bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromosome arrangement and nuclear architecture but not centromeric sequences are conserved between Arabidopsis thaliana and Arabidopsis lyrata
Authors: Berr Alexandre , Pecinka Ales , Meister Armin , Kreth Gregor , Fuchs Jörg , Blattner Frank R. , Lysak Martin A. , Schubert Ingo 
Published: November 2006

SummaryIn contrast to the situation described for mammals and Drosophila, chromosome territory (CT) arrangement and somatic homologous pairing in interphase nuclei of Arabidopsis thaliana (n = 5) are predominantly random except for a more frequent association of the chromosomes bearing a homologous nucleolus organizer region. To find out whether this chromosome arrangement is also characteristic for other species of the genus Arabidopsis, we investigated Arabidopsis lyrata ssp. lyrata (n = 8), one of the closest relatives of A. thaliana. First, we determined the size of each chromosome and chromosome arm, the sequence type of centromeric repeats and their distribution between individual centromeres and the position of the 5S/45S rDNA arrays in A. lyrata. Then we demonstrated that CT arrangement, homologous pairing and sister chromatid alignment of distinct euchromatic and/or heterochromatic regions within A. lyrata interphase nuclei are similar to that in A. thaliana nuclei. Thus, the arrangement of interphase chromosomes appears to be conserved between both taxa that diverged about 5 million years ago. Since the chromosomes of A. lyrata resemble those of the presumed ancestral karyotype, a similar arrangement of interphase chromosomes is also to be expected for other closely related diploid species of the Brassicaceae family.
Deficiency of Arabidopsis thaliana frataxin alters activity of mitochondrial Fe–S proteins and induces oxidative stress
Authors: Busi Maria V. , Maliandi María V. , Valdez Hugo , Clemente Marina , Zabaleta Eduardo J. , Araya Alejandro , Gomez‐Casati Diego F. 
Published: November 2006

SummaryFrataxin, a protein crucial for the biogenesis of mitochondria in different organisms, was recently identified in Arabidopsis thaliana. To investigate the role of frataxin in higher plants, we analyze two knock‐out and one knock‐down T‐DNA insertion mutants. The knock‐out mutants present an embryo‐lethal phenotype, indicating an essential role for frataxin. The knock‐down mutant has reduced frataxin mRNA and protein levels. This mutant also presents retarded growth, reduced fresh weight of fruits and reduced number of seeds per fruit. Surprisingly, transcription of aconitase and the Fe–S subunit of succinate dehydrogenase (SDH2‐1) are increased in mutant plants; however, the activity of these proteins is reduced, indicating a role for frataxin in Fe–S cluster assembly or insertion of Fe–S clusters into proteins. Mutant plants also have increased CO2 assimilation rates, exhibit increased formation of reactive oxygen species (ROS) and have increased levels of transcripts for proteins known to be involved in the ROS stress responses. These results indicate that frataxin is an essential protein in plants, required for full activity of mitochondrial Fe–S proteins and playing a protective role against oxidative damage.
Blatchford scoring system is a useful scoring system for detecting patients with upper gastrointestinal bleeding who do not need endoscopic intervention
Authors: Masaoka Tatsuhiro , Suzuki Hidekazu , Hori Shingo , Aikawa Naoki , Hibi Toshifumi 
Published: November 2006

AbstractBackground and Aim:  Several scoring systems have been devised to identify patients with upper gastrointestinal (UGI) bleeding who are at a high risk of adverse outcomes. We retrospectively evaluated the accuracy of the Blatchford scoring system for assessing the need for clinical intervention in cases of UGI bleeding admitted to the emergency department (ED).Methods:  This was a retrospective study conducted on patients who underwent emergency GI endoscopy at the ED of our hospital. Those who needed blood transfusion, operative or endoscopic interventions to control the hemorrhage were classified into the ‘high risk’ group.Results:  Of the 93 enrolled patients, 70 (75.3%) were classified into the high risk group. The Blatchford score was significantly higher in the high risk group than in the low risk group. When a cut‐off value of 2 was used, the sensitivity and specificity of the Blatchford scoring system were determined to be 100% and 13%, respectively. Thus, the Blatchford scoring system was deemed to be useful for distinguishing between the high risk group and the low risk group of patients with GI hemorrhage admitted to the ED.Conclusion:  The Blatchford scoring system is accurate for identifying definitively low‐risk patients of GI hemorrhage, even prior to the performance of emergency UGI endoscopy at the ED.
Influence of contact pressure on fretting fatigue behaviour of AA 2014 alloy with dissimilar mating material
Authors: SADELER R. 
Published: November 2006

