Mature Sheep Research Articles

Assessment of loliolide extracted from Biserula pelecinus, present during in vitro oocyte maturation, on fertilisation and embryo development in sheep

Context As a ‘duty of care’, it is important to test whether new forage plants for ruminants contain secondary compounds (PSCs) that affect reproductive performance. We have previously observed, a posteriori, that the presence of a methanolic extract of Biserrula pelecinus during maturation of sheep oocytes increased fertilisation rate and blastocyst development. This result needed to be verified a priori and, if the outcome was repeated, we needed to identify the plant secondary metabolite responsible. Aims To test whether PSCs from B. pelecinus, when added to the oocyte maturation medium, improve fertilisation rate and blastocyst development; to test whether loliolide is the active molecule produced by B. pelecinus. Methods Methanol–chloroform extracts of B. pelecinus were fractionated using rapid silica filtration and solvents of increasing polarity. Fractions at final concentrations of 0, 100 or 200 μg mL−1 were added to the medium used to mature sheep cumulus–oocyte complexes (COCs) and effects were determined for maturation, subsequent cleavage rate, blastocyst rate, hatching rate, blastocyst efficiency and total blastocyst cell number (TCN). Results Fraction BP-6 at 100 μg mL−1 reduced blastocyst rate (P < 0.05), but had no effect when the dose was doubled to 200 μg mL−1. Further fractionation using semi-preparative high-performance liquid chromatography showed loliolide as the most abundant compound in BP-6. Supplementation of the in vitro maturation medium with loliolide (0, 2.5, 5, 10 and 25 μg mL−1) did not affect any measure of embryo development. All COCs treated with B. pelecinus fractions reached the final stage of embryo development, blastocyst hatching. Total blastocyst cell number was not affected. Conclusion The presence of fractions of B. pelecinus extract during in vitro oocyte maturation can reduce embryo development. Implications In vitro techniques can detect potential effects of forages on reproduction. Some fractions from an extract of B. pelecinus when present during oocyte maturation can reduce embryo development. The abundant PSC, loliolide, was not responsible. There was no indication that a PSC in B. pelecinus improves outcomes.

A Mathematical Model for Postimplant Collagen Remodeling in an Autologous Engineered Pulmonary Arterial Conduit.

This study was undertaken to develop a mathematical model of the long-term in vivo remodeling processes in postimplanted pulmonary artery (PA) conduits. Experimental results from two extant ovine in vivo studies, wherein polyglycolic-acid (PGA)/poly-L-lactic acid tubular conduits were constructed, cell seeded, incubated for 4 weeks, and then implanted in mature sheep to obtain the remodeling data for up to two years. Explanted conduit analysis included detailed novel structural and mechanical studies. Results in both studies indicated that the in vivo conduits remained dimensionally stable up to 80 weeks, so that the conduits maintained a constant in vivo stress and deformation state. In contrast, continued remodeling of the constituent collagen fiber network as evidenced by an increase in effective tissue uniaxial tangent modulus, which then stabilized by one year postimplant. A mesostructural constitute model was then applied to extant planar biaxial mechanical data and revealed several interesting features, including an initial pronounced increase in effective collagen fiber modulus, paralleled by a simultaneous shift toward longer, more uniformly length-distributed collagen fibers. Thus, while the conduit remained dimensionally stable, its internal collagen fibrous structure and resultant mechanical behaviors underwent continued remodeling that stabilized by one year. A time-evolving structural mixture-based mathematical model specialized for this unique form of tissue remodeling was developed, with a focus on time-evolving collagen fiber stiffness as the driver for tissue-level remodeling. The remodeling model was able to fully reproduce (1) the observed tissue-level increases in stiffness by time-evolving simultaneous increases in collagen fiber modulus and lengths, (2) maintenance of the constant collagen fiber angular dispersion, and (3) stabilization of the remodeling processes at one year. Collagen fiber remodeling geometry was directly verified experimentally by histological analysis of the time-evolving collagen fiber crimp, which matches model predictions very closely. Interestingly, the remodeling model indicated that the basis for tissue homeostasis was maintenance of the collagen fiber ensemble stress for all orientations, and not individual collagen fiber stresses. Unlike other growth and remodeling models that traditionally treat changes in the external boundary conditions (e.g., changes in blood pressure) as the primary input stimuli, the driver herein is changes to the internal constituent collagen fiber themselves due to cellular mediated cross-linking.

Pharmacokinetics and pharmacodynamics of intravenously and subcutaneously administered pantoprazole in sheep (Ovis aries).

