bluuebunny/crossref_metadata_2025 huggingface dataset:
The application of grounded theory and symbolic interactionism
Authors: Jeon Yun‐Hee
Published: September 2004

This paper describes the methodological and theoretical context and underpinnings of a study that examined community psychiatric nurses’ work with family caregivers of older people with depression. The study used grounded theory research methods, with its theoretical foundations drawn from symbolic interactionism. The aims of the study were to describe and conceptualize the processes involved when community nurses work and interact with family caregivers and to develop an explanatory theory of these processes. This paper begins with an explanation of the rationale for using grounded theory as the method of choice, followed by a discussion of the theoretical underpinnings of the study, including a brief summary of the nature and origins of symbolic interactionism. Key premises of symbolic interactionism regarded as central to the study are outlined and an analytical overview of the grounded theory method is provided. The paper concludes with a commentary on some of the issues and debates in the use of grounded theory in nursing research. The main purpose of this paper is to provide a methodical and critical review of symbolic interactionism and grounded theory that can help readers, particularly those who are intending to use grounded theory, better understand the processes involved in applying this method to their research.
Testing of an audit instrument for the nursing discharge note in the patient record
Authors: Larson Jenny , Björvell Catrin , Billing Ewa , Wredling Regina
Published: September 2004

Objectives.  This study validates and tests the reliability of an audit instrument constructed to evaluate the content of nursing discharge notes.

Design.  Instrument validation and reliability testing.

Main outcome measures.  Factor analysis identifying structure through data summarization of the instrument, association between scores in test–retest, and interrater reliability between auditors.

Results.  Validity: Three factors emerged in the factor analysis: ‘General information’, ‘Planning’, and ‘Assessment’, accounting for 76% of the variance regarding the quantitative aspect and 79% of the variance regarding the qualitative aspect, confirming the distinctiveness. Reliability: The Spearman rank‐order correlation coefficient calculated per item in the test–retest ranged from 0.72 to 1.0 (p = 0.01). The correlation coefficient for the total score was 0.98 (p = 0.01). There were no differences in item scores between the test and retest in 93% of the comparisons (n = 486). Between the two auditors, the Spearman rank‐order correlation coefficient in each item ranged from 0.83 to 1.00 (p = 0.01) and weighted kappa values from 0.70 to 1.00 with the exception of one item in both calculations. The correlation coefficient for the auditors’ total score was 0.99 (p = 0.01). The Student's paired t‐test comparing the two auditors’ mean values in five different parts of the instrument showed no significant differences in score.

Conclusion.  The Cat‐ch‐Ing EPI instrument shows a high reliability and validity as an audit instrument to evaluate the content of nursing discharge notes.
The effect of a VIPS implementation programme on nurses’ knowledge and attitudes towards documentation
Authors: Darmer Mette Rosendal , Ankersen Lena , Nielsen Bettina Geissler , Landberger Gitte , Lippert Elisabeth , Egerod Ingrid
Published: September 2004

The Copenhagen University Hospital decided to adhere to the standards of the Joint Commission of International Accreditation in 2000. These standards require systematic assessment of patient care needs and include the use of written nursing care plans. In order to meet these standards, the hospital management decided to introduce the Swedish VIPS model, which is a model designed to structure nursing documentation (VIPS is an acronym for well‐being, integrity, prevention and safety). The present study explores the nurses’ knowledge and attitudes towards documentation and addresses the research questions: (a) what are the nurses’ attitudes towards documentation of nursing care? and (b) do nurses have sufficient knowledge of the documentation system to systematically document their patient assessment and clinical decisions? The research design was prospective, comparative, and quasi‐experimental (nonrandomized), including a study group (n = 72) and a control group (n = 57). A questionnaire was used to compare nurses’ self‐evaluated attitudes towards documentation, and a multiple‐choice test was given in order to assess nurses’ knowledge of the documentation system. The study group participated in a special implementation programme (response rate 82%), while the control group attended the regular 3‐day documentation course at the hospital (response rate 79%). The study showed that the two groups responded similarly, but the nurses in the study group were significantly stronger in their conviction that they had the knowledge to make care plans and that they routinely made them. The study group demonstrated slightly less motivation than the control group, while the two groups shared a positive attitude towards nursing documentation. The study group did consistently better on the knowledge tests. The findings show that the implementation programme had a positive impact on nursing documentation, and that the VIPS model increased the nurses’ understanding of the nursing process.
Patients' voices on satisfaction: unheeded women and maltreated men?
Authors: Foss Christina , Hofoss Dag
Published: September 2004

To capture the differences in female and male patients’ hospital experiences, this article discusses the gendered nature of 699 free‐text comments given in a survey of patient satisfaction at a Norwegian university hospital. The comments were analysed both quantitatively and qualitatively, and the impressions gained through the comments were then to a smaller extent compared with the patients’ multiple choice questionnaire ticking. Female responders added free‐text comments to their multiple‐choice responses more often than male responders did. Male and female patients also drew attention to different aspects of what it was like to be hospitalized, and male and female patients also expressed themselves differently. The voices of the patients were mainly the voices of contextualizing experiences, reflecting differences in male and female patient's experiences and in the meaning the patients attached to their experiences. The rather clear gender differences in our data emphasizes the need for a gender‐sensitive approach in the encounters between staff and patients as well as in the design of patient satisfaction research.
Radical changes in Islamic glass technology: evidence for conservatism and experimentation with new glass recipes from early and middle Islamic Raqqa, Syria*
Authors: Henderson J. , McLoughlin S. D. , McPhail D. S.
Published: September 2004

The chemical analysis of excavated glass fragments from dated archaeological contexts in Raqqa, Syria, has provided a detailed picture of the chemical compositions of artefacts deriving from eighth to ninth and 11th century glassmaking and glassworking activities. Evidence for primary glass production has been found at three excavated sites, of eighth to ninth, 11th and 12th century dates; the first two are discussed here. The 2 km long industrial complex at al‐Raqqa was associated with an urban landscape consisting of two Islamic cities (al‐Raqqa and al‐Rafika) and a series of palace complexes. The glass fused and worked there was presumably for local as well as for regional consumption.

