Unusual osteochondral lesions of the talus in a horse

A 2-year-old Thoroughbred gelding was evaluated for a grade 3 out of 5 unilateral hind limb lameness. Flexion of the right hock and stifle joints (spavin test) exacerbated the lameness. Response to intra-articular and perineural anaesthesia isolated the source of lameness to the tarsocrural area, despite an absence of tarsocrural joint effusion. Routine radiographic examination of the hock did not reveal any significant abnormalities. Skeletal nuclear scintigraphic evaluation revealed a focal region of increased bone activity in the proximal medial trochlear ridge of the talus. Flexed lateromedial radiographic views identified three discrete semicircular lytic lesions at the proximal articular margin of the medial trochlear ridge of the talus. Conservative management of the lesions was associated with a successful return to racing. The location and appearance of the osteochondral lesions of this report have not been previously reported and may be a manifestation of developmental orthopaedic disease and abnormal endochondral ossification. Nuclear scintigraphy and flexed lateromedial radiographic views facilitated identification of the lesions. This radiographic view is recommended when lameness is isolated to the tarsocrural joint and standard radio-graphic projections fail to identify a cause.     

Metathesis of Alkanes Catalyzed by Silica-Supported Transition Metal Hydrides

The silica-supported transition metal hydrides (=Si-O-Si=)(=Si-O-)2Ta-H and (=Si-O-)xM-H (M, chromium or tungsten) catalyze the metathesis reaction of linear or branched alkanes into the next higher and lower alkanes at moderate temperature (25degrees to 200degreesC). With (=Si-O-Si=)(=Si-O-)2Ta-H, ethane was transformed at room temperature into an equimolar mixture of propane and methane. Higher and lower homologs were obtained from propane, butane, and pentane as well as from branched alkanes such as isobutane and isopentane. The mechanism of the step leading to carbon-carbon bond cleavage and formation likely involves a four-centered transition state between a tantalum-alkyl intermediate and a carbon-carbon final sigma-bond of a second molecule of alkane.     

Review: The strobilurin fungicides

The original article to which this Correction refers was published in Pest Management Science 58 (7): 649–662 (2002).Copyright © 2004 Society of Chemical Industry     

Determination of Feeder Cell‐Based Cellular Niches Supporting the Colonization and Maintenance of Spermatogonial Stem Cells from Prepubertal Domestic Cat Testes

Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats.     

The Distribution of Bacteria (Other than Staphylococci and Propionibacterium acnes) on the Hair, at the Skin Surface and Within the Hair Follicles of Dogs

