bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Phosphonated Carbocyclic 2′-Oxa-3′-Aza-Nucleoside on Human T-Cell Leukemia Virus Type 1 Infection In Vitro
Authors: Balestrieri Emanuela , Matteucci Claudia , Ascolani Arianna , Piperno Anna , Romeo Roberto , Romeo Giovanni , Chiacchio Ugo , Mastino Antonio , Macchi Beatrice 
Published: October 2007

ABSTRACT
There is currently little research and development of new compounds with specific anti-human T-cell leukemia virus type 1 (HTLV-1) activity. The few antiretrovirals that have been tested against HTLV-1 in vitro have already been developed into anti-human immunodeficiency virus (HIV) drugs. Here, we show the effects of a newly synthesized family of phosphonated nucleoside compounds, phosphonated carbocyclic 2′-oxa-3′-aza-nucleosides (PCOANs), on HTLV-1 infection in vitro. To ascertain the anti-HTLV-1 activity of PCOANs, peripheral blood mononuclear cells from healthy donors were infected in vitro by coculture with an HTLV-1 donor cell line in the presence of three prototype PCOAN compounds. PCOANs were able to completely inhibit HTLV-1 infection in vitro at a concentration of 1 μM, similar to what has been observed for tenofovir and azidothymidine. Treatment with PCOANs was associated with inhibited growth of HTLV-1-infected cells, and their effects were 100 to 200 times more potent than that of tenofovir. The mechanisms involved in the anti-HTLV-1 effects of PCOANs can mainly be ascribed to their capacity to inhibit HTLV-1 reverse transcriptase activity, as ascertained by means of a cell-free assay. PCOANs caused little reduction in proliferation or induction of apoptotic cell death of uninfected cells, showing toxicity levels similar to tenofovir and lower than azidothymidine. Overall, these results indicate that the family of PCOANs includes potential candidate compounds for long-lasting control of HTLV-1 infection.
Pharmacokinetics and Efficacy of Piperaquine and Chloroquine in Melanesian Children with Uncomplicated Malaria
Authors: Karunajeewa Harin A. , Ilett Kenneth F. , Mueller Ivo , Siba Peter , Law Irwin , Page-Sharp Madhu , Lin Enmoore , Lammey Jovitha , Batty Kevin T. , Davis Timothy M. E. 
Published: October 2007

ABSTRACT

The disposition of chloroquine (CQ) and the related 4-aminoquinoline, piperaquine (PQ), were compared in Papua New Guinean children with uncomplicated malaria. Twenty-two children were randomized to 3 days of PQ phosphate at 20 mg/kg/day (12 mg of PQ base/kg/day) coformulated with dihydroartemisinin (DHA-PQ), and twenty children were randomized to 3 days of CQ at 10 mg base/kg/day with a single dose of sulfadoxine-pyrimethamine (CQ-SP). After a 42-day intensive sampling protocol, PQ, CQ, and its active metabolite monodesethyl-chloroquine (DECQ) were assayed in plasma by using high-performance liquid chromatography. A two-compartment model with first-order absorption was fitted to the PQ and CQ data. There were no significant differences in age, gender, body weight, or admission parasitemia between the two groups. The PCR-corrected 42-day adequate clinical and parasitological responses were 100% for DHA-PQ and 94% for CQ-SP, but
P. falciparum
reinfections during follow-up were common (33 and 18%, respectively). For PQ, the median volume of distribution at steady state, allowing for bioavailability (
V
ss
/F), was 431 liters/kg (interquartile range [IQR], 283 to 588 liters/kg), the median clearance (CL/F) was 0.85 liters/h/kg (IQR, 0.67 to 1.06 liters/h/kg), the median distribution half-life (
t
1/2
α
) was 0.12 h (IQR, 0.05 to 0.66 h), and the median elimination half-life (
t
1/2
β
) was 413 h (IQR, 318 to 516 h). For CQ, the median
V
ss
/F was 154 liters/kg (IQR, 101 to 210 liters/kg), the median CL/F was 0.80 liters/h/kg (IQR, 0.52 to 0.96 liters/h/kg), the median
t
1/2
α
was 0.43 h (IQR, 0.05 to 1.82 h), and the median
t
1/2
β
was 233 h (IQR, 206 to 298 h). The noncompartmentally derived median DECQ
t
1/2
β
was 290 h (IQR, 236 to 368 h). Combined molar concentrations of DECQ and CQ were higher than those of PQ during the elimination phase. Although PQ has a longer
t
1/2
β
than CQ, its prompt distribution and lack of active metabolite may limit its posttreatment malaria-suppressive properties.
Antimicrobial Resistance Genes Associated with
Salmonella enterica
Serovar Newport Isolates from Food Animals
Authors: Lynne Aaron M. , Rhodes-Clark Bobbie S. , Bliven Kimberly , Zhao Shaohua , Foley Steven L. 
Published: October 2007

