bluuebunny/crossref_metadata_2025_split huggingface dataset:
SleC Is Essential for Cortex Peptidoglycan Hydrolysis during Germination of Spores of the Pathogenic Bacterium
Clostridium perfringens
Authors: Paredes-Sabja Daniel , Setlow Peter , Sarker Mahfuzur R. 
Published: February 2009

ABSTRACT

Clostridial spore germination requires degradation of the spore's peptidoglycan (PG) cortex by cortex-lytic enzymes (CLEs), and two
Clostridium perfringens
CLEs, SleC and SleM, degrade cortex PG in vitro. We now find that only SleC is essential for cortex hydrolysis and viability of
C. perfringens
spores.
C. perfringens sleC
spores did not germinate completely with nutrients, KCl, or a 1:1 chelate of Ca
2+
and dipicolinic acid (Ca-DPA), and the colony-forming efficiency of
sleC
spores was 10
3
-fold lower than that of wild-type spores. However,
sleC
spores incubated with various germinants released most of their DPA, although slower than wild-type or
sleM
spores, and DPA release from
sleC sleM
spores was very slow. In contrast, germination and viability of
sleM
spores were similar to that of wild-type spores, although
sleC sleM
spores had 10
5
-fold-lower viability. These results allow the following conclusions about
C. perfringens
spore germination: (i) SleC is essential for cortex hydrolysis; (ii) although SleM can degrade cortex PG in vitro, this enzyme is not essential; (iii) action of SleC alone or with SleM can accelerate DPA release; and (iv) Ca-DPA does not trigger spore germination by activation of CLEs.
Identification of Major Histocompatibility Complex Restriction and Anchor Residues of Foot-and-Mouth Disease Virus-Derived Bovine T-Cell Epitopes
Authors: Gerner Wilhelm , Hammer Sabine E. , Wiesmüller Karl-Heinz , Saalmüller Armin 
Published: February 2009

ABSTRACTDespite intensive research on the identification of T-cell epitopes in cattle after foot-and-mouth disease virus (FMDV) infection during the last 20 years, knowledge of major histocompatibility complex (MHC) restriction and anchor residues of such epitopes is still sparse. Therefore, as a first step, we tested lymphocytes from two experimentally FMDV serotype A24-vaccinated and -challenged cattle for recognition of FMDV-derived pentadecapeptides in proliferation assays. Two epitopes were identified: amino acid residues 66 to 80 within the structural protein 1D and amino acid residues 22 to 36 within the structural protein 1A. The latter epitope was recognized by lymphocytes from both cattle. Peptide-specific proliferation was caused by a response of CD4+T helper cells as identified by carboxyfluorescein diacetate succinimidyl ester proliferation assays. Having identified one epitope that was recognized by two cattle, we hypothesized that these animals should have common MHC class II alleles. Cloning and sequencing of DRB3, DQA, and DQB alleles revealed that both animals possessed DQA allele 22021 and DQB allele 1301 but had no common DRB3 allele. A parallel analysis of amino acid residues involved in MHC presentation by peptides with alanine substitutions showed that the amino acid residues in positions 5 and 9 within the pentadecapeptide representing the 1A epitope were important for MHC binding in both cattle. These data indicate that the epitope located on FMDV protein 1A can be presented by MHC class II DQ molecules encoded by DQA allele 22021 and DQB allele 1301 and present the first evidence of the binding motif of this particular DQ molecule.
Role of Natural Killer Cells in a Cohort of Elite Suppressors: Low Frequency of the Protective KIR3DS1 Allele and Limited Inhibition of Human Immunodeficiency Virus Type 1 Replication In Vitro
Authors: O'Connell Karen A. , Han Yefei , Williams Thomas M. , Siliciano Robert F. , Blankson Joel N. 
Published: February 2009

