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Sample records for alters cartilage turnover

  1. Glucosamine but not ibuprofen alters cartilage turnover in osteoarthritis patients in response to physical training

    DEFF Research Database (Denmark)

    Petersen, S G; Saxne, T; Heinegard, D

    2010-01-01

    OBJECTIVE: To investigate changes in levels of serum cartilage oligomeric matrix protein (COMP) and urine c-telopeptide of type-2 collagen (CTX-II) as markers for cartilage turnover in patients with osteoarthritis (OA) of the knee, in response to muscle strength training in combination with treat......OBJECTIVE: To investigate changes in levels of serum cartilage oligomeric matrix protein (COMP) and urine c-telopeptide of type-2 collagen (CTX-II) as markers for cartilage turnover in patients with osteoarthritis (OA) of the knee, in response to muscle strength training in combination...... (n=12) during 12 weeks of strength training of both legs with focus on the quadriceps muscle. Strength tests (5 repetition maximum), blood and urine sampling were performed before and after the training period. Serum COMP and urinary CTX-II were measured by enzyme-linked immunosorbent assay (ELISA......). RESULTS: All three groups increased their muscle strength following 12 weeks of strength training (Ptraining period (P=0.012), whereas they did not change in the two other groups. Glucosamine reduced COMP statistically...

  2. Amino acid racemization reveals differential protein turnover in osteoarthritic articular and meniscal cartilages

    Science.gov (United States)

    Stabler, Thomas V; Byers, Samuel S; Zura, Robert D; Kraus, Virginia Byers

    2009-01-01

    Introduction Certain amino acids within proteins have been reported to change from the L form to the D form over time. This process is known as racemization and is most likely to occur in long-lived low-turnover tissues such as normal cartilage. We hypothesized that diseased tissue, as found in an osteoarthritic (OA) joint, would have increased turnover reflected by a decrease in the racemized amino acid content. Methods Using high-performance liquid chromatography methods, we quantified the L and D forms of amino acids reported to racemize in vivo on a biological timescale: alanine, aspartate (Asp), asparagine (Asn), glutamate, glutamine, isoleucine, leucine (Leu), and serine (Ser). Furthermore, using a metabolically inactive control material (tooth dentin) and a control material with normal metabolism (normal articular cartilage), we developed an age adjustment in order to make inferences about the state of protein turnover in cartilage and meniscus. Results In the metabolically inactive control material (n = 25, ages 13 to 80 years) and the normal metabolizing control material (n = 19, ages 17 to 83 years), only Asp + Asn (Asx), Ser, and Leu showed a significant change (increase) in racemization with age (P Asx, Ser, and Leu when compared with the normal articular cartilage control were 97%, 74%, and 73% in OA meniscal cartilage and 97%, 70%, and 78% in OA articular cartilage. We also observed lower amino acid content in OA articular and meniscal cartilages compared with normal articular cartilage as well as a loss of total amino acids with age in the OA meniscal but not the OA articular cartilage. Conclusions These data demonstrate comparable anabolic responses for non-lesioned OA articular cartilage and OA meniscal cartilage but an excess of catabolism over anabolism for the meniscal cartilage. PMID:19267899

  3. A Novel Approach to Stimulate Cartilage Repair: Targeting Collagen Turnover

    NARCIS (Netherlands)

    Y.M. Bastiaansen-Jenniskens (Yvonne)

    2009-01-01

    textabstractOA is a complex disease of which the ethiopathology is not completely known and therapies to repair cartilage are still under investigation. The increase of collagen type II expression in osteoarthritic cartilage suggests an activated repair mechanism that is however ineffective in

  4. Cartilage biomarkers in the osteoarthropathy of alkaptonuria reveal low turnover and accelerated ageing

    Science.gov (United States)

    Hsueh, Ming-Feng; Ranganath, Lakshminarayan R.; Gallagher, James A.; Dillon, Jane P.; Huebner, Janet L.; Catterall, Jon B.; Kraus, Virginia B.

    2017-01-01

    Objective. Alkaptonuria (AKU) is a rare autosomal recessive disease resulting from a single enzyme deficiency in tyrosine metabolism. As a result, homogentisic acid cannot be metabolized, causing systemic increases. Over time, homogentisic acid polymerizes and deposits in collagenous tissues, leading to ochronosis. Typically, this occurs in joint cartilages, leading to an early onset, rapidly progressing osteoarthropathy. The aim of this study was to examine tissue turnover in cartilage affected by ochronosis and its role in disease initiation and progression. Methods. With informed patient consent, hip and knee cartilages were obtained at surgery for arthropathy due to AKU (n = 6; 2 knees/4 hips) and OA (n = 12; 5 knees/7 hips); healthy non-arthritic (non-OA n = 6; 1 knee/5 hips) cartilages were obtained as waste from trauma surgery. We measured cartilage concentrations (normalized to dry weight) of racemized aspartate, GAG, COMP and deamidated COMP (D-COMP). Unpaired AKU, OA and non-OA samples were compared by non-parametric Mann–Whitney U test. Results. Despite more extractable total protein being obtained from AKU cartilage than from OA or non-OA cartilage, there was significantly less extractable GAG, COMP and D-COMP in AKU samples compared with OA and non-OA comparators. Racemized Asx (aspartate and asparagine) was significantly enriched in AKU cartilage compared with in OA cartilage. Conclusions. These novel data represent the first examination of cartilage matrix components in a sample of patients with AKU, representing almost 10% of the known UK alkaptonuric population. Compared with OA and non-OA, AKU cartilage demonstrates a very low turnover state and has low levels of extractable matrix proteins. PMID:28028161

  5. Cartilage integrity and proteoglycan turnover are comparable in canine experimentally induced and human joint degeneration

    Directory of Open Access Journals (Sweden)

    Femke Intema

    2010-10-01

    Full Text Available The value of experimental models of osteoarthritis (OA largely depends on the ability to translate observations to human OA. Surprisingly, direct comparison of characteristics of human and experimental OA is scarce. In the present study, cartilage integrity and matrix turnover in a canine model of joint degeneration were compared to human clinical OA. In 23 Beagle dogs, joint degeneration was induced in one knee, the contra-lateral knee served as a control. For comparison, human osteoarthritic and healthy knee cartilage were obtained at arthroplasty (n=14 and post-mortem (n=13. Cartilage was analyzed by histology and biochemistry. Values for cartilage integrity and proteoglycan (PG synthesis showed species specific differences; GAG content of healthy cartilage was 2-fold higher in canine cartilage and PG synthesis even 8-fold. However, the relative decrease in PG content between healthy and OA cartilage was similar for humans and canines (-17% vs. -15%, respectively, as was the histological damage (+7.0 vs. +6.1, respectively and the increase of PG synthesis (+100% vs. +70%, respectively. Remarkably, the percentage release of total and of newly formed PGs in human and canine controls was similar, as was the increase due to degeneration (+65% vs. +81% and +91% vs. +52%, respectively. Despite differences in control conditions, the observed changes in characteristics of cartilage integrity and matrix turnover are similar in a canine model of joint degeneration and human clinical OA. The canine Groove model shows that its characteristics reflect those of human OA which makes the model appropriate for studying human OA.

  6. Cartilage turnover reflected by metabolic processing of type II collagen

    DEFF Research Database (Denmark)

    Gudmann, Karoline Natasja Stæhr; Wang, Jianxia; Hoielt, Sabine

    2014-01-01

    The aim of this study was to enable measurement of cartilage formation by a novel biomarker of type II collagen formation. The competitive enzyme-linked immunosorbent assay (ELISA) Pro-C2 was developed and characterized for assessment of the beta splice variant of type II procollagen (PIIBNP....... To our knowledge this is the first assay, which is able to specifically evaluate PIIBNP excretion. The Pro-C2 assay seems to provide a promising and novel marker of type II collagen formation....

  7. Sprifermin (rhFGF18) modulates extracellular matrix turnover in cartilage explants ex vivo

    DEFF Research Database (Denmark)

    Reker, Ditte; Kjelgaard-Petersen, Cecilie Freja; Siebuhr, Anne Sofie

    2017-01-01

    Background: Sprifermin (recombinant human fibroblast growth factor 18) is in clinical development as a potential disease-modifying osteoarthritis drug (DMOAD). In vitro studies have shown that cartilage regenerative properties of sprifermin involve chondrocyte proliferation and extracellular matrix...... aggrecanase activity. Results: Sprifermin was able to reach the chondrocytes through the extracellular matrix, as it increased cell proliferation and metabolic activity of explants. ProC2 and CS846 was dose-dependently increased (P ... by immuno-histochemical detection of proliferating cell nuclear antigen. ECM turnover was quantified by biomarker ELISAs; ProC2 reflecting type II collagen formation, CS846 reflecting aggrecan formation, active MMP9, C2M and AGNx2 reflecting matrix metalloproteinase activity, and AGNx1 reflecting...

  8. Alterations in RNA turnover following x-irradiation

    International Nuclear Information System (INIS)

    Hetzel, F.W.; Kolodny, G.M.

    1975-01-01

    Mouse embryonic fibroblasts, 3T3, were irradiated in growing and confluent states with 280KV x-rays to a dose of 3750 rads. All cells were prelabeled while growing with 14 C thymidine for 24 hours and for 24 hours with 3 H uridine in either the growing or confluent state. The turnover of prelabeled cellular RNA was then studied. While RNA turnover normally occurs in confluent cells and does not occur in subconfluent cells the results of this study suggested the existence of RNA turnover in both cell populations following radiation. The rate of RNA turnover in irradiated confluent cells was less than that seen in normal confluent cells while for irradiated growing cells the rate of turnover was higher than in controls. The two rates were approximately equal in both irradiated populations. In each case the amount of prelabeled DNA lost from the acid insoluble fraction was approximately 50 percent after 10 days. The possible significance of these results in relation to radiation induced giant cell formation and alterations in RNA minor bases will be discussed

  9. PTH [1-34]-induced alterations predispose the mandibular condylar cartilage to mineralization.

    Science.gov (United States)

    Dutra, E H; O'Brien, M H; Gutierrez, T; Lima, A; Nanda, R; Yadav, S

    2017-06-01

    To study the effects of intermittent parathyroid hormone (PTH [1-34]) on the mandibular condylar cartilage (MCC) and subchondral bone in adult female mice. Twenty-two, 20-week-old female mice were used for in vivo experiments. The experimental mice (n=11) received daily intraperitoneal injections of PTH [1-34] for 3 weeks, while control mice (n=11) received intraperitoneal injections of 0.9% saline solution. Mice were euthanized and then micro-computed tomography (micro-CT); histology and immunostaining were carried out to assess the response. Intermittent PTH [1-34] led to early MCC breakdown and surface irregularities. Micro-CT analyses indicated that PTH [1-34] treatment led to increased bone volume fraction, tissue density and trabecular thickness, while decreasing the trabecular spacing. Histological analyses showed decreased proteoglycan secretion, increased bone turnover (TRAP staining) and increased mineralization. Furthermore, PTH [1-34] treatment showed increased apoptosis of the cells. Our immunohistochemistry showed increased expression of pSMAD158 in the MCC and subchondral bone with PTH administration, whereas sclerostin (SOST) expression was decreased. Intermittent PTH [1-34] results in early mineralization of the MCC, which may result in cartilage degeneration. Our results identified a novel mechanism by which PTH [1-34] induces alteration in the microarchitecture of the MCC and the subchondral bone. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. A Dual Role of Upper Zone of Growth Plate and Cartilage Matrix-Associated Protein in Human and Mouse Osteoarthritic Cartilage: Inhibition of Aggrecanases and Promotion of Bone Turnover.

    Science.gov (United States)

    Stock, Michael; Menges, Stefanie; Eitzinger, Nicole; Geßlein, Maria; Botschner, Renate; Wormser, Laura; Distler, Alfiya; Schlötzer-Schrehardt, Ursula; Dietel, Katharina; Distler, Jörg; Beyer, Christian; Gelse, Kolja; Engelke, Klaus; Koenders, Marije I; van den Berg, Wim; von der Mark, Klaus; Schett, Georg

    2017-06-01

    Cartilage damage and subchondral bone changes are closely connected in osteoarthritis. Nevertheless, how these processes are interlinked is, to date, incompletely understood. This study was undertaken to investigate the mechanistic role of a cartilage-derived protein, upper zone of growth plate and cartilage matrix-associated protein (UCMA), in osteoarthritis-related cartilage and bone changes. UCMA expression was assessed in healthy and osteoarthritic human and mouse cartilage. For analysis of cartilage and bone changes, osteoarthritis was induced by destabilization of the medial meniscus (DMM) in wild-type (WT) and Ucma-deficient mice. UCMA-collagen interactions, the effect of UCMA on aggrecanase activity, and the impact of recombinant UCMA on osteoclast differentiation were studied in vitro. UCMA was found to be overexpressed in human and mouse osteoarthritic cartilage. DMM-triggered cartilage changes, including increased structural damage, proteoglycan loss, and chondrocyte cell death, were aggravated in Ucma-deficient mice compared to WT littermates, thereby demonstrating the potential chondroprotective effects of UCMA. Moreover, UCMA inhibited ADAMTS-dependent aggrecanase activity and directly interacted with cartilage-specific collagen types. In contrast, osteoarthritis-related bone changes were significantly reduced in Ucma-deficient mice, showing less pronounced osteophyte formation and subchondral bone sclerosis. Mechanistically, UCMA directly promoted osteoclast differentiation in vitro. UCMA appears to link cartilage with bone changes in osteoarthritis by supporting cartilage integrity as an endogenous inhibitor of aggrecanases while also promoting osteoclastogenesis and subchondral bone turnover. Thus, UCMA represents an important link between cartilage and bone in osteoarthritis. © 2017, American College of Rheumatology.

  11. Structure of newly synthesized (/sup 35/S)-proteoglycans and (/sup 35/S)-proteoglycan turnover products of cartilage explant cultures from dogs with experimental osteoarthritis

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    Carney, S.L.; Billingham, M.E.; Muir, H.; Sandy, J.D.

    1985-01-01

    The structure of newly synthesized proteoglycans from explant cultures of cartilage from joints subjected to transection of the anterior cruciate ligament (osteoarthritic) and from normal (non- or sham-operated) joints was examined. The structure of the products of proteoglycan turnover was also examined using explants of normal and osteoarthritic cartilage maintained in culture for a 48 h chase period. The findings were as follows: Newly synthesized (/sup 35/S)-proteoglycans extracted from cartilage explants from osteoarthritic joints whether examined 3 weeks, 3 months, or 6 months after surgery were larger than those from corresponding normal cartilage. This can be explained by the synthesis in osteoarthritic cartilage of abnormally long chondroitin sulfate chains on newly synthesised proteoglycans. The extracts also contained a newly formed small proteoglycan species that was unable to interact with hyaluronic acid. The proportion of this species was higher in osteoarthritic cartilage compared with normal, examined 3 weeks after surgery, but was generally absent from cartilage obtained 3 and 6 months after surgery. Compared with controls, a smaller proportion of the (/sup 35/S)-proteoglycans released into the maintenance medium of explant cultures of osteoarthritic cartilage during a 48 h chase period was able to interact with hyaluronic acid. However, although furnished with longer (/sup 35/S)-glycosaminoglycan chains, these proteoglycans were smaller than those from control explants.

  12. Alteration of cartilage surface collagen fibers differs locally after immobilization of knee joints in rats

    Science.gov (United States)

    Nagai, Momoko; Aoyama, Tomoki; Ito, Akira; Tajino, Junichi; Iijima, Hirotaka; Yamaguchi, Shoki; Zhang, Xiangkai; Kuroki, Hiroshi

    2015-01-01

    The purpose of this study was to examine the ultrastructural changes of surface cartilage collagen fibers, which differ by region and the length of the experimental period in an immobilization model of rat. Male Wistar rats were randomly divided into histological or macroscopic and ultrastructural assessment groups. The left knees of all the animals were surgically immobilized by external fixation for 1, 2, 4, 8 or 16 weeks (n = 5/time point). Sagittal histological sections of the medial mid-condylar region of the knee were obtained and assessed in four specific regions (contact and peripheral regions of the femur and tibia) and two zones (superficial and deep). To semi-quantify the staining intensity of the collagen fibers in the cartilage, picrosirius red staining was used. The cartilage surface changes of all the assessed regions were investigated by scanning electron microscopy (SEM). From histological and SEM observations, the fibrillation and irregular changes of the cartilage surface were more severe in the peripheral region than in the contact region. Interestingly, at 16 weeks post-immobilization, we observed non-fibrous structures at both the contact and peripheral regions. The collagen fiber staining intensity decreased in the contact region compared with the peripheral region. In conclusion, the alteration of surface collagen fiber ultrastructure and collagen staining intensity differed by the specific cartilage regions after immobilization. These results demonstrate that the progressive degeneration of cartilage is region specific, and depends on the length of the immobilization period. PMID:25939458

  13. The response to estrogen deprivation on cartilage collagen degradation markers; CTX-II is unique compared to other markers of collagen turnover

    DEFF Research Database (Denmark)

    Bay-Jensen, Anne-Christine; Tabassi, Nadine; Sondergaard, Lene

    2009-01-01

    ABSTRACT: INTRODUCTION: The urinary level of type II collagen degradation marker CTX-II is increased in postmenopausal women and in ovariectomized rats, suggesting that estrogen deprivation induces cartilage breakdown. Here we investigate whether this response to estrogen holds true for other type...... II collagen turnover markers known to be affected in osteoarthritis, and whether it relates to its presence in specific areas of cartilage tissue. METHODS: The type II collagen degradation markers CTX-II and Helix-II were measured in body fluids of pre- and postmenopausal women and of ovariectomized...... rats receiving estrogen or not. Levels of PIIANP, a marker of type II collagen synthesis, were also measured in rats. Rat knee cartilage was analyzed for immunoreactivity of CTX-II and PIIANP and for type II collagen expression. RESULTS: As expected, urinary levels of CTX-II are significantly increased...

  14. Effect of Age-Related Cartilage Turnover on Serum C-Telopeptide of Collagen Type II and Osteocalcin Levels in Growing Rabbits with and without Surgically Induced Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Chung-Cheng Huang

    2014-01-01

    Full Text Available This study aims to determine the effect of age-related cartilage turnover on the serum C-telopeptide of type II collagen (CTX-II and osteocalcin (OC levels in growing rabbits with and without surgically induced osteoarthritis. Twenty-four New Zealand male 3-month-old rabbits were randomized into three operated groups (n = 6 per group, with surgically induced osteroarthritis in the right knee; after blood sampling, the knees were harvested following euthanization at 2, 3, and 6 months after surgery and a control group (n = 6, blood samples were obtained monthly between 3 and 15 months. Histomorphologically, the medial femoral condyles, particularly the central parts, harbored the most severe osteoarthritic changes among the operated rabbits. The serum levels of CTX-II and OC decreased in the controls from 3 to 11 months and then remained stable. No significant differences in the serum CTX-II and OC levels between the osteoarthritic rabbits and controls were observed. The osteoarthritic-to-normal ratios (ONRs, the ratios of serum CTX-II or OC levels in osteoarthritic rabbits to those of the controls at same ages enabled an overall assessment of osteoarthritis and age-related cartilage turnover. Elevated CTX-II ONRs were observed in rabbits with mild to advanced osteoarthritis. However, the OC ONRs were unhelpful in assessing osteoarthritic growing rabbits.

  15. Cartilage Turnover Reflected by Metabolic Processing of Type II Collagen: A Novel Marker of Anabolic Function in Chondrocytes

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    Natasja Stæhr Gudmann

    2014-10-01

    Full Text Available The aim of this study was to enable measurement of cartilage formation by a novel biomarker of type II collagen formation. The competitive enzyme-linked immunosorbent assay (ELISA Pro-C2 was developed and characterized for assessment of the beta splice variant of type II procollagen (PIIBNP. This is expected to originate primarily from remodeling of hyaline cartilage. A mouse monoclonal antibody (Mab was raised in mouse, targeting specifically PIIBNP (QDVRQPG and used in development of the assay. The specificity, sensitivity, 4-parameter fit and stability of the assay were tested. Levels of PIIBNP were quantified in human serum (0.6–2.2 nM, human amniotic fluid (163–188 nM and sera from different animal species, e.g., fetal bovine serum (851–901 nM with general good linearity (100% (SD 7.6 recovery and good intra- and inter-assay variation (CV% < 10. Dose (0.1 to 100 ng/mL and time (7, 14 and 21 days dependent release of PIIBNP were evaluated in the conditioned medium from bovine cartilage explants (BEX and human cartilage explants (HEX upon stimulation with insulin-like growth factor (IGF-1, transforming growth factor (TGF-β1 and fibroblastic growth factor-2 (FGF-2. TGF-β1 and IGF-1 in concentrations of 10–100 ng/mL significantly (p < 0.05 induced release of PIIBNP in BEX compared to conditions without treatment (WO. In HEX, IGF-1 100 ng/mL was able to induce a significant increase of PIIBNP after one week compared to WO. FGF-2 did not induce a PIIBNP release in our models. To our knowledge this is the first assay, which is able to specifically evaluate PIIBNP excretion. The Pro-C2 assay seems to provide a promising and novel marker of type II collagen formation.

  16. In vivo and in vitro studies of cartilage differentiation in altered gravities

    Science.gov (United States)

    Montufar-Solis, D.; Duke, P. J.; D'Aunno, D.

    The in vivo model our laboratory uses for studies of cartilage differentiation in space is the rat growth plate. Differences between missions, and in rat age and recovery times, provided differing results from each mission. However, in all missions, proliferation and differentiation of chondrocytes in the epiphyseal plate of spaceflown rats was altered as was matrix organization. In vitro systems, necessary complements to in vivo work, provide some advantages over the in vivo situation. In vitro, centrifugation of embryonic limb buds suppressed morphogenesis due to precocious differentiation, and changes in the developmental pattern suggest the involvement of Hox genes. In space, embryonic mouse limb mesenchyme cells differentiating in vitro on IML-1 had smoother membranes and lacked matrix seen in controls. Unusual formations, possibly highly ruffled membranes, were found in flight cultures. These results, coupled with in vivo centrifugation studies, show that in vivo or in vitro, the response of chondrocytes to gravitational changes follows Hert's curve as modified by Simon, i.e. decreased loading decreases differentiation, and increased loading speeds it up, but only to a point. After that, additional increases again slow down chondrogenesis.

  17. Studies on the possible role of thyroid hormone in altered muscle protein turnover during sepsis

    Energy Technology Data Exchange (ETDEWEB)

    Hasselgren, P.O.; Chen, I.W.; James, J.H.; Sperling, M.; Warner, B.W.; Fischer, J.E.

    1987-07-01

    Five days after thyroidectomy (Tx) or sham-Tx in young male Sprague-Dawley rats, sepsis was induced by cecal ligation and puncture (CLP). Control animals underwent laparotomy and manipulation of the cecum without ligation or puncture. Sixteen hours after CLP or laparotomy, protein synthesis and degradation were measured in incubated extensor digitorum longus (EDL) and soleus (SOL) muscles by determining rate of /sup 14/C-phenylalanine incorporation into protein and tyrosine release into incubation medium, respectively. Triiodothyronine (T3) was measured in serum and muscle tissue. Protein synthesis was reduced by 39% and 22% in EDL and SOL, respectively, 16 hours after CLP in sham-Tx rats. The response to sepsis of protein synthesis was abolished in Tx rats. Protein breakdown was increased by 113% and 68% in EDL and SOL, respectively, 16 hours after CLP in sham-Tx animals. The increase in muscle proteolysis during sepsis was blunted in hypothyroid animals and was 42% and 49% in EDL and SOL, respectively. T3 in serum was reduced by sepsis, both in Tx and sham-Tx rats. T3 in muscle, however, was maintained or increased during sepsis. Abolished or blunted response of muscle protein turnover after CLP in hypothyroid animals may reflect a role of thyroid hormones in altered muscle protein metabolism during sepsis. Reduced serum levels of T3, but maintained or increased muscle concentrations of the hormone, suggests that increased T3 uptake by muscle may be one mechanism of low T3 syndrome in sepsis, further supporting the concept of a role for thyroid hormone in metabolic alterations in muscle during sepsis.

  18. Studies on the possible role of thyroid hormone in altered muscle protein turnover during sepsis

    International Nuclear Information System (INIS)

    Hasselgren, P.O.; Chen, I.W.; James, J.H.; Sperling, M.; Warner, B.W.; Fischer, J.E.

    1987-01-01

    Five days after thyroidectomy (Tx) or sham-Tx in young male Sprague-Dawley rats, sepsis was induced by cecal ligation and puncture (CLP). Control animals underwent laparotomy and manipulation of the cecum without ligation or puncture. Sixteen hours after CLP or laparotomy, protein synthesis and degradation were measured in incubated extensor digitorum longus (EDL) and soleus (SOL) muscles by determining rate of 14 C-phenylalanine incorporation into protein and tyrosine release into incubation medium, respectively. Triiodothyronine (T3) was measured in serum and muscle tissue. Protein synthesis was reduced by 39% and 22% in EDL and SOL, respectively, 16 hours after CLP in sham-Tx rats. The response to sepsis of protein synthesis was abolished in Tx rats. Protein breakdown was increased by 113% and 68% in EDL and SOL, respectively, 16 hours after CLP in sham-Tx animals. The increase in muscle proteolysis during sepsis was blunted in hypothyroid animals and was 42% and 49% in EDL and SOL, respectively. T3 in serum was reduced by sepsis, both in Tx and sham-Tx rats. T3 in muscle, however, was maintained or increased during sepsis. Abolished or blunted response of muscle protein turnover after CLP in hypothyroid animals may reflect a role of thyroid hormones in altered muscle protein metabolism during sepsis. Reduced serum levels of T3, but maintained or increased muscle concentrations of the hormone, suggests that increased T3 uptake by muscle may be one mechanism of low T3 syndrome in sepsis, further supporting the concept of a role for thyroid hormone in metabolic alterations in muscle during sepsis

  19. Morphological and Microstructural Alterations of the Articular Cartilage and Bones during Treadmill Exercises with Different Additional Weight-Bearing Levels

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    Jiazi Gao

    2017-01-01

    Full Text Available The aim of this study was to investigate the morphological and microstructural alterations of the articular cartilage and bones during treadmill exercises with different exercise intensities. Sixty 5-week-old female rats were randomly divided into 10 groups: five additional weight-bearing groups (WBx and five additional weight-bearing with treadmill exercise groups (EBx, which were subjected to additional weight bearing of x% (x = 0, 5, 12, 19, and 26 of the corresponding body weight of each rat for 15 min/day. After 8 weeks of experiment, the rats were humanely sacrificed and their bilateral intact knee joints were harvested. Morphological analysis of the cartilages and microcomputed tomography evaluation of bones were subsequently performed. Results showed that increased additional weight bearing may lead to cartilage damage. No significant difference was observed among the subchondral cortical thicknesses of the groups. The microstructure of subchondral trabecular bone of 12% and 19% additional weight-bearing groups was significantly improved; however, the WB26 and EB26 groups showed low bone mineral density and bone volume fraction as well as high structure model index. In conclusion, effects of treadmill exercise on joints may be associated with different additional weight-bearing levels, and exercise intensities during joint growth and maturation should be selected reasonably.

  20. The collagen turnover profile is altered in patients with inguinal and incisional hernia

    DEFF Research Database (Denmark)

    Henriksen, Nadia A; Mortensen, Joachim H; Sorensen, Lars T

    2015-01-01

    BACKGROUND: Disturbed metabolism in the extracellular matrix (ECM) contributes to formation of abdominal wall hernias. The aim of this study was to gain deeper insight into the ECM turnover in hernia patients by analyzing serum biomarkers specifically reflecting collagen synthesis and breakdown......). Patients without hernias scheduled to undergo elective operation for gallstones (n = 18) served as controls. Whole venous blood was collected preoperatively. Biomarkers for synthesis of interstitial matrix (PINP, Pro-C3, P5CP) and basement membrane (P4NP) as well as corresponding degradation (C1M, C3M, C5M......, and C4M) were measured in serum by validated, solid-phase competitive assays. RESULTS: In inguinal hernia patients, the turnover of the interstitial matrix collagens type III (P turnover of the basement membrane collagen type IV...

  1. The response to oestrogen deprivation of the cartilage collagen degradation marker, CTX-II, is unique compared with other markers of collagen turnover

    DEFF Research Database (Denmark)

    Bay-Jensen, Anne-Christine; Tabassi, Nadine C B; Sondergaard, Lene V

    2009-01-01

    The urinary level of the type II collagen degradation marker CTX-II is increased in postmenopausal women and in ovariectomised rats, suggesting that oestrogen deprivation induces cartilage breakdown. Here we investigate whether this response to oestrogen is also true for other type II collagen tu...

  2. Preoperative imaging of cartilage

    International Nuclear Information System (INIS)

    Glaser, Christian

    2009-01-01

    Cartilage lesions are predisposing to osteoarthritis. The therapeutic approach is chosen according to depth and size of the lesions as well as to stability and quality of the cartilage fragment. Another important factor is the biomechanical environment in the affected joint (menisci, ligaments, joint stability, other compartments). MRI using high resolution and moderately T2w FS TSE sequences is the modality of choice for clinical routine imaging of cartilage. It is important to use a consistent protocol in order to achieve reliable results. Sequence parameters should be adapted to optimize contrast between intact cartilage, joint fluid, the subchondral bone and cartilage lesions. Grading scales mainly are derived from arthroscopy. Subchondral bone marrow edema like signal alterations, effusion and meniscal lesions are very useful secondary signs helping to detect cartilage lesions. (orig.)

  3. Priming Adipose-Derived Mesenchymal Stem Cells with Hyaluronan Alters Growth Kinetics and Increases Attachment to Articular Cartilage

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    Peter Succar

    2016-01-01

    Full Text Available Background. Biological therapeutics such as adipose-derived mesenchymal stem cell (MSC therapy are gaining acceptance for knee-osteoarthritis (OA treatment. Reports of OA-patients show reductions in cartilage defects and regeneration of hyaline-like-cartilage with MSC-therapy. Suspending MSCs in hyaluronan commonly occurs in animals and humans, usually without supporting data. Objective. To elucidate the effects of different concentrations of hyaluronan on MSC growth kinetics. Methods. Using a range of hyaluronan concentrations, we measured MSC adherence and proliferation on culture plastic surfaces and a novel cartilage-adhesion assay. We employed time-course and dispersion imaging to assess MSC binding to cartilage. Cytokine profiling was also conducted on the MSC-secretome. Results. Hyaluronan had dose-dependent effects on growth kinetics of MSCs at concentrations of entanglement point (1 mg/mL. At higher concentrations, viscosity effects outweighed benefits of additional hyaluronan. The cartilage-adhesion assay highlighted for the first time that hyaluronan-primed MSCs increased cell attachment to cartilage whilst the presence of hyaluronan did not. Our time-course suggested patients undergoing MSC-therapy for OA could benefit from joint-immobilisation for up to 8 hours. Hyaluronan also greatly affected dispersion of MSCs on cartilage. Conclusion. Our results should be considered in future trials with MSC-therapy using hyaluronan as a vehicle, for the treatment of OA.

  4. Psychological stress alters the ultrastructure and increases IL-1β and TNF-α in mandibular condylar cartilage

    International Nuclear Information System (INIS)

    Lv, Xin; Li, Qiang; Wu, Shun; Sun, Jing; Zhang, Min; Chen, Yong-Jin

    2012-01-01

    Psychological factors can be correlated with temporomandibular disorders (TMDs), but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ) in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g) were randomly divided into 3 groups: psychological stress (PS, N = 48), foot shock (FS, N = 24), and control (N = 48). After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs

  5. Psychological stress alters the ultrastructure and increases IL-1β and TNF-α in mandibular condylar cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xin; Li, Qiang; Wu, Shun; Sun, Jing; Zhang, Min; Chen, Yong-Jin [Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi (China)

    2012-06-22

    Psychological factors can be correlated with temporomandibular disorders (TMDs), but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ) in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g) were randomly divided into 3 groups: psychological stress (PS, N = 48), foot shock (FS, N = 24), and control (N = 48). After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs.

  6. Psychological stress alters the ultrastructure and increases IL-1β and TNF-α in mandibular condylar cartilage

    Directory of Open Access Journals (Sweden)

    Xin Lv

    2012-10-01

    Full Text Available Psychological factors can be correlated with temporomandibular disorders (TMDs, but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g were randomly divided into 3 groups: psychological stress (PS, N = 48, foot shock (FS, N = 24, and control (N = 48. After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β and tumor necrosis factor-α (TNF-α were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs.

  7. Inhibition of apoptosis signal-regulating kinase 1 alters the wound epidermis and enhances auricular cartilage regeneration.

    Science.gov (United States)

    Zhang, Qian-Shi; Kurpad, Deepa S; Mahoney, My G; Steinbeck, Marla J; Freeman, Theresa A

    2017-01-01

    Why regeneration does not occur in mammals remains elusive. In lower vertebrates, epimorphic regeneration of the limb is directed by the wound epidermis, which controls blastema formation to promote regrowth of the appendage. Herein, we report that knockout (KO) or inhibition of Apoptosis Signal-regulated Kinase-1 (ASK1), also known as mitogen-activated protein kinase kinase kinase 5 (MAP3K5), after full thickness ear punch in mice prolongs keratinocyte activation within the wound epidermis and promotes regeneration of auricular cartilage. Histological analysis showed the ASK1 KO ears displayed enhanced protein markers associated with blastema formation, hole closure and regeneration of auricular cartilage. At seven days after punch, the wound epidermis morphology was markedly different in the KO, showing a thickened stratum corneum with rounded cell morphology and a reduction of both the granular cell layer and decreased expression of filament aggregating protein. In addition, cytokeratin 6 was expressed in the stratum spinosum and granulosum. Topical application of inhibitors of ASK1 (NQDI-1), the upstream ASK1 activator, calcium activated mitogen kinase 2 (KN93), or the downstream target, c-Jun N-terminal kinase (SP600125) also resulted in enhanced regeneration; whereas inhibition of the other downstream target, the p38 α/β isoforms, (SB203580) had no effect. The results of this investigation indicate ASK1 inhibition prolongs keratinocyte and blastemal cell activation leading to ear regeneration.

  8. Inhibition of apoptosis signal-regulating kinase 1 alters the wound epidermis and enhances auricular cartilage regeneration.

    Directory of Open Access Journals (Sweden)

    Qian-Shi Zhang

    Full Text Available Why regeneration does not occur in mammals remains elusive. In lower vertebrates, epimorphic regeneration of the limb is directed by the wound epidermis, which controls blastema formation to promote regrowth of the appendage. Herein, we report that knockout (KO or inhibition of Apoptosis Signal-regulated Kinase-1 (ASK1, also known as mitogen-activated protein kinase kinase kinase 5 (MAP3K5, after full thickness ear punch in mice prolongs keratinocyte activation within the wound epidermis and promotes regeneration of auricular cartilage. Histological analysis showed the ASK1 KO ears displayed enhanced protein markers associated with blastema formation, hole closure and regeneration of auricular cartilage. At seven days after punch, the wound epidermis morphology was markedly different in the KO, showing a thickened stratum corneum with rounded cell morphology and a reduction of both the granular cell layer and decreased expression of filament aggregating protein. In addition, cytokeratin 6 was expressed in the stratum spinosum and granulosum. Topical application of inhibitors of ASK1 (NQDI-1, the upstream ASK1 activator, calcium activated mitogen kinase 2 (KN93, or the downstream target, c-Jun N-terminal kinase (SP600125 also resulted in enhanced regeneration; whereas inhibition of the other downstream target, the p38 α/β isoforms, (SB203580 had no effect. The results of this investigation indicate ASK1 inhibition prolongs keratinocyte and blastemal cell activation leading to ear regeneration.

  9. Shark Cartilage

    Science.gov (United States)

    ... inflammation of the intestine (enteritis). Some people apply shark cartilage directly to the skin for arthritis and psoriasis. ... ingredients. Additionally, there is no research showing that shark cartilage is absorbed through the skin. Psoriasis. Developing research suggests that a specific shark ...

  10. Lubrication and cartilage.

    Science.gov (United States)

    Wright, V; Dowson, D

    1976-02-01

    Mechanisms of lubrication of human synovial joints have been analysed in terms of the operating conditions of the joint, the synovial fluid and articular cartilage. In the hip and knee during a walking cycle the load may rise up to four times body weight. In the knee on dropping one metre the load may go up to 25 time body weight. The elastic modulus of cartilage is similar to that of the synthetic rubber of a car tyre. The cartilage surface is rough and in elderly specimens the centre line average is 2-75 mum. The friction force generated in reciprocating tests shows that both cartilage and synovial fluid are important in lubrication. The viscosity-shear rate relationships of normal synovial fluid show that it is non-Newtonian. Osteoarthrosic fluid is less so and rheumatoid fluid is more nearly Newtonian. Experiments with hip joints in a pendulum machine show that fluid film lubrication obtains at some phases of joint action. Boundary lubrication prevails under certain conditions and has been examined with a reciprocating friction machine. Digestion of hyaluronate does not alter the boundary lubrication, but trypsin digestion does. Surface active substances (lauryl sulphate and cetyl 3-ammonium bromide) give a lubricating ability similar to that of synovial fluid. The effectiveness of the two substances varies with pH.

  11. Lubrication and cartilage.

    Science.gov (United States)

    Wright, V; Dowson, D

    1976-01-01

    Mechanisms of lubrication of human synovial joints have been analysed in terms of the operating conditions of the joint, the synovial fluid and articular cartilage. In the hip and knee during a walking cycle the load may rise up to four times body weight. In the knee on dropping one metre the load may go up to 25 time body weight. The elastic modulus of cartilage is similar to that of the synthetic rubber of a car tyre. The cartilage surface is rough and in elderly specimens the centre line average is 2-75 mum. The friction force generated in reciprocating tests shows that both cartilage and synovial fluid are important in lubrication. The viscosity-shear rate relationships of normal synovial fluid show that it is non-Newtonian. Osteoarthrosic fluid is less so and rheumatoid fluid is more nearly Newtonian. Experiments with hip joints in a pendulum machine show that fluid film lubrication obtains at some phases of joint action. Boundary lubrication prevails under certain conditions and has been examined with a reciprocating friction machine. Digestion of hyaluronate does not alter the boundary lubrication, but trypsin digestion does. Surface active substances (lauryl sulphate and cetyl 3-ammonium bromide) give a lubricating ability similar to that of synovial fluid. The effectiveness of the two substances varies with pH. Images Fig. 10 PMID:3490

  12. Splenectomy alters distribution and turnover but not numbers or protective capacity of de novo generated memory CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Marie eKim

    2014-11-01

    Full Text Available The spleen is a highly compartmentalized lymphoid organ that allows for efficient antigen presentation and activation of immune responses. Additionally, the spleen itself functions to remove senescent red blood cells, filter bacteria, and sequester platelets. Splenectomy, commonly performed after blunt force trauma or splenomegaly, has been shown to increase risk of certain bacterial and parasitic infections years after removal of the spleen. Although previous studies report defects in memory B cells and IgM titers in splenectomized patients, the effect of splenectomy on CD8 T cell responses and memory CD8 T cell function remains ill defined. Using TCR-transgenic P14 cells, we demonstrate that homeostatic proliferation and representation of pathogen-specific memory CD8 T cells in the blood are enhanced in splenectomized compared to sham surgery mice. Surprisingly, despite the enhanced turnover, splenectomized mice displayed no changes in total memory CD8 T cell numbers nor impaired protection against lethal dose challenge with Listeria monocytogenes. Thus, our data suggest that memory CD8 T cell maintenance and function remain intact in the absence of the spleen.

  13. Mechanobiological implications of articular cartilage crystals.

    Science.gov (United States)

    Carlson, Alyssa K; McCutchen, Carley N; June, Ronald K

    2017-03-01

    Calcium crystals exist in both pathological and normal articular cartilage. The prevalence of these crystals dramatically increases with age, and crystals are typically found in osteoarthritic cartilage and synovial fluid. Relatively few studies have examined the effects of crystals on cartilage biomechanics or chondrocyte mechanotransduction. The purpose of this review is to describe how crystals could influence cartilage biomechanics and mechanotransduction in osteoarthritis. Crystals are found in both loaded and unloaded regions of articular cartilage. Exogenous crystals, in combination with joint motion, result in substantial joint inflammation. Articular cartilage vesicles promote crystal formation, and these vesicles are found near the periphery of chondrocytes. Crystallographic studies report monoclinic symmetry for synthetic crystals, suggesting that crystals will have a large stiffness compared with the cartilage extracellular matrix, the pericellular matrix, or the chondrocyte. This stiffness imbalance may cause crystal-induced dysregulation of chondrocyte mechanotransduction promoting both aging and osteoarthritis chondrocyte phenotypes. Because of their high stiffness compared with cartilage matrix, crystals likely alter chondrocyte mechanotransduction, and high concentrations of crystals within cartilage may alter macroscale biomechanics. Future studies should focus on understanding the mechanical properties of joint crystals and developing methods to understand how crystals affect chondrocyte mechanotransduction.

  14. Regulation of complement by cartilage oligomeric matrix protein allows for a novel molecular diagnostic principle in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Happonen, Kaisa E; Saxne, Tore; Aspberg, Anders

    2010-01-01

    Cartilage oligomeric matrix protein (COMP) is a structural component of cartilage, where it catalyzes collagen fibrillogenesis. Elevated amounts of COMP are found in serum during increased turnover of cartilage associated with active joint disease, such as rheumatoid arthritis (RA) and osteoarthr...

  15. Extracellular vesicles in cartilage homeostasis and osteoarthritis.

    Science.gov (United States)

    Miyaki, Shigeru; Lotz, Martin K

    2018-01-01

    Extracellular vesicles carry bioactive molecules that can be transferred between cells and tissues. The purpose of this review is to describe how extracellular vesicles regulate functions of cells in cartilage and other joint tissues. The potential application of extracellular vesicles in the treatment of osteoarthritis and as biomarkers will also be discussed. Extracellular vesicles are found in synovial fluid, in articular cartilage and in the supernatants of synoviocytes and chondrocytes. Extracellular vesicles in cartilage have been proposed to be involved in cross talk between cells in joint tissues and to affect extracellular matrix turnover and inflammation. Extracellular vesicles from arthritic joints can promote abnormal gene expression and changes in cartilage extracellular matrix, including abnormal mineralization. Promising results were obtained in the therapeutic application of mesenchymal stem cell-derived extracellular vesicles for cartilage repair and experimental osteoarthritis. Extracellular vesicles have emerged as vehicles for the exchange of bioactive signaling molecules within cartilage and between joint tissues to promote joint homeostasis and arthritis pathogenesis. As the molecular content of extracellular vesicles can be customized, they offer utility in therapeutic applications.

  16. Role of Chondrocytes in Cartilage Formation, Progression of Osteoarthritis and Cartilage Regeneration

    Directory of Open Access Journals (Sweden)

    Hemanth Akkiraju

    2015-12-01

    Full Text Available Articular cartilage (AC covers the diarthrodial joints and is responsible for the mechanical distribution of loads across the joints. The majority of its structure and function is controlled by chondrocytes that regulate Extracellular Matrix (ECM turnover and maintain tissue homeostasis. Imbalance in their function leads to degenerative diseases like Osteoarthritis (OA. OA is characterized by cartilage degradation, osteophyte formation and stiffening of joints. Cartilage degeneration is a consequence of chondrocyte hypertrophy along with the expression of proteolytic enzymes. Matrix Metalloproteinases (MMPs and A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS are an example of these enzymes that degrade the ECM. Signaling cascades involved in limb patterning and cartilage repair play a role in OA progression. However, the regulation of these remains to be elucidated. Further the role of stem cells and mature chondrocytes in OA progression is unclear. The progress in cell based therapies that utilize Mesenchymal Stem Cell (MSC infusion for cartilage repair may lead to new therapeutics in the long term. However, many questions are unanswered such as the efficacy of MSCs usage in therapy. This review focuses on the role of chondrocytes in cartilage formation and the progression of OA. Moreover, it summarizes possible alternative therapeutic approaches using MSC infusion for cartilage restoration.

  17. Role of hormones in cartilage and joint metabolism: understanding an unhealthy metabolic phenotype in osteoarthritis.

    Science.gov (United States)

    Bay-Jensen, Anne C; Slagboom, Eline; Chen-An, Pingping; Alexandersen, Peter; Qvist, Per; Christiansen, Claus; Meulenbelt, Ingrid; Karsdal, Morten A

    2013-05-01

    Joint health is affected by local and systemic hormones. It is well accepted that systemic factors regulate the metabolism of joint tissues, and that substantial cross-talk between tissues actively contributes to homeostasis. In the current review, we try to define a subtype of osteoarthritis (OA), metabolic OA, which is dependent on an unhealthy phenotype. Peer-reviewed research articles and reviews were reviewed and summarized. Only literature readily available online, either by download or by purchase order, was included. OA is the most common joint disease and is more common in women after menopause. OA is a disease that affects the whole joint, including cartilage, subchondral bone, synovium, tendons, and muscles. The clinical endpoints of OA are pain and joint space narrowing, which is characterized by cartilage erosion and subchondral sclerosis, suggesting that cartilage is a central tissue of joint health. Thus, the joint, more specifically the cartilage, may be considered a target of endocrine function in addition to the well-described traditional risk factors of disease initiation and progression such as long-term loading of the joint due to obesity. Metabolic syndrome affects a range of tissues and may in part be molecularly described as a dysregulation of cytokines, adipokines, and hormones (e.g., estrogen and thyroid hormone). Consequently, metabolic imbalance may both directly and indirectly influence joint health and cartilage turnover, altering the progression of diseases such as OA. There is substantial evidence for a connection between metabolic health and development of OA. We propose that more focus be directed to understanding this connection to improve the management of menopausal health and associated comorbidities.

  18. Prospective Clinical Trial for Septic Arthritis: Cartilage Degradation and Inflammation Are Associated with Upregulation of Cartilage Metabolites

    Directory of Open Access Journals (Sweden)

    Hagen Schmal

    2016-01-01

    Full Text Available Background. Intra-articular infections can rapidly lead to osteoarthritic degradation. The aim of this clinical biomarker analysis was to investigate the influence of inflammation on cartilage destruction and metabolism. Methods. Patients with acute joint infections were enrolled in a prospective clinical trial and the cytokine composition of effusions (n=76 was analyzed. Characteristics of epidemiology and disease severity were correlated with levels of cytokines with known roles in cartilage turnover and degradation. Results. Higher synovial IL-1β concentrations were associated with clinical parameters indicating a higher disease severity (p<0.03 excluding the incidence of sepsis. Additionally, intra-articular IL-1β levels correlated with inflammatory serum parameters as leucocyte counts (LC and C-reactive protein concentrations (p<0.05 but not with age or comorbidity. Both higher LC and synovial IL-1β levels were associated with increased intra-articular collagen type II cleavage products (C2C indicating cartilage degradation. Joints with preinfectious lesions had higher C2C levels. Intra-articular inflammation led to increased concentrations of typical cartilage metabolites as bFGF, BMP-2, and BMP-7. Infections with Staphylococcus species induced higher IL-1β expression but less cartilage destruction than other bacteria. Conclusion. Articular infections have bacteria-specific implications on cartilage metabolism. Collagen type II cleavage products reliably mark destruction, which is associated with upregulation of typical cartilage turnover cytokines. This trial is registered with DRKS00003536, MISSinG.

  19. Early detection and monitoring of cartilage alteration in the experimental meniscectomised guinea pig model of osteoarthritis by {sup 99m}Tc-NTP 15-5 scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Miot-Noirault, Elisabeth; Vidal, Aurelien; Bonafous, Jacques; Audin, Laurent; Madelmont, Jean-Claude; Moins, Nicole [UMR 484 INSERM, Rue Montalembert, BP 184, Clermont-Ferrand Cedex (France); Pastoureau, Philippe; Chomel, Agnes [Institut de Recherches Servier, Suresnes (France); Sarry, Laurent [ERI 14 INSERM - Faculte de Medecine, Clermont-Ferrand (France)

    2007-08-15

    This study in the meniscectomised guinea pig aimed to demonstrate that the radiotracer {sup 99m}Tc-NTP 15-5 would have pathophysiological validity for in vivo osteoarthritis imaging. The specificity of {sup 99m}Tc-NTP 15-5 for cartilage was determined in healthy animals (n = 13), by tissue radioactivity counting, joint autoradiography and scintigraphy. {sup 99m}Tc-NTP 15-5 scintigraphy was performed at 20, 50, 80, 115, 130, 150 and 180 days after medial meniscectomy (n = 10 MNX) or sham operation (n = 5), and scintigraphic ratios (operated/contralateral) were calculated for femoral (F) and tibial (T) areas. F and T ratios were compared with those of {sup 99m}Tc-MDP bone scintigraphy. At the study end-point, autoradiographic analysis of joint {sup 99m}Tc-NTP 15-5 distribution and macroscopic scoring of cartilage integrity were performed. The high and specific accumulation of {sup 99m}Tc-NTP 15-5 in normal cartilage (about 5.5 {+-} 1.7 % of injected dose/g of tissue), which permitted joint imaging with high contrast, was affected by osteoarthritis. In the MNX group, {sup 99m}Tc-NTP 15-5 accumulation in cartilage within the operated joint, relative to the contralateral joint, was observed to change in the same animals as pathology progressed. Although F and T ratios were significantly higher in MNX (F = 1.7 {+-} 0.2; T = 1.6 {+-} 0.1) than in shams (F = 1.0 {+-} 0.1; T = 1.0 {+-} 0.1) at day 50, they were significantly lower in MNX (F = 0.6 {+-} 0.1; T = 0.7 {+-} 0.1) than in shams (F = 1.0 {+-} 0.1; T = 0.9 {+-} 0.1) at day 180. No change in {sup 99m}Tc-MDP uptake was observed over 6 months. Macroscopic analysis confirmed features of osteoarthritis only in MNX knees. These results in MNX guinea pigs provide additional support for the use of {sup 99m}Tc-NTP 15-5 for in vivo imaging of osteoarthritis. (orig.)

  20. Degeneration of osteoarthritis cartilage

    DEFF Research Database (Denmark)

    Jørgensen, Dan Richter

    of sensitive biomarkers for monitoring disease progression. This thesis investigates how subregional measures of cartilage thickness can be used to improve upon current imaging biomarkers. The first part of this investigation aims to discover discriminative areas in the cartilage using machine-learning...... techniques specifically developed to take advantage of the spatial nature of the problem. The methods were evaluated on data from a longitudinal study where detailed cartilage thickness maps were quantified from magnetic resonance images. The results showed that focal differences in cartilage thickness may...... spatial cartilage changes that were observed in our study and in recent literature. The cartilage “Activity” marker is shown to have a state-of-the-art performance in separating healthy knees from OA knees and is also shown to predict knee replacement which is a clinically relevant endpoint for OA....

  1. Turnover among healthcare professionals.

    Science.gov (United States)

    Wood, Ben D

    2009-01-01

    Turnover among healthcare professionals is a costly consequence. The existing body of knowledge on healthcare professional turnover is correlated with job satisfaction levels. A landmark study differentiated 2 areas of job satisfaction categories: satisfiers and dissatisfiers (intrinsic and extrinsic motivators). The aim of this article is to examine existing research on precursors of turnover, such as burnout behaviors experienced by healthcare professionals, job satisfaction levels, employee organizational commitment, health complications which precede turnover, some current strategies to reduce turnover, and some effects CEO turnover has on employee turnover intentions.

  2. Degeneration of osteoarthritis cartilage

    DEFF Research Database (Denmark)

    Jørgensen, Dan Richter

    of sensitive biomarkers for monitoring disease progression. This thesis investigates how subregional measures of cartilage thickness can be used to improve upon current imaging biomarkers. The first part of this investigation aims to discover discriminative areas in the cartilage using machine...... spatial cartilage changes that were observed in our study and in recent literature. The cartilage “Activity” marker is shown to have a state-of-the-art performance in separating healthy knees from OA knees and is also shown to predict knee replacement which is a clinically relevant endpoint for OA....

  3. [Tribological assessment of articular cartilage. A system for the analysis of the friction coefficient of cartilage, regenerates and tissue engineering constructs; initial results].

    Science.gov (United States)

    Schwarz, M L R; Schneider-Wald, B; Krase, A; Richter, W; Reisig, G; Kreinest, M; Heute, S; Pott, P P; Brade, J; Schütte, A

    2012-10-01

    Values for the friction coefficient of articular cartilage are given in ranges of percentage and lower and are calculated as a quotient of the friction force and the perpendicular loading force acting on it. Thus, a sophisticated system has to be provided for analysing the friction coefficient under different conditions in particular when cartilage should be coupled as friction partner. It is possible to deep-freeze articular cartilage before measuring the friction coefficient as the procedure has no influence on the results. The presented tribological system was able to distinguish between altered and native cartilage. Furthermore, tissue engineered constructs for cartilage repair were differentiated from native cartilage probes by their friction coefficient. In conclusion a tribological equipment is presented to analyze the friction coefficient of articular cartilage, in vivo generated cartilage regenerates and in vitro tissue engineered constructs regarding their biomechanical properties for quality assessment.

  4. MRI of the cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, H.; Noebauer-Huhmann, I.-M.; Krestan, C.; Gahleitner, A.; Marlovits, S.; Trattnig, S. [Department of Osteology, Universitaetklinik fuer Radiodiagnostik, AKH-Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Sulzbacher, I. [Universitaetsklinik fuer Pathologie Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria)

    2002-11-01

    With the introduction of fat-suppressed gradient-echo and fast spin-echo (FSE) sequences in clinical routine MR visualization of the hyaline articular cartilage is routinely possible in the larger joints. While 3D gradient-echo with fat suppression allows exact depiction of the thickness and surface of cartilage, FSE outlines the normal and abnormal internal structures of the hyaline cartilage; therefore, both sequences seem to be necessary in a standard MRI protocol for cartilage visualization. In diagnostically ambiguous cases, in which important therapeutic decisions are required, direct MR arthrography is the established imaging standard as an add-on procedure. Despite the social impact and prevalence, until recent years there was a paucity of knowledge about the pathogenesis of cartilage damage. With the introduction of high-resolution MRI with powerful surface coils and fat-suppression techniques, visualization of the articular cartilage is now routinely possible in many joints. After a short summary of the anatomy and physiology of the hyaline cartilage, the different MR imaging methods are discussed and recommended standards are suggested. (orig.)

  5. Oxygen, nitric oxide and articular cartilage

    Directory of Open Access Journals (Sweden)

    B Fermor

    2007-04-01

    Full Text Available Molecular oxygen is required for the production of nitric oxide (NO, a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O2, while the deep zone exists at less than 1% O2. Furthermore, oxygen tension can alter matrix synthesis, and the material properties of articular cartilage in vitro.The increase in nitric oxide associated with arthritis can be caused by pro-inflammatory cytokines and mechanical stress. Oxygen tension significantly alters endogenous NO production in articular cartilage, as well as the stimulation of NO in response to both mechanical loading and pro-inflammatory cytokines. Mechanical loading and pro-inflammatory cytokines also increase the production of prostaglandin E2 (PGE2. There is a complex interaction between NO and PGE2, and oxygen tension can alter this interaction. These findings suggest that the relatively low levels of oxygen within the joint may have significant influences on the metabolic activity, and inflammatory response of cartilage as compared to ambient levels. A better understanding of the role of oxygen in the production of inflammatory mediators in response to mechanical loading, or pro-inflammatory cytokines, may aid in the development of strategies for therapeutic intervention in arthritis.

  6. Small molecule inhibitors of Staphylococcus aureus RnpA alter cellular mRNA turnover, exhibit antimicrobial activity, and attenuate pathogenesis.

    Directory of Open Access Journals (Sweden)

    Patrick D Olson

    2011-02-01

    Full Text Available Methicillin-resistant Staphylococcus aureus is estimated to cause more U.S. deaths annually than HIV/AIDS. The emergence of hypervirulent and multidrug-resistant strains has further amplified public health concern and accentuated the need for new classes of antibiotics. RNA degradation is a required cellular process that could be exploited for novel antimicrobial drug development. However, such discovery efforts have been hindered because components of the Gram-positive RNA turnover machinery are incompletely defined. In the current study we found that the essential S. aureus protein, RnpA, catalyzes rRNA and mRNA digestion in vitro. Exploiting this activity, high through-put and secondary screening assays identified a small molecule inhibitor of RnpA-mediated in vitro RNA degradation. This agent was shown to limit cellular mRNA degradation and exhibited antimicrobial activity against predominant methicillin-resistant S. aureus (MRSA lineages circulating throughout the U.S., vancomycin intermediate susceptible S. aureus (VISA, vancomycin resistant S. aureus (VRSA and other Gram-positive bacterial pathogens with high RnpA amino acid conservation. We also found that this RnpA-inhibitor ameliorates disease in a systemic mouse infection model and has antimicrobial activity against biofilm-associated S. aureus. Taken together, these findings indicate that RnpA, either alone, as a component of the RNase P holoenzyme, and/or as a member of a more elaborate complex, may play a role in S. aureus RNA degradation and provide proof of principle for RNA catabolism-based antimicrobial therapy.

  7. Magnetic resonance imaging of cartilage and cartilage repair

    International Nuclear Information System (INIS)

    Verstraete, K.L.; Almqvist, F.; Verdonk, P.; Vanderschueren, G.; Huysse, W.; Verdonk, R.; Verbrugge, G.

    2004-01-01

    Magnetic resonance (MR) imaging of articular cartilage has assumed increased importance because of the prevalence of cartilage injury and degeneration, as well as the development of new surgical and pharmacological techniques to treat damaged cartilage. This article will review relevant aspects of the structure and biochemistry of cartilage that are important for understanding MR imaging of cartilage, describe optimal MR pulse sequences for its evaluation, and review the role of experimental quantitative MR techniques. These MR aspects are applied to clinical scenarios, including traumatic chondral injury, osteoarthritis, inflammatory arthritis, and cartilage repair procedures

  8. Magnetic resonance imaging of cartilage and cartilage repair

    Energy Technology Data Exchange (ETDEWEB)

    Verstraete, K.L. E-mail: koenraad.verstraete@ugent.be; Almqvist, F.; Verdonk, P.; Vanderschueren, G.; Huysse, W.; Verdonk, R.; Verbrugge, G

    2004-08-01

    Magnetic resonance (MR) imaging of articular cartilage has assumed increased importance because of the prevalence of cartilage injury and degeneration, as well as the development of new surgical and pharmacological techniques to treat damaged cartilage. This article will review relevant aspects of the structure and biochemistry of cartilage that are important for understanding MR imaging of cartilage, describe optimal MR pulse sequences for its evaluation, and review the role of experimental quantitative MR techniques. These MR aspects are applied to clinical scenarios, including traumatic chondral injury, osteoarthritis, inflammatory arthritis, and cartilage repair procedures.

  9. Imaging Bone–Cartilage Interactions in Osteoarthritis Using [18F]-NaF PET-MRI

    Directory of Open Access Journals (Sweden)

    Dragana Savic MSc

    2016-12-01

    Full Text Available Purpose: Simultaneous positron emission tomography–magnetic resonance imaging (PET-MRI is an emerging technology providing both anatomical and functional images without increasing the scan time. Compared to the traditional PET/computed tomography imaging, it also exposes the patient to significantly less radiation and provides better anatomical images as MRI provides superior soft tissue characterization. Using PET-MRI, we aim to study interactions between cartilage composition and bone function simultaneously, in knee osteoarthritis (OA. Procedures: In this article, bone turnover and remodeling was studied using [18F]-sodium fluoride (NaF PET data. Quantitative MR-derived T1ρ relaxation times characterized the biochemical cartilage degeneration. Sixteen participants with early signs of OA of the knee received intravenous injections of [18F]-NaF at the onset of PET-MR image acquisition. Regions of interest were identified, and kinetic analysis of dynamic PET data provided the rate of uptake (Ki and the normalized uptake (standardized uptake value of [18F]-NaF in the bone. Morphological MR images and quantitative voxel-based T1ρ maps of cartilage were obtained using an atlas-based registration technique to segment cartilage automatically. Voxel-by-voxel statistical parameter mapping was used to investigate the relationship between bone and cartilage. Results: Increases in cartilage T1ρ, indicating degenerative changes, were associated with increased turnover in the adjoining bone but reduced turnover in the nonadjoining compartments. Associations between pain and increased bone uptake were seen in the absence of morphological lesions in cartilage, but the relationship was reversed in the presence of incident cartilage lesions. Conclusion: This study shows significant cartilage and bone interactions in OA of the knee joint using simultaneous [18F]-NaF PET-MR, the first in human study. These observations highlight the complex biomechanical and

  10. Nanotechnology Biomimetic Cartilage Regenerative Scaffolds

    Science.gov (United States)

    Sardinha, Jose Paulo; Myers, Simon

    2014-01-01

    Cartilage has a limited regenerative capacity. Faced with the clinical challenge of reconstruction of cartilage defects, the field of cartilage engineering has evolved. This article reviews current concepts and strategies in cartilage engineering with an emphasis on the application of nanotechnology in the production of biomimetic cartilage regenerative scaffolds. The structural architecture and composition of the cartilage extracellular matrix and the evolution of tissue engineering concepts and scaffold technology over the last two decades are outlined. Current advances in biomimetic techniques to produce nanoscaled fibrous scaffolds, together with innovative methods to improve scaffold biofunctionality with bioactive cues are highlighted. To date, the majority of research into cartilage regeneration has been focused on articular cartilage due to the high prevalence of large joint osteoarthritis in an increasingly aging population. Nevertheless, the principles and advances are applicable to cartilage engineering for plastic and reconstructive surgery. PMID:24883273

  11. Lubricin is expressed in chondrocytes derived from osteoarthritic cartilage encapsulated in poly (ethylene glycol) diacrylate scaffold

    Science.gov (United States)

    Musumeci, G.; Loreto, C.; Carnazza, M.L.; Coppolino, F.; Cardile, V.; Leonardi, R.

    2011-01-01

    Osteoarthritis (OA) is characterized by degenerative changes within joints that involved quantitative and/or qualitative alterations of cartilage and synovial fluid lubricin, a mucinous glycoprotein secreted by synovial fibroblasts and chondrocytes. Modern therapeutic methods, including tissue-engineering techniques, have been used to treat mechanical damage of the articular cartilage but to date there is no specific and effective treatment. This study aimed at investigating lubricin immunohistochemical expression in cartilage explant from normal and OA patients and in cartilage constructions formed by Poly (ethylene glycol) (PEG) based hydrogels (PEG-DA) encapsulated OA chondrocytes. The expression levels of lubricin were studied by immunohistochemistry: i) in tissue explanted from OA and normal human cartilage; ii) in chondrocytes encapsulated in hydrogel PEGDA from OA and normal human cartilage. Moreover, immunocytochemical and western blot analysis were performed in monolayer cells from OA and normal cartilage. The results showed an increased expression of lubricin in explanted tissue and in monolayer cells from normal cartilage, and a decreased expression of lubricin in OA cartilage. The chondrocytes from OA cartilage after 5 weeks of culture in hydrogels (PEGDA) showed an increased expression of lubricin compared with the control cartilage. The present study demonstrated that OA chondrocytes encapsulated in PEGDA, grown in the scaffold and were able to restore lubricin biosynthesis. Thus our results suggest the possibility of applying autologous cell transplantation in conjunction with scaffold materials for repairing cartilage lesions in patients with OA to reduce at least the progression of the disease. PMID:22073377

  12. Distribution of MRI signal alterations of the cartilage endplate in pre-operated patients with special focus on recurrent lumbar disc herniation; Verteilungsmuster von (Modic-)Signalveraenderungen an den vertebralen Endplatten voroperierter Patienten und ihr Bezug zu Rezidivvorfaellen

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G.T.; Liphofer, J.; Koester, O. [Inst. fuer Diagnostische und Interventionelle Radiologie und Nuklearmedizin, St. Josef-Hospital, Bochum (Germany); Willburger, R.E. [Abt. fuer Rheumaorthopaedie, St. Elisabeth-Hospital, Bochum (Germany); Schmid, G. [Klinik fuer Diagnostische und Interventionelle Radiologie, Johanna-Etienne-Krankenhaus, Neuss (Germany)

    2006-01-01

    Purpose: To study the location of (Modic) MR signal alterations (SA) of the cartilage endplate (CEP) in pre- and non-operated segments L3-S1 with special focus on the presence of recurrent lumbar disc herniation (RLDH). Materials and Methods: In a retrospective study the MR images of vertebrae L3-S1 of 65 consecutive patients with a history of microdiscectomy were evaluated. Of the 190 segments studied, 67 were pre-operated. These were divided into a group with recurrent lumbar disc herniation (RLDH) (n=19) and a group without evidence of RLDH (n=48). Non-operated segments (n=123) were also considered as a separate group. In these three groups the prevalence of different Modic types was determined using the sag. T1- and T2-weighted images, and, in particular, the distribution of SA at the upper and lower CEP was examined by evaluating the sag. T2-weighted images. In order to achieve this, each CEP was divided into nine regions. Results: Pre-operated segments showed significantly more frequent (p<0.001) and more expansive (p<0.001) SA than non-operated segments. Non-operated segments showed SA less frequently in the central region of both upper and lower CEP (p=0.056 and p=0.015, respectively). In operated segments without RLDH, the upper CEP had significantly more SA on the operation side than in the mid-sagittal and contra-lateral regions (p=0.016, p=0.037) and significantly more on the operation side of the lower CEP than in the contra-lateral region (p=0.027). Operated segments with RLDH did not show an emphasis of SA on the operation side. In this group SA occurred significantly more often in the central and ventral mid-sagittal regions of the upper CEP than in the preoperated segments without RLDH. (orig.)

  13. [Cartilage degradation in rheumatoid arthritis].

    Science.gov (United States)

    Ishiguro, Naoki

    2009-03-01

    Rheumatoid arthritis (RA) is a polyarticular joint disease. The inflammatory process is characterized by infiltration of inflammatory cells into the joints, leading to proliferation of synoviocytes and destruction of cartilage and bone. The Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases. It had been well recognized that MMP play major roles in the cartilage breakdown in RA and OA. Moreover ADAM-TS-1, -4, -5 have aggrecanase activity, and also involve the cartilage degradation in RA and OA. Of course they contribute the cartilage homeostasis in healthy subjects. Failure to regulate the synthesis, activation and inhibition of the proteinases finally leads to cartilage destruction. Aggrecan and type II collagen are major components in cartilage matrix. Cleavage of aggrecan by aggrecanase and that of collagen by collagenase are critical steps for degradation of articular cartilage in RA. To prevent the cartilage damage, inflammatory synovitis should be suppressed in early stage.

  14. Principles of cartilage repair

    CERN Document Server

    Erggelet, Christoph; Mandelbaum, Bert R

    2008-01-01

    Cartilage defects affect patients of all age groups. Surgeons, teamdoctors, general practitioners and physiotherapists alike are expected to provide adequate care. Only individual treatment plans combining a well balanced choice of various options will be successful. Background knowledge, operative and non-operative therapies are described in concise chapters: Articular cartilage biology - Diagnostics - Surgical techniques - Symptomatic and alternative medications - Physiotherapy. Diagnostic findings and surgical procedures are generously illustrated by aquarelles and colour photographs. Recommendations for additional reading, description of important clinical scoring systems and a listing of analytic tools are added for further information.

  15. Osteoarthritic cartilage is more homogeneous than healthy cartilage

    DEFF Research Database (Denmark)

    Qazi, Arish A; Dam, Erik B; Nielsen, Mads

    2007-01-01

    RATIONALE AND OBJECTIVES: Cartilage loss as determined by magnetic resonance imaging (MRI) or joint space narrowing as determined by x-ray is the result of cartilage erosion. However, metabolic processes within the cartilage that later result in cartilage loss may be a more sensitive assessment...... method for early changes. Recently, it was shown that cartilage homogeneity visualized by MRI representing the biochemical changes undergoing in the cartilage is a potential marker for early detection of knee osteoarthritis (OA) and is also able to significantly separate groups of healthy subjects from...... it evolves as a consequence to disease and thereby can be used as a progression biomarker. MATERIALS AND METHODS: A total of 283 right and left knees from 159 subjects aged 21 to 81 years were scanned using a Turbo 3D T1 sequence on a 0.18-T MRI Esaote scanner. The medial compartment of the tibial cartilage...

  16. INJURED ARTICULAR CARTILAGE REPAIR

    Directory of Open Access Journals (Sweden)

    Ariana Barlič

    2008-02-01

    Surveys show that the most frequently used surgical methods are mosaicplasty and bonemarrow stimulation with microfracturing. The efficacy of the autologous chondrocyte implantationmethod should be superior to microfracturing on a long run. Especially when(regeneration of the hyaline cartilage instead of fibrous tissue (fibrocartilage is concerned.However, it has not been scientifically proved yet

  17. Gene Therapy for Cartilage Repair

    Science.gov (United States)

    Madry, Henning; Orth, Patrick; Cucchiarini, Magali

    2011-01-01

    The concept of using gene transfer strategies for cartilage repair originates from the idea of transferring genes encoding therapeutic factors into the repair tissue, resulting in a temporarily and spatially defined delivery of therapeutic molecules to sites of cartilage damage. This review focuses on the potential benefits of using gene therapy approaches for the repair of articular cartilage and meniscal fibrocartilage, including articular cartilage defects resulting from acute trauma, osteochondritis dissecans, osteonecrosis, and osteoarthritis. Possible applications for meniscal repair comprise meniscal lesions, meniscal sutures, and meniscal transplantation. Recent studies in both small and large animal models have demonstrated the applicability of gene-based approaches for cartilage repair. Chondrogenic pathways were stimulated in the repair tissue and in osteoarthritic cartilage using genes for polypeptide growth factors and transcription factors. Although encouraging data have been generated, a successful translation of gene therapy for cartilage repair will require an ongoing combined effort of orthopedic surgeons and of basic scientists. PMID:26069580

  18. Engineering Lubrication in Articular Cartilage

    Science.gov (United States)

    McNary, Sean M.; Athanasiou, Kyriacos A.

    2012-01-01

    Despite continuous progress toward tissue engineering of functional articular cartilage, significant challenges still remain. Advances in morphogens, stem cells, and scaffolds have resulted in enhancement of the bulk mechanical properties of engineered constructs, but little attention has been paid to the surface mechanical properties. In the near future, engineered tissues will be able to withstand and support the physiological compressive and tensile forces in weight-bearing synovial joints such as the knee. However, there is an increasing realization that these tissue-engineered cartilage constructs will fail without the optimal frictional and wear properties present in native articular cartilage. These characteristics are critical to smooth, pain-free joint articulation and a long-lasting, durable cartilage surface. To achieve optimal tribological properties, engineered cartilage therapies will need to incorporate approaches and methods for functional lubrication. Steady progress in cartilage lubrication in native tissues has pushed the pendulum and warranted a shift in the articular cartilage tissue-engineering paradigm. Engineered tissues should be designed and developed to possess both tribological and mechanical properties mirroring natural cartilage. In this article, an overview of the biology and engineering of articular cartilage structure and cartilage lubrication will be presented. Salient progress in lubrication treatments such as tribosupplementation, pharmacological, and cell-based therapies will be covered. Finally, frictional assays such as the pin-on-disk tribometer will be addressed. Knowledge related to the elements of cartilage lubrication has progressed and, thus, an opportune moment is provided to leverage these advances at a critical step in the development of mechanically and tribologically robust, biomimetic tissue-engineered cartilage. This article is intended to serve as the first stepping stone toward future studies in functional

  19. Advances in cartilage tissue engineering : in vitro

    NARCIS (Netherlands)

    E.W. Mandl (Erik)

    2004-01-01

    textabstractWithin the body three subtypes of cartilage can be distinguished: hyaline cartilage, elastic cartilage and fibrocartilage. Hyaline cartilage is the predominant subtype and is mainly located in articular joints and in less extent in the nasal septum and cricoid. Elastic cartilage can be

  20. Lubrication of Articular Cartilage.

    Science.gov (United States)

    Jahn, Sabrina; Seror, Jasmine; Klein, Jacob

    2016-07-11

    The major synovial joints such as hips and knees are uniquely efficient tribological systems, able to articulate over a wide range of shear rates with a friction coefficient between the sliding cartilage surfaces as low as 0.001 up to pressures of more than 100 atm. No human-made material can match this. The means by which such surfaces maintain their very low friction has been intensively studied for decades and has been attributed to fluid-film and boundary lubrication. Here, we focus especially on the latter: the reduction of friction by molecular layers at the sliding cartilage surfaces. In particular, we discuss such lubrication in the light of very recent advances in our understanding of boundary effects in aqueous media based on the paradigms of hydration lubrication and of the synergism between different molecular components of the synovial joints (namely hyaluronan, lubricin, and phospholipids) in enabling this lubrication.

