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De Jager PL, Srivastava G, Lunnon K, Burgess J, Schalkwyk LC, Yu L, Eaton ML, Keenan BT, Ernst J, McCabe C, Tang A, Raj T, Replogle J, Brodeur W, Gabriel S, Chai HS, Younkin C, Younkin SG, Zou F, Szyf M, Epstein CB, Schneider JA, Bernstein BE, Meissner A, Ertekin-Taner N, Chibnik LB, Kellis M, Mill J, Bennett DA. Alzheimer's disease: early alterations in brain DNA methylation at ANK1, BIN1, RHBDF2 and other loci. Nat Neurosci 2014; 17:1156-63. [PMID: 25129075 PMCID: PMC4292795 DOI: 10.1038/nn.3786] [Citation(s) in RCA: 696] [Impact Index Per Article: 63.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/16/2014] [Indexed: 02/07/2023]
Abstract
We used a collection of 708 prospectively collected autopsied brains to assess the methylation state of the brain's DNA in relation to Alzheimer's disease (AD). We found that the level of methylation at 71 of the 415,848 interrogated CpGs was significantly associated with the burden of AD pathology, including CpGs in the ABCA7 and BIN1 regions, which harbor known AD susceptibility variants. We validated 11 of the differentially methylated regions in an independent set of 117 subjects. Furthermore, we functionally validated these CpG associations and identified the nearby genes whose RNA expression was altered in AD: ANK1, CDH23, DIP2A, RHBDF2, RPL13, SERPINF1 and SERPINF2. Our analyses suggest that these DNA methylation changes may have a role in the onset of AD given that we observed them in presymptomatic subjects and that six of the validated genes connect to a known AD susceptibility gene network.
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Research Support, N.I.H., Extramural |
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Wells AD, Li XC, Li Y, Walsh MC, Zheng XX, Wu Z, Nuñez G, Tang A, Sayegh M, Hancock WW, Strom TB, Turka LA. Requirement for T-cell apoptosis in the induction of peripheral transplantation tolerance. Nat Med 1999; 5:1303-7. [PMID: 10545998 DOI: 10.1038/15260] [Citation(s) in RCA: 462] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mechanisms of allograft tolerance have been classified as deletion, anergy, ignorance and suppression/regulation. Deletion has been implicated in central tolerance, whereas peripheral tolerance has generally been ascribed to clonal anergy and/or active immunoregulatory states. Here, we used two distinct systems to assess the requirement for T-cell deletion in peripheral tolerance induction. In mice transgenic for Bcl-xL, T cells were resistant to passive cell death through cytokine withdrawal, whereas T cells from interleukin-2-deficient mice did not undergo activation-induced cell death. Using either agents that block co-stimulatory pathways or the immunosuppressive drug rapamycin, which we have shown here blocks the proliferative component of interleukin-2 signaling but does not inhibit priming for activation-induced cell death, we found that mice with defective passive or active T-cell apoptotic pathways were resistant to induction of transplantation tolerance. Thus, deletion of activated T cells through activation-induced cell death or growth factor withdrawal seems necessary to achieve peripheral tolerance across major histocompatibility complex barriers.
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Ding Q, Lee YK, Schaefer EAK, Peters DT, Veres A, Kim K, Kuperwasser N, Motola DL, Meissner TB, Hendriks WT, Trevisan M, Gupta RM, Moisan A, Banks E, Friesen M, Schinzel RT, Xia F, Tang A, Xia Y, Figueroa E, Wann A, Ahfeldt T, Daheron L, Zhang F, Rubin LL, Peng LF, Chung RT, Musunuru K, Cowan CA. A TALEN genome-editing system for generating human stem cell-based disease models. Cell Stem Cell 2012; 12:238-51. [PMID: 23246482 DOI: 10.1016/j.stem.2012.11.011] [Citation(s) in RCA: 385] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 10/19/2012] [Accepted: 11/12/2012] [Indexed: 10/27/2022]
Abstract
Transcription activator-like effector nucleases (TALENs) are a new class of engineered nucleases that are easier to design to cleave at desired sites in a genome than previous types of nucleases. We report here the use of TALENs to rapidly and efficiently generate mutant alleles of 15 genes in cultured somatic cells or human pluripotent stem cells, the latter for which we differentiated both the targeted lines and isogenic control lines into various metabolic cell types. We demonstrate cell-autonomous phenotypes directly linked to disease-dyslipidemia, insulin resistance, hypoglycemia, lipodystrophy, motor-neuron death, and hepatitis C infection. We found little evidence of TALEN off-target effects, but each clonal line nevertheless harbors a significant number of unique mutations. Given the speed and ease with which we were able to derive and characterize these cell lines, we anticipate TALEN-mediated genome editing of human cells becoming a mainstay for the investigation of human biology and disease.
