Subconjunctival autologous muscle-derived mesenchymal stem cell therapy: A novel, minimally invasive approach for treating equine immune-mediated keratitis.

OBJECTIVE: To establish the safety of subconjunctival injections of autologous muscle-derived mesenchymal stem cells (mdMSCs) in healthy horses and to evaluate their effect in four horses (six eyes) with severe chronic equine immune-mediated keratitis (IMMK) that was unresponsive to medical treatments. METHODS: MdMSCs were cultured from minimally invasive muscle biopsies. In the safety group, four healthy horses received two subconjunctival injections of 2.5 and 5 million cells, respectively, at 1-month interval, to the same eye. Ocular side effects were monitored for 1 month following each injection. In the treatment group, six eyes received four to seven subconjunctival mdMSCs injections (2.5 or 5 million cells per injection) every 4 weeks, approximatively. Medical treatment was discontinued 1 week before and throughout the entire treatment period. A scoring system was used to assess the evolution of the ocular lesions. RESULTS: In the safety group, all horses exhibited mild to moderate chemosis and conjunctival hyperemia at the injection site, lasting 24-48 h. In the treatment group, all eyes initially responded positively to therapy, with a reduction in lesion scores observed after the first injection. Four eyes achieved control of the lesions with repeated injections during the 9.2 months of follow-up. CONCLUSION: The first subconjunctival injection of mdMSCs resulted in improvement of the ocular lesions. Repeated injections were found to be safe, minimally invasive and showed promise in managing refractory cases of equine IMMK. Further studies are warranted to demonstrate the long-term benefits of these injections and to optimize the therapeutic protocol.

Equine Muscle Derived Mesenchymal Stem Cells Loaded with Water-Soluble Curcumin: Modulation of Neutrophil Activation and Enhanced Protection against Intracellular Oxidative Attack.

We investigated the antioxidant potential of equine mesenchymal stem cells derived from muscle microbiopsies (mdMSCs), loaded by a water-soluble curcumin lysinate incorporated into hydroxypropyl-ß-cyclodextrin (NDS27). The cell loading was rapid and dependent on NDS27 dosage (14, 7, 3.5 and 1 µM). The immunomodulatory capacity of loaded mdMSCs was evaluated by ROS production, on active and total myeloperoxidase (MPO) degranulation and neutrophil extracellular trap (NET) formation after neutrophil stimulation. The intracellular protection of loaded cells was tested by an oxidative stress induced by cumene hydroperoxide. Results showed that 10 min of mdMSC loading with NDS27 did not affect their viability while reducing their metabolism. NDS27 loaded cells in presence of 14, 7 µM NDS27 inhibited more intensively the ROS production, the activity of the MPO released and bound to the NET after neutrophil stimulation. Furthermore, loaded cells powerfully inhibited intracellular ROS production induced by cumene as compared to control cells or cyclodextrin-loaded cells. Our results showed that the loading of mdMSCs with NDS27 significantly improved their antioxidant potential against the oxidative burst of neutrophil and protected them against intracellular ROS production. The improved antioxidant protective capacity of loaded mdMSCs could be applied to target inflammatory foci involving neutrophils.

Targeting Myeloperoxidase Activity and Neutrophil ROS Production to Modulate Redox Process: Effect of Ellagic Acid and Analogues.

Malaria is an infectious disease caused by a Plasmodium genus parasite that remains the most widespread parasitosis. The spread of Plasmodium clones that are increasingly resistant to antimalarial molecules is a serious public health problem for underdeveloped countries. Therefore, the search for new therapeutic approaches is necessary. For example, one strategy could consist of studying the redox process involved in the development of the parasite. Regarding potential drug candidates, ellagic acid is widely studied due to its antioxidant and parasite-inhibiting properties. However, its low oral bioavailability remains a concern and has led to pharmacomodulation and the synthesis of new polyphenolic compounds to improve antimalarial activity. This work aimed at investigating the modulatory effect of ellagic acid and its analogues on the redox activity of neutrophils and myeloperoxidase involved in malaria. Overall, the compounds show an inhibitory effect on free radicals as well as on the enzyme horseradish peroxidase- and myeloperoxidase (HRP/MPO)-catalyzed oxidation of substrates (L-012 and Amplex Red). Similar results are obtained with reactive oxygen species (ROS) produced by phorbol 12-mystate acetate (PMA)-activated neutrophils. The efficiency of ellagic acid analogues will be discussed in terms of structure-activity relationships.

