Relationship between the extent of vascular injury and the evolution of surgically induced osteochondrosis lesions in a piglet model.

Ostechondritis dissecans (OCD) is an orthopaedic disease characterized by formation of osteochondral defects in developing joints. Epiphyseal cartilage necrosis (osteochondrosis [OC]) caused by focal failure of vascular supply is the known precursor lesion of OCD, but it remains to be established how the severity of vascular failure drives lesion healing or progression. In the current study we have implemented a novel piglet model of induced osteochondrosis of the lateral trochlear ridge of the femur to determine the role that the extent of ischemia plays in the development and progression of OC/OCD lesions. Ten 4-week-old Yorkshire piglets underwent surgical interruption of the vascular supply to the entirety (n = 4 pigs) or the distal half (n = 6 pigs) of the lateral trochlear ridge of the femur. At 2, 6, and 12 weeks postoperatively, distal femora were evaluated by magnetic resonance imaging (MRI) to determine the fate of induced OC lesions. At 12 weeks, piglets were euthanized, and the surgical sites were examined histologically. After complete devascularization, lesion size increased between the 6- and 12-week MRI by an average of 24.8 mm2 (95% CI: [-2.2, 51.7]; p = 0.071). During the same period, lesion size decreased by an average of 7.6 mm2 (95% CI: [-24.5, 19.4]; p = 0.83) in piglets receiving partial devascularization. At 12 weeks, average ± SD lesion size was larger (p<0.001) in piglets undergoing complete (73.5 ± 17.6 mm2) vs. partial (16.5 ± 9.8 mm2) devascularization. Our study demonstrates how the degree of vascular interruption determines lesion size and likelihood of healing in a large animal model of trochlear OC.

Long-term use of an implantable loop recorder for ECG recording in horses.

Potential arrhythmias recorded by cardiac monitors using the built-in human algorithm are as follows: total number of episodes, ventricular tachycardia, asystole, bradycardia, atrial tachycardia, atrial fibrillation and the percentage of time spent in atrial tachycardia or atrial fibrillation. Long-term use of an insertable cardiac monitor (loop recorder) has been reported in one horse earlier, but its accurate role as a diagnostic tool is still unclear. The aim of the present study was to investigate the long-term applicability of the Reveal XT cardiac monitor for recording cardiac arrhythmias in adult horses. The Reveal XT cardiac monitor was implanted in 12 horses under sedation in standing position. Median duration of data recording calculated for the population was 1,169 days. The number of false positive detections of asystole and bradycardia was extremely high in all horses. For atrial fibrillation, false positive detection occurred in five and false negative detection occurred in one horse. The present study showed that the long-term use of the Reveal XT cardiac monitor is feasible, well-tolerated and the devices work reliably, without complications. The human algorithm could not be used for automatic detection of arrhythmic episodes in the study population. The device could detect atrial fibrillation in horses, but the recorded AF burden was inaccurate and the stored ECGs had to be manually interpreted. Because the human analyser algorithm of this cardiac monitor fails to identify bradyarrhythmias in horses based on our results, this instrument is not capable for accurately determining the aetiology of episodic collapse in this species.

Detection of early metaphyseal changes in a piglet model of Legg-Calvé-Perthes disease using quantitative mapping of MRI relaxation times.

