Longitudinal pilot study examining the effect of punch biopsy on equine sarcoid growth dynamics.

BACKGROUND: Nonexcisional tissue biopsies facilitate pre-operative confirmation of equine sarcoid yet fear of lesion deterioration currently limits its use in the diagnostic workup. OBJECTIVES: To evaluate the effect of a single punch biopsy on tumour growth dynamics [thickness, area, circumference, viral load (VL) and Visual Analog Scale (VAS)]. ANIMALS: Six client-owned horses with 11 sarcoids of various classification. MATERIALS AND METHODS: Growth dynamics were recorded on a weekly basis, 12 weeks pre- and 24 weeks post-biopsy. The effect of a single punch biopsy on growth dynamics was estimated by linear mixed-effect models. Spearman's rank correlation coefficient (SRCC) was calculated to investigate correlations with the number of weeks before and after the intervention. RESULTS: While statistically significant post-biopsy changes were recorded for all parameters except VL, no parameter was consistently increased after the biopsy intervention. In two of 11 sarcoids, the VL correlation pattern revealed significant strong correlations: sarcoid 6 (pre: r = -0.66, p < 0.05; post: r = 0.81, p < 0.001), increased VL; and sarcoid 8 (pre: r = 0.85, p < 0.001; post: r = 0.17, p > 0.05), no further increase after biopsy. CONCLUSIONS AND CLINICAL IMPORTANCE: Our results indicate that post-biopsy lesion deterioration is not a general concept that applies to all sarcoids, and both deterioration or improvement are possible outcomes over a 24-week period. Further clinical studies with a larger sample size are needed before a definitive conclusion can be made.

Biomechanical Evaluation of a Tubular Braided Construct for Primary Deep Flexor Tendon Surgery.

PURPOSE: Immediate postoperative mobilization has been shown to avoid adhesion formation and improve range of motion after flexor tendon repair. A tubular braided construct was designed to allow for these rehabilitation protocols. METHODS: In this ex vivo study, 92 ovine flexor tendons were divided randomly into 2 equal groups. After creating a transection, the tendons of the first group were repaired using a tubular braided construct. This construct, consisting of a tubular braid of polypropylene and polyethylene terephthalate fibers, exerts a grasping effect on the tendon ends. The control group received a multistrand modified Kessler repair with a looped polydioxanone suture (PDS) 4-0 suture and a Silfverskiöld epitendinous repair using an Ethilon 6-0 suture. After the repair, a static and an incremental cyclic tensile test was performed until failure. RESULTS: During the static test, the tubular braid resulted in a significantly higher load at 3 mm gap formation (86.3 N ± 6.0 vs 50.1 N ± 11.6), a higher ultimate load at failure (98.3 N ± 12.7 vs 63 N ± 11.1), higher stress at ultimate load (11.8 MPa ± 1.2 vs 8.1 MPa ± 3.1), and higher stiffness (7.1 N/mm ± 2.9 vs 8.7 N/mm ± 2.2). For the cyclic tests, survival analyses for 1-, 2- and 3-mm gap formation and failure demonstrated significant differences in favor of the tubular braided construct. CONCLUSION: The tubular braided construct withstands the required loads for immediate rehabilitation not only in static tests, but also during cyclic tests. This is in contrast with the control group, where sufficient strength is reached during static tests, but failures occur below the required loads during cyclic testing. CLINICAL RELEVANCE: The tubular braided construct provides a larger safety margin for immediate intensive rehabilitation protocols.

Single energy metal artifact reduction performs better than virtual monoenergetic dual-energy reconstruction in CT of the equine proximal phalanx.

