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PubMed2002

Diet and basal cell skin cancer: results from the EPIC-Norfolk cohort.

BACKGROUND: The incidence of non-melanoma skin cancer (NMSC) in Britain has been increasing over the past 50 years. This has been attributed to increased sunlight exposure, but the increased exposure has not been quantified, and in any case, much of the increase in incidence has occurred in those parts of the body, mainly the head and neck, that have always been exposed to sunlight. There is evidence that increased dietary fat intake has increased the sensitivity of the skin to the carcinogenic potential of sunlight, particularly in causing squamous cell tumours. OBJECTIVES: To test the hypothesis that increased dietary fat is a risk factor for NMSC. METHODS: The hypothesis was tested in a nested case-control study. The cohort was that recruited for the EPIC-Norfolk study, the cases (n = 123) were subjects with NMSC diagnosed since recruitment, and the controls (n = 247) were randomly selected from the same cohort. The effect of diet on the incidence of NMSC was assessed using conditional logistic regression. RESULTS: As there were so few cases (14) with squamous cell tumours they were excluded from the statistical analyses. Fat intake was not found to be a risk factor: the unadjusted odds ratio (OR) of basal cell cases vs. controls was estimated as 0.860/(25.5 g total fat daily) with 95% confidence interval (CI) (0.663, 1.116), P = 0.25. Exploratory analyses of diet components and food groups found a protective effect of increased vitamin E consumption: unadjusted OR of basal cell cases vs. controls was 0.731/(3.06 mg vitamin E daily), 95% CI (0.564, 0.948), P = 0.015. Adjusted analyses gave broadly similar results. CONCLUSIONS: The potentiating factor remains unknown: if dietary fat has any effect on NMSC, it is not apparent when basal cell tumours are considered. There was no evidence of a generalized healthy eating effect. A substantial protective effect was found in exploratory analyses for the fat soluble antioxidant vitamin E.

Aged↗
PubMed1996

Dopamine D2 receptor plays a critical role in cell proliferation and proopiomelanocortin expression in the pituitary.

BACKGROUND: It has been suggested that the dopaminergic system is involved in the inhibitory control of secretion of pituitary hormones and in the regulation of motor function in the striatum. To elucidate the specific role of the dopamine D2 receptor (D2R) in the pituitary and brain, we generated D2R deficient (D2R mutant) mice using the gene targeting method. RESULTS: Electrophysiological studies as well as ligand binding assays show no functional D2R in mutant mice. The D2R mutant mice display a hypoactivity and a slow, creeping movement. The expression of enkephalin mRNA in the striatum is increased in the mutant mice, but not that of dynorphin and substance P. D2R mutant mice have significantly darker coat colour than their wild-type littermates and show an elevation of plasma alpha-melanocyte stimulating hormone (alpha-MSH) levels. We found corresponding hyperplastic changes of intermediate lobe of the pituitary and the increased expression of pro opiomelanocortin (POMC) in the pituitary in D2R mutant mice. CONCLUSIONS: D2R plays a critical role in the inhibitory regulation of endocrine cell proliferation and the transcription of POMC mRNA, and consequently in the regulation of alpha-MSH in plasma. D2R might be involved in the regulation of enkephalin expression in the striatum, and hence might affect the movement and the behaviour.

Animals↗
PubMed1998

recessive spotting: a linked locus that interacts with W/Kit but is not allelic.

BACKGROUND: The murine coat-colour mutation recessive spotting (rs) maps very closely to the W/Kit locus, encoding the proto-oncoprotein Kit, the protein tyrosine kinase receptor for stem cell factor. Kit is important in the development of melanocytes, germ cells, interstitial cells of Cajal (ICC) and haemopoietic lineages, including mast cells. rs has never been genetically separated from Kit, and interacts with Kit mutations, suggesting that it is a recessive allele of Kit. Here we have tested this possibility. We have shown previously that diploid rs/rs melanocytes proliferated more slowly than did +/+ melanocytes, as did an immortal line of rs/rs melanocytes, melan-rs. RESULTS: The Kit mRNA level in rs/rs melanocytes was indistinguishable from that of other melanocyte lines. The Kit cDNA sequence from rs/rs melanocytes and the kinase activity of Kit in rs/rs mast cells appeared to be normal. No deficiency of mast cells or ICC was observed in rs/rs mice. Moreover, following the overexpression of a normal Kit cDNA, proliferation of rs/rs melanocytes was retarded further, but that of +/+ melanocytes was increased, indicating an intracellular interaction between rs and Kit. Of other closely linked tyrosine kinase genes, melanocytes and melanoblasts did not express mRNA for Pdgfra, Flk-1 or Txk, but both expressed Tec, encoding a nonreceptor kinase that interacts with Kit. CONCLUSIONS: rs is not a mutation in Kit, although we have confirmed that rs interacts with Kit. It seems unlikely that rs affects Pdgfra, Flk-1 or Txk, but Tec remains a candidate for rs.