  1. Mechanical confinement regulates cartilage matrix formation by chondrocytes

    Science.gov (United States)

    Lee, Hong-Pyo; Gu, Luo; Mooney, David J.; Levenston, Marc E.; Chaudhuri, Ovijit

    2017-12-01

    Cartilage tissue equivalents formed from hydrogels containing chondrocytes could provide a solution for replacing damaged cartilage. Previous approaches have often utilized elastic hydrogels. However, elastic stresses may restrict cartilage matrix formation and alter the chondrocyte phenotype. Here we investigated the use of viscoelastic hydrogels, in which stresses are relaxed over time and which exhibit creep, for three-dimensional (3D) culture of chondrocytes. We found that faster relaxation promoted a striking increase in the volume of interconnected cartilage matrix formed by chondrocytes. In slower relaxing gels, restriction of cell volume expansion by elastic stresses led to increased secretion of IL-1β, which in turn drove strong up-regulation of genes associated with cartilage degradation and cell death. As no cell-adhesion ligands are presented by the hydrogels, these results reveal cell sensing of cell volume confinement as an adhesion-independent mechanism of mechanotransduction in 3D culture, and highlight stress relaxation as a key design parameter for cartilage tissue engineering.

  2. Development of artificial articular cartilage

    Indian Academy of Sciences (India)

    The present study describes the development of artificial articular cartilage on the basis of mimicking structural gel properties and mechanical gel properties of natural articular cartilage. It is synthesized from PVA/Si nanocomposite containing 20% Tetra ethoxy silane (TEOS) by sol–gel method. Mechanical strength of ...

  3. Conditional knockdown of hyaluronidase 2 in articular cartilage stimulates osteoarthritic progression in a mice model.

    Science.gov (United States)

    Higuchi, Yoshitoshi; Nishida, Yoshihiro; Kozawa, Eiji; Zhuo, Lisheng; Arai, Eisuke; Hamada, Shunsuke; Morita, Daigo; Ikuta, Kunihiro; Kimata, Koji; Ushida, Takahiro; Ishiguro, Naoki

    2017-08-01

    The catabolism of hyaluronan in articular cartilage remains unclear. The aims of this study were to investigate the effects of hyaluronidase 2 (Hyal2) knockdown in articular cartilage on the development of osteoarthritis (OA) using genetic manipulated mice. Destabilization of the medial meniscus (DMM) model of Col2a promoter specific conditional Hyal2 knockout (Hyal -/- ) mice was established and examined. Age related and DMM induced alterations of articular cartilage of knee joint were evaluated with modified Mankin score and immunohistochemical staining of MMP-13, ADAMTS-5, KIAA11199, and biotinylated- hyaluronan binding protein staining in addition to histomorphometrical analyses. Effects of Hyal2 suppression were also analyzed using explant culture of an IL-1α induced articular cartilage degradation model. The amount and size of hyaluronan in articular cartilage were higher in Hyal2 -/- mice. Hyal2 -/- mice exhibited aggravated cartilage degradation in age-related and DMM induced mice. MMP-13 and ADAMTS-5 positive chondrocytes were significantly higher in Hyal2 -/- mice. Articular cartilage was more degraded in explant cultures obtained from Hyal2 -/- mice. Knockdown of Hyal2 in articular cartilage induced OA development and progression possibly mediated by an imbalance of HA metabolism. This suggests that Hyal2 knockdown exhibits mucopolysaccharidosis-like OA change in articular cartilage similar to Hyal1 knockdown.

  4. Avifauna: Turnover on Islands.

    Science.gov (United States)

    Mayr, E

    1965-12-17

    The percentage of endemic species of birds on islands increases with island area at a double logarithmic rate. This relation is apparently due to extinction, which is more rapid the smaller the island. The turnover resulting from extinction and replacement appears to be far more rapid than hitherto suspected.

  5. Managing teacher turnover

    African Journals Online (AJOL)

    Erna Kinsey

    tion and training costs as well as loss of productivity while the newly hired teacher comes up to speed (cf. Carrel et al., 1998:572; Special. Reports, 1999:1). Ingersoll (2002:4) postulates that staffing problems are created when employees leave the organisation and have to be replaced, especially since teacher turnover is ...

  6. Managing teacher turnover

    African Journals Online (AJOL)

    Erna Kinsey

    retention and thus attrition is a function of teachers' personal characte- ristics, educational preparation, initial commitment to teaching, quality of first teaching experience, social and professional integration into teaching and external influences. Khatri, Budhwar and Fern's study of employee turnover (1999) employs a model ...

  7. Predicting Turnover Intentions and Turnover Behavior: A Multivariate Analysis.

    Science.gov (United States)

    Parasuraman, Saroj

    1982-01-01

    Assessed the relative influence of personal, attitudinal, and behavioral variables on behavioral intentions and voluntary turnover among nonsupervisory plant workers. Results show that personal variables have little direct effect on turnover; rather, their influence on turnover is channeled through their effects on behavioral intentions. (Author)

  8. The Effect of Aging and Mechanical Loading on the Metabolism of Articular Cartilage

    DEFF Research Database (Denmark)

    Jørgensen, Adam El Mongy; Kjaer, Michael; Heinemeier, Katja Maria

    2017-01-01

    , with the literature search made on PubMed using appropriate keywords regarding AC, age, and mechanical loading. Results. Following skeletal maturation, chondrocyte numbers decline while increasing senescence occurs. Lower cartilage turnover causes diminished maintenance capacity, which produces accumulation......Objective. The morphology of articular cartilage (AC) enables painless movement. Aging and mechanical loading are believed to influence development of osteoarthritis (OA), yet the connection remains unclear. Methods. This narrative review describes the current knowledge regarding this area...... of fibrillar crosslinks by advanced glycation end products, resulting in increased stiffness and thereby destruction susceptibility. Conclusion. Mechanical loading changes proteoglycan content. Moderate mechanical loading causes hypertrophy and reduced mechanical loading causes atrophy. Overloading produces...

  9. The effect og aging and mechanical loading on the metabolism og articular cartilage

    DEFF Research Database (Denmark)

    Jørgensen, Adam El Mongy; Kjær, Michael; Heinemeier, Katja Maria

    2017-01-01

    , with the literature search made on PubMed using appropriate keywords regarding AC, age, and mechanical loading. Results. Following skeletal maturation, chondrocyte numbers decline while increasing senescence occurs. Lower cartilage turnover causes diminished maintenance capacity, which produces accumulation......Objective. The morphology of articular cartilage (AC) enables painless movement. Aging and mechanical loading are believed to influence development of osteoarthritis (OA), yet the connection remains unclear. Methods. This narrative review describes the current knowledge regarding this area...... of fibrillar crosslinks by advanced glycation end products, resulting in increased stiffness and thereby destruction susceptibility. Conclusion. Mechanical loading changes proteoglycan content. Moderate mechanical loading causes hypertrophy and reduced mechanical loading causes atrophy. Overloading produces...

  10. Seasonal groundwater turnover

    OpenAIRE

    Nordell, Bo; Engström, Maria

    2006-01-01

      Seasonal air temperature variations and corresponding changes in groundwater temperature cause convective movements in groundwater similar to the seasonal turnover in lakes. Numerical simulations were performed to investigate the natural conditions for thermally driven groundwater convection to take place. Thermally driven convection could be triggered by a horizontal groundwater flow, Convection then starts at a considerably lower Rayleigh number (Ra) than the general critical Rayleigh ...

  11. Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

    DEFF Research Database (Denmark)

    Leeming, Diana J; Byrjalsen, Inger; Qvist, Per

    2008-01-01

    BACKGROUND: Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover in ...... experiments revealed that osteoclasts released CTXI fragments but not CTXII from bone specimens. The same was observed for cathepsin K. CONCLUSION: Data suggest that an uncoupling between bone resorption and cartilage degradation occurs in breast and lung cancer patient....

  12. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and morphologic MRI of cartilage in the long-term follow-up after Legg–Calvé–Perthes disease (LCPD)

    International Nuclear Information System (INIS)

    Holstein, Arne; Zilkens, Christoph; Bittersohl, Bernd

    2011-01-01

    The purpose of the present study was to evaluate the feasibility of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) in the detection of cartilage changes versus morphologic imaging in the long-term course of Legg–Calvé–Perthes disease (LCPD). A total of 31 hips in 26 patients (mean age, 30.0 years; range, 18–54 years) who were diagnosed with LCPD in childhood were included. Twenty-one radiographically normal contralateral hips served as controls. dGEMRIC indices of femoral and acetabular cartilage in the weight-bearing zone. Cartilage morphology was classified on radial PD-weighted images according to the modified Outerbridge classification. Mean dGEMRIC values of cartilage were significantly lower in hips after LCPD than in the radiographically normal contralateral hips (513 ± 100 ms vs. 579 ± 103 ms; P = 0.026). In 24 out of 31 LCPD hips and in 4 out of 21 radiographically normal contralateral hips, morphological cartilage changes were noted. Analysis of variance analysis revealed a significant influence of Outerbridge grading on decreased T1-values (P = 0.031). Our results suggest that dGEMRIC at 1.5 T is suitable to assess cartilage quality changes in the long-term follow-up after LCPD. The evaluation of biochemical cartilage quality with dGEMRIC may provide additional information about early cartilage changes occurring without visible alterations of cartilage morphology.

  13. How Employee Turnover Affects Productivity

    DEFF Research Database (Denmark)

    Eriksen, Bo

    Research on employee turnover suggests that turnover results in negative organization-level outcomes. This paper provides a firm-level analysis of the impact of the in- and outflows of human resources on productivity and how the presence of organizational slack resources moderates the effects...... of employee turnover. Drawing on a unique longitudinal dataset of 2,926 Danish manufacturing firms that combine individual-level data with firm-level data, the paper shows that job turnover has a substantial negative effect on total productivity but that the firm’s size, its capital intensity, and its age...

  14. Transcriptomic profiling of cartilage ageing

    Directory of Open Access Journals (Sweden)

    Mandy Jayne Peffers

    2014-12-01

    Full Text Available The musculoskeletal system is severely affected by the ageing process, with many tissues undergoing changes that lead to loss of function and frailty. Articular cartilage is susceptible to age related diseases, such as osteoarthritis. Applying RNA-Seq to young and old equine cartilage, we identified an over-representation of genes with reduced expression relating to extracellular matrix, degradative proteases, matrix synthetic enzymes, cytokines and growth factors in cartilage from older donors. Here we describe the contents and quality controls in detail for the gene expression and related results published by Peffers and colleagues in Arthritis Research and Therapy 2013 associated with the data uploaded to ArrayExpress (E-MTAB-1386.

  15. Biomaterial and Cell Based Cartilage Repair

    NARCIS (Netherlands)

    Zhao, X

    2015-01-01

    Injuries to human native cartilage tissue are particularly troublesome because cartilage has little ability to heal or regenerate itself. The reconstruction, repair, and regeneration of cartilage tissue continue to be one of the greatest clinical challenges, especially in orthopaedic and plastic

  16. Microwave treatment of xenogeneic cartilage transplants

    NARCIS (Netherlands)

    Visser, C. E.; Boon, M. E.; Visser, P. E.; Kok, L. P.

    1989-01-01

    Human rib cartilage was irradiated with microwaves according to six different methods and transplanted into rabbits. Untreated rib cartilage preserved in Cialit served as a control. After 12 and 40 wk of implantation, the microscopic appearance of these xenogeneic cartilage transplants was given a

  17. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...... after 2 weeks in the diaphyseal fractures and after 6 weeks in the condylar fractures. The degradation of type I collagen increased after 4 days and reached a maximum at 2 weeks in both groups. The interindividual variation was wide. On a group basis, the turnover of types I and III collagen had...

  18. Different Patterns of Cartilage Mineralization Analyzed by Comparison of Human, Porcine, and Bovine Laryngeal Cartilages.

    Science.gov (United States)

    Claassen, Horst; Schicht, Martin; Fleiner, Bernd; Hillmann, Ralf; Hoogeboom, Sebastian; Tillmann, Bernhard; Paulsen, Friedrich

    2017-06-01

    Laryngeal cartilages undergo a slow ossification process during aging, making them an excellent model for studying cartilage mineralization and ossification processes. Pig laryngeal cartilages are similar to their human counterparts in shape and size, also undergo mineralization, facilitating the study of cartilage mineralization. We investigated the processes of cartilage mineralization and ossification and compared these with the known processes in growth plates. Thyroid cartilages from glutaraldehyde-perfused male minipigs and from domestic pigs were used for X-ray, light microscopic, and transmission electron microscopic analyses. We applied different fixation and postfixation solutions to preserve cell shape, proteoglycans, and membranes. In contrast to the ossifying human thyroid cartilage, predominantly cartilage mineralization was observed in minipig and domestic pig thyroid cartilages. The same subset of chondrocytes responsible for growth plate mineralization is also present in thyroid cartilage mineralization. Besides mineralization mediated by matrix vesicles, a second pattern of cartilage mineralization was observed in thyroid cartilage only. Here, the formation and growth of crystals were closely related to collagen fibrils, which served as guide rails for the expansion of mineralization. It is hypothesized that the second pattern of cartilage mineralization may be similar to a maturation of mineralized cartilage after initial matrix vesicles-mediated cartilage mineralization.

  19. Cartilage and bone malformations in the head of zebrafish (Danio rerio) embryos following exposure to disulfiram and acetic acid hydrazide

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Ruben, E-mail: Ruben.Strecker@cos.uni-heidelberg.de [Aquatic Ecology and Toxicology Section, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Weigt, Stefan, E-mail: stefan.weigt@merckgroup.com [Institute of Toxicology, Merck KGaA, 64293 Darmstadt (Germany); Braunbeck, Thomas, E-mail: braunbeck@uni-hd.de [Aquatic Ecology and Toxicology Section, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany)

    2013-04-15

    In order to investigate teratogenic effects, especially on cartilage and bone formation, zebrafish embryos were exposed for 144 h to the dithiocarbamate pesticide disulfiram (20–320 μg/L) and acetic acid hydrazide (0.375–12 g/L), a degradation product of isoniazid. After fixation and full-mount staining, disulfiram could be shown to induce strong cartilage malformations after exposure to ≥ 80 μg/L, whereas acetic acid hydrazide caused cartilage alterations only from 1.5 g/L. Undulating notochords occurred after exposure to disulfiram even at the lowest test concentration of 20 μg/L, whereas at the two lowest concentrations of acetic acid hydrazide (0.375 and 0.75 g/L) mainly fractures of the notochord were observed. Concentrations of acetic acid hydrazide ≥ 1.5 g/L resulted in undulated notochords similar to disulfiram. Cartilages and ossifications of the cranium, including the cleithrum, were individually analyzed assessing the severity of malformation and the degree of ossification in a semi-quantitative approach. Cartilages of the neurocranium such as the ethmoid plate proved to be more stable than cartilages of the pharyngeal skeleton such as Meckel's cartilage. Hence, ossification proved significantly more susceptible than cartilage. The alterations induced in the notochord as well as in the cranium might well be of ecological relevance, since notochord malformation is likely to result in impaired swimming and cranial malformation might compromise regular food uptake. - Highlights: ► Disulfiram and acetic acid hydrazide as notochord, cartilage and bone teratogens ► Zebrafish embryos to model effects on single cartilages and bones in the head ► LC50 calculation and head length measurements after six days post-fertilization ► Lethality, head length and teratogenic effects are dose-dependent. ► Cartilages of the neurocranium are the most stable elements in the head.

  20. T2* mapping for articular cartilage assessment: principles, current applications, and future prospects.

    Science.gov (United States)

    Hesper, Tobias; Hosalkar, Harish S; Bittersohl, Daniela; Welsch, Götz H; Krauspe, Rüdiger; Zilkens, Christoph; Bittersohl, Bernd

    2014-10-01

    With advances in joint preservation surgery that are intended to alter the course of osteoarthritis by early intervention, accurate and reliable assessment of the cartilage status is critical. Biochemically sensitive MRI techniques can add robust biomarkers for disease onset and progression, and therefore, could be meaningful assessment tools for the diagnosis and follow-up of cartilage abnormalities. T2* mapping could be a good alternative because it would combine the benefits of biochemical cartilage evaluation with remarkable features including short imaging time and the ability of high-resolution three-dimensional cartilage evaluation-without the need for contrast media administration or special hardware. Several in vitro and in vivo studies, which have elaborated on the potential of cartilage T2* assessment in various cartilage disease patterns and grades of degeneration, have been reported. However, much remains to be understood and certain unresolved questions have become apparent with these studies that are crucial to the further application of this technique. This review summarizes the principles of the technique and current applications of T2* mapping for articular cartilage assessment. Limitations of recent studies are discussed and the potential implications for patient care are presented.

  1. Chondroma of the cricoid cartilage

    Directory of Open Access Journals (Sweden)

    Melo, Giulianno Molina de

    2008-12-01

    Full Text Available Introduction: The larynx cartilaginous tumors are uncommon and comprise 1% of all cartilaginous tumors. The chondroma is the most common benign tumor affecting the larynx cricoid cartilage (75%, and manifests normally in the male gender with dysphonia, progressive dyspnea and dysphagy in some cases. Objective: The objective of this study is to report a case of cricoid cartilage chondroma, in a patient with the symptom of a nodular lesion in the frontal cervical region of slow and progressive growth. Case Report: The treatment was the modified partial laryngectomy with resection of the lower hemisegment of the thyroid cartilage, cricoid hemicartilage and the first tracheal ring with free margins and reconstruction with a pericondrium and muscular prethyroidean piece. The anatomopathological exam showed a chondroma of 1.1 cm, of atypical low cellularity and low figures of mitosis in the frontal region of the cricoid cartilage. Conclusion: In this report we agreed with the literature for the primarily extensive surgical treatment depending on the location and the size of the cricoid chondroma; however, other modalities of treatment may be adopted in cases where the tumor extension appoints a total laryngectomy or when this is not possible to carry out, aiming at the preservation of the larynx. For the suitable treatment of cricoid chondromas, the understanding of the disease natural evolution and more case reports are still necessary.

  2. Postnatal development of articular cartilage

    NARCIS (Netherlands)

    Turnhout, van M.C.

    2010-01-01

    Articular cartilage (AC) is the thin layer of tissue that covers the ends of the bones in the synovial joints in mammals. Functional adult AC has depth-dependent mechanical properties that are not yet present at birth. These depth-dependent mechanical properties in adult life are the result of a

  3. Development of artificial articular cartilage

    Indian Academy of Sciences (India)

    Mechanical strength of Poly(vinyl alcohol), PVA is improved up to 35 MPa. Manufacturing method is adopted considering colloidal stability of nano silica particle in PVA sol at specific pH = 1. An adhesive is also prepared from PVA/Si nanocomposite containing 40% TEOS for firm attachment of artificial articular cartilage on ...

  4. Ultrasonographic assessment of the quadriceps muscle and femoral cartilage in transtibial amputees using different prostheses.

    Science.gov (United States)

    Şahin Onat, Şule; Malas, Fevziye Ünsal; Öztürk, Gökhan Tuna; Akkaya, Nuray; Kara, Murat; Özçakar, Levent

    2016-08-01

    In patients with lower limb amputations, gait alteration, increased loading on the intact extremity, and use of prosthesis may lead to joint degeneration. To explore the effects of prosthesis type on quadriceps muscle and distal femoral cartilage thicknesses in transtibial amputees. A cross-sectional study. A total of 38 below-knee amputees were enrolled in the study, of which 13 patients were using vacuum system type prosthesis and 25 patients were using silicon liner pin system prosthesis. Patients' femoral cartilage and quadriceps muscle thickness measurements were performed using musculoskeletal ultrasound. When compared with the intact sides, cartilage and rectus femoris, vastus intermedius, and vastus medialis muscle thickness values were significantly decreased on the amputee sides (all p vacuum system type prosthesis to prevent possible knee osteoarthritis due to cartilage thinning in adult transtibial amputees. © The International Society for Prosthetics and Orthotics 2015.

  5. Cartilage-selective genes identified in genome-scale analysis of non-cartilage and cartilage gene expression

    Directory of Open Access Journals (Sweden)

    Cohn Zachary A

    2007-06-01

    Full Text Available Abstract Background Cartilage plays a fundamental role in the development of the human skeleton. Early in embryogenesis, mesenchymal cells condense and differentiate into chondrocytes to shape the early skeleton. Subsequently, the cartilage anlagen differentiate to form the growth plates, which are responsible for linear bone growth, and the articular chondrocytes, which facilitate joint function. However, despite the multiplicity of roles of cartilage during human fetal life, surprisingly little is known about its transcriptome. To address this, a whole genome microarray expression profile was generated using RNA isolated from 18–22 week human distal femur fetal cartilage and compared with a database of control normal human tissues aggregated at UCLA, termed Celsius. Results 161 cartilage-selective genes were identified, defined as genes significantly expressed in cartilage with low expression and little variation across a panel of 34 non-cartilage tissues. Among these 161 genes were cartilage-specific genes such as cartilage collagen genes and 25 genes which have been associated with skeletal phenotypes in humans and/or mice. Many of the other cartilage-selective genes do not have established roles in cartilage or are novel, unannotated genes. Quantitative RT-PCR confirmed the unique pattern of gene expression observed by microarray analysis. Conclusion Defining the gene expression pattern for cartilage has identified new genes that may contribute to human skeletogenesis as well as provided further candidate genes for skeletal dysplasias. The data suggest that fetal cartilage is a complex and transcriptionally active tissue and demonstrate that the set of genes selectively expressed in the tissue has been greatly underestimated.

  6. Collagen XI mutation lowers susceptibility to load-induced cartilage damage in mice.

    Science.gov (United States)

    Holyoak, Derek T; Otero, Miguel; Armar, Naa Shidaa; Ziemian, Sophia N; Otto, Ariana; Cullinane, Devinne; Wright, Timothy M; Goldring, Steven R; Goldring, Mary B; van der Meulen, Marjolein C H

    2018-02-01

    Interactions among risk factors for osteoarthritis (OA) are not well understood. We investigated the combined impact of two prevalent risk factors: mechanical loading and genetically abnormal cartilage tissue properties. We used cyclic tibial compression to simulate mechanical loading in the cho/+ (Col11a1 haploinsufficient) mouse, which has abnormal collagen fibrils in cartilage due to a point mutation in the Col11a1 gene. We hypothesized that the mutant collagen would not alter phenotypic bone properties and that cho/+ mice, which develop early onset OA, would develop enhanced load-induced cartilage damage compared to their littermates. To test our hypotheses, we applied cyclic compression to the left tibiae of 6-month-old cho/+ male mice and wild-type (WT) littermates for 1, 2, and 6 weeks at moderate (4.5 N) and high (9.0 N) peak load magnitudes. We then characterized load-induced cartilage and bone changes by histology, microcomputed tomography, and immunohistochemistry. Prior to loading, cho/+ mice had less dense, thinner cortical bone compared to WT littermates. In addition, in loaded and non-loaded limbs, cho/+ mice had thicker cartilage. With high loads, cho/+ mice experienced less load-induced cartilage damage at all time points and displayed decreased matrix metalloproteinase (MMP)-13 levels compared to WT littermates. The thinner, less dense cortical bone and thicker cartilage were unexpected and may have contributed to the reduced severity of load-induced cartilage damage in cho/+ mice. Furthermore, the spontaneous proteoglycan loss resulting from the mutant collagen XI was not additive to cartilage damage from mechanical loading, suggesting that these risk factors act through independent pathways. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:711-720, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  7. Association of Lateral Crural Overlay Technique With Strength of the Lower Lateral Cartilages.

    Science.gov (United States)

    Insalaco, Louis; Rashes, Emma R; Rubin, Samuel J; Spiegel, Jeffrey H

    2017-12-01

    The lateral crural overlay technique is a powerful technique for altering nasal tip projection and rotation. By overlapping and thus shortening the lateral crura, the nasal tip is shortened and rotated upward, thus decreasing projection and increasing rotation. There is no data to show the association of this technique with the strength of the lower lateral cartilage. Strengthening of the lower lateral cartilages would presumably lead to resistance to external nasal valve collapse and improved airway. In this cadaver study, we set out to determine the differences in the strength and resilience of the lateral crura after performing lateral crural overlay using 2 different techniques. Seven individual lower lateral cartilages were harvested from 6 cadavers for analysis. Each of the 7 cartilages was included sequentially in 3 test groups in the following order: a preprocedure group (preP), a postprocedure group (postP) in which the lateral crural overlay technique was performed, and a postprocedure with glue group (postPG) in which cyanoacrylate glue was added to the postP cartilages to simulate cartilage healing. A force gauge was used to measure the force required to deflect the lower lateral cartilages distances from 1 to 6 mm. Differences measured in newtons (N) for strength and resilience of lateral crura between the preP, postP, and postPG groups. A statistically significant increase in lower lateral cartilage resilience was noted between the preP and postPG groups at all distances of tip deflection (1 mm, 0.20 vs 0.70 N; P overlay technique affords increased strength and resilience to the lateral crura of the lower lateral cartilages, which should in turn decrease the likelihood of external nasal valve collapse postoperatively. NA.

  8. Physical properties of rabbit articular cartilage after transection of the anterior cruciate ligament.

    Science.gov (United States)

    Sah, R L; Yang, A S; Chen, A C; Hant, J J; Halili, R B; Yoshioka, M; Amiel, D; Coutts, R D

    1997-03-01

    The effect of unilateral transection of the anterior cruciate ligament on the confined compression and swelling properties of the distal femoral articular cartilage of skeletally mature rabbits at 9 weeks after surgery was determined. Gross morphological grading of the transected and contralateral control distal femora stained with India ink confirmed that cartilage degeneration had been induced by ligament transection. Osteochondral cores, 1.8 mm in diameter, were harvested from the medial femoral condyles. The modulus, permeability, and electrokinetic (streaming potential) coefficient of the articular cartilage of the osteochondral cores were assessed by confined compression creep experiments. The properties (mean +/- SD) of control cartilage were: confined compression modulus, 0.75 +/- 0.28 MPa; hydraulic permeability, 0.63 +/- 0.28 x 10(-15) m2/Pa*sec; and electrokinetic coefficient, 0.16 +/- 0.31 x 10(-9) V/Pa. In transected knees, the modulus was reduced by 18% (p = 0.04), while the permeability and electrokinetic coefficient were not detectably altered. The change in modulus was accompanied by a trend (p = 0.07) toward a decrease (-11%) in the glycosaminoglycan density within the tissue, a significant increase (p < 0.001) in the water content of the cartilage after equilibration in 1 x phosphate buffered saline from 70.3 +/- 4.1% in control knees to 75.2 +/- 4.0% in transected knees, and little further swelling after tissue equilibration in hypotonic saline. The compressive modulus of the cartilage from both control and transected knees was positively correlated with the density of tissue glycosaminoglycan. The alterations in the physical properties of the articular cartilage after transection of the anterior cruciate ligament in the rabbit show trends similar to those observed in human and other animal models of osteoarthritis and provide further support for the use of this model in the study of cartilage degeneration.

  9. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture....... The markers were the carboxy-terminal extension peptide of type I procollagen (PICP), the amino-terminal extension peptide of type III procollagen (PIIINP), and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP). The latter is a new serum marker of degradation of type I...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...

  10. In Vivo Tibial Cartilage Strains in Regions of Cartilage-to-Cartilage Contact and Cartilage-to-Meniscus Contact in Response to Walking.

    Science.gov (United States)

    Liu, Betty; Lad, Nimit K; Collins, Amber T; Ganapathy, Pramodh K; Utturkar, Gangadhar M; McNulty, Amy L; Spritzer, Charles E; Moorman, Claude T; Sutter, E Grant; Garrett, William E; DeFrate, Louis E

    2017-10-01

    There are currently limited human in vivo data characterizing the role of the meniscus in load distribution within the tibiofemoral joint. Purpose/Hypothesis: The purpose was to compare the strains experienced in regions of articular cartilage covered by the meniscus to regions of cartilage not covered by the meniscus. It was hypothesized that in response to walking, tibial cartilage covered by the meniscus would experience lower strains than uncovered tibial cartilage. Descriptive laboratory study. Magnetic resonance imaging (MRI) of the knees of 8 healthy volunteers was performed before and after walking on a treadmill. Using MRI-generated 3-dimensional models of the tibia, cartilage, and menisci, cartilage thickness was measured in 4 different regions based on meniscal coverage and compartment: covered medial, uncovered medial, covered lateral, and uncovered lateral. Strain was defined as the normalized change in cartilage thickness before and after activity. Within each compartment, covered cartilage before activity was significantly thinner than uncovered cartilage before activity ( P meniscus experiences lower strains than uncovered cartilage in the medial compartment. These findings provide important baseline information on the relationship between in vivo tibial compressive strain responses and meniscal coverage, which is critical to understanding normal meniscal function.

  11. Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

    Directory of Open Access Journals (Sweden)

    Fregerslev Michael

    2008-06-01

    Full Text Available Abstract Background Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover in breast and prostate cancer patients is associated with an increase in cartilage degradation and to test in vitro whether osteoclasts or cathepsin K alone generate CTXII from human bone. Methods The study included 132 breast and prostate cancer patient, where presence of bone metastases was graded according to the Soloway score. Total bone resorption (CTXItotal and cartilage degradation (CTXII were determined. Results Breast and prostate cancer patients with bone metastases revealed significant increased levels of CTXItotal at Soloway scores 1 and higher compared to patients without bone metastases (p total significantly decreased at score 3 and 4 (p total, CTXII and CTXII/CTXItotal changed +900%, +130%, and -90%, respectively at Soloway score 4 compared to score 0. The in vitro experiments revealed that osteoclasts released CTXI fragments but not CTXII from bone specimens. The same was observed for cathepsin K. Conclusion Data suggest that an uncoupling between bone resorption and cartilage degradation occurs in breast and lung cancer patient.

  12. Fractures of the distal phalanx and associated soft tissue and osseous abnormalities in 22 horses with ossified sclerotic ungual cartilages diagnosed with magnetic resonance imaging.

    Science.gov (United States)

    Selberg, Kurt; Werpy, Natasha

    2011-01-01

    Ungual cartilage ossification in the forelimb is a common finding in horses. Subtle abnormalities associated with the ungual cartilages can be difficult to identify on radiographs. Magnetic resonance (MR) imaging findings of 22 horses (23 forelimbs) with a fracture of the distal phalanx and ossified ungual cartilage were characterized and graded. All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. The ligamentous structures associated with the ungual cartilages were often affected, showed altered signal intensity as well as enlargement and were thought to be contributing to the lameness. In conclusion, ossified ungual cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungual cartilage ligaments. © 2011 Veterinary Radiology & Ultrasound.

  13. Texture analysis of articular cartilage traumatic changes in the knee calculated from morphological 3.0 T MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boutsikou, Konstantina [Department of Medical Radiologic Technology, Technological Educational Institute of Athens, Ag.Spyridonos, Egaleo, Athens 12210 (Greece); Kostopoulos, Spiros; Glotsos, Dimitris; Cavouras, Dionisis [Department of Medical Instruments Technology, Technological Educational Institute of Athens, Ag.Spyridonos, Egaleo, Athens 12210 (Greece); Lavdas, Eleftherios; Oikonomou, Georgia [Department of Medical Radiologic Technology, Technological Educational Institute of Athens, Ag.Spyridonos, Egaleo, Athens 12210 (Greece); Malizos, Konstantinos [Department of Orthopaedic Surgery, University of Thessaly, School of Health Sciences, University Hospital of Larissa, Biopolis, Larissa 41110 (Greece); Fezoulidis, Ioannis V. [Department of Radiology, University of Thessaly, School of Health Sciences, University Hospital of Larissa, Biopolis, Larissa 41110 (Greece); Vlychou, Marianna, E-mail: mvlychou@med.uth.gr [Department of Radiology, University of Thessaly, School of Health Sciences, University Hospital of Larissa, Biopolis, Larissa 41110 (Greece)

    2013-08-15

    Objectives: In the present work, we aim to identify changes in the cartilage texture of the injured knee in young, physically active, patients by computer analysis of MRI images based on 3.0 T morphological sequences. Methods: Fifty-three young patients with training injury or trauma in one knee underwent MRI and arthroscopy. Textural features were computed from the MRI images of the knee-cartilages and two classes were formed of 28 normal and 16 with pathology only in the medial femoral condyle (MFC) cartilage. Results: Textural features with statistically significant differences between the two classes were found only at the MFC and the medial tibial condyle (MTC) areas. Three features-combinations, at the MFC or the MTC, maximized the between classes separation, thus, rendering alterations in cartilage texture due to injury more evident. The MFC cartilage in the pathology class was found more inhomogeneous in the distribution of gray-levels and of lower texture anisotropy and the opposed MTC cartilage, though normal on MRI and arthroscopy, was found to have lower texture anisotropy than cartilage in the normal class. Conclusion: Texture analysis may be used as an adjunct to morphological MR imaging for improving the detection of subtle cartilage changes and contributes to early therapeutic approach.

  14. KECENDERUNGAN KEPUASAN KERJA SEBAGAI TRIGGER TURNOVER

    OpenAIRE

    Raditya Adi Saputra

    2017-01-01

    The purpose of this study are: (1) To determine the effect of job satisfaction on turnover intention; (2) To determine the effect of work stress on turnover intention; (3) To determine the effect of compensation on turnover intention; (4) To determine the effect of organizational climate on turnover intention; and (5) To determine the stress of work, compensation, organizational climate and job satisfaction effect on turnover intention. The population in this study are employees of the Coo...

  15. Predicting knee cartilage loss using adaptive partitioning of cartilage thickness maps

    DEFF Research Database (Denmark)

    Jørgensen, Dan Richter; Dam, Erik Bjørnager; Lillholm, Martin

    2013-01-01

    This study investigates whether measures of knee cartilage thickness can predict future loss of knee cartilage. A slow and a rapid progressor group was determined using longitudinal data, and anatomically aligned cartilage thickness maps were extracted from MRI at baseline. A novel machine learning...

  16. Advances in treatment of articular cartilage injuries

    Directory of Open Access Journals (Sweden)

    Yuan-cheng LI

    2013-05-01

    Full Text Available Cartilage is a kind of terminally differentiated tissue devoid of vessel or nerve, and it is difficult to repair by itself after damage. Many studies for the treatment of cartilage injuries were performed in recent years aiming at repair of the structure and restoration of its function for injured joint. This article reviews the traditional methods of treatment for cartilage injuries, such as joint lavage with the aid of arthroscope, abrasion chondroplasty, laser abrasion and chondroplasty, and drilling of the subchondral bone-marrow space. The research advances in treatment of articular cartilage injuries with tissue engineering were summarized.

  17. Quantitative Ultrasound Assessment of Cartilage Degeneration in Ovariectomized Rats with Low Estrogen Levels.

    Science.gov (United States)

    Wang, Qing; Liu, Zhiwei; Wang, Yinong; Pan, Qingya; Feng, Qianjin; Huang, Qinghua; Chen, Wufan

    2016-01-01

    The aim of this study was to assess quantitatively the site-specific degeneration of articular cartilage in ovariectomized rats with low estrogen levels using a high-frequency ultrasound system. Fourteen female Sprague-Dawley rats were randomly divided into two groups (n = 7 per group): a sham group in which only the peri-ovarian fatty tissue was exteriorized and an ovariectomized group that underwent bilateral ovariectomy to create a menopause model with low estrogen levels. All animals were sacrificed at the end of the third week after ovariectomy. Hindlimbs were harvested. The articular cartilage from five anatomic sites (i.e., femoral caput [FC], medial femoral condyle [MFC], lateral femoral condyle [LFC], medial tibial plateau [MTP] and lateral tibial plateau [LTP]) was examined with ultrasound. Four parameters were extracted from the ultrasound radiofrequency data: reflection coefficient of the cartilage surface (RC1), reflection coefficient of the cartilage-bone interface (RC2), ultrasound roughness index (URI) and thickness of the cartilage tissue. The results indicated significant (p reduction induces morphologic and acoustic alterations in the articular cartilage of the hip and knee joints in ovariectomized rats. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  18. In situ friction measurement on murine cartilage by atomic force microscopy.

    Science.gov (United States)

    Coles, Jeffrey M; Blum, Jason J; Jay, Gregory D; Darling, Eric M; Guilak, Farshid; Zauscher, Stefan

    2008-01-01

    Articular cartilage provides a low-friction, wear-resistant surface for the motion of diarthrodial joints. The objective of this study was to develop a method for in situ friction measurement of murine cartilage using a colloidal probe attached to the cantilever of an atomic force microscope. Sliding friction was measured between a chemically functionalized microsphere and the cartilage of the murine femoral head. Friction was measured at normal loads ranging incrementally from 20 to 100 nN with a sliding speed of 40 microm/s and sliding distance of 64 microm. Under these test conditions, hydrostatic pressurization and biphasic load support in the cartilage were minimized, providing frictional measurements that predominantly reflect boundary lubrication properties. Friction coefficients measured on murine tissue (0.25+/-0.11) were similar to those measured on porcine tissue (0.23+/-0.09) and were in general agreement with measurements of boundary friction on cartilage by other researchers. Using the colloidal probe as an indenter, the elastic mechanical properties and surface roughness were measured in the same configuration. Interfacial shear was found to be the principal mechanism of friction generation, with little to no friction resulting from plowing forces, collision forces, or energy losses due to normal deformation. This measurement technique can be applied to future studies of cartilage friction and mechanical properties on genetically altered mice or other small animals.

  19. Histone turnover within nonproliferating cells

    International Nuclear Information System (INIS)

    Commerford, S.L.; Carsten, A.L.; Cronkite, E.P.

    1982-01-01

    The turnover of DNA and histones in the livers and brains of mice has been determined. These mice had been exposed to constant levels of tritiated water from conception until they were 8 months old. At this point, exposure to tritium was discontinued, and the tritium remaining in DNA and histones was measured at various intervals afterward. The half-lives calculated for these components (with 95% confidence limits given in parentheses) were 117 (85 to 188) days for liver histone, 318 (241 to 466) days for liver DNA, 159 (129 to 208) days for brain histone and 593 (376 to 1406) days for brain DNA. The difference between histone and DNA turnover is statistically significant for both tissues and indicates that histone turnover within tissues cannot be solely accounted for by cell turnover within the tissue but also must include histone turnover within living cells. The half-life of histone within cells is estimated to be 117 (88 to 178) days in liver and 223 (187 to 277) days in brain

  20. Modeling the transport of cryoprotective agents in articular cartilage for cryopreservation

    Science.gov (United States)

    Torqabeh, Alireza Abazari

    Loading vitrifiable concentrations of cryoprotective agents is an important step for cryopreservation of biological tissues by vitrification for research and transplantation purposes. This may be done by immersing the tissue in a cryoprotective agent (CPA) solution, and increasing the concentration, continuously or in multiple steps, and simultaneously decreasing the temperature to decrease the toxicity effects of the cryoprotective agent on the tissue cellular system. During cryoprotective agent loading, osmotic water movement from the tissue to the surrounding solution, and the resultant tissue shrinkage and stress-strain in the tissue matrix as well as on the cellular system can significantly alter the outcome of the cryopreservation protocol. In this thesis, a biomechanical model for articular cartilage is developed to account for the transport of the cryoprotective agent, the nonideal-nondilute properties of the vitrifiable solutions, the osmotic water movement and the resultant tissue shrinkage and stress-strain in the tissue matrix, and the osmotic volume change of the chondrocytes, during cryoprotective agent loading in the cartilage matrix. Four essential transport parameters needed for the model were specified, the values of which were obtained uniquely by fitting the model to experimental data from porcine articular cartilage. Then, it was shown that using real nonuniform initial distributions of water and fixed charges in cartilage, measured separately in this thesis using MRI, in the model can significantly affect the model predictions. The model predictions for dimethyl sulfoxide diffusion in porcine articular cartilage were verified by comparing to spatially and temporally resolved measurements of dimethyl sulfoxide concentration in porcine articular cartilage using a spectral MRI technique, developed for this purpose and novel to the field of cryobiology. It was demonstrated in this thesis that the developed mathematical model provides a novel tool

  1. Correlation of laminated MR apperance of articular cartilage with histology

    International Nuclear Information System (INIS)

    Kim, Dong Joon; Suh, Jin Suck; Jeong, Eun Kee; Shin, Kyu Ho; Yang, Woo Ick

    1999-01-01

    To determine the correlation of laminae of different signal intensities (SI) of articular cartilage, as seen on magnetic resonance(MR) imaging with histologic layers, using artificially constructed landmarks. For a landmark that can exactly correlate the cartilage specimen with the MR image, five 'V'-shaped markings of different depths were made on the surface of bovine patella. Both T1-weighted (TR/TE : 300/14) and FSE T2-weighted images (TR/TE : 2000/53) were obtained on a 1.5T system with high gradient echo strength (25mT/m) and a voxel size of 78X78X2000μm. Images were obtained with 1) changed frequency-encoding directions on T1-weighted study, and 2) changed readout gradient strength ( X2, X1/2) on T2-weighted sequence. Raw image data were transferred to a workstation and signal intensity profile was generated for each image. 1 : 1 correlation of histologic specimens and MR images was performed. Line profile through the cartilage showed few peaks, suggesting changes in signal intensity profile in the cartilage. On the basis of artificial landmarks, the histologic zone was accurately identified. The histologic tangential and transitional zones correlated with superficial high SI on T1WI, as well as high and low SI on T2WI. On T1WI, the radial zone correlated with a lamina of intermediate SI, and on T2WI, with a lamina for which SI gradually decreased from high to low. Additional well-defined low and intermediate SI bands were noted on bovine T1WI in the lower radial zone. In both T1 and T2 studies, calcified cartilage layers were of low SI. On T1-weighted study, changes in the direction of frequency gradient did not lead to changes in the laminae. The alteration of readout gradient strengths did not result in an inversely proportional difference in the thickness of the laminae. These became more distinct thus ruling out chemical shift and susceptibility artifacts. The laminated appearance of articular cartilage, as seen on spin echo and fast spin-echo MR

  2. Dynamics of Adipocyte Turnover in Humans

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, K; Arner, E; Westermark, P; Bernard, S; Buchholz, B; Bergmann, O; Blomqvist, L; Hoffstedt, J; Naslund, E; Britton, T; Concha, H; Hassan, M; Ryden, M; Frisen, J; Arner, P

    2007-07-16

    Obesity is increasing in an epidemic fashion in most countries and constitutes a public health problem by enhancing the risk for cardiovascular disease and metabolic disorders such as type 2 diabetes. Owing to the increase in obesity, life expectancy may start to decrease in developed countries for the first time in recent history. The factors determining fat mass in adult humans are not fully understood, but increased lipid storage in already developed fat cells is thought to be most important. We show that adipocyte number is a major determinant for the fat mass in adults. However, the number of fat cells stays constant in adulthood in lean and obese and even under extreme conditions, indicating that the number of adipocytes is set during childhood and adolescence. To establish the dynamics within the stable population of adipocytes in adults, we have measured adipocyte turnover by analyzing the integration of {sup 14}C derived from nuclear bomb tests in genomic DNA. Approximately 10% of fat cells are renewed annually at all adult ages and levels of body mass index. Neither adipocyte death nor generation rate is altered in obesity, suggesting a tight regulation of fat cell number that is independent of metabolic profile in adulthood. The high turnover of adipocytes establishes a new therapeutic target for pharmacological intervention in obesity.

  3. Animal experimental research on microstructural behavior on the hyaline arthroidal cartilage after immobilization and remobilization

    Science.gov (United States)

    Refior, H. J.

    1980-01-01

    The degeneration of the articular cartilage after a period of immobilization was investigated. The experiment was carried out by the immobilization of the knee joints of rabbits. Even after remobilization there was an increase in the alterations. These changes did not prove to be reversible.

  4. Human rheumatoid arthritis tissue production of IL-17A drives matrix and cartilage degradation: synergy with tumour necrosis factor-alpha, Oncostatin M and response to biologic therapies.

    LENUS (Irish Health Repository)

    Moran, Ellen M

    2009-01-01

    INTRODUCTION: The aim of this study was to examine IL-17A in patients, following anti-TNF-alpha therapy and the effect of IL-17A on matrix turnover and cartilage degradation. METHODS: IL-17A expression was examined by ELISA and immunohistology in the rheumatoid arthritis (RA) joints. RA whole synovial tissue explant (RA ST), primary synovial fibroblasts (RASFC), human cartilage and chondrocyte cultures were stimulated with IL-17A +\\/- TNF-alpha and Oncostatin M (OSM). Matrix metalloproteinase (MMP) and tissue inhibitor (TIMP-1) were assessed by ELISA and zymography. Cartilage proteoglycan release was assessed histologically by Safranin-O staining. Clinical parameters, IL-17A, MMP\\/TIMP were assessed in patients pre\\/post biologic therapy. RESULTS: IL-17A levels were higher in RA vs osteoarthritis (OA)\\/normal joints (P < 0.05). IL-17A up-regulated MMP-1, -2, -9, and -13 in RA ST, RASFC, cartilage and chondrocyte cultures (P < 0.05). In combination with TNF-alpha and OSM, IL-17A shifted the MMP:TIMP-1 ratio in favor of matrix degradation (all P < 0.05). Cartilage proteoglycan depletion in response to IL-17A was mild; however, in combination with TNF-alpha or OSM showed almost complete proteoglycan depletion. Serum IL-17A was detected in 28% of patients commencing biologic therapy. IL-17A negative patients demonstrated reductions post therapy in serum MMP1\\/TIMP4, MMP3\\/TIMP1 and MMP3\\/TIMP4 ratios and an increase in CS846 (all P < 0.05). No significant changes were observed in IL-17A positive patients. CONCLUSIONS: IL-17A is produced locally in the inflamed RA joint. IL-17A promotes matrix turnover and cartilage destruction, especially in the presence of other cytokines, mimicking the joint environment. IL-17A levels are modulated in vivo, following anti-TNF therapy, and may reflect changes in matrix turnover.

  5. Biochemical markers of bone turnover

    International Nuclear Information System (INIS)

    Kim, Deog Yoon

    1999-01-01

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays

  6. Biochemical markers of bone turnover

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Deog Yoon [College of Medicine, Kyunghee Univ., Seoul (Korea, Republic of)

    1999-08-01

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays.

  7. Cysts of the semilunar cartilage

    International Nuclear Information System (INIS)

    Bruessermann, M.

    1981-01-01

    On the basis of the studies listed in the bibliography, this dissertation reports on the pathology, clinical symptoms and radiology of cysts of the semilunar cartilage. The author analyses 118 cases of his own, with special regard to the results of pneumo-arthrographic investigations carried through according to a special technique by Schaefer. In the course of this work, measurements of the meniscal base are for the first time used as radiological criteria indicating the presence of a cyst of the semilunar cartilage. Furthermore the well-known radiological signs of cysts, such as bone defects according to Albert and Keller, light central spot in the meniscal body, as well as Rauber's sign and horizontal rupture, are investigated as to the frequency of their incidence. For that purpose all the X-ray pictures were subjected to a further dose scrutiny. A list of all the 118 cases with their clinical and radiological data is found in the annex, together with the results of the operations and patho-anatomical investigations. (orig.) [de

  8. Assessing the effect of football play on knee articular cartilage using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC).

    Science.gov (United States)

    Wei, Wenbo; Lambach, Becky; Jia, Guang; Flanigan, David; Chaudhari, Ajit M W; Wei, Lai; Rogers, Alan; Payne, Jason; Siston, Robert A; Knopp, Michael V

    2017-06-01

    The prevalence of cartilage lesions is much higher in football athletes than in the general population. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) has been shown to quantify regional variations of glycosaminoglycan (GAG) concentrations which is an indicator of early cartilage degeneration. The goal of this study is to determine whether dGEMRIC can be used to assess the influence in cartilage GAG concentration due to college level football play. Thirteen collegiate football players with one to four years of collegiate football play experience were recruited and both knee joints were scanned using a dedicated 8-channel phased array knee coil on a 3T MRI system. The contrast concentrations within cartilage were calculated based on the T 1 values from dGEMRIC scans. No substantial differences were found in the contrast concentrations between the pre- and post-season across all the cartilage compartments. One year collegiate football players presented an average contrast concentration at the pre-season of 0.116±0.011mM and post-season of 0.116±0.011mM. In players with multiple years of football play, contrast uptake was elevated to 0.141±0.012mM at the pre-season and 0.139±0.012mM at the post-season. The pre-season 0.023±0.016mM and post-season 0.025±0.016mM increase in contrast concentration within the group with multiple years of experience presented with a >20% increase in contrast uptake. This may indicate the gradual, cumulative damage of football play to the articular cartilage over years, even though the effect may not be noticeable after a season of play. Playing collegiate football for a longer period of time may lead to cartilage microstructural alterations, which may be linked to early knee cartilage degeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Chronic Teacher Turnover in Urban Elementary Schools

    OpenAIRE

    Kacey Guin

    2004-01-01

    This study examines the characteristics of elementary schools that experience chronic teacher turnover and the impacts of turnover on a school’s working climate and ability to effectively function. Based on evidence from staff climate surveys and case studies, it is clear that high turnover schools face significant organizational challenges. Schools with high teacher turnover rates have difficulty planning and implementing a coherent curriculum and sustaining positive working relationships am...

  10. IL-1ß and BMPs - Interactive players of cartilage matrix degradation and regeneration

    Directory of Open Access Journals (Sweden)

    T Aigner

    2006-10-01

    Full Text Available Intact human adult articular cartilage is central for the functioning of the articulating joints. This largely depends on the integrity of its extracellular matrix, given the high loading forces during movements in particular in the weight-bearing joints. Unlike the first impression of a more or less static tissue, articular cartilage shows - albeit in the adult organism a slow - tissue turnover. Thus, one of the most important questions in osteoarthritis research is to understand the balance of catabolic and anabolic factors in articular cartilage as this is the key to understand the biology of cartilage maintenance and degeneration. Anabolic and catabolic pathways are very much intermingled in articular cartilage. The balance between anabolism and catabolism is titrated on numerous levels, starting from the mediator-synthesizing cells which express either catabolic or anabolic factors. Also, on the level of the effector cells (i.e. chondrocytes anabolic and catabolic gene expression compete for a balance of matrix homeostasis, namely the synthesis of matrix components and the expression and activation of matrix-degrading proteases. Also, there are multiple layers of intracellular cross-talks in between the anabolic and catabolic signalling pathways. Maybe the most important lesson from this overview is the notion that the anabolic-catabolic balance as such counts and not so much sufficient net anabolism or limited catabolism alone. Thus, it might be neither the aim of osteoarthritis therapy to foster anabolism nor to knock down catabolism, but the balance of anabolic-catabolic activities as a total might need proper titration and balancing.

  11. Regulatory Challenges for Cartilage Repair Technologies.

    Science.gov (United States)

    McGowan, Kevin B; Stiegman, Glenn

    2013-01-01

    In the United States, few Food and Drug Administration (FDA)-approved options exist for the treatment of focal cartilage and osteochondral lesions. Developers of products for cartilage repair face many challenges to obtain marketing approval from the FDA. The objective of this review is to discuss the necessary steps for FDA application and approval for a new cartilage repair product. FDA Guidance Documents, FDA Panel Meetings, scientific organization recommendations, and clinicaltrials.gov were reviewed to demonstrate the current thinking of FDA and the scientific community on the regulatory process for cartilage repair therapies. Cartilage repair therapies can receive market approval from FDA as medical devices, drugs, or biologics, and the specific classification of product can affect the nonclinical, clinical, and regulatory strategy to bring the product to market. Recent FDA guidance gives an outline of the required elements to bring a cartilage repair product to market, although these standards are often very general. As a result, companies have to carefully craft their study patient population, comparator group, and clinical endpoint to best showcase their product's attributes. In addition, regulatory strategy and manufacturing process validation need to be considered early in the clinical study process to allow for timely product approval following the completion of clinical study. Although the path to regulatory approval for a cartilage repair therapy is challenging and time-consuming, proper clinical trial planning and attention to the details can eventually save companies time and money by bringing a product to the market in the most expeditious process possible.

  12. Current concepts of articular cartilage repair.

    Science.gov (United States)

    Schindler, Oliver S

    2011-12-01

    Articular cartilage provides a vital function in the homeostasis of the joint environment. It possesses unique mechanical properties, allowing for the maintenance of almost frictionless motion over a lifetime. However, cartilage is vulnerable to traumatic injury and due to its poor vascularity and inability to access mesenchymal stem cells, unable to facilitate a satisfactory healing response. Untreated chondral defects are thus likely to predispose patients to the development of osteoarthritis. Reconstitution and repair of articular cartilage is dependent on the neosynthesis or implantation of cartilage matrix elements, a goal which can be achieved through a variety of surgical means. Commonly used repair techniques include marrow stimulation, structural osteo-articular autografts or chondrocyte implantation. Despite substantial differences in the complexity and technical application of each method, all are united in the endeavour to restore joint function and prevent joint degeneration. Anyone attempting to treat cartilage defects must possess a basic understanding of the physiology of cartilage growth, and relevant factors affecting cartilage healing and repair. Furthermore, knowledge of the biomechanics and kinematics of the knee are essential in order to appreciate the forces acting on joint surfaces and repair tissues. Although clinical success is dependent on appropriate patient selection, accurate clinical assessment, definition of root causes and application of the right choice of treatment modality, the ultimate outcome of any intervention remains heavily reliant on the surgeon's proficiency in the technical aspects of the chosen surgical procedure.

  13. Allogenic lyophilized cartilage grafts for craniomaxillofacial reconstruction

    International Nuclear Information System (INIS)

    Pill Hoon Choung

    1999-01-01

    Allogenic lyophilized cartilages were made in our clinic after Sailer methods and some modification. In our clinic, we have used allogenic cartilage grafts on 102 defects of craniomaxillofacial area; 1) for defects from cyst or ameloblastoma, 2) for lack of continuity of the mandible, 3) for rhinoplasty, 4) for paranasal augmentation, 5) for augmentation genioplasty, 6) for reconstruction of orbital floor, 7) for oroantral fistula, 8) for temporal augmentation, 9) for TMJ surgery 10) for condyle defect as a costochondral graft, 11) for filling of tooth socket and alveolus augmentation,12) for correction or orbital height and 13) for guided bone regeneration in peripheral implant. The types of lyophilized cartilage used were chip, sheet and block types developed by freeze-dried methods. Some grafts showed change of ossification, in which case we could perform implant on it. We have good results on reconstruction of craniomaxillofacial defects. Allogenic cartilage have advantages such as 1) it has no immune reaction clinically, 2) it is more tolerable to infection than that of autogenous cartilage, 3) it has character of less resorption which require no over correction, 4) it is easy to manipulate contouring, and 5) it has possibility of undergoing ossification. Allogenic cartilage has been considered as good substitutes for bone. The author would like to report the results on 102 allogenic cartilage have

  14. Motion of the Tympanic Membrane after Cartilage Tympanoplasty Determined by Stroboscopic Holography

    Science.gov (United States)

    Aarnisalo, Antti A.; Cheng, Jeffrey T.; Ravicz, Michael E.; Furlong, Cosme; Merchant, Saumil N.; Rosowski, John J.

    2009-01-01

    Stroboscopic holography was used to quantify dynamic deformations of the tympanic membrane (TM) of the entire surface of the TM before and after cartilage tympanoplasty of the posterior or posterior-superior part of the TM. Cartilage is widely used in tympanoplasties to provide mechanical stability for the TM. Three human cadaveric temporal bones were used. A 6 mm × 3 mm oval cartilage graft was placed through the widely opened facial recess onto the medial surface of the posterior or posterior-superior part of the TM. The graft was either in contact with the bony tympanic rim and manubrium or not. Graft thickness was either 0.5 or 1.0 mm. Stroboscopic holography produced displacement amplitude and phase maps of the TM surface in response to stimulus sound. Sound stimuli were 0.5, 1, 4 and 7 (or 8) kHz tones. Middle ear impedance was measured from the motion of the entire TM. Cartilage placement generally produced reductions in the motion of the TM apposed to the cartilage, especially at 4 kHz and 7 or 8 kHz. Some parts of the TM showed altered motion compared to the control in all three cases. In general, middle ear impedance was either unchanged or increased somewhat after cartilage reconstruction both at low (0.5 and 1 kHz) and high (4 and 7 kHz) frequencies. At 4 kHz, with the 1.0 mm thick graft that was in contact with the bony tympanic rim, the impedance slightly decreased. While our earlier work with time-averaged holography allowed us to observe differences in the pattern of TM motion caused by application of cartilage to the TM, stroboscopic holography is more sensitive to TM motions and allowed us to quantify the magnitude and phase of motion of each point on the TM surface. Nonetheless, our results are similar to those of our earlier work: The placement of cartilage on the medial surface of TM reduces the motion of the TM that apposes the cartilage. These obvious local changes occur even though the cartilage had little effect on the sound-induced motion

  15. Motion of the tympanic membrane after cartilage tympanoplasty determined by stroboscopic holography.

    Science.gov (United States)

    Aarnisalo, Antti A; Cheng, Jeffrey T; Ravicz, Michael E; Furlong, Cosme; Merchant, Saumil N; Rosowski, John J

    2010-05-01

    Stroboscopic holography was used to quantify dynamic deformations of the tympanic membrane (TM) of the entire surface of the TM before and after cartilage tympanoplasty of the posterior or posterior-superior part of the TM. Cartilage is widely used in tympanoplasties to provide mechanical stability for the TM. Three human cadaveric temporal bones were used. A 6 mm x 3 mm oval cartilage graft was placed through the widely opened facial recess onto the medial surface of the posterior or posterior-superior part of the TM. The graft was either in contact with the bony tympanic rim and manubrium or not. Graft thickness was either 0.5 or 1.0mm. Stroboscopic holography produced displacement amplitude and phase maps of the TM surface in response to stimulus sound. Sound stimuli were 0.5, 1, 4 and 7 (or 8)kHz tones. Middle-ear impedance was measured from the motion of the entire TM. Cartilage placement generally produced reductions in the motion of the TM apposed to the cartilage, especially at 4 kHz and 7 or 8 kHz. Some parts of the TM showed altered motion compared to the control in all three cases. In general, middle-ear impedance was either unchanged or increased somewhat after cartilage reconstruction both at low (0.5 and 1 kHz) and high (4 and 7 kHz) frequencies. At 4 kHz, with the 1.0mm thick graft that was in contact with the bony tympanic rim, the impedance slightly decreased. While our earlier work with time-averaged holography allowed us to observe differences in the pattern of TM motion caused by application of cartilage to the TM, stroboscopic holography is more sensitive to TM motions and allowed us to quantify the magnitude and phase of motion of each point on the TM surface. Nonetheless, our results are similar to those of our earlier work: The placement of cartilage on the medial surface of TM reduces the motion of the TM that apposes the cartilage. These obvious local changes occur even though the cartilage had little effect on the sound-induced motion of

  16. Effect of dietary consistency on matrix synthesis and composition in the rat condylar cartilage.

    Science.gov (United States)

    Hinton, R J

    1993-01-01

    Little is known of how the matrix of the condylar cartilage of the mandible changes in response to an alteration in local biomechanical circumstances, although this has been a habitual focus of studies of articular cartilage in the orthopedic literature. This study was formulated to investigate (1) whether matrix changes would occur in the condylar cartilage of rats fed a diet of soft consistency, a circumstance which would presumably reduce articular forces at the mandibular joint; (2) whether these changes, once established, could be reversed by restoring a diet of hard rat pellets, and (3) if these changes were localized to a particular region(s) of the cartilage. In the first experiment, male Sprague-Dawley rats were provisioned with either a soft, mushy diet or hard rat pellets beginning at weaning and subsequently sacrificed at 44 days of age. In the second experiment, all animals were initially given the soft diet, but in half a normal hard diet was reinstituted for 7 days prior to sacrifice at 44 days of age. In the third experiment, cartilages from rats fed soft and hard diets were subdivided into a superior fraction (that portion directly opposite the cranial articulation) and a posterior fraction. The results of experiment 1 showed the water content of the condylar cartilage to be significantly reduced in the soft-diet group, as well as one measure of [35S]uptake into sulfated glycosaminoglycans ([35S]sulfate dpm/micrograms uronic acid). Both wet and dry tissue weights of the condylar cartilage were greatly reduced in rats fed a soft diet.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. An equine joint friction test model using a cartilage-on-cartilage arrangement.

    Science.gov (United States)

    Noble, Prisca; Collin, Bernard; Lecomte-Beckers, Jacqueline; Magnée, Adrien; Denoix, Jean M; Serteyn, Didier

    2010-02-01

    This study describes an equine joint friction test using a cartilage-on-cartilage arrangement and investigates the influence of age and load on the frictional response. Osteochondral plugs were extracted from equine shoulder joints (2-5 years, n=12; 10-14 years, n=15), and mounted in a pin-on-disc tribometer. The frictional response was then measured under constant conditions (2N; 20 degrees C; 5 mm/s), and with increasing load (2N, 5N, 10N). In all experiments, the friction coefficient of young cartilage was significantly (Plubrication remained stable, cartilage ageing may have been responsible for lubrication regime change. The cartilage-on-cartilage model could be used to better understand lubrication regime disturbances in healthy and diseased equine joints, and to test the efficacy of various bio-lubricant treatments. Copyright (c) 2008 Elsevier Ltd. All rights reserved.

  18. [Surgical therapeutic possibilities of cartilage damage].

    Science.gov (United States)

    Burkart, A C; Schoettle, P B; Imhoff, A B

    2001-09-01

    Therapy of cartilage damage is a frequent problem, especially in the young and active patient. For the treatment of a cartilage damage we have to consider the size of the defect, age and weight of the patient, meniscal tears, ligament instabilities and varus-/valgus-malalignment. Lavage, shaving and debridement are only sufficient for a short time and have no long term effect. Abrasio and drilling could be useful in eldery people. Microfracturing seems to be an effective alternative for small defects. The restoration of the cartilage surface with the use of autologous chondrocyte transplantation, osteochondral autograft transplantation and posterior condyle transfer seems to be an adequate treatment for younger patients.

  19. Experimental friction coefficients for bovine cartilage measured with a pin-on-disk tribometer: testing configuration and lubricant effects.

    Science.gov (United States)

    Shi, Liu; Sikavitsas, Vassilios I; Striolo, Alberto

    2011-01-01

    The friction coefficient between wet articular cartilage surfaces was measured using a pin-on-disk tribometer adopting different testing configurations: cartilage-on-pin vs. alumina-on-disk (CA); cartilage-on-pin vs. cartilage-on-disk (CC); and alumina-on-pin vs. cartilage-on-disk (AC). Several substances were dissolved in the phosphate buffered saline (PBS) solution to act as lubricants: 10,000 molecular weight (MW) polyethylene glycol (PEG), 100,000 MW PEG, and chondroitin sulfate (CS), all at 100 mg/mL concentration. Scanning electron microscopy photographs of the cartilage specimens revealed limited wear due to the experiment. Conducting the experiments in PBS solutions we provide evidence according to which a commercial pin-on-disk tribometer allows us to assess different lubrication mechanisms active in cartilage. Specifically, we find that the measured friction coefficient strongly depends on the testing configuration. Our results show that the friction coefficient measured under CC and AC testing configurations remains very low as the sliding distance increases, probably because during the pin displacement the pores present in the cartilage replenish with PBS solution. Under such conditions the fluid phase supports a large load fraction for long times. By systematically altering the composition of the PBS solution we demonstrate the importance of solution viscosity in determining the measured friction coefficient. Although the friction coefficient remains low under the AC testing configuration in PBS, 100 mg/mL solutions of both CS and 100,000 MW PEG in PBS further reduce the friction coefficient by ~40%. Relating the measured friction coefficient to the Hersey number, our results are consistent with a Stribeck curve, confirming that the friction coefficient of cartilage under the AC testing configuration depends on a combination of hydrodynamic, boundary, and weep bearing lubrication mechanisms.

  20. Bone turnover in postmenopausal osteoporosis

    International Nuclear Information System (INIS)

    Thomsen, K.

    1988-02-01

    Studies of the bone turnover in postmenopausal osteoporosis are essential, because the associated bone loss is inevitably due to the relative increase of bone resorption compared with bone formation. Measurement of the bone mineral content (BMC) in normal adults is assessed - partly on the uncorrected values and partly in proportion to the body muscle mass. The whole body retention (WBR) method is presented. The WBR and alternative urinary excretion (UE) methods used by the author are characterised and compared with the retention methods described in the literature. The representativity of WBR and UE for the estimation of bone turnover in normal subjects and patients with various bone metabolic diseases is discussed. The conclusion is that the modified retention methods used by the author have a satisfactory precision and accuracy in relation to the clinical studies carried out. The author's modification of the WBR method for determination of bone turnover and the alternative urinary excretion method (UE) consists in continuous scanning in the whole body count, using a gamma camera, and with the collimator a short distance from the volunteer. This procedure has the advantage of restricting the radioactive dose to 2 mCi (72 MBa). This is smaller by a factor of 5-10 than the dose used to measure WBR with equally simple counting equipment: With the author's procedure, using frontal counting, WBR is systematically underestimated by about 4 per cent point compared to the purely dorsal count, but since the frontal position is the most comfortable, requires a smaller radioactive dose, and the error is systematic, it is the preferred counting procedure. Correction of WBR and UE for bone mineral content is in principle a new parameter of bone turnover, whose improved accuracy increases the validity of the retention determinations. 136 refs. (EG)

  1. Partial genetic turnover in Neandertals

    DEFF Research Database (Denmark)

    Dalén, Love; Orlando, Ludovic Antoine Alexandre; Shapiro, Beth

    2012-01-01

    that recent western European neandertals (48 kyr) European neandertals. Using control region sequences, Bayesian demographic simulations provide higher support for a model of population fragmentation followed by separate demographic trajectories in subpopulations over a null model of a single stable...... population. The most parsimonious explanation for these results is that of a population turnover in western Europe during early Marine Isotope Stage 3, predating the arrival of anatomically modern humans in the region....

  2. Histological comparison of the alar nasal cartilages in unilateral cleft lip

    Directory of Open Access Journals (Sweden)

    Modolin Miguel

    2002-01-01

    Full Text Available Patients with unilateral cleft lip display characteristic nasal changes that are independent of the degree of deformity. Defenders of the intrinsic theory consider these deformities to be due to embryogenic alterations of the alar nasal cartilages. Those that propose the extrinsic theory defend the thesis that the deformity is due to disorganization of the perioral muscles deformed by the cleft. The purpose of this study is to contribute histological evidence to help clarify the issue. PATIENTS AND METHODS: Specimens of the lateral portion of both the healthy and the cleft side of the alar cartilages were obtained from 18 patients. These uniformly cut specimens were stained by hematoxylin and eosin. Samples from 2 patients were excluded due to imperfections. The same pathologist examined all the slides. He was unaware of the origins of the specimens; he counted the number of chondrocytes and quantified the cartilage matrixes. RESULTS: All data was analyzed statistically, and no significant statistical differences were apparent, either in the number of chondrocytes or the cartilage matrix between the healthy side and the cleft side. DISCUSSION: These results apparently support the group that defend the extrinsic theory; nevertheless, the doubt about the composition of the cartilage matrix remains, not only concerning the glycosaminoglycans that compose them, but also regarding elastin and collagen and its linkages that can cause different degrees of collagen consistency.

  3. The polymethylmethacrylate effects on auricle conchal cartilage: report of 21 cases.

    Science.gov (United States)

    Caldellas, Andressa Vieria; de Castro, Claudio Cardoso; Aboudib, Jose Horácio; Guimarães, Leonardo Araújo; Geissler, Palmyra; Cedrola, Juan

    2010-01-01

    Both surgical and nonsurgical techniques, including soft tissue augmentation, are available to restore a youthful appearance to the face. Soft tissue augmentation with nonabsorbable fillers is increasingly important, as a growing number of patients are seeking aesthetic improvement without the downtime and cost of major surgical procedures. Polymethylmethacrylate (PMMA), an injectable implant composed of a suspension of microspheres in different media, is one such soft tissue filler. Because the application of PMMA into the pericartilage of the ear is becoming a more common practice among plastic surgeons, the authors offer a systematic analysis of its effects. They believe this information to be of paramount importance to prevent injuries and deformities. Twenty-one patients who presented to the lead author's clinic with prominent ears during a period of 16 months between 2007 and 2008 were retrospectively reviewed. The authors analyzed PMMA's effects on each patient's ear shell cartilage, which was extracted during correction without causing any kind of injury or deformity to the participants in this study. The histopathologic study from the excised skin and cartilage samples showed a granulomatous inflammation in all patients. There was no association between the incidence of tissue alterations and the mean length of PMMA on the conchal cartilage. The potential consequences of PMMA injection in close proximity to cartilage cannot be predicted and the possibility of myxomatous cartilage degeneration is a serious potential adverse event because it can cause permanent deformities of the cartilaginous skeleton.

  4. Impact of peat mining, and restoration on methane turnover potentials and methane-cycling microorganisms in a northern bog

    NARCIS (Netherlands)

    Reumer, Max; Harnisz, M.; Lee, H.J.; Reim, A.; Grunert, O.; Putkinen, A.; Fritze, H.; Bodelier, P.L.E.; Ho, A.

    2018-01-01

    Ombrotrophic peatlands are a recognized global carbon reservoir. Without restoration and peat regrowth, harvested peatlands are dramatically altered, impairing its carbon sink function, with consequences for methane turnover. Previous studies determined the impact of commercial mining on the peat

  5. Analysis and control of employee turnover.

    Science.gov (United States)

    McConnell, Charles R

    2007-01-01

    Turnover is a relatively simple and easily described concept. However, considerable confusion often results when addressing turnover because of differences in how it is defined; that is, what is counted, how it is counted, and how the turnover rates are expressed. Turnover is also costly, although not enough attention is paid to its cost because so much of it is indirect, and thus, not readily visible. There are a variety of causes of turnover, some which can be corrected and some which cannot be avoided. Reducing or otherwise controlling turnover requires continuing management attention to its causes and constant recognition of what can and should be controlled and what cannot be controlled. Ongoing attention to turnover is an essential part of the department manager's role.

  6. Supervisory turnover in outpatient substance abuse treatment.

    Science.gov (United States)

    Knight, Danica K; Broome, Kirk M; Edwards, Jennifer R; Flynn, Patrick M

    2011-01-01

    Staff turnover is a significant issue within substance abuse treatment, with implications for service delivery and organizational health. This study examined factors associated with turnover among supervisors in outpatient substance abuse treatment. Turnover was conceptualized as being an individual response to organizational-level influences, and predictors represent aggregate program measures. Participants included 532 staff (including 467 counselors and 65 clinical/program directors) from 90 programs in four regions of the USA. Using logistic regression, analyses of structural factors indicated that programs affiliated with a parent organization and those providing more counseling hours to clients had higher turnover rates. When measures of job attitudes were included, only parent affiliation and collective appraisal of satisfaction were related to turnover. Subsequent analyses identified a trend toward increased supervisory turnover when satisfaction was low following the departure of a previous supervisor. These findings suggest that organizational-level factors can be influential in supervisory turnover.

  7. Nanomechanics of the Cartilage Extracellular Matrix

    Science.gov (United States)

    Han, Lin; Grodzinsky, Alan J.; Ortiz, Christine

    2011-08-01

    Cartilage is a hydrated biomacromolecular fiber composite located at the ends of long bones that enables proper joint lubrication, articulation, loading, and energy dissipation. Degradation of extracellular matrix molecular components and changes in their nanoscale structure greatly influence the macroscale behavior of the tissue and result in dysfunction with age, injury, and diseases such as osteoarthritis. Here, the application of the field of nanomechanics to cartilage is reviewed. Nanomechanics involves the measurement and prediction of nanoscale forces and displacements, intra- and intermolecular interactions, spatially varying mechanical properties, and other mechanical phenomena existing at small length scales. Experimental nanomechanics and theoretical nanomechanics have been applied to cartilage at varying levels of material complexity, e.g., nanoscale properties of intact tissue, the matrix associated with single cells, biomimetic molecular assemblies, and individual extracellular matrix biomolecules (such as aggrecan, collagen, and hyaluronan). These studies have contributed to establishing a fundamental mechanism-based understanding of native and engineered cartilage tissue function, quality, and pathology.

