A comparative histochemical and morphometric study of canine skeletal muscle.

The purpose of this study was to determine whether there were differences in skeletal muscle properties in the hindlimb muscles of different types of dogs. Muscle samples were obtained from the gracilis, sartorius cranial head, sartorius caudal head and tibialis anterior muscles of mixed-breed and hound-type dogs and Beagles. Fiber type, fiber size and capillary morphometry determinations of each muscle from each dog were made from sections stained for myofibrillar ATPase activity. Individual animals were bilaterally symmetric for all measured variables. Fiber type, fiber size and capillary geometry varied between dogs of a given type and muscles within a given dog. There were no differences between dog types for fiber type or fiber size; significant variation in log(muscle)/log(body) mass ratios between dog types was observed for all muscles. The results indicate that for a given muscle, significant variation can occur in skeletal muscle characteristics between different types of dogs and that these differences can be independent of differences in exercise history.     

Management of cervical spondylopathy-associated intervertebral, disc protrusions using metal washers in 78 dogs

Intervertebral 7.5 mm (n = 75) and 6.0 mm (n = 22) metal washers were used to distract intervertebral spaces in 78 consecutive cases of canine cervical spondylopathy-associated disc protrusions, where myelography had demonstrated traction-responsive spinal cord compression. Nineteen dogs had compressive lesions at two sites. Fifty lesions were evaluated myelographically on immediate postoperative radiographs; of these, 32 compressions had been eliminated and 18 had been reduced. Euthanasia was performed in nine dogs within six months of surgery and 15 dogs had varying degrees of neck pain during this period. Long-term follow-up information was available on 65 dogs nine to 70 months following surgery (median 32 months). Sixty-three of these dogs improved postoperatively. Neurological function subsequently deteriorated in 17 dogs 10 to 59 months following surgery (median 34 months). Eight of these 17 cases had further myelographic investigations and all had additional disc protrusions with no evidence of cord compression at the previous sites of surgery. The remaining nine cases had a deterioration in hindlimb function but were not investigated further.     

Virus infection in South American potatoes

Summary Methods used to test for virus infection in potato samples from South America are described and the incidence of infection in the samples is recorded. Samples were classified according to provenance, ploidy, altitude of collection, and as weed or cultivated forms to investigate the influence of these factors. The advantages of maintenance of potato collections as seed lines are discussed with special reference to prevention of spread of introduced viruses.

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Zusammenfassung Die bei der Untersuchung auf Virusbefall bei Kartoffelmustern aus Südamerika angewendeten Methoden werden beschrieben. Es wird über den Umfang der Infektion durch die Kartoffelviren X(PVX), S(PVS) und Y(PVY) und den nekrotischen Tabakrippenbr?une-Stamm von Virus Y(TVN) in 784 Mustern berichtet, ebenso über das Auftreten von Blattroll in 241 Mustern (Tabelle 1). Um den Einfluss verschiedener Faktoren zu untersuchen, wurden die Muster eingeteilt nach Herkunft (Tabelle 1), Ploidiestufe (Tabelle 2), H?henlage der Herkunftsorte (Tabelle 3) oder nach dem Gesichtspunkt, ob es sich um wilde beziehungsweise unkrautartige oder kultivierte Formen handelte (Tabelle 4). Die Vorteile der Aufrechterhaltung von Kartoffelsammlungen als Samen-Familien werden besprochen, besonders in bezug auf die Verhütung der Ausbreitung von eingeschleppten Viren.

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Résumé L’auteur décrit les méthodes utilisées pour détecter les infections virologiques dans les échantillons de pommes de terre en provenance de l’Amérique du Sud et rapporte l’importance de l’infection par les virus X (PVX), S (PVS), Y (PVY) et par la souche du virus Y causant la nécrose nervienne du tabac (TVN), dans 784 échantillons, et en même temps l’importance de l’infection par le virus de l’enroulement dans 241 échantillons (Tableau 1). Pour déterminer l’influence de ces facteurs, les échantillons ont été classés suivant la provenance (Tableau 1), l’état plo?dique (Tableau 2), l’altitude du prélèvement (Tableau 3), et le fait qu’il s’agit de formes cultivées ou sauvages et adventices (Tableau 4). L’auteur discute de l’opportunité de conserver les collections de pommes de terre sous forme de lignées en semences dans le but particulier d’empêcher l’extension des virus introduits.