Legg-Calvé-Perthes disease (LCPD) is a childhood hip disorder characterized by ischemic injury to the epiphysis of the femoral head, but changes to the metaphysis have also been implicated in its pathogenesis. Quantitative magnetic resonance imaging (MRI) relaxation time mapping techniques are potentially useful to detect injury in LCPD, but studies to date have focused on the epiphysis. The purpose of this study was to assess whether T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation times can detect early metaphyseal changes in an LCPD piglet model. Complete epiphyseal ischemia of one femoral head was surgically induced and confirmed using contrast-enhanced MRI in n = 10 6-week-old piglets; the contralateral side was unoperated. The bilateral hips were imaged 1 week after surgery in vivo at 3T MRI using relaxation time mapping and contrast-enhanced MRI. Relaxation times and thicknesses of the metaphyseal primary and secondary spongiosa were measured and compared between the ischemic and contralateral-control femoral heads using paired t-tests. In the ischemic femoral heads, T2 relaxation times were significantly increased in the primary spongiosa (6.7 ± 9.8 ms, p = 0.029), and T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation times were significantly decreased in the secondary spongiosa (respectively: -13.3 ± 9.3 ms, p = 0.013; -32 ± 23 ms, p < 0.001; -43 ± 41 ms, p = 0.009; and -39 ± 13 ms, p < 0.001). The secondary spongiosa thickness was also significantly decreased in the ischemic femoral heads (p < 0.001). In conclusion, T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation time mapping techniques can detect early changes in the metaphysis following ischemic injury to the epiphysis of the femoral head in a piglet model of LCPD.

Intravoxel incoherent motion (IVIM) detects femoral head ischemia in a piglet model of Legg-Calvé-Perthes disease.

There is a clinical need for alternatives to gadolinium contrast-enhanced magnetic resonance imaging (MRI) to facilitate early detection and assessment of femoral head ischemia in pediatric patients with Legg-Calvé-Perthes disease (LCPD), a juvenile form of idiopathic osteonecrosis of the femoral head. The purpose of this study was to determine if intravoxel incoherent motion (IVIM), a noncontrast-enhanced MRI method to simultaneously measure tissue perfusion and diffusion, can detect femoral head ischemia using a piglet model of LCPD. Twelve 6-week-old piglets underwent unilateral hip surgery to induce complete femoral head ischemia. The unoperated, contralateral femoral head served as a perfused control. The bilateral hips of the piglets were imaged in vivo at 3T MRI using IVIM and contrast-enhanced MRI 1 week after surgery. Median apparent diffusion coefficient (ADC) and IVIM parameters (diffusion coefficient: Ds; perfusion coefficient: Df; perfusion fraction: f; and perfusion flux: f*Df) were compared between regions of interest comprising the epiphyseal bone marrow of the ischemic and control femoral heads. Contrast-enhanced MRI confirmed complete femoral head ischemia in 11/12 piglets. IVIM perfusion fraction (f) and flux (f*Df) were significantly decreased in the ischemic versus control femoral heads: on average, f decreased 47 ± 27% (Δf = -0.055 ± 0.034; p = 0.0003) and f*Df decreased 50 ± 27% (Δf*Df = -0.59 ± 0.49 × 10-3 mm2/s; p = 0.0026). In contrast, IVIM diffusion coefficient (Ds) and ADC were significantly increased in the ischemic versus control femoral heads: on average, Ds increased 78 ± 21% (ΔDs = 0.60 ± 0.14 × 10-3 mm2/s; p < 0.0001) and ADC increased 60 ± 36% (ΔADC = 0.50 ± 0.23 × 10-3 mm2/s; p < 0.0001). In conclusion, IVIM is sensitive in detecting bone marrow ischemia in a piglet model of LCPD.

Epiphyseal cartilage vascular architecture at the distal humeral osteochondritis dissecans predilection site in juvenile pigs.

Failure of endochondral ossification due to interruption of the vascular supply to the epiphyseal cartilage is a critical step in the development of osteochondritis dissecans (OCD). Herein we describe the vascular architecture of the distal humeral epiphyseal cartilage in pigs and identify characteristic features that have been associated with sites predisposed to OCD development across species. Distal humeral specimens were harvested from pigs (n = 5, ages = 1, 10, 18, 30, and, 42 days old) and imaged at 9.4T magnetic resonance imaging (MRI) using a 3D gradient recalled echo sequence. The MRI data were processed using a quantitative susceptibility mapping (QSM) pipeline to visualize the vascular architecture. Specimens were also evaluated histologically to identify the presence of ischemic epiphyseal cartilage necrosis (osteochondrosis [OC]-latens) and associated failure of endochondral ossification (OC-manifesta). The QSM data enabled visualization of two distinct vascular beds arising from the perichondrium at the lateral and medial aspects of the distal humeral epiphysis. Elongated vessels originating from these beds coursed axially to supply the lateral and medial thirds of epiphyseal cartilage. At 18 days of age and older, a shift from perichondrial to transosseous blood supply was noted axially, which appeared more pronounced on the lateral side. This shift coincided with histologic identification of OC-latens (30- and 42-day-old specimens) and OC-manifesta (18- and 42-day-old specimens) lesions in the corresponding regions. The vascular anatomy and its evolution at the distal humeral epiphysis closely resembles that previously reported at predilection sites of knee OCD, suggesting a shared pathophysiology between the knee and elbow joints.

