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Hadjigeorgiou GM, Comi GP, Bordoni A, Shen J, Chen YT, Salani S, Toscano A, Fortunato F, Lucchiari S, Bresolin N, Rodolico C, Piscaglia MG, Franceschina L, Papadimitriou A, Scarlato G. Novel donor splice site mutations of AGL gene in glycogen storage disease type IIIa. J Inherit Metab Dis 1999; 22:762-3. [PMID: 10472540 DOI: 10.1023/a:1005572906807] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Sheu WH, Lee WJ, Chen YT. Gender differences in relation to leptin concentration and insulin sensitivity in nondiabetic Chinese subjects. Int J Obes (Lond) 1999; 23:754-9. [PMID: 10454110 DOI: 10.1038/sj.ijo.0800925] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To investigate the relationship between fasting plasma leptin concentrations and insulin resistance in Chinese men and women. DESIGN Cross-sectional study design. SUBJECTS Ninety-six nondiabetic Chinese (51 men and 45 women) with body mass index (BMI) between 18.4-35.8 kg/m2 were studied. MEASUREMENTS Plasma glucose and insulin concentrations were measured every 30 min for 2 h after a 75 g oral glucose load. The degree of insulin resistance was assessed using a modified insulin suppression test. Plasma leptin values were determined by radioimmunoassay. RESULTS Fasting plasma glucose, glucose areas, fasting insulin, insulin areas, most of the lipoprotein concentrations and steady state plasma glucose (SSPG) concentrations were relatively similar between men and women. Despite the fact that men had higher BMI values (26.1 +/- 0.5 vs 24.7 +/- 0.5 kg/m2, P < 0.05), fasting plasma leptin concentrations were significantly lower in men than in women (4.9 +/- 0.5 vs 9.0 +/- 0.8 ng/ml, P < 0.001). Fasting leptin values were positively related to SSPG concentrations by simple correlation analysis in both sexes. However, this relationship persisted in men (r = 0.513, P < 0.01) but not in women (r = 0.119, P = NS) after adjustment for BMI. Multiple regression analysis showed that SSPG concentrations, BMI, glucose and insulin responses together accounted for 62.5% and 52.2% of the variation in plasma leptin concentrations in Chinese men and women respectively. CONCLUSION Fasting plasma leptin concentrations were lower in Chinese men than in Chinese women despite the higher BMI observed in men. After adjustment for BMI, plasma leptin values correlated with the degree of insulin resistance in men but not in women.
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Sheu WH, Juang BL, Chen YT, Lee WJ. Endothelial dysfunction is not reversed by simvastatin treatment in type 2 diabetic patients with hypercholesterolemia. Diabetes Care 1999; 22:1224-5. [PMID: 10389000 DOI: 10.2337/diacare.22.7.1224] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Krumholz HM, Chen J, Wang Y, Radford MJ, Chen YT, Marciniak TA. Comparing AMI mortality among hospitals in patients 65 years of age and older: evaluating methods of risk adjustment. Circulation 1999; 99:2986-92. [PMID: 10368115 DOI: 10.1161/01.cir.99.23.2986] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Interest in the reporting of risk-adjusted outcomes for patients with acute myocardial infarction is growing. A useful risk-adjustment model must balance parsimony and ease of data collection with predictive ability. METHODS AND RESULTS From our analysis of 82 359 patients >/=65 years of age admitted with acute myocardial infarction to 2401 hospitals, we derived a parsimonious model that predicts 30-day mortality. The model was validated on a similar group of 78 699 patients from 2386 hospitals. Of the 73 candidate predictor variables examined, 7 variables describing patient characteristics on arrival were selected for inclusion in the final model: age, cardiac arrest, anterior or lateral location of myocardial infarction, systolic blood pressure, white blood cell count, serum creatinine, and congestive heart failure. The area under the receiver-operating characteristic curve for the final model was 0.77 in the derivation cohort and 0.77 in the validation cohort. The rankings of hospitals by performance (in deciles) with this model were most similar to a comprehensive 27-variable model based on medical chart review and least similar to models based on administrative billing codes. CONCLUSIONS A simple 7-variable risk model performs as well as more complex models in comparing hospital outcomes for acute myocardial infarction. Although there is a continuing need to improve methods of risk adjustment, our results provide a basis for hospitals to develop a simple approach to compare outcomes.