Al‐Raqqa currently appears to have produced the earliest well‐dated production on record in the Middle East of an Islamic high‐magnesia glass based on an alkaline plant ash flux and quartz. An eighth to ninth century late ‘Roman’/Byzantine soda–lime recipe of natron and sand begins to be replaced in the eighth to ninth century by a plant ash – quartz Islamic soda–lime composition. By the 11th century, this process was nearly complete. The early Islamic natron glass compositional group from al‐Raqqa shows very little spread in values, indicating a repeatedly well‐controlled process with the use of chemically homogeneous raw materials.

A compositionally more diffuse range of eighth to ninth century plant ash glass compositions have been identified. One is not only distinct from established groups of plant ash and natron glasses, but is believed to be the result of experimentation with new raw material combinations. Compositional analysis of primary production waste including furnace glass (raw glass adhering to furnace brick) shows that contemporary glasses of three distinct plant ash types based on various combinations of plant ash, quartz and sand were being made in al‐Raqqa during the late eighth to ninth centuries. This is a uniquely wide compositional range from an ancient glass production site, offering new insights into the complexity of Islamic glass technology at a time of change and innovation.
Risk factors for oral cancer in newly diagnosed patients aged 45 years and younger: a case–control study in Southern England
Authors: Llewellyn C. D. , Johnson N. W. , Warnakulasuriya K. A. A. S.
Published: September 2004

Background:  This case–control study aimed to identify the risk factors for oral cancer in patients aged 45 years and under.

Methods:  Patients were recruited over a 3‐year period between 1999 and 2001 from 14 hospitals in the southeast of England, UK.

Results:  Fifty‐three (80%) newly diagnosed patients with squamous cell carcinoma (SCC) of the oral cavity participated. The mean age of cases at diagnosis was 38.5 years (SD = 7.0) and 53% were male. Patients were interviewed about main risk factors of tobacco, alcohol, cannabis and their consumption of fresh fruit and vegetables in the past. Ninety‐one matched control patients were also recruited. Odds ratios (ORs) and 95% confidence intervals (CI) were obtained from adjusted conditional logistic analyses. Significantly elevated ORs were evidenced amongst males who had started to smoke under the age of 16 years (OR = 14.3; 95% CI: 1.1–178.8). A significant reduction in risk was also shown for ex‐smokers (OR = 0.2; 95% CI: 0.5–0.8). Consumption of alcohol in excess of recommended amounts also produced an eightfold risk in males (OR = 8.1; 95% CI: 1.6–40.1) and over a fourfold risk of oral cancer from the consumption of excessive amounts of alcohol and having ever smoked (OR = 4.4; 95% CI: 1.1–17.7).

Conclusion:  The study shows that the traditional behavioural risk factors are present in younger people diagnosed with oral cancer. The relatively short duration of exposure and the substantial number of cases without any known risk factors, particularly amongst females, however, suggest that factors other than tobacco and alcohol may also be implicated in the development of oral cancer in a proportion of these younger patients.
The involvement of Kv3.4 voltage‐gated potassium channel in the growth of an oral squamous cell carcinoma cell line
Authors: Lew Tien‐Shen , Chang Che‐Shoa , Fang Kung‐Ping , Chen Chian‐Yi , Chen Cheng‐Hsiung , Lin Shu‐Chun
Published: September 2004

Background:  In our previous study, an A‐type voltage‐gated K+ channel, Kv3.4, was found more frequently expressed in oral squamous cell carcinoma (OSCC) when compared with non‐cancerous matched oral tissue. An OSCC cell line, OECM‐1, was found to have moderate level of Kv3.4 expression.

Methods:  To further elucidate the roles of Kv3.4 for the involvement of neoplastic process, we amplified Kv3.4 coding sequence by reverse transcriptase polymerase chain reaction (RT‐PCR), constructed an expression vector carrying this sequence and then stably transfected into OECM‐1 OSCC cells.

Results:  We demonstrated the integration and constitutive expression of Kv3.4 in the cell. A unique A‐type current elicited by such expression in OECM‐1 cells was defined by patch clamp analysis. This current pattern can be reversibly blocked by an A‐type K+ channel blocker 2 mM 4‐aminopyridine (4‐AP). The acquisition of Kv3.4 activity in OECM‐1 cells bestowed growth advantage. However, in 3T3 cell, transfected Kv3.4 caused only limited increase of growth without forming transformation foci.

