Ex vivo evaluation of a percutaneous thread-transecting technique for desmotomy of normal palmar/plantar annular ligaments in horses

Objective: To develop and describe a minimally invasive, ultrasound-guided, percutaneous technique for the desmotomy of equine palmar/plantar annular ligaments (PALs) using a transecting thread. Study design: Ex vivo study. Sample population: Twenty-one normal equine distal limb specimens. Methods: Under ultrasonographic guidance, a surgical thread was percutaneously placed around the PAL through 2 skin punctures (proximal and distal) using a 18 gauge spinal needle in equine limbs (11 forelimbs, 10 hindlimbs) with normal PALs. The ligament was transected by a back-and-forth motion of the thread until the loop emerged from the proximal skin puncture site. Each specimen was dissected and assessed for completeness of transection and iatrogenic damage under direct visualization. Descriptive statistics were reported. Results: The PAL was completely transected in 17/21 limbs. The mean duration of the procedure was 16 minutes. Superficial needle puncture or subtle abrasion of the superficial digital flexor tendon was noticed in 4 limbs. No iatrogenic injury to other intrathecal structures was identified. After PAL division, the needle entry and exit points had a mean diameter of 1.2 and 1 mm, respectively. Conclusion: Desmotomy of normal PALs in equine limb specimens was performed effectively using the percutaneous thread-transecting technique with minimal iatrogenic damage to adjacent structures. Clinical significance: Information from this study will allow refinement of the technique for use in equine clinical cases either in standing or anesthetized horses

Anesthetic recovery assisted by rope at three points in horses

ABSTRACT: This study evaluated the quality of anesthesyc recovery of horses using a three-point assisted method. Sixty-eight horses (37 females and 31 males) of different breeds, age and weight submitted to general anesthesia for abdominal - ABD (n=15), arthroscopy - ART (n=17), other orthopedic - ORT (n=18) and miscellaneous - MIX (n=18) surgical procedures. Isoflurane resulted in shorter recovery time (67.4±25.7min) compared to halothane (88.0±37.8min). The mean duration (±SD) of anesthesia for ABD, ORT, ART and MIXgroups was 166.7 (±14), 54.9 (±5.9), 86.5 (±7.3) and 76.4 (±32.5) minutes (min) respectively. Quality of recovery wasn’t influenced by duration of anesthesia or by use of analgesic, sedative and/or anesthetic drugs or not (p>0.05). Mean standing time (TEst) during anesthetic recovery was 67.5 (±29.9) min in ABD, 44.4 (±27) min in ORT, 42.2 (±23.2) min in ART and 39 (±14.7) min in MIX group. Average number of attempts (Ast) to stand was 1.8 (±0.8) in ABD group, 3.1 (±4.7) in ORT, 1.8 (±1.2) in ART and 1.8 (±1.2) in MIX. Recovery time (TRec) in ABD group was 102.2 (±36.5) min, ORT 70.1 (±36.5) min, ART 72.2 (±24.8) min and MIX group 66.6 (±19.1) min. TRec differed (p<0.05) between ABDand other groups. Three-point assisted recoveryfrom anesthesia showed to be a safe procedure during horses’ recovery. This method is easy to apply and well tolerated by horses regardless of the surgical procedure

Lipid rafts regulate 2-arachidonoylglycerol metabolism and physiological activity in the striatum

Several G protein-associated receptors and synaptic proteins function within lipid rafts, which are subdomains of the plasma membranes that contain high concentrations of cholesterol. In this study we addressed the possible role of lipid rafts in the control of endocannabinoid system in striatal slices. Disruption of lipid rafts following cholesterol depletion with methyl-beta-cyclodestrin (MCD) failed to affect synthesis and degradation of anandamide, while it caused a marked increase in the synthesis and concentration of 2-arachidonoylglycerol (2-AG), as well as in the binding activity of cannabinoid CB1 receptors. Surprisingly, endogenous 2-AG-mediated control of GABA transmission was not potentiated by MCD treatment and, in contrast, neither basal nor 3,5-Dihydroxyphenylglycine-stimulated 2-AG altered GABA synapses in cholesterol-depleted slices. Synaptic response to the cannabinoid CB1 receptor agonist HU210 was however intact in MCD-treated slices, indicating that reduced sensitivity of cannabinoid CB1 receptors does not explain why endogenous 2-AG is ineffective in inhibiting striatal GABA transmission after cholesterol depletion. Confocal microscopy analysis suggested that disruption of raft integrity by MCD might uncouple metabotropic glutamate 5-CB1 receptor interaction by altering the correct localization of both receptors in striatal neuron elements. In conclusion, our data indicate that disruption of raft integrity causes a complex alteration of the endocannabinoid signalling in the striatum

Horses naturally infected by Trypanosoma vivax in southern Brazil

In this study, we reported the first outbreak of the infection by Trypanosoma vivax in horses in southern Brazil, a non-endemic region where bovines have only recently been found infected by this trypanosome species. We evaluated 12 horses from a farm in southern Brazil, where four horses displayed pale mucous membranes, fever, weight loss, and swelling of abdomen, prepuce, or vulva. The diagnosis of T vivax was confirmed in four horses by morphological parameters of trypomastigotes in blood smears and species-specific PCR. All T vivax-infected animals showed anemia, and most showed increased levels of beta-1, beta-2, and gamma globulins. Horses were treated with diminazene aceturate, but cure was not achieved, and the disease relapsed after therapy. These findings demonstrated that Brazilian T vivax isolates, which were already reported infecting cattle, buffaloes, goats, and sheep, can be highly pathogenic for horses, causing severe disease and even death of the animals due to the recurrence of the infection

