The diets of populations in industrialized nations have shifted to dramatically increased consumption of ω6 polyunsaturated fatty acids (PUFA), with a corresponding decrease in the consumption of ω3 PUFA. This dietary shift may be related to observed increases in obesity, chronic inflammation, and comorbidities in the human population. We examined the effects of ω3:ω6 fatty acid ratios in the context of constant total dietary lipid on the growth, total body fat, and responses of key inflammatory markers in adult zebrafish (Danio rerio). Zebrafish were fed diets in which the ω3:ω6 PUFA ratios were representative of those in a purported ancestral diet (1:2) and more contemporary Western diets (1:5 and 1:8). After 5 mo, weight gain (fat free mass) of zebrafish was highest for those that received the 1:8 ratio treatment, but total body fat was lowest at this ratio. Measured by quantitative real-time RT–PCR, mRNA levels from liver samples of 3 chronic inflammatory response genes (C-reactive protein, serum amyloid A, and vitellogenin) were lowest at the 1:8 ratio. These data provide evidence of the ability to alter zebrafish growth and body composition through the quality of dietary lipid and support the application of this model to investigations of human health and disease related to fat metabolism.

Electrocardiography is an important method for evaluation and risk stratification of patients with cardiac hypertrophy. We hypothesized that the recently developed transgenic mouse model of cardiac hypertrophy (ErbB2^tg) will display distinct ECG features, enabling WT (wild type) mice to be distinguished from transgenic mice without using conventional PCR genotyping. We evaluated more than 2000 mice and developed specific criteria for genotype determination by using cageside ECG, during which unanesthetized mice were manually restrained for less than 1 min. Compared with those from WT counterparts, the ECG recordings of ErbB2^tg mice were characterized by higher P- and R-wave amplitudes, broader QRS complexes, inverted T waves, and ST interval depression. Pearson's correlation matrix analysis of combined WT and ErbB2^tg data revealed significant correlation between heart weight and the ECG parameters of QT interval (corrected for heart rate), QRS interval, ST height, R amplitude, P amplitude, and PR interval. In addition, the left ventricular posterior wall thickness as determined by echocardiography correlated with ECG-determined ST height, R amplitude, QRS interval; echocardiographic left ventricular mass correlated with ECG-determined ST height and PR interval. In summary, we have determined phenotypic ECG criteria to differentiate ErbB2^tg from WT genotypes in 98.8% of mice. This inexpensive and time-efficient ECG-based phenotypic method might be applied to differentiate between genotypes in other rodent models of cardiac hypertrophy. Furthermore, with appropriate modifications, this method might be translated for use in other species.

Uremia due to chronic kidney disease (CKD) in humans is associated with immune dysfunction, increased susceptibility to infections, immune-activation–associated inflammation, and poor responses to vaccines. The pathophysiologic basis of these immune defects is hypothesized to be associated with a wide range of immunologic abnormalities, including an inability to sufficiently express the B7 family (B7-1, CD80; B7-2, CD86) of T-cell costimulatory molecules. However, testing the hypothesis that a state of chronic uremia contributes to attenuated expression of CD80 or CD86 has been difficult because few animal models faithfully recapitulate the immune defects observed in human CKD patients. We used a humanized mouse in a model of surgically induced renal failure and secondary chronic uremia to evaluate the effect of uremia on the expression of these markers. In a manner that resembles the changes observed in CKD patients, surgically induced CKD in mice resulted in decreased costimulatory CD86 expression compared with that in sham-operated controls. Immunodeficiency was functionally demonstrated in this mouse model by documenting an attenuated immune response to a cholera-toxin–based hepatitis B vaccine. This model will be useful for investigating the mechanisms involved in chronic uremia-associated immunodeficiency, poor response to vaccination, and problems associated with immunization of CKD patients.

Infection with respiratory syncytial virus (RSV) generally presents as a mild, upper airway disease in human patients but may cause severe lower airway disease in the very young and very old. Progress toward understanding the mechanisms of RSV pathogenesis has been hampered by a lack of relevant rodent models. Mice, the species most commonly used in RSV research, are resistant to upper respiratory infection and do not recapitulate the pattern of virus spread in the human host. To address the need for better rodent models of RSV infection, we have characterized the acute and chronic pathology of RSV infection of a relatively permissive host, cotton rats (Sigmodon hispidus). We demonstrate that virus delivered to the upper airway results in widespread RSV replication in the ciliated respiratory epithelial cells of the nasal cavity and, to a lesser extent, of the lung. Although acute inflammation is relatively mild and rapidly eliminated after viral clearance, chronic, eosinophilic lung pathology persists. These data support the use of cotton rats as a robust rodent model of human RSV disease, including the association between RSV pneumonia and subsequent development of allergic asthma.