ABSTRACTThe effect of contact pressure on the fretting fatigue behaviour of 2014 Al alloy which has been solution heat treated and age hardened (T6 heat treatment) with dissimilar mating materials, was investigated. The fretting fatigue configuration involved bridge‐type contact pads on a flat fatigue specimen. Specimens were made of 2014 Al alloy and bridge‐type pads were made AISI 4140 steel. All the fatigue tests were conducted at a rotational speed of 5000 rpm with a rotating bending fatigue machine (R=−1), using S–N curves to evaluate the fatigue and fretting fatigue properties. The fretting fatigue strength of the material subject to a T6 heat treatment condition at 1 × 107 cycles was dramatically reduced, as compared to that without fretting and with as‐cast. The fretting fatigue life exhibited a variable behaviour with an increase in the contact pressure. A scanning electron microscope was employed to observe the fretting scars and fracture surfaces of the specimens. This analysis showed that cracks originated at the contact surface and crack orientations were approximately ±56 ° from perpendicular to the loading direction.
High‐dose‐rate brachytherapy for intranasal tumours in dogs: results of a pilot study
Authors: Klueter S. , Krastel D. , Ludewig E. , Reischauer A. , Heinicke F. , Pohlmann S. , Wolf U. , Grevel V. , Hildebrandt G. 
Published: November 2006

AbstractThis prospective study describes the feasibility and toxicity of192Iridium high‐dose‐rate (HDR) brachytherapy as an alternative strategy for the treatment of canine intranasal tumours. Fifteen dogs with malignant intranasal tumours were treated twice weekly using a hypofractionated protocol with eight fractions, 5 Gy per fraction, resulting in a total dose of 40 Gy. Acute and chronic adverse side‐effects appeared to be rare. Only 7% of the acute side‐effects and 5% of the chronic were classified as severe (grade 3). Eight dogs showed clinical complete remission, and five dogs had partial remission, with a resolution of tumour‐related symptoms. Magnetic resonance imaging showed a reduced tumour mass in 12 cases. Median survival time was 17 months (range 4–48 months), with four dogs (three without disease) still alive. Median time to recurrence of these dogs was 14 months. In nine dogs, progression or recurrence of the tumour was the cause of death. This study suggests that HDR brachytherapy is feasible and well tolerated.
Usefulness of contrast‐enhanced ultrasonography with abdominal virtual ultrasonography in assessing therapeutic response in hepatocellular carcinoma treated with radiofrequency ablation
Authors: Kisaka Yoshiyasu , Hirooka Masasi , Kumagi Teru , Uehara Takahide , Hiasa Yoichi , Kumano Seishi , Tanaka Hiroaki , Michitaka Kojiro , Horiike Norio , Mochizuki Teruhito , Onji Morikazu 
Published: November 2006

Abstract: Objective: Contrast‐enhanced computed tomography (CECT) is regarded as the gold standard for assessing the efficacy of radiofrequency ablation (RFA) against hepatocellular carcinoma (HCC). We evaluated the efficacy of virtual ultrasonography (VUS) with contrast‐enhanced ultrasonography (CEUS) vs. CECT for assessing the response to RFA.Materials and methods: Study 1:
The therapeutic responses in 22 patients with 26 HCC nodules were assessed by CEUS with VUS as well as by CECT. The efficacy of treatment was based on whether the safety margin was greater than 5 mm after RFA.Study 2: In seven patients with seven HCC nodules, the nodules were treated by RFA and the therapeutic efficacy was assessed by CEUS with VUS. The number of RFA sessions was assessed.Results: Compared with CECT, CEUS with VUS had a specificity of 77%, a sensitivity of 91.6%, and an accuracy of 84%. When the therapeutic response to RFA was analyzed by CECT only, 1.86±0.69 assessments (mean) were required, while when response was assessed by CEUS with VUS, 1.14±0.38 CECT assessments were required (P=0.03).Conclusion: CEUS with VUS is effective in assessing the therapeutic response to RFA of HCC. Moreover, the number of CECT scans required is reduced by this approach.
Liver regeneration in acute severe liver impairment: a clinicopathological correlation study
Authors: Katoonizadeh Aezam , Nevens Frederik , Verslype Chris , Pirenne Jacques , Roskams Tania 
Published: November 2006