ABSTRACT

Natural killer (NK) cells are associated with the innate immune response and are important in many viral infections. Recent studies indicate that NK cells can control human immunodeficiency virus type 1 (HIV-1) replication. We studied the effect of NK cells on HIV-1 replication in a subpopulation of HIV-1-infected individuals termed elite suppressors (ES) or elite controllers. These patients maintain a clinically undetectable viral load without treatment and thus provide a fascinating cohort in which to study the immunological response to HIV-1. Using an autologous system, we analyzed the effects of NK cells and CD8
+
T cells on viral replication in CD4
+
T lymphoblasts. Although we had postulated that NK cells of ES would be highly effective at controlling viral replication, we found that NK cells from some, but not all, ES were capable of inhibiting replication in the presence of interleukin-2, and the inhibition was less robust than that mediated by CD8
+
T cells. Additionally, we examined whether particular alleles of the KIR receptors, specifically KIR3DS1 and KIR3DL1, or allele-ligand combinations correlated with the control of HIV-1 replication by NK cells and whether any specific KIR alleles were overrepresented in ES. Our ES cohort did not differ from the general population with respect to the frequency of individual KIR. However, of the eight ES studied, the four exhibiting the most NK cell-mediated control of viral replication also had the fewest activating KIR and were haplotype A. Thus, the strong NK cell-mediated inhibition of viral replication is not necessary for the immunological control of HIV-1 in all ES.
Nipah Virus Edits Its P Gene at High Frequency To Express the V and W Proteins
Authors: Kulkarni Sachin , Volchkova Valentina , Basler Christopher F. , Palese Peter , Volchkov Viktor E. , Shaw Megan L. 
Published: February 2009

ABSTRACT
Nipah virus (NiV) is predicted to encode four proteins from its P gene (P, V, W, and C) via mRNA editing and an alternate open reading frame. By use of specific antibodies, the expression of the V, W, and C proteins in NiV-infected cells has now been confirmed. Analysis of the P-gene transcripts shows a ratio of P:V:W mRNA of 1:1:1, but this differs over time, with greater proportions of V and W transcripts observed as the infection progresses. Eighty-two percent of transcripts are edited, with up to 11 G insertions observed. This exceptionally high editing frequency ensures expression of the V and W proteins.
Mortality and cancer incidence in workers in two Australian prebake aluminium smelters
Authors: Sim M R , Monaco A Del , Hoving J L , MacFarlane E , McKenzie D , Benke G , de Klerk N , Fritschi L 
Published: February 2009

Background:Exposures in the aluminium production industry have been declining and this study aimed to investigate cancer and mortality in two Australian prebake aluminium smelters.Methods:The cohort included 4396 males who had worked in a prebake smelter for at least 3 months. They were matched against the National Death Index and the National Cancer Statistics Clearing House to obtain cause of death and type of cancer. Standardised Mortality Ratios (SMRs) and Standardised Incidence Ratios (SIRs) were calculated for the whole cohort, for production or maintenance work categories and for duration of employment categories.Results:The SMRs for all causes, circulatory, respiratory and injury deaths were at or below expected. Mesothelioma was the only significantly increased cause of death (SMR 3.52, 95% CI 1.47 to 8.46). Death from prostate cancer in production workers was elevated (SMR 2.39, 95% CI 1.29 to 4.44) and in those who had worked for more than 20 years in production or maintenance jobs (SMR 3.67, 95% CI 1.53 to 8.81). There were statistically significant excesses of incident stomach cancer, mesothelioma, and kidney cancer cases, while the SIR for melanoma was significantly reduced. There was no significant trend for duration of exposure for any type of incident cancer.Conclusions:This study found no overall excess of mortality or cancer, but incident mesothelioma and kidney cancer risks were elevated. The lack of excess risk for lung or bladder cancer or deaths from respiratory disease may be related to the different level and pattern of exposure between Søderberg and prebake smelters.
Philip Morris involvement in the development of an air quality laboratory in El Salvador
Authors: Kummerfeldt C E , Barnoya J , Bero L 
Published: February 2009

Background:The tobacco industry has organised research institutions to generate misleading data on indoor air quality, including second-hand smoke exposure and health effects.Objectives:To describe tobacco industry involvement in the organisation and financial support of an air quality research laboratory in El Salvador.Methods:Tobacco industry documents on the internet were systematically searched from August 2007 to February 2008 for air quality studies undertaken in El Salvador, and laboratory personnel were interviewed.Results:Philip Morris sought to establish a network of air quality laboratories throughout Latin America. In El Salvador, in 1997, through Tabacalera de El Salvador (a subsidiary of Philip Morris) and the Salvadoran Foundation for Economic Development (FUSADES), the industry organised an air quality research laboratory. FUSADES was part of the industry’s Latin American Scientific Network, which consisted of doctors hired as consultants who would send air samples from their research to FUSADES. Philip Morris Scientific Affairs personnel hired LabStat, a Canadian-based laboratory, to provide technical assistance to FUSADES (train and assist the laboratory in air quality measurements). In addition, the Washington-based HMS Group successfully implemented a plan to upgrade the laboratory and obtain international certifications. HMS Group also assisted in searching for sustainable funding for FUSADES, including seeking funds from international aid for Hurricane Mitch.Conclusion:Air quality studies that have used the FUSADES laboratory should be carefully interpreted, given the support that this laboratory received from Philip Morris.
Open Wedge High Tibial Osteotomy
Authors: Matar Wadih Y. , Boscariol Rya , Dervin Geoffrey F. 
Published: February 2009

