bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of c‐kit and Sca‐1 and their relationship with multidrug resistance protein 1 in mouse bone marrow mononuclear cells
Authors: Kyle‐Cezar Fernanda , Echevarria‐Lima Juliana , Goldenberg Regina Coeli dos Santos , Rumjanek Vivian M. 
Published: January 2007

SummaryP‐glycoprotein (Pgp) and multidrug resistance protein 1 (MRP1) are members of the ATP‐binding cassette (ABC) family of transporter proteins. Both molecules are membrane‐associated, energy‐dependent efflux pumps with different substrate selectivity and they may play a role in the activation, differentiation and function of haematopoietic cells. Mouse haematopoietic cells are characterized by the expression of the cell surface molecules c‐kit and Sca‐1. Herein, the presence and activities of Pgp and MRP1 in mouse bone marrow mononuclear cells (BMMC) and their relationship with the proteins c‐kit and Sca‐1 were evaluated. Pgp and MRP activities were measured based on the extrusion of rhodamine 123 (for Pgp) and Fluo‐3 (for MRP). Cell populations were assessed by cytometry using anti‐c‐kit and anti‐Sca1 antibodies. Pgp activity was present in 5% of BMMC while 50% of BMMC cells showed MRP activity. These findings agreed with the proportion of cells expressing the MRP1 surface molecule (51·3 ± 4·17%). About 14% of BMMC were positive for c‐kit and/or Sca‐1 (9·3% c‐kit– Sca‐1+, 4·2% c‐kit+ Sca‐1– and 0·9% c‐kit+ Sca‐1+). Among these subpopulations only c‐kit– Sca‐1+ cells presented Pgp activity (21·36%). On the other hand, MRP activity was present in all three subpopulations. Most cells (82·5%) of the c‐kit+ Sca‐1– subpopulation presented MRP1 activity compared to only 54·1% of c‐kit+ Sca‐1+ and 38·8% of c‐kit– Sca‐1+. This study demonstrates the expression and activity of MRP1 in BMMC. While only a small proportion of precursor cells had Pgp activity, MRP1 activity was present among different subpopulations of precursor cells. Further studies are necessary to establish the role of these transporters in haematopoietic cells.
Fracture resistance of the buccal cuSPS of root filled maxillary premolar teeth restored with various techniques
Authors: Siso Ş. H. , Hürmüzlü F. , Turgut M. , Altundaşar E. , Serper A. , Er K. 
Published: January 2007

AbstractAim  To compare the cusp fracture resistance of teeth restored with composite resins and two post systems.Methodology  Eighty extracted single‐rooted human maxillary premolars were randomly assigned to eight groups (n = 10). Group 1 (control) did not receive any preparation. From groups 2 to 8, the teeth were root filled and mesio‐occluso‐distal (MOD) cavities were prepared. Group 2 remained unrestored. Group 3 was restored with packable resin composite using a single‐step adhesive. Group 4 was restored with packable resin composite using a single‐step adhesive and a thin layer of flowable resin composite. Group 5 was restored with packable resin composite using a total‐etch two‐step adhesive. Group 6 was restored with ormocer resin composite using a total‐etch two‐step adhesive. Group 7 was restored with an endodontic glass fibre post and hybrid resin composite using a total‐etch two‐step adhesive. Group 8 was restored with an endodontic zirconium post and hybrid resin composite using a total‐etch two‐step adhesive. The teeth were then mounted in a universal testing machine, the buccal cusp loaded (30°) until fracture, and the data analysed statistically.Results  Group 1 had the greatest fracture resistance, and group 2 the poorest. Groups 5–8 had significantly greater (P < 0.05) fracture resistance than groups 3 and 4. No significant differences were found between groups 3 and 4, or amongst groups 5–8 (P > 0.05).Conclusions  For root filled maxillary premolars with MOD cavities, adhesive resin composite restorations, with and without glass and zirconium posts, increased the fracture resistance of the buccal cuSPS. A total‐etch two‐step adhesive increased significantly fracture resistance more than a one‐step adhesive. For the one‐step adhesive, an additional layer of flowable resin composite did not enhance fracture resistance.
Imaging of root canal fillings: a comparison of subjective image quality between limited cone‐beam CT, storage phosphor and film radiography
Authors: Soğur E. , Baksı B. G. , Gröndahl H.‐G. 
Published: January 2007

