Age-related changes in the proteoglycans of human skin.

Skin undergoes dramatic age-related changes in its mechanical properties, including changes in tissue hydration and resiliency. Proteoglycans are macromolecular conjugates of protein and carbohydrate (glycosaminoglycan) which are involved in these tissue properties. In order to examine whether age-related changes in skin proteoglycans may contribute to the age-related changes in the mechanical properties of skin, proteoglycans from human skin of various ages were extracted and analyzed. Samples were obtained from two different fetal ages, from mature skin, and from senescent skin. As a function of age, there is a decrease in the proportion of large chondroitin sulfate proteoglycans (versican) and a concomitant increase in the proportion of small dermatan sulfate proteoglycans (decorin). Based on reactivity with antibodies to various chondroitin sulfate epitopes, fetal versican differs from the versican found in older skin with respect to the chondroitin sulfate chains. Also, the decorin of fetal skin is slightly larger, while the decorin of older skin shows greater polydispersity in both its size and its charge to mass ratio. There are also age-related differences in the size and polydispersity of the core proteins of decorin. The most pronounced change in skin proteoglycans is the appearance in mature skin of a proteoglycan which is smaller than decorin, but which has the same amino terminal amino acid sequence as decorin. This small proteoglycan is abundant in mature skin and may be a catabolic fragment of decorin or an alternatively spliced form of decorin. In light of the known ability of decorin to influence collagen fibrillogenesis and fibril diameter, the appearance of this small decorin-related proteoglycan may have a significant effect on skin elasticity. The observation that proteoglycans in skin show dramatic age-related differences suggests that these changes may be involved in the age-related changes in the physical properties of skin.

A monoclonal antibody which recognizes a glycosaminoglycan epitope in both dermatan sulfate and chondroitin sulfate proteoglycans of human skin.

Studies have been initiated to identify various cell surface and matrix components of normal human skin through the production and characterization of murine monoclonal antibodies. One such antibody, termed PG-4, identifies both cell surface and matrix antigens in extracts of human foetal and adult skin as the dermatan sulfate proteoglycans, decorin and biglycan, and the chondroitin sulfate proteoglycan versican. Treatment of proteoglycans with chondroitinases completely abolishes immunoreactivity for all of these antigens which suggests that the epitope resides within their glycosaminoglycan chains. Further evidence for the carbohydrate nature of the epitope derives from competition studies where protein-free chondroitin sulfate chains from shark cartilage react strongly; however, chondroitin sulfate chains from bovine tracheal cartilage fail to exhibit a significant reactivity, an indication that the epitope, although present in some chondroitin sulfate chains, does not consist of random chondroitin 4- or 6-sulfate disaccharides. The presence of the epitope on dermatan sulfate chains and on decorin was also demonstrated using competition assays. Thus, PG-4 belongs to a class of antibodies that recognize native epitopes located within glycosaminoglycan chains. It differs from previously described antibodies in this class in that it identifies both chondroitin sulfate and dermatan sulfate proteoglycans. These characteristics make PG-4 a useful monoclonal antibody probe to identify the total population of proteoglycans in human skin.

Studying patient satisfaction: patient voices of quality.

The purpose of this qualitative research study was to describe the lived experience and satisfaction of 20 patients after discharge from two acute care rural hospitals. Issues involved in measuring patient satisfaction are discussed in this article. Results of the research are discussed within the themes of (1) knowledgeable watchfulness, (2) thoughtful presencing, and (3) hospital: home and homeless. One pattern, nursing as a bridge, was found throughout the interviews. The authors recommend incorporating qualitative components in the study of patient satisfaction to capture the subtle, invisible ways that nursing interventions can enhance patient satisfaction with quality health care.

Dynamic expression of proteoglycans during chicken skeletal muscle development and maturation.

Skeletal muscle development is a complex process in which cell migration and adhesion play important roles. Because these cellular activities involve cell surface and extracellular matrix molecules, proteoglycan analysis was performed for developing chick skeletal muscle. Proteoglycans are macromolecular conjugates of protein and carbohydrate found in the extracellular matrix and at the cell surface. In developing muscle, both in vivo and in vitro, there is a development-related progression from synthesis of primarily large proteoglycans at earlier stages to mainly small proteoglycans at later stages. This progression was demonstrated by radiolabeling developing muscle and extracting and characterizing the proteoglycans. The large proteoglycans synthesized earlier in myogenesis have been identified as the large chondroitin sulfate proteoglycan, versican. Among the small proteoglycans synthesized at later stages is the small dermatan sulfate proteoglycan, decorin. Immunolocalization of these proteoglycans shows that versican is initially present in pericellular locations around developing myotubes, whereas decorin is observed in the epimysium early in development, and then its distribution gradually spreads to also include the perimysium and endomysium. Studies of regenerating muscle show that there is a recapitulation of the embryonic pattern of proteoglycan synthesis, which, coupled with the results from embryonic muscle development, suggests a role for versican in some early aspect of myogenesis.

Creative winds of change: nurses collaborating for quality outcomes.

