bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vectors designed for efficient molecular manipulation in Candida albicans
Authors: Park Nok‐Hyun , Choi Wonja 
Published: September 2002

AbstractFunctional studies on genes of Candida albicans have been hampered by the fact that few vectors are available for efficient cloning and expression in C. albicans, in contrast to Saccharomyces cerevisiae. Here we report that six vectors were constructed for molecular manipulation in C. albicans. All of them contained the autonomous replicating sequence ARS2 and the uracil gene as a selective marker. Introduction of multicloning site (MCS) facilitated directional cloning into various convenient restriction sites is discussed. Distal to the MCS, the additions of sequences encoding yeast‐enhanced green fluorescent protein 3 (yEGFP3) and the terminator of chitin synthase 2 (TCHS2) enabled us to express an open reading frame (ORF) with its own promoter as a GFP fusion protein, so that its intracellular localization could be easily determined. A vector of 7.4 kb was also constructed to express a cloned ORF as a GFP fusion protein under the control of an inducible MET3 promoter (PMET3) located proximal to the MCS. Since this vector was relatively large in size for expressing ORFs, two additional vectors of 6.7 kb were constructed by inserting PMET3 and TCHS2 proximal and distal to the MCS of the above vector containing MCS only, respectively. These six vectors made it possible to study C. albicans in greater detail. They can be used in identification of a promoter, intracellular localization of a protein, and in the induction of lethal genes. Copyright © 2002 John Wiley & Sons, Ltd.
Genetic interactions link ARF1, YPT31/32 and TRS130
Authors: Zhang Chun‐jiang , Bradford Bowzard J. , Greene Michelle , Anido Aimee , Stearns Katherine , Kahn Richard A. 
Published: September 2002

AbstractA genetic screen for synthetic lethal interactions with arf1− identified a recessive mutation in TRS130, one of 10 components in the trafficking protein particle (TRAPP) complex (Sacher et al., 2000). As TRS130 is an essential gene, the synthetic lethal allele (trs130‐101) is a novel one that requires ARF1 for viability. This allele was found to exhibit no defects in secretory function, i.e. processing of carboxypeptidase Y or invertase. YPT31 and YPT32 were identified in a subsequent screen as high‐copy suppressors of arf1−trs130‐101. Increasing the gene dosage of YPT31/32 also suppressed lethality resulting from deletion of TRS130 or TRS120 but not three other essential TRAPP subunit‐encoding genes. Although unable to suppress defects in several alleles of ARF1, increasing the gene dosage of YPT31/32 suppressed the cold sensitivity of gcs1−, an Arf GTPase‐activating protein (GAP). Thus, these genetic interactions provide initial evidence for linkage of Arf and TRAPP signalling and for Ypt31/32 proteins functioning downstream of both components in the TRAPP complex and of Arf signalling via the Gcs1 Arf GAP. Copyright © 2002 John Wiley & Sons, Ltd.
Mutational analysis of HOXD13 and HOXA13 genes in the triphalangeal thumb—brachyectrodactyly syndrome
Authors: Pérez‐Cabrera A. , Kofman‐Alfaro S. , Zenteno J. C. 
Published: August 2002

AbstractThe triphalangeal thumb‐brachyectrodactyly syndrome is a very rare autosomal dominant disorder of unknown etiology characterized by an unusual pattern of limb malformations: triphalangeal thumbs and brachyectrodactyly in the hands, and ectrodactyly in the feet. In a previous report, we described the clinical and radiographical features of three related subjects with the disease and suggest that due to the unusual combination of limb defects and to its phenotypic similarity with the limb malformative pattern induced by disrupting the Hoxd13 gene in mouse, the triphalangeal thumb‐brachyectrodactyly syndrome might be caused by mutations in a HOX gene. After sequencing the entire coding region of HOXD13 and the highly conserved homeodomain encoding region of HOXA13, we do not detect any deleterious mutation in any of the patients excluding that alterations at these sequences are responsible for the disease. Mutations in regulatory regions of these genes or in other genes involved in limb development might be responsible for the disease.© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Insulin‐like growth factor‐I improves cellular and molecular aspects of healing in a collagenase‐induced model of flexor tendinitis
Authors: Dahlgren Linda A. , van der Meulen Marjolein C. H. , Bertram John E. A. , Starrak Greg S. , Nixon Alan J. 
Published: August 2002

