Histological Properties Research Articles

Effect of Fluorinert on the Histological Properties of Formalin-Fixed Human Brain Tissue.

Fluorinert (perfluorocarbon) represents an inexpensive option for minimizing susceptibility artifacts in ex vivo brain MRI scanning, and provides an alternative to Fomblin. However, its impact on fixed tissue and histological analysis has not been rigorously and quantitatively validated. In this study, we excised tissue blocks from 2 brain regions (frontal pole and cerebellum) of 5 formalin-fixed specimens (2 progressive supranuclear palsy cases, 3 controls). We excised 2 blocks per region per case (20 blocks in total), one of which was subsequently immersed in Fluorinert for a week and then returned to a container with formalin. The other block from each region was kept in formalin for use as control. The tissue blocks were then sectioned and histological analysis was performed on each, including routine stains and immunohistochemistry. Visual inspection of the stained histological sections by an experienced neuropathologist through the microscope did not reveal any discernible differences between any of the samples. Moreover, quantitative analysis based on automated image patch classification showed that the samples were almost indistinguishable for a state-of-the-art classifier based on a deep convolutional neural network. The results showed that Fluorinert has no effect on subsequent histological analysis of the tissue even after a long (1 week) period of immersion, which is sufficient for even the lengthiest scanning protocols.

Automated muscle histopathology analysis using CellProfiler

BackgroundHistological assessment of skeletal muscle sections is important for the research of muscle physiology and diseases. Quantifiable measures of skeletal muscle often include mean fiber diameter, fiber size distribution, and centrally nucleated muscle fibers. These parameters offer insights into the dynamic adaptation of skeletal muscle cells during repeated cycles of degeneration and regeneration associated with many muscle diseases and injuries. Computational programs designed to obtain these parameters would greatly facilitate such efforts and offer significant advantage over manual image analysis, which is very labor-intensive and often subjective. Here, we describe a customized pipeline termed MuscleAnalyzer for muscle histology analysis based upon CellProfiler, a free, open-source software for measuring and analyzing cell images.ResultsThe MuscleAnalyzer pipeline consists of loading, adjusting, and running a series of image-processing modules provided by CellProfiler. This pipeline was evaluated using wild-type and mdx muscle sections co-stained with laminin (to demarcate the muscle fiber boundaries) and 4′,6-diamidino-2-phenylindole (DAPI, to label the nuclei). The immunofluorescence images analyzed using the MuscleAnalyzer pipeline or manually yielded similar results in the number of muscle fibers per image (p = 0.42) and central nucleated fiber (CNF) percentage (p = 0.29) in mdx mice. However, for a total of 67 images, CellProfiler completed the analysis in ~ 10 min on a regular PC while it took an investigator ~ 3 h using the manual approach in order to quantify the number of muscle fibers and CNF. Moreover, the MuscleAnalyzer pipeline also provided the measurement of the cross-sectional area (CSA) and minimal Feret’s diameter (MFD) of muscle fibers, and thus fiber size distribution can be plotted.ConclusionsOur data indicate that the MuscleAnalyzer pipeline can efficiently and accurately analyze laminin and DAPI co-stained muscle images in a batch format and provide quantitative measurements for muscle histological properties such as muscle fiber diameters, fiber size distribution, and CNF percentage.

Supraspinatus Tendons Have Different Mechanical Properties Across Sex.

Sex differences in the mechanical properties of different musculoskeletal tissues and their impact on tendon function and disease are becoming increasingly recognized. Tendon mechanical properties are influenced by the presence or absence of sex hormones and these effects appear to be tendon- or ligament-specific. The objective of this study was to determine how sex and hormone differences in rats affect supraspinatus tendon and muscle properties. We hypothesized that male supraspinatus tendons would have increased cross-sectional area but no differences in tendon material properties or muscle composition when compared to supraspinatus tendons from female or ovariectomized (OVX) female rats. Uninjured supraspinatus tendons and muscles from male, female, and OVX female rats were collected and mechanical and histological properties were determined. Our analysis demonstrated decreased dynamic modulus and increased hysteresis and cross-sectional area in male tendons. We found that male tendons exhibited decreased dynamic modulus (during low strain frequency sweep and high strain fatigue loading), increased hysteresis, and increased cross-sectional area compared to female and OVX female tendons. Despite robust mechanical differences, tendon cell density and shape, and muscle composition remained unchanged between groups. Interestingly, these differences were unique compared to previously reported sex differences in rat Achilles tendons, which further supports the concept that the effect of sex on tendon varies anatomically. These differences may partially provide a mechanistic explanation for the increased rate of acute supraspinatus tendon ruptures seen in young males.