Claudicação em cavalos Crioulos atletas Lameness in athletic Criollo horses

O objetivo deste trabalho foi identificar as principais causas de claudicação em cavalos Crioulos em treinamento para a prova do Freio de Ouro e competições de rédeas. Foram avaliados os registros clínicos de 201 cavalos Crioulos, 5,6 2,1 anos de idade, submetidos a exame físico devido à presença de claudicação ou histórico de baixo rendimento atlético entre os anos de 2002 a 2009. A claudicação foi localizada nos membros torácicos e pélvicos em 47,1% (n=105) e 52,9% (n=118), respectivamente. Nos machos, houve uma predominância de claudicação nos membros pélvicos (60,0%) e nas fêmeas nos membros torácicos (57,1%). Nos membros torácicos, 17,1% (18/105) das alterações foram diagnosticadas proximais à articulação metacarpofalangeana, 14,3% (15/105) na articulação metacarpofalangeana e 68,6% (72/105) estavam localizadas distais à articulação metacarpofalangeana. Nos membros pélvicos, 78,8% (93/118) apresentaram a origem da dor na região do tarso, 17,8% (21/118) proximal ao tarso e 3,4% (4/118) distal ao tarso. As articulações interfalangeanas distais e intertarsiana distal/tarsometatarsiana são importantes fontes de dor e inflamação e estiveram mais frequentemente envolvidas em claudicações de membro torácico e pélvico, respectivamente. Os cavalos Crioulos apresentam problemas de claudicação semelhantes aos descritos em outras raças que participam de provas de rodeio.<br>This study aimed to identify the source of lameness in Criollo horses that are competing in the most important discipline for this breed in Southern Brazil and also in reining competitions. Clinical records of adult Criollo horses (n=201), 5.6 2.1 years of age, that underwent lameness examination due to history of poor performance or lameness between 2002/2009 were analyzed. Lameness was diagnosed in the front limbs in 47.1% (n=105) and in the hind limbs 52.9% of the cases (n=118). In males 60.0% of the lameness cases were located in the hind limbs. In females 57.1% of the lameness cases were located in the front limbs. In the front limbs (47.1%, n=105/201), problems proximal to the fetlock were diagnosed in 17.1% (18/105). Fetlock problems were diagnosed in 14.3% (15/105) and lesions located distal to the fetlock level were seen in 68.6% (72/105) of the lameness cases diagnosed in the front limbs. In the hind limbs, problems located proximal to the tarsus were seen in 17.8% (21/118), 78.8% (93/118) in the tarsus and 3.4% (4/118) of the cases were seen distal to the tarsus. The distal interfalangeal joint in the front limbs and the distal tarsal joints in the hind limbs were the two most important sources of lameness. Criollo horses presented similar lameness problems as described in other show horses (reining, cutting and roping). This is the first lameness study done in Criollo horses and it will help to better understand the musculoskeletal diseases affecting this breed

Type-1 cannabinoid receptors colocalize with caveolin-1 in neuronal cells

Type-1 (CB1) and type-2 (CB2) cannabinoid receptors belong to the rhodopsin family of G protein-coupled receptors, and are activated by endogenous lipids termed “endocannabinoids”. Recent reports have demonstrated that CB1R, unlike CB2R and other receptors and metabolic enzymes of endocannabinoids, functions in the context of lipid rafts, i.e. plasma membrane microdomains which may be important in modulating signal transduction. Here, we present novel data based on cell subfractionation, immunoprecipitation and confocal microscopy studies, that show that in C6 cells CB1R co-localizes almost entirely with caveolin-1. We also show that trafficking of CB1R in response to the raft disruptor methyl-β-cyclodextrin (MCD) is superimposable on that of caveolin-1, and that MCD treatment increases the accessibility of CB1R to its specific antibodies. These findings may be relevant for the manifold CB1R-dependent activities of endocannabinoids, like the regulation of apoptosis and of neurodegenerative diseases

Anandamide inhibits metabolism and physiological actions of 2-arachidonoylglycerol in the striatum

Of the endocannabinoids (eCBs), anandamide (AEA) and 2-arachidonoylglycerol (2-AG) have received the most study. A functional interaction between these molecules has never been described. Using mouse brain slices, we found that stimulation of metabotropic glutamate 5 receptors by 3,5-dihydroxyphenylglycine (DHPG) depressed inhibitory transmission in the striatum through selective involvement of 2-AG metabolism and stimulation of presynaptic CB1 receptors. Elevation of AEA concentrations by pharmacological or genetic inhibition of AEA degradation reduced the levels, metabolism and physiological effects of 2-AG. Exogenous AEA and the stable AEA analog methanandamide inhibited basal and DHPG-stimulated 2-AG production, confirming that AEA is responsible for the downregulation of the other eCB. AEA is an endovanilloid substance, and the stimulation of transient receptor potential vanilloid 1 (TRPV1) channels mimicked the effects of endogenous AEA on 2-AG metabolism through a previously unknown glutathione-dependent pathway. Consistently, the interaction between AEA and 2-AG was lost after pharmacological and genetic inactivation of TRPV1 channels