bluuebunny/crossref_metadata_2025 huggingface dataset:
Spontaneous coronary artery dissection
Authors: Almeda Francis Q. , Barkatullah Sameer , Kavinsky Clifford J.
Published: June 2007

Spontaneous coronary artery dissection (SCAD) is an unusual cause of acute myocardial ischemia with complex pathophysiology. This paper reviews the major diagnostic and therapeutic issues of this rare but important disease. The diagnosis of SCAD should be strongly considered in any patient who presents with symptoms suggestive of acute myocardial ischemia, particularly in young subjects without traditional risk factors for coronary artery disease (especially in young women during the peripartum period or in association with oral contraceptive use). Urgent coronary angiography is indicated to establish the diagnosis and to determine the appropriate therapeutic approach. The decision to pursue medical management, percutaneous coronary intervention, or surgical revascularization is based primarily on the clinical presentation, extent of dissection, and amount of ischemic myocardium at risk.
A systolic murmur is a common presentation of aortic regurgitation detected by echocardiography
Authors: Heidenreich Paul A. , Schnittger Ingela , Hancock Stsven L. , Atwood J. Edwin
Published: June 2007

Background: The finding of aortic regurgitation at a classical examination is a diastolic murmur.

Hypothesis: Aortic regurgitation is more likely to be associated with a systolic than with a diastolic murmur during routine screening by a noncardiologist physician.

Methods: In all, 243 asymptomatic patients (mean age 42 ±10 years) with no known cardiac disease but at risk for aortic valve disease due to prior mediastinal irradiation (≥ 35 Gy) underwent auscultation by a noncardiologist followed by echocardiography. A systolic murmur was considered benign if it was grade ≤ II/VI, not holosystolic, was not heard at the apex, did not radiate to the carotids, and was not associated with a diastolic murmur.

Results: Of the patients included, 122 (49%) were male, and 86 (35%) had aortic regurgitation, which was trace in 20 (8%), mild in 52 (21%), and moderate in 14 (6%). A systolic murmur was common in patients with aortic regurgitation, occurring in 12 (86%) with moderate, 26 (50%) with mild, 6 (30%) with trace, and 27 (17%) with no aortic regurgitation (p < 0.0001). The systolic murmurs were classified as benign in 21 (78%) patients with mild and 8 (67%) with moderate aortic regurgitation. Diastolic murmurs were rare, occurring in two (14%) with moderate, two (4%) with mild, and three (2%) with no aortic regurgitation (p = 0.15).

Conclusions: An isolated systolic murmur is a common auscultatory finding by a noncardiologist in patients with moderate or milder aortic regurgitation. A systolic murmur in patients at risk for aortic valve disease should prompt a more thorough physical examination for aortic regurgitation.
Interleukin‐1 receptor antagonist levels correlate with extent of myocardial loss in patients with acute myocardial infarction
Authors: Patti Giuseppe , Mega Simona , Pasceri Vincenzo , Nusca Annunziata , Giorgi Gabriele , Zardi Enrico Maria , D'Ambrosio Andrea , Dobrina Aldo , Di Sciascio Germano
Published: June 2007

Background: Interleukin‐1 receptor antagonist (IL‐1 Ra) levels are elevated early in patients with acute myocardial infarction (MI) and often precede release of markers of necrosis; however, IL‐1Ra levels did not correlate previously with infarct size and prognosis in such patients.

Hypothesis: The goal of our study was to evaluate prospectively the correlation between IL‐1Ra levels upon emergency department (ED) presentation and the extent of myocardial necrosis and prognosis in patients with ST‐segment elevation MI.

Methods: Levels of IL‐1Ra were measured upon ED presentation in 44 consecutive patients (40 men, aged 55 ± 10 years). Peak values of creatine kinase (CK) and CK‐MB were determined during hospitalization, and left ventricular ejection fraction (LVEF) was evaluated by echocardiography before discharge. All patients were followed prospectively and underwent clinical and echocardiographic assessment at 42 ± 3 months after the infarction.

Results: Levels of IL‐1Ra upon ED presentation correlated directly with CK (p = 0.002) and CK‐MB (p = 0.01) peak levels and correlated inversely with LVEF before discharge (p = 0.009). Patients with in‐hospital adverse events had significantly higher IL‐1Ra levels upon ED admission (n = 10,2620 ± 4706 pg/ml) than those without events (n = 34, 598 ± 457 pg/ml)(p = 0.015).

Conclusions: In patients with MI, levels of IL‐1Ra upon ED presentation correlated significantly with the extent of myocardial necrosis, as measured by cardiac enzymes peak and reduction of LVEF, and are predictive of in‐hospital events. Results of this study may influence early therapeutic approach in patients with acute MI.
Study on changes of heme oxygenase‐1 expression in patients with coronary heart disease
Authors: Chen S. M. , Li Y. G. , Wang D. M.
Published: June 2007

Background: Heme oxygenase (HO) is a rate‐limiting enzyme of endogenetic carbon monoxide (CO) that degrades heme into carbon monoxide, bilirubin, and iron. These products have important physiologic effects: bilirubin is a potent antioxidant that can act against ischemia/reperfusion injury; there is a negative correlation between the content of HO‐1 and the incidence of coronary heart disease (CHD).

Hypothesis: This study was undertaken to investigate the changes of HO‐1 in patients with CHD.

