Genetic parameters of biokinematic variables of the trot in Spanish Purebred horses under experimental treadmill conditions.

The purpose of this study was to estimate the genetic parameters of biokinematic variables in Spanish Purebred (SPB) horses in order to select those of sufficient interest to be measured in the pre-selection of the animals for possible inclusion in the breeding programme. Kinematic analysis of 130 SPB horses 4.6+/-1.5 years old were recorded at the trot (4m/s) on a treadmill. Genetic parameters were estimated using VCE software and a bivariate mixed animal model including age and stud as fixed effects and animal additive genetic effect and residual error as random effects. In general, heritabilities were high (0.33-0.88). The angular variables presented the lowest heritabilities, whereas the maximum height of the fore-hoof and the duration of swing phase in the hindlimb gave the highest scores. Genetic correlations were also very high, so it was possible to reduce the number of breeding programme characteristics to stride duration, hindlimb swing phase duration, range of stifle and elbow angles, minimal angle of carpus, and minimal retraction-protraction angle of the hindlimb.

Insulinización en la diabetes gestacional: cuándo y cómo / Insulin treatment in gestational diabetes: when and how

La diabetes mellitus es una de las patologías que con mayor frecuencia complican la gestación. En el 90-95% de los casos, se trata de diabetes gestacional. Existe controversia sobre el beneficio de tratar a estas pacientes de forma intensiva, independientemente de la gravedad del trastorno metabólico. No obstante, hasta disponer de los resultados de estudios prospectivos en curso, las recomendaciones actuales establecen la necesidad de iniciar tratamiento farmacológico una vez que el programa de dieta y ejercicio físico no consigue mantener los objetivos de glucemia basal y posprandial establecidos. Otro factor a tener en cuenta para el inicio de la insulinización es la valoración ecográfica del crecimiento fetal. El fármaco de elección es la insulina humana en pauta bolo-basal, con una o dos dosis de insulina NPH acompañada de insulina regular preprandial si se precisa. Aunque la experiencia actual con antidiabéticos orales, glibenclamida especialmente, plantea una prometedora alternativa tanto por efi cacia como por seguridad, puede ser prematuro considerar esta opción recomendable. El empleo del análogo rápido lispro no ha demostrado hasta la fecha mayores beneficios para el feto y para la madre que la insulina humana habitual. No obstante, al no confirmarse el riesgo de teratogenicidad ni de progresión de la retinopatía materna, puede utilizarse si el control metabólico lo requiere. No existe experiencia suficiente en la gestación con el resto de los análogos disponibles (aspart, glargina o detemir) y, por tanto, no se recomienda su utilización en la gestante diabética

Diabetes mellitus is one of the most common complications of pregnancy. Gestational diabetes accounts for 90-95% of cases. There is still controversial about the benefits of intensive insulin therapy in these patients regardless of their severity. However, until new data of on-going prospective studies were available, present guidelines recommends start pharmacological treatment after diet and exercise failure to achieve basal and postprandial glycemic targets. Ultrasound evaluation of fetal growth may also be useful to choose initiation of insulin therapy. Human insulin is recommended in a bolus/basal regime, with one or two NPH insulin doses accompanied with preprandial human regular insulin if necessary. Even though the experience with oral hypoglycaemic agents in pregnancy, specially glyburide, is a promising alternative either by efficacy or security, it is premature to consider a recommended option. The rapid-acting insulin analogue lyspro has not demonstrated until now major benefits for the fetus and the mother against the human regular insulin. However, because the risks of teratogenicity or progression of maternal retinopathy have not been confirmed, lyspro may be used to intensify the metabolic control. It is still not recommended the use of other rapid-acting (aspart) or long-acting insulin analogues (glargine or detemir) in pregnancy and more extensive follow-up data on safety are needed

Changes due to age in the kinematics of trotting Andalusian foals.

The purpose of this study was to evaluate the effect of growth on biokinematic characteristics at the trot in a group of 9 Andalusian foals from age 12 to 36 months in order to identify which stride variables change or remain invariable. Biokinematic analysis was performed by using a computer-assisted videography system (25 Hz frame rate). An increase in stride length as well as the fore- and hindlimb stride duration was found. A tendency to increase flexion of the shoulder, elbow and carpal joints was observed while the forelimb fetlock increased its maximal extension. In the hindlimb, most of the differences were exhibited by the hip and stifle joints, which showed a tendency to a lesser flexion with age. However, at landing the extension was bigger. The hindlimb fetlock extended more in older foals, whereas flexion decreased. Significant differences in the maximal extension and flexion instants in the forelimb joints were not detected (except in the elbow joint). The same was found in the angular range of motion (ARM) of the scapula inclination and the shoulder and forelimb fetlock joints. Differences in retraction-protraction angles in both the fore- and hindlimbs were very slight, and ARM values for these parameters were similar in all age groups. It can be concluded that Andalusian horses modified their locomotor pattern at the trot between age 12 and 36 months, particularly up to 24 months, by increasing stride length as well as shoulder, elbow and carpus flexion, while hip and stifle flexion decreased and hindlimb joints were more extended during the stance phase. One of the most striking features was that maximal retraction and protraction angles did not change in foals age 12-36 months in either fore- or hindlimbs. These results could be useful for the prediction of some kinematic parameters of mature horses from data obtained at younger ages.

