Abstract: Obesity and diabetes mellitus are common diseases in humans, dogs and cats and their prevalence is increasing. Obesity has been clearly identified as a risk factor for type 2 diabetes in humans and cats but recent data are missing in dogs, although there is evidence that the unprecedented rise in canine obesity in the last decade has led to a rise in canine diabetes of similar magnitude. The insulin resistance of obesity has often been portrayed as major culprit in the loss of glucose control; however, insulin resistance alone is not a good indicator of progression to diabetes in people or pets. A loss of beta cell function is necessary to provide the link to impaired fasting and post-prandial plasma glucose. Increased endogenous glucose output by the liver is also a prerequisite for the increase in fasting blood glucose when non-diabetic obese humans and pets develop diabetes. This may be due to decreased hepatic insulin sensitivity, decreased insulin concentrations, or a combination of both. While inflammation is a major link between obesity and diabetes in humans, there is little evidence that a similar phenomenon exists in cats. In dogs, more studies are needed to examine this important issue.
Abstract: Prophylactic local treatment involving percutaneous vertebral augmentation using bioactive materials is a new treatment strategy in spine surgery in humans for vertebral bodies at risk. Standardized animal models for this procedure are almost non-existent. The purpose of this study was to: (i) prove the efficacy of PTH derivate bioactive materials for new bone formation; and (ii) create a new, highly standardized cervical vertebral augmentation model in sheep. Three different concentrations of a modified form of parathyroid hormone (PTH) covalently bound to a fibrin matrix containing strontium carbonate were used. The same matrix without PTH and shams were used as controls. The bioactive materials were locally injected. Using a ventral surgical approach, a pre-set amount of material was injected under fluoroscopic guidance into the intertrabecular space of three vertebral bodies. Intravital fluorescent dyes were used to demonstrate new bone formation. After an observation period of four months, the animals were sacrificed, and vertebral bodies were processed for µCT, histomorphometry, histology and sequential fluorescence evaluation. Enhanced localized bone activity and new bone formation in the injected area could be determined for all experimental groups in comparison to the matrix alone and sham with the highest values detected for the group with a medium concentration of PTH.
Abstract: Animal models with an eco-ethological relevance can help in identifying novel and reliable stress-related markers. To this end, 3-month-old C57BL/6J male mice were exposed to social defeat (SD) stress for 10 days as this stressor shows good face and predictive validity for several models of human affective disorders including depression, social phobia and post-traumatic stress disorder. Social avoidance and pain threshold were assessed 24 h and 4 weeks after the end of SD stress, while corticosterone was assayed at the beginning and at the end of the stressful procedure (days 1 and 10). SD subjects were characterized by increased corticosterone levels (30 min following stress exposure), increased latency to approach the social target in the short-term as well as increased emotionality in the long-term. Moreover, an increase in nociceptive threshold (stress-induced analgesia) was found both in the short-term and 4 weeks after the end of stress. These data indicate that the SD paradigm is able to induce emotional changes associated with a stressful/traumatic event. In addition, they indicate that variations in the nociceptive threshold might represent a physiological marker of both short- and long-term effects of stress.
Abstract: Common marmosets (Callithrix jacchus) are small non-human primates (NHPs) that are often used for respiratory research. Translational animal models of various pulmonary diseases in marmosets have been developed in favor of models in old world monkeys (OWM, e.g., rhesus or cynomolgus monkeys). The marmoset has the size of a rat (350–450 g), is easier to handle, and the husbandry, care, and management of colonies is much easier compared to OWMs. In contrast to rodents, marmosets provide a high homology to humans, which become especially visible in lung architecture and branching pattern. Features of inflammatory (e.g., COPD) pulmonary diseases can be modeled in marmosets as well the species is used to study bacterial and viral infection. Models for human melioidosis, tuberculosis, anthrax, as well as infections with SARS-associated coronavirus (SARS-CoV), influenza A virus and adenovirus are already established. Toxicological studies often use marmoset monkeys for the advantage of immunological identical twins that are produced by a Callitrichinae-specific placentation type, which ultimately causes blood chimerism. Relatively new approaches in gene therapy use marmosets for respiratory disease research. In this review we will give an overview of existing respiratory marmoset models and their impact on biomedical research.
Abstract: Smallpox, one of the most destructive diseases, has been successfully eradicated through a worldwide vaccination campaign. Since immunization programs have been stopped, the number of people with vaccinia virus induced immunity is declining. This leads to an increase in orthopoxvirus (OPXV) infections in humans, as well as in animals. Additionally, potential abuse of Variola virus (VARV), the causative agent of smallpox, or monkeypox virus, as agents of bioterrorism, has renewed interest in development of antiviral therapeutics and of safer vaccines. Due to its high risk potential, research with VARV is restricted to two laboratories worldwide. Therefore, numerous animal models of other OPXV infections have been developed in the last decades. Non-human primates are especially suitable due to their close relationship to humans. This article provides a review about on non-human primate models of orthopoxvirus infections.
Abstract: Prostate cancer bone metastases are associated with a poor prognosis and are considered incurable. Insight into the formation and growth of prostate cancer bone metastasis is required for development of new imaging and therapeutic strategies to combat this devastating disease. Animal models are indispensable in investigating cancer pathogenesis and evaluating therapeutics. Multiple animal models of prostate cancer bone metastasis have been developed, but few effectively model prostatic neoplasms and osteoblastic bone metastases as they occur in men. This review discusses the animal models that have been developed to investigate prostate cancer bone metastasis, with a focus on canine models and also includes human xenograft and rodent models. Adult dogs spontaneously develop benign prostatic hyperplasia and prostate cancer with osteoblastic bone metastases. Large animal models, such as dogs, are needed to develop new molecular imaging tools and effective focal intraprostatic therapy. None of the available models fully reflect the metastatic disease seen in men, although the various models have provided important insight into the metastatic process. As additional models are developed and knowledge from the different models is combined, the molecular mechanisms of prostate cancer bone metastasis can be deciphered and targeted for development of novel therapies and molecular diagnostic imaging.