bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extracellular matrix scaffolds are repopulated by bone marrow‐derived cells in a mouse model of achilles tendon reconstruction
Authors: Zantop Thore , Gilbert Thomas W. , Yoder Mervin C. , Badylak Stephen F. 
Published: April 2006

AbstractThe extracellular matrix derived from porcine small intestinal submucosa (SIS‐ECM), an FDA‐approved material currently used clinically for rotator cuff repair, has been shown to attract bone marrow‐derived cells during in vivo remodeling of a subcutaneous implant and produce chemoattractant peptides following chemical degradation in vitro. The purpose of the present study was to determine if bone marrow‐derived cells participate in the long‐term remodeling of the Achilles tendon in a mouse model when repaired with SIS‐ECM. A 2‐mm gap was produced in the Achilles tendon of 40 chimeric mice produced to express green fluorescent protein (GFP) in all of their bone marrow‐derived cells. Tendons were repaired by replacing the resected section with autologous tendon tissue or with a single layer sheet of lyophilized SIS‐ECM. Four animals from each treatment group were sacrificed at 1, 2, 4, 8, and 16 weeks, and sections were harvested for histologic and fluorescence microscopy. Both groups showed accumulation of GFP‐expressing marrow‐derived cells at the site of tendon remodeling at 1 and 2 weeks that were associated with areas of angiogenesis and inflammation. By 16 weeks, the SIS‐ECM‐treated group showed GFP expressing cells throughout the remodeled tendon in the absence of any inflammatory response, while the autologous tendon repair group showed no GFP expressing cells within the tendon except for occasional cells in the lumen of blood vessels. An SIS‐ECM scaffold used for tendon repair recruits a population of bone marrow‐derived cells that participates in the long‐term remodeling process. The ability of SIS‐ECM to recruit a population of marrow‐derived cells to the remodeling site may alter the default mechanism of tendon healing. The involvement of these cells in the remodeling process may explain in part the process of site specific constructive remodeling as opposed to scar tissue formation when the ECM is used as a biologic scaffold for tendon reconstruction. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Phosphorus and Aluminum Interactions in Soybean in Relation to Aluminum Tolerance. Exudation of Specific Organic Acids from Different Regions of the Intact Root System
Authors: Liao Hong , Wan Huiyan , Shaff Jon , Wang Xiurong , Yan Xiaolong , Kochian Leon V. 
Published: April 2006

AbstractAluminum (Al) toxicity and phosphorus (P) deficiency often coexist in acid soils that severely limit crop growth and production, including soybean (Glycine max). Understanding the physiological mechanisms relating to plant Al and P interactions should help facilitate the development of more Al-tolerant and/or P-efficient crops. In this study, both homogeneous and heterogeneous nutrient solution experiments were conducted to study the effects of Al and P interactions on soybean root growth and root organic acid exudation. In the homogenous solution experiments with a uniform Al and P distribution in the bulk solution, P addition significantly increased Al tolerance in four soybean genotypes differing in P efficiency. The two P-efficient genotypes appeared to be more Al tolerant than the two P-inefficient genotypes under these high-P conditions. Analysis of root exudates indicated Al toxicity induced citrate exudation, P deficiency triggered oxalate exudation, and malate release was induced by both treatments. To more closely mimic low-P acid soils where P deficiency and Al toxicity are often much greater in the lower soil horizons, a divided root chamber/nutrient solution approach was employed to impose elevated P conditions in the simulated upper soil horizon, and Al toxicity/P deficiency in the lower horizon. Under these conditions, we found that the two P-efficient genotypes were more Al tolerant during the early stages of the experiment than the P-inefficient lines. Although the same three organic acids were exuded by roots in the divided chamber experiments, their exudation patterns were different from those in the homogeneous solution system. The two P-efficient genotypes secreted more malate from the taproot tip, suggesting that improved P nutrition may enhance exudation of organic acids in the root regions dealing with the greatest Al toxicity, thus enhancing Al tolerance. These findings demonstrate that P efficiency may play a role in Al tolerance in soybean. Phosphorus-efficient genotypes may be able to enhance Al tolerance not only through direct Al-P interactions but also through indirect interactions associated with stimulated exudation of different Al-chelating organic acids in specific roots and root regions.
Aging in Legume Symbiosis. A Molecular View on Nodule Senescence in Medicago truncatula
Authors: Van de Velde Willem , Guerra Juan Carlos Pérez , Keyser Annick De , De Rycke Riet , Rombauts Stéphane , Maunoury Nicolas , Mergaert Peter , Kondorosi Eva , Holsters Marcelle , Goormachtig Sofie 
Published: April 2006

