Ye F, Li SY, Zheng JP, Zhang NF, Zhong NS, He JX. Clinical characteristics and outcomes of hospitalised patients with COVID-19 treated in Hubei (epicentre) and outside Hubei (non-epicentre): a nationwide analysis of China. Eur Respir J 2020; 55:2000562. [PMID: 32269086 PMCID: PMC7144336 DOI: 10.1183/13993003.00562-2020] [Citation(s) in RCA: 190] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 03/29/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND During the outbreak of coronavirus disease 2019 (COVID-19), consistent and considerable differences in disease severity and mortality rate of patients treated in Hubei province compared to those in other parts of China have been observed. We sought to compare the clinical characteristics and outcomes of patients being treated inside and outside Hubei province, and explore the factors underlying these differences. METHODS Collaborating with the National Health Commission, we established a retrospective cohort to study hospitalised COVID-19 cases in China. Clinical characteristics, the rate of severe events and deaths, and the time to critical illness (invasive ventilation or intensive care unit admission or death) were compared between patients within and outside Hubei. The impact of Wuhan-related exposure (a presumed key factor that drove the severe situation in Hubei, as Wuhan is the epicentre as well the administrative centre of Hubei province) and the duration between symptom onset and admission on prognosis were also determined. RESULTS At the data cut-off (31 January 2020), 1590 cases from 575 hospitals in 31 provincial administrative regions were collected (core cohort). The overall rate of severe cases and mortality was 16.0% and 3.2%, respectively. Patients in Hubei (predominantly with Wuhan-related exposure, 597 (92.3%) out of 647) were older (mean age 49.7 versus 44.9 years), had more cases with comorbidity (32.9% versus 19.7%), higher symptomatic burden, abnormal radiologic manifestations and, especially, a longer waiting time between symptom onset and admission (5.7 versus 4.5 days) compared with patients outside Hubei. Patients in Hubei (severe event rate 23.0% versus 11.1%, death rate 7.3% versus 0.3%, HR (95% CI) for critical illness 1.59 (1.05-2.41)) have a poorer prognosis compared with patients outside Hubei after adjusting for age and comorbidity. However, among patients outside Hubei, the duration from symptom onset to hospitalisation (mean 4.4 versus 4.7 days) and prognosis (HR (95%) 0.84 (0.40-1.80)) were similar between patients with or without Wuhan-related exposure. In the overall population, the waiting time, but neither treated in Hubei nor Wuhan-related exposure, remained an independent prognostic factor (HR (95%) 1.05 (1.01-1.08)). CONCLUSION There were more severe cases and poorer outcomes for COVID-19 patients treated in Hubei, which might be attributed to the prolonged duration of symptom onset to hospitalisation in the epicentre. Future studies to determine the reason for delaying hospitalisation are warranted.
Collapse
|
research-article |
5 |
190 |
19
|
Sun L, Tran N, Liang C, Tang F, Rice A, Schreck R, Waltz K, Shawver LK, McMahon G, Tang C. Design, synthesis, and evaluations of substituted 3-[(3- or 4-carboxyethylpyrrol-2-yl)methylidenyl]indolin-2-ones as inhibitors of VEGF, FGF, and PDGF receptor tyrosine kinases. J Med Chem 1999; 42:5120-30. [PMID: 10602697 DOI: 10.1021/jm9904295] [Citation(s) in RCA: 187] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Receptor tyrosine kinases (RTKs) have been implicated as therapeutic targets for the treatment of human diseases including cancers, inflammatory diseases, cardiovascular diseases including arterial restenosis, and fibrotic diseases of the lung, liver, and kidney. Three classes of 3-substituted indolin-2-ones containing propionic acid functionality attached to the pyrrole ring at the C-3 position of the core have been identified as catalytic inhibitors of the vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF) RTKs. Some of the compounds were found to inhibit the tyrosine kinase activity associated with isolated vascular endothelial growth factor receptor 2 (VEGF-R2) [fetal liver tyrosine kinase 1 (Flk-1)/kinase insert domain-containing receptor (KDR)], fibroblast growth factor receptor (FGF-R), and platelet-derived growth factor receptor (PDGF-R) tyrosine kinase with IC(50) values at nanomolar level. Thus, compound 1 showed inhibition against VEGF-R2 (Flk-1/KDR) and FGF-R1 tyrosine kinase activity with IC(50) values of 20 and 30 nM, respectively, while compound 16f inhibited the PDGF-R tyrosine kinase activity with IC(50) value of 10 nM. Structural models and structure-activity relationship analysis of these compounds for the target receptors are discussed. The cellular activities of these compounds were profiled using cellular proliferation assays as measured by bromodeoxyuridine (BrdU) incorporation. Specific and potent inhibition of cell growth was observed for some of these compounds. These data provide evidence that these compounds can be used to inhibit the function of these target receptors.
