bluuebunny/crossref_metadata_2025_split huggingface dataset:
Telomere shortening in human fibroblasts is not dependent on the size of the telomeric‐3′‐overhang
Authors: Keys Barbara , Serra Violeta , Saretzki Gabriele , Von Zglinicki Thomas 
Published: May 2004

SummaryTelomeres shorten in human somatic cells with each round of DNA replication, and this shortening is thought to ultimately trigger replicative senescence. Telomere shortening is caused partly by the inability of semiconservative DNA replication to copy a linear strand of DNA to its very end. Post‐replicative processing of telomeric ends, producing single‐stranded G‐rich 3′ overhangs, has also been suggested to contribute to telomere shortening. This suggestion implies that a positive correlation should exist between the length of 3′ overhangs and the rate of telomere shortening. We confirmed shortening of overhangs as human lung (MRC5) and foreskin (BJ) fibroblasts approach senescence by measuring overhang length using in‐gel hybridization. However, a large study of fibroblast strains from 21 donors maintained under conditions which lead to two orders of magnitude of variation in telomere shortening rate failed to show any correlation between telomere overhang length and shortening rate, suggesting that overhang length is neither a cause nor a correlate of telomere shortening.
Review of Studies of Healing Touch
Authors: Wardell Diane Wind , Weymouth Kathryn F. 
Published: May 2004

Purpose:

To review studies of healing touch and its implications for practice and research.
Design:

A review of the literature from published works, abstracts from conference proceedings, theses, and dissertations was conducted to synthesize information on healing touch. Works available until June 2003 were referenced.
Methods:

The studies were categorized by target of interventions and outcomes were evaluated.
Findings and Conclusions:

Over 30 studies have been conducted with healing touch as the independent variable. Although no generalizable results were found, a foundation exists for further research to test its benefits.
Joblessness and Homelessness as Precursors of Health Problems in Formerly Incarcerated African American Men
Authors: Cooke Cheryl L. 
Published: May 2004

Purpose:To explore how joblessness and homelessness influence the health of men leaving prison.Design:A qualitative study using semi‐structured interviews was conducted with 17 formerly incarcerated African American men. Participants were interviewed for 1‐2 hours in a private setting. Data were collected over 3 months in late 2001.Methods:Questions were focused on the experiences of participants during incarceration and after release from prison. Discourse analysis was used to analyze the data.Finding:Findings related to unemployment included, (a) being incarcerated was associated with decreased types of employment available after release from prison, (b) a history of incarceration altered how participants were able to conduct job searches, and (c) men who did well after release were those who were self‐employed. Findings related to homelessness showed that barriers in either systems or relationships interfered with finding homes.Conclusions:If formerly incarcerated African American men are to reenter society in meaningful ways, steady, living‐wage employment and a stable living environment are needed for these men to be able to successfully reintegrate into both families and the larger society, and to avoid conditions that are precursors of health problems.
A Meta‐Analysis of Predictors of Positive Health Practices
Authors: Yarcheski Adela , Mahon Noreen E. , Yarcheski Thomas J. , Cannella Barbara L. 
Published: May 2004

Purpose:

To identify predictors of positive health practices from empirical studies in which the Personal Lifestyle Questionnaire was used.
Methods:

Meta‐analysis to determine the magnitude of the relationships between each of the predictors identified and positive health practices. Fourteen predictors of positive health practices were identified in 37 studies published since 1983; a meta‐analysis was conducted on 14 predictors.
Results:

Eight predictors (loneliness, social support, perceived health status, self‐efficacy, future time perspective, self‐esteem, hope, and depression) had moderate effect sizes, and six (stress, education, marital status, age, income, and sex) had small effect sizes.
Conclusions:

Findings enable health care professionals and researchers designing intervention studies to use the strongest predictors identified in this meta‐analysis to promote positive health practices.
Physical Activity in Low‐Income Postpartum Women
Authors: Wilkinson Susan , Huang Chiu‐Mieh , Walker Lorraine O. , Sterling Bobbie Sue , Kim Minseong 
Published: May 2004

Purpose:

To validate the 7‐day physical activity recall (PAR), including alternative PAR scoring algorithms, using pedometer readings with low‐income postpartum women, and to describe physical activity patterns of a low‐income population of postpartum women.
Methods:

Forty‐four women (13 African American, 19 Hispanic, and 12 White) from the Austin New Mothers Study (ANMS) were interviewed at 3 months postpartum. Data were scored alternatively according to the Blair (sitting treated as light activity) and Welk (sitting excluded from light activity and treated as rest) algorithms. Step counts based on 3 days of wearing pedometers served as the validation measure.
Findings:

Using the Welk algorithm, PAR components significantly correlated with step counts were: minutes spent in light activity, total activity (sum of light to very hard activity), and energy expenditure. Minutes spent in sitting were negatively correlated with step counts. No PAR component activities derived with the Blair algorithm were significantly related to step counts. The largest amount of active time was spent in light activity: 384.4 minutes with the Welk algorithm. Mothers averaged fewer than 16 minutes per day in moderate or high intensity activity. Step counts measured by pedometers averaged 6,262 (SD=2,712) per day.
Conclusions:

The findings indicate support for the validity of the PAR as a measure of physical activity with low‐income postpartum mothers when scored according to the Welk algorithm. On average, low‐income postpartum women in this study did not meet recommendations for amount of moderate or high intensity physical activity.
Using Technology to Promote Self‐Efficacy for Healthy Eating in Adolescents
Authors: Long JoAnn D. , Stevens Kathleen R. 
Published: May 2004

Purpose:

To test the effects of a classroom and World Wide Web (WWW) educational intervention on self‐efficacy (SE) for healthy eating (HE) and to examine the relationship of the theoretical concepts in a hypothesized model of eating behavior in adolescents.
Design:

A quasiexperimental pretest, posttest design was used in a random sample of students in two junior high schools.
Methods:

The intervention consisted of a combination of 5 hours of Web‐based instruction and 10 hours of classroom curriculum, compared to nutrition education embedded in the standard school curriculum during a 1‐month period. Participants completed six questionnaires. Data were analyzed using descriptive statistics, t tests, and Pearson's r correlation coefficient.
Findings and Conclusions:

The intervention group had significantly higher scores for SE for fruits and vegetables, SE for lower fat, usual food choices, and dietary knowledge of fat compared to the control group. No difference was found between groups in food consumption. Self‐efficacy was significantly associated with dietary knowledge of lower fat, usual food choices, and was inversely associated with lower‐fat consumption in the hypothesized model of eating behavior. The intervention was tailored to the social and developmental preferences of adolescents and effectively increased SE for HE. The mediating role of SE in the hypothesized model of adolescent eating behavior warrants further investigation.
International Content of High‐Ranking Nursing Journals in the Year 2000
Authors: Dougherty Molly C. , Lin Shu‐Yuan , McKenna Hugh P. , Seers Kate 
Published: May 2004

Purpose:

To evaluate the extent of an international perspective in publication in nursing journals.
Design:

Characteristics of 2,581 articles, authors of articles, and journals (editorial purpose and editorial team) of 42 high‐ranking nursing journals for the year 2000 were analyzed.
Methods:

The characteristics were assessed using seven operational definitions of “international.”
Findings:

Major findings were: (a) 747 (28.9%) articles were identified as international, of which (b) 705 (94.3%) were placed in the scholarly or empirical categories; (c) more articles were categorized as empirical in the international articles; more articles were categorized as scholarly among the noninternational articles; (d) 763 (79.3%) articles met an international definition based on author characteristics; and (e) 20 (47.6%) journals had international editorial teams.
Conclusions:

Nearly 30% of articles had international content. Articles with international content were more frequently databased than were noninternational articles. The study provides a baseline indication of the extent of international perspectives in published articles in nursing journals. The extent to which these international articles make substantial contributions to knowledge has yet to be discovered.
An Integrative Review of American Nurses' Perceived Cultural Self‐Efficacy
Authors: Coffman Maren J. , Shellman Juliette , Bernal Henrietta 
Published: May 2004

Purpose:

To review use of the Cultural Self‐Efficacy Scale (CSES) and to summarize the cumulative findings.
Methods:

A combination of literature searches and questionnaires to those who have requested the scale indicated 26 known uses. Fifteen reported sufficient data for statistical analysis.
Findings:

Of the 26 known uses of the CSES, 8 were published in peer‐reviewed journals, 5 in dissertations, 8 in theses, and 3 as data sets only. Two additional theses were not retrievable for the study. On a 5‐point Likert‐type scale, nurses reported the highest degree of self‐efficacy with African American (3.1) and Hispanic (3.1) patients and the lowest with Asian American patients (2.4). Six of the reports include Cronbach's alpha coefficients, ranging from .86 to .98. In the final sample of 15 studies, nurses did not report feeling confident caring for patients from other cultures.
Conclusions:

Although the CSES has been used in many settings with over 3,000 nurses, inconsistencies in the data preclude specific conclusions. Further research is needed using consistent reporting practices and sufficient predictor variables to draw further conclusions regarding the scale's psychometric properties.
Degeneration and Regeneration of Murine Skeletal Neuromuscular Junctions after Intramuscular Injection with a Sublethal Dose of
Clostridium sordellii
Lethal Toxin
Authors: Barbier Julien , Popoff Michel R. , Molgó Jordi 
Published: May 2004

ABSTRACT

Clostridium sordellii
lethal toxin (LT), a 250-kDa protein which is the bacteria's major virulence factor, belongs to a family of large clostridial cytotoxins which glucosylate small GTP-binding proteins. Here, we report the results of our ex vivo analysis of the structure and function of skeletal neuromuscular tissue obtained from mice at various times after intramuscular injection of a sublethal dose of LT (0.25 ng/g of body wt). The toxin caused, within 24 h, pronounced localized edema, inflammation, myofibril disassembly, and degeneration of skeletal muscle fibers in the injected area, and it glucosylated the muscle tissue's small GTPases. Regeneration of the damaged fibers was evident 6 to 9 days postinjury and was completed by 60 days. The expression of dystrophin, laminin, and fast and neonatal myosin in regenerating fibers, detected by immunofluorescence microscopy, confirmed that LT does not impair the high regenerative capacity of murine skeletal muscle fibers. Functional studies revealed that LT affects muscle contractility and neuromuscular transmission. However, partial recovery of nerve-evoked muscle twitches and tetanic contractions was observed by day 15 postinjection, and extensive remodeling of the neuromuscular junction's nerve terminals and clusters of muscle acetylcholine receptors was still evident 30 days postinjection. In conclusion, to the best of our knowledge, this is the first report to characterize the degeneration and regeneration of skeletal neuromuscular tissue after in vivo exposure to a large clostridial cytotoxin. In addition, our data may provide an explanation for the severe neuromuscular alterations accompanying wound infections caused by
C. sordellii
.
PneumocystisActivates Human Alveolar Macrophage NF-κB Signaling through Mannose Receptors
Authors: Zhang Jianmin , Zhu Jinping , Imrich Amy , Cushion Melanie , Kinane T. Bernard , Koziel Henry 
Published: May 2004

ABSTRACTAlveolar macrophages (AM) represent important effector cells in the innate immune response to the AIDS-related pathogenPneumocystis, but the early AM host defense signaling events are poorly defined. Using AM from healthy individuals, we showed in the present study thatPneumocystisorganisms stimulate AM NF-κB p50 and p65 nuclear translocation in a time-dependent and multiplicity-of-infection-dependent manner as determined by electrophoretic mobility shift assay and immunofluorescence microscopy and that NF-κB nuclear translocation is associated with I-κB phosphorylation. Importantly, competitive inhibition of mannose receptor and targeted short interfering RNA-mediated gene suppression of mannose receptor mRNA and protein is associated with complete elimination of NF-κB nuclear translocation in response toPneumocystis. Furthermore, human immunodeficiency virus (HIV) infection of AM (as a model human disease state of reduced AM mannose receptor expression and function) inhibitsPneumocystis-mediated NF-κB nuclear translocation and is associated with reduced I-κB phosphorylation and reduced interleukin-8 (IL-8) release. In contrast, NF-κB nuclear translocation and IL-8 release in response to lipopolysaccharide are intact in AM from both healthy and HIV-infected individuals, indicating that the observed impairment is not a global disturbance of the NF-κB pathway. Thus, in addition to phagocytic and endocytic effector functions, the present study identifies mannose receptors as pattern recognition receptors capable of NF-κB activation in response to infectious non-self challenge. AM mannose receptor-mediated NF-κB activation may represent an important mechanism of the host cell response toPneumocystis, and altered NF-κB activation in the context of HIV infection may impair a critical innate immune signaling response and may contribute to pathogenesis of opportunistic lung infections.
Myeloid Differentiation Antigen 88 Deficiency Impairs Pathogen Clearance but Does Not Alter Inflammation inBorrelia burgdorferi-Infected Mice
Authors: Liu Nengyin , Montgomery Ruth R. , Barthold Stephen W. , Bockenstedt Linda K. 
Published: May 2004