Comparison of single-breath continuous positive airway pressure manoeuvre with inhaled salbutamol to improve oxygenation in horses anaesthetized for laparotomy.

OBJECTIVE: To compare the efficacy of single-breath continuous positive airway pressure manoeuvre (CPAP-M) with inhaled salbutamol, and a combination of both. STUDY DESIGN: Randomized, clinical study. ANIMALS: A total of 62 client-owned horses (American Society of Anesthesiologists status III-V) anaesthetized for laparotomy. METHODS: Horses were premedicated with intravenous (IV) xylazine (0.4-0.6 mg kg-1), anaesthesia was induced with midazolam (0.06 mg kg-1 IV) and ketamine (2.2 mg kg-1 IV) and maintained with isoflurane in oxygen using volume-controlled ventilation without positive end-expiratory pressure. If PaO2 was < 100 mmHg (13.3 kPa), either a CPAP-M (50 cmH2O for 45 seconds) or salbutamol (0.002 mg kg-1) was administered. The intervention was considered successful if PaO2 reached 100 mmHg (13.3 kPa). If PaO2 remained < 100 mmHg (13.3 kPa), treatments were switched. PaO2/FiO2 ratio and estimated shunt fraction (F-shunt) were derived from data obtained from arterial blood gas measurements. Dynamic compliance (Cdyn) was calculated from variables recorded at the moment of arterial blood analysis. Fisher's exact tests compared success rates between treatments, and linear models were performed to test whether the treatment modified the values of the measurements; p < 0.05. RESULTS: Salbutamol was the first intervention in 28 horses and was effective in 22 horses. CPAP-M was the first intervention in 34 horses and was effective in 26 horses. CPAP-M after salbutamol was performed in six horses, with four responders, and salbutamol after CPAP-M was administered to eight horses, with one responder. Salbutamol, but not CPAP-M, significantly decreased F-shunt. Both salbutamol and CPAP-M significantly increased Cdyn. CONCLUSIONS AND CLINICAL RELEVANCE: Salbutamol and CPAP-M were comparably effective in improving oxygenation and Cdyn in anaesthetized horses with PaO2 < 100 mmHg (13.3 kPa). Whether combining both treatments might be beneficial needs to be confirmed on a larger number of horses.

Priming of mesenchymal stem cells with a hydrosoluble form of curcumin allows keeping their mesenchymal properties for cell-based therapy development.

Mesenchymal stem cells are increasingly studied for their use as drug-carrier in addition to their intrinsic potential for regenerative medicine. They could be used to transport molecules with a poor bioavailability such as curcumin in order to improve their clinical usage. This natural polyphenol, well-known for its antioxidant and anti-inflammatory properties, has a poor solubility that limits its clinical potential. For this purpose, the use of NDS27, a curcumin salt complexed with hydroxypropyl-beta-cyclodextrin (HPßCD), displaying an increased solubility in aqueous solution, is preferred. This study aims to evaluate the uptake of NDS27 into skeletal muscle-derived mesenchymal stem cells (mdMSCs) and the effects of such uptake onto their mesenchymal properties. It appeared that the uptake of NDS27 into mdMSCs is concentration-dependent and not time-dependent. The use of a concentration of 7 µmol/L which does not affect the viability and proliferation also allows preservation of their adhesion, invasion and T cell immunomodulatory abilities.

Unlocking the Real Potential of Black Soldier Fly (Hermetia illucens) Larvae Protein Derivatives in Pet Diets.