AbstractFlexor tendinitis is a common and debilitating injury of elite and recreational athletes. Healing may be improved through intratendinous injection of insulin‐like growth factor‐I (IGF‐I), which has been shown in vitro to stimulate mitogenesis and enhance tendon matrix production. This study investigated the effects of intratendinous injection of IGF‐I on tendon healing in an equine model of flexor tendinitis. Collagenase‐induced lesions were created in the tensile region of theflexor digitorum superficialistendon of both forelimbs of eight horses. Treated tendons were injected with 2 μg rhIGF‐I intralesionally every other day for 10 injections, while controls received 0.9% NaCl. Tendon fiber deposition and organization were evaluated serially using ultrasonography throughout the 8 week trial period. Following euthanasia, the tendons were harvested and DNA, hydroxyproline, and glycosaminoglycan content determined, mechanical strength and stiffness evaluated, gene expression and spatial arrangement of collagen types I and III assessed by northern blot and in situ hybridization, and tendon fiber architecture assessed by polarized light microscopy. Local soft tissue swelling was reduced in the IGF‐I treated limbs. Similarly, lesion size in IGF‐I treated tendons was smaller 3 and 4 weeks after initiation of treatment. Cell proliferation and collagen content of the IGF‐I treated tendons were increased compared to controls. Mechanically, IGF‐I treated tendons showed a trend toward increased stiffness compared to saline treated controls. Considered together with the decreased soft tissue swelling and improved sonographic healing, these data support the potential use of intralesional IGF‐I for treatment of debilitating tendon injuries.
Rib cage surgery for the treatment of scoliosis: a biomechanical study of correction mechanisms
Authors: Gréalou L. , Aubin C.‐É. , Labelle H. 
Published: August 2002

AbstractRib shortening or lengthening are surgical options that are used to address the cosmetic rib cage deformity in scoliosis, but can also alter the equilibrium of forces acting on the spine, thus possibly counteracting in a mechanical way the scoliotic process and correcting the spinal deformities. Although rib surgeries have been successful in animal models, they have not gained wide clinical acceptance for mechanical correction of scoliosis due to the lack of understanding of the complex mechanisms of action involved during and after the operation. The objective of this study was to assess the biomechanical action of different surgical approaches on the rib cage for the treatment of scoliosis using a patient‐specific finite element model of the spine and rib cage. Several unilateral and bilateral rib shortening/lengthening procedures were tested at different locations on the ribs (convex/concave side of the thoracic curvature; at the costo‐transverse/costo‐chondral joint; 20 and 40 mm adjustments). A biomechanical analysis was performed to assess the resulting geometry and load patterns in ribs, costo‐vertebral articulations and vertebrae. Only slight immediate geometric variations were obtained. However, concave side rib shortening and convex side rib lengthening induced important loads on vertebral endplates that may lead to possible scoliotic spine correction depending on the remaining growth potential. Convex side rib shortening and concave side rib lengthening produced mostly cosmetic rib cage correction, but generated inappropriate loads on the vertebral endplates that could aggravate vertebral wedging. This study supports the concept of using concave side rib shortening or convex side rib lengthening as useful means to induce correction of the spinal scoliotic deformity during growth, though the effects of growth modulation from induced loads must be addressed in more detail to prove the usefulness of rib shortening/lengthening techniques.© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Retention of 125I‐labeled recombinant human bone morphogenetic protein‐2 by biphasic calcium phosphate or a composite sponge in a rabbit posterolateral spine arthrodesis model
Authors: Louis‐Ugbo John , Kim Hak‐Sun , Boden Scott D. , Mayr Matthew T. , Li Ronald C. , Seeherman Howard , D'Augusta Darren , Blake Cara , Jiao Aiping , Peckham Steve 
Published: August 2002

AbstractThe purpose of this study was to characterize the retention kinetics of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) applied to two calcium‐based delivery matrices. Biphasic calcium phosphate (BCP) and a composite containing BCP in an absorbable collagen sponge (BCP/ACS) were evaluated using a spinal fusion model in rabbits. rhBMP‐2 labeled with radioactive iodine (125I) was used as a tracer to assess in vivo retention of rhBMP‐2 in the presence of these materials (nine animals per material studied). Over a 36 day study period, animals were assessed for the following: percent administered dose retained at the implant site as measured by scintigraphic imaging (counting) with a gamma camera (all animals), radiography of the implant site (all animals), radioactivity in blood and plasma (all animals), and radioactivity in the urine and feces (three animals for each material). Radioactivity data were corrected for the decay of 125I and the attenuation between the implant in vivo and the gamma camera.Differences observed between the two materials for the area under the retention vs. time profile (AUC; 988%day for BCP vs. 1070%day for BCP/ACS, p = 0.57) and the mean residence time (MRT; 10.2 days for BCP vs. 7.6 days for BCP/ACS, p = 0.06) were not statistically significant. Initial retention/incorporation of rhBMP‐2 was slightly higher for rhBMP‐2/BCP/ACS than for rhBMP‐2/BCP (96.8% vs. 86.0%, p lt; 0.05). Animals receiving rhBMP‐2/BCP showed a longer terminal retention half‐life (t1/2) than did those receiving rhBMP‐2/BCP/ACS (7.5 vs. 4.5 days, p < 0.05). The urinary radioactivity recovery data supported the data obtained by scintigraphy. Over the 36 day collection period, essentially complete recovery of radioactivity (dose) in urine was observed for rhBMP‐2/BCP and rhBMP‐2/BCP/ACS and the majority of the radioactivity (approximately 95%) was soluble in trichloroacetic acid, suggesting extensive catabolism of rhBMP‐2 before renal excretion. Fecal recovery of radioactivity was low, approximately 2–3%.In conclusion, rhBMP‐2 was retained at the implant site when delivered with either BCP or BCP/ACS based on mean residence time and area under the retention curve vs. time profile. Use of these matrices resulted in detectable rhBMP‐2 levels at the surgical site for over a week in contrast to data reported with several other matrices that lasted less time. Systemic catabolism and elimination of the rhBMP‐2 was extensive and systemic presence of the protein was negligible.© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Vascular physiology and long‐term healing of partial ligament tears
Authors: Bray Robert C. , Leonard Catherine A. , Salo Paul T. 
Published: August 2002

