bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting Effects of Physical Wear on Elution of Two Antibiotics from Orthopedic Cement
Authors: Dodds S. , Smith T. J. , Akid R. , Stephenson J. , Nichol T. , Banerjee R. D. , Stockley I. , Townsend R. 
Published: December 2011

ABSTRACT
The use of antibiotics as a supplement to bone cement for the purposes of providing a local release of antibiotics is common practice in arthroplasty surgery and the kinetics of elution of the antibiotics in such systems have been investigated previously. However, in these previous studies no account was taken of the potential effects that wear may have on the elution kinetics of the antibiotic. Here, we have modified an existing wear testing rig to allow the simultaneous study of the elution kinetics of bone cement samples containing antibiotics being subjected to immersion only and immersion and conjoint wear. The results show contrasting effects with two commonly used antibiotics. Bone cement containing daptomycin showed no substantial change in antibiotic elution due to wear, while cement containing gentamicin (the most commonly used antibiotic in this application) in contrast demonstrated a substantial reduction in the rate of antibiotic elution when wear was applied. Scanning electron microscopy revealed a possible explanation for these diverse results, due to wear-induced “sealing” of the surface in conjunction with the crystal morphology of the antibiotic.
High Prevalence of Isolates with Reduced Glycopeptide Susceptibility in Persistent or Recurrent Bloodstream Infections Due to Methicillin-Resistant Staphylococcus aureus
Authors: Uçkay Ilker , Bernard Louis , Buzzi Marta , Harbarth Stephan , François Patrice , Huggler Elzbieta , Ferry Tristan , Schrenzel Jacques , Renzoni Adriana , Vaudaux Pierre , Lew Daniel P. 
Published: December 2011

ABSTRACT

Reduced susceptibility to glycopeptides in methicillin-resistant
Staphylococcus aureus
(MRSA) clinical isolates is considered a risk factor for failure of glycopeptide therapy. We compared the prevalences of MRSA isolates with reduced glycopeptide susceptibility in patients with versus without persistent or recurrent MRSA bloodstream infections. A retrospective cohort study at the University Hospital of Geneva identified 27 patients with persistent or recurrent clonally related MRSA bacteremic episodes over an 8-year period, which included 208 consecutive nosocomial MRSA bacteremic episodes. Vancomycin and teicoplanin MICs were determined by a modified macrodilution assay allowing improved detection of glycopeptide-intermediate MRSA isolates (GISA), characterized by elevated teicoplanin or/and vancomycin MICs (≥4 μg/ml). For 16 patients (59%), their pretherapy and/or posttherapy MRSA isolates showed elevated teicoplanin MICs, among which 10 (37%) concomitantly displayed elevated vancomycin MICs. In contrast, 11 other patients (41%) were persistently or recurrently infected with non-GISA isolates. In comparison, only 39 (22%) of 181 single isolates from patients with no microbiological evidence of persistent or recurrent infections showed elevated teicoplanin MICs, among which 14 (8%) concomitantly displayed elevated vancomycin MICs. Clinical, microbiological, and pharmacokinetic variables for patients persistently or recurrently infected with GISA or non-GISA isolates were similar. Bacteremic patients with a poor response to glycopeptide therapy had a 2.8-fold- and 4.8-fold-higher rates of MRSA isolates displaying elevated teicoplanin and vancomycin MICs, respectively, than patients with single isolates (
P
< 0.0001). Detection of elevated teicoplanin MICs may help to predict a poor response to glycopeptide therapy in MRSA bacteremic patients.
Prospective Multicenter Study of the Impact of Carbapenem Resistance on Mortality in Pseudomonas aeruginosa Bloodstream Infections
Authors: Peña Carmen , Suarez Cristina , Gozalo Mónica , Murillas Javier , Almirante Benito , Pomar Virginia , Aguilar Manuela , Granados Ana , Calbo Esther , Rodríguez-Baño Jesús , Rodríguez Fernando , Tubau Fe , Martínez-Martínez Luis , Oliver Antonio ,   for the Spanish Network for Research in Infectious Diseases (REIPI)
Published: December 2011