Changes in tissue sodium concentration and sodium relaxation times during the maturation of human knee cartilage: Ex vivo 23 Na MRI study at 10.5 T.

PURPOSE: To evaluate the influence of skeletal maturation on sodium (23 Na) MRI relaxation parameters and the accuracy of tissue sodium concentration (TSC) quantification in human knee cartilage. METHODS: Twelve pediatric knee specimens were imaged with whole-body 10.5 T MRI using a density-adapted 3D radial projection sequence to evaluate 23 Na parameters: B1 + , T1 , biexponential T 2 * $$ {\mathrm{T}}_2^{\ast } $$ , and TSC. Water, collagen, and sulfated glycosaminoglycan (sGAG) content were calculated from osteochondral biopsies. The TSC was corrected for B1 + , relaxation, and water content. The literature-based TSC (TSCLB ) used previously published values for corrections, whereas the specimen-specific TSC (TSCSP ) used measurements from individual specimens. 23 Na parameters were evaluated in eight cartilage compartments segmented on proton images. Associations between 23 Na parameters, TSCLB - TSCSP difference, biochemical content, and age were determined. RESULTS: From birth to 12 years, cartilage water content decreased by 18%; collagen increased by 59%; and sGAG decreased by 36% (all R2 ≥ 0.557). The short T 2 * $$ {\mathrm{T}}_2^{\ast } $$ ( T 2 * S $$ {{\mathrm{T}}_2^{\ast}}_{\mathrm{S}} $$ ) decreased by 72%, and the signal fraction relaxing with T 2 * S $$ {{\mathrm{T}}_2^{\ast}}_{\mathrm{S}} $$ ( fT 2 * S $$ {{\mathrm{fT}}_2^{\ast}}_{\mathrm{S}} $$ ) increased by 55% during the first 5 years but remained relatively stable after that. TSCSP was significantly correlated with sGAG content from biopsies (R2 = 0.739). Depending on age, TSCLB showed higher or lower values than TSCSP . The TSCLB - TSCSP difference was significantly correlated with T 2 * S $$ {{\mathrm{T}}_2^{\ast}}_{\mathrm{S}} $$ (R2 = 0.850), fT 2 * S $$ {{\mathrm{fT}}_2^{\ast}}_{\mathrm{S}} $$ (R2 = 0.651), and water content (R2 = 0.738). CONCLUSION: TSC and relaxation parameters measured with 23 Na MRI provide noninvasive information about changes in sGAG content and collagen matrix during cartilage maturation. Cartilage TSC quantification assuming fixed relaxation may be feasible in children older than 5 years.

Cell Count and Cell Density Decrease as Age Increases in Cadaveric Pediatric Medial Menisci.