Résumé— La distribution des bactéries, autres que les staphlocoques sur la tige des poils, à la surface cutanée et dans les follicules pileux de 8 chiens est analysée. Sur la tige des poils Micrococcus spp. et les bactéries aérobies gram mégatifs sont plus nombreuses avec des numérations variant de 1,12 à 0,84 log₁₀ (colonies formant unites par cm²). Des nombres hautement significatifs (p < 0,05) sont également trouvés. A la surface cutanée Micrococcus spp. des bactéries aérobies gram négatifs et Clostridium sp. sont les plus nombreuses avec des numérations respectives variant de 0,62, 1,12 et 0,84 log₁₀ (colonies formant unités par cm²). Des nombres hautement significatifs (p < 0,05) de Micrococcus spp. sont trouvés de façon plus importante à l'intérieur des follicules pileux qu' à la surface cutanée, les Streptocoques et Bacillus sp. ont été trouvés respectivement sur cinq et quatre chiens. Proteus sp., Pseudomonas sp. Nocardia sp. sont occasion-nellement trouvés. [HARVEY, R.G., LLOYD, D.H. The distribution of bacteria (other than Staphylococci and Propionibacterium acnes) on the hair, at the skin surface and within the hair follicles of dogs (Distribution des bactéries autres que Staphylococci et Propionibacterium acnes) sur le poil, à la surface de al peau et dans les follicules pileux). Resumen— Presentamos la localizatión de bacterias noestafilocócicas en el pelo, en la superficie cutánea y dentro del foliculo piloso de ocho perros. En los pelos, Micrococcus spp. abundantes, con contajes medios entre 1.12 a 0.84 Log₁₀ (unidades formadoras de colonias +1) cm^-1, respectivamente. Se encontró a nivel proximal un número significativamente mayor (p < 0.05) de bacterias aeróbicas gram-negativas y Bacillus spp. En la superficie cutánea, Micrococcus spp., las bacterias aeróbicas contajes medios de 0.62, 1.12 y 0.84 Log₁₀ (unidades formadoras de colonias +1) cm“², respectivamente. Se aisló un número significativamente mayor (p < 0.05) de Micrococcus spp. dentro de los foliculos pilosos que en la superficie cutánea (p < 0.05). Se aisló Streptococi y Bacillus spp. en cinco y cuatro perros, respectivamente. Proteus spp., Pseudomonas spp. y Nocardia spp. fueron hallados ocasionalmente. [HARVEY, R.G., LLOYD, D.H. The distribution of bacteria (other than Staphylococci and Propionibacterium acnes) on the hair, at the skin surface and within the hair follicles of dogs (Localizatión de bacterias (exceptuando Staphilococci y Propionibacterium acnes) en el pelo, en la superficie cutánea y dentro de los foliculos pilosos). Abstract— The distribution of bacteria, other than staphylococci, on the hair shaft, at the skin surface and within the hair follicles of eight dogs is reported. On the hair shafts Micrococcus spp. and aerobic Gram-negative bacteria were most numerous, with mean counts ranging from 1.12 to 0.84 Log₁₀(colony forming units + 1) cm“¹ respectively. Significantly higher numbers (p < 0.05) of Gram-negative bacteria and Bacillus sp. were found proximally. At the skin surface Micrococcus spp., aerobic Gram-negative bacteria and Clostridium spp. were the most numerous with mean counts of 0.62, 1.12 and 0.84 Log₁₀(colony forming units + 1) cm”², respectively. Significantly higher numbers (p < 0.05) of Micrococcus spp. were found within the hair follicles than on the skin surface (p < 0.05). Streptococci and Bacillus spp. were found on five and four dogs, respectively. Proteus spp., Pseudomonas spp. and Nocardia spp. were occasionally found.     