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Research Support, Non-U.S. Gov't |
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Buxton AE, Lee KL, DiCarlo L, Gold MR, Greer GS, Prystowsky EN, O'Toole MF, Tang A, Fisher JD, Coromilas J, Talajic M, Hafley G. Electrophysiologic testing to identify patients with coronary artery disease who are at risk for sudden death. Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med 2000; 342:1937-45. [PMID: 10874061 DOI: 10.1056/nejm200006293422602] [Citation(s) in RCA: 356] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The mortality rate among patients with coronary artery disease, abnormal ventricular function, and unsustained ventricular tachycardia is high. The usefulness of electrophysiologic testing for risk stratification in these patients is unclear. METHODS We performed electrophysiologic testing in patients who had coronary artery disease, a left ventricular ejection fraction of 40 percent or less, and asymptomatic, unsustained ventricular tachycardia. Patients in whom sustained ventricular tachyarrhythmias could be induced were randomly assigned to receive either antiarrhythmic therapy guided by electrophysiologic testing or no antiarrhythmic therapy. The primary end point was cardiac arrest or death from arrhythmia. Patients without inducible tachyarrhythmias were followed in a registry. We compared the outcomes of 1397 patients in the registry with those of 353 patients with inducible tachyarrhythmias who were randomly assigned to receive no antiarrhythmic therapy in order to assess the prognostic value of electrophysiologic testing. RESULTS Patients were followed for a median of 39 months. In a Kaplan-Meier analysis, two-year and five-year rates of cardiac arrest or death due to arrhythmia were 12 and 24 percent, respectively, among the patients in the registry, as compared with 18 and 32 percent among the patients with inducible tachyarrhythmias who were assigned to no antiarrhythmic therapy (adjusted P<0.001). Overall mortality after five years was 48 percent among the patients with inducible tachyarrhythmias, as compared with 44 percent among the patients in the registry (adjusted P=0.005). Deaths among patients without inducible tachyarrhythmias were less likely to be classified as due to arrhythmia than those among patients with inducible tachyarrhythmias (45 and 54 percent, respectively; P=0.06). CONCLUSIONS Patients with coronary artery disease, left ventricular dysfunction, and asymptomatic, unsustained ventricular tachycardia in whom sustained ventricular tachyarrhythmias cannot be induced have a significantly lower risk of sudden death or cardiac arrest and lower overall mortality than similar patients with inducible sustained tachyarrhythmias.
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Clinical Trial |
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Tang A, Amagai M, Granger LG, Stanley JR, Udey MC. Adhesion of epidermal Langerhans cells to keratinocytes mediated by E-cadherin. Nature 1993; 361:82-5. [PMID: 8421498 DOI: 10.1038/361082a0] [Citation(s) in RCA: 344] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Langerhans cells (LC) are the principal accessory cells present in epidermis. Because LC have limited capacity for self-renewal, epidermis is continually repopulated by as-yet uncharacterized bone marrow-derived LC progenitors. In addition, although LC persist in epidermis for extended periods, LC are induced to migrate from skin to regional lymph nodes after antigen exposure. To begin to elucidate mechanisms involved in LC trafficking, we characterized LC-keratinocyte (KC) interactions. Here we report that fresh murine LC express cadherins, and that LC adhere to KC in vitro through E-cadherin. Cultured LC (which may bear a phenotypic and functional relationship to LC that have migrated to lymph nodes) express lower levels of E-cadherin and exhibit decreased affinity for KC. These results suggest that expression of E-cadherin by LC promotes persistence of these cells in epidermis, and that cadherins may play important and unanticipated roles in interactions between leukocytes and epithelia.
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Ettinger B, Tang A, Citron JT, Livermore B, Williams T. Randomized trial of allopurinol in the prevention of calcium oxalate calculi. N Engl J Med 1986; 315:1386-9. [PMID: 3534570 DOI: 10.1056/nejm198611273152204] [Citation(s) in RCA: 220] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In a double-blind study, we examined the efficacy of allopurinol in the prevention of recurrent calcium oxalate calculi of the kidney. Sixty patients with hyperuricosuria and normocalciuria who had a history of calculi were randomly assigned to receive either allopurinol (100 mg three times daily) or a placebo. After the study, the placebo group had 63.4 percent fewer calculi (P less than 0.001), whereas the allopurinol group had 81.2 percent fewer calculi (P less than 0.001). During the study period, the mean rate of calculous events was 0.26 per patient per year in the placebo group and 0.12 in the allopurinol group. When the treatment groups were compared by actuarial analysis, the allopurinol group was found to have a significantly longer time before recurrence of calculi (P less than 0.02). We conclude that allopurinol is effective in the prevention of calcium oxalate stones in patients with hyperuricosuria. The large reduction in the frequency of calculi in the placebo group underscores the positive treatment bias that regularly occurs in trials of prophylaxis against renal calculi when historical controls are used.
