Mechanistic Basis and Therapeutic Strategies in Immune Evasion in Cancer

One of the most popular types of skin cancer is acral lentiginous melanoma, which usually appears as an irregular, prominent growth on the palms of the hands, feet, or under the nails. In fact, the symptoms of this cancer, which is a prominent colored spot on the skin, slowly begin to appear. In the first stage, malignant cells remain inside the tissue for months or years. The lesion then acts aggressively and appears on the skin as it exits the epidermis. Experts say this type of melanoma can grow rapidly and penetrate deep into the skin. Unlike other skin cancers that occur due to overexposure to the sun, acral melanoma has nothing to do with it. In appearance, these types of cancer spots are more than 6 mm in size and can be brown, blue-gray, black or red. Early in the onset of the disease, the melanoma may have a smooth surface, but over time it becomes thicker and has a dry, uneven surface. Bleeding and sores on the cancerous spot are also possible in some cases. Now that we know that this type of cancer is not caused by the sun's rays, then what is the reason for its occurrence? Experts say our skin has natural pigments. However, melanoma linginosis develops when some malignant pigment cells begin to proliferate in the primary layers of the epidermis. Scientists do not yet know for sure why pigment cells become malignant, but it may be rooted in genetic mutations. When a doctor diagnoses skin cancer in a person, he or she removes the cancerous spots. This process can be more complicated depending on the size of the cancer cells. If the cancer has spread to the lymph nodes, the healing process will take longer. As with other cancers, early detection of skin cancer can speed up the healing process. Therefore, after seeing any spots or colored spots on the palms of your hands, feet or under your nails, see a specialist immediately. Keywords: Cancer; Cells; Tissues; Tumors; Prevention; Prognosis; Diagnosis; Imaging; Screening; Treatment; Management

Neomarica castaneomaculata and N. involuta (Iridaceae): two new endemic species from the Atlantic Forest, Brazil

Based on field studies, herbarium specimens and cultivated plants, two new species of Neomarica, collected in the states of Bahia, Espírito Santo, Rio de Janeiro and Minas Gerais, are described. Neomarica castaneomaculata differs from all other known species of the genus by the presence of a conspicuous triangular chestnut colored spot at the apex of the inner tepals, as well as a combination of other vegetative and floral characters. Neomarica involuta can be distinguished from other species by the conspicuously involute apical inner tepals margins. Illustrations, distribution maps and a commentary on morphology, taxonomic relationships and the conservation status of the new species are also provided.

THE DETECTION AND RECOGNITION OF COLOR STIMULI BY HONEYBEES: PERFORMANCE AND MECHANISMS

In a detection paradigm, honeybees Apis mellifera were trained to distinguish between the presence and the absence of a rewarded colored spot, presented on a vertical, achromatic plane in a Y-maze. In a recognition paradigm, bees were trained to distinguish between a trained colored disk and alternative stimuli differing in their green contrast and/or chromatic contrast. Results from the first experimental paradigm allowed the establishment of αmin, the visual angle subtended by a colored target at the bee eye at which the bees detect a given stimulus with a probability Po = 0.6. This angle was 5° for stimuli presenting both chromatic contrast and green contrast, and 15° for stimuli presenting chromatic but no green contrast. Therefore, green contrast contributes decisively to the detection task. Results from the second experimental paradigm showed that chromatic and green contrasts are alternatively used depending on the visual angle subtended by a trained chromatic target and that bees also learn the green-contrast difference between a trained and a nonrewarded alternative. Finally, when trained at different visual angles with an achromatic stimulus providing green contrast, bees were capable of learning and detecting the achromatic target only for visual angles from 10° to 5°. Thus, green-contrast and chromatic-contrast channels are tuned to signals of different angular sizes: the chromatic channel conveys the signals of objects of large angular size, while the green contrast channel conveys those of objects of reduced angular size.

Perceived Motion of a Colored Spot in a Noisy Achromatic Background

It is shown that human observers can use color both for detecting and for discriminating motion. The contributions of chromaticity and luminance to the detection and discrimination of motion are investigated with a high-contrast, nonisoluminant stimulus. The motion stimulus is a rectangular ‘particle’ defined by its luminance and chromaticity, which moves against a background containing luminance noise. Although the luminance noise is found to make achromatic particles undetectable over a large range of luminances, the addition of color to a particle can render it detectable and also enable accurate speed discriminations to be made. The contributions of both luminance and chromaticity were measured. The effect of changing the hue angle of the particle as it moves was also examined, and it was found that the detectability of motion is low in that circumstance.

Multilayer film analysis for glucose in 1-microL samples of plasma.

With the ultramicroanalytical system described here we can measure glucose in 1 microL of plasma or serum. The sample is placed on a dry, multilayer film element (Eastman Kodak), where a colored spot about 3.5 mm in diameter develops. The reflectance of these spots is measured with a reflectance digital matrix photometer that was conceived, designed, and constructed in our laboratory. The spot is illuminated with monochromatic light and its image is projected by a camera lens onto the photosensitive surface of a linear photodiode array containing 512 individual photodetectors. The photodetector signals are processed by a computer to obtain the reflectance and diameter of the spot. The latter is proportional to sample volume. Because the reflectance of the spot does not depend greatly on sample volume, accurate pipetting is not required. The coefficients of variation of repeatable glucose analyses were, for 400, 3000, and 5120 mg/L, 1.7, 2.3, and 2.8%, respectively. The correlation coefficient (r) between glucose analyses by our method (y) and with the Ektachem 400 (x) was 0.9918; the regression equation was y = 1.07x - 94.3 mg/L.

Determination of Compounds Related to Vanillin in Vanilla Extracts

A method has been developed for the estimation of the quantities of vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde in vanilla extracts. This method separates these compounds from each other and from vanillin by two-dimensional paper chromatography. An estimate of the quantity of each of these compounds is obtained by measuring the area of the colored spot produced on reacting the compounds with chromogenic reagents. The vanillin content was also determined by two different methods. Vanilla planifolia was found to have an unidentified phenolic component not present in V. tahitensis. The Tahiti vanillas contained over twice as much p-hydroxybenzoic acid as any other vanilla extracts.

The Sensitive Detection of Organically Combined Bromine

When a few drops of concentrated copper sulfate solution are added to a concentrated solution of potassium bromide, this solution turns yellow or brownish. When it is warmed, the color darkens, and on cooling or by dilution it becomes light again; finally at a definite concentration the color becomes yellow-green. If a drop of the concentrated solution is placed on chemically pure filter paper and is allowed to dry, a bright or dark purple-red color is obtained, the shade depending on the method of drying. This color appears even when drying is at room temperature; it becomes paler when one breathes on the sample, and disappears completely when the colored spot is moistened with water, but on drying reappears as a pale rose color, the intensity of which depends on the concentration. The same purple color, but more brilliant, appears when a few drops of concentrated sulfuric acid are added to potassium bromide—copper bromide solution. In this case the color is extraordinarily intense, and it is visible even when only 0.5 mg. of bromine per liter is present.