AbstractAim  To compare the subjective quality of limited cone‐beam computed tomography (LCBCT), storage phosphor plate (SPP) and F‐speed film images for the evaluation of length and homogeneity of root fillings.Methodology  Root canals of 17 extracted permanent mandibular incisor teeth were filled. With the teeth placed in their jaws, images were obtained with Accu‐I‐Tomo LCBCT, Digora® Optime image plate system and F‐speed film using exposure parameters yielding ‘clinically’ acceptable density and contrast. Three radiologists and three endodontists independently rated the quality of all images in respect to homogeneity and the length of root fillings using a 3‐graded scale. Evaluations were undertaken in two sessions. In the first, the coronal LCBCT images were not included. In the second, both coronal and sagittal LCBCT images were rated along with F‐speed film and SPP images. Results were compared using the Friedman test (P < 0.05). Pair‐wise comparisons of systems were completed using the Wilxocon signed‐ranks test (P < 0.05). Kappa was used to measure interobserver agreement.Results  Digora images were rated superior, consecutively followed by F‐speed films and LCBCT images, for the evaluation of both homogeneity and length of root fillings in both the evaluation sessions (P < 0.05). Kappa ranged from slight to moderate for the length evaluation of root fillings and from poor to fair for the evaluation of homogeneity of root fillings.Conclusion  Image quality of storage phosphor images was subjectively as good as conventional film images and superior to LCBCT images for the evaluation of both homogeneity and length of root fillings in single‐rooted teeth.
Long‐term follow‐up of a complicated crown fracture treated by partial pulpotomy
Authors: Sonmez I.S. , Sonmez H. 
Published: January 2007

AbstractAim  To present the 7‐year follow‐up of a permanent incisor with complicated crown fracture, treated by partial pulpotomy.Summary  A healthy permanent right central maxillary incisor with complicated crown fracture was treated by partial pulpotomy and reviewed clinically and radiographically for 7 years. At each recall, there was no spontaneous pain; the pulp showed signs of vitality and no periapical radiolucency developed.Key learning points• Partial pulpotomy may be a successful permanent treatment in cases of complicated crown fracture.
Clinical evaluation of root filled teeth restored with or without post‐and‐core systems in a specialist practice setting
Authors: Salvi G. E. , Siegrist Guldener B. E. , Amstad T. , Joss A. , Lang N. P. 
Published: January 2007

AbstractAim  To assess survival rates and complications of root‐filled teeth restored with or without post‐and‐core systems over a mean observation period of ≥4 years.Methodology  A total of 325 single‐ and multirooted teeth in 183 subjects treated in a private practice were root filled and restored with either a cast post‐and‐core or with a prefabricated titanium post and composite core. Root‐filled teeth without post‐retained restorations served as controls. The restored teeth served as abutments for single unit metal‐ceramic or composite crowns or fixed bridges. Teeth supporting cantilever bridges, overdentures or telescopic crowns were excluded.Results  Seventeen teeth in 17 subjects were lost to follow‐up (17/325: 5.2%). The mean observation period was 5.2 ± 1.8 (SD) years for restorations with titanium posts, 6.2 ± 2.0 (SD) years for cast post‐and‐cores and 4.4 ± 1.7 (SD) years for teeth without posts. Overall, 54% of build‐ups included the incorporation of a titanium post and 26.5% the cementation of a cast post‐and‐core. The remaining 19.5% of the teeth were restored without intraradicular retention. The adjusted 5‐year tooth survival rate amounted to 92.5% for teeth restored with titanium posts, to 97.1% for teeth restored with cast post‐and‐cores and to 94.3% for teeth without post restorations, respectively. The most frequent complications included root fracture (6.2%), recurrent caries (1.9%), post‐treatment periradicular disease (1.6%) and loss of retention (1.3%).Conclusion  Provided that high‐quality root canal treatment and restorative protocols are implemented, high survival and low complication rates of single‐ and multirooted root‐filled teeth used as abutments for fixed restorations can be expected after a mean observation period of ≥4 years.
Predictive factors for an increased risk of sperm aneuploidies in oligo‐astheno‐teratozoospermic males
Authors: Faure A. K. , Aknin‐Seifer I. , Frérot G. , Pelletier R. , De Robertis C. , Cans C. , Levy R. , Jimenez C. , Lejeune H. , Terrier N. , Bergues U. , Hennebicq S. , Rousseaux S. 
Published: January 2007