Abstract
Rhizobia reside as symbiosomes in the infected cells of legume nodules to fix atmospheric nitrogen. The symbiotic relation is strictly controlled, lasts for some time, but eventually leads to nodule senescence. We present a comprehensive transcriptomics study to understand the onset of nodule senescence in the legume Medicago truncatula. Distinct developmental stages with characteristic gene expression were delineated during which the two symbiotic partners were degraded consecutively, marking the switch in nodule tissue status from carbon sink to general nutrient source. Cluster analysis discriminated an early expression group that harbored regulatory genes that might be primary tools to interfere with pod filling-related or stress-induced nodule senescence, ultimately causing prolonged nitrogen fixation. Interestingly, the transcriptomes of nodule and leaf senescence had a high degree of overlap, arguing for the recruitment of similar pathways.
Phosphorus Deficiency Decreases Cell Division and Elongation in Grass Leaves
Authors: Kavanová Monika , Lattanzi Fernando Alfredo , Grimoldi Agustín Alberto , Schnyder Hans 
Published: April 2006

Abstract
Leaf growth in monocotyledons results from the flux of newly born cells out of the division zone and into the adjacent elongation-only zone, where cells reach their final length. We used a kinematic method to analyze the effect of phosphorus nutrition status on cell division and elongation parameters in the epidermis of Lolium perenne. Phosphorus deficiency reduced the leaf elongation rate by 39% due to decreases in the cell production rate (−19%) and final cell length (−20%). The former was solely due to a lower average cell division rate (0.028 versus 0.046 cell cell−1 h−1) and, thus, a lengthened average cell cycle duration (25 versus 15 h). The number of division cycles of the initial cell progeny (five to six) and, as a result, the number of meristematic cells (32–64) and division zone length were independent of phosphorus status. Accordingly, low-phosphorus cells maintained meristematic activity longer. Lack of effect of phosphorus deficiency on meristematic cell length implies that a lower division rate was matched to a lower elongation rate. Phosphorus deficiency did not affect the elongation-only zone length, thus leading to longer cell elongation duration (99 versus 75 h). However, the substantially reduced postmitotic average relative elongation rate (0.045 versus 0.064 mm mm−1 h−1) resulted in shorter mature cells. In summary, phosphorus deficiency did not affect the general controls of cell morphogenesis, but, by slowing down the rates of cell division and expansion, it slowed down its pace.
High Light Response of the Thylakoid Proteome in Arabidopsis Wild Type and the Ascorbate-Deficient Mutant vtc2-2. A Comparative Proteomics Study
Authors: Giacomelli Lisa , Rudella Andrea , van Wijk Klaas Jan 
Published: April 2006

Abstract
The thylakoid proteome of chloroplasts contains multiple proteins involved in antioxidative defense, protein folding, and repair. To understand this functional protein network, we analyzed the quantitative response of the thylakoid-associated proteome of Arabidopsis (Arabidopsis thaliana) wild type and the ascorbate-deficient mutant vtc2-2 after transition to high light (HL; 1,000 μmol photons m−2 s−1). The soluble thylakoid proteomes of wild type and vtc2-2 were compared after 0, 1, 3, and 5 d of HL using two-dimensional gels with three independent experiments, followed by a multivariant statistical analysis and tandem mass spectrometry. After 5 d of HL, both wild-type and vtc2-2 plants accumulated anthocyanins, increased their total ascorbate content, and lost 10% of photosystem II efficiency, but showed no bleaching. Anthocyanin and total ascorbate concentrations in vtc2-2 were respectively 34% and 20% of wild type, potentially leading to enhanced oxidative stress in vtc2-2. Forty-five protein spots significantly changed as a consequence of genotype, light treatment, or both. Independent confirmation was obtained from western blots. The most significant response was the up-regulation of thylakoid YCF37 likely involved in photosystem I assembly, and specific fibrillins, a flavin reductase-like protein, and an aldolase, each located in thylakoid-associated plastoglobules. Fe-superoxide dismutase was down-regulated in vtc2-2, while Cu,Zn-superoxide dismutase was up-regulated. vtc2-2 also showed a systematic up-regulation of a steroid dehydrogenase-like protein. A number of other stress-related proteins, several thylakoid proteases, and lumenal isomerases did not change, while PsbS increased in wild type upon light stress. These findings are discussed in terms of plastid metabolism and oxidative stress defense, and emphasize that understanding of the chloroplast stress-response network must include the enzymatic role of plastoglobules.
Maintenance of DNA Methylation during theArabidopsisLife Cycle Is Essential for Parental Imprinting
Authors: Jullien Pauline E. , Kinoshita Tetsu , Ohad Nir , Berger Frédéric 
Published: April 2006