  8. Current strategies for articular cartilage repair

    OpenAIRE

    Redman S. N.; Oldfield S. F.; Archer C. W.

    2005-01-01

    Defects of articular cartilage that do not penetrate to the subchondral bone fail to heal spontaneously. Defects that penetrate to the subchondral bone elicit an intrinsic repair response that yields a fibrocartilaginous repair tissue which is a poor substitute for hyaline articular cartilage. Many arthroscopic repair strategies employed utilise this intrinsic repair response to induce the formation of a repair tissue within the defect. The goal, however, is to produce a repair tissue that ha...

  9. Materials science: Like cartilage, but simpler

    DEFF Research Database (Denmark)

    Skov, Anne Ladegaard

    2015-01-01

    The properties of articular cartilage, which lines bones in joints, depend partlyon repulsion between components of the material. A new synthetic gel that mimics this feature has rare, direction-dependent properties.......The properties of articular cartilage, which lines bones in joints, depend partlyon repulsion between components of the material. A new synthetic gel that mimics this feature has rare, direction-dependent properties....

  10. Modern cartilage imaging of the ankle

    International Nuclear Information System (INIS)

    Weber, Marc-Andre; Wuennemann, Felix; Rehnitz, Christoph; Jungmann, Pia M.; Kuni, Benita

    2017-01-01

    Talar osteochondral lesions are an important risk factor for the development of talar osteoarthritis. Furthermore, osteochondral lesions might explain persistent ankle pain. Early diagnosis of accompanying chondral defects is important to establish the optimal therapy strategy and thereby delaying or preventing the onset of osteoarthritis. The purpose of this review is to explain modern cartilage imaging with emphasis of MR imaging as well as the discussion of more sophisticated imaging studies like CT-arthrography or functional MR imaging. Pubmed literature search concerning: osteochondral lesions, cartilage damage, ankle joint, talus, 2 D MR imaging, 3 D MR imaging, cartilage MR imaging, CT-arthrography, cartilage repair, microfracture, OATS, MACT. Dedicated MR imaging protocols to delineate talar cartilage and the appearance of acute and chronic osteochondral lesions were discussed. Recent developments of MR imaging, such as isotropic 3 D imaging that has a higher signal-to noise ratio when compared to 2 D imaging, and specialized imaging methods such as CT-arthrography as well as functional MR imaging were introduced. Several classifications schemes and imaging findings of osteochondral lesions that influence the conservative or surgical therapy strategy were discussed. MRI enables after surgery the non-invasive assessment of the repair tissue and the success of implantation. Key points: Modern MRI allows for highly resolved visualization of the articular cartilage of the ankle joint and of subchondral pathologies. Recent advances in MRI include 3 D isotropic ankle joint imaging, which deliver higher signal-to-noise ratios of the cartilage and less partial volume artifacts when compared with standard 2 D sequences. In case of osteochondral lesions MRI is beneficial for assessing the stability of the osteochondral fragment and for this discontinuity of the cartilage layer is an important factor. CT-arthrography can be used in case of contraindications of MRI and

  11. KECENDERUNGAN KEPUASAN KERJA SEBAGAI TRIGGER TURNOVER

    Directory of Open Access Journals (Sweden)

    Raditya Adi Saputra

    2017-06-01

    Full Text Available The purpose of this study are: (1 To determine the effect of job satisfaction on turnover intention; (2 To determine the effect of work stress on turnover intention; (3 To determine the effect of compensation on turnover intention; (4 To determine the effect of organizational climate on turnover intention; and (5 To determine the stress of work, compensation, organizational climate and job satisfaction effect on turnover intention. The population in this study are employees of the Cooperative KOKAPURA AVIA totaling 180 people, while employees who have worked more than three years as many as 128 people. Samples were taken 97 people. The technique of collecting data using questionnaires. The analysis used is multiple regression analysis and path analysis using PLS 3.0 Smart program. Based on the results of the study concluded that: (1 Job satisfaction significantly influence employee turnover intention; (2 Work stress significantly influence employee turnover intention; (3 Compensation incentives significantly influence employee turnover intention; (4 organizational climate significantly influence employee turnover intention; and (5 Work stress, incentive compensation, organizational climate and job satisfaction simultaneously significantly influence employee turnover intention.

  12. Articular cartilage tissue engineering: the role of signaling molecules

    Science.gov (United States)

    Kwon, Heenam; Paschos, Nikolaos K.; Hu, Jerry C.; Athanasiou, Kyriacos

    2017-01-01

    Effective early disease modifying options for osteoarthritis remain lacking. Tissue engineering approach to generate cartilage in vitro has emerged as a promising option for articular cartilage repair and regeneration. Signaling molecules and matrix modifying agents, derived from knowledge of cartilage development and homeostasis, have been used as biochemical stimuli toward cartilage tissue engineering and have led to improvements in the functionality of engineered cartilage. Clinical translation of neocartilage faces challenges, such as phenotypic instability of the engineered cartilage, poor integration, inflammation, and catabolic factors in the arthritic environment; these can all contribute to failure of implanted neocartilage. A comprehensive understanding of signaling molecules involved in osteoarthritis pathogenesis and their actions on engineered cartilage will be crucial. Thus, while it is important to continue deriving inspiration from cartilage development and homeostasis, it has become increasing necessary to incorporate knowledge from osteoarthritis pathogenesis into cartilage tissue engineering. PMID:26811234

  13. Accelerated extracellular matrix turnover during exacerbations of COPD.

    Science.gov (United States)

    Sand, Jannie M B; Knox, Alan J; Lange, Peter; Sun, Shu; Kristensen, Jacob H; Leeming, Diana J; Karsdal, Morten A; Bolton, Charlotte E; Johnson, Simon R

    2015-06-11

    Exacerbations of chronic obstructive pulmonary disease (COPD) contribute significantly to disease progression. However, the effect on tissue structure and turnover is not well described. There is an urgent clinical need for biomarkers of disease activity associated with disease progression. Extracellular matrix (ECM) turnover reflects activity in tissues and consequently assessment of ECM turnover may serve as biomarkers of disease activity. We hypothesized that the turnover of lung ECM proteins were altered during exacerbations of COPD. 69 patients with COPD hospitalised for an exacerbation were recruited at admission and returned for a 4 weeks follow-up. Competitive ELISAs measuring circulating protein fragments in serum or plasma assessed the formation and degradation of collagen types III (Pro-C3 and C3M, respectively), IV (P4NP 7S and C4M, respectively), and VI (Pro-C6 and C6M, respectively), and degradation of elastin (ELM7 and EL-NE) and versican (VCANM). Circulating levels of C3M, C4M, C6M, ELM7, and EL-NE were elevated during an exacerbation of COPD as compared to follow-up (all P <0.0001), while VCANM levels were decreased (P <0.0001). Pro-C6 levels were decreased and P4NP 7S levels were elevated during exacerbation (P <0.0001). Pro-C3 levels were unchanged. At time of exacerbation, degradation/formation ratios were increased for collagen types III and VI and decreased for collagen type IV. Exacerbations of COPD resulted in elevated levels of circulating fragments of structural proteins, which may serve as markers of disease activity. This suggests that patients with COPD have accelerated ECM turnover during exacerbations which may be related to disease progression.

  14. Study of the collagen structure in the superficial zone and physiological state of articular cartilage using a 3D confocal imaging technique

    Directory of Open Access Journals (Sweden)

    Zheng Ming H

    2008-07-01

    the collagen network in the superficial zone during early physiological alteration of articular cartilage. The fibre confocal imaging technology used in this study has allowed developing confocal arthroscopy for in vivo studying the chondrocytes in different depth of articular cartilage. Therefore, the current study has potential to develop an in vivo 3D histology for diagnosis of early osteoarthritis.

  15. Cartilage Repair Surgery: Outcome Evaluation by Using Noninvasive Cartilage Biomarkers Based on Quantitative MRI Techniques?

    Directory of Open Access Journals (Sweden)

    Pia M. Jungmann

    2014-01-01

    Full Text Available Background. New quantitative magnetic resonance imaging (MRI techniques are increasingly applied as outcome measures after cartilage repair. Objective. To review the current literature on the use of quantitative MRI biomarkers for evaluation of cartilage repair at the knee and ankle. Methods. Using PubMed literature research, studies on biochemical, quantitative MR imaging of cartilage repair were identified and reviewed. Results. Quantitative MR biomarkers detect early degeneration of articular cartilage, mainly represented by an increasing water content, collagen disruption, and proteoglycan loss. Recently, feasibility of biochemical MR imaging of cartilage repair tissue and surrounding cartilage was demonstrated. Ultrastructural properties of the tissue after different repair procedures resulted in differences in imaging characteristics. T2 mapping, T1rho mapping, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC, and diffusion weighted imaging (DWI are applicable on most clinical 1.5 T and 3 T MR scanners. Currently, a standard of reference is difficult to define and knowledge is limited concerning correlation of clinical and MR findings. The lack of histological correlations complicates the identification of the exact tissue composition. Conclusions. A multimodal approach combining several quantitative MRI techniques in addition to morphological and clinical evaluation might be promising. Further investigations are required to demonstrate the potential for outcome evaluation after cartilage repair.

  16. Adipokines induce catabolism of newly synthesized matrix in cartilage and meniscus tissues.

    Science.gov (United States)

    Nishimuta, James F; Levenston, Marc E

    Altered synovial levels of various adipokines (factors secreted by fat as well as other tissues) have been associated with osteoarthritis (OA) onset and progression. However, the metabolic effects of adipokines on joint tissues, in particular the fibrocartilaginous menisci, are not well understood. This study investigated effects of several adipokines on release of recently synthesized extracellular matrix in bovine cartilage and meniscus tissue explants. After labeling newly synthesized proteins and sulfated glycosaminoglycans (sGAGs) with 3 H-proline and 35 S-sulfate, respectively; bovine cartilage and meniscus tissue explants were cultured for 6 days in basal medium (control) or media supplemented with adipokines (1 µg/ml of leptin, visfatin, adiponectin, or resistin) or 20 ng/ml interleukin-1 (IL-1). Release of radiolabel and sGAG to the media during culture and the final explant water, DNA, sGAG, and retained radiolabel were measured. Matrix metalloproteinase (MMP-2) and MMP-3 activities were assessed using gelatin and casein zymography, respectively. Water and DNA contents were not significantly altered by any treatment. Visfatin, adiponectin, resistin, and IL-1 stimulated sGAG release from meniscus, whereas only IL-1 stimulated sGAG release from cartilage. Release of 3 H and 35 S was stimulated not only by resistin and IL-1 in meniscus but also by IL-1 in cartilage. Retained 3 H was unaltered by any treatment, while retained 35 S was reduced by visfatin, resistin, and IL-1 in meniscus and by only IL-1 in cartilage. Resistin and IL-1 elevated active MMP-2 and total MMP-3 in meniscus, whereas cartilage MMP-3 activity was elevated by only IL-1. Resistin stimulated rapid and extensive catabolism of meniscus tissue, similar to IL-1, whereas adipokines minimally affected cartilage. Release of newly synthesized matrix was similar to overall release in both tissues. These observations provide further indications that meniscal tissue is more sensitive to pro

  17. Active G protein-coupled receptors (GPCR), matrix metalloproteinases 2/9 (MMP2/9), heparin-binding epidermal growth factor (hbEGF), epidermal growth factor receptor (EGFR), erbB2, and insulin-like growth factor 1 receptor (IGF-1R) are necessary for trenbolone acetate-induced alterations in protein turnover rate of fused bovine satellite cell cultures.

    Science.gov (United States)

    Thornton, K J; Kamanga-Sollo, E; White, M E; Dayton, W R

    2016-06-01

    Trenbolone acetate (TBA), a testosterone analog, increases protein synthesis and decreases protein degradation in fused bovine satellite cell (BSC) cultures. However, the mechanism through which TBA alters these processes remains unknown. Recent studies indicate that androgens improve rate and extent of muscle growth through a nongenomic mechanism involving G protein-coupled receptors (GPCR), matrix metalloproteinases (MMP), heparin-binding epidermal growth factor (hbEGF), the epidermal growth factor receptor (EGFR), erbB2, and the insulin-like growth factor-1 receptor (IGF-1R). We hypothesized that TBA activates GPCR, resulting in activation of MMP2/9 that releases hbEGF, which activates the EGFR and/or erbB2. To determine whether the proposed nongenomic pathway is involved in TBA-mediated alterations in protein turnover, fused BSC cultures were treated with TBA in the presence or absence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R, and resultant protein synthesis and degradation rates were analyzed. Assays were replicated at least 9 times for each inhibitor experiment utilizing BSC cultures obtained from at least 3 different steers that had no previous exposure to steroid compounds. As expected, fused BSC cultures treated with 10 n TBA exhibited increased ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R suppressed ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R in the presence of 10 n TBA each had no ( > 0.05) effect on TBA-mediated decreases in protein degradation. However, inhibition of both EGFR and erbB2 in the presence of 10 n TBA resulted in decreased ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, and IGF-1R. However, the mechanism through which TBA mediates changes in protein degradation is different and appears to involve only the EGFR and erbB2. Furthermore, it appears the protein kinase B pathway is involved in TBA's effects on fused BSC cultures.

  18. Tritium turnover in succulent plants

    International Nuclear Information System (INIS)

    Krishnamoorthy, T.M.; Gogate, S.S.; Soman, S.D.

    1977-01-01

    Measurements of turnover rates for tissue free water tritium (TFWT) and tissue bound tritium (TBT) were carried out in three succulent plants, Opuntia sp., E. Trigona and E. Mili using tritiated water as tracer. The estimated half-times were 52, 57.5 and 80 days for TFWT and 212, 318 and 132 days for TBT in the stems of the above plants respectively. Opuntia sp. showed significant incorporation of TBT, 10% of TFWT on weight basis, while the other two plants showed lesser incorporation, 2-3% of TFWT. However, the leaves of E. Mili indicated the same level of fixation of TBT as the stem of Opuntia sp. (author)

  19. Manager's guide to reducing dental hygiene turnover.

    Science.gov (United States)

    Loiacono, C

    1989-09-01

    The purpose of this paper is to address the issue of dental hygiene turnover and provide managers with strategies for preventing and reducing turnover. Employee turnover is a problem which affects dental health care delivery and the health of the public. Employee turnover is costly to work settings and creates a stressful working environment which has an impact on professional-client relationships. To reduce or prevent turnover in a private practice setting, office managers must be informed about the causes and effects of this problem and be able to implement solutions. Some strategies managers can use to reduce turnover are hiring employees who have the same goals as the organization; improving the working climate; rewarding longevity; encouraging the active participation of all staff members in office management; improving office communication; and providing opportunities for self-growth, recognition, and greater responsibilities.

  20. Aggrecan structure in amphibian cartilage

    Directory of Open Access Journals (Sweden)

    Covizi D.Z.

    2000-01-01

    Full Text Available The structure of the large proteoglycan present in the bullfrog epiphyseal cartilage was studied by immunochemical and biochemical methods. The isolated monomer showed a polydisperse behavior on Sepharose CL2B, with a peak at Kav = 0.14. Chondroitin sulfate chains were identified by HPLC analysis of the products formed by chondroitinase digestion and mercuric acetate treatment. These chains have approximately 38 disaccharides, a Di45:Di68 ratio of 1.6 and GalNAc4S + GalNAc4,6S are the main non-reducing terminals. Keratan sulfate was identified by the use of two monoclonal antibodies in Western blots after chondroitinase ABC treatment. A keratan sulfate-rich region (~110 kDa was isolated by sequential treatment with chondroitinase ABC and proteases. We also employed antibodies in Western blotting experiments and showed that the full length deglycosylated core protein is about 300 kDa after SDS-PAGE. Domain-specific antibodies revealed the presence of immunoreactive sites corresponding to G1/G2 and G3 globular domains and the characterization of this large proteoglycan as aggrecan. The results indicate the high conservation of the aggrecan domain structure in this lower vertebrate.

  1. Supervisory Turnover in Outpatient Substance Abuse Treatment

    OpenAIRE

    Knight, Danica K.; Broome, Kirk M.; Edwards, Jennifer R.; Flynn, Patrick M.

    2009-01-01

    Staff turnover is a significant issue within substance abuse treatment, with implications for service delivery and organizational health. This study examined factors associated with turnover among supervisors in outpatient substance abuse treatment. Turnover was conceptualized as being an individual response to organizational-level influences, and predictors represent aggregate program measures. Participants included 532 staff (including 467 counselors and 65 clinical/program directors) from ...

  2. Trade and Turnover: Theory and Evidence

    OpenAIRE

    Carl Davidson; Steven Matusz

    2005-01-01

    Is the pattern of trade correlated with cross-sector differences in job turnover? Theoretically, external shocks feed through to changes in domestic employment and cross-sector differences in turnover give rise to compensating wage differentials, which feed through to output prices. Using two different data sets on turnover, we find strong evidence that normalized US net exports by sector are negatively correlated with job destruction and worker separation rates. Weaker evidence suggests a po...

  3. Optimal Employee Turnover Rate: Theory and Evidence

    OpenAIRE

    Mark N. Harris; Kam-Ki Tang; Yi-Ping Tseng

    2002-01-01

    This paper investigates the quantitative effects of employee turnover on firms’ productivity. The Australian Business Longitudinal Survey 1995-98, a unique survey providing firm level data on both production and employee turnover, is used as the data source. Theoretical studies have advocated that firm specific human capital and job matching to be the two major, but competing, mechanisms through which turnover affects productivity. Our results indicate that the effect of job matching dominate...

  4. [New nurse turnover intention and influencing factors].

    Science.gov (United States)

    Han, Sang Sook; Sohn, In Soon; Kim, Nam Eun

    2009-12-01

    The study was done to identify turnover intention in new nurses according to characteristics of the nurses and other factors affecting turnover and to provide data to set up a strategy to reduce the turnover. Data were collected from 1,077 new nurses who had less than 12 months employment experience and worked in one of 188 hospitals. Eight research instruments were used. Data analysis was done using SPSS WIN 15.0 program. Several factors influence new nurse turnover intention. The average score for turnover intention was 2.12. The scores for subscales were self efficacy, 3.76, nursing performance, 3.90, job satisfaction, 2.09, organization commitment, 1.28, stress, 1.32, burnout, 2.82 and nursing organizational culture, 3.29. Turnover intention was related to self efficacy, nursing performance, job satisfaction, organization commitment, stress, burnout, nursing organizational culture, duration of in-class training, duration of on the job training, number of hospital beds, length of employment and duration of employment in current workplace. The predicting factors for turnover intention were burnout, stress, duration of employment in the current workplace, self efficacy and nursing performance. Those factors explained 51.6% of turnover intention. New nurse turnover intention can be reduced by mitigating the factors affecting this intention.

  5. "Changes in cartilage of rats after treatment with Quinolone and in Magnesium-deficient diet "

    Directory of Open Access Journals (Sweden)

    Shakibaei M

    2002-07-01

    Full Text Available Ultrastructural changes in immature articular carilage were studied after treatment of 5-weeks-old rats with ofloxacin, a fluoroquinolone, and in magnesium deficiency.We concluded that quinolone-induced arthropathy is probably due to chelation of functionally available magnesium in joint cartilage as magnesium deficiency in joint cartilage could impair chondrocyte-matrix- interaction which is mediated by cation-dependent integrin-receptors of the β1-subfamily. With immuno-histochemical methods using monoclonal and polyclonal antibodies we showed that B1 integrins were expressed in rat joint cartilage. Joint cartilage lesions were detected in ofloxacin-treated and magnesium-deficient rats. Lesions were more pronounced in the quinolone-treated group. Expression of several integrins was reduced in the vicinity of lesions after oral treatment with 2×600 mg ofloxacin/kg body wt for one day. Gross-structural lesions (e.g. cleft formation, unmasked collagen fibres in magnesium deficient rats were very similar but changes in intergrin expression were less pronounced. Alterations observed on the ultrastructural level showed striking similarities in magnesium-deficient rats and in rats treated with single doses of 600 mg ofloxacin per kg body wt.Typical observation were: bundle shaped, electron-dense aggregates on the surface and in the cytoplasm of chondrocytes, detachement of the cell membrance from the matrix and necrotic chondrocytes, reduced synthesis and/or reduced of extracellular matrix and swelling of cell organelles such as mitochondria.The results of this study confirm our previously reported finding that quinolone-induced arthropathy probably is caued by a reduction of functionally available magnesium (ionized Mg2+ in cartilage. Furthermore, they provide a basis for aimed studies with human cartilage samples from quinolone-treated patients which might be available postmortal or after hip replacement surgery

  6. Coordinate and synergistic effects of extensive treadmill exercise and ovariectomy on articular cartilage degeneration.

    Science.gov (United States)

    Miyatake, Kazumasa; Muneta, Takeshi; Ojima, Miyoko; Yamada, Jun; Matsukura, Yu; Abula, Kahaer; Sekiya, Ichiro; Tsuji, Kunikazu

    2016-05-31

    Although osteoarthritis (OA) is a multifactorial disease, little has been reported regarding the cooperative interaction among these factors on cartilage metabolism. Here we examined the synergistic effect of ovariectomy (OVX) and excessive mechanical stress (forced running) on articular cartilage homeostasis in a mouse model resembling a human postmenopausal condition. Mice were randomly divided into four groups, I: Sham, II: OVX, III: Sham and forced running (60 km in 6 weeks), and IV: OVX and forced running. Histological and immunohistochemical analyses were performed to evaluate the degeneration of articular cartilage and synovitis in the knee joint. Morphological changes of subchondral bone were analyzed by micro-CT. Micro-CT analyses showed significant loss of metaphyseal trabecular bone volume/tissue volume (BV/TV) after OVX as described previously. Forced running increased the trabecular BV/TV in all mice. In the epiphyseal region, no visible alteration in bone morphology or osteophyte formation was observed in any of the four groups. Histological analysis revealed that OVX or forced running respectively had subtle effects on cartilage degeneration. However, the combination of OVX and forced running synergistically enhanced synovitis and articular cartilage degeneration. Although morphological changes in chondrocytes were observed during OA initiation, no signs of bone marrow edema were observed in any of the four experimental groups. We report the coordinate and synergistic effects of extensive treadmill exercise and ovariectomy on articular cartilage degeneration. Since no surgical procedure was performed on the knee joint directly in this model, this model is useful in addressing the molecular pathogenesis of naturally occurring OA.

  7. Moderate loading of the human osteoarthritic knee joint leads to lowering of intraarticular cartilage oligomeric matrix protein

    DEFF Research Database (Denmark)

    Helmark, Ida C; Petersen, Marie C H; Christensen, Helle E

    2012-01-01

    osteoarthritic joint determined by biochemical markers of cartilage turnover and inflammation in the synovial fluid (SF), serum and urine. Eleven subjects with OA of the knee(s), but with no other joint- or inflammatory disorders, volunteered for the study and had samples of blood, urine and synovial fluid drawn...... knee joint in human subjects with knee OA resulted in a reduced COMP concentration in SF.......The non-pharmacological treatment of osteoarthritis (OA) includes exercise therapy; however, little is known about the specific effect of exercise on the joint per se. The purpose of the present study was to investigate the direct effects of a load-bearing exercise upon cartilage in a single, human...

  8. Fatty acid uptake and turnover rate in the ischemic before and after bypass surgery

    International Nuclear Information System (INIS)

    Freundlieb, C.; Hoeck, A.; Vyska, K.; Erbel, R.; Feinendegen, L.E.

    1982-01-01

    17-123-Iodo-heptadecanoic acid (IHA) turnover in myocardium signals myocardial metabolism of free fatty acids. Thus, it appeared promising to examine the influence of cardiovascular surgery on coronary perfusion and on the metabolic state of the ischemic myocardium by use of IHA. The data show that IHA uptake and elimination are two separate parameters which may be changed in the ischemic heart. The two parameters do not necessarily change in parallel. In ischemic heart disease at rest a normal IHA accumulation pattern may be associated with altered regional IHA turnover rates. On the other hand also accumulation defects without changes in IHA turnover rate were observed. Although the relationship between IHA uptake and turnover is not yet sufficiently understood that statements about the indication and prognosis of bypass surgery can be derived

  9. ESTABLISHING A LIVE CARTILAGE-ON-CARTILAGE INTERFACE FOR TRIBOLOGICAL TESTING.

    Science.gov (United States)

    Trevino, Robert L; Stoia, Jonathan; Laurent, Michel P; Pacione, Carol A; Chubinskaya, Susan; Wimmer, Markus A

    2017-03-01

    Mechano-biochemical wear encompasses the tribological interplay between biological and mechanical mechanisms responsible for cartilage wear and degradation. The aim of this study was to develop and start validating a novel tribological testing system, which better resembles the natural joint environment through incorporating a live cartilage-on-cartilage articulating interface, joint specific kinematics, and the application of controlled mechanical stimuli for the measurement of biological responses in order to study the mechano-biochemical wear of cartilage. The study entailed two parts. In Part 1, the novel testing rig was used to compare two bearing systems: (a) cartilage articulating against cartilage (CoC) and (b) metal articulating against cartilage (MoC). The clinically relevant MoC, which is also a common tribological interface for evaluating cartilage wear, should produce more wear to agree with clinical observations. In Part II, the novel testing system was used to determine how wear is affected by tissue viability in live and dead CoC articulations. For both parts, bovine cartilage explants were harvested and tribologically tested for three consecutive days. Wear was defined as release of glycosaminoglycans into the media and as evaluation of the tissue structure. For Part I, we found that the live CoC articulation did not cause damage to the cartilage, to the extent of being comparable to the free swelling controls, whereas the MoC articulation caused decreased cell viability, extracellular matrix disruption, and increased wear when compared to CoC, and consistent with clinical data. These results provided confidence that this novel testing system will be adequate to screen new biomaterials for articulation against cartilage, such as in hemiarthroplasty. For Part II, the live and dead cartilage articulation yielded similar wear as determined by the release of proteoglycans and aggrecan fragments, suggesting that keeping the cartilage alive may not be

  10. Evaluation of body composition and cartilage biomarkers in large-breed dogs fed two foods designed for growth.

    Science.gov (United States)

    Schoenherr, William D; Macleay, Jennifer M; Yamka, Ryan M

    2010-08-01

    To evaluate cartilage and bone biomarkers and body composition in growing large-breed dogs consuming a diet designed for growth. 43 large-breed 2 month-old-puppies. Dogs were randomly assigned to receive 1 of 2 foods until 18 months of age. Dogs were evaluated at 2, 5, 12, and 18 months of age via dual energy x-ray absorptiometry (DEXA), CBC, serum biochemical profile, and concentrations or activities of taurine, vitamin E, fatty acids, glutathione peroxidase, C-propeptide of type II collagen (CPII), cartilage oligomeric matrix protein (COMP), carboxy-terminal cross-linked fragment of type II collagen (CTXII), bone specific alkaline phosphatase (BAP), osteocalcin, ghrelin, and growth hormone. Blood components largely reflected the composition of the foods. Dogs fed the food with a higher concentration of protein, calcium, n-3 fatty acids, and antioxidants had a lower percentage of body fat and greater percentage of lean body mass at 5, 12, and 18 months of age, and higher CPII:CTXII ratio and lower COMP at 18 months of age. The BAP activity, osteocalcin concentration, and CTXII concentration declined with age, whereas COMP concentration and CPII concentration were similar at all time points for both foods. The BAP activity, osteocalcin concentration, and CTXII concentration were greater during growth than at 18 months of age. The food that was proportionately higher in protein, calcium, n-3 fatty acids, and antioxidants increased lean body mass and may have positively affected cartilage turnover as maturity was attained. Whether the rate of cartilage turnover during growth affects development of orthopedic disease or arthritis in adulthood has yet to be determined.

  11. Repair of osteochondral defects in rabbits with ectopically produced cartilage

    NARCIS (Netherlands)

    Emans, PJ; Hulsbosch, M; Wetzels, GMR; Bulstra, SK; Kuijer, R

    2005-01-01

    Cartilage has poor regenerative capacity. Donor site morbidity and interference with joint homeostasis should be considered when applying the autologous chondrocyte transplantation technique. The use of ectopically produced cartilage, derived from periosteum, might be a novel method to heal

  12. Induction of mesenchymal stem cell chondrogenic differentiation and functional cartilage microtissue formation for in vivo cartilage regeneration by cartilage extracellular matrix-derived particles.

    Science.gov (United States)

    Yin, Heyong; Wang, Yu; Sun, Zhen; Sun, Xun; Xu, Yichi; Li, Pan; Meng, Haoye; Yu, Xiaoming; Xiao, Bo; Fan, Tian; Wang, Yiguo; Xu, Wenjing; Wang, Aiyuan; Guo, Quanyi; Peng, Jiang; Lu, Shibi

    2016-03-01

    We propose a method of preparing a novel cell carrier derived from natural cartilage extracellular matrix (ECM), designated cartilage ECM-derived particles (CEDPs). Through a series of processes involving pulverization, sieving, and decellularization, fresh cartilage was made into CEDPs with a median diameter of 263 ± 48 μm. Under microgravity culture conditions in a rotary cell culture system (RCCS), bone marrow stromal cells (BMSCs) can proliferate rapidly on the surface of CEDPs with high viability. Histological evaluation and gene expression analysis indicated that BMSCs were differentiated into mature chondrocytes after 21 days of culture without the use of exogenous growth factors. Functional cartilage microtissue aggregates of BMSC-laden CEDPs formed as time in culture increased. Further, the microtissue aggregates were directly implanted into trochlear cartilage defects in a rat model (CEDP+MSC group). Gait analysis and histological results indicated that the CEDP+MSC group obtained better and more rapid joint function recovery and superior cartilage repair compared to the control groups, in which defects were treated with CEDPs alone or only fibrin glue, at both 6 and 12 weeks after surgery. In conclusion, the innovative cell carrier derived from cartilage ECM could promote chondrogenic differentiation of BMSCs, and the direct use of functional cartilage microtissue facilitated cartilage regeneration. This strategy for cell culture, stem cell differentiation and one-step surgery using cartilage microtissue for cartilage repair provides novel prospects for cartilage tissue engineering and may have further broad clinical applications. We proposed a method to prepare a novel cell carrier derived from natural cartilage ECM, termed cartilage ECM-derived particles (CEDPs), which can support proliferation of MSCs and facilitate their chondrogenic differentiation. Further, the direct use of functional cartilage microtissue of MSC-laden CEDP aggregates for

  13. The Role of Changes in Extracellular Matrix of Cartilage in the Presence of Inflammation on the Pathology of Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Maricela Maldonado

    2013-01-01

    Full Text Available Osteoarthritis (OA is a degenerative disease that affects various tissues surrounding joints such as articular cartilage, subchondral bone, synovial membrane, and ligaments. No therapy is currently available to completely prevent the initiation or progression of the disease partly due to poor understanding of the mechanisms of the disease pathology. Cartilage is the main tissue afflicted by OA, and chondrocytes, the sole cellular component in the tissue, actively participate in the degeneration process. Multiple factors affect the development and progression of OA including inflammation that is sustained during the progression of the disease and alteration in biomechanical conditions due to wear and tear or trauma in cartilage. During the progression of OA, extracellular matrix (ECM of cartilage is actively remodeled by chondrocytes under inflammatory conditions. This alteration of ECM, in turn, changes the biomechanical environment of chondrocytes, which further drives the progression of the disease in the presence of inflammation. The changes in ECM composition and structure also prevent participation of mesenchymal stem cells in the repair process by inhibiting their chondrogenic differentiation. This review focuses on how inflammation-induced ECM remodeling disturbs cellular activities to prevent self-regeneration of cartilage in the pathology of OA.

  14. Tissue engineering techniques to regenerate articular cartilage using polymeric scaffolds.

    OpenAIRE

    PÉREZ OLMEDILLA, MARCOS

    2016-01-01

    [EN] Articular cartilage is a tissue that consists of chondrocytes surrounded by a dense extracellular matrix (ECM). The ECM is mainly composed of type II collagen and proteoglycans. The main function of articular cartilage is to provide a lubricated surface for articulation. Articular cartilage damage is common and may lead to osteoarthritis. Articular cartilage does not have blood vessels, nerves or lymphatic vessels and therefore has limited capacity for intrinsic healing and repair. ...

  15. Turnover, Biographical Data, and Fair Employment Practice

    Science.gov (United States)

    Cascio, Wayne F.

    1976-01-01

    Describes a study that tested the validity of using job applicants' biographical data to predict employee turnover among minority and nonminority female clerical personnel. Findings showed that even after satisfying legal requirements for using such information, turnover can be predicted quite accurately. For availability see EA 507 670.…

  16. Relationship between Job Satisfaction and Turnover Intention ...

    African Journals Online (AJOL)

    This study explores the association between job satisfaction and turnover intentions among lecturers in three public universities in Tanzania. It had three objectives: (1) to determine the level of perceived job satisfaction among lecturers; (2) to determine the association between job satisfaction and turnover intention; and (3) ...

  17. Employee Turnover: Evidence from a Case Study.

    Science.gov (United States)

    Borland, Jeff

    1997-01-01

    Patterns of employee turnover from a medium-sized law firm in Australia were examined in regard to theories of worker mobility (matching, sectoral shift, and incentive). Results support a role for matching effects, but personnel practices affect the timing of turnover. Matching and incentive-based theories do not explain the high rates of turnover…

  18. University Lecturers' Professional Empowerment and Turnover in ...

    African Journals Online (AJOL)

    Many universities in Uganda are grappling with the challenge of academic staff turnover. While research conducted so far has established different factors explaining the problems of turnover, many of which have been addressed, this challenge has not been resolved. Hitherto, attention has not been paid to whether ...

  19. An ex vivo human cartilage repair model to evaluate the potency of a cartilage cell transplant.

    Science.gov (United States)

    Bartz, Christoph; Meixner, Miriam; Giesemann, Petra; Roël, Giulietta; Bulwin, Grit-Carsta; Smink, Jeske J

    2016-11-15

    Cell-based therapies such as autologous chondrocyte implantation are promising therapeutic approaches to treat cartilage defects to prevent further cartilage degeneration. To assure consistent quality of cell-based therapeutics, it is important to be able to predict the biological activity of such products. This requires the development of a potency assay, which assesses a characteristic of the cell transplant before implantation that can predict its cartilage regeneration capacity after implantation. In this study, an ex vivo human cartilage repair model was developed as quality assessment tool for potency and applied to co.don's chondrosphere product, a matrix-associated autologous chondrocyte implant (chondrocyte spheroids) that is in clinical use in Germany. Chondrocyte spheroids were generated from 14 donors, and implanted into a subchondral cartilage defect that was manually generated in human articular cartilage tissue. Implanted spheroids and cartilage tissue were co-cultured ex vivo for 12 weeks to allow regeneration processes to form new tissue within the cartilage defect. Before implantation, spheroid characteristics like glycosaminoglycan production and gene and protein expression of chondrogenic markers were assessed for each donor sample and compared to determine donor-dependent variation. After the co-cultivation, histological analyses showed the formation of repair tissue within the cartilage defect, which varied in amount for the different donors. In the repair tissue, aggrecan protein was expressed and extra-cellular matrix cartilage fibers were present, both indicative for a cartilage hyaline-like character of the repair tissue. The amount of formed repair tissue was used as a read-out for regeneration capacity and was correlated with the spheroid characteristics determined before implantation. A positive correlation was found between high level of aggrecan protein expression in spheroids before implantation and a higher regeneration potential

  20. An ex vivo human cartilage repair model to evaluate the potency of a cartilage cell transplant

    Directory of Open Access Journals (Sweden)

    Christoph Bartz

    2016-11-01

    Full Text Available Abstract Background Cell-based therapies such as autologous chondrocyte implantation are promising therapeutic approaches to treat cartilage defects to prevent further cartilage degeneration. To assure consistent quality of cell-based therapeutics, it is important to be able to predict the biological activity of such products. This requires the development of a potency assay, which assesses a characteristic of the cell transplant before implantation that can predict its cartilage regeneration capacity after implantation. In this study, an ex vivo human cartilage repair model was developed as quality assessment tool for potency and applied to co.don’s chondrosphere product, a matrix-associated autologous chondrocyte implant (chondrocyte spheroids that is in clinical use in Germany. Methods Chondrocyte spheroids were generated from 14 donors, and implanted into a subchondral cartilage defect that was manually generated in human articular cartilage tissue. Implanted spheroids and cartilage tissue were co-cultured ex vivo for 12 weeks to allow regeneration processes to form new tissue within the cartilage defect. Before implantation, spheroid characteristics like glycosaminoglycan production and gene and protein expression of chondrogenic markers were assessed for each donor sample and compared to determine donor-dependent variation. Results After the co-cultivation, histological analyses showed the formation of repair tissue within the cartilage defect, which varied in amount for the different donors. In the repair tissue, aggrecan protein was expressed and extra-cellular matrix cartilage fibers were present, both indicative for a cartilage hyaline-like character of the repair tissue. The amount of formed repair tissue was used as a read-out for regeneration capacity and was correlated with the spheroid characteristics determined before implantation. A positive correlation was found between high level of aggrecan protein expression in spheroids

  1. Body weight independently affects articular cartilage catabolism.

    Science.gov (United States)

    Denning, W Matt; Winward, Jason G; Pardo, Michael Becker; Hopkins, J Ty; Seeley, Matthew K

    2015-06-01

    Although obesity is associated with osteoarthritis, it is unclear whether body weight (BW) independently affects articular cartilage catabolism (i.e., independent from physiological factors that also accompany obesity). The primary purpose of this study was to evaluate the independent effect of BW on articular cartilage catabolism associated with walking. A secondary purpose was to determine how decreased BW influenced cardiovascular response due to walking. Twelve able-bodied subjects walked for 30 minutes on a lower-body positive pressure treadmill during three sessions: control (unadjusted BW), +40%BW, and -40%BW. Serum cartilage oligomeric matrix protein (COMP) was measured immediately before (baseline) and after, and 15 and 30 minutes after the walk. Heart rate (HR) and rate of perceived exertion (RPE) were measured every three minutes during the walk. Relative to baseline, average serum COMP concentration was 13% and 5% greater immediately after and 15 minutes after the walk. Immediately after the walk, serum COMP concentration was 14% greater for the +40%BW session than for the -40%BW session. HR and RPE were greater for the +40%BW session than for the other two sessions, but did not differ between the control and -40%BW sessions. BW independently influences acute articular cartilage catabolism and cardiovascular response due to walking: as BW increases, so does acute articular cartilage catabolism and cardiovascular response. These results indicate that lower-body positive pressure walking may benefit certain individuals by reducing acute articular cartilage catabolism, due to walking, while maintaining cardiovascular response. Key pointsWalking for 30 minutes with adjustments in body weight (normal body weight, +40% and -40% body weight) significantly influences articular cartilage catabolism, measured via serum COMP concentration.Compared to baseline levels, walking with +40% body weight and normal body weight both elicited significant increases in

  2. Predictors of turnover intention in nurse faculty.

    Science.gov (United States)

    Gormley, Denise K; Kennerly, Susan

    2011-04-01

    Turnover of nurse faculty is an increasingly important issue in nursing as the available number of qualified faculty continues to decrease. Understanding the factors that contribute to turnover is important to academic administrators to retain and recruit qualified nursing faculty. The purpose of this study was to examine predictors of turnover intention in nurse faculty working in departments and schools of nursing in Carnegie Doctoral/Research Universities-Extensive, public and private, not-for-profit institutions. The multidimensional model of organizational commitment was used to frame this study. The predictor variables explored were organizational climate, organizational commitment, work role balance, role ambiguity, and role conflict. The work roles examined were research, teaching, and service. Logistical regression was performed to examine the predictors of turnover intention. Organizational climate intimacy and disengagement, affective and continuance organizational commitment, and role ambiguity were shown to predict turnover intention in nurse faculty. Copyright 2011, SLACK Incorporated.

  3. Chronic Teacher Turnover in Urban Elementary Schools

    Directory of Open Access Journals (Sweden)

    Kacey Guin

    2004-08-01

    Full Text Available This study examines the characteristics of elementary schools that experience chronic teacher turnover and the impacts of turnover on a school’s working climate and ability to effectively function. Based on evidence from staff climate surveys and case studies, it is clear that high turnover schools face significant organizational challenges. Schools with high teacher turnover rates have difficulty planning and implementing a coherent curriculum and sustaining positive working relationships among teachers. The reality of these organizational challenges is particularly alarming, given that high turnover schools are more likely to serve low-income and minority students. The negative relationship between teacher turnover and school functioning, and the fact that turbulent schools are disproportionately likely to serve lowincome and minority students have important implications for both district and school-level policies. Specifically: Teacher turnover rates are one indicator of school health, which school districts should consider when focusing on school improvements. Districts need to begin by developing the means to identify individual schools that experience high levels of teacher turnover. Current district policies in implementing professional development for teachers in low-performing schools are inefficient when teachers do not remain in the schools in which they are trained. In order for low-performing schools to improve, districts need to consider providing incentive programs so that high quality teachers apply for, and remain in, these schools. Future research is needed to address the causal link between turnover, organizational functioning and student outcomes. Additionally, there is a need for research examining district policies that may facilitate teacher turnover within a district, including how districts place and transfer teachers, as well as how teachers’ salaries are budgeted.

  4. Deficient Mechanical Activation of Anabolic Transcripts and Post-Traumatic Cartilage Degeneration in Matrilin-1 Knockout Mice.

    Directory of Open Access Journals (Sweden)

    Yupeng Chen

    Full Text Available Matrilin-1 (Matn1, a cartilage-specific peri-cellular and extracellular matrix (ECM protein, has been hypothesized to regulate ECM interactions and transmit mechanical signals in cartilage. Since Matn1 knock-out (Matn1-/- mice exhibit a normal skeleton, its function in vivo is unclear. In this study, we found that the anabolic Acan and Col2a transcript levels were significantly higher in wildtype (Matn1+/+ mouse cartilage than that of MATN1-/- mice in vivo. However, such difference was not observed between Matn1+/+ and MATN1-/- chondrocytes cultured under stationary conditions in vitro. Cyclic loading significantly stimulated Acan and Col2a transcript levels in Matn1+/+ but not in MATN1-/- chondrocytes. This suggests that, while Matn1+/+ chondrocytes increase their anabolic gene expression in response to mechanical loading, the MATN1-/- chondrocytes fail to do so because of the deficiency in mechanotransduction. We also found that altered elastic modulus of cartilage matrix in Matn1-/- mice, suggesting the mechanotransduction has changed due to the deficiency of Matn1. To understand the impact of such deficiency on joint disease, mechanical loading was altered in vivo by destabilization of medial meniscus. While Matn1+/+ mice exhibited superficial fissures and clefts consistent with mechanical damage to the articular joint, Matn1-/- mice presented more severe cartilage lesions characterized by proteoglycan loss and disorganization of cells and ECM. This suggests that Matn1 deficiency affects pathogenesis of post-traumatic osteoarthritis by failing to up-regulate anabolic gene expression. This is the first demonstration of Matn1 function in vivo, which suggests its protective role in cartilage degeneration under altered mechanical environment.

  5. System turnover and acceptance procedure of Qingshan NPP

    International Nuclear Information System (INIS)

    Sun Guangdi; Wu Guanxin

    1993-01-01

    Turnover and acceptance process of nuclear power plant has direct influence on construction scheduling. The authors describe organization, conditions and implementation of system turnover and acceptance. The paper also gives some suggestions as reference of turnover and acceptance work

  6. FUNCTIONS OF THE mTOR SIGNALING PATHWAY IN NORMAL ARTICULAR CARTILAGE CHONDROCYTES AND IN OSTEOARTHRITIS

    Directory of Open Access Journals (Sweden)

    E. V. Chetina

    2016-01-01

    Full Text Available Osteoarthritis  (OA is a chronic disease associated with pain, stiffness, limited mobility and joint inflammation, as well as articular cartilage destruction.  Recent studies have shown the importance  of chondrocyte  differentiation (hypertrophy as one of the mechanisms  of cartilage degradation in OA. This suggests that chondrocyte  metabolism undergoes the profound changes during cartilage resorption,  which are due to dysregulation of cell function. One of the major cellular metabolic regulators is the protein mTOR (mechanistic target of rapamycin that controls cell growth, proliferation, protein biosynthesis and integrates extracellular signals from growth factors and hormones with amino acid availability and intracellular energy status. The importance  of mTOR activity for articular cartilage destruction  in OAis confirmed by significant changes in the work of mTOR regulatory network that involves multiple intracellular (growth factors, adenosine triphosphate, oxygen availability, and autophagy and extracellular (glucose, amino acids, lipids, and hexosamine signals. Moreover, the altered expression of the mTOR gene in the blood of patients with OA is associated with either increased pain or synovitis, which indicates that there is a strong metabolic heterogeneity in patients with OA and a need for a differentiated therapeutic  approach. The above problems are discussed in this review.

  7. Influence of dynamic load on friction behavior of human articular cartilage, stainless steel and polyvinyl alcohol hydrogel as artificial cartilage.

    Science.gov (United States)

    Li, Feng; Su, Yonglin; Wang, Jianping; Wu, Gang; Wang, Chengtao

    2010-01-01

    Many biomaterials are being developed to be used for cartilage substitution and hemiarthroplasty implants. The lubrication property is a key feature of the artificial cartilage. The frictional behavior of human articular cartilage, stainless steel and polyvinyl alcohol (PVA) hydrogel were investigated under cartilage-on-PVA hydrogel contact, cartilage-on-cartilage contact and cartilage-on-stainless steel contact using pin-on-plate method. Tests under static load, cyclic load and 1 min load change were used to evaluate friction variations in reciprocating motion. The results showed that the lubrication property of cartilage-on-PVA hydrogel contact and cartilage-on-stainless steel contact were restored in both 1 min load change and cyclic load tests. The friction coefficient of PVA hydrogel decreased from 0.178 to 0.076 in 60 min, which was almost one-third of the value under static load in continuous sliding tests. In each test, the friction coefficient of cartilage-on-cartilage contact maintained far lower value than other contacts. It is indicated that a key feature of artificial cartilage is the biphasic lubrication properties.

  8. Cartilage oligomeric matrix protein associates differentially with erosions and synovitis and has a different temporal course in cyclic citrullinated peptide antibody (anti-CCP)-positive versus anti-CCP-negative early rheumatoid arthritis

    DEFF Research Database (Denmark)

    Christensen, Anne F; Lindegaard, Hanne; Hørslev-Petersen, Kim

    2011-01-01

    . We aimed to compare circulating cartilage oligomeric matrix protein (COMP), a marker of cartilage turnover, in untreated anti-CCP-positive and anti-CCP-negative RA, and to study the temporal pattern of COMP through 4 years of treatment, including the relationship to imaging and clinical findings.......Cyclic citrullinated peptide antibody (anti-CCP)-positive and anti-CCP-negative rheumatoid arthritis (RA) have been suggested as 2 distinctive disease subsets with respect to disease activity and prognosis. Previously, we proposed that anti-CCP antibodies might have a chondrocyte-suppressive effect...

  9. Cartilage oligomeric matrix protein associates differentially with erosions and synovitis and has a different temporal course in cyclic citrullinated peptide antibody (anti-CCP)-positive versus anti-CCP-negative early rheumatoid arthritis

    DEFF Research Database (Denmark)

    Christensen, Anne F; Lindegaard, Hanne; Hørslev-Petersen, Kim

    2011-01-01

    -suppressive effect. We aimed to compare circulating cartilage oligomeric matrix protein (COMP), a marker of cartilage turnover, in untreated anti-CCP-positive and anti-CCP-negative RA, and to study the temporal pattern of COMP through 4 years of treatment, including the relationship to imaging and clinical findings.......048). In anti-CCP-positive patients, COMP exhibited a parabolic course over 4 years, while COMP in anti-CCP-negative patients had an almost linear course. In anti-CCP-positive patients, COMP was associated with MRI edema and erosion score, while COMP was correlated with synovitis score in anti...

  10. Bone turnover markers: Emerging tool in the management of osteoporosis

    Directory of Open Access Journals (Sweden)

    Sahana Shetty

    2016-01-01

    Full Text Available Bone is a dynamic tissue which undergoes constant remodeling throughout the life span. Bone turnover is balanced with coupling of bone formation and resorption at various rates leading to continuous remodeling of bone. A study of bone turnover markers (BTMs provides an insight of the dynamics of bone turnover in many metabolic bone disorders. An increase in bone turnover seen with aging and pathological states such as osteoporosis leads to deterioration of bone microarchitecture and thus contributes to an increase in the risk of fracture independent of low bone mineral density (BMD. These microarchitectural alterations affecting the bone quality can be assessed by BTMs and thus may serve as a complementary tool to BMD in the assessment of fracture risk. A systematic search of literature regarding BTMs was carried out using the PubMed database for the purpose of this review. Various reliable, rapid, and cost-effective automated assays of BTMs with good sensitivity are available for the management of osteoporosis. However, BTMs are subjected to various preanalytical and analytical variations necessitating strict sample collection and assays methods along with utilizing ethnicity-based reference standards for different populations. Estimation of fracture risk and monitoring the adherence and response to therapy, which is a challenge in a chronic, asymptomatic disease such as osteoporosis, are the most important applications of measuring BTMs. This review describes the physiology of bone remodeling, various conventional and novel BTMs, and BTM assays and their role in the assessment of fracture risk and monitoring response to treatment with antiresorptive or anabolic agents.

  11. Articular cartilage-derived cells hold a strong osteogenic differentiation potential in comparison to mesenchymal stem cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Salamon, Achim, E-mail: achim.salamon@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Jonitz-Heincke, Anika, E-mail: anika.jonitz@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Adam, Stefanie, E-mail: stefanie.adam@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Rychly, Joachim, E-mail: joachim.rychly@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Müller-Hilke, Brigitte, E-mail: brigitte.mueller-hilke@med.uni-rostock.de [Institute of Immunology, Rostock University Medical Center, Schillingallee 68, D-18057 Rostock (Germany); Bader, Rainer, E-mail: rainer.bader@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Lochner, Katrin, E-mail: katrin.lochner@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Peters, Kirsten, E-mail: kirsten.peters@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany)

    2013-11-01

    Cartilaginous matrix-degenerative diseases like osteoarthritis (OA) are characterized by gradual cartilage erosion, and also by increased presence of cells with mesenchymal stem cell (MSC) character within the affected tissues. Moreover, primary chondrocytes long since are known to de-differentiate in vitro and to be chondrogenically re-differentiable. Since both findings appear to conflict with each other, we quantitatively assessed the mesenchymal differentiation potential of OA patient cartilage-derived cells (CDC) towards the osteogenic and adipogenic lineage in vitro and compared it to that of MSC isolated from adipose tissue (adMSC) of healthy donors. We analyzed expression of MSC markers CD29, CD44, CD105, and CD166, and, following osteogenic and adipogenic induction in vitro, quantified their expression of osteogenic and adipogenic differentiation markers. Furthermore, CDC phenotype and proliferation were monitored. We found that CDC exhibit an MSC CD marker expression pattern similar to adMSC and a similar increase in proliferation rate during osteogenic differentiation. In contrast, the marked reduction of proliferation observed during adipogenic differentiation of adMSC was absent in CDC. Quantification of differentiation markers revealed a strong osteogenic differentiation potential for CDC, however almost no capacity for adipogenic differentiation. Since in the pathogenesis of OA, cartilage degeneration coincides with high bone turnover rates, the high osteogenic differentiation potential of OA patient-derived CDC may affect clinical therapeutic regimens aiming at autologous cartilage regeneration in these patients. - Highlights: • We analyze the mesenchymal differentiation capacity of cartilage-derived cells (CDC). • CDC express mesenchymal stem cell (MSC) markers CD29, CD44, CD105, and CD166. • CDC and MSC proliferation is reduced in adipogenesis and increased in osteogenesis. • Adipogenic differentiation is virtually absent in CDC, but

  12. Articular cartilage-derived cells hold a strong osteogenic differentiation potential in comparison to mesenchymal stem cells in vitro

    International Nuclear Information System (INIS)

    Salamon, Achim; Jonitz-Heincke, Anika; Adam, Stefanie; Rychly, Joachim; Müller-Hilke, Brigitte; Bader, Rainer; Lochner, Katrin; Peters, Kirsten

    2013-01-01

    Cartilaginous matrix-degenerative diseases like osteoarthritis (OA) are characterized by gradual cartilage erosion, and also by increased presence of cells with mesenchymal stem cell (MSC) character within the affected tissues. Moreover, primary chondrocytes long since are known to de-differentiate in vitro and to be chondrogenically re-differentiable. Since both findings appear to conflict with each other, we quantitatively assessed the mesenchymal differentiation potential of OA patient cartilage-derived cells (CDC) towards the osteogenic and adipogenic lineage in vitro and compared it to that of MSC isolated from adipose tissue (adMSC) of healthy donors. We analyzed expression of MSC markers CD29, CD44, CD105, and CD166, and, following osteogenic and adipogenic induction in vitro, quantified their expression of osteogenic and adipogenic differentiation markers. Furthermore, CDC phenotype and proliferation were monitored. We found that CDC exhibit an MSC CD marker expression pattern similar to adMSC and a similar increase in proliferation rate during osteogenic differentiation. In contrast, the marked reduction of proliferation observed during adipogenic differentiation of adMSC was absent in CDC. Quantification of differentiation markers revealed a strong osteogenic differentiation potential for CDC, however almost no capacity for adipogenic differentiation. Since in the pathogenesis of OA, cartilage degeneration coincides with high bone turnover rates, the high osteogenic differentiation potential of OA patient-derived CDC may affect clinical therapeutic regimens aiming at autologous cartilage regeneration in these patients. - Highlights: • We analyze the mesenchymal differentiation capacity of cartilage-derived cells (CDC). • CDC express mesenchymal stem cell (MSC) markers CD29, CD44, CD105, and CD166. • CDC and MSC proliferation is reduced in adipogenesis and increased in osteogenesis. • Adipogenic differentiation is virtually absent in CDC, but

  13. PRP and Articular Cartilage: A Clinical Update

    Directory of Open Access Journals (Sweden)

    Antonio Marmotti

    2015-01-01

    Full Text Available The convincing background of the recent studies, investigating the different potentials of platelet-rich plasma, offers the clinician an appealing alternative for the treatment of cartilage lesions and osteoarthritis. Recent evidences in literature have shown that PRP may be helpful both as an adjuvant for surgical treatment of cartilage defects and as a therapeutic tool by intra-articular injection in patients affected by osteoarthritis. In this review, the authors introduce the trophic and anti-inflammatory properties of PRP and the different products of the available platelet concentrates. Then, in a complex scenario made of a great number of clinical variables, they resume the current literature on the PRP applications in cartilage surgery as well as the use of intra-articular PRP injections for the conservative treatment of cartilage degenerative lesions and osteoarthritis in humans, available as both case series and comparative studies. The result of this review confirms the fascinating biological role of PRP, although many aspects yet remain to be clarified and the use of PRP in a clinical setting has to be considered still exploratory.

  14. Cartilage repair: Generations of autologous chondrocyte transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Marlovits, Stefan [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)]. E-mail: stefan.marlovits@meduniwien.ac.at; Zeller, Philip [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Singer, Philipp [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Resinger, Christoph [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Vecsei, Vilmos [Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2006-01-15

    Articular cartilage in adults has a limited capacity for self-repair after a substantial injury. Surgical therapeutic efforts to treat cartilage defects have focused on delivering new cells capable of chondrogenesis into the lesions. Autologous chondrocyte transplantation (ACT) is an advanced cell-based orthobiologic technology used for the treatment of chondral defects of the knee that has been in clinical use since 1987 and has been performed on 12,000 patients internationally. With ACT, good to excellent clinical results are seen in isolated post-traumatic lesions of the knee joint in the younger patient, with the formation of hyaline or hyaline-like repair tissue. In the classic ACT technique, chondrocytes are isolated from small slices of cartilage harvested arthroscopically from a minor weight-bearing area of the injured knee. The extracellular matrix is removed by enzymatic digestion, and the cells are then expanded in monolayer culture. Once a sufficient number of cells has been obtained, the chondrocytes are implanted into the cartilage defect, using a periosteal patch over the defect as a method of cell containment. The major complications are periosteal hypertrophy, delamination of the transplant, arthrofibrosis and transplant failure. Further improvements in tissue engineering have contributed to the next generation of ACT techniques, where cells are combined with resorbable biomaterials, as in matrix-associated autologous chondrocyte transplantation (MACT). These biomaterials secure the cells in the defect area and enhance their proliferation and differentiation.

  15. Distinct responses of protein turnover regulatory pathways in hypoxia- and semistarvation-induced muscle atrophy

    NARCIS (Netherlands)

    de Theije, Chiel C.; Langen, Ramon C. J.; Lamers, Wouter H.; Schols, Annemie M. W. J.; Köhler, S. Eleonore

    2013-01-01

    The balance of muscle protein synthesis and degradation determines skeletal muscle mass. We hypothesized that hypoxia-induced muscle atrophy and alterations in the regulation of muscle protein turnover include a hypoxia-specific component, in addition to the observed effects of reduction in food

  16. Osteoarthritis: Control of human cartilage hypertrophic differentiation. Research highlight van: Gremlin1, frizzled-related protein, and Dkk-1 are key regulators of human articular cartilage homeostasis

    NARCIS (Netherlands)

    Buckland, J.; Leijten, Jeroen Christianus Hermanus; van Blitterswijk, Clemens; Karperien, Hermanus Bernardus Johannes

    2012-01-01

    Disruption of articular cartilage homeostasis is important in osteoarthritis (OA) pathogenesis, key to which is activation of articular chondrocyte hypertrophic differentiation. Healthy articular cartilage is resistant to hypertrophic differentiation, whereas growth-plate cartilage is destined to

  17. Empirical Prediction of Turnovers in NFL Football

    Directory of Open Access Journals (Sweden)

    Joel R. Bock

    2016-12-01

    Full Text Available Turnovers in the National Football League (NFL occur whenever a team loses possession of the ball due to a fumble, or an interception. Turnovers disrupt momentum of the offensive team, and represent lost opportunities to advance downfield and score. Teams with a positive differential turnover margin in a given game win 70 % of the time. Turnovers are statistically rare events, occurring apparently randomly. These characteristics make them difficult to predict. This investigation advances the hypothesis that turnovers are predictable in NFL football. Machine learning models are developed to learn the concept: At any point within a football game, what is the likelihood that a turnover will be observed on the next play from scrimmage? NFL play-by-play data for 32 teams spanning seven full seasons were used to train the models. Results presented suggest evidence to support the working hypothesis. Under certain conditions, both fumbles and interceptions can be anticipated at low false discovery rates (less than 15 % . When a turnover is predicted on the impending play from scrimmage, a high degree of confidence is associated with that prediction. The ability to anticipate catastrophic in-game events may lead to their management and control, ultimately improving the performance of individual athletes and their teams. This investigation contributes to the sports science literature by demonstrating the predictability of in-game events often considered to be essentially random in their occurrence. To the author’s knowledge, direct prediction of turnovers has not previously appeared in the literature, which has focused on retrospective statistical analyses of turnover margin in football games.

  18. Nurse turnover: a literature review - an update.

    Science.gov (United States)

    Hayes, Laureen J; O'Brien-Pallas, Linda; Duffield, Christine; Shamian, Judith; Buchan, James; Hughes, Frances; Laschinger, Heather K Spence; North, Nicola

    2012-07-01

    Concerns related to the complex issue of nursing turnover continue to challenge healthcare leaders in every sector of health care. Voluntary nurse turnover is shown to be influenced by a myriad of inter-related factors, and there is increasing evidence of its negative effects on nurses, patients and health care organizations. The objectives were to conduct a comprehensive review of the related literature to examine recent findings related to the issue of nursing turnover and its causes and consequences, and to identify on methodological challenges and the implications of new evidence for future studies. A comprehensive search of the recent literature related to nursing turnover was undertaken to summarize findings published in the past six years. Electronic databases: MEDLINE, CINAHL and PubMed, reference lists of journal publications. Keyword searches were conducted for publications published 2006 or later that examined turnover or turnover intention in employee populations of registered or practical/enrolled or assistant nurses working in the hospital, long-term or community care areas. Literature findings are presented using an integrative approach and a table format to report individual studies. From about 330 citations or abstracts that were initially scanned for content relevance, 68 studies were included in this summary review. The predominance of studies continues to focus on determinants of nurse turnover in acute care settings. Recent studies offer insight into generational factors that should be considered in strategies to promote stable staffing in healthcare organizations. Nursing turnover continues to present serious challenges at all levels of health care. Longitudinal research is needed to produce new evidence of the relationships between nurse turnover and related costs, and the impact on patients and the health care team. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Recent developments in scaffold-guided cartilage tissue regeneration.

    Science.gov (United States)

    Liao, Jinfeng; Shi, Kun; Ding, Qiuxia; Qu, Ying; Luo, Feng; Qian, Zhiyong

    2014-10-01

    Articular cartilage repair is one of the most challenging problems in biomedical engineering because the regenerative capacity of cartilage is intrinsically poor. The lack of efficient treatment modalities motivates researches into cartilage tissue engineering such as combing cells, scaffolds and growth factors. In this review we summarize the current developments on scaffold systems available for cartilage tissue engineering. The factors that are critical to successfully design an ideal scaffold for cartilage regeneration were discussed. Then we present examples of selected material types (natural polymers and synthetic polymers) and fabricated forms of the scaffolds (three-dimensional scaffolds, micro- or nanoparticles, and their composites). In the end of review, we conclude with an overview of the ways in which biomedical nanotechnology is widely applied in cartilage tissue engineering, especially in the design of composite scaffolds. This review attempts to provide recommendations on the combination of qualities that would produce the ideal scaffold system for cartilage tissue engineering.

  20. The influence of collagen network integrity on the accumulation of gadolinium-based MR contrast agents in articular cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Wiener, Edzard; Schmidt, C.; Diederichs, G. [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie; Settles, M. [Klinikum rechts der Isar, Muenchen (Germany). Inst. fuer Roentgendiagnostik; Weirich, G. [Klinikum Rechts der Isar, Muenchen (Germany). Inst. fuer Pathologie und Pathologische Anatomie

    2011-03-15

    Delayed gadolinium-enhanced MR imaging of cartilage is used to quantify the proteoglycan loss in early osteoarthritis. It is assumed that T 1 after Gd-DTPA administration in the near equilibrium state reflects selective proteoglycan loss from cartilage. To investigate the influence of the collagen network integrity on contrast accumulation, the relaxation rates {delta}R1 and {delta}R2 were compared after Gd-DTPA administration in a well established model of osteoarthritis. Collagen or proteoglycan depletion was induced by the proteolytic enzymes papain and collagenase in healthy bovine patellar cartilage. Using a dedicated MRI sequence, T{sub 1} and T{sub 2} maps were simultaneously acquired before and 11 h after Gd-DTPA administration. Depth-dependent profiles of {delta}R1 and {delta}R2 were calculated in healthy, proteoglycan and collagen-depleted articular cartilage and the mean values of different cartilage layers were compared using the Mann-Whitney-U test. In superficial layers (1 mm) there was no significant difference (p > 0.05) in either {delta}R1 or {delta}R2 between proteoglycan-depleted (16.6 {+-} 1.2 s{sup -1}, 15.9 {+-} 1.0 s{sup -1}) and collagen-depleted articular cartilage (15.3 {+-} 0.9 s{sup -1}, 15.5 {+-} 0.9 s{sup -1}). In deep layers (3 mm) both parameters were significantly higher (p = 0.005, 0.03) in proteoglycan-depleted articular cartilage (12.3 {+-} 1.1 s{sup -1}, 9.8 {+-} 0.8 s{sup -1}) than in collagen-depleted articular cartilage (9.1 {+-} 1.1 s{sup -1}, 8.7 {+-} 0.7 s{sup -1}). Both proteoglycan loss and alterations in the collagen network influence the accumulation of Gd-DTPA in articular cartilage with significant differences between superficial and deep cartilage layers. (orig.)

  1. The validation of the turnover intention scale

    Directory of Open Access Journals (Sweden)

    Chris F.C. Bothma

    2013-04-01

    Full Text Available Orientation: Turnover intention as a construct has attracted increased research attention in the recent past, but there are seemingly not many valid and reliable scales around to measure turnover intention. Research purpose: This study focused on the validation of a shortened, six-item version of the turnover intention scale (TIS-6. Motivation for the study: The research question of whether the TIS-6 is a reliable and a valid scale for measuring turnover intention and for predicting actual turnover was addressed in this study. Research design, approach and method: The study was based on a census-based sample (n= 2429 of employees in an information, communication and technology (ICT sector company (N= 23 134 where the TIS-6 was used as one of the criterion variables. The leavers (those who left the company in this sample were compared with the stayers (those who remained in the employ of the company in this sample in respect of different variables used in the study. Main findings: It was established that the TIS-6 could measure turnover intentions reliably (α= 0.80. The TIS-6 could significantly distinguish between leavers and stayers (actual turnover, thereby confirming its criterion-predictive validity. The scale also established statistically significant differences between leavers and stayers in respect of a number of the remaining theoretical variables used in the study, thereby also confirming its differential validity. These comparisons were conducted for both the 4-month and the 4-year period after the survey was conducted. Practical/managerial implications: Turnover intention is related to a number of variables in the study which necessitates a reappraisal and a reconceptualisation of existing turnover intention models. Contribution/value-add: The TIS-6 can be used as a reliable and valid scale to assess turnover intentions and can therefore be used in research to validly and reliably assess turnover intentions or to

  2. AN ECONOMETRIC APPROACH ABOUT VOLUNTARY TURNOVER

    Directory of Open Access Journals (Sweden)

    ADALET EREN

    2013-06-01

    Full Text Available This study analyzes individual and organizational variables that affect voluntary turnover are determined in the special defence and security companies. A binomial logistic regression model is used to estimate voluntary turnover.  Binomial Logistic regression, reliability test (scale alfa, variance (ANOVA, Post-hoc/Tukey, correlation (Pearson and other basic statistical techniques  with SPSS 13 statistical packet program was used in the analyzes ofresearch data. The study finds that; situation of suppose working, number of child, number of death child, number of home’s moving, support of rent, total monthly income of household, last work’s region, number of prizes, affect voluntary turnover are determined.

  3. Magnetization transfer analysis of cartilage repair tissue: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Palmieri, F. [University ' Federico II' , Department of Radiology, Naples (Italy); Keyzer, F. de [University Hospitals Leuven, Department of Radiology, Leuven (Belgium); Maes, F. [Catholic University Leuven, Department of Electrotechnics, Faculty of Engineering, Leuven (Belgium); Breuseghem, I. van [Ghent University Hospital, Department of Radiology, Gent (Belgium)

    2006-12-15

    To evaluate the magnetization transfer ratio (MTR) after two different cartilage repair procedures, and to compare these data with the MTR of normal cartilage. Twenty-seven patients with a proven cartilage defect were recruited: 13 were treated with autologous chondrocyte implantation (ACI) and 14 were treated with the microfracture technique (MFR). All patients underwent MRI examinations with MT-sequences before the surgical treatment, after 12 months (26 patients) and after 24 months (11 patients). Eleven patients received a complete follow-up study at all three time points (five of the ACI group and six of the MFR group). All images were transferred to a workstation to calculate MTR images. For every MT image set, different ROIs were delineated by two radiologists. Means were calculated per ROI type in the different time frames and in both groups of cartilage repair. The data were analyzed with unpaired t- and ANOVA tests, and by calculating Pearson's correlation coefficient. No significant differences were found in the MTR of fatty bone marrow, muscle and normal cartilage in the different time frames. There was a significant but small difference between the MTR of normal cartilage and the cartilage repair area after 12 months for both procedures. After 24 months, the MTR of ACI repaired cartilage (0.31{+-}0.07) was not significantly different from normal cartilage MTR (0.34{+-}0.05). The MTR of MFR repaired cartilage (0.28{+-}0.02), still showed a significant difference from normal cartilage. The differences between damaged and repaired cartilage MTR are too small to enable MT-imaging to be a useful tool for postoperative follow-up of cartilage repair procedures. There is, however, an evolution towards normal MTR-values in the cartilage repair tissue (especially after ACI repair). (orig.)

  4. Magnetization transfer analysis of cartilage repair tissue: a preliminary study

    International Nuclear Information System (INIS)

    Palmieri, F.; Keyzer, F. de; Maes, F.; Breuseghem, I. van

    2006-01-01

    To evaluate the magnetization transfer ratio (MTR) after two different cartilage repair procedures, and to compare these data with the MTR of normal cartilage. Twenty-seven patients with a proven cartilage defect were recruited: 13 were treated with autologous chondrocyte implantation (ACI) and 14 were treated with the microfracture technique (MFR). All patients underwent MRI examinations with MT-sequences before the surgical treatment, after 12 months (26 patients) and after 24 months (11 patients). Eleven patients received a complete follow-up study at all three time points (five of the ACI group and six of the MFR group). All images were transferred to a workstation to calculate MTR images. For every MT image set, different ROIs were delineated by two radiologists. Means were calculated per ROI type in the different time frames and in both groups of cartilage repair. The data were analyzed with unpaired t- and ANOVA tests, and by calculating Pearson's correlation coefficient. No significant differences were found in the MTR of fatty bone marrow, muscle and normal cartilage in the different time frames. There was a significant but small difference between the MTR of normal cartilage and the cartilage repair area after 12 months for both procedures. After 24 months, the MTR of ACI repaired cartilage (0.31±0.07) was not significantly different from normal cartilage MTR (0.34±0.05). The MTR of MFR repaired cartilage (0.28±0.02), still showed a significant difference from normal cartilage. The differences between damaged and repaired cartilage MTR are too small to enable MT-imaging to be a useful tool for postoperative follow-up of cartilage repair procedures. There is, however, an evolution towards normal MTR-values in the cartilage repair tissue (especially after ACI repair). (orig.)

  5. Improvements to Kramers turnover theory.

    Science.gov (United States)

    Pollak, Eli; Ankerhold, Joachim

    2013-04-28

    The Kramers turnover problem, that is, obtaining a uniform expression for the rate of escape of a particle over a barrier for any value of the external friction was solved in the 1980s. Two formulations were given, one by Mel'nikov and Meshkov (MM) [V. I. Mel'nikov and S. V. Meshkov, J. Chem. Phys. 85, 1018 (1986)], which was based on a perturbation expansion for the motion of the particle in the presence of friction. The other, by Pollak, Grabert, and Hänggi (PGH) [E. Pollak, H. Grabert, and P. Hänggi, J. Chem. Phys. 91, 4073 (1989)], valid also for memory friction, was based on a perturbation expansion for the motion along the collective unstable normal mode of the particle. Both theories did not take into account the temperature dependence of the average energy loss to the bath. Increasing the bath temperature will reduce the average energy loss. In this paper, we analyse this effect, using a novel perturbation theory. We find that within the MM approach, the thermal energy gained from the bath diverges, the average energy gain becomes infinite implying an essential failure of the theory. Within the PGH approach increasing the bath temperature reduces the average energy loss but only by a finite small amount of the order of the inverse of the reduced barrier height. Then, this does not seriously affect the theory. Analysis and application for a cubic potential and Ohmic friction are presented.

  6. Freeze-thaw treatment effects on the dynamic mechanical properties of articular cartilage

    Directory of Open Access Journals (Sweden)

    Muldrew Ken

    2010-10-01

    Full Text Available Abstract Background As a relatively non-regenerative tissue, articular cartilage has been targeted for cryopreservation as a method of mitigating a lack of donor tissue availability for transplant surgeries. In addition, subzero storage of articular cartilage has long been used in biomedical studies using various storage temperatures. The current investigation studies the potential for freeze-thaw to affect the mechanical properties of articular cartilage through direct comparison of various subzero storage temperatures. Methods Both subzero storage temperature as well as freezing rate were compared using control samples (4°C and samples stored at either -20°C or -80°C as well as samples first snap frozen in liquid nitrogen (-196°C prior to storage at -80°C. All samples were thawed at 37.5°C to testing temperature (22°C. Complex stiffness and hysteresis characterized load resistance and damping properties using a non-destructive, low force magnitude, dynamic indentation protocol spanning a broad loading rate range to identify the dynamic viscoelastic properties of cartilage. Results Stiffness levels remained unchanged with exposure to the various subzero temperatures. Hysteresis increased in samples snap frozen at -196°C and stored at -80°C, though remained unchanged with exposure to the other storage temperatures. Conclusions Mechanical changes shown are likely due to ice lens creation, where frost heave effects may have caused collagen damage. That storage to -20°C and -80°C did not alter the mechanical properties of articular cartilage shows that when combined with a rapid thawing protocol to 37.5°C, the tissue may successfully be stored at subzero temperatures.