SummaryPatients with severe spermatogenesis impairment can now successfully father a child thanks to the use of intracytoplasmic sperm injection (ICSI). In oligozoospermic patients, many studies have reported significantly higher sperm aneuploidy rates and therefore an increased risk of transmitting a chromosomal abnormality via the injection of abnormal spermatozoa. However, the frequency of aneuploidy is highly variable between patients. The aim of the present work was to identify clinical and biological factors, which, together with non‐obstructive oligozoospermia, could be predictive of elevated sperm aneuploidies. The sperm aneuploidy rates for chromosomes X, Y, 13, 18 and 21 were assessed in 31 infertile men with well‐characterized spermatogenesis impairment, and in a population of control men with proven fertility. The frequency of sperm aneuploidy was compared between several patient subgroups according to their clinical and biological factors. Nearly half of the oligozoospermic males (15/31) had a significantly increased disomy rate for at least one of the five chromosomes compared with that observed in the control population (mean disomy rates + 1.96 standard deviation). Factors significantly associated with higher numbers of aneuploid sperm were cigarette smoking, an elevated follicle‐stimulating hormone level, a sperm concentration less than 1 m/mL, and a severe teratozoospermia. Hence, several factors predictive of an increased risk of sperm aneuploidy rates were identified in ICSI male candidates with a non‐obstructive oligozoospermia.
Within‐subject variation of seminal parameters in men with infertile marriages
Authors: Francavilla F. , Barbonetti A. , Necozione S. , Santucci R. , Cordeschi G. , Macerola B. , Francavilla S. 
Published: January 2007

SummaryAs little information exists on the semen variability in infertile men, this study aimed at analysing the within‐subject variability of semen from men with infertile marriages included in an intrauterine insemination (IUI) programme. Five ejaculates from each of 436 men (2180 specimens) were analysed. The within‐subject coefficients of variation (CVw) were high for all parameters (semen volume, sperm concentration, forward motility and combined parameters), ranging from 0.73 for the total motile sperm count to 0.27 for the semen volume. Nevertheless, within‐subject fluctuations were smaller than the between‐subject variability, as indicated by high Intraclass Correlation Coefficient (ICC) values, which, however, significantly lowered when ≤3 samples were analysed against five samples. Neither seasonality nor the length of abstinence between 3 and 7 days significantly affected within‐subject semen variability, whereas total motile sperm count was significantly and negatively affected at 2 days of abstinence. In 253 cycles of double IUI, performed in two consecutive days, semen volume and parameters including volume decreased in the second sample, but semen quality improved in most cases of oligo‐ and/or asthenozoospermia. Useful information for clinical purposes is provided.
Clinical impact of selective serotonin reuptake inhibitors therapy with bleeding risks
Authors: Turner M. S. , May D. B. , Arthur R. R. , Xiong G. L. 
Published: January 2007

Abstract.The selective serotonin reuptake inhibitors (SSRIs) are extensively used for the treatment of multiple psychiatric conditions. In vitro and ex vivo data with these agents indicate they may have varying degrees of antiplatelet activity via multiple receptors. Reports of bleeding in patients receiving SSRIs appeared soon after their introduction. A review of the literature suggests SSRI therapy may increase the risk of bleeding especially with concomitant aspirin or nonsteroidal anti‐inflammatory agents. Clinicians should exercise caution when prescribing these agents in high risk patients and maintain awareness of the potential contribution of SSRIs to unexplained bleeding episodes.
Biochemical and bioimaging markers for risk assessment and diagnosis in major cardiovascular diseases: a road to integration of complementary diagnostic tools
Authors: Marcovina S. M. , Crea F. , Davignon J. , Kaski J. C. , Koenig W. , Landmesser U. , Pieri P. L. , Schulz‐Menger J. , Shaw L. J. , Sobesky J. 
Published: January 2007

Abstract.This report from the first International Course on Integrated Biomarkers, Biochemical and Bioimaging Endpoints in Cardiovascular Diagnosis, Prevention, Therapy and Drug Development provides the basis for optimizing diagnostic, prognostic and therapeutic information in four areas of cardiovascular medicine: primary prevention of cardiovascular diseases, acute coronary syndromes, heart failure and stroke. Risk stratification and treatment strategies can be refined and enhanced through integration of bioimaging and biochemical markers to characterize sub‐clinical and clinical atherosclerosis. For the integrative approach to be useful, each of the biomarkers must be validated and cost‐effective. Clinical decision is the primary level of integration and is based on clinical evaluation and the use of a combination of bioimaging and biochemical markers. The decision to initiate preventive or therapeutic intervention must take into account the factors affecting the levels of expression of the biomarker and the potential input the biomarker has on metabolic processes or modulation of other biomarkers. The optimal approach to intervention must take into consideration the risk–benefit and cost–effectiveness ratios.
Transformation in Streptococcus pneumoniae: formation of eclipse complex in a coiA mutant implicates CoiA in genetic recombination
Authors: Desai Bhushan V. , Morrison Donald A. 
Published: January 2007

