Management of hemodynamic changes associated with removal of a large abdominal myofibroblastic tumor in a pony

A 22-year-old female Welsh-cross pony was evaluated because of intermittent colic, signs of depression, pyrexia, anorexia, muscle wasting with abdominal distention, and weight gain over the preceding 12 months. A large abdominal mass was detected and surgically removed; the hemodynamic alterations and complications caused by the dramatic fluid losses and shifts that can occur in association with removal of a large abdominal mass required extensive postoperative management. Monitoring of clinical and hematologic variables such as attitude, heart rate, mucous membrane color, mean arterial blood pressure, PCV, and plasma total protein concentration provided useful information for successful management of the patient after surgery. On removal, the tumor weighed 19% of the pony's body weight and was characterized as a myofibroblastic tumor. Myofibroblastic tumors should be considered as a differential for large internal abdominal masses in horses, and surgical removal may be feasible and life extending with appropriate postoperative care.     

Comparative analysis of neonicotinoid binding to insect membranes: I. A structure-activity study of the mode of [3H]imidacloprid displacement in Myzus persicae and Aphis craccivora

Neonicotinoids bind selectively to insect nicotinic acetylcholine receptors with nanomolar affinity to act as potent insecticides. While the members of the neonicotinoid class have many structural features in common, it is not known whether they also share the same mode of binding to the target receptor. Previous competition studies with [3H]imidacloprid, the first commercialised neonicotinoid, indicated that thiamethoxam, representing a novel structural sub-class, may bind in a different way from that of other neonicotinoids. In the present work we analysed the mode of [3H]imidacloprid displacement by established neonicotinoids and newly synthesized analogues in the aphids Myzus persicae Sulzer and Aphis craccivora Koch. We found two classes of neonicotinoids with distinct modes of interference with [3H]imidacloprid, described as direct competitive inhibition and non-competitive inhibition, respectively. Competitive neonicotinoids were acetamiprid, nitenpyram, thiacloprid, clothianidin and nithiazine, whereas thiamethoxam and the N-methyl analogues of imidacloprid and clothianidin showed non-competitive inhibition. The chloropyridine or chlorothiazole heterocycles, the polar pharmacophore parts, such as nitroimino, cyanoimino and nitromethylene, and the cyclic or acyclic structure of the pharmacophore were not relevant for the mode of inhibition. Consensus structural features of the neonicotinoids were defined for the two mechanisms of interaction with [3H]imidacloprid binding. Furthermore, two sub-classes of non-competitive inhibitors can be discriminated on the basis of their Hill coefficients for imidacloprid displacement. We conclude from the present data that the direct competitors share the binding site with imidacloprid, whereas non-competitive compounds, like thiamethoxam, bind to a different site or in a different mode.     

Eisenmenger's complex in a Holstein-Friesian cow

A 4.5-year-old, Holstein-Friesian cow presented with a 1-month history of severe exercise intolerance. Rectal examination and transrectal ultrasonography revealed a large mass in the left retroperitoneum. The heart rate was 70 to 80/min. Premature ventricular complexes and ventricular bigeminy were present on an electrocardiogram. Erythrocytosis was present and blood gas analysis revealed marked hypoxaemia. An echocardiogram demonstrated a large ventricular septal defect, a partially dextroposed aorta, and concentric hypertrophy of the right ventricular free wall. Colour flow Doppler echocardiography and a contrast echocardiographic study demonstrated a right-to-left shunt through the ventricular septal defect. Eisenmenger's complex was diagnosed. The patient was euthanased. Necropsy confirmed the gross cardiac lesions identified by echocardiography and an abscess in the apex of the left ventricle. Severe pulmonary arterial lesions were present, consistent with a marked increased in pulmonary vascular resistance. Actinomyces pyogenes was cultured from abscesses of the retroperitoneum and the ventricular apex.     