Pulsed and continuous accelerated scleral cross-linking using riboflavin and ultraviolet A irradiation for the prevention of myopia progression in a guinea pig model

Objective To evaluated the effect of oral administration of riboflavin combined with pulsed and continuous light accelerated scleral cross-linking on the histological and biomechanical properties of sclera in a guinea pig model to control the progression of myopia. Methods Thirty 4-week-old guinea pigs were divided into 5 groups, or the control group, non cross-linking group, conventional cross-linking group, pulse light cross-linking group and continuous light cross-linking group with 6 guinea pigs in each group.Three cross-linking groups were administered 0.1% riboflavin solution with vitamin C by gavage from 3 days before modeling to modeling process.The conventional cross-linking group underwent cross-linking with 1 hour of (ultraviolet A (UVA) exposure at 0.67 mW/cm2, the pulse light cross-linking group received a pulsed-light accelerated crosslinking for 8 minuctes (1 second on/1 second off) of UVA exposure at 10 mW/cm2, and the continuous light accelerated cross-linking group was crosslinked with continuous-light accelerated crosslinking at 10 mW/cm2 for 4 minuctes.The same procedure was conducted on the non cross-linking group without UVA irradiation and 0.1% riboflavin solution before modeling and modeling process.No any intervene was carried out in the control group.Retinoscopy and the axial length measurement were performed before and after experiment.The animals were euthanized 2 weeks after experiment and then biomechanical and histopathological examinations of scleras were conducted.The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results Myopia models were established with an increased axial length and myopic diopter 2 weeks after myopic modeling process.Axial length in the non cross-linking group was longer than that of the control group at 2 weeks, with a siginificant difference between them (P<0.01). The myopic Diopter in the non cross-linking group was significantly increased in comprasion with the control group at 2 weeks (P<0.01). Compared with myopic eyes in the non cross-linking groups, axial length, diopter and strain assessment values were decreased significantly in three scleral cross-linking groups (all at P<0.01). The sclera ultimate load and stress assessment in the conventinal cross-lingking group, pulse light cross-linking group, continuous light cross-linking group were significantly higher than those in the non-cross-linking group Max stress: [2.20±0.03], [2.67±0.05], [2.41±0.04]Mpa vs.[1.30±0.02]Mpa; Max load: [1.92±0.03], [2.33±0.28], [1.91±0.03]P vs.[1.54±0.06]P) (all at P<0.01). Collagenous tissue of the scleras in the pulse light cross-linking group and continious ligh cross-linking group was similar in appearance to the control group.In addition, MMP2 expression of pulse light cross-linking group and continuous light cross-linking group was significantly increased, and TIMP-2 expression showed a reduce. Conclusions Pulsed and continuous light accelerated scleral cross-linking using oral administration of riboflavin and riboflavin UVA irradiation can effectively prevent the myopia development by increasing scleral biomechanical strength in guinea pig. Key words: Riboflavin; Ultraviolet A; Scleral cross-linking; Myopia; Guinea

Porous titanium-coated polyetheretherketone implants exhibit an improved bone-implant interface: an in vitro and in vivo biochemical, biomechanical, and histological study.

