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ADULT-syndrome: an autosomal-dominant disorder with pigment anomalies, ectrodactyly, nail dysplasia, and hypodontia.

We describe a family with at least seven living persons who are affected by an hitherto undescribed autosomal-dominant syndrome with variable expression, bearing close resemblance to the EEC syndrome and related disorders. The main manifestations are hypodontia and/or early loss of permanent teeth, ectrodactyly, obstruction of lacrimal ducts, onychodysplasia, and excessive freckling. We propose the acronym ADULT (acro-dermato-ungual-lacrimal-tooth)-syndrome for this condition.

Abnormalities, Multiple↗

A novel approach to gene therapy of albino hair in histoculture with a retroviral streptomyces tyrosinase gene.

In order to induce melanin production in mammalian cells with pigment disorders such as albino hair, a recombinant retrovirus containing the mel locus of Streptomyces antibioticus was constructed. The S. antibioticus mel locus, which consists of the open reading frame (ORF)-438 and the tyrosinase gene, was specifically derived by polymerase chain reaction (PCR) from Streptomyces plasmid pIJ702. The ORF-438 is required for the transfer of copper to apotyrosinase, which is essential for tyrosinase enzymatic activity. The tyrosinase gene was inserted into the XhoI/BamHI cloning site of the pLXSN retroviral vector to obtain pLtyrSN. An internal ribosome entry site (IRES) suitable for mammalian cell expression was obtained from the pLXIN retroviral vector by PCR. The ORF-438 and IRES DNA fragments were inserted into the pLtyrSN vector to obtain the tyrosinase-expression retroviral vector pLmelSN. The expression vector was amplified in murine PT67 packaging cells, where the ORF-438 and tyrosinase genes were also co-expressed as determined by reverse transcription-PCR. In order to evaluate the vector's ability to restore pigment production in cells with a pigment disorder, albino-mouse skins were histocultured and then infected with the pLmelSN retrovirus. Six days after infection, melanin granules were observed in approximately 60% of albino-mouse hair follicles in the histocultured skin. These results demonstrated that the S. antibioticus mel operon could express an active tyrosinase and produce melanin in the albino-mouse hair follicles. This novel gene therapy approach, using a small and simple tyrosinase operon in a high-expression vector, has a potentially wide application for therapy of pigment disorders in hair follicles.

Albinism↗

[Trisomy 20 mosaicism revealed by pigmentary mosaicism of the Ito-type].

INTRODUCTION: Ito hypomelanosis-type pigmentary mosaicism is characterized by congenital pigmentation disorders along Blaschko's lines. We report a case of Ito-type pigmentary mosaicism associated with a congenital growth hormone deficiency having revealed trisomy 20 mosaicism. OBSERVATION: A 4 year-old boy presented with congenital pigmentation disorders. His history was marked by: inter-uterine delayed growth of unknown etiology, a dysmorphic syndrome, psychomotor retardation with speech problems, right cryptorchidia and an isolated, idiopathic, congenital growth hormone deficiency that had been treated with recombinant somatropine since the age of three. The clinical examination revealed alternating hypo and hyper-pigmented maculae with linear distribution on the limbs and in "twirls" on the trunk following Blaschko's lines. The blood karyotype was normal, the karyotype on fibroblasts of hypopigmented skin revealed trisomy 20 mosaicism. DISCUSSION: The occurrence of pigmentary mosaicism related to trisomy 20 mosaicism is exceptional. The combination of Ito hypomelanosis-type pigmentary mosaicism and delayed growth due to growth hormone deficiency has never been reported before. Our observation, unusual because of such an association, raises the question of the eventual existence of associated genes located on the chromosome 20 implied in the secretion of growth hormone and/or melanogenesis. It also underlines the interest of conducting cytogenic explorations on fibroblasts of damaged skin in the case of Ito-type pigmentary mosaicism, even if the blood karyotype is normal or in the absence of a patent phenotype abnormality.

