bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Regulation of Melanocyte Differentiation
Authors: TAKEUCHI TAKUJI , YAMAMOTO HIROAKI 
Published: July 2006

Melanocytes originate from the neural crest in vertebrates and migrate to the body surface where they differentiate into functional cells. Genes involved in melanocyte differentiation can be classified into two groups. One of them consists of the functional genes that control proteins specific to the function of the melanocyte. As the representative gene of this category, albino (c) locus in the mouse is considered to control tyrosinase, the key enzyme in melanogenesis. cDNA for mouse tyrosinase has been cloned and sequenced. The cDNA can be used to detect tyrosinase mRNA synthesized during melanocyte differentiation. On the other hand, genes such as brown (b) or pink‐eyed dilution (p) have been assumed to control melanosome proteins.The other category consists of genes that regulate the expression of these functional genes directly or indirectly. In the mouse, so‐called white‐spotting genes and genes of the agouti series are considered to fall into this category. Based on the fact that mutations at the white‐spotting loci result in the absence of melanocytes in a particular area of skin, it is assumed that some of these loci control the factors that promote either differentiation or migration of melanoblasts and are candidates for the classic regulator genesGenes at the agouti (a) locus in the mouse determine the type of melanin synthesized in hair follicle melanocytes, that is eumelanin or pheomelanin. An interesting feature of this locus is that the site of gene action is not within the melanocytes but in the cells surrounding them. The results of our study indicate that the gene product of the a‐locus interacts with α‐MSH at the α‐MSH receptor site, regulates the cellular cAMP level via a signal transduction system and, in turn, determines the type of melanin synthesized in the cells.
Dysplastic Nevus Syndromes
Authors: ELDER DAVID. E. 
Published: July 2006

Dysplastic nevi (DMN) were first recognized as an autosomal dominant genetic marker of melanoma risk in hereditary cutaneous melanoma (HCMM) kindreds, families in which at least two melanomas have occurred. Subsequently, DMN have been identified in people with a personal but no family history of melanoma (SCMM), and with no history of melanoma. The lesions themselves may similarly be familial (FDMN) or sporadic (SDMN). A good deal is known about HCMM/FDMN kindreds and about patients with SCMM and DMN, while information about other subsets of DMN cases is slowly accumulating. Clinical evidence suggests that DMN may usually be familial when case‐finding is adequate.Although DMN are potential precursors of melanoma, the risk of progression of individual lesions is low, and their major significance is as markers of prospective risk for melanoma. This risk is heterogeneous, and there are important interactions with other risk factors, especially prior personal or familial melanoma. Traditional risk factors for melanoma, such as susceptibility to sunburn and ability to tan, may be expected to interact with the DMN trait to establish groups at heterogeneous risk. These groups may be regarded as syndromes of DMN cases, but to avoid confusion, it seems more appropriate to refer to cases by descriptive labels such as FDMN with HCMM, FDMN with personal CMM, FDMN without CMM, SDMN, and so on.
Ionic Requirements for Melanin Concentrating Hormone (MCH) Actions on Teleost Poecilia reticulata Melanophores
Authors: VISCONTI MARIA A. , CASTRUCCI ANA MARIA DE L. , MAC HADLEY E. , HRUBY VICTOR J. 
Published: July 2006

Melanin concentrating hormone (MCH) is a cyclic heptadecapeptide, Asp‐Thr‐Met‐Arg‐Cys‐Met‐Val‐Gly‐Arg‐Val‐Tyr‐Arg‐Pro‐Cys‐Trp‐Glu‐Val, synthesized in the hypothalamus and released by the neurohypophysis of teleost fish. This hormone is a potent lightening agent of fish skin. This lightening results from the stimulation of a centripetal melanosome (melanin granule) migration to a perinuclear position within integumental melanophores.MCH and related fragment analogues, MCH5‐17 and MCH1‐14 were used to investigate the ionic requirements for receptor activation by MCH on dermal melanophores of the fish Poecilia reticulata. In calcium‐free saline, the sensitivity of the melanophores to MCH and MCH1‐14 increased, whereas the sensitivity of the cells to MCH5‐17 decreased. Verapamil diminished the sensitivity to MCH5‐17, but did not affect melanophore responses to MCH or MCH1‐14. The melanosome aggregating response to MCH was not affected in the presence of tetrodotoxin or in sodium‐ or potassium‐free (choline‐substituted) saline. These results suggest that neither TTX‐sensitive sodium channels nor extracellular sodium or potassium ions play a role in MCH‐induced melanosome aggregation.It is known that MCH and MCH1‐14 also exhibit MSH‐like melanosome dispersion within melanophores, skin darkening activity on fish melanophores whereas MCH5‐17 lacks this characteristic. Since the darkening activity of MCH and MCH1‐14 requires calcium, these analogues exhibited a diminished lightening (MCH‐like) activity in the presence of the divalent cation. In the absence of the N‐terminal tetrapeptide sequence (necessary for the expression of MSH‐like activity), a role for calcium on melanosome aggregation became evident. These results demonstrate a bifunctional role of calcium on melanosome movements.
Neutron‐Induced Gamma Dose From a Reactor Beam Filter for Boron Neutron Capture Therapy
Authors: HARRINGTON BAIBA V. 
Published: July 2006

