bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assignment of the ǵene for F‐type phosphofructokinase to human chromosome 10 by somatic cell hybridization and specific immunoprecipitation
Authors: WEIL DOMINIQUE , COTTREAU DOMINIQUE , CONG NGUYEN VAN , REBOURCET RÉGIS , FOUBERT CHANTAL , GROSS MARIE‐SYLVIE , DREYFUS JEAN‐CLAUDE , KAHN AXEL 
Published: October 2007

SummaryA method of specific immunoprecipitation of minor isozymes was developed and applied to the detection of human F‐type phosphofructokinase in man‐rodent somatic cell hybrids.This method allowed us to assign the gene for this newly discovered isozyme of phosphofructokinase to chromosome 10.
Two‐stage computing budget allocation approach for the response surface method
Authors: Peng J. , Lee L. H. , Ng S. H. 
Published: October 2007

AbstractResponse surface methodology (RSM) is one of the main statistical approaches to search for an input combination that optimizes the simulation output. In the early stages of RSM, an iterative steepest ascent search procedure is frequently used. In this paper, we attempt to improve this procedure by considering a more realistic case where there are computing budget constraints, and formulate a new computing budget allocation problem to look into the important issue of allocating computing budget to the design points in the local region of experimentation. We propose a two‐stage computing budget allocation approach, which uses a limited budget to estimate the response surface in the first stage and then uses the rest of the budget to improve the lower bound of the estimated response at the center of the next design region in the second stage. Several numerical experiments are carried out to compare the two‐stage approach with the regular factorial design, which allocates budget equally to each design point. The results show that our two‐stage allocation outperforms the equal allocation, especially when the system noise is large.
Long swings in exchange rates: a stochastic control approach
Authors: Castellano Rosella , D'Ecclesia Rita L. 
Published: October 2007

AbstractA regime‐switching model to describe the exchange rate dynamics is derived as solution to a stochastic control problem. We assume exchange rates evolve according to some macroeconomic variables (fundamental) whose dynamics could be described by a Brownian motion with a state‐dependent drift. The local Monetary Authority is assumed to intervene influencing the evolution of the fundamental, causing the exchange rate to switch from a depreciating to an appreciating regime (and vice versa). We assume the behaviour of the Monetary Authority can be modeled using an optimal control framework where the state variable is represented by the fundamental. The solution of the model allows the determination of an endogenous tolerance band within which the exchange rate freely fluctuates.
Productivity and costs for firms in presence of technology renewal processes
Authors: Cerqueti Roy , Rotundo Giulia 
Published: October 2007

AbstractWide empirical analyses investigated the size and growth rate distribution of business firms, providing a relevant empirical support to economic theory. We rely on such analyses and on studies on technology renewal costs and productivity, in order to draw sufficient conditions for the optimality of firms' profit with respect to time. The relationships that hold among productivity, costs of renewal and growth rates of the companies at the optimal profit time are shown, and suggestions for firms' policies are proposed.
Bactericidal Action of Daptomycin against Stationary-Phase and Nondividing
Staphylococcus aureus
Cells
Authors: Mascio Carmela T. M. , Alder Jeff D. , Silverman Jared A. 
Published: October 2007

ABSTRACT

Most antibiotics with bactericidal activity require that the bacteria be actively dividing to produce rapid killing. However, in many infections, such as endocarditis, prosthetic joint infections, and infected embedded catheters, the bacteria divide slowly or not at all. Daptomycin is a lipopeptide antibiotic with a distinct mechanism of action that targets the cytoplasmic membrane of gram-positive organisms, including
Staphylococcus aureus
. Daptomycin is rapidly bactericidal against exponentially growing bacteria (a 3-log reduction in 60 min). The objectives of this study were to determine if daptomycin is bactericidal against nondividing
S. aureus
and to quantify the extent of the bactericidal activity. In high-inoculum methicillin-sensitive
S. aureus
cultures in stationary phase (10
10
CFU/ml), daptomycin displayed concentration-dependent bactericidal activity, requiring 32 μg/ml to achieve a 3-log reduction. In a study comparing several antibiotics at 100 μg/ml, daptomycin demonstrated faster bactericidal activity than nafcillin, ciprofloxacin, gentamicin, and vancomycin. In experiments where bacterial cell growth was halted by the metabolic inhibitor carbonyl cyanide
m
-chlorophenylhydrazone or erythromycin, daptomycin (10 μg/ml) achieved the bactericidal end point (a 3-log reduction) within 2 h. In contrast, ciprofloxacin (10 μg/ml) did not produce bactericidal activity. Daptomycin (2 μg/ml) remained bactericidal against cold-arrested
S. aureus
, which was protected from the actions of ciprofloxacin and nafcillin. The data presented here suggest that, in contrast to that of other classes of antibiotics, the bactericidal activity of daptomycin does not require cell division or active metabolism, most likely as a consequence of its direct action on the bacterial membrane.
In Vitro Study of
Candida tropicalis
Isolates Exhibiting Paradoxical Growth in the Presence of High Concentrations of Caspofungin
Authors: Sóczó G. , Kardos G. , Varga I. , Kelentey B. , Gesztelyi R. , Majoros L. 
Published: October 2007