Abnormalities, Multiple↗

[Culture of human melanocytes. Its contribution to the knowledge of melanocyte physiology].

Culture techniques for normal human melanocytes have been developed over the last ten years. This in vitro model for studying pigment-producing cells can be expected to provide major advances in the knowledge of cell-to-cell anc cell-to-matrix interactions, melanocyte and melanin biology, pathophysiology of pigment disorders, and malignant melanomas. 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. Melanocyte cultures also enable in vitro studies of melanocyte responses to ultraviolet radiations and of the biologic messengers involved in these responses. Lastly, they provide a means for investigating endocrine and paracrine mechanisms involved in the regulation of melanogenesis, including the role of melanotropins, estrogens and vitamin D. Improved knowledge of the molecular biology of melanocytes provides hope for rapid advances in the understanding of tyrosinase and posttyrosinase regulation of melanogenesis. Lastly, melanocyte cultures can be expected to find useful applications in the pathophysiologic study of pigment disorders and of pharmacologic modulation of skin pigmentation.

Cells, Cultured↗

[Cutaneous side effects of systemic drugs. Part 4 of a synopsis. 6/7. Drugs affecting the central nervous system. C. Drug-induced photosensitivity. D. Drug-induced changes of skin color].

This, the fourth part of a synopisis of cutaneous side effects of drugs, covers the drugs affecting the central nervous system: antiepileptics, hypnotics, narcotics and psychopharmaceutics; the myorelaxants and antiallergics follow, and lastly there is a section on drug addiction and placebo. The various cutaneous side effects are listed in chart form referring to more than 500 sources. A drug index is attached for handy reference. The reviews of certain drug induced skin disorders are continued with tables covering photosensitivity and changes in skin colour. Phototoxicity, photoallergy and light sensitivity by porphyria are differentiated. The various pigmentation disorders, colour changes due to metal deposits as well as different localisations are included.

Anticonvulsants↗

Piebaldism.

A 46-year-old man presented with a history of a congenital pigment disorder. On physical examination hypopigmented and depigmented patches were present on the mid-forehead, anterior chest, and extremities. He also had loss of pigment of the medial eyebrows and a white forelock. The patient has a family history of a similar congenital pigment disorder, the pattern of which is indicative of the autosomal dominant disorder piebaldism.

Humans↗

Retrotransposon insertion in SILV is responsible for merle patterning of the domestic dog.

Merle is a pattern of coloring observed in the coat of the domestic dog and is characterized by patches of diluted pigment. This trait is inherited in an autosomal, incompletely dominant fashion. Dogs heterozygous or homozygous for the merle locus exhibit a wide range of auditory and ophthalmologic abnormalities, which are similar to those observed for the human auditory-pigmentation disorder Waardenburg syndrome. Mutations in at least five genes have been identified as causative for Waardenburg syndrome; however, the genetic bases for all cases have not been determined. Linkage disequilibrium was identified for a microsatellite marker with the merle phenotype in the Shetland Sheepdog. The marker is located in a region of CFA10 that exhibits conservation of synteny with HSA12q13. This region of the human genome contains SILV, a gene important in mammalian pigmentation. Therefore, this gene was evaluated as a candidate for merle patterning. A short interspersed element insertion at the boundary of intron 10/exon 11 was found, and this insertion segregates with the merle phenotype in multiple breeds. Another finding was deletions within the oligo(dA)-rich tail of the short interspersed element. Such deletions permit normal pigmentation. These data show that SILV is responsible for merle patterning and is associated with impaired function of the auditory and ophthalmologic systems. Although the mutant phenotype of SILV in the human is unknown, these results make it an intriguing candidate gene for human auditory-pigmentation disorders.

Animals↗

Retinal pigment epithelium disorder in Vogt-Koyanagi-Harada disease revealed by hyperosmolarity response of ocular standing potential.

