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Biomedical subjects

D Weis

Publications and source records attributed to D Weis.

At least 19 recordsLinked to original sources
PubMed2001

Loss of collagen type IV in rheumatoid synovia and cytokine effect on the collagen type-IV gene expression in fibroblast-like synoviocytes from rheumatoid arthritis.

Collagen type IV is a structural matrix protein which contributes to the structural organization of the synovia. In order to characterize the distribution of this protein in synovia with chronic synovitis, collagen type IV was detected by immunochemistry in normal synovia and in synovia from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). A decrease of collagen type IV was observed in synovial layers of rheumatoid synovia, which statistically correlated with the grade of inflammation and with the thickness of the synovial layer. In vitro, we found no differences in the gene expression of collagen type IV in cultures of fibroblast-like synoviocytes (FLS) derived from OA and RA using a reverse-transcriptase polymerase chain reaction. Nevertheless, we observed a downregulating effect of tumor necrosis factor-alpha and interleukin (IL)-1beta on the gene expression of collagen type IV only in FLS isolated from patients with RA. The effect of IL-1beta was dose dependent. In summary, we observed an inflammation-associated decrease of collagen type IV in the synovial layer of rheumatoid synovia. Inflammatory cytokines may play a role in regulating the synthesis of collagen type IV in the rheumatoid process in vivo.

Arthritis, Rheumatoid↗
PubMed2000

An instrument to measure professional nursing values.

PURPOSE: To describe the Nursing Professional Values Scale (NPVS), its development, reliability and validity, and its derivation from the Code of Ethics of the American Nurses Association. DESIGN: The NPVS was tested on 599 subjects, including baccalaureate and masters' students and practicing nurses. The students were enrolled in one of 25 programs selected at random from all NLN accredited programs in the United States. Practicing nurses were randomly selected from a State Board of Nursing list. METHOD: A 44-item, norm-referenced instrument with a Likert-scale format was tested. The responses of participants to this instrument were subjected to principal axis factor analysis with varimax rotation. FINDINGS: Eight factors were identified, accounting for 58% of the total variance. The two major factors were Caregiving and Activism. CONCLUSIONS: Initial results showed a high level of reliability and validity for the NPVS. The NPVS is a useful instrument for measuring professional nursing values and enhancing professional socialization.

Ethics, Nursing↗
PubMed1999

Assessment of pollution aerosols sources above the Straits of Dover using lead isotope geochemistry.

We assess the capability of lead isotopes to study the transport of pollution aerosols above the Straits of Dover by collecting atmospheric aerosols above the Eastern Channel and the Southern Bight of the North Sea. During the same period, we characterized the lead isotopic signature of the main industrial sources on the French coast near the Straits of Dover. Urban and automobile-derived aerosols were also collected. Due to the phasing out of lead in gasoline, the urban isotopic composition (206Pb/207Pb = 1.158 +/- 0.003) has become more radiogenic, although it is highly variable. On a regional scale, major industrial emissions have a well-defined isotopic composition (1.13 < 206Pb/207Pb < 1.22), more radiogenic than the petrol-lead signature (1.06 < 206Pb/207Pb < 1.12). These results together with those measured near the main coastal highway show that the automobile source has become a minor component of particulate lead in air. On a local scale, Dunkerque, the most urbanized and industrialized area along the Straits of Dover, may transiently control elevated lead concentrations. Except for the occurrence of local and regional range transport episodes, lead concentrations in the Straits of Dover can be related to remote or semi-remote pollution source emissions. Combining air mass retrospective trajectories and related lead abundances and isotopic compositions, it can be shown that lead aerosols originating from eastern Europe have an isotopic signature (1.145 < 206Pb/207Pb < 1.169) different from the isotopic composition of west-European lead aerosols (1.111 < 206Pb/207Pb < 1.142). The influence of remote North American sources is suggested, with caution, due to uncertainties in meteorological calculations.

Aerosols↗
PubMed1998

Loss of laminin and of the laminin receptor integrin subunit alpha 6 in situ correlates with cytokine induced down regulation of alpha 6 on fibroblast-like synoviocytes from rheumatoid arthritis.

