bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differentiation and enrichment of expandable chondrogenic cells from human embryonic stem cells in vitro
Authors: Toh Wei Seong , Guo Xi‐Min , Choo Andre B. , Lu Kai , Lee Eng Hin , Cao Tong 
Published: May 2009

AbstractHuman embryonic stem cells (hESCs) are considered as useful tools for pre‐clinical studies in regenerative medicine. Although previous reports have shown direct chondrogenic differentiation of mouse and hESCs, low yield and cellular heterogenicity of the resulting cell population impairs the generation of sufficient numbers of differentiated cells for further testing and applications. Based on our previously established high‐density micromass model system to study hESC chondrogenesis, we evaluated the effects of transforming growth factor (TGF)‐β1 and bone morphogenetic protein‐2 on early stages of chondrogenic differentiation and commitment by hESCs. Significant chondrogenic induction of hESCs, as determined by quantitative measurements of cartilage‐related gene expression and matrix protein synthesis, was achieved in the presence of TGF‐β1. By means of selective growth factor combination (TGF‐β1, FGF‐2 and platelet‐derived growth factor‐bb) and plating on extracellular matrix substratum, we report here the reproducible isolation of a highly expandable, homogenous and unipotent chondrogenic cell population, TC1, from chondrogenically committed hESCs. Like primary chondrocytes, TC1 rapidly dedifferentiates upon isolation and monolayer expansion but retains the chondrogenic differentiation potential and responds to TGF‐β1 for cartilaginous tissue formation both in vitro and in vivo. In addition, TC1 displays a somatic cell cycle kinetics, a normal karyotype and does not produce teratoma in vivo. Thus, TC1 may provide a potential source of chondrogenic cells for drug testing, gene therapy and cell‐based therapy.
Membrane‐type 4 matrix metalloproteinase (MT4‐MMP) induces lung metastasis by alteration of primary breast tumour vascular architecture
Authors: Chabottaux Vincent , Ricaud Stéphanie , Host Laurent , Blacher Silvia , Paye Alexandra , Thiry Marc , Garofalakis Anikitos , Pestourie Carine , Gombert Karine , Bruyere Françoise , Lewandowsky Daniel , Tavitian Bertrand , Foidart Jean‐Michel , Duconge Frédéric , Noel Agnès 
Published: May 2009

AbstractThe present study aims at investigating the mechanism by which membrane‐type 4 matrix metalloproteinase (MT4‐MMP), a membrane‐anchored MMP expressed by human breast tumour cells promotes the metastatic dissemination into lung. We applied experimental (intravenous) and spontaneous (subcutaneous) models of lung metastasis using human breast adenocarcinoma MDA‐MB‐231 cells overexpressing or not MT4‐MMP. We found that MT4‐MMP does not affect lymph node colonization nor extravasation of cells from the bloodstream, but increases the intravasation step leading to metastasis. Ultrastructural and fluorescent microscopic observations coupled with automatic computer‐assisted quantifications revealed that MT4‐MMP expression induces blood vessel enlargement and promotes the detachment of mural cells from the vascular tree, thus causing an increased tumour vascular leak. On this basis, we propose that MT4‐MMP promotes lung metastasis by disturbing the tumour vessel integrity and thereby facilitating tumour cell intravasation.
Tweak induces proliferation in renal tubular epithelium: a role in uninephrectomy induced renal hyperplasia
Authors: Sanz Ana B. , Sanchez‐Niño Maria Dolores , Izquierdo Maria Concepcion , Jakubowski Aniela , Justo Pilar , Blanco‐Colio Luis M. , Ruiz‐Ortega Marta , Egido Jesús , Ortiz Alberto 
Published: May 2009

