Multi-Pulse Corona Discharges in Thunderclouds Observed in Optical and Radio Bands.

How lightning initiates inside thunderclouds remains a major puzzle of atmospheric electricity. By monitoring optical emissions from thunderstorms, the Atmosphere-Space Interactions Monitor (ASIM) onboard the International Space Station is providing new clues about lightning initiation by detecting Blue LUminous Events (BLUEs), which are manifestations of electrical corona discharges that sometimes precedes lightning. Here we combine optical and radio observations from a thunderstorm near Malaysia to uncover a new type of event containing multiple optical and radio pulses. We find that the first optical pulse coincides with a strong radio signal in the form of a Narrow Bipolar Event (NBE) but subsequent optical pulses, delayed some milliseconds, have weaker radio signals, possibly because they emanate from a horizontally oriented electrical discharges which does not trigger full-fledged lightning. Our results cast light on the differences between isolated and lightning-initiating electrical discharges.

Secondary Fast Breakdown in Narrow Bipolar Events.

The physical mechanism of Narrow bipolar events (NBEs) has been studied for decades but it still holds many mysteries. Recent observations indicate that the fast breakdown discharges that produce NBEs sometimes contain a secondary fast breakdown that propagates back in the opposite direction but this has not been fully addressed so far in electromagnetic models. In this study, we investigate fast breakdown using different approaches that employ a Modified Transmission Line with Exponential decay (MTLE) model and propose a new model, named "rebounding MTLE model," which reproduces the secondary fast breakdown current in NBEs. The model provides new insights into the physics of the fast breakdown mechanism.

Global Distribution of Key Features of Streamer Corona Discharges in Thunderclouds.

We present nighttime worldwide distributions of key features of Blue LUminous Events (BLUEs) detected by the Modular Multispectral Imaging Array of the Atmosphere-Space Interaction Monitor. Around 10% of all detected BLUEs exhibit an impulsive single pulse shape. The rest of BLUEs are unclear (impulsive or not) single, multiple or with ambiguous pulse shapes. BLUEs exhibit two distinct populations with peak power density <25 µWm-2 (common) and ≥25 µWm-2 (rare) with different rise times and durations. The altitude (and depth below cloud tops) zonal distribution of impulsive single pulse BLUEs indicate that they are commonly present between cloud tops and a depth of ≤4 km in the tropics and ≤1 km in mid and higher latitudes. Impulsive single pulse BLUEs in the tropics are the longest (up to ∼4 km height) and have the largest number of streamers (up to ∼3 × 109). Additionally, the analysis of BLUEs has turned out to be particularly complex due to the abundance of radiation belt particles (at high latitudes and in the South Atlantic Anomaly [SAA]) and cosmic rays all over the planet. True BLUEs can not be fully distinguished from radiation belt particles and cosmic rays unless other ground-based measurements associated with the optically detected BLUEs are available. Thus, the search algorithm of BLUEs presented in Soler et al. (2021), https://doi.org/10.1029/2021gl094657 is now completed with a new additional step that, if used, can considerably smooth the SAA shadow but can also underestimate the number of BLUEs worldwide.

Health risk assessment in children living in an urban area with hydrofluorosis: San Luis Potosí Mexico case study.

BACKGROUND: Fluoride is an inorganic element, which can be found in high concentrations in groundwater. Its consumption and exposure have consequences on human health. The objective of this study was to evaluate fluoride exposure and develop a health risk assessment in children from an urban area with hydrofluorosis in Mexico. METHODS: Water fluoride levels in active wells were provided by the Water State Agency and divided into three zones: agriculture zone (Zone A), metallurgical zone (Zone B), and industrial zone (Zone C). Urinary fluoride levels were determined by potentiometric method using an ion-selective electrode. Health risk assessment was performed through Monte Carlo model analysis and hazard quotient was calculated. RESULTS: According to fluoride well concentration, all zones have high concentration especially Zone B (2.55 ± 0.98 mg/L). Urinary fluoride concentrations were highest in children in Zone B (1.42 ± 0.8 mg/L). The estimated median daily intake dose of fluoride was 0.084 mg/Kg-day for the children living in zone B. The highest mean HQ value was to Zone B (1.400 ± 0.980), followed by Zone C (0.626 ± 0.443). CONCLUSION: The levels of fluoride exposure registered are a potential risk to generate adverse health effects in children in the San Luis Potosi metropolitan area.

