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PubMed1991

Left ventricular hypertrophy and skin color among American blacks.

The association between skin color, a measure of black-white genetic admixture, and left ventricular hypertrophy was examined in 551 black men and women, from three US cities, who underwent electrocardiography and skin reflectance measurements during 1972-1974. The overall prevalence of left ventricular hypertrophy (Minnesota Code 3-1 or 3-3) was 14% (18% in men; 11% in women). Left ventricular hypertrophy was strongly associated with systolic (p less than 0.001) and diastolic (p = 0.001) blood pressure, but less so with skin color (p = 0.09) [corrected]. The prevalence of left ventricular hypertrophy was 16% in the darkest versus 12% in the lightest quartile of skin color. In a multiple logistic regression model, adjusting for systolic blood pressure and blood pressure medication use, the relation between left ventricular hypertrophy and skin color was insignificant (p = 0.18); the odds ratio of having left ventricular hypertrophy in dark (75th percentile of skin color) versus light (25th percentile) skinned blacks after adjustment for systolic blood pressure, systolic blood pressure medications, age, and sex was 1.2 (95 percent confidence interval 0.8-1.8). Overall, the association between left ventricular hypertrophy and skin color was weak and not statistically significant, suggesting that black individuals do not have a genetic susceptibility to the effects of blood pressure on the myocardium. We did not postulate any significant effect modification of this association by sex. However, the data suggest that the association between skin color and left ventricular hypertrophy may be different between men and women.

Adult↗

PubMed1998

The relationship of broiler breast color to meat quality and shelf-life.

A total of three experiments were conducted to compare physical and microbiological properties of raw and marinated broiler breast fillets selected as being either lighter or darker than normal. Visibly light- and dark-colored breast fillets were divided into marinated and control groups, and vacuum-tumbled for 20 min at 4 C under 80 kPa pressure. Breast fillets from the four treatment groups were evaluated for shear values, raw and cooked meat pH, drip-loss, cook-loss, water-holding capacity, and 7 d psychrotrophic count. The light-colored fillets were significantly lighter, less red, and more yellow than the dark fillets. Lightness values increased when fillets were marinated. Moreover, the light fillets had a lower pH than dark fillets. The pH values of raw and cooked breast meat were related to meat color but not marination. Dark-colored fillets had significantly higher marination pick-up and a higher fraction of bound moisture and significantly lower drip and cook-loss. No differences were observed in shear values between color or marination treatments. There were no significant differences in psychrotrophic plate counts (PPC) or capacitance detection times (CDT) due to color or treatment at Day 1. After 7 d of storage at 4 C, PPC was significantly lower for marinated samples. No correlations were observed between pH and PPC, CDT, or odor. Based on these differences in physical and microbiological properties, further processors may consider separating breast fillets according to color.

Animals↗

PubMed2000

Latanoprost-induced iris color darkening: a case report with long-term follow-up.

PURPOSE: To determine the effect on iris color of discontinuing latanoprost (LP) treatment in a patient with pronounced iris color darkening, and to assess the possible role of sympathetic innervation. METHODS: In a patient demonstrating pronounced iris color darkening in both eyes after treatment with LP for 6 months, magnified iris color photographs were taken at 3- to 6-month intervals for 5 years after discontinuation of LP treatment. Pupillary testing for sympathetic insufficiency was performed with cocaine 10% or hydroxyamphetamine 1%. RESULTS: The iris color did not appreciably change after discontinuing LP. The cocaine-induced increase in pupillary diameter was considerably greater for the control subject than for the patient who demonstrated the LP-induced color change. CONCLUSIONS: Latanoprost-induced iris color darkening does not appreciably change for several years after discontinuing treatment. Some eyes that show LP-induced darkening may have relative ocular sympathetic insufficiency.

Antihypertensive Agents↗

PubMed2006

A POCS-based restoration algorithm for restoring halftoned color-quantized images.