For the boron neutron capture therapy (NCT) of deep‐seated metastatic melanoma, an epithermal (up to a few keV energy) neutron beam from a reactor horizontal facility could be useful if the inherent contamination from fast neutrons and gamma rays could be minimised.Calculations for ANSTO's 10 MW research reactor HIFAR have shown that, even though a filter material such as A1F3 attenuates the fast neutron dose, the beam quality improvement is counteracted by a relative increase in the gamma dose because of gammas arising from neutron captures in the filter material, particularly the aluminium. The aluminium gammas, most of which arise from thermal neutron capture, are hard and cannot be attenuated by lead or bismuth without comparable attenuation of the epithermal neutron flux. Addition of an absorber such as 6Li to the AlF3 filter was investigated as a means of reducing the hard gamma dose, but the improvement in beam quality was small and at considerable cost to dose intensity. Dose characteristics calculations confirmed the superiority of a tangential beam over a radial beam with better results from an unfiltered tangential beam than from an AlF3 filter in a radial beam.This study showed conclusively that assessments of filter assemblies based on the effect of individual components on either the neutron or gamma dose in isolation are inadequate. In assessing any epithermal neutron filter, thermal neutron shield, and gamma shield combination, the total effect of each on the neutron, gamma, and boron‐10 dose must be considered.
Use of an Alpha‐Melanocyte‐Stimulating Hormone Analogue to Improve Alpha‐Melanocyte‐Stimulating Hormone Receptor Binding Assay in Human Melanoma
Authors: LIBERT ANITA , GHANEM GHANEM , ARNOULD ROLAND , LEJEUNE FERDY J. 
Published: July 2006

In order to optimize the detection and measurement of α‐melanocyte‐stimulating hormone (α‐MSH) receptivity in human melanoma cells, and the authors replaced the natural hormone by [Nle4,D‐Phe7]‐α‐MSH, a more stable and potent analogue in the receptor binding assay commonly performed with α‐MSH. The following parameters were investigated: temperature, incubation time, number of cells, and ratio of labelled to unlabelled hormone. Optimal conditions for each assay were determined.The results demonstrate that the analogue has identical binding sites to α‐MSH, as similar reciprocal displacements of each labelled (125I) hormone by serial dilutions of unlabelled α‐MSH or [Nle4,D‐Phe7]‐α‐MSH (10−12 M to 10−6 M) were obtained. To further compare the two hormones, we performed a screening of various human cell lines: ten melanomas and five nonmelanomas. The assay with [Nle4,D‐Phe7]‐α‐MSH yielded more receptor expression on six often melanoma lines against only four often with the natural hormone.In conclusion, the use of radiolabelled [Nle4,D‐Phe7]‐α‐MSH analogue instead of labelled α‐MSH improved both sensitivity and reproducibility in this receptor binding assay on human melanoma lines.
Electrophoretic Heterogeneity of Pigmented Hamster Melanoma Cells
Authors: HYRC KRZYSZTOF , WILCZEK ADAM , CIESZKA KRYSTYNA 
Published: July 2006