Abomasal ulcers are recognized in sheep of all ages, but research regarding therapeutic interventions is limited. Proton Pump Inhibitors (PPIs) such as pantoprazole, are clinically used with a paucity of evidence regarding efficacy in mature sheep. Intravenous and subcutaneously administered pantoprazole dosed at 1.0 mg/kg in adult sheep will increase the pH of abomasal fluid compared to pre-administration baseline. The objectives were to assess the effect of pantoprazole, after single and multiple administration, on abomasal fluid pH in adult sheep. A third objective was to describe the pharmacokinetic parameters of IV and SC pantoprazole. Four clinically healthy adult Southdown ewes previously fitted with a gastrostomy tube in the abomasum were utilized in this randomized, 2-way cross-over trial. Ewes received pantoprazole (1.0 mg/kg) as a single and 3-dose regimen (every 24 hours). After a 10 day washout period the reverse treatment was applied. Blood for analysis of pantoprazole concentration was collected intermittently for 24 hours, and abomasal fluid pH was measured at intervals for a 96-hour period. The pH of the abomasal fluid was higher in pantoprazole treatments for up to 24 hours after dosing. Following intravenous administration of pantoprazole to study ewes, elimination half-life, volume of distribution, and clearance of pantoprazole was estimated as 3.29 hours, 0.35 L/kg, and 65.26 mL/hr/kg respectively. After subcutaneous dosing, maximum concentration, time to maximum concentration, half-life of elimination, and volume of distribution, were estimated as 2604 ng/mL, 0.55 hours, 2.48 hours, and 0.37 L/kg. Additionally, the bioavailability was estimated as 83.33%. Pantoprazole administered IV or SC may be useful for treatment or prevention of abomasal ulcers in adult sheep.

A Study of the Relationship between Initial Grape Yield and Soil Properties Based on Organic Fertilization

Increasing the use of organic fertilizers is an effective measure to improve, increase soil fertility and maintain crop yields. The aim of this study was to investigate the influence of different types of organic fertilizers on the early yield of grapes and soil parameters, as well as the relationship between soil parameters and grape yield under fertilization conditions. The ‘Shine Muscat’ grape was used as the material, with early maturing cultivation in the solar greenhouse. From the time of grape planting, three-year continuous fertilization management was carried out using five types of base fertilizers: chemical fertilizer (CK), fermented corn stalk residue (A1), mature sheep manure (A2) and two types of commercial organic fertilizers (B1 and B2). In the third year, berry and soil samples were collected to determine grape yield and evaluate soil physicochemical properties, nutrient status and changes in enzyme activity, studying the relationship between grape yield and soil indicators. The results show that compared to CK, the grape yields with B1 and B2 increased by 19.04% and 16.26%, respectively, while A1 and A2 decreased by 24.09% and 18.97%. Organic fertilizer application reduced soil bulk density, increased soil porosity, enhanced soil organic matter content and effectively buffered soil pH levels. Two types of commercial fertilizers (B1 and B2) improved soil total nitrogen, total phosphorus, total potassium, available nitrogen and available phosphorus content to varying degrees. All organic fertilizer treatments effectively increased soil enzyme activity, except for soil sucrase activity. Through correlation and regression analyses, it was found that in this study, the levels of available nitrogen, available potassium and soil saccharase activity were most closely related to early grape yield. Their influence on grape yield was in the order of available nitrogen > soil saccharase activity > available potassium. Therefore, with a combined organic and inorganic basal fertilization system, the fertilizer nutrients are more comprehensive and help to increase the productivity of grapes at the beginning of the fruiting period. Nitrogen and phosphorus are very important in the maintaining of grape yields and improving sucrose activity in the soil through the application of organic fertilizers cannot be ignored when increasing yields.

Skeletotopic features of the chin opening in animals

The article presents the features in the skeletotopia of the mental foramen in different animal species (sheep, horse, dog). The research was conducted at the Department of Anatomy and Histology of Animals named after Prof. A.F. Klimov of the K.I. Skryabin Moscow State Automobile Academy of Veterinary Medicine and Biology. The object of the study was: sexually mature sheep (Ovis aries) (n=10), domestic horse (Equus caballus) (n=10) and dog (Canis lupus familiaris) (n=10). The material for the research was mandibles (n=30). A comprehensive methodological approach was used, including anatomical preparation and measurement of linear parameters (height of the mandibular body and distance from the chin aperture to the upper edge of the diastema) with subsequent digital processing of the results. Based on these studies, species regularities and peculiarities of anatomical organization of the mental foramen in different taxonomic groups were revealed. At the analysis of the received linear parameters the index of relative height of a chin aperture was calculated, which is a percentage relation of distance from a chin aperture to the top edge of diastema to height of a body of a mandible on which it is established, that on the digital expressions the dog (69) was in the lead, while the sheep (36) had the minimum digital values. Horse (51) occupied an intermediate position according to the studied index. The results obtained can be used in the development of new methods of tooth extirpation, in the performance of local anesthesia of the trigeminal nerve in veterinary dentistry, as well as in the identification of the animal species by the head skeleton.