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Nohria A, Chen YT, Morton DJ, Walsh R, Vlasses PH, Krumholz HM. Quality of care for patients hospitalized with heart failure at academic medical centers. Am Heart J 1999; 137:1028-34. [PMID: 10347327 DOI: 10.1016/s0002-8703(99)70358-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND The purpose of this study was to determine the standard of care provided by academic medical centers for the management of congestive heart failure (CHF). METHODS AND RESULTS The standard of care was estimated by assessing adherence to the treatment guidelines published by the US Agency for Health Care Policy and Research among 522 patients hospitalized at 7 university hospitals with a diagnosis of CHF. Data were abstracted by retrospective chart review. Of the 522 patients analyzed, 435 (83%) had a left ventricular ejection fraction (LVEF) measured or documented. Among these patients, 192 were considered "ideal" candidates for angiotensin-converting enzyme (ACE) inhibitor therapy (ie, with systolic dysfunction [LVEF <40%] and no contraindications to ACE inhibitors). In this cohort of "ideal" candidates, 138 (72%) were receiving ACE inhibitors at hospital discharge, including 60 (44%) who were prescribed doses recommended in large clinical trials. Compliance with patient education guidelines was assessed in all 487 patients who were alive at the time of discharge. Of these patients, 365 (75%) received dietary counseling, 404 (83%) were educated about exercise, 54 (11%) were instructed to follow daily weights, and 468 (96%) were counseled regarding medication compliance. Among the 87 smokers who were alive at time of discharge, 8 (9%) had documented advice to quit smoking. CONCLUSIONS This study indicates that academic medical centers performed fairly well on the assessment of LVEF, the prescription of ACE inhibitors at discharge, and on education regarding diet, exercise, and compliance with medications. However, the results suggest opportunities for improvement in ACE inhibitor dosing and patient education regarding the importance of monitoring daily weights and smoking cessation.
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Chen YT, Vaccarino V, Williams CS, Butler J, Berkman LF, Krumholz HM. Risk factors for heart failure in the elderly: a prospective community-based study. Am J Med 1999; 106:605-12. [PMID: 10378616 DOI: 10.1016/s0002-9343(99)00126-6] [Citation(s) in RCA: 191] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The risk factors for the development of heart failure are not clearly defined, particularly for older adults. We undertook the current investigation to examine the associations of traditional cardiovascular risk factors, comorbidity, and psychosocial factors with the risk of heart failure during 10 years of follow-up in a community-based elderly population. SUBJECTS AND METHODS We evaluated 1,749 subjects, 65 years of age or older, free of heart failure, myocardial infarction, and angina at baseline, who were participating in the New Haven, Connecticut cohort of the Established Population for Epidemiologic Studies of the Elderly program. Cox proportional hazards regression models were used to determine risk ratios (RR) and 95% confidence intervals (CI). RESULTS During 13,811 person-years of follow-up, 173 subjects developed incident heart failure, as confirmed by chart review. Five factors were independent predictors of heart failure: male sex (RR = 1.7; CI, 1.3 to 2.4), older age (RR = 1.9; CI, 1.3 to 2.7 for age 75 to 84 years, RR = 3.0; CI, 1.7 to 5.5 for age 85 years and older, compared with < or = 74 years), diabetes (RR = 2.9; CI, 2.0 to 4.3), pulse pressure > or = 70 mm Hg (RR = 2.3; CI, 1.3 to 4.3, compared with <50 mm Hg), and body mass index > or = 28 kg/m2 (RR = 1.6; CI, 1.0 to 2.4, compared with <24 kg/ m2). Myocardial infarction occurred during follow-up in 8% of the cohort and was also an important predictor of heart failure (RR = 21; CI, 15 to 31). CONCLUSIONS Age and traditional cardiovascular risk factors are associated with the development of heart failure in the elderly. Preventive strategies should focus on the management of diabetes, blood pressure, and weight, in addition to the prevention and management of myocardial infarction.