Black soldier fly larvae (BSFL)-derived proteins are gaining popularity as sustainable pet food ingredients. According to the literature, these ingredients have strong antioxidant and antimicrobial activities. Due to the ability of BSFL protein derivatives to donate hydrogen atoms and/or electrons to counterpoise unstable molecules, they could possibly help in the prevention of osteoarthritis. During this study, the antiarthritic potential of BSFL protein derivatives was evaluated using the following assays: (1) proteinase inhibition, (2) erythrocyte membrane stability, (3) reactive oxygen species (ROS) production by activated macrophages, (4) ROS production by monocytes, and (5) cellular toxicity. Additionally, the glucosamine content of these ingredients was also evaluated. Chicken meal is commonly used in pet food formulations and was used as an industrial benchmark. The results obtained during this study demonstrated the strong antiarthritic potential of BSFL protein derivatives. We found that BSFL protein derivatives are not only useful in preventing the development of arthritis but could also help to cure it due to the presence of glucosamine. We also found that chicken meal could contribute to the development of arthritis by increasing ROS production by monocytes.

Altered mitochondrial oxidative phosphorylation capacity in horses suffering from polysaccharide storage myopathy.

Polysaccharide storage myopathy (PSSM) is a widely described cause of exertional rhabdomyolysis in horses. Mitochondria play a central role in cellular energetics and are involved in human glycogen storage diseases but their role has been overlooked in equine PSSM. We hypothesized that the mitochondrial function is impaired in the myofibers of PSSM-affected horses. Nine horses with a history of recurrent exercise-associated rhabdomyolysis were tested for the glycogen synthase 1 gene (GYS1) mutation: 5 were tested positive (PSSM group) and 4 were tested negative (horses suffering from rhabdomyolysis of unknown origin, RUO group). Microbiopsies were collected from the gluteus medius (gm) and triceps brachii (tb) muscles of PSSM, RUO and healthy controls (HC) horses and used for histological analysis and for assessment of oxidative phosphorylation (OXPHOS) using high-resolution respirometry. The modification of mitochondrial respiration between HC, PSSM and RUO horses varied according to the muscle and to substrates feeding OXPHOS. In particular, compared to HC horses, the gm muscle of PSSM horses showed decreased OXPHOS- and electron transfer (ET)-capacities in presence of glutamate&malate&succinate. RUO horses showed a higher OXPHOS-capacity (with glutamate&malate) and ET-capacity (with glutamate&malate&succinate) in both muscles in comparison to the PSSM group. When expressed as ratios, our results highlighted a higher contribution of the NADH pathway (feeding electrons into Complex I) to maximal OXPHOS or ET-capacity in both rhabdomyolysis groups compared to the HC. Specific modifications in mitochondrial function might contribute to the pathogenesis of PSSM and of other types of exertional rhabdomyolyses.

Microbiota Quality and Mitochondrial Activity Link with Occurrence of Muscle Cramps in Hemodialysis Patients using Citrate Dialysate: A Pilot Study.

BACKGROUND/AIMS: Hemodialysis-associated muscle cramp (HAMC) is a common complication under citrate dialysate (CD) occurring in 30% of cases. Our objectives were to assess the gut microbiota quality, mitochondrial activity, and to investigate their possible relationship with HAMC. METHODS: Ten end-stage renal disease patients (78.9 ± 2.1 years) treated by hemodialysis (HD) with CD were enrolled and then classified according to the frequency of HAMCs: "frequent HAMCs group" (n = 5) and "absence of HAMCs group" (n = 5). Gut microbiota quality, mitochondrial activity, and some markers of oxidative stress (OS) were investigated. RESULTS: In patients with cramps, gut microbiota diversity seemed lower and some genera including Helicobacter, Lachnospira, Roseburia, and Haemophilus seemed over-expressed, a significant increase of citratemia and significant lowering mitochondrial function were observed. No difference was observed on the OS markers. CONCLUSION: This first clinical study revealed a possible dysbiosis of microbiota and a mitochondrial dysfunction into HD patients with cramps under CD compared to patients without cramp.