Collapse
|
|
26 |
187 |
20
|
Dai Z, Zhang X, Tang C, Muhammad N, Wu J, Brookes PC, Xu J. Potential role of biochars in decreasing soil acidification - A critical review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 581-582:601-611. [PMID: 28063658 DOI: 10.1016/j.scitotenv.2016.12.169] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/24/2016] [Accepted: 12/25/2016] [Indexed: 05/24/2023]
Abstract
A large number of soils, worldwide, are acid (normally pH<5.5) and suffering from on-going soil acidification. Acid soils or soils undergoing acidification generally have low fertility and low crop productivity. Biochars have been reported to be of potential value in agriculture for improving soil properties and in reducing the hazards caused by soil acidification and in naturally acidic soils. However, the ameliorant effects of biochars on acid soils and the mechanisms involved have not previously been critically reviewed. Here we summarize the phenomena, and mechanisms involved in the improvement of soil acidity by biochars, the alleviation of aluminum toxicity, the enhancement of nutrient availability, and changes in nitrification by collating data in the literature. In addition, the agronomic effectiveness and environmental concerns in the incorporation of biochar and other soil additives (i.e. lime, industrial by-products, organic wastes and plant residues) to acid soils are systemically compared. We conclude that biochar is a potentially effective amendment to reverse or to prevent acidification in acid soils. Finally, perspectives for further research in terms of soil acidification are presented to address some issues that are still poorly understood and/or highly controversial.
Collapse
|
Review |
8 |
179 |
21
|
Kohmoto M, Sutherland B, Tang C. Critical wave functions and a Cantor-set spectrum of a one-dimensional quasicrystal model. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 35:1020-1033. [PMID: 9941510 DOI: 10.1103/physrevb.35.1020] [Citation(s) in RCA: 173] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
|
38 |
173 |
22
|
Rosker MJ, Wise FW, Tang CL. Femtosecond relaxation dynamics of large molecules. PHYSICAL REVIEW LETTERS 1986; 57:321-324. [PMID: 10034030 DOI: 10.1103/physrevlett.57.321] [Citation(s) in RCA: 171] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
|
39 |
171 |
23
|
Ho YH, Cheong WK, Tsang C, Ho J, Eu KW, Tang CL, Seow-Choen F. Stapled hemorrhoidectomy--cost and effectiveness. Randomized, controlled trial including incontinence scoring, anorectal manometry, and endoanal ultrasound assessments at up to three months. Dis Colon Rectum 2000; 43:1666-1675. [PMID: 11156449 DOI: 10.1007/bf02236847] [Citation(s) in RCA: 171] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Stapled hemorrhoidectomy is performed without leaving painful perianal wounds. The aim of this study was to assess any benefits, compared with a conventional open diathermy technique. METHODS A total of 119 consecutive patients with prolapsed irreducible hemorrhoids were randomly assigned (conventional open diathermy technique = 62; stapled hemorrhoidectomy = 57). Preoperative fecal incontinence scoring, anorectal manometry, and endoanal ultrasound were performed. Postoperatively, these were repeated at up to three months with pain scores, analgesic requirements, quality of life assessment, and total related medical costs. RESULTS Conventional open diathermy technique was quicker to perform (mean, 11.4 (standard error of the mean, 0.9) vs. 17.6 (3.1) minutes). Hospitalization was similar, but conventional open diathermy technique patients felt more pain during defecation (5.1 (0.4) vs. 2.6 (0.4); P < 0.005) at two weeks, and analgesic requirements were more for up to six weeks (P < 0.05). Up to the latter, 85.5 percent conventional open diathermy technique wounds remained unhealed, with more bleeding (33 (53.2 percent) vs. 19 (33.3 percent); P < 0.05) and pruritus (27 (43.5 percent) vs. 9 (15.8 percent); P < 0.05). Total complication rates were similar (conventional open diathermy technique 16 (25.8 