Metal artifacts in CT negatively impact the evaluation of surgical implants and the surrounding tissues. The aim of this prospective experimental study was to evaluate the ability of a single energy metal artifact reduction (SEMAR™, Canon) algorithm and virtual monoenergetic (VM) dual-energy CT (DECT) scanning techniques to reduce metal artifacts from stainless steel screws surgically inserted into the equine proximal phalanx. Seven acquisitions of 18 cadaver limbs were performed on a Canon Aquilion One Vision CT scanner (Helical +SEMAR, Volume +SEMAR, Standard Helical, Standard Volume and VM DECT at 135, 120, and 105 keV) and reconstructed in a bone kernel. Blinded subjective evaluation performed by three observers indicated a significant effect of acquisition in both adjacent tissues (P < 0.001) and distant tissues (P < 0.001) and the best metal artifact reduction was seen with Helical +SEMAR and Volume +SEMAR. The subjective overall preference of CT acquisition type was (1) Helical +SEMAR, (2) Volume +SEMAR, (3) VM DECT 135 keV, (4) VM DECT 120 keV, (5) VM DECT 105 keV, (6) Standard Helical, (7) Standard Volume (P < 0.001). Unblinded objective evaluation performed by one observer showed that VM DECT 120 keV, Helical +SEMAR, and Volume +SEMAR performed similarly and were objectively the best at reducing blooming artifact. Overall, the best metal artifact reduction was obtained with SEMAR, followed by VM DECT. However, VM DECT performance varies with energy level and was associated with decreased image quality in distant tissues and artifactual overcorrection of metal artifacts at high energy levels.

Role of Laparoscopy in Diagnosis and Management of Equine Colic.

Laparoscopy can be valuable in the diagnosis and treatment of specific types of colic in horses. Most commonly, it is used for horses with chronic recurrent colic for further diagnosis, such as by taking biopsies or to perform treatment. Laparoscopy is also often used for prevention of colic, for example, by closing the nephrosplenic space or epiploic foramen. There are fewer indications for laparoscopy in acute colic, though in some cases the technique can be useful for diagnosis, after which the procedure is converted to a hand-assisted laparoscopy. However, manipulation of the intestine is limited compared with an open laparotomy.

New approach for genomic characterisation of equine sarcoid-derived BPV-1/-2 using nanopore-based sequencing.

BACKGROUND: Bovine papillomavirus (BPV) types 1 and 2 play a central role in the etiology of the most common neoplasm in horses, the equine sarcoid. The unknown mechanism behind the unique variety in clinical presentation on the one hand and the host dependent clinical outcome of BPV-1 infection on the other hand indicate the involvement of additional factors. Earlier studies have reported the potential functional significance of intratypic sequence variants, along with the existence of sarcoid-sourced BPV variants. Therefore, intratypic sequence variation seems to be an important emerging viral factor. This study aimed to give a broad insight in sarcoid-sourced BPV variation and explore its potential association with disease presentation. METHODS: In order to do this, a nanopore sequencing approach was successfully optimized for screening a wide spectrum of clinical samples. Specimens of each tumour were initially screened for BPV-1/-2 by quantitative real-time PCR. A custom-designed primer set was used on BPV-positive samples to amplify the complete viral genome in two multiplex PCR reactions, resulting in a set of overlapping amplicons. For phylogenetic analysis, separate alignments were made of all available complete genome sequences for BPV-1/-2. The resulting alignments were used to infer Bayesian phylogenetic trees. RESULTS: We found substantial genetic variation among sarcoid-derived BPV-1, although this variation could not be linked to disease severity. Several of the BPV-1 genomes had multiple major deletions. Remarkably, the majority of them cluster within the region coding for late viral genes. Together with the extensiveness (up to 603 nucleotides) of the described deletions, this suggests an altered function of L1/L2 in disease pathogenesis. CONCLUSIONS: By generating a significant amount of complete-length BPV genomes, we succeeded to introduce next-generation sequencing into veterinary research focusing on the equine sarcoid, thus facilitating the first report of both nanopore-based sequencing of complete sarcoid-sourced BPV-1/-2 and the simultaneous nanopore sequencing of multiple complete genomes originating from a single clinical sample.

Ultrasonographic evaluation of the width, thickness, and length of the normal linea alba in standing and dorsal recumbent horses.