Inter-breed differences in equine forelimb kinematics at the walk.

Linear, temporal and angular biokinematic characteristics of the forelimb at the walk in different breeds were determined, highlighting inter-breed differences. Twenty-three healthy stallions were used: ten Andalusians (AN), seven Arabs (AR) and six Anglo-Arabs (AA). Height at the withers was significantly different between groups (P < 0.001). Six trials per horse were recorded using a levelled video camera (sampling frame rate 25 frames/s), digitized and analysed using a semi-automatic movement analysis system. No statistically significant differences in speeds were recorded between breeds (P > 0.05). The only temporal parameter which was similar in the three breeds was the moment at which the hoof reached the highest point in its trajectory. The variables presenting the most significant differences were the percentages of deceleration and propulsion within the stance phase. ANOVA for angular variables showed that the greatest difference was in the range of angular movement of the carpal joint, being higher in AN, due to a lower minimum value. In the fetlock joint, the greatest difference was observed in minimum values, which differed in all three breeds. Significant inter-breed differences were also observed for maximum limb retraction, being lowest in the AN group, followed by the AA and AR groups. This finding was reflected in the angular range of motion, despite smaller differences in the degree of limb protraction; very similar values were reported in all three breeds. As regards the elbow joint, no inter-breed differences were observed in terms of minimum values, whereas differences were recorded for maximum and angular range of motion, higher values being displayed by the AR and AN groups than by AA animals. In conclusion, inter-breed differences may be determined in equine forelimb biokinematics at the walk. This study distinguished between AN, AR and AA horses.

Kinematic characteristics of Andalusian, Arabian and Anglo-Arabian horses: a comparative study.

The aim of this study was to compare the kinematic trot characteristics of three different breeds of horse: Andalusian (AN, n = 15), Arabian (AR, n = 7) and Anglo-Arabian (AA, n = 5) using standard computer-assisted videography (25 Hz). Linear, temporal and angular parameters in fore- and hind limbs were analysed in six randomly selected strides per horse. Normalised angle-time diagrams along the complete stride were obtained for all joints angles in each breed and specific kinematic characteristics were detected graphically. AA horses displayed longer swing durations in both limbs ans a shorter angular range of motion (ARM) in scapula and pelvis inclination and in shoulder, hip and forelimb retraction-protraction angles. At lift off, stifle and tarsal joint angles were more flexed. In general, only small differences were observed in AR horse kinematics when compared with the other 2 breeds. AN horses presented negative overtracking length, which was positive in AR and AA. In AN horses the elbow and carpal joints were more flexed at the moment of maximal elevation, elbow and fore-fetlock joints also exhibited a larger ARM due to a smaller angle at maximal flexion. In the hind limbs, tarsal, hind fetlock and retraction-protraction angles presented a larger ARM in AN horses due to greater maximal flexion in the tarsal and hind fetlock joints. Fore- and hind fetlocks were also more flexed in horses from this breed. In conclusion, differences between kinematic variables at the trot were observed in the three breeds studied here, mainly in forelimb joints. The most outstanding feature was the greater forelimb flexion recorded in AN horses than in the other breeds which is consistent with the elevated movements in this breed. In AA horses, the ARM of proximal joints involved in retraction protraction in both fore- and hind limbs was smaller. All the differences observed highlighted the idiosyncratic nature of the trot in each breed; this may influence the functional capacity of each breed.

Influence of training on the biokinematics in trotting Andalusian horses.

The aim of this study was to determine the influence of a 10-month training programme on the linear, temporal and angular characteristics of the fore and hind limbs at the trot in the Andalusian horse, using standard computer-aided videography. Sixteen male Andalusian horses were observed before and after training. Six strides were randomly selected for analysis in each horse and linear, temporal and angular parameters were calculated for fore and hind limbs. The training programme used here produced significant changes in kinematic parameters, such as shortening of stride length, and increase in swing duration and a decrease in hind limb stance percentage. No significant differences were recorded in the angular values for the forelimb joints. In trained horses, the more proximal joints of the hind limb, especially the hip and stifle, had a greater flexion while the fetlock showed a smaller extension angle. At the beginning of the swing phase, hip and stifle joints presented angles that were significantly more flexed. When the hind limbs came into contact with the ground, all the joints presented greater flexion after training.