ABSTRACTThe spirocheteBorrelia burgdorfericauses acute inflammation in mice that resolves with the development of pathogen-specific adaptive immunity.B. burgdorferilipoproteins activate innate immune cells via Toll-like receptor 2 (TLR2), but TLR2-deficient mice are not resistant toB. burgdorferi-induced disease, suggesting the involvement of other TLRs or non-TLR mechanisms in the induction of acute inflammation. For this study, we used mice that were deficient in the intracellular adapter molecule myeloid differentiation antigen 88 (MyD88), which is required for all TLR-induced inflammatory responses, to determine whether the interruption of this pathway would alterB. burgdorferi-induced disease. Infected MyD88−/−mice developed carditis and arthritis, similar to the disease in wild-type (WT) mice analyzed at its peak (days 14 and 28) and during regression (day 45). MyD88−/−macrophages produced tumor necrosis factor alpha only when spirochetes were opsonized, suggesting a role forB. burgdorferi-specific antibody in disease expression. MyD88−/−mice produced stronger pathogen-specific Th2-dependent immunoglobulin G1 (IgG1) responses than did WT mice, and their IgM titers remained significantly elevated through 90 days of infection. Despite specific antibodies, the pathogen burden was 250-fold higher in MyD88−/−mice than in WT mice 45 days after infection; by 90 days of infection, the pathogen burden had diminished substantially in MyD88−/−mice, but it was still elevated compared to that in WT mice. The elevated pathogen burden may be explained in part by the finding that MyD88−/−peritoneal macrophages could ingest spirochetes but degraded them more slowly than WT macrophages. Our results show that MyD88-dependent signaling pathways are not required forB. burgdorferi-induced inflammation but are necessary for the efficient control of the pathogen burden by phagocytes.
Virulent and Avirulent Strains ofFrancisella tularensisPrevent Acidification and Maturation of Their Phagosomes and Escape into the Cytoplasm in Human Macrophages
Authors: Clemens Daniel L. , Lee Bai-Yu , Horwitz Marcus A. 
Published: May 2004

ABSTRACTFrancisella tularensis, the agent of tularemia, is an intracellular pathogen, but little is known about the compartment in which it resides in human macrophages. We have examined the interaction of a recent virulent clinical isolate ofF. tularensissubsp.tularensisand the live vaccine strain with human macrophages by immunoelectron and confocal immunofluorescence microscopy. We assessed the maturation of theF. tularensisphagosome by examining its acquisition of the lysosome-associated membrane glycoproteins (LAMPs) CD63 and LAMP1 and the acid hydrolase cathepsin D. Two to four hours after infection, vacuoles containing liveF. tularensiscells acquired abundant staining for LAMPs but little or no staining for cathepsin D. However, after 4 h, the colocalization of LAMPs with liveF. tularensisorganisms declined dramatically. In contrast, vacuoles containing formalin-killed bacteria exhibited intense staining for all of these late endosomal/lysosomal markers at all time points examined (1 to 16 h). We examined the pH of the vacuoles 3 to 4 h after infection by quantitative immunogold staining and by fluorescence staining for lysosomotropic agents. Whereas phagosomes containing killed bacteria stained intensely for these agents, indicating a marked acidification of the phagosomes (pH 5.5), phagosomes containing liveF. tularensisdid not concentrate these markers and thus were not appreciably acidified (pH 6.7). An ultrastructural analysis of theF. tularensiscompartment revealed that during the first 4 h after uptake, the majority ofF. tularensisbacteria reside within phagosomes with identifiable membranes. The cytoplasmic side of the membranes of ∼50% of these phagosomes was coated with densely staining fibrils of ∼30 nm in length. In many cases, these coated phagosomal membranes appeared to bud, vesiculate, and fragment. By 8 h after infection, the majority of liveF. tularensisbacteria lacked any ultrastructurally discernible membrane separating them from the host cell cytoplasm. These results indicate thatF. tularensisinitially enters a nonacidified phagosome with LAMPs but without cathepsin D and that the phagosomal membrane subsequently becomes morphologically disrupted, allowing the bacteria to gain direct access to the macrophagic cytoplasm. The capacity ofF. tularensisto alter the maturation of its phagosome and to enter the cytoplasm is likely an important element of its capacity to parasitize macrophages and has major implications for vaccine development.
RecombinantStreptococcus equiProteins Protect Mice in Challenge Experiments and Induce Immune Response in Horses
Authors: Flock Margareta , Jacobsson Karin , Frykberg Lars , Hirst Timothy R. , Franklin Anders , Guss Bengt , Flock Jan-Ingmar 
Published: May 2004

