Canine ocular histiocytic sarcoma

OBJECTIVE: To describe and characterize histiocytic sarcoma (HS) first detected in the eyes of dogs using the large database at the comparative ocular pathology laboratory of Wisconsin (COPLOW). METHODS: Cases diagnosed as HS were selected from the COPLOW database. Slides were reviewed to describe the cellular morphology, localize the tumor within the globe, record the tumor distribution and measure the size of the tumor. Further sections were taken to perform immunohistochemistry for Melan-A, CD18 and S-100, and for ferric iron staining. The following clinical information was recorded: breed, age, gender, laterality, clinical signs upon presentation and follow-up information obtained by response to a mailed survey and phone contact. RESULTS: Twenty-six cases were confirmed as being HS according to the immunohistochemical results (CD18 positive and Melan-A negative). The most prevalent breed was Rottweiler (eight cases), followed by Retriever breeds (seven Golden Retrievers and five Labrador Retrievers). The mean age was 8.61 +/- 2.43 years. There were three intact male, eight castrated male, one intact female and 14 spayed female dogs. In 15 dogs there were no concurrent systemic clinical signs at the time of diagnosis. Sixteen of 19 dogs with follow-up information available died as a result of causes related to the tumor, although only three of them received a necropsy. Survival time varied between 5 days and 6 months after enucleation. Three of the dogs were alive at the time the information was gathered. Mean tumor surface was 0.613 +/- 0.38 cm(2). S-100 was diffusely positive in 10 cases, isolated positive cells were found in 11 cases and five cases were completely negative. Seven of the cases were positive for ferric iron. CONCLUSIONS: Histiocytic sarcoma must be considered in the differential diagnosis of dogs with intraocular masses, especially in Rottweilers and Retriever breeds. Because it carries poor prognosis, it must be distinguished from melanoma. A good discriminator for this purpose in paraffin-embedded tissues is finding CD18-positive cells and no reactivity against Melan-A. S-100 and ferric iron staining does not seem to be useful. Ocular HS is considered to be a manifestation of a systemic disease even when the disease is first recognized in the eye.     

Differentiating between analytical and diagnostic performance evaluation with a focus on the method comparison study and identification of bias

Prior to introduction of a new method to the diagnostic laboratory, analytical performance must be validated to ensure operation within the manufacturer's specifications and/or within predetermined quality requirements. In addition, the new method may require diagnostic performance assessment to ensure it differentiates between diseased and nondiseased individuals as intended. These 2 phases of assessment, while complementary, are not equivalent and require a different set of experiments, statistical analyses, and interpretation. Studies of analytical performance typically include a method comparison experiment, the purpose of which is to identify bias (inaccuracy) of the “test” (or “index”) method (new method) relative to a “comparative method” (established method). Analysis of method comparison data is facilitated by commercial software programs that present the statistical significance of identified bias; however, the clinical relevance of any bias also should be considered. Studies of diagnostic performance should not be pursued until analytical performance is fully characterized and may not be required for well‐established tests or for those for which results are nonspecific (ie, not referable to a specific disease or condition). Diagnostic performance assessment may include assessment of sensitivity, specificity, predictive values, odds ratios, and/or likelihood ratios. The purpose of this review is to clarify differences between the assessment of analytical and diagnostic performance, and to explore the method comparison study and bias assessment from a perspective not addressed in prior veterinary articles.     

On a razor's edge: Status and prospects of the critically endangered Bellinger River snapping turtle,Myuchelys georgesi

1. In the summer and autumn of 2015, the Bellinger River snapping turtle (Myuchelys georgesi), a narrow‐range endemic of eastern New South Wales, Australia, suffered mass mortality from epidemic disease, apparently caused by a previously unknown virus. Information on the current population size and structure of M. georgesi, and the body condition and growth of the surviving individuals, is needed to support planning of conservation actions. Population estimates are also needed for a sympatric population of the widely distributed Macquarie turtle (Emydura macquarii), which has probably been introduced to the Bellinger River and may threaten the persistence of M. georgesi through hybridization, competition, and disease transmission.
2. Data from five turtle surveys between November 2015 and November 2018 were used to estimate populations of the two species in the Bellinger River by an analysis based on habitat extent and turtle detectability. Changes in the body condition of M. georgesi and the body growth of both species were also assessed.
3. Current populations of ~150 M. georgesi and ~500 E. macquarii are indicated, although the uncertainty of these estimates is high. The estimate for M. georgesi represents a decline of >90% from the historical population. Moreover, about 88% of the surviving M. georgesi are immature, and only about 5% are mature females. However, the body condition of the survivors has improved recently. Growth models suggest that M. georgesi matures later than E. macquarii, which may provide the latter with a competitive advantage.
4. Evidence presented here does not support a previous hypothesis that M. georgesi were predisposed to disease through malnutrition and consequently reduced immune competence caused by high water temperatures and low river flows. Continuing disease, hybridization, and interspecific competition are probably the greatest threats to the persistence of the species.