PurposeSpinal interbody fusion cages are designed to provide immediate stabilization for adjoining vertebrae and ideally enable bony ingrowth to achieve successful integration. For such an implant, cells must be able to attach, move, grow, and differentiate on its surface. These cellular interactions are dependent on how the implant surface enables the coating and binding of blood and tissue fluid proteins that support cell adhesion. The purpose of this study was to evaluate the in vitro and in vivo osteoblast cell–implant surface interactions that result in osseointegration onto a surface composed of plasma-sprayed titanium on a polyetheretherketone (PEEK) substrate or titanium-coated PEEK (Ti-PEEK) (PlasmaporeXP®) as compared to uncoated PEEK implants.Materials and methodsThe influence of the Ti-PEEK surface modification on the biochemical, biomechanical, and histological properties at the bone–implant interface is demonstrated both in vitro using simulated bone-forming cell culture experiments and in vivo using a 12- and 24-week ovine implant model.ResultsOsteoblast-like cells attached to the Ti-PEEK surface upregulated early bone-forming activity as measured by an increase in transcription and translation of ALP and BMP-2 when compared to cells on PEEK. Similarly, a significant increase in new bone formation, bony apposition, and pullout strength was demonstrated on Ti-PEEK implants when compared to PEEK implants at 12 and 24 weeks in an ovine implant in vivo model.ConclusionThe study shows that the Ti-PEEK surface demonstrated enhanced osseointegrative properties compared to PEEK both in vitro and in vivo.

Histological staining properties of Khaya senegalensis wood dust extracts: a preliminary study

Crude aqueous and methanol extracts of Khaya senegalensis wood dust were employed as histological stains for the demonstration of general tissue architecture. Preliminary phytochemical screening of the extracts was conducted. Mixtures of the extracts of K. senegalensis in acidic, alkaline and neutral solutions were used to stain tissue sections. Preliminary phytochemical screening revealed that K. senegalensis extracts contains flavonoids, saponins, tannins, glycosides and reducing sugars. Optimum staining time was 15 minutes for both extracts and they stained the tissues in different shades of red and brown in the various media used. The best and worst stain uptake of tissues was observed with both extracts in alkaline and neutral media respectively. Mordant preparation of the extracts produced no significant staining difference from the non-mordant preparations. Staining solutions of the extracts have better affinity for the cellular cytoplasm and hence gave a good contrast when compared with Hematoxylin and Eosin control sections. In conclusion, Khaya senegalensis wood extract is a promising histological stain for the demonstration of general tissue architecture.Keywords: Khaya senegalensis, wood dust, stain, histology, mordant

Development of long in vivo tissue-engineered “Biotube” vascular grafts

In-body tissue architecture (iBTA), a cell-free, in vivo tissue engineering technology that can produce autologous implantable tissues of the desired shape by subcutaneously embedding specially designed molds, was used to develop long tubular collagenous tissues called Biotubes. Spiral molds for long Biotubes were assembled with an outer pipe-shaped spiral shell and an inner spiral mandrel, and embedded into subcutaneous pouches of beagle dogs or goats for 1 or 2 months. Tubular collagenous tissues were formed at the space between the shell and the mandrel of the mold. Depending on the spiral turn number in the mold, Biotubes of 25 cm or 50 cm (internal diameter 4 mm or 5 mm) were prepared with nearly homogeneous mechanical and histological properties over their entire length. Biotubes stored in 70% ethanol were allogenically implanted into beagle dogs or goats to evaluate their in vivo performance. The 25-cm Biotubes functioned as arterial grafts with no need for luminal modification or mechanical support, and demonstrated vascular reconstruction within 3 months after implantation into dogs. The 50-cm Biotubes functioned as arteriovenous shunt grafts in the neck region of goats without thrombus formation and vascular deformation for 1 month. Thus, the world's longest tissue-engineered vascular grafts with small diameter could be developed using iBTA.

Voxel-wise analysis of dynamic 18F-FET PET: a novel approach for non-invasive glioma characterisation