ABSTRACT

Paradoxical growth was noted in RPMI 1640 and antibiotic medium 3 in the case of 14 and 1 of 15
Candida tropicalis
strains, respectively, at a caspofungin concentration of 12.5 μg/ml using minimum fungicidal concentration tests. Time-kill assays showed that against isolates killed at lower concentrations, caspofungin at a concentration of 12.5 μg/ml was only fungistatic.
In Immunization with
Plasmodium falciparum
Apical Membrane Antigen 1, the Specificity of Antibodies Depends on the Species Immunized
Authors: Miura Kazutoyo , Zhou Hong , Muratova Olga V. , Orcutt Andrew C. , Giersing Birgitte , Miller Louis H. , Long Carole A. 
Published: October 2007

ABSTRACT

At least a million people, mainly African children under 5 years old, still die yearly from malaria, and the burden of disease and death has increased.
Plasmodium falciparum
apical membrane antigen 1 (PfAMA1) is one of the most promising blood-stage malarial vaccine candidates. However, the allelic polymorphism observed in this protein is a potential stumbling block for vaccine development. To overcome the polymorphism- and strain-specific growth inhibition in vitro, we previously showed in a rabbit model that vaccination with a mixture of two allelic forms of PfAMA1 induced parasite growth-inhibitory antisera against both strains of
P. falciparum
parasites in vitro. In the present study, we have established that, in contrast to a single-allele protein, the antigen mixture elicits primarily antibodies recognizing antigenic determinants common to the two antigens, as judged by an antigen reversal growth inhibition assay (GIA). We also show that a similar reactivity pattern occurs after immunization of mice. By contrast, sera from rhesus monkeys do not distinguish the two alleles when tested by an enzyme-linked immunosorbent assay or by GIA, regardless of whether the immunogen is a single AMA1 protein or the mixture. This is the first report that a malarial vaccine candidate induced different specificities of functional antibodies depending on the animal species immunized. These observations, as well as data available on human immune responses in areas of endemicity, suggest that polymorphism in the AMA1 protein may not be as formidable a problem for vaccine development as anticipated from studies with rabbits and mice.
Immune Distribution and Localization of Phosphoantigen-Specific Vγ2Vδ2 T Cells in Lymphoid and Nonlymphoid Tissues inMycobacterium tuberculosisInfection
Authors: Huang Dan , Shen Yun , Qiu Liyou , Chen Crystal Y. , Shen Ling , Estep Jim , Hunt Robert , Vasconcelos Daphne , Du George , Aye Pyone , Lackner Andrew A. , Larsen Michelle H. , Jacobs William R. , Haynes Barton F. , Letvin Norman L. , Chen Zheng W. 
Published: October 2007