AbstractThe tumour necrosis factor (TNF) family member TWEAK activates the Fn14 receptor and has pro‐apoptotic, proliferative and pro‐inflammatory actions that depend on the cell type and the microenvironment. We explored the proliferative actions of TWEAK on cultured tubular cells and in vivo on renal tubules. Additionally, we studied the role of TWEAK in compensatory proliferation following unilateral nephrectomy and in an inflammatory model of acute kidney injury (AKI) induced by a folic acid overdose. TWEAK increased the proliferation, cell number and cyclin D1 expression of cultured tubular cells, in vitro. Exposure to serum increased TWEAK and Fn14 expression and the proliferative response to TWEAK. TWEAK activated the mitogen‐activated protein kinases ERK and p38, the phosphatidyl‐inositol 3‐kinase (PI3K)/Akt pathway and NF‐κB. TWEAK‐induced proliferation was prevented by inhibitors of these protein kinases and by the NF‐κB inhibitor parthenolide. TWEAK‐induced tubular cell proliferation as assessed by PCNA and cyclin D1 expression in the kidneys of adult healthy mice in vivo. By contrast, TWEAK knock‐out mice displayed lower tubular cell proliferation in the remnant kidney following unilateral nephrectomy, a non‐inflammatory model. This is consistent with TWEAK‐induced proliferation on cultured tubular cells in the absence of inflammatory cytokines. Consistent with our previously published data, in the presence of inflammatory cytokines TWEAK promoted apoptosis, not proliferation, of cultured tubular cells. In this regard, TWEAK knock‐out mice with AKI displayed less tubular apoptosis and proliferation, as well as improved renal function. In conclusion, TWEAK actions in tubular cells are context dependent. In a non‐inflammatory milieu TWEAK induces proliferation of tubular epithelium. This may be relevant for compensatory renal hyperplasia following nephrectomy.
High‐throughput gene expression analysis in bone healing around titanium implants by DNA microarray
Authors: Kojima Norinaga , Ozawa Shogo , Miyata Yasuhiro , Hasegawa Hideki , Tanaka Yoshinobu , Ogawa Takahiro 
Published: May 2009

AbstractObjective: Bone generation occurs around titanium implants; however, its underlying mechanisms are relatively unknown. We attempt to identify gene transcripts specifically upregulated in in vivo bone healing with titanium implants using DNA microarray.Material and methods: Titanium implants were placed into rat femurs, and total RNA was extracted from the implant‐associated tissue at weeks 1, 2 and 4 of healing. As a control, RNA was extracted from the tissue undergoing osteotomy healing. The RNA samples were hybridized onto oligo DNA microarray.Results: Most of the 20,000 genes tested were expressed similarly in both the implant‐ and osteotomy‐healing groups. Eighty‐six genes were upregulated (>2‐fold) in the implant‐healing group compared with the osteotomy‐healing group in at least one time point of healing. Twelve genes were upregulated in the implant healing at week 2 and earlier, while 31 genes were upregulated at week 2 and later. Only one gene was upregulated specifically at week 1, while three genes were consistently upregulated from weeks 1 to 4. The upregulated genes included collagenous and non‐collagenous extracellular matrix (ECM)‐related genes, proteoglycans and bone resorption‐related genes. Pathway analysis revealed the involvement of ECM and receptor interaction in implant healing.Conclusions: This study provides evidence that a set of gene transcripts is upregulated in the implant healing over the osteotomy healing, which seems to represent the coordinated biological events of long‐lasting osteogenesis and bone remodeling required for osseointegration. Further studies are needed to identify the significance and biological roles of the transcripts in osseointegration. Proven reliability and usefulness of microarray technology should encourage future approaches to develop a high‐throughput molecular assessment for osseointegration capacity of new implant surfaces.
Reproductive performance in arctic‐nesting geese is influenced by environmental conditions during the wintering, breeding and migration seasons
Authors: Trinder Mark N. , Hassell David , Votier Stephen 
Published: May 2009