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Krumholz HM, Chen YT, Bradford WD, Cerese J. Variations in and correlates of length of stay in academic hospitals among patients with heart failure resulting from systolic dysfunction. THE AMERICAN JOURNAL OF MANAGED CARE 1999; 5:715-23. [PMID: 10538451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
OBJECTIVE Given the high cost of caring for patients with congestive heart failure, there are strong incentives to decrease hospital costs by shortening length of hospital stay. We sought to identify factors associated with length of stay among patients admitted for the treatment of heart failure resulting from systolic dysfunction. STUDY DESIGN Retrospective cohort study. METHODS We examined data from patients with a principal discharge diagnosis of congestive heart failure who had been admitted to 1 of the 49 academic hospitals across the United States that participated in the CHF Benchmark Project, a large collaborative quality improvement project coordinated by the University HealthSystem Consortium. Patients were discharged between January 1 and June 30, 1996. We obtained patient characteristics and hospitalization data by retrospectively reviewing medical records. We used linear regression models to identify major determinants of length of stay. RESULTS Among the 1046 patients eligible for the study, 59% were women, 55% were white, and 58% were aged 65 years or older. Adjusting for patient demographic and admission clinical characteristics, the mean length of stay was 4.9 +/- 0.9 days. Length of stay varied significantly among hospitals, even after adjusting for differences in patient characteristics. In multivariate regression models, factors that were independently associated with a significantly longer length of stay were prior renal failure, peripheral edema, atrial fibrillation, hyponatremia, urinary catheter on admission, initiation of an antiarrhythmic or warfarin, and major complications. Patient characteristics and hospital events combined explained 16% of the variation in the length of stay. Adjusting for the individual hospitals explained an additional 10% of the variation in the length of stay. CONCLUSIONS Although a number of patient and hospitalization factors were associated with length of stay in patients with congestive heart failure resulting from systolic dysfunction, much unexplained variation remained. Clinical factors alone explained about 50% more variation than did factors specific to the individual hospitals.
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Sheu WH, Lee WJ, Yao YE, Jeng CY, Young MM, Chen YT. Lack of association between genetic variation in the beta3-adrenergic receptor gene and insulin resistance in patients with coronary heart disease. Metabolism 1999; 48:651-4. [PMID: 10337869 DOI: 10.1016/s0026-0495(99)90066-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The beta-adrenergic system plays a critical role in regulating lipolysis and thermogenesis. Recent studies have suggested that a missense Trp64Arg mutation in the beta3-adrenergic receptor gene is involved in visceral obesity and insulin resistance. We investigated the effect of this mutation on insulin resistance in patients with angiographically documented coronary heart disease ([CHD]n = 137) and normal subjects (n = 188). Plasma glucose and insulin responses to a 75-g oral glucose tolerance test and insulin resistance measured by the insulin suppression test, were determined in 58 (42%) patients with CHD and 121 (64%) controls. The genotype and allele frequency of the beta3-adrenergic receptor did not differ between patients with CHD and controls. The blood pressure, body mass index (BMI), waist to hip ratio, fasting plasma glucose, insulin, and lipid, and plasma glucose and insulin responses to the glucose load were relatively similar in subjects with and without the mutation in CHD and normal groups. The degree of insulin sensitivity, ie, the steady-state plasma glucose concentration, was not significantly different between subjects with and without the mutation in the CHD group (11.3 +/- 1.2, n = 11 v 11.9 +/- 0.6 mmol/L, n = 47, P = NS) and control group (8.4 +/- 0.7, n = 30 v 8.2 +/- 0.4 mmol/L, n = 91, P = NS). We conclude that Trp64Arg polymorphism of the beta3-adrenergic receptor gene does not likely play a major role in the development of CHD in the Chinese population. In addition, it appears to have no association with the insulin resistance syndrome in either CHD or non-CHD subjects.