OBJECTIVE: To determine the variability in length, width, and thickness of the equine linea alba (LA) and the effect of a standing vs dorsal recumbent position on these measurements. STUDY DESIGN: Descriptive anatomical comparative study. ANIMALS: Standing horses (N = 75; in 30 horses, measurements were obtained in dorsal recumbency first and repeated after horses were standing). METHODS: Linea alba length was measured in standing position from xiphoid to umbilicus, and transverse ultrasonographic images were obtained at five reference points to measure LA width and thickness. In 30 horses, measurements were obtained in dorsal recumbency first and repeated after horses were standing. RESULTS: There was wide variation in LA width and thickness between standing horses, with gradual increase from xiphoid (range, 0.14-0.64 cm) to umbilicus (range, 0.2-2.97 cm). Linea alba length in standing position was 51.09 ± 6.219 cm. Width was independent of the size of the horse; thickness and length were correlated at some reference points to height (r = 0.346-585, P < .05) and weight (r = 0.324-0.642, P < .05). Different LA shapes could be identified. In dorsal recumbency, the LA was smaller in width at all reference points (15%-23%, P < .05) and shorter (20%, P < .001) compared with standing. CONCLUSION: In addition to the wide variability in LA measurements and shapes between horses, there was a significant decrease in LA width and length when horses changed from standing to dorsal recumbency. CLINICAL SIGNIFICANCE: The difference in LA length and width between dorsal recumbency and when standing could increase tension on sutures after laparotomy and should be taken into account when surgeons are closing the abdomen.

A retrospective multicenter study on the use of locking compression plates for scapulohumeral arthrodesis in small equids.

OBJECTIVE: To report on technical aspects and outcomes after scapulohumeral arthrodesis (SHA) with a locking compression plate (LCP) in small equids. STUDY DESIGN: Retrospective multicenter case series. ANIMALS: Client-owned Shetland Ponies, Miniature Shetlands, and American Miniature Horses (n = 15). METHODS: Inclusion criteria were completed SHA with an LCP to treat scapulohumeral osteoarthritis/subluxation and availability of postoperative radiographs. Contributing surgeons completed a questionnaire to collect data. All radiographs were reviewed for this study. Follow-up information was obtained via re-admission to the hospital or telephone interview of the referring veterinarian or owner. Outcome was subjectively scored as excellent, good, moderate, or poor based on lameness and function. RESULTS: Sixteen SHAs were performed in 15 equids (body weight 65-145 kg) by nine different surgeons. A narrow 4.5/5.0 mm LCP (7-16 holes) was used in 14 of the 16 SHAs. Follow-up was collected 2.5 years after surgery (median; range: 9 weeks to 10 years). Major complications related to the SHAs were noted in 4 of the 13 horses alive long term, consisting of implant failure (n = 1), surgical site infection (n = 2), and scapular fracture (n = 1). The outcome was graded as excellent in 4, good in 5, and moderate in 4 horses. Two ponies were euthanized because scapulohumeral osteoarthritis and subluxation developed in the contralateral limb. CONCLUSION: Although major complications occurred in about one-third of ponies, SHA with LCP led to long-term survival with good function in most ponies. CLINICAL SIGNIFICANCE: SHA with an LCP offers a high chance for good long-term outcome in small equids although contralateral disease may affect outcome.

Investigation of age-related differences in toxicokinetic processes of deoxynivalenol and deoxynivalenol-3-glucoside in weaned piglets.

