Assessment of alterations in triglyceride and glycogen concentrations in muscle tissue of Alaskan sled dogs during repetitive prolonged exercise

OBJECTIVE: To assess changes in muscle glycogen (MG) and triglyceride (MT) concentrations in aerobically conditioned sled dogs during prolonged exercise. ANIMALS: 54 Alaskan sled dogs fed a high-fat diet. PROCEDURES: 48 dogs ran 140-km distances on 4 consecutive days (cumulative distance, up to 560 km); 6 dogs remained as nonexercising control animals. Muscle biopsies were performed immediately after running 140, 420, or 560 km (6 dogs each) and subsequently after feeding and 7 hours of rest. Single muscle biopsies were performed during recovery at 28 hours in 7 dogs that completed 560 km and at 50 and 98 hours in 7 and 6 dogs that completed 510 km, respectively. Tissue samples were analyzed for MG and MT concentrations. RESULTS: In control dogs, mean +/- SD MG and MT concentrations were 375 +/- 37 mmol/kg of dry weight (kgDW) and 25.9 +/- 10.3 mmol/kgDW, respectively. Compared with control values, MG concentration was lower after dogs completed 140 and 420 km (137 +/- 36 mmol/kgDW and 203 +/- 30 mmol/kgDW, respectively); MT concentration was lower after dogs completed 140, 420, and 560 km (7.4 +/- 5.4 mmol/kgDW; 9.6 +/- 6.9 mmol/kgDW, and 6.3 +/- 4.9 mmol/kgDW, respectively). Depletion rates during the first run exceeded rates during the final run. Replenishment rates during recovery periods were not different, regardless of distance; only MG concentration at 50 hours was significantly greater than the control value. CONCLUSIONS AND CLINICAL RELEVANCE: Concentration of MG progressively increased in sled dogs undergoing prolonged exercise as a result of attenuated depletion.     

Turkey origin reovirus-induced immune dysfunction in specific pathogen free and commercial turkey poults

Recently, pathogenesis studies, using genetically distinct turkey-origin reoviruses (TRVs), revealed that poults infected with certain TRV isolates had moderate to severe bursal atrophy, suggesting virus-induced immune dysfunction. In order to characterize the effect of TRV infection on the turkey immune system, classical assays were undertaken to quantify the humoral and cell-mediated immune responses in small Beltsville and broad-breasted white poults infected with the TRV isolate NC/SEP-R44/03. A marked effect on the cutaneous basophil hypersensitivity response, and on the antibody response to Newcastle disease virus (NDV) exposure, was noted in commercial and specific pathogen free (SPF) poults inoculated with NC/SEP-R44/03 at three days of age. Moderate to severe bursal atrophy, similar to that noted previously in SPF poults, occurred in commercial poults inoculated at three days of age. This immune dysfunction and bursal atrophy was not present in commercial poults inoculated at three weeks of age.     

Localization and genotyping of canine papillomavirus in canine inverted papillomas

Numerous canine papillomaviruses (CPVs) have been identified (CPV1–23). CPV1, 2, and 6 have been associated with inverted papillomas (IPs). We retrieved 19 IPs from 3 histopathology archives, and evaluated and scored koilocytes, inclusion bodies, giant keratohyalin granules, cytoplasmic pallor, ballooning degeneration, and parakeratosis. IHC targeting major capsid proteins of PV was performed, and CPV genotyping was achieved by PCR testing. Tissue localization of CPV DNA and RNA was studied by chromogenic and RNAscope in situ hybridization (DNA-CISH, RNA-ISH, respectively). IPs were localized to the limbs (50%), trunk (30%), and head (20%), mainly as single nodules (16 of 19). In 15 of 19 cases, immunopositivity was detected within the nuclei in corneal and subcorneal epidermal layers. PCR revealed CPV1 in 11 IPs and CPV2 DNA in 3 IPs. Overall, 14 of 17 cases were positive by both DNA-CISH and RNA-ISH, in accord with PCR results. A histologic score >5 was always obtained in cases in which the viral etiology was demonstrated by IHC, DNA-CISH, and RNA-ISH. IHC and molecular approaches were useful to ascertain the viral etiology of IPs. Although IHC is the first choice for diagnostic purposes, ISH testing allows identification of PV type and the infection phase. RNA-ISH seems a promising tool to deepen our understanding of the pathogenesis of different PV types in animal species.     

Abrupt decrease in tropical Pacific sea surface salinity at end of Little Ice Age

A 420-year history of strontium/calcium, uranium/calcium, and oxygen isotope ratios in eight coral cores from the Great Barrier Reef, Australia, indicates that sea surface temperature and salinity were higher in the 18th century than in the 20th century. An abrupt freshening after 1870 occurred simultaneously throughout the southwestern Pacific, coinciding with cooling tropical temperatures. Higher salinities between 1565 and 1870 are best explained by a combination of advection and wind-induced evaporation resulting from a strong latitudinal temperature gradient and intensified circulation. The global Little Ice Age glacial expansion may have been driven, in part, by greater poleward transport of water vapor from the tropical Pacific.     