The hyperosmolarity response of the ocular standing potential was examined in 14 eyes of 7 cases of Harada's disease between 8 and 1,341 days after the onset of the disease. The hyperosmolarity response remained normal at the initial stage of the disease when choroiditis, retinal detachment and iridocyclitis were the main manifestations. The hyperosmolarity response was suppressed when depigmentation of the fundus progressed to the stage of the "sunset glow" appearance. The present study suggests that a sensitivity reduction to osmotic stress takes place in the retinal pigment epithelium concomitantly with the transition from the stage of depigmentation to the stage of "sunset glow". This dysfunction can be disclosed by the hyperosmolarity response, but not by the conventional examination of the light peak/dark trough ratio of the ocular standing potential.

Adult↗

Inhibition of tyrosinase by protocatechuic aldehyde.

The purpose of this study was to determine the inhibitory action of protocatechuic aldehyde (PCA) on tyrosinase activity. PCA is one of the compounds found in the root of Salvia miltiorrhiza. Our study documented that PCA has a potent inhibitory effect on tyrosinase, which catalyzes the rate-limiting step of melanin biosynthesis. Although melanin biosynthesis has an essential function normally in human skin for defense against ultraviolet light of the sun, its abnormal activity as seen in pigmentation disorder could lead to serious medical problems. Our data showed that PCA, with concentrations ranging from 1 x 10(-5) M to 8 x 10(-5) M, exhibited dose-dependent inhibition of the enzyme activity with 50% of inhibition at 19.92 x 10(-6) M. A further kinetic analysis on PCA inactivation of tyrosinase activity revealed a competitive inhibition of the enzyme at the L-tyrosine binding site. The findings of our present study merit further research on the applicability of PCA as a potential agent for treatment of pigmentation disorder.

Benzaldehydes↗

Melanosis coli or mucosa ischemia? A case report.

The presence of a black or brown stoma may indicate a serious problem, such as a necrotic stoma, or may be the result of a benign pigmentation disorder known as melanosis coli. Melanosis coli is caused by anthraquinone laxative abuse and has no associated morbidity. The case report involves a 63 year old white female admitted to the hospital emergency room. Secondary to uterine choriocarcinoma, an end sigmoid colostomy was created. The mucosa was moist but black, despite the fact that the serosa had been pink and bled easily. Biopsy revealed neither necrotic stoma nor infarcted bowel but melanosis coli related to the patient's 20 year history of laxative use for chronic constipation. Melanosis coli does not require medical or surgical intervention and is considered a benign pigmentation disorder. However, knowledge of this condition and of the bowel patterns and habits of patients prior to their ostomy surgery, is essential to establishing the differential diagnosis for a brown or black stoma.

Anthraquinones↗

MYOGLOBINURIA.

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Adolescent↗

Hyperplastic neuroretinopathy and disorder of pigment epithelial cells precede accelerated retinal degeneration in the SJL/N mouse.

We have found a complex eye disease in the SJL/N mouse. This animal is closely related to the SJL/J mouse, which is homozygous for retinal degeneration (rd) and which also suffers from extraocular reticulum cell sarcomas at around 200 days of age. In the SJL/N animal, a high incidence of subretinal tumor is present at 9 days after birth. Furthermore, we have observed an extensive neuroretinal hyperplasia, a phenomenon that is termed "hyperplastic neuroretinopathy", and that is probably the consequence of elevated levels of cytokines in the animals. In addition to these anomalies, the SJL/N mouse shows progressive dystrophy of the retinal pigment epithelium (RPE) from day 4 onwards, and accelerated photoreceptor cell degeneration is completed by day 16. The early RPE dystrophy appears to be a secondary autoimmune disease, since cells in this structure and in the choroid develop MHC class II antigens, whereas we suspect that the accelerated photoreceptor cell loss is induced by a soluble toxic agent. The F1 progeny derived from cross-breeding the SJL/N and Balb/c +/+ strains also shows a high incidence of subretinal tumor and hyperplastic neuroretinopathy, but neither the RPE dystrophy nor retinal degeneration.

Age Factors↗