Age-related differences in toxicokinetic processes of deoxynivalenol (DON) and deoxynivalenol-3-glucoside (DON3G) were studied. DON3G [55.7 µg/kg bodyweight (BW)] and an equimolar dose of DON (36 µg/kg BW) were administered to weaned piglets (4 weeks old) by single intravenous and oral administration in a double two-way cross-over design. Systemic and portal blood was sampled at different time points pre- and post-administration and plasma concentrations of DON, DON3G and their metabolites were quantified using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-high-resolution mass spectrometry (LC-HRMS) methods. Data were processed using tailor-made compartmental toxicokinetic (TK) models to accurately estimate TK parameters. Results were statistically compared to data obtained in a previous study on 11-week-old pigs using identical experimental conditions. Significant age-related differences in intestinal and systemic exposure to both DON and DON3G were noted. Most remarkably, a significant difference was found for the absorbed fraction of DON3G, after presystemic hydrolysis to DON, in weaned piglets compared to 11-week-old piglets (83% vs 16%, respectively), assumed to be mainly attributed to the higher intestinal permeability of weaned piglets. Other differences in TK parameters could be assigned to a higher water/fat body ratio and longer gastrointestinal transit time of weaned piglets. Results may further refine current risk assessment concerning DON and DON3G in animals. Additionally, since piglets possibly serve as a human paediatric surrogate model, results may be extrapolated to human infants.

Surgical treatment of epiploic foramen entrapment in 142 horses (2008-2016).

OBJECTIVE: To report the clinical features, outcomes, and prognostic factors associated with the surgical treatment of epiploic foramen entrapment (EFE). STUDY DESIGN: Retrospective study at a single referral hospital. ANIMALS: Horses (n = 142) undergoing surgery (n = 145) for EFE. METHODS: Preoperative, perioperative, and postoperative data of surgeries on horses that underwent exploratory laparotomy for EFE were obtained. The postoperative outcome was assessed by follow-up telephone calls with the owners/caregivers. Factors associated with postoperative reflux (POR), relaparotomy, hospital discharge, colic after hospital discharge, and survival after discharge were assessed. RESULTS: In total, 145 surgeries were performed on 142 horses (recurrence rate, 3%). Warmblood horses represented 85% of the horses that underwent surgery. Windsucking/crib-biting was confirmed in 60% of these surgery cases. Left-to-right entrapment was diagnosed in all horses. Ileal involvement was recorded in 74% of the cases. Uncontrollable intraoperative hemorrhage was encountered in 6% of the surgeries. One hundred seven (74%) horses recovered from surgery, and 65% of those survived to discharge. The rate of survival to discharge of all surgeries was 48%. The median survival of the cases that were discharged exceeded 3193 days. Horses requiring intestinal resection were predisposed to POR, and those undergoing jejunoileostomy were more prone to POR than those undergoing jejunojejunostomy. Horses with POR were less likely to be discharged than those without POR, and those that underwent resection had shorter life expectancy after hospital discharge than those that did not undergo resection. CONCLUSION: Surgical treatment of EFE was associated with high morbidity and mortality, with recurrence in at least 3% of surviving horses. CLINICAL SIGNIFICANCE: Owners of horses with EFE should be informed of the guarded prognosis associated with current surgical treatment.

Clinical applicability of detomidine and methadone constant rate infusions for surgery in standing horses.

OBJECTIVE: To determine the required rate of a detomidine infusion (loading dose 5 µg kg-1; initial rate 12.5 µg kg-1 hour-1) added to a constant infusion of methadone (0.2 mg kg-1; 0.05 mg kg-1 hour-1) for sedation in standing horses and ponies undergoing elective surgeries with appropriate local anaesthetic techniques. STUDY DESIGN: Prospective, clinical study. ANIMALS: Adult, healthy, client-owned, non-food-producing horses or ponies sedated for elective standing surgeries longer than 45 minutes. METHODS: At baseline (in the stables before administration of sedative agents), at 10 minutes after sedation and every 5 minutes thereafter, ataxia, sedation and surgical condition were evaluated; each scored 0-3. These scores were used to adjust the detomidine administration rate using the Ghent Sedation Algorithm. A 10 cm visual analogue scale (VAS) was used by the main surgeon at the end of the procedure to evaluate the surgical conditions. Heart rate, systolic arterial pressure and respiratory frequency were also recorded at each time point. For statistical analysis, anova for normal, Kruskal-Wallis H-test for non-normal variables, and Mann-Whitney U test for VAS were used. RESULTS: From the 42 horses/ponies included in this study, 28 underwent dental procedures and 14 other types of procedures. Overall, dental procedures required higher mean detomidine rates compared with other types of surgeries (16.9 ± 4.5 versus 9.0 ± 1.9 µg kg-1 hour-1) (p < 0.001). Dental procedures were assigned similar VAS scores, median (range), of 7.8 (5.8-10) with other procedures, 8.7 (2.8-10). Cardiovascular changes were not clinically significant. No signs or behavioural changes of abdominal pain were observed postoperatively. CONCLUSIONS AND CLINICAL RELEVANCE: Satisfactory surgical conditions were achieved using a combination of detomidine and methadone infusions with locoregional anaesthesia, with no adverse effects. Dental procedures required higher detomidine dose rates compared with other surgeries.

