Left Forelimb Research Articles

Three-dimensional inverse dynamics of the forelimb of Beagles at a walk and trot.

OBJECTIVE To perform 3-D inverse dynamics analysis of the entire forelimb of healthy dogs during a walk and trot. ANIMALS 5 healthy adult Beagles. PROCEDURES The left forelimb of each dog was instrumented with 19 anatomic markers. X-ray fluoroscopy was used to optimize marker positions and perform scientific rotoscoping for 1 dog. Inverse dynamics were computed for each dog during a walk and trot on the basis of data obtained from an infrared motion-capture system and instrumented quad-band treadmill. Morphometric data were obtained from a virtual reconstruction of the left forelimb generated from a CT scan of the same dog that underwent scientific rotoscoping. RESULTS Segmental angles, torque, and power patterns were described for the scapula, humerus, ulna, and carpus segments in body frame. For the scapula and humerus, the kinematics and dynamics determined from fluoroscopy-based data varied substantially from those determined from the marker-based data. The dominant action of scapular rotation for forelimb kinematics was confirmed. Directional changes in the torque and power patterns for each segment were fairly consistent between the 2 gaits, but the amplitude of those changes was often greater at a trot than at a walk. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that control of the forelimb joints of dogs is similar for both a walk and trot. Rotation of the forelimb around its longitudinal axis and motion of the scapula should be reconsidered in the evaluation of musculoskeletal diseases, especially before and after treatment or rehabilitation.

Cutaneous Angiolymphoid Hyperplasia in a Dog

A 5-year-old male miniature dachshund was presented with a dermal nodule on the left forelimb that increased to 5mm in diameter over a 2-month period. Grossly, the nodule was firm, and both the external and cut surfaces were homogeneously pale pink in colour. Microscopically, the nodule was comprised of mainly plump endothelial cells and inflammatory cells; among the latter, lymphocytes were predominant, with few scattered plasma cells, mast cells and macrophages. Lymphoid follicles with germinal centres were often observed. Mitotic figures were not observed amongst the endothelial cells. Immunohistochemically, the endothelial cells were positive for vimentin, factor VIII-related antigen and CD31, and the surrounding cells were positive for smooth muscle actin. Lymphocytes expressed CD3 or BLA36. These findings led to a diagnosis of cutaneous angiolymphoid hyperplasia. To the best of our knowledge, this is the first report of a cutaneous proliferative disorder comprising an admixture of proliferating vascular endothelial cells and lymphocytic infiltration with follicle formation in a dog.

Malignant peripheral nerve sheath tumour with metastasis and expression of endothelial differentiation factors in a horse

SummaryMalignant peripheral nerve sheath tumour (MPNST) has not previously been well documented in veterinary literature. This article reports the case of a 12‐year‐old Mangalarga Marchador gelding presented for evaluation of a large, ulcerated and pruritic lesion in the elbow of the left forelimb. Biopsy of the mass indicated an undifferentiated sarcoma. Considering the chronicity of the condition, poor prognosis and extensive nature of the neoplasm, the horse was subjected to euthanasia. A MPNST with expression of endothelial differentiation factors was diagnosed based on gross morphology results, histological features and immunohistochemical findings.

Asymmetrical responses of skin blood flow in ischemic hindlimbs to electrical stimulation of the unilateral forelimb

The regulation of skin blood flow (SBF) is primarily mediated by the sympathetic nervous system, but the effects of electrical stimulation (ES) of one limb on SBF in the other limbs remain unknown. The present study investigated the effects of unilateral forelimb ES on SBF in the bilateral hindlimbs in anesthetized rats. Bilateral hindlimb ischemia was induced by tourniquet application for 60min. After reperfusion for 24h, ES (3 or 125Hz) was applied to the upper one-fourth of the triceps brachii muscle of the left or right forelimb for 30min. Rats that did not receive ES were used as the controls. Bilateral hindlimb SBF was measured by a laser Doppler line scanner for 20min before ES, 30min during ES, and 9min after ES. The results showed significant differences in SBF in the right but not left hindlimb between the control group and experimental group that received 125-Hz ES of the right forelimb. Right hindlimb SBF significantly increased within 3min following the application of 125-Hz ES to the right forelimb. No significant changes in SBF were observed in the left or right hindlimb when 125-Hz ES was applied to the left forelimb. Moreover, 3-Hz ES of the left or right forelimb did not significantly change SBF in either hindlimb compared with the control group. These results indicate that unilateral forelimb ES causes a differential SBF response in the hindlimb via a specific somatosympathetic reflex, and ES-induced SBF improvements in the ischemic hindlimb are frequency-dependent.

