Abstract：
:Backpropagation neural networks are a computer-based pattern-recognition method that has been applied to the interpretation of clinical data. Unlike rule-based pattern recognition, backpropagation networks learn by being repetitively trained with examples of the patterns to be differentiated. We describe and analyze the phenomenon of overtraining in backpropagation networks. Overtraining refers to the reduction in generalization ability that can occur as networks are trained. The clinical application we used was the differentiation of giant cell arteritis (GCA) from other forms of vasculitis (OTH) based on results for 807 patients (593 OTH, 214 GCA) and eight clinical predictor variables. The 807 cases were randomly assigned to either a training set with 404 cases or to a cross-validation set with the remaining 403 cases. The cross-validation set was used to monitor generalization during training. Results were obtained for eight networks, each derived from a different random assignment of the 807 cases. Training error monotonically decreased during training. In contrast, the cross-validation error usually reached a minimum early in training while the training error was still decreasing. Training beyond the minimum cross-validation error was associated with an increased cross-validation error. The shape of the cross-validation error curve and the point during training corresponding to the minimum cross-validation error varied with the composition of the data sets and the training conditions. The study indicates that training error is not a reliable indicator of a network's ability to generalize. To find the point during training when a network generalizes best, one must monitor cross-validation error separately.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Astion ML,Wener MH,Thomas RG,Hunder GG,Bloch DAsubject
Has Abstractpub_date
1993-09-01 00:00:00pages
1998-2004issue
9eissn
0009-9147issn
1530-8561journal_volume
39pub_type
临床试验,杂志文章,随机对照试验abstract：BACKGROUND:Gradient gel electrophoresis (GGE) and nuclear magnetic resonance (NMR) spectroscopy are both widely accepted methods for measuring LDL and HDL particle size. However, whether or not GGE- or NMR-measured LDL or HDL particle size predicts coronary heart disease (CHD) risk to a similar extent is currently unkn...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.140939
更新日期：2010-05-01 00:00:00
abstract：:The manual Reference Method of the Centers for Disease Control for serum iron (CDC/RM/Fe) and a semiautomated adaptation of it were used to evaluate two working methods: one, a detergent solubilization procedure for the Roche Cobas-Bio analyzer, the other, the Kodak Ektachem 700 procedure, based on dry-film technology...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-10-01 00:00:00
abstract：BACKGROUND:HDL is quantitatively the most important lipoprotein in most species and mechanistic evidence points toward a role for HDL in normal immune function. We tested the hypothesis that concentrations of HDL cholesterol are associated with risk of autoimmune disease. METHODS:From 2 studies of the general populati...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.299636
更新日期：2019-05-01 00:00:00
abstract：BACKGROUND:Recent studies have suggested that single-stranded DNA (ssDNA) library preparation can enrich short DNA species from the plasma of healthy individuals, cancer patients, and transplant recipients. Based on previous observations that fetal DNA molecules in the maternal plasma are shorter than maternal DNA mole...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2016.268656
更新日期：2017-05-01 00:00:00
abstract：:It has been hypothesized over many years that the autoimmune endocrine diseases are each due to antigen-specific defects in suppressor (regulatory) T lymphocyte function. There is now increasing evidence in studies of autoimmune thyroid disease and insulin-dependent diabetes mellitus that suppressor cells are activate...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1994-11-01 00:00:00
abstract：BACKGROUND:The aims of this study were to measure the N-terminal fragment of pro-brain natriuretic peptide (proBNP) in plasma in medical conditions commonly found in primary care and to evaluate the utility of these measurements in identifying impaired cardiac function in elderly patients with symptoms associated with ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.8.1337
更新日期：2003-08-01 00:00:00
abstract：:Monoclonal antibody CKM-G01 inhibited greater than 99% of the activity of porcine and human creatine kinase(CK)-MM isoenzyme purified from muscle. However, it inhibited only 54% of CK-MM in human serum. Chromatofocusing of serum CK-MM showed that CKM-G01 inhibited 100% of MM3 but not isoform MM1. CKM-G01 inhibited CK-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-01-01 00:00:00