Arctic regions are expected to experience pronounced changes in climate during the current century. Large numbers of waterfowl breed in these regions, and any climate induced changes are likely to have consequences for their demographics. Moreover, environmental changes experienced during migration and on the wintering grounds may also have impacts but remain poorly understood.We investigate the role of climate variation during breeding, migration and wintering, while controlling for possible effects of mammalian predation and density dependence on the reproduction of Svalbard breeding barnacle geeseBranta leucopsisusing 40 years of observations.Breeding success was significantly positively correlated with temperature on both the wintering grounds (Scotland) and breeding grounds (Svalbard), but negatively correlated with the number of days of strong cross‐winds during the northward migration period. These factors remained significant when controlling for a strong negative effect of population size.Goose reproduction on Svalbard was also linked to fluctuations in arctic foxAlopex lagopuspopulations occurring elsewhere in the arctic. This reveals the importance of mammalian predation, which may vary as a non‐linear function of conditions within the wider arctic region.Climate predictions were used to project barnacle goose reproduction and hence the population until 2050. These simulations suggest the population will grow at between 1% and 2.7% per year, in response to increasing temperatures. However, it is harder to predict how changes in other factors, such as reductions in sea ice, may impact on arctic breeding birds.
Guidelines for procedural pain in the newborn
Authors: Lago Paola , Garetti Elisabetta , Merazzi Daniele , Pieragostini Luisa , Ancora Gina , Pirelli Anna , Bellieni Carlo Valerio ,   on behalf of the Pain Study Group of the Italian Society of Neonatology
Published: May 2009

AbstractDespite accumulating evidence that procedural pain experienced by newborn infants may have acute and even long‐term detrimental effects on their subsequent behaviour and neurological outcome, pain control and prevention remain controversial issues. Our aim was to develop guidelines based on evidence and clinical practice for preventing and controlling neonatal procedural pain in the light of the evidence‐based recommendations contained in the SIGN classification. A panel of expert neonatologists used systematic review, data synthesis and open discussion to reach a consensus on the level of evidence supported by the literature or customs in clinical practice and to describe a global analgesic management, considering pharmacological, non‐pharmacological, behavioural and environmental measures for each invasive procedure. There is strong evidence to support some analgesic measures, e.g. sucrose or breast milk for minor invasive procedures, and combinations of drugs for tracheal intubation. Many other pain control measures used during chest tube placement and removal, screening and treatment for ROP, or for postoperative pain, are still based not on evidence, but on good practice or expert opinions.Conclusion: These guidelines should help improving the health care professional's awareness of the need to adequately manage procedural pain in neonates, based on the strongest evidence currently available.
Passive induction of hypothermia during transport of asphyxiated infants: a risk of excessive cooling
Authors: Hallberg Boubou , Olson Linus , Bartocci Marco , Edqvist Ingela , Blennow Mats 
Published: May 2009

AbstractBackground: Induced mild hypothermia is an emerging therapy that has been shown to reduce the combined outcome of death or severe neurodevelopmental disabilities in asphyxiated full‐term infants if started within 6 h after birth.Aim: To study the feasibility and safety of inducing hypothermia in asphyxiated infants already at the referring hospital by stopping active warming.Methods: Temperatures during passive induction of hypothermia were prospectively collected from transported asphyxiated infants.Results: Between December 2006 and April 2008, 37 infants of the total birth cohort of 40 350 fulfilled the criteria for hypothermia treatment. Eighteen of 34 infants treated with induced hypothermia were outborn. The rectal temperatures of the infants were 33.0–36.4°C before transport and 31.0–36.5°C on arrival. Six of the infants had a sub‐therapeutic (<33.0°C) rectal temperature on arrival.Conclusion: Passive induction of hypothermia by turning off active warming devices is possible, making an earlier start of hypothermia achievable. However, there is a substantial risk of unintended excessive cooling; therefore, continuous monitoring of the central temperature is mandatory when such a strategy is used.
Changes in Sexual Expression as Result of Defoliation and Environment in a Monoecious Shrub in Mexico: Implications for Pollination
Authors: Arceo‐Gómez Gerardo , Parra‐Tabla Víctor , Navarro Jorge 
Published: May 2009

ABSTRACTFolivory may indirectly impact plant reproduction through changes in sexual expression (i.e., number or proportion of male and female flowers produced), which influence plant–pollinator interactions via changes in pollinator preference or efficiency. This study is an experimental evaluation of the effect that defoliation has on sex expression in the monoecious shrubCnidoscolus aconitifolius, how such effect varies across sites, as well as how such changes indirectly affect pollinator visitation rates. The present study used three populations ofC. aconitifolius, each one located in a different site in Yucatán (México): pasture, deciduous forest and subdeciduous medium height forest and three levels of defoliation: 50 percent, 100 percent, and a control (no damage). Results showed that defoliation reduced significantly the total number of male flowers produced in two of the sites. Defoliation did not impact female flower production or the proportion of female flowers produced. Finally, floral visit rates were not affected by defoliation via changes in sexual expression and neither by site or by the interaction site × defoliation. Findings showed that defoliation had an effect on sex expression inC. aconitifolius, although apparently this change did not affect the plant–pollinator interactions.
The effects of nurse practitioner cultural competence on Latina patient satisfaction
Authors: Castro Anabell , Ruiz Ester 
Published: May 2009