ABSTRACTLittle is known about the immune distribution and localization of antigen-specific T cells in mucosal interfaces of tissues/organs during infection of humans. In this study, we made use of a macaque model ofMycobacterium tuberculosisinfection to assess phosphoantigen-specific Vγ2Vδ2 T cells regarding their tissue distribution, anatomical localization, and correlation with the presence or absence of tuberculosis (TB) lesions in lymphoid and nonlymphoid organs/tissues in the progression of severe pulmonary TB. Progression of pulmonaryM. tuberculosisinfection generated diverse distribution patterns of Vγ2Vδ2 T cells, with remarkable accumulation of these cells in lungs, bronchial lymph nodes, spleens, and remote nonlymphoid organs but not in blood. Increased numbers of Vγ2Vδ2 T cells in tissues were associated withM. tuberculosisinfection but were independent of the severity of TB lesions. In lungs with apparent TB lesions, Vγ2Vδ2 T cells were present within TB granulomas. In extrathoracic organs, Vγ2Vδ2 T cells were localized in the interstitial compartment of nonlymphoid tissues, and the interstitial localization was present despite the absence of detectable TB lesions. Finally, Vγ2Vδ2 T cells accumulated in tissues appeared to possess cytokine production function, since granzyme B was detectable in the γδ T cells present within granulomas. Thus, clonally expanded Vγ2Vδ2 T cells appeared to undergotrans-endothelial migration, interstitial localization, and granuloma infiltration as immune responses toM. tuberculosisinfection.
The TolC-Like Protein of
Neisseria meningitidis
Is Required for Extracellular Production of the Repeats-in-Toxin Toxin FrpC but Not for Resistance to Antimicrobials Recognized by the Mtr Efflux Pump System
Authors: Kamal Nazia , Rouquette-Loughlin Corinne , Shafer William M. 
Published: October 2007

ABSTRACT

A 2.9-kilobase pair locus in
Neisseria meningitidis
was identified as containing transcriptionally linked open reading frames encoding TolC- and HlyD-like proteins. Although the meningococcal TolC protein was required for extracellular production of the repeats-in-toxin (RTX) FrpC toxin, it could not functionally replace the MtrE protein as the outer membrane protein channel for drug export by the MtrC-MtrD-MtrE efflux pump.
Erwinia carotovora elicitors and Botrytis cinerea activate defense responses in Physcomitrella patens
Authors: Ponce de León Inés , Oliver Juan Pablo , Castro Alexandra , Gaggero Carina , Bentancor Marcel , Vidal Sabina 
Published: October 2007

Abstract

Background
Vascular plants respond to pathogens by activating a diverse array of defense mechanisms. Studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. However, very little is known about the infection and defense responses of the bryophyte, Physcomitrella patens, to well-studied phytopathogens. The purpose of this study was to determine: i) whether two representative broad host range pathogens, Erwinia carotovora ssp. carotovora (E.c. carotovora) and Botrytis cinerea (B. cinerea), could infect Physcomitrella, and ii) whether B. cinerea, elicitors of a harpin (HrpN) producing E.c. carotovora strain (SCC1) or a HrpN-negative strain (SCC3193), could cause disease symptoms and induce defense responses in Physcomitrella.

Results

B. cinerea and E.c. carotovora were found to readily infect Physcomitrella gametophytic tissues and cause disease symptoms. Treatments with B. cinerea spores or cell-free culture filtrates from E.c. carotovora
SCC1 (CF(SCC1)), resulted in disease development with severe maceration of Physcomitrella tissues, while CF(SCC3193) produced only mild maceration. Although increased cell death was observed with either the CFs or B. cinerea, the occurrence of cytoplasmic shrinkage was only visible in Evans blue stained protonemal cells treated with CF(SCC1) or inoculated with B. cinerea. Most cells showing cytoplasmic shrinkage accumulated autofluorescent compounds and brown chloroplasts were evident in a high proportion of these cells. CF treatments and B. cinerea inoculation induced the expression of the defense-related genes: PR-1, PAL, CHS and LOX.

Conclusion

B. cinerea and E.c. carotovora elicitors induce a defense response in Physcomitrella, as evidenced by enhanced expression of conserved plant defense-related genes. Since cytoplasmic shrinkage is the most common morphological change observed in plant PCD, and that harpins and B. cinerea induce this type of cell death in vascular plants, our results suggest that E.c. carotovora CFSCC1 containing HrpN and B. cinerea could also induce this type of cell death in Physcomitrella. Our studies thus establish Physcomitrella as an experimental host for investigation of plant-pathogen interactions and B. cinerea and elicitors of E.c. carotovora as promising tools for understanding the mechanisms involved in defense responses and in pathogen-mediated cell death in this simple land plant.
Molecular epidemiology of Hepatitis B virus genotypes in Pakistan
Authors: Alam Muhammad Masroor , Zaidi Sohail Zahoor , Malik Salman Akbar , Shaukat Shahzad , Naeem Asif , Sharif Salmaan , Angez Mehar , Butt Javed Aslam 
Published: October 2007

Abstract

Background
Eight genotypes of Hepatitis B virus designated A-H, have been known but in Pakistan, no such data is available on the prevalent HBV genotypes. Therefore, the subject study was conducted to determine HBV genotypes in the indigenous Pakistani population.