Modified Thomas splint-cast combination for the management of limb fractures in small equids.

OBJECTIVE: To describe the management and outcome of limb fractures in small domestic equids treated with a modified Thomas splint-cast combination (MTSCC). STUDY DESIGN: Retrospective case series. ANIMALS: Client owned horses and donkeys. METHODS: Medical records, including radiographs, were reviewed for details of animals diagnosed with a limb fracture and treated by external coaptation using a MTSCC (2001-2012). Follow-up >6 months after discharge was obtained via telephone consultation with owners or veterinarians. RESULTS: Nine horses and 4 donkeys were identified with fractures of the tibial diaphysis (n = 4), ulna (n = 3), distal metatarsus (n = 2), proximal metacarpus (n = 1), radial diaphysis (n = 1), calcaneus (n = 1), and distal femoral physis (n = 1). Follow-up was available for 12 equids, of which 8 (67%) recovered from the fracture and became pasture sound. Six equids developed obvious external deformation of the affected limb. CONCLUSION: Selected small equids with long bone fractures, and without athletic expectations, can be managed with external coaptation using an MTSCC. The owner should be informed that the treatment is considered a salvage procedure.

Use of cis-atracurium to maintain moderate neuromuscular blockade in experimental pigs.

OBJECTIVE: To determine the dose of cis-atracurium needed to produce a moderate neuromuscular blockade (NMB) in pigs. STUDY DESIGN: Prospective experimental study. ANIMALS: Seven pigs [five females and two males; median (range) body weight: 47 (36-64) kg]. METHODS: Pigs were premedicated with intramuscular midazolam (0.3 mg kg-1) and ketamine (7 mg kg-1). Anaesthesia was induced with intravenous (IV) propofol 3 (1-4) mg kg-1 and maintained with isoflurane in oxygen. Based on a preliminary study, the subjects were administered 0.3 mg kg-1 cis-atracurium followed by 0.48 mg kg-1 hour-1 constant rate infusion (CRI) IV. A moderate NMB was defined as a train-of-four (TOF) count of ≤2 by acceleromyography. When the TOF count was >2, 0.1 mg kg-1 cis-atracurium was administered and the CRI was increased. The cis-atracurium CRI was decreased when the TOF count was under 2 for more than 15 minutes. The total dose of cis-atracurium required to maintain a moderate NMB was calculated as the total amount of cis-atracurium used (both CRI and supplementary boluses) divided by the administration time. RESULTS: The cis-atracurium CRI lasted for 87 (76-151) minutes. To induce and maintain a moderate neuromuscular blockade, the initial dose of cis-atracurium was 0.3 (0.3- 0.5) mg kg-1 and the CRI was 0.71 (0.37-0.98) mg kg-1 hour-1. CONCLUSIONS AND CLINICAL RELEVANCE: The doses described in our study may help researchers obtain a moderate NMB using cis-atracurium in pigs.

Substitution of egg yolk by a cyclodextrin-cholesterol complex allows a reduction of the glycerol concentration into the freezing medium of equine sperm.

The aim of this work was to completely replace the egg yolk a classical diluent for freezing equine semen by a cyclodextrin-cholesterol complex. At the same time, the reduction in the glycerol content used for cryopreservation and the incubation time between sperm and the freezing media were evaluated. Horse ejaculates were frozen with four different freezing extenders: a frozen reference medium (IF) containing egg yolk and 2.5% glycerol and media without egg yolk but supplemented with 1.5 mg 2-hydroxypropyl-beta-cyclodextrin cholesterol (HPßCD-C) complex and containing either 1% (G1), 2% (G2) or 3% glycerol (G3). Three incubation times (90, 120 and 180 min) at 4 °C between the fresh semen and the different media were tested before freezing. Viability and motility analyses were performed with computer assisted semen analysis (CASA). Results showed that the freezing media containing the HPßCD-C complex with 1%, 2% and 3% glycerol significantly improve the 3 in vitro parameters of post thawing semen quality (viability, progressive and total mobilities) compared to IF. The best improvement of the parameters was obtained with G1 medium and the longest contact time. The substitution of egg yolk by HPßCD-C complex allows the decrease of protein charge of the medium while favouring the cholesterol supply to membrane spermatozoa offering it a better resistance to osmotic imbalance and a better tolerance to the glycerol toxicity. Our results highlight that the egg yolk of an extender for the freezing of horse semen can be completely substituted by HPßCD-C complex.