BackgroundGlioma grading with dynamic 18F-FET PET (0–40 min p.i.) is typically performed by analysing the mean time-activity curve of the entire tumour or a suspicious area within a heterogeneous tumour. This work aimed to ensure a reader-independent glioma characterisation and identification of aggressive sub-volumes by performing a voxel-based analysis with diagnostically relevant kinetic and static 18F-FET PET parameters.One hundred sixty-two patients with a newly diagnosed glioma classified according to histologic and molecular genetic properties were evaluated. The biological tumour volume (BTV) was segmented in static 20–40 min p.i. 18F-FET PET images using the established threshold of 1.6 × background activity. For each enclosed voxel, the time-to-peak (TTP), the late slope (Slope15–40), and the tumour-to-background ratios (TBR5–15, TBR20–40) obtained from 5 to 15 min p.i. and 20 to 40 min p.i. images were determined. The percentage portion of these values within the BTV was evaluated with percentage volume fractions (PVFs) and cumulated percentage volume histograms (PVHs). The ability to differentiate histologic and molecular genetic classes was assessed and compared to volume-of-interest (VOI)-based parameters.ResultsAggressive WHO grades III and IV and IDH-wildtype gliomas were dominated by a high proportion of voxels with an early peak, negative slope, and high TBR, whereby the PVHs with TTP < 20 min p.i., Slope15–40 < 0 SUV/h, and TBR5–15 and TBR20–40 > 2 yielded the most significant differences between glioma grades. We found significant differences of the parameters between WHO grades and IDH mutation status, where the effect size was predominantly higher for voxel-based PVHs compared to the corresponding VOI-based parameters. A low overlap of BTV sub-volumes defined by TTP < 20 min p.i. and negative Slope15–40 with TBR5–15 > 2- and TBR20–40 > 2-defined hotspots was observed.ConclusionsThe presented approach applying voxel-wise analysis of dynamic 18F-FET PET enables an enhanced characterisation of gliomas and might potentially provide a fast identification of aggressive sub-volumes within the BTV. Parametric 3D 18F-FET PET information as investigated in this study has the potential to guide individual therapy instrumentation and may be included in future biopsy studies.

The Histological Composition of Capsular Contracture Focussed on the Inner Layer of the Capsule: An Intra-Donor Baker-I Versus Baker-IV Comparison

BackgroundCapsular contracture remains one of the major complications after breast implantation surgery. The extent of capsular contraction is scored using the Baker scale. The aim of this study was to compare intra-individual Baker-I with Baker-IV capsules, and in particular the prevalence and histological properties of the inner capsule layer.MethodsTwenty capsules from ten patients were included after bilateral explantation surgery due to unilateral capsular contracture (Baker-IV) after cosmetic augmentation with textured implants. All capsules underwent (immune-)histochemical analysis: haematoxylin–eosin (morphology), CD68 (macrophages), cytokeratin (epithelial cells) and vimentin (fibroblasts), and were visually scored for cell density and the presence of an inner layer and measured for thickness.ResultsBaker-IV (n = 10) capsules were significantly thicker compared to Baker-I (n = 10) capsules (P = 0.004). An inner layer was present in 8 Baker-I capsules. All Baker-I capsules were vimentin and CD68-positive and cytokeratin-negative. Positive vimentin was seen throughout the inner layer, and CD-68 staining was observed adjacent to the intermediate capsule layer. In contrast, only 2 Baker-IV capsules had an inner layer, of which only 1 showed the same profile as Baker-I capsules (P = 0.016). No cytokeratin positivity was seen in any capsule. In Baker-IV capsules, outer layers showed more positivity for both vimentin and CD68.ConclusionThe inner layer is morphologically consistent with synovial metaplasia and is more prevalent in healthy, uncontracted Baker-I capsules. This inverse relation between the presence of the inner layer and higher Baker classification or pathological contracture could indicate a protective role of the inner layer against capsular contracture formation.Level of Evidence IIIThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Adipose-derived Human Perivascular Stem Cells May Improve Achilles Tendon Healing in Rats.