ABSTRACTHorses that have undergone infection caused byStreptococcus equisubspeciesequi(strangles) were found to have significantly increased serum antibody titers against three previously characterized proteins, FNZ (cell surface-bound fibronectin binding protein), SFS (secreted fibronectin binding protein), and EAG (α2-macroglobulin, albumin, and immunoglobulin G [IgG] binding protein) fromS. equi. To assess the protective efficacy of vaccination with these three proteins, a mouse model of equine strangles was utilized. Parts of the three recombinant proteins were used to immunize mice, either subcutaneously or intranasally, prior to nasal challenge withS. equisubsp.equi. The adjuvant used was EtxB, a recombinant form of the B subunit ofEscherichia coliheat-labile enterotoxin. It was shown that nasal colonization ofS. equisubsp.equiand weight loss due to infection were significantly reduced after vaccination compared with a mock-vaccinated control group. This effect was more pronounced after intranasal vaccination than after subcutaneous vaccination; nearly complete eradication of nasal colonization was obtained after intranasal vaccination (P< 0.001). When the same antigens were administered both intranasally and subcutaneously to healthy horses, significant mucosal IgA and serum IgG antibody responses against FNZ and EAG were obtained. The antibody response was enhanced when EtxB was used as an adjuvant. No adverse effects of the antigens or EtxB were observed. Thus, FNZ and EAG in conjunction with EtxB are promising candidates for an efficacious and safe vaccine against strangles.
Induction of Morphological and Electrophysiological Changes in Hamster Cornea after In Vitro Interaction with Trophozoites of
Acanthamoeba
spp
Authors: Omaña-Molina Maritza , Navarro-García Fernando , González-Robles Arturo , Serrano-Luna José de Jesús , Campos-Rodríguez Rafael , Martínez-Palomo Adolfo , Tsutsumi Víctor , Shibayama Mineko 
Published: May 2004

ABSTRACT

Acanthamoeba castellani
and
Acanthamoeba polyphaga
are free-living amebae that cause keratitis and granulomatous encephalitis in humans. We have analyzed the early morphological and electrophysiological changes occurring during the in vitro interaction of cultured amebae with intact or physically damaged corneas obtained from hamsters. Both species of
Acanthamoeba
produced similar cytopathic changes, as seen by light microscopy and scanning electron microscopy. After adhesion to the epithelial surface, trophozoites formed clumps and migrated toward the cell borders, causing the separation of adjacent cells at 1 h of coculture. At later stages (2 to 4 h), some amebae were found under desquamating epithelial cells whereas others were seen associated with damaged cells or forming amebostome-like structures to ingest detached epithelial cells. Control corneas incubated in culture medium conditioned with amebae showed a cytoplasmic vacuolization and blurring of the epithelial-stromal junction. The early stages of corneal epithelial damage caused by amebae were also analyzed by measuring the transepithelial resistance changes in corneas mounted in Ussing chambers. Both species of
Acanthamoeba
caused a rapid decrease in electrical resistance. The present observations demonstrate that under in vitro conditions,
Acanthamoeba
trophozoites rapidly cause significant damage to the corneal epithelium. Furthermore, in our experimental model, previous physical damage to the corneas was not a prerequisite for the development of amebic corneal ulcerations.