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Clinical Trial |
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Friedman KG, Gauvreau K, Hamaoka-Okamoto A, Tang A, Berry E, Tremoulet AH, Mahavadi VS, Baker A, deFerranti SD, Fulton DR, Burns JC, Newburger JW. Coronary Artery Aneurysms in Kawasaki Disease: Risk Factors for Progressive Disease and Adverse Cardiac Events in the US Population. J Am Heart Assoc 2016; 5:JAHA.116.003289. [PMID: 27633390 PMCID: PMC5079009 DOI: 10.1161/jaha.116.003289] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background The natural history of coronary artery aneurysms (CAA) after intravenous immunoglobulin (IVIG) treatment in the United States is not well described. We describe the natural history of CAA in US Kawasaki disease (KD) patients and identify factors associated with major adverse cardiac events (MACE) and CAA regression. Methods and Results We evaluated all KD patients with CAA at 2 centers from 1979 to 2014. Factors associated with CAA regression, maximum CA z‐score over time (zMax), and MACE were analyzed. We performed a matched analysis of treatment effect on likelihood of CAA regression. Of 2860 KD patients, 500 (17%) had CAA, including 90 with CAA z‐score >10. Most (91%) received IVIG within 10 days of illness, 32% received >1 IVIG, and 27% received adjunctive anti‐inflammatory medications. CAA regression occurred in 75%. Lack of CAA regression and higher CAA zMax were associated with earlier era, larger CAA z‐score at diagnosis, and bilateral CAA in univariate and multivariable analyses. MACE occurred in 24 (5%) patients and was associated with higher CAA z‐score at diagnosis and lack of IVIG treatment. In a subset of patients (n=132) matched by age at KD and baseline CAA z‐score, those receiving IVIG plus adjunctive medication had a CAA regression rate of 91% compared with 68% for the 3 other groups (IVIG alone, IVIG ≥2 doses, or IVIG ≥2 doses plus adjunctive medication). Conclusions CAA regression occurred in 75% of patients. CAA z‐score at diagnosis was highly predictive of outcomes, which may be improved by early IVIG treatment and adjunctive therapies.
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Journal Article |
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Tang A, Eller MS, Hara M, Yaar M, Hirohashi S, Gilchrest BA. E-cadherin is the major mediator of human melanocyte adhesion to keratinocytes in vitro. J Cell Sci 1994; 107 ( Pt 4):983-92. [PMID: 8056851 DOI: 10.1242/jcs.107.4.983] [Citation(s) in RCA: 174] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
E- and P-cadherin are calcium (Ca2+)-dependent cell adhesion molecules important in the morphogenesis and maintenance of skin structure. By use of flow cytometry and specific antibodies, we now show that cultured human melanocytes express E- and P-cadherin on their surfaces, and that these molecules have the same characteristics as reported for other cell types. Specifically, melanocyte cadherins are sensitive to trypsin digestion in the absence of Ca2+ and are protected from trypsin degradation by Ca2+, and are functional at 37 degrees C but not at 4 degrees C. We further show that melanocytes contain mRNA transcripts encoding both E- and P-cadherin. Adhesion of cultured melanocytes to keratinocyte monolayers is abolished by pre-treatment of the melanocytes with trypsin/EDTA, which degrades E- and P-cadherins, is greatly reduced by anti-E-cadherin antibodies and is slightly reduced by antibodies to P-cadherin, alpha 2, alpha 3 and beta 1 integrins. In contrast to normal melanocytes, eight of nine melanoma cell lines lacked E-cadherin (or expressed markedly reduced levels) and five were negative for P-cadherin. Melanoma cells also failed to adhere to keratinocyte monolayers. These results demonstrate that normal human melanocytes express functional E- and P-cadherin and that E-cadherin is primarily responsible for adhesion of human melanocytes to keratinocytes in vitro. In addition, transformed melanocytes express markedly reduced levels of E- and P-cadherin, and exhibit decreased affinity for normal keratinocytes in vitro, suggesting that loss of cadherins may play a role in melanoma metastasis.
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Wong SM, Griffith JF, Hui ACF, Tang A, Wong KS. Discriminatory sonographic criteria for the diagnosis of carpal tunnel syndrome. ARTHRITIS AND RHEUMATISM 2002; 46:1914-21. [PMID: 12124876 DOI: 10.1002/art.10385] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Sonographic examination of the median nerve has been suggested as a useful alternative to electrophysiologic study in the diagnosis of carpal tunnel syndrome. To determine its usefulness and the best diagnostic criterion, sonograms of patients with the disease were compared with sonograms of healthy subjects in a case-control study. METHODS Patients with carpal tunnel syndrome and asymptomatic controls who were matched for age and sex were enrolled and underwent sonography of the wrists. Eight separate sonographic criteria were analyzed in each wrist. Data from the patient group and the control group were compared to establish optimal diagnostic criteria for carpal tunnel syndrome, using receiver operating characteristic analytic techniques. RESULTS Thirty-five patients with carpal tunnel syndrome and 35 asymptomatic controls were examined. Increased cross-sectional area of the median nerve was found to be the most predictive measure of carpal tunnel syndrome, proximal to the tunnel inlet, at the tunnel inlet, and at the tunnel outlet, with significant differences between patients and controls. Using a receiver operating characteristic curve, a cut-off value >0.098 cm(2) at the tunnel inlet provided a diagnostic sensitivity of 89% and a specificity of 83%. CONCLUSION Sonographic measurement of the median nerve cross-sectional area is both sensitive and specific for the diagnosis of carpal tunnel syndrome.
