(n.) The state or condition of being an albino: abinoism; leucopathy.
Example Sentences:
(1) The nucleotide sequences presented thus enable us to discriminate the tyrosinase gene from its related sequences and are invaluable for a gene diagnosis of oculocutaneous albinism.
(2) The presence of a ring-like figure in the centre of the fundus oculi may be regarded as an additional clinical sign of albinism of the fundus oculi.
(3) Resuscitation was significantly more often successful with the Bunegin-Albin catheter (six of nine dogs) than with either Sorenson catheter (zero of seven in both groups) or the Swan-Ganz RA port (one of seven).
(4) Based upon the finding of giant pigment granules in clinically normal skin of the patient's mother, the patient was diagnosed as a case of dyschromatosis universalis with X-linked ocular albinism.
(5) These findings suggest that there is a partial block in the distal eumelanin pathway in this form of albinism.
(6) Minimal pigment, a new type of oculocutaneous albinism (OCA), is described.
(7) Two female patients with familial diffuse fibrosing alveolitis associated with oculocutaneous albinism are presented.
(8) Several types of autosomal recessive oculocutaneous albinism (OCA) are associated with abnormal tyrosinase function and a generalized reduction in or absence of cutaneous and eye melanin.
(9) Amplitudes were reduced compared with those obtained with the sclera unoccluded, suggesting that responses to transscleral illumination contributed to the ERG in this type of albinism.
(10) On account of a recently developed tinnitus, a young woman with the characteristic features of Klein-Waardenburg's syndrome (impairment of hearing, partial albinism, telecanthus) was hospitalised.
(11) The introducer sheath was compared to a Sorenson CVP catheter, a Bunegin-Albin Air Aspiration CVP Catheter, and the proximal port of a pulmonary artery catheter.
(12) An 11-year-old boy had dyskeratosis congenita, elevated fetal hemoglobin level, X-linked ocular albinism, and juvenile-onset diabetes mellitus.
(13) A family was studied in which four siblings had oculocutaneous albinism.
(14) The broader category of mild to moderate hypopigmentation without all of the features of albinism may ultimately prove to be as important in understanding melanin metabolism.
(15) The absence of the foveolar pit and the decrease of visual acuity in tyrosinase-positive albinism is caused by definite morphologic alteration in the arrangement of ganglion cells in the macular region in the sense of a foveolar aplasia.
(16) Ocular albinism is distinguished from the more common oculocutaneous albinism by the presence of normal pigmentation of skin and hair in the former condition.
(17) The iris shows the lack of pigmentation in various types of albinism.
(18) It has recently been suggested that aberrant misrouting of retino-geniculate-cortical (RGC) projections, a finding previously noted only in albinism, may be an additional feature of the Prader-Willi syndrome.
(19) Histopathologic and ultrastructural findings in an eye from a patient with complete oculocutaneous albinism are reported.
(20) This is believed to be the first case of albinism reported in sheep.
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.