Pigmented hamster melanoma tumors growing in situ contain two subpopulations of melanoma cells that have different electrophoretic mobilities (EPM). A mild neuraminidase treatment, which removes sialic acid residues from the cell surface glycoproteins, reduces the EPM of both groups of melanoma cells yielding an electrophoretically uniform population. This shows that the differences in the EPM between the subpopulations of pigmented melanoma cells stem from the different content of sialic acid residues on the cell surface. The relationship between the different EPM melanoma cell subpopulations was, therefore, examined during tumor growth, development, and formation of metastases.The relative content of cells having high electrophoretic mobility, the “fast moving” cells, increases as the tumors grow larger. However, tumors of the same diameter contain nearly the same fraction of “fast moving” cells despite their age. The proportion of the “fast moving” cells is significantly higher in the central part than in the outermost layer of pigmented melanoma tumors. These data suggest that the development of “fast moving” cells is promoted by some size‐dependent changes in the intratumor environment.In vivo selection of melanoma cells for their ability to colonize lungs renders tumors that reveal elevated metastatic potential and contain a significantly higher fraction of cells possessing high electrophoretic mobility than the parent tumor. Moreover, the metastatic nodules contain a remarkably elevated fraction of the “fast moving” cells. The reported correlation between the “fast moving” cell fraction and the metastatic potential suggests that the relative content of cells having high electrophoretic mobility may determine the metastaticity of pigmented hamster melanoma.
Pigment Cell Research: What Directions?
Authors: PROTA GIUSEPPE 
Published: July 2006

Over the past few years, Pigment Cell Research has experienced unprecedented impetus in practically all areas. However, as is usually the case in periods of rapid development, several critical issues buried under the glitz of recent success are more or less the same as they have been for many years. Persisting misconceptions and scientific prejudices also contribute to cloud many issues. It appears, for example, that the common perception of melanocyte function is still biased by the traditional concept of a pigment producing cell. In fact, in addition to melanin, epidermal melanocytes are known to produce and excrete a number of melanin‐related metabolites, such as DHI and DHICA, which appear to play a critical role in protection of epidermal tissues against toxic oxygen radical species as well as in inflammatory and immune reactions.Another major gap concerns the pheomelanin pigmentary system. This has traditionally been a neglected area of research in spite of compelling evidence for the abnormal susceptibility of red heads to sun damage and skin cancer. An increased attention to the peculiar biological and biochemical features of the pheomelanin forming cells will expectedly open new vistas on the UV susceptibility trait and the etiology of melanoma.
The Role of Alpha‐MSH, Its Agonists, and C‐AMP in In Vitro Avian Melanocytes
Authors: BOWERS ROGER R. , BIBOSO ARCADIO , CHAVEZ OFELIA 
Published: July 2006

Little is known about the effect of alpha‐MSH and other melanogenic stimulators on avian melanocytes. Tissue cultures of Barred Plymouth Rock regenerating feather melanocytes were established and the culture medium contained selected concentrations of alpha‐MSH and other melanogenic stimulators in Ham's F‐10 medium supplemented with antibiotics and 10% new born calf serum. Cultures were maintained at 37°C in 95% air/5% CO2.No increase in melanogenesis over control levels due to the addition of 10‐5 M Forskolin, 10‐4 M IBMX, 10‐3 M c‐GMP, and 10‐3 M db‐c‐AMP was observed in the cultures on days 5 and 7. However, 2.5 (optimum), 5, and 10 μg/ml alpha‐MSH and 10‐3 M 8‐bromo‐c‐AMP significantly increased melanogenesis over control levels on days 5 and 7. The stimulation of melanogenesis was detectable by a significantly increased number of melanocytes containing numerous stage IV melanosomes. No increase in melanocyte cell number was observed in any of the experimental cultures. The addition of 1, 2 (optimum), or 3 mM calcium did enhance the increased pigmentation effect of 2.5 μg/ml alpha‐MSH.Two very convincing experiments showed that c‐AMP was the second messenger for alpha‐MSH in these birds. First, the c‐AMP inhibitor, 10‐3 M Rp‐c‐AMPS, completely inhibited the stimulatory effect of alpha‐MSH in these in vitro melanocytes. Second, direct measurements of c‐AMP levels in feather tissue showed a significant increase in c‐AMP levels 10 min after alpha‐MSH treatment. Controls received no alpha‐MSH.The results showed that these avian melanocytes have alpha‐MSH receptors and were able to respond to the hormone. C‐AMP was the second messenger in this system. Apparently db‐c‐AMP was not able to enter these mature, highly‐differentiated cells and c‐AMP agonists, Forskolin and IBMX, were also either unable to enter these older cells or if they did enter the cells, were unable to stimulate c‐AMP production. Evidently the more lipophilic 8‐bromo‐c‐AMP was able to enter these cells and stimulate melanogenesis.
Pigmented Human Skin Equivalent: New Method of Reconstitution by Grafting an Epithelial Sheet Onto a Non‐Contractile Dermal Equivalent
Authors: NAKAZAWA KEIKO , NAKAZAWA HISAYOSHI , SAHUC FLORENT , LEPAVEC ANNIE , COLLOMBEL CHRISTIAN , DAMOUR ODILE 
Published: July 2006

