Giant crystals inside mitochondria of equine chondrocytes

The present study reports for the first time the presence of giant crystals in mitochondria of equine chondrocytes. These structures show dark contrast in TEM images as well as a granular substructure of regularly aligned 12 nm small units. Different zone axes of the crystalline structure were analysed by means of Fourier transformation of lattice-resolution TEM images proving the crystalline nature of the structure. Elemental analysis reveals a high content of nitrogen referring to protein. The outer shape of the crystals is geometrical with an up to hexagonal profile in cross sections. It is elongated, spanning a length of several micrometres through the whole cell. In some chondrocytes, several crystals were found, sometimes combined in a single mitochondrion. Crystals were preferentially aligned along the long axis of the cells, thus appearing in the same orientation as the chondrocytes in the tissue. Although no similar structures have been found in the cartilage of any other species investigated, they have been found in cartilage repair tissue formed within a mechanically stimulated equine chondrocyte construct. Crystals were mainly located in superficial regions of cartilage, especially in joint regions of well-developed superficial layers, more often in yearlings than in adult horses. These results indicate that intramitochondrial crystals are related to the high mechanical stress in the horse joint and potentially also to the increased metabolic activity of immature individuals.(VLID)353386

Master of Arts

thesisThis thesis examines comics' use of animal and otherwise non-normative bodies to portray queer identities and examine how the portrayal of the queer and monstrous can be seen as a reflection of the medium itself. Comics is a hybrid medium in which words and images coexist, favoring neither and flouting categorization in art or literature. Comics relishes the instability and subversive nature of its form, and has been a tool for challenging conventions of acceptable representation. Comics' refusal to accept a secure, unified definition is analogous to the object of queer theory, suggesting that comics are particularly well suited to depict queer narratives. Close readings of Diane Obomsawin's graphic narrative On Loving Women and Noelle Stevenson's webcomic Nimona serve as examples of the possibilities of reading comics through a queer lens. Both texts are examples of queer narratives that use animal, monster, and nonhuman bodies to articulate otherness. On Loving Women's anthropomorphic animals represent different lesbians as they recount short biographical sketches. This text layers narrative voice, giving the text a sense of polysemy and evoking the multiplicity of queer identity. Nimona follows the misadventures of a shapeshifting sidekick and her cyborg supervillain boss. Nimona depicts the threat posed by fluid and non-normative identities to heteronormative hegemonic institutions, ultimately demanding that the binary systems that persecute queerness be abolished. Both texts call into question the nature of identity in terms of sex, gender, and humanity. As examples of the possibilities of comics to attack exclusionary systems that place queerness as the ultimate other, these texts reveal the diverse ways in which representational space is queered. Comics repositions the body on the page, allowing for iterative acts of queering that cannot be limited to any singular form. The medium continues to develop new modes of representation that challenge and subvert normative systems

Comparison of nanoparticular hydroxyapatite pastes of different particle content and size in a novel scapula defect model

Nanocrystalline hydroxyapatite (HA) has good biocompatibility and the potential to support bone formation. It represents a promising alternative to autologous bone grafting, which is considered the current gold standard for the treatment of low weight bearing bone defects. The purpose of this study was to compare three bone substitute pastes of different HA content and particle size with autologous bone and empty defects, at two time points (6 and 12 months) in an ovine scapula drillhole model using micro-CT, histology and histomorphometry evaluation. The nHA-LC (38% HA content) paste supported bone formation with a high defect bridging-rate. Compared to nHA-LC, Ostim(®) (35% HA content) showed less and smaller particle agglomerates but also a reduced defect bridging-rate due to its fast degradation The highly concentrated nHA-HC paste (48% HA content) formed oversized particle agglomerates which supported the defect bridging but left little space for bone formation in the defect site. Interestingly, the gold standard treatment of the defect site with autologous bone tissue did not improve bone formation or defect bridging compared to the empty control. We concluded that the material resorption and bone formation was highly impacted by the particle-specific agglomeration behaviour in this study

Compensation irradiance and depth limits of transplanted eelgrass (Zostera marina) along a eutrophication gradient