percent) vs. stapled hemorrhoidectomy 10 (17.5 percent)), including mild strictures and bleeding in both groups. Minor incontinence occurred postoperatively in two conventional open diathermy technique and two stapled hemorrhoidectomy patients at six weeks. Endoanal ultrasound internal anal sphincter defects were found in the incontinent conventional open diathermy technique patients, but were asymptomatic in another one conventional open diathermy technique and one stapled hemorrhoidectomy. Only one patient (conventional open diathermy technique with internal sphincter defect) remained incontinent at three months. Changes between preoperative and postoperative anorectal manometry were similar in the two groups. Patients' satisfaction scores and quality of life assessments were also similar. Conventional open diathermy technique patients resumed work later (mean 22.9 (1.8) vs. 17.1 (1.9) days; P < 0.05), but the total costs incurred were less ($921.17 (16.85) vs. $1,283.09 (31.59); P < 0.005). CONCLUSIONS Stapled hemorrhoidectomy is a safe and effective option in treating irreducible prolapsed piles. It is more expensive but less painful, with less time needed off work. Nonetheless, long-term results are still awaited.
Collapse
|
Clinical Trial |
25 |
171 |
24
|
Kaptain S, Downey WE, Tang C, Philpott C, Haile D, Orloff DG, Harford JB, Rouault TA, Klausner RD. A regulated RNA binding protein also possesses aconitase activity. Proc Natl Acad Sci U S A 1991; 88:10109-13. [PMID: 1946430 PMCID: PMC52877 DOI: 10.1073/pnas.88.22.10109] [Citation(s) in RCA: 160] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A clone for the iron-responsive element (IRE)-binding protein (IRE-BP) has been transfected and expressed in mouse fibroblasts. The IRE-BP gene product binds IREs with high affinity and specificity. Amino acid alignments reveal that the IRE-BP is 30% identical to mitochondrial aconitase. The 18 active site residues of mitochondrial aconitase are identical to those in the IRE-BP, suggesting that the IRE-BP may possess aconitase activity. After purification of native IRE-BP and immunoaffinity purification of transfected and expressed IRE-BP, we demonstrate that the purified IRE-BP has aconitase activity.
Collapse
|
research-article |
34 |
160 |
25
|
Feigin A, Tang C, Ma Y, Mattis P, Zgaljardic D, Guttman M, Paulsen JS, Dhawan V, Eidelberg D. Thalamic metabolism and symptom onset in preclinical Huntington's disease. Brain 2007; 130:2858-67. [PMID: 17893097 PMCID: PMC4455546 DOI: 10.1093/brain/awm217] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The neural basis for the transition from preclinical to symptomatic Huntington's disease (HD) is unknown. We used serial positron emission tomography (PET) imaging in preclinical HD gene carriers (p-HD) to assess the metabolic changes that occur during this period. Twelve p-HD subjects were followed longitudinally with [11C]-raclopride and [18F]-fluorodeoxyglucose PET imaging, with scans at baseline, 18 and 44 months. Progressive declines in striatal D2-receptor binding were correlated with concurrent changes in regional metabolism and in the activity of an HD-related metabolic network. We found that striatal D2 binding declined over time (P < 0.005). The activity of a reproducible HD-related metabolic covariance pattern increased between baseline and 18 months (P < 0.003) but declined at 44 months (P < 0.04). These network changes coincided with progressive declines in striatal and thalamic metabolic activity (P < 0.01). Striatal metabolism was abnormally low at all time points (P < 0.005). By contrast, thalamic metabolism was elevated at baseline (P < 0.01), but fell to subnormal levels in the p-HD subjects who developed symptoms. These findings were confirmed with an MRI-based atrophy correction for each individual PET scan. Increases in network expression and thalamic glucose metabolism may be compensatory for early neuronal losses in p-HD. Declines in these measures may herald the onset of symptoms in gene carriers.
Collapse
|
Research Support, N.I.H., Extramural |
18 |
139 |