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Tang A, Rymer WZ. Abnormal force--EMG relations in paretic limbs of hemiparetic human subjects. J Neurol Neurosurg Psychiatry 1981; 44:690-8. [PMID: 7299407 PMCID: PMC491089 DOI: 10.1136/jnnp.44.8.690] [Citation(s) in RCA: 128] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The relations between surface EMG and isometric force generated by elbow flexor muscles were compared in normal and paretic limbs of 17 hemiparetic human subjects. Similar analyses were performed on both arms of 11 normal subjects. In almost half of the hemiparetic subjects examined (8/17), the slope of the relation between elbow flexion force and surface EMG, measured over the biceps-brachialis and brachioradialis muscle groups was increased in the paretic limb. A mechanism based on anomalous reductions in mean motor unit discharge rate in paretic muscles is advanced as the most likely cause of the findings.
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Yang WT, Ahuja A, Tang A, Suen M, King W, Metreweli C. High resolution sonographic detection of axillary lymph node metastases in breast cancer. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 1996; 15:241-246. [PMID: 8919506 DOI: 10.7863/jum.1996.15.3.241] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Axillary lymph node status is crucial in the evaluation of prognosis and in treatment planning of breast cancer. High-resolution real-time sonographic scans of the breast and both axillae were performed on 114 patients with breast carcinoma, all of whom had axillary lymph node dissection and histologic assessment. The sensitivity of high-resolution ultrasonography in the detection of axillary nodal metastases was 84.1%, with a specificity of 97.1%, accuracy of 92.1%, positive predictive value of 94.9%, and negative predictive value 90.7%. Ultrasonography of the axilla provides good information on anatomy and pathology and may have a potential role in the prognostic work-up of patients who are not surgical candidates.
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Tang A, Thickbroom G, Rodger J. Repetitive Transcranial Magnetic Stimulation of the Brain: Mechanisms from Animal and Experimental Models. Neuroscientist 2016; 23:82-94. [PMID: 26643579 DOI: 10.1177/1073858415618897] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Since the development of transcranial magnetic stimulation (TMS) in the early 1980s, a range of repetitive TMS (rTMS) protocols are now available to modulate neuronal plasticity in clinical and non-clinical populations. However, despite the wide application of rTMS in humans, the mechanisms underlying rTMS-induced plasticity remain uncertain. Animal and in vitro models provide an adjunct method of investigating potential synaptic and non-synaptic mechanisms of rTMS-induced plasticity. This review summarizes in vitro experimental studies, in vivo studies with intact rodents, and preclinical models of selected neurological disorders-Parkinson's disease, depression, and stroke. We suggest that these basic research findings can contribute to the understanding of how rTMS-induced plasticity can be modulated, including novel mechanisms such as neuroprotection and neurogenesis that have significant therapeutic potential.
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Wong KS, Ng PW, Tang A, Liu R, Yeung V, Tomlinson B. Prevalence of asymptomatic intracranial atherosclerosis in high-risk patients. Neurology 2007; 68:2035-8. [PMID: 17548555 DOI: 10.1212/01.wnl.0000264427.09191.89] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We used transcranial Doppler to screen 3,057 patients who had at least one vascular risk factor of hypertension, diabetes, or hyperlipidemia and found 385 (12.6%) had middle cerebral artery stenosis. Elderly, hypertension, diabetes, and hyperlipidemia were associated factors. The prevalence escalated quadratically with increasing number of associated factors: from 7.2% for one, to 29.6% for four associated factors. Asymptomatic middle cerebral artery stenosis is common in patients with vascular risk factors.
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Wong KS, Huang YN, Yang HB, Gao S, Li H, Liu JY, Liu Y, Tang A. A door-to-door survey of intracranial atherosclerosis in Liangbei County, China. Neurology 2007; 68:2031-4. [PMID: 17548554 DOI: 10.1212/01.wnl.0000264426.63544.ee] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We studied 590 asymptomatic villagers aged > or =40 years in Liangbei County in central rural China and found 41 subjects (prevalence 6.9%) with intracranial atherosclerosis. In a multivariate analysis, the significant risk factors for intracranial stenosis were hypertension (OR 2.53; 95% CI 1.12 to 5.72), glycosuria (OR 3; 1.19 to 7.97), heart disease (OR 4; 1.39 to 11.6), and family history of stroke (OR 5.2; 1.38 to 20). Intracranial atherosclerosis is not uncommon among asymptomatic Chinese subjects.