Head and pelvic movement asymmetries at trot in riding horses in training and perceived as free from lameness by the owner.

Recent studies evaluating horses in training and considered free from lameness by their owners have identified a large proportion of horses with motion asymmetries. However the prevalence, type and magnitude of asymmetries when trotting in a straight line or on the lunge have not been investigated. The aim of this study was to objectively investigate the presence of motion asymmetries in riding horses in training by identifying the side and quantifying the degree and type (impact, pushoff) of forelimb and hind limb asymmetries found during straight line trot and on the lunge. In a cross-sectional study, vertical head and pelvic movement symmetry was measured in 222 Warmblood type riding horses, all without perceived performance issues and considered free from lameness by their owners. Body-mounted uni-axial accelerometers were used and differences between maximum and minimum head (HDmax, HDmin) and pelvic (PDmax, PDmin) vertical displacement between left and right forelimb and hind limb stances were calculated during straight line trot and on the lunge. Previously reported symmetry thresholds were used. The thresholds for symmetry were exceeded in 161 horses for at least one variable while trotting in a straight line, HDmin (n = 58, mean 14.3 mm, SD 7.1), HDmax (n = 41, mean 12.7 mm, SD 5.5), PDmax (n = 87, mean 6.5 mm, SD 3.10), PDmin (n = 79, mean 5.7 mm, SD 2.1). Contralateral and ipsilateral concurrent forelimb and hind limb asymmetries were detected in 41 and 49 horses, respectively. There was a linear association between the straight line PDmin values and the values on the lunge with the lame limb to the inside of the circle. A large proportion (72.5%) of horses in training which were perceived as free from lameness by their owner showed movement asymmetries above previously reported asymmetry thresholds during straight line trot. It is not known to what extent these asymmetries are related to pain or to mechanical abnormalities. Therefore, one of the most important questions that must be addressed is how objective asymmetry scores can be translated into pain, orthopedic abnormality, or any type of unsoundness.

Response Properties of Motor Equivalence Neurons of the Primate Premotor Cortex.

To study the response properties of cells that could participate in eye-hand coordination we trained two macaque monkeys to perform center-out saccades and pointing movements with their right or left forelimb toward visual targets presented on a video display. We analyzed the phasic movement related discharges of neurons of the periarcuate cortex that fire before and during saccades and movements of the hand whether accompanied by movements of the other effector or not. Because such cells could encode an abstract form of the desired displacement vector without regard to the effector that would execute the movement we refer to such cells as motor equivalence neurons (Meq). Most of them (75%) were found in or near the smooth pursuit region and the grasp related region in the caudal bank of the arcuate sulcus. The onset of their phasic discharges preceded saccades by about 70 ms and hand movements by about 150 ms and was often correlated to both the onset of saccades and the onset of hand movements. The on-direction of Meq cells was uniformly distributed without preference for ipsiversive or contraversive movements. In about half of the Meq cells the preferred direction for saccades was the preferred direction for hand movements as well. In the remaining cells the difference was considerable (>90 deg), and the on-direction for eye-hand movements resembled that for isolated saccades in some cells and for isolated hand movements in others. A three layer neural network model that used Meq cells as its input layer showed that the combination of effector invariant discharges with non-invariant discharges could help reduce the number of decoding errors when the network attempts to compute the correct movement metrics of the right effector.