Active and total myeloperoxidase in coronary artery disease and relation to clinical instability.

OBJECTIVES: The aim of this study was to evaluate the correlation between serum total and active myeloperoxidase (MPO) levels and the presence of coronary artery disease in consecutive patients evaluated by coronary angiography and to correlate the levels of the enzyme with instability. METHODS AND RESULTS: Prospective analysis of serum samples of patients before coronary angiography. Total and active MPO concentrations were assessed by the sandwich Elisa and SIEFED® methods. Stable and unstable patients were separated into two groups. Differences between groups were analysed using the Student t test, chi square test or Fisher exact test, as appropriate. The relationship between total and active MPO was assessed using linear and curvilinear regression. Two hundred and twenty patients were included (age 66±11 years, 67% male) in the study. Among these, 62% presented significant coronary artery disease. Twenty-four patients (11%) presented unstable coronary syndrome. Mean active and total MPO levels in the population were 50.1±63.5 and 147.6±223.3 ng.mL(-1), respectively. In stable patients, mean active MPO was 47.1±47.9 ng.mL(-1) and in unstable patients 75.1±135.2 ng.mL(­1) (P=0.04). Mean total MPO was 146.3±224.7 ng.mL(-1) in the stable patients and 158.2±215.8 ng.mL(-1) in the unstable patients (P=0.8). Unstable patients had a significantly higher level of active MPO than stable patients but there was no significant difference between unstable and stable patients regarding total MPO. CONCLUSION: A correlation was observed between active MPO and clinical instability but not with total MPO. These results suggest that this marker could be a powerful indicator of instability and could have a prognostic impact.

Optimization of the Amplification of Equine Muscle-Derived Mesenchymal Stromal Cells in a Hollow-Fiber Bioreactor.

The main causes of mortality in horses are the gastrointestinal pathologies associated with septic shock. Stem cells have shown, through systemic injection, a capacity to decrease inflammation and to regenerate injured tissue faster. Nevertheless, to achieve this rapid and total regeneration, systemic injections of 1 to 2 million cells per kilogram of body weight must be considered. Here, we demonstrate for the first time the feasibility and expansion capacity of equine muscle-derived mesenchymal stromal cells (mdMSCs) in a functionally closed, automated, perfusion-based, hollow-fiber bioreactor (HFBR) called the Quantum™ Cell Expansion System (Terumo Blood and Cell Technologies). This feature greatly increases the number of generated cells with a surface area of 1.7 m2. The expansion of mdMSCs is very efficient in this bioreactor. The maximum expansion generated twenty times more cells than the initial seeding in nine days. The best returns were observed with an optimal seeding between 10 and 25 million mdMSCs, using the Bull's eye loading method and with a run duration between 7 and 10 days. Moreover, all the generated cells kept their stem properties: the ability to adhere to plastic and to differentiate into chondroblasts, osteoblasts and adipocytes. They also showed the expression of CD-44 and CD-90 markers, with a positive rate above 93%, while CD-45 and MHCII were non-expressed, with a positive rate below 0.5%. By capitalizing on the scalability, automation and 3D culture capabilities of the Quantum™, it is possible to generate large quantities of high-quality equine mdMSCs for gastrointestinal disorders and other clinical applications.

Neutrophil extracellular traps and active myeloperoxidase concentrate in lamellar tissue of equids with naturally occurring laminitis.