SummaryCoiA is a transient protein expressed specifically during competence and required for genetic transformation in Streptococcus pneumoniae, but not for DNA uptake. It is widely conserved among Gram‐positive bacteria but its function is unknown. Here we report that although the rate of DNA uptake was not affected in a coiA mutant, the internalized donor DNA did not recombine into the host chromosome to form a physical and genetic heteroduplex. Instead, DNA taken up by a coiA mutant accumulated in the form of a single‐stranded (ss) DNA–protein complex indistinguishable from the eclipse complex formed as a recombination intermediate in wild‐type competent cells. Internalized donor DNA in a dprA mutant did not accumulate either as ss DNA or as an eclipse complex. Together, these results establish that a coiA mutant exhibits a phenotype different from that of dprA or recA mutants, and that CoiA functions at a later step in promoting recombination during genetic transformation in Streptococcus pneumoniae.
A horizontally acquired filamentous phage contributes to the pathogenicity of the plague bacillus
Authors: Derbise Anne , Chenal‐Francisque Viviane , Pouillot Flavie , Fayolle Corinne , Prévost Marie‐Christine , Médigue Claudine , Hinnebusch Bernard Joseph , Carniel Elisabeth 
Published: January 2007

Summary Yersinia pestis, the plague bacillus, has an exceptional pathogenicity but the factors responsible for its extreme virulence are still unknown. A genome comparison with its less virulent ancestor Yersinia pseudotuberculosis identified a few Y. pestis‐specific regions acquired after their divergence. One of them potentially encodes a prophage (YpfΦ), similar to filamentous phages associated with virulence in other pathogens. We show here that YpfΦ forms filamentous phage particles infectious for other Y. pestis isolates. Although it was previously suggested that YpfΦ is restricted to the Orientalis branch, our results indicate that it was acquired by the Y. pestis ancestor. In Antiqua and Medievalis strains, YpfΦ genome forms an unstable episome whereas in Orientalis isolates it is stably integrated as tandem repeats. Deletion of the YpfΦ genome does not affect Y. pestis ability to colonize and block the flea proventriculus, but results in an alteration of Y. pestis pathogenicity in mice. Our results show that transformation of Y. pestis from a classical enteropathogen to the highly virulent plague bacillus was accompanied by the acquisition of an unstable filamentous phage. Continued maintenance of YpfΦ despite its high in vitro instability suggests that it confers selective advantages to Y. pestis under natural conditions.
Genetic mechanisms involved in the repression of flagellar assembly by Pseudomonas aeruginosa in human mucus
Authors: Jyot Jeevan , Sonawane Avinash , Wu Weihui , Ramphal Reuben 
Published: January 2007

Summary Pseudomonas aeruginosa downregulates flagellin transcription when it is grown in purulent mucus from patients with cystic fibrosis (CF) and non‐CF bronchiectasis. This response possibly abrogates the potent inflammatory response mediated by the interaction of flagellin with Toll‐like receptor 5. The molecular mechanisms involved are thus far unknown. Known flagellar transcriptional regulators were not involved, thus Tn5 mutagenesis was used to ascertain whether novel regulators existed. Five clones with independent Tn5 insertions in flgM showed derepression of flagellin synthesis, suggesting that FlgM was involved in this phenomenon. Furthermore, examination of mucus‐grown bacteria showed FlgM accumulation and overexpression of fliA in mucus‐grown bacteria reversed the repression of flagellin synthesis. A related study from our laboratory had identified neutrophil elastase in mucus as the molecule responsible for fliC repression, therefore we examined whether loss of the flagellar hook (FlgE), by proteolysis was involved, because the flagellar hook is required for FlgM export. Western immunoblot of membranes from mucus‐grown bacteria showed the absence of FlgE, despite the fact that the protein is made and the operon encoding FlgE is upregulated in mucus. A model is proposed wherein neutrophil elastase in mucus proteolytically cleaves the flagellar hook, thus completion of the hook basal body is never sensed, resulting in FlgM accumulation within the cell, causing repression of flagellin synthesis. We speculate that the cyclical bouts of inflammation observed in CF patients may result from flagellin synthesis and its repression, caused by presence of neutrophils at the site of infection.
A PerR‐regulated metal transporter (PmtA) is an interface between oxidative stress and metal homeostasis inStreptococcus pyogenes
Authors: Brenot Audrey , Weston Benjamin F. , Caparon Michael G. 
Published: January 2007