Epidemiological Data Regarding the Distribution of Gastrointestinal Parasites in Albanian Small Ruminants

Background: Gastrointestinal infection of small ruminants is becoming a real problem due to the resistance against anthelmintic treatment. These parasitic infections are prevalent among grazing ruminants and result in significant economic losses by reduced production. The aim of the study was to evaluate and estimate the total loud of parasitic infection is small ruminants, sheep’s and goats from different farms located in Korça district. Methods: This study investigates parasitic infections in sheep and goats across 40 farms situated in Korça district in southeastern Albania. The primary objective is to assess the prevalence of gastrointestinal parasites within feces samples from mature sheep and goats. In total, 121 feces samples were meticulously collected. Samples were analysed and processed using the Mini-FLOTAC technique in order to identify eggs and oocysts in each herd. Result: The results of the investigation revealed the presence of Strongyloides papillosus in 45.45% of samples, Ostertagia spp. eggs in 40.9% of samples, Monezia expansa eggs in 27.2% of samples, Dictiocaulus filaria in 22.3% of samples, Nematodirus spathiger eggs in 13.2% of samples, Haemonchus contortus eggs in 13.3%, Cooperia spp. eggs in 9% of samples, Trichostrongylus axei in 9% of samples, Coccidian oocysts in 4.1% of samples and Trichuris ovis in 1.6% of samples.

Effect of organic fertilisation on yield and soil factor values of extensive grassland

The effect of different rates of organic fertilizer was investigated on a natural grassland with solonyec soil conditions at the Karcag Research Institute in the second year after application. Of the mature sheep manure treatments applied at 0-10-15-20 t/ha, the 20 t/ha dose was shown to result in higher dry matter yields. In addition, the 20 t/ha dose of organic manure was shown to stimulate soil life, as supported by measurements of carbon dioxide emissions, and to help better conserve soil moisture.

Combining adhesive and nonadhesive injectable hydrogels for intervertebral disc repair in an ovine discectomy model.

Intervertebral disc (IVD) disorders (e.g., herniation) directly contribute to back pain, which is a leading cause of global disability. Next-generation treatments for IVD herniation need advanced preclinical testing to evaluate their ability to repair large defects, prevent reherniation, and limit progressive degeneration. This study tested whether experimental, injectable, and nonbioactive biomaterials could slow IVD degeneration in an ovine discectomy model. Ten skeletally mature sheep (4-5.5 years) experienced partial discectomy injury with cruciate-style annulus fibrosus (AF) defects and 0.1 g nucleus pulposus (NP) removal in the L1-L2, L2-L3, and L3-L4 lumbar IVDs. L4-L5 IVDs were Intact controls. IVD injury levels received: (1) no treatment (Injury), (2) poly (ethylene glycol) diacrylate (PEGDA), (3) genipin-crosslinked fibrin (FibGen), (4) carboxymethylcellulose-methylcellulose (C-MC), or (5) C-MC and FibGen (FibGen + C-MC). Animals healed for 12 weeks, then IVDs were assessed using computed tomography (CT), magnetic resonance (MR) imaging, and histopathology. All repaired IVDs retained ~90% of their preoperative disc height and showed minor degenerative changes by Pfirrmann grading. All repairs had similar disc height loss and Pfirrmann grade as Injury IVDs. Adhesive AF sealants (i.e., PEGDA and FibGen) did not herniate, although repair caused local endplate (EP) changes and inflammation. NP repair biomaterials (i.e., C-MC) and combination repair (i.e., FibGen + C-MC) exhibited lower levels of degeneration, less EP damage, and less severe inflammation; however, C-MC showed signs of herniation via biomaterial expulsion. All repair IVDs were noninferior to Injury IVDs by IVD height loss and Pfirrmann grade. C-MC and FibGen + C-MC IVDs had the best outcomes, and may be appropriate for enhancement with bioactive factors (e.g., cells, growth factors, and miRNAs). Such bioactive factors appear to be necessary to prevent injury-induced IVD degeneration. Application of AF sealants alone (i.e., PEGDA and FibGen) resulted in EP damage and inflammation, particularly for PEGDA IVDs, suggesting further material refinements are needed.