Trastornos respiratorios del sueño en la gestación y sus implicaciones maternofetales / Respiratory sleep disorders in gestation and their maternal-foetal implications

La asociación entre trastornos del sueño durante el embarazo y los resultados perinatales es esencial en pro de una buena atención maternoinfantil. Los cambios adversos producidos en el curso de la gestación, debidos al trastorno del sueño, pueden resultar permanentes y estructurales en los bebés. Los trastornos del sueño son poco comunes en mujeres en edad fértil, pero varios factores pueden contribuir a que sea más común durante la gestación. La falta de información y de formación a las gestantes hace que estas no perciban esta patología con suficiente importancia.(AU)

The association between sleep disorders during pregnancy and perinatal outcomes is essential for good maternal childcare. Adverse changes in the course of pregnancy due to sleep disorder can be permanent and structural in infants. Sleep disorders are rare in women of childbearing age, but several factors can contribute to making it more common during pregnancy. The lack of information and training for pregnant women, means that they do not give significant importance to this disorder.(AU)

Outcomes in patients with acute pulmonary embolism and patent foramen ovale: Findings from the RIETE registry.

INTRODUCTION: An increased risk of ischemic stroke in patients with acute pulmonary embolism (PE) and patent foramen ovale (PFO) was reported but few data exist regarding prognostic outcomes of those patients. MATERIAL AND METHODS: Using data in the RIETE registry, we compared the characteristics, therapeutic approaches and outcomes of patients with PE according to the presence or absence of PFO. RESULTS: From August 2016 to January 2020, 4148 patients with acute PE were enrolled. Of these, 2775 (67%) had no transthoracic echocardiogram (TTE), 993 (24%) underwent TTE but had no reported results on PFO. Among the remaining 380 patients, 287 (74%) did not have PFO and 93 (26%) had PFO. Patients with PFO were more likely to have chronic heart failure, prior myocardial infarction or ischemic stroke than those without PFO. Patients with PFO had a higher rate of subsequent ischemic stroke than those without PFO (hazard ratio (HR): 9.28; 95% CI: 1.83-69.1), than those with TTE but no data on PFO (HR: 10.1; 95% CI: 2.56-42.4) or without TTE (HR: 9.78; 95% CI: 3.02-28.4). On multivariable analysis, patients with PFO were at increased risk for subsequent ischemic stroke than those without PFO (HR: 8.96; 95% CI: 1.68-47.7). CONCLUSIONS: PFO was searched in a minority of patients with an acute PE in real life setting. Subject to possible selection and measurement biases, our results confirmed a higher risk of ischemic stroke in PE patients with PFO compared to those without PFO. This association warrants further investigation before determining the best therapeutic option in patients with acute PE and concomitant PFO.

Submicrosecond Spectroscopy of Lightning-Like Discharges: Exploring New Time Regimes.

Submicrosecond (0.476 µs per frame with an exposure time of 160 ns) high-resolution (0.38 nm) time-resolved spectra of laboratory-produced lightning-like electrical discharges have been recorded for the first time within the visible spectral range (645-665 nm). The spectra were recorded with the GrAnada LIghtning Ultrafast Spectrograph (GALIUS), a high-speed imaging spectrograph recently developed for lightning research in the IAA-CSIC. Unprecedented spectral time dynamics are explored for meter long laboratory electrical discharges produced with a 2.0 MV Marx generator. The maximum electron density and gas temperature measured in a timescale of ≤0.50 µs (160 ns) were, respectively, ≃1018 cm-3 and ≃32,000 K. Overpressure in the lightning-like plasma channel, black-body dynamics, and self-absorption in spectral lines were investigated.

[Dosage of presurgical cefazolin in obese and non-obese patients. Does weight matter?] / Dosificación de cefazolina prequirúrgica en pacientes obesos y no obesos. ¿Importa el peso?