Conclusion:  The present study established a stable keratinocyte system carrying functional Kv3.4 and increase of growth, by which the anti‐Kv3.4 modalities for potential OSCC control can be further investigated.
Relative frequency of solitary melanocytic lesions of the oral mucosa
Authors: Buchner A. , Merrell P. W. , Carpenter W. M.
Published: September 2004

Background:  Solitary pigmented lesions of melanocytic origin are uncommon in the oral mucosa. These lesions include the oral and labial melanotic macule, oral melanocytic nevus, oral melanoacanthoma, oral melanoma and atypical melanocytic proliferation. The purpose of the study was twofold: to report a large series of solitary melanocytic lesions from one source, and to determine the relative frequency of these lesions.

Methods:  The study was based on a systematic search of the files of the Pacific Oral and Maxillofacial Pathology Laboratory, University of the Pacific, San Francisco for solitary pigmented melanocytic lesions (benign and malignant) accessed during the years 1984–2002.

Results:  Of the 89 430 biopsies accessed during the 19‐year period, 773 (0.83%) cases of solitary pigmented melanocytic lesions in the oral mucosa were identified. Oral and labial melanotic macules were the most common melanocytic lesions comprising 86.1% of the entire group and 0.7% of the total number of accessed biopsies. The vermilion border and gingiva were the most common sites (31.1% and 31.0% respectively). Oral melanocytic nevi comprised 11.8% of the entire melanocytic group and 0.1% of the total number of biopsies. The most common site was the palate (44%). Intramucosal nevi were the most common (64%), followed by compound nevi (16.5%) and common blue nevi (16.5%). Junctional nevi were uncommon (3.0%). Oral melanoacanthoma comprised only 0.9% of the entire melanocytic group and 0.008% of the total number of biopsies. Oral melanoma and atypical melanocytic proliferation were the least common lesions each comprising 0.6% of the entire melanocytic group and 0.006% of the total number of biopsies. The most common site for oral melanoma was the palate (60%).

Conclusion:  The palate was the most common location for both melanocytic nevi and oral melanoma. Thus, all melanocytic lesions in the palate should be viewed with caution and biopsy is recommended to rule out melanoma. Further studies are required to elucidate the entity of oral atypical melanocytic proliferation.
An exploration of point, annual, and lifetime prevalence in characterizing recurrent aphthous stomatitis in USA children and youths
Authors: Shulman Jay D.
Published: September 2004

Background:  This report presents and contrasts the prevalence of recurrent aphthous stomatitis (RAS) in 51 471 children and adolescents from two major studies: the Third National Health and Nutrition Examination Survey, 1988–1994 (NHANES III) and the National Survey of Oral Health in USA Schoolchildren, 1986–1987 (OHSC), large USA studies based on multistage probability sampling.

Methods:  Prevalence proportions, 95% confidence limits and multivariate logistic regression models were constructed for point, 12‐month, and lifetime RAS prevalence using SAS‐callable SUDAAN 8.0.2.

Results:  Examinations were performed on 51 471 children and adolescents. Point prevalence was 1.51% (NHANES III) and 1.21% (OHSC); annual prevalence was 19.84% (NHANES III); and lifetime prevalence was 40.18% (OHSC). Multivariate logistic models showed that being white, having a history of herpes labialis, (NHANES III), and being white and an adolescent (OHSC) were predictors of RAS.

Conclusions:  Caution should be used in interpreting 12‐month and lifetime RAS prevalence based a subject's recall.
Melanocyte Development: With a Message of Encouragement to Young Women Scientists
Authors: Mizoguchi Masako
Published: September 2004

This is a semi‐biographical review describing my research on melanocyte development and related personal experiences. Having been educated and trained as a dermatologist, I have been involved in many clinically‐oriented studies, however, what has always interested me the most is pigment cell biology. Since I started working at St Marianna University in 1991, I have been undertaking research on melanocyte development and relevant growth factors using mice as models. My research in this field was inspired by my collaborations with various scientists, mostly from the field of biology. Many of these specialists I have met at meetings of the Societies of Pigment Cell Research (PCR). Stem cell factor (SCF, Kitl) and endothelin 3 (EDN3) have been identified as indispensable factors regulating the development of melanocytes. Mice mutant at loci encoding those factors (or their receptors) such as Sl/Sl (receptors W/W) and ls/ls (receptors s/s) have white coat colors and white patches, respectively. Our murine neural crest cell (NCC) primary cultures derived from Sl/Sl embryos showed that EDN3 cannot develop melanocyte precursors without SCF and that EDN3 can elicit proliferation and differentiation in the presence of SCF. These results suggest that without EDN3 and the endothelin type B receptor (EDNRB), melanocytes can not fully increase in number, which could well be the cause of the partial white coat color of ls/ls and s/s mice. Contamination with factors derived from the serum in medium or in feeder cells sometimes causes experimental errors, and therefore we established three immortal cell lines derived from NCC in different developmental stages and designated them as NCCmelb4, NCCmelb4M5 and NCCmelan5, all of which can survive without feeder cells. Using these cell lines and NCC primary cultures, we studied the effect of many factors related to melanocyte development. From the results, it has become evident that Vitamin D3 induces EDNRB expression by NCCmelb4 cells. In addition to the International Pigment Cell Conference (IPCC), I have also taken part in many annual meetings of the Japanese Society for Pigment Cell Research (JSPCR), Pan American Society for Pigment Cell Research (PASPCR) and European Society for Pigment Cell Research (ESPCR). Not only have I learned a great deal, I have enjoyed myself immensely at those meetings. Moreover, I have made many good friends there, some of whom I have collaborated with in my research. To conclude, I would like to give my message ‘be ambitious’ to young scientists, especially young women.
Stimulation of Cyclic GMP Efflux in Human Melanocytes by Hypergravity Generated by Centrifugal Acceleration
Authors: Ivanova Krassimira , Zadeh Nahid Hamidi , Block Ingrid , Das Pranab K. , Gerzer Rupert
Published: September 2004