ABSTRACT

The impact of antimicrobial resistance on clinical outcomes is the subject of ongoing investigations, although uncertainty remains about its contribution to mortality. We investigated the impact of carbapenem resistance on mortality in
Pseudomonas aeruginosa
bacteremia in a prospective multicenter (10 teaching hospitals) observational study of patients with monomicrobial bacteremia followed up for 30 days after the onset of bacteremia. The adjusted influence of carbapenem resistance on mortality was studied by using Cox regression analysis. Of 632 episodes, 487 (77%) were caused by carbapenem-susceptible
P. aeruginosa
(CSPA) isolates, and 145 (23%) were caused by carbapenem-resistant
P. aeruginosa
(CRPA) isolates. The median incidence density of nosocomial CRPA bacteremia was 2.3 episodes per 100,000 patient-days (95% confidence interval [CI], 1.9 to 2.8). The regression demonstrated a time-dependent effect of carbapenem resistance on mortality as well as a significant interaction with the Charlson index: the deleterious effect of carbapenem resistance on mortality decreased with higher Charlson index scores. The impact of resistance on mortality was statistically significant only from the fifth day after the onset of the bacteremia, reaching its peak values at day 30 (adjusted hazard ratio for a Charlson score of 0 at day 30, 9.9 [95% CI, 3.3 to 29.4]; adjusted hazard ratio for a Charlson score of 5 at day 30, 2.6 [95% CI, 0.8 to 8]). This study clarifies the relationship between carbapenem resistance and mortality in patients with
P. aeruginosa
bacteremia. Although resistance was associated with a higher risk of mortality, the study suggested that this deleterious effect may not be as great during the first days of the bacteremia or in the presence of comorbidities.
Resuscitation-Promoting Factors Are Required for β-Lactam Tolerance and the Permeability Barrier in Mycobacterium tuberculosis
Authors: Wivagg Carl N. , Hung Deborah T. 
Published: December 2011

ABSTRACT

Mycobacterial resuscitation-promoting factors (RPFs) have been of great interest since the discovery that they promote the growth of nonculturable
Mycobacterium tuberculosis
cells. Yet, their precise role in mycobacterial survival and infection has remained elusive. We performed a chemical screen to identify molecules that show preferential killing of a
Mycobacterium tuberculosis
mutant lacking RPFs over wild-type bacilli and found that the mutant has enhanced sensitivity to the β-lactam class of antibiotics. By monitoring β-lactam diffusion across the mycobacterial outer membrane, we found that the RPFs are required to maintain the outer membrane integrity, as their deletion results in an increase in outer membrane permeability.
The ties linking rock and fossil records and why they are important for palaeobiodiversity studies
Authors: Smith Andrew B. , McGowan Alistair J. 
Published: December 2011

Abstract
A correlation exists between the quality of the rock record and the diversity of fossils recorded from that rock record but what drives that correlation, and how consistent that correlation is across different environments, remain to be determined. Palaeontologists wishing to investigate past diversity patterns need to first address issues of geological bias in their data.
Uncovering the diversification history of marine tetrapods: ecology influences the effect of geological sampling biases
Authors: Benson Roger B. J. , Butler Richard J. 
Published: December 2011

Abstract
Mesozoic terrestrial vertebrates gave rise to sea-going forms independently among the ichthyosaurs, sauropterygians, thalattosaurs, crocodyliforms, turtles, squamates, and other lineages. Many passed through a shallow marine phase before becoming adapted for open ocean life. This allows quantitative testing of factors affecting our view of the diversity of ancient organisms inhabiting different oceanic environments. We implemented tests of correlation using generalized difference transformed data, and multiple regression models. These indicate that shallow marine diversity was driven by changes in the extent of flooded continental area and more weakly influenced by uneven fossil sampling. This is congruent with studies of shallow marine invertebrate diversity and suggests that ‘common cause’ effects are influential in the shallow marine realm. In contrast, our view of open ocean tetrapod diversity is strongly distorted by temporal heterogeneity in fossil record sampling, and has little relationship with continental flooding. Adaptation to open ocean life allowed plesiosaurs, ichthyosaurs and sea turtles to ‘escape’ from periodic extinctions driven by major marine regressions, which affected shallow marine taxa in the Late Triassic and over the Jurassic–Cretaceous boundary. Open ocean taxa declined in advance of the end-Cretaceous extinction. Shallow marine taxa continued diversifying in the terminal stages due to increasing sea-level.