abstract：:We assessed the accuracy and precision of seven commercial kits for serum ferritin. The concentration of ferritin as determined by these assays for a liver ferritin reference standard, a human heart ferritin standard, and normal sera correlated highly, but the absolute values varied widely. Use of an international ref...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-02-01 00:00:00
abstract：:We report here the development of a new method that allows continuous determination of the oxygen dissociation curve for microsamples (600 mul) of whole blood under conditions of pH, pCO2, methemoglobin concentration, and 2,3-diphosphoglycerate content closely approaching those found in the circulatory system. The met...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-11-01 00:00:00
abstract：:A new method for quantifying specific amino acids in small volumes of plasma and whole blood has been developed. Based on isotope-dilution tandem mass spectrometry, the method takes only a few minutes to perform and requires minimal sample preparation. The accurate assay of both phenylalanine and tyrosine in dried blo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-01-01 00:00:00
abstract：:In the diagnosis of chronic (as opposed to acute) liver diseases, combinations of indicators are needed to improve specificity. Alanine aminopeptidase (AAP; microsomal aminopeptidase, EC 3.4.11.2) activity in serum reportedly is a very sensitive indicator of intrahepatic cholestasis and biliary obstruction; it is also...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-03-01 00:00:00
abstract：:A method is presented for the assay of delta-aminolaevulinate dehydratase (EC 4.2.1.24) to be performed on 10 microL of whole blood. Results compare favorably with those obtained with an accepted method (J. Clin. Chem. Clin. Bio-chem. 12: 389-390, 1974) that involves use of 200 microL of blood. ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-01-01 00:00:00
abstract：BACKGROUND:Bilirubin has antioxidative and cytoprotective properties. Low plasma concentrations of bilirubin are reportedly associated with the development of coronary and cerebrovascular disease, and bilirubin concentrations are strongly correlated with the enzyme activity of the hepatic uridine diphosphate glucuronos...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2007.102046
更新日期：2008-05-01 00:00:00
abstract：:A reaction of urea, o-phthalaldehyde and N-(1-naphthyl)ethylenediamine is described for measurement of urea by manual, continuous-flow, and kinetic methods. The continuous-flow system requires 25 mu-l of sample; 40 samples can be analyzed per hour. The kinetic method requires no enzymes, has no lag phase, and has good...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-07-01 00:00:00
abstract：BACKGROUND:We evaluated the completeness of reporting of diagnostic test accuracy (DTA) systematic reviews using the recently developed Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA)-DTA guidelines. METHODS:MEDLINE® was searched for DTA systematic reviews published October 2017 to January 2...
journal_title：Clinical chemistry
pub_type： 杂志文章,meta分析
doi：10.1373/clinchem.2018.292987
更新日期：2019-02-01 00:00:00
abstract：:We describe an automated determination of serum hexosamine by the Elson-Morgan reaction, together with reagent modifications that minimiz interference from amino acids and sugars present in acid hydrolysates of sera. We used a novel 15-min autoclave procedure for the acid hydrolysis of sera before analysis to facilita...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-08-01 00:00:00
abstract：:Ethchlorvynol is a commonly abused sedative hypnotic. I report here a seven-day study of serum ethchlorvynol concentrations in a patient who had received an extreme overdose. These concentrations were correlated with the patient's response to stimuli. Serum ethchlorvynol concentrations were logarithmically related to ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-06-01 00:00:00
abstract：:During phase I/II clinical trials of sirolimus (rapamycin; SRL), therapeutic drug monitoring was performed with a multistep liquid-liquid extraction of 1-mL aliquots of whole blood followed by reversed-phase HPLC with ultraviolet detection. Blood was sampled according to a standardized protocol and clinical status. SR...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-12-01 00:00:00
