bluuebunny/crossref_metadata_2025_split huggingface dataset:
From the Crest to the Periphery: Control of Pigment Cell Migration and Lineage Segregation
Authors: ERICKSON CAROL A. 
Published: July 2006

Pigment cells are one of many cell types derived from the neural crest. This review focuses on the mechanisms that control the timing and pathways of migration of pigment cells into the epidermis and determinants that control the differentiation of pigment cells. Several factors may control the timing and pattern of pigment cell migration in the dorsolateral space including the loss of inhibitory molecules in the pathway, the appearance of chemotactic molecules emanating from the dispersing dermatome, and the differentiation of pigment cells, which may be the only neural crest derivative capable of utilizing the substratum found in the dorsolateral pathControl of pigment cell differentiation remains controversial. A working model presented in this review suggests that multipotent neural crest cells that disperse ventrally upon separation from the neural tube preserve neurogenic ability and lose melanogenic ability, whereas those cells that are arrested at the entrance to the dorsolateral path lose neurogenic ability so that the population becomes primarily melanogenic. During the time that the latter population is arrested in migration it is speculated that the neural crest cells are exposed to an environment comprised of specific extracellular matrix molecules and/or growth factors that enhance pigment cell differentiation.
Calcium Plays a Complex Role in the Regulation of Melanogenesis in Murine B16 Melanoma Cells
Authors: BUFFEY JAYNE A. , EDGECOMBE MANDY , NEIL SHEILA MAC 
Published: July 2006

To learn more of the role of calcium in the regulation of melanogenesis, we have used direct manipulation of medium calcium and pharmacological modulation of intracellular calcium to examine the consequences on unstimulated and cyclic AMP elevated tyrosinase activity and melanin synthesis and distribution in B16 melanoma cells.In unstimulated cells, calcium is clearly inhibitory to tyrosinase activity. However, in cells stimulated with cAMP‐elevating agents the requirement for extracellular calcium was changed such that cells required a minimum of 0.4–0.6 mmol medium calcium for maximum tyrosinase response to these agents.Paradoxically, pharmacologically increasing intracellular calcium in cAMP‐stimulated cells with ionophore inhibited tyrosinase activity, and the calcium‐lowering agent TMB8 and the calcium channel blocker verapamil both stimulated tyrosinase activity.When melanin synthesis was measured in cAMP‐stimulated cells, TMB8 was found to significantly increase the sensitivity and the maximum melanogenic response to α‐MSH, suggesting the presence of at least one level of endogenous calcium inhibitory control operative in these cells. In addition, TMB8 changed the distribution of melanin between the cell and the medium such that, in the presence of α‐MSH and TMB8, significantly more melanin was secreted into the medium.These data suggest that calcium is required for several steps in melanogenesis, having an apparently inhibitory effect on pre‐tyrosinase activity in unstimulated cells, but also showing evidence of a positive role in cyclic AMP‐stimulated tyrosinase activity, as well as a further possible inhibitory role in melanin movement or secretion.
Modulation of Normal Human Melanocyte Dendricity by Growth‐Promoting Agents
Authors: NAKAZAWA KEIKO , DAMOUR ODILE , COLLOMBEL CHRISTIAN 
Published: July 2006