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Jungbluth AA, Iversen K, Coplan K, Williamson B, Chen YT, Stockert E, Old LJ, Busam KJ. Expression of melanocyte-associated markers gp-100 and Melan-A/MART-1 in angiomyolipomas. An immunohistochemical and rt-PCR analysis. Virchows Arch 1999; 434:429-35. [PMID: 10389626 DOI: 10.1007/s004280050362] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Angiomyolipomas are tumours of uncertain histogenesis, most often occurring in association with the kidney. A characteristic finding is their reactivity with HMB-45, a monoclonal antibody to the melanocyte-associated antigen gp-100. We tested 18 angiomyolipomas for their reactivity with A103, a monoclonal antibody to Melan-A (MART-1), another melanocyte-associated marker, and compared it with HMB-45. All cases were positive with both antibodies, yet most cases showed a more homogeneous staining pattern with A103. Normal kidney was immunohistochemically negative for both antibodies. We also performed RT-PCR assays for gp-100 and Melan-A in 4 of the 18 angiomyolipoma samples and in three normal kidney samples. All 4 angiomyolipoma specimens revealed mRNA for both melanocyte differentiation markers. gp-100 mRNA was found in the samples of normal kidney, but Melan-A mRNA was not. Our study shows that angiomyolipomas express the melanocyte-associated antigens Melan-A and gp-100 at the protein and at the mRNA level, suggesting a true expression of these antigens rather than cross-reacting epitopes. Based on the mRNA expression pattern, immunohistochemical analysis is the preferred method for the detection of gp-100, while Melan-A can be used at the protein and mRNA levels. Our study demonstrates that A103 is a useful marker for the diagnosis of angiomyolipomas.
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Scanlan MJ, Williamson B, Jungbluth A, Stockert E, Arden KC, Viars CS, Gure AO, Gordan JD, Chen YT, Old LJ. Isoforms of the human PDZ-73 protein exhibit differential tissue expression. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1445:39-52. [PMID: 10209257 DOI: 10.1016/s0167-4781(99)00033-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Patients with renal and colon cancer frequently develop IgG autoantibodies toward the NY-CO-38/PDZ-73 antigen, a protein of 652 amino acids (73 kDa) which contains three copies of the PDZ protein-protein interaction domain. The gene encoding PDZ-73 mapped to chromosome 11p15.4-p15.1. Additional tissue-specific isoforms were identified: PDZ-45, which lacks the third PDZ domain and the putative PEST protein degradation motif, is expressed in kidney, colon, small intestine, brain and testis; PDZ-54 and PDZ-59, which also lack the third PDZ domains, have unique carboxyl terminal amino acids and are expressed in brain, kidney, bladder, colon cancer and renal cancer; and a putative PDZ-37 isoform, containing only the third PDZ domain, that is expressed in the central nervous system. Immunohistochemical staining with anti-PDZ 73 monoclonal antibodies showed strong cytoplasmic reactivity in epithelial cells of the small intestine, colon and kidney tubules, with a prominent apical staining pattern in cells of the small intestine. The reactivity pattern of the antibodies with various tissues correlated with the mRNA expression pattern of the PDZ-45 isoform. The existence of multiple PDZ-73 isoforms with variations in tissue distribution, PDZ domains, protein degradation sequences and carboxyl terminal structure indicate that these isoforms have distinct tissue-specific functions.