SummaryInStreptococcus pyogenes, mutation of the peroxide sensor PerR results in avirulence despite producing hyper‐resistance to peroxide stress. To understand the basis of this effect, global transcription profiling was conducted revealing one highly downregulated gene (czcD), and five highly upregulated genes in the mutant. Of the latter, onlypmtAcontained a binding site for PerR, whilephtY,phtD,lspandrpsN2harboured an AdcR motif and were regulated by AdcR, a repressor of an ABC‐type metal transporter. Furthermore, only the PerR‐regulatedpmtA(PerR‐regulated metal transporter A), a putative metal transporter, contributed to resistance against peroxide stress, while AdcR and the other AdcR‐regulated genes did not. However, overexpression ofpmtAresulted in upregulation of several AdcR‐regulated genes, suggesting that the AdcR regulon is sensitive to PerR regulation of metal homeostasis. Finally, examination ofS. pyogenesfollowing murine subcutaneous infection revealed that whilepmtAwas not upregulated in a late infection, the AdcR‐regulated genes were. Taken together, these data suggest that PerR has a greater impact on the transcriptome than can be predicted by its binding sites and thatpmtAfunctions to link metal homeostasis and oxidative stress responses.
Protection of antiterminator RNA by the transcript elongation complex
Authors: Sloan Sieghild , Rutkai Edit , King Rodney A. , Velikodvorskaya Tatyana , Weisberg Robert A. 
Published: January 2007

SummaryNascent transcripts encoded by the putL and putR sites of phage HK022 bind the transcript elongation complex and suppress termination at downstream transcription terminators. We report here that the chemical stability of putL RNA is considerably greater than that of the typical Escherichia coli message because the elongation complex protects this RNA from degradation. When binding to the elongation complex was prevented by mutation of either putL or RNA polymerase, RNA stability decreased more than 50‐fold. The functional modification conferred by putL RNA on the elongation complex is also long‐lived: the efficiency of terminator suppression remained high for at least 10 kb from the putL site. We find that RNase III rapidly and efficiently cleaved the transcript just downstream of the putL sequences, but such cleavage changed neither the stability of putL RNA nor the efficiency of antitermination. These results argue that the continuity of the RNA that connects put sequences to the growing point is not required for persistence of the antiterminating modification in vivo.
A plasmodesmata‐associated β‐1,3‐glucanase in Arabidopsis
Authors: Levy Amit , Erlanger Michael , Rosenthal Michal , Epel Bernard L. 
Published: January 2007

SummaryPlasmodesmal conductivity is regulated in part by callose turnover, which is hypothesized to be determined by β‐1,3‐glucan synthase versus glucanase activities. A proteomic analysis of an Arabidopsis thaliana plasmodesmata (Pd)‐rich fraction identified a β‐1,3‐glucanase as present in this fraction. The protein encoded by the putative plasmodesmal associated protein (ppap) gene, termed AtBG_ppap, had previously been found to be a post‐translationally modified glycosylphosphatidylinositol (GPI) lipid‐anchored protein. When fused to green fluorescent protein (GFP) and expressed in tobacco (Nicotiana tabacum) or Nicotiana benthamiana epidermal cells, this protein displays fluorescence patterns in the endoplasmic reticulum (ER) membrane system, along the cell periphery and in a punctate pattern that co‐localizes with aniline blue‐stained callose present around the Pd. Plasma membrane localization was verified by co‐localization of AtBG_ppap:GFP together with a plasma membrane marker N‐[3‐triethylammoniumpropyl]‐4‐[p‐diethylaminophenylhexatrienyl] pyridinium dibromide (FM4‐64) in plasmolysed cells. In Arabidopsis T‐DNA insertion mutants that do not transcribe AtBG_ppap, functional studies showed that GFP cell‐to‐cell movement between epidermal cells is reduced, and the conductivity coefficient of Pd is lower. Measurements of callose levels around Pd after wounding revealed that callose accumulation in the mutant plants was higher. Taken together, we suggest that AtBG_ppap is a Pd‐associated membrane protein involved in plasmodesmal callose degradation, and functions in the gating of Pd.