abstract：:This assay was developed to measure apolipoprotein (apo) B in blood samples spotted onto filter paper. The long-term aim is to detect young families with the dominantly inherited familial hypercholesterolemia, during current neonatal screening programs. The interassay CV was 5.6%, and apo B concentrations correlated c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-06-01 00:00:00
abstract：:In routine analysis for immunoglobulin light chains in pediatric diagnostics, the age-related reference intervals for serum kappa (kappa) and lambda (lambda) light chains were evaluated in 1543 healthy subjects (newborns to age 16 years, including 168 premature infants). Light-chain analysis was performed by rate neph...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-04-01 00:00:00
abstract：:We present a case of advanced ovarian carcinoma associated with high concentrations of serum and urine amylase. Biochemical analysis to elucidate the nature and origin of the hyperamylasemia identified seven amylase isoenzymes, of which five appeared to be distinct from normal salivary and pancreatic amylase. We discu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-06-01 00:00:00
abstract：:We studied the EMIT (Enzyme Multiplied Immunoassay Technique, Syva) procedures for the assay of phenytoin and phenobarbital in serum, adapting them to the miniature Centrifugal Fast Analyzer. For different concentrations of drug, each rate of reaction decreased continuously with time, tending to converge on a single c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-08-01 00:00:00
abstract：:We have improved the protocol for RNA quantification by using RNase protection. Instead of precipitation and extraction with phenol and chloroform, we use a faster and more reliable precipitation based on guanidinium thiocyanate (GdSCN). The internal standard is produced by in vitro transcription of a DNA template con...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-11-01 00:00:00
abstract：:Kappa Bence Jones proteinuria was found by immunoelectrophoretic techniques in a patient with plasma cell leukemia, who presented with no M-proteins either in serum or urine. However, a significant decrease in normal immunoglobulins was observed. On microscopic examination of kidney sections obtained a autopsy, protei...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-10-01 00:00:00
abstract：:We report a method for the extraction of angiotensin peptides from plasma with a mixture of acetone, 1 mol/L HCl, and water (40/1/5 by vol). The method is highly reproducible for the measurement of angiotensin I and angiotensin II in small sample volumes, with analytical recoveries of about 80% for both peptides. We i...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-06-01 00:00:00
abstract：BACKGROUND:Current noninvasive assays for urothelial carcinoma (UC) lack clinical sensitivity and specificity. Given the utility of plasma cell-free DNA (cfDNA) biomarkers, the development of urinary cfDNA biomarkers may improve the diagnostic sensitivity. METHODS:We assessed copy number alterations (CNAs) by shallow ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2019.309633
更新日期：2020-01-01 00:00:00
abstract：BACKGROUND:One of the aims of cardiovascular genetics is to test the efficacy of the use of genetic information to predict cardiovascular risk. We therefore investigated whether inclusion of a set of common variants in candidate genes along with conventional risk factor (CRF) assessment enhanced coronary heart disease ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.074591
更新日期：2007-01-01 00:00:00
abstract：:We developed a novel noncompetitive immunoassay format for monoepitopic analytes and describe here a model assay for triiodothyronine (T3), performed on Ciba Corning's ACS:180 analyzer. Acridinium ester (AE)-labeled bivalent anti-T3 was incubated with the sample, producing AE-anti-T3/T3 complexes and unreacted AE-anti...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-07-01 00:00:00
abstract：:We describe a mass-fragmentographic method for determination in urine of the following metabolites of L-3,4-dihydroxyphenylalanine and dopamine: vanillactic acid, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylethanol, and 3,4-dihydroxyphenylethanol. Deuterated analogs were used as internal standards. The me...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-01-01 00:00:00
abstract：:Transcutaneous pCO2 electrode response time was optimized by use of a new electrode filling solution composed of NaCl/NaHCO3 electrolyte buffer (100 and 20 mmol/L, respectively) in an equivolume mixture of glycerol and water. The 95% response time to a step change in pCO2 was 49.9 +/- 2.8 s (mean +/- SD) when there wa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-07-01 00:00:00