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Yeo W, Mo FKF, Koh J, Chan ATC, Leung T, Hui P, Chan L, Tang A, Lee JJ, Mok TSK, Lai PBS, Johnson PJ, Zee B. Quality of life is predictive of survival in patients with unresectable hepatocellular carcinoma. Ann Oncol 2006; 17:1083-1089. [PMID: 16600982 DOI: 10.1093/annonc/mdl065] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Patients with unresectable hepatocellular carcinoma (HCC) have a dismal prognosis. The objective of this study was to evaluate whether patient-reported baseline quality of life (QoL) measured by the EORTC QLQ-C30 instrument is predictive of survival for these patients. MATERIALS AND METHODS Two hundred and thirty-three patients with unresectable HCC (mainly hepatitis B-associated) who were recruited into two separate randomized phase III clinical studies, based on palliative chemotherapy and palliative hormonal therapy, respectively, gave consent and received pretreatment QoL assessment. EORTC QLQ-C30 scores and clinical variables at the time of study entry were analyzed to identify factors that influenced survival by applying multivariate analysis. Independent prognostic factors for survival were studied by Cox regression analysis. RESULTS Median survival of the 233 patients was 5.5 months (95% CI 4.2-6.5 months). Significant independent predictors of shorter survival were advanced Okuda staging (P = 0.0030; HR = 2.058), high baseline total bilirubin (P = 0.0008; HR = 1.013) and worse QoL score in the appetite score domain (P = 0.0028; HR for 10 point increase = 1.070). Patients who were entered into the chemotherapy trial (P = 0.0002; HR = 0.503), those who scored better in the physical functioning domain (P = 0.0034; HR for 10 point decrease = 0.911) and the role functioning domain (P = 0.0383; HR for 10 point decrease = 0.944) of the QoL questionnaire, were associated with longer survival. CONCLUSIONS In the studied HCC population, patient-reported baseline QoL provides additional prognostic information that supplements traditional clinical factors, and is a new prognostic marker for survival for patients with unresectable HCC.
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Nichol G, McAlister F, Pham B, Laupacis A, Shea B, Green M, Tang A, Wells G. Meta-analysis of randomised controlled trials of the effectiveness of antiarrhythmic agents at promoting sinus rhythm in patients with atrial fibrillation. Heart 2002; 87:535-43. [PMID: 12010934 PMCID: PMC1767130 DOI: 10.1136/heart.87.6.535] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To conduct a meta-analysis of randomised controlled trials to estimate the effectiveness of antiarrhythmic drugs at promoting sinus rhythm in patients with atrial fibrillation. DESIGN Articles were identified by using a comprehensive search of English language papers indexed in Medline from 1966 to August 2001. For the outcomes of sinus rhythm and death, a random effects model was used to model repeated assessments within a study at different time points. SETTING Emergency departments and ambulatory clinics. PATIENTS Patients with atrial fibrillation. INTERVENTIONS Antiarrhythmic agents grouped according to their Vaughan-Williams class. MAIN OUTCOME MEASURES Sinus rhythm and mortality. RESULTS 91 articles met a priori criteria for inclusion in the analysis. Median duration of follow up was one day (range 0.04-1096, mean (SD) 46 (136) days). The median proportion of patients in sinus rhythm at follow up was 55% (range 0-100%) and 32% (range 0-90%) receiving active treatment and placebo, respectively. Median survival was 99% (range 55-100%) and 99% (range 55-100%). Compared with placebo, the following drug classes were associated with increased sinus rhythm at follow up: IA (treatment difference 21.5%, 95% confidence interval (CI) 16.3% to 26.8%); IC (treatment difference 33.1%, 95% CI 23.3% to 42.9%); and III (treatment difference 17.4%, 95% CI 11.5% to 23.3%). Class IC drugs were associated with increased sinus rhythm at follow up compared with class IV drugs (treatment difference 43.2%, 95% CI 11.5% to 75.0%). There was no significant difference in mortality between any drug classes. CONCLUSIONS Class IA, IC, and III drugs are associated with increased sinus rhythm at follow up compared with placebo. It is unclear whether any antiarrhythmic drug class is associated with increased or decreased mortality.