AbstractImprinted genes are expressed predominantly from either their paternal or their maternal allele. To date, all imprinted genes identified in plants are expressed in the endosperm. In Arabidopsis thaliana, maternal imprinting has been clearly demonstrated for the Polycomb group gene MEDEA (MEA) and for FWA. Direct repeats upstream of FWA are subject to DNA methylation. However, it is still not clear to what extent similar cis-acting elements may be part of a conserved molecular mechanism controlling maternally imprinted genes. In this work, we show that the Polycomb group gene FERTILIZATION-INDEPENDENT SEED2 (FIS2) is imprinted. Maintenance of FIS2 imprinting depends on DNA methylation, whereas loss of DNA methylation does not affect MEA imprinting. DNA methylation targets a small region upstream of FIS2 distinct from the target of DNA methylation associated with FWA. We show that FWA and FIS2 imprinting requires the maintenance of DNA methylation throughout the plant life cycle, including male gametogenesis and endosperm development. Our data thus demonstrate that parental genomic imprinting in plants depends on diverse cis-elements and mechanisms dependent or independent of DNA methylation. We propose that imprinting has evolved under constraints linked to the evolution of plant reproduction and not by the selection of a specific molecular mechanism.
The effect of red light in the high irradiance reaction of phytochrome:
Authors: JOHNSON C. B. 
Published: April 2006

Abstract. A proposal has recently been made (Johnson & Tasker, 1979) that phytochrome acts through the multiplicative effect of two components of the phytochrome system, only one of them being Pfr and the other a product of the photoconversion reaction Pr→Pfr. It has been shown previously that HIR action spectra based on this assumption show a good resemblance to the observed responses with the possible exception of the red region of the spectrum. There, a greater response is predicted than is often observed and fluence rate dependency is predicted, on which matter there is disagreement in the literature.The experiments reported here show that, because chlorophyll is formed in red light but not in far‐red, chlorophyll screening lowers the effective fluence rate in red light with respect to phytochrome. When such screening is eliminated the observed responses show strong fluence rate dependency, as predicted. Evidence is also presented to support the conclusion that the two proposed effectors must act together multiplicatively.
Phloem sap exudation in Ricinus communis: elastic responses and anatomical implications
Authors: KALLARACKAL J. , MILBURN J. A. 
Published: April 2006

Abstract. Ricinus communis plants have an unusually high capacity to exude considerable quantities of phloem sap from bark incisions. We have used Ricinus as an experimental system to study different aspects of sap exudation. Dimensional changes in the bark, monitored by a displacement transducer, showed that pressure release in the sieve tubes was accompanied by elastic shrinkage. The rate of exudation was also controlled by the degree of pressurization and elastic properties of the sieve tubes. A displacement transducer was used to measure the elastic modulus (ɛ) of phloem samples by immersing them in a range of different osmotica. The cells had a low elastic modulus (ɛ= 1.62 ± 0.41 MPa at full turgor). ɛ of phloem tissue in massage pretreated bark, from which exudation was enhanced, was not significantly different from that of unmassaged bark in contrast with the suggestion of Lee (1981). However, anatomical studies showed that massage pretreatment has a stimulating influence on the cambial cell division, which increased the phloem tissue cross‐section up to 160%. The newly‐formed sieve tubes were ‘spliced’ into existing ones in the unmassaged zone to re‐establish vascular continuity. Plants with a greater capacity to exude phloem sap from a given stem location had a greater cross‐sectional area of sieve tubes in the vicinity.The significance of observations with respect to other sap exudation phenomenon is discussed. The importance of the present work in understanding the technique of palm tapping, on which the palm sugar industry depends, is also considered.
Phytochrome‐mediated responses in light‐grown corn showing rapid, reverse reciprocity failure*
Authors: GORTON HOLLY L. , BRIGGS WINSLOW R. 
Published: April 2006

