Russell, A.P. and Oetelaar, G.S. 2016. Limb and digit orientation during vertical clinging in Bibron's gecko, Chondrodactylus bibronii (A. Smith, 1846) and its bearing on the adhesive capabilities of geckos. -Acta Zoologica (Stockholm) 97: 345-360.Geckos with subdigital adhesive pads can scale smooth vertical surfaces in defiance of gravity. The deployment of the adhesive system is activated by the musculoskeletal system during active traverses of such surfaces, but adhesion on such substrata can also be achieved by passive means, with the body weight of the gecko applying tensile loading to the adhesive setae, maintaining prolonged, static contact with the surface. To investigate whether passively induced adhesion is employed by geckos holding station on smooth vertical surfaces, we investigated the magnitude of shear force generation for the manus and pes, and the positioning of the limb segments and digits in Chondrodactylus bibronii in freely selected resting postures (head-up, head-down and facing laterally to the left and right). Our results indicate that different subsets of digits occupy positions consistent with them being passively loaded in different body orientations. Limb segment and digit orientation are consistent within, and differ between, the resting postures, and relatively few of the 20 digits are positioned to take advantage of gravitationally induced loading in any posture. The pedal digits have greater adhesive potential than the manual ones and, more frequently, capitalize on passive loading than do manual digits. This is especially evident in the commonly adopted head-down resting posture.

Published findings on the computed tomographic (CT) appearance of sialoceles are limited to brief descriptions from reported cases in eight dogs and one cat. The authors have seen sialoceles with CT characteristics that are not consistent with these previous reports. The purpose of this multicenter, retrospective, descriptive, case series study was to provide more detailed descriptions of the CT appearance of confirmed sialoceles in dogs. Dogs over a 10-year period with cytologically or histologically confirmed sialoceles and pre-and postcontrast CT studies of the head were included.Multiple qualitative and quantitative features were described for each sialocele with histological correlation. Twelve dogs with a total of 13 sialoceles were identified, including: seven cervical sialoceles, three complex (combined cervical and sublingual) sialoceles, two sublingual sialoceles, and one zygomatic sialocele. All sialoceles were characterized by fluid attenuating, non-contrast enhancing contents (median 18.5 HU) and soft tissue attenuating, contrast-enhancing walls. The external margins of all sialocele walls were smooth; however, the internal margins in six sialoceles were irregular with poorly defined nodular to frond-like protrusions. Mineralized foci of variable size (range < 1 mm to 4.8 mm) and attenuation (range 119 to 1253 HU) were present in seven sialoceles and histologically identified as sialoliths (three sialoceles) and osseous metaplasia (two sialoceles). A unique finding in the sialoceles in this study was the presence of intraluminal nodular to frond-like protrusions arising from the wall. This study also reports the CT appearance of cervical and complex sialoceles and sialocele mineralizations.

A 10-year-old male neutered Domestic Shorthair cat was referred for chronic inappetence, weight loss, and hematochezia and an abdominal mass. Abdominal ultrasonography revealed a heterogeneously hypoechoic transmural colonic mass, which extended beyond the serosa and into the adjacent mesentery. Cytology and clonality assays of fine needle aspirates of the mass and mesenteric nodules yielded a diagnosis of B-cell lymphoma. Colonic lymphoma with mesenteric involvement can have a similar appearance to carcinomatosis, therefore a definitive diagnosis requires sampling and further testing of the mesenteric lesions.

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