Purpose: To examine the histologic changes in terms of cellularity, cell density, and nuclear shape in medial meniscal cellularity during skeletal development using pediatric cadaver specimens. Methods: Medial menisci from 26 pediatric cadavers, 11 female and 15 male (total 36 menisci), were obtained from tissue bank. Mean age of female donors was 34 months (1-108 months) and of male donors was 52 months (1-132 months). Menisci were processed and embedded in paraffin blocks. Each tissue block containing 6 representative areas of meniscus (anterior root, anterior horn, body [n = 2], posterior horn, and posterior root) was sectioned at 4 microns and stained with hematoxylin and eosin for evaluation of chondrocyte nuclei. Each of the 6 representative areas was imaged at 10×; one image on peripheral one-third of section, the second image on central two-thirds of the section. FIJI imaging software was used to measure cell count, cell density, and nuclear morphology (1 = perfect circle). Data analysis included linear mixed models, Type II analysis of variance tests, and pairwise tests with the Tukey correction to assess statistical significance. Results: Peripheral meniscus was more cellular than central meniscus. The cell count was found to decrease by 14% per year of age. Peripheral cell count decreased at a rate similar to the cell count in the central meniscus. Meniscal cell density was 2× higher peripherally than centrally. Overall average cell density in all locations in the menisci decreased by an average of 14% per year of age. Conclusions: The results of this study reveal decreases in cell count, cell density, and circularity as age increases in cadaveric pediatric medial menisci. Clinical Relevance: To better understand the development of pediatric menisci at a cellular level and use this knowledge in the future on how to maintain the menisci in a younger, healthier state.

Aqueous Extracts of Organic Mulch Materials Have Nematicide and Repellent Effect on Meloidogyne incognita Infective Juveniles: A Laboratory Study.

While the nematicidal effectiveness of mulching against root-knot nematodes (Meloidogyne spp.) is calculated within organic crop protection, underlying mechanisms are not yet fully explored. Laboratory experiments were set up to determine whether mulch-derived substances cause mortality directly, or repel Meloidogyne juveniles from crop rhizosphere. Mortality and area choice tests were conducted with mulch-derived extracts, supported by the measurements on tannic acid content and the pH values of extracts as supplementary examinations. In our study, leaf litter and straw extracts were generally found lethal to the juveniles, which is in line with the results from area preference tests. However, compost extract had no effect on Meloidogyne incognita juveniles. Tannic acid content showed positive correlation with mortality only in the case of straw and sycamore leaf litter extracts. Tannic acid and pH weakly correlated with repellent effect of the applied extracts generally. Our results have inspired further experiments to explore nematicidal components of leaf litters, contributing to the development of a new approach in crop protection based on the repellent effect of these materials.

ß-Tricalcium Phosphate-Modified Aerogel Containing PVA/Chitosan Hybrid Nanospun Scaffolds for Bone Regeneration.

Electrospinning has recently been recognized as a potential method for use in biomedical applications such as nanofiber-based drug delivery or tissue engineering scaffolds. The present study aimed to demonstrate the electrospinning preparation and suitability of ß-tricalcium phosphate-modified aerogel containing polyvinyl alcohol/chitosan fibrous meshes (BTCP-AE-FMs) for bone regeneration under in vitro and in vivo conditions. The mesh physicochemical properties included a 147 ± 50 nm fibrous structure, in aqueous media the contact angles were 64.1 ± 1.7°, and it released Ca, P, and Si. The viability of dental pulp stem cells on the BTCP-AE-FM was proven by an alamarBlue assay and with a scanning electron microscope. Critical-size calvarial defects in rats were performed as in vivo experiments to investigate the influence of meshes on bone regeneration. PET imaging using 18F-sodium fluoride standardized uptake values (SUVs) detected 7.40 ± 1.03 using polyvinyl alcohol/chitosan fibrous meshes (FMs) while 10.72 ± 1.11 with BTCP-AE-FMs after 6 months. New bone formations were confirmed by histological analysis. Despite a slight change in the morphology of the mesh because of cross-linking, the BTCP-AE-FM basically retained its fibrous, porous structure and hydrophilic and biocompatible character. Our experiments proved that hybrid nanospun scaffold composite mesh could be a new experimental bone substitute bioactive material in future medical practice.

Naturally occurring osteochondrosis latens lesions identified by quantitative and morphological 10.5 T MRI in pigs.