Anatomy of the vestibulum esophagi and surgical implications during prosthetic laryngoplasty in horses.

OBJECTIVE: To describe the anatomy of the entry to the equine esophagus (vestibulum esophagi) and to assess the risk of penetrating its adventitia and/or lumen during laryngoplasty. STUDY DESIGN: Ex vivo cadaveric study. SAMPLE POPULATION: Five isolated equine larynges and 39 equine head and neck specimens. METHODS: The anatomy of the vestibulum esophagi was studied by dissection of 5 cadaver specimens. Then, a bilateral laryngoplasty was performed, including 5 suture placements through the muscular processes, caudal, rostral, and sagittal, with straight and curved needles. Two of the 3 surgeons performing the implantations were unaware of the goals of the study. Suture positions and iatrogenic trauma to the lumen and/or adventitia of the vestibulum esophagi were identified during dissection of the specimens. Risk factors for penetrating the adventitia were evaluated with a multivariate regression model. RESULTS: The vestibulum esophagi spans between both wings of the thyroid cartilage over the entire width of the larynx, covering the rostral spine (arcuate crest) of the arytenoid cartilages. It is covered by the thyropharyngeus and cricopharyngeus muscles. Masked surgeons were associated with a significantly higher number of adventitia penetrations (72%) compared to the nonmasked surgeon (9%). The lumen of the vestibulum esophagi was penetrated in 4.6% of suture placements and only by the 2 masked surgeons. CONCLUSION: Penetration of the adventitia was more common when surgeons were unaware of the anatomical extent of the vestibulum esophagi. CLINICAL SIGNIFICANCE: Anatomical knowledge of the extent of the vestibulum esophagi reduces the risk of penetrating its lumen or adventitia during suture placement on the muscular process of the arytenoid cartilage.

Topical use of 5% acyclovir cream for the treatment of occult and verrucous equine sarcoids: a double-blinded placebo-controlled study.

BACKGROUND: Previous studies mention the use of topical acyclovir for the treatment of equine sarcoids. Success rates vary and since the bovine papillomavirus (BPV) lacks the presence of a kinase necessary to activate acyclovir, there is no proof of its activity against equine sarcoids. RESULTS: Twenty-four equine sarcoids were topically treated with acyclovir cream and 25 with a placebo. Both creams were applied twice daily during 6 months. Before the start of the treatment and further on a monthly basis, photographs and swabs were obtained. On the photographs, sarcoid diameter and surface area were measured and verrucosity of the tumours was quantified using a visual analog scale (VAS). The swabs were analysed by PCR for the presence of BPV DNA and positivity rates were calculated as the number of positive swabs divided by the total number of swabs for each treatment group at each time point. Success rates were not significantly different between both treatment groups. There was also no significant effect of treatment on sarcoid diameter, surface area or VAS score. For the swabs, a significantly higher BPV positivity rate was found for acyclovir treated tumours compared to placebo treated sarcoids only after 1 month of treatment and not at other time points. CONCLUSIONS: None of the results indicate that treatment with acyclovir yields any better results compared to placebo treatment.