OBJECTIVE: Evaluation of the effectiveness of a standard dose of cefalozin 2 grams for surgical site infection (SSI) prevention in obese patients compared to non-obese patients. There is no still controversy surrounding which is the best dosage of this antibiotic in obese patients for surgical prophylaxis. METHODS: Retrospective review of men who received prophylactic cefazolin between January 1st, 2019 and June 30th, 2019 in a traumatology department of a university hospital. Patients were stratified into 2 groups: obese (≥ 100 kg and body mass index (BMI)> 30 kg / m2) and non-obese. Patients without a 90 days follow-up after surgery and/or with an active infection at the time of surgery and/or treated with immunosuppressants were excluded. Demographic data, height, real weight, smoking, diabetes, concomitant use of immunosuppressants, surgery data and presence of infection until day 90 were collected. RESULTS: A total of 57 patients underwent traumatic surgery with prophylactic cefazolin, 26 non-obese and 23 obese, were studied. Both groups presented statistically significant differences in weight, BMI and post-surgery use of cefazolin. No significant differences were observed in the other variables. Two obese (8.7%) and two non-obese (7.7%) patients developed SSIs after 63 days post-surgery on average, following the difference between the groups being statistically non-significant. CONCLUSIONS: This study shows that there is no significant difference in SSI with a standard prophylactic dose of two grams of cefazolin between obese and non-obese patients.

Long-term response control in a patient with metastatic squamous cell lung cancer after treatment with nivolumab: a case report.

INTRODUCTION: Nivolumab is a fully human programmed death control immune point 1 immune checkpoint inhibitor antibody which promotes antitumor immunity. Cutaneous toxicity associated with nivolumab, immune system related, could be linked to a more durable response in patients with squamous cell lung cancer. CASE REPORT: We present the case of a 62-year-old male diagnosed with metastatic squamous cell lung cancer, who was treated with nivolumab after cytotoxic chemotherapy. After treatment discontinuation, due to grade 2 cutaneous toxicity, the patient is maintaining with durable partial response for more than one year with close follow-up. MANAGEMENT AND OUTCOME: Cumulative doses of nivolumab could cause immunological toxicities that may prolong survival of these patients even after discontinuation of treatment. DISCUSSION: Nivolumab was approved by European Medicines Agency (EMA), as second-line therapeutic, for the treatment of squamous cell lung cancer, showing a median of 9.23 months of overall survival. The development of immune-related skin toxicities has been associated with greater clinical benefit in patients with lung cancer. When cutaneous toxicity forces to nivolumab suspension, in certain cases, the option of not starting again and closely following up the patient may appear reasonable, even though there are no survival data in this context. Suspension of treatment with close monitoring of these patients until progression may be an alternative, since immune-related skin toxicities could be related to a greater clinical benefit and a durable response to nivolumab.

The immune response to Hymenolepis nana in mice decreases tumorigenesis induced by 7,12 dimethylbenz-anthracene.

BACKGROUND: Cancer is a high-impact disease throughout the world. A negative correlation has been established between the development of cancer and the Th2 immune response. Infection by helminth parasites is characterized by the induction of a strong and long-lasting Th2 response. The aim of this work was to evaluate the effect of the immune response induced by the infection with the helminth Hymenolepis nana, on the tumorigenesis induced by dimethylbenz-anthracene (DMBA) in mice. METHODOLOGY: Four different groups of 14 female BALB/c mice were formed; Group A, dimethyl sulfoxide (DMSO) (vehicle) was administered cutaneously, Group B infected with H. nana, group C, cutaneously DMBA and finally Group D infected with H. nana and cutaneous DMBA. The tumor load was determined in those animals that developed cancerous lesions. In all groups were determined: serum concentration of IgE, IFNγ, IL-10, IL-5 and malondialdehyde (MDA). The inflammatory infiltrate was analyzed from skin samples and the expression of the main eosinophilic protein and myeloperoxidase was determined. RESULTS: The group previously infected with H. nana had a reduced amount of tumors with smaller size, in comparison to the group that received only DMBA; this reduction was associated with lower levels of IFNγ and IL-10, while levels of IgE, IL-5 and MDA were higher. Further, the number of eosinophils and neutrophils was statistically higher in the animals that were previously infected with the helminth and developed less tumors. CONCLUSION: The immune response induced by H. nana infection is associated with the reduction of tumors probably due to the activity of eosinophils and neutrophils.

Analysis of the Spatial Nonuniformity of the Electric Field in Spectroscopic Diagnostic Methods of Atmospheric Electricity Phenomena.