Unusual soft tissue preservation in the Early Cretaceous (Aptian) crocodile cf. Susisuchus from the Crato Formation of north east Brazil

A new specimen of the neosuchian crocodylomorph, Susisuchus sp. from the Lower Cretaceous (Aptian) Crato Formation of Ceará, North East Brazil is remarkable for extensive preservation of the epidermis and limb musculature. The specimen comprises incomplete post-cranial remains, including an articulated sequence of thirteen thoracic vertebrae, a disarticulated pair of lumbar vertebrae and all four limbs articulated in varying degrees of completeness but divorced from the axial skeleton. Soft tissues are preserved in two distinct modes, in close association with the skeletal remains. An external mould of the dorsolateral scales of the trunk extends over a bedding plane surface while mineralisation of soft tissues preserving the musculature surrounds the left forelimb. Soft tissue preservation is extremely rare in crocodylomorphs and this is only the second report of soft tissue preservation in a crocodilian from the Crato Formation.

The effect of ambient temperature on infrared thermographic images of joints in the distal forelimbs of healthy racehorses

The aim of the study was to describe the dependence on ambient temperature of distal joint temperature at the forelimbs of racehorses. The study also investigated the influence of differing ambient temperatures on the temperature difference between joints: this was measured ipsilaterally (i.e. between the carpal and fetlock joints along each forelimb) and contralaterally (i.e. between the same joints of the left and right forelimbs). Sixty-four healthy racehorses were monitored over 10 months. At each session, three thermographic images were taken of the dorsal, lateral and medial aspects of the distal forelimbs. Temperature measurements were made from regions of interest (ROIs) covering the carpal and fetlock joints. There was a strong correlation between ambient temperature and absolute joint temperature at all ROIs. The study also observed a moderate correlation between ambient temperature and the ipsilateral temperature differences between joints when measured from the medial and lateral aspects. No significant correlation was noted when measured dorsally. The mean contralateral temperature differences between joints were all close to 0°C. The data support previous reports that the temperature distribution between the forelimbs of the healthy equine is generally symmetric, although some horses differ markedly from the average findings.

Atrophy of the supra and infraspinatus muscles due to injury of the suprascapular nerve in horse (sweeny)

This is a case report of atrophy of the shoulder muscles (sweeny) – supra and infraspinatusdue to suprascapular nerve injury in a horse, cross breed, male, with 15 years of age, weigh350 kg, used for traction, seen at the Veterinary Hospital (HCV) from the Santa Catarina StateUniversity (UDESC), Agroveterinary Sciences Center (CAV) from Lages, SC, Brazil. Theanimal showed clinical signs such as muscle atrophy of the scapular region and moderateinstability of the shoulder joint of the left forelimb. Due to chronic and irreversible changes inthe musculature, with no further complications to the animal, treatment was based onreducing workload and suitability of tack used in the animal. This is the first clinicaldescription in Brazil of atrophy of the supra and infraspinatus muscles due to injury of thesuprascapular nerve with chronic presentation.

Influences of high-voltage electrical burns on microcirculation perfusion on serosal surface of small intestine of rats and the interventional effects of pentoxifylline

