(n.) A person, whether negro, Indian, or white, in whom by some defect of organization the substance which gives color to the skin, hair, and eyes is deficient or in a morbid state. An albino has a skin of a milky hue, with hair of the same color, and eyes with deep red pupil and pink or blue iris. The term is also used of the lower animals, as white mice, elephants, etc.; and of plants in a whitish condition from the absence of chlorophyll.
Example Sentences:
(1) The urine compositions of the European mole Talpa europaea and of the white rat Rattus norvegicus (albino) kept on a carnivore's diet were compared.
(2) In the liver of albino rats with experimental thyrotoxicosis a study was made of nucleic acids and some indices of phosphorus metabolism: total and inorganic phosphorus, total and acid-soluble phosphorus, phosphorus of RNA, DNA and phosphoproteins.
(3) Hyperimmunization with the tick encephalitis and Western horse encephalomyelitis viruses reproduced in the brain of albino mice, intensified the protein synthesis in the splenic tissue during the productive phase of the immunogenesis (the 7th day).
(4) Differences between the albino vs pigmented strains were observed following injections of saline.
(5) In contrast, albino rats and rabbits failed to succumb to overt disease by subcutaneous and intraperitoneal routes of inoculation.
(6) CW Nd:YAG light transmitted by fiber optic cable and sapphire crystal was applied transsclerally to the ciliary body of pigmented and albino rabbits.
(7) The flash visually evoked cortical potential (VECP) was recorded in 18 human albinos.
(8) The contralateral projection in all divisions of the CN of both albino and 'red eyed' ferrets was normal.
(9) A cluster of unlinked genes encoding gluconeogenic enzymes in the mouse is characterized by the failure of normal hormone-inducible expression in animals homozygous for one of several overlapping deletions mapping on chromosome 7 near the albino locus.
(10) Male albino rats were tested in three conspecific conditions: estrous female, anestrous female, or no conspecific.
(11) In albino rabbits aged from the 16th postconceptional day (16PCD) to adulthood, the number of axons in the optic nerves were estimated from sample areas totalling 1-12% of the cross-sectional area of the nerve.
(12) Beryllium, cadmium, and tellurium assay data are reported for the fresh tissues of albino rats exposed to inorganic chemicals by oral or intraperitoneal routes.
(13) Lactate dehydrogenase (LDH) levels and subunit isozyme patterns in cornea were monitored in 36 albino rabbits wearing thick, rigid, gas-permeable contact lenses for periods of 24 h, 2 and 7 days, and 1 and 3 months.
(14) Thiabendazole was found to be specifically effective against maximal electroshock seizures in albino rats.
(15) The broad overlap in the distributions of neuronal size in the abducens nucleus between groups indicated that not all cells in the albino brainstem are significantly smaller than normal.
(16) The ceramic sections, approximately 15.3 mg, were implanted into both proximal femurs of 10 male and 10 female albino SW rats.
(17) Intravitreal injections of hCG in albino rabbits provoked a reduction of intraocular pressure (IOP).
(18) There was marked destruction of the ciliary body in pigmented rabbit eyes, but no histologic effect was observed in albino rabbit eyes.
(19) When twenty Swiss albino mice (male) were fed a vitamin A deficient diet for 18-24 months, Mallory bodies (MB(s] were observed.
(20) Tests were conducted on albino male-rats in which an experimental gastric ulcer failing to heal for a long time had been induced through introduction of a 5% acetic acid solution into the subserous membrane of the stomach.
Melanin
Definition:
(n.) A black pigment found in the pigment-bearing cells of the skin (particularly in the skin of the negro), in the epithelial cells of the external layer of the retina (then called fuscin), in the outer layer of the choroid, and elsewhere. It is supposed to be derived from the decomposition of hemoglobin.
Example Sentences:
(1) Although the mechanism(s) by which melanin augments inflammation has not been defined, these data suggest that the binding of serum components (such as antibodies) to melanin may contribute to its proinflammatory effect.
(2) An unusual case of medullary carcinoma of the thyroid gland with melanin production is described.
(3) The melanins examined show significant differences in conductivity, thermal activation energy and photocurrent intensity values.
(4) The total number of neuronal cell bodies was 25% lower in AIDS (P less than 0.01) than in 12 age-matched controls, although the volume density of neuronal melanin did not differ from that of controls because the percentage of pigmented cell bodies was higher (P less than 0.01) and the cell bodies were more fully packed with melanin in AIDS.
(5) Comparison of the melanin-related metabolites excreted in urine of people with different capacities for melanin biosynthesis indicates that, of all measured substances, 5H6MI2C is the best urinary marker of melanin formation in the skin pigmentary system.
(6) Since neuromelanin in SN is the end-product of nonenzymatic dopamine degradation, the amount of melanin probably depends on the overall amount of dopamine produced during life.
(7) 1 After the injection of labelled procaine and lidocaine in mice, the location and concentration of radioactivity was demonstrated by autoradiographical methods.2 An accumulation in some endocrine cells such as the pancreatic islets, the hypophysis, the adrenal medulla and certain cells of the thyroid (probably representing the calcitonin-producing parafollicular cells) was shown.3 After the injection of [(14)C]-procaine in chicks, an accumulation of radioactivity was observed in the ultimobranchial gland (which produces calcitonin in birds), but not in the thyroid.4 Radioactivity was also shown to be strongly concentrated in structures containing melanin, such as the pigment of the eye, skin and hair and in some organs involved in the metabolism and excretion of these drugs.
(8) Microautoradiography showed that melanin-containing cells in the trunk and head kidney and in the olfactory rosettes also accumulated high amounts of radioactivity.
(9) In all cases there was a reduction of the melanin of the basal layer.
(10) Two melanotropic peptides, melanin concentration hormone (MCH) and alpha-melanocyte stimulating hormone (alpha-MSH), exert opposing actions on melanosome (melanin granule) movements within teleost pigment cells, melanocytes (melanophores).
(11) The varying epidermal melanin content that produces racial pigmentation determines the number of photons that reach the lower (malpighian) cellular layers, where vitamin D3 synthesis takes place.
(12) The synthesis of melanin involves the oxidation of phenolic substrates by the enzyme tyrosinase.
(13) Since such rats supposedly have a normal pigment distribution and a normal pattern of decussation at the optic chiasm, this finding appears to undermine the suggested role played by stalk melanin in establishing the laterality of retinal fibre projections in other mammalian species.
(14) The MNT was composed mainly of two cell types: small immature neuroblast-like cells and large columnar or cuboidal epithelial-like cells with or without melanin granules.
(15) L-tyrosine, a precurosr to melanin, has recently been shown to be a regulator of the melanogenic pathway in some cultured melanoma cell lines.
(16) By analysis of co-variance, the melanin content of melanocytes of black and white subjects was significantly (p less than 0.05) associated with susceptibility to UVA killing; melanocytes with high melanin content had high resistance to UVA cytotoxicity and those with low melanin content had low resistance to UVA cytotoxicity.
(17) Melanin biosynthesis is a multistep process with the first step being the conversion of L-tyrosine to L-Dopa catalyzed by the enzyme tyrosinase.
(18) The results showed that there was no correlation between the GABA concentration and the number of melanin-rich nigral cell bodies.
(19) These fluorescent substances were heterogeneous: fluorescence was detected both in main high molecular fraction and in low molecular substances (fluorescence was absent in the initial melanin and its fractions).
(20) Melanocyte cultures have already shed new light on keratinocyte-melanocyte interactions within the epidermal melanin unit by showing that keratinocytes produce "melanotrophic factors" which modulate growth, melanin production, and dendricity of melanocytes.