The spatial nonuniformity of the electric field in air discharges, such as streamers, can influence the accuracy of spectroscopic diagnostic methods and hence the estimation of the peak electric field. In this work, we use a self-consistent streamer discharge model to investigate the spatial nonuniformity in streamer heads and streamer glows. We focus our analysis on air discharges at atmospheric pressure and at the low pressure of the mesosphere. This approach is useful to investigate the spatial nonuniformity of laboratory discharges as well as sprite streamers and blue jet streamers, two types of transient luminous events taking place above thunderclouds. This characterization of the spatial nonuniformity of the electric field in air discharges allows us to develop two different spectroscopic diagnostic methods to estimate the peak electric field in cold plasmas. The commonly employed method to derive the peak electric field in streamer heads underestimates the electric field by about 40-50% as a consequence of the high spatial nonuniformity of the electric field. Our diagnostic methods reduce this underestimation to about 10-20%. However, our methods are less accurate than previous methods for streamer glows, where the electric field is uniformly distributed in space. Finally, we apply our diagnostic methods to the measured optical signals in the second positive system of N2 and the first negative system of N 2 + of sprites recorded by Armstrong et al. (1998, https://doi.org/10.1016/S1364-6826(98)00026-1) during the SPRITE's 1995 and 1996 campaigns.

Practical considerations for clinical use of mesenchymal stem cells: From the laboratory to the horse.

Since the clinical use of mesenchymal stem cells (MSCs) for treating musculoskeletal injuries is gaining popularity, practitioners should be aware of the factors that may affect MSCs from tissue harvesting for MSC isolation to cell delivery into the injury site. This review provides equine practitioners with up-to-date, practical knowledge for the treatment of equine patients using MSCs. A brief overview of laboratory procedures affecting MSCs is provided, but the main focus is on shipping conditions, routes of administration, injection methods, and which commonly used products can be combined with MSCs and which products should be avoided as they have deleterious effects on cells. There are still several knowledge gaps regarding MSC-based therapies in horses. Therefore, it is important to properly manage the factors which are currently known to affect MSCs, to further strengthen the evidence basis of this treatment.

Sex difference in counts of α4 and α7 nicotinic acetylcholine receptors in the nasal polyps of adults with or without exposure to tobacco smoke.

OBJECTIVE: To assess counts of α4 and α7 nicotinic acetylcholine receptors in nasal polyps of adults with or without long-term exposure to cigarette tobacco smoke. METHODS: Twenty-two patients with and 22 patients without exposure to cigarette tobacco smoke participated in the study. After endoscopic polypectomy, the fragments of the nasal polyps were analysed by immunohistochemistry. RESULTS: Compared to patients with no exposure, patients with exposure showed higher counts of α4 and α7 nicotinic acetylcholine receptors (t-test, p 0.05). CONCLUSION: Exposure to cigarette tobacco smoke may induce increased counts of α4 and α7 nicotinic acetylcholine receptors in nasal polyps of adults, with lower counts in males than females without exposure to tobacco smoke.

Comparison of autologous bone marrow and adipose tissue derived mesenchymal stem cells, and platelet rich plasma, for treating surgically induced lesions of the equine superficial digital flexor tendon.

Several therapies have been investigated for equine tendinopathies, but satisfactory long term results have not been achieved consistently and a better understanding of the healing mechanism elicited by regenerative therapies is needed. The aim of this study was to assess the separate effects of autologous bone marrow (BM) and adipose tissue (AT) derived mesenchymal stem cells (MSCs), and platelet rich plasma (PRP), for treating lesions induced in the superficial digital flexor tendon (SDFT) of horses. Lesions were created surgically in both SDFTs of the forelimbs of 12 horses and were treated with BM-MSCs (six tendons), AT-MSCs (six tendons) or PRP (six tendons). The remaining six tendons received lactated Ringer's solution as control. Serial ultrasound assessment was performed prior to treatment and at 2, 6, 10, 20 and 45 weeks post-treatment. At 45 weeks, histopathology and gene expression analyses were performed. At week 6, the ultrasound echogenicity score in tendons treated with BM-MSCs suggested earlier improvement, whilst all treatment groups reached the same level at week 10, which was superior to the control group. Collagen orientation scores on histological examination suggested a better outcome in treated tendons. Gene expression was indicative of better tissue regeneration after all treatments, especially for BM-MSCs, as suggested by upregulation of collagen type I, decorin, tenascin and matrix metalloproteinase III mRNA. Considering all findings, a clear beneficial effect was elicited by all treatments compared with the control group. Although differences between treatments were relatively small, BM-MSCs resulted in a better outcome than PRP and AT-MSCs.

Preferred Management of Primary Deep Arm Vein Thrombosis.