ABSTRACT

Salmonella enterica
serotype Newport is an important cause of salmonellosis, with strains increasingly being resistant to multiple antimicrobial agents. The increase is associated with the acquisition of multiple resistance genes. This study characterizes the genetic basis of resistance of serotype Newport isolates collected from veterinary sources by PCR and DNA sequencing analysis.
Human Immunodeficiency Virus Types 1 and 2 Exhibit Comparable Sensitivities to Zidovudine and Other Nucleoside Analog Inhibitors In Vitro
Authors: Smith Robert A. , Gottlieb Geoffrey S. , Anderson Donovan J. , Pyrak Crystal L. , Preston Bradley D. 
Published: October 2007

ABSTRACTUsing an indicator cell assay that directly quantifies viral replication, we show that human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2, respectively) exhibit similar sensitivities to 3′-azido-3′-deoxythymidine (zidovudine) as well as other nucleoside analog inhibitors of reverse transcriptase. These data support the use of nucleoside analogs for antiviral therapy of HIV-2 infection.
A LysR-Type Transcriptional Regulator in
Burkholderia cenocepacia
Influences Colony Morphology and Virulence
Authors: Bernier Steve P. , Nguyen David T. , Sokol Pamela A. 
Published: October 2007

ABSTRACT

Burkholderia cenocepacia
strain K56-2 typically has rough colony morphology on agar medium; however, shiny colony variants (shv) can appear spontaneously. These shv all had a minimum of 50% reduction in biomass formation and were generally avirulent in an alfalfa seedling infection model. Three shv—K56-2 S15, K56-2 S76, and K56-2 S86—were analyzed for virulence in a chronic agar bead model of respiratory infection and, although all shv were able to establish chronic infection, they produced significantly less lung histopathology than the rough K56-2. Transmission electron microscopy revealed that an extracellular matrix surrounding bacterial cells was absent or reduced in the shv compared to the rough wild type. Transposon mutagenesis was performed on the rough wild-type strain and a mutant with an insertion upstream of ORF BCAS0225, coding for a putative LysR-type regulator, exhibited shiny colony morphology, reduced biofilm production, increased
N
-acyl homoserine lactone production, and avirulence in alfalfa. The rough parental colony morphotype, biofilm formation, and virulence in alfalfa were restored by providing BCAS0225 in
trans
in the BCAS0225::pGSVTp-
luxCDABF
mutant. Introduction of BCAS0225 restored the rough morphotype in several shv which were determined to have spontaneous mutations in this gene. In the present study, we show that the conversion from rough wild type to shv in
B. cenocepacia
correlates with reduced biofilm formation and virulence, and we determined that BCAS0225 is one gene involved in the regulation of these phenotypes.
Use of a Genetically Engineered Strain To Evaluate the Pathogenic Potential of Yeast Cell and Filamentous Forms duringCandida albicansSystemic Infection in Immunodeficient Mice
Authors: Saville Stephen P. , Lazzell Anna L. , Chaturvedi Ashok K. , Monteagudo Carlos , Lopez-Ribot Jose L. 
Published: October 2007

ABSTRACTThe pathogenesis ofCandida albicanssystemic infection is complex and results from the balance between its intrinsic virulence attributes and the host immune responses. Morphogenetic transitions between yeast cell and filamentous forms are considered one of the main virulence attributes inC. albicans. We have examined the pathogenesis of a genetically engineeredC. albicansstrain in which morphogenetic conversions can be externally manipulated in immunodeficient mice; these included B-cell deficient, nude (T cell deficient), SCID (lacking both functional T and B cells), and DBA/2N (C5 deficient with impaired neutrophil activity) mice. We also tested mice severely immunosuppressed by cyclophosphamide-cortisone acetate treatment. Mice with specific immune defects were able to survive an infection by yeast cells but not filamentous forms. However, yeast cells displayed a pathogenic effect leading to lethality in the severely immunosuppressed mice.
Surfactant-Associated Protein A Provides Critical Immunoprotection in Neonatal Mice
Authors: George Caroline L. S. , Goss Kelli L. , Meyerholz David K. , Lamb Fred S. , Snyder Jeanne M. 
Published: October 2007