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Oliver M, Inaba K, Tang A, Branco BC, Barmparas G, Schnüriger B, Lustenberger T, Demetriades D. The changing epidemiology of spinal trauma: a 13-year review from a Level I trauma centre. Injury 2012; 43:1296-300. [PMID: 22648015 DOI: 10.1016/j.injury.2012.04.021] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 12/20/2011] [Accepted: 04/27/2012] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Spinal injuries secondary to trauma are a major cause of patient morbidity and a source of significant health care expenditure. Increases in traffic safety standards and improved health care resources may have changed the characteristics and incidence of spinal injury. The purpose of this study was to review a single metropolitan Level I trauma centre's experience to assess the changing characteristics and incidence of traumatic spinal injuries and spinal cord injuries (SCI) over a 13-year period. PATIENTS AND METHODS A retrospective review of patients admitted to a Level I trauma centre between 1996 and 2008 was performed. Patients with spinal fractures and SCI were identified. Demographics, mechanism of injury, level of spinal injury and Injury Severity Score (ISS) were extracted. The outcomes assessed were the incidence rate of SCI and in-hospital mortality. RESULTS Over the 13-year period, 5.8% of all trauma patients suffered spinal fractures, with 21.7% of patients with spinal injuries having SCI. Motor vehicle accidents (MVAs) were responsible for the majority of spinal injuries (32.6%). The mortality rate due to spinal injury decreased significantly over the study period despite a constant mean ISS. The incidence rate of SCI also decreased over the years, which was paralleled by a significant reduction in MVA associated SCI (from 23.5% in 1996 to 14.3% in 2001 to 6.7% in 2008). With increasing age there was an increase in spinal injuries; frequency of blunt SCI; and injuries at multiple spinal levels. CONCLUSION This study demonstrated a reduction in mortality attributable to spinal injury. There has been a marked reduction in SCI due to MVAs, which may be related to improvements in motor vehicle safety and traffic regulations. The elderly population was more likely to suffer SCI, especially by blunt injury, and at multiple levels. Underlying reasons may be anatomical, physiological or mechanism related.
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Tang A, Gilchrest BA. Regulation of keratinocyte growth factor gene expression in human skin fibroblasts. J Dermatol Sci 1996; 11:41-50. [PMID: 8867766 DOI: 10.1016/0923-1811(95)00418-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Human keratinocyte growth factor (KGF) is a recently identified mitogen for epithelial cells produced by normal stromal fibroblasts. KGF has been shown to stimulate keratinocyte migration and promote re-epithelialization of skin suggesting a critical role for KGF in wound healing. To understand how KGF might be regulated during wound healing, we examined the ability of the pro-inflammatory cytokines interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta) interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) transforming growth factor-beta 1 (TGF-beta 1) and interferon-gamma (IFN-gamma) to modulate KGF gene expression in cultured human fibroblasts, using northern blot analysis. Exposure to IL-1 alpha (20 units/ml) or IL-1 beta (100 units/ml) for 24 h increased KGF mRNA expression by 352% and 504%, respectively, with early induction seen at 2 h and maximal induction seen at 8 h. TNF-alpha (30 ng/ml) increased KGF mRNA expression by 535% at 24 h, with induction first seen at 8 h. The maximal induction of KGF mRNA was observed when IL-1 alpha, IL-1 beta and TNF-alpha were used at 100 units/ml, and 3 ng/ml, respectively, although concentrations 100-500-fold lower (IL-1 alpha, 0.02 units/ml; IL-beta, 0.02 units/ml; and TNF-alpha, 0.03 ng/ml) were nearly as stimulatory, increasing KGF mRNA expression by 175%, 254% and 322%, respectively. IL-6 (200 units/ml), TGF-beta 1 (5 ng/ml) and IFN-gamma (200 units/ml) did not change the level of KGF mRNA at 24 h in human fibroblasts under the same conditions. The protein synthesis inhibitor cycloheximide abrogated the effects of IL-1 alpha, IL-1 beta and TNF-alpha on KGF gene induction, indicating that new protein synthesis is required in the process. Dexamethasone (10(-7) M), known to inhibit inflammatory reactions and retard wound healing, also inhibited the induction of KGF mRNA expression by IL-1 alpha, IL-1 beta and TNF-alpha. Individual variation in KGF mRNA expression was see when fibroblasts from different aged donors were analysed, but no consistent age-associated change was observed. These results suggest that IL-1 alpha, IL-1 beta and TNF-alpha up-regulate KGF gene expression in fibroblasts and might be responsible for its induction following skin wounding or other injury.
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Tsang MW, Mok M, Kam G, Jung M, Tang A, Chan U, Chu CM, Li I, Chan J. Improvement in diabetes control with a monitoring system based on a hand-held, touch-screen electronic diary. J Telemed Telecare 2001; 7:47-50. [PMID: 11265938 DOI: 10.1258/1357633011936138] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We conducted a six-month prospective interventional crossover study examining a computerized diabetes monitoring system (DMS) that conveyed dietary information. The objectives were to compare glycaemic control between intervention and control periods, and to assess patients' acceptance of the DMS. Nineteen patients were randomized into two groups, each using the DMS for three months and serving as the control group for another three months. The patients recorded information about their meal portions and blood glucose readings in a hand-held electronic diary. After transmitting the data to the DMS through a telephone modem, the patients received immediate feedback about the carbohydrate, protein and fat content of the meal, as well as the calorie content. A significant improvement in glycaemic control was achieved during intervention compared with control periods (mean HbA1C reduction of 0.825%). The DMS was also highly acceptable: 95% patients found it easy to operate while 63% found it useful. The DMS was thus a feasible model of telemedicine in diabetes care and a larger study is warranted to examine its cost-effectiveness.