  7. Chemical changes demonstrated in cartilage by synchrotron infrared microspectroscopy in an antibody-induced murine model of rheumatoid arthritis

    Science.gov (United States)

    Croxford, Allyson M.; Selva Nandakumar, Kutty; Holmdahl, Rikard; Tobin, Mark J.; McNaughton, Don; Rowley, Merrill J.

    2011-06-01

    Collagen antibody-induced arthritis develops in mice following passive transfer of monoclonal antibodies (mAbs) to type II collagen (CII) and is attributed to effects of proinflammatory immune complexes, but transferred mAbs may react directly and damagingly with CII. To determine whether such mAbs cause cartilage damage in vivo in the absence of inflammation, mice lacking complement factor 5 that do not develop joint inflammation were injected intravenously with two arthritogenic mAbs to CII, M2139 and CIIC1. Paws were collected at day 3, decalcified, paraffin embedded, and 5-μm sections were examined using standard histology and synchrotron Fourier-transform infrared microspectroscopy (FTIRM). None of the mice injected with mAb showed visual or histological evidence of inflammation but there were histological changes in the articular cartilage including loss of proteoglycan and altered chondrocyte morphology. Findings using FTIRM at high lateral resolution revealed loss of collagen and the appearance of a new peak at 1635 cm-1 at the surface of the cartilage interpreted as cellular activation. Thus, we demonstrate the utility of synchrotron FTIRM for examining chemical changes in diseased cartilage at the microscopic level and establish that arthritogenic mAbs to CII do cause cartilage damage in vivo in the absence of inflammation.

  8. Endogenous Turnover of Cyanogenic Glycosides in Plants

    DEFF Research Database (Denmark)

    Picmanova, Martina

    through the formation of β- cyanoalanine, or, potentially, in an alternative endogenous turnover pathway circumventing the release of HCN. The investigation of the latter is the primary focus of this PhD project. Scattered data from the literature indicated that CNglcs co-occur in plants...... revealed the formation of glycosides of amides, carboxylic acids and "anitriles", including their di- and triglycosides, evidently derived from CNglcs. Based on results common to the three phylogenetically unrelated plant species, a recycling endogenous turnover pathway for CNglcs was suggested in which...... with an N-terminal TCP domain, showed that these enzymes do not recognize CNglcs as their substrates. However, the activity of NIT4s on a nitrile glucoside indicates that the enzymatic formation of glycosylated turnover products might be an integral part of the endogenous turnover of CNglcs. The elucidation...

  9. Organisational Commitment, Job Satisfaction and Turnover ...

    African Journals Online (AJOL)

    This study investigated organisational commitment, job satisfaction and turnover intentions among records management personnel in Ondo State Civil Service, Akure, Nigeria. Simple random sampling technique was used to draw 240 subjects from a population size of 275 records management personnel.

  10. Spatial turnover in the global avifauna.

    Science.gov (United States)

    Gaston, Kevin J; Davies, Richard G; Orme, C David L; Olson, Valerie A; Thomas, Gavin H; Ding, Tzung-Su; Rasmussen, Pamela C; Lennon, Jack J; Bennett, Peter M; Owens, Ian P F; Blackburn, Tim M

    2007-07-07

    Despite its wide implications for many ecological issues, the global pattern of spatial turnover in the occurrence of species has been little studied, unlike the global pattern of species richness. Here, using a database on the breeding distributions of birds, we present the first global maps of variation in spatial turnover for an entire taxonomic class, a pattern that has to date remained largely a matter of conjecture, based on theoretical expectations and extrapolation of inconsistent patterns from different biogeographic realms. We use these maps to test four predictions from niche theory as to the form that this variation should take, namely that turnover should increase with species richness, towards lower latitudes, and with the steepness of environmental gradients and that variation in turnover is determined principally by rare (restricted) species. Contrary to prediction, we show that turnover is high both in areas of extremely low and high species richness, does not increase strongly towards the tropics, and is related both to average environmental conditions and spatial variation in those conditions. These results are closely associated with a further important and novel finding, namely that global patterns of spatial turnover are driven principally by widespread species rather than the restricted ones. This complements recent demonstrations that spatial patterns of species richness are also driven principally by widespread species, and thus provides an important contribution towards a unified model of how terrestrial biodiversity varies both within and between the Earth's major land masses.

  11. Hydrogels as a Replacement Material for Damaged Articular Hyaline Cartilage

    Directory of Open Access Journals (Sweden)

    Charlotte M. Beddoes

    2016-06-01

    Full Text Available Hyaline cartilage is a strong durable material that lubricates joint movement. Due to its avascular structure, cartilage has a poor self-healing ability, thus, a challenge in joint recovery. When severely damaged, cartilage may need to be replaced. However, currently we are unable to replicate the hyaline cartilage, and as such, alternative materials with considerably different properties are used. This results in undesirable side effects, including inadequate lubrication, wear debris, wear of the opposing articular cartilage, and weakening of the surrounding tissue. With the number of surgeries for cartilage repair increasing, a need for materials that can better mimic cartilage, and support the surrounding material in its typical function, is becoming evident. Here, we present a brief overview of the structure and properties of the hyaline cartilage and the current methods for cartilage repair. We then highlight some of the alternative materials under development as potential methods of repair; this is followed by an overview of the development of tough hydrogels. In particular, double network (DN hydrogels are a promising replacement material, with continually improving physical properties. These hydrogels are coming closer to replicating the strength and toughness of the hyaline cartilage, while offering excellent lubrication. We conclude by highlighting several different methods of integrating replacement materials with the native joint to ensure stability and optimal behaviour.

  12. Knee cartilage segmentation and thickness computation from ultrasound images.

    Science.gov (United States)

    Faisal, Amir; Ng, Siew-Cheok; Goh, Siew-Li; Lai, Khin Wee

    2018-04-01

    Quantitative thickness computation of knee cartilage in ultrasound images requires segmentation of a monotonous hypoechoic band between the soft tissue-cartilage interface and the cartilage-bone interface. Speckle noise and intensity bias captured in the ultrasound images often complicates the segmentation task. This paper presents knee cartilage segmentation using locally statistical level set method (LSLSM) and thickness computation using normal distance. Comparison on several level set methods in the attempt of segmenting the knee cartilage shows that LSLSM yields a more satisfactory result. When LSLSM was applied to 80 datasets, the qualitative segmentation assessment indicates a substantial agreement with Cohen's κ coefficient of 0.73. The quantitative validation metrics of Dice similarity coefficient and Hausdorff distance have average values of 0.91 ± 0.01 and 6.21 ± 0.59 pixels, respectively. These satisfactory segmentation results are making the true thickness between two interfaces of the cartilage possible to be computed based on the segmented images. The measured cartilage thickness ranged from 1.35 to 2.42 mm with an average value of 1.97 ± 0.11 mm, reflecting the robustness of the segmentation algorithm to various cartilage thickness. These results indicate a potential application of the methods described for assessment of cartilage degeneration where changes in the cartilage thickness can be quantified over time by comparing the true thickness at a certain time interval.

  13. Cartilage collagen type II seromarker patterns in axial spondyloarthritis and psoriatic arthritis

    DEFF Research Database (Denmark)

    Munk, Heidi Lausten; Gudmann, Natasja Staehr; Christensen, Anne Friesgaard

    2016-01-01

    The aim of the study was to assess the possible association between type II collagen turnover seromarkers and disease profile in patients with axial spondyloarthritis (SpA) and psoriatic arthritis (PsA). Outpatients with axial SpA (n = 110) or PsA (n = 101) underwent clinical examination including......-smokers, 0.43 ng/ml (p = 0.02), while PIIANP was higher in HLA-B27 positive, 2312 ng/ml versus negative patients, 2021 ng/ml (p = 0.03). In PsA, PIIANP and C2M did not differ between patients and controls, but PIIANP was elevated in patients not receiving DMARDs, 2726 ng/ml. In PsA, PIIANP and C2M did...... not differ according to smoking and HLA-B27. Cartilage degradation assessed by C2M is increased in SpA irrespective of treatment but not in PsA. Cartilage synthesis reflected by PIIANP is increased in untreated SpA and PsA. PIIANP correlates with CRP in SpA while not in PsA. In DMARD-naïve SpA but not in PsA...

  14. The Effects of Employee Turnover on Those Who Stay.

    Science.gov (United States)

    Sheehan, Eugene P.; Hockett, Cherri

    Research on employee turnover which has examined why employees quit their jobs has identified a wide range of variables that are associated with turnover, but has provided little information about the consequences of turnover for those who remain in an organization. This study was conducted to examine whether the manner in which turnover is…

  15. Addressing employee turnover and retention: keeping your valued performers.

    Science.gov (United States)

    McConnell, Charles R

    2011-01-01

    Employee turnover and employee retention are inextricably linked; to control turnover is to enhance retention. Turnover is a relatively simple concept; however, considerable confusion often results when addressing turnover because of differences in how it is defined; that is, what is counted, how it is counted, and how the turnover rates are expressed. Turnover is also costly, although not enough attention is paid to its cost because so much of it is indirect and thus not readily visible. There are a variety of causes of turnover, some that can be corrected and some that cannot be avoided. Reducing or otherwise controlling turnover requires continuing management attention to its causes and constant recognition of what can and should be controlled and what cannot be controlled. Ongoing attention to turnover is an essential part of the department manager's role; every improvement in turnover is a direct improvement in retention, with eventual positive effects on the bottom line.

  16. The minor collagens in articular cartilage

    DEFF Research Database (Denmark)

    Luo, Yunyun; Sinkeviciute, Dovile; He, Yi

    2017-01-01

    , especially minor collagens, including type IV, VI, IX, X, XI, XII, XIII, and XIV, etc. Although accounting for only a small fraction of the mature matrix, these minor collagens not only play essential structural roles in the mechanical properties, organization, and shape of articular cartilage, but also...... these minor collagens. The generation and release of fragmented molecules could generate novel biochemical markers with the capacity to monitor disease progression, facilitate drug development and add to the existing toolbox for in vitro studies, preclinical research and clinical trials....... fulfil specific biological functions. Genetic studies of these minor collagens have revealed that they are associated with multiple connective tissue diseases, especially degenerative joint disease. The progressive destruction of cartilage involves the degradation of matrix constituents including...

  17. Modified technique to increase nostril cross-sectional area after using rib and septal cartilage graft over alar nasal cartilages.

    Science.gov (United States)

    Wulkan, Marcelo; Sá, Alvaro Julio de Andrade; Alonso, Nivaldo

    2012-10-01

    Describe a modified technique to increase nostril cross-sectional area using rib and septal cartilage graft over alar nasal cartilages. A modified surgical technique was used to obtain, carve and insert cartilage grafts over alar nasal cartilages. This study used standardized pictures and measured 90 cadaveric nostril cross-sectional area using Autocad(®); 30 were taken before any procedure and 60 were taken after grafts over lateral crura (30 using costal cartilage and 30 using septal cartilage). Statistical analysis were assessed using a model for repeated measures and ANOVA (Analysis of Variance) for the variable "area". There's statistical evidence that rib cartilage graft is more effective than septal cartilage graft. The mean area after the insertion of septal cartilage graft is smaller than the mean area under rib graft treatment (no confidence interval for mean difference contains the zero value and all P-values are below the significance level of 5%). The technique presented is applicable to increase nostril cross section area in cadavers. This modified technique revealed to enhance more nostril cross section area with costal cartilage graft over lateral crura rather than by septal graft.

  18. Dietary loading and aggrecanase-1/TIMP-3 expression in rat mandibular condylar cartilage.

    Science.gov (United States)

    Yu, Dahai; Tiilikainen, Petri; Raustia, Aune; Pirttiniemi, Pertti

    2007-01-01

    To examine the expression of aggrecanase-1 and a tissue inhibitor of metalloproteinases (TIMP-3) in the condylar cartilage of young rats and to determine their relationship during altered dietary loading at different time points after weaning. One hundred Sprague-Dawley rats were randomly assigned to 1 of 2 groups: the soft-diet group, which served as the control group (n=50), or the hard-diet group, which served as the experimental group (n=50). Ten soft- and 10 hard-diet rats were killed at 6 hours, 12 hours, 24 hours, 48 hours, and 9 days after weaning (i.e., after initiation of diet change for hard-diet rats). The right-side temporomandibular joints (TMJs) were prepared for immunohistochemical staining. The cartilage from the left-side mandibular condyles of all 10 animals in each group was combined for Western blot analysis. Immunohistochemical analysis revealed strong staining for aggrecanase-1 localized mainly in the chondrocytes of proliferative and upper hypertrophic cartilage zones at all time points in both groups. The immunohistological expression of aggrecanase-1 was significantly higher in the hard-diet group at 12 and 24 hours than in the soft-diet group. Strong staining for TIMP-3 was mainly localized in the chondrocytes of proliferative and upper hypertrophic zones at all time points in both groups. The expression of TIMP-3 in the hard-diet group was at a significantly lower level compared to the soft-diet group at 6 hours. Western blot analysis also showed time-related differences in aggrecanase-1 and TIMP-3, but there was no significant difference between the 2 groups. The temporary change in aggrecanase-1 and TIMP-3 expression reflects the complex interaction of these enzymes in the physiologic range and cartilage response to altered dietary loading.

  19. Cellular reprogramming for clinical cartilage repair

    OpenAIRE

    Driessen, Britta J.H.; Logie, Colin; Vonk, Lucienne A.

    2017-01-01

    The repair of articular cartilage needs a sufficient number of chondrocytes to replace the defect tissue, and therefore, expansion of cells is generally required. Chondrocytes derived by cellular reprogramming may provide a solution to the limitations of current (stem) cell-based therapies. In this article, two distinct approaches?induced pluripotent stem cell (iPSC)-mediated reprogramming and direct lineage conversion?are analysed and compared according to criteria that encompass the qualifi...

  20. Processed bovine cartilage: an improved biosynthetic implant for contour defects

    Energy Technology Data Exchange (ETDEWEB)

    Ersek, R.A.; Hart, W.G. Jr.; Greer, D.; Beisang, A.A.; Flynn, P.J.; Denton, D.R.

    1984-05-01

    Irradiated human cartilage has been found to be a superior implant material for correction of contour defects; however, availability problems have prevented this material from gaining wide acceptance. Implantation of processed irradiated bovine cartilage in primates and rabbits, as described here, provides strong evidence that this material performs like irradiated allograft cartilage antigenically and has certain cosmetic advantages over allograft cartilage. Our studies in primates have shown that there is no systemically measurable antibody-antigen reaction, either cellular or noncellular, to irradiated processed bovine cartilage. Neither primary nor second-set provocative implantations produced any measurable rejection. In rabbits, composite grafts of two pieces of irradiated bovine cartilage adjacent to each other were also well tolerated, with no measurable absorption and with capsule formation typical of a foreign body reaction to an inert object.

  1. Secondary Cartilage Revealed in a Non-Avian Dinosaur Embryo

    OpenAIRE

    Bailleul, Alida M.; Hall, Brian K.; Horner, John R.

    2013-01-01

    The skull and jaws of extant birds possess secondary cartilage, a tissue that arises after bone formation during embryonic development at articulations, ligamentous and muscular insertions. Using histological analysis, we discovered secondary cartilage in a non-avian dinosaur embryo, Hypacrosaurus stebingeri (Ornithischia, Lambeosaurinae). This finding extends our previous report of secondary cartilage in post-hatching specimens of the same dinosaur species. It provides the first information ...

  2. AMIC Cartilage Repair in a Professional Soccer Player

    OpenAIRE

    Bark, S.; Riepenhof, H.; Gille, J.

    2012-01-01

    We report a case of a professional soccer player suffering from a traumatic cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle treated with an enhanced microfracture technique (AMIC). Autologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. Because of the cartilage lesion (3 cm2), an AMIC procedure was perfo...

  3. Predictors of Staff Turnover and Turnover Intentions within Addiction Treatment Settings: Change over Time Matters

    Directory of Open Access Journals (Sweden)

    Bryan R. Garner

    2014-01-01

    Full Text Available This study examined the extent to which changes over time in clinicians’ responses to measures of work attitude (eg, job satisfaction and psychological climate (eg, supervisor support could predict actual turnover and turnover intentions above and beyond absolute levels of these respective measures. Longitudinal data for this study were collected from a sample of clinicians ( N = 96 being trained to implement an evidence-based treatment for adolescent substance use disorders. Supporting findings from a recent staff turnover study, we found job satisfaction change was able to predict actual turnover above and beyond average levels of job satisfaction. Representing new contributions to the staff turnover literature, we also found that change over time in several other key measures (eg, job satisfaction, role manageability, role clarity explained a significant amount of variance in turnover intentions above and beyond the absolute level of each respective measure. A key implication of the current study is that organizations seeking to improve their ability to assess risk for staff turnover may want to consider assessing staff at multiple points in time in order to identify systematic changes in key employee attitudes like turnover intentions and job satisfaction.

  4. Role of tenascin-C in articular cartilage.

    Science.gov (United States)

    Hasegawa, Masahiro; Yoshida, Toshimichi; Sudo, Akihiro

    2018-03-01

    Tenascin-C (TN-C) is a glycoprotein component of the extracellular matrix (ECM). TN-C consists of four distinct domains, including the tenascin assembly domain, epidermal growth factor-like repeats, fibronectin type III-like repeats, and the fibrinogen-like globe (FBG) domain. This review summarizes the role of TN-C in articular cartilage. Expression of TN-C is associated with the development of articular cartilage but markedly decreases during maturation of chondrocytes and disappears almost completely in adult articular cartilage. Increased expression of TN-C has been found at diseased cartilage and synovial sites in osteoarthritis (OA) and rheumatoid arthritis (RA). TN-C is increased in the synovial fluid in patients with OA and RA. In addition, serum TN-C is elevated in RA patients. TN-C could be a useful biochemical marker for joint disease. The addition of TN-C results in different effects among TN-C domains. TN-C fragments might be endogenous inducers of cartilage matrix degradation; however, full-length TN-C could promote cartilage repair and prevent cartilage degeneration. The deficiency of TN-C enhanced cartilage degeneration in the spontaneous OA in aged joints and surgical OA model. The clinical significance of TN-C effects on cartilage is not straightforward.

  5. Mesenchymal Stem Cells for Treating Articular Cartilage Defects and Osteoarthritis.

    Science.gov (United States)

    Wang, Yu; Yuan, Mei; Guo, Quan-yi; Lu, Shi-bi; Peng, Jiang

    2015-01-01

    Articular cartilage damage and osteoarthritis are the most common joint diseases. Joints are prone to damage caused by sports injuries or aging, and such damage regularly progresses to more serious joint disorders, including osteoarthritis, which is a degenerative disease characterized by the thinning and eventual wearing out of articular cartilage, ultimately leading to joint destruction. Osteoarthritis affects millions of people worldwide. Current approaches to repair of articular cartilage damage include mosaicplasty, microfracture, and injection of autologous chondrocytes. These treatments relieve pain and improve joint function, but the long-term results are unsatisfactory. The long-term success of cartilage repair depends on development of regenerative methodologies that restore articular cartilage to a near-native state. Two promising approaches are (i) implantation of engineered constructs of mesenchymal stem cell (MSC)-seeded scaffolds, and (ii) delivery of an appropriate population of MSCs by direct intra-articular injection. MSCs may be used as trophic producers of bioactive factors initiating regenerative activities in a defective joint. Current challenges in MSC therapy are the need to overcome current limitations in cartilage cell purity and to in vitro engineer tissue structures exhibiting the required biomechanical properties. This review outlines the current status of MSCs used in cartilage tissue engineering and in cell therapy seeking to repair articular cartilage defects and related problems. MSC-based technologies show promise when used to repair cartilage defects in joints.

  6. Evaluation of laryngeal cartilage calcification in computed tomography

    International Nuclear Information System (INIS)

    Laskowska, K.; Serafin, Z.; Lasek, W.; Maciejewski, M.; Wieczor, W.; Wisniewski, S.

    2008-01-01

    Computed tomography (CT) is one of the basic methods used for laryngeal carcinoma diagnostics. Osteosclerotic and osteolytic changes of the cartilages are considered as a common radiologic symptom of laryngeal neoplasms. The aim of this paper was to evaluate the prevalence of both osteosclerotic changes and focal calcification defects, which may be suggestive of osteolysis. Calcification was assessed in the thyroid, the cricoid and the arytenoids cartilages on CT images of the neck. We have retrospectively analyzed neck CT examinations of 50 patients without any laryngeal pathology in anamnesis. The grade and symmetry of calcifications was assessed in the thyroid, the cricoid and the arytenoids cartilages. Calcification of the laryngeal cartilages was present in 83% of the patients. Osteosclerotic lesions of the thyroid cartilage were seen in 70% of the patients (asymmetric in 60% of them), of the cricoid catrilage in 50% (asymmetric in 60%), and of the arytenoid cartilages in 24% (asymmetric in 67%). Focal calcification defects were present in the thyroid cartilage in 56% of the patients (asymmetric in 67% of them), in the cricoid catrilage in 8% (asymmetric in all cases), and in the arytenoid cartilages in 20% (asymmetric in 90%). Osteosclerotic changes and focal calcification defects, which may suggest osteolysis, were found in most of the patients. Therefore, they cannot be used as crucial radiological criteria of neoplastic invasion of laryngeal cartilages. (authors)

  7. Secondary cartilage revealed in a non-avian dinosaur embryo.

    Science.gov (United States)

    Bailleul, Alida M; Hall, Brian K; Horner, John R

    2013-01-01

    The skull and jaws of extant birds possess secondary cartilage, a tissue that arises after bone formation during embryonic development at articulations, ligamentous and muscular insertions. Using histological analysis, we discovered secondary cartilage in a non-avian dinosaur embryo, Hypacrosaurus stebingeri (Ornithischia, Lambeosaurinae). This finding extends our previous report of secondary cartilage in post-hatching specimens of the same dinosaur species. It provides the first information on the ontogeny of avian and dinosaurian secondary cartilages, and further stresses their developmental similarities. Secondary cartilage was found in an embryonic dentary within a tooth socket where it is hypothesized to have arisen due to mechanical stresses generated during tooth formation. Two patterns were discerned: secondary cartilage is more restricted in location in this Hypacrosaurus embryo, than it is in Hypacrosaurus post-hatchlings; secondary cartilage occurs at far more sites in bird embryos and nestlings than in Hypacrosaurus. This suggests an increase in the number of sites of secondary cartilage during the evolution of birds. We hypothesize that secondary cartilage provided advantages in the fine manipulation of food and was selected over other types of tissues/articulations during the evolution of the highly specialized avian beak from the jaws of their dinosaurian ancestors.

  8. Secondary cartilage revealed in a non-avian dinosaur embryo.

    Directory of Open Access Journals (Sweden)

    Alida M Bailleul

    Full Text Available The skull and jaws of extant birds possess secondary cartilage, a tissue that arises after bone formation during embryonic development at articulations, ligamentous and muscular insertions. Using histological analysis, we discovered secondary cartilage in a non-avian dinosaur embryo, Hypacrosaurus stebingeri (Ornithischia, Lambeosaurinae. This finding extends our previous report of secondary cartilage in post-hatching specimens of the same dinosaur species. It provides the first information on the ontogeny of avian and dinosaurian secondary cartilages, and further stresses their developmental similarities. Secondary cartilage was found in an embryonic dentary within a tooth socket where it is hypothesized to have arisen due to mechanical stresses generated during tooth formation. Two patterns were discerned: secondary cartilage is more restricted in location in this Hypacrosaurus embryo, than it is in Hypacrosaurus post-hatchlings; secondary cartilage occurs at far more sites in bird embryos and nestlings than in Hypacrosaurus. This suggests an increase in the number of sites of secondary cartilage during the evolution of birds. We hypothesize that secondary cartilage provided advantages in the fine manipulation of food and was selected over other types of tissues/articulations during the evolution of the highly specialized avian beak from the jaws of their dinosaurian ancestors.

  9. The Application of Sheet Technology in Cartilage Tissue Engineering.

    Science.gov (United States)

    Ge, Yang; Gong, Yi Yi; Xu, Zhiwei; Lu, Yanan; Fu, Wei

    2016-04-01

    Cartilage tissue engineering started to act as a promising, even essential alternative method in the process of cartilage repair and regeneration, considering adult avascular structure has very limited self-renewal capacity of cartilage tissue in adults and a bottle-neck existed in conventional surgical treatment methods. Recent progressions in tissue engineering realized the development of more feasible strategies to treat cartilage disorders. Of these strategies, cell sheet technology has shown great clinical potentials in the regenerative areas such as cornea and esophagus and is increasingly considered as a potential way to reconstruct cartilage tissues for its non-use of scaffolds and no destruction of matrix secreted by cultured cells. Acellular matrix sheet technologies utilized in cartilage tissue engineering, with a sandwich model, can ingeniously overcome the drawbacks that occurred in a conventional acellular block, where cells are often blocked from migrating because of the non-nanoporous structure. Electrospun-based sheets with nanostructures that mimic the natural cartilage matrix offer a level of control as well as manipulation and make them appealing and widely used in cartilage tissue engineering. In this review, we focus on the utilization of these novel and promising sheet technologies to construct cartilage tissues with practical and beneficial functions.

  10. Growth rate correlates negatively with protein turnover in Arabidopsis accessions.

    Science.gov (United States)

    Ishihara, Hirofumi; Moraes, Thiago Alexandre; Pyl, Eva-Theresa; Schulze, Waltraud X; Obata, Toshihiro; Scheffel, André; Fernie, Alisdair R; Sulpice, Ronan; Stitt, Mark

    2017-08-01

    Previous studies with Arabidopsis accessions revealed that biomass correlates negatively to dusk starch content and total protein, and positively to the maximum activities of enzymes in photosynthesis. We hypothesized that large accessions have lower ribosome abundance and lower rates of protein synthesis, and that this is compensated by lower rates of protein degradation. This would increase growth efficiency and allow more investment in photosynthetic machinery. We analysed ribosome abundance and polysome loading in 19 accessions, modelled the rates of protein synthesis and compared them with the observed rate of growth. Large accessions contained less ribosomes than small accessions, due mainly to cytosolic ribosome abundance falling at night in large accessions. The modelled rates of protein synthesis resembled those required for growth in large accessions, but were up to 30% in excess in small accessions. We then employed 13 CO 2 pulse-chase labelling to measure the rates of protein synthesis and degradation in 13 accessions. Small accessions had a slightly higher rate of protein synthesis and much higher rates of protein degradation than large accessions. Protein turnover was negligible in large accessions but equivalent to up to 30% of synthesised protein day -1 in small accessions. We discuss to what extent the decrease in growth in small accessions can be quantitatively explained by known costs of protein turnover and what factors may lead to the altered diurnal dynamics and increase of ribosome abundance in small accessions, and propose that there is a trade-off between protein turnover and maximisation of growth rate. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  11. Biochemical markers of bone turnover in benign paroxysmal positional vertigo

    Science.gov (United States)

    Lee, Sun Bin; Lee, Chang Ho; Kim, Young Ju; Kim, Hyoung-Mi

    2017-01-01

    Objective Several studies have suggested a possible relationship between recurrent benign paroxysmal positional vertigo (BPPV) and altered calcium homeostasis in the endolymph of the inner ear. The present study aimed to evaluate the association between Ca2+ and vitamin D status and BPPV occurrence as well as the status of bone biochemical markers in osteoporotic patients who were diagnosed with idiopathic BPPV. Methods The study included total 132 patients who were referred to our clinic between August 2008 and October 2013. Based on the bone mineral density (BMD) results, the subjects were divided into three groups: normal BMD (n = 34), osteopenia (n = 40) and osteoporosis (n = 58). The biochemical markers of bone turnover including serum Carboxy-terminal telopeptide of type I collagen (s-CTX), osteocalcin, alkaline phosphatase (ALP) and urinary free deoxypyridinoline (u-DPD), were analyzed, along with the serum Ca2+ and vitamin D levels. Results The mean serum calcium, phosphate and creatinine clearance levels were within the standard laboratory reference range. The incidence of vitamin D deficiency was 11.8% (4/34) in the normal BMD group, 15% (6/40) in the osteopenia group and 43.1% (25/58) in the osteoporosis group. There was a positive correlation between the 25(OH)D and BMD results in the patients with BPPV. Among the bone turnover markers, the osteocalcin and u-DPD levels were significantly elevated in the osteoporotic patients with BPPV. Multiple logistic regression analyses showed that osteoporosis and vitamin D deficiency were associated with BPPV. Conclusion Our findings suggest that the prevalence of BPPV in osteoporotic patients is associated with vitamin D deficiency and high bone turnover rates at systemic level, which could disturb local Ca2+ homeostasis in the inner ear. PMID:28467451

  12. Glutathione turnover in 14 rat tissues

    International Nuclear Information System (INIS)

    Potter, D.W.; Tran, T.

    1990-01-01

    GSH is a tripeptide found in all tissues and is important in maintaining cellular redox status. First-order rate constants for GSH turnover were determined for various tissues of Fischer male rats. Animals were administered [ 35 S]Cys by tail vein injection and GSH turnover was estimated by the decrease in GSH specific activity following incorporation of Cys, 1-102 hr after administration. Tissue nonprotein sulfhydryls (NPSH) were detected by Ellman's assay and compared with GSH and Cys concentrations determined by HPLC with electrochemical detection. [ 35 S]GSH was analyzed by HPLC equipped with a flow-through radioactivity detector. Although total GSH and Cys were usually slightly lower than NPSH concentrations for the tissues examined, both assay systems gave comparable results. An exception was the glandular stomach which had approximately 2-fold higher NPSH. Liver and kidney had rapid turnover rates with GSH half-lives between 2-5 hr, while heart and skeletal muscle tissue had half-lives of 80-90 hr. Turnover in the blood was slowest, with a half-life of 170 hr. Gastrointestinal tract tissues were shown to have intermediate turnover rates of the following order: glandular stomach > duodenum = small intestine = caecum = large intestine = colon > forestomach. GSH half-life in lung and skin was approximately 45 hr. These studies indicate that tissues utilize GSH at markedly different rates

  13. High-Bandwidth AFM-Based Rheology Reveals that Cartilage is Most Sensitive to High Loading Rates at Early Stages of Impairment

    Science.gov (United States)

    Nia, Hadi Tavakoli; Bozchalooi, Iman S.; Li, Yang; Han, Lin; Hung, Han-Hwa; Frank, Eliot; Youcef-Toumi, Kamal; Ortiz, Christine; Grodzinsky, Alan

    2013-01-01

    Utilizing a newly developed atomic-force-microscopy-based wide-frequency rheology system, we measured the dynamic nanomechanical behavior of normal and glycosaminoglycan (GAG)-depleted cartilage, the latter representing matrix degradation that occurs at the earliest stages of osteoarthritis. We observed unique variations in the frequency-dependent stiffness and hydraulic permeability of cartilage in the 1 Hz-to-10 kHz range, a frequency range that is relevant to joint motions from normal ambulation to high-frequency impact loading. Measurement in this frequency range is well beyond the capabilities of typical commercial atomic force microscopes. We showed that the dynamic modulus of cartilage undergoes a dramatic alteration after GAG loss, even with the collagen network still intact: whereas the magnitude of the dynamic modulus decreased two- to threefold at higher frequencies, the peak frequency of the phase angle of the modulus (representing fluid-solid frictional dissipation) increased 15-fold from 55 Hz in normal cartilage to 800 Hz after GAG depletion. These results, based on a fibril-reinforced poroelastic finite-element model, demonstrated that GAG loss caused a dramatic increase in cartilage hydraulic permeability (up to 25-fold), suggesting that early osteoarthritic cartilage is more vulnerable to higher loading rates than to the conventionally studied “loading magnitude”. Thus, over the wide frequency range of joint motion during daily activities, hydraulic permeability appears the most sensitive marker of early tissue degradation. PMID:23561529

  14. 3D double-echo steady-state sequence assessment of hip joint cartilage and labrum at 3 Tesla: comparative analysis of magnetic resonance imaging and intraoperative data

    Energy Technology Data Exchange (ETDEWEB)

    Schleich, Christoph; Antoch, Gerald [University of Dusseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Duesseldorf (Germany); Hesper, Tobias; Rettegi, Fanni; Zilkens, Christoph; Krauspe, Ruediger; Bittersohl, Bernd [University of Dusseldorf, Department of Orthopedic Surgery, Medical Faculty, Duesseldorf (Germany); Hosalkar, Harish S. [Paradise Valley Hospital, Joint Preservation and Deformity Correction, San Diego, CA (United States); Tri-city Medical Center, Hip Preservation, San Diego, CA (United States)

    2017-10-15

    To assess the diagnostic accuracy of a high-resolution, three-dimensional (3D) double-echo steady-state (DESS) sequence with radial imaging at 3 Tesla (T) for evaluating cartilage and labral alterations in the hip. Magnetic resonance imaging (MRI) data obtained at 3 T, including radially reformatted DESS images and intraoperative data of 45 patients (mean age 42 ± 13.7 years) who underwent hip arthroscopy, were compared. The acetabular cartilage and labrum of the upper hemisphere of the acetabulum and the central femoral head cartilage were evaluated. Sensitivity, specificity, accuracy, and negative and positive predictive values were determined. Sensitivity, specificity and accuracy of the DESS technique were 96.7%, 75% and 93.7% for detecting cartilage lesions and 98%, 76.2% and 95.9% for detecting labral lesions. The positive and negative predictive values for detecting or ruling out cartilage lesions were 96% and 78.9%. For labral lesions, the positive and negative predictive values were 97.5% and 80%. A high-resolution, 3D DESS technique with radial imaging at 3 T demonstrated high accuracy for detecting hip cartilage and labral lesions with excellent interobserver agreement and moderate correlation between MRI and intraoperative assessment. (orig.)

  15. Thallium increases monoamine oxidase activity and serotonin turnover rate in rat brain regions.

    Science.gov (United States)

    Osorio-Rico, L; Galván-Arzate, S; Ríos, C

    1995-01-01

    The effect of thallium acetate administration on monoaminergic pathways was studied in male Wistar rats using 30 mg/kg and 50 mg/kg acute IP doses. We found that thallium activated both monoamine oxidase (MAO) activity and serotonin turnover rate in rat brain regions, that may contribute to the neuronal damage mechanism of the agent. MAO activity in midbrain and pons was increased at both doses (at 30 mg/kg dose by 27.7% and 37%; at 50 mg/kg dose by 48% and 47%, respectively vs. control group). Serotonin turnover rate in pons was also increased at the 30 mg/kg dose (172%) while midbrain and pons serotonin turnover was increased only at the 50 mg/kg dose (56% and 166%, respectively vs. control group). Dopamine turnover rate was not significantly changed. The results indicate that thallium induced a significant increase in pons and midbrain MAO activity and also in serotonin turnover rate as compared with control animals, and this could led to behavioral and toxic alterations in the rats intoxicated with thallium.

  16. Differential regulation of proteoglycan 4 metabolism in cartilage by IL-1alpha, IGF-I, and TGF-beta1.

    Science.gov (United States)

    Schmidt, T A; Gastelum, N S; Han, E H; Nugent-Derfus, G E; Schumacher, B L; Sah, R L

    2008-01-01

    To determine (1) if interleukin-1 alpha (IL-1alpha), insulin like growth factor I (IGF-I), and transforming growth factor-beta 1 (TGF-beta1) regulate proteoglycan 4 (PRG4) metabolism in articular cartilage, in terms of chondrocytes expressing PRG4 and PRG4 bound at the articular surface, and (2) if these features of cartilage PRG4 metabolism correlate with its secretion. Articular cartilage explants were harvested and cultured for 6 days with or without 10% fetal bovine serum (FBS), alone, or with the addition of 10ng/ml IL-1alpha, 300ng/ml IGF-I, or 10ng/ml TGF-beta1. PRG4 expression by chondrocytes in the cartilage disks was assessed by immunohistochemistry (IHC). PRG4 bound to the articular surface of disks was quantified by extraction and enzyme-linked immunosorbent assay (ELISA). PRG4 secreted into culture medium was quantified by ELISA and characterized by Western Blot. PRG4 expression by chondrocytes near the articular surface was markedly decreased by IL-1alpha, stimulated by TGF-beta1, and not affected by IGF-I. The level of PRG4 accumulation in the culture medium was correlated with the number of chondrocytes expressing PRG4. The amount of PRG4 bound at the articular surface was modulated by incubation in medium including FBS, but did not correlate with levels of PRG4 secretion. Cartilage secretion of PRG4 is highly regulated by certain cytokines and growth factors, in part through alteration of the number of PRG4-secreting chondrocytes near the articular surface. The biochemical milieu may regulate the PRG4 content of synovial fluid during cartilage injury or repair.

  17. Changes of Protein Turnover in Aging Caenorhabditis elegans.

    Science.gov (United States)

    Dhondt, Ineke; Petyuk, Vladislav A; Bauer, Sophie; Brewer, Heather M; Smith, Richard D; Depuydt, Geert; Braeckman, Bart P

    2017-09-01

    Protein turnover rates severely decline in aging organisms, including C. elegans However, limited information is available on turnover dynamics at the individual protein level during aging. We followed changes in protein turnover at one-day resolution using a multiple-pulse 15 N-labeling and accurate mass spectrometry approach. Forty percent of the proteome shows gradual slowdown in turnover with age, whereas only few proteins show increased turnover. Decrease in protein turnover was consistent for only a minority of functionally related protein subsets, including tubulins and vitellogenins, whereas randomly diverging turnover patterns with age were the norm. Our data suggests increased heterogeneity of protein turnover of the translation machinery, whereas protein turnover of ubiquitin-proteasome and antioxidant systems are well-preserved over time. Hence, we presume that maintenance of quality control mechanisms is a protective strategy in aging worms, although the ultimate proteome collapse is inescapable. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Reducing voluntary, avoidable turnover through selection.

    Science.gov (United States)

    Barrick, Murray R; Zimmerman, Ryan D

    2005-01-01

    The authors investigated the efficacy of several variables used to predict voluntary, organizationally avoidable turnover even before the employee is hired. Analyses conducted on applicant data collected in 2 separate organizations (N = 445) confirmed that biodata, clear-purpose attitudes and intentions, and disguised-purpose dispositional retention scales predicted voluntary, avoidable turnover (rs ranged from -.16 to -.22, R = .37, adjusted R = .33). Results also revealed that biodata scales and disguised-purpose retention scales added incremental validity, whereas clear-purpose retention scales did not explain significant incremental variance in turnover beyond what was explained by biodata and disguised-purpose scales. Furthermore, disparate impact (subgroup differences on race, sex, and age) was consistently small (average d = 0.12 when the majority group scored higher than the minority group).

  19. Articular cartilage compression: how microstructural response influences pore pressure in relation to matrix health.

    Science.gov (United States)

    Fick, James M; Thambyah, Ashvin; Broom, Neil D

    2010-04-01

    Our research investigated the influence of degeneration on both the pore-pressure development and microstructural response of cartilage during indentation with a flat-porous-indenter. Experiments were conducted to link the mechanical and structural responses of normal and degenerate articular cartilage. We found that from the instant of loading the degenerate matrix generated a higher peak hydrostatic excess pore pressure in a shorter period of time than the normal matrix. Following the attainment of this peak value the pore pressure in both tissue groups then gradually decayed toward zero over time, thus demonstrating a classical consolidation response. The microstructural analysis provided a unique insight into the influence of degeneration on the mechanisms of internal stress-sharing within the loaded matrix. Both disruption of the articular surface and general matrix destructuring results in an altered deformation field in both the directly loaded and nondirectly loaded regions. It is argued that the higher levels of matrix shear combined with less of the applied load being redirected into the wider cartilage continuum accounts for the elevated levels of peak hydrostatic pore pressure generated in the degenerate matrix.

  20. Patient Profiling in Cartilage Regeneration Prognostic Factors Determining Success of Treatment for Cartilage Defects

    NARCIS (Netherlands)

    de Windt, Tommy S.; Bekkers, Joris E. J.; Creemers, Laura B.; Dhert, Wouter J. A.; Saris, Daniel B. F.

    2009-01-01

    Background: Cartilage therapy for focal articular lesions has been implemented for more than a decade, and it is becoming increasingly available. What is still lacking, however, is analysis of patient characteristics to help improve outcome or select patients for specific treatment. Purpose: To

  1. PTH [1-34]-induced alterations of the subchondral bone provoke early osteoarthritis.

    Science.gov (United States)

    Orth, P; Cucchiarini, M; Wagenpfeil, S; Menger, M D; Madry, H

    2014-06-01

    To test the hypothesis that changes in the subchondral bone induced by parathyroid hormone (PTH [1-34]) reciprocally affect the integrity of the articular cartilage within a naïve osteochondral unit in vivo. Daily subcutaneous injections of 10 μg PTH [1-34]/kg were given to adult rabbits for 6 weeks, controls received saline. Blood samples were continuously collected to monitor renal function. The subchondral bone plate and subarticular spongiosa of the femoral heads were separately assessed by micro-computed tomography. Articular cartilage was evaluated by macroscopic and histological osteoarthritis scoring, polarized light microscopy, and immunohistochemical determination of type-I, type-II, type-X collagen contents, PTH [1-34] receptor and caspase-3 expression. Absolute and relative extents of hyaline and calcified articular cartilage layers were measured histomorphometrically. The correlation between PTH-induced changes in subchondral bone and articular cartilage was determined. PTH [1-34] enhanced volume, mineral density, and trabecular thickness within the subarticular spongiosa, and increased thickness of the calcified cartilage layer (all P PTH [1-34] led to cartilage surface irregularities and reduced matrix staining (both P PTH [1-34] cause broadening of the calcified cartilage layer, resulting in osteoarthritic cartilage degeneration. These findings identify a mechanism by which PTH-induced alterations of the normal subchondral bone microarchitecture may provoke early osteoarthritis. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  2. Glycogen storage in tissue-engineered cartilage.

    Science.gov (United States)

    Suits, Jocelyne M T; Khan, Aasma A; Waldman, Stephen D

    2008-08-01

    Recent focus in cartilage tissue engineering has been to develop functional tissue that can survive after implantation. One such determinant is the ability of the engineered tissue to be able to sustain its metabolic activity post-implantation. In vivo, chondrocytes contain stores of intracellular glycogen to support metabolism and it is unknown whether these cells can store glycogen during tissue growth in vitro. Thus, the purpose of this study was to determine the appropriate nutrient conditions to elicit glycogen storage in tissue-engineered cartilage. Isolated bovine articular chondrocytes were seeded in scaffold-free, 3D culture and grown under different nutrient conditions (glucose concentrations and media volumes) for 4 weeks. Intracellular glycogen storage, glucose utilization and extracellular matrix (ECM) accumulation of the engineered tissues were then evaluated. Glucose concentration (5-10 mM) and media volume (1-4 ml) had no apparent effect on cartilaginous tissue formation. However, glucose consumption by the cells increased in proportion to the volume of medium provided. Lactate production was similarly affected but in direct proportion to the glucose consumed, indicating a change in glucose utilization. Similarly, under elevated medium volume, engineered tissues stained positive for intracellular glycogen, which was also confirmed biochemically (1 ml, 1 +/- 2; 2 ml, 13 +/- 4; 4 ml, 13 +/- 3 microg/construct). The storage of intracellular glycogen in engineered cartilage can be elicited by culturing the constructs in elevated volumes of medium (>or=1 ml medium/million cells), which might help to ensure appropriate metabolic function after implantation. (c) 2008 John Wiley & Sons, Ltd.

  3. Does Radio Frequency Ablation (RFA) Epiphysiodesis Affect Joint Cartilage?

    DEFF Research Database (Denmark)

    Shiguetomi Medina, Juan Manuel; Abood, Ahmed Abdul-Hussein; Rahbek, Ole

    the joint articular cartilage in all samples using T1-weighted, T2-weighted and water content sequences under a 1.5 T magnetic field Findings / Results: The intentionally-damaged articular cartilage showed intensity changes on the MR. This images were used as reference for damage. We found no evidence...

  4. Impact of a daily exercise dose on knee joint cartilage

    DEFF Research Database (Denmark)

    Bricca, A; Juhl, C B; Grodzinsky, A J

    2017-01-01

    OBJECTIVE: To investigate the impact of a daily exercise dose on cartilage composition and thickness, by conducting a systematic review of randomized controlled trials (RCTs) involving healthy animals. METHODS: A narrative synthesis of the effect of a daily exercise dose on knee cartilage aggrecan...

  5. Segmenting articular cartilage automatically using a voxel classification approach

    DEFF Research Database (Denmark)

    Folkesson, Jenny; Dam, Erik B; Olsen, Ole F

    2007-01-01

    We present a fully automatic method for articular cartilage segmentation from magnetic resonance imaging (MRI) which we use as the foundation of a quantitative cartilage assessment. We evaluate our method by comparisons to manual segmentations by a radiologist and by examining the interscan repro...

  6. Significance of cartilage endplate within herniated disc tissue.

    Science.gov (United States)

    Lama, Polly; Zehra, Uruj; Balkovec, Christian; Claireaux, Henry A; Flower, Luke; Harding, Ian J; Dolan, Patricia; Adams, Michael A

    2014-09-01

    Disc herniations sometimes contain hyaline cartilage fragments, but their origins and significance are uncertain. Herniations were removed surgically from 21 patients (aged 35-74 years) whose main symptom was sciatica (10 patients) or back pain (11 patients). Frozen sections, 5 µm thick, were examined histologically, and antibodies were used to label the matrix-degrading enzyme MMP 1, pro-inflammatory mediator TNFα, and cell proliferation marker Ki-67. Proportions of each tissue type were quantified by image analysis. Cartilage and bone components of the endplate were examined in 7-µm frozen sections from 16 cadaveric spines, aged 61-98 years. Cartilage fragments were found in 10/21 herniations. They averaged 5.0 mm in length, comprised 25 % of the herniation area, and two had some bone attached. Hyaline cartilage was more common in herniations from patients with sciatica (7/10) than with back pain (3/11, P = 0.050), and the area (%) of the herniation occupied by the cartilage was greater in sciatica patients (P Disc herniations often include hyaline cartilage pulled from the vertebral endplates. Cartilage fragments show little swelling or proteoglycan loss, and may be slow to resorb, increasing the risk of persisting sciatica. Loss of cartilage will increase endplate permeability, facilitating endplate inflammation and disc infection.

  7. The Application of Polysaccharide Biocomposites to Repair Cartilage Defects

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2014-01-01

    Full Text Available Owing to own nature of articular cartilage, it almost has no self-healing ability once damaged. Despite lots of restore technologies having been raised in the past decades, no repair technology has smoothly substituted for damaged cartilage using regenerated cartilage tissue. The approach of tissue engineering opens a door to successfully repairing articular cartilage defects. For instance, grafting of isolated chondrocytes has huge clinical potential for restoration of cartilage tissue and cure of chondral injury. In this paper, SD rats are used as subjects in the experiments, and they are classified into three groups: natural repair (group A, hyaluronic acid repair (group B, and polysaccharide biocomposites repair (hyaluronic acid hydrogel containing chondrocytes, group C. Through the observation of effects of repairing articular cartilage defects, we concluded that cartilage repair effect of polysaccharide biocomposites was the best at every time point, and then the second best was hyaluronic acid repair; both of them were better than natural repair. Polysaccharide biocomposites have good biodegradability and high histocompatibility and promote chondrocytes survival, reproduction, and spliting. Moreover, polysaccharide biocomposites could not only provide the porous network structure but also carry chondrocytes. Consequently hyaluronic acid-based polysaccharide biocomposites are considered to be an ideal biological material for repairing articular cartilage.

  8. Repair of osteochondral defects with allogeneic tissue engineered cartilage implants.

    Science.gov (United States)

    Schreiber, R E; Ilten-Kirby, B M; Dunkelman, N S; Symons, K T; Rekettye, L M; Willoughby, J; Ratcliffe, A

    1999-10-01

    The objective of this study was to evaluate the effect of allogeneic tissue engineered cartilage implants on healing of osteochondral defects. Rabbit chondrocytes were cultured in monolayer, then seeded onto biodegradable, three-dimensional polyglycolic acid meshes. Cartilage constructs were cultured hydrodynamically to yield tissue with relatively more (mature) or less (immature) hyalinelike cartilage, as compared with adult rabbit articular cartilage. Osteochondral defects in the patellar grooves of both stifle joints either were left untreated or implanted with allogeneic tissue engineered cartilage. Histologic samples from in and around the defect sites were examined 3, 6, 9, and 12, and 24 months after surgery. By 9 months after surgery, defects sites treated with cartilage implants contained significantly greater amounts of hyalinelike cartilage with high levels of proteoglycan, and had a smooth, nonfibrillated articular surface as compared to untreated defects. In contrast, the repair tissue formed in untreated defects had fibrillated articular surfaces, significant amounts of fibrocartilage, and negligible proteoglycan. These differences between treated and untreated defects persisted through 24 months after surgery. The results of this study suggest that the treatment of osteochondral lesions with allogenic tissue engineered cartilage implants may lead to superior repair tissue than that found in untreated osteochondral lesions.

  9. Combined role of type IX collagen and cartilage oligomeric matrix protein in cartilage matrix assembly: Cartilage oligomeric matrix protein counteracts type IX collagen-induced limitation of cartilage collagen fibril growth in mouse chondrocyte cultures

    NARCIS (Netherlands)

    Blumbach, K.; Bastiaansen-Jenniskens, Y.M.; Groot, J. de; Paulsson, M.; Osch, G.J.V.M. van; Zaucke, F.

    2009-01-01

    Objective. Defects in the assembly and composition of cartilage extracellular matrix are likely to result in impaired matrix integrity and increased susceptibility to cartilage degeneration. The aim of this study was to determine the functional interaction of the collagen fibril-associated proteins

  10. Endogenous Cartilage Repair by Recruitment of Stem Cells.

    Science.gov (United States)

    Im, Gun-Il

    2016-04-01

    Articular cartilage has a very limited capacity for repair after injury. The adult body has a pool of stem cells that are mobilized during injury or disease. These cells exist inside niches in bone marrow, muscle, adipose tissue, synovium, and other connective tissues. A method that mobilizes this endogenous pool of stem cells will provide a less costly and less invasive alternative if these cells successfully regenerate defective cartilage. Traditional microfracture procedures employ the concept of bone marrow stimulation to regenerate cartilage. However, the regenerated tissue usually is fibrous cartilage, which has very poor mechanical properties compared to those of normal hyaline cartilage. A method that directs the migration of a large number of autologous mesenchymal stem cells toward injury sites, retains these cells around the defects, and induces chondrogenic differentiation that would enhance success of endogenous cartilage repair. This review briefly summarizes chemokines and growth factors that induce recruitment, proliferation, and differentiation of endogenous progenitor cells, endogenous cell sources for regenerating cartilage, scaffolds for delivery of bioactive factors, and bioadhesive materials that are necessary to bring about endogenous cartilage repair.

  11. Effect of scopoletin on fascia-wrapped diced cartilage grafts

    African Journals Online (AJOL)

    Surgically wrapped diced cartilages exhibit various degrees of resorption; thus, it has been recommended that fascia be used to wrap diced cartilages. However, few surgeons suggest the use of AlloDerm for wrapping because the harvesting of fascia may cause hematoma and alopecia [17]. Additionally, block grafts have a.

  12. Cartilage imaging: motivation, techniques, current and future significance

    International Nuclear Information System (INIS)

    Link, Thomas M.; Stahl, Robert; Woertler, Klaus

    2007-01-01

    Cartilage repair techniques and pharmacological therapies are currently areas of major clinical interest and research, in particular to prevent and treat osteoarthritis. MR imaging-based techniques to visualize cartilage are prerequisites to guide and monitor these therapies. In this review article, standard MR imaging sequences are described, including proton density-weighted fast spin echo, spoiled gradient echo and dual echo steady state sequences. In addition, new sequences that have been developed and are currently being investigated are presented, including driven equilibrium Fourier transform and steady-state free precession-based imaging. Using high-field MR imaging at 3.0-T, visualization of cartilage and the related pathology has been improved. Volumetric quantitative cartilage MR imaging was developed as a tool to monitor the progression of osteoarthritis and to evaluate new pharmacological cartilage protective therapies. The most exciting developments, however, are in the field of cartilage matrix assessment with quantitative dGEMRIC, T2 and T1rho mapping techniques. These techniques aim at detecting cartilage damage at a stage when changes are potentially still reversible, before cartilage tissue is lost. There is currently substantial interest in these techniques from rheumatologists and orthopedists; radiologists therefore need to keep up with these developments. (orig.)

  13. Two dimensional spectral camera development for cartilage monitoring

    Science.gov (United States)

    Kuehn, A.; Graf, A.; Wenzel, U.; Princz, S.; Miller, R.; Mantz, H.; Hessling, M.

    2015-07-01

    In the joint project "BioopTiss" between the Ulm University Medical Center and Ulm University of Applied Sciences, a bioreactor is under development to grow facial cartilage by the methods of tissue engineering. In order to ensure a sufficient quality of the cartilage for implantation, the cartilage growth must be monitored continuously. Current monitoring methods destroy the cultured cartilage so that it is no longer suitable for implantation. Alternatively, it is possible to analyze the cartilage using fluorescence spectroscopy with UV light excitation. This allows a non-invasive assessment of cartilage in terms of composition and quality. The cultured cartilage tissue can reach a size of several square centimeters. For recording fluorescence spectra of every point of the cartilage sample, a highly sensitive spectral camera has been developed which allows distinguishing collagen I from collagen II non-invasively by their fluorescence. This spectral camera operates according to the computed tomography imaging spectrometry (CTIS) principle, which allows obtaining many spectra of a small area with only one snapshot.

  14. Synovial Fluid Profile at the Time of Anterior Cruciate Ligament Reconstruction and Its Association With Cartilage Matrix Composition 3 Years After Surgery.

    Science.gov (United States)

    Amano, Keiko; Huebner, Janet L; Stabler, Thomas V; Tanaka, Matthew; McCulloch, Charles E; Lobach, Iryna; Lane, Nancy E; Kraus, Virginia B; Ma, C Benjamin; Li, Xiaojuan

    2018-03-01

    , and cartilage breakdown products show promise as predictors of abnormal cartilage tissue integrity (increased T1ρ and T2 values) throughout the first 3 years after surgery. The results suggest an intricate relationship between inflammation and cartilage turnover, which can in turn be influenced by timing after injury and patient factors.

  15. Follistatin Alleviates Synovitis and Articular Cartilage Degeneration Induced by Carrageenan

    Directory of Open Access Journals (Sweden)

    Jun Yamada

    2014-01-01

    Full Text Available Activins are proinflammatory cytokines which belong to the TGFβ superfamily. Follistatin is an extracellular decoy receptor for activins. Since both activins and follistatin are expressed in articular cartilage, we hypothesized that activin-follistatin signaling participates in the process of joint inflammation and cartilage degeneration. To test this hypothesis, we examined the effects of follistatin in a carrageenan-induced mouse arthritis model. Synovitis induced by intra-articular injection of carrageenan was significantly alleviated by preinjection with follistatin. Macrophage infiltration into the synovial membrane was significantly reduced in the presence of follistatin. In addition, follistatin inhibited proteoglycan erosion induced by carrageenan in articular cartilage. These data indicate that activin-follistatin signaling is involved in joint inflammation and cartilage homeostasis. Our data suggest that follistatin can be a new therapeutic target for inflammation-induced articular cartilage degeneration.

  16. Injectable hydrogels for cartilage and bone tissue engineering

    Science.gov (United States)

    Liu, Mei; Zeng, Xin; Ma, Chao; Yi, Huan; Ali, Zeeshan; Mou, Xianbo; Li, Song; Deng, Yan; He, Nongyue

    2017-01-01

    Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix (ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed. PMID:28584674

  17. Antecedents of Norwegian Beginning Teachers' Turnover Intentions

    Science.gov (United States)

    Tiplic, Dijana; Brandmo, Christian; Elstad, Eyvind

    2015-01-01

    This study aims at exploring several individual, organizational, and contextual factors that may affect beginning teachers' turnover intentions during their first years of practice. The sample consists of 227 beginning teachers (69% female and 31% male) from 133 schools in Norway. The results show four important antecedents of beginning teachers'…

  18. Health care workplace discrimination and physician turnover.

    Science.gov (United States)

    Nunez-Smith, Marcella; Pilgrim, Nanlesta; Wynia, Matthew; Desai, Mayur M; Bright, Cedric; Krumholz, Harlan M; Bradley, Elizabeth H

    2009-12-01

    To examine the association between physician race/ ethnicity, workplace discrimination, and physician job turnover. Cross-sectional, national survey conducted in 2006-2007 of practicing physicians (n = 529) randomly identified via the American Medical Association Masterfile and the National Medical Association membership roster. We assessed the relationships between career racial/ethnic discrimination at work and several career-related dependent variables, including 2 measures of physician turnover, career satisfaction, and contemplation of career change. We used standard frequency analyses, odds ratios and chi2 statistics, and multivariate logistic regression modeling to evaluate these associations. Physicians who self-identified as nonmajority were significantly more likely to have left at least 1 job because of workplace discrimination (black, 29%; Asian, 24%; other race, 21%; Hispanic/Latino, 20%; white, 9%). In multivariate models, having experienced racial/ethnic discrimination at work was associated with high job turnover (adjusted odds ratio, 2.7; 95% CI, 1.4-4.9). Among physicians who experienced workplace discrimination, only 45% of physicians were satisfied with their careers (vs 88% among those who had not experienced workplace discrimination, p value workplace discrimination, p value Workplace discrimination is associated with physician job turnover, career dissatisfaction, and contemplation of career change. These findings underscore the importance of monitoring for workplace discrimination and responding when opportunities for intervention and retention still exist.

  19. A Turnover Model for the Mexican Maquiladoras.

    Science.gov (United States)

    Maertz, Carl P.; Stevens, Michael J.; Campion, Michael A.

    2003-01-01

    From interviews with 47 Mexican maquiladora workers, a model of voluntary turnover was created and compared with models from the United States, Canada, England, and Australia. Despite similarities, the cultural and economic environment affected the precise content of antecedents in the Mexican model. (Contains 63 references.) (SK)

  20. Primary care physician turnover in HMOs.

    Science.gov (United States)

    Kerstein, J; Pauly, M V; Hillman, A

    1994-01-01

    OBJECTIVE. We assess whether physician turnover stems from incorrect physician expectations about the practice environment or from actual constraints or rewards in that environment. DATA SOURCES. Our primary data source contains information about individual HMOs' primary care physicians incentive mechanisms and general HMO characteristics. Our secondary data source is the area resource file (ARF), which contains countywide information about the HMOs' market areas, including physician characteristics, population characteristics, and other market characteristics. DATA COLLECTION. Our primary data source is from a nationwide survey of all HMOs in operation in 1987-1988, as reported to Interstudy. PRINCIPAL FINDINGS. We find that turnover is higher on the part of physicians whose HMO enrollment comprises a greater percentage of their total practice. Our results further indicate that physicians whose compensation is dependent on the behavior of a group of other physicians are more likely to leave the plan than those who bear the risk (and control it) more directly. On the other hand, turnover is increased by basing bonuses on individual productivity and by not sharing surpluses among a group. Market characteristics also are significant in explaining physician turnover in HMOs. CONCLUSIONS. It appears that physicians accurately forecast how they will react to individual financial risk, although they dislike restrictions imposed by HMOs. PMID:8163378

  1. Does Judge Turnover Affect Judicial Performance?

    DEFF Research Database (Denmark)

    Guerra, Alice; Tagliapietra, Claudio

    2017-01-01

    Italy is among the countries with the highest litigation rate and those with the highest duration of trials. This article shows that judge turnover contributes negatively to delays in Italian courts and outlines possible policies for improvement. In Italy, judges can voluntarily move from one off...

  2. Effects of mazindol, a non-phenylethylamine anorexigenic agent, on biogenic amine levels and turnover rate.

    Science.gov (United States)

    Carruba, M O; Groppetti, A; Mantegazza, P; Vicentini, L; Zambotti, F

    1976-01-01

    1 Mazindol is a new anorexigenic agent which possesses a different chemical structure from that of phenylethylamines, but shows a pharmacological profile similar to that of (+)-amphetamine. 2 Mazindol neither altered whole brain monoamine levels (noradrenaline (NA), dopamine, 5-hydroxytryptamine (5-HT)) nor changed NA levels in the hypothalamus or dopamine levels in the caudate nucleus. 3 Mazindol enhanced dopamine turnover rate in the caudate nucleus, as shown by the increased rate of dopamine decline after blockade of catecholamine synthesis by alpha-methyl-p-tyrosine and decreased the conversion index of (3H)-tyrosine into brain NA. 4 Mazindol administration did not modify pargyline-induced decline of 5-hydroxyindoleacetic acid suggesting that 5-HT turnover is not altered by this drug. PMID:1260223

  3. Biochemical effects on long-term frozen human costal cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Santin, Stefany P.; Martinho Junior, Antonio C.; Yoshito, Daniele; Soares, Fernando A.N.; Mathor, Monica B., E-mail: mathor@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Currently, the progresses on treatment of musculoskeletal diseases with the evolving of artificial implants and the success of tissue transplantation between genetically different individuals have conducted to an increase in radiosterilization. Regarding to tissue transplantation, it is essential to have sterile tissue and many tissue banks use radiosterilization as an effective method to sterilize these tissues. However, high doses of ionizing radiation and the preservation method may induce structural modifications in the tissues, as degradation of structural scaffold, decreasing its mechanical properties. Particularly, cartilage have been preserved in high concentrations of glycerol or deep-frozen at -70 degree C for storage after radiosterilization. Therefore, it is important to study the modifications induced in cartilage by preservation methods and by radiosterilization to determine the appropriated parameters for high quality of human allografts. Costal cartilages were obtained from cadaveric donors and were frozen at -20 degree C for 2 years long in order to compare with previous studies for fresh, deep-frozen and glycerolised cartilages. The mechanical tests were carried out in a universal testing machine until sample failure. According our results, there is no significant statistical difference between stress at break of fresh, long-term - 20 degree C frozen cartilages and deep-frozen cartilage. This early result suggests, regarding to tensile property, that long-term - 20 degree C frozen cartilages corresponds to glycerolised costal cartilages irradiated with 25 kGy or deep-frozen cartilages irradiated with 25 and 50 kGy. Thus, this long-term frozen cartilages may be used for tissue banks, but more studies about effects of ionizing radiation are necessary. (author)

  4. Biochemical effects on long-term frozen human costal cartilage

    International Nuclear Information System (INIS)

    Santin, Stefany P.; Martinho Junior, Antonio C.; Yoshito, Daniele; Soares, Fernando A.N.; Mathor, Monica B.

    2011-01-01

    Currently, the progresses on treatment of musculoskeletal diseases with the evolving of artificial implants and the success of tissue transplantation between genetically different individuals have conducted to an increase in radiosterilization. Regarding to tissue transplantation, it is essential to have sterile tissue and many tissue banks use radiosterilization as an effective method to sterilize these tissues. However, high doses of ionizing radiation and the preservation method may induce structural modifications in the tissues, as degradation of structural scaffold, decreasing its mechanical properties. Particularly, cartilage have been preserved in high concentrations of glycerol or deep-frozen at -70 degree C for storage after radiosterilization. Therefore, it is important to study the modifications induced in cartilage by preservation methods and by radiosterilization to determine the appropriated parameters for high quality of human allografts. Costal cartilages were obtained from cadaveric donors and were frozen at -20 degree C for 2 years long in order to compare with previous studies for fresh, deep-frozen and glycerolised cartilages. The mechanical tests were carried out in a universal testing machine until sample failure. According our results, there is no significant statistical difference between stress at break of fresh, long-term - 20 degree C frozen cartilages and deep-frozen cartilage. This early result suggests, regarding to tensile property, that long-term - 20 degree C frozen cartilages corresponds to glycerolised costal cartilages irradiated with 25 kGy or deep-frozen cartilages irradiated with 25 and 50 kGy. Thus, this long-term frozen cartilages may be used for tissue banks, but more studies about effects of ionizing radiation are necessary. (author)

  5. A concept analysis of turnover intention: implications for nursing management.

    Science.gov (United States)

    Takase, Miyuki

    2010-01-01

    This paper provides a review and concept analysis of turnover intention. The aim was to promote Nurse Managers' understanding of the meanings and mechanisms of turnover intention, which could help them counteract nurse turnover. Sixty-six papers published between January 1998 and August 2007 were collected from CINAHL, PubMed, and PsycINFO databases, and were subjected to Rogers' concept analysis. The results showed that turnover intention is a multi-stage process involving the voluntary departure of employees from their current position, and is triggered by negative psychological responses to internal/external job context. These psychological responses evolve into withdrawal cognition and behaviours, and lead to actual turnover. To prevent nurse turnover, Nurse Managers should closely observe the internal and external causes of turnover, and the stage of nurses' turnover intention.

  6. Staff turnover: occasional friend, frequent foe, and continuing frustration.

    Science.gov (United States)

    McConnell, C R

    1999-09-01

    Turnover appears to be a relatively simple concept. However, considerable confusion results when discussing turnover because of differences in how it is defined--what is counted, how it is counted, and how the rate of turnover is expressed. Turnover is also costly, although not enough attention is paid to turnover's cost because so much of it is indirect and thus not readily visible. There are a variety of causes of turnover, some which can be corrected and some which cannot be avoided. Reducing or otherwise controlling turnover requires continuing management attention to its causes and constant recognition of what can and should be controlled and what cannot be controlled. Ongoing attention to turnover is an essential part of the department manager's role.

  7. Work-Related Variables and Turnover Intention among Registered Nurses.

    Science.gov (United States)

    Pooyan, Abdullah; And Others

    1990-01-01

    Health institutions have become more interested in the causes of job turnover among registered nurses. Proper management of job turnover can improve the financial health and long-term survival of health care institutions. (Author)

  8. Cartilage hair hypoplasia: characteristics and orthopaedic manifestations.

    Science.gov (United States)

    Riley, Patrick; Weiner, Dennis S; Leighley, Bonnie; Jonah, David; Morton, D Holmes; Strauss, Kevin A; Bober, Michael B; Dicintio, Martin S

    2015-04-01

    Cartilage hair hypoplasia (CHH) is a rare metaphyseal chondrodysplasia characterized by short stature and short limbs, found primarily in Amish and Finnish populations. Cartilage hair hypoplasia is caused by mutations in the RMRP gene located on chromosome 9p13.3. The disorder has several characteristic orthopaedic manifestations, including joint laxity, limited elbow extension, ankle varus, and genu varum. Immunodeficiency is of concern in most cases. Although patients exhibit orthopaedic problems, the orthopaedic literature on CHH patients is scant at best. The objective of this study was to characterize the orthopaedic manifestations of CHH based on the authors' unique access to the largest collection of CHH patients ever reported. The authors examined charts and/or radiographs in 135 cases of CHH. We analyzed the orthopaedic manifestations to better characterize and further understand the orthopaedic surgeon's role in this disorder. In addition to describing the clinical characteristics, we report on our surgical experience in caring for CHH patients. Genu varum, with or without knee pain, is the most common reason a patient with CHH will seek orthopaedic consultation. Of the cases reviewed, 32 patients had undergone surgery, most commonly to correct genu varum. This paper characterizes the orthopaedic manifestations of CHH. Characterizing this condition in the orthopaedic literature will likely assist orthopaedic surgeons in establishing a correct diagnosis and appreciating the orthopaedic manifestations. It is important that the accompanying medical conditions are appreciated and evaluated.

  9. Analysis of Soil Structure Turnover with Garnet Particles and X-Ray Microtomography.

    Science.gov (United States)

    Schlüter, Steffen; Vogel, Hans-Jörg

    2016-01-01

    Matter turnover in soil is tightly linked to soil structure which governs the heterogeneous distribution of habitats, reaction sites and pathways in soil. Thereby, the temporal dynamics of soil structure alteration is deemed to be important for essential ecosystem functions of soil but very little is known about it. A major reason for this knowledge gap is the lack of methods to study soil structure turnover directly at microscopic scales. Here we devise a conceptual approach and an image processing workflow to study soil structure turnover by labeling some initial state of soil structure with small garnet particles and tracking their fate with X-ray microtomography. The particles adhere to aggregate boundaries at the beginning of the experiment but gradually change their position relative to the nearest pore as structure formation progresses and pores are destructed or newly formed. A new metric based on the contact distances between particles and pores is proposed that allows for a direct quantification of soil structure turnover rates. The methodology is tested for a case study about soil compaction of a silty loam soil during stepwise increase of bulk density (ρ = {1.1, 1.3, 1.5} g/cm3). We demonstrate that the analysis of mean contact distances provides genuinely new insights about changing diffusion pathways that cannot be inferred neither from conventional pore space attributes (porosity, mean pore size, pore connectivity) nor from deformation analysis with digital image correlation. This structure labeling approach to quantify soil structure turnover provides a direct analogy to stable isotope labeling for the analysis of matter turnover and can be readily combined with each other.

  10. Regulation by turnover of Na,K-ATPase in HeLa cells.

    Science.gov (United States)

    Pollack, L R; Tate, E H; Cook, J S

    1982-01-01

    As in most if not all animal cells, HeLa Na,K-ATPase is an essential enzyme of the cell surface. The three ways, referred to in the Introduction, in which it is regulated may be summarized as follows: 1) The activity of the enzyme under normal conditions responds almost linearly to small perturbations in internal (Na+); this is short-term regulation. 2) In the normal steady state, the enzyme is one of the rapidly turning over components of the cell surface; this is part of long-term regulation. The functional importance of turnover to cell homeostasis depends on the reversibility of any event that may inactive the enzyme. Thus turnover is an important, but not the only, means of recovery from ouabain intoxication, and for an inactivating ligand that dissociates more readily than ouabain turnover may be relatively unimportant. Conversely, turnover may be the only means of recovery from thermal inactivation at physiological temperatures. 3) Under conditions of prolonged stress, turnover itself may be modulated so as to enhance the number of active enzymes on the cell surface. Regulation by turnover has the advantage of permitting a prompt response to a changing cell environment, whereas regulation by synthesis would introduce a delay in response at least equal to the transit time. Broadman et al [1974] have suggested that the signal for the increase in Na,K-ATPase is elevated cellular (Na+), but how this is translated into a mechanism for altering the specific clearance of this enzyme from the membrane is not known.

  11. Glucose turnover, gluconeogenesis from glycerol, and estimation of net glucose cycling in cancer patients

    International Nuclear Information System (INIS)

    Lundholm, K.; Edstroem, S.; Karlberg, I.; Ekman, L.; Schersten, T.

    1982-01-01

    A double isotope method was used in patients with progressive malignancy and in control patients to measure: glucose turnover, conversion rate of carbon skeleton of glycerol into glucose, and the interorgan cycling of glucose carbons (Cori-cycle plus alanine-glucose cycle). [U- 14 C]glycerol and [6- 3 H]glucose were given intravenously as a single dose injection. The time course of the specific radioactivities of [6- 3 H] and [U- 14 C]glucose was followed in blood. The pool size and the turnover rate of glucose were increased in the cancer group as compared with the control patients. The net recycling of glucose carbons was not increased in the cancer group, despite the increased turnover of glucose. The alterations in the metabolism of glucose did not correlate with the plasma levels of insulin or thyroid hormones (T4, T3, rT3) neither in the entire cancer group nor in those cancer patients who were repeatedly investigated at different intervals of time. The turnover rate of glucose in the cancer patients correlated inversely to their body weight index. The gluconeogenesis rate, given as the fractional conversion rate of the injected radioactive dose of [ 14 C]glycerol, or as mol glucose . kg body weight-1 . day-1, was increased in the cancer group, but still contributed only 3% of the glucose turnover rate in both cancer and control patients. We conclude that an increased gluconeogenesis from glycerol is not significant in terms of energy expenditure in patients with progressive malignancy, as has previously been concluded for the gluconeogenesis from alanine. It seems that increased turnover of glucose may contribute to inappropriately high energy expenditure in cancer patients

  12. Revision Surgery After Cartilage Repair: Data From the German Cartilage Registry (KnorpelRegister DGOU).

    Science.gov (United States)

    Pestka, Jan M; Luu, Nam H; Südkamp, Norbert P; Angele, Peter; Spahn, Gunther; Zinser, Wolfgang; Niemeyer, Philipp

    2018-02-01

    Various operative strategies have been introduced to restore the integrity of articular cartilage when injured. The frequency of revision surgery after cartilage regenerative surgery remains incompletely understood. The purpose of this study was to identify the reasons for revision surgery after cartilage regenerative surgery of the knee. We hypothesized that in a large patient cohort, revision rates would differ from those in the current literature. Case-control study; Level of evidence, 3. A total of 2659 complete data sets from the German Cartilage Registry were available for analyses. In brief, baseline data were provided by the attending physician at the time of index surgery. Follow-up data were collected using a web-based questionnaire inquiring whether patients had needed revision surgery during follow-up, which was defined as the endpoint of the present analysis. A total of 88 patients (3.3%) reported the need for revision surgery as early as 12 months postoperatively. Among the most common causes were arthrofibrosis (n = 27) and infection (n = 10). Female patients showed a significantly greater complication rate (4.5%) when compared with male patients (2.6%; P = .0071). The majority of cartilage lesions were located at the medial femoral condyle (40.2%), with a mean defect size of 3.5 ± 2.1 cm 2 . Neither the location nor defect size appeared to lead to an increased revision rate, which was greatest after osteochondral autografts (5.2%) and autologous chondrocyte implantation (4.6%). Revision rates did not differ significantly among surgical techniques. Chi-square analysis revealed significant correlations between the number of previous joint surgeries and the need for revision surgery ( P = .0203). Multivariate regression analysis further confirmed sex and the number of previous surgeries as variables predicting the need for early revision surgery. The low early revision rates found in this study underline that today's cartilage repair surgeries are

  13. Articulation of Native Cartilage Against Different Femoral Component Materials. Oxidized Zirconium Damages Cartilage Less Than Cobalt-Chrome.