Wound-healing markers after autologous and allogeneic epithelial-like stem cell treatment.

BACKGROUND AIMS: Several cytokines and growth factors play an essential role in skin regeneration and epithelial-like stem cells (EpSCs) have beneficial effects on wound healing in horses. However, there are no reports available on the expression of these growth factors and cytokines after EpSC therapy. METHODS: Wounds of 6 cm(2) were induced in the gluteus region of 6 horses and treated with (i) autologous EpSCs, (ii) allogeneic EpSCs, (iii) vehicle treatment or (iv) untreated control. Real time polymerase chain reaction was performed on tissue biopsies taken 1 and 5 weeks after these treatments to evaluate mRNA expression of interferon (IFN)-γ, interleukin (IL)-6, vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), insulin-like growth factor (IGF)-1 and epidermal keratin (eKER). RESULTS: One week after treatments, mRNA levels of IL-6 (P = 0.012) and VEGF (P = 0.008) were higher in allogeneic EpSC-treated wounds compared with controls. Also, mRNA levels of IGF-1 were higher at 1 week in both autologous (P = 0.027) and allogeneic (P = 0.035) EpSC-treated wounds. At week 5, all EpSC- and vehicle-treated wounds demonstrated significantly higher IFN-γ, VEGF and eKER mRNA expression compared with controls and compared with their respective levels at week 1. CONCLUSIONS: Equine wounds treated with allogeneic EpSCs demonstrate a significant increase in mRNA expression of IL-6, VEGF and IGF-1 in the acute phase. In the longer term, an increase in IFN-γ, VEGF and eKER mRNA was detected in the wounds treated with allogenic EpSCs, autologous EpSCs or their vehicle.

Laparoscopic Evaluation of the Epiploic Foramen after Celiotomy for Epiploic Foramen Entrapment in the Horse.

OBJECTIVES: To evaluate the epiploic foramen using laparoscopy in horses previously treated for epiploic foramen entrapment to determine if spontaneous epiploic foramen closure had occurred. STUDY DESIGN: Non-consecutive case series. ANIMALS: Seven horses. METHODS: The epiploic foramen was inspected by right flank laparoscopy between 35 and 71 days after successful surgical treatment for epiploic foramen entrapment. Data were collected on the presence of behavior vices, details of surgery for epiploic foramen entrapment (time from colic onset to surgery, site and length of entrapped intestine, direction of entrapment, compromise of the intestine, intestine resected), the time between surgery for epiploic foramen entrapment and laparoscopy, and the laparoscopic appearance of the epiploic foramen. If the epiploic foramen was open, a mesh was introduced to obliterate the epiploic foramen (Foramen Epiploicum Mesh Closure [FEMC]). Clinical progress of the horses was followed by owner telephone interview at 1 and 4 months after laparoscopy, and a final interview between 135 and 282 days after laparoscopy. Owners were questioned on specific postoperative complications and the exercise level of the horse. RESULTS: At laparoscopy, 3/7 horses had complete closure of the epiploic foramen by dense fibrous tissue. The FEMC was performed in 4 horses without major complications. Postoperative colic episodes were recorded in 3 horses, all of them displaying windsucking/cribbing behavior. CONCLUSION: Laparoscopic evaluation after celiotomy for epiploic foramen entrapment revealed spontaneous closure of the epiploic foramen in 3/7 horses. This finding could explain the reported low recurrence rate after surgical treatment for epiploic foramen entrapment.

A novel murine model for evaluating bovine papillomavirus prophylactics/therapeutics for equine sarcoid-like tumours.