Gravity alteration (micro‐ and hypergravity) is known to influence cell functions. As guanosine 3′,5′‐cyclic monophosphate (cGMP) plays an important role in human melanocyte functions and different guanylyl cyclase isoforms are responsible for cGMP synthesis in human non‐metastatic and metastatic melanoma cells, we investigated the effects of hypergravity on the regulation of cGMP levels in cultured human melanocytes and in melanoma cell lines with different metastatic potentials. Hypergravity was produced by horizontal centrifugal acceleration. Here we report that long‐term application of hypergravity (up to 5 g for 24 h) stimulated cGMP efflux in cultured melanocytes and in non‐metastatic melanoma cells in the presence of 0.1 mM 3‐isobutyl‐1‐methylxanthine (IBMX), a non‐selective phosphodiesterase (PDE) inhibitor. Under these conditions, cAMP synthesis and melanin production were up‐regulated in pigmented melanocytes and non‐metastatic melanoma cells. Hypergravity also stimulated cGMP transport in the presence of 1 μM trequinsin, an inhibitor of cGMP‐binding PDE (PDE5) and of transport by multidrug resistance proteins MRP4/5, whereas 50 μM trequinsin partially inhibited cGMP transport. Transport was further inhibited by probenecid, an inhibitor of endogenous non‐selective transporters as well as of MRP4/5 and by cycloheximide as an inhibitor of de novo protein synthesis. In contrast, hypergravity did not affect cGMP efflux in metastatic melanoma cells, which might be related to an up‐regulated cGMP efflux at 1 g. The results of the present study indicate that hypergravity may stimulate cGMP efflux in melanocytes and in non‐metastatic melanoma cells most probably by an enhanced expression of endogenous transporters and/or MRP4/5. Thus, an altered acceleration vector may induce signaling events in melanocytic cells.
Absence of TRP‐2 in Melanogenic Melanocytes of Human Hair
Authors: Commo Stéphane , Gaillard Olivier , Thibaut Sonia , Bernard Bruno A.
Published: September 2004

Skin and hair colour mostly depend on the activity of melanogenic melanocytes. Numerous proteins involved in melanocyte function have been identified including pMel‐17, Mitf‐M, Sox10, tyrosinase, tyrosinase related proteins‐1 (TRP‐1) and ‐2 (TRP‐2). In the hair, melanogenic activity occurs only during the anagen phase of the hair cycle. In order to evaluate the implications of some known melanogenic proteins in human hair pigmentation, we performed immunohistochemical studies to reveal the expression of pMel‐17, Mitf‐M, tyrosinase, TRP‐1 and TRP‐2 in active bulb melanocytes of eumelanic brown and black anagen hairs of different ethnic origins, e.g. brown Caucasian, black Asian and African hairs. The labelling was compared with that observed in Caucasian and African scalp epidermis (interfollicular epidermis) melanocytes. We found that while pMel‐17, TRP‐1 and TRP‐2 were expressed in epidermal melanocytes irrespective of ethnic origin and melanin content of the scalp epidermis, Mitf‐M and tyrosinase expression were clearly evidenced only in pigmented epidermis, e.g. African scalps. Regarding human hair, pMel‐17, Mitf‐M, tyrosinase and TRP‐1 were detected in a similar manner in active bulb melanocytes of brown and black hairs. In contrast and unexpectedly, TRP‐2 could not be detected in hair bulb melanocytes, whatever the hair colour and ethnic origin. The lack of TRP‐2 was further confirmed by western blot analyses. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) performed on hair bulb mRNA demonstrated that Mitf‐M, tyrosinase and TRP‐1 amplimer signals were easily detected, whereas the TRP‐2 amplimer signal was barely detectable. Furthermore Sox10 was not detected in hair bulb. Altogether our results suggest that the absence of detectable level of TRP‐2 is due to transcriptional control in active melanocytes of human eumelanic hair bulbs. According to the absence of TRP‐2 in melanin‐producing melanocytes of brown and black hair bulbs, one must consider that eumelanogenesis as well as brown and black colour do not require TRP‐2 expression in human hair.
The Endothelin/Sarafotoxin‐Induced Increase of the Proliferation of Undifferentiated and DMSO‐Differentiated GEM‐81 Goldfish Erythrophoroma Cells is Mediated by ETB Receptors
Authors: Filadelfi Ana Maria Caliman , Ramanzini Guilherme Corrêa , Visconti Maria Aparecida , Castrucci Ana Maria de Lauro
Published: September 2004