Methods: Thirty‐five patients with acute myocardial infarction (AMI), 40 patients with unstable angina pectoris (UAP, diagnosed by coronary angiography), and 30 patients with stable angina pectoris (AP, diagnosed by coronary angiography) were selected for the study; another 30 patients with normal coronary artery (diagnosed by coronary angiography) were selected as controls. The levels of HO‐1 protein expression in monocyte and lymphocyte in the subjects were tested by immunohistochemistry and western blot. Computer picture analyzing systems were also used to measure the levels of HO‐1 protein expression.

Results: Heme oxygenase‐1 protein is located in cell plasma. The levels of HO‐1 protein expression in patients with CHD were significantly higher than in those without CHD (p<0.01). There were significant differences of HO‐1 expression among the three groups of patients with CHD. The group with AMI was the highest, followed by the group with UAP and finally by the group with AP.

Conclusions: There is a higher expression of HO‐1 in patients with CHD. The levels of HO‐1 protein are associated with the severity of CHD.
Long‐term efficacy and stability of atrial sensing in VDD pacing
Authors: Huang Chun‐Yao , Tuan Ta‐Chuan , Lee Wen‐Shin , Cheng Chien‐Ming , Lin Shing‐Jong , Kong Chi‐Woon
Published: June 2007

Background: The efficacy and stability of atrial electrode sensing function is essential in maintaining atrioventricular (AV) synchrony and activity response in VDD pacing. Studies to evaluate the relationship between atrial sensing efficacy, stability, and implantation strategy are few.

Hypothesis: This study sought to determine the possible predictors, among the recipients' underlying clinical conditions and the implantation strategies used, of achieving the most stable and effective atrial sensing.

Methods: Eighty consecutive adults implanted with VDD pacemakers were studied retrospectively. Atrial electrodes were positioned where the optimal atrial potentials (APs) were measured during implantation. Interrogation parameters, including AV‐synchrony ratio, were acquired immediately post implantation, at 1 year, and at 2 years after pacemaker implantation. Appropriate atrial sensing efficacy was defined as AV‐synchrony ratio ≥ 90%. The stability of atrial sensing was evaluated by the variation ranges of measured APs.

Results: The measured APs showed no statistical difference when age, gender, orcomorbidity was considered. However, with pacing‐lead bending angles ≤ 90°, patients may have presented with larger APs and narrower AP variation than patients with obtuse angles. There were no clinical parameters in our study that could have predicted the proper atrial sensing efficacy with an AV‐synchrony ratio ≥ 90%.

Conclusions: The long‐term sensing efficacy and stability of VDD pacing is reliable. More sophisticated implantation strategies may further improve the atrial sensing stability and efficacy in VDD pacing.
Global differences in blood pressure control and clinical outcomes in the INternational VErapamil SR‐Trandolapril Study (INVEST)
Authors: Zineh Issam , Cooper‐Dehoff Rhonda M. , Wessel Timothy R. , Arant Christopher B. , Sleight Peter , Geiser Edward A. , Pepine Carl J.
Published: June 2007

Background: The INternational VErapamil SR‐Trandolapril Study (INVEST), a prospective, randomized, antihypertensive trial, found that two different medication regimens produced similar blood pressure (BP) control with equivalent cardiovascular (CV) outcomes (death from any cause, nonfatal myocardial infarction [MI], or nonfatal stroke).

Hypothesis: The study was undertaken to investigate whether differences exist by global regions in demographics, treatment, and outcomes in the INVEST trial.

Methods: Data were analyzed for 22,576 patients with stable coronary artery disease (CAD) enrolled in INVEST. We investigated differences in patient characteristics, treatment approaches, BP control, and clinical outcomes by creating three global regions based on geographical location: Northern Americas (NA), Caribbean (CA), and Eurasia (EA).

Results: We observed significant regional differences in patient characteristics, treatment patterns, BP control, and CV outcomes. At baseline, patients from NA were older and had greater body mass index, higher rates of diabetes, peripheral vascular disease, and coronary revascularization, but lower rates of MI or left ventricular hypertrophy than patients in CA and EA. At 24 months, there were regional differences in both study and nonstudy antihypertensive drug use. Despite having higher mean baseline BP, patients from CA and EA achieved lower mean systolic BP throughout study follow‐up. Furthermore, patients from both CA and EA had lower rates of all‐cause mortality, fatal or nonfatal MI, fatal or nonfatal stroke, and newly diagnosed diabetes than patients from NA.

Conclusions: In INVEST, regional differences in medication utilization, BP control, and CV outcomes were identified. These disparities warrant further investigation to define appropriate care for patients with hypertension and stable CAD from an international public health perspective.
Adjunctive handgrip during dobutamine stress echocardiography: Invasive assessment of myocardial oxygen consumption in humans
Authors: Khan Ijaz A. , Otero F. Javier , Font‐Cordoba Jose , McCulloch Marti , Sheahan Richard G. , Parmar Rohit , Defilippi Christopher R.
Published: June 2007

Background: Adjunctive isometric exercise in the form of sustained submaximal handgrip (HG) is considered to increase the sensitivity of dobutamine stress echo (DSE) for detection of functionally significant coronary artery disease.

Hypothesis: The study was undertaken to quantify invasive‐ly the impact of HG in humans on hemodynamics and myocardial oxygen consumption (MVO2) during DSE.