This article describes the collaboration of two researchers and two clinicians at one rural medical center to develop and implement Phase I of a project that was part of the Quality Indicator Initiative of the American Nurses Association (ANA). Changes in the health care environment led the researchers to develop educational programs that eventually evolved into a pilot research project to explore the feasibility of data collection on ANA Quality Indicators. Collaboration between the researchers and clinicians led to outcomes that relate to future efforts for collecting and analyzing data on clinical outcome indicators.

Versican in human fetal skin development.

The extracellular matrix of human fetal skin differs substantially from that of adult skin. Fetal skin contains sparse amounts of fibrillar collagen enmeshed in a highly hydrated amorphous matrix composed of hyaluronan and sulfated proteoglycans. Both fetal and adult skin contain two major interstitial proteoglycans that are extracted by chaotrophic agents and detergents. These are the large chondroitin sulfate proteoglycan versican and the small dermatan sulfate proteoglycan decorin. For this study, proteoglycans extracted from fetal and adult skin were compared on Western blots to determine the relative amounts of versican. Decorin present in the same samples provided an internal standard for these studies. Fetal skin differed from adult skin in that it contained a significantly higher proportion of versican than did adult skin. Immunohistochemical studies compared early-fetal with mid-fetal skin and found that versican was a significant component of the interstitial extracellular matrix at both of these stages of skin development. However, by the mid-fetal period, interstitial versican became restricted to the upper half of the dermis, although versican also continued to be highly expressed around hair follicles, glands, and vasculature in the lower half of the dermis. Fetal skin extracts differed from an adult skin extract by the presence of a 66-kDa protein immunologically related to versican and by the absence of a 17-kDa core protein of a proteoglycan related to decorin. Both of these molecular species may represent degradation products of their respective proteoglycans. Monoclonal antibodies which detect epitopes in native chondroitin sulfate glycosaminoglycan chains recognized versican extracted from fetal skin. However, the tissue distribution of these antigens did not entirely conform to that for versican core protein, suggesting that versican in different regions of the skin may be substituted with glycosaminoglycan chains with different microchemistries. The results of these studies indicate that human fetal skin is structurally different from adult skin in terms of both the distribution and the composition of the large, aggregating chondroitin sulfate proteoglycan versican.

Connecting across the miles: interdisciplinary collaboration in the evaluation of critical thinking.

A pilot study in which faculty from nursing and English departments at two universities in different states shared a common evaluation tool and collaborated through e-mail to evaluate the evidence of critical thinking in writing portfolios of baccalaureate and masters' nursing students. Loxley's (1997) four processes--assessment, building, managing the process, and evaluating--are used as a framework for describing collaboration among the disciplines in the two universities. Social exchange theory was used to explain the collaboration between participants. All six professors learned a great deal from studying and scoring the writings, but they learned most from each other through their e-mail dialogue.

Nurses as writers.

Although nurses are expected to be competent in on-the-job writing, most nurses receive little formal education in the types of writing required in practice. Thus, it is important for faculty in schools of nursing to include in the curricula various types of writing assignments to help students develop these skills. This article describes how at one university a course, "Nurses as Writers," provides opportunities for students to learn and practice the types of writing needed in their professional careers.

The lived experiences of students in nursing: voices of caring speak of the tact of teaching.

The purpose of this phenomenological, Heideggerian hermeneutical study was to describe the lived experiences of 23 undergraduate nursing students in relation to their perceptions of "caring" experiences in their nursing programs. Data were collected by the primary investigators at a statewide nursing convention, with students relating stories of critical student experiences related to caring. Themes related to caring experiences included "caring as offering," "leaps ahead caring," and "creating a caring place." A recurrent pattern of "power inherent in teaching" was identified across student narratives, suggesting the need to study how teachers can use the tact of teaching to empower students. Implications drawn from the data suggest the need to explore how nursing students' learning is shaped by caring interactions with nurse clinicians and other health professionals as well as with nursing faculty.

Use of writing portfolios for interdisciplinary assessment of critical thinking outcomes of nursing students.

This article discusses an interdisciplinary research project in which faculty from nursing and english collaborated in the assessment of students' critical thinking skills as reflected in writing portfolios. Faculty reviewed students' writing portfolios and then corresponded on email from two different universities about evidence of critical thinking in the portfolios. Findings suggest that writing portfolios can provide important evidence of critical thinking outcomes. To do this, however, faculty need to design writing assignments to foster critical thinking skills, helping students to think not only about learning to write, but also about using writing to learn.

Creating a caring learning environment.

This article discusses creating a caring learning environment for undergraduate nursing students. The purpose is to apply the results of a research study in which students described their lived experience with caring in the nursing environment. Students (N = 23) shared caring and uncaring stories about their curricula. The study identified two patterns: "The Power of the Faculty" and "Creating a Caring Learning Environment." The authors discuss the implications of these patterns for developing caring faculty practices and a caring learning environment.

Distribution of keratan sulphate and chondroitin sulphate in wild type and white mutant axolotl embryos during neural crest cell migration.