Abstract.Three responses (mesocotyl and coleoptile elongation and anthocyanin accumulation in the coleoptile) to end‐ of‐day far‐red irradiation in light‐grown corn show rapid failure of the reciprocity law such that short, high fluence rate irradiations are much more effective than long, low fluence rate ones of the same fluence (reverse reciprocity failure). The reciprocity failure cannot be explained by escape from photoreversibility, a change in sensitivity to Pfr, reciprocity failure for photoconversion, or a high irradiance response taking over for long irradiation times. Fluence–response curves measured by varying irradiation time at a low fluence rate show the threshold fluence shifted to higher energy in comparison with fluence–response curves obtained at a high fluence rate. Red reversal of these responses also shows rapid reciprocity failure in the same direction, a process which can be only partially explained by escape.These responses to end‐of‐day far‐red and red illumination are distinguished from high irradiance reactions by their low fluence requirements and ready reversibility. These same characteristics are similar to those of classical phytochrome‐ mediated, induction‐reversion responses in etiolated tissue, but it is difficult to explain the rapid, reverse reciprocity failure in terms of standard phytochrome dogma.
Safety and efficacy of two dose formulations of alicaforsen enema compared with mesalazine enema for treatment of mild to moderate left‐sided ulcerative colitis: a randomized, double‐blind, active‐controlled trial
Authors: MINER P. B. , WEDEL M. K. , XIA S. , BAKER B. F. 
Published: April 2006

SummaryBackgroundAlicaforsen is an antisense oligonucleotide inhibitor of intercellular adhesion molecule 1 protein expression with activity in subjects with ulcerative colitis and pouchitis.AimTo compare the effects of alicaforsen enema to standard of care mesalazine (mesalamine) enema in subjects with mild to moderate active left‐sided ulcerative colitis.MethodA randomized, double‐blind, active‐controlled multicentre clinical trial. Subjects received a nightly enema of 120 mg alicaforsen (n = 55), 240 mg alicaforsen (n = 50), or 4 g mesalazine (n = 54) for 6 weeks, followed by a 24‐week monitoring period. The primary end point was Disease Activity Index at week 6. Clinical improvement, remission and relapse were secondary end points.ResultsNo significant difference was observed between treatment arms in the primary end point. However, the median duration of response to alicaforsen enema treatment was two‐ to threefold longer (128 and 146 days) in comparison with mesalazine (54 days). Complete mucosal healing occurred in 24% of the 240 mg alicaforsen group, when compared with 17% in the mesalazine.ConclusionsAlicaforsen enema demonstrated an acute response and safety profile similar to mesalazine enema, but was differentiated by a more durable response. The extended length of remission suggests that alicaforsen enema treatment may have a disease modifying effect.
Efficacy and safety of bisacodyl in the acute treatment of constipation: a double‐blind, randomized, placebo‐controlled study
Authors: KIENZLE‐HORN S. , VIX J.‐M. , SCHUIJT C. , PEIL H. , JORDAN C. C. , KAMM M. A. 
Published: April 2006