Background In patients with unicompartmental medial knee arthritis, medial opening wedge high tibial osteotomy is used to shift the mechanical weightbearing line laterally to reduce pain and improve function. There have been concerns that opening wedge high tibial osteotomy is associated with a reduction of patellar height and increase in the sagittal posterior tibial slope, both of which can adversely affect the final result. Hypothesis A more distal oblique osteotomy at the level of insertion of the patellar tendon should decrease these effects when compared with a horizontal osteotomy made proximal to the patellar tendon insertion. Study Design Cohort study; Level of evidence, 3. Methods Review of 22 horizontal and 19 oblique high tibial osteotomies with a mean follow-up of 4.2 ± 1.8 years (mean ± SD) was performed. Anatomic tibiofemoral angle, mechanical weightbearing line, medial coronal tibial plateau angle, patellar height (Blackburne and Peel ratio), and sagittal tibial slope were measured. Results In both groups, the weightbearing line was equally shifted toward the center of the plateau. In the horizontal group, the Blackburne and Peel ratio decreased from 0.85 ± 0.16 to 0.67 ± 0.12, and the sagittal tibial slope was increased from 7.7° ± 4.6° to 10.7° ± 3.8° ( P < .001). In comparison, the oblique group did not show any significant postoperative changes for these 2 parameters. In the oblique group, 2 patients sustained loss of correction and early failure when the osteotomy remained below the metaphyseal flare on the lateral cortex. Conclusion The oblique osteotomy group showed more normalized postoperative sagittal tibial slope and patellar height. Caution should be exercised not to osteotomize too distally.
Long-term Follow-up of Acute Arthroscopic Bankart Repair for Initial Anterior Shoulder Dislocations in Young Athletes
Authors: Owens Brett D. , DeBerardino Thomas M. , Nelson Bradley J. , Thurman John , Cameron Kenneth L. , Taylor Dean C. , Uhorchak John M. , Arciero Robert A. 
Published: February 2009

Background Little is known of the long-term results of acute arthroscopic Bankart repair for first-time traumatic anterior glenohumeral dislocations. Hypothesis Acute arthroscopic Bankart repair for first-time traumatic anterior glenohumeral dislocations will provide good results at long-term follow-up. Study Design Case series; Level of evidence, 4. Methods The authors evaluated a cohort of young patients who sustained first-time anterior glenohumeral dislocations and were acutely treated with arthroscopic Bankart repair using bioabsorbable tacks. Subjective outcome measures were obtained at a mean follow-up of 11.7 years (range, 9.1-13.9 years). Results Thirty-nine patients (40 shoulders) were available of the original cohort of 49 shoulders (82%). Two of the 9 who were lost to follow-up had revision surgery before being lost and are carried forward in the calculations of recurrent instability and revision surgery but are not included in the calculation of the functional scores. The mean Single Assessment Numeric Evaluation was 91.7, the mean Western Ontario Shoulder Instability score was 371.7, the mean subjective Rowe score was 25.3, the mean Simple Shoulder Test was 11.1, the mean American Shoulder and Elbow Society score was 90.9, the mean Short Form-36 Physical Component score was 94.4, and the mean Tegner score was 6.5. Six patients sustained recurrent dislocations for a redislocation rate of 14.3%. Nine patients (21.4%) reported experiencing subluxation events. Six patients (14.3%) underwent revision stabilization surgery. Conclusion At long-term follow-up, acute arthroscopic Bankart repair for first-time traumatic anterior glenohumeral dislocations resulted in excellent subjective function and return to athletics in young, active patients with an acceptable rate of recurrence and reoperation.
Magnetic Resonance Imaging in Acute Traumatic and Chronic Meniscal Tears of the Knee
Authors: Kuikka Paavo-Ilari , Sillanpää Petri , Mattila Ville M. , Niva Maria H. , Pihlajamäki Harri K. 
Published: February 2009