Juvenile osteochondritis dissecans (JOCD) is a pediatric orthopedic disorder that involves the articular-epiphyseal cartilage complex and underlying bone. Clinical disease is often characterized by the presence of radiographically apparent osteochondral flaps and fragments. The existence of early JOCD lesions (osteochondrosis latens [OCL] and osteochondrosis manifesta [OCM]) that precede the development of osteochondral flaps and fragments is also well recognized. However, identification of naturally occurring OCL lesions (confined to cartilage) using noninvasive imaging techniques has not yet been accomplished. We hypothesized that 10.5 T magnetic resonance imaging (MRI) can identify naturally occurring OCL lesions at predilection sites in intact joints of juvenile pigs. Unilateral elbows and knees (stifles) were harvested from three pigs aged 4, 8, and 12 weeks, and scanned in a 10.5 T MRI to obtain morphological 3D DESS images, and quantitative T2 and T1ρ relaxation time maps. Areas with increased T2 and T1ρ relaxation times in the articular-epiphyseal cartilage complex were identified in 1/3 distal femora and 3/3 distal humeri and were considered suspicious for OCL or OCM lesions. Histological assessment confirmed the presence of OCL or OCM lesions at each of these sites and failed to identify additional lesions. Histological findings included necrotic vascular profiles associated with areas of chondronecrosis either confined to the epiphyseal cartilage (OCL, 4- and 8-week-old specimens) or resulting in a delay in endochondral ossification (OCM, 12-week-old specimen). Future studies with clinical MR systems (≤7 T) are needed to determine whether these MRI methods are suitable for the in vivo diagnosis of early JOCD lesions in humans.

Effect of Entomopathogenic Fungi, Beauveria bassiana (Cordycipitaceae), on the Bark Beetle, Ips typographus (L.), under Field Conditions.

The spruce bark beetle, Ips typographus (L.), attack progression (adult and larval galleries) and parental and offspring mortality rate were assessed in managed forests of the Poiana Rusca and Bihor Mountains, along with Western Romanian Carpathians using fungal (Beauveria bassiana) treatments. The results show that the effect of B. bassiana on adult (maternal) gallery length was similar to the untreated variant and was less effective than the synthetic insecticide lambda-cyhalothrin applied at a dose of 50 g/L. Additionally, its effect on the mean larval gallery number per maternal gallery was low. B. bassiana did not have a significant influence on the attack progression. Significant correlations between log diameter and I. typographus attack progression were detected; such differences were higher than the effect of any treatment. Altogether, abiotic (low humidity, high temperature) and biotic factors (log diameter) influenced the bark beetles' attack progression and reduced the entomopathogenic fungal effects. Considering the efficacy of the B. bassiana treatment on logs infested with I. typographus, the results showed that parents and offspring were infected, but even if the fungal treatment was applied in high concentrations, the mortality rate remained relatively low. Further research is necessary to test if different B. bassiana strains and their commercially recommended concentrations might be more effective under dry and warm climate conditions, respectively.

Combined Release of Antiseptic and Antibiotic Drugs from Visible Light Polymerized Biodegradable Nanocomposite Hydrogels for Periodontitis Treatment.

The in situ application of the combination of different types of drugs revolutionized the area of periodontal therapy. The purpose of this study was to develop nanocomposite hydrogel (NCHG) as a pH-sensitive drug delivery system. To achieve local applicability of the NCHG in dental practice, routinely used blue-light photopolymerization was chosen for preparation. The setting time was 60 s, which resulted in stable hydrogel structures. Universal Britton-Robinson buffer solutions were used to investigate the effect of pH in the range 4-12 on the release of drugs that can be used in the periodontal pocket. Metronidazole was released from the NCHGs within 12 h, but chlorhexidine showed a much longer elution time with strong pH dependence, which lasted more than 7 days as it was corroborated by the bactericidal effect. The biocompatibility of the NCHGs was proven by Alamar-blue test and the effectiveness of drug release in the acidic medium was also demonstrated. This fast photo-polymerizable NCHG can help to establish a locally applicable combined drug delivery system which can be loaded with the required amount of medicines and can reduce the side effects of the systemic use of drugs that have to be used in high doses to reach an ideal concentration locally.