     

A preliminary evaluation of throughfall sampling techniques in a mature coniferous forest

Rainfall, throughfall and stemflow were measured and canopy interception loss was derived for 14 rainfall events from June 22 to August 30, 2008 within a mature declining hybrid white spruce(Picea glauca(Moench) Voss × P. engelmannii Parry ex Engelm.)- subalpine fir(Abies lasiocarpa(Hook.) Nutt.)- lodgepole pine(Pinus contorta var.latifolia Dougl. ex Loud.) stand in south-central British Columbia, Canada. Stemflow was negligible during the study period, while, respectively throughfall and canopy interception loss accounted for approximately59.4% and 40.6% of the 50.1 mm of cumulative rainfall. Throughfall variability was assessed with three approaches involving roving and stationary wedge-type gauges, and stationary trough gauges. Throughfall exhibited large spatial variability with the coefficient of variability of study period throughfall sampled using 16 stationary trough gauges being30.3%, while it was 38.0% and 28.7% for 32 stationary and 32 roving wedge gauges, respectively. Our analysis suggests that a roving gauge method is better than a stationary approach since the errors associated with event mean throughfalls are summed quadratically and a greater portion of the canopy area is sampled. Trough gauges were more efficient than wedge gauges; however, this efficiency was less than expected given their much larger sampling areas, suggesting that spatial autocor-relation lengths of throughfall may be longer than the trough systems. The spatial distribution of throughfall showed a high degree of temporal persistence throughout the study suggesting the existence of stable "wet" and "dry" inputs to the floors of these coniferous forests.     

Ossification of the infraspinatus tendon-bursa in 13 dogs

Ossification of the infraspinatus tendon-bursa was diagnosed in 13 labrador retrievers, 12 of which were lame in one thoracic limb and the other in both. They ranged in age from 28 to 121 months (mean 69.4 months). The lameness developed gradually and was progressive in 11 of the 14 affected joints. Scapular muscle atrophy and signs of pain on direct pressure over the infraspinatus tendon of insertion were key clinical signs. Caudocranial radiographs revealed multiple mineralised masses lateral to the proximal humerus or glenohumeral joint in 11 of the 26 joints and single masses in 12. An arthroscopic examination revealed concomitant ligament or tendon abnormalities in six of seven shoulders. The dogs were followed up from one to 55 months (mean 20 months). Of five shoulders treated with non-steroidal anti-inflammatory drugs (nsaids), one resolved, two improved and two were managed surgically. Of six shoulders treated by the injection of long-acting intra-articular corticosteroid (five before and one after surgery), three resolved, two improved and one was unchanged. Of six shoulders treated by the surgical resection of the infraspinatus tendon and bursa (three before and two after treatment with nsaids, and one after treatment with a long-acting intra-articular corticosteroid), four improved, one was unchanged and one was managed with an intra-articular long-acting corticosteroid. One shoulder was managed by restricted exercise and the lameness resolved. Histological examination of the excised tissues revealed heterotopic bone within the infraspinatus tendon and/or bursa.     

Genetic diversity analysis of avocado (Persea americana Miller) rootstocks selected under greenhouse conditions for tolerance to phytophthora root rot caused by Phytophthora cinnamomi

Phytophthora cinnamomi, the causal agent of Phytophthora Root Rot (PRR) of avocado, is the most serious disease of avocado worldwide. The development of tolerant rootstocks to control PRR has proven to be an effective means to control the disease. However, using traditional breeding approaches can take over a decade to produce results and there has been a limited use to integrate molecular data into breeding efforts. Therefore, the objective of this work was to use amplified fragment length polymorphism (AFLP) to genetically characterize greenhouse selected PRR tolerant rootstocks, some that had been field-tested and others that had not. Sixty-one polymorphic markers were identified among the 83 cultivars/selections tested. Based on UPGMA analysis, extensive genotypic diversity was found with the closest genotypes differing by six markers. No obvious trends were observed based on the cluster analysis with regards to known tolerant and susceptible rootstocks but rootstocks that have been field-tested and determined to be very tolerant rootstocks such as Latas, Dusa, PP14 (Uzi), PP4 (Zentmyer), and PP24 (Steddom) were distributed across the tree. This suggests that the same mechanisms for resistance may not be shared among these various selections. Therefore, these best-performing and most genetically diverse rootstocks will be combined in future breeding efforts to potentially pyramid diverse sources of resistance into future selections.     

Similarity of synthetic peptide from human tumor to parathyroid hormone in vivo and in vitro

One mechanism considered responsible for the hypercalcemia that frequently accompanies malignancy is secretion by the tumor of a circulating factor that alters calcium metabolism. The structure of a tumor-secreted peptide was recently determined and found to be partially homologous to parathyroid hormone (PTH). The amino-terminal 1-34 region of the factor was synthesized and evaluated biologically. In vivo it produced hypercalcemia, acted on bone and kidney, and stimulated 1,25-dihydroxy-vitamin D3 formation. In vitro it interacted with PTH receptors and, in some systems, was more potent than PTH. These studies support a long-standing hypothesis regarding pathogenesis of malignancy-associated hypercalcemia.     

INTERACTION BETWEEN CRYSTALLINE PENICILLIN AND HUMAN PLASMA PROTEINS

Penicillin combines with human serum albumin, as demonstrated by dialysis experiments. Unlike the sulfonamfide-albumin complex, the penicillin-albumin possesses antibiotic activity. Such a complex can be freed of unbound penicillin by repeated precipitation at 50 per cent. alcohol and obtained as a dried powder. Mouse excretion studies indicated that the penicillin-albumin complex was excreted more slowly than the sodium salt of penicillin.