AbstractFunctional outcomes of anterior cruciate ligament (ACL) injury are generally poorer than those of medial collateral ligament (MCL) tears. Following ligament damage, all phases of ligament healing require an adequate blood supply. We hypothesized that the differences in healing properties of the ACL and MCL would reflect their vascular responses to joint injury. This paper examines the long‐term changes in blood flow and vascular volume of rabbit knee ligaments after direct injury, and under conditions of chronic joint instability induced by section of the posterior cruciate ligament (PCL).Standardized injuries were surgically induced in adult rabbit knee ligaments: partial MCL transection, partial ACL transection, or complete PCL transection (joint instability). Sixteen weeks later the blood flow and vascular volume of the ACL and MCL were measured and compared to control and sham‐operated animals.Direct ligament injury induced significant increases in standardized blood flow and vascular volume of both ACL and MCL after 16 weeks; however, the vascular volume of the ACL was not higher than the control levels in the MCL. We conclude that direct injury to both the anterior cruciate and MCLs induces long‐term physiological responses.Joint laxity is a common sequel to PCL injury. Chronic joint laxity failed to induce adaptive vascular responses in the ACL, while the MCL shows significant amplification of blood supply. Although both MCL and ACL showed increased weight after PCL transection, the lack of a long‐term vascular response in the ACL may be a major factor in its the diminished healing potential.© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Particle size and morphology of UHMWPE wear debris in failed total knee arthroplasties—a comparison between mobile bearing and fixed bearing knees
Authors: Huang Chun‐Hsiung , Ho Fang‐Yuan , Ma Hon‐Ming , Yang Chan‐Tsung , Liau Jiann‐Jong , Kao Hung‐Chan , Young Tai‐Horng , Cheng Cheng‐Kung 
Published: August 2002

AbstractOsteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long‐term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous‐coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light‐scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 μm in LCS, 1.17 μm in PCA and 5.23 μm in M/G) and more granular debris (mean value: 93% in LCS, 77% in PCA and 15% in M/G).© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Multilineage mesenchymal differentiation potential of human trabecular bone‐derived cells
Authors: Nöth Ulrich , Osyczka Anna M. , Tuli Richard , Hickok Noreen J. , Danielson Keith G. , Tuan Rocky S. 
Published: August 2002

AbstractExplant cultures of adult human trabecular bone fragments give rise to osteoblastic cells, that are known to express osteoblast‐related genes and mineralize extracellular matrix. These osteoblastic cells have also been shown to undergo adipogenesis in vitro and chondrogenesis in vivo. Here we report the in vitro developmental potential of adult human osteoblastic cells (hOB) derived from explant cultures of collagenase‐pretreated trabecular bone fragments. In addition to osteogenic and adipogenic differentiation, these cells are capable of chondrogenic differentiation in vitro in a manner similar to adult human bone marrow‐derived mesenchymal progenitor cells. High‐density pellet cultures of hOB maintained in chemically defined serum‐free medium, supplemented with transforming growth factor‐β1, were composed of morphologically distinct, chondrocyte‐like cells expressing mRNA transcripts of collagen types II, IX and X, and aggrecan. The cells within the high‐density pellet cultures were surrounded by a sulfated prote‐oglycan‐rich extracellular matrix that immunostained for collagen type II and proteoglycan link protein. Osteogenic differentiation of hOB was verified by an increased number of alkaline phosphatase‐positive cells, that expressed osteoblast‐related transcripts such as alkaline phosphatase, collagen type I, osteopontin and osteocalcin, and formed mineralized matrix in monolayer cultures treated with ascorbate, β‐glycerophosphate, and bone morphogenetic protein‐2. Adipogenic differentiation of hOB was determined by the appearance of intracellular lipid droplets, and expression of adipocyte‐specific genes, such as lipoprotein lipase and peroxisome proliferator‐activated receptor γ2, in monolayer cultures treated with dexamethasone, indomethacin, insulin and 3‐isobutyl‐l‐methylxanthine. Taken together, these results show that cells derived from collagenase‐treated adult human trabecular bone fragments have the potential to differentiate into multiple mesenchymal lineages in vitro, indicating their developmental plasticity and suggesting their mesenchymal progenitor nature.© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Polyethylene and methyl methacrylate particle‐stimulated inflammatory tissue and macrophages up‐regulate bone resorption in a murine neonatal calvaria in vitro organ system
Authors: Ren Weiping , Wu Bin , Mayton Lois , Wooley Paul H. 
Published: August 2002