Laminitis is a pathology of the equine digit ultimately leading to a failure of the dermo-epidermal interface. Neutrophil activation is recognized as a major factor in SIRS-associated laminitis and has recently been described in induced endocrinopathic laminitis evidenced by the presence of myeloperoxidase (MPO). Neutrophil extracellular traps (NET) are released with neutrophil activation. This study aimed to investigate the presence and activity of MPO and NET in the lamellar tissue of equids presented with naturally occurring laminitis. Samples of lamellar tissue of five horses and five donkeys presented with laminitis, as well as eight control horses without laminitis, were collected. Lamellar tissue extracts were submitted to ELISA and specific immuno-extraction followed by enzymatic detection (SIEFED) assays to confirm the presence and activity of both MPO and NET. Lamellar sections were also immunohistopathologically stained for MPO and NET. Analysis of lamellar tissue extracts revealed that laminitis cases had significantly higher levels of total MPO concentration, MPO activity, and NET-bound MPO activity in comparison to control horses. Moreover, a strong correlation was identified between the activity of NET-bound MPO and the total MPO activity, which suggests that MPO activity partly originates from NET-bound MPO. Immunohistochemical staining showed that MPO and NET labelling in laminitis cases was moderate to marked, primarily in the epidermis and in inflammatory infiltrates containing neutrophils, while labelling in control horses was minimal. This article constitutes the first indication of the presence and activity of NET-bound MPO in the lamellar tissue of horses and donkeys with naturally occurring laminitis. Targeting these substances may provide new treatment possibilities for this debilitating disease.

Free Radical Inhibition Using a Water-Soluble Curcumin Complex, NDS27: Mechanism Study Using EPR, Chemiluminescence, and Docking.

There is a growing interest in the use of natural compounds to tackle inflammatory diseases and cancers. However, most of them face the bioavailability and solubility challenges to reaching cellular compartments and exert their potential biological effects. Polyphenols belong to that class of molecules, and numerous efforts have been made to improve and overcome these problems. Curcumin is widely studied for its antioxidant and anti-inflammatory properties as well as its use as an anticancer agent. However, its poor solubility and bioavailability are often a source of concern with disappointing or unexpected results in cellular models or in vivo, which limits the clinical use of curcumin as such. Beside nanoparticles and liposomes, cyclodextrins are one of the best candidates to improve the solubility of these molecules. We have used lysine and cyclodextrin to form a water-soluble curcumin complex, named NDS27, in which potential anti-inflammatory effects were demonstrated in cellular and in vivo models. Herein, we investigated for the first time its direct free radicals scavenging activity on DPPH/ABTS assays as well as on hydroxyl, superoxide anion, and peroxyl radical species. The ability of NDS27 to quench singlet oxygen, produced by rose bengal photosensitization, was studied, as was the inhibiting effect on the enzyme-catalyzed oxidation of the co-substrate, luminol analog (L012), using horseradish peroxidase (HRP)/hydrogen peroxide (H2O2) system. Finally, docking was performed to study the behavior of NDS27 in the active site of the peroxidase enzyme.

Surgical Closure of Equine Abdomen, Prevention, and Management of Incisional Complications.

Although rarely fatal, complications of ventral midline laparotomy incision in equine patients increase hospitalization cost and duration and may jeopardize return to athletic function. Therefore, many techniques have been developed to reduce their occurrence and expedite their resolution when they occur. Our technique of celiotomy incision closure includes the use of tension sutures (vertical U mattress) of polyglactin 910 on the linea alba, which is then apposed by polyglactin 910 interrupted sutures or a simple continuous pattern suture with a stop midway before routine closure of the superficial layers. The celiotomy incision is protected by an elastic bandage during the immediate postoperative period. This technique has been associated with favorable results: 5.3% confirmed incisional infections after a single celiotomy and 26.7% after repeat celiotomy. The overall incisional complication (serous/sanguineous discharge, hematoma, infection, hernia formation, and complete wound breakdown) occurrence was 9.5% and 33.3% after single and repeat laparotomy, respectively. In cases considered more susceptible to infection (early relaparotomy or laparotomy incisions longer than 30 cm), negative pressure therapy was found easy to apply on closed incisions. No detrimental effects were observed. However, the potential prophylactic benefit of this therapy needs to be confirmed in a larger group. In infected laparotomy wounds requiring drainage, the use of negative pressure therapy seemed to have a positive effect on the formation of granulation tissue. However, there was no control group to allow statistical confirmation. Finally, one case of complete breakdown of the laparotomy incision was managed by stainless steel retention sutures, the application of negative pressure therapy, and a hernia belt. At re-evaluation 15 months post-surgery, several small hernias were detected, but the horse had returned to his previous level of sports performance and had not shown any episode of colic.