ABSTRACTThe collectins surfactant-associated protein A (SP-A) and SP-D are components of innate immunity that are present before birth. Both proteins bind pathogens and assist in clearing infection. The significance of SP-A and SP-D as components of the neonatal immune system has not been investigated. To determine the role of SP-A and SP-D in neonatal immunity, wild-type, SP-A null, and SP-D null mice were bred in a bacterium-laden environment (corn dust bedding) or in a semisterile environment (cellulose fiber bedding). When reared in the corn dust bedding, SP-A null pups had significant mortality (P< 0.001) compared to both wild-type and SP-D null pups exposed to the same environment. The mortality of the SP-A null pups was associated with significant gastrointestinal tract pathology but little lung pathology. Moribund SP-A null newborn mice exhibitedBacillussp. andEnterococcussp. peritonitis. When the mother or newborn produced SP-A, newborn survival was significantly improved (P< 0.05) compared to the results when there was a complete absence of SP-A in both the mother and the pup. Significant sources of SP-A likely to protect a newborn include the neonatal lung and gastrointestinal tract but not the lactating mammary tissue of the mother. Furthermore, exogenous SP-A delivered by mouth to newborn SP-A null pups with SP-A null mothers improved newborn survival in the corn dust environment. Therefore, a lack of SP-D did not affect newborn survival, while SP-A produced by either the mother or the pup or oral exogenous SP-A significantly reduced newborn mortality associated with environmentally induced infection in SP-A null newborns.
Toll-Like Receptor 2-Mediated Interleukin-8 Expression in Gingival Epithelial Cells by the
Tannerella forsythia
Leucine-Rich Repeat Protein BspA
Authors: Onishi Shinsuke , Honma Kiyonobu , Liang Shuang , Stathopoulou Panagiota , Kinane Denis , Hajishengallis George , Sharma Ashu 
Published: October 2007

ABSTRACT

Tannerella forsythia
is a gram-negative anaerobe strongly associated with chronic human periodontitis. This bacterium expresses a cell surface-associated and secreted protein, designated BspA, which has been recognized as an important virulence factor. The BspA protein belongs to the leucine-rich repeat (LRR) and bacterial immunoglobulin-like protein families. BspA is, moreover, a multifunctional protein which interacts with a variety of host cells, including monocytes which appear to respond to BspA through Toll-like receptor (TLR) signaling. Since gingival epithelium forms a barrier against periodontal pathogens, this study was undertaken to determine if gingival epithelial cells respond to BspA challenge and if TLRs play any role in BspA recognition. This study was also directed towards identifying the BspA domains responsible for cellular activation. We provide direct evidence for BspA binding to TLR2 and demonstrate that the release of the chemokine interleukin-8 from human gingival epithelial cells by BspA is TLR2 dependent. Furthermore, the LRR domain of BspA is involved in activation of TLR2, while TLR1 serves as a signaling partner. Thus, our findings suggest that BspA is an important modulator of host innate immune responses through activation of TLR2 in cooperation with TLR1.
Oral Vaccination withSalmonella entericaas a Cruzipain-DNA Delivery System Confers Protective Immunity againstTrypanosoma cruzi
Authors: Cazorla Silvia I. , Becker Pablo D. , Frank Fernanda M. , Ebensen Thomas , Sartori María J. , Corral Ricardo S. , Malchiodi Emilio L. , Guzmán Carlos A. 
Published: October 2007

ABSTRACTTo stimulate both local and systemic immune responses againstTrypanosoma cruzi,Salmonella entericaserovar TyphimuriumaroAwas exploited as a DNA delivery system for cruzipain (SCz). In a murine model we compared SCz alone (GI) or coadministered withSalmonellacarrying a plasmid encoding granulocyte-macrophage colony-stimulating factor (GII), as well as protocols in which SCz priming was followed by boosting with recombinant cruzipain (rCz) admixed with either CpG-ODN (GIII) or MALP-2, a synthetic derivative of a macrophage-activating lipopeptide of 2 kDa fromMycoplasma fermentans(GIV). The results showed that protocols that included four oral doses of SCz (GI) elicited mainly a mucosal response characterized by immunoglobulin A (IgA) secretion and proliferation of gut-associated lymphoid tissue cells, with weak systemic responses. In contrast, the protocol that included a boost with rCz plus CpG (GIII) triggered stronger systemic responses in terms of Cz-specific serum IgG titers, splenocyte proliferation, gamma interferon (IFN-γ) secretion, and delayed-type hypersensitivity response. Trypomastigote challenge of vaccinated mice resulted in significantly lower levels of parasitemia compared to controls. Protection was abolished by depletion of either CD4+or CD8+T cells. Parasite control was also evident from the reduction of tissue damage, as revealed by histopathologic studies and serum levels of enzymes that are markers of muscle injury in chronic Chagas' disease (i.e., creatine kinase, aspartate aminotransferase, and lactate dehydrogenase). Enhanced release of IFN-γ and interleukin-2 was observed in GI and GII upon restimulation of splenocytes in the nonparasitic phase of infection. Our results indicate thatSalmonella-mediated delivery of Cz-DNA by itself promotes the elicitation of an immune response that controlsT. cruziinfection, thereby reducing parasite loads and subsequent damage to muscle tissues.
SOLITON AUTOMATA BASED ON TREES
Authors: JÜRGENSEN HELMUT , KRAAK PAULINE 
Published: October 2007