English

The current experiment aimed to determine the effects of the growing site on the chemical composition and fermentation parameters of carob pods. Carob pods from ten different trees were hand harvested from seven different growing sites namely; Silifke, Akdeniz, Tarsus, Aydincik, Taşucu, Toroslar and Gülnar in Mersin, Turkey in 2019 and oven dried at 50°C for three days. After drying, the carob pods were ground through a 1 mm-wide sieve for analysis and in vitro gas production (GP) testing. The growing site had a significant effect on the chemical composition, GP, and digestion values of carob pods. The crude ash (CA), crude protein (CP), ether extracts (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), and condensed tannin (CT) contents of carob pods ranged from 2.49 to 3.51%, 5.58 to 9.14%, 2.88 to 3.38%, 17.67 to 28.03%, 11.17 to 17.94%, and 1.98 to 5.05%, respectively. The GP, methane (CH4 (mL), percentage of CH4, metabolizable energy (ME), and organic matter digestibility (OMD) ranged from 95.66 to 123.0 mL g-1 DM, 16.23 to 20.12 mL g-1 DM, 15.69 to 16.96%, 8.24 to 9.72 MJ kg-1 DM, and 54.53 to 63.40%, respectively. The GP, CH4 production, and ME contents of carob pods obtained from Silifke, Akdeniz, Tarsus, and Tasucu were significantly higher than those from the other growing sites, whereas the OMD of carob pods from Silifke and Tarsus was significantly higher than that from the other sites. The true digestible substrate (TDS), microbial protein yield (MPY), efficiency of microbial protein yield (EMPY), and true substrate digestibility (TSD) of carob pods ranged from 319.54 to 469.62 mg, 109.07 to 207.09 mg, 32.34 to 44.10%, and 68.43 to 96.11%, respectively. The TDS, MPY, EMPY, and TSD of carob pods from Tasucu were significantly higher than those from the other sites. The current study revealed valuable insight regarding the chemical composition and fermentation parameters of carob pods grown at different sites. Carop pods can be used in sheep diets to meet the energy requirement of mature sheep for maintenance and lactation whereas protein supplementation is essential when incorporating carob pods into the diets of lactating sheep to fulfill their dietary requirements.

Peculiarities of organometry and morphoarchitectonics of the heart of the Domestic ram (Ovis aries L., 1758)

Today, cardiovascular diseases are the dominant diseases of animals, which most often lead to their death both in Ukraine and worldwide. Therefore, morphological studies of the heart at the cellular, tissue, and organ levels are essential in clinical cardiology for in vivo ultrasound diagnosis of functional and organic heart lesions. The aim of the study was to perform a histological and cytomorphometric assessment of the morphological structures of the sheep heart using macroscopic, histological, and morphometric methods. Using morphological methods, the hearts of sexually mature clinically healthy animals (n=5) belonging to the class Mammalia – Mammals, species Ovis aries L., 1758 – domestic sheep (ram) were studied. The absolute and relative heart weights of mature sheep were determined, which are, respectively, 208.4±9.82 g and 0.44±0.007%, and the weight without epicardial fat is 175.0±8.17 g. The heart of sheep, according to the development index (145.5±4.02%), belongs to the expanded-shortened anatomical type. The most developed components are the ventricles. At the same time, the ratio of the mass of the heart ventricles to its net mass is 1:0.78, respectively, the ratio of the mass of the atria is 1:0.22, and the ratio of the mass of the atrial myocardium to the mass of the ventricular myocardium is 1:0.29. The largest volume was found in the cardiomyocytes of the left ventricle – 3982.99±423.96 μm3 , the smaller – in the right ventricle – 2463.02±318.04 μm3 and the smallest – in the atrial cardiomyocytes – 1215.93±176.94 μm3 . The volumes of cardiomyocyte nuclei in the left (53.42±5.18 μm3 ), right (52.85±4.33 μm3 ) ventricles and atria (50.16±4.57 μm3 ) were almost identical. Nuclear-cytoplasmic ratio was the lowest in cardiomyocytes of the left ventricle – 0.0136±0.0062, slightly higher in cardiomyocytes of the right ventricle – 0.0219±0.0079 and the highest – 0.0430±0.0096 in atrial cardiomyocytes. The obtained results on the macroand microscopic structure of the heart of bighorn sheep (Ovis aries L., 1758) complement the information on the morphology of the sheep heart in the relevant sections of histology and comparative anatomy and are necessary for clinical cardiology

A new minimal-invasive approach for total hip replacement in sheep.

Over the last 50 years arthroplasty became the gold-standard treatment for disabling conditions of the coxofemoral joint. Variations of anterior, lateral, and dorsal incision have been applied, but as each approach requires the incision and reflection of various muscles to gain adequate exposure of the joint results are still controversial. The purpose of this study was to develop a minimal-invasive, tissue-sparing approach in sheep with reduced risks in animal testing. 12 mature sheep underwent hip surgery as part of a study to evaluate a hip resurfacing system. In line with the preliminary cadaveric tests a modified, minimal-invasive, musclepreserving surgical approach was sought after. We developed a surgical approach to the coxofemoral joint in sheep using only blunt tissue dissection after skin incision without any limitations in joint exposure or increased blood loss/duration of surgery. Even though limitations occur and femoral orientation in sheep differs from man, joint forces have similar relative directions to the bone with similar bony and vascular anatomy. Therefore, this minimal-invasive muscle preserving approach might be a safe and comparable alternative in still inevitable animal testing.

The Use of Stromal Vascular Fraction in Long Bone Defect Healing in Sheep.