Methods: An invasive hemodynamic evaluation was performed during DSE and with addition of adjunctive HG in 11 subjects. Coronary sinus (CS) blood flow, right‐sided and systemic pressures, oxygen saturations, and transthoracic two‐dimensional echocardiography were obtained at each 3‐min stage and after adding HG at peak DSE. Myocardial oxygen consumption was calculated by the Fick method and circumferential end‐systolic wall stress (ESWS) by Mirsk's formula.

Results: At peak DSE, heart rate, left ventricular ejection fraction, CS flow, and MVO2 increased, whereas pulmonary capillary wedge pressure (PCWP) and circumferential end‐systolic wall stress (ESWS) decreased from baseline. Compared with peak DSE, the addition of isometric HG at peak DSE caused an increase in PCWP (7 ± 3 vs. 8.4 ± 3 mmHg, p < 0.05), ESWS (112 ± 25 × 103 vs. 125 ± 32 × 103 dyne·s·cm2, p = 0.02), and CS flow (260 ± 92 vs. 301 ± 105 ml/min, p < 0.05). There was a minimal increase in left ventricular volumes, heart rate, and systolic blood pressure. The MVO2 increased from 29 ± 8 ml/min at peak DSE to 31 ± 9 ml/min with adjunctive HG (p = 0.03).

Conclusion: Handgrip adjunctive to peak DSE results in a modest increase in MVO2, primarily by an increase in end‐systolic wall stress.
Prevalence of amiodarone‐related hepatotoxicity in 720 Chinese patients with or without baseline liver dysfunction
Authors: Kum Leo C. C. , Chan Winnie W. L. , Hui Helen H. Y. , Wong Grace W. M. , Ho Susan S. S. , Sanderson John E. , Yu Cheuk‐Man , Fung Jeffery W. H.
Published: June 2007

Background: The prevalence of hepatotoxicity after longterm oral amiodarone therapy in Chinese patients with or without elevated liver enzymes at baseline is unknown.

Hypothesis: Amiodarone may still be safely prescribed for Chinese patients who have baseline liver dysfunction.

Methods: This is a retrospective cross‐sectional study. Significant liver dysfunction (SLD) was defined as alanine aminotransferase (ALT) > 2 times upper limit of normal range.

Results: Baseline liver function was checked in 628 of the 720 Chinese patients identified. The mean duration of amiodarone use was 615.9 ± 703.1 days. Ninety patients (14.3%) had elevated baseline ALT. The prevalence of SLD was 3.7% (confidence interval [CI] 2.1–5.3%) and 4.4% (CI 0.2–8.6%) in patients with normal (n = 53 8) and elevated (n = 90) baseline ALT, respectively (p = 0.765). Therapy was continued in 42 patients with elevated baseline ALT until final follow‐up. Eight of these (19.0%) had elevated ALT upon final follow‐up, but the derangement was mild (mean ALT 134.8 ± 145.9 IU/l, median 76 IU/l). During follow up, 24 patients developed SLD and half of these subsequently withdrew from therapy. The ALT levels at final follow‐up had improved overtime in both groups, but the mean difference was not significant (255.1 ± 706.4 vs. 131.0 ±207.5 IU/l, p = 0.312).

Conclusion: The prevalence of SLD in Chinese patients taking oral amiodarone with or without elevated baseline ALT was similar (4.4 vs. 3.7%). It seems that amiodarone may be safely prescribed in patients with elevated baseline ALT.
Association between Pro12Ala polymorphism of peroxisome proliferator‐activated receptor‐gamma 2 and myocardial infarction in the Chinese Han population
Authors: Li Lin , Cheng Long‐Xian , Nsenga Ripen , He Mei‐An , Wu Tang‐Chun
Published: June 2007

Background: Peroxisome proliferator‐activated receptor‐gamma 2 (PPAR‐gamma 2) is a nuclear receptor that plays an important role in adipocyte differentiation, energy metabolism, and homeostasis. The Pro12Ala polymorphism of PPAR‐gamma 2 is associated with decreased risk of diabetes mellitus. Presumably, it may have a protective effect on myocardial infarction (MI).

Hypothesis: The purpose of the study was to explore the association between the Pro12Ala polymorphism and the risk of MI in the Chinese population.

Methods: The Pro12Ala polymorphism was detected by polymerase chain reaction‐restriction fragment length polymorphism among 844 subjects, including 218 patients with MI and 626 controls. Clinical parameters such as fasting serum total cholesterol, triglycerides, and plasma glucose were detected by autoanalyzer assay. Waist circumference, weight, height, and blood pressure (BP) were measured and body mass index (BMI) was calculated.

Results: The frequencies of the Ala allele in the MI and control groups were 0.053 and 0.032, respectively. There was a significant difference in genotype and allele frequency distribution between the two groups (after adjustment for age, gender, BP, fasting plasma glucose, total cholesterol, triglycerides, and smoking, odds ratio [OR] = 2.51,95% confidence interval [CI]: 1.26–5.00, p = 0.009). In the group with MI, the difference in frequency of the Ala allele in women (0.241) compared with that of men (0.056) was significant (OR = 4.29, 95% CI: 1.96–9.37, p<0.001). There was no relationship between the Pro12Ala polymorphism and waist circumference, weight, BMI, BP, or triglycerides (p>0.05).