Endothelins (ETs) and sarafotoxins (SRTXs) have been reported to exert ETB‐mediated effects on vertebrate pigment cells. GEM‐81 cell line, a red pigment cell‐derived cutaneous tumor of the teleost Carassius auratus, expresses ETB receptors and can be differentiated with 1.5% DMSO treatment, thus constituting an useful model to investigate ET and SRTX effects on cultured fish pigment cells. Our aim was to characterize the pharmacology and biological effects mediated by ET receptors in DMSO‐differentiated and undifferentiated cells. ET subtype receptors and their respective Ki values in both cell types were determined by competitive binding assays using 125I ET‐1 and BQ‐485 (an ETA antagonist) or BQ‐788 (an ETB antagonist). BQ‐788, but not BQ‐485, significantly reduced 125I‐ET‐1 binding in both cell types, with similar low (Ki > nM) affinities. To determine the proliferation effects of ETs/SRTXs, cells were treated for 72 h with the hormones, and counted in a hemocytometer. The proliferation assays were repeated for SRTX S6c in the presence or absence of BQ‐788. The results demonstrated that, with the exception of ET‐1 (biphasic effect) and ET‐3 (no significant effect) in undifferentiated GEM‐81 cells, all the tested hormones induced increases in the proliferation of both types of cells. The hormones were equipotent in DMSO‐differentiated cells, which exhibited increased sensitivity to ETs, but not to SRTXs, as compared with undifferentiated cells. The BQ‐788 antagonistic effect was also exerted on the proliferation responses to SRTX S6c. These results corroborate the long and important evolutionary history of the ET/SRTX receptor system in vertebrate pigment cells.
Rab27b is Up‐Regulated in Human Griscelli Syndrome Type II Melanocytes and Linked to the Actin Cytoskeleton via Exon F‐Myosin Va Transcripts
Authors: Westbroek Wendy , Lambert Jo , Schepper Sofie De , Kleta Robert , Bossche Karolien Van Den , Seabra Miguel C. , Huizing Marjan , Mommaas Mieke , Naeyaert Jean Marie
Published: September 2004

Patients with the autosomal recessive Griscelli–Pruniéras syndrome type II are immunologically impaired and have an unusual silvery‐grey hypopigmented colour of scalp hair, eyelashes and eyebrows but no noteworthy pigmentary abnormalities of the skin. In most Griscelli patients, the RAB27A gene, which encodes a small GTPase that is associated with the melanosome membrane in melanocytes, is mutated. Here we discuss a genomic RAB27A deletion found in a 21‐month‐old Moroccan Griscelli patient. Additionally, we provide evidence that the loss of functional Rab27a in melanocytes of this Griscelli patient is partially compensated by the up‐regulation of Rab27b, a homologue of Rab27a. By real‐time quantitative PCR and western blot analysis, we found that Rab27b mRNA and protein, expressed at low levels in normal human melanocytes, is significantly up‐regulated in melanocytes derived from this patient. Our immunofluorescence and yeast two‐hybrid screening studies reveal that Rab27b can form a tripartite complex on the melanosome membrane with Melanophilin, a Rab27a effector, and protein products of Myosin Va transcripts that contain exon F. Our data suggest that up‐regulated Rab27b in melanocytes of the Griscelli patient can partially take over the function of Rab27a, which could explain the fact that this patient had an evenly pigmented skin and was able to tan.
Pheomelanin Production in the Epidermis from Newborn Agouti Mice is Induced by the Expression of the Agouti Gene in the Dermis
Authors: Hirobe Tomohisa , Takeuchi Sakae , Hotta Eri , Wakamatsu Kazumasa , Ito Shosuke
Published: September 2004

The present study was designed to clarify the role of the agouti gene in the regulation of the proliferation and differentiation of mouse epidermal melanocytes using serum‐free primary culture of epidermal melanocytes from 0.5‐d‐old black (a/a; C57BL/10JHir) mice and congenic, agouti (A/A; C57BL/10JHir‐A/A) mice. There was no significant difference in the proliferation or differentiation of melanocytes between a/a and A/A mice. However, the content of pheomelanin in culture media from A/A melanocytes was increased by l‐tyrosine compared with a/a melanocytes. In addition, the content of the pheomelanin precursor, 5‐S‐cysteinyldopa, in culture media from A/A melanocytes was dramatically increased by l‐tyrosine. Moreover, pheomelanin content in the epidermis from 3.5‐ and 5.5‐d‐old A/A mice was much higher than in a/a mice. Analysis of the A gene using reverse transcription‐polymerase chain reaction revealed that cultured keratinocytes and melanocytes do not express the A gene. Moreover, the A gene was expressed in the A/A dermis of 0.5‐, 3.5‐ and 5.5‐d‐old mice, but not in the a/a dermis nor in the A/A or a/a epidermis. These results suggest that A/A epidermal melanoblasts are influenced by the A gene from the dermis of neonatal mice, and are capable of synthesizing pheomelanin in the culture. Pheomelanin production in the epidermis from 3.5‐ and 5.5‐d‐old A/A mice may be induced by the expression of the agouti gene in the dermis.
The Pigmentation of Human Iris Influences the Uptake and Storing of Zinc
Authors: Kokkinou Despina , Kasper Haino Uwe , Bartz‐Schmidt Karl Ulrich , Schraermeyer Ulrich
Published: September 2004