The objectives of the present study were to evaluate (a) the feasibility of using stromal vascular fraction (SVF) and nanocrystalline hydroxyapatite (nHA) paste in combination for the treatment of segmental bone defect, (b) the quality of the callus produced, (c) the potential improvement of the autograft technique, and (d) the direct comparison of the biomaterial to the use of autogenous cancellous bone. Unilateral, segmental mid-diaphyseal bone defect was created on the right metatarsus of skeletally mature sheep animals (n = 24) under anesthesia (D0). Residual segments were stabilized by stainless-steel plates and appropriate screws. Defects were managed as follows: group A: use of nHA paste to filling, group B: use of autogenous bone graft mixed with nHA bone paste, placed in defect, group C: use of SVF mixed with nHA bone paste injected into defect, group D: use of bone graft and SVF with nHA paste before apposition in bone defect. SVF had been previously isolated from adipose tissue of the animals intra-operatively after digestion with collagenase solution and neutralization. Animals were evaluated clinically and by X-raying and ultrasonographic examination of the defect, at regular intervals, until D90. Ultrasonographic assessment performed along the length of the defect included calculation of the length of the bone defect and assessment of vascularization. SVF was successfully isolated from group C and D animals, with the average yield being 1.77 × 106 cells. The comparison of clinical scores (based on the 'Kaler scale') on each post-operative day indicated significant differences between the four groups on D1 to D30 (p < 0.01); the median clinical score within group A was 2.5 for D1-D30 and 1 for the entire period; respective scores for other groups were 1.5 (p = 0.07) and 0 (p = 0.033). Differences in radiographic assessment scores were significant for scores obtained on D60 (p = 0.049) and D90 (p = 0.006). There was a significant difference between the four groups in the length of the bone defect, as assessed ultrasonographically, for the entire length of the study; median values were 8, 8.5, 6, and 8 mm for groups A, B, C, and D, respectively (p = 0.008). There was a significance in the differences between median scores obtained during the histopathological examination: 2, 11, 13.5, and 12 for group A, B, C, and D (p = 0.022). There was an inverse correlation between the overall scores of histopathological evaluations and the length of the bone defect (observed on D90) (p < 0.0001) and a correlation between the overall scores and the radiographic assessment scores (obtained on D90) (p < 0.0001). This is the first study in which the efficacy of fresh autologous Stromal Vascular Fraction (SVF) from adipose tissue in enhancing bone healing in a long, weight-bearing, diaphyseal bone was evaluated. It is concluded that the lumbosacral region was an attractive site for harvesting adipose tissue, the use of SVF contributed to faster rehabilitation post-operatively, and SVF significantly enhanced bone formation; in general, the results indicated an osteogenic potential of SVF comparable to the gold standard autologous bone graft.

Novel Osteochondral Biotemplate Improves Long-term Cartilage Repair Compared With Microfracture in an Ovine Model

Background: Current cartilage repair therapies do not re-create the complex mechanical interface between cartilage and bone, which is critical for long-term repair durability. New biomaterial designs that include hard tissue–soft tissue interface structures offer promise to improve clinical outcomes. Purpose/Hypothesis: The purpose of this study was to evaluate the efficacy and safety of a naturally derived osteochondral biotemplate with a novel contiguous hard tissue–soft tissue interface in an ovine model as a regenerative solution for articular cartilage defects. It was hypothesized that the osteochondral biotemplate would produce structurally superior repair tissue compared with microfracture over a 13-month period. Study Design: Controlled laboratory study. Methods: Osteochondral biotemplates were manufactured from porcine cancellous bone. Skeletally mature sheep (N = 30) were randomly allocated to 3 groups: early healing stage (euthanasia at 4 months), 6-month treatment, and 13-month treatment. In the early healing stage group, an 8 mm–diameter by 5 mm–deep osteochondral defect was created on the medial femoral condyle and treated at the time of iatrogenic injury with an osteochondral biotemplate. The contralateral limb received the same treatment 2 months later. In the 6- and 13-month treatment groups, 1 limb received the same osteochondral procedure as the early healing stage group. In the contralateral limb, an 8 mm–diameter, full-thickness cartilage defect (1-2 mm deep) was created and treated with microfracture. Cartilage repair and integration were quantitatively and qualitatively assessed with gross inspection, histological evaluation, and magnetic resonance imaging (MRI). Wilcoxon signed-rank and McNemar tests were used to compare the treatments. Results: At 6 and 13 months after treatment, the biotemplate was not present histologically. At 13 months, the biotemplate treatment demonstrated statistically higher histological scores than microfracture for integration with surrounding cartilage (biotemplate: 74 ± 31; microfracture: 28 ± 39; P = .03), type 2 collagen (biotemplate: 72 ± 33; microfracture: 40 ± 38; P = .02), total cartilage (biotemplate: 71 ± 9; microfracture: 59 ± 9; P = .01), and total integration (biotemplate: 85 ± 15; microfracture: 66 ± 20; P = .04). The osteochondral biotemplate treatment produced a notable transient nonneutrophilic inflammatory response that appeared to approach resolution at 13 months. MRI results were not statistically different between the 2 treatments. Conclusion: Even with the inflammatory response, after 13 months, the osteochondral biotemplate outperformed microfracture in cartilage regeneration and demonstrated superiority in integration between the repair tissue and host tissue as well as integration between the newly formed cartilage and the underlying bone. Clinical Relevance: This work has demonstrated the clinical potential of a novel biomaterial template to regenerate the complex mechanical interface between cartilage and the subchondral bone.