This paper studies the restoration of images which are color-quantized with error diffusion. Though there are many reported algorithms proposed for restoring noisy blurred color images and inverse halftoning, restoration of color-quantized images is rarely addressed in the literature especially when the images are color-quantized with halftoning. Direct application of existing restoration techniques are generally inadequate to deal with this problem. In this paper, a restoration algorithm based on projection onto convex sets is proposed. This algorithm makes use of the available color palette and the mechanism of a halftoning process to derive useful a priori information for restoration. Simulation results showed that it could improve the quality of a halftoned color-quantized image remarkably in terms of both SNR and CIELAB color difference metric.

Algorithms↗

PubMed2005

Skin segmentation using color pixel classification: analysis and comparison.

This paper presents a study of three important issues of the color pixel classification approach to skin segmentation: color representation, color quantization, and classification algorithm. Our analysis of several representative color spaces using the Bayesian classifier with the histogram technique shows that skin segmentation based on color pixel classification is largely unaffected by the choice of the color space. However, segmentation performance degrades when only chrominance channels are used in classification. Furthermore, we find that color quantization can be as low as 64 bins per channel, although higher histogram sizes give better segmentation performance. The Bayesian classifier with the histogram technique and the multilayer perceptron classifier are found to perform better compared to other tested classifiers, including three piecewise linear classifiers, three unimodal Gaussian classifiers, and a Gaussian mixture classifier.

Algorithms↗

PubMed2002

The finger in flight: real-time motor control by visually masked color stimuli.

Current theories of dual visual systems suggest that color is processed in a ventral cortical stream that eventually gives rise to visual awareness but is only indirectly involved in visuomotor control mediated by the dorsal stream. If the dorsal stream is indeed less sensitive to color than the ventral stream, color stimuli blocked from awareness by visual masking should also be blocked from guiding fast motor responses. In this study, pointing movements to one of two isoluminant color targets were preceded by consistent or inconsistent color primes. Trajectories were strongly affected by priming, with kinematics implying a continuous flow of color information into executive brain areas while the finger was already moving. Motor effects were more sensitive to color of the primes than were deliberate attempts to identify the primes in forced-choice tasks based on visual awareness. Priming was observed even when masking was complete.

Adolescent↗

PubMed2005

Practical color calibration for dermoscopy, applied to a digital epiluminescence microscope.

BACKGROUND/PURPOSE: The assessment of colors is essential for melanoma (MM) diagnosis, both for pattern analysis on dermoscopic images, and when using semiquantitative methods. Our aim was to provide a simple, precise characterization and reproducible calibration of the color response for dermoscopic instruments. METHODS: Three processes were used to correct the non-uniform illumination pattern of the instrument, to easily estimate the camera gamma settings and to describe the color space conversion matrices required to produce standard images, in any color space. A specific color space was also developed to optimize the representation of dermatoscopic colors. The calibration technique was tested both on synthetic reference surfaces and on real images by comparing the difference between the images colors obtained with two different equipments. RESULTS: The differences between the images acquired by means of the two instruments, calculated on the reference patterns after calibration, were up to 10 times lower then before, while comparison of histograms referring to real images provided an improvement of about seven times on average. CONCLUSIONS: A complete workflow for dermatologic image calibration, which allows the user to continue using his own software and algorithms, but with a much higher informative content, is presented. The technique is simple and may improve cooperation between different research centers, in teleconsulting contexts or for result comparisons.

Algorithms↗

PubMed2004

Diverse p53 gene aberration in hepatocellular carcinoma detected by dual-color fluorescence in situ hybridization.