Supplementary material:

The data series and full analytical results are available at
http://www.geolsoc.org.uk/SUP18486
Geological and anthropogenic controls on the sampling of the terrestrial fossil record: a case study from the Dinosauria
Authors: Upchurch P. , Mannion P. D. , Benson R. B. J. , Butler R. J. , Carrano M. T. 
Published: December 2011

Abstract
Dinosaurs provide excellent opportunities to examine the impact of sampling biases on the palaeodiversity of terrestrial organisms. The stratigraphical and geographical ranges of 847 dinosaurian species are analysed for palaeodiversity patterns and compared to several sampling metrics. The observed diversity of dinosaurs, Theropoda, Sauropodomorpha and Ornithischia, are positively correlated with sampling at global and regional scales. Sampling metrics for the same region correlate with each other, suggesting that different metrics often capture the same signal. Regional sampling metrics perform well as explanations for regional diversity patterns, but correlations with global diversity are weaker. Residual diversity estimates indicate that sauropodomorphs diversified during the Late Triassic, but major increases in the diversity of theropods and ornithischians did not occur until the Early Jurassic. Diversity increased during the Jurassic, but many groups underwent extinction during the Late Jurassic or at the Jurassic/Cretaceous boundary. Although a recovery occurred during the Cretaceous, only sauropodomorphs display a long-term upward trend. The Campanian–Maastrichtian diversity ‘peak’ is largely a sampling artefact. There is little evidence for a gradualistic decrease in diversity prior to the end-Cretaceous mass extinction (except for ornithischians), and when such decreases do occur they are small relative to those experienced earlier in dinosaur evolution.

Supplementary material:

The full data set and details of analyses are available at
www.geolsoc.org.uk/SUP18487
The same materials (in the form of an Excel workbook) are also available from the first author on request.
Assessing the quality of the fossil record: insights from vertebrates
Authors: Benton Michael J. , Dunhill Alexander M. , Lloyd Graeme T. , Marx Felix G. 
Published: December 2011

Abstract

Assessing the quality of the fossil record is notoriously hard, and many recent attempts have used sampling proxies that can be questioned. For example, counts of geological formations and estimated outcrop areas might not be defensible as reliable sampling proxies: geological formations are units of enormously variable dimensions that depend on rock heterogeneity and fossil content (and so are not independent of the fossil record), and outcrop areas are not always proportional to rock exposure, probably a closer indicator of rock availability. It is shown that in many cases formation counts will always correlate with fossil counts, whatever the degree of sampling. It is not clear, in any case, that these proxies provide a good estimate of what is missing in the gap between the known fossil record and reality; rather they largely explore the gap between known and potential fossil records. Further, using simple, single numerical metrics to correct global-scale raw data, or to model sampling-driven patterns may be premature. There are perhaps four approaches to exploring the incompleteness of the fossil record, (1) regional-scale studies of geological completeness; (2) regional- or clade-scale studies of sampling completeness using comprehensive measures of sampling, such as numbers of localities or specimens or fossil quality; (3) phylogenetic and gap-counting methods; and (4) model-based approaches that compare sampling as one of several explanatory variables with measures of environmental change, singly and in combination. We suggest that palaeontologists, like other scientists, should accept that their data are patchy and incomplete, and use appropriate methods to deal with this issue in each analysis. All that matters is whether the data are
adequate
for a designated study or not. A single answer to the question of whether the fossil record is driven by macroevolution or megabias is unlikely ever to emerge because of temporal, geographical, and taxonomic variance in the data.
A Conversation with Karl K. Turekian
Authors: Turekian Karl K. , Cochran J. Kirk 
Published: December 2011

Editors' Note Each year, the editorial board invites a distinguished member of the oceanographic community to contribute a prefatory chapter; this year, we were delighted when Karl Turekian, Sterling Professor of Geology and Geophysics at Yale, accepted our invitation. Over the course of a long and productive career, Dr. Turekian has pursued his interests in marine and atmospheric geochemistry by using natural radioactive and radiogenic isotopes to study Earth's evolution and the impacts of global change. He has also directed both the Center for the Study of Global Change at Yale and the Yale Institute for Biospheric Studies. In this interview, conducted by his former student Kirk Cochran, Dr. Turekian tells the story of his early career and discusses some of the major scientific challenges and opportunities faced along the way. His personal account of the rise of geochemistry is a charming story of how chance events and personalities impact scientific careers. His technical insight into the future of this field is illuminating, particularly for scientific outsiders who appreciate the central role of geochemistry in discerning and understanding patterns of global change. –Craig A. Carlson and Stephen J. Giovannoni, Editors
S100A7 Enhances Mammary Tumorigenesis through Upregulation of Inflammatory Pathways
Authors: Nasser Mohd W. , Qamri Zahida , Deol Yadwinder S. , Ravi Janani , Powell Catherine A. , Trikha Prashant , Schwendener Reto A. , Bai Xue-Feng , Shilo Konstantin , Zou Xianghong , Leone Gustavo , Wolf Ronald , Yuspa Stuart H. , Ganju Ramesh K. 
Published: December 2011

