Mechanism of simmondsin decomposition during sodium hydroxide treatment

Jojoba seed meal shows appetite-suppressing activity due to the presence of simmondsin. This pharmacological activity disappears with treatment of the meal with sodium hydroxide. To elucidate this mechanism of inactivation, the reaction of simmondsin in 1 N NaOH at 20 degrees C was monitored as a function of time. The end products of the reaction as well as intermediates were isolated and identified. The half-life of simmondsin was approximately 60 min with d-glucose and 2-hydroxy-3-methoxyphenylacetonitrile as reaction end products. The reaction mechanism could be elucidated by the isolation of isosimmondsin and a simmondsin lactone derivative. Those compounds were isolated and purified by a combination of column chromatography and HPLC and identified mainly by HRMS and NMR spectroscopy.     

Variance of indirect blood pressure measurements and prevalence of hypertension in clinically normal dogs

In a series of 3 studies, indirect blood pressure measurements were obtained to define normal variance, identify hypertension, and estimate the prevalence of hypertension in apparently healthy dogs. In part 1, we measured values in 5 clinically normal dogs twice weekly for 5 weeks in a home setting. Mean +/- SD systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) was 150 +/- 16 and 86 +/- 13 mm of Hg, respectively. The DAP significantly (P less than 0.01) decreased with repeated measurements over the 5-week period. In part 2, we assessed the variation between blood pressures measured in a clinic vs those measured in the home. Within a 2-week period, measurements were obtained from 10 clinically normal dogs in a private veterinary clinic and again in their home. Significant differences were not observed between clinic and home measurements of SAP and DAP; however, heart rate was significantly (P less than 0.05) higher in the clinic. In part 3, SD about the SAP and DAP mean values were determined in 102 clinically normal dogs. Canine hypertensive status was determined, using statistical methods and data from 102 clinically normal dogs. Values of SAP greater than 202 mm of Hg and DAP greater than 116 mm of Hg were determined to be 2 SD beyond the mean and, therefore, were interpreted to be hypertensive. Approximately 10% of the 102 apparently healthy dogs measured in this study were considered hypertensive on the basis of these criteria. In addition, a border zone of suspected hypertension was estimated, using the mean + 1.282 SD. The SAP border zone was between 183 and 202 mm of Hg, whereas the DAP border zone was between 102 and 113 mm of Hg. Of the 102 dogs, 12 had values within these zones of suspected hypertension.     

Treatment of a second carpal bone fracture by removal under ultrasonographic guidance in a horse

OBJECTIVE: To report an unusual 2nd carpal bone (C2) slab fracture and its treatment, using an ultrasonographically assisted, minimally invasive arthrotomy technique, for fragment removal. STUDY DESIGN: Case report. ANIMALS: An 11-year-old crossbred Warmblood gelding. METHODS: A bone fragment, spanning the height of C2, identified on the palmaromedial aspect of C2 was demarcated intraoperatively using ultrasonographically guided needles and removed by arthrotomy. RESULTS: Fracture fragment removal was achieved using a small, ultrasonographically guided arthrotomy. The horse has become sound after treatment and returned to the previous level of pleasure riding activity. CONCLUSIONS: Perioperative ultrasonography was used to delineate and facilitate removal of an unusual slab fragment of C2, through a minimally sized arthrotomy. Despite the presence of pancarpal osteoarthritis and partial involvement of the medial collateral ligament, the prognosis appeared to be satisfactory for this pleasure riding horse. CLINICAL RELEVANCE: Ultrasonographic guidance may be used to optimize the approach to C2 articular bony fragments that may not be observed using arthroscopy.     

An outbreak of disease due to chicken anaemia agent in broiler chickens in England

Outbreaks of clinical chicken anaemia in four broiler chicken flocks affected chicks which were all the progeny of the same parent flock. Three of the flocks were reared on farms in the south-east of England and in these flocks clinical disease did not occur in other chicks of the same age. The fourth flock was reared in a positive-pressure isolator and clinical disease appeared at 10 days of age. Chicken anaemia agent was isolated from three of the flocks. The clinical signs, post mortem lesions and histopathological changes were similar to those reported in outbreaks of the disease in other countries. The parent flock seroconverted to chicken anaemia agent, as determined by fluorescent antibody tests, during the course of the outbreaks.     

A biomechanical comparison of headless tapered variable pitch compression and ao cortical bone screws for fixation of a simulated midbody transverse fracture of the proximal sesamoid bone in horses

OBJECTIVE: To compare mechanical properties and failure characteristics of 2 methods of fixation for repair of a transverse, midbody fracture of the proximal sesamoid bone (PSB): 4.5-mm AO cortical bone screw (AO) placed in lag fashion and 4/5-mm Acutrak (AT) self-compressing screw. STUDY DESIGN: An in vitro biomechanical evaluation of intact forelimb preparations and forelimb preparations with a simulated midbody PSB fracture stabilized by a bone screw. SAMPLE POPULATION: Sixteen paired and 8 unilateral cadaveric equine forelimbs. METHODS: A midbody transverse osteotomy was created in the medial PSB of bilateral forelimbs of 8 equine cadavers. The osteotomized PSB in 1 forelimb from each cadaver was repaired with an AO screw. The osteotomized PSB in each contralateral limb was repaired with an AT screw. Eight unilateral intact control limbs were also studied. Mechanical properties were determined from axial compression, single cycle to failure, load-deformation curves. Failure characteristics were determined by evaluation of video images and radiographs. RESULTS: No statistically significant differences were found between repair groups. Both AO and AT groups had significantly lower mechanical properties than intact limbs except for stiffness. CONCLUSION: AO and AT constructs were mechanically comparable when used to stabilize a simulated midbody fracture of the medial PSB. Both constructs were mechanically inferior to intact limbs. Clinical Relevance- The AT screw should be considered for clinical use because of the potential for less soft tissue impingement and superior biocompatibility compared with the stainless-steel AO screw. However, postoperative external coaptation is necessary to augment initial fracture stability for either fixation method, and to maintain a standing metacarpophalangeal joint dorsiflexion angle between 150 degrees and 155 degrees.