The Effect of Heat Treatment of ß-Tricalcium Phosphate-Containing Silica-Based Bioactive Aerogels on the Cellular Metabolism and Proliferation of MG63 Cells.

ß-Tricalcium phosphate was combined with silica aerogel in composites prepared using the sol-gel technique and supercritical drying. The materials were used in this study to check their biological activity and bone regeneration potential with MG63 cell experiments. The composites were sintered in 100 °C steps in the range of 500-1000 °C. Their mechanical properties, porosities, and solubility were determined as a function of sintering temperature. Dissolution studies revealed that the released Ca-/P molar ratios appeared to be in the optimal range to support bone tissue induction. Cell viability, ALP activity, and type I collagen gene expression results all suggested that the sintering of the compound at approximately 700-800 °C as a scaffold could be more powerful in vivo to facilitate bone formation within a bone defect, compared to that documented previously by our research team. We did not observe any detrimental effect on cell viability. Both the alkaline phosphatase enzyme activity and the type I collagen gene expression were significantly higher compared with the control and the other aerogels heat-treated at different temperatures. The mesoporous silica-based aerogel composites containing ß-tricalcium phosphate particles treated at temperatures lower than 1000 °C produced a positive effect on the osteoblastic activity of MG63 cells. An in vivo 6 month-long follow-up study of the mechanically strongest 1000 °C sample in rat calvaria experiments provided proof of a complete remodeling of the bone.

T1ρ and T2 mapping detect acute ischemic injury in a piglet model of Legg-Calvé-Perthes disease.

This study investigated the sensitivity of T1ρ and T2 relaxation time mapping to detect acute ischemic injury to the secondary ossification center (SOC) and epiphyseal cartilage of the femoral head in a piglet model of Legg-Calvé-Perthes disease. Six piglets underwent surgery to induce global right femoral head ischemia and were euthanized 48 h later. Fresh operated and contralateral-control femoral heads were imaged ex vivo with T1, T2, and T1ρ mapping using a 9.4T magnetic resonance imaging scanner. The specimens were imaged a second time after a freeze/thaw cycle and then processed for histology. T1, T2, and T1ρ measurements in the SOC, epiphyseal cartilage, articular cartilage, and metaphysis were compared between operated and control femoral heads using paired t tests. The effects of freeze/thaw, T1ρ spin-lock frequency, and fat saturation were also investigated. Five piglets with histologically confirmed ischemic injury were quantitatively analyzed. T1ρ was increased in the SOC (101 ± 15 vs. 73 ± 16 ms; p = 0.0026) and epiphyseal cartilage (84.9 ± 9.2 vs. 74.3 ± 3.6 ms; p = 0.031) of the operated versus control femoral heads. T2 was also increased in the SOC (28.7 ± 2.0 vs. 22.7 ± 1.7; p = 0.0037) and epiphyseal cartilage (57.4 ± 4.7 vs. 49.0 ± 2.7; p = 0.0041). No changes in T1 were detected. The sensitivities of T1ρ and T2 mapping in detecting ischemic injury were maintained after a freeze/thaw cycle, and T1ρ sensitivity was maintained after varying spin-lock frequency and applying fat saturation. In conclusion, T1ρ and T2 mapping are sensitive in detecting ischemic injury to the SOC and epiphyseal cartilage of the femoral head as early as 48 h after ischemia induction.

Composted Municipal Green Waste Infused with Biocontrol Agents to Control Plant Parasitic Nematodes-A Review.