Conclusions: Our study suggests that Pro12Ala polymorphism is associated with increased risk of MI.
Is there a better way to predict death using heart rate recovery?
Authors: Gorelik Dmitry David , Hadley David , Myers Jonathan , Froelicher Victor
Published: June 2007

Background: Heart rate recovery (HRR) during exercise testing is an independent predictor of prognosis. The relative predictive power of computational analysis of HRR as a function of resting and maximum heart rate (HR) compared with direct measurement of the drop in HR has not been determined.

Hypothesis: We aimed to improve on the prognostic value of HRR by the use of mathematical representations of HRR kinetics.

Methods: In all, 2,193 patients who underwent exercise testing, coronary angiography, and clinical evaluation were followed up for 10.2 ±3.6 years. Mathematical functions were used to model HRR as a function of resting (HRRest), maximum HR (HRPeak) and time (t):

HRR = HRRest + (HRPeak ‐ HRRest)× e−kt and

HRR = HRRest + (HRPeak ‐ HRRest)× e−kt

Results: Equation (b) provided the best fit of the recovery HR curve. An abnormal HRR at 2 min was a better predictor of mortality than HRR at 1, 3, or 5 min. At 2 min, HRR also predicted mortality better than computational models of HRR, relating HRR as a function of maximum and resting HRs. After adjusting for univariately significant predictors of mortality, HRR, age, exercise capacity, and maximum HR were chosen in order as the best predictors of mortality.

Conclusion: Even though the computational models of HRR and the determination of HRR at different time intervals were significant predictors of mortality, the simple discrete measure of HRR at 2 min was the best predictor of mortality. At 2 min, HRR outperformed age, METs, and maximum exercise HR in predicting all‐cause mortality.
Coronary anomalies by cardiac computed tomographic angiography
Authors: Budoff Matthew J. , Ahmed Vasi , Gul Khawar M. , Mao Song S. , Gopal Ambarish
Published: June 2007

Background: Early identification of an anomalous coronary anatomy is quite relevant because of the increased incidence of sudden cardiac death or related symptoms of myocardial ischemia in the patients. Invasive coronary angiography (ICA) is not only invasive, but expensive, and cannot always adequately provide the required information about the abnormal coronary anatomy. Cardiac computed tomographic angiography (CTA) is a robust noninvasive imaging modality that has several clinical applications and is now being used increasingly in practices across the nation. It not only provides high‐resolution anatomical information of the coronary artery tree but also helps define other aspects of the cardiovascular anatomy, be it normal or abnormal.

Hypothesis: This study sought to determine the clinical role played by CTA in the evaluation of different types of coronary arterial anomalies by reviewing CTA studies since 1997.

Methods: We reviewed 6,089 case studies of contrast CTA conducted at our institution. There were 53 coronary anomalies in 39 patients (0.64%).

Results: Computed tomographic angiography correctly identified the course of coronary arteries in all cases.

Conclusion: The results of this study support the use of CTA as a safe and effective noninvasive imaging modality for defining coronary arterial anomalies in an appropriate clinical setting, providing detailed three‐dimensional anatomic information that may be difficult to obtain with invasive angiography.
Effect of concordance between sites of left ventricular pacing and dyssynchrony on acute electrocardiographic and echocardiographic parameters in patients with heart failure undergoing cardiac resynchronization therapy
Authors: Bedi Maninder , Suffoletto Matthew , Tanabe Masaki , Gorcsan John , Saba Samir
Published: June 2007

Background: Wide QRS complexes are associated with left ventricular (LV) dyssynchrony, but an optimal site of LV pacing has not been established.

Hypothesis: We hypothesized that concordance between the sites of LV pacing and of latest LV mechanical activation during cardiac resynchronization therapy (CRT) is associated with more favorable acute echocardiographic changes.

Methods: An analysis of 28 consecutive patients (64 ± 15 years, 46% male, 52% ischemic heart disease, LV ejection fraction 0.24 ± 0.07, QRS 163 ± 22 ms, New York Heart Association > 3 93%) implanted with biventricular (BIV) defibrillators was performed. Sites of latest LV activation were determined by tissue Doppler imaging (TDI) and speckle tracking (ST). The site of LV pacing was determined by fluoroscopy in two views. A concordance score (0‐5) was created to describe the proximity of the pacing site to the site of the latest mechanical activation.

Results: Compared with the worst concordance score, a perfect score was associated with shorter QRS width with LV (187 ± 40 vs. 246 ± 8 ms, p = 0.048) and BIV (134 ± 19 ms vs. 179 ± 39 ms, p = 0.05) but not with right ventricular pacing. A perfect concordance score was also associated with a greater acute reduction in LV volumes in systole (42 ± 36 ms 16 ± 22 ms, p = 0.068) and diastole (47 ± 37 vs. 8 ± 31 ml, p = 0.043) 24 h after CRT device implantation.

Conclusions: A high concordance is associated with shorter QRS width with LV and BIV pacing and greater acute reduction in LV volumes. The effect of concordance on the intermediate and long‐term response to BIV pacing deserves further evaluation.
Bendamustine hydrochloride in patients with refractory soft tissue sarcoma
Authors: Hartmann Joerg T. , Mayer Frank , Schleicher Jan , Horger Marius , Huober Jens , Meisinger Ines , Pintoffl Jan , Käfer Gabriele , Kanz Lothar , Grünwald Viktor
Published: June 2007

BACKGROUND.