Methods
A total of 690 individuals were enrolled for HBV screening with EIA and nested PCR. Positive samples were further analyzed to determine HBV genotypes (A-F) by multiplex-PCR using type specific primers.

Results
110 (15.94%) individuals were positive for HBV, including 64% males and 36% females. Out of these, 66 samples (65.34%) were classified into genotype D, 27 (26.73%) were of genotype B while 5(4.95%) had genotype A. In 3 (2.98%) samples, multiple genotypes were detected (genotype A+B; 2(1.99%) and genotypes B+D; 1(0.99%). Nine (8.18%) samples remained untyable.

Conclusion
In Asia, genotypes B and C are the most prevalent but our study reveals that genotype D is predominant and HBV infection constitutes a significant health problem in Pakistan.
High prevalence of lack of knowledge of symptoms of acute myocardial infarction inPakistan and its contribution to delayed presentationto the hospital
Authors: Khan Muhammad S , Jafary Fahim H , Faruqui Azhar M , Rasool Syed I , Hatcher Juanita , Chaturvedi Nish , Jafar Tazeen H 
Published: October 2007

AbstractBackgroundWe conducted an observational study to determine the delay in presentation to hospital, and its associates among patients experiencing first Acute Myocardial Infarction (AMI) in Karachi, Pakistan.MethodsA hospital based cross-sectional study was conducted at National Institute of Cardiovascular Disease (NICVD) in Karachi. A structured questionnaire was used to collect data. The primary outcome was delay in presentation, defined as a time interval of six or more hours from the onset of symptoms to presentation to hospital. Logistic regression analysis was performed to determine the factors associated with prehospital delay.ResultsA total of 720 subjects were interviewed; 22% were females. The mean age (SD) of the subjects was 54 (± 12) years. The mean (SE) and median (IQR) time to presentation was 12.3 (1.7) hours and 3.04 (6.0) hours respectively. About 34% of the subjects presented late. Lack of knowledge of any of the symptoms of heart attack (odds ratio (95% CI)) (1.82 (1.10, 2.99)), and mild chest pain (10.05 (6.50, 15.54)) were independently associated with prehospital delay.ConclusionOver one-third of patients with AMI in Pakistan present late to the hospital. Lack of knowledge of symptoms of heart attack, and low severity of chest pain were the main predictors of prehospital delay. Strategies to reduce delayed presentation in this population must focus on education about symptoms of heart attack.
High content image analysis for human H4 neuroglioma cells exposed to CuO nanoparticles
Authors: Li Fuhai , Zhou Xiaobo , Zhu Jinmin , Ma Jinwen , Huang Xudong , Wong Stephen TC 
Published: October 2007

Abstract

Background
High content screening (HCS)-based image analysis is becoming an important and widely used research tool. Capitalizing this technology, ample cellular information can be extracted from the high content cellular images. In this study, an automated, reliable and quantitative cellular image analysis system developed in house has been employed to quantify the toxic responses of human H4 neuroglioma cells exposed to metal oxide nanoparticles. This system has been proved to be an essential tool in our study.

Results
The cellular images of H4 neuroglioma cells exposed to different concentrations of CuO nanoparticles were sampled using IN Cell Analyzer 1000. A fully automated cellular image analysis system has been developed to perform the image analysis for cell viability. A multiple adaptive thresholding method was used to classify the pixels of the nuclei image into three classes: bright nuclei, dark nuclei, and background. During the development of our image analysis methodology, we have achieved the followings: (1) The Gaussian filtering with proper scale has been applied to the cellular images for generation of a local intensity maximum inside each nucleus; (2) a novel local intensity maxima detection method based on the gradient vector field has been established; and (3) a statistical model based splitting method was proposed to overcome the under segmentation problem. Computational results indicate that 95.9% nuclei can be detected and segmented correctly by the proposed image analysis system.