Equine sarcoids are highly recurrent bovine papillomavirus (BPV)-induced fibroblastic neoplasms that are the most common skin tumours in horses. In order to facilitate the study of potential equine sarcoid prophylactics or therapeutics, which can be a slow and costly process in equines, a murine model for BPV-1 protein-expressing equine sarcoid-like tumours was developed in mice through stable transfection of BPV-1 E5 and E6 in a murine fibroblast tumour cell line (K-BALB). Like equine sarcoids, these murine tumour cells (BPV-KB) were of fibroblast origin, were tumorigenic and expressed BPV-1 proteins. As an initial investigation of the preclinical potential of this tumour model for equine sarcoids prophylactics, mice were immunized with BPV-1 E5E6 Venezuelan equine encephalitis virus replicon particles, prior to BPV-KB challenge, which resulted in an increased tumour-free period compared with controls, indicating that the BPV-KB murine model may be a valuable preclinical alternative to equine clinical trials.

Regenerative Skin Wound Healing in Mammals: State-of-the-Art on Growth Factor and Stem Cell Based Treatments.

Mammal skin has a crucial function in several life-preserving processes such as hydration, protection against chemicals and pathogens, initialization of vitamin D synthesis, excretion and heat regulation. Severe damage of the skin may therefore be life-threatening. Skin wound repair is a multiphased, yet well-orchestrated process including the interaction of various cell types, growth factors and cytokines aiming at closure of the skin and preferably resulting in tissue repair. Regardless various therapeutic modalities targeting at enhancing wound healing, the development of novel approaches for this pathology remains a clinical challenge. The time-consuming conservative wound management is mainly restricted to wound repair rather than restitution of the tissue integrity (the so-called "restitutio ad integrum"). Therefore, there is a continued search towards more efficacious wound therapies to reduce health care burden, provide patients with long-term relief and ultimately scarless wound healing. Recent in vivo and in vitro studies on the use of skin wound regenerative therapies provide encouraging results, but more protracted studies will have to determine whether the effect of observed effects are clinically significant and whether regeneration rather than repair can be achieved. For all the aforementioned reasons, this article reviews the emerging field of regenerative skin wound healing in mammals with particular emphasis on growth factor- and stem cell-based therapies.

Comparison of autologous versus allogeneic epithelial-like stem cell treatment in an in vivo equine skin wound model.

BACKGROUND AIMS: Several studies report beneficial effects of autologous and allogeneic stem cells on wound healing. However, no comparison between autologous versus allogeneic epithelial-like stem cells (EpSCs) has been made so far. For this reason, we first hypothesize that both EpSC types enhance wound healing in comparison to vehicle treatment and untreated controls. Second, on the basis of other studies, we hypothesized that there would be no difference between autologous and allogeneic EpSCs. METHODS: Twelve full-thickness skin wounds were created in six horses. Each horse was subjected to (i) autologous EpSCs, (ii) allogeneic EpSCs, (iii) vehicle treatment or (iv) untreated control. Wound evaluation was performed at day 3, 7 and 14 through wound exudates and at week 1, 2 and 5 through biopsies. RESULTS: Wound circumference and surface were significantly smaller in autologous EpSC-treated wounds. A significantly lower amount of total granulation tissue (overall) and higher vascularization (week 1) was observed after both EpSC treatments. Significantly more major histocompatibility complex II-positive and CD20-positive cells were noticed in EpSC-treated wounds at week 2. In autologous and allogeneic groups, the number of EpSCs in center biopsies was low after 1 week (11.7% and 6.1%), decreased to 7.6% and 1.7%, respectively (week 2), and became undetectable at week 5. CONCLUSIONS: These results confirm the first hypothesis and partially support the second hypothesis. Besides macroscopic improvements, both autologous and allogeneic EpSCs had similar effects on granulation tissue formation, vascularization and early cellular immune response.

Sphere-forming capacity as an enrichment strategy for epithelial-like stem cells from equine skin.