Dendrite formation and extension, which comprise a characteristic morphology of human normal melanocytes in the skin, represent one of the functional activities of melanocytes, the ability to transfer melanosomes into neighboring keratinocytes. However, the morphology of the melanocyte in vitro is usually quite different from that observed in vivo. it is probably due to the hyperproliferative condition of the melanocytes in culture. No studies have ever compared the effects of a single factor on both dendricity and proliferation at the same time. Therefore, we have compared the effects of six growth‐promoting agents commonly used for melanocyte cultures on dendrite formation and proliferation.The addition of agents that increase the intracellular levels of cyclic adenosine monophosphate (cAMP)—dibutyryl cyclic adenosine monophosphate (db cAMP; 1 mM) or isobutylmethyl xanthine (IBMX; 0.1 mM)—had a strong effect on dendrite formation and a negative effect on proliferation. This was especially true with db cAMP. In the presence of 2% or 5% of heat‐inactivated fetal bovine serum (FBS), dendrite formation was significantly increased as was proliferation. The number of dendrites was decreased in the culture with 12‐o‐tetradecanoylphorbol‐13‐acetate (TPA), but cell growth was slightly increased. With human recombinant basic fibroblast growth factor (bFGF) (0.5, 1.0 ng/ml) in the presence of bovine pituitary extract (BPE) (60 μg/ml), cell growth was increased. With 2 ng/ml of bFGF, however, a strong inhibitory effect on proliferation was observed. However, dendrite formation was constant at all concentrations of bFGF tested (0.5, 1.0 or 2.0 ng/ml) with BPE (30 or 60 μg/ml).In this study, we have demonstrated that dendrite formation was suppressed by the reagents that stimulate melanocyte proliferation, and vice versa, with the only exception being heat‐inactivated FBS. Both dendrite formation and proliferation were induced by the heat‐inactivated FBS. This approach is crucial to the development of an adequate culture system for proliferation and/or dendrite formation of normal human melanocytes. It is necessary to keep these aspects in mind as we further investigate the biology of melanocytes, especially the cell‐to‐cell interactions between melanocytes and keratinocytes, involved in melanogenesis and melanin pigmentation in vivo. This study also provides practical and important information for a future reconstitutive skin system composed of melanocytes, keratinocytes, and fibroblasts in a single culture medium.
Molecular and Biological Control of Melanogenesis Through Tyrosinase Genes and Intrinsic and Extrinsic Regulatory Factors
Authors: MISHIMA YUTAKA 
Published: July 2006

Non‐premelanosomal melanogenic compartments and their melanogenesis‐controlling functions have been further elucidated. In addition to enzymatic and nonenzymatic controlling factors, we have also been exploring the role of melanogenesis‐related genes. Naturally occurring intrinsic melanogenic inhibitors, MW <6,000(α), 6,000‐30,000(β), and >30,000(γ), having different modes of action, have been identified within melanoma cells. One of the α‐type melanogenic inhibitors of isolated tyrosinase(Ty) nonsuppressive types, later identified as lactic acid, induces depigmentation of cultured B‐16 cells by the reduction in Ty activity level due to the inhibition of its mRNA expression.The transfection of Ty cDNA, rather than nuclear DNA‐binding master regulatory gene, can induce, within both Ty‐deficient amelanotic melanoma cells and also within fibroblasts, melanin polymer formation. This multisequential step occurs not only by the induction of Ty synthesis but also by the induction of other regulatory proteins and factors such as dopachrome tautomerase, DHICA‐oxidase, catalase, Ty‐glycosylation in GERL, and Ty‐transfer by coated vesicles to newly assigned melanogenic vacuoles in which not only eumelanin but also rather pronounced concomitant pheomelanin formation is seen.Investigation of melanin‐producing vacuoles in transfected fibroblasts and reexamination of premelanosomes in pigment cells has revealed the following: 1) Melanosomes possess phagocytic ability; 2) melanosomes receive tyrosinase and hydrolases via coated vesicles from GERL; 3) melanosomes possess lysosome‐associated membrane protein 1 (LAMP‐1); 4) amelanotic melanoma contains lysosome‐like vacuoles with myelin figures that acquire typical premelanosome structure after Ty‐cDNA transfection. Thus it is proposed that melanosomes are specialized lysosomes in pigment cells.Coated vesicles synthesize melanin monomers such as DHICA and some DHI, and have a monomer‐stabilizing system. Thus they can transport them in intact form with Ty to premelanosomes, which subsequently polymerize these monomers by the action of DHICA‐oxidase and T3‐Ty.Selective eradication and diagnosis of malignant melanoma using our 10B‐dopa analogue has been successfully performed in human melanoma patients using combined thermal neutron irradiation for the former and positron emission CT for the latter.
Formation of the Dermal Chromatophore Unit (DCU) in the Tree Frog Hyla Arborea
Authors: YASUTOMI MASUMI , YAMADA SHINPEI 
Published: July 2006

