COMPARISON OF SONOGRAPHIC FEATURES OF BENIGN AND NEOPLASTIC DEEP LYMPH NODES IN DOGS

The differentiation of benign vs. neoplastic lymph nodes impacts patient management. Specific sonographic features are typically considered when assessing lymph nodes in dogs. However, the usefulness of these criteria in distinguishing benign vs. malignant lymph nodes remains largely unknown, especially for deep lymph nodes. Our aim was to compare sonographic features in benign and neoplastic deep lymph nodes with the hope of identifying predictive criteria. Thirty‐one deep lymph nodes (16 mesenteric, 10 medial iliac, three hepatic, one sternal, and one cranial mediastinal) in 31 dogs were examined prospectively with B‐mode and Color flow Doppler. Lymph nodes were aspirated using ultrasound‐guidance and final diagnosis were established based on cytologic and/or histopathologic interpretation. Prevalence of each sonographic feature and combinations of two features was calculated for each group and compared using a χ²‐test or Student's t‐test for unequal variances. Ten lymph nodes were benign (hyperplastic and/or inflammatory) and 21 were neoplastic. All were hypoechoic, except for one neoplastic lymph node. Maximal short‐axis diameter (P=0.0006) and long‐axis diameter (P=0.01), and SA/LA ratio (P=0.008) were increased significantly for neoplastic (2.8, 5.5 cm, and 0.50, respectively) vs. benign (1.2, 3.8 cm, and 0.34, respectively) lymph nodes. The prevalence of other features was similar between groups. Doppler evaluation was possible in 77% of lymph nodes, but there was no significant difference between groups. When any two ultrasound features were combined, the only difference between benign and neoplastic lymph nodes was for the combination of contour regularity and appearance of the perinodal fat (P=0.03).     

Mandibular Osteodistraction for Correction of Deep Bite Class II Malocclusion in a Horse

Objective— To describe a technique for, and outcome after, mandibular osteodistraction in the horse.
Study Design— Clinical report.
Animals— Warmblood horse.
Methods— A half ring external fixator was applied on both sides of an osteotomy site performed on the mandible of a colt. A bite plate was placed on the upper incisors creating occlusion between lower and upper jaw. After a 5-day latency period, distraction was applied (1 mm/day) until the overjet was judged normal.
Results— Mandibular elongation and correction of brachygnathia was obtained without major complications. Six months after the procedure the overjet reduction was considered stable.
Conclusions— Mandibular osteodistraction can be considered for treatment of severe brachygnathia in yearlings.
Clinical Relevance— Distraction osteogenesis has the advantage of progressive elongation of the mandible, allowing concurrent bone remodeling and soft tissue adaptation. Severe mandibular incisor malocclusion in horses outside the maximal growth phase can be corrected using this technique.     

ÉTUDES SUR LE MODE D'ACTION DU PHÉNYLCAR-BAMOYLOXY-2 N-ÉTHYLPROPIONAMIDE, ISOMÉRE D

Summary. 2-Phenylcarbamoyloxy-N-ethylpropionamide, D isomer (11.561 R.P.) was submitted to various physiological tests in order to characterize its properties. Although it does not affect the Hill reaction, it is able to disorganize the plant cell and inhibits tissue differentiation. It penetrates rapidly into susceptible and resistant plants, but the degradation varies with the plant family. It disappears very rapidly from susceptible species, whereas resistant plants accumulate it without any apparent damage. One of its metabolites, aniline, is present in small quantities soon after treatment but is very rapidly eliminated.
Studies showed that residues in plants were negligible at harvest.
Untersuchungen über Wirkimgsweise und Rückslände des Carbanilsäureesters des D-Milchsäure-äthylamids in Pflanzen     

Use of Computed Tomography in Standing Position to Identify Guidelines for Screw Insertion in the Distal Phalanx of Horses: An Ex Vivo Study

Objectives— To compare the precision of radiography and computed tomography (CT) preoperatively in the standing position for identification of guidelines for screw insertion in the distal phalanx, and to identify whether standing CT might improve operative time compared with preoperative radiographic planning.
Study Design— Experimental ex vivo study.
Animals— Cadaveric equine thoracic limb pairs (n=10).
Methods— Insertion of a 4.5 mm cortex screw in lag fashion into an intact distal phalanx was evaluated in 2 groups (n=10) of cadaveric equine thoracic limbs. In 1 group, the site, direction, and length of the implant were determined by radiography, and in the other group, by CT. Accuracy of screw placement was verified by specimen dissection. Outcomes were (1) absence of penetration of the articular surface, the solar surface, or the semilunar canal (2) appropriate length and direction of the screw. Surgical time was also measured.
Results— No screw penetrated the articular surface, the solar surface, or the semilunar canal in either group. CT was more accurate to identify guidelines for screw insertion (U=23.50, P =.049). With CT, surgical time (mean, 7.7 minutes) was significantly shorter (U=0.000, P =.000) than with radiography (mean, 12.7 minutes).
Conclusion— Standing CT can be used to accurately determine anatomic landmarks for screw insertion in lag fashion in sagittal fractures of the distal phalanx.
Clinical Relevance— This study has a clear clinical relevance for improved internal fixation of sagittal fractures of the distal phalanx.     

