Leading the pack: Best practices in comparative canine cancer genomics to inform human oncology

Pet dogs develop spontaneous cancers at a rate estimated to be five times higher than that of humans, providing a unique opportunity to study disease biology and evaluate novel therapeutic strategies in a model system that possesses an intact immune system and mirrors key aspects of human cancer biology. Despite decades of interest, effective utilization of pet dog cancers has been hindered by a limited repertoire of necessary cellular and molecular reagents for both in vitro and in vivo studies, as well as a dearth of information regarding the genomic landscape of these cancers. Recently, many of these critical gaps have been addressed through the generation of a highly annotated canine reference genome, the creation of several tools necessary for multi-omic analysis of canine tumours, and the development of a centralized repository for key genomic and associated clinical information from canine cancer patients, the Integrated Canine Data Commons. Together, these advances have catalysed multidisciplinary efforts designed to integrate the study of pet dog cancers more effectively into the translational continuum, with the ultimate goal of improving human outcomes. The current review summarizes this recent progress and provides a guide to resources and tools available for comparative study of pet dog cancers.     

In vitro and in vivo germination of spores of Marssonina brunnea (Ell. et Ev.) P. Magn

A water soluble inhibitor of germination is present on the surfaces of freshly collected spores of Marssonina brunnea (Ell et Ev.) P. Magn. Spores of this pathogen have a high potential for germination even in the absence of external substrates. Among the poplar clones examined there was no correlation between spore germination on leaf discs and the disease reaction of the discs under controlled conditions. However under these conditions the disease development on leaf discs taken from clone I-69/55 was correlated with the high resistance of this clone to Marssonina leaf spot in the field.     

Temperature-light sensitivity of infection types expressed by cultivars of Populus deltoides Marsh. to races of Melampsora medusae Thüm.

Infection types were assessed when four cultivars of Populus deltoides Marsh. were inoculated with six races of Melampsora medusae Thüm. and incubated in combinations of light intensity (100, 500 and 1000 μEm^-2s^-1) and temperature (15 and 25°C). Resistance in the cultivars was always at a maximum when the race/cultivar complexes were incubated in the light intensity (1000 μ^-2s^-1)/high temperature (25°C) regime. Inereasing light intensity was generally associated with reduced infection type in the cultivars; the reduction was more pronounced in an incubation temperature of 25 than 15°C. The potential epidemiological significance of the results is discussed.     

Comparison of children's diets as reported by the child via the Youth/Adolescent Questionnaire and the parent via the Willett food-frequency questionnaire

OBJECTIVE: A comparison of a parent-completed Willett food-frequency questionnaire (FFQ) and a self-completed Youth/Adolescent Questionnaire (YAQ) has not yet been conducted. SETTING: In the Diabetes Autoimmunity Study in the Young (DAISY), parents report their child's diet on the FFQ annually from birth until age 10 years, when the child begins to report their own diet using the YAQ. SUBJECTS: To determine the comparability of these collection methods, 89 children aged 10-17 years and their parents completed the YAQ and FFQ, respectively, for the child's previous year's diet. DESIGN: We compared reported intakes for energy, the macronutrients and a variety of micronutrients of interest to the DAISY study. RESULTS: Bland-Altman plots of energy-adjusted differences between questionnaire responses against their means suggested that the two collection methods gave similar results. The average Spearman correlation coefficient of all energy-adjusted nutrient intakes was 0.50, and did not differ significantly by gender (males, r=0.48; females, r=0.46) or age (10-11 years, r=0.49; 12-17 years, r=0.51). While correlated, the nutrient values from the FFQ were higher than the nutrient values from the YAQ. CONCLUSIONS: While reported nutrient intakes are correlated, an indicator variable defining which survey method a nutrient was collected with should be included in any longitudinal data analyses examining nutrient intakes collected with the YAQ and the FFQ as independent predictors of a disease outcome.     