Objective: To investigate influences of high-voltage electrical burns on microcirculation perfusion on serosal surface of small intestine of rats and the interventional effects of pentoxifylline (PTX). Methods: Totally 180 SD rats were divided into sham injury group, simple electrical burn group, and treatment group according to the random number table, with 60 rats in each group. The electrical current was applied to the outside proximal part of left forelimb of rats and exited from the outside proximal part of right hind limb of rats. Rats in simple electrical burn group and treatment group were inflicted with high-voltage electrical burn wounds of 1cm×1cm at current entrances and exits, with the voltage regulator and experimental transformer. Rats in sham injury group were sham injured through connecting the same equipments without electricity. At 2 min post injury, rats in sham injury group and simple electrical burn group were intraperitoneally injected with 2 mL normal saline, and rats in treatment group were injected with 2 mL PTX injection (50 mg/mL). At 15 min before injury and 5 min, 1 h, 2 h, 4 h, and 8 h post injury, 10 rats in each group were selected to collect blood of heart respectively. Serum were separated from the blood to determine the level of soluble vascular cell adhesion molecule-1(sVCAM-1) with enzyme-linked immunosorbent assay method. The number of adhesional leukocyte in mesenteric venule of rats was determined with Bradford variable projection microscope system. The microcirculation perfusion on serosal surface of small intestine of rats was detected with laser Doppler perfusion imager. Data were processed with analysis of variance of factorial design and LSD test. Results: (1) At 5 min, 1 h, 2 h, 4 h, 8 h post injury, the serum content of sVCAM-1 in rats of simple electrical burn group were (8 502±1 158), (11 793±3 310), (9 960±2 146), (9 708±1 429), (7 292±1 386) ng/mL respectively, higher than that in sham injury group and treatment group [ (1 897±946), (1 882±940), (1 882±938), (1 888±946), (1 884±942) ng/mL, and (6 840±1 558), (6 742±2 465), (5 625±2 593), (2 373±1 463), (5 187±2 797) ng/mL, respectively, with P values below 0.001]. The serum content of sVCAM-1 in rats of sham injury group and treatment group at all time points post injury, except 4 h post injury of treatment group, was higher than that of the same group at 15 min before injury (with P values below 0.001). (2) At all time points post injury, the number of adhesional leukocyte in mesenteric venule of rats in simple electrical burn group was higher than that in sham injury group and treatment group (with P values below 0.001). The number of adhesional leukocyte in mesenteric venule of rats in simple electrical burn group and treatment group at all time points post injury was higher than that of the same group at 15 min before injury (with P values below 0.001). (3) At all time points post injury, the microcirculation perfusion on serosal surface of small intestine of rats in simple electrical burn group was lower than that in sham injury group and treatment group (with P values below 0.001). The microcirculation perfusion on serosal surface of small intestine of rats in simple electrical burn group and treatment group at all time points post injury was lower than that of the same group at 15 min before injury (with P values below 0.001). Conclusions: High-voltage electrical burns can increase the serum content of sVCAM-1, the number of adhesional leukocyte in mesenteric venule, and reduce microcirculation perfusion on serosal surface of small intestine of rats. PTX can inhibit secretion of serum sVCAM-1, reduce the number of adhensional leukocyte in mesenteric venule to alleviate microcirculation disturbance caused by high-voltage electrical burns.

Management of a Soft Tissue Sarcoma in a Bog Turtle (Glyptemys muhlenbergii)

Abstract A focal, necrotic soft tissue mass was diagnosed on the left forelimb of an adult, wild, intact female bog turtle (Glyptemys muhlenbergii). Excisional biopsy revealed a soft tissue sarcoma, and a full limb amputation was performed. Because mesenchymal tumors are rarely reported in chelonians, this case demonstrates that neoplasia should be considered as a differential for subcutaneous masses even in wild turtles. This is the first report of a soft tissue sarcoma in the genus Glyptemys. To the authors' knowledge, this is only the second case report of a soft tissue sarcoma reported in the Order Testudines.

A horse's locomotor signature: COP path determined by the individual limb.

IntroductionGround reaction forces in sound horses with asymmetric hooves show systematic differences in the horizontal braking force and relative timing of break-over. The Center Of Pressure (COP) path quantifies the dynamic load distribution under the hoof in a moving horse. The objective was to test whether anatomical asymmetry, quantified by the difference in dorsal wall angle between the left and right forelimbs, correlates with asymmetry in the COP path between these limbs. In addition, repeatability of the COP path was investigated.MethodsA larger group (n = 31) visually sound horses with various degree of dorsal hoof wall asymmetry trotted three times over a pressure mat. COP path was determined in a hoof-bound coordinate system. A relationship between correlations between left and right COP paths and degree of asymmetry was investigated.ResultsUsing a hoof-bound coordinate system made the COP path highly repeatable and unique for each limb. The craniocaudal patterns are usually highly correlated between left and right, but the mediolateral patterns are not. Some patterns were found between COP path and dorsal wall angle but asymmetry in dorsal wall angle did not necessarily result in asymmetry in COP path and the same could be stated for symmetry.ConclusionThis method is a highly sensitive method to quantify the net result of the interaction between all of the forces and torques that occur in the limb and its inertial properties. We argue that changes in motor control, muscle force, inertial properties, kinematics and kinetics can potentially be picked up at an early stage using this method and could therefore be used as an early detection method for changes in the musculoskeletal apparatus.