For patients with advanced soft tissue sarcoma (STS), no standard treatment is established after previous chemotherapy with anthracyclines and ifosfamide. Bendamustine hydrochloride is a bifunctional alkylating agent that is not cross‐resistant to other DNA‐interacting substances including anthracyclines and oxazaphosphorines. It has shown single‐agent activity in refractory lymphoma, myeloma, and some solid tumors. A phase 2 study was initiated to evaluate the efficacy of bendamustine in previously treated patients.

METHODS.

Thirty‐six of 44 screened patients were included and received a total of 101 cycles (median, 2 cycles; range, 1–8 cycles), 21 as second‐line treatment and 15 as third‐line treatment. The median age was 55 years (range, 18–79 years). Bendamustine was given as an intravenous infusion over 30 minutes at a dose of 100 mg/m2 on 2 consecutive days and repeated every 28 days. Eighty‐eight percent of cycles could be given without dose or schedule modification.

RESULTS.

The toxicity profile was mild, consisting of National Cancer Institute Common Toxicity Criteria (CTC) grade 3 neutropenia in 11% and grade 3 anemia in 9% of patients. Nonhematologic toxicities were noticed with CTC grade 3 fever in 3% of patients. No other grade 3 toxicity and no treatment‐related toxic deaths were observed. The best overall response according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria was 1 partial remission (3%) and disease stabilizations in 31% of patients. Six of 15 patients (40%) with leiomyosarcoma histology achieved stable disease. The estimated 3‐month and 6‐month progression‐free survival rates were 35.3% and 23.5%, respectively, for all histologic subtypes included.

CONCLUSIONS.

In patients with refractory STS, bendamustine is well tolerated and appears moderately effective, particularly in patients with leiomyosarcoma histology. Cancer 2007. © 2007 American Cancer Society.
Chromatic Difference Steps of Moderate Size Measured along Theoretically Critical Axes
Authors: Boynton Robert M. , Kambe Naotake
Published: June 2007

A new method of measuring chromatic discrimination steps is described where observers must indicate in which direction a change has occurred, as well as the fact of its occurrence. This procedure seems to stabilize the subject's criterion of difference and yields step sizes more akin to those of Wright's “dashes” than MacAdam's ellipses. Tests have been made along two critical dimensions of variation: (1) the tritan axis, where discriminations depend initially only on variations in blue‐cone (B) excitation and (2) the red‐green axis, where discriminations depend on the substitution of red‐cone (R) excitation for that of green cones (G), or vice versa. Discriminations dependent on blue cones are affected by the level of B‐cone excitation but are independent of R/G. After individual differences are taken into account by a simple scaling factor, an equation of the form ΔB/ B + Bo = K accounts well for the data. Blue‐cone discrimination is found to be independent of the ratio of red‐to‐green‐cone excitation, with an optimal Weber fraction of about 18%. Discriminations dependent on the exchange of red‐and green‐cone excitation yield an optimal Weber fraction of about 2%. This ratio is increased, though not greatly, by an imbalance of the red‐green ratio relative to a neutral condition, and by increasing the level of blue‐cone excitation. At 120 td, the ratio between a MacAdam step and ours is approximately constant at about 13:1.
The Color Rule: A Device for Color‐Vision Testing
Authors: Kaiser Peter K. , Hemmendinger Henry
Published: June 2007

The D & H Color Rule, available since 1967, is useful as a color‐vision test and to check on the specification of secondary standard illuminants. The data of several authors are combined for ready availability as a diagnostic aid. Normal trichromats make responses with the Color Rule that are dependent on age. The apparent yellowing of the lens results in the same change in responses on the Color Rule as by an illuminant change of 50–75 MK−1.
Evaluation of Automotive Color Matches
Authors: Longley William V.
Published: June 2007

Suppliers of color‐matched automotive parts are sometimes frustrated when match tolerances set by automotive stylists seem inconsistent or unrealistic. The stylist, on the other hand, sees a perplexingly wide range of quality and is aware of vast differences in expertise among those supplying material or parts. Here we explore the parameters affecting color match and discuss the role of color measurement in facing the problems.
OSA uniform color scale samples: A unique set
Authors: Nickerson Dorothy
Published: June 2007

The Optical Society of America, in early 1977, published a set of uniformly scaled coor samples based on specifications developed after long years of study by its Committee on Uniform Color Scales. The model for arranging and specifying the samples is based on an octahedral unit which consists of a cluster of 12 colors equally different from a central color and from each of its nearest neighbors. This space lattice, extended to accommodate all samples that can be produced within the gamut of present‐day colorants, is described, together with the adopted system of notation. The lattice provides three sets of square grids and four sets of triangular grids that correspond to the seven pairs of parallel faces of a cuboctahedron. Horizontal, vertical, and oblique cleavage planes through the lattice are described and illustrated. The OSA‐UCS set consists of 558 samples: 424 represent a regular 2‐unit sampling of OSA‐UCS committee space; 134 additional samples are provided in the much used, near‐neutral, central‐lightness region of color space. The set is unique because each sample in the regular set is represented in six different uniform color scales. These appear as linear arrays that pass in six different directions through each sample. The samples are intended for use by artists and designers as well as by scientists. With a relatively small number of samples, material is provided for constructing color scales and charts with colors uniformly spaced in six directions in any chosen part of color space. The OSA‐UCS set provides a “storehouse of color‐contrast information in efficient form.” It provides useful color research material such as has never before been available.
Formulation of a Nonlinear Model of Chromatic Adaptation
Authors: Nayatani Yoshinobu , Takahama Kotaro , Sobagaki Hiroaki
Published: June 2007