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Chen YT, Krumholz HM. Impact of cholesterol on cardiovascular morbidity and mortality in older adults. Nutrition 1999; 15:242-4. [PMID: 10198923 DOI: 10.1016/s0899-9007(98)00187-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Chen YT, Stewart DB, Nelson WJ. Coupling assembly of the E-cadherin/beta-catenin complex to efficient endoplasmic reticulum exit and basal-lateral membrane targeting of E-cadherin in polarized MDCK cells. J Biophys Biochem Cytol 1999; 144:687-99. [PMID: 10037790 PMCID: PMC2132940 DOI: 10.1083/jcb.144.4.687] [Citation(s) in RCA: 239] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The E-cadherin/catenin complex regulates Ca++-dependent cell-cell adhesion and is localized to the basal-lateral membrane of polarized epithelial cells. Little is known about mechanisms of complex assembly or intracellular trafficking, or how these processes might ultimately regulate adhesion functions of the complex at the cell surface. The cytoplasmic domain of E-cadherin contains two putative basal-lateral sorting motifs, which are homologous to sorting signals in the low density lipoprotein receptor, but an alanine scan across tyrosine residues in these motifs did not affect the fidelity of newly synthesized E-cadherin delivery to the basal-lateral membrane of MDCK cells. Nevertheless, sorting signals are located in the cytoplasmic domain since a chimeric protein (GP2CAD1), comprising the extracellular domain of GP2 (an apical membrane protein) and the transmembrane and cytoplasmic domains of E-cadherin, was efficiently and specifically delivered to the basal-lateral membrane. Systematic deletion and recombination of specific regions of the cytoplasmic domain of GP2CAD1 resulted in delivery of <10% of these newly synthesized proteins to both apical and basal-lateral membrane domains. Significantly, >90% of each mutant protein was retained in the ER. None of these mutants formed a strong interaction with beta-catenin, which normally occurs shortly after E-cadherin synthesis. In addition, a simple deletion mutation of E-cadherin that lacks beta-catenin binding is also localized intracellularly. Thus, beta-catenin binding to the whole cytoplasmic domain of E-cadherin correlates with efficient and targeted delivery of E-cadherin to the lateral plasma membrane. In this capacity, we suggest that beta-catenin acts as a chauffeur, to facilitate transport of E-cadherin out of the ER and the plasma membrane.
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Troxell ML, Chen YT, Cobb N, Nelson WJ, Marrs JA. Cadherin function in junctional complex rearrangement and posttranslational control of cadherin expression. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:C404-18. [PMID: 9950768 DOI: 10.1152/ajpcell.1999.276.2.c404] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of E-cadherin, a calcium-dependent adhesion protein, in organizing and maintaining epithelial junctions was examined in detail by expressing a fusion protein (GP2-Cad1) composed of the extracellular domain of a nonadherent glycoprotein (GP2) and the transmembrane and cytoplasmic domains of E-cadherin. All studies shown were also replicated using an analogous cell line that expresses a mutant cadherin construct (T151) under the control of tet repressor. Mutant cadherin was expressed at approximately 10% of the endogenous E-cadherin level and had no apparent effect on tight junction function or on distributions of adherens junction, tight junction, or desmosomal marker proteins in established Madin-Darby canine kidney cell monolayers. However, GP2-Cad1 accelerated the disassembly of epithelial junctional complexes and delayed their reassembly in calcium switch experiments. Inducing expression of GP2-Cad1 to levels approximately threefold greater than endogenous E-cadherin expression levels in control cells resulted in a decrease in endogenous E-cadherin levels. This was due in part to increased protein turnover, indicating a cellular mechanism for sensing and controlling E-cadherin levels. Cadherin association with catenins is necessary for strong cadherin-mediated cell-cell adhesion. In cells expressing low levels of GP2-Cad1, protein levels and stoichiometry of the endogenous cadherin-catenin complex were unaffected. Thus effects of GP2-Cad1 on epithelial junctional complex assembly and stability were not due to competition with endogenous E-cadherin for catenin binding. Rather, we suggest that GP2-Cad1 interferes with the packing of endogenous cadherin-catenin complexes into higher-order structures in junctional complexes that results in junction destabilization.