Achilles tendon rupture is a common injury and the best treatment option remains uncertain between surgical and nonoperative methods. Biologic approaches using multipotent stem cells such as perivascular stem cells pose a possible treatment option, although there is currently a paucity of evidence regarding their clinical therapeutic use. The purpose of this study was to determine whether injected perivascular stem cells (PSCs) would (1) improve histologic signs of tendon healing (such as percent area of collagen); and (2) improve biomechanical properties (peak load or stiffness) in a rat model of Achilles tendon transection. Two subtypes of PSCs were derived from human adipose tissue: pericytes (CD146CD34CD45CD31) and adventitial cells (CD146CD34CD45CD31). Thirty-two athymic rats underwent right Achilles transection and were randomized to receive injection with saline (eight tendons), hydrogel (four tendons), pericytes in hydrogel (four tendons), or adventitial cells in hydrogel (eight tendons) 3 days postoperatively with the left serving as an uninjured control. Additionally, a subset of pericytes was labeled with CM-diI to track cell viability and localization. At 3 weeks, the rats were euthanized, and investigators blinded to treatment group allocation evaluated tendon healing by peak load and stiffness using biomechanical testing and percent area of collagen using histologic analysis with picrosirius red staining. Histologic analysis showed a higher mean percent area collagen for pericytes (30%) and adventitial cells (28%) than hydrogel (21%) or saline (26%). However, a nonparametric statistical analysis yielded no statistical difference. Mechanical testing demonstrated that the pericyte group had a higher peak load than the saline group (41 ± 7 N versus 26 ± 9 N; mean difference 15 N; 95% confidence interval [CI], 4-27 N; p = 0.003) and a higher peak load than the hydrogel group (41 ± 7 N versus 25 ± 3 N; mean difference 16; 95% CI, 8-24 N; p = 0.001). The pericyte group demonstrated higher stiffness than the hydrogel group (36 ± 12 N/mm versus 17 ± 6 N/mm; mean difference 19 N/mm; 95% CI, 5-34 N/mm; p = 0.005). Our results suggest that injection of PSCs improves mechanical but not the histologic properties of early Achilles tendon healing. This is a preliminary study that provides more insight into the use of adipose-derived PSCs as a percutaneous therapy in the setting of Achilles tendon rupture. Further experiments to characterize the function of these cells may serve as a pathway to development of minimally invasive intervention aimed at improving nonoperative management while avoiding the complications associated with surgical treatment down the line.

Effect of 3 Preservation Methods (Freezing, Cryopreservation, and Freezing + Irradiation) on Human Menisci Ultrastructure: An Ex Vivo Comparative Study With Fresh Tissue as a Gold Standard

Background: Three main meniscus preservation methods have been advocated: freezing (–80°C), freezing with gamma irradiation (–80°C + 25 kGy), and cryopreservation (–140°C). Hypothesis: All preservation methods will result in structural and architectural properties similar to those of fresh meniscus, defined as the gold standard. Study Design: Controlled laboratory study. Methods: Five human intact menisci were collected from 5 patients undergoing total knee arthroplasty. The inclusion criteria were patients <70 years old with primary unilateral (medial) femorotibial knee osteoarthritis and without surgical or traumatic history on the operated knee. Four cubes (9 mm3) were cut inside of the white, or avascular, area of each specimen’s middle horn and divided into 4 groups: “fresh” control, frozen (–80°C), cryopreserved (–140°C), and frozen + irradiated (–80°C + 25 kGy). Specimens of the control group were evaluated at day 1, and specimens from the frozen, cryopreserved, and frozen + irradiated groups were evaluated after 1 month of storage. Evaluation was performed with electron microscopy according a validated protocol to analyze (1) mean diameters of the collagen fibers in longitudinal and transverse sections in 5 points per section and (2) validated architectural scores. Results: No significant difference was found between the control and cryopreserved groups regarding mean transverse and longitudinal diameters (transverse: 95.39 ± 15.87 nm vs 99.62 ± 19.23 nm, P = .1; longitudinal: 96.31 ± 13.96 nm vs 94.57 ± 16.42 nm, P = .1). Significant differences were found between the control and frozen groups (transverse: 95.39 ± 15.87 nm vs 70.20 ± 13.94 nm, P < .001; longitudinal: 96.31 ± 13.96 nm vs 71.28 ± 10.64 nm, P < .001) and the control and frozen + irradiated groups (transverse: 95.39 ± 15.87 nm vs 63.1 ± 15.57 nm, P < .001; longitudinal: 96.31 ± 13.96 nm vs 60.9 ± 14.8 nm, P < .001). Regarding architectural score calculation, there were significant differences between the control and frozen groups (4.5 ± 1.3 vs 2.3 ± 1.4, P = .02) and the control and frozen + irradiated groups (4.5 ± 1.3 vs 1.4 ± 0.9, P = .02). Conclusion: Cryopreservation is the only method that preserves fresh meniscus architectural specificities. Freezing and freezing + irradiation methods modify histologic properties of meniscal allograft. Irradiation deeply alters diameters and the organization of collagen fibers, and this method should be used with caution to preserve and sterilize meniscus tissue. Clinical Relevance: The results of our study exhibited detrimental effects of simple freezing and freezing + irradiation on the collagen network of sample meniscus. If those effects occur in menisci prepared for allograft procedures, important differences could appear on the basis of the preservation procedure in terms of the graft’s mechanical properties and, thus, the patient’s outcomes.