In the tadpole of the tree frog Hyla arborea, the color of the dorsal skin was dark brown. Dermal melanophores, xanthophores, and iridophores were scattered randomly under the subepidermal collagen layer (SCL). After metamorphosis, the dorsal color of the animal changed to green and the animal acquired the ability of dramatic color change, demonstrating that the dermal chromatophore unit (DCU) was formed at metamorphosis. Fibroblasts invaded the SCL and divided it into two parts: the stratum spongiosum (SS) and the stratum compactum (SC). The activity of collagenase increased at metamorphosis. The fibroblasts appeared to dissolve the collagen matrix as they invaded the SCL. Then, three types of chromatophores migrated through the SCL and the DCU was formed in the SS. The mechanism how the three types of chromatophores were organized into a DCU is uncertain, but different migration rates of the three chromatophore types may be a factor that determines the position of the chromatophores in the DCU.Almost an equal number of each chromatophore type is necessary to form the DCUs. However, the number of dermal melanophores in the tadpoles was less than the number of xanthophores and iridophores. It was suggested that epidermal melanophores migrated to the dermis at metamorphosis and developed into dermal melanophores. This change may account for smaller number of dermal melanophores available to form the DCUs.
Civil Cases and Society: Process and Order in the Civil Justice System
Authors: Engel David M. , Steele Eric H. 
Published: July 2006

It is not an exaggeration to say that we live in an era preoccupied with the problems and challenges of obtaining justice in civil cases. Concerns expressed about the civil justice system range from warnings that civil court dockets are clogged by disputants too litigious for their own good to complaints that the legal system is used too rarely in civil cases.The authors approach their analysis with a sense that this subject area is in need of more and better theory. It is an unfortunate fact that discussions of civil justice—and suggestions for reform—have been marked by contradiction and confusion and have been engrossed with small matters that tend to obscure from view the system as a whole.The first part of this essay focuses on what the civil justice system is and does. It presents a five-stage model of civil case processing and examines relationships between this model and the criminal justice system. The second part of the essay considers this model in a broader context. Here the authors examine two paradigms of civil case processing and their implications for the implementation of legal norms and the pursuit of justice in society.
Foucault's Expulsion of Law: Toward a Retrieval
Authors: Hunt Alan 
Published: July 2006

This essay argues that there is an important sense in which Foucault gets law wrong—that the pursuit of Foucault's own objectives had the unintended consequence of inhibiting a fruitful interrogation of the place of law in modernity. His immediate concern was with the emergence of distinctive manifestations of modern power that constitute a new configuration, the disciplinary society. The most distinctive feature of his account of the historical emergence of modernity was his expulsion of law from modernity. This “expulsion of law” is found in his metahistorical thesis that law constituted the primary form of power in the premodern era, and that although law lingers on in the doctrine of sovereignty, it is supplanted by discipline and government as the key embodiments of modernity.
The essay proposes an exercise in retrieval, a “retrieval of law,” to recuperate much in Foucault's thought that is suggestive for our understanding of law's role in the constitution of modern society. It rejects Foucault's opposition of law and discipline and makes use of his treatment of government and governmentality toward that end. It argues that a more adequate grasp of the place of law in modernity can be developed by establishing that law and discipline are complementary and characteristically combine in the ubiquitous presence of regulation as the mark of the modem condition.
Liberty without Equality: The Property-Rights Connection in a “Negative Citizenship” Regime
Authors: Abraham David 
Published: July 2006

Why, in comparison with other liberal capitalist democracies, is the social welfare state so poorly anchored in American law and public discourse? Surely American political and social history have contributed much to the weakness of our “social state.” But law, too, has played a significant material, as well as ideological, role and has provided the terrain for much of our social development. This essay explores the particular contribution of the property-liberty nexus to the stunted development of positive liberty and social citizenship in the United States. It traces this connection from the natural rights and bourgeois Founders through several key conjunctures in American history, including Reconstruction, the New Deal, and the civil rights periods and compares some of the results with developments in Germany and the aspirations of American progressives.
The essay contends that left and right alike have operated within a highly resilient and constricting framework that has made progress in the area of social citizenship both awkward and fragile. Although some possibilities for forward movement have always existed and still remain, the prospects for positive-liberty social-state law are not abundant: The master's house is not about to be taken down with his own tools.
Ambiguous Responsibilities: Law and Conflicting Expert Testimony on the Abused Woman Who Shot Her Sleeping Husband
Authors: Römkens Renée 
Published: July 2006

