The desired postoperative TPA of 5 degrees is dependent on a precise initial measure of TPA preoperatively. This study indicates that there is statistically significant interobserver variability with measurement of TPA, which, therefore, can result in a similar amount of variability with the final tibial plateau slope obtained postoperatively.

No abstract

A retrospective survey from January 1989 to January 1999 of Tufts University Foster Hospital for Small Animals radiology records of 12 dogs and seven cats with cytologically or histopathologically confirmed abdominal mast cell disease was performed. Ultrasound changes in hepatic mast cell infiltration in dogs included a subjective increase in size, a diffuse increase in echogenicity, and one or more hypoechoic nodules. Ultrasound findings in the affected canine spleen included one or more hypoechoic nodules and a subjective increase in size. Two ultrasonographically unremarkable canine livers and one unremarkable spleen were found to be infiltrated by mast cells. The mast cell-infiltrated feline spleen was subjectively increased in size, mottled, irregular, or contained nodules. The affected lymph nodes in both dogs and cats were hypoechoic or inhomogeneous, subjectively increased in size, and rounded. Gastrointestinal involvement in cats was characterized by a thickened ileocecocolic junction or colon with loss of wall layering. Mast cells were not found in the gastrointestinal tract in any dog. One dog with mast cell infiltrate of the kidneys had multiple hypoechoic nodules in the cortex that distorted the outer contour of the kidney. Although these findings are not specific to the disease in either species, abdominal ultrasound is considered a useful tool for determining the extent of disease in small-animal patients with mast cell tumor if used in conjunction with histopathology or cytology.

A fundamental assumption of today's molecular genetics paradigm is that complex morphology emerges from the combined activity of low-level processes involving proteins and nucleic acids. An inherent characteristic of such nonlinear encodings is the difficulty of creating the genetic and epigenetic information that will produce a given self-assembling complex morphology. This 'inverse problem' is vital not only for understanding the evolution, development and regeneration of bodyplans, but also for synthetic biology efforts that seek to engineer biological shapes. Importantly, the regenerative mechanisms in deer antlers, planarian worms and fiddler crabs can solve an inverse problem: their target morphology can be altered specifically and stably by injuries in particular locations. Here, we discuss the class of models that use pre-specified morphological goal states and propose the existence of a linear encoding of the target morphology, making the inverse problem easy for these organisms to solve. Indeed, many model organisms such as Drosophila, hydra and Xenopus also develop according to nonlinear encodings producing linear encodings of their final morphologies. We propose the development of testable models of regeneration regulation that combine emergence with a topdown specification of shape by linear encodings of target morphology, driving transformative applications in biomedicine and synthetic bioengineering.

Genitalia are morphologically variable across many taxa and in physical contact during intromission, but little is known about how variation in form correlates with function during copulation. Marine mammals offer important insights into the evolutionary forces that act on genital morphology because they have diverse genitalia and are adapted to aquatic living and mating. Cetaceans have a fibroelastic penis and muscular vaginal folds, while pinnipeds have a baculum and lack vaginal folds. We examined copulatory fit in naturally deceased marine mammals to identify anatomical landmarks in contact during copulation and the potential depth of penile penetration into the vagina. Excised penises were artificially inflated to erection with pressurized saline and compared with silicone vaginal endocasts and within excised vaginas in simulated copulation using high-resolution, diffusible iodine-based, contrast-enhanced computed tomography. We found evidence suggestive of both congruent and antagonistic genital coevolution, depending on the species. We suggest that sexual selection influences morphological shape. This study improves our understanding of how mechanical interactions during copulation influence the shape of genitalia and affect fertility, and has broad applications to other taxa and species conservation.