BACKGROUND AND AIM: In order to evaluate loss of the p53 gene more precisely, we performed dual-color fluorescence in situ hybridization (dual-color FISH) for chromosome 17 and p53 gene together with DNA polymorphism analysis of the p53 gene in hepatocellular carcinoma (HCC). METHODS: Dual-color FISH using probes specific for the centromere of chromosome 17 and the p53 gene was performed for 41 HCC and DNA polymorphism analysis was also performed for them. RESULTS: Of the 34 HCC tested by dual-color FISH, 20 had loss of at least one p53 gene (58.8%). In contrast, of the 32 HCC tested by DNA polymorphism analysis, 23 gave informative results, among which only eight had loss of heterozygosity (LOH) of the p53 gene (34.8%). Notably, among 14 cases positive for loss of the p53 gene by dual-color FISH, seven cases were negative for LOH of the p53 gene. Moreover, dual-color FISH revealed that the percentage of cells that lost at least one p53 gene increased as the HCC became less differentiated (P < 0.01), whereas LOH did not reveal any such correlation. CONCLUSIONS: These data suggest that loss of the p53 gene was present in a considerable number of HCC, and diversity of the p53 gene aberration increases with progression of HCC. Dual-color FISH is an effective method for detection of p53 gene aberration, and it can provide new insight into oncogenesis in HCC.

Adult↗

PubMedDate not supplied

Jumping genes and AFLP maps: transforming lepidopteran color pattern genetics.

The color patterns on the wings of lepidopterans are among the most striking patterns in nature and have inspired diverse biological hypotheses such as the ecological role of aposomatic coloration, the evolution of mimicry, the role of human activities in industrial melanism, and the developmental basis of phenotypic plasticity. Yet, the developmental mechanisms underlying color pattern development are not well understood for three reasons. First, few mutations that alter color patterns have been characterized at the molecular level, so there is little mechanistic understanding of how mutant phenotypes are produced. Second, although gene expression patterns resembling adult color patterns are suggestive, there are few data available showing that gene products have a functional role in color pattern formation. Finally, because with few exceptions (notably Bombyx), genetic maps for most species of Lepidoptera are rudimentary or nonexistent, it is very difficult to characterize spontaneous mutants or to determine whether mutations with similar phenotypes are because of lesions in the same gene or different genes. Discussed here are two strategies for overcoming these difficulties: germ-line transformation of lepidopteran species using transposon vectors and amplified frequency length polymorphism-based genetic mapping using variation between divergent strains within a species or between closely related and interfertile species. These advances, taken together, will create new opportunities for the characterization of existing genetic variants, the creation of new sequence-tagged mutants, and the testing of proposed functional genetic relationships between gene products, and will greatly facilitate our understanding of the evolution and development of lepidopteran color patterns.

Animals↗

PubMed1990

The use of intraoperative echocardiography with Doppler color flow imaging in the repair of congenital heart defects.

Surgical repair of congenital cardiac defects has undergone a remarkable evolution in the past decade. Major defects are now often completely corrected in early infancy with continually improving rates of survival. It has become clear that the next major focus will be improvements in the long-term quality-of-life and this has prompted many innovations in surgical technique and approach. One advance is the use of intraoperative echocardiography with Doppler color flow imaging to evaluate the exactness of operative repair. Aside from anecdotal reports, very little information is available regarding the interpretation of images produced by this technology in the operating room. Furthermore, there have been no studies addressing the predictive value of intraoperative echocardiography with Doppler color flow imaging findings with respect to outcome for patients undergoing repair of congenital cardiac defects. The prospective data obtained by following the course of 273 patients receiving intraoperative echocardiography with Doppler color flow imaging has been reviewed after repair of a variety of congenital cardiac defects (age range 1-53 years; mean 5.3 years; smallest patient 1.8 kg). The average time required to perform a complete intraoperative echocardiography with Doppler color flow imaging evaluation was 3.64 +/- 1.73 minutes. Except for mild ectopy induced by pressure from the transducer, complications of the procedure were minimal. Echocardiography with Doppler color flow imaging revealed previously unsuspected details of the anatomy in 21% of patients and in 47% of patients, it was felt that the prebypass echocardiography with Doppler color flow imaging impacted in some way on planning of the operative procedure. Echocardiography with Doppler color flow imaging was 2.5 times more likely to provide help in planning the operation if a previously unrecognized anatomical finding was disclosed. Postbypass evaluation revealed that 47 patients (17%) had initially unacceptable results, by echocardiography, at the completion of their repair. Eighteen of these patients (7% of the entire series) had no clinical problems and the defects were discernible only by echocardiography. Twenty-six patients with initially unacceptable results had their repairs revised in the operating room and left with an acceptable result by echocardiography. Twenty-one patients were allowed to leave the operating room with echocardiographically discernible defects. Follow-up of these patients demonstrated a significantly higher (P less than 0.006) rate of reoperation (42% vs 3%) and an early death (29% vs 10%) for those patients whose defects were left unrepaired compared to those whose problems were corrected before leaving the operating room.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1991