    Science.gov (United States)

    Vanlommel, Jan; De Corte, Ronny; Luyckx, Jean Philippe; Anderson, Melissa; Labey, Luc; Bellemans, Johan

    2017-01-01

    Oxidized zirconium (OxZr) is produced by thermally driven oxidization creating an oxidized surface with the properties of a ceramic at the top of the Zr metal substrate. OxZr is much harder and has a lower coefficient of friction than cobalt-chrome (CoCr), both leading to better wear characteristics. We evaluated and compared damage to the cartilage of porcine patella plugs, articulating against OxZr vs CoCr. Our hypothesis was that, owing to its better wear properties, OxZr would damage cartilage less than CoCr. If this is true, OxZr might be a better material for the femoral component during total knee arthroplasty if the patella is not resurfaced. Twenty-one plugs from porcine patellae were prepared and tested in a reciprocating pin-on-disk machine while lubricated with bovine serum and under a constant load. Three different configurations were tested: cartilage-cartilage as the control group, cartilage-OxZr, and cartilage-CoCr. Macroscopic appearance, cartilage thickness, and the modified Mankin score were evaluated after 400,000 wear cycles. The control group showed statistically significant less damage than plugs articulating against both other materials. Cartilage plugs articulating against OxZr were statistically significantly less damaged than those articulating against CoCr. Although replacing cartilage by an implant always leads to deterioration of the cartilage counterface, OxZr results in less damage than CoCr. The use of OxZr might thus be preferable to CoCr in case of total knee arthroplasty without patella resurfacing. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Salary and Ranking and Teacher Turnover: A Statewide Study

    Science.gov (United States)

    Garcia, Cynthia Martinez; Slate, John R.; Delgado, Carmen Tejeda

    2009-01-01

    This study examined three years of data obtained from the Academic Excellence Indicator System of the State of Texas regarding teacher turnover rate and teacher salary. Across all public school districts, teacher salary was consistently negatively related to teacher turnover; that is, where salary was lower, turnover rate was higher When data were…

  15. Cartilage Degeneration and Alignment in Severe Varus Knee Osteoarthritis.

    Science.gov (United States)

    Nakagawa, Yasuaki; Mukai, Shogo; Yabumoto, Hiromitsu; Tarumi, Eri; Nakamura, Takashi

    2015-10-01

    The aim of this study was to examine the relationship between cartilage, ligament, and meniscus degeneration and radiographic alignment in severe varus knee osteoarthritis in order to understand the development of varus knee osteoarthritis. Fifty-three patients (71 knees) with primary varus knee osteoarthritis and who underwent total knee arthroplasty were selected for this study. There were 6 men and 47 women, with 40 right knees and 31 left knees studied; their mean age at operation was 73.5 years. The ligament, meniscus, degeneration of joint cartilage, and radiographic alignments were examined visually. The tibial plateau-tibial shaft angle was larger if the condition of the cartilage in the lateral femoral condyle was worse. The femorotibial angle and tibial plateau-tibial shaft angle were larger if the conditions of the lateral meniscus or the cartilage in the lateral tibial plateau were worse. Based on the results of this study, progression of varus knee osteoarthritis may occur in the following manner: medial knee osteoarthritis starts in the central portion of the medial tibial plateau, and accompanied by medial meniscal extrusion and anterior cruciate ligament rupture, cartilage degeneration expands from the anterior to the posterior in the medial tibial plateau. Bone attrition occurs in the medial tibial plateau, and the femoro-tibial angle and tibial plateau-tibial shaft angle increase. Therefore, the lateral intercondylar eminence injures the cartilage of the lateral femoral condyle in the longitudinal fissure type. Thereafter, the cartilage degeneration expands in the whole of the knee joints.

  16. Comparison of Different Approaches for Measuring Tibial Cartilage Thickness

    Directory of Open Access Journals (Sweden)

    Maier Jennifer

    2017-07-01

    Full Text Available Osteoarthritis is a degenerative disease affecting bones and cartilage especially in the human knee. In this context, cartilage thickness is an indicator for knee cartilage health. Thickness measurements are performed on medical images acquired in-vivo. Currently, there is no standard method agreed upon that defines a distance measure in articular cartilage. In this work, we present a comparison of different methods commonly used in literature. These methods are based on nearest neighbors, surface normal vectors, local thickness and potential field lines. All approaches were applied to manual segmentations of tibia and lateral and medial tibial cartilage performed by experienced raters. The underlying data were contrast agent-enhanced cone-beam C-arm CT reconstructions of one healthy subject’s knee. The subject was scanned three times, once in supine position and two times in a standing weight-bearing position. A comparison of the resulting thickness maps shows similar distributions and high correlation coefficients between the approaches above 0.90. The nearest neighbor method results on average in the lowest cartilage thickness values, while the local thickness approach assigns the highest values. We showed that the different methods agree in their thickness distribution. The results will be used for a future evaluation of cartilage change under weight-bearing conditions.

  17. The Influence of Articular Cartilage Thickness Reduction on Meniscus Biomechanics.

    Science.gov (United States)

    Łuczkiewicz, Piotr; Daszkiewicz, Karol; Chróścielewski, Jacek; Witkowski, Wojciech; Winklewski, Pawel J

    2016-01-01

    Evaluation of the biomechanical interaction between meniscus and cartilage in medial compartment knee osteoarthritis. The finite element method was used to simulate knee joint contact mechanics. Three knee models were created on the basis of knee geometry from the Open Knee project. We reduced the thickness of medial cartilages in the intact knee model by approximately 50% to obtain a medial knee osteoarthritis (OA) model. Two variants of medial knee OA model with congruent and incongruent contact surfaces were analysed to investigate the influence of congruency. A nonlinear static analysis for one compressive load case was performed. The focus of the study was the influence of cartilage degeneration on meniscal extrusion and the values of the contact forces and contact areas. In the model with incongruent contact surfaces, we observed maximal compressive stress on the tibial plateau. In this model, the value of medial meniscus external shift was 95.3% greater, while the contact area between the tibial cartilage and medial meniscus was 50% lower than in the congruent contact surfaces model. After the non-uniform reduction of cartilage thickness, the medial meniscus carried only 48.4% of load in the medial compartment in comparison to 71.2% in the healthy knee model. We have shown that the change in articular cartilage geometry may significantly reduce the role of meniscus in load transmission and the contact area between the meniscus and cartilage. Additionally, medial knee OA may increase the risk of meniscal extrusion in the medial compartment of the knee joint.

  18. A novel in vitro bovine cartilage punch model for assessing the regeneration of focal cartilage defects with biocompatible bacterial nanocellulose

    Science.gov (United States)

    2013-01-01

    Introduction Current therapies for articular cartilage defects fail to achieve qualitatively sufficient tissue regeneration, possibly because of a mismatch between the speed of cartilage rebuilding and the resorption of degradable implant polymers. The present study focused on the self-healing capacity of resident cartilage cells in conjunction with cell-free and biocompatible (but non-resorbable) bacterial nanocellulose (BNC). This was tested in a novel in vitro bovine cartilage punch model. Methods Standardized bovine cartilage discs with a central defect filled with BNC were cultured for up to eight weeks with/without stimulation with transforming growth factor-β1 (TGF-β1. Cartilage formation and integrity were analyzed by histology, immunohistochemistry and electron microscopy. Content, release and neosynthesis of the matrix molecules proteoglycan/aggrecan, collagen II and collagen I were also quantified. Finally, gene expression of these molecules was profiled in resident chondrocytes and chondrocytes migrated onto the cartilage surface or the implant material. Results Non-stimulated and especially TGF-β1-stimulated cartilage discs displayed a preserved structural and functional integrity of the chondrocytes and surrounding matrix, remained vital in long-term culture (eight weeks) without signs of degeneration and showed substantial synthesis of cartilage-specific molecules at the protein and mRNA level. Whereas mobilization of chondrocytes from the matrix onto the surface of cartilage and implant was pivotal for successful seeding of cell-free BNC, chondrocytes did not immigrate into the central BNC area, possibly due to the relatively small diameter of its pores (2 to 5 μm). Chondrocytes on the BNC surface showed signs of successful redifferentiation over time, including increase of aggrecan/collagen type II mRNA, decrease of collagen type I mRNA and initial deposition of proteoglycan and collagen type II in long-term high-density pellet cultures

  19. MR imaging of cartilage and its repair in the knee - a review

    Energy Technology Data Exchange (ETDEWEB)

    Trattnig, S.; Welsch, G.W. [Medical University Vienna, MR Centre of Excellence, Department of Radiology, Vienna (Austria); Domayer, S. [Medical University Vienna, MR Centre of Excellence, Department of Radiology, Vienna (Austria); Medical University Vienna, Department of Orthopedics, Vienna (Austria); Mosher, T. [Penn State University, College of Medicine, Department of Radiology and Orthopaedic Surgery, Hershey, PA (United States); Eckstein, F. [Paracelsus Medical University, Institute of Anatomy and Musculoskeletal Research, Salzburg (Austria); Chondrometrics GmbH, Ainring (Germany)

    2009-07-15

    Chondral injuries are common lesions of the knee joint, and many patients could benefit from cartilage repair. Widespread cartilage repair techniques require sophisticated noninvasive follow-up using MRI. In addition to the precise morphological assessment of this area of cartilage repair, the cartilage's biochemical constitution can be determined using biochemical MRI techniques. The combination of the clinical outcome after cartilage repair together with the morphological and biochemical description of the cartilage repair tissue as well as the surrounding cartilage can lead to an optimal follow-up evaluation. The present article on MR imaging techniques of cartilage repair focuses on morphological description and scoring using techniques from conventional 2D through advanced isotropic 3D MRI sequences. Furthermore the ultrastructure of the repair tissue and the surrounding cartilage is evaluated in-vivo by biochemical T1-delayed gadolinium enhanced MRI of cartilage (dGEMRIC), T2 relaxation, and diffusion-weighted imaging techniques. (orig.)

  20. CT and MRI of aggressive osteoblastoma of thyroid cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Agarwala, R.; Graham, R.J.; Panella, J.S. [Northwestern Univ., Evanston, IL (United States)

    1996-01-01

    We present a unique case of aggressive osteoblastoma arising from thyroid cartilage. A 52-year-old man presented with a 10 month history of neck discomfort but without frank pain. CT and MR examinations disclosed a well defined mass arising from the thyroid cartilage. This lesion had areas of coarse calcifications and a central area of lucency. The appearance suggested chondrosarcoma. Hemilaryngectomy was performed to remove the mass en bloc. Surgical pathology diagnosed aggressive osteoblastoma arising from thyroid cartilage. 8 refs., 2 figs.

  1. Hyaluronan protects against cartilage damage by decreasing stiffness and changing3-D microarchitecture of subchondral bone in guinea pig primary osteoarthrosis

    DEFF Research Database (Denmark)

    Ding, Ming

    significantly lower bone volume fraction, and typical rod-like structure. In the long-term study, these latter changes were more pronounced, with an additionally significant decrease in connectivity and bone surface density (Fig. 2). In the short-term study, HA-treated cortical bone had significantly greater...... HA on the articular cartilage and subchondral bone tissues were seen. HA protects against OA-related cartilage degradation to almost normal level, and effectively changes the subchondral bone tissue microarchitecture, collagen and mineral content and density without altering the mechanical properties...... of cancellous bone. The most striking features are the microarchitectural changes in the subchondral cancellous bone that lead to lower bone density and markedly rod-like structure, and thus reducing cartilage stress during impact loading. Still, the subchondral bone has a greater mineral concentration...

  2. How Wage Compression Affects Job Turnover

    OpenAIRE

    Heyman, Fredrik

    2008-01-01

    I use Swedish establishment-level panel data to test Bertola and Rogerson’s (1997) hypothesis of a positive relation between the degree of wage compression and job reallocation. Results indicate that the effect of wage compression on job turnover is positive and significant in the manufacturing sector. The wage compression effect is stronger on job destruction than on job creation, consistent with downward wage rigidity. Further results include a strong positive relationship between the fract...

  3. Employee turnover, HRM and institutional contexts.

    OpenAIRE

    Croucher, Richard; Wood, Geoffrey; Brewster, Chris; Brookes, Michael

    2012-01-01

    Literature on comparative capitalism remains divided between approaches founded on stylized case study evidence and descriptions of broad trends, and those that focus on macro data. In contrast, this study explores the relevance of Amable’s approach to understanding differences in employment relations practice, based on firm-level micro data. The article examines employee–employer interdependence (including turnover rates) in different categories of economy as classified by Amable. The findin...

  4. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C

    1993-01-01

    in lumbar bone mineral density, femoral neck bone mineral density, serum levels of alkaline phosphatase, osteocalcin, ionized calcium and phosphate. The urinary excretion of both hydroxyproline and calcium relative to urinary creatinine excretion was significantly higher in patients with fibromyalgia, p = 0.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  5. High bone turnover in Irish professional jockeys.

    LENUS (Irish Health Repository)

    Waldron-Lynch, F

    2012-02-01

    SUMMARY: Professional jockeys are routinely exposed to high impact trauma and sustain fractures frequently. We found that jockeys restrict their caloric intake in order to maintain regulation weights, and that bone turnover is high. There are significant health and safety implications for the racing industry. INTRODUCTION: Professional jockeys routinely sustain fractures from high impact falls. Jockeys maintain a low percentage body fat and a low body mass index (BMI) to achieve low weight targets in order to race. We evaluated dietary habits and bone metabolism in jockeys. METHODS: Bone mineral density (BMD) was measured in 27 male jockeys of the 144 jockeys licensed in Ireland. Fourteen (52%) had BMD T score below -1.0, of whom 12 consented to clinical review, nutritional survey, endocrine studies, and bone turnover markers (BTM). BTM were compared to age- and sex-matched controls (n = 16). RESULTS: BMI was 20.6 +\\/- 1.7 kg\\/m(2); previous fracture frequency was 3.2 +\\/- 2.0 per rider. All had normal endocrine axes. The jockeys\\' diet as determined by a 7-day dietary recall was deficient in energy, calcium, and vitamin D intake. Compared with the control group, the jockey group had evidence of increased bone turnover. CONCLUSIONS: A substantial proportion of the professional jockeys in Ireland have low-normal BMD, low BMI, and high bone turnover that may result from weight and dietary restrictions. These factors seem to have a deleterious effect on their bone health and predispose the jockeys to a high fracture risk that should be remediated.

  6. Norepinephrine turnover in brown adipose tissue is stimulated by a single meal

    International Nuclear Information System (INIS)

    Glick, Z.; Raum, W.J.

    1986-01-01

    A single meal stimulates brown adipose tissue (BAT) thermogenesis in rats. In the present study the role of norepinephrine in this thermogenic response was assessed from the rate of its turnover in BAT after a single test meal. For comparison, norepinephrine turnover was determined in the heart and spleen. A total of 48 male Wistar rats (200 g) were trained to eat during two feeding sessions per day. On the experimental day, one group (n = 24) was meal deprived and the other (n = 24) was given a low-protein high-carbohydrate test meal for 2 h. The synthesis inhibition method with α-methyl-p-tyrosine was employed to determine norepinephrine turnover from its concentration at four hourly time points after the meal. Tissue concentrations of norepinephrine were determined by radioimmunoassay. Norepinephrine concentration and turnover rate were increased more than threefold in BAT of the meal-fed compared with the meal-deprived rats. Neither were significantly altered by the meal in the heart or spleen. The data suggest that norepinephrine mediates a portion of the thermic effect of meals that originate in BAT

  7. Evaluating the Role of Microbial Internal Storage Turnover on Nitrous Oxide Accumulation During Denitrification

    Science.gov (United States)

    Liu, Yiwen; Peng, Lai; Guo, Jianhua; Chen, Xueming; Yuan, Zhiguo; Ni, Bing-Jie

    2015-01-01

    Biological wastewater treatment processes under a dynamic regime with respect to carbon substrate can result in microbial storage of internal polymers (e.g., polyhydroxybutyrate (PHB)) and their subsequent utilizations. These storage turnovers play important roles in nitrous oxide (N2O) accumulation during heterotrophic denitrification in biological wastewater treatment. In this work, a mathematical model is developed to evaluate the key role of PHB storage turnovers on N2O accumulation during denitrification for the first time, aiming to establish the key relationship between N2O accumulation and PHB storage production. The model is successfully calibrated and validated using N2O data from two independent experimental systems with PHB storage turnovers. The model satisfactorily describes nitrogen reductions, PHB storage/utilization, and N2O accumulation from both systems. The results reveal a linear relationship between N2O accumulation and PHB production, suggesting a substantial effect of PHB storage on N2O accumulation during denitrification. Application of the model to simulate long-term operations of a denitrifying sequencing batch reactor and a denitrifying continuous system indicates the feeding pattern and sludge retention time would alter PHB turnovers and thus affect N2O accumulation. Increasing PHB utilization could substantially raise N2O accumulation due to the relatively low N2O reduction rate when using PHB as carbon source. PMID:26463891

  8. Tissue engineering of cartilages using biomatrices

    DEFF Research Database (Denmark)

    Melrose, J.; Chuang, C.; Whitelock, J.

    2008-01-01

    Tissue engineering is an exciting new cross-disciplinary methodology which applies the principles of engineering and structure-function relationships between normal and pathological tissues to develop biological substitute to restore, maintain or improve tissue function. Tissue engineering...... therefore involves a melange of approaches encompassing developmental biology, tissue mechanics, medicine, cell differentiation and survival biology, mechanostransduction and nano-fabrication technology. The central tissue of interest in this review is cartilage. Traumatic injuries, congenital abnormalities...... engineering approaches and many of these are discussed and their in vitro and in vivo applications covered in this review. Tissue engineering is entering an exciting era; significant advances have been made; however, many technical challenges remain to be solved before this technology becomes widely...

  9. PERAN STRES KERJA DAN KEPUASAN KERJA UNTUK MENGURANGI TURNOVER INTENTION

    Directory of Open Access Journals (Sweden)

    Syarifah Nazenin

    2014-09-01

    Full Text Available Tujuan penelitian ini untuk menguji pengaruh variabel stres kerja dan kepuasan kerja pada turnover intention karyawan tetap bagian produksi. Sampel penelitian ini adalah 86 responden, menggunakan metode Slovin dengan teknik probability sampling dengan jenis proportionate random sampling. Berdasarkan hasil penelitian, menunjukkan bahwa stres kerja berpengaruh positif signifikan pada turnover intention. Kemudian, kepuasan kerja berpengaruh negatif signifikan. Penelitian ini menyimpulkan, bahwa stres kerja berpengaruh positif dan signifikan pada turnover intention karyawan dan kepuasan kerja berpengaruh negatif dan signifikan terhadap turnover intention karyawan. Implikasi manajerial yang bisa dilakukan adalah dengan pengurangan tingkat stres karyawan dan membuat program untuk tujuan menekan turnover intention, seperti kesempatan promosi dan meningkatkan reward karyawan. The purpose of this study conducted to examine the effect of work stress and job satisfaction on turnover intention of employee in production department. The sample was 86 respondent, using Slovin method with proportionate random sampling technique. The result showed that job stress has a positive effect on turnover intention while job satisfaction has a negative effect on turnover intention. This study conclude that job stress has positive and significant impact on employee turnover intention and job satisfaction significantly and negatively related to turnover intention of employees. Therefore, it is recommended to managerial level people to reduce stress levels in employees and to create a program for pressing turnover intention, such as promotional opportunities and improve employee rewards.

  10. Characteristics and time-dependence of cut marks and blunt force fractures on costal cartilages: an experimental study.

    Science.gov (United States)

    Spagnoli, Laura; Amadasi, Alberto; Frustaci, Michela; Mazzarelli, Debora; Porta, Davide; Cattaneo, Cristina

    2016-03-01

    The distinction between cut marks and blunt force injuries on costal cartilages is a crucial issue in the forensic field. Moreover, a correct distinction may further be complicated by decomposition, so the need arises to investigate the distinctive features of lesions on cartilage and their changes over time. This study aimed to assess the stereomicroscopic features of cut marks (performed with six different knives) and blunt fractures (performed with a hammer and by means of manual bending) on 48 fragments of human costal cartilages. Moreover, in order to simulate decomposition, the cut and fractured surfaces were checked with stereomicroscopy and through casts after 1 and 2 days, 1 week, and 1, 2 and 4 months of drying in ambient air. In fresh samples, for single and unique cuts, striations were observed in between 44 and 88% of cases when non-serrated blades were used, and between 77 and 88% for serrated blades; in the case of "repeated" (back and forth movement) cuts, striations were detected in between 56 and 89% of cases for non-serrated blades, and between 66 and 100% for serrated blades. After only 1 week of decomposition the detection rates fell to percentages of between 28 and 39% for serrated blades and between 17 and 33% for non-serrated blades. Blunt force injuries showed non-specific characteristics, which, if properly assessed, may lead to a reliable distinction between different cut marks in fresh samples. The most evident alterations of the structure of the cartilage occurred in the first week of decomposition in ambient air. After one week of drying, the characteristics of cut marks were almost undetectable, thereby making it extremely challenging to distinguish between cut marks, blunt force fractures and taphonomic effects. The study represents a contribution to the correct assessment and distinction of cut marks and blunt force injuries on cartilages, providing a glimpse on the modifications such lesions may undergo with decomposition.

  11. The development of the collagen fibre network in tissue-engineered cartilage constructs in vivo. Engineered cartilage reorganises fibre network

    Directory of Open Access Journals (Sweden)

    H Paetzold

    2012-04-01

    Full Text Available For long term durability of tissue-engineered cartilage implanted in vivo, the development of the collagen fibre network orientation is essential as well as the distribution of collagen, since expanded chondrocytes are known to synthesise collagen type I. Typically, these properties differ strongly between native and tissue-engineered cartilage. Nonetheless, the clinical results of a pilot study with implanted tissue-engineered cartilage in pigs were surprisingly good. The purpose of this study was therefore to analyse if the structure and composition of the artificial cartilage tissue changes in the first 52 weeks after implantation. Thus, collagen network orientation and collagen type distribution in tissue-engineered cartilage-carrier-constructs implanted in the knee joints of Göttinger minipigs for 2, 26 or 52 weeks have been further investigated by processing digitised microscopy images of histological sections. The comparison to native cartilage demonstrated that fibre orientation over the cartilage depth has a clear tendency towards native cartilage with increasing time of implantation. After 2 weeks, the collagen fibres of the superficial zone were oriented parallel to the articular surface with little anisotropy present in the middle and deep zones. Overall, fibre orientation and collagen distribution within the implants were less homogenous than in native cartilage tissue. Despite a relatively low number of specimens, the consistent observation of a continuous approximation to native tissue is very promising and suggests that it may not be necessary to engineer the perfect tissue for implantation but rather to provide an intermediate solution to help the body to heal itself.

  12. The development of the collagen fibre network in tissue-engineered cartilage constructs in vivo. Engineered cartilage reorganises fibre network.

    Science.gov (United States)

    Paetzold, H; Goepfert, C; Huber, G; Hoenig, E; Pörtner, R; Schilling, A F; Meenen, N M; Morlock, M M

    2012-04-05

    For long term durability of tissue-engineered cartilage implanted in vivo, the development of the collagen fibre network orientation is essential as well as the distribution of collagen, since expanded chondrocytes are known to synthesise collagen type I. Typically, these properties differ strongly between native and tissue-engineered cartilage. Nonetheless, the clinical results of a pilot study with implanted tissue-engineered cartilage in pigs were surprisingly good. The purpose of this study was therefore to analyse if the structure and composition of the artificial cartilage tissue changes in the first 52 weeks after implantation. Thus, collagen network orientation and collagen type distribution in tissue-engineered cartilage-carrier-constructs implanted in the knee joints of Göttinger minipigs for 2, 26 or 52 weeks have been further investigated by processing digitised microscopy images of histological sections. The comparison to native cartilage demonstrated that fibre orientation over the cartilage depth has a clear tendency towards native cartilage with increasing time of implantation. After 2 weeks, the collagen fibres of the superficial zone were oriented parallel to the articular surface with little anisotropy present in the middle and deep zones. Overall, fibre orientation and collagen distribution within the implants were less homogenous than in native cartilage tissue. Despite a relatively low number of specimens, the consistent observation of a continuous approximation to native tissue is very promising and suggests that it may not be necessary to engineer the perfect tissue for implantation but rather to provide an intermediate solution to help the body to heal itself.

  13. The active form of MMP-3 is a marker of synovial inflammation and cartilage turnover in inflammatory joint diseases

    DEFF Research Database (Denmark)

    Sun, Shu; Bay-Jensen, Anne-Christine; Karsdal, Morten A

    2014-01-01

    to treatment. Hence, we aimed to develop a sensitive assay specifically measuring the active form of MMP-3 (act-MMP-3) both in ex vivo models and in human sera. METHODS: A monoclonal antibody against the first 6 amino acids of act-MMP-3 was developed, and the specificity was carefully tested by comparing total...

  14. Culture environment regulates amino acid turnover and glucose utilisation in human ES cells.

    Science.gov (United States)

    Rathjen, Joy; Yeo, Christine; Yap, Charlotte; Tan, Boon Siang Nicholas; Rathjen, Peter D; Gardner, David K

    2014-06-01

    Human embryonic stem (ES) cells have been proposed as a renewable source of pluripotent cells that can be differentiated into various cell types for use in research, drug discovery and in the emerging area of regenerative medicine. Exploitation of this potential will require the development of ES cell culture conditions that promote pluripotency and a normal cell metabolism, and quality control parameters that measure these outcomes. There is, however, relatively little known about the metabolism of pluripotent cells or the impact of culture environment and differentiation on their metabolic pathways. The effect of two commonly used medium supplements and cell differentiation on metabolic indicators in human ES cells were examined. Medium modifications and differentiation were compared in a chemically defined and feeder-independent culture system. Adding serum increased glucose utilisation and altered amino acid turnover by the cells, as well as inducing a small proportion of the cells to differentiate. Cell differentiation could be mitigated by inhibiting p38 mitogen-activated protein kinase (p38 MAPK activity). The addition of Knockout Serum Replacer also increased glucose uptake and changed amino acid turnover by the cells. These changes were distinct from those induced by serum and occurred in the absence of detectable differentiation. Induction of differentiation by bone morphogenetic protein 4 (BMP4), in contrast, did not alter metabolite turnover. Deviations from metabolite turnover by ES cells in fully defined medium demonstrated that culture environment can alter metabolite use. The challenge remains to understand the impact of metabolic changes on long-term cell maintenance and the functionality of derived cell populations.

  15. Tamarind Seed (Tamarindus indica) Extract Ameliorates Adjuvant-Induced Arthritis via Regulating the Mediators of Cartilage/Bone Degeneration, Inflammation and Oxidative Stress.

    Science.gov (United States)

    Sundaram, Mahalingam S; Hemshekhar, Mahadevappa; Santhosh, Martin S; Paul, Manoj; Sunitha, Kabburahalli; Thushara, Ram M; NaveenKumar, Somanathapura K; Naveen, Shivanna; Devaraja, Sannaningaiah; Rangappa, Kanchugarakoppal S; Kemparaju, Kempaiah; Girish, Kesturu S

    2015-06-10

    Medicinal plants are employed in the treatment of human ailments from time immemorial. Several studies have validated the use of medicinal plant products in arthritis treatment. Arthritis is a joint disorder affecting subchondral bone and cartilage. Degradation of cartilage is principally mediated by enzymes like matrix metalloproteinases (MMPs), hyaluronidases (HAase), aggrecanases and exoglycosidases. These enzymes act upon collagen, hyaluronan and aggrecan of cartilage respectively, which would in turn activate bone deteriorating enzymes like cathepsins and tartrate resistant acid phosphatases (TRAP). Besides, the incessant action of reactive oxygen species and the inflammatory mediators is reported to cause further damage by immunological activation. The present study demonstrated the anti-arthritic efficacy of tamarind seed extract (TSE). TSE exhibited cartilage and bone protecting nature by inhibiting the elevated activities of MMPs, HAase, exoglycosidases, cathepsins and TRAP. It also mitigated the augmented levels of inflammatory mediators like interleukin (IL)-1β, tumor necrosis factor-α, IL-6, IL-23 and cyclooxygenase-2. Further, TSE administration alleviated increased levels of ROS and hydroperoxides and sustained the endogenous antioxidant homeostasis by balancing altered levels of endogenous antioxidant markers. Overall, TSE was observed as a potent agent abrogating arthritis-mediated cartilage/bone degradation, inflammation and associated stress in vivo demanding further attention.

  16. The composition of engineered cartilage at the time of implantation determines the likelihood of regenerating tissue with a normal collagen architecture.

    Science.gov (United States)

    Nagel, Thomas; Kelly, Daniel J

    2013-04-01

    The biomechanical functionality of articular cartilage is derived from both its biochemical composition and the architecture of the collagen network. Failure to replicate this normal Benninghoff architecture in regenerating articular cartilage may in turn predispose the tissue to failure. In this article, the influence of the maturity (or functionality) of a tissue-engineered construct at the time of implantation into a tibial chondral defect on the likelihood of recapitulating a normal Benninghoff architecture was investigated using a computational model featuring a collagen remodeling algorithm. Such a normal tissue architecture was predicted to form in the intact tibial plateau due to the interplay between the depth-dependent extracellular matrix properties, foremost swelling pressures, and external mechanical loading. In the presence of even small empty defects in the articular surface, the collagen architecture in the surrounding cartilage was predicted to deviate significantly from the native state, indicating a possible predisposition for osteoarthritic changes. These negative alterations were alleviated by the implantation of tissue-engineered cartilage, where a mature implant was predicted to result in the formation of a more native-like collagen architecture than immature implants. The results of this study highlight the importance of cartilage graft functionality to maintain and/or re-establish joint function and suggest that engineering a tissue with a native depth-dependent composition may facilitate the establishment of a normal Benninghoff collagen architecture after implantation into load-bearing defects.

  17. Treatment staff turnover in organizations implementing evidence-based practices: turnover rates and their association with client outcomes.

    Science.gov (United States)

    Garner, Bryan R; Hunter, Brooke D; Modisette, Kathryn C; Ihnes, Pamela C; Godley, Susan H

    2012-03-01

    High staff turnover has been described as a problem for the substance use disorder treatment field. This assertion is based primarily on the assumption that staff turnover adversely impacts treatment delivery and effectiveness. This assumption, however, has not been empirically tested. In this study, we computed annualized rates of turnover for treatment staff (N = 249) participating in an evidence-based practice implementation initiative and examined the association between organizational-level rates of staff turnover and client-level outcomes. Annualized rates of staff turnover were 31% for clinicians and 19% for clinical supervisors. In addition, multilevel analyses did not reveal the expected relationship between staff turnover and poorer client-level outcomes. Rather, organizational-level rates of staff turnover were found to have a significant positive association with two measures of treatment effectiveness: less involvement in illegal activity and lower social risk. Possible explanations for these findings are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Costal cartilage fractures and disruptions in a rugby football player.

    Science.gov (United States)

    Lopez, Victor; Ma, Richard; Li, Xinning; Steele, John; Allen, Answorth A

    2013-05-01

    Costal cartilage fracture of the rib cage, or costochondral, is a rare sporting injury. For contact athletes, the instability of the rib cage may lead to potential serious complications, similar to rib fractures or thorax disruption. Most authors recommend initial conservative treatment with surgery reserved for only recalcitrant cases. We report a case of an amateur American male rugby football player who sustained a costal cartilage fracture and disruption involving the anterior left fifth and sixth rib costal cartilages. The case highlights the difficulty in establishing the diagnosis based on clinical examination and standard radiographs alone. Computed tomography was used to assist in diagnosing this destabilizing injury to the rib cage. Costal cartilage fractures and disruptions in athletes are rarely reported in the literature and can have serious implications for the athlete's ability to return to play if the rib cage is destabilized.

  19. Bioluminescence Assays for Monitoring Chondrogenic Differentiation and Cartilage Regeneration

    Directory of Open Access Journals (Sweden)

    Hyeon Jeong Je

    2017-06-01

    Full Text Available Since articular cartilage has a limited regeneration potential, for developing biological therapies for cartilage regeneration it is important to study the mechanisms underlying chondrogenesis of stem cells. Bioluminescence assays can visualize a wide range of biological phenomena such as gene expression, signaling, metabolism, development, cellular movements, and molecular interactions by using visible light and thus contribute substantially to elucidation of their biological functions. This article gives a concise review to introduce basic principles of bioluminescence assays and applications of the technology to visualize the processes of chondrogenesis and cartilage regeneration. Applications of bioluminescence assays have been highlighted in the methods of real-time monitoring of gene expression and intracellular levels of biomolecules and noninvasive cell tracking within animal models. This review suggests that bioluminescence assays can be applied towards a visual understanding of chondrogenesis and cartilage regeneration.

  20. Namaste (counterbalancing technique: Overcoming warping in costal cartilage

    Directory of Open Access Journals (Sweden)

    Kapil S Agrawal

    2015-01-01

    Full Text Available Background: Indian noses are broader and lack projection as compared to other populations, hence very often need augmentation, that too by large volume. Costal cartilage remains the material of choice in large volume augmentations and repair of complex primary and secondary nasal deformities. One major disadvantage of costal cartilage grafts (CCG which offsets all other advantages is the tendency to warp and become distorted over a period of time. We propose a simple technique to overcome this menace of warping. Materials and Methods: We present the data of 51 patients of rhinoplasty done using CCG with counterbalancing technique over a period of 4 years. Results: No evidence of warping was found in any patient up to a maximum follow-up period of 4 years. Conclusion: Counterbalancing is a useful technique to overcome the problem of warping. It gives liberty to utilize even unbalanced cartilage safely to provide desired shape and use the cartilage without any wastage.

  1. Cartilage (Bovine and Shark) (PDQ®)—Health Professional Version

    Science.gov (United States)

    Expert-reviewed information summary about the use of bovine and shark cartilage as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  2. New Techniques for Cartilage Magnetic Resonance Imaging Relaxation Time Analysis: Texture Analysis of Flattened Cartilage and Localized Intra- and Inter-subject Comparisons

    OpenAIRE

    Carballido-Gamio, Julio; Link, Thomas M.; Majumdar, Sharmila

    2008-01-01

    MR relaxation time measurements of knee cartilage have shown potential to characterize knee osteoarthritis (OA). In this work, techniques that allow localized intra- and inter-subject comparisons of cartilage relaxation times, as well as cartilage flattening for texture analysis parallel and perpendicular to the natural cartilage layers, are presented. The localized comparisons are based on the registration of bone structures and the assignment of relaxation time feature vectors to each point...

  3. Articular cartilage repair and the evolving role of regenerative medicine

    Directory of Open Access Journals (Sweden)

    Pieter K Bos

    2010-10-01

    Full Text Available Pieter K Bos1, Marloes L van Melle1, Gerjo JVM van Osch1,21Department of Orthopaedic Surgery, Erasmus MC, Rotterdam, the Netherlands; 2Department of Otorhinolaryngology, Erasmus MC, Rotterdam, the NetherlandsAbstract: Among the growing applications of regenerative medicine, clinical articular cartilage repair has now been used for 2 decades and forms a successful example of translational medicine. Cartilage is characterized by a limited intrinsic repair capacity following injury. Articular cartilage defects cause symptoms, are not spontaneously repaired, and are generally believed to result in early osteoarthritis. Marrow stimulation techniques, osteochondral transplantation, and cell-based therapies, such as autologous chondrocyte implantation (ACI and use of mesenchymal stem cells (MSCs, are used for tissue regeneration, symptom relief, and prevention of further joint degeneration. The exact incidence of cartilage defects and the natural outcome of joints with these lesions are unclear. Currently available cartilage repair techniques are designed for defect treatment in otherwise healthy joints and limbs, mostly in young adults. The natural history studies presented in this review estimated that the prevalence of cartilage lesions in this patient group ranges from 5% to 11%. The background and results from currently available randomized clinical trials of the three mostly used cartilage repair techniques are outlined in this review. Osteochondral transplantation, marrow stimulation, and ACI show improvement of symptoms with an advantage for cell-based techniques, but only a suggestion that risk for joint degeneration can be reduced. MSCs, characterized by their good proliferative capacity and the potential to differentiate into different mesenchymal lineages, form an attractive alternative cell source for cartilage regeneration. Moreover, MSCs provide a regenerative microenvironment by the secretion of bioactive factors. This trophic activity

  4. Comparative digital cartilage histology for human and common osteoarthritis models

    Directory of Open Access Journals (Sweden)

    Pedersen DR

    2013-02-01

    Full Text Available Douglas R Pedersen, Jessica E Goetz, Gail L Kurriger, James A MartinDepartment of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, USAPurpose: This study addresses the species-specific and site-specific details of weight-bearing articular cartilage zone depths and chondrocyte distributions among humans and common osteoarthritis (OA animal models using contemporary digital imaging tools. Histological analysis is the gold-standard research tool for evaluating cartilage health, OA severity, and treatment efficacy. Historically, evaluations were made by expert analysts. However, state-of-the-art tools have been developed that allow for digitization of entire histological sections for computer-aided analysis. Large volumes of common digital cartilage metrics directly complement elucidation of trends in OA inducement and concomitant potential treatments.Materials and methods: Sixteen fresh human knees, 26 adult New Zealand rabbit stifles, and 104 bovine lateral plateaus were measured for four cartilage zones and the cell densities within each zone. Each knee was divided into four weight-bearing sites: the medial and lateral plateaus and femoral condyles.Results: One-way analysis of variance followed by pairwise multiple comparisons (Holm–Sidak method at a significance of 0.05 clearly confirmed the variability between cartilage depths at each site, between sites in the same species, and between weight-bearing articular cartilage definitions in different species.Conclusion: The present study clearly demonstrates multisite, multispecies differences in normal weight-bearing articular cartilage, which can be objectively quantified by a common digital histology imaging technique. The clear site-specific differences in normal cartilage must be taken into consideration when characterizing the pathoetiology of OA models. Together, these provide a path to consistently analyze the volume and variety of histologic slides necessarily generated

  5. Modern cartilage imaging of the ankle; Moderne Knorpelbildgebung des Sprunggelenks

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Marc-Andre; Wuennemann, Felix; Rehnitz, Christoph [University Hospital Heidelberg (Germany). Diagnostic and Interventional Radiology; Jungmann, Pia M. [Technical Univ. Munich (Germany). Radiology; Kuni, Benita [Ortho-Zentrum Karlsruhe (Germany). Orthopedics and Trauma Surgery

    2017-10-15

    Talar osteochondral lesions are an important risk factor for the development of talar osteoarthritis. Furthermore, osteochondral lesions might explain persistent ankle pain. Early diagnosis of accompanying chondral defects is important to establish the optimal therapy strategy and thereby delaying or preventing the onset of osteoarthritis. The purpose of this review is to explain modern cartilage imaging with emphasis of MR imaging as well as the discussion of more sophisticated imaging studies like CT-arthrography or functional MR imaging. Pubmed literature search concerning: osteochondral lesions, cartilage damage, ankle joint, talus, 2 D MR imaging, 3 D MR imaging, cartilage MR imaging, CT-arthrography, cartilage repair, microfracture, OATS, MACT. Dedicated MR imaging protocols to delineate talar cartilage and the appearance of acute and chronic osteochondral lesions were discussed. Recent developments of MR imaging, such as isotropic 3 D imaging that has a higher signal-to noise ratio when compared to 2 D imaging, and specialized imaging methods such as CT-arthrography as well as functional MR imaging were introduced. Several classifications schemes and imaging findings of osteochondral lesions that influence the conservative or surgical therapy strategy were discussed. MRI enables after surgery the non-invasive assessment of the repair tissue and the success of implantation. Key points: Modern MRI allows for highly resolved visualization of the articular cartilage of the ankle joint and of subchondral pathologies. Recent advances in MRI include 3 D isotropic ankle joint imaging, which deliver higher signal-to-noise ratios of the cartilage and less partial volume artifacts when compared with standard 2 D sequences. In case of osteochondral lesions MRI is beneficial for assessing the stability of the osteochondral fragment and for this discontinuity of the cartilage layer is an important factor. CT-arthrography can be used in case of contraindications of MRI and

  6. Hypoxia, RONS and energy metabolism in articular cartilage.

    Science.gov (United States)

    Fermor, B; Gurumurthy, A; Diekman, B O

    2010-09-01

    Increased pro-inflammatory cytokines and reactive oxygen and nitrogen species (RONS) occur in osteoarthritis (OA). Oxygen tension can alter the levels of RONS induced by interleukin-1 (IL-1). RONS such as nitric oxide (NO) can alter energy metabolism. The aim of this study was to determine if oxygen tension alters energy metabolism, in articular cartilage, in response to IL-1 or NO and to determine if cell death occurred. Porcine articular chondrocytes were incubated with IL-1 or the NO donor NOC-18 for 48 h in either 1, 5 or 20% O(2). Adenosine triphosphate (ATP) levels were measured and immunoblots for adenosine monophosphate-activated protein kinase (AMPK) were done. Protein translation was measured by S6 activation. Senescence and autophagy were determined by increased caveolin or conversion of LC3-I to LC3-II respectively. One percent O(2) significantly reduced ATP levels compared with 20% O(2). Five percent O(2) significantly increased ATP levels compared with 20% O(2). One percent O(2) significantly increased phospho-AMPK (pAMPK) protein expression compared with 5 or 20% O(2). Oxygen tension had no effects on pS6, caveolin or LC3-II levels. IL-1-induced NO production was significantly reduced with decreased oxygen tension, and significantly reduced ATP levels at all oxygen tensions, but pAMPK was only significantly increased at 5% O(2). IL-1 significantly reduced pS6 at all oxygen tensions. IL-1 had no effects on caveolin and significantly increased LC3-II at 20% O(2) only. NOC-18 significantly reduced ATP levels at all oxygen tensions, and significantly increased pAMPK at 5% O(2) only, and significantly decreased pAMPK at 1% O(2). NOC-18 significantly reduced pS6 at 1% O(2) and significantly increased caveolin at 5% O(2), and LC3-II at 1% O(2). Our data suggest 5% O(2) is optimal for energy metabolism and protective to some effects of IL-1 and NO. NO has the greatest effects on ATP levels and the induction of autophagy at 1% O(2). Copyright 2010

  7. Vulnerability of the Superficial Zone of Immature Articular Cartilage to Compressive Injury

    Energy Technology Data Exchange (ETDEWEB)

    Rolauffs, R.; Muehleman, C; Li, J; Kurz, B; Kuettner, K; Frank, E; Grodzinsky, A

    2010-01-01

    The zonal composition and functioning of adult articular cartilage causes depth-dependent responses to compressive injury. In immature cartilage, shear and compressive moduli as well as collagen and sulfated glycosaminoglycan (sGAG) content also vary with depth. However, there is little understanding of the depth-dependent damage caused by injury. Since injury to immature knee joints most often causes articular cartilage lesions, this study was undertaken to characterize the zonal dependence of biomechanical, biochemical, and matrix-associated changes caused by compressive injury. Disks from the superficial and deeper zones of bovine calves were biomechanically characterized. Injury to the disks was achieved by applying a final strain of 50% compression at 100%/second, followed by biomechanical recharacterization. Tissue compaction upon injury as well as sGAG density, sGAG loss, and biosynthesis were measured. Collagen fiber orientation and matrix damage were assessed using histology, diffraction-enhanced x-ray imaging, and texture analysis. Injured superficial zone disks showed surface disruption, tissue compaction by 20.3 {+-} 4.3% (mean {+-} SEM), and immediate biomechanical impairment that was revealed by a mean {+-} SEM decrease in dynamic stiffness to 7.1 {+-} 3.3% of the value before injury and equilibrium moduli that were below the level of detection. Tissue areas that appeared intact on histology showed clear textural alterations. Injured deeper zone disks showed collagen crimping but remained undamaged and biomechanically intact. Superficial zone disks did not lose sGAG immediately after injury, but lost 17.8 {+-} 1.4% of sGAG after 48 hours; deeper zone disks lost only 2.8 {+-} 0.3% of sGAG content. Biomechanical impairment was associated primarily with structural damage. The soft superficial zone of immature cartilage is vulnerable to compressive injury, causing superficial matrix disruption, extensive compaction, and textural alteration, which results

  8. Turnover in health care: the mediating effects of employee engagement.

    Science.gov (United States)

    Collini, Stevie A; Guidroz, Ashley M; Perez, Lisa M

    2015-03-01

    This study aimed to understand the interaction between interpersonal respect, diversity climate, mission fulfilment and engagement to better predict turnover in health care. Registered nurse turnover has averaged 14% and current nursing shortages are expected to spread. Few studies have studied employee engagement as a mediator between organisational context and turnover. Study participants were employees working within 185 departments across ten hospitals within a large healthcare organisation in the USA. Although a total of 5443 employees work in these departments, employee opinion survey responses were aggregated by department before being linked to turnover rates gathered from company records. Engagement fully mediated the relationship between respect and turnover and the relationship between mission fulfilment and turnover. Diversity climate was not related to turnover. Turnover in health care poses a significant threat to the mission of creating a healing environment for patients and these results demonstrate that workplace respect and connection to the mission affect turnover by decreasing engagement. The findings demonstrated that to increase engagement, and improve turnover rates in health care, it would be beneficial for organisations, and nurse management to focus on improving mission fulfilment and interpersonal relationships. © 2013 John Wiley & Sons Ltd.

  9. Mesenchymal Stem Cells for Cartilage Regeneration of TMJ Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Dixin Cui

    2017-01-01

    Full Text Available Temporomandibular joint osteoarthritis (TMJ OA is a degenerative disease, characterized by progressive cartilage degradation, subchondral bone remodeling, synovitis, and chronic pain. Due to the limited self-healing capacity in condylar cartilage, traditional clinical treatments have limited symptom-modifying and structure-modifying effects to restore impaired cartilage as well as other TMJ tissues. In recent years, stem cell-based therapy has raised much attention as an alternative approach towards tissue repair and regeneration. Mesenchymal stem cells (MSCs, derived from the bone marrow, synovium, and even umbilical cord, play a role as seed cells for the cartilage regeneration of TMJ OA. MSCs possess multilineage differentiation potential, including chondrogenic differentiation as well as osteogenic differentiation. In addition, the trophic modulations of MSCs exert anti-inflammatory and immunomodulatory effects under aberrant conditions. Furthermore, MSCs combined with appropriate scaffolds can form cartilaginous or even osseous compartments to repair damaged tissue and impaired function of TMJ. In this review, we will briefly discuss the pathogenesis of cartilage degeneration in TMJ OA and emphasize the potential sources of MSCs and novel approaches for the cartilage regeneration of TMJ OA, particularly focusing on the MSC-based therapy and tissue engineering.

  10. The Role of Interstitial Fluid Pressurization in Articular Cartilage Lubrication

    Science.gov (United States)

    Ateshian, Gerard A.

    2009-01-01

    Over the last two decades, considerable progress has been reported in the field of cartilage mechanics that impacts our understanding of the role of interstitial fluid pressurization on cartilage lubrication. Theoretical and experimental studies have demonstrated that the interstitial fluid of cartilage pressurizes considerably under loading, potentially supporting most of the applied load under various transient or steady-state conditions. The fraction of the total load supported by fluid pressurization has been called the fluid load support. Experimental studies have demonstrated that the friction coefficient of cartilage correlates negatively with this variable, achieving remarkably low values when the fluid load support is greatest. A theoretical framework that embodies this relationship has been validated against experiments, predicting and explaining various outcomes, and demonstrating that a low friction coefficient can be maintained for prolonged loading durations under normal physiological function. This paper reviews salient aspects of this topic, as well as its implications for improving our understanding of boundary lubrication by molecular species in synovial fluid and the cartilage superficial zone. Effects of cartilage degeneration on its frictional response are also reviewed. PMID:19464689

  11. Mesenchymal stem cells for cartilage repair in osteoarthritis.

    Science.gov (United States)

    Gupta, Pawan K; Das, Anjan K; Chullikana, Anoop; Majumdar, Anish S

    2012-07-09

    Osteoarthritis (OA) is a degenerative disease of the connective tissue and progresses with age in the older population or develops in young athletes following sports-related injury. The articular cartilage is especially vulnerable to damage and has poor potential for regeneration because of the absence of vasculature within the tissue. Normal load-bearing capacity and biomechanical properties of thinning cartilage are severely compromised during the course of disease progression. Although surgical and pharmaceutical interventions are currently available for treating OA, restoration of normal cartilage function has been difficult to achieve. Since the tissue is composed primarily of chondrocytes distributed in a specialized extracellular matrix bed, bone marrow stromal cells (BMSCs), also known as bone marrow-derived 'mesenchymal stem cells' or 'mesenchymal stromal cells', with inherent chondrogenic differentiation potential appear to be ideally suited for therapeutic use in cartilage regeneration. BMSCs can be easily isolated and massively expanded in culture in an undifferentiated state for therapeutic use. Owing to their potential to modulate local microenvironment via anti-inflammatory and immunosuppressive functions, BMSCs have an additional advantage for allogeneic application. Moreover, by secreting various bioactive soluble factors, BMSCs can protect the cartilage from further tissue destruction and facilitate regeneration of the remaining progenitor cells in situ. This review broadly describes the advances made during the last several years in BMSCs and their therapeutic potential for repairing cartilage damage in OA.

  12. Extraction of aggrecan-peptide from cartilage by tissue autolysis.

    Science.gov (United States)

    Nakano, Takuo; Srichamroen, Anchalee; Ozimek, Lech

    2014-01-01

    Aggrecan is a cartilage specific proteoglycan containing chondroitin sulfate (CS) and keratan sulfate (KS). CS is an acidic polysaccharide having wide range of applications in pharmaceutical, cosmetic, and food industries. CS is extracted from cartilage by tissue proteolysis with an exogenous proteinase or by activating endogenous proteinases (autolysis) to release aggrecan-peptides from the tissue. This review is focused on the latter technique. Bovine nasal and tracheal cartilages, and broiler chicken sternum cartilage have been used for autolysis studies. To extract aggrecan-peptide, cartilage tissues are cut into small pieces, and incubated in a monovalent or divalent salt solution (e.g., 0.1 M sodium or calcium acetate) at pH 4.5 and 37 °C for 7 - 24 h. Most (~80% or more) of total tissue uronic acid, a constituent sugar of aggrecan, is extracted and released into the salt solution during incubation. Reextraction of the tissue residue results in release of a small amount of uronic acid. Aggrecan-peptides purified using anion exchange chromatography are large compounds containing CS and KS. On gel chromatography, they are excluded from the column of Sephacryl S-300. Chemical composition analysis demonstrated that aggrecan-peptides from either bovine or chicken cartilage contain >90% CS with small amount (autolysis has been used as a plate coating antigen in enzyme- linked immunosorbent assay (ELISA) to determine KS.

  13. Radiation synovectomy stimulates glycosaminoglycan synthesis by normal articular cartilage

    International Nuclear Information System (INIS)

    Myers, S.L.; Slowman, S.D.; Brandt, K.D.

    1989-01-01

    Radiation synovectomy has been considered a therapeutic alternative to surgical synovectomy. Whether intraarticular irradiation affects the composition or biochemistry, and therefore the biomechanical properties, of normal articular cartilage has not been established. In the present study, yttrium 90 silicate was injected into one knee of nine normal adult dogs, and three other dogs received nonradioactive yttrium silicate. When the animals were killed 4 to 13 weeks after the injection, synovium from the irradiated knees showed areas of necrosis and fibrosis. Up to 29% less hyaluronate was synthesized in vitro by the synovial intima from irradiated knees than by the intima from the contralateral knees (mean difference 18%). Morphologic abnormalities were not observed in articular cartilage from either the irradiated or control knees, nor did the water content or concentrations of uronic acid or DNA in cartilage from the irradiated knees differ from that in cartilage from the contralateral knees. However, net 35 SO 4 -labeled glycosaminoglycan synthesis in organ cultures of cartilage from irradiated knees was increased (mean difference 21%, p = 0.03) in comparison with that in cultures of contralateral knee cartilage

  14. Radiation synovectomy stimulates glycosaminoglycan synthesis by normal articular cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Myers, S.L.; Slowman, S.D.; Brandt, K.D.

    1989-07-01

    Radiation synovectomy has been considered a therapeutic alternative to surgical synovectomy. Whether intraarticular irradiation affects the composition or biochemistry, and therefore the biomechanical properties, of normal articular cartilage has not been established. In the present study, yttrium 90 silicate was injected into one knee of nine normal adult dogs, and three other dogs received nonradioactive yttrium silicate. When the animals were killed 4 to 13 weeks after the injection, synovium from the irradiated knees showed areas of necrosis and fibrosis. Up to 29% less hyaluronate was synthesized in vitro by the synovial intima from irradiated knees than by the intima from the contralateral knees (mean difference 18%). Morphologic abnormalities were not observed in articular cartilage from either the irradiated or control knees, nor did the water content or concentrations of uronic acid or DNA in cartilage from the irradiated knees differ from that in cartilage from the contralateral knees. However, net /sup 35/SO/sub 4/-labeled glycosaminoglycan synthesis in organ cultures of cartilage from irradiated knees was increased (mean difference 21%, p = 0.03) in comparison with that in cultures of contralateral knee cartilage.

  15. Rapid isolation of intact, viable fetal cartilage models

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.R.; Chepenik, K.P.; Paynton, B.V.; Cotler, J.M.

    1982-04-01

    A rapid procedure is described for the isolation of viable, intact, femoral cartilage models (humeri and femora) obtained from pregnant rats on the 18th day of gestation. Viability of these models is demonstrated in an in vitro system where the incorporation of /sup 35/S-sulfate was linear with time of incubation and with numbers of cartilage models utilized. Treatment of cartilage models with ice-cold trichloroacetic acid and a boiling water bath prior to incubation with radiolabel, reduced the amount of radioactivity incorporated to 1.3% of that observed for models incubated by routine procedures. Furthermore, digestion of cartilage model homogenates with protease yielded a supernatant from which 51% to 57% of the radioactivity was precipitated as GAG. This method may also be used to isolate fetal cartilage models as early as the 16th day of gestation. with this system, specific biochemical parameters of mammalian fetal chondrogenesis may be surveyed in normally and abnormally developing fetal cartilage free of surrounding soft tissue.

  16. Rapid isolation of intact, viable fetal cartilage models

    International Nuclear Information System (INIS)

    Schmidt, R.R.; Chepenik, K.P.; Paynton, B.V.; Cotler, J.M.

    1982-01-01

    A rapid procedure is described for the isolation of viable, intact, femoral cartilage models (humeri and femora) obtained from pregnant rats on the 18th day of gestation. Viability of these models is demonstrated in an in vitro system where the incorporation of 35 S-sulfate was linear with time of incubation and with numbers of cartilage models utilized. Treatment of cartilage models with ice-cold trichloroacetic acid and a boiling water bath prior to incubation with radiolabel, reduced the amount of radioactivity incorporated to 1.3% of that observed for models incubated by routine procedures. Furthermore, digestion of cartilage model homogenates with protease yielded a supernatant from which 51% to 57% of the radioactivity was precipitated as GAG. This method may also be used to isolate fetal cartilage models as early as the 16th day of gestation. with this system, specific biochemical parameters of mammalian fetal chondrogenesis may be surveyed in normally and abnormally developing fetal cartilage free of surrounding soft tissue

  17. Quantitative imaging of excised osteoarthritic cartilage using spectral CT

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, Kishore; Bateman, Christopher J.; Younis, Raja Aamir; De Ruiter, Niels J.A.; Ramyar, Mohsen; Anderson, Nigel G. [University of Otago - Christchurch, Department of Radiology, Christchurch (New Zealand); Loebker, Caroline [University of Otago, Christchurch Regenerative Medicine and Tissue Engineering Group, Department of Orthopaedic Surgery and Musculoskeletal Medicine, Christchurch (New Zealand); University of Twente, Department of Developmental BioEngineering, Enschede (Netherlands); Schon, Benjamin S.; Hooper, Gary J.; Woodfield, Tim B.F. [University of Otago, Christchurch Regenerative Medicine and Tissue Engineering Group, Department of Orthopaedic Surgery and Musculoskeletal Medicine, Christchurch (New Zealand); Chernoglazov, Alex I. [University of Canterbury, Human Interface Technology Laboratory New Zealand, Christchurch (New Zealand); Butler, Anthony P.H. [University of Otago - Christchurch, Department of Radiology, Christchurch (New Zealand); European Organisation for Nuclear Research (CERN), Geneva (Switzerland); MARS Bioimaging, Christchurch (New Zealand)

    2017-01-15

    To quantify iodine uptake in articular cartilage as a marker of glycosaminoglycan (GAG) content using multi-energy spectral CT. We incubated a 25-mm strip of excised osteoarthritic human tibial plateau in 50 % ionic iodine contrast and imaged it using a small-animal spectral scanner with a cadmium telluride photon-processing detector to quantify the iodine through the thickness of the articular cartilage. We imaged both spectroscopic phantoms and osteoarthritic tibial plateau samples. The iodine distribution as an inverse marker of GAG content was presented in the form of 2D and 3D images after applying a basis material decomposition technique to separate iodine in cartilage from bone. We compared this result with a histological section stained for GAG. The iodine in cartilage could be distinguished from subchondral bone and quantified using multi-energy CT. The articular cartilage showed variation in iodine concentration throughout its thickness which appeared to be inversely related to GAG distribution observed in histological sections. Multi-energy CT can quantify ionic iodine contrast (as a marker of GAG content) within articular cartilage and distinguish it from bone by exploiting the energy-specific attenuation profiles of the associated materials. (orig.)

  18. Cationic Contrast Agent Diffusion Differs Between Cartilage and Meniscus.

    Science.gov (United States)

    Honkanen, Juuso T J; Turunen, Mikael J; Freedman, Jonathan D; Saarakkala, Simo; Grinstaff, Mark W; Ylärinne, Janne H; Jurvelin, Jukka S; Töyräs, Juha

    2016-10-01

    Contrast enhanced computed tomography (CECT) is a non-destructive imaging technique used for the assessment of composition and structure of articular cartilage and meniscus. Due to structural and compositional differences between these tissues, diffusion and distribution of contrast agents may differ in cartilage and meniscus. The aim of this study is to determine the diffusion kinematics of a novel iodine based cationic contrast agent (CA(2+)) in cartilage and meniscus. Cylindrical cartilage and meniscus samples (d = 6 mm, h ≈ 2 mm) were harvested from healthy bovine knee joints (n = 10), immersed in isotonic cationic contrast agent (20 mgI/mL), and imaged using a micro-CT scanner at 26 time points up to 48 h. Subsequently, normalized X-ray attenuation and contrast agent diffusion flux, as well as water, collagen and proteoglycan (PG) contents in the tissues were determined. The contrast agent distributions within cartilage and meniscus were different. In addition, the normalized attenuation and diffusion flux were higher (p meniscus. These tissue specific variations can affect the interpretation of CECT images and should be considered when cartilage and meniscus are assessed simultaneously.

  19. Plasma transthyretin. Tissue sites of degradation and turnover in the rat

    International Nuclear Information System (INIS)

    Makover, A.; Moriwaki, H.; Ramakrishnan, R.; Saraiva, M.J.; Blaner, W.S.; Goodman, D.S.

    1988-01-01

    Transthyretin (TTR) is involved in the plasma transport of both retinol and thyroid hormones. TTR is synthesized in the liver and choroid plexus, and in small amounts in several other tissues. A study was conducted to determine the tissue sites of degradation and turnover of TTR in the rat. The study employed TTR labeled with tyramine cellobiose (TC) and the trapped ligand method. Samples of purified rat TTR were labeled either with 125I-TC or directly with 131I. A mixture of the two labeled TTRs was injected intravenously into six rats. Blood samples were collected via a venous catheter for kinetic (turnover) analysis. After 24 or 48 h, the rats were killed, and 23 different tissues/organs were assayed as possible sites of TTR degradation. Derivatization of TTR with TC did not appreciably alter TTR plasma kinetics. Plasma turnover data were best fit by a three-pool model. The mean fractional turnover of plasma TTR was 0.15/h, and of total body TTR 0.04/h. The major sites of TTR degradation were the liver (36-38% of total body TTR degradation, almost all in hepatocytes), muscle (12-15%), and skin (8-10%). Tissues that were sites of 1-8% of body TTR degradation included kidneys, adipose tissue, testes, and the gastrointestinal tract. Less than 1% of total TTR degradation occurred in the other tissues examined. A second study was conducted in which labeled TTR was injected intraventricularly into the cerebrospinal fluid in order to explore the degradation of TTR of choroid plexus origin. The kinetics of the appearance and disappearance of such labeled TTR in plasma were physiologically reasonable, with an estimated turnover of cerebrospinal fluid TTR of the order of 0.33/h. The major tissue sites of degradation of labeled TTR injected into cerebrospinal fluid and into plasma were approximately the same

  20. The effect of fixed charge density and cartilage swelling on mechanics of knee joint cartilage during simulated gait.

    Science.gov (United States)

    Räsänen, Lasse P; Tanska, Petri; Zbýň, Štefan; van Donkelaar, Corrinus C; Trattnig, Siegfried; Nieminen, Miika T; Korhonen, Rami K

    2017-08-16

    The effect of swelling of articular cartilage, caused by the fixed charge density (FCD) of proteoglycans, has not been demonstrated on knee joint mechanics during simulated walking before. In this study, the influence of the depth-wise variation of FCD was investigated on the internal collagen fibril strains and the mechanical response of the knee joint cartilage during gait using finite element (FE) analysis. The FCD distribution of tibial cartilage was implemented from sodium ( 23 Na) MRI into a 3-D FE-model of the knee joint ("Healthy model"). For comparison, models with decreased FCD values were created according to the decrease in FCD associated with the progression of osteoarthritis (OA) ("Early OA" and "Advanced OA" models). In addition, a model without FCD was created ("No FCD" model). The effect of FCD was studied with five different collagen fibril network moduli of cartilage. Using the reference fibril network moduli, the decrease in FCD from "Healthy model" to "Early OA" and "Advanced OA" models resulted in increased axial strains (by +2 and +6%) and decreased fibril strains (by -3 and -13%) throughout the stance, respectively, calculated as mean values through cartilage depth in the tibiofemoral contact regions. Correspondingly, compared to the "Healthy model", the removal of the FCD altogether in "NoFCD model" resulted in increased mean axial strains by +16% and decreased mean fibril strains by -24%. This effect was amplified as the fibril network moduli were decreased by 80% from the reference. Then mean axial strains increased by +6, +19 and +49% and mean fibril strains decreased by -9, -20 and -32%, respectively. Our results suggest that the FCD in articular cartilage has influence on cartilage responses in the knee during walking. Furthermore, the FCD is suggested to have larger impact on cartilage function as the collagen network degenerates e.g. in OA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Interleukin-6 markedly decreases skeletal muscle protein turnover and increases nonmuscle amino acid utilization in healthy individuals

    DEFF Research Database (Denmark)

    van Hall, Gerrit; Steensberg, Adam; Fischer, Christian

    2008-01-01

    CONTEXT: IL-6 is a key modulator of immune function and suggested to be involved in skeletal muscle wasting as seen in sepsis. OBJECTIVE: Our objective was to determine the role of IL-6 in human in vivo systemic and skeletal muscle amino acid metabolism and protein turnover. SUBJECTS AND METHODS...... differences and m. vastus lateralis biopsies after 2-h basal, 3-h infusion, and 3 h after infusion. RESULTS: The IL-6 concentration after 30-min infusion was approximately 4 (saline) and 140 pg/ml (rhIL-6). Three-hour rhIL-6 infusion caused an approximate 50% decrease in muscle protein turnover, albeit...... synthesis was more suppressed than breakdown, causing a small increase in net muscle protein breakdown. Furthermore, rhIL-6 decreased arterial amino acid concentration with 20-40%, despite the increase net release from muscle. CONCLUSIONS: We demonstrated that IL-6 profoundly alters amino acid turnover...

  2. DNA turnover in rat cerebral cortex.

    Science.gov (United States)

    Perrone-Capano, C; D'Onofrio, G; Giuditta, A

    1982-01-01

    After the intracranial injection of [methyl-3H]thymidine the specific activity of rat cortical DNA increases rapidly, reaching a maximum at about 5 h. More than half of the radioactive DNA disappears from the tissue in the following few hours. During the same period of time the concentration of radioactive DNA in liver remains essentially constant. Minor variations occur in both organs after 41 h. An apparent rapid turnover of DNA is also present in a fraction of purified neuronal perikarya prepared from the cerebral cortex.

  3. Bone Cysts After Osteochondral Allograft Repair of Cartilage Defects in Goats Suggest Abnormal Interaction Between Subchondral Bone and Overlying Synovial Joint Tissues

    Science.gov (United States)

    Pallante-Kichura, Andrea L.; Cory, Esther; Bugbee, William D.; Sah, Robert L.

    2013-01-01

    The efficacy of osteochondral allografts (OCA) may be affected by osseous support of the articular cartilage, and thus affected by bone healing and remodeling in the OCA and surrounding host. Bone cysts, and their communication pathways, may be present in various locations after OCA insertion and reflect distinct pathogenic mechanisms. Previously, we analyzed the effect of OCA storage (FRESH, 4°C/14d, 4°C/28d, FROZEN) on cartilage quality in fifteen adult goats after 12 months in vivo. The objectives of this study were to further analyze OCA and contralateral non-operated (Non-Op) CONTROLS from the medial femoral condyle to (1) determine the effect of OCA storage on local subchondral (ScB) and trabecular (TB) bone structure, (2) characterize the location and structure of bone cysts and channels, and (3) assess the relationship between cartilage and bone properties. (1) Overall bone structure after OCA was altered compared to Non-Op, with OCA samples displaying bone cysts, ScB channels, and ScB roughening. ScB BV/TV in FROZEN OCA was lower than Non-Op and other OCA. TB BV/TV in FRESH, 4°C/14d, and 4°C/28d OCA did not vary compared to Non-Op, but BS/TV was lower. (2) OCA contained “basal” cysts, localized to deeper regions, some “subchondral” cysts, localized near the bone-cartilage interface, and some ScB channels. TB surrounding basal cysts exhibited higher BV/TV than Non-Op. (3) Basal cysts occurred (a) in isolation, (b) with subchondral cysts and ScB channels, (c) with ScB channels, or (d) with subchondral cysts, ScB channels, and ScB erosion. Deterioration of cartilage gross morphology was strongly associated with abnormal μCT bone structure. Evidence of cartilage-bone communication following OCA repair may favor fluid intrusion as a mechanism for subchondral cyst formation, while bone resorption at the graft-host interface without affecting overall bone and cartilage structure may favor bony contusion mechanism for basal cyst formation. These

  4. PENGARUH KEPUASAN KERJA DAN KOMITMEN ORGANISASI TERHADAP TURNOVER INTENTION

    Directory of Open Access Journals (Sweden)

    V. Mardi Widyadmono

    2017-04-01

    Full Text Available This study assesses the influence of job satisfaction and organizational commitment on Turnover Intention. Futhermore, the study identify the mediation role of organizational commitment in the relationship between job satifaction and Turnover Intention. The participants of the study are 98 employees working in private companies operated in Yogyakarta, (36 men and 62 women. Respondents complete questionnaire containing questions on job satisfaction variable, questions on organizational commitment and questions on Turnover Intention. The statistics tools applied are regression analysis to assess the relation between variables and Sobel test to measure the mediation role of organizational commitment. The results of the investigation revealed that job satisfication and organizational commitment influence negatively and significantly Turnover Intention. The higher the job satisfication and the organizational commitment of employees lead to the lower Turnover Intention. The organizational commitment does not play mediation role in the relationship between job satisfication and Turnover Intention

  5. MR imaging of patellar cartilage degeneration at 0.02 T

    International Nuclear Information System (INIS)

    Koskinen, S.K.; Komu, M.; Aho, H.J.; Kormano, M.; Turku University Hospital

    1991-01-01

    MR imaging with a 0.02 T resistive magnet was used to establish the correlation between the histologic grading of patellar cartilage degeneration and fat water separation images or T1- and T2-relaxation times. We examined 23 cadaveric patellae. There was a positive correlation between histologically graded cartilage degeneration and T1-relaxation time. Patellar cartilage was well differentiated from surrounding structures on chemical shift water proton images, and an evaluation of cartilage degeneration was possible. No correlation was found between cartilage degeneration damage and T2-relaxation time. Chemical shift imaging at 0.02 T is easy to perform and gives further information of cartilage disorders. (orig.)

  6. Hydrogen peroxide induced oxidative damage on mechanical properties of the articular cartilage.

    Science.gov (United States)

    Cicek, Ekrem

    2017-12-01

    Articular cartilage has unique mechanical and physicochemical properties which are responsible for its load carrying capabilities. This work investigates the effects of hydrogen peroxide induced oxidative damage on mechanical properties of articular cartilage. Bovine articular cartilage was exposed to hydrogen peroxide for a week. Dynamic and static mechanical tests applied to calculate articular cartilage compressive modulus. We observed higher control curve slopes than that of hydrogen peroxide curves which account for lesser stiffness values in the exposed articular cartilage. For the instantaneous experiments, results were statistically significant (p = 0.01, p hydrogen peroxide induced oxidative damage causes reduction in the stiffness of the articular cartilage.

  7. Explaining turnover intention in Korean public community hospitals: occupational differences.

    Science.gov (United States)

    Hwang, Jee-In; Chang, Hyejung

    2008-01-01

    Personnel in public hospitals had relatively low job satisfaction despite of tenure employment. High turnover rates degrade hospital image and incur additional costs related to recruitment and training. The purposes of this study were to describe the occupational differences and to identify factors affecting turnover intention among public hospital personnel. A questionnaire survey was conducted as part of Administrative Services Quality Evaluation Program by Seoul metropolitan municipality from 1 November to 1 December in 2003. The subjects were 1251 entire hospital personnel in four hospitals. The questionnaire was designed to measure job satisfaction, organizational commitment, turnover intention, and demographic characteristics. Logistic regression analysis was performed to determine factors influencing turnover intention. There were significant differences in job satisfaction, organizational commitment, and turnover intention according to the occupations. The turnover intention rates were highest among physicians, followed by paramedicals and nursing staffs and then administrators. The significant factors affecting turnover intention were involvement and loyalty among physicians, hospital type, satisfaction with systems and loyalty among nursing staffs, satisfaction with relationship and loyalty among administrators, and loyalty among paramedicals. There were different moderators that influence turnover intentions of hospital personnel. Loyalty had the most important effect upon turnover intention in all occupations. 2007 John Wiley & Sons, Ltd

  8. Radiographic predictability of cartilage damage in medial ankle osteoarthritis.

    Science.gov (United States)

    Moon, Jeong-Seok; Shim, Jae-Chan; Suh, Jin-Soo; Lee, Woo-Chun

    2010-08-01

    Radiographic grading has been used to assess and select between treatment options for ankle osteoarthritis. To use radiographic grading systems in clinical practice and scientific studies one must have reliable systems that predict the fate of the cartilage. We therefore asked whether (1) radiographic grading of ankle osteoarthritis is reliable and (2) grading reflects cartilage damage observed during arthroscopy. We then (3) determined the sensitivity, specificity, and predictive values of the radiographic findings. We examined 74 ankles with medial osteoarthritis and 24 with normal articular cartilage based on arthroscopy. Arthroscopic findings were graded according to the modified Outerbridge grades and all radiographs were graded using the modified Kellgren-Lawrence, Takakura et al., and van Dijk et al. grading systems. The reliability of each radiographic grading system was evaluated. We correlated the radiographic grades and severity of cartilage damage for each radiographic grading system. Sensitivity, specificity, and predictive values of spurs and joint space narrowing with or without talar tilting then were determined. The interobserver weighted kappa ranged from 0.58 to 0.89 and the intraobserver weighted kappa from 0.51 to 0.85. The correlation coefficients for the Kellgren-Lawrence, Takakura et al., and van Dijk et al. grades were 0.53, 0.42, and 0.42, respectively. Ankles with medial joint space narrowing (Stage 2 of Takakura et al. and van Dijk et al. grades) showed varying severity of cartilage damage. The positive predictive value of cartilage damage increased from 77% for medial joint space narrowing regardless of the presence of talar tilting to 98% for medial joint space narrowing with talar tilting. Our observations suggest the inclusion of talar tilting in grading schemes enhances the assessment of cartilage damage. Level II, diagnostic study. See the Guidelines for Authors for a complete description of level of evidence.