Abstract: Background: Although normally quiescent, the adult mammalian liver possesses a great capacity to regenerate after different types of injury. Major players in the regeneration process are mature residual cells, including hepatocytes, cholangiocytes and stromal cells. However, if the regenerative capacity of mature cells is impaired, hepatic progenitor cells (HPCs) are activated and expand into the liver parenchyma. Upon transit amplification, the progenitor cells generate new hepatocytes and biliary cells to restore liver homeostasis.Aims/Methods: To study the relationship between different histopathological parameters as well as their correlations with clinical parameters and outcome, we examined liver specimens from 74 patients with acute or subacute severe liver impairment by immunohistochemistry for CK7/CK19 (evaluation of HPCs activation/differentiation), Mib1(Ki 67)/P21 (evaluation of proliferative activity/proliferation arrest of hepatocytes) and hematoxylin and eosin (evaluation of hepatocyte loss).Results: Of the 74 patients, 32% survived without transplantation, 14% died without transplantation and 54% were transplanted. Our results show that a threshold of 50% loss of hepatocytes, associated with significant decrease in the proliferative activity of remaining mature hepatocytes, is needed for extensive hepatic progenitor cell activation. Such activation is a sign of disease severity and occurs early (within 1 week) in the disease course. However, development of intermediate hepatocytes, suggesting HPCs differentiation towards mature hepatocytes, takes at least 1 week's time. We found a positive correlation between histopathological parameters (percentage hepatocyte loss, number of proliferating hepatocytes and number of HPCs) and clinical parameters of liver impairment such as model for end stage liver diseases (MELD). Surviving patients compared with those who either died or were transplanted had significantly less hepatocyte loss, less HPCs activation and more mature hepatocyte proliferative activity. Hepatocyte proliferative activity and degree of hepatocyte loss were the most important independent histopathological parameters in predicting outcome.Conclusion: Liver biopsy can provide important additional information in a patient with severe acute liver impairment.
Mobilizing the Latino Youth Vote: Some Experimental Results*
Authors: Michelson Melissa R. 
Published: November 2006

Objectives. The objectives of this article are to test whether Latino canvassers are more effective than non‐Latino canvassers at increasing voter turnout among young Latinos, and to test whether young Latinos are more receptive to a mobilization message that stresses ethnic group solidarity or one that emphasizes civic duty.Methods. A randomized field experiment, conducted in Fresno, California in the fall of 2002, is the basis for the results reported here.Results. Young Latino voters targeted by Latino canvassers are more likely to be contacted. However, once contacted, Latinos reached by non‐Latino canvassers are just as likely to turn out to vote as are those reached by non‐Latino canvassers. The mobilization effect is particularly strong among voters who have participated in at least one prior election.Conclusions. The importance of using Latino canvassers to get out the Latino vote is confirmed, but should not be overemphasized. More importantly, this experiment demonstrates that door‐to‐door canvassing can have a substantively large and statistically significant effect on turnout among young Latinos, a demographic group often overlooked by parties and campaigns.
The expression of CD23 and CD40 in primary cutaneous B‐cell lymphomas
Authors: Magro Cynthia 
Published: November 2006

Background:  CD23 expression in normal B lymphocytes is limited to autoreactive B cells, naïve B cells and mature B cells manifesting an activated phenotype. As a marker of hematologic dyscrasia/malignancy, expression of CD23 is associated with small lymphocytic lymphoma/chronic lymphocytic leukemia. An absence of CD23 expression within small lymphocytes is typically seen in marginal zone lymphoma and mantle cell lymphoma. Positive CD23 expression amidst neoplastic cells in primary cutaneous B‐cell lymphoma is not a reported phenomenon.Methods:  This paper reports nine patients with cutaneous B‐cell lymphoma manifesting CD23 expression.Results:  In seven of the nine cases CD23 expression was observed in the setting of recurrent disease, being present in both large and small lymphocytes. CD23 expression paralleled staining for CD40 in all but one case.Conclusions:  A potential mechanism of CD23 upregulation may involve the anti‐apoptotic nuclear kappa beta CD40–CD40 ligand pathway. Neoplastic B cells manifesting CD23 expression could have a survival advantage, predisposing to recurrent disease and or oncogenic events permissive to disease progression.
Inflammatory Response to a Titanium Surface with Potential Bioactive Properties: An In Vitro Study
Authors: Göransson Anna , Gretzer Christina , Johansson Anna , Sul Young‐Taeg , Wennerberg Ann 
Published: November 2006