Comparative biokinematic study of young and adult Andalusian horses at the trot.

The purpose of this study was to determine basic kinematic parameters (linear, temporal and angular) in young and adult Andalusian horses (P.R.E.) at the trot, using a normal computer-aided videography system. The trotting gaits of 16 horses were analysed: seven young horses (3.7 +/- 0.2 years old, height at withers 167.1 +/- 4.1 cm) and nine adult stallions (12.3 +/- 2.9 years old, height at withers 162.9 +/- 3.6 cm) were recorded at least 6 times at the trot using a 25-Hz video-camera filming from the side. Video images were processed with a real-time digital system (SMVD). Speeds averaged 3.84 and 3.75 m/s for young and adult horses, respectively. Differences between age groups for speed and linear and temporal parameters of the stride were not significant. However, variations in angular parameters were detected: adults showed a greater ARM than younger horses for most forelimb joints. In the hind limb, hip, stifle, and, to a lesser degree, the tarsal joint, a smaller degree of extension during the stance phase was observed in adult horses.

The influence of speed and height at the withers on the kinematics of sound horses at the hand-led trot.

The influence of speed and height at the withers on some biokinematic stride parameters (linear, temporal and angular) was measured in 15 Spanish Thoroughbreds (Andalusian Purebred) trotted hand-led along a track; analysis was made of the correlation between speed and height at the withers and of some biokinematic parameters of equine locomotion. Both height at the withers and speed were positively and significantly correlated to the linear parameters examined. Temporal parameters did not reveal a significant correlation with the height at the withers. The correlations with the angular parameters were variable, often being significant for both height at withers and speed, although in most cases the coefficient was relatively low, probably owing to the narrow ranges of speed and height at the withers and their low variability. It was concluded that horses at the hand-led trot tend to have low variability in speed during successive trials, although the speed at which they move does have a significant influence on both linear and temporal stride parameters, and also on several angular parameters, while height at the withers has a major effect on linear parameters but less on angular parameters, and does not affect the temporal parameters.

Kinematics in horses at the trot before and after an induced forelimb supporting lameness.

The aim of this study was to analyse the biokinematic alterations caused by an induced lameness in the right forelimb of Dutch Warmblood (DWB) horses using a system of computer-aided normal videography. Five mature DWB were recorded with a videocamera (frame rate 1/25) from a lateral view before and after an induced lameness. Before videotaping, passive markers were placed on the skin, over easily identifiable anatomical references to determine the joint angles in the forelimb (always on the flexor side). Lameness was induced using special horseshoes. The lameness was evident at the trot and mild at walk. The images were analysed using a real time digitalising system combined with a previously designed spreadsheet. Linear, temporal and angular parameters (maximum, minimum and angular range of motion) along the stride were calculated as well as the moments of highest extension (Pmax) and flexion (Pmin), expressed as a percentage of the whole stride. Results before and after the induced lameness were compared by a paired Student's t test at a significance level of P<0.05. No differences in speeds before and after the induced lameness were found. Stride length was significantly shorter in the lameness condition. Stride duration was slightly shorter in lameness. The diagonal stance phase increased, while the swing phase decreased. Angular parameters changed mainly in elbow, carpus, fetlock and retraction-protraction angles. This indicated that the angular range of motion in the elbow and carpal joints decreased, and the elbow Pmin occurred later in the stride. The results are useful in the development of video-based equine lameness diagnostics.

Posterior vitreoschisis. An echographic finding in proliferative diabetic retinopathy.

PURPOSE: To describe the echographic characteristics of splitting the outer posterior cortical vitreous in patients with proliferative diabetic retinopathy and vitreous hemorrhage. METHODS: The authors retrospectively reviewed the echographic findings in 270 patients who were evaluated at the Doheny Eye Institute between January 1983 to December 1989 for proliferative diabetic retinopathy and vitreous hemorrhage. None of the eyes had undergone pars plana vitrectomy before echographic examination. RESULTS: Forty-five patients (17%) had echographic evidence of splitting of the outer posterior vitreous cortex, a finding the authors have termed posterior vitreoschisis. In all patients, differentiation of the posterior vitreoschisis from a true posterior hyaloid detachment was possible, either on the initial or on serial echographic examination, by the separate detachment of the inner wall of the vitreoschisis cavity and the true posterior hyaloid from the retinal surface. The vitreoschisis cavities often were found to contain unclotted blood. In some eyes, the inner wall of the vitreoschisis cavity was adherent to the apex of the most highly elevated area of traction retinal detachment, suggesting that posterior vitreoschisis may itself result in clinically significant vitreoretinal traction, independent of the presence or extent of true posterior hyaloid separation. CONCLUSIONS: The authors' finding suggest that spontaneous splitting of the outer posterior vitreous cortex may occur in patients with proliferative diabetic retinopathy and vitreous hemorrhage, which may mimic a true posterior cortical vitreous detachment on echographic examination. Preoperative recognition of posterior vitreoschisis may be important in the surgical management of these patients.