  9. Biochemical composition of the superficial layer of articular cartilage.

    Science.gov (United States)

    Crockett, R; Grubelnik, A; Roos, S; Dora, C; Born, W; Troxler, H

    2007-09-15

    To gain more information on the mechanism of lubrication in articular joints, the superficial layer of bovine articular cartilage was mechanically removed in a sheet of ice that formed on freezing the cartilage. Freeze-dried samples contained low concentrations of chondroitin sulphate and protein. Analysis of the protein by SDS PAGE showed that the composition of the sample was comparable to that of synovial fluid (SF). Attenuated total reflection infrared (ATR-IR) spectroscopy of the dried residue indicated that the sample contained mostly hyaluronan. Moreover, ATR-IR spectroscopy of the upper layer of the superficial layer, adsorbed onto silicon, showed the presence of phospholipids. A gel could be formed by mixing hyaluronan and phosphatidylcholine in water with mechanical properties similar to those of the superficial layer on cartilage. Much like the superficial layer of natural cartilage, the surface of this gel became hydrophobic on drying out. Thus, it is proposed that the superficial layer forms from hyaluronan and phospholipids, which associate by hydrophobic interactions between the alkyl chains of the phospholipids and the hydrophobic faces of the disaccharide units in hyaluronan. This layer is permeable to material from the SF and the cartilage, as shown by the presence of SF proteins and chondroitin sulphate. As the cartilage dries out after removal from the joint, the phospholipids migrate towards the surface of the superficial layer to reduce the surface tension. It is also proposed that the highly efficient lubrication in articular joints can, at least in part, be attributed to the ability of the superficial layer to adsorb and hold water on the cartilage surface, thus creating a highly viscous boundary protection. Copyright 2007 Wiley Periodicals, Inc.

  10. When is cartilage repair successful?; Wann ist eine Knorpelreparatur erfolgreich

    Energy Technology Data Exchange (ETDEWEB)

    Raudner, M.; Roehrich, S.; Zalaudek, M.; Trattnig, S. [Medizinische Universitaet Wien, Exzellenzzentrum Hochfeld-MR, Universitaetsklinik fuer Radiologie und Nuklearmedizin, Wien (Austria); Schreiner, M.M. [Medizinische Universitaet Wien, Universitaetsklinik fuer Orthopaedie, Wien (Austria)

    2017-11-15

    Focal cartilage lesions are a cause of long-term disability and morbidity. After cartilage repair, it is crucial to evaluate long-term progression or failure in a reproducible, standardized manner. This article provides an overview of the different cartilage repair procedures and important characteristics to look for in cartilage repair imaging. Specifics and pitfalls are pointed out alongside general aspects. After successful cartilage repair, a complete, but not hypertrophic filling of the defect is the primary criterion of treatment success. The repair tissue should also be completely integrated to the surrounding native cartilage. After some months, the transplants signal should be isointense compared to native cartilage. Complications like osteophytes, subchondral defects, cysts, adhesion and chronic bone marrow edema or joint effusion are common and have to be observed via follow-up. Radiological evaluation and interpretation of postoperative changes should always take the repair method into account. (orig.) [German] Die Therapie fokaler Knorpelschaeden ist weiterhin eine klinische Herausforderung. Nach erfolgter Sanierung gilt es daher besonders, Erfolg und Misserfolg zu evaluieren und den Verlauf standardisiert und somit reproduzierbar zu beurteilen. Dieser Artikel bietet einen Ueberblick ueber gaengige Reparaturverfahren und deren Charakteristika in der Magnetresonanztomographie. Nach einer erfolgreichen Knorpelreparatur ist eine vollstaendige, aber nicht hypertrophe Fuellung des Knorpeldefekts das primaere Kriterium. Zum umgebenden Nativknorpel ist ausserdem eine durchgehende Integration des Transplantats vordergruendig. Im weiteren postoperativen Verlauf sollte das Transplantat ausserdem ein im Vergleich zu nativem Knorpel isointenses Signalverhalten zeigen. Haeufig beobachtete Komplikationen sind zentrale Osteophyten, subchondrale Defekte, Zysten, chronifizierte Knochenmarksoedeme, Gelenkserguesse oder Adhaesionen. Die radiologische Beurteilung dieser

  11. Brother of CDO (BOC) expression in equine articular cartilage.

    Science.gov (United States)

    Vanderman, K S; Tremblay, M; Zhu, W; Shimojo, M; Mienaltowski, M J; Coleman, S J; MacLeod, J N

    2011-04-01

    Brother of CDO (BOC) is a cell surface receptor that derives its name from the structurally related protein, cell adhesion molecule-related/down-regulated by oncogenes (CDO, sometimes CDON). High levels of BOC mRNA and protein expression have been described in embryonic tissues with active cell proliferation and ongoing cellular differentiation(1,2). A microarray-based screen of RNA isolated from 11 different adult equine tissues unexpectedly identified BOC as having an expression pattern restricted to articular cartilage. The objective of this study was to further investigate BOC expression in adult articular cartilage relative to other tissues. Both RT-qPCR and mRNA sequencing confirmed the microarray data. Steady state BOC mRNA levels in articular cartilage were substantially higher than in the other adult tissues tested, neonatal tendon, placenta, and whole embryo. The expression of BOC displayed a pattern of tissue specificity comparable to well established cartilage matrix protein biomarkers. BOC mRNA levels in articular cartilage increased with age, but were rapidly down-regulated when chondrocytes were enzymatically isolated from the cartilage matrix and expanded in monolayer culture. Relative expression patterns of CDO were broadly similar, but displayed lower fold change differences. A functional role in articular cartilage that involves Hedgehog signaling is suggested by the known binding affinity of BOC for all three Hedgehog ligands. These data also extend BOC and CDO biology to a post-mitotic and highly differentiated cell type within a mature tissue. Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  12. Relationships between Bone Turnover and Energy Metabolism

    Directory of Open Access Journals (Sweden)

    Tânia A. P. Fernandes

    2017-01-01

    Full Text Available It is well established that diabetes can be detrimental to bone health, and its chronic complications have been associated with an increased risk of osteoporotic fracture. However, there is growing evidence that the skeleton plays a key role in a whole-organism approach to physiology. The hypothesis that bone may be involved in the regulation of physiological functions, such as insulin sensitivity and energy metabolism, has been suggested. Given the roles of insulin, adipokines, and osteocalcin in these pathways, the need for a more integrative conceptual approach to physiology is emphasized. Recent findings suggest that bone plays an important role in regulating intermediary metabolism, being possibly both a target of diabetic complications and a potential pathophysiologic factor in the disease itself. Understanding the relationships between bone turnover and glucose metabolism is important in order to develop treatments that might reestablish energy metabolism and bone health. This review describes new insights relating bone turnover and energy metabolism that have been reported in the literature.

  13. Osteoarthritic Cartilage is more Homogeneous than Healthy Cartilage – Identification of a Superior ROI Co-localised with a Major Risk Factor for Osteoarthritis

    DEFF Research Database (Denmark)

    Qazi, Arish Asif; Dam, Erik B.; Nielsen, Mads

    2007-01-01

    Rationale and Objectives Cartilage loss as determined by magnetic resonance imaging (MRI) or joint space narrowing as determined by x-ray is the result of cartilage erosion. However, metabolic processes within the cartilage that later result in cartilage loss may be a more sensitive assessment...... method for early changes. Recently, it was shown that cartilage homogeneity visualized by MRI representing the biochemical changes undergoing in the cartilage is a potential marker for early detection of knee osteoarthritis (OA) and is also able to significantly separate groups of healthy subjects from...... it evolves as a consequence to disease and thereby can be used as a progression biomarker. Materials and Methods A total of 283 right and left knees from 159 subjects aged 21 to 81 years were scanned using a Turbo 3D T1 sequence on a 0.18-T MRI Esaote scanner. The medial compartment of the tibial cartilage...

  14. Evaluation of influence of proteoglycans on hydration of articular cartilage with the use of ultrasound

    Directory of Open Access Journals (Sweden)

    Yi-yi YANG

    2015-04-01

    Full Text Available Objective To monitor the changes in hydration behaviour of articular cartilage induced by degradation of proteoglycans, and to explore the effect of proteoglycans on hydration behaviour of articular cartilage by using high-frequency ultrasound. Methods Twelve porcine patellae with smooth cartilage surface were prepared and equally divided into two groups: normal group without any enzyme treatment, and trypsin group they were treated with 0.25% trypsin for 8h to digest proteoglycan in the cartilage. The hydration behaviour of the cartilage tissue was scanned by high-frequency ultrasound system with a central frequency of 25MHz. Parameters including cartilage hydration strain and cartilage thickness were measured. The histopathological changes in the articular cartilage were observed under a light microscope. Results It took approximately 20min to reach equilibrium during the hydration process in the normal cartilages, while proteoglycan-degraded cartilage took only about 5min to achieve equilibrium. The equilibrium strain of normal cartilage was 3.5%±0.5%. The degradation of proteoglycans induced a significant decrease in equilibrium strain (1.8%±0.2%, P0.05. Conclusion Proteoglycans play an important role in hydration behaviour of articular cartilage. The degradation of proteoglycans could induce degeneration of cartilage structure and decrease in hydration behaviour after dehydration. DOI: 10.11855/j.issn.0577-7402.2015.03.03

  15. Immunohistochemical detection of interstitial collagens in bone and cartilage tissue remnants in an infant Peruvian mummy.

    Science.gov (United States)

    Nerlich, A G; Parsche, F; Kirsch, T; Wiest, I; von der Mark, K

    1993-07-01

    We investigated the immunohistochemical presence of various collagen types in bone and cartilage tissue from an infant Peruvian mummy dating between 500 and 1000 A.D. which had been excavated at the necropolis of Las Trancas in the Nazca region in Peru. Following careful rehydration and decalcification of the tissue, the mummy tissue showed morphologically good preservation of the matrix, which could be shown to be composed of various collagen types in a typical pattern. Bone consisted of a collagen I matrix with a small rim of collagen III and V at the endosteal lining and a pericellular collagen V staining around osteocytic holes. In the hypertrophic cartilage of the epiphyseal growth plate, a typical pattern of collagen types II and X could be found. These observations provide evidence that in well-preserved mummy tissue the antigenic determinants of major matrix components are still adequately preserved for an immunohistochemical analysis. This technique may thus be a very helpful tool for the analysis of pathologic processes of historic bone tissue. It may also allow in certain circumstances a distinction between pseudopathologic tissue destruction and pathologic tissue alteration.

  16. Atypical Pharyngeal Pouch Arising Bilaterally between the Hyoid Bone and Thyroid Cartilage

    Directory of Open Access Journals (Sweden)

    Lawrence J. Oh

    2017-01-01

    Full Text Available Introduction. Pharyngoesophageal diverticuli are a common cause of dysphagia; they are associated with various morbidities and a decreased quality of life. There are several different types of the diverticuli, and they are divided based on the anatomical location of origin relative to the cricopharyngeal muscle; these include Zenker’s, Killian-Jamieson’s, and Laimer’s diverticula. The authors present a unique case of pharyngoesophageal diverticulum that has not been previously described. Case Presentation. A 65-year-old male presented with a 12-month history of dysphagia and odynophagia for solids. Barium swallow revealed bilateral moderately sized diverticuli that altered in size during the different phases of swallow. CT scan of the neck with oral contrast further identified the anatomy of the diverticuli, arising between the hyoid bone and thyroid cartilage. Discussion. An external transcervical approach was utilised to successfully repair the diverticuli. Subsequent cricopharyngeal spasm was treated with botulinum toxin, and the patient recovered with no ongoing symptoms. The barium swallow study is a commonly utilised initial investigation as it is easy to perform and safe and has good diagnostic value. Definitive management usually involves either endoscopic or open surgery. This case depicts a unique case of a pharyngeal diverticulum arising between the hyoid bone and thyroid cartilage.

  17. Assessment of the 18-month permanence of onlay tip cartilage grafts following rhinoplasty.

    Science.gov (United States)

    Persichetti, Paolo; Simone, Pierfranco; Carusi, Carlo

    2013-09-01

    Augmentation rhinoplasty requires addition of materials of various natures to reshape the nasal pyramid. Onlay tip grafts are single or multilayered grafts placed horizontally over the alar domes. The aim of the present study was to assess the 18-month permanence of onlay septal cartilage grafts. Twenty-eight patients underwent rhinoplasty with onlay tip cartilage graft, between June 2008 and November 2008 at the Campus Bio-Medico University in Rome, Italy. They were reviewed and photographed 6 months and 18 months postoperatively. Comparison of 6-month and 18-month postoperative pictures was performed with Adobe Photoshop CS. Measurements on pictures were taken with AutoCAD. Comparison of photographs showed no visible difference in nasal tip projection. Comparison of the measurements of tip projection showed a mean reduction of 0.06 mm (0.19%). Considerable stability of nasal tip projection after rhinoplasty with onlay tip grafts was observed postoperatively. Comparison of standardised digital photographs is a valid procedure to assess contour alterations of various anatomical structures after plastic surgery.

  18. Increased hypothalamic serotonin turnover in inflammation-induced anorexia.

    Science.gov (United States)

    Dwarkasing, J T; Witkamp, R F; Boekschoten, M V; Ter Laak, M C; Heins, M S; van Norren, K

    2016-05-20

    Anorexia can occur as a serious complication of disease. Increasing evidence suggests that inflammation plays a major role, along with a hypothalamic dysregulation characterized by locally elevated serotonin levels. The present study was undertaken to further explore the connections between peripheral inflammation, anorexia and hypothalamic serotonin metabolism and signaling pathways. First, we investigated the response of two hypothalamic neuronal cell lines to TNFα, IL-6 and LPS. Next, we studied transcriptomic changes and serotonergic activity in the hypothalamus of mice after intraperitoneal injection with TNFα, IL-6 or a combination of TNFα and IL-6. In vitro, we showed that hypothalamic neurons responded to inflammatory mediators by releasing cytokines. This inflammatory response was associated with an increased serotonin release. Mice injected with TNFα and IL-6 showed decreased food intake, associated with altered expression of inflammation-related genes in the hypothalamus. In addition, hypothalamic serotonin turnover showed to be elevated in treated mice. Overall, our results underline that peripheral inflammation reaches the hypothalamus where it affects hypothalamic serotoninergic metabolism. These hypothalamic changes in serotonin pathways are associated with decreased food intake, providing evidence for a role of serotonin in inflammation-induced anorexia.

  19. Deferasirox limits cartilage damage following haemarthrosis in haemophilic mice.

    Science.gov (United States)

    Nieuwenhuizen, Laurens; Roosendaal, Goris; Mastbergen, Simon C; Coeleveld, Katja; Biesma, Douwe H; Lafeber, Floris P J G; Schutgens, Roger E G

    2014-11-01

    Joint bleeds in haemophilia result in iron-mediated synovitis and cartilage damage. It was evaluated whether deferasirox, an iron chelator, was able to limit the development of haemophilic synovitis and cartilage damage. Haemophilic mice were randomly assigned to oral treatment with deferasirox (30 mg/kg) or its vehicle (control) (30 mg/kg). Eight weeks after start of treatment, haemarthrosis was induced. After another five weeks of treatment, blood-induced synovitis and cartilage damage were determined. Treatment with deferasirox resulted in a statistically significant (pdeferasirox group. However, deferasirox treatment resulted in a statistically significant (pdeferasirox group with the control group: score 2 (65.4 % vs 4.2 %), score 3 (26.9 % vs 4.2 %), score 4 (7.7 % vs 20.8 %), score 5 (0 % vs 54.2 %), and score 6 (0 % vs 16.7 %). Treatment with deferasirox limits cartilage damage following the induction of a haemarthrosis in haemophilic mice. This study demonstrates the role of iron in blood-induced cartilage damage. Moreover, these data indicate that iron chelation may be a potential prevention option to limit the development of haemophilic arthropathy.

  20. Mesenchymal Stem Cell-Based Cartilage Regeneration Approach and Cell Senescence: Can We Manipulate Cell Aging and Function?

    Science.gov (United States)

    Szychlinska, Marta A; Stoddart, Martin J; D'Amora, Ugo; Ambrosio, Luigi; Alini, Mauro; Musumeci, Giuseppe

    2017-12-01

    Aging is the most prominent risk factor triggering several degenerative diseases, such as osteoarthritis (OA). Due to its poor self-healing capacity, once injured cartilage needs to be reestablished. This process might be approached through resorting to cell-based therapies and/or tissue engineering. Human mesenchymal stem cells (MSCs) represent a promising approach due to their chondrogenic differentiation potential. Presently, in vitro chondrogenic differentiation of MSCs is limited by two main reasons as follows: aging of MSCs, which determines the loss of cell proliferative and differentiation capacity and MSC-derived chondrocyte hypertrophic differentiation, which limits the use of these cells in cartilage tissue regeneration approach. The effect of aging on MSCs is fundamental for stem cell-based therapy development, especially in older subjects. In the present review we focus on homeostasis alterations occurring in MSC-derived chondrocytes during in vitro aging. Moreover, we deal with potential cell aging regulation approaches, such as cell stimulation through telomerase activators, mechanical strain, and epigenetic regulation. Future investigations in this field might provide new insights into innovative strategies for cartilage regeneration and potentially inspire novel therapeutic approaches for OA treatment.

  1. Multi-physics computational models of articular cartilage for estimation of its mechanical and physical properties

    NARCIS (Netherlands)

    Arbabi, V.

    2016-01-01

    Recent advances in the realm of computational modeling of complex multiphysics phenomena in articular cartilage enabled efficient and precise determination of articular cartilage properties. However, still accurate quantification of complicated indentation and diffusion processes tying closely with

  2. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C

    1993-01-01

    Physical inactivity accelerates bone loss. Since patients with fibromyalgia are relatively physically inactive, bone mass and markers of bone metabolism were determined in 12 premenopausal women with fibromyalgia and in healthy age matched female control subjects. No differences were found...... in lumbar bone mineral density, femoral neck bone mineral density, serum levels of alkaline phosphatase, osteocalcin, ionized calcium and phosphate. The urinary excretion of both hydroxyproline and calcium relative to urinary creatinine excretion was significantly higher in patients with fibromyalgia, p = 0.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  3. Organizational commitment and turnover intentions in humanitarian organizations

    NARCIS (Netherlands)

    Wijnmalen, Julia; Heyse, Liesbet; Voordijk, Hans

    2016-01-01

    Unwanted staff turnover is a prominent HRM problem in humanitarian organisations. In the profit sector, HRM tools such as pay, benefits, socialisation and training have proven to be effective in increasing organisational commitment and decreasing staff turnover. This study explores whether such

  4. Health workforce acquisition, retention and turnover in southwest ...

    African Journals Online (AJOL)

    Background: Skill mix of health professionals, staff acquisition and turnover rate are among the major challenges for the delivery of quality health care. This study assessed the health workforce acquisition, retention, turnover rate and their intention to leave. Methods: A cross-sectional survey with quantitative and qualitative ...

  5. Work-life balance, job satisfaction and turnover intention amongst

    African Journals Online (AJOL)

    kirstam

    consider the relationships between work-life balance, job satisfaction and turnover intention. 21Key words: Knowledge workers, IT employees, work-life balance, job satisfaction, turnover intention, talent management, talent retention. Prof. R.M. Oosthuizen and Prof. M. Coetzee are in the Department of Industrial and ...

  6. Below the Surface of Special Education Administrator Turnover

    Science.gov (United States)

    Meeks, Amy

    2016-01-01

    The field of special education administration has experienced a shortage of high quality special education leadership candidates for several decades. If school districts are to effectively address the turnover of educational leaders, they must know what is happening that affects turnover of their leadership team. The intent of this study was to…

  7. Survey of pay satisfaction, job satisfaction and employee turnover in ...

    African Journals Online (AJOL)

    Survey of pay satisfaction, job satisfaction and employee turnover in selected business organisations in Lagos, Nigeria. ... Global Journal of Social Sciences ... The study was an attempt at investigating the relatedness of pay satisfaction, job satisfaction and employee turnover in business organizations in Lagos Nigeria.

  8. Voluntary Turnover and Women Administrators in Higher Education

    Science.gov (United States)

    Jo, Victoria H.

    2008-01-01

    A salient characteristic about the U.S. workforce is the continual process of voluntary employee turnover, which can be problematic for employers who invest a substantial amount of time and money in recruiting and training employees. This paper discusses the effects of workplace policies and practices on the voluntary turnover of women…

  9. Low friction hydrogel for articular cartilage repair: evaluation of mechanical and tribological properties in comparison with natural cartilage tissue.

    Science.gov (United States)

    Blum, Michelle M; Ovaert, Timothy C

    2013-10-01

    The mechanical and tribological properties of a novel biomaterial, a boundary lubricant functionalized hydrogel, were investigated and compared to natural cartilage tissue. This low friction hydrogel material was developed for use as a synthetic replacement for focal defects in articular cartilage. The hydrogel was made by functionalizing the biocompatible polymer polyvinyl alcohol with a carboxylic acid derivative boundary lubricant molecule. Two different gel processing techniques were used to create the hydrogels. The first method consisted of initially functionalizing the boundary lubricant to the polyvinyl alcohol and then creating hydrogels by physically crosslinking the reacted polymer. The second method consisted of creating non-functionalized polyvinyl alcohol hydrogels and then performing the functionalization reaction on the fully formed gel. Osteochondral bovine samples were collected and replicate experiments were conducted to compare the mechanical and tribological performance of the boundary lubricant functionalized hydrogels to non-functionalized hydrogels and native cartilage. Friction experiments displayed a maximum decrease in friction coefficient of 70% for the functionalized hydrogels compared to neat polyvinyl alcohol. Indentation investigated the elastic modulus of the hydrogels, demonstrating that stability of the hydrogel was affected by processing method. Hydrogel performance was within the lower ranges of natural cartilage tested under the exact same conditions, showing the potential of the boundary lubricant functionalized hydrogels to perform as a biomimetic synthetic articular cartilage replacement. © 2013.

  10. The amphoteric effect on friction between the bovine cartilage/cartilage surfaces under slightly sheared hydration lubrication mode.

    Science.gov (United States)

    Pawlak, Zenon; Gadomski, Adam; Sojka, Michal; Urbaniak, Wieslaw; Bełdowski, Piotr

    2016-10-01

    The amphoteric effect on the friction between the bovine cartilage/cartilage contacts has been found to be highly sensitive to the pH of an aqueous solution. The cartilage surface was characterized using a combination of the pH, wettability, as well as the interfacial energy and friction coefficient testing methods to support lamellar-repulsive mechanism of hydration lubrication. It has been confirmed experimentally that phospholipidic multi-bilayers are essentially described as lamellar frictionless lubricants protecting the surface of the joints against wear. At the hydrophilicity limit, the low friction would then be due to (a) lamellar slippage of bilayers and (b) a short-range (nanometer-scale) repulsion between the interfaces of negatively charged (PO4(-)) cartilage surfaces, and in addition, contribution of the extracellular matrix (ECM) collagen fibers, hyaluronate, proteoglycans aggregates (PGs), glycoprotein termed lubricin and finally, lamellar PLs phases. In this paper we demonstrate experimentally that the pH sensitivity of cartilage to friction provides a novel concept in joint lubrication on charged surfaces. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Electromechanical response of articular cartilage in indentation--considerations on the determination of cartilage properties during arthroscopy.

    Science.gov (United States)

    Li, L P; Herzog, W

    2005-04-01

    A finite element formulation of streaming potentials in articular cartilage was incorporated into a fibril-reinforced model using the commercial software ABAQUS. This model was subsequently used to simulate interactions between an arthroscopic probe and articular cartilage in a knee joint. Fibril reinforcement was found to account for large fluid pressure at considerable strain rates, as has been observed in un-confined compression. Furthermore, specific electromechanical responses were associated with specific changes in tissue properties that occur with cartilage degeneration. For example, the strong strain-rate dependence of the load response was only observed when the collagen network was intact. Therefore, it is possible to use data measured during arthroscopy to evaluate the degree of cartilage degeneration and the source causing changed properties. However, practical problems, such as the difficulty of controlling the speed of the hand-held probe, may greatly reduce the reliability of such evaluations. The fibril-reinforced electromechanical model revealed that high-speed transient responses were associated with the collagen network, and equilibrium response was primarily determined by proteoglycan matrix. The results presented here may be useful in the application of arthroscopic tools for evaluating cartilage degeneration, for the proper interpretation of data, and for the optimization of data collection during arthroscopy.

  12. Use of Adult Stem Cells for Cartilage Tissue Engineering: Current Status and Future Developments

    OpenAIRE

    Catherine Baugé; Karim Boumédiene

    2015-01-01

    Due to their low self-repair ability, cartilage defects that result from joint injury, aging, or osteoarthritis, are the most often irreversible and are a major cause of joint pain and chronic disability. So, in recent years, researchers and surgeons have been working hard to elaborate cartilage repair interventions for patients who suffer from cartilage damage. However, current methods do not perfectly restore hyaline cartilage and may lead to the apparition of fibro- or hypertrophic cartil...

  13. Characterization of Engineered Cartilage Constructs Using Multiexponential T2 Relaxation Analysis and Support Vector Regression

    OpenAIRE

    Irrechukwu, Onyi N.; Reiter, David A.; Lin, Ping-Chang; Roque, Remigio A.; Fishbein, Kenneth W.; Spencer, Richard G.

    2012-01-01

    Increased sensitivity in the characterization of cartilage matrix status by magnetic resonance (MR) imaging, through the identification of surrogate markers for tissue quality, would be of great use in the noninvasive evaluation of engineered cartilage. Recent advances in MR evaluation of cartilage include multiexponential and multiparametric analysis, which we now extend to engineered cartilage. We studied constructs which developed from chondrocytes seeded in collagen hydrogels. MR measurem...

  14. Visualisation of collagen fibrils in joint cartilage using STIM

    International Nuclear Information System (INIS)

    Reinert, T.; Reibetanz, U.; Vogt, J.; Butz, T.; Werner, A.; Gruender, W.

    2001-01-01

    The scanning transmission ion microscopy (STIM) method was used to investigate the collagen network structure of the articular cartilage from a pig's knee in comparison with high resolution nuclear magnetic resonance imaging (microscopic NMR-tomography) and polarised light microscopy (PLM). Single collagen fibrils down to 200 nm in diameter were visualised. It was proved that the cartilage collagen network consists partly of zones of oriented fibrils as suggested by NMR measurements. Radially oriented fibrils were found in the zone near the calcified zone (hypertrophic zone) of both tibia and femur, and in the tibial radial zone. Tangentially oriented fibrils were found in the femoral and tibial superficial zone and in a second zone of the femoral cartilage. Polarisation light microscopy reveals broader zones of orientation than it was found with STIM

  15. Cartilage oligomeric matrix protein enhances the vascularization of acellular nerves

    Directory of Open Access Journals (Sweden)

    Wei-ling Cui

    2016-01-01

    Full Text Available Vascularization of acellular nerves has been shown to contribute to nerve bridging. In this study, we used a 10-mm sciatic nerve defect model in rats to determine whether cartilage oligomeric matrix protein enhances the vascularization of injured acellular nerves. The rat nerve defects were treated with acellular nerve grafting (control group alone or acellular nerve grafting combined with intraperitoneal injection of cartilage oligomeric matrix protein (experimental group. As shown through two-dimensional imaging, the vessels began to invade into the acellular nerve graft from both anastomotic ends at day 7 post-operation, and gradually covered the entire graft at day 21. The vascular density, vascular area, and the velocity of revascularization in the experimental group were all higher than those in the control group. These results indicate that cartilage oligomeric matrix protein enhances the vascularization of acellular nerves.

  16. AMIC Cartilage Repair in a Professional Soccer Player

    Directory of Open Access Journals (Sweden)

    S. Bark

    2012-01-01

    Full Text Available We report a case of a professional soccer player suffering from a traumatic cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle treated with an enhanced microfracture technique (AMIC. Autologous Matrix-Induced Chondrogenesis (AMIC is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. Because of the cartilage lesion (3 cm2, an AMIC procedure was performed followed by a rehabilitation program according to the protocols in the literature, (Steadman et al.; 2003. After 8 months of rehabilitation, the player returned to team training and after 10 months to competition. Altogether he returned to the same skill level for almost one year after the index operation. He is very satisfied with the clinical results after AMIC, which corresponds with the Lysholm score of 90 points at 12 months.

  17. AMIC Cartilage Repair in a Professional Soccer Player.

    Science.gov (United States)

    Bark, S; Riepenhof, H; Gille, J

    2012-01-01

    We report a case of a professional soccer player suffering from a traumatic cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle treated with an enhanced microfracture technique (AMIC). Autologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. Because of the cartilage lesion (3 cm(2)), an AMIC procedure was performed followed by a rehabilitation program according to the protocols in the literature, (Steadman et al.; 2003). After 8 months of rehabilitation, the player returned to team training and after 10 months to competition. Altogether he returned to the same skill level for almost one year after the index operation. He is very satisfied with the clinical results after AMIC, which corresponds with the Lysholm score of 90 points at 12 months.

  18. Advancing cartilage tissue engineering: the application of stem cell technology.

    Science.gov (United States)

    Raghunath, Joanne; Salacinski, Henryk J; Sales, Kevin M; Butler, Peter E; Seifalian, Alexander M

    2005-10-01

    The treatment of cartilage pathology and trauma face the challenges of poor regenerative potential and inferior repair. Nevertheless, recent advances in tissue engineering indicate that adult stem cells could provide a source of chondrocytes for tissue engineering that the isolation of mature chondrocytes has failed to achieve. Various adjuncts to their propagation and differentiation have been explored, such as biomaterials, bioreactors and growth hormones. To date, all tissue engineered cartilage has been significantly mechanically inferior to its natural counterparts and further problems in vivo relate to poor integration and deterioration of tissue quality over time. However, adult stem cells--with their high rate of proliferation and ease of isolation--are expected to greatly further the development and usefulness of tissue engineered cartilage.

  19. Excessive activity of cathepsin K is associated with cartilage defects in a zebrafish model of mucolipidosis II

    Directory of Open Access Journals (Sweden)

    Aaron C. Petrey

    2012-03-01

    The severe pediatric disorder mucolipidosis II (ML-II; also known as I-cell disease is caused by defects in mannose 6-phosphate (Man-6-P biosynthesis. Patients with ML-II exhibit multiple developmental defects, including skeletal, craniofacial and joint abnormalities. To date, the molecular mechanisms that underlie these clinical manifestations are poorly understood. Taking advantage of a zebrafish model of ML-II, we previously showed that the cartilage morphogenesis defects in this model are associated with altered chondrocyte differentiation and excessive deposition of type II collagen, indicating that aspects of development that rely on proper extracellular matrix homeostasis are sensitive to decreases in Man-6-P biosynthesis. To further investigate the molecular bases for the cartilage phenotypes, we analyzed the transcript abundance of several genes in chondrocyte-enriched cell populations isolated from wild-type and ML-II zebrafish embryos. Increased levels of cathepsin and matrix metalloproteinase (MMP transcripts were noted in ML-II cell populations. This increase in transcript abundance corresponded with elevated and sustained activity of several cathepsins (K, L and S and MMP-13 during early development. Unlike MMP-13, for which higher levels of protein were detected, the sustained activity of cathepsin K at later stages seemed to result from its abnormal processing and activation. Inhibition of cathepsin K activity by pharmacological or genetic means not only reduced the activity of this enzyme but led to a broad reduction in additional protease activity, significant correction of the cartilage morphogenesis phenotype and reduced type II collagen staining in ML-II embryos. Our findings suggest a central role for excessive cathepsin K activity in the developmental aspects of ML-II cartilage pathogenesis and highlight the utility of the zebrafish system to address the biochemical underpinnings of metabolic disease.

  20. JNK/ERK-AP-1/Runx2 induction "paves the way" to cartilage load-ignited chondroblastic differentiation.

    Science.gov (United States)

    Papachristou, Dionysios J; Pirttiniemi, Pertti; Kantomaa, Tuomo; Papavassiliou, Athanasios G; Basdra, Efthimia K

    2005-09-01

    Chondro-osteogenesis and subsequently skeletal morphology are greatly influenced by mechanical loads. The exact mechanism(s) by which mechanical stimuli are transduced in chondrocytes remains obscure and appears to be equally complex with similar signal transducing systems. Here we investigated whether and to what extent the MAPK (JNK/ERK)-AP-1/Runx2 signaling pathways are engaged in this phenomenon, and assessed their involvement in the functional biology of articular cartilage. For this purpose, 14-day-old female Wistar rats were divided into 2 groups: the first group was fed hard diet (simulating physiologic temporomandibular joint (TMJ) loading), while the second group was fed soft diet (reduced TMJ loading). On day 21 (experiment initiation day - weaning day), biopsies from condyles of both groups were obtained after 6, 12 and 48 h of functional TMJ loading. Immunohistochemical methodology was employed to evaluate the expression levels of pc-Jun, c-Fos, JNK2, p-JNK, p-ERK and Runx2 due to alteration in functional load. Our data demsonstrate that the protein levels of all the aforementioned molecules were markedly increased in animals fed with the hard diet, throughout the experimental procedure. These results indicate that functional cartilage loading induces the AP-1 and Runx2 transcription factors through the JNK and ERK MAPK cascades. In as much as the above signaling mediators/effectors are considered to be crucial in the differentiation/maturation process of cartilage tissue, we pose that functional mechanical loading of condylar cartilage serves to "fine tune" chondroblastic differentiation/maturation.

  1. PENGARUH KEPUASAN KERJA TERHADAP KOMITMEN ORGANISASI DAN TURNOVER INTENTION

    Directory of Open Access Journals (Sweden)

    Agi Syarif Hidayat

    2018-03-01

    Full Text Available The high level of employee turnover in the marketing department at PT. Toyamilindo indicates low organizational commitment and high turnover intention. The purpose of this study is to determine the effect of job satisfaction on organizational commitment and turnover intention. Quantitative methods are used in this study. Population is the  employees of marketing department at PT. Toyamilindo with 50 people. Sampling technique used is sampling saturated with the number of samples of 50 people. Data collection technique uses questionnaires and regression analysis. Finding on the research results shows that there are positive and significant influence of job satisfaction on organizational commitment and negative and significant influence of job satisfaction on turnover intention, and also the influence of organizational commitment on work satisfaction to turnover intention. The managerial implications of corporate leaders must improve employee work satisfaction, especially in terms of salary.

  2. One hundred years of employee turnover theory and research.

    Science.gov (United States)

    Hom, Peter W; Lee, Thomas W; Shaw, Jason D; Hausknecht, John P

    2017-03-01

    We review seminal publications on employee turnover during the 100-year existence of the Journal of Applied Psychology . Along with classic articles from this journal, we expand our review to include other publications that yielded key theoretical and methodological contributions to the turnover literature. We first describe how the earliest papers examined practical methods for turnover reduction or control and then explain how theory development and testing began in the mid-20th century and dominated the academic literature until the turn of the century. We then track 21st century interest in the psychology of staying (rather than leaving) and attitudinal trajectories in predicting turnover. Finally, we discuss the rising scholarship on collective turnover given the centrality of human capital flight to practitioners and to the field of human resource management strategy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. Pitfalls in quantifying species turnover: the residency effect

    Directory of Open Access Journals (Sweden)

    Kevin Chase Burns

    2014-03-01

    Full Text Available The composition of ecological communities changes continuously through time and space. Understanding this turnover in species composition is a central goal in biogeography, but quantifying species turnover can be problematic. Here, I describe an underappreciated source of bias in quantifying species turnover, namely ‘the residency effect’, which occurs when the contiguous distributions of species across sampling domains are small relative to census intervals. I present the results of a simulation model that illustrates the problem theoretically and then I demonstrate the problem empirically using a long-term dataset of plant species turnover on islands. Results from both exercises indicate that empirical estimates of species turnover may be susceptible to significant observer bias, which may potentially cloud a better understanding of how the composition of ecological communities changes through time.

  4. Analysis of Cartilage-Polydioxanone Foil Composite Grafts

    Science.gov (United States)

    Kim, James H.; Wong, Brian

    2014-01-01

    This study presents an analytical investigation into the mechanical behavior of a cartilage-polydioxanone (PDS) plate composite grafts. Numerical methods are used to provide a first-order, numerical model of the flexural stiffness of a cartilage-PDS graft. Flexural stiffness is a measure of resistance to bending and is inversely related to the amount of deformation a structure may experience when subjected to bending forces. The cartilage-PDS graft was modeled as a single composite beam. Using Bernoulli-Euler beam theory, a closed form equation for the theoretical flexural stiffness of the composite graft was developed. A parametric analysis was performed to see how the flexural properties of the composite model changed with varying thicknesses of PDS foil. The stiffness of the cartilage-PDS composite using 0.15-mm-thick PDS was four times higher than cartilage alone. The composite with a 0.5-mm-thick PDS graft was only 1.7 times stiffer than the composite with the 0.15-mm-thick PDS graft. Although a thicker graft material will yield higher flexural stiffness for the composite, the relationship between composite stiffness and PDS thickness is nonlinear. After a critical point, increments in graft thickness produce gradually smaller improvements in flexural stiffness. The small increase in stiffness when using the thicker PDS foils versus the 0.15 mm PDS foil may not be worth the potential complications (prolonged foreign body reaction, reduction in nutrient diffusion to cartilage) of using thicker artificial grafts. PMID:24327249

  5. Bilateral same-day endoscopic transcanal cartilage tympanoplasty: initial results.

    Science.gov (United States)

    Daneshi, Ahmad; Jahandideh, Hesam; Daneshvar, Ali; Safdarian, Mahdi

    Same-day closure of bilateral tympanic membrane perforations is a quick and more comfortable procedure for the patients. However, conventional bilateral same-day tympanoplasty or myringoplasty has been rarely performed because of the theoretical risk of postoperative complications. To evaluate the advantages and outcomes of bilateral simultaneous endoscopic cartilage tympanoplasty in patients with bilateral tympanic membrane perforations. From February 2012 to March 2013, patients with bilateral dry tympanic membrane perforations who had some degree of hearing loss corresponding to the size and location of the perforation entered the study. There was no suspicion to disrupted ossicular chain, mastoid involvement or other middle or inner ear pathology. Endoscopic transcanal cartilage tympanoplasty was done using the underlay (medial) technique. The graft was harvested from cymba cartilage in just one ear with preservation of perichondrium in one side. A 1.5cm×1.5cm cartilage seemed to be enough for tympanoplasty in both sides. Nine patients (4 males and 5 females) with the mean age of 37.9 years underwent bilateral transcanal cartilage tympanoplasty in a same-day surgery. The mean duration of follow up was 15.8 months. There were detected no complications including hearing loss, otorrhea and wound complication with no retraction pocket or displaced graft during follow-up period. The grafts take rate was 94.44% (only one case of unilateral incomplete closure). The mean of air-bone gap overall improved from 13.88dB preoperatively to 9.16dB postoperatively (p<0.05). Bilateral endoscopic transcanal cartilage tympanoplasty can be considered as a safe minimally invasive procedure that can be performed in a same-day surgery. It reduces the costs and operation time and is practical with a low rate of postoperative complications. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights

  6. Phospholipid Vesicles in Media for Tribological Studies against Live Cartilage

    Science.gov (United States)

    Veselack, Teresa; Aldebert, Gregoire; Trunfio-Sfarghiu, Ana-Maria; Schmid, Thomas M.; Laurent, Michel P.; Wimmer, Markus A.

    2018-01-01

    Introduction Pre-clinical testing of hemiarthroplasty devices requires that the tribological conditions present in vivo with live cartilage be closely duplicated. A current limitation in the tribological testing of live cartilage involves the use of cell-culture media as lubricant. Study Aim to develop and test a new hyaluronan-phospholipid based medium (HA–phospholipid medium) that combines the rheological and frictional properties of synovial fluid with the nourishing properties of culture media to keep cells alive. Materials and Methods The HA–phospholipid medium consisted of culture medium with added phospholipid dipalmitoylphosphatidylcholine (0.3 mg/mL), and hyaluronic acid (2.42 mg/mL). A standard cell culture medium was used as the control. The rheology of each medium was determined using a flat plate configuration. Bovine calf cartilage was used to assess cell viability and friction in each medium. For friction measurements, a cobalt-chrome alloy ball was articulated against cartilage disks immersed in medium. Results Lipid vesicles 0.1 to 50 μm in diameter were identified in the HA–phospholipid medium. Cartilage cell viability was significantly higher in the HA–phospholipid medium (62% ± 8%, 95% CI) than in control medium (49.5% ± 5%) (p = 0.009). The HA–phospholipid medium exhibited strong shear-thinning behavior, similar to synovial fluid, with viscosities ~100-fold higher at 10 s−1 and 5-fold higher at 20,000 s−1 than the approximately Newtonian control medium. The HA–phospholipid medium also yielded 20% lower friction values than the control medium after one hour of testing. Conclusions The rheological and friction results indicate that the HA–phospholipid medium is superior to the control cell culture medium in emulating the shear thinning and lubricative properties of natural synovial fluid, making it more clinically relevant for in vitro wear and friction testing with live cartilage. PMID:29527359

  7. Bone turnover, calcium homeostasis, and vitamin D status in Danish vegans.

    Science.gov (United States)

    Hansen, Tue H; Madsen, Marie T B; Jørgensen, Niklas R; Cohen, Arieh S; Hansen, Torben; Vestergaard, Henrik; Pedersen, Oluf; Allin, Kristine H

    2018-01-23

    A vegan diet has been associated with increased bone fracture risk, but the physiology linking nutritional exposure to bone metabolism has only been partially elucidated. This study investigated whether a vegan diet is associated with increased bone turnover and altered calcium homeostasis due to insufficient intake of calcium and vitamin D. Fractionated and total 25-hydroxyvitamin D (25(OH)-D), parathyroid hormone (PTH), calcium, and four bone turnover markers (osteocalcin, N-terminal propeptide of type I procollagen (PINP), bone-specific alkaline phosphatase (BAP), and C-terminal telopeptide of type I collagen (CTX)) were measured in serum from 78 vegans and 77 omnivores. When adjusting for seasonality and constitutional covariates (age, sex, and body fat percentage) vegans had higher concentrations of PINP (32 [95% CI: 7, 64]%, P = 0.01) and BAP (58 [95% CI: 27, 97]%, P Vegans had higher serum PTH concentration (38 [95% CI: 19, 60]%; P Vegans have higher levels of circulating bone turnover markers compared to omnivores, which may in the long-term lead to poorer bone health. Differences in dietary habits including intake of vitamin D and calcium may, at least partly, explain the observed differences.

  8. Estimation of cyclic AMP turnover in normal and methylprednisolone-treated dogs: effect of catecholamines.

    Science.gov (United States)

    Issekutz, T B

    1975-08-01

    The turnover rate of plasma cAMP was measured in unanesthetized normal and methylprednisolone (MP)-treated dogs with [8-3H]cAMP. Determination of specific activity was based on saturation of the specific binding protein, thus bypassing the need to know the plasma level of cAMP. In normal dogs the infusion of epinephrine increased plasma glucose by 33% and both the plasma level and rate of appearance (Ra) of cAMP 2.5-fold. Treatment with MP decreased the concentration as well as the turnover rate of cAMP by about 50%. It greatly potentiated not only the hyperglycemic effect (4-fold) of epinephrine but also the rise of plasma cAMP (8.5-fold) and that of Ra (6.8-fold). Norepinephrine infusion increased cAMP only by 50%. This effect was not potentiated by MP treatment and not altered by Na nicotinate. There was a linear correlation between plasma cAMP concentration and the rate of disappearance (Rd) of cAMP. It is concluded that: a) the increase of hepatic glycogenolysis is accompanied by a rise of cAMP output, whereas that of lipolysis is not; b) glucocorticoid treatment affects cAMP turnover; and c) the plasma level of cAMP is controlled by Ra, whereas Rd is the result of the mass-action effect of the concentration.

  9. In vitro and in vivo modulation of cartilage degradation by a standardized Centella asiatica fraction.

    NARCIS (Netherlands)

    Hartog, A.; Smit, H.F.; Kraan, P.M. van der; Hoijer, M.A.; Garssen, J.

    2009-01-01

    Osteoarthritis (OA) is a degenerative joint disease in which focal cartilage destruction is one of the primary features. The present study aims to evaluate the effect of a Centella asiatica fraction on in vitro and in vivo cartilage degradation. Bovine cartilage explants and bovine chondrocytes

  10. Articular Cartilage Thickness Measured with US is Not as Easy as It Appears

    DEFF Research Database (Denmark)

    Torp-Pedersen, Søren; Bartels, E. M.; Wilhjelm, Jens E.

    2011-01-01

    Background: Theoretically, the high spatial resolution of US makes it well suited to monitor the decrease in articular cartilage thickness in osteoarthritis. A requirement is, however, that the borders of the cartilage are correctly identified and that the cartilage ismeasured under orthogonal...

  11. Cartilage repair by mesenchymal stem cells: Clinical trial update and perspectives

    Directory of Open Access Journals (Sweden)

    Wayne Yuk-wai Lee

    2017-04-01

    The translational potential of this article: This review summarises recent MSC-related clinical research that focuses on cartilage repair. We also propose a novel possible translational direction for hyaline cartilage formation and a new paradigm making use of extra-cellular signalling and epigenetic regulation in the application of MSCs for cartilage repair.

  12. Growth of the mandible and biological characteristics of the mandibular condylar cartilage

    Directory of Open Access Journals (Sweden)

    Itaru Mizoguchi

    2013-11-01

    Full Text Available Mandibular condylar cartilage is the center of greatest growth in the craniofacial complex, and is associated with maxillofacial skeleton morphogenesis and temporomandibular joint function. The condylar process grows in a wide range of directions from anterosuperior to posterior, resulting in highly diverse mandibular growth and morphology. Condylar growth direction is closely related to mandibular displacement direction and vertical jaw deviations (i.e., high or low angle. Condylar cartilage, which is ontogenetically designated secondary cartilage, differs from other primary cartilage (e.g., articular cartilage and growth plate of a long bone cranial base cartilage, nasal septal cartilage in the following ways. (1 Condylar cartilage is a heterogeneous tissue containing fibroblasts, osteochondral progenitor cells, and chondrocytes. (2 Type I collagen, which is derived from progenitor cells, and cartilage-characteristic type II collagen are colocalized in the cartilaginous cell layer. Colocalization of both collagen types may be an adaptation to the complex biomechanical environments of condylar cartilage. (3 Peripheral condylar cartilage contains chondroid bone, a specialized calcified tissue with morphological properties intermediate between those of bone and cartilage. This hybrid tissue may play an important role in regulating different rates of bone formation in intramembranous and endochondral ossification, allowing for highly diverse growth directions and condylar and maxillofacial morphology.

  13. Chondronecrosis of the cricoid cartilage following radiation therapy

    International Nuclear Information System (INIS)

    Tanabe, Masahiro; Isshiki, Nobuhiko; Kojima, Hisayoshi

    1979-01-01

    Chondronecrosis of the laryngeal cartilage following radiation therapy is a rare but serious complication. We report herein a case of post-radiation chondronecrosis and discuss factors predisposing to its development. A 67-year-old man received telecobalt therapy for cancer of the right vocal cord. A year after the radiation therapy given in a dose of 7,000r, the patient developed dysphagia and dyspnea. Following tracheotomy, he underwent total laryngectomy. The surgical specimen showed no cancer but chondronecrosis of the cricoid cartilage was present. After laryngectomy he developed progressive soft tissue necrosis of the neck and died following a carotid hemorrhage. (author)

  14. Cell-laden hydrogels for osteochondral and cartilage tissue engineering.

    Science.gov (United States)

    Yang, Jingzhou; Zhang, Yu Shrike; Yue, Kan; Khademhosseini, Ali

    2017-07-15

    Despite tremendous advances in the field of regenerative medicine, it still remains challenging to repair the osteochondral interface and full-thickness articular cartilage defects. This inefficiency largely originates from the lack of appropriate tissue-engineered artificial matrices that can replace the damaged regions and promote tissue regeneration. Hydrogels are emerging as a promising class of biomaterials for both soft and hard tissue regeneration. Many critical properties of hydrogels, such as mechanical stiffness, elasticity, water content, bioactivity, and degradation, can be rationally designed and conveniently tuned by proper selection of the material and chemistry. Particularly, advances in the development of cell-laden hydrogels have opened up new possibilities for cell therapy. In this article, we describe the problems encountered in this field and review recent progress in designing cell-hydrogel hybrid constructs for promoting the reestablishment of osteochondral/cartilage tissues. Our focus centers on the effects of hydrogel type, cell type, and growth factor delivery on achieving efficient chondrogenesis and osteogenesis. We give our perspective on developing next-generation matrices with improved physical and biological properties for osteochondral/cartilage tissue engineering. We also highlight recent advances in biomanufacturing technologies (e.g. molding, bioprinting, and assembly) for fabrication of hydrogel-based osteochondral and cartilage constructs with complex compositions and microarchitectures to mimic their native counterparts. Despite tremendous advances in the field of regenerative medicine, it still remains challenging to repair the osteochondral interface and full-thickness articular cartilage defects. This inefficiency largely originates from the lack of appropriate tissue-engineered biomaterials that replace the damaged regions and promote tissue regeneration. Cell-laden hydrogel systems have emerged as a promising tissue

  15. PTH(1-34) Treatment Increases Bisphosphonate Turnover in Fracture Repair in Rats.

    Science.gov (United States)

    Murphy, Ciara M; Schindeler, Aaron; Cantrill, Laurence C; Mikulec, Kathy; Peacock, Lauren; Little, David G

    2015-06-01

    Bisphosphonates (BP) are antiresorptive drugs with a high affinity for bone. Despite the therapeutic success in treating osteoporosis and metabolic bone diseases, chronic BP usage has been associated with reduced repair of microdamage and atypical femoral fracture (AFF). The latter has a poor prognosis, and although anabolic interventions such as teriparatide (PTH(1-34) ) have been suggested as treatment options, there is a limited evidence base in support of their efficacy. Because PTH(1-34) acts to increase bone turnover, we hypothesized that it may be able to increase BP in turnover in the skeleton, which, in turn, may improve bone healing. To test this, we employed a mixture of fluorescent Alexa647-labelled pamidronate (Pam) and radiolabeled (14) C-ZA (zoledronic acid). These traceable BPs were dosed to Wistar rats in models of normal growth and closed fracture repair. Rats were cotreated with saline or 25 μg/kg/d PTH(1-34) , and the effects on BP liberation and bone healing were examined by X-ray, micro-CT, autoradiography, and fluorescent confocal microscopy. Consistent with increased BP remobilization with PTH(1-34) , there was a significant decrease in fluorescence in both the long bones and in the fracture callus in treated animals compared with controls. This was further confirmed by autoradiography for (14) C-ZA. In this model of acute BP treatment, callus bone volume (BV) was significantly increased in fractured limbs, and although we noted significant decreases in callus-bound BP with PTH(1-34) , these were not sufficient to alter this BV. However, increased intracellular BP was noted in resorbing osteoclasts, confirming that, in principle, PTH(1-34) increases bone turnover as well as BP turnover. © 2015 American Society for Bone and Mineral Research.

  16. Understanding the factors that determine registered nurses' turnover intentions.

    Science.gov (United States)

    Osuji, Joseph; Uzoka, Faith-Michael; Aladi, Flora; El-Hussein, Mohammed

    2014-01-01

    Turnover among registered nurses (RNs) produces a negative impact on the health outcomes of any health care organization. It is also recognized universally as a problem in the nursing profession. Little is known about the turnover intentions and career orientations of RNs working in Calgary, Alberta, Canada. The aim of this study is to contribute to the knowledge of and to advance the discussion on the turnover of nursing professionals. The study population consisted of RNs employed in the five major hospitals in Calgary. There were 193 surveys returned, representing a response rate of 77.2%. The results show that age and education have a negative effect on turnover intention. Education was found to have a significant negative effect on career satisfaction but not on job satisfaction and organizational commitment. Length of service has a significant negative effect on turnover intention. Role ambiguity has significant highly negative effect on career satisfaction. Growth opportunity and supervisor support have a very significant positive effect on job satisfaction, career satisfaction, and organizational commitment. External career opportunities and organizational commitment do not seem to have a significant effect on turnover intention. Career satisfaction, on the other hand, had negative significant effects on turnover intention.

  17. Measurements of protein turnover in man with nitrogen-15

    International Nuclear Information System (INIS)

    Garlick, P.J.; Waterlow, J.C.

    1977-01-01

    Past and present methods of measuring total body protein turnover with 15 N-labelled compounds are reviewed, and a short assessment made of results achieved. Protein turnover in man was first measured by Sprinson and Rittenberg (1949) using 15 N glycine as tracer. The rate of turnover was calculated from the fraction of the dose excreted in urine in the days following a single oral dose of the isotope. In the following years a number of similar methods were devised but interest waned, perhaps because consistent changes in turnover rate under different conditions were not detected. A revival of interest came with the measurement of changes in protein turnover in malnourished and recovering children by Picou and Taylor-Roberts (1969). Nitrogen-15-glycine was infused and measurements were made of the abundance of 15 N in urinary urea, which reached a plateau in about 24 hours. Turnover rates were calculated from the proportion of the infused dose excreted in urea after the plateau had been reached. This method has also been used successfully on adults when the isotope has been given as three-hourly oral doses. In adults, however, plateau labelling in urea is not usually reached for two days. In our laboratory the use of urinary ammonia, which reaches a plateau more quickly than urea, has been examined. In addition, comparisons have been made between constant infusion and single dose of isotope. Halliday and McKeran (1975) infused 15 N-lysine and measured the 15 N abundance in the free lysine of plasma, which reached a plateau in about 12 hours. Turnover in the whole body and turnover of muscle proteins and of plasma albumin were estimated separately. These methods of measuring protein turnover with 15 N are described and results reviewed of the effects of food intake, nutritional status and age. (author)

  18. Novel Genetic Variants for Cartilage Thickness and Hip Osteoarthritis

    NARCIS (Netherlands)

    Castaño-Betancourt, Martha C.; Evans, Dan S.; Ramos, Yolande F M; Boer, Cindy G.; Metrustry, Sarah; Liu, Youfang; den Hollander, Wouter; van Rooij, Jeroen; Kraus, Virginia B.; Yau, Michelle S.; Mitchell, Braxton D.; Muir, Kenneth; Hofman, Albert; Doherty, Michael; Doherty, Sally; Zhang, Weiya; Kraaij, Robert; Rivadeneira, Fernando; Barrett-Connor, Elizabeth; Maciewicz, Rose A.; Arden, Nigel; Nelissen, Rob G H H; Kloppenburg, Margreet; Jordan, Joanne M.; Nevitt, Michael C.; Slagboom, Eline P.; Hart, Deborah J.; Lafeber, Floris; Styrkarsdottir, Unnur; Zeggini, Eleftheria; Evangelou, Evangelos; Spector, Tim D.; Uitterlinden, Andre G.; Lane, Nancy E.; Meulenbelt, Ingrid; Valdes, Ana M.; van Meurs, Joyce B J

    2016-01-01

    Osteoarthritis is one of the most frequent and disabling diseases of the elderly. Only few genetic variants have been identified for osteoarthritis, which is partly due to large phenotype heterogeneity. To reduce heterogeneity, we here examined cartilage thickness, one of the structural components

  19. Novel Genetic Variants for Cartilage Thickness and Hip Osteoarthritis

    NARCIS (Netherlands)

    M.C. Castaño Betancourt (Martha); D.S. Evans (Daniel); Y.F.M. Ramos (Yolande); Boer, C.G. (Cindy G.); S. Metrustry (Sarah); Liu, Y. (Youfang); W. den Hollander (Wouter); J. Van Rooij (Jeroen); Kraus, V.B. (Virginia B.); Yau, M.S. (Michelle S.); B.D. Mitchell (Braxton); Muir, K. (Kenneth); A. Hofman (Albert); M. Doherty (Michael); S. Doherty (Sally); W. Zhang (Weiya); R. Kraaij (Robert); F. Rivadeneira Ramirez (Fernando); Barrett-Connor, E. (Elizabeth); R.A. MacIewicz (Rose); N.K. Arden (Nigel); R.G.H.H. Nelissen (Rob); M. Kloppenburg (Margreet); Jordan, J.M. (Joanne M.); M.C. Nevitt (Michael); E. Slagboom (Eline); D. Hart (Deborah); F.P.J.G. Lafeber (Floris); U. Styrkarsdottir (Unnur); E. Zeggini (Eleftheria); E. Evangelou (Evangelos); T.D. Spector (Timothy); A.G. Uitterlinden (André); N.E. Lane; I. Meulenbelt (Ingrid); A.M. Valdes (Ana Maria); J.B.J. van Meurs (Joyce)

    2016-01-01

    textabstractOsteoarthritis is one of the most frequent and disabling diseases of the elderly. Only few genetic variants have been identified for osteoarthritis, which is partly due to large phenotype heterogeneity. To reduce heterogeneity, we here examined cartilage thickness, one of the structural

  20. NONINVASIVE DETERMINATION OF KNEE CARTILAGE DEFORMATION DURING JUMPING

    Directory of Open Access Journals (Sweden)

    Djordje Kosanic

    2009-12-01

    Full Text Available The purpose of this investigation was to use a combination of image processing, force measurements and finite element modeling to calculate deformation of the knee cartilage during jumping. Professional athletes performed jumps analyzed using a force plate and high-speed video camera system. Image processing was performed on each frame of video using a color recognition algorithm. A simplified mass-spring-damper model was utilized for determination of global force and moment on the knee. Custom software for fitting the coupling characteristics was created. Simulated results were used as input data for the finite element calculation of cartilage deformation in the athlete's knee. Computer simulation data was compared with the average experimental ground reaction forces. The results show the three-dimensional mechanical deformation distribution inside the cartilage volume. A combination of the image recognition technology, force plate measurements and the finite element cartilage deformation in the knee may be used in the future as an effective noninvasive tool for prediction of injury during jumping

  1. Segmentation of articular cartilage using active contours and prior knowledge.

    Science.gov (United States)

    Tejos, Cristian; Hall, Laurance; Cardenas-Blanco, Arturo

    2004-01-01

    A diffusion snake segmentation algorithm was evaluated on synthetic and real MR images of articular cartilage. The algorithm proved to be robust to missing boundaries and the initial contour converges over large distances. Compared with a standard B-spline snake, more accurate and reproducible segmentations were obtained, with less effort during initialization of the algorithm.

  2. Evaluation of early changes of cartilage biomarkers following ...

    African Journals Online (AJOL)

    Hamdy Khamis Koryem

    2014-08-15

    Aug 15, 2014 ... In fat-suppressed 3D-WS-bSSFP, the articular carti- lage has very high signal intensity, joint fluid has an intermedi- ate to low signal intensity, and subchondral bone and bone marrow are dark. Reported sensitivity and specificity for detec- tion of cartilage loss are 75–85% and 95–97%, respectively.25.

  3. Evaluation of early changes of cartilage biomarkers following ...

    African Journals Online (AJOL)

    Evaluation of early changes of cartilage biomarkers following arthroscopic meniscectomy in young Egyptian adults. ... Among the individual biochemical markers, PIICP had the highest significant diagnostic accuracy quantified as the area under the receiver-operator characteristics curve (AUC) of 0.75 (95% confidence ...

  4. Human Endogenous Retrovirus W Activity in Cartilage of Osteoarthritis Patients

    Directory of Open Access Journals (Sweden)

    Signy Bendiksen

    2014-01-01

    Full Text Available The etiology of viruses in osteoarthritis remains controversial because the prevalence of viral nucleic acid sequences in peripheral blood or synovial fluid from osteoarthritis patients and that in healthy control subjects are similar. Until now the presence of virus has not been analyzed in cartilage. We screened cartilage and chondrocytes from advanced and non-/early osteoarthritis patients for parvovirus B19, herpes simplex virus-1, Epstein Barr virus, cytomegalovirus, human herpes virus-6, hepatitis C virus, and human endogenous retroviruses transcripts. Endogenous retroviruses transcripts, but none of the other viruses, were detected in 15 out the 17 patients. Sequencing identified the virus as HERV-WE1 and E2. HERV-W activity was confirmed by high expression levels of syncytin, dsRNA, virus budding, and the presence of virus-like particles in all advanced osteoarthritis cartilages examined. Low levels of HERV-WE1, but not E2 envelope RNA, were observed in 3 out of 8 non-/early osteoarthritis patients, while only 3 out of 7 chondrocytes cultures displayed low levels of syncytin, and just one was positive for virus-like particles. This study demonstrates for the first time activation of HERV-W in cartilage of osteoarthritis patients; however, a causative role for HERV-W in development or deterioration of the disease remains to be proven.

  5. Effect of histone deacetylase inhibitor, trichostatin A, on cartilage ...

    African Journals Online (AJOL)

    transplanted onto the paravertebral muscle of the face of each rabbit. The rabbits were separated into ... Conclusion: Treatment with trichostatin A, an HDAC inhibitor, enhances cartilage regeneration in rabbit recipients of a perichondrial graft. ..... Stillaert FB, Monstrey S. The use of platelet-rich plasma in plastic surgery: a ...

  6. Current perspectives in stem cell research for knee cartilage repair

    Directory of Open Access Journals (Sweden)

    Orth P

    2014-01-01

    Full Text Available Patrick Orth,1 Ana Rey-Rico,2 Jagadeesh K Venkatesan,2 Henning Madry,1,2 Magali Cucchiarini2 1Department of Orthopaedic Surgery, 2Center of Experimental Orthopaedics, Saarland University Medical Center, Homburg, Germany Abstract: Protocols based on the delivery of stem cells are currently applied in patients, showing encouraging results for the treatment of articular cartilage lesions (focal defects, osteoarthritis. Yet, restoration of a fully functional cartilage surface (native structural organization and mechanical functions especially in the knee joint has not been reported to date, showing the need for improved designs of clinical trials. Various sources of progenitor cells are now available, originating from adult tissues but also from embryonic or reprogrammed tissues, most of which have already been evaluated for their chondrogenic potential in culture and for their reparative properties in vivo upon implantation in relevant animal models of cartilage lesions. Nevertheless, particular attention will be needed regarding their safe clinical use and their potential to form a cartilaginous repair tissue of proper quality and functionality in the patient. Possible improvements may reside in the use of biological supplements in accordance with regulations, while some challenges remain in establishing standardized, effective procedures in the clinics. Keywords: cartilage repair, knee, focal defects, osteoarthritis, stem cells, clinical trials

  7. Calcineurin Inhibition at Physiological Osmolarity: Toward improving cartilage regeneration

    NARCIS (Netherlands)

    A.E. van der Windt (Anna)

    2017-01-01

    markdownabstractArticular hyaline cartilage is a white, smooth structure covering the ends of bones in synovial joints, like in the hip and knee. Because of its unique stiff yet flexible properties, it distributes the loads, as a consequence of weight bearing and locomotion, over the surface of the

  8. Mesenchymal stem cells for cartilage regeneration in osteoarthritis.

    Science.gov (United States)

    Kristjánsson, Baldur; Honsawek, Sittisak

    2017-09-18

    Osteoarthritis (OA) is a slowly progressive disease where cartilage of the synovial joint degenerates. It is most common in the elderly where patients experience pain and reduce physical activity. In combination with lack of conventional treatment, patients are often left with no other choices than arthroplasty. Over the last years, multipotent stromal cells have been used in efforts to treat OA. Mesenchymal stem/progenitor cells (MSCs) are stromal cells that can differentiate into bone, fat, and cartilage cells. They reside within bone marrow and fat. MSCs can also be found in synovial joints where they affect the progression of OA. They can be isolated and proliferated in an incubator before being applied in clinical trials. When it comes to treatment, emphasis has hitherto been on autologous MSCs, but allogenic cells from healthy donors are emerging as another source of the cells. The first adaptations of MSCs revolved in the use of cell-rich matrix, delivered as invasive surgical procedure, which resulted in production of hyaline cartilage and fibrocartilage. However, the demand for less invasive delivery of cells has prompted the use of direct intra-articular injections, wherein a large amount of suspended cells are implanted in the cartilage defect.

  9. Evaluation of early changes of cartilage biomarkers following ...

    African Journals Online (AJOL)

    Evaluation of early changes of cartilage biomarkers following arthroscopic meniscectomy in young Egyptian adults. ... Asked Questions about PDFs. Alternatively, you can download the PDF file directly to your computer, from where it can be opened using a PDF reader. To download the PDF, click the Download link above.

  10. Experimental articular cartilage repair in the Göttingen minipig

    DEFF Research Database (Denmark)

    Christensen, Bjørn Borsøe; Foldager, Casper Bindzus; Olesen, Morten Lykke

    2015-01-01

    treated with one of the following: Matrix-induced autologous chondrocyte implantation (MACI), microfracture (MFx), autologous-dual-tissue transplantation (ADTT), autologous bone graft, autologous cartilage chips. Empty chondral and osteochondral defects were used as controls. MRI and CT were performed 3...

  11. Bone morphogenetic protein-induced cartilage development in tissue culture

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K.; Urist, M.R.

    1984-03-01

    Outgrowths of mesenchyme-type cells from explants of allogeneic rat muscle onto a substratum of bone matrix containing bone morphogenetic protein (BMP) differentiate into cartilage. When BMP is chemically extracted from the bone matrix, the explanted cells develop only into fibrous tissue. When exogenous bovine BMP is introduced into the culture medium, either as a microsuspension or as a layer of particles between the matrix and the muscle cell tissue, cartilage develops at the interface between the matrix and the mesenchymal cell outgrowth. The chondrogenetic response is induced by as little as 2 micrograms of BMP; the optimum dose is 10 micrograms/40 mg (wet weight) of explant. The endogenous BMP equivalent for a comparable chondrogenetic response is about 0.6 micrograms/mg of allogeneic matrix. The minimum time for transfer of BMP to mesenchymal cell receptors is 1.0 hour, adequate time is 2.5 hours, and optimum time is approximately 5.0 hours. Measured in terms of incorporation of /sup 3/H-thymidine into DNA and of /sup 35/S sulfate into glycosaminoglycan, there is a latent period of one to three days preceeding the differentiation of mesenchyme-type cells into cartilage. During this latent period BMP-modulated mesenchymal cells disaggregate, migrate, reaggregate, and proliferate on new surfaces and constitute the morphogenetic phase of bone development. By the fourth day cells simultaneously undergo mitotic division, synthesize extracellular cartilage matrix, and establish the cytodifferentiation phase of development.

  12. Effect of histone deacetylase inhibitor, trichostatin A, on cartilage ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of histone deacetylase (HDAC) inhibitor, trichostatin A (TCA), on cartilage regeneration in a rabbit perichondrial graft model. Methods: Perichondrial grafts (20 × 20 mm2) were derived from the ears of New Zealand rabbits and transplanted onto the paravertebral muscle of the face of each ...

  13. Healing Osteoarthritis: Engineered Proteins Created for Therapeutic Cartilage Regeneration

    Directory of Open Access Journals (Sweden)

    Kevin M. Cherry

    2012-01-01

    Full Text Available Millions of people worldwide are afflicted with painfulosteoarthritis, which is characterized by degradationof articular cartilage found in major joints such as thehip or knee. Symptoms include inflammation, pain,and decreased mobility. Because cartilage has a limitedability to self-heal, researchers have focused efforts onmethods that trigger cartilage regeneration. Our approachis to develop an injectable, protein-based hydrogel withmechanical properties analogous to healthy articularcartilage. The hydrogel provides an environment for cellgrowth and stimulates new tissue formation. We utilizedrecombinant DNA technology to create multifunctional,elastomeric proteins. The recombinant proteins weredesigned with biologically active domains to influence cellbehavior and resilin structural domains that mimic thestiffness of native cartilage. Resilin, a protein found in thewing and leg joints of mosquitoes, provided inspiration forthe mechanical domain in the recombinant protein. Thenew resilin-based protein was expressed in E. coli bacteria.Forming hydrogels requires a large quantity of engineeredprotein, so parameters such as bacterial host, incubationtemperature, expression time, and induction method wereoptimized to increase the protein yield. Using salt toprecipitate the protein and exploiting resilin’s heat stability,27 mg/L of recombinant protein was recovered at 95%purity. The protein expression and purification protocolswere established by analyzing experimental samples onSDS-PAGE gels and by Western blotting. The mechanicalproperties and interactions with stem cells are currentlybeing evaluated to assess the potential of the resilin-basedhydrogel as a treatment for osteoarthritis.

  14. Excised larynx evaluation of subthyroid cartilage approach to medialization thyroplasty.

    Science.gov (United States)

    Thompson, James D; Hoffman, Matthew R; Scholp, Austin; Devine, Erin E; Jiang, Jack J; McCulloch, Timothy M

    2018-03-01

    To describe an alternative approach to medialization thyroplasty involving dissection underneath the thyroid cartilage with placement of a Gore-Tex implant, and to evaluate its effect on a range of phonatory measures using an excised canine larynx model. Animal model. On each of eight excised canine larynges, the conditions of normal, paralysis, medialization thyroplasty by standard transthyroid cartilage approach, and medialization thyroplasty by experimental subthyroid cartilage approach were performed. Aerodynamic, acoustic, and mucosal wave parameters were measured for each condition. Compared to the vocal fold paralysis state, both the transthyroid and subthyroid approaches for Gore-Tex insertion resulted in significant decreases in phonation threshold pressure and phonation threshold flow. Both approaches also significantly decreased percent jitter, decreased percent shimmer, and improved signal-to-noise ratio. The mucosal wave was preserved after insertion of the Gore-Tex implant for both approaches. For all the phonatory measures except phonation threshold flow, there were no significant differences between the transthyroid and subthyroid approaches. Gore-Tex implantation via a subthyroid approach in an excised canine larynx model can produce effective medialization, preserve the mucosal wave, and significantly improve aerodynamic and acoustic parameters without meaningful difference compared to a traditional transthyroid approach. The subthyroid approach does not require creation of a thyroid cartilage window and could be a potentially valuable alternative method of performing medialization thyroplasty. NA. Laryngoscope, 128:675-681, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  15. Optical coherence tomography detection of subclinical traumatic cartilage injury.

    Science.gov (United States)

    Bear, David M; Szczodry, Michal; Kramer, Scott; Coyle, Christian H; Smolinski, Patrick; Chu, Constance R

    2010-09-01

    Posttraumatic arthritis is a major cause of disability. Current clinical imaging modalities are unable to reliably evaluate articular cartilage damage before surface breakdown, when potentially reversible changes are occurring. Optical coherence tomography (OCT) is a nondestructive imaging technology that can detect degenerative changes in articular cartilage with an intact surface. This study tests the hypothesis that OCT detects acute articular cartilage injury after impact at energy levels resulting in chondrocyte death and microstructural changes, but insufficient to produce macroscopic surface damage. Bovine osteochondral cores underwent OCT imaging and were divided into a control with no impact or were subjected to low (0.175 J) or moderate (0.35 J) energy impact. Cores were reimaged with OCT after impact and the OCT signal intensity quantified. A ratio of the superficial to deep layer intensities was calculated and compared before and after impact. Chondrocyte viability was determined 1 day after impact followed by histology and polarized microscopy. Macroscopic changes to the articular surface were not observed after low and moderate impact. The OCT signal intensity ratio demonstrated a 27% increase (P = 0.006) after low impact and a 38% increase (P = 0.001) after moderate impact. Cell death increased by 150% (P death and microscopic matrix damage. This finding supports the use of OCT to detect microstructural subsurface cartilage damage that is poorly visualized with conventional imaging.