AbstractPurpose: To explore the relationship between degree of cultural competence in nurse practitioners (NPs) and measures of patient satisfaction among Latinas.Data sources: A descriptive correlational design was used to examine the degree of cultural competence in NPs and measures of patient satisfaction among Latinas. A convenience sample of 15 licensed NPs from 11 different clinics in a large southwestern city completed two self‐administered questionnaires. A convenience sample of 218 Latina patients completed three self‐administered questionnaires available in both English and Spanish. Descriptive statistics and correlations were used to analyze the data.Conclusions: Latina patients reported greater satisfaction with NPs of Latina origin who were certified, had received cultural competence training, could speak Spanish, and had attended master’s level programs. Latina patients were also most satisfied with decreased clinic waiting time. The two NPs with the highest levels of cultural competency scores were non‐Latinas. Noticeable differences were found in the amount of cultural competence exhibited by NPs.Implications for practice: The provision of culturally competent care leads to negotiation, mutual exchange of information, increased compliance, and improved patient‐provider communication. Similarly, patient satisfaction with care is associated with increased compliance and greater continuity of care. Employers seeking to meet the healthcare demands of a growing Latino population must look at extrinsic values such as NPs’ certification, cultural competence training, education, and ability to speak Spanish.
Coxiella burnetiiSurvives in Monocytes from Patients with Q Fever Endocarditis: Involvement of Tumor Necrosis Factor
Authors: Dellacasagrande Jérôme , Ghigo Eric , Capo Christian , Raoult Didier , Mege Jean-Louis 
Published: May 2009

ABSTRACTEndocarditis is the most frequent form of chronic Q fever, an infectious disease caused byCoxiella burnetii. As this obligate intracellular bacterium inhabits monocytes and macrophages, we wondered if pathogenesis of Q fever endocarditis is related to defective intracellular killing ofC. burnetiiby monocytes. Monocytes from healthy controls eliminated virulentC. burnetiiwithin 3 days. In contrast, monocytes from patients with ongoing Q fever endocarditis were unable to eliminate bacteria even after 6 days. In patients who were cured of endocarditis, the monocyte infection was close to that of control monocytes. This killing deficiency was not the consequence of generalized functional impairment, since patient monocytes eliminated avirulentC. burnetiias did control cells. The addition of supernatants ofC. burnetii-stimulated monocytes from patients with ongoing endocarditis to control monocytes enabled them to supportC. burnetiisurvival, suggesting that some soluble factor is responsible for bacterial survival. This factor was related to tumor necrosis factor (TNF): expression of TNF mRNA and TNF release were increased in response toC. burnetiiin patients with ongoing endocarditis compared to cured patients and healthy controls. In addition, neutralizing anti-TNF antibodies decreasedC. burnetiiinternalization, an early step of bacterial killing, in monocytes from patients with ongoing endocarditis but did not affect delayed steps of intracellular killing. We suggest that Q fever-associated activation of monocytes allows the survival ofC. burnetiiby modulating early phases of microbial killing.
Inhibition of Human NK Cell Function by Valinomycin, a Toxin fromStreptomyces griseusin Indoor Air
Authors: Paananen Auli , Mikkola Raimo , Sareneva Timo , Matikainen Sampsa , Andersson Maria , Julkunen Ilkka , Salkinoja-Salonen Mirja S. , Timonen Tuomo 
Published: May 2009