The last few years have witnessed the emergence of alternative measures to control plant parasitic nematodes (PPNs). We briefly reviewed the potential of compost and the direct or indirect roles of soil-dwelling organisms against PPNs. We compiled and assessed the most intensively researched factors of suppressivity. Municipal green waste (MGW) was identified and profiled. We found that compost, with or without beneficial microorganisms as biocontrol agents (BCAs) against PPNs, were shown to have mechanisms for the control of plant parasitic nematodes. Compost supports a diverse microbiome, introduces and enhances populations of antagonistic microorganisms, releases nematicidal compounds, increases the tolerance and resistance of plants, and encourages the establishment of a "soil environment" that is unsuitable for PPNs. Our compilation of recent papers reveals that while the scope of research on compost and BCAs is extensive, the role of MGW-based compost (MGWC) in the control of PPNs has been given less attention. We conclude that the most environmentally friendly and long-term, sustainable form of PPN control is to encourage and enhance the soil microbiome. MGW is a valuable resource material produced in significant amounts worldwide. More studies are suggested on the use of MGWC, because it has a considerable potential to create and maintain soil suppressivity against PPNs. To expand knowledge, future research directions shall include trials investigating MGWC, inoculated with BCAs.

The Effect of the PVA/Chitosan/Citric Acid Ratio on the Hydrophilicity of Electrospun Nanofiber Meshes.

In this study, scaffolds were prepared via an electrospinning method for application in oral cavities. The hydrophilicity of the fiber mesh is of paramount importance, as it promotes cell spreading; however, the most commonly used polyvinyl alcohol (PVA) and other hydrophilic fiber meshes immediately disintegrate in aqueous media. In contrast, the excessive hydrophobicity of the scaffolds already inhibits cells adhesion on the surface. Therefore, the hydrophilicity of the fiber meshes needed to be optimized. Scaffolds with different polyvinyl alcohol (PVA)/chitosan/citric acid ratios were prepared. The addition of chitosan and the heat initiated cross-linkage of the polymers via citric acid enhanced the scaffolds' hydrophobicity. The optimization of this property could be followed by contact angle measurements, and the increased number of cross-linkages were also supported by IR spectroscopy results. The fibers' physical parameters were monitored via low-vacuum scanning electron microscopy (SEM) and atomic force microscopy (AFM). As biocompatibility is essential for dental applications, Alamar Blue assay was used to prove that meshes do not have any negative effects on dental pulp stem cells. Our results showed that the optimization of the fiber nets was successful, as they will not disintegrate in intraoral cavities during dental applications.

Institutionally Adopted Perioperative Blood Management Program Significantly Decreased the Transfusion Rate of Patients Having Primary Total Hip Replacement Surgery.

Perioperative transfusion in patients undergoing orthopedic surgery increases the number of postoperative complications. Thus, we have introduced an institution-tailored perioperative blood management program (PBM) to decrease the amount of blood transfused in patients going through primary total hip replacement (THR) surgery. We have conducted a before-after observational cohort study in two predetermined observational periods. Demographic and clinical data, ASA scores, laboratory parameters, features of surgical procedure, and anesthesia were registered. Parameters of perioperative fluid administration, transfusion rate, and postoperative complications were also assessed. One hundred patients in the first and 108 patients in the second observational period were enrolled. Eventhough the ratio of posttraumatic THR procedures increased (9% vs. 17%), the PBM protocol has been utilized effectively and a significant decrease in perioperative blood transfusion rate has been observed (61% vs. 21%). The abolishment of routine preoperative LMWH prophylaxis (90% vs. 16%), intraoperative use of tranexamic acid (10% vs. 84%), and the encouraged exploitation of our postoperative observational facility (5% vs. 39%) were abided by our colleagues. Patients still requiring transfusion had lower preoperative hemoglobin levels (129 vs. 147 g/l), scored higher in ASA (ASA III: 46% vs. 19%), and more often presented postoperative hypotension (40% vs. 7%), oliguria (23% vs. 5%), and infections (9% vs. 2%). We conclude that the individualized perioperative blood management protocol was successfully implemented and yielded a lower transfusion rate and better outcomes. Our study suggests that a partial, institution-tailored PBM program may be suitable and beneficial in countries where the modalities of perioperative blood management are limited.

Introduction of day case hip and knee replacement programme at an inpatient ward is safe and may expedite shortening of hospital stays of traditional arthroplasties.