An Immunological and Biomechanical Comparison of PEEK-Zeolite and PEEK Interbody Fusion Devices.

A laboratory study comparing PEEK-zeolite and PEEK spinal implants in an ovine model. This study challenges a conventional spinal implant material, PEEK, to PEEK-zeolite using a non-plated cervical ovine model. Although widely used for spinal implants due to its material properties, polyether ether ketone (PEEK) is hydrophobic, resulting in poor osseointegration, and elicits a mild non-specific foreign body response. Zeolites are negatively-charged aluminosilicate materials that are hypothesized to reduce this pro-inflammatory response when used as a compounding material with PEEK. Fourteen skeletally mature sheep were each implanted with one PEEK-zeolite interbody device and one PEEK interbody device. Both devices were packed with autograft and allograft material and randomly assigned to one of two cervical disc levels. The study involved two survival timepoints (12 and 26wk) and biomechanical, radiographic, and immunological endpoints. One sheep expired from complications not related to the device or procedure. Biomechanical evaluation was based on measures of segmental flexibility, using a six-degrees-of-freedom pneumatic spine tester. Radiographic evaluation was performed using microCT scans in a blinded manner by three physicians. Levels of the pro-inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor alpha at the implant were quantified using immunohistochemistry. PEEK-zeolite and PEEK exhibited equivalent range of motion in flexion extension, lateral bending and axial torsion. Motion was significant reduced for implanted devices at both time points as compared to native segments. Radiographic assessments of fusion and bone formation were similar for both devices. PEEK-zeolite exhibited lower levels of interleukin-1β (P=0.0003) and interleukin-6 (P=0.0300). PEEK-zeolite interbody fusion devices provide initial fixation substantially equivalent to PEEK implants but exhibit a reduced pro-inflammatory response. PEEK-zeolite devices may reduce the chronic inflammation and fibrosis previously observed with PEEK devices.

THE USE OF AN INTERPOSITION POLYPROPYLENE MESH IN ROTATOR CUFF REPAIR: A BIOMECHANICAL STUDY

This study aims to investigate the mechanical properties of a rotator cuff tear repaired with a polypropylene interposition graft in an ovine infraspinatus ex-vivo model.Twenty fresh shoulders from skeletally mature sheep were used in this study. A tear size of 20 mm from the tendon joint was created in the infraspinatus tendon to simulate a large tear in fifteen specimens. This was repaired with a polypropylene mesh used as an interposition graft between the ends of the tendon. Eight specimens were secured with mattress stitches while seven were secured to the remnant tendon on the greater tuberosity side by continuous stitching. Remaining five specimens with an intact tendon served as a control group. All specimens underwent cyclic loading with a universal testing machine to determine the ultimate failure load and gap distance.Gap distance increased with progressive cyclic loading through 3000 cycles for all repaired specimens. Mean gap distance after 3000 cycles for both continuous and mattress groups are 1.7 mm and 4.2 mm respectively (P = .001). Significantly higher mean ultimate failure load was also observed with 549.2 N in the continuous group, 426.6 N in the mattress group and 370 N in the intact group.The use of a polypropylene mesh as an interposition graft for large irreparable rotator cuff tears is biomechanically suitable and results in a robust repair that is comparable to an intact rotator cuff tendon. When paired with a continuous suturing technique, it demonstrates significantly resultant superior biomechanical properties that may potentially reduce re-tear rates after repairing large or massive rotator cuff tears.

Biphasic Interpositional Allograft for Rotator Cuff Repair Augmentation Is Safe in an Ovine Model