ABSTRACTStreptomyces griseusstrains isolated from indoor dust have been shown to synthesize valinomycin. In this report, we show that human peripheral blood lymphocytes treated with small doses (30 ng ml−1) of pure valinomycin or high-pressure liquid chromatography-pure valinomycin fromS. griseusquickly show mitochondrial swelling and reduced NK cell activity. Larger doses (>100 ng/ml−1) induced NK cell apoptosis within 2 days. Within 2 h, the toxin at 100 ng ml−1dramatically inhibited interleukin-15 (IL-15)- and IL-18-induced granulocyte-macrophage colony-stimulating factor and gamma interferon (IFN-γ) production by NK cells. However, IFN-γ production induced by a combination of IL-15 and IL-18 was somewhat less sensitive to valinomycin, suggesting a protective effect of the cytokine combination against valinomycin. Thus, valinomycin in very small doses may profoundly alter the immune response by reducing NK cell cytotoxicity and cytokine production.
Cytolethal Distending Toxin Sequence and Activity in the Enterohepatic PathogenHelicobacter hepaticus
Authors: Young Vincent B. , Knox Kimberly A. , Schauer David B. 
Published: May 2009

ABSTRACTLittle is known about the molecular pathogenesis of hepatitis and enterocolitis caused by enterohepaticHelicobacterspecies. Sonicates of the murine pathogenHelicobacter hepaticuswere found to cause progressive cell distension, accumulation of filamentous actin, and G2/M cell cycle arrest in HeLa cell monolayers. The genes encoding this cytotoxic activity were cloned fromH. hepaticus. Three open reading frames with closest homology tocdtA,cdtB, andcdtCfromCampylobacter jejuniwere identified. Sonicates of a laboratory strain ofEscherichia colicarrying the clonedcdtABCgene cluster fromH. hepaticusreproduced the cytotoxic activities seen with sonicates ofH. hepaticus. Cytolethal distending toxin activity is a potential virulence determinant ofH. hepaticusthat may play a role in the pathogenesis ofHelicobacter-associated hepatitis and enterocolitis.
Differences in Resistance of C57BL/6 and C57BL/10 Mice to Infection byMycobacterium aviumAre Independent of Gamma Interferon
Authors: Appelberg Rui , Leal Irene S. , Pais Teresa F. , Pedrosa Jorge , Flórido Manuela 
Published: May 2009

ABSTRACTAfter infection with a low-virulence strain ofMycobacterium avium, C57BL/6 and C57BL/10 mice had clear differences in the control of the infection in their livers and spleens. This difference in susceptibility was not associated with differences in theH-2complex. It was dependent on the activity of CD4+T cells but unrelated to the ability of these cells to secrete gamma interferon or to the development of delayed-type hypersensitivity responses at 3 weeks of infection. It was associated with lower total numbers of CD4+cells present in infected spleens and was related to an earlier induction of protective T cells, as measured by adoptive-transfer assays. These data further strengthen the notion of gamma-interferon-independent mechanisms of protection against mycobacteria.
Invasion and Intracellular Survival of
Burkholderia cepacia
Authors: Martin Daniel W. , Mohr Christian D. 
Published: May 2009

ABSTRACT

Burkholderia cepacia
has emerged as an important pulmonary pathogen in immunocompromised patients and in patients with cystic fibrosis (CF). Little is known about the virulence factors and pathogenesis of
B. cepacia
, although the persistent and sometimes invasive infections caused by
B. cepacia
suggest that the organism possesses mechanisms for both cellular invasion and evasion of the host immune response. In this study, cultured human cells were used to analyze the invasion and intracellular survival of
B. cepacia
J2315, a highly transmissible clinical isolate responsible for morbidity and mortality in CF patients. Quantitative invasion and intracellular growth assays demonstrated that
B. cepacia
J2315 was able to enter, survive, and replicate intracellularly in U937-derived macrophages and A549 pulmonary epithelial cells. Transmission electron microscopy of infected macrophages confirmed the presence of intracellular
B. cepacia
and showed that intracellular bacteria were contained within membrane-bound vacuoles. An environmental isolate of
B. cepacia
, strain J2540, was also examined for its ability to invade and survive intracellularly in cultured human cells. J2540 entered cultured macrophages with an invasion frequency similar to that of the clinical strain, but it was less invasive than the clinical strain in epithelial cells. In marked contrast to the clinical strain, the environmental isolate was unable to survive or replicate intracellularly in either cultured macrophages or epithelial cells. Invasion and intracellular survival may play important roles in the ability of virulent strains of
B. cepacia
to evade the host immune response and cause persistent infections in CF patients.