The global seagrass decline has prompted numerous restoration efforts to reverse current trends. Yet, restoration efforts are challenged by ecological feedbacks and prevalent stressors. Identifying these stressors and the thresholds where seagrass shoot production becomes negative is vital to improve site-selection procedures and increase restoration success. In this study, we investigated the ecological compensation irradiance (ECI) and depth limit of eelgrass (Zostera marina L) transplants along a eutrophication gradient. This was accomplished by establishing eelgrass transplants along eutrophication and depth gradients while continuously measuring benthic Photosynthetically Active Radiation (PAR). High-temporal monitoring of shoot count allowed precise estimates of shoot production, which was applied to modified photosynthesis-irradiance curves, thereby estimating the ECI. The ECI fell within the interval 2.6 – 9.8 E m-2 d-1 and responded distinctly along the eutrophication gradient, decreasing as eutrophication and nutrient-derived stressors were alleviated. The depth limits were concurrently controlled by irradiance and ECI and similarly responded along the eutrophication gradient, increasing from 1.1 m at the innermost station to 4.7 – 5.6 m at the two outermost least eutrophic stations. The results demonstrate that the ECI of eelgrass varies according to the local environment, with implications for habitat suitability assessment and site selection procedures in restoration efforts.</p

MMP-9 Concentration in Peritoneal Fluid Is a Valuable Biomarker Associated with Endotoxemia in Equine Colic

The purpose of the study was to compare the results of sepsis scoring (clinical examination and clinical pathology) to the concentrations of matrix-metalloproteinases (MMPs) -2, -8, and -9; tissue-inhibitor of metalloproteinases (TIMPs) -1 and -2; and inflammatory chemokines interleukin (IL) 1 beta and tumor-necrosis-factor-alpha (TNF-alpha) in plasma and peritoneal fluid of equine colic patients. A modified sepsis scoring including general condition, heart and respiratory rate, rectal temperature, mucous membranes, white blood cell count (WBC), and ionized calcium was applied in 47 horses presented with clinical signs of colic. Using this scoring system, horses were classified as negative (n=32, = 10/19 points) for sepsis. MMPs, TIMPs, IL-1 beta, and TNF-alpha concentrations were evaluated in plasma and peritoneal fluid using species-specific sandwich ELISA kits. In a linear discriminant analysis, all parameters of sepsis scoring apart from calcium separated well between sepsis severity groups (P113 ng/ml in the peritoneal fluid was found to be the ideal cutoff to identify positive sepsis scoring (>= 10/19 points; sensitivity of 83.3% and specificity of 82.9%). In conclusion, MMP-9 was found to be a biomarker of high diagnostic value for sepsis and endotoxemia in equine colic. The evaluation of peritoneal fluid seems preferable in comparison to plasma. As abdominocentesis is commonly performed in the diagnostic work-up of equine colic, a pen-side assay would be useful and easy-to-perform diagnostic support in the decision for therapeutic intervention

Functional Scaffold‐Free Bone Equivalents Induce Osteogenic and Angiogenic Processes in a Human In Vitro Fracture Hematoma Model

After trauma, the formed fracture hematoma within the fracture gap contains all the important components (immune/stem cells, mediators) to initiate bone regeneration immediately. Thus, it is of great importance but also the most susceptible to negative influences. To study the interaction between bone and immune cells within the fracture gap, up-to-date in vitro systems should be capable of recapitulating cellular and humoral interactions and the physicochemical microenvironment (eg, hypoxia). Here, we first developed and characterized scaffold-free bone-like constructs (SFBCs), which were produced from bone marrow-derived mesenchymal stromal cells (MSCs) using a macroscale mesenchymal condensation approach. SFBCs revealed permeating mineralization characterized by increased bone volume (mu CT, histology) and expression of osteogenic markers (RUNX2, SPP1, RANKL). Fracture hematoma (FH) models, consisting of human peripheral blood (immune cells) mixed with MSCs, were co-cultivated with SFBCs under hypoxic conditions. As a result, FH models revealed an increased expression of osteogenic (RUNX2, SPP1), angiogenic (MMP2, VEGF), HIF-related (LDHA, PGK1), and inflammatory (IL6, IL8) markers after 12 and 48 hours co-cultivation. Osteogenic and angiogenic gene expression of the FH indicate the osteoinductive potential and, thus, the biological functionality of the SFBCs. IL-6, IL-8, GM-CSF, and MIP-1 beta were detectable within the supernatant after 24 and 48 hours of co-cultivation. To confirm the responsiveness of our model to modifying substances (eg, therapeutics), we used deferoxamine (DFO), which is well known to induce a cellular hypoxic adaptation response. Indeed, DFO particularly increased hypoxia-adaptive, osteogenic, and angiogenic processes within the FH models but had little effect on the SFBCs, indicating different response dynamics within the co-cultivation system. Therefore, based on our data, we have successfully modeled processes within the initial fracture healing phase in vitro and concluded that the cross-talk between bone and immune cells in the initial fracture healing phase is of particular importance for preclinical studies. (c) 2021 American Society for Bone and Mineral Research (ASBMR)