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Chang HM, Ou-Yang RF, Chen YT, Chen CC. Productivity and some properties of immunoglobulin specific against Streptococcus mutans serotype c in chicken egg yolk (IgY). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 1999; 47:61-66. [PMID: 10563850 DOI: 10.1021/jf980153u] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Hens were immunized on thighs by using whole cells of Streptococcus mutans MT8148 serotype c strain as antigen through intramuscular (im) and subcutaneous (sc) routes to investigate the difference of immunization reactions and the changes in yolk antibody activities against antigen after initial immunization. Several properties of crude IgY were examined to evaluate the stability during food processing. Results showed that the specificity of IgY of im treated hens was nearly 10 times as high as those of sc treated antibody. IgY from the hens immunized with the serotype c strain showed significant cross-reactions against serotypes e and f, while minor reactions against serotypes a, b, d, and g were observed. In thermal stability tests, IgY activity in both yolk and crude IgY decreased with the increasing temperature, from 70 to 80 degrees C, but the thermal denaturation rates between those two samples were not significantly different. The addition of high levels sucrose, maltose, glycerol, or 2% glycine displayed effective protection against thermal denaturation of IgY. Lyophilized yolk-5% gum arabic powder showed better stability against proteases.
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Conte HA, Chen YT, Mehal W, Scinto JD, Quagliarello VJ. A prognostic rule for elderly patients admitted with community-acquired pneumonia. Am J Med 1999; 106:20-8. [PMID: 10320113 DOI: 10.1016/s0002-9343(98)00369-6] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
PURPOSE We sought to identify admission characteristics predicting mortality in elderly patients hospitalized with community-acquired pneumonia and to develop a prognostic staging system and discriminant rule. PATIENTS AND METHODS We retrospectively analyzed data from 2,356 patients aged > or = 65 years admitted with community-acquired pneumonia. Multivariable analyses of a derivation cohort (n = 1,000) identified characteristics associated with hospital mortality. A staging system and discriminant rule based on these characteristics were tested in a validation cohort (n = 1,356). Our discriminant rule was compared with a rule formulated from a heterogeneous adult population with community-acquired pneumonia. RESULTS Hospital mortality rates were 9% (derivation cohort) and 12% (validation cohort). We identified five independent predictors of mortality: age > or = 85 years [odds ratio 1.8 (95% confidence interval 1.1-3.1)], comorbid disease [odds ratio 4.1 (2.1-8.1)], impaired motor response [odds ratio 2.3 (1.4-3.7)], vital sign abnormality [odds ratio 3.4 (2.1-5.4)], and creatinine level > or = 1.5 mg/dL [odds ratio 2.5 (1.5-4.2)]. These variables stratified patients into four distinct stages with increasing mortality in the derivation cohort (Stage 1, 2%; Stage 2, 7%; Stage 3, 22%; Stage 4, 45%; P = 0.001) as well as in the validation cohort (Stage 1, 4%; Stage 2, 11%; Stage 3, 23%; Stage 4, 41%; P = 0.001). The discriminant rule developed from the derivation cohort had greater overall accuracy (77.1%) in the validation cohort than a rule formulated from a heterogeneous adult population (68.0%, P = 0.001). CONCLUSION Elderly patients with community-acquired pneumonia have characteristics at admission that can predict mortality. Our staging system and discriminant rule improve prognostic stratification of these patients.
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Chen YT, Cheng KS, Liu JK. Improving cephalogram analysis through feature subimage extraction. IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE : THE QUARTERLY MAGAZINE OF THE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY 1999; 18:25-31. [PMID: 9934597 DOI: 10.1109/51.740961] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
An MLP with a GA was proposed to extract feature subimages containing orthodontic landmarks. Simulated images and cephalograms were used to investigate its performance in comparison with the cross-correlation method. From the results of simulated image containing shapes with different geometrical conditions, it was shown that the fault tolerance of the MLP for rotation, scaling, brightness variety, and other anomalous deformations is good enough to overcome the clinical application problems. It was also shown that the stability, accuracy, and speed of this proposed algorithm are very promising. Moreover, the performance of the MLP can be significantly improved by collecting, more "representative" false patterns. The GA is a good approach to speed up the process of feature subimage extraction based on the fitness evaluated using the MLP.