OBJECTIVE: To investigate in situ the expression of the integrin receptor subunits alpha 6 and beta 1 and the distribution of the ligand laminin in the synovia from osteoarthritis (OA) and rheumatoid arthritis (RA) patients and to study the effect of cytokines and antirheumatic drugs on the expression of the alpha 6 and beta 1 integrin subunits on long term cultures of fibroblast-like synoviocytes (FBS) derived from OA and RA. METHODS: The expression of the alpha 6 and beta 1 integrin subunits and the distribution of laminin were examined immunohistochemically in normal synovia and in synovia from patients with OA and RA. The effect of proinflammatory cytokines (IL1 beta and TNF alpha), and of antirheumatic drugs (salicylic acid, dexamethasone, and methotrexate) on the alpha 6 and beta 1 expression of cultured normal FBS and FBS from patients with OA and RA was determined by flow cytometry. RESULTS: In normal synovia and in OA synovia samples with a low grade of inflammation, synovial lining cells (SLC) showed a parallel expression and distribution of alpha 6 and laminin. In synovia samples of OA with a higher grade of inflammation and in the majority of RA synovia samples laminin was pericellularly distributed in a low number of SLC, whereas alpha 6 was expressed on the surface of a high number of SLC. In RA synovia samples with severe inflammatory changes the gradual loss of laminin generally corresponded to a decrease of the alpha 6 integrin subunit. beta 1 was always strongly expressed in all synovia samples detected. Proinflammatory cytokines up regulated the expression of alpha 6 and beta 1 on OA-FBS, whereas these effectors decreases alpha 6 and beta 1 on RA-FBS. In contrast, antirheumatic drugs, in particular methotrexate and dexamethasone, reduced the expression of alpha 6 and beta 1 on OA-FBS, whereas the same treatment on RA-FBS stimulated the expression of these integrin subunits. CONCLUSION: The gradual loss of laminin in chronic synovitis may contribute to the altered expression of alpha 6 in SLC. IL1 beta and TNF alpha down regulated the expression of the alpha 6 and beta 1 integrin subunits on long term cultures of FBS derived from RA. Therefore, these cytokines may be among the effectors regulating the expression of the alpha 6 integrin subunit in SLC in vivo. As antirheumatic drugs increase the expression of alpha 6 on RA-FBS, the presence of the laminin receptor may confer a protective effect on the synovia in vivo.

Antigens, CD↗
PubMed1997

Toward building an international consensus in professional values.

Although the importance of professional values has been espoused and national codes for nurses exist, there is a lack of systematic study to ascertain the commonalities of values among professional nurses. As part of a larger international study of professional values, nursing students from England and the USA (n = 130) were surveyed to determine congruence of values. The Professional Values Scale (PVS) instrument was used to collect data. Results showed a high degree of congruence among nursing students. The incongruencies found may be related to cultural differences in education and practice.

Adult↗
PubMed1997

Health care delivery in faith communities: the parish nurse model.

Religious institutions and nurses have a common bond--both are committed to empowering individuals to achieve their full potential and believe in the self-care capacity of individuals. The purpose of this study was to examine parish nursing as an evolving model of care within faith communities. Annualization of monthly reports and parish nurse interviews revealed that parish nurse activities contributed to the empowerment process and to the attainment of Healthy People 2000 objectives.

Community Health Nursing↗
PubMed1997

Increased expression of integrins on fibroblast-like synoviocytes from rheumatoid arthritis in vitro correlates with enhanced binding to extracellular matrix proteins.

OBJECTIVE: To compare in vitro expression of beta 1, beta 3, and beta 4 integrins in normal fibroblast-like synoviocytes (FBS) and in FBS from rheumatoid arthritis (RA) synovium and to investigate the adhesion of normal FBS and RA-FBS to the integrin binding extracellular matrix (ECM) proteins: collagen type IV, fibronectin, laminin, and tenascin. METHODS: Expression of integrin receptors of cultured FBS was detected by flow cytometry. Attachment of FBS to ECM proteins was quantified by adhesion assays. Inhibition studies were performed using monoclonal antibodies to the integrin subunits. RESULTS: Compared with normal FBS, RA-FBS showed increased expression of alpha 1 to alpha 6, beta 1, and beta 4 integrin subunits and enhanced binding of ECM proteins. Binding to ECM proteins was partly or completely blocked by an anti-beta 1 integrin antibody and antibodies to alpha 3, alpha 5, and alpha 6 integrin subunits. The blocking efficiency was significantly (P < 0.05) higher in RA-FBS than in normal FBS. CONCLUSIONS: The enhanced expression of the beta 1 integrin receptors on cultured RA-FBS correlated with increased attachment to ECM proteins. Adhesion of normal and RA-FBS to ECM proteins is mediated through beta 1 integrin receptors. Therefore, the tight binding of rheumatoid FBS to the matrix via beta 1 integrins might play a role in ECM remodelling in the rheumatoid process in vivo.

Arthritis, Rheumatoid↗
PubMed1997

Differential expression and functional behaviour of the alpha v and beta 3 integrin subunits in cytokine stimulated fibroblast-like cells derived from synovial tissue of rheumatoid arthritis and osteoarthritis in vitro.