Effect of Cold Hip Bath on Autonomic Variables in Healthy Individuals - A Randomized Control Trial

Objectives: Laksha Guggulu, an Ayurvedic formulation advocated to enhance the fracture healing in ancient Indian texts, was selected to validate its effect on fracture healing on certain scientific parameters like Radiological, Serological and Histopathological studies in an experimental rat model. Methods: Eighteen Wistar rats (Rattus norvegicus) were taken to create identical fractures by a transverse osteotomy of Radial bone of their left fore limb under Ketamine and Xylazine anesthesia (intraperitoneally). Intact ulna acted as an internal splint hence, no other external or internal support to the fractures was given. Post operatively injectable antibiotic (Gentamicin) was given. These osteotomised rats were divided into three groups of six each. Group I rats were given 13.5mg/100gm body weight of the trial drug (Laksha Guggulu) twice daily through oral route. Group II rats were given half of the Group I dose of the trial drug whereas in Group III, no drug was given (Control group). The drug was given oraly with Cow’s milk. Total duration of trial was of four weeks. Healing was assessed Radiologically, Biochemically and Histopathologically. Results: Assessment of results was done according to pre-designed protocol and data analysis done statistically. Histopathological and Serological studies revealed significant results in Group I animals as compared to Group II and Group III. Radiologically the difference between the groups was not detectable. Conclusion: Laksha Guggulu has got a definite role in the enhancement of fracture healing by forming early and improved quality of the callus. However, further studies on large sample size, with more advanced investigations like Histomorphometery, Bone turnover markers and Micro CT scanning are required

Tbx5 Buffers Inherent Left/Right Asymmetry Ensuring Symmetric Forelimb Formation.

The forelimbs and hindlimbs of vertebrates are bilaterally symmetric. The mechanisms that ensure symmetric limb formation are unknown but they can be disrupted in disease. In Holt-Oram Syndrome (HOS), caused by mutations in TBX5, affected individuals have left-biased upper/forelimb defects. We demonstrate a role for the transcription factor Tbx5 in ensuring the symmetric formation of the left and right forelimb. In our mouse model, bilateral hypomorphic levels of Tbx5 produces asymmetric forelimb defects that are consistently more severe in the left limb than the right, phenocopying the left-biased limb defects seen in HOS patients. In Tbx hypomorphic mutants maintained on an INV mutant background, with situs inversus, the laterality of defects is reversed. Our data demonstrate an early, inherent asymmetry in the left and right limb-forming regions and that threshold levels of Tbx5 are required to overcome this asymmetry to ensure symmetric forelimb formation.

A subjective descriptive study of the warm‐up and turn to a fence, approach, take‐off, suspension, landing and move‐off in 10 showjumpers

SummaryThere is limited knowledge about causes of musculoskeletal injury in showjumpers. The objectives were to describe features of the turn, approach and jump in a group of experienced showjumpers believed by their riders to be sound, to relate these findings to clinical findings, and to identify features that may predispose to injury. Ten experienced showjumpers in normal competition training jumped an upright and a parallel fence four times off the left and right reins respectively, after a rider‐defined period of warm‐up. Real‐time and high‐speed motion capture was undertaken. Detailed subjective assessment of the gait was performed during the warm‐up, on the turn and approach to the jump and all phases of the jump. Six horses had thoracolumbar pain or epaxial muscle tension. Six horses exhibited a poor‐quality canter. The mean duration of warm‐up was 7 min (range 5–10 min). All horses had lean of the trunk and hindlimbs >45° on the turn. The inside hindlimb was placed in front of the outside hindlimb in 75% of the turns. Sideways oscillations of the hocks during stance were seen in all horses on the turn and on the straight approach in five horses. The inside hindlimb had greater magnitude of oscillation than the outside hindlimb on the turns. Repeated asynchronous push‐off with the hindlimbs at take‐off was seen in three horses. The hindlimbs drifted to the left or right during the ascent‐phase of suspension in four horses, reflecting asymmetrical push‐off. Only two horses landed consistently with the correct forelimb leading relative to the direction in which the horse had to turn after the fence. Four horses landed seven (n = 2) or eight (n = 2) times each with the left (n = 2) and right (n = 2) forelimbs respectively. Repetitive overload through asymmetrical use of the left and right canter leads, inadequate warm‐up, and limb instability could potentially predispose to injury.