Massive suprachoroidal hemorrhage with central retinal apposition. A clinical and echographic study.

We reviewed the charts of 18 patients diagnosed with a massive suprachoroidal hemorrhage (MSCH) with central retinal apposition (kissing configuration). Four cases occurred intraoperatively (expulsive), eight after a surgical procedure (delayed), and six associated with blunt or perforating injury (traumatic). In this study, echography was used to monitor the course of MSCH; the mean time for clot lysis was 14 days, and the mean duration of central retinal apposition was 15 days. The expulsive MSCHs were all allowed to resolve spontaneously, with good initial visual outcome in three of the four eyes in which they occurred. In the delayed MSCH group, the majority of patients attained their prehemorrhage visual acuity, with or without early surgical intervention. In the traumatic MSCH group, retinal detachment was a constant complication in all patients. All six patients in the traumatic MSCH group had a poor visual outcome, despite early surgical intervention in five patients. The results of this study suggest that not all MSCHs need to be drained surgically and that, when surgical drainage is indicated, echography may be a useful adjunct in determining the optimal time of drainage.

Papillopathies associated with unusual calcifications in the retrolaminar optic nerve.

We examined three patients with optic disc edema and peripapillary hemorrhages. Each was found by standard echography to have calcified nodules within the retrobulbar portion of the optic nerves. These nodules were located approximately 2 mm posterior to the lamina cribrosa. Each patient had unilateral congestion of the optic nerve head with dilated, tortuous retinal veins that appeared much like a partial central retinal vein occlusion; one patient subsequently developed optic atrophy. The central location of the calcifications within the anterior aspect of the optic nerves suggests that each nodule may have been situated within the central retinal vein or artery. Calcifications within the retrolaminar space may be associated with some etiologies of unilateral congestion of the optic nerve head.

Echographic characteristics of ocular toxocariasis.

Ocular toxocariasis most commonly presents as one of three distinct clinical syndromes: endophthalmitis, localized posterior granuloma, or peripheral granuloma. Using standardized echography, the authors studied 11 toxocariasis patients presenting with one of these syndromes. Common echographic findings were noted in ten of these patients, and included: (1) a solid, high-reflective peripheral mass, (2) a vitreous band or membranes extending between the posterior pole and the mass, and (3) a traction retinal detachment or fold from the posterior pole to the mass. These findings were present in patients presenting with leukocoria or endophthalmitis, as well as in patients in whom the peripheral nematode lesion could be visualized clinically. In combination with the history, clinical examination, and enzyme-linked immunosorbent assay (ELISA), standardized echography may be useful in establishing the diagnosis of ocular toxocariasis in cases of leukocoria in which nematode endophthalmitis is suspected.

Echographic features of the Vogt-Koyanagi-Harada syndrome.

Vogt-Koyanagi-Harada (VKH) syndrome represents a spectrum of bilateral panuveitis with associated central nervous system and dermatologic manifestations. The diagnosis is based on clinical and angiographic findings, but some of the characteristic features may be either absent or difficult to visualize in the presence of opaque media. With the use of standardized echography (standardized A-scan and contact B-scan echography), we examined nine patients with clear media and clinical evidence of VKH syndrome. Consistent echographic findings included (1) diffuse, low to medium reflective thickening of the choroid posteriorly; (2) serous retinal detachment, located inferiorly or in the posterior pole; (3) mild vitreous opacities with no posterior vitreous detachment; and (4) thickening of the sclera and/or episclera posteriorly. Resolution of these findings occurred with systemic corticosteroid therapy. Standardized echography should be considered an important diagnostic tool in VKH syndrome, especially when visualization of the fundus is poor or when clinical presentation is atypical.

Orbital myositis involving the oblique muscles. An echographic study.

Idiopathic orbital myositis is a common nonspecific orbital inflammatory syndrome that can involve one or more of the extraocular muscles. Oblique muscle involvement is infrequently reported, possibly because such involvement is difficult to identify clinically or by computed tomography (CT). The authors reviewed seven cases of orbital myositis involving the oblique muscles solely or in association with rectus muscle involvement. Standardized echography demonstrated homogeneous low-reflective enlargement, diagnostic of myositis, of the superior and inferior oblique muscles and tendons along their courses. The finding of massive inferior chemosis was associated with involvement of the inferior oblique muscle. Although the disease typically responds to therapy with systemic steroids, residual gaze restriction may occur. The oblique muscles may be frequently involved in idiopathic orbital myositis when evaluated by standardized orbital echography. In these cases, echography provides rapid, accurate, and reliable confirmation of the diagnosis of myositis, differentiates other orbital inflammatory diseases, and provides an objective measure of the therapeutic response.