Limitations of flow detection by color Doppler: in vitro comparison to conventional Doppler.

There is little awareness of the limitations of flow detection with the commercially available color Doppler flow mapping system. The influence of flow velocity, ultrasound attenuation, and penetration depth on flow detection in color Doppler (Toshiba SSH 65A) were therefore studied in vitro and compared with conventional Doppler. The flow model had physiological flow volumes and laminar flow with parabolic velocity profile in a horizontal tube of Lucite with less than 3 degrees of coincidence. Conventional Doppler flow velocity measurements correlated highly with laser Doppler anemometry results (r = 0.99, SEE = 3 cm/sec). Signal strength of color Doppler and pulsed Doppler was semi-quantitatively graded using a scale from 0 to 5. Scale 1 (sparse signals) was useless for any assessment in color Doppler but just allowed velocity measurement in pulsed Doppler. Using 19-dB attenuation, flow velocities greater than 100 cm/sec had good scores with moderate gain, 60-100 cm/sec needed increasing gain, and velocities less than 40 cm/sec were not detectable with color Doppler but readily so with pulsed Doppler. With increasing attenuation (1-29 dB) and also with increasing penetration depth, flow detection was reduced significantly (P less than 0.001) more in color Doppler than in the pulsed technique (P less than 0.01). In conclusion, low flow velocities, high attenuation, and greater than 8 cm penetration depth may hamper flow detection in color Doppler and, thus, diagnostic accuracy. Conventional Doppler with its superior accuracy and sensitivity should therefore consolidate diagnostic ultrasound assessment.

Blood Flow Velocity↗

PubMedDate not supplied

Macro-optical color assessment of the pulmonary airways with subsequent three-dimensional multidetector-x-ray-computed-tomography assisted display.

Bronchial diseases alter the color and structural characteristics of the pulmonary mucosa through changes in blood flow, epithelial thickening, and abnormal cell growth. Current analysis of these subtle changes includes visual interpretation of the airway color and topography through bronchoscopy procedures, and quantitative multidetector-x-ray-computed-tomography (MDCT)-based structural analysis, each affording valuable insights to the health of the lungs. The fusion of the bronchoscopy and MDCT image data promises to provide a synergistic data set exhibiting both mucosal color and topography crucial to fostering an understanding of airway structure and function. A real-time airway color analysis imaging system is developed and utilized to perform pulmonary mucosal color assessment in healthy volunteers with subsequent comparative studies performed in example disease states. Our results indicate that macro-optical digital bronchoscopes with appropriate image analysis may have a significant impact on understanding bronchial diseases. To ensure the correct interpretation of scene content, which is critical in the assessment of airway topography, we are developing methods of extracting 3-D structure from 2-D bronchoscope images utilizing MDCT imaging techniques. The resulting 3-D true-color images of the pulmonary mucosa facilitate the combination of mucosal color and topography analysis as well as region of interest localization within the airway tree.

Bronchoscopy↗

PubMed1981

Effect of antibiotics on the dynamics of color change in Ureaplasma urealyticum cultures.