OBJECTIVE: The aim of this study was to investigate in situ the expression of the classic vitronectin (VN) receptor consisting of the alpha v and beta 3 subunits in synovial lining cells (SLC) of chronic synovitis occurring in osteoarthritis (OA) and in rheumatoid arthritis (RA). The expression and function of alpha v and beta 3 as VN receptor in cultured fibroblast-like synoviocytes (FBS) derived from patients with OA and RA was also compared. METHODS: Expression of alpha v and beta 3 was examined immunohistochemically in normal synovial tissue and in synovial tissue from patients with OA and RA. The effect of proinflammatory cytokines and of a synovial fluid of a patient with RA on the expression of the alpha v and beta 3 subunits of cultured FBS was determined by flow cytometry. Binding of OA and RA-FBS to VN was quantified using adhesion assays and the effect of interleukin 1 beta (IL1 beta) and tumour necrosis factor alpha (TNF alpha) on adhesion was measured. The specificity of the adhesion was tested by inhibition studies using monoclonal antibodies to integrin subunits. RESULTS: In in situ studies normal SLC showed a parallel distribution of alpha v and beta 3 subunits. OA-SLC strongly and uniformly expressed alpha v whereas RA-SLC showed heterogeneous expression of alpha v. In situ both OA-SLC and RA-SLC lacked the expression of the integrin subunit beta 3. In in vitro studies, OA-FBS and RA-FBS did not differ as regards expression of alpha v and beta 3, and VN attachment. Binding of RA-FBS to VN was partially blocked by antibodies against alpha v, beta 1, and beta 3 subunits, whereas only antibodies against alpha v and beta 3 inhibited the binding of OA-FBS to VN. The proinflammatory cytokines TNF alpha and IL1 beta increased the expression of alpha v and beta 3, and the VN binding of OA-FBS, whereas alpha v and beta 3 expression, and VN binding were downregulated in RA-FBS. Similar effects were found when the synovial fluid of an RA patient was used. CONCLUSION: The integrin subunit beta 3 seems to be one partner but not the major one with which the subunit alpha v forms functional vitronectin receptors in OA-FBS and RA-FBS. The interaction between synovial cells and inflammatory cytokines seems to be different for OA and RA; the basis for this difference, however, remains to be established.

Arthritis, Rheumatoid↗
PubMed1994

Thermodynamics of the equilibrium unfolding of oxidized and reduced Saccharomyces cerevisiae iso-1-cytochromes c.

We report thermodynamic data for the chemical denaturation of iso-1-cytochromes c from Saccharomyces cerevisiae having amino acid substitutions R38A, N52I, and F82S in all possible combinations. The guanidine hydrochloride denaturation of isolated proteins was monitored by fluorescence measurements. The redox potentials, Eo', for both the folded and unfolded conformations have been measured. Free energy changes of chemical unfolding together with direct electrochemical measurement of the free energy changes of reduction for both the native and unfolded proteins yield a complete thermodynamic cycle, which includes four states of cytochrome c: oxidized folded, oxidized unfolded, reduced folded, and reduced unfolded. Completed cycles illustrate that the stability of cytochrome c to denaturing conditions is different for each amino acid substitution by an amount that depends on the heme oxidation state. Thus, the differential protein stability cannot be interpreted simply in terms of a hydrophobic effect, without also considering coupled Coulombic effects.

Base Sequence↗
PubMed1994

Importance of professional nursing values: a national study of baccalaureate programs.

Research about professional nursing values is scarce. The purpose of this study was to determine if there were different perceptions about professional nursing values between senior baccalaureate nursing students and their faculty. The Professional Nursing Behavior Instrument (PNB) used in this research was based on the nursing role behaviors identified in the AACN's (1986) Essentials Report as exemplars of seven essential values. A national sample of 10 public and 16 private baccalaureate programs resulted in a return of 656 students (57%) and 350 faculty (70%). Faculty values were significantly higher than students' (p < .045) with faculty valuing equality, human dignity, and freedom more highly. Enrollment or employment in a public or private institution or studying ethics, theology, and philosophy did not significantly affect values. Faculty with more teaching experience had higher value scores (p < .004).

Education, Nursing, Baccalaureate↗
PubMed1992

Uninsured maternity clients: a concern for quality.

Differences among demographic characteristics, health status indicators, and resource use of maternity clients privately insured, insured through public entitlement funds, or uninsured were examined in a public hospital. The uninsured were in their early twenties, black (44%), single (52%), lived in the central city area, employed in service occupations without health care benefits, and either sought prenatal care later in the pregnancy or not at all. Compared with the privately insured, the uninsured had more lifestyle risks. The uninsured women had a shorter hospital stay with more maternal complications. Insurance coverage and prenatal care were positive predictors of birth weight and lifestyle risk factors detracted. Length of stay was not influenced by insurance coverage but rather by health problems before delivery. Earlier discharge of the uninsured patients suggest the need for quality of care monitoring and outreach programs.

Adolescent↗