Colonization of the canine skin with bacteria

Abstract Aspects of colonization of the canine skin with bacteria are reviewed. Owing to variability in sampling techniques, anatomical sites involved and lack of temporal studies, there is still controversy as to which bacteria are residents or transients on the canine skin. The establishment of the cutaneous flora is determined by the ability of bacteria to adhere to canine corneocytes, to use available nutrients from skin secretions and to resist challenge from competing bacteria. Variations in humidity and temperature due to environment, skin folds or differences in the haircoat are also likely to have an effect. Much research has focused around Staphylococcus intermedius, the main pathogen of the canine skin but its cutaneous residency status remains questionable. Pathological conditions such as atopy and seborrhoea favour the colonization of S. intermedius and predispose to infection. Recent studies indicate that bacterial interference as a method of preventing colonization of pathogenic staphylococci may be feasible. Résumé— Les aspects de la colonisation de la peau canine par des bactéries sont étudiées. A cause de la variabilité des techniques de prélèvements, des sites anatomiques, et du caratère ponctuel des études, le doute subsiste toujours quant à savoir quelle sont les bactéries résidentes ou transitoires sur la peau de chien. L'établissement d'une flore cutanée est déterminée par la capacité de la bactérie à adhérer aux cornéocytes canines, à utiliser les nutriments disponibles à partir des sécrétions cutanées et à résister aux autres bactéries qui concourent à l'occupation des memes sites. Les variations d'humidité et de température, dues à l'environnement, aux plis de peau et aux différences de pelage jouent probablement un role. La plupart des études concernent Staphylococcus intermedius, l'agent pathogène principal de la peau du chien, mais son statut de résident cutané est toujours débattu. Des conditions pathologiques telles que l'atopie et la séborrhée favorisent la colonisation par S. intermedius et prédisposent à l'infection. Des études récentes indiquent que l'interférence bactérienne peut être envisagée comme une méthode de prévention de la colonisation cutanée par un staphylocoque pathogène. [Saijonmaa-Koulumies, L. & Lloyd, D. H. Colonization of the canine skin with bacteria (Colonisation de la peau canine par des bactéries). Veterinary Dermatology 1996; 7 : 153–162.] Resumen Se revisan algunos aspectos de la colonización bacteriana en la piel canina. Existe aún controversia sobre qué bacterias son résidentes o transitorias en la piel del perro, debido a la variabilidad en las técnicas de recolección, localización y falta de estudios temporales. El establecimiento de la flora cutánea depende de su capacidad de adhesión a los corneocitos, de utilizar los nutrientes de las secreciones cutáneas y de resistir la competencia de otras bacterias. También es probable que tengan un papel los cambios de humedad y temperatura por los pliegues cutáneos o las diferencias en el pelaje. Se ha centrado mucha investigación en Staphylococcus intermedius, el principal patógeno de la piel canina, aunque se sigue cuestionando su existencia como residente cutáneo. Situaciones patológicas como la atopia o la seborrea favorecen la colonización por S. intermedius y predisponen a infección. Algunos estudios recientes indican que es factible la interferencia bacteriana como método de prevenir la colonización por estafilococos patógenos. [Saijonmaa-Koulumies, L. & Lloyd, D. H. Colonization of the canine skin with bacteria (Colonizacion de la piel cannina con bacterias). Veterinary Dermatology 1996; 7 : 153–162.] Zusammenfassung— Es werden Aspekte der Besiedelung der Hundehaut mit Bakterien dargestellt. Entsprechend der Variabilität in der Probenentnahme, verwendeten anatomischen Regionen und dem Mangel an temporären Studien exisitieren immer noch unterschiedliche Ansichten, ob Bakterien auf der Haut des Hundes als resident oder transient gelten. Die Aufstellung der kutanen Flora wird durch die Fähigkeit der Bakterien bestimmt, sich an die kaninen Korneozyten anzuheften, verfügbare Nährstoffe aus den Hautsekretionen zu verwenden und sich gegenüber konkurrierenden Keimen zu behaupten. Veränderungen in Feuchtigkeit und Temperatur in Abhängigkeit von Umgebung, Hautfalten oder Unterschieden im Haarkleid scheinen ebenfalls einen Effekt zu besitzen. Viele Untersuchungen konzentrierten sich auf Staphylococcus aureus, der hauptpathogene Keim auf der Hundehaut, aber sein Status als residenter Keim bleibt fraglich. Pathologische Zustände wie Atopie und Seborrhoe begünstigen die Besiedelung mit S. intermedius und prädisponieren für eine Infektion. Kürzliche Studien zeigen, daß bakterielle Interferenzen als Methode zur Verhinderung der Ansiedlung von pathogenen Staphylokokken möglich sein könnten. [Saijonmaa-Koulumies, L., Lloyd, D.H. Colonization of the canine skin with bacteria (Besiedelung der Haut des Hundes mit Bakterien). Veterinary Dermatology 1996; 7 : 153–162.]     

Warfarin in the dog: pharmacokinetics as related to clinical response

Warfarin was administered intravenously (i.v.) as a single dose of 1.5 mg/kg to healthy dogs and the pharmacokinetic parameters were investigated. Elimination could be described by a one-compartment open model. Values for the elimination half-life and apparent specific volume of distribution were 14.5 ± 4.1 h and 0.22 ± 0.04 litre/kg, respectively. Oral maintenance doses were calculated from the data collected following i.v. administration and administered every 12 h for a total of five doses after an initial i.v. loading dose of 1.5 mg/kg. Prothrombin times increased from a control value of 8.6 ± 0.3 sec to 55.2 ± 5.2 sec over a period of 96 h. Prothrombin time returned to control values by 62 h after withdrawal of the drug. We propose a dosage regimen of warfarin for anticoagulant therapy in the dog of 0.22 mg/kg to be given orally every 12 h. Prothrombin time should be monitored during therapy and the dose of warfarin modified according to the degree of suppression of coagulation factors desired.     

PREVENTION OF SALMONELLA TYPHIMURIUM INFECTION IN POULTRY BY PRETREATMENT OF CHICKENS AND POULTS WITH INTESTINAL EXTRACTS

Day-old chickens or turkey poults when pretreated with an oral dose of intestinal fluid froma healthy adult bird, were considerably more resistant to the subsequent establishment of Salmonella typhimurium in their intestinal tract than were non-treated chickens or turkey poults. Caecal fluid was more effective as a pretreatment than were washings taken from other parts of the gastro-intestinal tract of a healthy adult bird. This increased resistance of pretreated chickens or poults is thought to result from the rapid establishment of a conventional indigenous microflora which inhabits establishment and growth by the invading enteric pathogen.