Background No previous research has investigated the diagnostic validity of magnetic resonance imaging for acute versus chronic meniscal tears using comparable materials and methods. Hypothesis There is no difference in the diagnostic validity of magnetic resonance imaging for acute versus chronic meniscal tears in young adults. Study Design Cohort study (diagnosis); Level of evidence, 2. Methods A total of 628 young adult military personnel underwent magnetic resonance imaging and arthroscopy of the knee over a 6-year period. Inclusion criteria were met by 82 patients with acute knee trauma (magnetic resonance imaging within 30 days from trauma) and 40 patients with chronic knee symptoms (symptoms lasting over 6 months before magnetic resonance imaging). The original magnetic resonance imaging and arthroscopy records were reviewed twice by a musculoskeletally trained radiologist, blinded to previous magnetic resonance imaging and arthroscopy findings. Interobserver correlations and intraobserver reliability were calculated and reported. Arthroscopy served as the gold standard when calculating the diagnostic values of magnetic resonance imaging for acute and chronic meniscal tears. Results The median age of the patients was 20 years (range, 18-25). Magnetic resonance imaging detected acute meniscal tears with sensitivity of 67%, specificity of 93%, and diagnostic accuracy of 88% and chronic meniscal tears with 64%, 91%, and 86%, respectively. There was no statistically significant difference in magnetic resonance imaging results between the 2 groups. Conclusion The diagnostic validity of magnetic resonance imaging is similar for meniscal tears in acute knee trauma and in knee symptoms lasting over 6 months in young adults. The results also suggest that effusion or hemarthrosis do not weaken the diagnostic validity of magnetic resonance imaging. The magnetic resonance imaging sensitivity achieved in the present study was relatively poor, but the specificity was good for both acute and chronic meniscal tears. Despite negative magnetic resonance imaging findings at the acute stage of knee trauma, patient monitoring and readiness for arthroscopy should be considered if justified by the patient's symptoms.
Proximal Hamstring Tendinopathy
Authors: Lempainen Lasse , Sarimo Janne , Mattila Kimmo , Vaittinen Samuli , Orava Sakari 
Published: February 2009

Background Tendon disorders are common problems in sports and are known to be difficult to treat. Only limited information is available concerning treatment of proximal hamstring tendinopathy. To the authors’ knowledge, no histopathologic findings of proximal hamstring tendinosis have been published. Hypothesis Surgery (semimembranosus tenotomy and exploration of the sciatic nerve) is an effective treatment for proximal hamstring tendinopathy. Study Design Case series; Level of evidence, 4. Methods A total of 103 cases of proximal hamstring tendinopathy in athletes (58 men, 32 women; 13 bilateral operations) with surgical treatment were included. The cases were retrospectively analyzed, and a 4-category rating system was used to evaluate the overall result. At the follow-up, the patients were asked about possible symptoms and their return to sports. Biopsy samples from 15 of the operated tendons were taken and analyzed by a pathologist. Results The average follow-up was 49 months (range, 12-156 months). The result was evaluated to be excellent in 62 cases, good in 30, fair in 5, and poor in 6. After surgery, 80 of the 90 patients were able to return to the same level of sporting activity as before the onset of the symptoms. This took a mean of 5 months (range, 2-12 months). Typical morphologic findings of tendinosis were found in all biopsy specimens. Conclusion Given the good functional outcome and low complication rate, the authors present surgical treatment as a valuable option in proximal hamstring tendinopathy if conservative treatment fails.
Role of ephrinB2 in nonproductive angiogenesis induced by Delta-like 4 blockade
Authors: Yamanda Shinsuke , Ebihara Satoru , Asada Masanori , Okazaki Tatsuma , Niu Kaijun , Ebihara Takae , Koyanagi Akemi , Yamaguchi Noriko , Yagita Hideo , Arai Hiroyuki 
Published: February 2009

AbstractDelta-like 4 (DLL4) is one of the Notch ligands and plays an important role in vascular development. DLL4 blockade inhibits tumor growth by promoting nonproductive angiogenesis, which is characterized by an increase in vascular density and decrease in tissue perfusion. However, a detailed mechanism remains unclear. In this study, newly developed neutralizing antibodies against mouse and human DLL4 were used to investigate the possible involvement of VEGF-DLL4-ephrinB2 cascade in nonproductive angiogenesis caused by DLL4 blockade. DLL4 blockade and soluble ephrinB2 treatment suppressed tumor growth and induced nonproductive angiogenesis. DLL4 was expressed in subcutaneous tumors, and DLL4 blockade suppressed ephrinB2 expression in the tumors. DLL4 blockade significantly promoted human umbilical vein endothelial cell (HUVEC) proliferation in vitro, and the effect was additive to that of VEGF. Both DLL4 blockade and VEGF significantly increased cord length and branch points in a tubular formation assay. Expression of ephrinB2 in HUVECs was enhanced by VEGF alone, and the enhancement was inhibited by DLL4 blockade. Moreover, when we studied the effect of ephrinB2 RNA interference on HUVEC tubular formation, knockdown of ephrinB2 mimicked the effect of DLL4. These results suggest that ephrinB2 plays a crucial role in nonproductive angiogenesis caused by DLL4 blockade.
C-terminal ADAMTS-18 fragment induces oxidative platelet fragmentation, dissolves platelet aggregates, and protects against carotid artery occlusion and cerebral stroke
Authors: Li Zongdong , Nardi Michael A. , Li Yong-Sheng , Zhang Wei , Pan Ruimin , Dang Suying , Yee Herman , Quartermain David , Jonas Saran , Karpatkin Simon 
Published: February 2009