Clinical application of scaffolds for cartilage tissue engineering

The purpose of this paper is to review the basic science and clinical literature on scaffolds clinically available for the treatment of articular cartilage injuries. The use of tissue-engineered grafts based on scaffolds seems to be as effective as conventional ACI clinically. However, there is limited evidence that scaffold techniques result in homogeneous distribution of cells. Similarly, few studies exist on the maintenance of the chondrocyte phenotype in scaffolds. Both of which would be potential advantages over the first generation ACI. The mean clinical score in all of the clinical literature on scaffold techniques significantly improved compared with preoperative values. More than 80% of patients had an excellent or good outcome. None of the short- or mid-term clinical and histological results of these tissue-engineering techniques with scaffolds were reported to be better than conventional ACI. However, some studies suggest that these methods may reduce surgical time, morbidity, and risks of periosteal hypertrophy and post-operative adhesions. Based on the available literature, we were not able to rank the scaffolds available for clinical use. Firm recommendations on which cartilage repair procedure is to be preferred is currently not known on the basis of these studies. Randomized clinical trials and longer follow-up periods are needed for more widespread information regarding the clinical effectiveness of scaffold-based, tissue-engineered cartilage repair

Ålegræstransplantering og tangdyrkning som marine virkemidler:Potentialer, effekter og juridiske aspekter: Opsummering af hovedresultater fra projektet

Denne rapport opsummerer hovedresultaterne fra forskningsprojektet ”Udviklingsinitiativer for marine virkemidler”, der er besluttet og finansieret af ”Aftale om grøn omstilling af dansk landbrug” fra 2021 og udmøntet via Miljøstyrelsen. Projektet skal danne grundlag for beslutning om, og i givet fald hvordan de marine virkemidler ”reetablering af ålegræs” og ”dyrkning af tang” kan anvendes i vandplanlægningen til at opsamle næringsstoffer og/eller opnå andre positive miljøeffekter, som kan bidrage til hurtigere opnåelse af god økologisk tilstand i danske kystvandområder i overensstemmelse med vandrammedirektivet.Forskningsprojektet og nærværende opsummerende rapport er ledet af DTU Aqua ved projektleder Karen Timmermann og udført i samarbejde med Syddansk Universitet (SDU), Københavns Universitet (KU), Aarhus Universitet (AU) og DHI. Rapporten er en del af rapportserien ”Udviklingsinitiativer for marine virkemidler”, som udover den opsummerende rapport omfatter en række baggrundsrapporter med videnskabelig dokumentation for projektets resultater.Baggrundsrapporterne i serien udgives i løbet af 2024 og udgøres af:• En dybdegående projektsynteserapport.• Vidensyntese om ålegræstransplantering.• Videnssyntese om tangdyrkning.• Rapporten ”Muligheder for at indregne marine virkemidler i den nationale drivhusgasopgørelse”.• Rapporten ”Retlige rammer for marine virkemidler og marin natur”.• Arbejdspakkerapporter med videnskabelig dokumentation for resultaterne fra hver af projektets centrale faglige arbejdspakker omhandlende ”Ålegræstransplantering”, ”Dyrkning af sukkertang” og "Modellering af virkemiddeleffekter”.Miljøstyrelsen har haft rapportudkast til kommentering undervejs i projektgruppens arbejde, men valg af metoder og konklusioner er alene projektgruppens ansvar