An experimentally naïve 37.7-kg Yorkshire-crossbred gilt died unexpectedly 2 d after arrival. Necropsy revealed severe dilated cardiomyopathy characterized grossly by markedly dilated ventricles and thinned ventricular walls and interventricular septum. Histologically there was multifocal myofiber attenuation and patchy loss of myofiber cross striations. The liver contained submassive to massive, diffuse hepatic centrilobular hemorrhage and degeneration. These lesions supported a diagnosis of dilated cardiomyopathy with right heart failure and secondary hepatic degeneration due to marked acute passive congestion. To our knowledge, this case is the first report of spontaneous dilated cardiomyopathy in swine and represents a potential diagnostic challenge regarding the differentiation of the cardiac-associated liver lesion from hepatosis dietetica. The diagnosis of dilated cardiomyopathy and right-sided heart failure was supported by the character of the hepatic lesion, absence of typical gross or histologic lesions of mulberry heart disease, and normal selenium levels.

Göttingen minipigs are a useful model for diseases having an inflammatory component, and the associated use of acute-phase proteins (APP) as biomarkers of inflammation warrants establishment of their reference ranges. The objective of this study was to establish reference values for selected APP in Göttingen minipigs and to investigate the effects of age, sex, and various stimuli on these ranges. Serum concentrations of C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin, pig major acute-phase protein (PMAP), albumin, and porcine α-1 acid glycoprotein (PAGP) were evaluated in 4 age groups (6, 16, 24 and 40–48 wk) of male and female Göttingen minipigs. In addition, minipigs were tested under 2 housing conditions, after acute LPS challenge, and after diet-induced obesity with and without mild diabetes. Changing the pigs to a new environment induced significant increases in CRP, PMAP, haptoglobin and PAGP and a decrease in albumin. An acute LPS stimulus increased CRP, PMAP, haptoglobin, and SAA; PAGP was unchanged and albumin decreased. Obese pigs with and without diabetes showed increases in CRP and PAGP, albumin decreased, and haptoglobin and SAA were unchanged. PMAP was increased only in obese pigs without diabetes. In conclusion, reference values for CRP, PMAP, haptoglobin, SAA, PAGP and albumin were established for male and female Göttingen minipigs of different ages. These APP were influenced by age and sex, underlining the importance of considering these factors when designing and interpreting studies including aspects of inflammation. In addition, an APP response was verified after both acute and chronic stimuli.

The objective of this project was to develop and test a new technology for imaging growing joints by means of diffraction-enhanced imaging (DEI) combined with CT and using a synchrotron radiation source. DEI–CT images of an explanted 4-wk-old piglet stifle joint were acquired by using a 40-keV beam. The series of scanned slices was later 'stitched' together, forming a 3D dataset. High-resolution DEI-CT images demonstrated fine detail within all joint structures and tissues. Striking detail of vasculature traversing between bone and cartilage, a characteristic of growing but not mature joints, was demonstrated. This report documents for the first time that DEI combined with CT and a synchrotron radiation source can generate more detailed images of intact, growing joints than can currently available conventional imaging modalities.

A 20-y-old, male, ring-tailed lemur (Lemur catta) presented with a large, firm mass on the proximal caudolateral left femur. The animal displayed no clinical signs associated with the mass. Radiographs revealed a mineralized mass protruding from the femur, with an intact femoral cortex. Histopathology diagnosed osteochondroma in view of the presence of a peripheral layer of cartilage with progressive endochondral ossification and typical remodeling of bony trabeculae. The mass grew quickly after the initial biopsy, and a second surgery to debulk 95% of the tumor was performed. Histopathologic features of the larger samples were similar to those of the initial biopsies, with the cartilage layer being discontinuous and development of bone from some borders progressing directly from a periost-like layer. Nineteen months after the second surgery, the mass had regrown and extended further proximally on the femur toward the epiphysis, but the animal remained asymptomatic, and additional debulking was not attempted. This report is the first description of an osteochondroma in a prosimian and describes unique behavior of the tumor compared with osteochondromas found in humans, dogs, and cats.

A 5.5-y-old intact male cynomolgus macaque (Macaca fasicularis) presented with inappetence and weight loss 57 d after heterotopic heart and thymus transplantation while receiving an immunosuppressant regimen consisting of tacrolimus, mycophenolate mofetil, and methylprednisolone to prevent graft rejection. A serum chemistry panel, a glycated hemoglobin test, and urinalysis performed at presentation revealed elevated blood glucose and glycated hemoglobin (HbA1c) levels (727 mg/dL and 10.1%, respectively), glucosuria, and ketonuria. Diabetes mellitus was diagnosed, and insulin therapy was initiated immediately. The macaque was weaned off the immunosuppressive therapy as his clinical condition improved and stabilized. Approximately 74 d after discontinuation of the immunosuppressants, the blood glucose normalized, and the insulin therapy was stopped. The animal's blood glucose and HbA1c values have remained within normal limits since this time. We suspect that our macaque experienced new-onset diabetes mellitus after transplantation, a condition that is commonly observed in human transplant patients but not well described in NHP. To our knowledge, this report represents the first documented case of new-onset diabetes mellitus after transplantation in a cynomolgus macaque.