A Cross-Sectional Survey of Forelimb Hoof Conformation and the Prevalence of Flat Feet in a Cohort of Thoroughbred Racehorses in New Zealand

Racehorses in New Zealand predominantly train counter clockwise. This training pattern has been associated with between forelimb differences in bone mineral density profile and asymmetrical limb loading after training. At present, there is limited data on the hoof conformation of these racehorses. Distal forelimb and digital hoof conformation data were collected from 75 Thoroughbred racehorses (2–5 years old) from two training yards. Digital conformation was subjectively graded, and multiple hoof measurements were made with a modified tire gauge (sole and sulci depth) and from digital photographs. All the horses were shod by two registered master farriers within a median of 15 (interquartile range [IQR], 1–25) days before measurement. There were few distal limb conformation abnormalities scored. Most (62/75) horses presented with some deviation from normal hoof parameters, with 2 (IQR, 1–3) abnormalities reported per horse. The most common hoof abnormality was uneven sulci, which was identified in 43 horses and 59 affected hooves, followed by higher medial hoof wall height in 38 horses and 53 affected hooves. Many of the linear and hoof angle measurements and their ratios were within the bounds reported within the literature and indicative of a balanced foot. The length and width measurements increased with horse age. The dorsal hoof wall (DHW) length:heel length ratios were consistently less than 3:1, and the absolute difference between toe and heel angle was generally greater than 5°. Between limb hoof variation was identified for a number of the morphologic measurements including frog length and sole length and the ratio of sole width:sole length. Flat feet (lack of concave solar surface) were identified in 21/75 (28%) horses and in 28/150 (19%) forelimb hoofs. More horses had a flat left foot (10/75) than right foot (4/75), but seven horses had both feet classified as being flat. Flat feet had 2.4 (1.1–5.6, P = .036) greater odds of presenting with uneven sulci. These data indicate that uneven sulci depth and flatter hooves with may be a typical presentation of Thoroughbred feet. Asymmetry in measurements between limb may reflect the greater loading of the left forelimb when race training counter clockwise.

Collateral ligament reconstruction in two horses following traumatic avulsion fracture using a knotless suture anchor construct

SummaryThis case report describes a technique for repair of medial collateral ligament avulsions in two horses. Both horses sustained traumatic injuries resulting in avulsion fractures at the origin of their medial tarsal and carpal collateral ligaments. This report describes the use of a knotless suture anchor to mechanically reconstruct medial collateral ligament avulsion injuries in two horses. The first horse, a 9‐year‐old Hannovarian Warmblood gelding presented for an acute nonweightbearing lameness in the right hindlimb. The injury was localised to the medial malleolus of the tibia and an avulsion fracture of the origin of the short medial collateral ligament of the tibiotarsal joint with disruption of the ligament was found on radiographs and ultrasound. The horse was taken to surgery and a reconstruction of the short medial collateral ligament was performed with a modified single row construct using a biocompatible, multistrand, long chain ultra‐high molecular weight polyethylene braided composite suture tape (2 mm Fibertape) and a single knotless suture anchor (5.5 × 19.1 mm PEEK SwivelLock C). The second horse, a 5‐year‐old Thoroughbred gelding presented for an acute nonweightbearing lameness in the left forelimb. The injury was localised to the medial styloid process of the radius and an avulsion fracture of the origin of the medial collateral ligament of the antebrachial carpal joint was found on radiographs and ultrasound. The horse was taken to surgery and a similar reconstruction procedure was performed to the collateral ligament. Both horses were recovered in a Robert Jones bandage without the use of casts or splints and recovered without incident. Both horses are sound and returned to previous level of athletic performance at 18 months and 8 months, respectively.

Evaluation of the use of the combination of propofol and midazolam in the chemical restraint and anesthesia of the turtle-de-beard Phrynops geoffroanus Schweigger, 1812 (Testudines, Chelidae)

The objective of this research was to determine a protocol for effective and safe pharmacological restraint (Phrynops geoffroanusi), with average weight of 1.9 ± 0.77 kg, clinically healthy, 02 males and 18 females, capturing in Uberabinha river in the city of Uberlândia - MG under license M ° 032/2006 IBAMA-RAN, were housed in a tank with running water and water heaters with an average temperature of 27 ° C. the turtles were divided into two groups of 10 animals: G1 - midazolam (2.0 mg / kg IM) and propofol (5.0 mg / kg IV) and G2 - midazolam (2.0 mg / kg IM) and propofol 2.5 mg / kg IV). Midazolam was administered in the left forelimb and propofol was injected directly in the cervical vertebral sinus. There was the anesthetic parameters of movement, muscular relaxation, in response to stimuli forelimbs and tail, ease of handling and heart rate, at 0 and 5, 10, 20, 30, 45, 60, 90, 120, 150 and 180 minutes after the injections. There was no statistically significant between two groups, so this protocol is not indicated for surgical procedures in Phrynops geoffroanus.