Abstract
S100A7/psoriasin, a member of the epidermal differentiation complex, is widely overexpressed in invasive estrogen receptor (ER)α-negative breast cancers. However, it has not been established whether S100A7 contributes to breast cancer growth or metastasis. Here, we report the consequences of its expression on inflammatory pathways that impact breast cancer growth. Overexpression of human S100A7 or its murine homologue mS100a7a15 enhanced cell proliferation and upregulated various proinflammatory molecules in ERα-negative breast cancer cells. To examine in vivo effects, we generated mice with an inducible form of mS100a7a15 (MMTV-mS100a7a15 mice). Orthotopic implantation of MVT-1 breast tumor cells into the mammary glands of these mice enhanced tumor growth and metastasis. Compared with uninduced transgenic control mice, the mammary glands of mice where mS100a7a15 was induced exhibited increased ductal hyperplasia and expression of molecules involved in proliferation, signaling, tissue remodeling, and macrophage recruitment. Furthermore, tumors and lung tissues obtained from these mice showed further increases in prometastatic gene expression and recruitment of tumor-associated macrophages (TAM). Notably, in vivo depletion of TAM inhibited the effects of mS100a7a15 induction on tumor growth and angiogenesis. Furthermore, introduction of soluble hS100A7 or mS100a7a15 enhanced chemotaxis of macrophages via activation of RAGE receptors. In summary, our work used a powerful new model system to show that S100A7 enhances breast tumor growth and metastasis by activating proinflammatory and metastatic pathways. Cancer Res; 72(3); 604–15. ©2011 AACR.
Targeting Quiescent Tumor Cells via Oxygen and IGF-I Supplementation
Authors: Kyle Alastair H. , Baker Jennifer H.E. , Minchinton Andrew I. 
Published: December 2011

Abstract
Conventional chemotherapy targets proliferating cancer cells, but most cells in solid tumors are not in a proliferative state. Thus, strategies to enable conventional chemotherapy to target noncycling cells may greatly increase tumor responsiveness. In this study, we used a 3-dimensional tissue culture system to assay diffusible factors that can limit proliferation in the context of the tumor microenvironment, with the goal of identifying targets to heighten proliferative capacity in this setting. We found that supraphysiologic levels of insulin or insulin-like growth factor I (IGF-I) in combination with oxygen supplementation were sufficient to initiate proliferation of quiescence cells in this system. At maximal induction with IGF-I, net tissue proliferation increased 3- to 4-fold in the system such that chemotherapy could trigger a 3- to 6-fold increase in cytotoxicity, compared with control conditions. These effects were confirmed in vivo in colon cancer xenograft models with demonstrations that IGF-I receptor stimulation was sufficient to generate a 45% increase in tumor cell proliferation, along with a 25% to 50% increase in chemotherapy-induced tumor growth delay. Although oxygen was a dominant factor limiting in vitro tumor cell proliferation, we found that oxygen supplementation via pure oxygen breathing at 1 or 2 atmospheres pressure (mimicking hyperbaric therapy) did not decrease hypoxia in the tumor xenograft mouse model and was insufficient to increase tumor proliferation. Thus, our findings pointed to IGF-I receptor stimulation as a rational strategy to successfully increase tumor responsiveness to cytotoxic chemotherapy. Cancer Res; 72(3); 801–9. ©2011 AACR.
Association of polymorphisms in the AGT gene with essential hypertension in the Chinese population
Authors: Xi Bo , Shen Yue , Yan Yinkun , Mi Jie 
Published: December 2011