Age‐related macular degeneration (AMD) is more prevalent among the elderly Caucasians than in Africans. A significant association between light iris colour, fundus pigmentation and incidence of AMD is reported, suggesting a possible correlation with melanin pigment. Zinc is known to bind to melanin in pigmented tissues and to enhance antioxidant capacity by function as a cofactor or gene expression factor of antioxidant enzymes in the eye. In this in vitro study, we investigated the uptake and storage of zinc in human irides. Irides of blue and brown human eyes were used. The number of melanocytes was measured. Tissues without any treatment served as controls. The irides were incubated with 100 μM zinc chloride in culture medium for 24 h. Specimens of the tissues were stored for the uptake examination. The remained pieces were further incubated for 3 and 7 d to investigate the storage of zinc. The concentration of zinc was measured by inductively coupled plasma mass spectrometry (ICP‐MS). Melanocytes count was significantly higher in the brown tissues (P < 0.0001). Zinc concentration of blue coloured irides after 24 h zinc treatment was close to the controls. We did not observe any significant storing. In contrast, the concentration of zinc in brown irides was significantly increased after 24 h (P ≤ 0.01) and remained at a high level for 7 d. The uptake of zinc is likely dependent on the amount of pigmentation in human iris. Therefore, we assume that in patients suffering from AMD the degree of pigmentation of the irides and eventually fundi should be under consideration when the patients are treated with zinc supplementation.
Direct Effects of Visible and UVA Light on Pigment Migration in Erythrophores of Nile Tilapia
Authors: Sato Masako , Ishikura Ryo , Oshima Noriko
Published: September 2004

Erythrophores derived from Nile tilapia (Oreochromis niloticus) are sensitive to visible light of defined wavelengths in primary culture in the same manner as erythrophores in the skin. Cultured erythrophores aggregate their pigment in response to light with peak wavelengths near 400 or 600 nm, while dispersion is caused by light near 500 nm. In this study, we report that ultraviolet A (UVA) with a peak wavelength near 365 nm also induces pigment aggregation in erythrophores in the skin and in primary culture. The responses of erythrophores in the skin or in culture depend on the light intensity, although the photo‐sensitivity differs among individual cells. From the results, we conclude that the action of visible light and UVA light on tilapia erythrophores is direct, and that multiple types of visual pigments may coexist in individual erythrophores.
Expression of gp100 and CDK2 in Melanoma Cells is not Co‐Regulated by a Shared Promoter Region
Authors: Stennett Lawrence S. , Riker Adam I. , Kroll Tara M. , ChaMberlin Janine , Miki Toru , Nickoloff Brian J. , Caroline Le Poole I.
Published: September 2004

Expression of the pigmentation‐associated gene PMel17 is regulated by a 1 kB promoter region shared between the PMel17 and CDK2 genes. The encoded melanosomal glycoprotein gp100 and the cell cycle regulatory protein CDK2 are transcribed in opposite directions. Luciferase reporter constructs were generated for subregions of the promoter containing 0, 1, 2 or 3 putative binding sites for transcription factors with basic helix–loop–helix (bHLH) motifs. The potential contribution of bHLH transcription factor microphthalmia transcription factor (MITF) to promoter activity was investigated by re‐introducing microphthalmia into melanoma cells lacking expression. A bi‐directional reporter construct was generated to investigate potential co‐regulation of gp100 and CDK2 transcription. Promoter activity was assessed in presence and absence of phorbol ester tetradecanoyl phorbol 13‐acetate (TPA). FACS analysis and immunohistology served to evaluate co‐regulation of gp100 and CDK2 expression at the protein level. The full‐length promoter, including a consensus binding site for MITF was found to contain sequences that suppressed gp100 expression. Introduction of MITF into non‐expressing 1123 melanoma cells did not restore gp100 expression levels. A lack of coregulation for gp100 and CDK2 as suggested by immunostaining was supported by findings of dissimilar expression regulation by TPA for either gene. The current study provides insight into transcriptional regulation of the PMel17 and CDK2 genes, important to identify strategies for modulating expression of gp100 and CDK2 proteins by melanoma cells.
Melatonin, Melatonin Receptors and Melanophores: A Moving Story
Authors: Sugden David , Davidson Kathryn , Hough Kate A. , Teh Muy‐Teck
Published: September 2004

Melatonin (5‐methoxy N‐acetyltryptamine) is a hormone synthesized and released from the pineal gland at night, which acts on specific high affinity G‐protein coupled receptors to regulate various aspects of physiology and behaviour, including circadian and seasonal responses, and some retinal, cardiovascular and immunological functions. In amphibians, such as Xenopus laevis, another role of melatonin is in the control of skin coloration through an action on melanin‐containing pigment granules (melanosomes) in melanophores. In these cells, very low concentrations of melatonin activate the Mel1c receptor subtype triggering movement of granules toward the cell centre thus lightening skin colour. Mel1c receptor activation reduces intracellular cAMP via a pertussis toxin‐sensitive inhibitory G‐protein (Gi), but how this and other intracellular signals regulate pigment movement is not yet fully understood. However, melanophores have proven an excellent model for the study of the molecular mechanisms which coordinate intracellular transport. Melanosome transport is reversible and involves both actin‐ (myosin V) and microtubule‐dependent (kinesin II and dynein) motors. Melanosomes retain both kinesin and dynein during anterograde and retrograde transport, but the myosin V motor seems to be recruited to melanosomes during dispersion, where it assists kinesin II in dominating dynein thus driving net dispersion. Recent work suggests an important role for dynactin in coordinating the activity of the opposing microtubule motors. The melanophore pigment aggregation response has also played a vital role in the ongoing effort to devise specific melatonin receptor antagonists. Much of what has been learnt about the parts of the melatonin molecule required for receptor binding and activation has come from detailed structure‐activity data using novel melatonin ligands. Work aiming to devise ligands specific for the distinct melatonin receptor subtypes stands poised to deliver selective agonists and antagonists which will be valuable tools in understanding the role of this enigmatic hormone in health and disease.
Functional Genomics Tools for the Analysis of Zebrafish Pigment
Authors: Pickart Michael A. , Sivasubbu Sridhar , Nielsen Aubrey L. , Shriram Sabitha , King Richard A. , Ekker Stephen C.
Published: September 2004