A chromatic‐adaptation model which consists of a modified von Kries and a succeeding nonlinear transformation is formulated provided that a medium‐gray background is always used as an adapting field. The formulation uses (1) the absolute tristimulus values in luminance units, (2) the principles of brightness and achromaticness constancy for a medium‐gray sample on the same medium‐gray background, (3) a simple power law whose exponent increases with an increase of the effective adapting level of each of three visual mechanisms, and (4) the noise components. Predictions are compared between the new nonlinear model and the linkage model of Takahama et al. for the chromatic‐adaptation effect between CIE Illuminants D65 and A and also for the Hunt effect.
Assessment of Color‐Measuring Instruments
Authors: Billmeyer Fred W. , Alessi Paula J.
Published: June 2007

The U.S. Army has undertaken a program to develop an instrumental method for assessing the acceptability of textiles for color difference from a standard. This article reports the results of the first phase of the program, an assessment of three commercial color‐measuring instruments (Diano Match‐Scan, Hunter D‐54P‐5, Macbeth MS‐2000) for objective textile acceptability judgment. It is concluded that the three instruments are essentially equivalent in the precision and accuracy of the measurement of color and color difference using a wide variety of samples, at least over periods of up to seven weeks. All measures of repeatability lead to the conclusion that the uncertainties involved are well below the just‐perceptible color difference. Levels of absolute accuracy achieved depend greatly on the details of operation, data treatment, and calibration, but are considered satisfactory for each of the instruments tested. With respect to certain other parameters, the performance of the instruments is less satisfactory. Rejection of the specular component differs significantly among the three, as does the selection of weights for tristimuus calculations. One instrument, as tested, exhibited significant sensitivity to weave orientation in textile samples. Finally, we find that the distributions of tristimulus values obtained with each of the instruments show large deviations from normality, severely limiting the significance of conventional statistical treatment of such data.
A simplified method for formulating pseudo‐object colors
Authors: Ohta Noboru
Published: June 2007

A simplified method is proposed in an attempt to formulate spectral reflectance functions of actual object colors. The method is applied to evaluate the optimal color gamuts and chromaticity‐mismatch limits for actual object colors.
Comparison of correcting methods for chromatic adaptation used for color‐rendering specification
Authors: Fuchida Takayoshi , Mori Leo
Published: June 2007

Recently, several methods for correcting for chromatic adaptation have been proposed by Richter, Bartleson, Nayatani, and others. Psychometric‐chroma coordinates are calculated according to these methods for surface colors illuminated by various light sources, and are compared with the results of subjective experiments on color appearance. For this purpose some experiments using saturated color illuminants are included. The nonlinear transformation proposed by Nayatani and others applied in CIELAB space correlates best with the subjective appearance of surface colors.
Energy transfer between fluorescent organic pigments
Authors: Billmeyer Fred W. , Hepfinger Lisa B.
Published: June 2007

Energy transfer between fluorescent organic pigments (fluorophors) dispersed in a paint vehicle was studied for mixtures of a yellow, a red, and an orange fluorescent pigment, and for mixtures of these with titanium dioxide. Radiative energy transfer occurs among the fluorophors, but not between them and titanium dioxide A shift to longer wavelengths of the emission peak of a fluorophor with increasing paint‐film thickness was noted and was ascribed to reabsorption and reemission of fluoresced radiation within the overlapping excitation and emission region typical of these organic fluorophors.
Colors of dope and yamn of spun‐dyed cellulose acetate
Authors: Nava Alberto , Bianchi Donate , Pitea Demetrio
Published: June 2007

A method of color control of bulk‐dyed cellulose acetate is described, based on the transmittance spectrum of the dope. Control can be effected only if the spectrum is recorded from thick samples which amplify the absorption from small amounts of impurities that later cause unacceptable color differences on the yarn. The calculation of the reflectance spectrum, and hence the color, of the yarn from the transmittance spectrum of the dope by Kubelka‐Munk theory is not satisfactory due to faint turbidity of the ‘bright’ dope. The reflectance spectrum of the yarn can be calculated from a series expansion of the experimental Lambert law absorption coefficient with very satisfactory results. A fully computer‐managed color‐control method is employed successfully in industrial practice.
A flaw in equations for predicting chromatic differences
Authors: Boynton Robert M. , Nagy Allen L. , Olson Conrad X.
Published: June 2007

Many formulas for predicting perceived color differences require that three terms be squared prior to the extraction of the square root of their sums. Two of these terms relate to chromatic differences measured along tritan and red‐green axes. The root‐mean‐square calculational procedure predicts that the relative directions of simultaneous chromaticity changes along these principal axes should not affect the perceived color difference. Experimental data are presented which strongly disconfirm this prediction.
Formulation of blends of precolored nylon fiber
Authors: Burlone Dominick A.
Published: June 2007