An investigation of left-right vocal fold symmetry in rheological and histological properties.

The primary objective was to investigate the left-right vocal fold symmetry in rheological and histological properties using a rabbit model. The other objective was to develop statistical models for the comparison of rheological properties between paired vocal folds. Viscoelastic shear properties of six pairs of vocal fold lamina propria specimens were measured over a frequency range of 1 to 250 Hz by a linear, controlled-strain, simple-shear rheometer. The rheological data of the left and right vocal folds was statistically compared using the mixed-effects model approach. Six additional rabbit larynges were histologically analyzed for left-right symmetry in distribution patterns and relative densities of major extracellular matrix constituents. There were no significant differences in elastic shear modulus (P = 0.1069) and dynamic viscosity (P = 0.944) of the lamina propria between the two vocal folds of the same larynx. Left-right vocal fold symmetry in densities and distribution patterns of the key molecular constituents was also demonstrated in histological results. By showing that the left and right vocal folds were rheologically and histologically symmetrical in rabbit, this study validated an underlying assumption made in many previous reports. Statistical models for the analysis of hierarchically correlated left-right vocal fold rheological data were also presented. NA. Laryngoscope, 128:E359-E364, 2018.

Hemorrhagic shock alters fracture callus composition and activates the IL6 and RANKL/OPG pathway in mice.

Fracture and hemorrhagic shock often lead to impaired fracture healing. To elucidate underlying pathogenesis, this study aimed to analyze histological properties during fracture healing after hemorrhagic shock and involved signaling pathways in mice. Male C57BL/6NCrl mice were assigned into five groups. Control group underwent no interventions. Sham group had a catheter and external fixator but neither blood loss nor osteotomy. Trauma-hemorrhage (TH) group received a pressure-controlled hemorrhagic shock; osteotomy (Fx) group, an osteotomy and fixator; and combined trauma (THFx) group, both hemorrhagic shock and externally fixed osteotomy. After 1, 2, 3, and 4 weeks, the animals were killed. Undecalcified bones were analyzed histologically and signaling pathways relevant for fracture healing by polymerase chain reaction and Western blot. Statistical significance was set at 0.05 or less. Comparisons were performed using the Mann-Whitney U or Kruskal-Wallis test. In the THFx group, a decreased bone formation after 3 weeks, a reduction of both bone and cartilage after 2 weeks, and an enhanced activation of the RANKL/OPG and IL6 signaling pathway after 1 week were shown in comparison to Fx. Hemorrhagic shock has a retarding effect on fracture healing in the early phase of fracture healing and leads to activation of the IL6 and RANKL/OPG signaling pathways.

Changes in protein properties and tissue histology of tuna meat as affected by salting and subsequent freezing

The effects of salting and subsequent freezing on the physicochemical and histological properties of frozen-thawed tuna meat were investigated. Salting facilitated the microstructural recovery as indicated by the decrease or disappearance of intracellular holes. The yield of the 0.5 M and 1 M salted samples increased by 20% which was evaluated by the mass ratio of products to raw material. Morphological transformation from ice columns to spherical or ellipsoidal ice crystals was tentatively attributed to the extraction/solubilization of myofibrillar proteins, contributing to increased water-holding capacity. However, increased thawing loss and centrifuging loss after thawing were observed in the 2 M and 3 M salted samples with large ice crystals and enlarged extracellular spaces. These modifications were closely associated with the changes in protein properties. In conclusion, enhanced water-holding capacity, high yield, and good freezing stability can be achieved by optimal salting.