Genetic model organisms are increasingly valuable in the post‐genomics era to provide a basis for comparative analysis of the human genome. For higher order processes of vertebrate pigment cell biology and development, the mouse has historically been the model of choice. A complementary organism, the zebrafish (Danio rerio), shares many of the signaling and biological processes of vertebrates, e.g. neural crest development. The zebrafish has a number of characteristics that make it an especially valuable model for the study of pigment cell biology and disease. Large‐scale genetic screens have identified a collection of pigmentation mutants that have already made valuable contributions to pigment research. An increasing repertoire of genomic resources such as an expressed sequence tag‐based Gene Index (The Institute for Genomic Research) and improving methods of mutagenesis, transgenesis, and gene targeting make zebrafish a particularly attractive model. Morpholino phosphorodiamidate oligonucleotide (MO) ‘knockdown’ of pigment gene expression provides a non‐conventional antisense tool for the analysis of genes involved in pigment cell biology and disease. In addition, an ongoing, reverse‐genetic, MO‐based screen for the rapid identification of gene function promises to be a valuable complement to other high‐throughput microarray and proteomic approaches for understanding pigment cell biology. Novel reagents for zebrafish transgenesis, such as the Sleeping Beauty transposon system, continue to improve the capacity for genetic analysis in this system and ensure that the zebrafish will be a valuable genetic model for understanding a variety of biological processes and human diseases for years to come.
Ultraviolet Radiation Induces Dose‐Dependent Pigment Dispersion in Crustacean Chromatophores
Authors: Gouveia Glauce Ribeiro , Lopes Thaís Martins , Neves Carla Amorim , Nery Luiz Eduardo Maia , Trindade Gilma Santos
Published: September 2004

Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm2 for UVA and 2.15 J/cm2 for UVB. Maximal response was achieved with 10.0 J/cm2 UVA and 8.6 J/cm2 UVB. UVA was more effective than UVB in inducing pigment dispersion. Soon after UV exposure, melanophores once again reached the initial stage of pigment aggregation after 45 min. Aggregated erythrophores of shrimps adapted to a white background showed significant pigment dispersion with 2.5 J/cm2 UVA and 0.29 J/cm2 UVC. Dispersed erythrophores of shrimps adapted to a black background did not show any significant response to UVA, UVB or UVC radiation. UVB did not induce any significant pigment dispersion in shrimps adapted to either a white or a black background. As opposed to the tanning response, which only protects against future UV exposure, the pigment dispersion response could be an important agent protecting against the harmful effects of UV radiation exposure.
The Influence of Fluid Management Policy and Operational Changes on Metalworking Fluid Functionality
Authors: Greeley M. H. , DeVor R. E. , Kapoor S. G. , Rajagopalan N.
Published: September 2004

This paper discusses the influence of metalworking fluid management policy and operational changes on metalworking fluid functionality in terms of lubricating and cooling ability. Several important pathways for metalworking fluid depletion are reviewed. Using an instrumented drilling-based test-bed, the effects of lubricating component depletion, microfiltration, and dilutant water hardness were assessed. It was observed that microfiltration had no effect on fluid functionality. Increases in dilutant water hardness were found to produce decreases in drilling forces and temperature. Additionally, increasing dilutant hardness decreased microfiltration flux, but this effect can be counteracted with the addition of a chelating agent.
Simulation and Analysis of Rigid/Foil Electrolytic In-Process Dressing (ELID) Systems for Grinding
Authors: Zhu Zhenqi , Wang Xiaohua , Thangam Siva
Published: September 2004

The fluid flow problem in a traditional electrolytic in-process dressing (ELID) system is analyzed and solved numerically. The predicted mean velocity profiles in the dressing zone show flow patterns that are in good agreement with the mean velocity distributions for plane laminar/turbulent Couette flows observed in the experiments. The computational results reveal that insufficient electrolyte supply rate is the cause of the failure of the traditional ELID system for high-speed grinding. Results also show that to obtain effective high-speed ELID grinding, a consistent high inlet electrolyte velocity or supply rate is required. For the foil ELID system, governing equations describing the fluid flow in the dressing zone and the foil elastic deformation are formulated. Analytical solution based on unidirectional flow model for the problem is presented and effects of wheel surface speed and foil tension on the performance of the dressing system are discussed. It is shown that the foil ELID system has the potential to be effective for high-speed grinding with low electrolyte supply rates. The results will be useful to the development of new machine systems and processes for high-speed grinding.
Influence of Surface Roughness on Shear Flow
Authors: Bhattacharyya S. , Mahapatra S. , Smith F. T.
Published: September 2004

The local planar flow of incompressible fluid past an obstacle of semi-circular cross section is considered, the obstacle being mounted on a long flat surface. The far-field motion is one of uniform shear. Direct numerical solutions of the Navier-Stokes equations are described over a range of Reynolds numbers. The downstream eddy length and upstream position of maximum pressure gradient are found to agree with increased Reynolds number theory; in particular the agreement for the former quantity is close for Reynolds numbers above about 50.
Effect of Residual Stress on Cavitation Instabilities in Constrained Metal Wires
Authors: Tvergaard Viggo
Published: September 2004