ABSTRACTBackground:  The current hard tissue implants research aims to accelerate bone healing by designing surfaces that are bioactive. However, the role of the inflammatory response to these surfaces is so far incompletely described.Purpose:  The aim of the study was to evaluate early inflammatory response in vitro to a potentially bioactive surface—an anodized surface with Mg ions incorporated (anodized/Mg)—and to compare it to a turned, a blasted, and an anodized surface.Materials and Methods:  An interferometer was used for topographical characterizations. The disks were incubated with human mononuclear cells. Adherent cells were investigated with respect to number of cells, viability, differentiation, and cytokine production with and without lipopolysaccharide stimulation after 24 and 72 hours.Results:  The number of adhered mononuclear cells differed significantly between the different modified surfaces, with the highest number on the anodized surface. However, there were no significant differences in cytokine production and differentiation between the different modified surfaces. The amount of anti‐inflammatory mediator interleukin‐10 remained over time, while the number of cells and pro‐inflammatory cytokine tumor necrosis factor‐α decreased. The cells were viable on all surfaces, respectively.Conclusion:  The anodized surfaces with and without Mg ions showed an increased cell adherence, however, otherwise an inflammatory response similar to the turned and blasted surfaces. Furthermore, the potentially bioactive anodized/Mg surface showed a similar response to the TiUnite‐like anodized surface despite the former having a surface roughness of a smoother character.
Effect of H2 and Redox Condition on Biotic and Abiotic MTBE Transformation
Authors: Bradley P.M. , Chapelle F.H. , Landmeyer J.E. 
Published: November 2006

AbstractLaboratory studies conducted with surface water sediment from a methyl tert‐butyl ether (MTBE)‐contaminated site in South Carolina demonstrated that, under methanogenic conditions, [U‐14C] MTBE was transformed to 14C tert‐butyl alcohol (TBA) with no measurable production of 14CO2. Production of TBA was not attributed to the activity of methanogenic microorganisms, however, because comparable transformation of [U‐14C] MTBE to 14C‐TBA also was observed in heat‐sterilized controls with dissolved H2 concentrations > 5 nM. The results suggest that the transformation of MTBE to TBA may be an abiotic process that is driven by biologically produced H2 under in situ conditions. In contrast, mineralization of [U‐14C] MTBE to 14CO2 was completely inhibited by heat sterilization and only observed in treatments characterized by dissolved H2 concentrations < 2 nM. These results suggest that the pathway of MTBE transformation is influenced by in situ H2 concentrations and that in situ H2 concentrations may be an useful indicator of MTBE transformation pathways in ground water systems.
Effect of Sequence-Directed Nucleosome Disruption on Cell-Type-Specific Repression by α2/Mcm1 in the Yeast Genome
Authors: Morohashi Nobuyuki , Yamamoto Yuichi , Kuwana Shunsuke , Morita Wataru , Shindo Heisaburo , Mitchell Aaron P. , Shimizu Mitsuhiro 
Published: November 2006