Alleles↗
PubMed2002

Genetic diversity and differentiation of Kermode bear populations.

The Kermode bear is a white phase of the North American black bear that occurs in low to moderate frequency on British Columbia's mid-coast. To investigate the genetic uniqueness of populations containing the white phase, and to ascertain levels of gene flow among populations, we surveyed 10 highly polymorphic microsatellite loci, assayed from trapped bear hairs. A total of 216 unique bear genotypes, 18 of which were white, was sampled among 12 localities. Island populations, where Kermodes are most frequent, show approximately 4% less diversity than mainland populations, and the island richest in white bears (Gribbell) exhibited substantial genetic isolation, with a mean pairwise FST of 0.14 with other localities. Among all localities, FST for the molecular variant underlying the coat-colour difference (A893G) was 0.223, which falls into the 95th percentile of the distribution of FST values among microsatellite alleles, suggestive of greater differentiation for coat colour than expected under neutrality. Control-region sequences confirm that Kermode bears are part of a coastal or western lineage of black bears whose existence predates the Wisconsin glaciation, but microsatellite variation gave no evidence of past population expansion. We conclude that Kermodism was established and is maintained in populations by a combination of genetic isolation and somewhat reduced population sizes in insular habitat, with the possible contribution of selective pressure and/or nonrandom mating.

Alleles↗
PubMed2003

Microspatial genetic heterogeneity and gene flow in stray cats (Felis catus L.): a comparison of coat colour and microsatellite loci.

We analysed levels of genetic differentiation between nine local urban colonies of stray cats using eight coat colour and nine microsatellite loci. Both types of markers revealed a strong differentiation between colonies (FST = 0.15 and 0.09 for coat colour and microsatellite loci, respectively). Three coat colour loci showed extreme levels of genetic differentiation comparatively to other loci and are strongly suspected to be under divergent selective pressures. Microsatellite loci showed significant heterozygote deficiency within colonies (FIS = 0.14), suggesting that coat colour loci are not appropriate to investigate genetic structure at a fine scale because coat colour allele frequencies are based on Hardy-Weinberg equilibrium. The reported pattern conformed to that predicted from the social structuring of cat colonies: aggressive exclusion of immigrants, inbreeding and very low dispersal rate.

Animals↗
PubMed1997

Clinical characteristics of progressive vitiligo.

BACKGROUND: Vitiligo is an acquired hypopigmentary disorder with a progressive clinical course. Various clinical characteristics and their significance in the progression of vitiligo were evaluated. METHODS: A clinical study was carried out on 400 patients who had visited the Vitiligo Special Clinic of Severance Hospital, Yonsei University College of Medicine. Questionnaires were completed regarding progression, sex, family history, clinical type, onset age, duration of disease, Koebner's phenomenon, leukotrichia, and mucosal involvement, and the results were recorded. RESULTS: Progression of vitiligo was seen in 355 patients (88.8%); 45 patients (11.2%) did not show progression. No difference in sex, onset age, or leukotrichia was noted between the two groups; however, patients with positive family histories, nonsegmental clinical type, longer duration, Koebner's phenomenon, and mucous membrane involvement showed more progression of vitiligo. CONCLUSIONS: Clinical characteristics such as family history, clinical type, duration of disease, Koebner's phenomenon, and mucous membrane involvement, may be relevant in predicting the progression or prognosis of vitiligo.

Adolescent↗
PubMed2003

Blondes, lost and found: representations of genes, identity, and history.

Research carried out during recent decades has revealed our genome not only to be a unique mine of information about health, disease and the human condition, but also about the origin and dispersal history of the species. In this context, the genome is simply an additional source of information about human history, epistemologically no different from other historical sources. However, media and public interpretation of genetic studies of human history are complicated by the wider connotations of genes as the determinants of hereditary features and identity. We discuss two examples of media and public fascination with the interrelated themes of history, identity and heredity, pointing out some implications of historical research using genetic data in the context of our own ongoing study of Inuit groups in Greenland and Victoria Island, Canada.

Arctic Regions↗
PubMed1999

The changes in hair growth pattern after autologous hair transplantation.