OBJECTIVE: Given its rarity, the management of primary upper extremity deep vein thrombosis is controversial. Although anticoagulation alone is commonly advocated for its treatment, it is unclear if this will reduce the risk of developing post-thrombotic syndrome (PTS). The aim of this "Evidence Driven" Clinical Scenario is to evaluate whether more aggressive treatments (including catheter directed thrombolysis or surgery) might help reduce the risk of PTS or recurrent venous thromboembolism in patients with primary upper extremity deep vein thrombosis (DVT). METHODS: An electronic systematic review of Ovid MEDLINE and Embase was conducted. Randomised controlled trials and observational studies were eligible. The primary outcome was PTS. RESULTS: The initial search identified 146 articles, and 36 more were identified during a secondary search. In total, 25 studies, reporting the outcome of 1271 patients, were included. None of the studies included was a randomised controlled trial and the large majority of studies were retrospective cohorts. The use of anticoagulation alone was associated with a significant risk of PTS. In patients treated with surgery with or without thrombolysis the incidence of PTS was significantly reduced. CONCLUSION: Current evidence, albeit with some methodological limitations, suggests that anticoagulation may not be sufficient to prevent PTS in patients with primary upper extremity DVT and that surgery with or without thrombolysis to repair the anatomical defects is needed.

Biomonitoring of persistent organic pollutants (POPs) in child populations living near contaminated sites in Mexico.

The aim of this study was to conduct a POP biomonitoring programme for children in high-risk areas. We evaluated 247 serum samples from children between the ages of 6 and 12years old from two zones in Mexico: (1) indigenous zones, which included Cuatlamayan (CUA), Tocoy (TOC), and Santa Maria Picula (SAM); and (2) industrial zones, which included Tercera Chica (TC), Industrial San Luis (IND) and Rincon de San Jose (SJR); Mundo Nuevo (MN); and Alpuyeca (ALP). Our results showed that α-endosulfan was similar to CUA, TOC, SAM, TC and MN (178.6-306.9ng/g lipid). ß-Endosulfan levels were higher in ALP (901.5ng/g lipid), followed by CUA (139.9ng/g lipid) and TOC, SAM, TC and MN, which had similar levels (55.4-64.5ng/g lipid). For endosulfan sulfate, the ALP community had the highest concentration levels (1096.4ng/g lipid), whereas CUA and TOC (212.3 and 289ng/g lipid, respectively) had concentrations similar to those found in SAM and TC (99.5 and 119.1ng/g lipid, respectively). DDE levels were found in malaria-endemic areas of SAM, CUA and TOC (1782.2, 1358.3 and 57.0ng/g lipid), followed by MN (35.1ng/g lipid). HCB concentration levels were found to be higher in MN and SJR (691.8 and 575.4ng/g lipid, respectively), followed by CUA and TC (363.9 and 269.1ng/g lipid, respectively), with levels similar to those found in TOC and SAM (191.8 and 181.9ng/g lipid, respectively). Finally, PCB 101 concentration levels were found to be the highest in ALP (1032.7ng/g lipid), followed by similar levels of SJR and IND (567.5 and 327.3ng/g lipid, respectively) and TC and MN, with 109.1 and 144.5ng/g lipid, respectively. The evidence provided by this exploratory study indicates that the evaluation of the health risks posed to children living in contaminated areas is a high priority health issue.

Inflammatory response to the administration of mesenchymal stem cells in an equine experimental model: effect of autologous, and single and repeat doses of pooled allogeneic cells in healthy joints.

BACKGROUND: Mesenchymal stem cells (MSCs) transplantation has become a promising therapeutic choice for musculoskeletal injuries. Joint-related disorders are highly prevalent in horses. Therefore, these animals are considered as suitable models for testing MSC-based therapies for these diseases. The aim of this study was to investigate the clinical and inflammatory responses to intra-articular single and repeat dose administration of autologous or of pooled allogeneic MSCs in healthy equine healthy joints. Six horses were intra-articularly injected with a single autologous dose of bone marrow derived MSCs (BM-MSCs) and two separate doses of allogeneic BM-MSCs pooled from several donors. All contralateral joints were injected with Lactated Ringer's Solution (LRS) as the control vehicle. Signs of synovitis and lameness were evaluated at days 0, 1, 2, 3, 5 and 10 after injection. Total protein (TP), white blood cell count (WBC) and neutrophil count (NC) in synovial fluid were also measured at the same time-points. RESULTS: A mild synovial effusion without associated lameness was observed after all BM-MSCs injections. The second allogeneic injection caused the lowest signs of synovitis. Local temperature slightly increased after all BM-MSCs treatments compared to the controls. TP, WBC and NC in synovial fluids also increased during days 1 to 5 after all BM-MSCs injections. Both, clinical and synovial parameters were progressively normalized and by day 10 post-inoculation appeared indistinguishable from controls. CONCLUSIONS: Intra-articular administration of an allogeneic pool of BM-MSCs represents a safe therapeutic strategy to enhance MSCs availability. Importantly, the absence of hypersensitivity response to the second allogeneic BM-MSCs injection validates the use of repeat dose treatments to potentiate the therapeutic benefit of these cells. These results notably contribute to the development of stem cell based therapies for equine and human joint diseases.