Color change of pH indicators in broth medium is commonly used to quantify growth of ureaplasmas. These organisms differ from other members of the Mollicutes by their ability to hydrolyze urea to CO2 and NH3. This study describes a method which continuously monitors color change in ureaplasmal broth cultures. Using this technique we found: (i) there was a pH-dependent absorbance at 554 nm in ureaplasmal broth medium containing phenol red, (ii) a sigmoidal-shaped color changing curve (absorbance at 554 nm versus time) was produced by metabolizing organisms whereas a linear curve was generated by antibiotic-inhibited ureaplasmas, and (iii) the minimum cell density which elicited a growth-inhibited color change was 1.25 x 10(4) colony-forming units per ml. Other have shown that apparently dead ureaplasmas can cause a color change in broth media. This color change is probably due to the presence of an active urease. This study graphically and quantitatively assesses growth-inhibited color change.

Bacteriological Techniques↗

PubMed1994

Hepatocellular adenoma: color Doppler US and pathologic correlations.

PURPOSE: To describe the color Doppler ultrasound (US) features of hepatocellular adenoma (HA) and correlate these findings with pathologic findings, with special emphasis on the blood vessels. MATERIALS AND METHODS: Color Doppler US was prospectively performed in eight patients with histologic proof of HA. Eleven lesions were studied. RESULTS: In seven lesions, color Doppler US demonstrated central color flow. In six of these lesions, pulse-wave Doppler US demonstrated a continuous and flat venous spectrum with frequency shifts of 0.20-0.60 kHz (mean, 0.37 kHz), which corresponded to pathologic findings of intratumoral veins 1-5 mm in diameter. The other lesion with central color flow demonstrated a triphasic venous waveform with 1.20-kHz frequency shift, which corresponded pathologically to a central vein 10 mm in diameter. In these seven lesions, color Doppler examination demonstrated both venous and arterial peritumoral flow. CONCLUSION: Color Doppler US enables detection of intratumoral veins associated with peritumoral veins and arteries in patients with HA; these findings correlate well with pathologic data. These results might help in the differential diagnosis of HA and focal nodular hyperplasia.

Adenoma, Liver Cell↗

PubMed1994

Pediatric testicular tumors: evaluation with gray-scale and color Doppler US.

PURPOSE: To evaluate the appearance of testicular neoplasms in pediatric patients at examination with gray-scale and color Doppler ultrasonography (US). MATERIALS AND METHODS: Gray-scale and color Doppler US were performed in seven patients aged 8 1/2 months to 17 years 6 months (mean age, 7.8 years) with testicular neoplasms proved at histologic examination. Gray-scale images were evaluated for echogenicity and presence of testicular masses; color Doppler US was used to assess the presence and distribution of color flow. RESULTS: Gray-scale US showed enlargement of the affected testis in all patients. Testicular echogenicity was normal in four prepubertal patients; discrete masses were seen in all three postpubertal patients. The gray-scale findings correlated with patient age. Color Doppler US demonstrated increased blood flow in six of seven testicular neoplasms. Three of the four patients with normal gray-scale echogenicity had diffuse hypervascularity and one had a focal hypervascular mass on color Doppler scans. CONCLUSION: Color Doppler US is more helpful than gray-scale US in identification of testicular tumor.

Blood Vessels↗

PubMed1991

A new method for quantification of regurgitant flow rate using color Doppler flow imaging of the flow convergence region proximal to a discrete orifice. An in vitro study.