Super-Critical-CO2 De-ECM Process

ABSTRACTExtracellular Matrix (ECM), a natural biomaterials, have recently garnered attention in tissue engineering for their high degree of cell proliferative capacity, biocompatibility, biodegradability, and tenability in the body. Decellularization process offers a unique approach for fabricating ECM-based natural scaffold for tissue engineering application by removing intracellular contents in a tissue that could cause any adverse host responses. The effects of Supercritical carbon dioxide (Sc-CO2) treatment on the histological and biochemical properties of the decellularized extracellular matrix (de-ECM) were evaluated and compared with de-ECM from conventional decellularization process to see if it offers significantly reduced treatment times, complete decellularization, and well preserved extracellular matrix structure. The study has shown that a novel method of using supercritical fluid extraction system indeed removed all unnecessary residues and only leaving ECM. The potential of Sc-CO2 de-ECM progressed as a promising approach in tissue repair and regeneration.

Nonarticular osseous cyst-like lesions of the intermedioradial carpal bone may be incidental magnetic resonance imaging findings in dogs.

As magnetic resonance imaging (MRI) becomes more readily available and more frequently utilized in the assessment of canine carpal lameness, both normal variations and early pathologic conditions must be recognized to optimize patient care and provide accurate diagnosis. On cross sectional studies of the canine carpus, cyst-like lesions have been detected at the dorsolateral aspect of the intermedioradial carpal bone. The cross-sectional imaging and histologic properties of these lesions have not been described. The purpose of this observational study is to evaluate the MRI and histologic features of these cyst-like lesions in a cohort of clinically sound dogs. It was hypothesized that the lesions would show features similar to intraosseous ganglion cysts of the human wrist. Twenty-five cadaveric canine carpi were obtained and a total of 13 lesions were detected on MRI. Based on MRI, six carpi with lesions of varying size and one normal carpus were submitted for histological evaluation. Five of the abnormal carpi had nonarticular cyst-like lesions; one specimen with a positive magnetic resonance image for a cyst-like lesion had no cyst-like lesion on histology. Conspicuity of a medium-size lesion as evaluated on radiographs was poor. Given the presence of these nonarticular cyst-like lesions in a population of clinically sound patients, their clinical importance is uncertain. The development of these lesions may relate to altered mechanics or genetic predispositions, requiring additional study.

Tsmu solution improves rabbit osteochondral allograft preservation and transplantation outcome.

To compare the effects of Tsmu solution with vitrification on chondrocyte viability and examine histological and biomechanical properties of osteochondral allografts (OCAs) after storage, OCAs from femoral condyles of New Zealand rabbits were harvested, stored for 35days in Tsmu solution or by in vitro vitrification, and subjected to in vivo and in vitro assays. Stored OCAs were transplanted into knee femoral condyle cartilage defects in recipient rabbits. Chondrocyte viability and histological changes of cartilage grafts were assessed in vitro. Gross assessment, chondrocyte viability, histological assessment, OCA biomechanics, and immunological markers were evaluated in vivo 6months after transplantation. Fresh OCAs served as in vitro and in vivo controls. Chondrocyte viability and scores for cartilage surface and histological quantitative assessment were superior for Tsmu solution compared with vitrification, but inferior compared with fresh OCAs in vitro and in vivo. With the exception of interleukin 6 content, biomechanical features of samples stored in Tsmu solution were superior to vitrification, and inferior to fresh OCAs in vivo. Thus, Tsmu solution provided suitable storage that improved chondrocyte viability, intact OCA cartilage matrix architecture, and transplantation outcomes.