ABSTRACT

In
Saccharomyces cerevisiae
, a-cell-specific genes are repressed in
MAT
α cells by α2/Mcm1, acting in concert with the Ssn6-Tup1 corepressors and the Isw2 chromatin remodeling complex, and nucleosome positioning has been proposed as one mechanism of repression. However, prior studies showed that nucleosome positioning is not essential for repression by α2/Mcm1 in artificial reporter plasmids, and the importance of the nucleosome positioning remains questionable. We have tested the function of positioned nucleosomes through alteration of genomic chromatin at the
a
-cell-specific gene
BAR1
. We report here that a positioned nucleosome in the
BAR1
promoter is disrupted in
cis
by the insertion of diverse DNA sequences such as poly(dA) · poly(dT) and poly(dC-dG) · poly(dC-dG), leading to inappropriate partial derepression of
BAR1
. Also, we show that
isw2
mutation causes loss of nucleosome positioning in
BAR1
in
MAT
α cells as well as partial disruption of repression. Thus, nucleosome positioning is required for full repression, but loss of nucleosome positioning is not sufficient to relieve repression completely. Even though disruption of nucleosome positioning by the
cis
- and
trans
-acting modulators of chromatin has a modest effect on the level of transcription, it causes significant degradation of the α-mating pheromone in
MAT
α cells, thereby affecting its cell type identity. Our results illustrate a useful paradigm for analysis of chromatin structural effects at genomic loci.
Molecular Characterization of the Minimal Replicon and the Unidirectional Theta Replication of pSCM201 in Extremely Halophilic Archaea
Authors: Sun Chaomin , Zhou Meixian , Li Yun , Xiang Hua 
Published: November 2006

ABSTRACTA 3,463-bp plasmid, pSCM201, was isolated from a halophilic archaeon,Haloarculasp. strain AS7094. The minimal replicon that is essential and sufficient for autonomous replication and stable maintenance inHaloarcula hispanicawas determined by deletion analysis of the plasmid. This minimal replicon (∼1.8 kb) consisted of only two functionally related segments: (i) a putative origin (ori201) containing an AT-rich region and sets of repeats and (ii) an adjacent gene encoding a putative replication initiation protein (Rep201). Electron microscopic observation and Southern blotting analysis demonstrated that pSCM201 replicates via a theta mechanism. Precise mapping of the putative origin suggested that the replication initiated from a fixed site close to the AT-rich region and proceeded unidirectionally toward the downstreamrep201gene, which was further confirmed by electron microscopic analysis of the ClaI-digested replication intermediates. To our knowledge, this is the first unidirectional theta replication plasmid experimentally identified in the domain of archaea. It provides a novel plasmid system to conduct research on archaeal DNA replication.
Detection of Multidrug Resistance in
Mycobacterium tuberculosis
Authors: Sekiguchi Jun-ichiro , Miyoshi-Akiyama Tohru , Augustynowicz-Kopeć Ewa , Zwolska Zofia , Kirikae Fumiko , Toyota Emiko , Kobayashi Intetsu , Morita Koji , Kudo Koichiro , Kato Seiya , Kuratsuji Tadatoshi , Mori Toru , Kirikae Teruo 
Published: November 2006

ABSTRACT

We developed a DNA sequencing-based method to detect mutations in the genome of drug-resistant
Mycobacterium tuberculosis
. Drug resistance in
M. tuberculosis
is caused by mutations in restricted regions of the genome. Eight genome regions associated with drug resistance, including
rpoB
for rifampin (RIF),
katG
and the
mabA
(
fabG1
)-
inhA
promoter for isoniazid (INH),
embB
for ethambutol (EMB),
pncA
for pyrazinamide (PZA),
rpsL
and
rrs
for streptomycin (STR), and
gyrA
for levofloxacin, were amplified simultaneously by PCR, and the DNA sequences were determined. It took 6.5 h to complete all procedures. Among the 138 clinical isolates tested, 55 were resistant to at least one drug. Thirty-four of 38 INH-resistant isolates (89.5%), 28 of 28 RIF-resistant isolates (100%), 15 of 18 EMB-resistant isolates (83.3%), 18 of 30 STR-resistant isolates (60%), and 17 of 17 PZA-resistant isolates (100%) had mutations related to specific drug resistance. Eighteen of these mutations had not been reported previously. These novel mutations include one in
rpoB
, eight in
katG
, one in the
mabA-inhA
regulatory region, two in
embB
, five in
pncA
, and one in
rrs. Escherichia coli
isolates expressing individually five of the eight
katG
mutations showed loss of catalase and INH oxidation activities, and isolates carrying any of the five
pncA
mutations showed no pyrazinamidase activity, indicating that these mutations are associated with INH and PZA resistance, respectively. Our sequencing-based method was also useful for testing sputa from tuberculosis patients and for screening of mutations in
Mycobacterium bovis
. In conclusion, our new method is useful for rapid detection of multiple-drug-resistant
M. tuberculosis
and for identifying novel mutations in drug-resistant
M. tuberculosis
.