Triphenylphosphonium salts of 1,2,4-benzothiadiazine 1,1-dioxides related to diazoxide targeting mitochondrial ATP-sensitive potassium channels.

The present work aims at identifying new ion channel modulators able to target mitochondrial ATP-sensitive potassium channels (mitoKATP channels). An innovative approach should consist in fixing a cationic and hydrophobic triphenylphosphonium fragment on the structure of known KATP channel openers. Such phosphonium salts are expected to cross the biological membranes and to accumulate into mitochondria. Previous works revealed that the presence of an (R)-1-hydroxy-2-propylamino chain at the 3-position of 4H-1,2,4-benzothiadiazine 1,1-dioxides KATP channel openers increased, in most cases, the selectivity towards the pancreatic-type (SUR1/Kir6.2) KATP channel. In order to target cardiac mitoKATP channels, we decided to introduce a triphenylphosphonium group through an ester link on the SUR1-selective (R)-7-chloro-3-(1-hydroxy-2-propyl)amino-4H-1,2,4-benzothiadiazine 1,1-dioxide. The new compounds were found to preserve an inhibitory activity on insulin secretion (SUR1-type KATP channel openers) while no clear demonstration of an impact on mitochondria from cardiomyocytes (measurement of oxygen consumption, respiratory parameters and ATP production on H9C2 cells) was observed. However, the most active (inhibition of insulin release) compound 17 was found to penetrate the cardiac cells and to reach mitochondria.

Myeloperoxidase-dependent LDL modifications in bloodstream are mainly predicted by angiotensin II, adiponectin, and myeloperoxidase activity: a cross-sectional study in men.

The present paradigm of atherogenesis proposes that low density lipoproteins (LDLs) are trapped in subendothelial space of the vascular wall where they are oxidized. Previously, we showed that oxidation is not restricted to the subendothelial location. Myeloperoxidase (MPO), an enzyme secreted by neutrophils and macrophages, can modify LDL (Mox-LDL) at the surface of endothelial cells. In addition we observed that the activation of the endothelial cells by angiotensin II amplifies this process. We suggested that induction of the NADPH oxidase complex was a major step in the oxidative process. Based on these data, we asked whether there was an independent association, in 121 patients, between NADPH oxidase modulators, such as angiotensin II, adiponectin, and levels of circulating Mox-LDL. Our observations suggest that the combination of blood angiotensin II, MPO activity, and adiponectin explains, at least partially, serum Mox-LDL levels.

Sevoflurane inhibits equine myeloperoxidase release and activity in vitro.

OBJECTIVE: To investigate the effects of the volatile anaesthetic sevoflurane on the release of total and active myeloperoxidase (MPO) by non-stimulated and stimulated polymorphonuclear neutrophils (PMNs) in whole blood from healthy horses. STUDY DESIGN: In vitro experimental study. ANIMALS: Adult healthy horses. METHODS: Samples of whole venous blood were collected and incubated in air or in air plus 2.3% or 4.6% sevoflurane for 1 hour. PMNs were stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), with a combination of cytochalasin B (CB) and fMLP or with phorbol myristate acetate (PMA). Total and active MPO contents released by PMNs in blood were measured by enzyme-linked immunosorbent assay (ELISA) and specific immunological extraction followed by enzymatic detection (SIEFED) respectively. Additional experiments were performed to assess the effect of sevoflurane on the peroxidase and chlorination cycles of purified equine MPO using Amplex Red and 3'-(p-aminophenyl) fluorescein as fluorogenic substrates respectively. RESULTS: As compared with air alone, 1 hour exposure of whole blood to 4.6% sevoflurane in air significantly inhibited the release of total and active MPO by unstimulated and both fMLP- and CB + fMLP-stimulated PMNs but not by PMA-stimulated PMNs. Although 2.3% sevoflurane had no effect on total MPO release by unstimulated and stimulated PMNs, it significantly reduced the release of active MPO by unstimulated and fMLP-stimulated PMNs. Additionally, sevoflurane reversibly inhibited the activity of MPO, especially the peroxidase cycle of the enzyme. CONCLUSIONS AND CLINICAL RELEVANCE: Although our experimental study was not designed to assess the effects of sevoflurane in vivo, this inhibition of MPO release and activity may have relevance for anaesthetized horses and deserves further studies to examine the clinical importance of these findings.