Truth is a thing of this world: It is produced only by virtue of multiple forms of constraint.—Michel Foucault 1977Law is less than ever the exclusive domain of legal experts. However, scientific experts often disagree on what constitutes scientifically reliable and valid knowledge. In sociolegal debates about whether luw or science is ultimately decisive in this decision-making process, the focus is primarily on the competition between the powers of law or science.Using a detailed analysis of a Dutch appellate case of a battered woman who killed her husband, I will argue that the legal decision on conflicting expert testimonies in the field of forensic psychiatry and psychology resulted from a much more complex intersection of power, struggles between law and science, but also among scientists. Various aspects of expert testimony, unrelated to the scientific validity of the knowledge, profoundly influence how specialized knowledge from experts will or will not be validated by the law. Such aspects include status differences between institutionalized and less-established disciplines, and gender bias. While exercising its ultimate obligation and power to judge in an arena of disputing experts, law in this case rhetorically constructs an image of rationality, Objectivity, and neutrality of its own decision-making process. In so doing, it masks the underlying umbiguities, its arbitrariness, and its gender bias in the process of inclusion or exclusion of expert knowledge.
Realism and Anti‐Realism in Kant's Second Critique
Authors: Kain Patrick 
Published: July 2006

AbstractThis article surveys recent work on Kant's Critique of Practical Reason, with a particular focus on his doctrine of the fact of reason and his doctrine of the practical postulates, assessing the implications of such work for the debate about realism and antirealism in Kant's moral philosophy. Section 1 briefly surveys some salient considerations raised by Kant's first Critique and Groundwork. In section 2, I survey recent work on the Kant's doctrine of the fact of reason and argue that it does not support an anti‐realist interpretation of Kant's ethics. In section 3, I argue that recent work on Kant's doctrine of the practical postulates does not support an anti‐realist interpretation of Kant's ethics.
Association of laboratory data and death within one month in cats with chronic renal failure
Authors: Kuwahara Y. , Ohba Y. , Kitoh K. , Kuwahara N. , Kitagawa H. 
Published: July 2006

Objectives: To retrospectively compare the data taken at the first visit of 34 cats with chronic renal failure surviving more than one month (surviving group) and 16 cats dying within one month (non‐surviving group). Methods: Records were collected on cats with chronic renal failure presented to a private veterinary practice in Nagoya, Japan, from March 1996 to March 2005. All cats with chronic renal failure diagnosed on the basis of case histories, clinical signs (such as, lethargy, anorexia, loss of bodyweight and vomiting) and a high plasma creatinine (>180 μmol/l) were included in the study. Results: Plasma creatinine, urea nitrogen, inorganic phosphate, packed cell volume and urine protein/creatinine ratio were significantly different between cats of the surviving and non‐surviving groups. In the surviving group, survival statuses were recorded, and laboratory data was obtained within one month before death in 13 cats. In the 13 cats, plasma creatinine, packed cell volume and urine protein/creatinine ratio showed significant differences between the data taken within one month before death and that taken at first visit, and only urine protein/creatinine ratio exhibited a consistent alteration (increase) in relation to first visit data. Clinical Significance: These results indicated that plasma creatinine, urea nitrogen, inorganic phosphate, packed cell volume and urine protein/creatinine ratio were associated with death within one month and urine protein/creatinine ratio was most likely to be associated with mortality in cats with chronic renal failure.
Rhinovirus Replication in Human Macrophages Induces NF-κB-Dependent Tumor Necrosis Factor Alpha Production
Authors: Laza-Stanca Vasile , Stanciu Luminita A. , Message Simon D. , Edwards Michael R. , Gern James E. , Johnston Sebastian L. 
Published: July 2006