BACKGROUND: Recently donor dominance has been emphasized in autologous hair transplantation while the influence of the recipient site has been considered negligible. In fact, there have been few studies that show this. OBJECTIVE: This study was performed to examine the influence of the recipient site on transplanted hairs. A clinical study of 19 leprosy patients was performed. These patients had received single hair transplantation due to madarosis and were admitted to The Leprosy Mission, Jesus Hospital, Taegu, Korea, or had visited its outpatient clinic. METHODS: In this study, the rate of growth, thickness of shaft, and graying rate between the transplanted eyebrow hair in the recipient site and scalp hair near the donor site were compared to observe the changes in the growth pattern of the hairs after transplantation. RESULTS: For most of the patients, the growth rate and graying rate of transplanted hairs were lower than those of hairs in the donor site. CONCLUSION: It seems that the recipient site may have an influence on the transplanted hairs. Further studies are needed, including clinical, histopathologic, and molecular biological methods.

Aged↗
PubMedDate not supplied

Two siblings born preterm with large ears and hypopigmented hair who developed palmoplantar keratoderma and frontal skull bossing: a new syndrome?

This article discusses two children with an unknown syndrome characterized by palmoplantar keratoderma (PPK), hypopigmented hair, large ears, and frontal bossing. The children were both born preterm, with low birthweights, to consanguineous parents. They developed PPK shortly after birth. In addition, the younger child also has esotropia affecting the right eye. We made a thorough review of the literature but were unable to find a syndrome with all the features described above. To the best of our knowledge, we describe a new syndrome with an autosomal recessive mode of inheritance.

Child, Preschool↗
PubMed2003

Mapping and characterization of the dominant black colour locus in sheep.

Dominant black pigment synthesis in sheep is caused by alterations of the melanocortin-1 receptor (MC1-R) coding sequence. Using five bovine microsatellite markers we have mapped the sheep MC1-R gene to chromosome 14, corresponding to the location in other mammalian species. The existence of two independent mutations, both causing an amino acid substitution, in distantly related breeds of sheep, support the hypothesis that the observed black pigment synthesis is caused by a mutual effect of the two mutations. As similar mutations are found separately at both locations in dominant black variants of other animal species, it is also possible that any of the two mutations could be sufficient for a partial pigment switch.

Animals↗
PubMed1980

Induction of autumn moult in mink (Mustela vison Peale and Beauvois) with melatonin.

Adult female mink, living in natural conditions of temperature and photoperiod, were treated by melatonin implants in mid-July, when the summer coat was in its resting stage. As a result, a moult was induced 5 to 6 weeks before the normal time; its showed the characteristics of an autumn moult as observed by the gradient of hair changes over the body and the high number of hair follicles per bundle (47 p. 100 more than in the summer coat). The winter coats produced in this way were mature in the early days of October, i.e. 6 to 7 weeks before those of the control group.

Animals↗
PubMed1982

[Waardenburg syndrome type I--autosomal dominant hereditary combination of multiple facial anomalies with cochlear deafness (author's transl)].

Waardenburg syndrome Type I is described on the basis of an observation of a family. The characteristic signs including lateral displacement of medial canthi ("telecanthus"), wide bridge of the nose, white forelock and severe cochlear deafness are found in one female patient only; however, her eyes are not of different colour. Five further bearers of characteristic signs in four generations are not so severely affected and show the facial anomalies only. To differentiate this syndrome against Waardenburg syndrome Type II which is complicated by deafness twice as often but occurs without the lateral displacement of the medial canthi, accurate measurement of the distance between the canthi is helpful. Waardenburg syndromes are hereditary according to the autosomal dominant principle with high penetration; intrafamiliarly, too, expressivity can vary greatly. To date treatment has been directed at the signs and symptoms; prognosis is usually favourable. Prevention appears possible through genetic family counseling.

Abnormalities, Multiple↗
PubMed1987

Ataxia-deafness-retardation syndrome in three sisters.

Three sisters aged 16, 12 and 8 years from a consanguineous family presented with a progressive spinocerebellar ataxia combined with moderate mental retardation, progressive sensorineural hearing loss and signs of both upper and lower motor neuron disease. The patients represent the only known cases of the ataxia-deafness-retardation syndrome (McKusick #20885) except for the three brothers in the original description by Berman et al (1973). In the family described here transmission of the disease appears to be linked with occurrence of red hair colour.

Adolescent↗
PubMed1991

[Subacute chloroquine overdosage].

Owing to a misunderstanding a 26-year-old man took for malaria prevention 2 tablets (1.0 g) chloroquine daily instead of the recommended dose of two tablets weekly. After 2 weeks he developed vertigo, generalized weakness and, after sun-bathing, severe bullous light reaction. After 4 weeks generalized hair depigmentation occurred. Two weeks later abnormal accommodation and double vision set in so that he lost distant and near vision. All these signs disappeared after the drug was discontinued (vertigo, weakness and abnormal accommodation within 2 weeks; hair regrew in normal colour after 8 weeks). This case shows the whole spectrum of subacute chloroquine overdosage.

Accommodation, Ocular↗