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Chen YT. A novel point mutation in an acceptor splice site of intron 32 (IVS32 A-12-->G) but no exon 3 mutations in the glycogen debranching enzyme gene in a homozygous patient with glycogen storage disease type IIIb. Hum Genet 1999; 104:111-2. [PMID: 10071203 DOI: 10.1007/s004390050920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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218
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Chen YT, Old LJ. Cancer-testis antigens: targets for cancer immunotherapy. THE CANCER JOURNAL FROM SCIENTIFIC AMERICAN 1999; 5:16-7. [PMID: 10188055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Heiat A, Mattera JA, Henry GA, Chen YT, Krumholz HM. Trends in costs of percutaneous transluminal coronary angioplasty. THE AMERICAN JOURNAL OF MANAGED CARE 1998; 4:1667-74. [PMID: 10339099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
OBJECTIVE To evaluate recent trends in the cost of percutaneous transluminal coronary angioplasty (PTCA), particularly the impact of newer technology and changing patient profile. STUDY DESIGN Retrospective study with a 6-month follow up. PATIENTS AND METHODS We compared the data on two groups of 100 consecutive patients admitted for elective PTCA at Yale-New Haven Hospital in 1995 and 1996. Hospital records, cineangiograms, and hospital cost accounting system were reviewed, and 6-month clinical outcomes were obtained from telephone interviews and medical chart review. RESULTS Demographic and clinical characteristics did not differ between the 1995 and 1996 groups of patients, nor was a difference detected in in-hospital and 6-month clinical outcomes between 1995 and 1996. Angiographic features of treated lesions were different between the two groups, with a significantly higher frequency of type C and totally occluded lesions in 1996 (p = 0.002 and p = 0.04, respectively). The total hospital costs were higher in 1996 compared with 1995 ($11,799 +/- $6189 vs $10,087 +/- $5608; p = 0.04). This difference persisted after adjustment for changes in patient population. The major factor responsible for escalating costs was a 45% increase in catheterization laboratory costs ($8575 +/- $4524 in 1996 vs $5916 +/- $3030 in 1995; P < 0.0001). In contrast, the noncatheterization costs decreased substantially during this period, largely as a result of an approximately 33% decrease in length of stay (3.75 +/- 2.66 days in 1995 vs 2.57 +/- 1.99 days in 1996; P = 0.0005). In a multiple linear regression model, the most important determinants of cost were lesion characteristics, stent use, and radiographic contrast volume. CONCLUSIONS Despite cost reduction efforts, the costs of PTCA are rising because of increased consumption of resources in the catheterization laboratory.
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Chang CK, Yu HJ, Chan KW, Chie WC, Chen J, Chen YT, Lai MK. Factors related to delayed treatment and posttreatment symptom severity in Taiwanese patients with benign prostatic hyperplasia. J Formos Med Assoc 1998; 97:757-62. [PMID: 9872032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
We evaluated the sociodemographic and clinical factors of delayed treatment and posttreatment symptom severity in outpatients with benign prostatic hyperplasia (BPH). The study included 146 BPH patients treated at the National Taiwan University Hospital in early 1997. All patients were treated with alpha-adrenergic antagonists or finasteride for at least 2 weeks. A questionnaire based on Andersen's Health Behavior Model was used to assess various sociodemographic features, while the pre- and posttreatment symptoms severity was rated according to the International Prostate Symptom Score (IPSS). Multiple logistic regression was used to assess the associations of these factors with delayed treatment and posttreatment symptom severity. Subjects who had recently quit smoking or were blue-collar workers tended to delay treatment, while those who chose a medical center as the care provider for chronic diseases tended to be less likely to delay treatment. However, none of these associations were statistically significant. No enabling factors (income, insurance) or need factors (symptom scores) evaluated were associated with delayed treatment. Predisposing factors associated with higher posttreatment symptom severity were delayed treatment (over 12 months) (adjusted odds ratio [OR]: 2.67, 95% confidence interval [CI]: 1.16-6.16), quitting smoking (adjusted OR: 4.47, 95% CI: 1.34-14.94), and having never smoked (adjusted OR: 3.73, 95% CI: 1.15-12.11). Subjects with severe pretreatment symptoms were far more likely than subjects with mild pretreatment symptoms to have severe symptoms after treatment (adjusted OR: 52.69, 95% CI: 54.46-621.90). Our findings, though based on a limited number of subjects, suggest sociodemographic factors rather than objective clinical attributes (prostate specific antigen level, prostate volume, and urodynamic results) are associated with delayed treatment in Taiwanese men with BPH. Both pretreatment symptom severity and sociodemographic factors are related to posttreatment symptom severity.