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Clinical Trial |
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Baldwin SL, D'Souza CD, Orme IM, Liu MA, Huygen K, Denis O, Tang A, Zhu L, Montgomery D, Ulmer JB. Immunogenicity and protective efficacy of DNA vaccines encoding secreted and non-secreted forms of Mycobacterium tuberculosis Ag85A. TUBERCLE AND LUNG DISEASE : THE OFFICIAL JOURNAL OF THE INTERNATIONAL UNION AGAINST TUBERCULOSIS AND LUNG DISEASE 2000; 79:251-9. [PMID: 10692994 DOI: 10.1054/tuld.1998.0196] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To determine the efficacy of Ag85A-DNA against challenge with a highly virulent human clinical isolate of Mycobacterium tuberculosis (CSU37) and to compare the potencies of two types of Ag85A-DNA vaccines; those expressing secreted and non-secreted forms of the protein. DESIGN Ag85A-DNA vaccinated mice were challenged with a highly virulent clinical isolate of M. tuberculosis (CSU37) in order to compare the efficacy of these vaccines. In vitro studies were also performed. RESULTS Enhanced humoral and cellular responses were induced in mice vaccinated with the secreted Ag85A-DNA compared to the non-secreted Ag85A-DNA. In addition, secreted Ag85A-DNA conferred protective immunity against infection with M. tuberculosis (CSU37). CONCLUSIONS DNA vaccines encoding M. tuberculosis Ag85A have been shown to induce potent humoral and cellular immune responses leading to protection from M. tuberculosis (Erdman) challenge in mouse models. In this study we demonstrate that Ag85A can confer protection in a rigorous challenge model using a highly virulent human clinical isolate of M. tuberculosis (CSU37). This challenge model appears able to discriminate between DNA vaccines of differing potencies, as the more immunogenic DNA construct encoding a secreted form of Ag85A was protective, whereas the less immunogenic DNA construct encoding a non-secreted form of Ag85A was not.
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Poon RTP, Yeung C, Liu CL, Lam CM, Yuen WK, Lo CM, Tang A, Fan ST. Intravenous bolus somatostatin after diagnostic cholangiopancreatography reduces the incidence of pancreatitis associated with therapeutic endoscopic retrograde cholangiopancreatography procedures: a randomised controlled trial. Gut 2003; 52:1768-73. [PMID: 14633959 PMCID: PMC1773906 DOI: 10.1136/gut.52.12.1768] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Previous studies suggested that somatostatin given before endoscopic retrograde cholangiopancreatography (ERCP) may reduce the incidence of post-ERCP pancreatitis. However, the routine use of somatostatin in all patients undergoing ERCP is not likely to be cost effective. This study evaluated whether intravenous bolus somatostatin given after diagnostic cholangiopancreatography could reduce the incidence of pancreatitis in a group of patients undergoing therapeutic ERCP procedures. METHODS In a randomised, double blind, controlled trial, the effect of intravenous bolus somatostatin 250 microg given immediately after diagnostic cholangiopancreatography was compared with that of placebo in patients who required endoscopic sphincterotomy or other therapeutic procedures. The primary end point was the incidence of post-ERCP clinical pancreatitis, and a secondary end point was the incidence of hyperamylasemia. RESULTS A total of 270 patients were randomised. The somatostatin group (n=135) and the placebo group (n=135) were comparable in age, sex, indications for treatment, and types of procedure. The frequencies of clinical pancreatitis (4.4% v 13.3%; p=0.010) and hyperamylasemia (26.0% v 38.5%; p=0.036) were both significantly lower in the somatostatin group compared with the placebo group. CONCLUSIONS A single dose of intravenous bolus somatostatin, given immediately after diagnostic cholangiopancreatography, is effective in reducing the incidence of pancreatitis after therapeutic ERCP. This novel approach of administering prophylactic somatostatin may offer a cost effective prophylaxis for post-ERCP pancreatitis.
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Cullen CL, Senesi M, Tang AD, Clutterbuck MT, Auderset L, O'Rourke ME, Rodger J, Young KM. Low-intensity transcranial magnetic stimulation promotes the survival and maturation of newborn oligodendrocytes in the adult mouse brain. Glia 2019; 67:1462-1477. [PMID: 30989733 PMCID: PMC6790715 DOI: 10.1002/glia.23620] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 03/05/2019] [Accepted: 03/25/2019] [Indexed: 11/23/2022]
Abstract
Neuronal activity is a potent extrinsic regulator of oligodendrocyte generation and central nervous system myelination. Clinically, repetitive transcranial magnetic stimulation (rTMS) is delivered to noninvasively modulate neuronal activity; however, the ability of rTMS to facilitate adaptive myelination has not been explored. By performing cre‐lox lineage tracing, to follow the fate of oligodendrocyte progenitor cells in the adult mouse brain, we determined that low intensity rTMS (LI‐rTMS), administered as an intermittent theta burst stimulation, but not as a continuous theta burst or 10 Hz stimulation, increased the number of newborn oligodendrocytes in the adult mouse cortex. LI‐rTMS did not alter oligodendrogenesis per se, but instead increased cell survival and enhanced myelination. These data suggest that LI‐rTMS can be used to noninvasively promote myelin addition to the brain, which has potential implications for the treatment of demyelinating diseases such as multiple sclerosis.