Daily rhythms in the somatotropic axis of Senegalese sole (Solea senegalensis): The time of day influences the response to GH administration.

Growth factors in vertebrates display daily rhythms, which, while widely described in mammals, are still poorly understood in teleost fish. Here, we investigated the existence of daily rhythms in the somatotropic axis of the flatfish Solea senegalensis. In a first experiment, daily rhythms of the expression of pituitary adenylate cyclase-activating polypeptide (pacap), growth hormone (gh), insulin-like growth factor 1 (igf1) and its receptor (igf1r) were analyzed under a 12:12 h light:dark cycle. All genes displayed daily rhythms with the acrophases of pacap, gh and igf1 located in the second half of the dark phase (ZT 20:28-0:04 h), whereas the acrophase of igf1r was located around mid-light (ZT 5:33 h). In a second experiment, the influence of the time of day (mid-light, ML, versus mid-darkness, MD) of GH administration on the expression of these factors and on plasma glucose levels was tested. The response observed depended on the time of injection: the strongest effects were observed at MD, when GH administration significantly reduced pituitary gh and enhanced liver igf1 expression. These results provide the first evidence of daily rhythms and differential day/night effects in growth factors in S. senegalensis, suggesting new insights for investigating the physiology of growth and possible applications to improve fish aquaculture.

Effect of inflammatory environment on equine bone marrow derived mesenchymal stem cells immunogenicity and immunomodulatory properties.

Mesenchymal stem cells (MSCs) are being investigated for the treatment of equine joint diseases because of their regenerative potential. Recently, the focus mainly has addressed to their immunomodulatory capacities. Inflammation plays a central role in joint pathologies, since the release of proinflammatory mediators to the synovial fluid (SF) leads to the activation of enzymatic degradation of the cartilage. MSCs can modulate the local immune environment through direct or paracrine interaction with immune cells, suppressing their proliferation and re-addressing their functions. Proinflammatory molecules can induce MSC immunoregulatory potential, but they could also increase the expression of immunogenic molecules. Studying the effect of inflammatory environment on MSC immunomodulation and immunogenicity profiles is mandatory to improve cellular therapies. The aim of this study was to analyse the response of equine bone marrow MSCs (eBM-MSCs) to three inflammatory conditions. Equine BM-MSCs from three animals were exposed to: (a) 20% allogeneic inflammatory SF (SF); (b) 50 ng/ml of TNFα and IFNγ (CK50) and (c) 20 ng/ml of TNFα and IFNγ (CK20). After 72 h of exposure, expression of immunogenic and immunomodulation-related molecules, including cell-to-cell contact and paracrine signalling molecules, were analysed by RT-qPCR and flow cytometry. The gene expression of adhesion molecules was upregulated whereas MSC migration-related genes were downregulated by all inflammatory conditions tested. CK culture conditions significantly upregulated the expression of COX-2, iNOS, IDO and IL-6. MHC-I gene expression was upregulated by all conditions, whereas MHC-II was upregulated only after CK priming. The expression of CD40 did not significantly change, whereas the ligand, CD40L, was downregulated in CK conditions. Flow cytometry showed an increase in the percentage of positive cells and mean fluorescence intensity (MFI) of the MHC-I and MHC-II molecules at CK50 conditions, supporting the gene expression results. These outcomes reinforce the change of the immunophenotype of the eBM-MSCs according to the surrounding conditions. Inflammatory synovial environment did not lead to significant changes, so the environment found by eBM-MSCs when they are intraarticular administered may not be enough to activate their immunomodulatory potential. CK priming at tested doses enhances the immunoregulatory profile of eBM-MSCs, which may promote a therapeutic benefit. Even if CK priming induced an upregulation of MHC expression, costimulatory molecule expression however was not upregulated, suggesting that immunogenicity might not be increased. This study provides a better understanding about the behaviour of eBM-MSCs inside the inflamed joint and constitutes a first step to improve MSC-based therapies for equine joint diseases.