BACKGROUND: Mammal skin plays a pivotal role in several life preserving processes and extensive damage may therefore be life threatening. Physiological skin regeneration is achieved through ongoing somatic stem cell differentiation within the epidermis and the hair follicle. However, in severe pathological cases, such as burn wounds, chronic wounds, and ulcers, the endogenous repair mechanisms might be insufficient. For this reason, exogenous purification and multiplication of epithelial-like stem/progenitor cells (EpSCs) might be useful in the treatment of these skin diseases. However, only few reports are available on the isolation, purification and characterization of EpSCs using suspension cultures. METHODS: In the present study, skin was harvested from 6 mares and EpSCs were isolated and purified. In addition to their characterization based on phenotypic and functional properties, sphere formation was assessed upon isolation, i.e. at passage 0 (P0), and at early (P4) and late (P10) passages using different culture conditions. RESULTS: On average 0.53 ± 0.28% of these primary skin-derived cells showed the capacity to form spheres and hence possessed stem cell properties. Moreover, significantly more spheres were observed in EpSC medium versus differentiation medium, corroborating the EpSCs' privileged ability to survive in suspension. Furthermore, the number of cells per sphere significantly increased over time as well as with subsequent passaging. Upon immunophenotyping, the presumed EpSCs were found to co-express cytokeratin (CK) 14, Casein kinase 2 beta and Major Histocompatibility Complex (MHC) I and expressed no pan CK and wide CK. Only a few cells expressed MHC II. Their differentiation towards keratinocytes (at P4 and P10) was confirmed based on co-expression of CK 14, Casein kinase 2 beta, pan CK and wide CK. In one of six isolates, a non-EpSC cell type was noticed in adherent culture. Although morphological features and immunohistochemistry (IHC) confirmed a keratinocyte phenotype, this culture could be purified by seeding the cells in suspension at ultralow clonal densities (1 and 10 cells/cm(2)), yet with a significantly lower sphere forming efficiency in comparison to pure EpSCs (P = 0.0012). CONCLUSION: The present study demonstrated sphere formation as a valuable tool to purify EpSCs upon their isolation and assessed its effectiveness at different clonal seeding densities for eliminating a cellular contamination.

Septins in the glial cells of the nervous system.

The capacity of cytoskeletal septins to mediate diverse cellular processes is related to their ability to assemble as distinct heterooligomers and higher order structures. However, in many cell types the functional relevance of septins is not well understood. This minireview provides a brief overview of our current knowledge about septins in the non-neuronal cells of the vertebrate nervous system, collectively termed 'glial cells', i.e., astrocytes, microglia, oligodendrocytes, and Schwann cells. The dysregulation of septins observed in various models of myelin pathology is discussed with respect to implications for hereditary neuralgic amyotrophy (HNA) caused by mutations of the human SEPT9-gene.

Safety assessment of equine allogeneic tenogenic primed mesenchymal stem cells in horses with naturally occurring tendon and ligament injuries.

Background: Mesenchymal stem cells provide a valuable treatment option in orthopedic injuries in horses. Objectives: The aim of this study was to evaluate the hematological, biochemical, immunological and immunomodulatory parameters following intralesional treatment with tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in client-owned horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. Methods: The immunogenicity and immunomodulatory capacities of tpMSCs were assessed in a modified mixed lymphocyte reaction, including peripheral blood mononuclear cells (PBMCs) of 14 horses with SDFT and SL injuries after treatment with tpMSCs. In a second study, 18 horses with SDFT and SL injuries received either an intralesional injection with tpMSCs (n = 9) or no treatment (n = 9). Results: The tpMSCs did not provoke a cellular immune response (p < 0.001) and were able to immunomodulate stimulated T lymphocytes (p < 0.001) in vitro. Therapeutic use of tpMSCs did not result in relevant hematologic or biochemical abnormalities. Main limitations: Both studies had a small sample size. No statistical analyses were performed in the second study. Fibrinogen was only analyzed in a single horse prior to treatment. Conclusion: Co-incubation of tpMSCs and PBMCs of horses that have been previously exposed to tpMSCs did not elicit a cellular immune response and tpMSCs were able to immunomodulate stimulated T lymphocytes. Intralesional treatment with tpMSCs did not provoke abnormal changes in hematological and biochemical parameters.