Evaluation of acepromazine-induced hemodynamic alterations and reversal with norepinephrine infusion in standing horses.

The effects of norepinephrine (NOR) infusion on hemodynamic alterations induced with sedative doses of acepromazine (ACP) were evaluated. Infusion of NOR at 1 µg/kg body weight (BW)/minute for 15 min was administered to 5 standing horses 45 min (T45) after intravenous injection of ACP at 0.1 mg/kg BW. Systolic arterial blood pressure (SAP) and hemodynamic parameters were evaluated on the median artery. Parameters were evaluated every 5 min from 45 to 65 min (T65) at 75 (T75), 90 (T90), and 105 (T105) minutes after ACP administration, and the vessel's surface (SURF), diameter (DIAM), circumference (CIRC), peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV), volumetric flow (VF) and resistivity index (RI) of the flow were calculated. Acepromazine induced hypotension and vasodilation with a significant rise in SURF, DIAM, CIRC, PSV, EDV, MV, and VF and a reduction in RI and SAP, which were significantly counteracted from T50 to T60 for EDV, VF, MV and RI, and to T65 for SAP, from T50 to T90 for CIRC and SURF and to T60 for DIAM. These findings demonstrate that a 1 µg/kg BW/minute NOR infusion can reverse ACP's vasodilatory effects, restoring hemodynamic parameters and blood pressure in horses.

Évaluation d'altérations hémodynamiques induites par l'acépromazine et inversion par une infusion de norépinéphrine chez des chevaux debout. Les effets d'une infusion de norépinéphrine (NOR) sur les altérations hémodynamiques induites avec des doses sédatives d'acépromazine (ACP) ont été évalués. Une infusion de NOR à 1 µg/kg poids corporel (PC)/minute pendant 15 minutes a été administrée à 5 chevaux debout 45 minutes (T45) après une injection intraveineuse d'ACP à 0,1 mg/kg PC. La tension artérielle systolique (TAS) et les paramètres hémodynamiques ont été évalués sur l'artère médiane. Les paramètres ont été évalués toutes les 5 minutes, de 45 à 65 minutes (T65), puis 75 (T75), 90 (T90) et 105 (T105) minutes après l'administration d'ACP et la surface (SURF), le diamètre (DIAM), la circonférence (CIRC), le pic de vélocité systolique (PVS), la vélocité en fin de diastole (VFD), la vélocité moyenne (VM) et l'écoulement volumétrique (EV) du vaisseau ainsi que l'indice de résistivité (IR) du débit ont été calculés. L'hypotension et la vasodilatation induites par l'acépromazine causant une hausse significative de SURF, de DIAM, de CIRC, de PVS, d'EV, de VM et de EV ainsi qu'une réduction d'IR et de TAS ont été significativement compensées de T50 à T60 pour EDV, VF, MV et RI, à T65 pour SAP, de T50 à T90 pour CIRC et SURF et à T60 pour DIAM. Ces constatations démontrent qu'une infusion de 1 µg/kg PC/minute NOR peut inverser les effets vasodilatoires d'ACP, rétablissant les paramètres hémodynamiques et la tension artérielle chez les chevaux.(Traduit par Isabelle Vallières).