PR527: Histological and nanomechanical properties of a new nanometric hydroxyapatite implant surface in a diabetic model

PR527: Histological and nanomechanical properties of a new nanometric hydroxyapatite implant surface in a diabetic model

Mo1310 CHOLECYSTOENTEROSTOMY AS AN ALTERNATIVE TO CONVENTIONAL TREATMENT FOR CHOELCYSTITIS AND THE ROLE OF SEROTROPIC STENTS

Laparoscopic cholecystectomy for cholecystitis is the standard of care . Percutaneous cholecystostomy is used in patients deemed unfit for surgery . Endoscopic interventions include natural orifice trans-luminal endoscopic surgery (NOTES), per-oral endoscopic trans-papillary drainage and endoscopic ultrasound- guided endoluminal gallbladder drainage. There are a few EUS- specific stents that have shown promise through decreased tissue ingrowth, leakage and migration yet ensure drainage through apposition of lumens. Our index case highlights one stent but autopsy findings did not demonstrate apposition. A 26-year-old female presented with decompensated alcoholic cirrhosis with ascites, abdominal pain and hyperbilirubinemia. After a negative serologic evaluation, we requested a magnetic resonance cholangiopancreatography (MRCP) which demonstrated multiple gallstones and a mildly thickened gallbladder wall. We performed an endoscopic ultrasound which confirmed cholelithiasis, gallbladder distention and estimated the gall bladder wall thickness to be 2.4 mm. We then performed a cholecystoduodenostomy using the AXIOS™ stent and electrocautery enhanced delivery system (AXIOS, Boston Scientific, Natick, MA). Within 24 hours, the patient showed significant improvement in her abdominal pain. Second-look esophagogastroduodenoscopy 48 hours after the initial procedure to evaluate post procedural anemia was unrevealing. Two weeks after gallbladder drainage her hepatic status worsened and she expired. We participated in a limited autopsy to evaluate the effect of the stent invivo and reviewed the histological properties of the lumen. There was evidence of focal adherence of the gallbladder to the duodenum at the site of stent deployment with circumferential serosal formation. Figure 1. The diameter of the tract was 15 mm which was the diameter of the stent used. Histology demonstrated gallbladder serosa continuous with the neo-serosa of the tract and there was no evidence of significant adhesions. Figure 2. The AXIOS™ stent is FDA approved for trans-enteric drainage of pancreatic pseudocysts but recently has been used successfully for gallbladder drainage. Data describing adherence of the gallbladder to the duodenal wall in human subjects using the AXIOS™ stent is limited. Animal model studies have shown serosal adhesion of the stomach to gallbladder at 4 weeks. We observed serosal formation rather than adhesion after two weeks. Studies indicate that adhesions occur after disruption of serosal surfaces and tissue apposition. If tissue apposition does not occur, a new serosal surface will be formed similar to cutaneous wound healing. Trans-luminal stents likely decompress and drain but also are a conduit for serosal formation without direct tissue apposition. We refer to this process as “serotropism.”Figure 2. Histology showing continuation of gallbladder serosa with neo-serosa of the drainage tract created by the stent.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Does Adding Silver Nanoparticles to Leukocyte- and Platelet-Rich Fibrin Improve Its Properties?

Objectives Leucocyte- and platelet-rich fibrin (L-PRF) membrane can be used in various regenerative treatments. In the case of classical heterologous membrane exposure, microorganisms can be colonized on it and jeopardize the success of treatment. The aim of this study was to compare the antibacterial, mechanical, and histologic characteristics of the L-PRF membrane before and after the addition of silver nanoparticles (SNP). Materials and Method This study was performed on 10 volunteer men aged 25-35 years. 20 ml whole bloods were collected from each person and L-PRFs were made by routine and SNP modified method. Mechanical, antibacterial, and histological properties were evaluated. Results The antibacterial efficacy of L-PRF and nanosilver-modified L-PRF was presented as Klebsiella pneumonia had growth on the L-PRF membrane after 12 hours. After 24 hours, Klebsiella pneumonia and Streptococcus viridans had growth on L-PRF and only Klebsiella pneumonia had growth on SNP-L-PRF. The tensile strength and stiffness were significantly higher in the SNP-L-PRF. Precipitation of the SNPs was patchy in the outer layers and quite homogeneous in the inner core. Conclusion Modification of L-PRF with SNP improves the mechanical properties and antibacterial activity of the L-PRF. It can play an important role in regenerative procedures.