Two‐constant Kubelka‐Munk formalism was used to describe the color of blends of precolored nylon fibers. Pseudo‐Kubelka‐Munk absorption constants K and pseudo‐Kubelka‐Munk scattering constants S were calculated using masstone samples and blends of colored fiber with white. A masstone means 100% colored fiber in which no white or black is mixed. Various mixtures with white were tried and no systematic dependence of the calculated optical parameters on composition was discernable. With some colors, notably yellow and orange, mixtures with black were required for the calibration. Accurate color matches were obtained using the two‐constant formalism especially when the proposed match contained the same primary fibers as did the standard. For matches in which the primary fibers used in the sample differed from those in the standard, the closeness of the visual match depended on how closely the primary colors in the sample resembled those in the standard. Since the eye can discern individual colors in a fiber blend, it was possible to have a visual mismatch despite colorimetric equivalence. With a large enough group of primary colors, it was generally possible to find one or more alternative formulations which matched the standard. Sample‐preparation and measurement errors were found to be critical for determining color‐matching accuracy. All of the color‐matching error could be accounted for in terms of the sample‐preparation and measurement errors alone. This suggests that the sampling error was, in fact, a limiting factor in determining color‐matching accuracy.
The distimulus method of assessing luminous efficiency of the spectrally pure stimuli
Authors: Fry Glenn A.
Published: June 2007

In the tristimulus method of photometry, the luminance of any monochromatic stimulus can be assessed by matching it in hue and brightness to a mixture of two primaries and then reducing the saturation of the test stimulus to obtain a complete match. The luminances of the stimuli are considered to be additive, and the luminances of the two mixtures to be equal. In this article it is shown that if the primaries are properly chosen, it is not necessary to desaturate the test stimulus. The difference in saturation between the test stimulus and the mixture of the two primaries can be ignored and it may be assumed that the luminance of the test stimulus is equal to the sum of the luminances of the two primaries when the mixture and the test stimulus match in hue and brightness. Luminous efficiencies assessed in this way agree well with assessments based on flicker photometry. Flicker photometry has been used to assess the luminances of the primaries.
Carbon black as a dulling agent for nylon 6 filaments and the lightfastness of dyes on dulled filaments
Authors: Datye Keshav V. , Mishra Sachi , Srivastava Jitendra
Published: June 2007

Nylon 6 filaments containing 0–1.5% carbon‐black pigment are dyed to different depths of shade. The colour on the substrate is evaluated on CIELAB a* b* diagrams at given concentrations of carbon black and dye. The carbon‐black pigment acts essentially as a neutral dulling agent and only with a few dyes does it appear to alter the hue angle slightly. Thus, it is possible to use nylon 6 filaments containing carbon‐black pigment to produce dull shades by the overdyeing process. The dyed samples thus produced are exposed to mercury‐lamp light as well as daylight. The lightfastness is evaluated visually using the Blue Wool Scale. There is a remarkable improvement in the lightfastness of all dyes on nylon 6 containing carbon‐black pigment. The carbon black in the filament appears to protect both the dye and the polymer from the degrading action of actinic radiation. However, the remarkable improvement in the lightfastness is essentially due to the optical effect.
Theoretical and practical aspects of selected fiber‐blend color‐formulation functions
Authors: Burlone Dominick A.
Published: June 2007

Color matching blends of precolored fiber using three different methods was studied. Best color‐matching accuracy was obtained using a two‐constant Kubelka‐Munk (KM) procedure. First‐formula color differences averaged 1.6 CIELAB units and were found to be within the experimental error of 1.6 CIELAB units. Useful approximations were obtained using the methods proposed by Friele and by Stearns. First‐formula color matches averaged 2.4 CIELAB units for the Stearns and 2.7 CIELAB units for the Friele methods. The methods are mathematically compared and the merits of each are discussed. Where possible, interpretation of the empirical parameters each method employs is attempted. It is pointed out that absorption and scattering constants calculated for fibers using the KM formalism are not true KM absorption and scattering constants. It is demonstrated that too literal an interpretation of these constants leads to apparent anomalies. It is shown that the fiber KM scattering constants which are normally considered unchanged as dye is applied cannot be considered unchanged if these same fibers are subsequently to be used in blends with other colored fibers.
Perceptual factors affecting colour order systems
Authors: Hunt Robert W. G.
Published: June 2007

The perceptual colour attributes relevant for ordering unrelated, related, luminous, and nonluminous colours are different insome respects. Colour order systems for related nonluminous colours have been the most fully developed, but different systems depend on different types of experimental data, such as equalization of small perceptual differences, colour scaling, and some relationships to properties of the stimuli. The resulting systems have both similarities and differences, which are worthy of careful study. Chromatic adaptation is an important factor affecting and appearances of samples of colour order systems viewed in illuminants of various colours, and requires further study.
Reader survey results
Authors: Alman David H.
Published: June 2007

A survey of the subscribers to Color Research and Application was conducted by the publisher in January, 1983. The results of the survey are reported here with special emphasis on those sections of the survey which indicate the readers' views on editorial content. Based on our analysis of the survey results, the editorial board is announcing several changes in policy and content. The intent of these changes is to tune the information presented in Color to better meet the readers' needs as indicated by the survey.
Color samples for colorimetric fidelity testing in television
Authors: Hisdal B.
Published: June 2007