A polyphasic taxonomy of Daldinia (Xylariaceae)

For a monograph based on a polythetic concept, several thousands of herbarium specimens, and several hundreds of freshly collected and cultured specimens of Daldinia and allied Xylariaceae, originating from around the world, were studied for morphological traits, including by SEM, and chemically by HPLC profiles using UV-visible and mass spectrometric detection. Emphasis was given to tropical material, and importantly, ancient specimens, including as many types as possible, were tracked and studied to review earlier taxonomic concepts. An epitype of D. eschscholtzii was selected as representative of the morphochemotype that is most widely distributed in the tropics. Six new species of Daldinia from the tropics and the southern Hemisphere are described. Daldinia asphalatum is resurrected, and D. cudonia is regarded as its synonym. In addition, the following binomials are epi-, iso-, neo- and/or lectotypified: Daldinia asphalatum, D. caldariorum, D. clavata, D. cuprea, D. durissima, D. eschscholtzii, D. grandis, D. loculata, and D. vernicosa. Annellosporium and Versiomyces are regarded as synonyms of Daldinia. Many new synonymies in Daldinia are proposed, and some previously published names are rejected. In total, 47 taxa in Daldinia are recognised and a key is provided. Their biogeography, chorology, and ecology, as well as the importance of their secondary metabolites, are also discussed. The previous definition of the genus is emended. The species concept is based mainly on morphological and other phenotype-derived characters because, despite diligent search, no molecular data or cultures of several of the accepted species could be obtained. Daldinia is segregated into five major groups, based on phenotypic characteristics. Some unnamed but aberrant specimens were not found in good condition and are therefore not formally described as new species. However, they are illustrated in detail in a hope that this will facilitate the discovery of fresh material in future. A preliminary molecular phylogeny based on 5.8S/ITS nrDNA including numerous representatives of all hitherto described taxa for which cultures are extant, was found basically in agreement with the above mentioned segregation of the genus, based on morphological and chemotaxonomic evidence. In the rDNA based phylogenetic tree, Daldinia appears clearly distinct from members of the genera Annulohypoxylon and Hypoxylon; nevertheless, representatives of small genera of predominantly tropical origin (Entonaema, Phylacia, Ruwenzoria, Rhopalostroma, Thamnomyces) appear to have evolved from daldinioid ancestors and are nested inside the Daldinia clade. Interestingly, these findings correlate with chemotaxonomic characters to a great extent, especially regarding the distribution of marker metabolites in their mycelial cultures. Hence, the current study revealed for the first time that fungal secondary metabolite profiles can have taxonomic value beyond the species rank and even coincide with phylogenetic data.

Taxonomic novelties:

Daldinia andina sp. nov., D. australis sp. nov., D. hausknechtii sp. nov., D. rehmii sp. nov., D. starbaeckii sp. nov., D. theissenii sp. nov., D. cahuchosa comb. nov., D. nemorosa comb. nov.Key words: Ascomycota, biodiversity, chemotaxonomy, systematics, Xylariales     

Evaluation of a technique for collection of cancellous bone graft from the proximal humerus in horses

OBJECTIVES: To describe a technique for collecting cancellous bone graft from the proximal humerus in horses. STUDY DESIGN: Prospective evaluation of an experimental bone graft collection technique. ANIMAL POPULATION: Eight horses, 3-15 years, weighing 495-605 kg. METHODS: Horses were anesthetized and positioned in lateral recumbency. The lateral aspect of the proximal humerus was exposed by a 7-10-cm incision extending distally from the greater humeral tubercle, followed by sharp dissection through the omotransversarius muscle and between the infraspinatus and deltoideus muscles. A 12-mm cortical defect was incrementally created in the lateral proximal humerus. Human bone graft harvesting equipment (Acumed, Beaverton, OR) was drilled through this defect to collect a core of cancellous bone. In five horses additional cancellous bone was then collected with conventional instruments. Bone samples were weighed and histologically examined. Horses were monitored and graded for quality of anesthetic recovery, incisional complications, and postoperative lameness. RESULTS: Total mean (+/-SD) surgical time for harvesting bone with the Acumed system and traditional techniques (n=5) was 38+/-6 minutes (range, 32-47 minutes). Mean cancellous bone weight collected with the Acumed system was 3.6+/-0.8 g (range, 2.0-4.6 g), and cancellous bone collected conventionally was 25.6+/-7.5 g (range, 16.8-34.2 g). Minimal incisional complications or postoperative lameness were observed. Mortality was 12.5%; one horse fractured the operated humerus during anesthetic recovery. CONCLUSION: The Acumed system provided limited cancellous bone when used with the technique described. However, the quantity of cancellous bone collected with traditional harvesting instruments was comparable to other sites used in horses. The procedure was associated with minimal postoperative incisional complications or lameness, but because one horse suffered a catastrophic humeral fracture further research is required to assess the effects of this procedure on humeral breaking strength. CLINICAL RELEVANCE: Based on the risk of catastrophic fracture, this technique cannot be recommended for use in clinical cases, especially if an unassisted recovery from general anesthesia is planned.