Numerical calculations are carried out for a test specimen geometry used by Ashby et al. to study effects of ductile reinforcements in brittle materials. A lead wire well bonded to an outer glass cylinder was used to investigate crack bridging by ductile particles. The main focus here is on a single void growing very large in the metal wire, in the crack plane, perhaps involving a cavitation instability. Therefore, full finite strain elastic-plastic theory is used for the analyses, and remeshing procedures are applied to avoid unacceptable mesh distortion. Residual stresses induced by thermal contraction mismatch during cooling from the processing temperature can have a noticeable influence on the results, and this is quantified by the analyses.
Two-Phase Flow Through Square and Circular Microchannels—Effects of Channel Geometry
Authors: Chung Peter M.-Y. , Kawaji Masahiro , Kawahara Akimaro , Shibata Yuichi
Published: September 2004

An adiabatic experiment was conducted to investigate the effect of channel geometry on gas-liquid two-phase flow characteristics in horizontal microchannels. A water-nitrogen gas mixture was pumped through a 96 μm square microchannel and the resulting flow pattern, void fraction and frictional pressure drop data were compared with those previously reported by the authors for a 100 μm circular microchannel. The pressure drop data were best estimated using a separated-flow model and the void fraction increased non-linearly with volumetric quality, regardless of the channel shape. However, the flow maps exhibited transition boundaries that were shifted depending on the channel shape.
Interfacial Structures and Regime Transition in Co-Current Downward Bubbly Flow
Authors: Kim S. , Paranjape S. S. , Ishii M. , Kelly J.
Published: September 2004

The vertical co-current downward air-water two-phase flow was studied under adiabatic condition in round tube test sections of 25.4-mm and 50.8-mm ID. In flow regime identification, a new approach was employed to minimize the subjective judgment. It was found that the flow regimes in the co-current downward flow strongly depend on the channel size. In addition, various local two-phase flow parameters were acquired by the multi-sensor miniaturized conductivity probe in bubbly flow. Furthermore, the area-averaged data acquired by the impedance void meter were analyzed using the drift flux model. Three different distributions parameters were developed for different ranges of non-dimensional superficial velocity, defined by the ration of total superficial velocity to the drift velocity.
An Improved Three-Dimensional Level Set Method for Gas-Liquid Two-Phase Flows
Authors: Takahira Hiroyuki , Horiuchi Tomonori , Banerjee Sanjoy
Published: September 2004

For the present study, we developed a three-dimensional numerical method based on the level set method that is applicable to two-phase systems with high-density ratio. The present solver for the Navier-Stokes equations was based on the projection method with a non-staggered grid. We improved the treatment of the convection terms and the interpolation method that was used to obtain the intermediate volume flux defined on the cell faces. We also improved the solver for the pressure Poisson equations and the reinitialization procedure of the level set function. It was shown that the present solver worked very well even for a density ratio of the two fluids of 1:1000. We simulated the coalescence of two rising bubbles under gravity, and a gas bubble bursting at a free surface to evaluate mass conservation for the present method. It was also shown that the volume conservation (i.e., mass conservation) of bubbles was very good even after bubble coalescence.
Local Liquid Velocity in Vertical Air-Water Downward Flow
Authors: Sun Xiaodong , Paranjape Sidharth , Kim Seungjin , Goda Hiroshi , Ishii Mamoru , Kelly Joseph M.
Published: September 2004

This paper presents an experimental study of local liquid velocity measurement in downward air-water bubbly and slug flows in a 50.8 mm inner-diameter round pipe. The axial liquid velocity and its fluctuations were measured by a laser Doppler anemometry (LDA) system. It was found that the maximum liquid velocity in a downward two-phase flow could occur off the pipe centerline at relatively low liquid flow rates and this observation is consistent with other researchers’ results. The comparisons between the liquid flow rates measured by a magnetic flow meter and those obtained from the local LDA and multi-sensor conductivity probe measurements showed good agreement. In addition, based on the local measurements the distribution parameter and the drift velocity in the drift-flux model were obtained for the current downward flow tests.
A Port Ontology for Conceptual Design of Systems
Authors: Liang Vei-Chung , Paredis Christiaan J. J.
Published: September 2004

During conceptual design of systems, the emphasis is on generating the system architecture: the configuration of sub-systems and the interactions between them. Ports, as locations of intended interaction, play an important role at this stage of design. They are convenient abstractions for representing the intended exchange of signals, energy or material; they can be applied at different levels of detail, across different energy domains, and to all aspects of design: form, function, and behavior. But to play this versatile role, ports need to be represented in an unambiguous yet flexible fashion, accommodating the differences in vocabulary and approach across different disciplines and perspectives. In this article, we introduce the semantic structure for such an unambiguous representation: a port ontology. The ontology formalizes the conceptualization of ports such that engineers and computer aided design applications can reason about component connections and interactions in system configuration. It defines ports in terms of form, function and behavior attributes and further includes axioms that can be used to support a variety of engineering design tasks, such as port refinement, port compatibility checking, and the instantiation of interaction models. A LEGO example is used to illustrate the ontology and its applications in conceptual design.