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Research Support, Non-U.S. Gov't |
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Nadel B, Tang A, Escuro G, Lugo G, Feeney AJ. Sequence of the spacer in the recombination signal sequence affects V(D)J rearrangement frequency and correlates with nonrandom Vkappa usage in vivo. J Exp Med 1998; 187:1495-503. [PMID: 9565641 PMCID: PMC2212273 DOI: 10.1084/jem.187.9.1495] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/1998] [Revised: 02/27/1998] [Indexed: 11/04/2022] Open
Abstract
Functional variable (V), diversity (D), and joining (J) gene segments contribute unequally to the primary repertoire. One factor contributing to this nonrandom usage is the relative frequency with which the different gene segments rearrange. Variation from the consensus sequence in the heptamer and nonamer of the recombination signal sequence (RSS) is therefore considered a major factor affecting the relative representation of gene segments in the primary repertoire. In this study, we show that the sequence of the spacer is also a determinant factor contributing to the frequency of rearrangement. Moreover, the effect of the spacer on recombination rates of various human Vkappa gene segments in vitro correlates with their frequency of rearrangement in vivo in pre-B cells and with their representation in the peripheral repertoire.
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research-article |
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Son MBF, Gauvreau K, Kim S, Tang A, Dedeoglu F, Fulton DR, Lo MS, Baker AL, Sundel RP, Newburger JW. Predicting Coronary Artery Aneurysms in Kawasaki Disease at a North American Center: An Assessment of Baseline z Scores. J Am Heart Assoc 2017; 6:JAHA.116.005378. [PMID: 28566299 PMCID: PMC5669166 DOI: 10.1161/jaha.116.005378] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background Accurate risk prediction of coronary artery aneurysms (CAAs) in North American children with Kawasaki disease remains a clinical challenge. We sought to determine the predictive utility of baseline coronary dimensions adjusted for body surface area (z scores) for future CAAs in Kawasaki disease and explored the extent to which addition of established Japanese risk scores to baseline coronary artery z scores improved discrimination for CAA development. Methods and Results We explored the relationships of CAA with baseline z scores; with Kobayashi, Sano, Egami, and Harada risk scores; and with the combination of baseline z scores and risk scores. We defined CAA as a maximum z score (zMax) ≥2.5 of the left anterior descending or right coronary artery at 4 to 8 weeks of illness. Of 261 patients, 77 patients (29%) had a baseline zMax ≥2.0. CAAs occurred in 15 patients (6%). CAAs were strongly associated with baseline zMax ≥2.0 versus <2.0 (12 [16%] versus 3 [2%], respectively, P<0.001). Baseline zMax ≥2.0 had a C statistic of 0.77, good sensitivity (80%), and excellent negative predictive value (98%). None of the risk scores alone had adequate discrimination. When high‐risk status per the Japanese risk scores was added to models containing baseline zMax ≥2.0, none were significantly better than baseline zMax ≥2.0 alone. Conclusions In a North American center, baseline zMax ≥2.0 in children with Kawasaki disease demonstrated high predictive utility for later development of CAA. Future studies should validate the utility of our findings.
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Journal Article |
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Wong KS, Mok V, Lam WW, Kay R, Tang A, Chan YL, Woo J. Aspirin-associated intracerebral hemorrhage: clinical and radiologic features. Neurology 2000; 54:2298-301. [PMID: 10881256 DOI: 10.1212/wnl.54.12.2298] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify the clinical and radiologic features of intracerebral hemorrhage (ICH) in aspirin users. BACKGROUND Although the benefits of aspirin outweigh its hemorrhagic risks for patients at high risk of vascular diseases, prolonged use of aspirin is associated with an increased risk of ICH. METHODS The authors enrolled consecutive patients with acute stroke who were admitted to a regional hospital from 1993 to 1998 into a stroke registry. From this registry, they identified all stroke patients who had ICH confirmed by CT scan and then selected those taking regular aspirin before ICH as the study group. For each study patient, they selected the immediate next two patients with ICH but not taking aspirin as controls. RESULTS The authors identified 58 aspirin users and 1193 nonusers among all patients hospitalized for ICH. From the group of nonusers, they selected 116 patients as controls. The locations of the hematoma were different (p = 0.002), with more lobar hematoma in the aspirin group (32.8%) than in the control group (10.3%). Prior cerebrovascular disease was the reason for taking aspirin in 37 (64%) patients but five patients had prior ICH. CONCLUSIONS The propensity for lobar hematoma in aspirin-associated ICH suggests its pathology may be somewhat different from spontaneous ICH among nonaspirin users. Further research to examine the risks and benefits of aspirin use in certain subgroups at risk of both thrombotic and hemorrhagic events is needed.
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