ABSTRACTRhinoviruses (RV) are the major cause of acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD). Rhinoviruses have been shown to activate macrophages, but rhinovirus replication in macrophages has not been reported. Tumor necrosis factor alpha (TNF-α) is implicated in the pathogenesis of acute exacerbations, but its cellular source and mechanisms of induction by virus infection are unclear. We hypothesized that rhinovirus replication in human macrophages causes activation and nuclear translocation of NF-κB, leading to TNF-α production. Using macrophages derived from the human monocytic cell line THP-1 and from primary human monocytes, we demonstrated that rhinovirus replication was productive in THP-1 macrophages, leading to release of infectious virus into supernatants, but was limited in monocyte-derived macrophages, likely due to type I interferon production, which was robust in monocyte-derived but deficient in THP-1-derived macrophages. Similar to bronchial epithelial cells, only small numbers of cells supported complete virus replication. We demonstrated RV-induced activation of NF-κB and colocalization of p65/NF-κB nuclear translocation with virus replication in both macrophage types. The infection induced TNF-α release in a time- and dose-dependent, RV serotype- and receptor-independent manner and was largely (THP-1 derived) or completely (monocyte derived) dependent upon virus replication. Finally, we established the requirement for NF-κB but not p38 mitogen-activated protein kinase in induction of TNF-α. These data suggest RV infection of macrophages may be an important source of proinflammatory cytokines implicated in the pathogenesis of exacerbations of asthma and COPD. They also confirm inhibition of NF-κB as a promising target for development of new therapeutic intervention strategies.
Structure-Function Analysis of Rotavirus NSP2 Octamer by Using a Novel Complementation System
Authors: Taraporewala Zenobia F. , Jiang Xiaofang , Vasquez-Del Carpio Rodrigo , Jayaram Hariharan , Prasad B. V. Venkataram , Patton John T. 
Published: July 2006

ABSTRACTViral inclusion bodies, or viroplasms, that form in rotavirus-infected cells direct replication and packaging of the segmented double-stranded RNA (dsRNA) genome. NSP2, one of two rotavirus proteins needed for viroplasm assembly, possesses NTPase, RNA-binding, and helix-unwinding activities. NSP2 of the rotavirus group causing endemic infantile diarrhea (group A) was shown to self-assemble into large doughnut-shaped octamers with circumferential grooves and deep clefts containing nucleotide-binding histidine triad (HIT)-like motifs. Here, we demonstrate that NSP2 of group C rotavirus, a group that fails to reassort with group A viruses, retains the unique architecture of the group A octamer but differs in surface charge distribution. By using an NSP2-dependent complementation system, we show that the HIT-dependent NTPase activity of NSP2 is necessary for dsRNA synthesis, but not for viroplasm formation. The complementation system also showed that despite the retention of the octamer structure and the HIT-like fold, group C NSP2 failed to rescue replication and viroplasm formation in NSP2-deficient cells infected with group A rotavirus. The distinct differences in the surface charges on the Bristol and SA11 NSP2 octamers suggest that charge complementarity of the viroplasm-forming proteins guides the specificity of viroplasm formation and, possibly, reassortment restriction between rotavirus groups.
Recombinant Nipah Virus Vaccines Protect Pigs against Challenge
Authors: Weingartl Hana M. , Berhane Yohannes , Caswell Jeff L. , Loosmore Sheena , Audonnet Jean-Christophe , Roth James A. , Czub Markus 
Published: July 2006

ABSTRACTNipah virus (NiV), of the familyParamyxoviridae, was isolated in 1999 in Malaysia from a human fatality in an outbreak of severe human encephalitis, when human infections were linked to transmission of the virus from pigs. Consequently, a swine vaccine able to abolish virus shedding is of veterinary and human health interest. Canarypox virus-based vaccine vectors carrying the gene for NiV glycoprotein (ALVAC-G) or the fusion protein (ALVAC-F) were used to intramuscularly immunize four pigs per group, either with 108PFU each or in combination. Pigs were boosted 14 days postvaccination and challenged with 2.5 × 105PFU of NiV two weeks later. The combined ALVAC-F/G vaccine induced the highest levels of neutralization antibodies (2,560); despite the low neutralizing antibody levels in the F vaccinees (160), all vaccinated animals appeared to be protected against challenge. Virus was not isolated from the tissues of any of the vaccinated pigs postchallenge, and a real-time reverse transcription (RT)-PCR assay detected only small amounts of viral RNA in several samples. In challenge control pigs, virus was isolated from a number of tissues (104.4PFU/g) or detected by real-time RT-PCR. Vaccination of the ALVAC-F/G vaccinees appeared to stimulate both type 1 and type 2 cytokine responses. Histopathological findings indicated that there was no enhancement of lesions in the vaccinees. No virus shedding was detected in vaccinated animals, in contrast to challenge control pigs, from which virus was isolated from the throat and nose (102.9PFU/ml). Based on the data presented, the combined ALVAC-F/G vaccine appears to be a very promising vaccine candidate for swine.