The mutational landscape of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a common, morbid, and frequently lethal malignancy. To uncover its mutational spectrum, we analyzed whole-exome sequencing data from 74 tumor-normal pairs. The majority exhibited a mutational profile consistent with tobacco exposure; human papillomavirus was detectable by sequencing DNA from infected tumors. In addition to identifying previously known HNSCC genes (TP53, CDKN2A, PTEN, PIK3CA, and HRAS), our analysis revealed many genes not previously implicated in this malignancy. At least 30% of cases harbored mutations in genes that regulate squamous differentiation (for example, NOTCH1, IRF6, and TP63), implicating its dysregulation as a major driver of HNSCC carcinogenesis. More generally, the results indicate the ability of large-scale sequencing to reveal fundamental tumorigenic mechanisms.     

Blood and bone marrow findings in two pups with mucopolysaccharidosis type VII

Routine blood smear findings in two of four 11‐day‐old mixed‐breed dog littermates were suggestive of a lysosomal storage disease (LSD) that was documented to be mucopolysaccharidosis type VII (MPS VII) by molecular testing. In this condition, a functional β‐glucuronidase deficiency results in the accumulation of glycosaminoglycans (GAGs) in cells and tissues where β‐glucuronidase is important in GAG degradation. Most neutrophils and a moderate number of lymphocytes within the blood had atypical cytoplasmic magenta inclusions. The bone marrow assessment from one of the two affected pups at 24 days of age revealed similar magenta granulation in myeloid precursor cells that was most prominent in promyelocytes and myelocytes. Moreover, atypical magenta material was present within vacuoles as well as extracellularly in some osteoblasts and macrophages. Histologic bone marrow sections revealed prominent vacuolation of osteoblasts, and some osteoclasts appeared separated from the bone by layers of osteoblasts or hematopoietic cells. At 2 months of age, the second affected dog showed moderate growth retardation and had similar but more prominent hematologic findings that extended to monocytes, eosinophils, and eosinophil precursors. It had an increased number of bone marrow macrophages with many vacuoles that could be seen cytologically to contain magenta material, and there was mild nonselective phagocytosis of hemic cells. Of the hematologic cells, inclusions were most prominent in promyelocytes, myelocytes, and macrophages, cells with relatively high β‐glucuronidase activity, and GAG exposure within lysosomes or lysosome‐like primary granules of granulocyte precursors.     

Retrospective and prospective studies of transmissible viral proventriculitis in broiler chickens in Brazil

We investigated the occurrence and pathologic findings of transmissible viral proventriculitis (TVP) associated with the chicken proventricular necrosis virus (CPNV) in commercial broiler chickens in southeastern Brazil. Seventy-three broilers, 25–36 d old, with a history of reduced growth, were referred to our veterinary pathology services from 2013 to 2017. Broilers were clinically examined, weighed, and euthanized for postmortem examination. Broilers of different ages with proventricular histologic lesions were positive for CPNV by RT-PCR; however, the intensity of histologic lesions was higher among 33-d-old animals, and viral RNA detection was more frequent among those that were 28 d old. In the proventriculi of 35 of 73 (48%) broilers, lesions were characterized by glandular epithelial necrosis, lymphoplasmacytic and histiocytic infiltrates, and metaplasia of glandular epithelium to ductal epithelium. In 24 of 73 (36%) broilers with histologic TVP-compatible lesions, CPNV was detected by RT-PCR for the viral protein 1 (VP1) gene. Broilers with histologic lesions were lighter than expected compared to the Cobb 500 standard weight. TVP has not been reported previously in broiler chickens in Brazil, to our knowledge.     

Variation in NH4 mineralization and microbial communities with stand age in lodgepole pine (Pinus contorta) forests, Yellowstone National Park (USA)

Soils and vegetation were analyzed in 20 lodgepole pine (Pinus contorta) forest stands, varying in age from 50 to 350 years, that had initiated following stand-replacing fire. Our goal was to determine how nitrogen availability (NH₄⁺-N) and microbial community composition varied with stand age-class and to determine whether differences could be explained by canopy, soil, or understory characteristics. Gross NH₄⁺ mineralization was measured using laboratory isotopic pool dilution, and microbial community composition was evaluated using microbial membrane lipids. The microbial community composition of stands in the 300-350 age class was distinct from stands in younger age classes. Microbial community composition among sites varied with pH, % organic matter, and phosphorus. Gross NH₄⁺ mineralization rates averaged 1.45±0.07 mg NH₄⁺ kg soil⁻¹ d⁻¹ while consumption averaged 1.37±0.20 mg NH₄⁺ kg soil⁻¹ d⁻¹, resulting in low net NH₄⁺ mineralization rates (0.08±0.18 mg NH₄⁺ kg soil⁻¹ d⁻¹), but rates were not significantly different with stand age-class at p<0.05. At p<0.10, net NH₄⁺ mineralization was significantly higher in the 300-350 age class compared to the 125-175 age class. None of the measured variables significantly explained NH₄⁺ consumption and net mineralization patterns. However, gross NH₄⁺ mineralization rates were best explained by information on microbial community structure (i.e. lipids). Variation among stands within a given age-classes was high, indicating that patterns of N cycling across landscapes reflect substantial heterogeneity among mature stands.