AbstractThere is considerable evidence that orthopaedic wear debris plays a crucial role in the pathology of aseptic loosening of joint prostheses. This study examined the effect of inflammatory membranes stimulated with methyl methacrylate and polyethylene on bone resorption, using the murine air pouch model. The capacity of RAW 264.7 mouse macrophages exposed to polymer particles to produce factors affecting bone metabolism was also studied. Neonatal calvaria bones were co‐cultured with either pouch membranes or conditioned media from activated macrophages. Bone resorption was measured by the release of calcium from cultured bones, and the activity of tartrate‐resistant acid phosphatase in both bone sections and culture medium was also assayed. Results showed that inflammatory pouch membrane activated by methyl methacrylate and polyethylene enhanced osteoclastic bone resorption. Conditioned media from particles stimulated mouse macrophages also stimulated bone resorption, although this effect was weaker than resorption induced by inflammatory pouch membranes. The addition of the particles directly into the medium of cultured calvaria bones had little effect on bone resorption. Our observations indicate that both inflammatory tissue and macrophages provoked by particles can stimulate bone resorption in cultured mouse neonatal calvaria bones. This simple in vitro bone resorption system allows us to investigate the fundamental cellular and molecular mechanism of wear debris induced bone resorption and to screen potential therapeutic approaches for aseptic loosening.© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
High intratendinous lactate levels in painful chronic Achilles tendinosis. An investigation using microdialysis technique
Authors: Alfredson Håkan , Bjur Dennis , Thorsen Kim , Lorentzon Ronny , Sandström Patrick 
Published: August 2002

AbstractIn this investigation the microdialysis technique was used to study the concentrations of lactate in Achilles tendons with painful chronic tendinosis and in normal pain‐free tendons. In four patients (mean age 40.7 years) with a painful thickening localized at the 2–6 cm level in the Achilles tendon (chronic Achilles tendinosis) and in five controls (mean age 37.2 years) with normal Achilles tendons, the local concentrations of lactate were registered under resting conditions. All tendons were examined using ultrasonography. In the tendons with tendinosis the painful thickening corresponded to a widened tendon and structural tendinosis changes. Normal tendons showed no widening and a normal structure. A standard microdialysis catheter was inserted into the Achilles tendon under local anesthesia. Samplings were done every 15 min during a 4 h period.The results showed significantly higher mean concentrations of lactate in tendons with tendinosis compared to normal tendons (2.15 mmol/l vs. 1.14 mmol/l). The lactate concentrations in the tendons with tendinosis were stable, and approximately twofold higher than in the normal tendons during the whole 4 h investigation period.In conclusion, the higher concentrations of lactate in Achilles tendons with painful tendinosis indicate that there are anaerobic conditions in the area with tendinosis. The importance of this finding for the pathogenesis and pain mechanisms in this chronic condition needs to be further investigated.© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Chondropathy after meniscal tear or partial meniscectomy in a canine model
Authors: Wyland Douglas J. , Guilak Farshid , Elliott Dawn M. , Setton Lori A. , Vail Thomas P. 
Published: August 2002

AbstractA primary goal in considering treatment for meniscal injuries is the preservation of the health of the articular cartilage. However, the chondroprotective effects of various techniques for meniscal injury treatments are unknown. We used a canine model to quantify articular cartilage degeneration in the medial compartment of the canine knee, resulting from a surgically created tear or a partial meniscectomy (PM) of the posterior region of the medial meniscus (each group, n = 10). After sacrifice at 12 weeks, the development of gross chondropathy and the changes in cartilage tensile stiffness were quantified, and correlations between these measurements were examined. Both treatment surgical treatment groups caused significantly greater gross chondropathy as compared to the unoperated contralateral controls. Cartilage tensile stiffness was significantly lower than unoperated controls by nearly 28% in both experimental groups. However, there were no significant differences observed between the gross chondropathy or the cartilage mechanical property changes between the experimental groups. Importantly, the severity of gross chondropathy was found to significantly correlate with the decrement in tensile stiffness properties of the articular cartilage. These findings indicate that significant degeneration of canine articular cartilage develops to a similar degree in the presence of a partially healed meniscus tear or a PM of the knee. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.