While color Doppler flow mapping has yielded a quick and relatively sensitive method for visualizing the turbulent jets generated in valvular insufficiency, quantification of the degree of valvular insufficiency has been limited by the dependence of visualization of turbulent jets on hemodynamic as well as instrument-related factors. Color Doppler flow imaging, however, does have the capability of reliably showing the spatial relations of laminar flows. An area where flow accelerates proximal to a regurgitant orifice is commonly visualized on the left ventricular side of a mitral regurgitant orifice, especially when imaging is performed with high gain and a low pulse repetition frequency. This area of flow convergence, where the flow stream narrows symmetrically, can be quantified because velocity and the flow cross-sectional area change in inverse proportion along streamlines centered at the orifice. In this study, a gravity-driven constant-flow system with five sharp-edged diaphragm orifices (ranging from 2.9 to 12 mm in diameter) was imaged both parallel and perpendicular to the direction of flow through the orifice. Color Doppler flow images were produced by zero shifting so that the abrupt change in display color occurred at different velocities. This "aliasing boundary" with a known velocity and a measurable radial distance from the center of the orifice was used to determine an isovelocity hemisphere such that flow rate through the orifice was calculated as 2 pi r2 x Vr, where r is the radial distance from the center of the orifice to the color change and Vr is the velocity at which the color change was noted. Using Vr values from 54 to 14 cm/sec obtained with a 3.75-MHz transducer and from 75 to 18 cm/sec obtained with a 2.5-MHz transducer, we calculated flow rates and found them to correlate with measured flow rates (r = 0.94-0.99). The slope of the regression line was closest to unity when the lowest Vr and the correspondingly largest r were used in the calculation. The flow rates estimated from color Doppler flow imaging could also be used in conjunction with continuous-wave Doppler measurements of the maximal velocity of flow through the orifice to calculate orifice areas (r = 0.75-0.96 correlation with measured areas).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2000

Relationship between skin color and blood pressure in egyptian adults: results from the national hypertension project.

In many, but not all societies, dark skin color is associated with high blood pressure. Whether the association between skin color and blood pressure is independent of known determinants of blood pressure remains controversial. We examined the association between skin color and blood pressure in 835 Egyptian adults (370 men and 465 women) participating in the National Hypertension Project, a national survey of hypertension prevalence and blood pressure-related complications conducted in Egypt during 1991-1993. Skin color was assessed by measuring the concentration of cutaneous melanin in an unexposed area with the use of reflectance spectrophotometry. Higher concentrations of melanin were associated with lower body mass index, less education, manual labor (among men), and a lower urinary sodium-to-potassium ratio (among women). In multivariate regression analyses adjusted for age, body mass index, and education, there was a significant nonlinear association between blood pressure and skin color among women; in the lower to intermediate range of skin pigmentation, both systolic and diastolic blood pressures were higher in women with greater concentrations of cutaneous melanin. In men, blood pressure was not associated with skin color. When we used a subjective assessment of skin color, there was no significant difference in blood pressure between black-skinned Egyptians (predominantly of Nubian descent) and fair-skinned Egyptians for either gender. While the significant relationship in women appeared to be independent of known risk factors for hypertension, residual confounding may explain the association.

Adult↗

PubMed1994

A novel triple-color detection procedure for brightfield microscopy, combining in situ hybridization with immunocytochemistry.

We describe a fast light microscopic procedure for the simultaneous enzyme cytochemical detection of three different DNA target sequences in contrasting colors in both interphase and metaphase cell preparations. Chromosome-specific DNA probes labeled with either biotin, digoxygenin, or fluorescein were hybridized as a mixture and detected clearly and accurately by precipitates of the horseradish peroxidase-diaminobenzidine (PO-DAB, brown color), alkaline phosphatase-Fast Red (APase-Fast Red, red color), or horseradish peroxidase-tetramethylbenzidine (PO-TMB, green color) reaction, respectively. The PO-TMB reaction product was stabilized effectively by the addition of sodium tungstate to the reaction mixture, thus making the PO-TMB reaction now generally applicable to in situ hybridization (ISH). To avoid mixing of the precipitates of the two PO reactions used in the triple-color ISH method, the first detected PO activity was always completely inactivated by a mild acid treatment before the second one was applied. Finally, the cell preparations were embedded in a thin protein layer cross-linked by formaldehyde to ensure permanent stabilization of the enzyme reaction products and optimal visualization of color contrast. The triple-color ISH detection procedure could be combined with beta-galactosidase-5-bromo-4-chloro-3-indolyl-beta- D-galactoside (beta-Gal-BCIG) immunocytochemistry (ICC), leading to the simultaneous localization of multiple DNA targets and a protein target in the same cell. The described procedure may therefore be a valuable tool in the areas of cytogenetics, cell biology, and molecular pathology.

Cells, Cultured↗