We have established a new protocol for reconstituting a pigmented human skin equivalent (PSE) and have evaluated its functional responses to environmental stimulus, UVB. The PSE is reconstituted by grafting an epithelial sheet consisting of keratinocytes and melanocytes onto a porous non‐contractile dermal equivalent populated with mitotically and metabolically active fibroblasts. i) The PSE has a multilayered, well‐differentiated epidermis with cuboidal basal cells and highly organised dermis with newly synthesised extracellular matrix components. ii) Ki67‐positive proliferating keratinocytes (18.1 ± 7.4%) were detected on the basal layer of the epidermis. iii) Melanocytes located exclusively within the basal layer were detected by monoclonal antibody against tyrosinase‐related protein (TRP‐1). iv) After exposure to UVB (100 mJ/cm2 per day) for 7 consecutive days, the intensity of TRP‐1 staining was increased in the PSE, showing their functional state, whereas the number of melanocytes was not changed.This non‐contractile and functioning new PSE is potentially useful as a model for studying the role of melanocyte‐keratinocyte‐fibroblast interactions in photoprotection of the skin in more complex cutaneous microenvironment than monolayer culture, and for developing in vitro disease models and therapeutic protocols with genetically altered cells both in epidermis and dermis.
An Ex Vivo Study of Congenital Pigmented Nevi in Epidermal Reconstructs
Authors: BESSOU‐TOUYA SANDRINE , MORICHON FABIENNE , SURLÈVE‐BAZEILLE JEAN‐ETIENNE , BIOULAC‐SAGE PAULETTE , PAIN CATHERINE , TAÏEB ALAIN 
Published: July 2006

In order to study morphologic and functional characteristics of pigment cells in congenital pigmented nevi, autologous or heterologous reconstructs have been made using normal keratinocytes and nevus cells from the dermal‐epidermal junction or from the dermis. All these cells, keratinocytes and nevus cells, were used as cell suspensions immediately after dissociation from the tissues or after subsequent brief cultivation in a serum‐free medium. Reconstructed epidermis were cultured for 15 days at the air‐liquid interface with or without ultraviolet (UV) B exposure. The reconstructs were examined macroscopically (formation of hyperpigmented macules), histologically (pigment cell nesting) and ultrastructurally (pigment structure and transfer).Typical nesting of nevus cells was observed in the dermal‐epidermal junction or in the superficial dermis associated with macroscopically detectable small pigmented macules. UVB exposure induced an upward migration of nevus cells in the suprabasal layers of the epidermis.This tissue model can be considered as an excellent system for the ex vivo reproduction of pigmented nevi and as an assay of the sensitivity of nevus cells towards UVB irradiation.
Dental Status in the Elderly: A Review of the Swedish Literature1
Authors: Nordenram Gunilla , Böhlin Erling 
Published: July 2006

SUMMARY1. Elderly persons living in their own homes have over the past 20 years tended to retain an increased number of natural teeth. This tendency is confirmed especially in the ongoing studies by Tor Österberg, nr 12 and 13. These studies indicate a decreasing edentulous part of the 70‐year old cohorts from 1971, 1976 and 1981.2. Elderly persons dependent on institutional care are edentulous in as high degree today as 20 years ago. According to this criterion, therefore, their dental health has not improved.3. Dentures worn by elderly persons frequently are defective in fit and function. For the general wellbeing and health in later life, mastication of a well‐balanced diet and lack of discomfort from denture‐bearing mucosal surfaces are important. Information in this respect and measures to improve masticating function are greatly needed among persons in the higher age groups, whether living at home or in institutional care.4. Caries activity is increasing among elderly persons.5. Periodontitis (loosening of the teeth) is very frequently found in elderly persons.6. Oral hygiene requires improvement.7. Among the elderly, living in their own homes or in institutions, the need for odontologic care is objectively great, but the demands currently made are remarkably low.8. Of the aged in institutional care, about 75 per cent are suitable for measures of oral care.A change in dental health seems to be slowly taking place among the elderly, in that increasing numbers keep more of their own teeth longer in life. The demands made by the high age groups on the odontologic services, though increasing, are still very low relative to the objective and consequently great accumulated needs. This contrast is especially pronounced among geriatric patients in institutions.An aggressive, searching approach to both restorative and preventive oral care in the higher age groups is of pressing importance if optimum conditions for eating and chewing late in life are to be achieved. For timely counteraction of the tendency to a more passive attitude t o dental care that commonly accompanies rising age, information on these matters should be energetically disseminated among persons due for retirement or new‐l y retired.
Regulation of Legal Service Plans
Authors: Pfennigstorf Werner , Kimball Spencer L. 
Published: July 2006