Neurovascular unit remodelling in the subacute stage of stroke recovery

Brain plasticity following focal cerebral ischaemia has been observed in both stroke survivors and in preclinical models of stroke. Endogenous neurovascular adaptation is at present incompletely understood yet its potentiation may improve long-term functional outcome. We employed longitudinal MRI, intracranial array electrophysiology, Montoya Staircase testing, and immunofluorescence to examine function of brain vessels, neurons, and glia in addition to forelimb skilled reaching during the subacute stage of ischemic injury progression. Focal ischemic stroke (~100mm3 or ~20% of the total brain volume) was induced in adult Sprague-Dawley rats via direct injection of endothelin-1 (ET-1) into the right sensori-motor cortex, producing sustained impairment in left forelimb reaching ability. Resting perfusion and vascular reactivity to hypercapnia in the peri-lesional cortex were elevated by approximately 60% and 80% respectively seven days following stroke. At the same time, the normal topological pattern of local field potential (LFP) responses to peripheral somatosensory stimulation was abolished and the average power of spontaneous LFP activity attenuated by approximately 50% relative to the contra-lesional cortex, suggesting initial response attenuation within the peri-infarct zone. By 21 days after stroke, perilesional blood flow resolved, but peri-lesional vascular reactivity remained elevated. Concomitantly, the LFP response amplitudes increased with distance from the site of ET-1 injection, suggesting functional remodelling from the core of the lesion to its periphery. This notion was further buttressed by the lateralization of spontaneous neuronal activity: by day 21, the average ipsi-lesional power of spontaneous LFP activity was almost twice that of the contra-lesional cortex. Over the observation period, the peri-lesional cortex exhibited increased vascular density, along with neuronal loss, astrocytic activation, and recruitment and activation of microglia and macrophages, with neuronal loss and inflammation extending beyond the peri-lesional cortex. These findings highlight the complex relationship between neurophysiological state and behaviour and provide evidence of highly dynamic functional changes in the peri-infarct zone weeks following the ischemic insult, suggesting an extended temporal window for therapeutic interventions.

Arthroscopic Removal of Large Cartilage Fragment in a Dog with Osteochondritis Dissecans of Shoulder Joint

An 11-month-old, 19.5 kg, intact male Border collie was referred with intermittent left forelimb lameness to the Gyeongsang Animal Medical Center. The symptom was first discovered about 6 months ago, and it has gotten worse for the last 10 days with non-weight bearing on the left forelimb. During the physical examination, the patient showed painful reaction when the left shoulder was abducted. On radiographic assessment, a radiolucent line and some osteophytes were found in both humeral heads. Based on patient’s clinical signs and radiographic findings, osteochondritis dissecans (OCD) was very suspicious. So, we decided to perform an arthroscopic surgery on left shoulder for definitive diagnosis and treatment because the right forelimb revealed no clinical signs. During arthroscopic technique, we found a large OCD flap on the caudo-central area of humeral head, and observed severe synovitis over a wide range on posterior area of the articular capsule. The large OCD flap was removed by a grasping forceps, and many joint mice were removed either. Curettage was performed using a curette on the articular surface until hemorrhage occurred, and articular capsule flushed with a lactated-ringer’s solution. The patient was discharged on the same day without any specific abnormal status. Antibiotic, anti-inflammatory and analgesic drugs were administered. Mild lameness on left forelimb was observed in 2 weeks after surgery, but after 4 weeks, the patient showed complete normal gait without any lameness. Although surgical removal of OCD flap with arthroscopic was previously reported, We would like note that a large OCD flap can also be removed by arthroscopic surgery in this report.