In embryos of the white mutant axolotl, prospective pigment cells are unable to migrate from the neural crest (NC) due to a deficiency in the subepidermal extracellular matrix (ECM). This raises the question of the molecular nature of this functional defect. Some PGs can inhibit cell migration on ECM molecules in vitro, and an excess of this class of molecules in the migratory pathways of neural crest cells might cause the restricted migration of prospective pigment cells seen in the white mutant embryo. In the present study, we use several monoclonal antibodies against epitopes on keratan sulphate (KS) and chondroitin sulphate (CS) and LM immunofluorescence to examine the distribution of these glycosaminoglycans at initial (stage 30) and advanced (stage 35) stages of neural crest cell migration. Most KS epitopes are more widely distributed in the white mutant than in the wild type embryo, whereas CS epitopes show very similar distributions in mutant and wild type embryos. This is confirmed quantitatively by immunoblotting: certain KS epitopes are more abundant in the white mutant. TEM immunogold staining reveals that KS as well as CS are present both in the basal lamina and in the interstitial ECM in both types of embryos. It remains to be investigated whether the abundance of certain KS epitopes in the white mutant embryo might contribute to the deficiency in supporting pigment cell migration shown by its ECM.

Construction of a bilayered dermal equivalent containing human papillary and reticular dermal fibroblasts: use of fluorescent vital dyes.

Bilayered dermal equivalents were constructed by seeding human papillary and reticular dermal fibroblasts into separate layers of type I collagen and allowing these layers to gel into a single entity. That these bilayered gels had fused was established through histologic examination and from the fact that these gels, when detached, contracted as a single unit. Papillary and reticular dermal fibroblasts remained in their respective layers as established by differentially labeling these dermal cells with fluorescent vital dyes l,l'-dioctacecyl-3,3,3',3'-tetramethylindocabocyanine perchlorate, DiIC(18)(3) (Dil), and 3,3'-dioctadecyloxacarbocyanine perchlorate, DiOC(18)(3) (DiO). The labeling with these vital dyes did not interfere with the ability of the cells to proliferate or to contract floating type I collagen gels. Thus, these bilayered gels can provide the means of creating dermal equivalents that contain a variety of different dermal cell types to assess their relative abilities, either alone or in various combinations, to support keratinocyte proliferation and differentiation and to contribute, eventually, to the formation of a multilayered skin equivalent.

From Carper's patterns of knowing to ways of being: an ontological philosophical shift in nursing.

Carper's 1978 article in the premiere issue of Advances in Nursing Science encouraged nurses to consider four fundamental patterns of knowing. Through illustrations from literature and the performing arts, the authors address Carper's patterns of knowing in the context of an emerging philosophical shift. First, they critique the major strengths and limitations of the article. Next, they explore an emerging philosophical shift in nursing from Carper's epistemological focus to ontological reflections on ways of being. Finally, they discuss the significance of the emerging philosophical shift and the ways of being for the science-art of nursing.

Designing class participation experiences for the introverted student.

Class participation for students is such a common expectation of nurse educators that it is easy to overlook the need to tailor class participation activities to individual student needs. An understanding of the various temperaments of individuals, especially preferences related to extroversion and introversion, can help nurse educators to plan class participation experiences that foster skills in critical thinking and enhance personal growth.

Interviews in qualitative nursing research: differing approaches for ethnographic and phenomenological studies.

Interviews form an essential part of data collection for many qualitative nursing studies. Information about how to individualize interview formats to meet the purpose and style of specific qualitative research approaches, however, is not readily accessible to the researcher. This paper offers an overview of use of the interviewer as an instrument in qualitative research, as well as ways in which the differing purposes and styles of ethnographic and phenomenological research approaches affect the format for the interview.

Immunology of chondroitin/dermatan sulfate.

Variable substitutions and locations of the sulfate esters along the backbone of chondroitin/dermatan sulfate chains, combined with their carbohydrate structures, present topographies to immune systems which can be recognized as antigenic. This has led to the development of a number of monoclonal antibodies which recognize distinct epitopes in the native structures of these glycosaminoglycan chains. In some studies, the original chondroitin/dermatan sulfate proteoglycan was digested with chondroitinase enzymes before being used as an immunogen. in this case, the linkage oligosaccharides remaining bound to the core protein contain a modified (4,5-unsaturated) hexuronic acid derivative at their non-reducing ends as a result of the eliminase mechanism of the enzyme. This 'haptenic' structure is highly antigenic and has led to the development of a number of monoclonal antibodies which recognize this structure as part of their epitopes. Examples of the use of some of these monoclonal antibodies for localization of proteoglycan structures in tissue sections and on transblots are described. The precise structures are known for only a few of the native epitopes recognized by these monoclonal antibodies. Recent analytical methods have been developed for determining structures of chondroitin sulfate oligosaccharides. An example of the use of these methods to analyze the structures of the non-reducing termini of chondroitin/dermatan sulfate chains is discussed. The results show their potential value for quantifying the native epitope recognized by a monoclonal antibody, designated 3B3, which recognizes chains terminated by glucuronic acid-N-acetylgalactosamine-6-sulfate. Such methods should be useful for determining the epitope structures for other monoclonal antibodies in this class.