Objective: Although the angiotensinogen ( AGT) gene has been implicated in the pathogenesis of essential hypertension, the results have been inconsistent. In this study, we performed a meta-analysis to assess the association of A-6G, A-20C and G-217A polymorphisms in the AGT gene with essential hypertension in the Chinese population. Methods: Published literature from PubMed, Embase, China National Knowledge Infrastructure, China Biological Medicine and Wanfang Data was retrieved. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects models. Results: Sixteen studies (4223 cases and 3743 controls) for A-6G polymorphism, ten studies (3116 cases and 2678 controls) for A-20C polymorphism and five studies (1268 cases and 1081 controls) for G-217A polymorphism were identified. The results from the meta-analyses indicated significant association of all three polymorphism with the risk of essential hypertension in the Chinese population (A-6G polymorphism: GG vs AA: OR = 1.45, 95% CI 1.17–1.81; A-20C polymorphism: CC vs AA: OR = 1.52, 95% CI 1.10–2.08; G-217A polymorphism: AA vs GG: OR = 2.36, 95% CI 1.44–3.89). Conclusions: Our study indicated that three polymorphisms (A-6G, A-20C and G-217A) in the AGT gene are associated with essential hypertension in the Chinese population.
Enhanced outgrowth of EBV-transformed chronic lymphocytic leukemia B cells mediated by coculture with macrophage feeder cells
Authors: Hwang Kwan-Ki , Chen Xi , Kozink Daniel M. , Gustilo Marietta , Marshall Dawn J. , Whitesides John F. , Liao Hua-Xin , Catera Rosa , Chu Charles C. , Yan Xiao-Jie , Luftig Micah A. , Haynes Barton F. , Chiorazzi Nicholas 
Published: December 2011

AbstractB-cell chronic lymphocytic leukemia (B-CLL) is characterized by the clonal expansion of CD5-expressing B lymphocytes that produce mAbs often reactive with microbial or autoantigens. Long-term culture of B-CLL clones would permit the collection and characterization of B-CLL mAbs to study antigen specificity and of B-CLL DNA to investigate molecular mechanisms promoting the disease. However, the derivation of long-term cell lines (eg, by EBV), has not been efficient. We have improved the efficiency of EBV B-CLL transformation of CpG oligonucleotide-stimulated cells by incubating patient peripheral blood mononuclear cells in the presence of an irradiated mouse macrophage cell line, J774A.1. Using this approach, peripheral blood mononuclear cells isolated from 13 of 21 B-CLL patients were transformed as documented by IGHV-D-J sequencing. Four clones grew and retained CD5 expression in culture for 2 to 4 months. However, despite documentation of EBV infection by expression of EBNA2 and LMP1, B-CLL cells died after removal of macrophage feeder cells. Nevertheless, using electrofusion technology, we generated 6 stable hetero-hybridoma cell lines from EBV-transformed B-CLL cells, and these hetero-hybridomas produced immunoglobulin. Thus, we have established enhanced methods of B-CLL culture that will enable broader interrogation of B-CLL cells at the genetic and protein levels.
Prognostic factors in transformed mycosis fungoides: a retrospective analysis of 100 cases
Authors: Benner Marchina F. , Jansen Patty M. , Vermeer Maarten H. , Willemze Rein 
Published: December 2011

Abstract
Large cell transformation (LCT) in mycosis fungoides (MF) is generally associated with an aggressive clinical course and poor survival, requiring aggressive therapeutic approach. However, a proportion of cases may follow an indolent clinical course. To identify prognostic factors, we analyzed the prognostic relevance of clinical, histologic, and immunophenotypical features in a large cohort of transformed MF patients, including 75 patients with only skin lesions, 19 patients with LCT in skin and lymph nodes, and 6 patients with LCT in lymph nodes only. Multivariate analysis of the total group showed that CD30 negativity, folliculotropic MF, extent of skin lesions and extracutaneous transformation were associated with reduced disease-specific survival (DSS) and, except for CD30 negativity and folliculotropic MF, also overall survival. In a multivariate analysis of 75 patients with only skin lesions at the time of LCT, CD30 negativity, folliculotropic MF and extent of skin lesions were independent parameters for both DSS and overall survival. Using the most discriminating parameters as a prognostic index, in both study groups differences in DSS between patients with 0-1 unfavorable prognostic factor(s) and ≥ 2 unfavorable prognostic factors were statistically significant (P < .001). This prognostic index may be helpful in predicting prognosis and selecting the most appropriate treatment in patients with transformed MF.