Predicting skipjack tuna forage distributions in the equatorial Pacific using a coupled dynamical bio-geochemical model

Skipjack tuna ( Katsuwonus pelamis ) contributes ≈70% of the total tuna catch in the Pacific Ocean. This species occurs in the upper mixed-layer throughout the equatorial region, but the largest catches are taken from the warmpool in the western equatorial Pacific. Analysis of catch and effort data for US purse seine fisheries in the western Pacific has demonstrated that one of the most successful fishing grounds is located in the vicinity of a convergence zone between the warm (>28–29°C) low-salinity water of the warmpool and the cold saline water of equatorial upwelling in the central Pacific (Lehodey et al ., 1997). This zone of convergence, identified by a well-marked salinity front and approximated by the 28.5°C isotherm, oscillates zonally over several thousands of km in correlation with the El Niño–Southern Oscillation. The present study focuses on the prediction of skipjack tuna forage that is expected to be a major factor in explaining the basin-scale distribution of the stock. It could also explain the close relation between displacements of skipjack tuna and the convergence zone on the eastern edge of the warmpool. A simple bio-geochemical model was coupled with a general circulation model, allowing reasonable predictions of new primary production in the equatorial Pacific from mid-1992 to mid-1995. The biological transfer of this production toward tuna forage was simply parameterized according to the food chain length and redistributed by the currents using the circulation model. Tuna forage accumulated in the convergence zone of the horizontal currents, which corresponds to the warmpool/equatorial upwelling boundary. Predicted forage maxima corresponded well with high catch rates.     

Characterization of isolates of Phytophthora infestans collected in northwestern France from 1988 to 1992

Isolates of the potato late-blight pathogen Phytophthora infestans , collected in several French regions from 1988 to 1992, were characterized in order to determine the structure and pathogenicity of French populations and to compare them with other European samples. All 254 French isolates tested were of the Al mating type, as were two Sicilian, five Portuguese and one Spanish isolate. Metalaxyl sensitivity of 157 isolates was investigated. The frequency of resistance to this chemical decreased in western France from 1989 to 1992. Two glucose phosphate isomerase phenotypes (90/100 and 90/90) were detected among the 46 isolates tested; the former largerly predominated (75–80%) in the samples investigated. Both phenotypes corresponded to the population recently introduced into Europe. A third genotype (86/100), typical of the former European population, was found in one isolate from Picardy, originating from an artificially infected field trial. Five isolates from Portugal and Italy were of the 100/100 phenotype. Race patterns among 26 isolates from western France were very similar, and could not be explained by local selection. The unusual composition of the Brittany population, consisting of 'new' genotypes but all belonging to the Al mating type, is possibly related to the metapopulation type of structure of P. infestans in Europe.     

Rapid dissipation of atrazine in soils taken from various maize fields

A laboratory study was carried out in order to measure the degradation rate of atrazine in 36 different soils taken from maize ( Zea mays L.) fields in Belgium. These soils differed in their alrazme treatment histories. pH. organic matter content and type of organic and mineral fertili-zation, Half-lives of less than 10 days were found in more than 60% of the soils sampled. This rapid dissipation could be linked in a significant way to repeated pretreaiments with atrazine (intensive maize cropping) as well as to higher pH values (from neutral to alkaline), A low organic matter content might also be a factor explaining the rapid degradation of atrazine. but to a lesser extent than the first two factors. On the other hand mineral fertilization was shown to slow down atrazine dissipation. It is hypothesized that repeated treatments of atrazine cause a mi-crobial adaptation to atrazine degradation and that acidic soil conditions impede this adaptation. To date, this is the first time that evidence for widespread accelerated degradation of atrazine has been reported.     

MAGNETIC RESONANCE IMAGING IN THE DIAGNOSIS OF CANINE INFLAMMATORY MYOPATHIES IN THREE DOGS

In humans affected with inflammatory myopathies, regions of altered signal intensity are found on magnetic resonance (MR) images of affected muscles. Although electromyography (EMG) is more practical for muscle disease evaluation, and a muscle biopsy is the only manner in which a definitive diagnosis can be made, MR imaging has proven useful if a specific anatomic localization is difficult to achieve. Three dogs with focal inflammatory myopathy diagnosed with the assistance of MR imaging are discussed and the findings are compared with those found in humans. MR images of the affected muscles in each dog were characterized by diffuse and poorly marginated abnormal signal on T1- and T2-weighted images. Marked enhancement was noted in these muscles after contrast medium administration. An inflammatory myopathy was confirmed histologically in all three dogs. A good association existed between the MR images and muscle inflammation identified histopathologically. MR imaging may be a useful adjunctive procedure for canine inflammatory myopathies.