The case for testing television (TV) colorimetric reproduction performance for groups of colors is discussed. The groups consist of colors which have some characteristic in common, like strong or moderate saturation. Such groups actually contain a large number of discernible colors but these are for testing purposes represented by a set with a limited number of reference samples. In recommended methods the evaluation of the performance for the group is based on the average of the individual color differences for the samples in the set. This average is here based on the CIE 1976 color difference ΔEuv* and designated ΔEa*. The question investigated is what properties the reference samples in the set should have to make D̊Ea* the best estimator of performance for the whole group. It is shown that the samples should be chosen for evenness in distribution and uniformity in lightness, preferably representative of average scene lightness. These points seem to have been overlooked for some presently recommended sets as illustrated by an example. Experimental data for TV cameras indicate that a collection of 10 color samples might be satisfactory for colorimetric acceptance testing.
Image reproduction colorimetry
Authors: Pearson Milton
Published: June 2007

The field of colorimetry appears to be arbitrarily divided into two areas, matching‐and‐formulation colorimetry and image‐reproduction colorimetry. It is believed that the end uses for the colorimetric data and the methods of color generation are sufficiently different in these two areas to warrant this division. Conditions that contribute to this division are the need for metamerism and the use of limited sets of primaries in reproduction work, the compromise of lightnesses due to tone reproduction, the availability and proper use of instrumentation compared to that desired, and the viewing conditions of the standard observer. All these contribute to produce significantly larger color differences in image‐reproduction work than in matching and formulation. However, workers in reproduction studies can still draw useful conclusions when these conditions are properly understood.
A FORTRAN program for predicting the effects of chromatic adaptation on color appearance based on current CIE recommendations
Authors: Berns Roy S.
Published: June 2007

The CIE has recently recommended for field trial a method for predicting corresponding colors with a change in chromatic adaptation. To aid the CIE in collecting results illustrating the accuracy of these predictions, a FORTRAN program currently used by the Munsell Color Science Laboratory is listed along with test data. This chromatic‐adaptation transform can be used to calculate CIELAB or CIELUV metrics for non‐daylight illuminants, indices of illuminant metamerism, and indices of color constancy. Including this transform in these calculations, it is hoped, will result in metrics with better correlation to visual assessments. It is hoped that readers will implement this method, compare the effectivness of this chromatic‐adaptation transform to visual evaluations, and report their results to CIE Technical Committee 1–06.
Colour and appearance in nature
Authors: Hutchings John B.
Published: June 2007

General Introduction

After spending many years working on colour and appearance in industry, I became aware of a gross ignorance of the origin of the colour and beauty existing around me in nature. The results of the succeeding awakening formed the theme of my retiring address as Chairman of The Colour Group (Great Britain) on 13th May, 1981, at the Royal Institution, London. Life, it seems, was destined to become coloured from the start and it has become a more and more colourful place as evolution has continued. Colour and design are vital, in different ways, to the life and perpetuation of different biological systems. I have attempted to amalgamate the views of the biologist, biochemist, anthropologist, and physicist (among others), to give a personal overall view of the driving forces and principles of appearance and colouration in the world of nature. The three articles to follow consider, first, the mechanisms which result in the colour of primary producers using the photosynthetic process; second, the mechanisms which produce colouration and total appearance in flowering plants and animals; and third, human colouration and man's use of colour, stopping short of modern technology. I hope that these findings will add to the everyday joy which you can experience in your natural environment.
Computer simulation of the error sensitivity of colorant mixtures
Authors: Alman David H.
Published: June 2007

Computer simulation of colorant mixtures is employed in this study to investigate color sensitivity to composition errors in four‐component blends. Color sensitivity as related to mixture composition is reported for concentration‐dependent strength errors and for concentration‐independent weighing errors. Color sensitivity to both types of errors varies regularly with the mixture‐composition variables. A conclusion of the study is that predictable changes in the color sensitivity to composition errors are observed in different regions of colorant‐mixture‐composition space.
Evidence for the three spectral responses of the normal human visual system
Authors: Thornton W. A.
Published: June 2007

Skilled human color‐matching experts developed 317 sample pairs that matched to them in daylight (the Bayer sample sets MV68 and AA17 of about 1970). One hundred of these pairs intersect only at three well‐defined wavelengths, near 458 nm, 541 nm, and 611 nm, and thus indicate visualsystem response peaks.
The effect of background luminance on color recognition
Authors: Jacobsen Alan R.
Published: June 2007

The effect of background raster luminance on the ability to learn and recall color‐coded information was studied via a paired‐associates paradigm. Twenty variously colored circles, paired with two‐digit numbers, were presented on a color‐graphics CRT terminal. On test trials each colored circle was presented by itself and observers were required to recall verbally the two‐digit number that was previously paired with the target color. Time to recall as well as actual responses were both recorded. Two raster luminance levels were tested: dark or perceptual black and one that appeared to be a shade of middle gray. Ten out of 10 observers reached the learning criterion with the middle‐gray background, while only 10 out of 15 were able to reach the criterion with the black background. In addition, those observers who reached the criterion on the black background still made significantly more errors than the observers presented with the middle‐gray background. There were no significant differences, however, in time to recall between the two types of backgrounds for observers who reached the learning criterion. These results are discussed in light of the CIELUV color‐difference metric AE*uv.