Abstract
Anti-platelet integrin GPIIIa49-66 antibody (Ab) induces complement-independent platelet oxidative fragmentation and death by generation of platelet peroxide following NADPH oxidase activation. A C-terminal 385–amino acid fragment of ADAMTS-18 (a disintegrin metalloproteinase with thrombospondin motifs produced in endothelial cells) induces oxidative platelet fragmentation in an identical kinetic fashion as anti–GPIIIa49-66 Ab. Endothelial cell ADAMTS-18 secretion is enhanced by thrombin and activated by thrombin cleavage to fragment platelets. Platelet aggregates produced ex vivo with ADP or collagen and fibrinogen are destroyed by the C-terminal ADAMTS-18 fragment. Anti–ADAMTS-18 Ab shortens the tail vein bleeding time. The C-terminal fragment protects against FeCI3-induced carotid artery thrombosis as well as cerebral infarction in a postischemic stroke model. Thus, a new mechanism is proposed for platelet thrombus clearance, via platelet oxidative fragmentation induced by thrombin cleavage of ADAMTS-18.
Interactions of platelet integrin αΙΙb and β3 transmembrane domains in mammalian cell membranes and their role in integrin activation
Authors: Kim Chungho , Lau Tong-Lay , Ulmer Tobias S. , Ginsberg Mark H. 
Published: February 2009

AbstractClustering and occupancy of platelet integrin αIIbβ3 (GPIIb-IIIa) generate biologically important signals: conversely, intracellular signals increase the integrins' affinity, leading to integrin activation; both forms of integrin signaling play important roles in hemostasis and thrombosis. Indirect evidence implicates interactions between integrin α and β transmembrane domains (TMDs) and cytoplasmic domains in integrin signaling; however, efforts to directly identify these associations have met with varying and controversial results. In this study, we develop mini-integrin affinity capture and use it in combination with nuclear magnetic resonance spectroscopy to show preferential heterodimeric association of integrin αIIbβ3 TMD tails via specific TMD interactions in mammalian cell membranes in lipid bicelles. Furthermore, charge reversal mutations at αIIb(R995)β3(D723) confirm a proposed salt bridge and show that it stabilizes the TMD-tail association; talin binding to the β3 tail, which activates the integrin, disrupts this association. These studies establish the preferential heterodimeric interactions of integrin αIIbβ3 TMD tails in mammalian cell membranes and document their role in integrin signaling.
Aberrant expression of the homeobox gene CDX2 in pediatric acute lymphoblastic leukemia
Authors: Riedt Tamara , Ebinger Martin , Salih Helmut R. , Tomiuk Jürgen , Handgretinger Rupert , Kanz Lothar , Grünebach Frank , Lengerke Claudia 
Published: February 2009

Abstract
Members of the caudal (cdx) family of homeobox proteins are essential regulators of embryonic blood development in zebrafish. Previously, we reported that the murine homologues (Cdx1, Cdx2, and Cdx4) affect formation and differentiation of embryonic stem cell (ESC)–derived hematopoietic progenitor cells. Consistent with the notion that embryonic pathways can reactivate during adult oncogenesis, recent studies suggest involvement of CDX2 in human acute myeloid leukemia (AML). Here we study CDX2 in healthy and leukemic human lymphoid cells, and show that a majority of leukemic samples display various degrees of aberrant CDX2 expression. Analysis of a cohort of 37 childhood acute lymphoblastic leukemia (ALL) patients treated in our hospital reveals that high CDX2 expression levels at diagnosis correlate with persistence of minimal residual disease (MRD) during the course of treatment. Thus, CDX2 expression levels may serve as a marker for adverse prognosis in pediatric ALL.