Soliton automata are a mathematical model for molecular switching devices. For even the simple case of soliton automata based on trees the behaviour is not known. For example, only two examples of such soliton automata were known the transition monoid of which is not the symmetric group on the set of states; and in these cases the transition monoid is the corresponding alternating group. We establish new bounds on the number of states of a tree-based soliton automaton and a sufficient condition for when the transition monoid of such a soliton automaton consists only of even permutations of the set of states. We also summarize the results of a systematic enumeration of tree-based soliton automata by which additional exceptions were found, each an alternating group in its natural representation.
MEMBRANE ALGORITHM WITH BROWNIAN SUBALGORITHM AND GENETIC SUBALGORITHM
Authors: NISHIDA TAISHIN Y. 
Published: October 2007

Membrane algorithms with subalgorithms inspired by simulated annealing are treated in this paper. Simulated annealing is inherently a kind of local search but it modifies a solution to a worse one with a probability determined by "temperature". The temperature of simulated annealing is changed according to "cooling schedule". On the other hand, the subalgorithm introduced here has constant temperature which is determined by the region where the subalgorithm is. It is called Brownian subalgorithm since the subalgorithm incorporates "thermal movement" of a solution in the search space but does not simulate "annealing". Computer simulations show that a membrane algorithm which has three regions and has a Brownian subalgorithm in each region can obtain very good approximate solutions for several benchmark problems of the traveling salesman problem. However, the algorithm, occasionally, gets quite bad solutions (twice as large as the optimum) for a problem. A membrane algorithm which has both Brownian and genetic subalgorithms never gets such a bad solution (only 8% worse than the optimum) for all problems examined, although, in average, it is not as good as the algorithm with Brownian only. The result indicates that membrane algorithm with subalgorithms under different approximate mechanisms may be robust under a wide range of problems.
A TREE-HEIGHT HIERARCHY OF CONTEXT-FREE LANGUAGES
Authors: REINHARDT KLAUS 
Published: October 2007

We consider the minimal height of a derivation tree as a complexity measure for context-free languages and show that this leads to a strict and dense hierarchy between logarithmic and linear (arbitrary) tree height. In doing so, we improve a result obtained by Gabarro in [7]. Furthermore, we provide a counter-example to disprove a conjecture of Čulik and Maurer in [6] who suggested that all languages with logarithmic tree height would be regular. As a new method, we use counter-representations where the successor relation can be handled as the complement of context-free languages. A similar hierarchy is obtained considering the ambiguity as a complexity measure.
Electrophoretic Studies of Silk
Authors: Sookne Arnold M. , Harris Milton 
Published: October 2007

A micro-electrophoretic technique was used to determine the characteristic pH-mobility curves for fibroin and for sericin and to ascertain the extent of removal of the latter during degumming by the soap and enzyme processes. The data suggest that sericin contains a much greater proportion of reactive groups than fibroin, and indicate the importance of obtaining either uniform or complete removal of sericin during degumming processes. The isoelectric points are shown to vary slightly with ionic strength. In acetate buffers of 0.02 M ionic strength, the isoelectric point of fibroin is 3.6 and that of sericin, 4.3. Large ions of complex structure such as phthalate or picrate appear to have specific effects which are readily detectable by the electrophoretic technique. Dissolved fibroin adsorbed on glass particles and fibroin regenerated from similar solutions had the same isoelectric points but different pH-mobility curves. Fibroin regenerated after dissolving in solutions of lithium bromide gave the same pH-mobility curve as untreated fibroin.
Observation of the Internal Structure of the Human Hair Cuticle Cell by SEM
Authors: Hunter Leroy D. , Garcia Mario L. , Newman Walter , Cohen George L. 
Published: October 2007