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Sahin U, Türeci O, Chen YT, Seitz G, Villena-Heinsen C, Old LJ, Pfreundschuh M. Expression of multiple cancer/testis (CT) antigens in breast cancer and melanoma: basis for polyvalent CT vaccine strategies. Int J Cancer 1998; 78:387-9. [PMID: 9766577 DOI: 10.1002/(sici)1097-0215(19981029)78:3<387::aid-ijc22>3.0.co;2-2] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Sahin U, Türeci O, Chen YT, Seitz G, Villena-Heinsen C, Old LJ, Pfreundschuh M. Expression of multiple cancer/testis (CT) antigens in breast cancer and melanoma: basis for polyvalent CT vaccine strategies. Int J Cancer 1998. [PMID: 9766577 DOI: 10.1002/(sici)1097-0215(19981029)78:3<387::aid-ijc22>3.0.co;2-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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223
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Chen YT, Makuch RW. Use of calcium channel blockers and risk of suicide. Perscriptions for particular drug are influenced by numerous factors. BMJ (CLINICAL RESEARCH ED.) 1998; 317:1077. [PMID: 9841040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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224
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Meng M, Chen YT, Hsiao YY, Itoh Y, Bagdasarian M. Mutational analysis of the conserved cationic residues of Bacillus stearothermophilus 6-phosphoglucose isomerase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1998; 257:500-5. [PMID: 9826199 DOI: 10.1046/j.1432-1327.1998.2570500.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The importance in catalysis of the conserved arginine (R207) and lysine residues (K144, K294, K356, and K425) of 6-phosphoglucose isomerase from Bacillus stearothermophilus was assessed by site-directed mutagenesis and kinetic analysis. In general mutations had minor effects on the Km for fructose 6-phosphate. More dramatic effects were seen on kcat. The R207A mutant had a five orders of magnitude decrease in kcat relative to the wild-type enzyme. There was a significant recovery, by three orders of magnitude, in the kcat for the R207K mutant. The results suggest that the positive charge provided by R207 plays a critical role in the isomerization reaction. K425 was substituted with alanine, valine, phenylalanine, tryptophan and aspartate. All mutant enzymes at position 425 had kcat decreased in the range of several-hundred-fold. For the other mutants, K294A and K144A, the kcat values were 3.5% and 27% of the wild-type enzyme, respectively. No effects on catalysis were observed for the K356A mutant. The results suggest that R207, K144, K294, and K425 are located in the active site of the enzyme. The active-site location and the catalytic roles of K425 and K294 are supported further by the inhibitory effects of pyridoxal 5'-phosphate on enzymatic activities. The data also confirm the importance of K425 and K144 anticipated by the affinity labeling studies of the corresponding residues by pyridoxal 5'-phosphate in pig muscle phosphoglucose isomerase.
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225
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Chen YT, Singh R, Brett RH. Diagnostic red herring in an infant with stridor. Singapore Med J 1998; 39:471-2. [PMID: 9885712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Foreign body aspiration in children may present with a variety of symptoms. We report here an unusual case of laryngeal foreign body in an infant masquerading as laryngeal web in its clinical presentation as well as radiological findings. The diagnosis was only made at endoscopy, thus emphasising the limited sensitivity of radiographic studies in identifying this condition.
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