Conclusion
The proposed automated image analysis system can effectively segment the images of human H4 neuroglioma cells exposed to CuO nanoparticles. The computational results confirmed our biological finding that human H4 neuroglioma cells had a dose-dependent toxic response to the insult of CuO nanoparticles.
Quantum dot imaging for embryonic stem cells
Authors: Lin Shuan , Xie Xiaoyan , Patel Manishkumar R , Yang Yao-Hung , Li Zongjin , Cao Feng , Gheysens Oliver , Zhang Yan , Gambhir Sanjiv S , Rao Jiang Hong , Wu Joseph C 
Published: October 2007

Abstract

Background
Semiconductor quantum dots (QDs) hold increasing potential for cellular imaging both in vitro and in vivo. In this report, we aimed to evaluate in vivo multiplex imaging of mouse embryonic stem (ES) cells labeled with Qtracker delivered quantum dots (QDs).

Results
Murine embryonic stem (ES) cells were labeled with six different QDs using Qtracker. ES cell viability, proliferation, and differentiation were not adversely affected by QDs compared with non-labeled control cells (P = NS). Afterward, labeled ES cells were injected subcutaneously onto the backs of athymic nude mice. These labeled ES cells could be imaged with good contrast with one single excitation wavelength. With the same excitation wavelength, the signal intensity, defined as (total signal-background)/exposure time in millisecond was 11 ± 2 for cells labeled with QD 525, 12 ± 9 for QD 565, 176 ± 81 for QD 605, 176 ± 136 for QD 655, 167 ± 104 for QD 705, and 1,713 ± 482 for QD 800. Finally, we have shown that QD 800 offers greater fluorescent intensity than the other QDs tested.

Conclusion
In summary, this is the first demonstration of in vivo multiplex imaging of mouse ES cells labeled QDs. Upon further improvements, QDs will have a greater potential for tracking stem cells within deep tissues. These results provide a promising tool for imaging stem cell therapy non-invasively in vivo.
Elevated extracellular matrix production and degradation upon bone morphogenetic protein-2 (BMP-2) stimulation point toward a role for BMP-2 in cartilage repair and remodeling
Authors: Blaney Davidson Esmeralda N , Vitters Elly L , van Lent Peter LEM , van de Loo Fons AJ , van den Berg Wim B , van der Kraan Peter M 
Published: October 2007

AbstractBone morphogenetic protein-2 (BMP-2) has been proposed as a tool for cartilage repair and as a stimulant of chondrogenesis. In healthy cartilage, BMP-2 is hardly present, whereas it is highly expressed during osteoarthritis. To assess its function in cartilage, BMP-2 was overexpressed in healthy murine knee joints and the effects on proteoglycan (PG) synthesis and degradation were evaluated. Moreover, the contribution of BMP in repairing damage induced by interleukin-1 (IL-1) was investigated. Ad-BMP-2 was injected intra-articularly into murine knee joints, which were isolated 3, 7, and 21 days after injection for histology, immunohistochemistry, and autoradiography. In addition, patellar and tibial cartilage was isolated for RNA isolation or measurement of PG synthesis by means of 35SO42- incorporation. To investigate the role for BMP-2 in cartilage repair, cartilage damage was induced by intra-articular injection of IL-1. After 2 days, Ad-BMP-2, Ad-BMP-2 + Ad-gremlin, Ad-gremlin, or a control virus was injected. Whole knee joints were isolated for histology at day 4 or patellae were isolated to measure 35SO42- incorporation. BMP-2 stimulated PG synthesis in patellar cartilage on all days and in tibial cartilage on day 21. Aggrecan mRNA expression had increased on all days in patellar cartilage, with the highest increase on day 7. Collagen type II expression showed a similar expression pattern. In tibial cartilage, collagen type II and aggrecan mRNA expression had increased on days 7 and 21. BMP-2 overexpression also induced increased aggrecan degradation in cartilage. VDIPEN staining (indicating matrix metalloproteinase activity) was elevated on day 3 in tibial cartilage and on days 3 and 7 in patellar cartilage, but no longer was by day 21. Increased NITEGE staining (indicating aggrecanase activity) was found on days 7 and 21. In IL-1-damaged patellar cartilage, BMP-2 boosted PG synthesis. Blocking of BMP activity resulted in a decreased PG synthesis compared with IL-1 alone. This decreased PG synthesis was associated with PG depletion in the cartilage. These data show that BMP-2 boosts matrix turnover in intact and IL-damaged cartilage. Moreover, BMP contributes to the intrinsic repair capacity of damaged cartilage. Increased matrix turnover might be functional in replacing matrix molecules in the repair of a damaged cartilage matrix.