Direct observation with a. scanning electron microscope of some aspects of the internal structure of the human hair cuticte cell has been accomplished. Long-term exposure of hair to sun and atmosphere resulted in a breakdown of the cuticle cells on the surface of the hair. Cleavage of the cuticle cells was observed to have occurred within the endocuticle layer in many cases. Remains of the endocuticle layer on the hair surface-gave the appearance of an amorphous globular material. A layer believed to he an under membrane that was readily observed on the sun- and atmosphere-exposed samples has also been found on many different hair samples subjected to "normal" wear. Longitudinal striations originating within the cuticle cell similar to but less discernihle than those found in some types of. wool, were also observed on the human hair samples.
Some Structural and Physical Properties of Yarn Made on the Integrated Composite Spinning System
Authors: Mohamed M.H. , Rqchow T.G. , Heeralal R. 
Published: October 2007

One of the most recent systems of yarn production is the Bototex Integrated Composite Spinning (ICS) process. The process is capable of producing spun-like yarn from a composite of two or three components. In the case of three-component yams, a filamerat feeder yarn is passed through the polymer extrusion spinnerette to pick up the molten polymer resin. Staple fibers are then deposited onto the surface of the yarn and the assembly is consolidated by twisting. Production by this system ranges between 1000 and 2000 ft/min (305-610 m/min). The yarn count ranges from 30-300 tex (20's-2's cotton count). This paper presents a discussion of the capabilities of this system. A light-microscopical study of some yarn cross sections and some scanning electron micrographs of yarns and a double-knit fabric are presented. Some of the physical properties of yarn samples were investigated and the results are presented.
Measurement of Crease Recovery Properties of Yarns and Fibers1,2
Authors: Venkatesh G.M. , Dweltz N.E. 
Published: October 2007

At present, no simple and satisfactory method exists to measure the crease recovery properties of fibers and yarns; consequently, this paper attempts to describe a simple method for this purpose. A thin parallelized bundle of fibers or yarns is creased for five minutes under a constant weight, and the crease recovery angles are measured on a Monsanto Wrinkle Recovery Tester. There is good correspondence between the crease recovery angles of the resin finished fabrics and of the yarns extracted from these fabrics. In the case of fibers, a definite relationship has been found to exist between the bound formaldehyde expressed as a percentage and the corresponding increase in dry crease recovery or loss in tensile strength or the reduction in the work of rupture. A similar relationship also exists between the loss in tensile strength and increase in crease recovery angles. Significant differences exist between the crease recovery angles of different cottons after crosslinking.
Flame Retardant Cellulose Acetate and Arnel Triacetate
Authors: Vandermaas J.K. , Holmes T.L. , Zybko W.C. 
Published: October 2007

In order to provide a variety of fabrics and constructions which meet the Children's Sleepwear Standard, DOC FF-3-71, Celanese has developed flame retardant variants of two of its fibers. Acetate filament was developed for the warp knit segment of the sleepwear market and Arnel® triacetate for use in blends with polyester for circular knits and wovens. In the course of this development the effect of fabric construction on flammability performance was explored, as well as the influence of dyeing and finishing chemicals such as dyes and carriers. A fabric bulk factor is derived which is of value in predicting the residual flame time behavior of single knit polyester or triacetate/polyester jersey. In addition an attempt is made to correlate dye structure with its effect on flammability performance of Arnel triacetate/polyester blends.
A Study of the Reaction Between Protein Monolayers and Wool-Reactive Dyes
Authors: Giles Charles H. , Mciver Norman 
Published: October 2007

Monolayers of edestin, as a model for protein fibers, have been spread on water and on aqueous solutions of three wool-reactive dyes with and without the addition of urea. The film area, compressibility, and viscosity values were measured and interpreted. Surface tension measurements on aqueous solutions of the dyes agree qualitatively with the expected effects of their structural differences. The most surface-active dye, containing a single reactive group, penetrates the protein film rather slowly, slightly increasing the compressibility. On standing overnight, dye-protein reaction occurs, and the film becomes more rigid. A dye with two reactive groups causes a marked increase of rigidity of the film, and the dye-fiber reaction appears to be more rapid than the rate of dye penetration into the film. The third dye, with a single reactive group, is intermediate in effect on the film. Urea expands the film and appears to open the protein structure without causing crosslinking. In presence of dye the more open protein structure appears to persist but on standing the film rigidity increases.