  16. Thermosensitive hydrogels for 3D bioprinting of cartilage constructs

    NARCIS (Netherlands)

    Abbadessa, A.

    2017-01-01

    Tissue engineering (TE) aims to regenerate damaged tissues by the combined use of biomaterials and cells, often in presence of bioactive molecules, such as growth factors. Particularly for tissues with poor regenerative capacity, such as articular cartilage, TE approaches may lead to promising

  17. Automatic quantification of local and global articular cartilage surface curvature

    DEFF Research Database (Denmark)

    Folkesson, Jenny; Dam, Erik B; Olsen, Ole F

    2008-01-01

    The objective of this study was to quantitatively assess the surface curvature of the articular cartilage from low-field magnetic resonance imaging (MRI) data, and to investigate its role in populations with varying radiographic signs of osteoarthritis (OA), cross-sectionally and longitudinally. ...... curvature estimates from low-field MRI at different scales could potentially become biomarkers targeted at different stages of OA....

  18. Employee turnover and productivity among small business entities in Nigeria

    Directory of Open Access Journals (Sweden)

    John N. N. Ugoani

    2016-12-01

    Full Text Available This study was designed to evaluate the problems of employee turnover on productivity among small business entities in Nigeria, and recommend remedial actions. Employee turnover is the separation of employees from employers and replacement with other employees. Productive manpower is a critical element for the economic survival of any small business entity. The survey research design was used for the study. The sample comprised of 320 respondents. Data generated were analyzed by using descriptive, and Z-test statistical techniques. It was found that employee turnover adversely affects productivity in small business entities.

  19. Colloidal 234Th and the turnover of oceanic DOC

    International Nuclear Information System (INIS)

    Murray, J.W.; Balistrieri, L.S.

    1994-01-01

    234 Th has been proposed to be a tracer for the labile, colloidal fraction of DOC in seawater. During the recent North Atlantic Bloom Experiment (NABE) the turnover of DOC was directly measured. 234 Th and total suspended matter (C p ) were also measured by different research groups. Using the NABE 234 Th data the authors have calculated the turnover rate of colloidal material using the Brownian Pumping model of Honeyman and Santschi and the 4-box particle cycling model of Moran and Buesseler. The rate constants for colloid cycling determined from the 234 Th data agree well with the experimentally determined rate constants for turnover of DOC

  20. Turnover and employment in the German wind energy industry

    International Nuclear Information System (INIS)

    Keuper, A.

    1995-01-01

    Results of the fast growing wind energy market in 1994 are the turnover reaching more than 800 million DM, and the number of employees to about 3,700. In 1995 the manufacturers expect to need less than 4 employees to build and to install 1 MW rated power and to decrease the ratio of manufacturer's turnover per installed power unit to about 1900 DM/kW. In spite of this development it is expected that the turnover and the number of employees will increase due to the still fast growing market. (orig.)

  1. The Influence of Job Satisfaction on Employee Turnover

    OpenAIRE

    Krempl, Jan

    2016-01-01

    This Master's Thesis deals with the topics of employee turnover and job satisfaction, more precisely with the way in which job satisfaction can influence employee turnover in a company. The goal of the Thesis is to design a way to analyse job satisfaction in an organization and determine the way in which job satisfaction influences the turnover potential of current employees. The Thesis is divided into three main chapters. The first chapter is a literary research that deals with topics of emp...

  2. The immunomodulatory effects of shark cartilage on the mouse and human immune system

    Directory of Open Access Journals (Sweden)

    ali Sheikhian

    2007-01-01

    Materials and methods: In an experimental study, the effects of different doses of shark cartilage on humoral (antibody titer immune response against sheep red blood cells (SRBC, were measured in mouse. In addition, we evaluated the modulatory effects of the shark cartilage on the natural killer (NK activity of the peritoneal cells of mouse against a tumor cell line called K562, according to the standard methods. The proliferative response of the human peripheral blood mononuclear cells was measured under the influence of shark cartilage. Results: Pure shark cartilage enhanced antibody response against SRBC in vivo. The hemagglutination titer which was 1/147 in the control group (injected with hen cartilage, increased to 1/1355 in the test group. The optimal dose was 100 mg/ml. both type of cartilage had blastogenic effect on peripheral blood mononuclear cells (the blastogenic index was 6.7 and 4.9 for impure shark cartilage and hen cartilage, respectively. NK activity was inhibited completely by pure shark cartilage (the amount of the killing activity of the effector peritoneal cells for the control and test groups against target cells was 25.9% and 5.5% respectively. Conclusion: Shark cartilage has a potent immunomodulatory effect on the specific immune mechanisms and some inhibitory effects on the innate immune mechanisms such as NC activity. Since the specific immunity has a more pivotal role against tumor formation, shark cartilage can be used as a cancer immunotherapeutic.

  3. Effects of mechanical loading on human mesenchymal stem cells for cartilage tissue engineering.

    Science.gov (United States)

    Choi, Jane Ru; Yong, Kar Wey; Choi, Jean Yu

    2018-03-01

    Today, articular cartilage damage is a major health problem, affecting people of all ages. The existing conventional articular cartilage repair techniques, such as autologous chondrocyte implantation (ACI), microfracture, and mosaicplasty, have many shortcomings which negatively affect their clinical outcomes. Therefore, it is essential to develop an alternative and efficient articular repair technique that can address those shortcomings. Cartilage tissue engineering, which aims to create a tissue-engineered cartilage derived from human mesenchymal stem cells (MSCs), shows great promise for improving articular cartilage defect therapy. However, the use of tissue-engineered cartilage for the clinical therapy of articular cartilage defect still remains challenging. Despite the importance of mechanical loading to create a functional cartilage has been well demonstrated, the specific type of mechanical loading and its optimal loading regime is still under investigation. This review summarizes the most recent advances in the effects of mechanical loading on human MSCs. First, the existing conventional articular repair techniques and their shortcomings are highlighted. The important parameters for the evaluation of the tissue-engineered cartilage, including chondrogenic and hypertrophic differentiation of human MSCs are briefly discussed. The influence of mechanical loading on human MSCs is subsequently reviewed and the possible mechanotransduction signaling is highlighted. The development of non-hypertrophic chondrogenesis in response to the changing mechanical microenvironment will aid in the establishment of a tissue-engineered cartilage for efficient articular cartilage repair. © 2017 Wiley Periodicals, Inc.

  4. Correlation between apparent diffusion coefficient and viscoelasticity of articular cartilage in a porcine model.

    Science.gov (United States)

    Aoki, T; Watanabe, A; Nitta, N; Numano, T; Fukushi, M; Niitsu, M

    2012-09-01

    Quantitative MR imaging techniques of degenerative cartilage have been reported as useful indicators of degenerative changes in cartilage extracellular matrix, which consists of proteoglycans, collagen, non-collagenous proteins, and water. Apparent diffusion coefficient (ADC) mapping of cartilage has been shown to correlate mainly with the water content of the cartilage. As the water content of the cartilage in turn correlates with its viscoelasticity, which directly affects the mechanical strength of articular cartilage, ADC can serve as a potentially useful indicator of the mechanical strength of cartilage. The aim of this study was to investigate the correlation between ADC and viscoelasticity as measured by indentation testing. Fresh porcine knee joints (n = 20, age 6 months) were obtained from a local abattoir. ADC of porcine knee cartilage was measured using a 3-Tesla MRI. Indentation testing was performed on an electromechanical precision-controlled system, and viscosity coefficient and relaxation time were measured as additional indicators of the viscoelasticity of cartilage. The relationship between ADC and viscosity coefficient as well as that between ADC and relaxation time were assessed. ADC was correlated with relaxation time and viscosity coefficient (R(2) = 0.75 and 0.69, respectively, p viscoelasticity in the superficial articular cartilage. Both molecular diffusion and viscoelasticity were higher in weight bearing than non-weight-bearing articular cartilage areas.

  5. Alterations of the subchondral bone in osteochondral repair – translational data and clinical evidence

    Directory of Open Access Journals (Sweden)

    P Orth

    2013-06-01

    Full Text Available Alterations of the subchondral bone are pathological features associated with spontaneous osteochondral repair following an acute injury and with articular cartilage repair procedures. The aim of this review is to discuss their incidence, extent and relevance, focusing on recent knowledge gained from both translational models and clinical studies of articular cartilage repair. Efforts to unravel the complexity of subchondral bone alterations have identified (1 the upward migration of the subchondral bone plate, (2 the formation of intralesional osteophytes, (3 the appearance of subchondral bone cysts, and (4 the impairment of the osseous microarchitecture as potential problems. Their incidence and extent varies among the different small and large animal models of cartilage repair, operative principles, and over time. When placed in the context of recent clinical investigations, these deteriorations of the subchondral bone likely are an additional, previously underestimated, factor that influences the long-term outcome of cartilage repair strategies. Understanding the role of the subchondral bone in both experimental and clinical articular cartilage repair thus holds great promise of being translated into further improved cell- or biomaterial-based techniques to preserve and restore the entire osteochondral unit.

  6. The distribution of YKL-40 in osteoarthritic and normal human articular cartilage

    DEFF Research Database (Denmark)

    Volck, B; Ostergaard, K; Johansen, J S

    1999-01-01

    YKL-40, also called human cartilage glycoprotein-39, is a major secretory protein of human chondrocytes in cell culture. YKL-40 mRNA is expressed by cartilage from patients with rheumatoid arthritis, but is not detectable in normal human cartilage. The aim was to investigate the distribution of YKL......-40 in osteoarthritic (n=9) and macroscopically normal (n=5) human articular cartilage, collected from 12 pre-selected areas of the femoral head, to discover a potential role for YKL-40 in cartilage remodelling in osteoarthritis. Immunohistochemical analysis showed that YKL-40 staining was found...... staining for YKL-40 was in general low in normal cartilage. The present findings, together with previous observations, suggests that YKL-40 may be of importance in cartilage remodelling/degradation of osteoarthritic joints....

  7. Sildenafil Stimulates Aqueous Humor Turnover in Rabbits

    Science.gov (United States)

    Alvarez, Lawrence J.; Zamudio, Aldo C.; Candia, Oscar A.

    2013-01-01

    Sildenafil citrate increases ocular blood flow and accelerates the rate of anterior chamber refilling after paracentesis. The latter effect could have resulted from a reduction in outflow facility or from an increase in aqueous humor (AH) production. In this study, we used scanning ocular fluorophotometry to examine the effects of sildenafil on AH turnover, and thus, AH production in eyes of live normal rabbits. For this, the rate of aqueous humor flow (AHF) was quantified with a commercially available fluorophotometer that measured the rate of fluorescein clearance from the anterior segment, which predominantly occurs via the trabecular meshwork. After ≈ 2 hrs of control scans to determine the baseline rate of AHF, the rabbits were fed 33 mg of sildenafil and allowed ≈ 45 min for the drug to enter the systemic circulation. Thereafter, fluorescence scans were retaken for an additional 90–120 min. Sildenafil ingestion increased AHF by about 36%, from 2.31 μL/min to 3.14 μL/min (PViagra, Revatio), stimulates AHF in rabbits. Our results seem consistent with reports indicating that the drug dilates intraocular arteries and augments intraocular vascular flow. These physiological responses to the agent apparently led to increased fluid entry into the anterior chamber. As such, the drug might have utility in patients with ocular hypotony resulting from insufficient AH formation. PMID:23562660

  8. Transforming growth factor β-induced superficial zone protein accumulation in the surface zone of articular cartilage is dependent on the cytoskeleton.

    Science.gov (United States)

    McNary, Sean M; Athanasiou, Kyriacos A; Reddi, A Hari

    2014-03-01

    The phenotype of articular chondrocytes is dependent on the cytoskeleton, specifically the actin microfilament architecture. Articular chondrocytes in monolayer culture undergo dedifferentiation and assume a fibroblastic phenotype. This process can be reversed by altering the actin cytoskeleton by treatment with cytochalasin. Whereas dedifferentiation has been studied on chondrocytes isolated from the whole cartilage, the effects of cytoskeletal alteration on specific zones of cells such as superficial zone chondrocytes are not known. Chondrocytes from the superficial zone secrete superficial zone protein (SZP), a lubricating proteoglycan that reduces the coefficient of friction of articular cartilage. A better understanding of this phenomenon may be useful in elucidating chondrocyte dedifferentiation in monolayer and accumulation of the cartilage lubricant SZP, with an eye toward tissue engineering functional articular cartilage. In this investigation, the effects of cytoskeletal modulation on the ability of superficial zone chondrocytes to secrete SZP were examined. Primary superficial zone chondrocytes were cultured in monolayer and treated with a combination of cytoskeleton modifying reagents and transforming growth factor β (TGFβ) 1, a critical regulator of SZP production. Whereas cytochalasin D maintains the articular chondrocyte phenotype, the hallmark of the superficial zone chondrocyte, SZP, was inhibited in the presence of TGFβ1. A decrease in TGFβ1-induced SZP accumulation was also observed when the microtubule cytoskeleton was modified using paclitaxel. These effects of actin and microtubule alteration were confirmed through the application of jasplakinolide and colchicine, respectively. As Rho GTPases regulate actin organization and microtubule polymerization, we hypothesized that the cytoskeleton is critical for TGFβ-induced SZP accumulation. TGFβ-mediated SZP accumulation was inhibited by small molecule inhibitors ML141 (Cdc42), NSC23766 (Rac1

  9. Boundary lubrication of articular cartilage: role of synovial fluid constituents.

    Science.gov (United States)

    Schmidt, Tannin A; Gastelum, Nicholas S; Nguyen, Quynhhoa T; Schumacher, Barbara L; Sah, Robert L

    2007-03-01

    To determine whether the synovial fluid (SF) constituents hyaluronan (HA), proteoglycan 4 (PRG4), and surface-active phospholipids (SAPL) contribute to boundary lubrication, either independently or additively, at an articular cartilage-cartilage interface. Cartilage boundary lubrication tests were performed with fresh bovine osteochondral samples. Tests were performed using graded concentrations of SF, HA, and PRG4 alone, a physiologic concentration of SAPL, and various combinations of HA, PRG4, and SAPL at physiologic concentrations. Static (mu(static, Neq)) and kinetic () friction coefficients were calculated. Normal SF functioned as an effective boundary lubricant both at a concentration of 100% ( = 0.025) and at a 3-fold dilution ( = 0.029). Both HA and PRG4 contributed independently to a low mu in a dose-dependent manner. Values of decreased from approximately 0.24 in phosphate buffered saline to 0.12 in 3,300 mug/ml HA and 0.11 in 450 mug/ml PRG4. HA and PRG4 in combination lowered mu further at the high concentrations, attaining a value of 0.066. SAPL at 200 mug/ml did not significantly lower mu, either independently or in combination with HA and PRG4. The results described here indicate that SF constituents contribute, individually and in combination, both at physiologic and pathophysiologic concentrations, to the boundary lubrication of apposing articular cartilage surfaces. These results provide insight into the nature of the boundary lubrication of articular cartilage by SF and its constituents. They therefore provide insight regarding both the homeostatic maintenance of healthy joints and pathogenic processes in arthritic disease.

  10. Novel Genetic Variants for Cartilage Thickness and Hip Osteoarthritis.

    Directory of Open Access Journals (Sweden)

    Martha C Castaño-Betancourt

    2016-10-01

    Full Text Available Osteoarthritis is one of the most frequent and disabling diseases of the elderly. Only few genetic variants have been identified for osteoarthritis, which is partly due to large phenotype heterogeneity. To reduce heterogeneity, we here examined cartilage thickness, one of the structural components of joint health. We conducted a genome-wide association study of minimal joint space width (mJSW, a proxy for cartilage thickness, in a discovery set of 13,013 participants from five different cohorts and replication in 8,227 individuals from seven independent cohorts. We identified five genome-wide significant (GWS, P≤5·0×10-8 SNPs annotated to four distinct loci. In addition, we found two additional loci that were significantly replicated, but results of combined meta-analysis fell just below the genome wide significance threshold. The four novel associated genetic loci were located in/near TGFA (rs2862851, PIK3R1 (rs10471753, SLBP/FGFR3 (rs2236995, and TREH/DDX6 (rs496547, while the other two (DOT1L and SUPT3H/RUNX2 were previously identified. A systematic prioritization for underlying causal genes was performed using diverse lines of evidence. Exome sequencing data (n = 2,050 individuals indicated that there were no rare exonic variants that could explain the identified associations. In addition, TGFA, FGFR3 and PIK3R1 were differentially expressed in OA cartilage lesions versus non-lesioned cartilage in the same individuals. In conclusion, we identified four novel loci (TGFA, PIK3R1, FGFR3 and TREH and confirmed two loci known to be associated with cartilage thickness.The identified associations were not caused by rare exonic variants. This is the first report linking TGFA to human OA, which may serve as a new target for future therapies.

  11. Boundary mode lubrication of articular cartilage by recombinant human lubricin.

    Science.gov (United States)

    Gleghorn, Jason P; Jones, Aled R C; Flannery, Carl R; Bonassar, Lawrence J

    2009-06-01

    Lubrication of cartilage involves a variety of physical and chemical factors, including lubricin, a synovial glycoprotein that has been shown to be a boundary lubricant. It is unclear how lubricin boundary lubricates a wide range of bearings from tissue to artificial surfaces, and if the mechanism is the same for both soluble and bound lubricin. In the current study, experiments were conducted to investigate the hypothesis that recombinant human lubricin (rh-lubricin) lubricates cartilage in a dose-dependent manner and that soluble and bound fractions of rh-lubricin both contribute to the lubrication process. An rh-lubricin dose response was observed with maximal lubrication achieved at concentrations of rh-lubricin greater than 50 microg/mL. A concentration-response variable-slope model was fit to the data, and indicated that rh-lubricin binding to cartilage was not first order. The pattern of decrease in equilibrium friction coefficient indicated that aggregation of rh-lubricin or steric arrangement may regulate boundary lubrication. rh-lubricin localized at the cartilage surface was found to lubricate a cartilage-glass interface in boundary mode, as did soluble rh-lubricin at high concentrations (150 microg/mL); however, the most effective lubrication occurred when both soluble and bound rh-lubricin were present at the interface. These findings point to two distinct mechanisms by which rh-lubricin lubricates, one mechanism involving lubricin bound to the tissue surface and the other involving lubricin in solution. Copyright 2008 Orthopaedic Research Society

  12. Chondroitin sulfate reduces the friction coefficient of articular cartilage.

    Science.gov (United States)

    Basalo, Ines M; Chahine, Nadeen O; Kaplun, Michael; Chen, Faye H; Hung, Clark T; Ateshian, Gerard A

    2007-01-01

    The objective of this study was to investigate the effect of chondroitin sulfate (CS)-C on the frictional response of bovine articular cartilage. The main hypothesis is that CS decreases the friction coefficient of articular cartilage. Corollary hypotheses are that viscosity and osmotic pressure are not the mechanisms that mediate the reduction in the friction coefficient by CS. In Experiment 1, bovine articular cartilage samples (n=29) were tested in either phosphate buffered saline (PBS) or in PBS containing 100mg/ml of CS following 48h incubation in PBS or in PBS+100mg/ml CS (control specimens were not subjected to any incubation). In Experiment 2, samples (n=23) were tested in four different solutions: PBS, PBS+100mg/ml CS, and PBS+polyethylene glycol (PEG) (133 or 170mg/ml). In Experiment 3, samples (n=18) were tested in three solutions of CS (0, 10 and 100mg/ml). Frictional tests (cartilage-on-glass) were performed under constant stress (0.5MPa) for 3600s and the time-dependent friction coefficient was measured. Samples incubated or tested in a 100mg/ml CS solution exhibited a significantly lower equilibrium friction coefficient than the respective PBS control. PEG solutions delayed the rise in the friction coefficient relative to the PBS control, but did not reduce the equilibrium value. Testing in PBS+10mg/ml of CS did not cause any significant decrease in the friction coefficient. In conclusion, CS at a concentration of 100mg/ml significantly reduces the friction coefficient of bovine articular cartilage and this mechanism is neither mediated by viscosity nor osmolarity. These results suggest that direct injection of CS into the joint may provide beneficial tribological effects.

  13. Survivorship After Meniscal Allograft Transplantation According to Articular Cartilage Status.

    Science.gov (United States)

    Lee, Bum-Sik; Bin, Seong-Il; Kim, Jong-Min; Kim, Won-Kyeong; Choi, Jun Weon

    2017-04-01

    Clinical outcomes after meniscal allograft transplantation (MAT) in arthritic knees are unclear, and objective estimates of graft survival according to the articular cartilage status have not been performed. MAT should provide clinical benefits in knees with high-grade cartilage damage, but their graft survivorship should be inferior to that in knees with low-grade chondral degeneration after MAT. Cohort study; Level of evidence, 3. The records of 222 consecutive patients who underwent primary MAT were reviewed to compare clinical outcomes and graft survivorship. The patients were grouped according to the degree and location of articular cartilage degeneration: low-grade chondral lesions (International Cartilage Repair Society [ICRS] grade ≤2) on both the femoral and tibial sides (ideal indication), high-grade lesions (ICRS grade 3 or 4) on either the femoral or tibial side (relative indication), and high-grade lesions on both sides (salvage indication). Kaplan-Meier survival analysis with the log-rank test was performed to compare the clinical survival rates and graft survival rates between the groups. A Lysholm score of meniscal tear or meniscectomy of greater than one-third of the allograft, objectively evaluated by magnetic resonance imaging (MRI) and second-look arthroscopic surgery. The mean (±SD) Lysholm score significantly improved from 63.1 ± 15.1 preoperatively to 85.1 ± 14.3 at the latest follow-up of a mean 44.6 ± 19.7 months ( P lesions. However, better graft survival can be expected when articular cartilage is intact or if chondral damage is limited to a unipolar lesion. MAT should be considered before the progression of chondral damage to a bipolar lesion for better graft survivorship and should be performed cautiously in arthritic knees.

  14. The Top 50 Most Cited Articles in Cartilage Regeneration

    Directory of Open Access Journals (Sweden)

    Ciaran K. Mc Donald

    2017-06-01

    Full Text Available The aim of this study was to identify and analyze the top 50 most cited articles in cartilage regeneration. The impact of a scientific journal can be gauged by the total number of citations it has accrued. The top 50 most cited articles involving cartilage regeneration represent the most quoted level of evidence among this new subspecialty. This study aims to identify and analyze the 50 most cited articles in cartilage regeneration. The Web of Science™ citation indexing service was utilized to determine the most frequently cited articles published after 1956 containing “cartilage regeneration” in the “topic” or “title.” The 50 most cited articles were included. The number of citations, year of publication, country of article origin, article institution, journal of publication, publication format, and authorship were then calculated for each article. The span of citations ranged from 1287 to 203 citations, with a mean of 361.02 citations per article in question. The articles originated from 11 countries, with the United States contributing 34 articles, followed by Japan with 5 articles. The articles were distributed across 34 high-impact journals. Biomaterials was the journal with the highest number of publications (seven articles followed by the Journal of Orthopaedic Research (three articles. Of the 50 articles, 2 were clinical observational studies, 47 concerned basic science, and 1 was review article. The most cited articles involving cartilage regeneration are detected in both experimental and clinical research fields. The high ratio of basic science to clinical articles reflects the infancy of this relatively new specialty and that further clinical research is required in this area.

  15. The Top 50 Most Cited Articles in Cartilage Regeneration

    Science.gov (United States)

    Mc Donald, Ciaran K.; Moriarty, Peter; Varzgalis, Manvydas; Murphy, Colin

    2017-01-01

    Abstract The aim of this study was to identify and analyze the top 50 most cited articles in cartilage regeneration. The impact of a scientific journal can be gauged by the total number of citations it has accrued. The top 50 most cited articles involving cartilage regeneration represent the most quoted level of evidence among this new subspecialty. This study aims to identify and analyze the 50 most cited articles in cartilage regeneration. The Web of Science™ citation indexing service was utilized to determine the most frequently cited articles published after 1956 containing “cartilage regeneration” in the “topic” or “title.” The 50 most cited articles were included. The number of citations, year of publication, country of article origin, article institution, journal of publication, publication format, and authorship were then calculated for each article. The span of citations ranged from 1287 to 203 citations, with a mean of 361.02 citations per article in question. The articles originated from 11 countries, with the United States contributing 34 articles, followed by Japan with 5 articles. The articles were distributed across 34 high-impact journals. Biomaterials was the journal with the highest number of publications (seven articles) followed by the Journal of Orthopaedic Research (three articles). Of the 50 articles, 2 were clinical observational studies, 47 concerned basic science, and 1 was review article. The most cited articles involving cartilage regeneration are detected in both experimental and clinical research fields. The high ratio of basic science to clinical articles reflects the infancy of this relatively new specialty and that further clinical research is required in this area. PMID:28736688

  16. A high throughput mechanical screening device for cartilage tissue engineering.

    Science.gov (United States)

    Mohanraj, Bhavana; Hou, Chieh; Meloni, Gregory R; Cosgrove, Brian D; Dodge, George R; Mauck, Robert L

    2014-06-27

    Articular cartilage enables efficient and near-frictionless load transmission, but suffers from poor inherent healing capacity. As such, cartilage tissue engineering strategies have focused on mimicking both compositional and mechanical properties of native tissue in order to provide effective repair materials for the treatment of damaged or degenerated joint surfaces. However, given the large number design parameters available (e.g. cell sources, scaffold designs, and growth factors), it is difficult to conduct combinatorial experiments of engineered cartilage. This is particularly exacerbated when mechanical properties are a primary outcome, given the long time required for testing of individual samples. High throughput screening is utilized widely in the pharmaceutical industry to rapidly and cost-effectively assess the effects of thousands of compounds for therapeutic discovery. Here we adapted this approach to develop a high throughput mechanical screening (HTMS) system capable of measuring the mechanical properties of up to 48 materials simultaneously. The HTMS device was validated by testing various biomaterials and engineered cartilage constructs and by comparing the HTMS results to those derived from conventional single sample compression tests. Further evaluation showed that the HTMS system was capable of distinguishing and identifying 'hits', or factors that influence the degree of tissue maturation. Future iterations of this device will focus on reducing data variability, increasing force sensitivity and range, as well as scaling-up to even larger (96-well) formats. This HTMS device provides a novel tool for cartilage tissue engineering, freeing experimental design from the limitations of mechanical testing throughput. © 2013 Published by Elsevier Ltd.

  17. Binding and lubrication of biomimetic boundary lubricants on articular cartilage.

    Science.gov (United States)

    Samaroo, Kirk J; Tan, Mingchee; Putnam, David; Bonassar, Lawrence J

    2017-03-01

    The glycoprotein, lubricin, is the primary boundary lubricant of articular cartilage and has been shown to prevent cartilage damage after joint injury. In this study, a library of eight bottle-brush copolymers were synthesized to mimic the structure and function of lubricin. Polyethylene glycol (PEG) grafted onto a polyacrylic acid (pAA) core mimicked the hydrophilic mucin-like domain of lubricin, and a thiol terminus anchored the polymers to cartilage surfaces much like lubricin's C-terminus. These copolymers, abbreviated as pAA-g-PEG, rapidly bound to cartilage surfaces with binding time constants ranging from 20 to 39 min, and affected lubrication under boundary mode conditions with coefficients of friction ranging from 0.140 ± 0.024 to 0.248 ± 0.030. Binding and lubrication were highly correlated (r 2  = 0.89-0.99), showing that boundary lubrication in this case strongly depends on the binding of the lubricant to the surface. Along with time-dependent and dose-dependent behavior, lubrication and binding of the lubricin-mimetics also depended on copolymer structural parameters including pAA backbone length, PEG side chain length, and PEG:AA brush density. Polymers with larger backbone sizes, brush sizes, or brush densities took longer to bind (p lubricate and protect cartilage in vivo. In copolymers with shorter pAA backbones, increasing hydrodynamic size inhibited lubrication (p lubricating efficacy as recombinant lubricins and as such have potential for in vivo treatment of post-traumatic osteoarthritis. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:548-557, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  18. Evaluation of nasal cartilage using three-dimensional soft tissue images in patients with unilateral cleft lip

    International Nuclear Information System (INIS)

    Hasegawa, Yoshimichi; Saijo, Hideto; Yonehara, Yoshiyuki; Takato, Tsuyoshi; Nakatuka, Takashi

    2008-01-01

    In the treatment of nasal deformities associated with cleft lip and palate, deformities of the alar cartilage and upper lateral cartilage are usually repaired. It is very useful if deformities of the nasal cartilage are evaluated preoperatively. We created three-dimensional CT images of soft tissues by the volume rendering method, the nasal cartilage. In 26 patients with unilateral cleft lip and palate, the alar cartilage, upper lateral cartilage, and septal cartilage were evaluated morphologically. As a result, in each case, these cartilages were deviated and deformed. However, the size of both the alar cartilage and the upper lateral cartilage on the cleft side were approximately similar to those on the healthy side. It is suggested that using this method formulated for the imaging of cartilaginous morphology, preoperative planning and follow-up can be performed easily. (author)

  19. Turnover of grain legume N rhizodeposits and effect of rhizodeposition on the turnover of crop residues

    DEFF Research Database (Denmark)

    Mayer, J.; Buegger, F.; Jensen, E.S.

    2004-01-01

    C). A sandy loam soil for the experiment was either stored at 6 degreesC or planted with the respective grain legume in pots. Legumes were in situ N-15 stem labelled during growth and visible roots were removed at maturity. The remaining plant-derived N in soil was defined as N rhizodeposition....... In the experiment the turnover of C and N was compared in soils with and without previous growth of three legumes and with and without incorporation of crop residues. After 168 days, 21% (lupin), 26% (faba bean) and 27% (pea) of rhizodeposition N was mineralised in the treatments without crop residues. A smaller...

  20. Species Turnover across Different Life Stages from Seedlings to Canopy Trees in Swamp Forests of Central Brazil

    Directory of Open Access Journals (Sweden)

    Clarissa G. Fontes

    2015-01-01

    Full Text Available Processes driving the assembly of swamp forest communities have been poorly explored. We analyzed natural regeneration and adult tree communities data of a swamp gallery forest in Central Brazil to discuss the role of ecological filters in shaping plant species turnover in a successional gradient. Species data of 120 plots were used to assess species turnover between natural regeneration and adult tree communities. Our analyses were based on 4995 individuals belonging to 72 species. Community patterns were discerned using ordination analyses. A clear floristic turnover among plant life stages was distinguished. Regeneration community of swamp forests was richer in species composition than the adult community. Tree species commonly found in nonflooded gallery forests were present in the regeneration plots but not in the adult community. Differences in the floristic composition of these two strata suggest that not all species in the seedling stage can stand permanent flooding conditions and only a few tolerant species survive to become adult trees. We propose that natural disturbances play an important role by altering limiting resources, allowing seeds of nonflooded forest species to germinate. This paper elucidates the turnover between plant life stages in swamp forests and suggests mechanisms that may shape these communities.

  1. The bio in the ink : cartilage regeneration with bioprintable hydrogels and articular cartilage-derived progenitor cells

    NARCIS (Netherlands)

    Levato, Riccardo; Webb, William R; Otto, Iris A; Mensinga, Anneloes; Zhang, Yadan; van Rijen, Mattie; van Weeren, P. René; Khan, Ilyas M.; Malda, Jos

    2017-01-01

    Cell-laden hydrogels are the primary building blocks for bioprinting, and, also termed bioinks, are the foundations for creating structures that can potentially recapitulate the architecture of articular cartilage. To be functional, hydrogel constructs need to unlock the regenerative capacity of

  2. Raman microspectrometry of laser-reshaped rabbit auricular cartilage: preliminary study on laser-induced cartilage mineralization

    NARCIS (Netherlands)

    Heger, Michal; Mordon, Serge; Leroy, Gérard; Fleurisse, Laurence; Creusy, Colette

    2006-01-01

    Laser-assisted cartilage reshaping (LACR) is a relatively novel technique designed to noninvasively and permanently restructure cartilaginous tissue. It is believed that heat-induced stress relaxation, in which a temperature-mediated disruption of H2O binding is associated with conformational

  3. Cortico-striatal oxidative status, dopamine turnover and relation with stereotypy in the deer mouse.

    Science.gov (United States)

    Güldenpfennig, Marianne; Wolmarans, De Wet; du Preez, Jan L; Stein, Dan J; Harvey, Brian H

    2011-06-01

    The deer mouse presents with spontaneous stereotypic movements that resemble the repetitive behaviours of obsessive-compulsive disorder (OCD), and demonstrates a selective response to serotonin reuptake inhibitors. OCD has been linked to altered redox status and since increased dopamine signalling can promote stereotypies as well as oxidative stress, we investigated whether the severity of deer mouse stereotypy may be associated with altered dopamine turnover and cortico-striatal redox status. Deer mice were separated into high (HSB), low (LSB) and non-stereotypy (NS) groups. Frontal cortical and striatal dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), as well as superoxide dismutase (SOD) activity, reduced (GSH) and oxidised (GSSG) glutathione and glutathione redox index, were analysed as markers for regional dopamine turnover and oxidative stress, respectively. Dopamine and its metabolites and SOD activity did not differ across the stereotypy groups. Significantly reduced GSH and GSSG and increased glutathione redox index were only observed in the frontal cortex of HSB animals. Frontal cortical GSH and GSSG were inversely correlated while glutathione redox index was positively correlated with stereotypy. Deer mouse stereotypy is thus characterised by a deficient glutathione system in the frontal cortex but not striatum, and provides a therapeutic rationale for using glutathione-active antioxidants in OCD. The evidence for a primary frontal lesion has importance for future OCD research. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Global Distribution of Root Turnover in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — Estimates of root turnover rates were calculated from measurements of live root standing crop and belowground net primary production (BNPP) compiled from the primary...

  5. Job turnover and regional attrition among physiotherapists in northern Ontario.

    Science.gov (United States)

    Noh, S; Beggs, C E

    1993-01-01

    Results of an initial study indicated that the most significant factor affecting retention for Physiotherapists in Northern Ontario was perceived opportunity for career development. A follow-up study was completed two years later to determine: 1) actual job turnover and regional attrition among physiotherapists in Northern Ontario; and 2) the predictive validity of variables identified in the first study regarding job turnover and regional attrition. Job turnover occurred in 29.5% of those sampled and the regional attrition rate was 12%. Discriminant function analysis revealed factors affecting job turnover and regional attrition including professional experience, practice location, opportunity for career development and size of community of residence. Based on previous intention, indicated by participants, follow-up revealed that the initial study correctly predicted 77.5% of those who changed their jobs and 74.1% of those who left Northern Ontario. Identified factors provide direction for the development of strategies for recruitment and retention of physiotherapists.

  6. Protein turnover in children studied using 15N

    International Nuclear Information System (INIS)

    Pencharz, P.B.

    1983-01-01

    In 12 neonates the effect of the route of feeding on protein turnover rates was studied, and in 8 children suffering from cystic fibrosis the effect of nutritional rehabilitation on the protein metabolism was examined

  7. Report: Remedial Project Manager Turnover at Superfund Sites

    Science.gov (United States)

    Report #2001-M-000015, June 15, 2001. We determined that EPA Region III did not have formal procedures in place to mitigate continuity problems caused by turnover of EPA personnel in the Superfund program.

  8. Autoradiographic imaging of phosphoinositide turnover in the brain

    International Nuclear Information System (INIS)

    Hwang, P.M.; Bredt, D.S.; Snyder, S.H.

    1990-01-01

    With [ 3 H]cytidine as a precursor, phosphoinositide turnover can be localized in brain slices by selective autoradiography of the product [ 3 H]cytidine diphosphate diacylglycerol, which is membrane-bound. In the cerebellum, glutamatergic stimulation elicits an increase of phosphoinositide turnover only in Purkinje cells and the molecular layer. In the hippocampus, both glutamatergic and muscarinic cholinergic stimulation increase phosphoinositide turnover, but with distinct localizations. Cholinergic stimulation affects CA1, CA3, CA4, and subiculum, whereas glutamatergic effects are restricted to the subiculum and CA3. Imaging phosphoinositide turnover in brain slices, which are amenable to electrophysiologic studies, will permit a dynamic localized analysis of regulation of this second messenger in response to synaptic stimulation of specific neuronal pathways

  9. Global Distribution of Root Turnover in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Estimates of root turnover rates were calculated from measurements of live root standing crop and belowground net primary production (BNPP) compiled from...

  10. Wind energy industry in Germany. Turnover and employment

    International Nuclear Information System (INIS)

    Keuper, A.; Schmidt, A.

    1994-01-01

    As a consequence of the growing wind energy market in Germany the importance of the industry in this business are has grown. In 1994 the turnover will go beyond 500 million DM, and the number of employees will reach 2,900. The turnover and the number of employees are increasing in spite of the higher efficiency. In 1994 only 5 employees are needed by a manufacturer to install 1 MW rated power instead of 15 in 1989, and the ratio of installed power to manufacturer's turnover has risen from 0,25 W/DM in 1988 to 0,455 W/DM in 1994. On the other hand the turnover of the manufacturers per employee has increased from 80,000 DM in 1988 to 440,000 DM in 1994. Economic development has considerably been advanced by subsidies for the application of wind energy technology. (orig.)

  11. [A predictive model on turnover intention of nurses in Korea].

    Science.gov (United States)

    Moon, Sook Ja; Han, Sang Sook

    2011-10-01

    The purpose of this study was to propose and test a predictive model that could explain and predict Korean nurses' turnover intentions. A survey using a structured questionnaire was conducted with 445 nurses in Korea. Six instruments were used in this model. The data were analyzed using SPSS 15.0 and Amos 7.0 program. Based on the constructed model, organizational commitment, and burnout were found to have a significant direct effect on turnover intention of nurses. In addition, factors such as empowerment, job satisfaction, and organizational commitment were found to indirectly affect turnover intention of nurse. The final modified model yielded χ²=402.30, pturnover intention in Korean nurses. Findings from this study can be used to design appropriate strategies to further decrease the nurses' turnover intention in Korea.

  12. Rationale for the evaluation of trabecular bone turnover

    International Nuclear Information System (INIS)

    Kimmel, D.B.; Jee, W.S.S.

    1976-01-01

    A procedure for the morphometric evaluation of trabecular bone is identified. Its scrupulous use allows total identification of bone formation and resorption rates, items necessary for the direct histologic analysis of bone turnover

  13. Influence of Religiosity on Turnover Intention: Empirical Evidence ...

    African Journals Online (AJOL)

    Influence of Religiosity on Turnover Intention: Empirical Evidence from Selected Employees in Lagos and Ogun States. Elizabeth I. Olowookere, Olujide A. Adekeye, Gbadebo O. Adejumo, Benedict. C. Agoha, Muyiwa A. Sholarin ...

  14. High-bandwidth AFM-based rheology is a sensitive indicator of early cartilage aggrecan degradation relevant to mouse models of Osteoarthritis

    Science.gov (United States)

    Nia, Hadi Tavakoli; Gauci, Stephanie; Azadi, Mojtaba; Hung, Han-Hwa; Frank, Eliot; Fosang, Amanda; Ortiz, Christine; Grodzinsky, Alan J.

    2014-01-01

    Murine models of osteoarthritis (OA) and post-traumatic OA have been widely used to study the development and progression of these diseases using genetically engineered mouse strains along with surgical or biochemical interventions. However, due to the small size and thickness of murine cartilage, the relationship between mechanical properties, molecular structure and cartilage composition has not been well studied. We adapted a recently developed AFM-based nano-rheology system to probe the dynamic nanomechanical properties of murine cartilage over a wide frequency range of 1 Hz to 10 kHz, and studied the role of glycosaminoglycan (GAG) on the dynamic modulus and poroelastic properties of murine femoral cartilage. We showed that poroelastic properties, highlighting fluid-solid interactions, are more sensitive indicators of loss of mechanical function compared to equilibrium properties in which fluid flow is negligible. These fluid-flow-dependent properties include the hydraulic permeability (an indicator of the resistance of matrix to fluid flow) and the high frequency modulus, obtained at high rates of loading relevant to jumping and impact injury in vivo. Utilizing a fibril-reinforced finite element model, we estimated the poroelastic properties of mouse cartilage for the first time, and show that the hydraulic permeability increased by a factor ~16 from knormal = 7.80×10−16±1.3×10−16 m4/N•s to kGAG-depleted = 1.26×10−14±6.73×10−15 m4/N•s after GAG depletion. The high-frequency modulus, which is related to fluid pressurization and the fibrillar network, decreased significantly after GAG depletion. In contrast, the equilibrium modulus, which is fluid-flow independent, did not show a statistically significant alteration following GAG depletion. PMID:25435386

  15. Turnover of nursing employees in a Gauteng hospital group

    OpenAIRE

    Japie Greyling; Karel Stanz

    2010-01-01

    Orientation: The South African nursing profession is in a crisis as professional nurses leave the country in search of lucrative work overseas. Research purpose: The purpose of this study was to investigate individual determinants of voluntary turnover to identify a risk-group profile. Motivation for the study: Nursing employers should have a clearer understanding of the dynamics around nurses’ turnover behaviour and embark on strategies to retain their talent. Research design, app...

  16. Liquid Crystal Gel Reduces Age Spots by Promoting Skin Turnover

    OpenAIRE

    Mina Musashi; Ariella Coler-Reilly; Teruaki Nagasawa; Yoshiki Kubota; Satomi Kato; Yoko Yamaguchi

    2014-01-01

    Studies have shown that liquid crystals structurally resembling the intercellular lipids in the stratum corneum can beneficially affect the skin when applied topically by stimulating the skin’s natural regenerative functions and accelerating epidermal turnover. In the present study, the effects of applying low concentrations of a liquid crystal gel of our own creation were evaluated using epidermal thickening in mouse skin as an assay for effective stimulation of epidermal turnover. A liquid ...

  17. Kramers Turnover Theory for a Triple Well Potential

    International Nuclear Information System (INIS)

    Pollak, E.; Talkner, P.

    2001-01-01

    Kramers turnover theory is solved for a particle in a symmetric triple well potential for temperatures above the crossover temperature between tunneling and activated barrier crossing. Comparison with the turnover theory for a double well potential shows that the presence of the intermediate well always leads to a decrease of the reaction rate. At most though, the rate is a factor of two smaller than in the case of a double well potential. (author)

  18. Turnover rate of hypoxic cells in solid tumors

    International Nuclear Information System (INIS)

    Ljungkvist, A.S.E.; Bussink, J.; Rijken, P.F.J.W.; Van Der Kogel, A.J.

    2003-01-01

    Most solid tumors contain hypoxic cells, and both the amount and duration of tumor hypoxia has been shown to influence the effect of radiation treatment negatively. It is important to understand the dynamic processes within the hypoxic cell population in non-treated tumors, and the effect of different treatment modalities on the kinetics of hypoxic cells to be able to design optimal combined modality treatments. The turnover rate of hypoxic cells was analyzed in three different solid tumor models with a double bio-reductive hypoxic marker assay with sequential injection of the two hypoxic markers. Previously it was shown that this assay could be used to detect both a decrease and an increase of tumor hypoxia in relation to the tumor vasculature with high spatial resolution. In this study the first hypoxic marker, pimonidazole, was administered at variable times relative to tumor harvest, and the second hypoxic marker, CCI-103F, was injected at a fixed time before harvest. The hypoxic cell turnover rate was calculated as the loss of pimonidazole positive cells relative to CCI-103F. The murine C38 line had the fastest hypoxic turnover rate of 60% /24h and the human xenograft line SCCNij3 had the slowest hypoxic turnover rate of 30% /24 h. The hypoxic turnover rate was most heterogeneous in the SCCNij3 line that even contained viable groups of cells that had been hypoxic for at least 5 days. The human xenograft line MEC82 fell in between with a hypoxic turnover rate of 50% /24 h. The hypoxic cell turnover was related to the potential tumor volume doubling time (Tpot) with a Tpot of 26h in C38 and 103h in SCCNij3. The dynamics of hypoxic cells, quantified with a double hypoxic marker method, showed large differences in hypoxic cell turnover rate and were related to Tpot

  19. Exercise, training and red blood cell turnover.

    Science.gov (United States)

    Smith, J A

    1995-01-01

    Endurance training can lead to what has been termed 'sports anaemia'. Although under normal conditions, red blood cells (RBCs) have a lifespan of about 120 days, the rate of aging may increase during intensive training. However, RBC deficiency is rare in athletes, and sports anaemia is probably due to an expanded plasma volume. Cycling, running and swimming have been shown to cause RBC damage. While most investigators measure indices of haemolysis (for example, plasma haemoglobin or haptoglobin), RBC removal is normally an extravascular process that does not involve haemolysis. Attention is now turning to cellular indices (such as antioxidant depletion, or protein or lipid damage) that may be more indicative of exercise-induced damage. RBCs are vulnerable to oxidative damage because of their continuous exposure to oxygen and their high concentrations of polyunsaturated fatty acids and haem iron. As oxidative stress may be proportional to oxygen uptake, it is not surprising that antioxidants in muscle, liver and RBCs can be depleted during exercise. Oxidative damage to RBCs can also perturb ionic homeostasis and facilitate cellular dehydration. These changes impair RBC deformability which can, in turn, impede the passage of RBCs through the microcirculation. This may lead to hypoxia in working muscle during single episodes of exercise and possibly an increased rate of RBC destruction with long term exercise. Providing RBC destruction does not exceed the rate of RBC production, no detrimental effect to athletic performance should occur. An increased rate of RBC turnover may be advantageous because young cells are more efficient in transporting oxygen. Because most techniques examine the RBC population as a whole, more sophisticated methods which analyse cells individually are required to determine the mechanisms involved in exercise-induced damage of RBCs.

  20. Telaah Hubungan Kepuasan Kerja Dan Komitmen Organisasional Terhadap Turnover Intention

    Directory of Open Access Journals (Sweden)

    Ali Amran

    2017-04-01

    ABSTRACT       Employees are the most important resources of company. They are human resources to do and move all of the activities of company. Therefore, company needs to keep and maintain their job satisfaction and organizational commitment in order to reduce the intention to leave the company (turnover intention. It is necessary to study the relationship among job satisfaction, organizational commitment and turnover intention. This will give benefit to determine the important values of employees’ job satisfaction and organizational commitment and its influences on turnover intention. The research methods are descriptive survey and verificative survey that is used to assess the performance of independent variables: those are job satisfaction and organizational commitment,  and dependent variable: that is turnover intention with doing observation to employees of PT. Alexindo Bekasi. The result of this research is there is influence of job satisfaction and organizational commitment on turnover intention. This research is the improvement of existing researches which can be applied in the other companies specially for the human resource or employee behavior field.   Keywords: Job Satisfaction, Organizational Commitment, Turnover Intention

  1. Long-period astronomical forcing of mammal turnover.

    Science.gov (United States)

    van Dam, Jan A; Abdul Aziz, Hayfaa; Alvarez Sierra, M Angeles; Hilgen, Frederik J; van den Hoek Ostende, Lars W; Lourens, Lucas J; Mein, Pierre; van der Meulen, Albert J; Pelaez-Campomanes, Pablo

    2006-10-12

    Mammals are among the fastest-radiating groups, being characterized by a mean species lifespan of the order of 2.5 million years (Myr). The basis for this characteristic timescale of origination, extinction and turnover is not well understood. Various studies have invoked climate change to explain mammalian species turnover, but other studies have either challenged or only partly confirmed the climate-turnover hypothesis. Here we use an exceptionally long (24.5-2.5 Myr ago), dense, and well-dated terrestrial record of rodent lineages from central Spain, and show the existence of turnover cycles with periods of 2.4-2.5 and 1.0 Myr. We link these cycles to low-frequency modulations of Milankovitch oscillations, and show that pulses of turnover occur at minima of the 2.37-Myr eccentricity cycle and nodes of the 1.2-Myr obliquity cycle. Because obliquity nodes and eccentricity minima are associated with ice sheet expansion and cooling and affect regional precipitation, we infer that long-period astronomical climate forcing is a major determinant of species turnover in small mammals and probably other groups as well.

  2. Factors influencing turnover intention among registered nurses in Samar Philippines.

    Science.gov (United States)

    Labrague, Leodoro J; Gloe, Donna; McEnroe, Denise M; Konstantinos, Kostas; Colet, Paolo

    2018-02-01

    Despite the massive nurse migration and turnover of nurses in the Philippines, there remains a lack of studies describing factors influencing the migration of Filipino nurses. This study explored the effects of nurses' characteristics, work satisfaction, and work stress with the intent to leave an organization among registered nurses in the Philippines. This study utilized a descriptive, cross-sectional approach. One hundred sixty six (166) nurses participated in the study during the months of September 2015 to December 2015. Three standardized instruments were used in the study: Job Satisfaction Index (JSI), Job Stress Scale (JSS), and Turnover Intention Inventory Scale (TIIS). Data were analyzed using descriptive and inferential statistical tools. Nurses' ages were found to significantly influence their turnover intentions. Job satisfaction (β=-0.47, p=0.001) and job stress (β=0.23, p=0.001) strongly predicted turnover intentions in the nurses. The mean values for the job satisfaction scale, job stress scale, and turnover intention inventory scale were 3.13 (SD=0.60), 2.74 (SD=0.71), and 2.43 (SD=0.67) respectively. Several predictors of turnover intentions were determined in this study through nurses' age, job satisfaction, and job stress as being the most influential factors. Efforts to increase nurses' job satisfaction and reduce job stress should be implemented to halt further loss of these skilled groups of healthcare professionals. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Stable isotopic constraints on global soil organic carbon turnover

    Science.gov (United States)

    Wang, Chao; Houlton, Benjamin Z.; Liu, Dongwei; Hou, Jianfeng; Cheng, Weixin; Bai, Edith

    2018-02-01

    Carbon dioxide release during soil organic carbon (SOC) turnover is a pivotal component of atmospheric CO2 concentrations and global climate change. However, reliably measuring SOC turnover rates on large spatial and temporal scales remains challenging. Here we use a natural carbon isotope approach, defined as beta (β), which was quantified from the δ13C of vegetation and soil reported in the literature (176 separate soil profiles), to examine large-scale controls of climate, soil physical properties and nutrients over patterns of SOC turnover across terrestrial biomes worldwide. We report a significant relationship between β and calculated soil C turnover rates (k), which were estimated by dividing soil heterotrophic respiration rates by SOC pools. ln( - β) exhibits a significant linear relationship with mean annual temperature, but a more complex polynomial relationship with mean annual precipitation, implying strong-feedbacks of SOC turnover to climate changes. Soil nitrogen (N) and clay content correlate strongly and positively with ln( - β), revealing the additional influence of nutrients and physical soil properties on SOC decomposition rates. Furthermore, a strong (R2 = 0.76; p global models of soil C turnover and thereby improving predictions of multiple global change influences over terrestrial C-climate feedback.

  4. Pengaruh Leadership Capability Terhadap Turnover Intention Melalui Job Satisfaction Di PT. Rajawali Nusindo

    OpenAIRE

    Kevin, Brillian

    2017-01-01

    Employee turnover mengarah pada Kenyataan akhir yang dihadapi Perusahaan (kehilangan sejumlah karyawan) pada periode tertentu, sedangkan keinginan pindah kerja (turnover intentions) sendiri mengacu kepada hasil evaluasi individu mengenai kelanjutan hubungannya dengan sebuah Perusahaan yang belum diwujudkan dalam tindakan nyata meninggalkan Perusahaan tersebut.Bagi PT Rajawali Nusindo, turnover intention juga menjadi salah satu masalah yang dihadapi oleh Perusahaan dikarenakan turnover yang te...

  5. Characterization of pediatric microtia cartilage: a reservoir of chondrocytes for auricular reconstruction using tissue engineering strategies.

    Science.gov (United States)

    Melgarejo-Ramírez, Y; Sánchez-Sánchez, R; García-López, J; Brena-Molina, A M; Gutiérrez-Gómez, C; Ibarra, C; Velasquillo, C

    2016-09-01

    The external ear is composed of elastic cartilage. Microtia is a congenital malformation of the external ear that involves a small reduction in size or a complete absence. The aim of tissue engineering is to regenerate tissues and organs clinically implantable based on the utilization of cells and biomaterials. Remnants from microtia represent a source of cells for auricular reconstruction using tissue engineering. To examine the macromolecular architecture of microtia cartilage and behavior of chondrocytes, in order to enrich the knowledge of this type of cartilage as a cell reservoir. Auricular cartilage remnants were obtained from pediatric patients with microtia undergoing reconstructive procedures. Extracellular matrix composition was characterized using immunofluorescence and histological staining methods. Chondrocytes were isolated and expanded in vitro using a mechanical-enzymatic protocol. Chondrocyte phenotype was analyzed using qualitative PCR. Microtia cartilage preserves structural organization similar to healthy elastic cartilage. Extracellular matrix is composed of typical cartilage proteins such as type II collagen, elastin and proteoglycans. Chondrocytes displayed morphological features similar to chondrocytes derived from healthy cartilage, expressing SOX9, COL2 and ELN, thus preserving chondral phenotype. Cell viability was 94.6 % during in vitro expansion. Elastic cartilage from microtia has similar characteristics, both architectural and biochemical to healthy cartilage. We confirmed the suitability of microtia remnant as a reservoir of chondrocytes with potential to be expanded in vitro, maintaining phenotypical features and viability. Microtia remnants are an accessible source of autologous cells for auricular reconstruction using tissue engineering strategies.

  6. Co-culture systems-based strategies for articular cartilage tissue engineering.

    Science.gov (United States)

    Zhang, Yu; Guo, Weimin; Wang, Mingjie; Hao, Chunxiang; Lu, Liang; Gao, Shuang; Zhang, Xueliang; Li, Xu; Chen, Mingxue; Li, Penghao; Jiang, Peng; Lu, Shibi; Liu, Shuyun; Guo, Quanyi

    2018-03-01

    Cartilage engineering facilitates repair and regeneration of damaged cartilage using engineered tissue that restores the functional properties of the impaired joint. The seed cells used most frequently in tissue engineering, are chondrocytes and mesenchymal stem cells. Seed cells activity plays a key role in the regeneration of functional cartilage tissue. However, seed cells undergo undesirable changes after in vitro processing procedures, such as degeneration of cartilage cells and induced hypertrophy of mesenchymal stem cells, which hinder cartilage tissue engineering. Compared to monoculture, which does not mimic the in vivo cellular environment, co-culture technology provides a more realistic microenvironment in terms of various physical, chemical, and biological factors. Co-culture technology is used in cartilage tissue engineering to overcome obstacles related to the degeneration of seed cells, and shows promise for cartilage regeneration and repair. In this review, we focus first on existing co-culture systems for cartilage tissue engineering and related fields, and discuss the conditions and mechanisms thereof. This is followed by methods for optimizing seed cell co-culture conditions to generate functional neo-cartilage tissue, which will lead to a new era in cartilage tissue engineering. © 2017 Wiley Periodicals, Inc.

  7. Quantification of collagen distributions in rat hyaline and fibro cartilages based on second harmonic generation imaging

    Science.gov (United States)

    Zhu, Xiaoqin; Liao, Chenxi; Wang, Zhenyu; Zhuo, Shuangmu; Liu, Wenge; Chen, Jianxin

    2016-10-01

    Hyaline cartilage is a semitransparent tissue composed of proteoglycan and thicker type II collagen fibers, while fibro cartilage large bundles of type I collagen besides other territorial matrix and chondrocytes. It is reported that the meniscus (fibro cartilage) has a greater capacity to regenerate and close a wound compared to articular cartilage (hyaline cartilage). And fibro cartilage often replaces the type II collagen-rich hyaline following trauma, leading to scar tissue that is composed of rigid type I collagen. The visualization and quantification of the collagen fibrillar meshwork is important for understanding the role of fibril reorganization during the healing process and how different types of cartilage contribute to wound closure. In this study, second harmonic generation (SHG) microscope was applied to image the articular and meniscus cartilage, and textural analysis were developed to quantify the collagen distribution. High-resolution images were achieved based on the SHG signal from collagen within fresh specimens, and detailed observations of tissue morphology and microstructural distribution were obtained without shrinkage or distortion. Textural analysis of SHG images was performed to confirm that collagen in fibrocartilage showed significantly coarser compared to collagen in hyaline cartilage (p wound repair following cartilage injury.

  8. Osteoprotegerin deficiency leads to deformation of the articular cartilage in femoral head.

    Science.gov (United States)

    Liu, Yi; Ge, Jianping; Chen, Danying; Weng, Yuteng; Du, Haiming; Sun, Yao; Zhang, Qi

    2016-10-01

    Osteoarthritis (OA) was a degenerative joint disease characterized by articular cartilage degradation and extensive remodeling of the subchondral bone. Multiple lines of evidence indicated that Osteoprotegerin (OPG), a member of TNF receptor superfamily that was expressed in the chondrocytes of articular cartilage and adjacent locations in the physiological setting, was involved in maintaining integrity of articular cartilage. OPG could prevent subchondral bone from resorption, and also protect cartilage from degradation. In this study, we used Osteoprotegerin-knockout mice (Opg-KO mice) to find out the role of OPG in articular cartilage. We examined articular cartilage in the femoral head of Opg-KO mice began in early adulthood using modern molecular and imaging methods. We found cartilage changes starting from adulthood and progressively with age, reminiscent of pathological changes in OA. Deficiency of OPG caused thinned articular cartilage and extensive remodeling of the subchondral bone in femoral head in comparison with wild-type mice (WT mice). Also, the articular cartilage of femoral head expressed significantly less of Aggrecan, Col-II and Col-X, but more Col-I and Matrix Metalloproteinases-13 (Mmp-13) than WT mice both at gene and protein level. Moreover, increased chondrocyte apoptosis and decreased chondrocyte proliferation were observed in femoral head of Opg-KO mice compared to WT mice. These data suggested that OPG played an important role in maintaining the homeostasis of articular cartilage of femoral head.

  9. Mechanical testing of hydrogels in cartilage tissue engineering: beyond the compressive modulus.

    Science.gov (United States)

    Xiao, Yinghua; Friis, Elizabeth A; Gehrke, Stevin H; Detamore, Michael S

    2013-10-01

    Injuries to articular cartilage result in significant pain to patients and high medical costs. Unfortunately, cartilage repair strategies have been notoriously unreliable and/or complex. Biomaterial-based tissue-engineering strategies offer great promise, including the use of hydrogels to regenerate articular cartilage. Mechanical integrity is arguably the most important functional outcome of engineered cartilage, although mechanical testing of hydrogel-based constructs to date has focused primarily on deformation rather than failure properties. In addition to deformation testing, as the field of cartilage tissue engineering matures, this community will benefit from the addition of mechanical failure testing to outcome analyses, given the crucial clinical importance of the success of engineered constructs. However, there is a tremendous disparity in the methods used to evaluate mechanical failure of hydrogels and articular cartilage. In an effort to bridge the gap in mechanical testing methods of articular cartilage and hydrogels in cartilage regeneration, this review classifies the different toughness measurements for each. The urgency for identifying the common ground between these two disparate fields is high, as mechanical failure is ready to stand alongside stiffness as a functional design requirement. In comparing toughness measurement methods between hydrogels and cartilage, we recommend that the best option for evaluating mechanical failure of hydrogel-based constructs for cartilage tissue engineering may be tensile testing based on the single edge notch test, in part because specimen preparation is more straightforward and a related American Society for Testing and Materials (ASTM) standard can be adopted in a fracture mechanics context.

  10. The Effects of Smoking on Ultrasonographic Thickness and Elastosonographic Strain Ratio Measurements of Distal Femoral Cartilage

    Directory of Open Access Journals (Sweden)

    Harun R. Gungor

    2016-04-01

    Full Text Available Although adverse effects of smoking on bone health are all well known, data on how smoking interacts with cartilage structure in otherwise healthy individuals remains conflicting. Here, we ascertain the effects of cigarette smoking on sonoelastographic properties of distal femoral cartilage in asymptomatic adults. Demographic characteristics and smoking habits (packets/year of healthy volunteers were recorded. Medial, intercondylar, and lateral distal femoral cartilage thicknesses and strain ratios on the dominant extremity were measured with ultrasonography (US and real time US elastography. A total of 88 subjects (71 M, 17 F; aged 18–56 years, N = 43 smokers and N = 45 nonsmokers were evaluated. Mean amount of cigarette smoking was 10.3 ± 8.9 (1–45 packets/year. Medial, intercondylar and lateral cartilage were thicker in smokers than nonsmokers (p = 0.002, p = 0.017, and p = 0.004, respectively. Medial distal femoral cartilage strain ratio was lower in smokers (p = 0.003. The amount of smoking was positively correlated with cartilage thicknesses and negatively correlated with medial cartilage strain ratios (p < 0.05. Femoral cartilage is thicker in smokers but has less strain ratio representing harder cartilage on the medial side. Future studies are needed to understand how these structural changes in the knee cartilage should be interpreted with regard to the development of knee osteoarthritis in smokers.

  11. Strain ratio measurement of femoral cartilage by real-time elastosonography: preliminary results

    International Nuclear Information System (INIS)

    Ipek, Ali; Unal, Ozlem; Kartal, Merve Gulbiz; Arslan, Halil; Isik, Cetin; Bozkurt, Murat

    2015-01-01

    The purpose of this study was to evaluate strain ratio measurement of femoral cartilage using real-time elastosonography. Twenty-five patients with femoral cartilage pathology on MRI (study group) were prospectively compared with 25 subjects with normal findings on MRI (control group) using real-time elastosonography. Strain ratio measurements of pathologic and normal cartilage were performed and compared, both within the study group and between the two groups. Elastosonography colour-scale coding showed a colour change from blue to red in pathologic cartilage and only blue colour-coding in normal cartilage. In the study group, the median strain ratio was higher in pathologic cartilage areas compared to normal areas (median, 1.49 [interquartile range, 0.80-2.53] vs. median, 0.01 [interquartile range, 0.01-0.01], p < 0.001, respectively). The median strain ratio of the control group was 0.01 (interquartile range, 0.01-0.01), and there was no significant difference compared to normal areas of the study group. There was, however, a significant difference between the control group cartilage and pathologic cartilage of the study group (p < 0.001). Elastosonography may be an effective, easily accessible, and relatively simple tool to demonstrate pathologic cartilage and to differentiate it from normal cartilage in the absence of advanced imaging facility such as MRI. (orig.)

  12. Strain ratio measurement of femoral cartilage by real-time elastosonography: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Ipek, Ali; Unal, Ozlem; Kartal, Merve Gulbiz; Arslan, Halil [Yildirim Beyazit University, Department of Radiology, Faculty of Medicine, Ataturk Training and Research Hospital, Ankara (Turkey); Isik, Cetin; Bozkurt, Murat [Yildirim Beyazit University, Department of Orthopedics, Faculty of Medicine, Ataturk Training and Research Hospital, Ankara (Turkey)

    2015-04-01

    The purpose of this study was to evaluate strain ratio measurement of femoral cartilage using real-time elastosonography. Twenty-five patients with femoral cartilage pathology on MRI (study group) were prospectively compared with 25 subjects with normal findings on MRI (control group) using real-time elastosonography. Strain ratio measurements of pathologic and normal cartilage were performed and compared, both within the study group and between the two groups. Elastosonography colour-scale coding showed a colour change from blue to red in pathologic cartilage and only blue colour-coding in normal cartilage. In the study group, the median strain ratio was higher in pathologic cartilage areas compared to normal areas (median, 1.49 [interquartile range, 0.80-2.53] vs. median, 0.01 [interquartile range, 0.01-0.01], p < 0.001, respectively). The median strain ratio of the control group was 0.01 (interquartile range, 0.01-0.01), and there was no significant difference compared to normal areas of the study group. There was, however, a significant difference between the control group cartilage and pathologic cartilage of the study group (p < 0.001). Elastosonography may be an effective, easily accessible, and relatively simple tool to demonstrate pathologic cartilage and to differentiate it from normal cartilage in the absence of advanced imaging facility such as MRI. (orig.)

  13. Multiparametric MRI of Epiphyseal Cartilage Necrosis (Osteochondrosis with Histological Validation in a Goat Model.

    Directory of Open Access Journals (Sweden)

    Luning Wang

    Full Text Available To evaluate multiple MRI parameters in a surgical model of osteochondrosis (OC in goats.Focal ischemic lesions of two different sizes were induced in the epiphyseal cartilage of the medial femoral condyles of goats at 4 days of age by surgical transection of cartilage canal blood vessels. Goats were euthanized and specimens harvested 3, 4, 5, 6, 9 and 10 weeks post-op. Ex vivo MRI scans were conducted at 9.4 Tesla for mapping the T1, T2, T1ρ, adiabatic T1ρ and TRAFF relaxation times of articular cartilage, unaffected epiphyseal cartilage, and epiphyseal cartilage within the area of the induced lesion. After MRI scans, safranin O staining was conducted to validate areas of ischemic necrosis induced in the medial femoral condyles of six goats, and to allow comparison of MRI findings with the semi-quantitative proteoglycan assessment in corresponding safranin O-stained histological sections.All relaxation time constants differentiated normal epiphyseal cartilage from lesions of ischemic cartilage necrosis, and the histological staining results confirmed the proteoglycan (PG loss in the areas of ischemia. In the scanned specimens, all of the measured relaxation time constants were higher in the articular than in the normal epiphyseal cartilage, consistently allowing differentiation between these two tissues.Multiparametric MRI provided a sensitive approach to discriminate between necrotic and viable epiphyseal cartilage and between articular and epiphyseal cartilage, which may be useful for diagnosing and monitoring OC lesions and, potentially, for assessing effectiveness of treatment interventions.

  14. Autofluorescence lifetime metrology for label-free detection of cartilage matrix degradation

    Science.gov (United States)

    Nickdel, Mohammad B.; Lagarto, João. L.; Kelly, Douglas J.; Manning, Hugh B.; Yamamoto, Kazuhiro; Talbot, Clifford B.; Dunsby, Christopher; French, Paul; Itoh, Yoshifumi

    2014-03-01

    Degradation of articular cartilage extracellular matrix (ECM) by proteolytic enzyme is the hallmark of arthritis that leads to joint destruction. Detection of early biochemical changes in cartilage before irreversible structural damages become apparent is highly desirable. Here we report that the autofluorescence decay profile of cartilage is significantly affected by proteolytic degradation of cartilage ECM and can be characterised by measurements of the autofluorescence lifetime (AFL). A multidimensional fluorometer utilizing ultraviolet excitation at 355 nm or 375 nm coupled to a fibreoptic probe was developed for single point time-resolved AFL measurements of porcine articular cartilage explants treated with different proteinases. Degradation of cartilage matrix components by treating with bacterial collagenase, matrix metalloproteinase 1, or trypsin resulted in significant reduction of AFL of the cartilage in both a dose and time dependent manner. Differences in cartilage AFL were also confirmed by fluorescence lifetime imaging microscopy (FLIM). Our data suggest that AFL of cartilage tissue is a potential non-invasive readout to monitor cartilage matrix integrity that may be utilized for diagnosis of arthritis as well as monitoring the efficacy of anti-arthritic therapeutic agents.

  15. The Potential for Synovium-derived Stem Cells in Cartilage Repair.

    Science.gov (United States)

    Kubosch, Eva Johanna; Lang, Gernot; Furst, David; Kubosch, David; Izadpanah, Kaywan; Rolauffs, Bernd; Sudkamp, Norbert P; Schmal, Hagen

    2018-02-23

    Articular cartilage defects often result in pain, loss of function and finally osteoarthritis. Developing cell-based therapies for cartilage repair is a major goal of orthopaedic research. Autologous chondrocyte implantation is currently the gold standard cell-based surgical procedure for the treatment of large, isolated, full thickness cartilage defects. Several disadvantages such as the need for two surgical procedures or hypertrophic regenerative cartilage, underline the need for alternative cell sources. Mesenchymal stem cells, particularly synovium-derived mesenchymal stem cells, represent a promising cell source. Synovium-derived mesenchymal stem cells have attracted considerable attention since they display great chondrogenic potential and less hypertrophic differentiation than mesenchymal stem cells derived from bone marrow. The aim of this review was to summarize the current knowledge on the chondrogenic potential for synovial stem cells in regard to cartilage repair purposes. A literature search was carried out identifying 260 articles in the databases up to January 2017. Several in vitro and initial animal in vivo studies of cartilage repair using synovia stem cell application showed encouraging results. Since synvoium-derived stem cells are located in the direct vicinity of cartilage and cartilage lesions these cells might even contribute to natural cartilage regeneration. The only one published human in vivo study with 10 patients revealed good results concerning postoperative outcome, MRI, and histologic features after a two-stage implantation of synovial stem cells into an isolated cartilage defect of the femoral condyle. Synovium-derived stem cells possess great chondrogenic potential and showed encouraging results for cartilage repair purposes. Furthermore, synovial stem cells play an important role in joint homeostasis and possibly in natural cartilage repair. Further studies are needed to elucidate the interplay of synovial stem cells and

  16. Automatic atlas-based three-label cartilage segmentation from MR knee images.

    Science.gov (United States)

    Shan, Liang; Zach, Christopher; Charles, Cecil; Niethammer, Marc

    2014-10-01

    Osteoarthritis (OA) is the most common form of joint disease and often characterized by cartilage changes. Accurate quantitative methods are needed to rapidly screen large image databases to assess changes in cartilage morphology. We therefore propose a new automatic atlas-based cartilage segmentation method for future automatic OA studies. Atlas-based segmentation methods have been demonstrated to be robust and accurate in brain imaging and therefore also hold high promise to allow for reliable and high-quality segmentations of cartilage. Nevertheless, atlas-based methods have not been well explored for cartilage segmentation. A particular challenge is the thinness of cartilage, its relatively small volume in comparison to surrounding tissue and the difficulty to locate cartilage interfaces - for example the interface between femoral and tibial cartilage. This paper focuses on the segmentation of femoral and tibial cartilage, proposing a multi-atlas segmentation strategy with non-local patch-based label fusion which can robustly identify candidate regions of cartilage. This method is combined with a novel three-label segmentation method which guarantees the spatial separation of femoral and tibial cartilage, and ensures spatial regularity while preserving the thin cartilage shape through anisotropic regularization. Our segmentation energy is convex and therefore guarantees globally optimal solutions. We perform an extensive validation of the proposed method on 706 images of the Pfizer Longitudinal Study. Our validation includes comparisons of different atlas segmentation strategies, different local classifiers, and different types of regularizers. To compare to other cartilage segmentation approaches we validate based on the 50 images of the SKI10 dataset. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Automatic atlas-based three-label cartilage segmentation from MR knee images

    Science.gov (United States)

    Shan, Liang; Zach, Christopher; Charles, Cecil; Niethammer, Marc

    2016-01-01

    Osteoarthritis (OA) is the most common form of joint disease and often characterized by cartilage changes. Accurate quantitative methods are needed to rapidly screen large image databases to assess changes in cartilage morphology. We therefore propose a new automatic atlas-based cartilage segmentation method for future automatic OA studies. Atlas-based segmentation methods have been demonstrated to be robust and accurate in brain imaging and therefore also hold high promise to allow for reliable and high-quality segmentations of cartilage. Nevertheless, atlas-based methods have not been well explored for cartilage segmentation. A particular challenge is the thinness of cartilage, its relatively small volume in comparison to surrounding tissue and the difficulty to locate cartilage interfaces – for example the interface between femoral and tibial cartilage. This paper focuses on the segmentation of femoral and tibial cartilage, proposing a multi-atlas segmentation strategy with non-local patch-based label fusion which can robustly identify candidate regions of cartilage. This method is combined with a novel three-label segmentation method which guarantees the spatial separation of femoral and tibial cartilage, and ensures spatial regularity while preserving the thin cartilage shape through anisotropic regularization. Our segmentation energy is convex and therefore guarantees globally optimal solutions. We perform an extensive validation of the proposed method on 706 images of the Pfizer Longitudinal Study. Our validation includes comparisons of different atlas segmentation strategies, different local classifiers, and different types of regularizers. To compare to other cartilage segmentation approaches we validate based on the 50 images of the SKI10 dataset. PMID:25128683

  18. Influence of polydioxanone foil on growing septal cartilage after surgery in an animal model: new aspects of cartilage healing and regeneration (preliminary results)

    NARCIS (Netherlands)

    Boenisch, Miriam; Tamás, Hajas; Nolst Trenité, Gilbert J.