PURPOSE: We investigated the safety of primary hip and knee replacements with same day discharge (SDD) and their effect on length of stay (LOS) of traditional inpatient arthroplasties at our elective orthopaedic ward. METHODS: 200 patients underwent elective, unilateral primary day case total hip (THA, n = 94), total knee (TKA, n = 60) and unicondylar knee replacements (UKA, n = 46). SDD rates, reasons for failure to discharge, readmission, complication and satisfaction rates were recorded at 6-week follow up. Changes in LOS of inpatient arthroplasties (n = 6518) and rate of patients discharged with only one night stay treated at the same ward were tracked from 1 year prior to introduction of day case arthroplasty (DCA) program to the end of observation period. RESULTS: 166 patients (83%) had SDD while 34 (17%) needed overnight stay. Main reasons for failure to discharge were lack of confidence (4%) fainting due to single vasovagal episode (3.5%), urine retention (3%) and late resolution of spinal anaesthesia (3%). 5 patients (3%) had readmission within 6 weeks, including 1 (0.6%) with a partial and treated pulmonary embolism. 163 patients were satisfied with SDD (98%). After launching the DCA program, average LOS of inpatients was reduced from 2.3 days to 1.8 days and rate of discharge with only 1-night stay increased from 12% to around 60%. CONCLUSION: Introduction of routine SDD hip and knee arthroplasty programme at an elective orthopaedic centre is safe and also may confer wider benefits leading to shorter inpatient hospital stays.

Effect of Inducible BMP-7 Expression on the Osteogenic Differentiation of Human Dental Pulp Stem Cells.

BMP-7 has shown inductive potential for in vitro osteogenic differentiation of mesenchymal stem cells, which are an ideal resource for regenerative medicine. Externally applied, recombinant BMP-7 was able to induce the osteogenic differentiation of DPSCs but based on our previous results with BMP-2, we aimed to study the effect of the tetracyclin-inducible BMP-7 expression on these cells. DPSC, mock, and DPSC-BMP-7 cell lines were cultured in the presence or absence of doxycycline, then alkaline phosphatase (ALP) activity, mineralization, and mRNA levels of different osteogenic marker genes were measured. In the DPSC-BMP-7 cell line, the level of BMP-7 mRNA significantly increased in the media supplemented with doxycycline, however, the expression of Runx2 and noggin genes was upregulated only after 21 days of incubation in the osteogenic medium with doxycycline. Moreover, while the examination of ALP activity showed reduced activity in the control medium containing doxycycline, the accumulation of minerals remained unchanged in the cultures. We have found that the induced BMP-7 expression failed to induce osteogenic differentiation of DPSCs. We propose three different mechanisms that may worth investigating for the engineering of expression systems that can be used for the induction of differentiation of mesenchymal stem cells.

A pilot study to assess the healing of meniscal tears in young adult goats.

Meniscal tears are a common orthopedic injury, yet their healing is difficult to assess post-operatively. This impedes clinical decisions as the healing status of the meniscus cannot be accurately determined non-invasively. Thus, the objectives of this study were to explore the utility of a goat model and to use quantitative magnetic resonance imaging (MRI) techniques, histology, and biomechanical testing to assess the healing status of surgically induced meniscal tears. Adiabatic T1ρ, T2, and T2* relaxation times were quantified for both operated and control menisci ex vivo. Histology was used to assign healing status, assess compositional elements, and associate healing status with compositional elements. Biomechanical testing determined the failure load of healing lesions. Adiabatic T1ρ, T2, and T2* were able to quantitatively identify different healing states. Histology showed evidence of diminished proteoglycans and increased vascularity in both healed and non-healed menisci with surgically induced tears. Biomechanical results revealed that increased healing (as assessed histologically and on MRI) was associated with greater failure load. Our findings indicate increased healing is associated with greater meniscal strength and decreased signal differences (relative to contralateral controls) on MRI. This indicates that quantitative MRI may be a viable method to assess meniscal tears post-operatively.