Legal service plans, widely regarded as the key to better availability of legal services for Americans of moderate incomes, have not yet found their proper place in the legal and regulatory framework. Uncertainty about regulatory requirements threatens to hold up progress. This article presents the results of a three-year study of alternative approaches to the regulation of legal service plans. It analyzes the inherent dangers of various types of plans and suggests ways of providing adequate protection for consumers while preserving maximum freedom and flexibility for experimentation with new delivery systems. Specifically, the authors recommend the existing and time-tested system of insurance regulation as the most suitable model for plans having a significant risk-carrying element, subject, however, to appropriate amendments to accommodate the unique features of some kinds of plans, such as bar-sponsored nonprofit organizations, and with special procedures to ensure close cooperation with disciplinary authorities as far as the conduct of lawyers is concerned.A volume containing all the principal and background papers prepared in this study, including a modified version of the present article, will be published by the American Bar Foundation as Legal Service Plans: Approaches to Regulation.
Lustration and Truth Claims: Unfinished Revolutions in Central Europe
Authors: Łoś Maria 
Published: July 2006

This article focuses on discourses conducted in Central/East European countries, and Poland in particular, with respect to the issue of participation of former secret agents in the new power structures. It exposes the reader to the range, style, content, and variety of lustration discourses. It explores their relevance for the ongoing power struggle, paying special attention to their focus on and contribution to the processes of construction and control of truth about the past.
Given that the procedural and legal-institutional issues occupy a marginal place in the debate, it is inferred that the main sources of discord are more ideological and political than legal. The two main strains within the global lustration discourse are identified as: (1) dystopian discourses that paint a frightful picture of a lustrated society and imply that the upheaval of lustration would ruin the chance for democratic evolution, and (2) affirmative discourses that assert the need for lustration and portray the refusal to implement it as a barrier to successful transition to democracy. The article elaborates on assumptions and beliefs, which tend to link the dystopian opposition to lustration with the left-wing political affiliation or self-identification and the affirmative discourse with the right-wing orientation.
Reproducing a Fit Citizenry: Dependency, Eugenics, and the Law of Marriage in the United States, 1860–1920
Authors: Lindsay Matthew J. 
Published: July 2006

Between the Gilded Age and the Progressive Era, American state legislatures enacted a series of new laws that delineated a class of citizens who were deemed ineligible to participate in the institution of marriage. Scholars have characterized this development as evidence that lawmakers had lost faith in a laissez-faire approach to nuptial governance, and thus transformed marriage into an object of public regulation. This essay argues that behind the ostensible nuptial privatism of the mid-nineteenth century lay a self-conscious policy of judicial governance. Judges invoked the language of nuptial privacy and the common law of contract strategically to advance their vision of moral and economic discipline. The new marital prohibitions thus represented, the essay argues, not the expansion of the state's police power into the previously private realm of domestic relations, but rather a critical transformation in how nuptial reformers and lawmakers understood the relationship between marriage and the well-being of the polity.
Fueled by growing concerns about pauperism, the racial character of the urban proletariat, and the collapse of the economically independent single-male-breadwinner household, the changing form of nuptial governance signaled a thoroughgoing intellectual and strategic reorientation from an understanding of marriage as forming economically and morally viable households—the fundamental units of society—to an understanding of marriage as a largely procreative institution, as the literal source of the citizenry. This reconceptualization of marriage underwrote a strategy of nuptial governance that mobilized marriage as a strategy in the state's regulation of social reproduction.