    2003-01-01

    To determine whether late complications after septoplasty in growing septal cartilage in children can be prevented by the use of a resorbable polydioxanone (PDS) foil in combination with the cartilage. Animal study with 45 young rabbits, operated on at the nasal septum. Four typical septoplasty

  19. Co-Expression and Co-Localization of Cartilage Glycoproteins CHI3L1 and Lubricin in Osteoarthritic Cartilage: Morphological, Immunohistochemical and Gene Expression Profiles.

    Science.gov (United States)

    Szychlinska, Marta Anna; Trovato, Francesca Maria; Di Rosa, Michelino; Malaguarnera, Lucia; Puzzo, Lidia; Leonardi, Rosy; Castrogiovanni, Paola; Musumeci, Giuseppe

    2016-03-11

    Osteoarthritis is the most common human arthritis characterized by degeneration of articular cartilage. Several studies reported that levels of human cartilage glycoprotein chitinase 3-like-1 (CHI3L1) are known as a potential marker for the activation of chondrocytes and the progression of Osteoarthritis (OA), whereas lubricin appears to be chondroprotective. The aim of this study was to investigate the co-expression and co-localization of CHI3L1 and lubricin in normal and osteoarthritic rat articular cartilage to correlate their modified expression to a specific grade of OA. Samples of normal and osteoarthritic rat articular cartilage were analyzed by the Kellgren-Lawrence OA severity scores, the Kraus' modified Mankin score and the Histopathology Osteoarthritis Research Society International (OARSI) system for histomorphometric evaluations, and through CHI3L1 and lubricin gene expression, immunohistochemistry and double immuno-staining analysis. The immunoexpression and the mRNA levels of lubricin increased in normal cartilage and decreased in OA cartilage (normal vs. OA, p < 0.01). By contrast, the immunoexpression and the mRNA levels of CHI3L1 increased in OA cartilage and decreased in normal cartilage (normal vs. OA, p < 0.01). Our findings are consistent with reports suggesting that these two glycoproteins are functionally associated with the development of OA and in particular with grade 2/3 of OA, suggesting that in the future they could be helpful to stage the severity and progression of the disease.

  20. Co-Expression and Co-Localization of Cartilage Glycoproteins CHI3L1 and Lubricin in Osteoarthritic Cartilage: Morphological, Immunohistochemical and Gene Expression Profiles

    Directory of Open Access Journals (Sweden)

    Marta Anna Szychlinska

    2016-03-01

    Full Text Available Osteoarthritis is the most common human arthritis characterized by degeneration of articular cartilage. Several studies reported that levels of human cartilage glycoprotein chitinase 3-like-1 (CHI3L1 are known as a potential marker for the activation of chondrocytes and the progression of Osteoarthritis (OA, whereas lubricin appears to be chondroprotective. The aim of this study was to investigate the co-expression and co-localization of CHI3L1 and lubricin in normal and osteoarthritic rat articular cartilage to correlate their modified expression to a specific grade of OA. Samples of normal and osteoarthritic rat articular cartilage were analyzed by the Kellgren–Lawrence OA severity scores, the Kraus’ modified Mankin score and the Histopathology Osteoarthritis Research Society International (OARSI system for histomorphometric evaluations, and through CHI3L1 and lubricin gene expression, immunohistochemistry and double immuno-staining analysis. The immunoexpression and the mRNA levels of lubricin increased in normal cartilage and decreased in OA cartilage (normal vs. OA, p < 0.01. By contrast, the immunoexpression and the mRNA levels of CHI3L1 increased in OA cartilage and decreased in normal cartilage (normal vs. OA, p < 0.01. Our findings are consistent with reports suggesting that these two glycoproteins are functionally associated with the development of OA and in particular with grade 2/3 of OA, suggesting that in the future they could be helpful to stage the severity and progression of the disease.

  1. Using Job Embeddedness Factors to Explain Voluntary Turnover in Five European Countries

    OpenAIRE

    Tanova, Cem

    2006-01-01

    This paper investigates actual voluntary turnover from the employee's perspective using a large European dataset integrating the available job factors related to job embeddedness and other variables that have been related to turnover in previous turnover models. The study shows that the traditional turnover model, where ease of movement and desire of movement are regarded as important predictors of turnover, receives support. However, the study also shows the job embeddedness factors play a k...

  2. Effects of γ irradiation on cartilage matrix calcification

    International Nuclear Information System (INIS)

    Nijweide, P.J.; Burger, E.H.; van Delft, J.L.; Kawilarange-de Haas, E.W.M.; Wassenaar, A.M.; Mellink, J.H.

    1980-01-01

    The effect of γ irradiation on cartilage matrix calcification was studied in vitro. Metatarsal bones of 14- to 17-day-old embryonic mice were dissected and cultured under various conditions. Prior to culture, half of the metatarsal bones received absorbed doses of 1.0 to 30.0 Gy γ radiation. Their paired counterparts served as controls. Irradiation inhibited longitudinal growth and calcification of the cartilage matrix during culture. In addition, a number of histological changes were noted. The inhibition of matrix calcification appeared to be due to an inhibition of the intracellular calcium accumulation. The formation of extracellular calcification foci and the growth of the calcified area already present at the moment of explanation were not inhibited during culture

  3. Piezoelectric smart biomaterials for bone and cartilage tissue engineering.

    Science.gov (United States)

    Jacob, Jaicy; More, Namdev; Kalia, Kiran; Kapusetti, Govinda

    2018-01-01

    Tissues like bone and cartilage are remodeled dynamically for their functional requirements by signaling pathways. The signals are controlled by the cells and extracellular matrix and transmitted through an electrical and chemical synapse. Scaffold-based tissue engineering therapies largely disturb the natural signaling pathways, due to their rigidity towards signal conduction, despite their therapeutic advantages. Thus, there is a high need of smart biomaterials, which can conveniently generate and transfer the bioelectric signals analogous to native tissues for appropriate physiological functions. Piezoelectric materials can generate electrical signals in response to the applied stress. Furthermore, they can stimulate the signaling pathways and thereby enhance the tissue regeneration at the impaired site. The piezoelectric scaffolds can act as sensitive mechanoelectrical transduction systems. Hence, it is applicable to the regions, where mechanical loads are predominant. The present review is mainly concentrated on the mechanism related to the electrical stimulation in a biological system and the different piezoelectric materials suitable for bone and cartilage tissue engineering.

  4. Uptake of 35S sulphate by Xenopus cartilage

    International Nuclear Information System (INIS)

    Ishii, Takehisa; Kikuyama, Sakae

    1984-01-01

    Hypohysectomized juvenile Xenopus were injected with growth hormone (GH) or prolactin (PRL) of either ovine or bullfrog origin and the growthpromoting activity of these hormones was measured by monitoring the uptake of 35 S sulphate by the xiphisternal cartilage in vitro. Analysis of the labelled cartilage revealed that the acid mucopolysaccharide fraction contained about 60 - 80 % of the label and that most of them were incorporated into chondroitin sulphates. All of the hormones tested enhaced the 35 S sulphate uptake dose-dependently. Among them bullfrog GH was most effective, then followed ovine GH and ovine PRL. Bullfrog PRL was far less effective than other three. The sensitive assay for frog GH developed in the present experiment may be applicable to the assay for somatomedin-like activity and contribute to the analysis of the mode of action of GH in amphibians. (author)

  5. Gene therapy for cartilage and bone tissue engineering

    CERN Document Server

    Hu, Yu-Chen

    2014-01-01

    "Gene Therapy for Cartilage and Bone Tissue Engineering" outlines the tissue engineering and possible applications of gene therapy in the field of biomedical engineering as well as basic principles of gene therapy, vectors and gene delivery, specifically for cartilage and bone engineering. It is intended for tissue engineers, cell therapists, regenerative medicine scientists and engineers, gene therapist and virologists. Dr. Yu-Chen Hu is a Distinguished Professor at the Department of Chemical Engineering, National Tsing Hua University and has received the Outstanding Research Award (National Science Council), Asia Research Award (Society of Chemical Engineers, Japan) and Professor Tsai-Teh Lai Award (Taiwan Institute of Chemical Engineers). He is also a fellow of the American Institute for Medical and Biological Engineering (AIMBE) and a member of the Tissue Engineering International & Regenerative Medicine Society (TERMIS)-Asia Pacific Council.

  6. Radiological, computertomographic, pathoanatomical and histological examination of the rib cartilage of the dog

    International Nuclear Information System (INIS)

    Lorber, B.

    2000-06-01

    This study was concerned with the representation and description of the rib cartilage of the dog and the abnormalities of such by means of radiological, computer tomographic, pathoanatomical and histological examinations and the comparison of the results of the various examination methods. The study material consisted of 100 ventral thorax walls of dogs of different ages and breeds. In 39 of the subjects, no abnormalities of rib cartilage other than unremarkable calcification were observed. Among the subjects, there were 11 puppies (0-3 months), whose rib cartilage appeared soft tissue dense due to the absence of calcification, 14 juvenile animals (4-18 months), the rib cartilage of which showed a typical finely granulated structure, and 14 adult dogs (over 18 months), whose rib cartilage exhibited a homogeneous to net-like calcified appearance. In the calcified rib cartilage, the histological section showed a centrally located spongiosa rod surrounded by a hyaline cartilage shell. The calcification tendency of the first pair of rib cartilage was remarkable: in 70 dogs, the first pair of rib cartilage remained uncalcified despite calcification of the other rib cartilage. Sixty-one dogs exhibited rib cartilage abnormalities. According to the radiological appearance of the abnormalities, they were divided into groups and their incidence was calculated. Abnormalities seen included interruption in the continuity of the calcified rib cartilage with and without callus formation, enlargement of rib cartilage, cuff formation, and abnormalities on the Articulationes sternocostales (projections in or around articulations, calcified and fractured joint surfaces). In addition, remarkable calcification patterns were observed. By means of CT examination the densities of the tissue forming the various abnormalities was determined. In the course of the pathoanatomical examination, it was shown that the interruptions in continuity with callus and the various enlarged areas of the

  7. Bone turnover marker reference intervals in young females.

    Science.gov (United States)

    Callegari, Emma T; Gorelik, Alexandra; Garland, Suzanne M; Chiang, Cherie Y; Wark, John D

    2017-07-01

    Background The use of bone turnover markers in clinical practice and research in younger people is limited by the lack of normative data and understanding of common causes of variation in bone turnover marker values in this demographic. To appropriately interpret bone turnover markers, robust reference intervals specific to age, development and sex are necessary. This study aimed to determine reference intervals of bone turnover markers in females aged 16-25 years participating in the Safe-D study. Methods Participants were recruited through social networking site Facebook and were asked to complete an extensive, online questionnaire and attend a site visit. Participants were tested for serum carboxy-terminal cross-linking telopeptide of type 1 collagen and total procollagen type 1 N-propeptide using the Roche Elecsys automated analyser. Reference intervals were determined using the 2.5th to 97.5th percentiles of normalized bone turnover marker values. Results Of 406 participants, 149 were excluded due to medical conditions or medication use (except hormonal contraception) which may affect bone metabolism. In the remaining 257 participants, the reference interval was 230-1000 ng/L for serum carboxy-terminal cross-linking telopeptide of type 1 collagen and 27-131  µg/L for procollagen type 1 N-propeptide. Both marker concentrations were inversely correlated with age and oral contraceptive pill use. Therefore, intervals specific to these variables were calculated. Conclusions We defined robust reference intervals for cross-linking telopeptide of type 1 collagen and procollagen type 1 N-propeptide in young females grouped by age and contraceptive pill use. We examined bone turnover markers' relationship with several lifestyle, clinical and demographic factors. Our normative intervals should aid interpretation of bone turnover markers in young females particularly in those aged 16 to 19 years where reference intervals are currently provisional.

  8. A homeostatic function of CXCR2 signalling in articular cartilage.

    Science.gov (United States)

    Sherwood, Joanna; Bertrand, Jessica; Nalesso, Giovanna; Poulet, Blandine; Pitsillides, Andrew; Brandolini, Laura; Karystinou, Alexandra; De Bari, Cosimo; Luyten, Frank P; Pitzalis, Costantino; Pap, Thomas; Dell'Accio, Francesco

    2015-12-01

    ELR+ CXC chemokines are heparin-binding cytokines signalling through the CXCR1 and CXCR2 receptors. ELR+ CXC chemokines have been associated with inflammatory arthritis due to their capacity to attract inflammatory cells. Here, we describe an unsuspected physiological function of these molecules in articular cartilage homeostasis. Chemokine receptors and ligands were detected by immunohistochemistry, western blotting and RT-PCR. Osteoarthritis was induced in wild-type and CXCR2(-/-) mice by destabilisation of the medial meniscus (DMM). CXCR1/2 signalling was inhibited in vitro using blocking antibodies or siRNA. Chondrocyte phenotype was analysed using Alcian blue staining, RT-PCR and western blotting. AKT phosphorylation and SOX9 expression were upregulated using constitutively active AKT or SOX9 plasmids. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. CXCL6 was expressed in healthy cartilage and was retained through binding to heparan sulfate proteoglycans. CXCR2(-/-) mice developed more severe osteoarthritis than wild types following DMM, with increased chondrocyte apoptosis. Disruption of CXCR1/2 in human and CXCR2 signalling in mouse chondrocytes led to a decrease in extracellular matrix production, reduced expression of chondrocyte differentiation markers and increased chondrocyte apoptosis. CXCR2-dependent chondrocyte homeostasis was mediated by AKT signalling since forced expression of constitutively active AKT rescued the expression of phenotypic markers and the apoptosis induced by CXCR2 blockade. Our study demonstrates an important physiological role for CXCR1/2 signalling in maintaining cartilage homeostasis and suggests that the loss of ELR+ CXC chemokines during cartilage breakdown in osteoarthritis contributes to the characteristic loss of chondrocyte phenotypic stability. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go

  9. Applied osmotic loading for promoting development of engineered cartilage

    OpenAIRE

    Sampat, Sonal R.; Dermksian, Matthew V.; Oungoulian, Sevan R.; Winchester, Robert J.; Bulinski, J. Chloë; Ateshian, Gerard A.; Hung, Clark T.

    2013-01-01

    This study investigated the potential use of static osmotic loading as a cartilage tissue engineering strategy for growing clinically relevant grafts from either synovium-derived stem cells (SDSCs) or chondrocytes. Bovine SDSCs and chondrocytes were individually encapsulated in 2% w/v agarose and divided into chondrogenic media of osmolarities 300 (hypotonic), 330 (isotonic), and 400 (hypertonic, physiologic) mOsM for up to 7 weeks. The application of hypertonic media to constructs comprised ...

  10. Articular Cartilage Repair Through Muscle Cell-Based Tissue Engineering

    Science.gov (United States)

    2011-03-01

    TaqMan probe AAC-CCT-CTT- TTC -GGA-TTA-ACC-CTG-CGA- GTT. Articular cartilage defect model and cell transplanta- tion. All animal experiments were... inhalation mask. The knee joint was exposed by medial parapa- tellar incision, and the trochlear groove was exposed by lateral dislocation of the...least significant difference test. P values less than 0.05 were considered significant. RESULTS In vitro MDSC characterization. Flow cytometric analysis

  11. Chondrocalcinosis of the hyaline cartilage of the knee: MRI manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, J.; Marty-Delfaut, E.; Bencardino, J.; Rosenberg, Z.S. [Department of Radiology, Hospital for Joint Diseases, New York, NY (United States); Steiner, G. [Department of Pathology, Hospital for Joint Diseases, New York, NY (United States); Aparisi, F. [Department of Radiology, Residencia Sanitaria ``La Fe``, Valencia (Spain); Padron, M. [Clinica San Camilo, Madrid (Spain)

    1998-07-01

    Purpose. To determine the ability of MRI to detect the presence of crystals of calcium pyrophosphate in the articular cartilage of the knee. Design and patients. The MR studies of 12 knees (11 cases) were reviewed retrospectively and correlated with radiographs (12 cases) and the findings at arthroscopy (2 cases) and surgery (1 case). A total of 72 articular surfaces were evaluated. Radiographic, surgical or arthroscopic demonstration of chondrocalcinosis was used as the gold standard. Additionally, two fragments of the knee of a patient who underwent total knee replacement and demonstrated extensive chondrocalcinosis were studied with radiography and MRI using spin-echo T1-, T2- and proton-density-weighted images as well as two- and three-dimensional fat saturation (2D and 3D Fat Sat) gradient recalled echo (GRE) and STIR sequences. Results. MRI revealed multiple hypointense foci within the articular cartilage in 34 articular surfaces, better shown on 2D and 3D GRE sequences. Radiographs showed 12 articular surfaces with chondrocalcinosis. In three cases with arthroscopic or surgical correlation, MRI demonstrated more diffuse involvement of the articular cartilage than did the radiographs. The 3D Fat Sat GRE sequences were the best for demonstrating articular calcification in vitro. In no case was meniscal calcification identified with MRI. Hyperintense halos around some of the calcifications were seen on the MR images. Conclusion. MRI can depict articular cartilage calcification as hypointense foci using GRE techniques. Differential diagnosis includes loose bodies, post-surgical changes, marginal osteophytes and hemosiderin deposition. (orig.) With 4 figs., 14 refs.

  12. Human sclera maintains common characteristics with cartilage throughout evolution.

    Directory of Open Access Journals (Sweden)

    Yuko Seko

    Full Text Available BACKGROUND: The sclera maintains and protects the eye ball, which receives visual inputs. Although the sclera does not contribute significantly to visual perception, scleral diseases such as refractory scleritis, scleral perforation and pathological myopia are considered incurable or difficult to cure. The aim of this study is to identify characteristics of the human sclera as one of the connective tissues derived from the neural crest and mesoderm. METHODOLOGY/PRINCIPAL FINDINGS: We have demonstrated microarray data of cultured human infant scleral cells. Hierarchical clustering was performed to group scleral cells and other mesenchymal cells into subcategories. Hierarchical clustering analysis showed similarity between scleral cells and auricular cartilage-derived cells. Cultured micromasses of scleral cells exposed to TGF-betas and BMP2 produced an abundant matrix. The expression of cartilage-associated genes, such as Indian hedge hog, type X collagen, and MMP13, was up-regulated within 3 weeks in vitro. These results suggest that human 'sclera'-derived cells can be considered chondrocytes when cultured ex vivo. CONCLUSIONS/SIGNIFICANCE: Our present study shows a chondrogenic potential of human sclera. Interestingly, the sclera of certain vertebrates, such as birds and fish, is composed of hyaline cartilage. Although the human sclera is not a cartilaginous tissue, the human sclera maintains chondrogenic potential throughout evolution. In addition, our findings directly explain an enigma that the sclera and the joint cartilage are common targets of inflammatory cells in rheumatic arthritis. The present global gene expression database will contribute to the clarification of the pathogenesis of developmental diseases such as high myopia.

  13. Centralization of extruded medial meniscus delays cartilage degeneration in rats.

    Science.gov (United States)

    Ozeki, Nobutake; Muneta, Takeshi; Kawabata, Kenichi; Koga, Hideyuki; Nakagawa, Yusuke; Saito, Ryusuke; Udo, Mio; Yanagisawa, Katsuaki; Ohara, Toshiyuki; Mochizuki, Tomoyuki; Tsuji, Kunikazu; Saito, Tomoyuki; Sekiya, Ichiro

    2017-05-01

    Meniscus extrusion often observed in knee osteoarthritis has a strong correlation with the progression of cartilage degeneration and symptom in the patients. We recently reported a novel procedure "arthroscopic centralization" in which the capsule was sutured to the edge of the tibial plateau to reduce meniscus extrusion in the human knee. However, there is no animal model to study the efficacy of this procedure. The purposes of this study were [1] to establish a model of centralization for the extruded medial meniscus in a rat model; and [2] to investigate the chondroprotective effect of this procedure. Medial meniscus extrusion was induced by the release of the anterior synovial capsule and the transection of the meniscotibial ligament. Centralization was performed by the pulled-out suture technique. Alternatively, control rats had only the medial meniscus extrusion surgery. Medial meniscus extrusion was evaluated by micro-CT and macroscopic findings. Cartilage degeneration of the medial tibial plateau was evaluated macroscopically and histologically. By micro-CT analysis, the medial meniscus extrusion was significantly improved in the centralization group in comparison to the extrusion group throughout the study. Both macroscopically and histologically, the cartilage lesion of the medial tibial plateau was prevented in the centralization group but was apparent in the control group. We developed medial meniscus extrusion in a rat model, and centralization of the extruded medial meniscus by the pull-out suture technique improved the medial meniscus extrusion and delayed cartilage degeneration, though the effect was limited. Centralization is a promising treatment to prevent the progression of osteoarthritis. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Applications of Chondrocyte-Based Cartilage Engineering: An Overview

    Directory of Open Access Journals (Sweden)

    Abdul-Rehman Phull

    2016-01-01

    Full Text Available Chondrocytes are the exclusive cells residing in cartilage and maintain the functionality of cartilage tissue. Series of biocomponents such as different growth factors, cytokines, and transcriptional factors regulate the mesenchymal stem cells (MSCs differentiation to chondrocytes. The number of chondrocytes and dedifferentiation are the key limitations in subsequent clinical application of the chondrocytes. Different culture methods are being developed to overcome such issues. Using tissue engineering and cell based approaches, chondrocytes offer prominent therapeutic option specifically in orthopedics for cartilage repair and to treat ailments such as tracheal defects, facial reconstruction, and urinary incontinence. Matrix-assisted autologous chondrocyte transplantation/implantation is an improved version of traditional autologous chondrocyte transplantation (ACT method. An increasing number of studies show the clinical significance of this technique for the chondral lesions treatment. Literature survey was carried out to address clinical and functional findings by using various ACT procedures. The current study was conducted to study the pharmacological significance and biomedical application of chondrocytes. Furthermore, it is inferred from the present study that long term follow-up studies are required to evaluate the potential of these methods and specific positive outcomes.

  15. Hyaluronan in experimental injured/inflamed cartilage: In vivo studies.

    Science.gov (United States)

    Avenoso, Angela; D'Ascola, Angela; Scuruchi, Michele; Mandraffino, Giuseppe; Calatroni, Alberto; Saitta, Antonino; Campo, Salvatore; Campo, Giuseppe M

    2018-01-15

    Joint disease is characterized by an imbalance between the synthesis and degradation of articular cartilage and subchondral bone accompanied by capsular fibrosis, osteophyte formation and varying degrees of inflammation of the synovial membrane. Many animal models have been developed to study arthritis and osteoarthritis that enable experimental conditions, diet and environmental risk factors to be carefully controlled. Animal-based studies have demonstrated the positive effects of exogenous HA on the preservation of joint cartilage in different models of arthritis and osteoarthritis. Although many promising effects of exogenous HA have been reported, there remains uncertainty as to its effectiveness in reversing cartilage injury and other manifestations of joint diseases because of difficulties in interpreting and unifying the results of these studies. A review of the literature of the last decade was conducted to report the results and to determine what we have learned from animal models in relation to joint inflammation induced by experimental models and HA treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Immediate autogenous cartilage grafts in rhinoplasty after alloplastic implant rejection.

    Science.gov (United States)

    Raghavan, Ullas; Jones, Nick S; Romo, Thomas

    2004-01-01

    It is accepted in rhinoplasty that complications are more common with alloplastic implants than with autografts. There is little guidance in the literature on how to deal with the cosmetic and/or functional problems that follow alloplastic implant rejection. The conventional advice has been to remove the allograft and not place any graft at the same time. The present article presents our experience treating allograft rejection and immediately repairing any structural defect with autografts. To demonstrate that immediate nasal reconstruction using autogenous cartilage is a good technique when an alloplastic material has to be removed because of rejection, inflammation, or infection. A retrospective analysis of outcome for a case series. A retrospective review of the management of 8 patients who presented to 2 tertiary referral centers with alloplastic implant rejection following rhinoplasty. In 7 cases, the alloplastic implant had to be removed because it had migrated and caused a foreign body reaction; in 1 case, the implant had caused a bacterial infection. In all 8 cases, the nasal deformity that followed the removal of the allograft was so marked that the nose was immediately reconstructed with autogenous cartilage. The patients all made a good recovery after immediate reconstruction, although skin changes associated with the alloplastic implant remained after a mean follow-up of 3 years 3 months. The use of autogenous cartilage is a good option for nasal augmentation immediately after the removal of an alloplastic implant.

  17. Insights from amphioxus into the evolution of vertebrate cartilage.

    Directory of Open Access Journals (Sweden)

    Daniel Meulemans

    2007-08-01

    Full Text Available Central to the story of vertebrate evolution is the origin of the vertebrate head, a problem difficult to approach using paleontology and comparative morphology due to a lack of unambiguous intermediate forms. Embryologically, much of the vertebrate head is derived from two ectodermal tissues, the neural crest and cranial placodes. Recent work in protochordates suggests the first chordates possessed migratory neural tube cells with some features of neural crest cells. However, it is unclear how and when these cells acquired the ability to form cellular cartilage, a cell type unique to vertebrates. It has been variously proposed that the neural crest acquired chondrogenic ability by recruiting proto-chondrogenic gene programs deployed in the neural tube, pharynx, and notochord. To test these hypotheses we examined the expression of 11 amphioxus orthologs of genes involved in neural crest chondrogenesis. Consistent with cellular cartilage as a vertebrate novelty, we find that no single amphioxus tissue co-expresses all or most of these genes. However, most are variously co-expressed in mesodermal derivatives. Our results suggest that neural crest-derived cartilage evolved by serial cooption of genes which functioned primitively in mesoderm.

  18. Advances in electrospun nanofibers for bone and cartilage regeneration.

    Science.gov (United States)

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Balasubramanian, Preethi; Jin, Guorui; Valipouri, Afsaneh; Ramakrishna, Seeram

    2013-07-01

    Regeneration of bone and cartilage tissues has been an important issue for biological repair in the field of regenerative medicine. The rapidly emerging field of tissue engineering holds great promise for repair and generation of functional bone and cartilage substitutes with a combination of biomaterials, cells, drugs and growth factors. Scaffolds play a pivotal role in tissue engineering as they mimic the natural extracellular matrix (ECM) and play an important role in guiding cell adhesion and proliferation, and maintaining the normal phenotype of the tissues. The use of tissue-engineered grafts based on scaffolds has found to be a more effective method than conventional implantations of autograft, allograft, xenograft. In recent years much attention has been given to electrospinning as a feasible and versatile technique for fabrication of nanofibrous scaffolds, with large surface area to volume ratio, high porosity, mechanical properties and physical dimension similar to the ECM of natural tissues. Extensive research has been carried out for fabrication polymeric nanofibrous substrates with incorporation of hydroxyapatite nanoparticles or bone morphogenetic protein molecules for efficient tissue repair. Here we review on the literature of electrospun nanofibrous scaffolds, their modifications, and advances aimed towards the rapid regeneration of bone and cartilage.

  19. Hydrogels for Cartilage Regeneration, from Polysaccharides to Hybrids

    Directory of Open Access Journals (Sweden)

    Daniela Anahí Sánchez-Téllez

    2017-12-01

    Full Text Available The aims of this paper are: (1 to review the current state of the art in the field of cartilage substitution and regeneration; (2 to examine the patented biomaterials being used in preclinical and clinical stages; (3 to explore the potential of polymeric hydrogels for these applications and the reasons that hinder their clinical success. The studies about hydrogels used as potential biomaterials selected for this review are divided into the two major trends in tissue engineering: (1 the use of cell-free biomaterials; and (2 the use of cell seeded biomaterials. Preparation techniques and resulting hydrogel properties are also reviewed. More recent proposals, based on the combination of different polymers and the hybridization process to improve the properties of these materials, are also reviewed. The combination of elements such as scaffolds (cellular solids, matrices (hydrogel-based, growth factors and mechanical stimuli is needed to optimize properties of the required materials in order to facilitate tissue formation, cartilage regeneration and final clinical application. Polymer combinations and hybrids are the most promising materials for this application. Hybrid scaffolds may maximize cell growth and local tissue integration by forming cartilage-like tissue with biomimetic features.

  20. Chondrogenesis and cartilage tissue engineering: the longer road to technology development.

    Science.gov (United States)

    Mahmoudifar, Nastaran; Doran, Pauline M

    2012-03-01

    Joint injury and disease are painful and debilitating conditions affecting a substantial proportion of the population. The idea that damaged cartilage in articulating joints might be replaced seamlessly with tissue-engineered cartilage is of obvious commercial interest because the market for such treatments is large. Recently, a wealth of new information about the complex biology of chondrogenesis and cartilage has emerged from stem cell research, including increasing evidence of the role of physical stimuli in directing differentiation. The challenge for the next generation of tissue engineers is to identify the key elements in this new body of knowledge that can be applied to overcome current limitations affecting cartilage synthesis in vitro. Here we review the status of cartilage tissue engineering and examine the contribution of stem cell research to technology development for cartilage production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Laser-induced micropore formation and modification of cartilage structure in osteoarthritis healing

    Energy Technology Data Exchange (ETDEWEB)

    Sobol, Emil [Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, RussiabFederal Scientific Research Centre “Crystallography and Photonics” of the Russian Academy of Sciences, Institute of Photonic Technologies, Moscow, Russia; Baum, Olga [Federal Scientific Research Centre “Crystallography and Photonics” of the Russian Academy of Sciences, Institute of Photonic Technologies, Moscow, Russia; Shekhter, Anatoly [Sechenov First Medical University of Moscow, Institute of Regenerative Medicine, Moscow, Russia; Wachsmann-Hogiu, Sebastian [University of California, Center for Biophotonics, Department of Pathology and Laboratory Medicine, Sacramento, California, United StateseMcGill University, Department of Bioengineering, Montreal, Canada; Shnirelman, Alexander [Concordia University, Department of Mathematics and Statistics, Montreal, Canada; Alexandrovskaya, Yulia [Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, RussiabFederal Scientific Research Centre “Crystallography and Photonics” of the Russian Academy of Sciences, Institute of Photonic Technologies, Moscow, Russia; Sadovskyy, Ivan [Argonne National Laboratory, Materials Science Division, Argonne, Illinois, United States; Vinokur, Valerii [Argonne National Laboratory, Materials Science Division, Argonne, Illinois, United States

    2017-05-31

    Pores are vital for functioning of avascular tissues. Laser-induced pores play an important role in the process of cartilage regeneration. The aim of any treatment for osteoarthritis is to repair hyaline-type cartilage. The aims of this study are to answer two questions: (1) How do laser-assisted pores affect the cartilaginous cells to synthesize hyaline cartilage (HC)? and (2) How can the size distribution of pores arising in the course of laser radiation be controlled? We have shown that in cartilage, the pores arise predominately near chondrocytes, which promote nutrition of cells and signal molecular transfer that activates regeneration of cartilage. In vivo laser treatment of damaged cartilage of miniature pig joints provides cellular transformation and formation of HC. We propose a simple model of pore formation in biopolymers that paves the way for going beyond the trial-anderror approach when choosing an optimal laser treatment regime. Our findings support the approach toward laser healing of osteoarthritis.

  2. The architecture of cartilage: Elemental maps and scanning transmission ion microscopy/tomography

    International Nuclear Information System (INIS)

    Reinert, Tilo; Reibetanz, Uta; Schwertner, Michael; Vogt, Juergen; Butz, Tilman; Sakellariou, Arthur

    2002-01-01

    Articular cartilage is not just a jelly-like cover of the bone within the joints but a highly sophisticated architecture of hydrated macromolecules, collagen fibrils and cartilage cells. Influences on the physiological balance due to age-related or pathological changes can lead to malfunction and subsequently to degradation of the cartilage. Many activities in cartilage research are dealing with the architecture of joint cartilage but have limited access to elemental distributions. Nuclear microscopy is able to yield spatially resolved elemental concentrations, provides density information and can visualise the arrangement of the collagen fibres. The distribution of the cartilage matrix can be deduced from the elemental and density maps. The findings showed a varying content of collagen and proteoglycan between zones of different cell maturation. Zones of higher collagen content are characterised by aligned collagen fibres that can form tubular structures. Recently we focused on STIM tomography to investigate the three dimensional arrangement of the collagen structures

  3. Mechanical properties of the normal human cartilage-bone complex in relation to age

    DEFF Research Database (Denmark)

    Ding, Ming; Dalstra, M; Linde, F

    1998-01-01

    OBJECTIVE: This study investigates the age-related variations in the mechanical properties of the normal human tibial cartilage-bone complex and the relationships between cartilage and bone. DESIGN: A novel technique was applied to assess the mechanical properties of the cartilage and bone by mea...... that are of importance for the understanding of the etiology and pathogenesis of degenerative joint diseases, such as arthrosis....

  4. Relationship of chondrocyte apoptosis to matrix degradation and swelling potential of osteoarthritic cartilage.

    Science.gov (United States)

    Chen, Min-Huey; Wang, Jue-Long; Wong, Chi-Yin; Yao, Chung-Chen; Chen, Yi-Jane; Jiang, Ching-Chuan

    2005-04-01

    Softening of cartilage is the initial degenerative step of osteoarthritic cartilage by matrix degradation and corruption of interconnection of the collagen fibrillar network. The purpose of this study was to investigate the correlation of chondrocyte apoptosis, matrix degradation, and the corruption of collagen architecture in the development of severe swelling of osteoarthritic cartilage. Twenty osteoarthritic and 7 normal femoral neck fractured cartilage samples were obtained from patients with knee osteoarthritis and normal patients with femoral neck fracture at the time of total hip joint replacement surgery. Apoptosis was verified by TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end-labeling) staining and structural changes were observed under phase-contrast microscopy. Matrix degradation was evaluated by histochemical analysis of proteoglycans. Swelling tests were performed by immersing the cartilage slices in hypotonic solution. The results of ultrastructural study of collagen architecture of osteoarthritic cartilage performed by scanning electron microscopy before and after swelling were compared. Matrix degradation was most prominent in the middle zone of osteoarthritic cartilage. The percentage of chondrocytes in osteoarthritic cartilage showing apoptosis ranged from 15 to 20% (average, 18%; standard deviation (SD) = 3.2%) and was correlated with the extent of structural changes and matrix degradation. The swelling strain of the osteoarthritic cartilage varied from 120 to 200% (average, 160%; SD = 40%) depending on the degree of matrix degradation and structural changes. The loss of interconnectivity of collagen fibrillar architecture was correlated with the increased swelling potential of osteoarthritic cartilage. This study demonstrated that chondrocyte apoptosis was correlated with matrix degradation and the corruption of fibrillar architecture and that the extent of these manifestations correlated with the

  5. Cartilage status in FAI patients - results from the Danish Hip Arthroscopy Registry (DHAR)

    DEFF Research Database (Denmark)

    Lund, Bent; Nielsen, Torsten Grønbech; Lind, Martin

    2017-01-01

    on the acetabular side. Overall PROM including pain scores improved significantly from preoperative status to follow-up one and two years postoperatively. The Copenhagen Hip and Groin Outcome Score (HAGOS), Hip Sports Activity Scale (HSAS) and global hip function showed less improvements in patients with more...... of patients have cartilage debridement performed but rarely cartilage repair. The presence of severe cartilage injury at the time of arthroscopic FAI surgery results in reduced subjective outcome and hip function....

  6. Human adenosine deaminase: properties and turnover in cultured T and B lymphoblasts

    International Nuclear Information System (INIS)

    Daddona, P.E.

    1981-01-01

    In this study, the properties and rate of turnover of adenosine deaminase are compared in cultured human T and B lymphoblast cell lines. 1) Relative to B lymphoblasts, the level of adenosine deaminase activity in extracts of T lymphoblast cell lines (MOLT-4, RPMI-8402, CCRF-CEM, and CCRF-HSB-2) is elevated 7-14-fold and differs by 2-fold between the C cell lines. 2) In both T and B lymphoblast extracts, the enzyme is apparently identical, based on K/sub m/ for adenosine and deoxyadenosine, K/sub i/ for inosine, V/sub max/ for adenosine, /sub S20,w/, isoelectric pH, and heat stability. Furthermore, by radioimmunoassay, the quantity of adenosine deaminase-immunocreative protein is proportional to the level of enzyme activity in all cell lines studies. 3) Using a purification and selective immunoprecipitation technique, the enzyme turnover could be assessed in cell lines labeled with [ 35 S]methionine. The apparent rate of adenosine deaminase synthesis, relative to total protein, is 2-fold faster in both T cell lines (RPMI-8402 and CCRF-CEM) than in the B cell lines (MGL-8 and GM-130). The apparent half-life (tsub1/2) for the enzyme degradation is 19 and 39 h, respectively, in CCFR-CEM and RPMI-8402, while the tsub1/2 in both B cell lines is 7-9 h. From the net rate of synthesis and degradation, the T cell lines, respectively, exhibit approximately a 6- and 12-fold difference in adenosine deaminase turnover relative to B cells, consistent with the observed differences in enzyme activity. This study suggests that while adenosine deaminase is apparently identical in both T and B lymphoblast cell lines, alterations in both the rate of enzyme synthesis and degradation contribute to its high steady state level in T cells

  7. Developing human capital: what is the impact on nurse turnover?

    Science.gov (United States)

    Rondeau, Kent V; Williams, Eric S; Wagar, Terry H

    2009-09-01

    To investigate the impact that increasing human capital through staff training makes on the voluntary turnover of registered nurses. Healthcare organizations in Canada, the United Kingdom, the United States, and Australia are experiencing turbulent nursing labour markets characterized by extreme staff shortages and high levels of turnover. Organizations that invest in the development of their nursing human resources may be able to mitigate high turnover through the creation of conditions that more effectively develop and utilize their existing human capital. A questionnaire was sent to the chief nursing officers of 2208 hospitals and long-term care facilities in every province and territory of Canada yielding a response rate of 32.3%. The analysis featured a three-step hierarchical regression with two sets of control variables. After controlling for establishment demographics and local labour market conditions, perceptions of nursing human capital and the level of staff training provided were modestly associated with lower levels of establishment turnover. and implications for Nursing Management The results suggest that healthcare organizations that have made greater investments in their nursing human capital are more likely to demonstrate lower levels of turnover of their registered nursing personnel.

  8. Investigation on the turnover of plant proteins. 2

    International Nuclear Information System (INIS)

    Becker, R.; Winkler, E.; Jung, K.; Huebner, G.

    1981-01-01

    Based on kinetic analyses of amino acid and protein turnover by means of compartment models the synthesis and degradation of the soluble proteins in etiolated epicotyl segments of Pisum sativum L. as well as their dependence on the herbicide 2'-methyl-4'-chlorophenoxyacetic acid (MCPA) were determined quantitatively. The segments were incubated for 10 h in a medium containing 14 C-leucine and subsequently placed in an inactive medium. The radioactivity in the soluble proteins and in the amino acid fraction was followed up for a total of 24 h. A 3-pool model in which the total measurable amino acid pool was divided into a direct precursor pool for protein synthesis and into a degradation pool was best suited to interpret the data. The turnover rate for the soluble proteins of untreated epicotyl segments was determined to be 0.058 h -1 ; at an MCPA concentration of 10 -4 M this value was nearly doubled. An increased proteolytic activity in the epicotyl segments ran parallel to the change of the turnover rate in dependence on MCPA concentration. The heterogeneity of the soluble protein with respect to the turnover rate was investigated by means of 3 H/ 14 C double labelling for individual protein fractions separated by gel electrophoresis. The results obtained in this way were comparable with those of the total pool turnover. (author)

  9. Hepatic metallothionein turnover in toxic milk mutant mice

    International Nuclear Information System (INIS)

    Rauch, H.; Wells, A.J.

    1989-01-01

    Homozygous toxic milk (tx tx) mice are characterized by extraordinary hepatic copper levels, the excess copper being associated with metallothionein (MT). We have compared MT metabolism in normal and mutant animals. To evaluate MT turnover, animals were injected with 35 S-cysteine, followed in 24 hours by a cold cysteine chase. Animals were sacrificed daily and radioactivity in hepatic MT fractions was used to calculated MT half-life. Based on uptake of label, MT synthesis is very active in tx mice, this MT having a half life of 4-5 days. MT synthesis in normals is much lower, one fourth or less radioactivity. To increase MT synthesis, normals were primed by prior zinc (150 μg) or copper (90 μg) injection; MT label was doubled, the resulting MT showing a slow turnover rate, half-life about 6 days. Another group of normals were primed as above but with metal injections repeated daily so as to measure turnover under conditions of continuous high level MT synthesis, comparable to those prevailing in mutant animals. Although initial label uptake was the same as that of previously primed animals, turnover was hastened, half-life 2-3 days. Thus, copper accumulation in mutants is attributable at least in part to increased rate of synthesis coupled with decreased rate of turnover of MT

  10. Move over! Stock turnover, retrofit and industrial energy efficiency

    International Nuclear Information System (INIS)

    Worrell, Ernst; Biermans, Gijs

    2005-01-01

    We demonstrate the importance of stock turnover on industrial energy efficiency through a literature review and a case study of energy-intensive equipment, i.e. the electric arc furnace in the US steel industry. We describe the common methods for assessing stock turnover. We have found that both stock turnover and retrofit are important elements to explain the energy efficiency improvement rates. We investigated the development of electricity use in electric arc furnaces in the United States by tracking the development of individual furnaces over the period 1990-2002. This provides a detailed picture of changes in the stock or fleet of furnaces through turnover and/or retrofit. Our results confirm the results of other empirical studies that there is no clear lifetime of equipment. However, retired furnaces are distinctly less efficient than furnaces remaining in the stock, while new furnaces are distinctly more efficient than the average stock. We found an annual average improvement in specific electricity consumption of 1.3%/year over the studied period, of which 0.7%/year was due to stock turnover and 0.5%/year due to retrofit of stock in service throughout the period

  11. Turnover of recently assimilated carbon in arctic bryophytes.

    Science.gov (United States)

    Street, L E; Subke, J A; Sommerkorn, M; Heinemeyer, A; Williams, M

    2011-10-01

    Carbon (C) allocation and turnover in arctic bryophytes is largely unknown, but their response to climatic change has potentially significant impacts on arctic ecosystem C budgets. Using a combination of pulse-chase experiments and a newly developed model of C turnover in bryophytes, we show significant differences in C turnover between two contrasting arctic moss species (Polytrichum piliferum and Sphagnum fuscum). (13)C abundance in moss tissues (measured up to 1 year) and respired CO(2) (traced over 5 days) were used to parameterise the bryophyte C model with four pools representing labile and structural C in photosynthetic and stem tissue. The model was optimised using an Ensemble Kalman Filter to ensure a focus on estimating the confidence intervals (CI) on model parameters and outputs. The ratio of aboveground NPP:GPP in Polytrichum piliferum was 23% (CI 9-35%), with an average turnover time of 1.7 days (CI 1.1-2.5 days). The aboveground NPP:GPP ratio in Sphagnum fuscum was 43% (CI 19-65%) with an average turnover time of 3.1 days (CI 1.6-6.1 days). These results are the first to show differences in C partitioning between arctic bryophyte species in situ and highlight the importance of modelling C dynamics of this group separately from vascular plants for a realistic representation of vegetation in arctic C models.

  12. [A model on turnover intention of chief nurse officers].

    Science.gov (United States)

    Park, Kwang-Ok; Kim, Jong Kyung; Kim, Se Young; Chang, Sunju

    2012-02-01

    The purpose of this study was to test the turnover intention model for chief nurse officers in general hospitals. The variables for the study included job stress, social support, job satisfaction, and organization commitment. A predictive, non-experimental design was used with a sample of 144 chief nurse officers from 144 general hospitals. Data were collected using self-administered questionnaires and analyzed using SPSS, AMOS program. The overall fitness of the hypothetical model to the data was good (χ²=16.80, p=.052, GFI=.96, AGFI=.90, NFI=.97, CFI=.99). Job stress, social support, job satisfaction, and organization commitment explained 59.0% of the variance in turnover intention by chief nurse officers. Both organization commitment and social support directly influenced turnover intention for chief nurse officers, and job stress and job satisfaction indirectly influenced turnover intention. The results imply that chief nurse officers in hospitals need social support and management of job stress to increase job satisfaction and organization commitment, and lower turnover intention.

  13. Investigating the adequacy of the Competence-Turnover Intention Model: how does nursing competence affect nurses' turnover intention?

    Science.gov (United States)

    Takase, Miyuki; Teraoka, Sachiko; Kousuke, Yabase

    2015-03-01

    The aim of this study was to test the adequacy of the Competence-Turnover Intention Model, which was developed to identify how nursing competence could affect nurses' turnover intention (nurses' intention to voluntarily leave an organisation). Recent studies have suggested that the level of nursing competence is negatively related to nurses' intention to leave their jobs, suggesting that a lack of competence threatens both the quality and quantity of the nursing workforce. However, the mechanism of how nursing competence affects nurses' turnover intention has not been explored previously. A cross-sectional survey design was used. Surveys were distributed to 1337 Japanese registered nurses/midwives in October, 2013. The adequacy of the model was analysed using structural equation modelling. In total, 766 questionnaires were returned, with a return rate of 57%. The model fitted well with the data. The results showed that the level of nursing competence was related positively to the quantity of organisational rewards they felt they had received, and negatively related to the level of exhaustion they experienced. Moreover, the perceived organisational rewards and exhaustion were correlated with nurses' turnover intention through affective commitment. The Competence-Turnover Intention Model is useful for explaining how nursing competence impacts on their turnover intention. Clinical implications derived from the findings are that: promoting nursing competence is key to improving not only the quality of care provided by nurses, but also to retaining the nursing workforce, and the model can be used to develop strategies that would mitigate their turnover intention. © 2014 John Wiley & Sons Ltd.

  14. Repair of Cartilage injuries using in vitro engineered 3D cartilage tissue- Preliminary Results of Our Animal Studies.

    Science.gov (United States)

    Arumugam, S; Manjunath, S; Senthilkumar, R; Rajendiran, S; Yoshioka, H; Mori, Y; Abraham, S

    2011-01-01

    The cartilage injuries demand novel therapeutic approaches as the success rates of the current conventional strategies for the repair of injured articular cartilages are not that encouraging. Earlier we have reported that the Thermoreversible Gelation Polymer (TGP) is an ideal scaffold for human chondrocyte expansion in vitro. In this study, we report the preliminary results of the in vitro expansion, characterization and experimental in vivo transplantation of chondrocytes in a rabbit model of cartilage injury. Nine rabbits were included in this study scheduled for two years, after approval by the ethics committee. In the first animal, Chondrocytes were isolated from the weight bearing area of patellar groove in the left hindlimb and cultured in TGP Scaffold and maintained at 37°C in 5% carbon dioxide incubator for 64 days without growth factors. Then the TGP-Chondrocyte construct was transplanted into an experimental defect created in the knee of the right forelimb of the same rabbit. After a period of 10 weeks, a biopsy was taken from the transplanted region and subjected to morphological analysis, characterization by histopathology (H&E stain) and Immunohistochemistry (S-100 staining). The chondrocytes in the 3D TGP culture had round to oval shaped morphology without any de-differentiation which is otherwise observed in Conventional 2D cultures. A macroscopic structure which resembled cartilage was appreciated in the TGP construct in vitro after 64 days which was then transplanted to the rabbit. The H&E and Immunohistochemistry studies confirmed the presence of chondrocytes in the biopsy tissue. Based on the results, we conclude that the TGP significantly supports the in vitro expansion of chondrocytes for a longer period and the 3D culture using TGP preserves the phenotype of the articular chondrocytes. The tissue thus grown when implanted with the TGP has engrafted well without any adverse reactions and upon confirmation of safety following completion of the

  15. Cartilage oligomeric matrix protein (COMP) in rheumatoid arthritis and its correlation with sonographic knee cartilage thickness and disease activity.

    Science.gov (United States)

    Sakthiswary, Rajalingham; Rajalingam, Shamala; Hussein, Heselynn; Sridharan, Radhika; Asrul, Abdul Wahab

    2017-12-01

    The aim of the study is to investigate the correlation of serum cartilage oligomeric matrix protein (COMP) levels with articular cartilage damage based on sonographic knee cartilage thickness (KCT) and disease activity in rheumatoid arthritis (RA). A total of 61 RA patients and 27 healthy controls were recruited in this study. Serum samples were obtained from all subjects to determine the serum COMP levels. All subjects had bilateral ultrasound scan of their knees. The KCT was based on the mean of measurements at three sites: the medial condyle, lateral condyle and intercondylar notch. Besides, the RA patients were assessed for their disease activity based on 28-joint-based Disease Activity Score (DAS 28). Serum COMP concentrations were significantly elevated in the RA patients compared to the controls (p = 0.001). The serum COMP levels had an inverse relationship with bilateral KCT in RA subjects and the healthy controls. COMP correlated significantly with disease activity based on DAS 28 (r = 0.299, p = 0.010), disease duration (r = 0.439, p = correlation between serum COMP and DAS 28 scores was comparable to the traditional markers of inflammation: erythrocyte sedimentation rate (ESR) (r = 0.372, p = 0.003) and C-reactive protein (CRP) (r = 0.305, p = 0.017). The serum COMP is a promising biomarker in RA which reflects disease activity and damage to the articular cartilage.

  16. Semi-automated International Cartilage Repair Society scoring of equine articular cartilage lesions in optical coherence tomography images.

    Science.gov (United States)

    Te Moller, N C R; Pitkänen, M; Sarin, J K; Väänänen, S; Liukkonen, J; Afara, I O; Puhakka, P H; Brommer, H; Niemelä, T; Tulamo, R-M; Argüelles Capilla, D; Töyräs, J

    2017-07-01

    Arthroscopic optical coherence tomography (OCT) is a promising tool for the detailed evaluation of articular cartilage injuries. However, OCT-based articular cartilage scoring still relies on the operator's visual estimation. To test the hypothesis that semi-automated International Cartilage Repair Society (ICRS) scoring of chondral lesions seen in OCT images could enhance intra- and interobserver agreement of scoring and its accuracy. Validation study using equine cadaver tissue. Osteochondral samples (n = 99) were prepared from 18 equine metacarpophalangeal joints and imaged using OCT. Custom-made software was developed for semi-automated ICRS scoring of cartilage lesions on OCT images. Scoring was performed visually and semi-automatically by five observers, and levels of inter- and intraobserver agreement were calculated. Subsequently, OCT-based scores were compared with ICRS scores based on light microscopy images of the histological sections of matching locations (n = 82). When semi-automated scoring of the OCT images was performed by multiple observers, mean levels of intraobserver and interobserver agreement were higher than those achieved with visual OCT scoring (83% vs. 77% and 74% vs. 33%, respectively). Histology-based scores from matching regions of interest agreed better with visual OCT-based scoring than with semi-automated OCT scoring; however, the accuracy of the software was improved by optimising the threshold combinations used to determine the ICRS score. Images were obtained from cadavers. Semi-automated scoring software improved the reproducibility of ICRS scoring of chondral lesions in OCT images and made scoring less observer-dependent. The image analysis and segmentation techniques adopted in this study warrant further optimisation to achieve better accuracy with semi-automated ICRS scoring. In addition, studies on in vivo applications are required. © 2016 EVJ Ltd.

  17. 3D Human cartilage surface characterization by optical coherence tomography

    Science.gov (United States)

    Brill, Nicolai; Riedel, Jörn; Schmitt, Robert; Tingart, Markus; Truhn, Daniel; Pufe, Thomas; Jahr, Holger; Nebelung, Sven

    2015-10-01

    Early diagnosis and treatment of cartilage degeneration is of high clinical interest. Loss of surface integrity is considered one of the earliest and most reliable signs of degeneration, but cannot currently be evaluated objectively. Optical Coherence Tomography (OCT) is an arthroscopically available light-based non-destructive real-time imaging technology that allows imaging at micrometre resolutions to millimetre depths. As OCT-based surface evaluation standards remain to be defined, the present study investigated the diagnostic potential of 3D surface profile parameters in the comprehensive evaluation of cartilage degeneration. To this end, 45 cartilage samples of different degenerative grades were obtained from total knee replacements (2 males, 10 females; mean age 63.8 years), cut to standard size and imaged using a spectral-domain OCT device (Thorlabs, Germany). 3D OCT datasets of 8  ×  8, 4  ×  4 and 1  ×  1 mm (width  ×  length) were obtained and pre-processed (image adjustments, morphological filtering). Subsequent automated surface identification algorithms were used to obtain the 3D primary profiles, which were then filtered and processed using established algorithms employing ISO standards. The 3D surface profile thus obtained was used to calculate a set of 21 3D surface profile parameters, i.e. height (e.g. Sa), functional (e.g. Sk), hybrid (e.g. Sdq) and segmentation-related parameters (e.g. Spd). Samples underwent reference histological assessment according to the Degenerative Joint Disease classification. Statistical analyses included calculation of Spearman’s rho and assessment of inter-group differences using the Kruskal Wallis test. Overall, the majority of 3D surface profile parameters revealed significant degeneration-dependent differences and correlations with the exception of severe end-stage degeneration and were of distinct diagnostic value in the assessment of surface integrity. None of the 3D

  18. Chondroblastoma arising in the triradiate cartilage. Report of two cases with review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Matsuno, Takeo; Hasegawa, Isao; Masuda, Takeshi

    1987-04-01

    Chondroblastoma is a relatively rare benign bone tumor of cartilage origin. Roentgenologically it presents usually as a region of lytic destruction of bone with a thin sclerotic rim in the epiphysis of long tubular bone. Less than 9% occur in the pelvic bones but show a tendency to arise from the triradiate cartilage. We present two cases of chondroblastoma originating in the triradiate cartilage, each showing extensive lytic bony destruction and an intrapelvic soft tissue mass. A review of the literature suggests that chondroblastoma of the triradiate cartilage shows an aggressive radiological appearance.

  19. Comparison of temporalis fascia muscle and full-thickness cartilage grafts in type 1 pediatric tympanoplasties.

    Science.gov (United States)

    Yegin, Yakup; Çelik, Mustafa; Koç, Arzu Karaman; Küfeciler, Levent; Elbistanlı, Mustafa Suphi; Kayhan, Fatma Tülin

    Various graft materials have been used to close tympanic membrane perforations. In the literature, there are few studies in pediatric populations comparing different graft materials. To our knowledge, there is no reported study that measured the thickness of the tragal cartilage in pediatric tympanoplasties. The tragal cartilage is not of uniform thickness in every patient. To compare anatomical and functional outcomes of temporalis fascia muscle and full-thickness tragal cartilage in type 1 pediatric tympanoplasties. In total, 78 patients (38 males, 40 females; average age 10.02±1.98 years; range, 7-18 years) who underwent type 1 tympanoplasties in our clinic were included. Demographics, anatomical, and functional outcomes were collected. Temporalis fascia muscle and tragal cartilage were used as graft materials. Tragal cartilage was used without thinning, and the thickness of tragal cartilage was measured using a micrometer. Anatomical and functional outcomes of cartilage and fascia were compared. Audiometric results comparing the cartilage and fascia groups were conducted at 6 months, and we continued to follow the patients to 1 year after surgery. An intact graft and an air-bone gap≤20dB were regarded as a surgical success. Results with a p-valuefascia group. In the fascia group, the preoperative air-bone gap was 33.68±11.44 dB and postoperative air-bone gap was 24.25±12.68dB. In the cartilage group, the preoperative air-bone gap was 35.68±12.94dB and postoperative air-bone gap was 26.11±12.87dB. The anatomical success rate in the cartilage group was significantly better than that for the fascia group (pfascia and cartilage groups (p>0.05). The average thickness of tragal cartilage in the pediatric population was 0.693±0.094mm in males and 0.687±0.058 mm in females. Our data suggest that the anatomical success rate for a cartilage tympanoplasty was higher than for a fascia tympanoplasty. Functional results with cartilage were not different than with

  20. Application of a semi-automatic cartilage segmentation method for biomechanical modeling of the knee joint.

    Science.gov (United States)

    Liukkonen, Mimmi K; Mononen, Mika E; Tanska, Petri; Saarakkala, Simo; Nieminen, Miika T; Korhonen, Rami K

    2017-10-01

    Manual segmentation of articular cartilage from knee joint 3D magnetic resonance images (MRI) is a time consuming and laborious task. Thus, automatic methods are needed for faster and reproducible segmentations. In the present study, we developed a semi-automatic segmentation method based on radial intensity profiles to generate 3D geometries of knee joint cartilage which were then used in computational biomechanical models of the knee joint. Six healthy volunteers were imaged with a 3T MRI device and their knee cartilages were segmented both manually and semi-automatically. The values of cartilage thicknesses and volumes produced by these two methods were compared. Furthermore, the influences of possible geometrical differences on cartilage stresses and strains in the knee were evaluated with finite element modeling. The semi-automatic segmentation and 3D geometry construction of one knee joint (menisci, femoral and tibial cartilages) was approximately two times faster than with manual segmentation. Differences in cartilage thicknesses, volumes, contact pressures, stresses, and strains between segmentation methods in femoral and tibial cartilage were mostly insignificant (p > 0.05) and random, i.e. there were no systematic differences between the methods. In conclusion, the devised semi-automatic segmentation method is a quick and accurate way to determine cartilage geometries; it may become a valuable tool for biomechanical modeling applications with large patient groups.

  1. Menopause is associated with articular cartilage degeneration: a clinical study of knee joint in 860 women.

    Science.gov (United States)

    Lou, Chao; Xiang, Guangheng; Weng, Qiaoyou; Chen, Zhaojie; Chen, Deheng; Wang, Qingqing; Zhang, Di; Zhou, Bin; He, Dengwei; Chen, Hongliang

    2016-11-01

    The purpose of this study was to investigate the association between menopause and severity of knee joint cartilage degeneration using a magnetic resonance imaging-based six-level grading system, with six cartilage surfaces, the medial and lateral femoral condyle, the femoral trochlea, the medial and lateral tibia plateau, and the patella. The study cohort comprised 860 healthy women (age 36-83 y), and 5,160 cartilage surfaces were analyzed. Age, weight, height, age at natural menopause, and years since menopause (YSM) were obtained. Cartilage degeneration was assessed using a magnetic resonance imaging-based six-level grading system. After removing the age, height, and weight effects, postmenopausal women had more severe cartilage degeneration than pre- and perimenopausal women (P  0.05). No significant difference was observed in lateral tibia plateau and lateral femoral condyle in postmenopausal women. Menopause is associated with cartilage degeneration of knee joint. After menopause, cartilage showed progressive severe degeneration that occurred in the first 25 YSM, suggesting estrogen deficiency might be a risk factor of cartilage degeneration of the knee joint. Further studies are needed to investigate whether age or menopause plays a more important role in the progression of cartilage degeneration in the knee joint.

  2. Cartilage tissue engineering: From biomaterials and stem cells to osteoarthritis treatments.

    Science.gov (United States)

    Vinatier, C; Guicheux, J

    2016-06-01

    Articular cartilage is a non-vascularized and poorly cellularized connective tissue that is frequently damaged as a result of trauma and degenerative joint diseases such as osteoarthrtis. Because of the absence of vascularization, articular cartilage has low capacity for spontaneous repair. Today, and despite a large number of preclinical data, no therapy capable of restoring the healthy structure and function of damaged articular cartilage is clinically available. Tissue-engineering strategies involving the combination of cells, scaffolding biomaterials and bioactive agents have been of interest notably for the repair of damaged articular cartilage. During the last 30 years, cartilage tissue engineering has evolved from the treatment of focal lesions of articular cartilage to the development of strategies targeting the osteoarthritis process. In this review, we focus on the different aspects of tissue engineering applied to cartilage engineering. We first discuss cells, biomaterials and biological or environmental factors instrumental to the development of cartilage tissue engineering, then review the potential development of cartilage engineering strategies targeting new emerging pathogenic mechanisms of osteoarthritis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Treatment of human cartilage defects by means of Nd:YAG Laser Therapy.

    Science.gov (United States)

    Zati, A; Desando, G; Cavallo, C; Buda, R; Giannini, S; Fortuna, D; Facchini, A; Grigolo, B

    2012-01-01

    Articular cartilage lesions represent a challenging problem for orthopaedic surgeons. The purpose of this study was to evaluate the effect of a new pulsed Nd:YAG High Intensity Laser Therapy on the regeneration of cartilage tissue in patients with traumatic lesions. Clinical, histological and immunohistochemical evaluations were performed. Ten patients affected by chondral lesions scheduled for ACI procedure, were enrolled into the study. During the chondrocyte expansion for ACI procedure, cartilage from five patients was treated by Nd:YAG High Intensity Laser Therapy (HILT group). No laser treatment was performed in the remaining patients, who were used as controls. Cartilage repair was assessed by clinicians using two different scores: Cartilage Repair Assessment (CRA) and Overall Repair Assessment (ORA). Cartilage biopsy specimens were harvested to perform histological and immunohistochemical analyses at T0 (before laser treatment) and T1 (at the end of the treatment). A significant decrease in cartilage depth was noticed in the HILT group at T1. Histological and immunohistochemical evaluations showed some regenerative processes in cartilaginous tissue in terms of high amount of proteoglycans, integration with adjacent articular cartilage and good cellular arrangement in the HILT group. By contrast, a not well organized cartilaginous tissue with various fibrous features in the control group at T0 and T1 was observed. In conclusion, the use of this new pulsed Nd:YAG HILT resulted promising in the treatment of moderate cartilage lesions markedly in the young patients.

  4. Black Colouration of the Knee Articular Cartilage after Spontaneously Recurrent Haemarthrosis

    Directory of Open Access Journals (Sweden)

    Kazu Matsumoto

    2016-01-01

    Full Text Available Mild discolouration of the articular cartilage is known to gradually occur during aging. However, pathological tissue pigmentation is occasionally induced under several specific conditions. In the present case, we performed total knee replacement in a patient with recurrent haemarthrosis. However, during the operation, we observed severe black colouration of the knee articular cartilage, due to the deposition of hemosiderin and lipofuscin. To our knowledge, this is the first report of severe cartilage pigmentation, due to hemosiderin and lipofuscin deposition in articular cartilage.

  5. Development and characterization of decellularized human nasoseptal cartilage matrix for use in tissue engineering.

    Science.gov (United States)

    Graham, M Elise; Gratzer, Paul F; Bezuhly, Michael; Hong, Paul

    2016-10-01

    Reconstruction of cartilage defects in the head and neck can require harvesting of autologous cartilage grafts, which can be associated with donor site morbidity. To overcome this limitation, tissue-engineering approaches may be used to generate cartilage grafts. The objective of this study was to decellularize and characterize human nasoseptal cartilage with the aim of generating a biological scaffold for cartilage tissue engineering. Laboratory study using nasoseptal cartilage. Remnant human nasoseptal cartilage specimens were collected and subjected to a novel decellularization treatment. The decellularization process involved several cycles of enzymatic detergent treatments. For characterization, decellularized and fresh (control) specimens underwent histological, biochemical, and mechanical analyses. Scanning electron microscopy and biocompatibility assay were also performed. The decellularization process had minimal effect on glycosaminoglycan content of the cartilage extracellular matrix. Deoxyribonucleic acid (DNA) analysis revealed the near-complete removal of genomic DNA from decellularized tissues. The effectiveness of the decellularization process was also confirmed on histological and scanning electron microscopic analyses. Mechanical testing results showed that the structural integrity of the decellularized tissue was maintained, and biocompatibility was confirmed. Overall, the current decellularization treatment resulted in significant reduction of genetic/cellular material with preservation of the underlying extracellular matrix structure. This decellularized material may serve as a potential scaffold for cartilage tissue engineering. N/A. Laryngoscope, 126:2226-2231, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Smectite alteration

    International Nuclear Information System (INIS)

    Anderson, D.M.

    1984-11-01

    This report contains the proceedings of a second workshop in Washington DC December 8-9, 1983 on the alteration of smectites intended for use as buffer materials in the long-term containment of nuclear wastes. It includes extended summaries of all presentations and a transcript of the detailed scientific discussion. The discussions centered on three main questions: What is the prerequisite for and what is the precise mechanism by which smectite clays may be altered to illite. What are likly sources of potassium with respect to the KBS project. Is it likely that the conversion of smectite to illite will be of importance in the 10 5 to the 10 6 year time frame. The workshop was convened to review considerations and conclusions in connection to these questions and also to broaden the discussion to consider the use of smectite clays as buffer materials for similar applications in different geographical and geological settings. SKBF/KBS technical report 83-03 contains the proceedings from the first workshop on these matters that was held at the State University of New York, Buffalo May 26-27, 1982. (Author)

  7. Elevated CO2 alters root N uptake and C turnover in Larrea tridentata L

    Science.gov (United States)

    To examine the impact of elevated CO2 on root N uptake, soil N availability and the feedbacks between them, we quantified the effects of elevated CO2 and N additions on root N uptake and leaf C gain in Larrea tridentata seedlings grown in reconstituted Mojave Desert soils. After six months of growt...

  8. Changes of Protein Turnover in Aging Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Dhondt, Ineke; Petyuk, Vladislav A.; Bauer, Sophie; Brewer, Heather M.; Smith, Richard D.; Depuydt, Geert; Braeckman, Bart P.

    2017-07-05

    Protein turnover rates severely decline in aging organisms, including C. elegans. However, limited information is available on turnover dynamics at the individual protein level during aging. We followed changes in protein turnover at one-day resolution using a multiple-pulse 15Nlabeling and accurate mass spectrometry approach. Forty percent of the proteome shows gradual slowdown in turnover with age, whereas only few proteins show increased turnover. Decrease in protein turnover was consistent for only a minority of functionally related protein subsets, including tubulins and vitellogenins, whereas randomly diverging turnover patterns with age were the norm. Our data suggests increased heterogeneity of protein turnover of the translation machinery, whereas protein turnover of ubiquitin-proteasome and antioxidant systems are well-preserved over time. Hence, we presume that maintenance of quality control mechanisms is a protective strategy in aging worms, although the ultimate proteome collapse is inescapable.

  9. PENGARUH JOB SATISFACTION TERHADAP OCB DAN TURNOVER INTENTION

    Directory of Open Access Journals (Sweden)

    Febru Rida Ningsih

    2015-06-01

    Full Text Available This article aims to provide the impact of job satisfaction to OCB and turnover intention. This study used a quantitative method with a statistical analysis. Simple analysis regression used to test each hypotheses. The object of this research is a branch of national bank. Population in this research are entire employees of a brach of national bank that is e non frontliner employees. Non-probability sampling is used of this reseach. The measurement of job satiafaction and turnover intention variables used likert scale that developed by Rinaldi (2008 and measurement of OCB variable adopted from  Organ (1988.  The result of this research has shown that hypotheses one is rejected and hypotheses two is accepted. Eventually, through this article, an understanding that job satisfaction does not significantly influence to OCB but job satisfaction has significant influence to turnover intention.

  10. Quality of Working Life: An Antecedent to Employee Turnover Intention

    Science.gov (United States)

    Mosadeghrad, Ali Mohammad

    2013-01-01

    Background: The purpose of this study was to measure the level of quality of work life (QWL) among hospital employees in Iran. Additionally, it aimed to identify the factors that are critical to employees’ QWL. It also aimed to test a theoretical model of the relationship between employees’ QWL and their intention to leave the organization. Methods: A survey study was conducted based on a sample of 608 hospital employees using a validated questionnaire. Face, content and construct validity were conducted on the survey instrument. Results: Hospital employees reported low QWL. Employees were least satisfied with pay, benefits, job promotion, and management support. The most important predictor of QWL was management support, followed by job proud, job security and job stress. An inverse relationship was found between employees QWL and their turnover intention. Conclusion: This study empirically examined the relationships between employees’ QWL and their turnover intention. Managers can take appropriate actions to improve employees’ QWL and subsequently reduce employees’ turnover. PMID:24596835

  11. No turnover in lens lipids for the entire human lifespan.

    Science.gov (United States)

    Hughes, Jessica R; Levchenko, Vladimir A; Blanksby, Stephen J; Mitchell, Todd W; Williams, Alan; Truscott, Roger J W

    2015-03-11

    Lipids are critical to cellular function and it is generally accepted that lipid turnover is rapid and dysregulation in turnover results in disease (Dawidowicz 1987; Phillips et al., 2009; Liu et al., 2013). In this study, we present an intriguing counter-example by demonstrating that in the center of the human ocular lens, there is no lipid turnover in fiber cells during the entire human lifespan. This discovery, combined with prior demonstration of pronounced changes in the lens lipid composition over a lifetime (Hughes et al., 2012), suggests that some lipid classes break down in the body over several decades, whereas others are stable. Such substantial changes in lens cell membranes may play a role in the genesis of age-related eye disorders. Whether long-lived lipids are present in other tissues is not yet known, but this may prove to be important in understanding the development of age-related diseases.

  12. DNA turnover and strand breaks in Escherichia coli

    International Nuclear Information System (INIS)

    Hanawalt, P.; Grivell, A.; Nakayama, H.

    1975-01-01

    The extent of DNA turnover has been measured in a dnaB mutant of Escherichia coli, temperature sensitive for semiconservative DNA replication. At the nonpermissive temperature about 0.02 percent of the deoxynucleotides in DNA are exchanged per generation period. This turnover rate is markedly depressed in the presence of rifampicin. During thymine starvation strand breaks accumulate in the DNA of E. coli strains that are susceptible to thymineless death. Rifampicin suppresses the appearance of these breaks, consistent with our hypothesis that transcription may be accompanied by repairable single-strand breaks in DNA. DNA turnover is enhanced severalfold in strands containing 5-bromodeoxyuridine in place of thymidine, possibly because the analog (or the deoxyuridine, following debromination) is sometimes recognized and excised

  13. Firm-level innovation activity, employee turnover and HRM practices

    DEFF Research Database (Denmark)

    Eriksson, Tor; Qin, Zhihua; Wang, Wenjing

    2014-01-01

    ' innovation activities. Innovation is measured both by the number of ongoing projects and new commercialized products. The results show that higher R&D employee turnover is associated with a higher probability of being innovative, but decreases the intensity of innovation activities in innovating firms......This paper examines the relationship between employee turnover, HRM practices and innovation in Chinese firms in five high technology sectors. We estimate hurdle negative binomial models for count data on survey data allowing for analyses of the extensive as well as intensive margins of firms....... Innovating firms are more likely to have adopted high performance HRM practices, and the impact of employee turnover varies with the number of HRM practices implemented by the firm...

  14. Faster turnover of new soil carbon inputs under increased atmospheric CO2.

    Science.gov (United States)

    van Groenigen, Kees Jan; Osenberg, Craig W; Terrer, César; Carrillo, Yolima; Dijkstra, Feike A; Heath, James; Nie, Ming; Pendall, Elise; Phillips, Richard P; Hungate, Bruce A

    2017-10-01

    Rising levels of atmospheric CO 2 frequently stimulate plant inputs to soil, but the consequences of these changes for soil carbon (C) dynamics are poorly understood. Plant-derived inputs can accumulate in the soil and become part of the soil C pool ("new soil C"), or accelerate losses of pre-existing ("old") soil C. The dynamics of the new and old pools will likely differ and alter the long-term fate of soil C, but these separate pools, which can be distinguished through isotopic labeling, have not been considered in past syntheses. Using meta-analysis, we found that while elevated CO 2 (ranging from 550 to 800 parts per million by volume) stimulates the accumulation of new soil C in the short term (soil C pool over either temporal scale. Our results are inconsistent with predictions of conventional soil C models and suggest that elevated CO 2 might increase turnover rates of new soil C. Because increased turnover rates of new soil C limit the potential for additional soil C sequestration, the capacity of land ecosystems to slow the rise in atmospheric CO 2 concentrations may be smaller than previously assumed. © 2017 John Wiley & Sons Ltd.

  15. The microbial perspective of organic matter turnover and nutrient cycling in tropical soils

    Science.gov (United States)

    Rasche, Frank

    2017-04-01

    A primary goal of low-input small-holder farming systems in the tropics is the appropriate management of organic matter (OM) turnover and nutrient cycling via adapted agricultural practices. These emphasize the promotion of soil organic matter (SOM) turnover and carbon (C) sequestration, nutrient use efficiency and soil microbial activity. Since soil microbial communities are acknowledged as key players in the terrestrial C and nutrient (e.g., nitrogen (N), phosphorus (P)) cycles, they may respond sensitively to agricultural management with shifts in their community structure as well as functional traits (i.e., decomposition, mineralization). This may be in particular evident for tropical, agricultural soils which show an accelerated microbial decomposition activity induced by favourable climatic and unique physico-chemical soil conditions. While modern molecular techniques advanced primarily the understanding about the microbiome and their functional traits interacting closely with SOM dynamics in temperate soils, tropical soils under agricultural use have been still neglected to a great extent. Th