SummaryBackgroundAlthough laxatives are a first‐line treatment for constipation, there are few randomized placebo‐controlled trials assessing their efficacy.AimTo determine the effect and safety of oral bisacodyl on stool frequency and consistency in patients with idiopathic constipation.Methods55 patients (age 19–89 years) with idiopathic constipation were recruited from eight primary care practices and randomized to receive bisacodyl, 10 mg once daily, or placebo, on three successive days following a 3‐day run‐in period. Patients recorded stool frequency and consistency and adverse events.ResultsIn each treatment group, 27 patients were evaluable for efficacy. The mean number of stools per day was significantly greater in the bisacodyl‐treated group (1.8/day) compared with placebo (0.95/day) over the treatment phase (P = 0.0061). Mean stool consistency score improved from ‘hard’ (run‐in) to between ‘soft’ and ‘well‐formed’ during bisacodyl treatment, remaining between ‘moderately hard’ and ‘hard’ for placebo treatment (P < 0.0001). The investigator's global efficacy score was superior for the bisacodyl group compared with placebo. Both treatments were well tolerated. Serum electrolyte levels and incidence of adverse events were comparable between treatment groups.ConclusionsBisacodyl is effective and safe in improving stool frequency and consistency in acute treatment of idiopathic constipation.
Basiliximab for the treatment of steroid‐resistant ulcerative colitis: further experience in moderate and severe disease
Authors: CREED T. J. , PROBERT C. S. J. , NORMAN M. N. , MOORGHEN M. , SHEPHERD N. A. , HEARING S. D. , DAYAN C. M. ,   THE BASBUC INVESTIGATORS
Published: April 2006

SummaryBackgroundPreliminary data have suggested that interleukin‐2 receptor blockade with basiliximab may increase steroid sensitivity. We have previously reported a small case series demonstrating the potential of basiliximab as a novel agent for the treatment of steroid‐resistant ulcerative colitis.AimTo report further experience of the efficacy and safety of treatment with the interleukin‐2 receptor blocking monoclonal antibody basiliximab, in addition to steroids, for the treatment of severe and moderate steroid‐resistant ulcerative colitis.MethodsTwenty patients were enrolled – 13 patients with moderate steroid‐resistant ulcerative colitis (Ulcerative Colitis Symptom Score: ≥6) and seven patients with severe steroid‐resistant ulcerative colitis. All were given a single dose of 40 mg basiliximab plus standard steroid therapy in an open‐label, uncontrolled trial. Primary end point was clinical remission within 8 weeks (Ulcerative Colitis Symptom Score: ≤2).ResultsWithin 8 weeks, 10 of 20 (50%) patients achieved clinical remission (seven of 13 moderate, and three of seven severe). At 24 weeks, 13 of 20 (65%) patients were in clinical remission. Five patients required colectomy (four severe, one moderate ulcerative colitis) and one required rescue ciclosporin (moderate ulcerative colitis). Two patients developed herpes zoster, but treatment was generally well tolerated.ConclusionsBasiliximab appears to promote prolonged remission after a single treatment. Taken in combination with previously reported data, basiliximab shows particular promise in moderate steroid‐resistant ulcerative colitis.
Oats in the treatment of childhood coeliac disease: a 2‐year controlled trial and a long‐term clinical follow‐up study
Authors: HOLM K. , MÄKI M. , VUOLTEENAHO N. , MUSTALAHTI K. , ASHORN M. , RUUSKA T. , KAUKINEN K. 
Published: April 2006

SummaryBackgroundThe exclusion of oats from the diet in coeliac disease is controversial.AimTo study the long‐term safety of oats in the treatment of children with coeliac disease.MethodsAltogether 32 children with coeliac disease were enrolled in a 2‐year controlled trial. Twenty‐three children in remission were randomized either to oats or gluten challenge; when small bowel histological relapse was evident after gluten challenge, a gluten‐free diet including oats was started. Furthermore, nine newly detected coeliac patients adopted an oat‐containing gluten‐free diet. Small bowel mucosal morphology, CD3+, αβ+ and γδ+ intraepithelial lymphocytes, human leucocyte antigen (HLA) DR expression and coeliac serology were determined. After the trial, the children were allowed to eat oats freely; follow‐up was extended up to 7 years.ResultsIn coeliac children in remission, oats had no detrimental effect on intestinal histology or serology during the 2‐year trial. In contrast, the gluten‐challenge group relapsed after 3–12 months. Complete recovery from the disease was accomplished in all relapsed and newly detected patients on an oat‐containing gluten‐free diet. After the trial, 86% of the children preferred to consume oats and they all remained in remission.ConclusionIn most children with coeliac disease, long‐term consumption of oats is well tolerated, and it does not result in small bowel mucosal deterioration or immune activation.