This study is a preclinical histological assessment of a biphasic acellular interpositional cancellous allograft in an ovine model of rotator cuff repair (RCR) designed to better understand its safety profile and effects on tendon healing after rotator cuff repair. Thirty skeletally mature sheep with clinically normal shoulders with an artificially created degenerative infraspinatus tendon (IST) tear were randomized to control and treatment groups. Animals were euthanized at 3-weeks, 6-weeks, and 12-weeks. After gross dissection, rotator cuff specimens were fixed with formalin and polymerized for sectioning and staining. Blinded histological scores evaluated inflammatory cell infiltrates, signs of degradation, particulate debris, collagen arrangement, neo-vascularization, and enthesis qualitative measures. There were no treatment specimens that exhibited histological signs of a significant infection, inflammatory infiltrate, or foreign body reaction such as granuloma or fibrous capsule formation. Histological scores in all categories were not significantly different at all time points, including the primary endpoint mean cumulative inflammatory score (control: 3.66 ± 1.21 versus treated: 4.33 ± 1.51, p = 0.42), when comparing the treatment and control RCR groups. In general, the degree of tendon healing and host tissue response was essentially equivalent between the two groups with observation of low overall levels of inflammation and progressive improvements in collagen organization, reduced tenocyte activity, and fibrocartilaginous enthesis reformation. This histological study demonstrated the use of a biphasic interpositional allograft for rotator cuff repair augmentation in an ovine model does not generate an inflammatory response or foreign body reaction. Use of the biphasic interpositional allograft resulted in a histological profile that was essentially equivalent to that of a standard RCR at 3-, 6-, and 12-week post-operative timepoints. These findings suggest that a biphasic interpositional allograft is safe for further clinical investigation in humans before broader clinical application. Patch augmentation of RCR is a popular technique that has shown clinical success in improving the likelihood of a successful repair in patients at elevated risk for retear. Newer augmentation technologies are being developed to address the biology at the interface between the bone and soft tissue where failure typically occurs.

Safety evaluation of the Guardian device on the common carotid artery in sheep

BackgroundPulse pressure intensity in middle-aged adults is a risk factor for dementia. The Guardian device (The Brain Protection Company, Sydney, Australia) has been developed to reduce pulse pressure, as a potential therapy. ObjectivesThe aim of this study was to evaluate the safety of the Guardian, a novel pulse modulation device designed to reduce the intensity of the pulse pressure that penetrates into the cerebral small vessels. The Guardian is a helix that gently wraps around the common carotid artery (CCA) to slightly change its shape, to absorb pulsatility, without lowering flow. MethodsThe Guardian was implanted bilaterally on the CCAs of 10 mature sheep for chronic implant periods of 3, 6 or 8 months. The ratio of internal device diameter to outer diameter of the CCA varied from 63% to 92% (n = 20). The implant position on the vessel was marked surgically at implant. Gross pathology and histopathology of the CCA were examined at 3- and 6-months post explant. Most devices were explanted using open surgery, however minimally invasive surgical explant techniques were examined in 2 animals to assess the potential of this approach for explant in humans if required. ResultsThe Guardian was successfully implanted with no adverse events, and minimally invasive explant appeared to be viable for removal. Following implant, the device was surrounded by a thin fibrous capsule, with similar pathology at 3- and 6-months. Minimal or no movement was observed. CCA sections appeared histologically normal, with no evidence of thrombosis, stenosis, fibrosis, chronic inflammatory response, or vessel degeneration. ConclusionsThe feasibility of surgical implantation and biomaterial safety of the Guardian was confirmed over 8 months. Minimally invasive explant of the Guardian has the potential to be viable. Further work is required to demonstrate efficacy in vitro and/or in vivo before evaluation in humans.

GOING LOW: LOW MODULUS GRAFT-FREE 3D-PRINTED TITANIUM INTERBODY CAGES SHOW COMPARABLE BONE FORMATION TO PEEK WITH GRAFT

Polyetheretherketone (PEEK) interbody fusion cages combined with autologous bone graft is the current clinical gold standard treatment for spinal fusion, however, bone graft harvest increases surgical time, risk of infection and chronic pain. We describe novel low-stiffness 3D Printed titanium interbody cages without autologous bone graft and assessed their biological performance in a pre-clinical in vivo interbody fusion model in comparison to the gold standard, PEEK with graft.Titanium interbody spacers were 3D Printed with a microporous (Ti1: &lt;1000μm) and macroporous (Ti2: &gt;1000μm) design. Both Ti1 and Ti2 had an identical elastic modulus (stiffness), and were similar to the elastic modulus of PEEK. Interbody fusion was performed on L2-L3 and L4-L5 vertebral levels in 24 skeletally mature sheep using Ti1 or Ti2 spacers, or a PEEK spacer filled with iliac crest autograft, and assessed at 8 and 16 weeks. We quantitatively assessed bone fusion, bone area, mineral apposition rate and bone formation rate. Functional spinal units were biomechanically tested to analyse range of motion, neutral zone, and stiffness. Results: Bone formation in macroporous Ti2 was significantly greater than microporous Ti1 treatments (p=.006). Fusion scores for Ti2 and PEEK demonstrated greater rates of bone formation from 8 to 16 weeks, with bridging rates of 100% for Ti2 at 16 weeks compared to just 88% for PEEK and 50% for Ti1. Biomechanical outcomes significantly improved at 16 versus 8 weeks, with no significant differences between Ti and PEEK with graft.This study demonstrated that macroporous 3D Printed Ti spacers are able to achieve fixation and arthrodesis with complete bone fusion by 16 weeks without the need for bone graft. These significant data indicate that low-modulus 3D Printed titanium interbody cages have similar performance to autograft-filled PEEK, and could be reliably used in spinal fusion avoiding the complications of bone graft harvesting.