Adiposity, education and weight loss effort are independently associated with energy reporting quality in the Ontario Food Survey

OBJECTIVES: To examine the associations of adiposity, dietary restraint and other personal characteristics with energy reporting quality. DESIGN/SUBJECTS: Secondary analysis of 230 women and 158 men from the 1997/98 Ontario Food Survey. METHODS: Energy reporting quality was estimated by ratios of energy intake (EI) to both basal metabolic rate (BMR) and total energy expenditure (TEE). Multivariate regression analyses were conducted to examine energy reporting quality between two dietary recalls and in relation to body mass index (BMI) with adjustment for potential confounders. Energy reporting quality was explored across categories of age, BMI, income, education, dieting status and food insecurity through analysis of variance (ANOVA). RESULTS: From the ANOVA, energy reporting quality was associated with BMI group, age category and weight loss for men and women, as well as with education among women (P 0.05). EI:BMR and EI:TEE on the first and second 24-hour recalls were positively related (P < 0.0001 for men and women). A higher proportion of variance in energy reporting quality was explained for women than for men (R2 = 0.19 and 0.14, respectively). CONCLUSIONS: Studies of diet and adiposity are probably hindered to some extent by BMI-related variation in energy reporting quality. Methods to address this issue are urgently needed if population surveys will continue to serve as the primary source of dietary intake data.     

Detection of Erysiphe necator in Air Samples Using the Polymerase Chain Reaction and Species-Specific Primers

ABSTRACT A polymerase chain reaction (PCR) assay employing species-specific primers was developed to differentiate Erysiphe necator from other powdery mildews common in the northwest United States. DNA was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a Burkard cyclonic surface sampler. To differentiate E. necator from other erysiphaeceous fungi, primer pairs Uncin144 and Uncin511 were developed to select unique sequences of the internal transcribed spacer regions of E. necator. Using these primers in PCR amplifications, a 367-bp amplicon specific to E. necator was generated, but no amplicons were generated from other erysiphaceous species collected from 48 disparate hosts representing 26 vascular plant families. The PCR limit of detection was one to five conidia of E. necator placed directly into reaction mixtures or 100 to 250 conidia placed on glass rods coated with silicon grease. During field studies, this PCR assay facilitated the detection of E. necator inoculum in air samples within hours of sample rod collection and prior to disease onset. Amplification of E. necator DNA did not occur when the PCR assay was conducted on vineyard air samples collected while grapes were dormant or during periods when vine growth occurred but E. necator remained dormant. The initial PCR detection of E. necator of the season occurred during seasonal ascospore releases caused by precipitation events between bud burst and the prebloom period during the 3 years of the study. Detection ceased for 7 to 11 days following ascospore release and then resumed several days prior to the observance of microscopic symptoms and signs of powdery mildew in the field. Results of this study represent the initial step toward the goal of incorporating an inoculum availability component into current and future grapevine powdery mildew risk assessment models.     

Immune response to Sarcocystis neurona infection in naturally infected horses with equine protozoal myeloencephalitis

Equine protozoal myeloencephalitis (EPM) is one of the most common neurologic diseases of horses in the United States. The primary etiologic agent is Sarcocystis neurona. Currently, there is limited knowledge regarding the protective or pathophysiologic immune response to S. neurona infection or the subsequent development of EPM. The objectives of this study were to determine whether S. neurona infected horses with clinical signs of EPM had altered or suppressed immune responses compared to neurologically normal horses and if blood sample storage would influence these findings. Twenty clinically normal horses and 22 horses with EPM, diagnosed by the presence of S. neurona specific antibodies in the serum and/or cerebrospinal (CSF) and clinical signs, were evaluated for differences in the immune cell subsets and function. Our results demonstrated that naturally infected horses had significantly (P<0.05) higher percentages of CD4 T-lymphocytes and neutrophils (PMN) in separated peripheral blood leukocytes than clinically normal horses. Leukocytes from naturally infected EPM horses had significantly lower proliferation responses, as measured by thymidine incorporation, to a non-antigen specific mitogen than did clinically normal horses (P<0.05). Currently, studies are in progress to determine the role of CD4 T cells in disease and protection against S. neurona in horses, as well as to determine the mechanism associated with suppressed in vitro proliferation responses. Finally, overnight storage of blood samples appears to alter T lymphocyte phenotypes and viability among leukocytes.     

Oceanographic basis of the global surface distribution of Prochlorococcus ecotypes

By using data collected during a continuous circumnavigation of the Southern Hemisphere, we observed clear patterns in the population-genetic structure of Prochlorococcus, the most abundant photosynthetic organism on Earth, between and within the three Southern Subtropical Gyres. The same mechanisms that were previously invoked to account for the vertical distribution of ecotypes at local scales accounted for the global (horizontal) patterns we observed. Basin-scale and seasonal variations in the structure and strength of vertical stratification provide a basis for understanding large-scale horizontal distribution in genetic and physiological traits of Prochlorococcus, and perhaps of marine microbial communities in general.