     

Rare structural variants disrupt multiple genes in neurodevelopmental pathways in schizophrenia

Schizophrenia is a devastating neurodevelopmental disorder whose genetic influences remain elusive. We hypothesize that individually rare structural variants contribute to the illness. Microdeletions and microduplications >100 kilobases were identified by microarray comparative genomic hybridization of genomic DNA from 150 individuals with schizophrenia and 268 ancestry-matched controls. All variants were validated by high-resolution platforms. Novel deletions and duplications of genes were present in 5% of controls versus 15% of cases and 20% of young-onset cases, both highly significant differences. The association was independently replicated in patients with childhood-onset schizophrenia as compared with their parents. Mutations in cases disrupted genes disproportionately from signaling networks controlling neurodevelopment, including neuregulin and glutamate pathways. These results suggest that multiple, individually rare mutations altering genes in neurodevelopmental pathways contribute to schizophrenia.     

Sorption-desorption of imidacloprid and its metabolites in soil and vadose zone materials

Sorption-desorption is one of the most important processes affecting the leaching of pesticides through soil because it controls the amount of pesticide available for transport. Subsurface soil properties can significantly affect pesticide transport and the potential for groundwater contamination. This research characterized the sorption-desorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) and three of its metabolites, 1-[(6-chloro-3-pyridinyl)methyl]-2-imidazolidinone (imidacloprid-urea), 1-[(6-chloro-3-pyridinyl)methyl]-4,5-dihydro-1H-imidazol-2-amine (imidacloprid-guanidine), and 1-[(6-chloro-3-pyridinyl)methyl]-1H-imidazol-2-amine (imidacloprid-guanidine-olefin), as a function of changing soil properties with depth in two profiles extending from the surface to a depth of 1.8 or 8 m. Sorption of each compound was highly variable and hysteretic in all cases. Normalizing the sorption coefficients (K(f)) to the organic carbon or the clay content of the soil did not reduce the variability in sorption coefficients for any compound. These results illustrate the importance of evaluation of the sorption data used to predict potential mobility. Understanding the variability of soil properties and processes as a function of depth is necessary for accurate prediction of pesticide dissipation.     

Concentration of nitrite and nonthiol nitroso compounds in tissues as a high sensitive marker of leukocyte activity

This paper shows that the inflammation-induced appearance of nitrite and nonthiol nitroso compounds in the hen blood and cow milk is due to oxidation of dinitrosyl iron complexes (DNIC) and nitrosothiols (RSNO) by reactive oxygen species (ROS), which are produced by activated leukocytes. Since DNIC and RSNO are highly effective ROS scavengers, the content of nitrite and nonthiol nitroso compounds can be regarded as one of the most sensitive indicators of leukocyte activation.     

Monitoring Victoria’s public forests: implementation of the Victorian Forest Monitoring Program

A new strategic inventory across all publicly managed forests has been installed in Victoria. For the preceding two decades, Victoria’s forest inventory has been compiled from various data sources from across the state, an approach that doesn’t allow information about the nature and rate of changes to the resource to be estimated, or for projections or forecasts to be made. To address these limitations, the Victorian Forest Monitoring Program (VFMP) was established, to monitor Victoria’s progress in meeting a commitment towards sustainable forest management, and to satisfy requirements for state and national reporting. The purpose of the new program is to ‘assess and monitor the extent, state and sustainable development of Victoria’s public forests in a timely and accurate manner.’ The VFMP consists of a plot-based system of permanent observational units located on a state-wide grid. A combination of ground-based and aerial photo plots and remotely sensed data are used to capture a set of basic attributes that are used to derive indicators of sustainability. To meet the monitoring needs a remeasurement framework has been developed to guide the change estimation procedures. The program was designed and implemented between 2009 and 2015 and used to generate data and information for the most recent Victoria’s State of the Forest Report. The first annual change estimate is due to be completed in 2017. A summary of implementation and proposed maintenance is presented and discussed in this paper.     

Effects of Cover Crops on Soil Quality: Selected Chemical and Biological Parameters

Cover crops improve soil quality properties and thus land productivity. We compared soil chemical and biological changes influenced by hairy vetch (Vicia villosa Roth.) and cereal rye (Secale cereal) cover crops grown in Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs), Mexico silt loam (fine, smectitic, mesic Vertic Epiaqualfs), or sand in the greenhouse. Cover crop biomass, soil β-glucosidase, β-glucosaminidase, and fluorescein diacetate (FDA) hydrolase activities, and soil chemical properties were measured at six, nine, and twelve weeks after planting. Cover crop biomass increased with highest (p < 0.0001) yields for hairy vetch and cereal rye in Menfro and Mexico soils, respectively. β-glucosaminidase, FDA, organic carbon (C), total nitrogen (N), and total phosphorus (P) contents significantly decreased in all soils for both cover crops. However, β-glucosidase activity significantly increased (p < 0.0001). Long-term field studies are needed to evaluate soil quality improvement under cover crops, especially for soils with marginal organic matter and fertility.