Evaluation of the Potential of Umbilical Cord Mesenchymal Stromal Cell–Derived Small Extracellular Vesicles to Improve Rotator Cuff Healing: A Pilot Ovine Study

Background: Despite significant advancements in surgical techniques to repair rotator cuff (RC) injuries, failure rates remain high and novel approaches to adequately overcome the natural biological limits of tendon and enthesis regeneration of the RC are required. Small extracellular vesicles (sEVs) derived from the secretome of human multipotent mesenchymal stromal cells (MSCs) have been demonstrated to modulate inflammation and reduce fibrotic adhesions, and therefore their local application could improve outcomes after RC repair. Purpose: In this pilot study, we evaluated the efficacy of clinical-grade human umbilical cord (hUC) MSC-derived sEVs (hUC-MSC-sEVs) loaded onto a type 1 collagen scaffold in an ovine model of acute infraspinatus tendon injury to improve RC healing. Study Design: Controlled laboratory study. Methods: sEVs were enriched from hUC-MSC culture media and were characterized by surface marker profiling. The immunomodulatory capacity was evaluated in vitro by T-cell proliferation assays, and particle count was determined by nanoparticle tracking analysis. Twelve skeletally mature sheep were subjected to partial infraspinatus tenotomy and enthesis debridement. The defects of 6 animals were treated with 2 × 1010 hUC-MSC-sEVs loaded onto a type 1 collagen sponge, whereas 6 animals received only a collagen sponge, serving as controls. Six weeks postoperatively, the healing of the infraspinatus tendon and the enthesis was evaluated by magnetic resonance imaging (MRI) and hard tissue histology. Results: CD3/CD28-stimulated T-cell proliferation was significantly inhibited by hUC-MSC-sEVs (P = .015) that displayed the typical surface marker profile, including the presence of the MSC marker proteins CD44 and melanoma-associated chondroitin sulfate proteoglycan. The local application of hUC-MSC-sEVs did not result in any marked systemic adverse events. Histologically, significantly improved Watkins scores (P = .031) indicated improved tendon and tendon-to-bone insertion repair after sEV treatment and lower postcontrast signal of the tendon and adjacent structures on MRI suggested less residual inflammation at the defect area. Furthermore, the formation of osteophytes at the injury site was significantly attenuated (P = .037). Conclusion: A local, single-dose application of hUC-MSC-sEVs promoted tendon and enthesis healing in an ovine model of acute RC injury. Clinical Relevance: Surgical repair of RC tears generally results in a clinical benefit for the patient; however, considerable rerupture rates have been reported. sEVs have potential as a cell-free biotherapeutic to improve healing outcomes after RC injury.

Automatic multi-weigh-station for assessing sheep liveweight in small flocks

Sheep liveweight is a vital physiological parameter to monitor as it is directly correlated with the animals internal energy balance. Increases in liveweight in mature sheep coincide with an increase in fat and protein tissue while weight loss denotes an inverse relationship. This relationship underscores appropriate pasture stocking rates, production outputs, the correct dosing of medicinal treatments for maintaining a healthy flock and finding target markets. The sheep production industry is yearning for an accurate platform to provide real-time and accurate liveweight measurements without extensive labour. The two main methods for measuring sheep liveweight include; static yard weighting, which while accurate is labour intensive, and walk-over-weighing — which has the advantage of autonomy but lacks accuracy and requires the flock to be trained. In this work we describe a custom platform that accurately measures the liveweight of up-to three sheep simultaneously while they drink or eat from a field trough. A plywood frame consisting of three separated static weigh platforms — each with two commercially available weigh bars — was constructed to fit along side a conventional 3 metre trough. These strain gauges plug directly into a custom circuit board with a Teensy 3.6 microcontroller connected to several Analog-to-Digital converters, SDI-12, I2C and OneWire interfaces for additional environmental/agricultural sensors — all powered by a commonly available 12 V lead–acid battery and commercial solar charger. The device can communicate over LoRaWAN — a long range, low-power wireless communication architecture — making it suitable for remote deployment on large farms where traditional 3/4G telecommunications are unavailable. Firmware on the device sends device status updates every 15 min and calculates/transmits liveweight parameters in real-time — as animals use the trough. Five untrained mature wethers were given access to the device over a period of 57 days. A total of 1149 weights were captured, of that 853 were automatically flagged as reliable using algorithms provided in this work — equating to ∼74% of the original dataset. This work aims to enable producers to a quantify the physiological state of their flock without extensive labour, acting to increase their available decision making information in regards to flock productivity, stocking rates and animal welfare.