Imaging diagnosis--lack of contrast enhancement in metastatic cerebral adenocarcinoma

A 7-year-old female spayed Scottish Terrier was presented with central nervous system symptoms suggestive of a lesion in the forebrain. Magnetic resonance (MR) imaging revealed multifocal disease in the forebrain. Because of complete lack of contrast enhancement, the changes were attributed to lesions of inflammatory origin. Histopathology of the brain revealed multiple metastatic lesions of an adenocarcinoma. Brain metastases in general show contrast enhancement. The reason for a complete absence of contrast enhancement is unknown. Previous administration of corticosteroids, increased diffusion time of contrast medium, increased intracranial pressure in combination with an intact blood-tumor barrier is discussed as possible reasons.     

How timing of stem girdling affects needle xylem structure in Scots pine

While needles represent a proportionally large fraction of whole-plant hydraulic resistance, no studies to date have investigated how source–sink disturbances affect needle xylem structure. In this study, we evaluated structural changes in xylem in current-year needles of Scots pine 227 and 411 days after stem girdling (hereafter referred to as DAG). Maximum and minimum tracheid lumen diameters and therefore also the size of tracheid lumen areas increased in needles 227 DAG compared to control needles. In contrast, tracheid dimensions were similar in needles 411 DAG as in the control needles, but smaller xylem area and lower number of tracheids resulted in the lower theoretical needle hydraulic conductivity of those needles. Several needle xylem parameters were intercorrelated in both control and girdled trees. These observed changes provide a new understanding of the processes that occur following a source–sink disturbance. Considering anatomical parameters such as the number of tracheids, tracheid dimension, or needle xylem area, which are rarely described in physiological studies, could be helpful, for example, in understanding to tree hydraulic systems or for modeling gas exchange. Finally, empirical equations were developed to calculate needle theoretical hydraulic conductivity and the number of tracheids in needles using an easily measurable parameter of needle xylem area.     

Comparison of the effects of an intravenous lidocaine infusion combined with 1% isoflurane versus 2% isoflurane alone on selected cardiovascular variables and recovery characteristics during equine general anaesthesia

Objectives

To compare the effects of a lidocaine constant rate infusion (CRI) combined with 1% isoflurane versus those of 2% isoflurane alone on cardiovascular variables in anaesthetized horses, and to estimate the sample size required to detect a difference in recovery quality.

Distribution of three indigenous fern species along a rural–urban gradient in the city of Angers, France

The preservation of wild plants and animals in urban environments can be a good means to meet the demand for natural areas for recreational purposes. However, the impacts of urbanisation on native species distribution are poorly studied. A city environment has high impact on vegetal community dynamics, especially in terms of climate modification, level of perturbationand pattern of dispersion. We chose to study the three indigenous species of the genus Polypodium that are known to grow in a wide range of habitats, including forest and urban environments, and exhibit a priori a strong ability for dispersal. The aim of the study was to evaluate the factors involved in the Polypodium species distribution and to determine whether this distribution was influenced by the rural–urban gradient. The distribution of the three fern species was investigated in the city of Angers (France) at two levels: for a park (urban woodland) and for the whole city. A contrasted distribution of the three Polypodies has been recorded and shows a rural–urban gradient. This can be explained by the ecology of each species and some biological traits. It means that differences in the spatial structure of the city lead to particular patterns of distribution for these plants. Thus, preserved indigenous vegetation may be influenced in its species composition by the surrounding urban development.     

Concentration of ivermectin in bovine serum and its effect on the fecundity of psoroptic mange mites

The concentration-time profile of ivermectin in serum was determined for 3 Hereford heifers. The mean maximum serum concentration, 29 ng of ivermectin/ml, was obtained 48 hours after single subcutaneous injection of 200 micrograms/kg of body weight. The fecundity of mites placed on 9 treated animals at 5, 9, 12, 15, 18, and 21 days after injection was reduced by 96% to 99%. At 24 days after treatment, when serum concentration had decreased to about 2 ng/ml, the capability of mites to produce eggs increased to 50% of mites from nontreated calves. At 27 and 30 days after the drug was injected, egg production by mites on treated calves was equivalent to that of mites on nontreated calves. The reduced fecundity resulted from an almost complete cessation of oviposition by females after only a 1-day exposure to ivermectin-treated calves.     

Parasite control in Canadian companion animal shelters and a cost-comparison of anthelmintics

Animal shelters have limited resources and must accommodate large numbers of animals at unpredictable intake rates. These dogs and cats are often parasitized, which can adversely affect the health of animals and expose shelter workers and adoptive owners to zoonoses. We analyzed survey responses from rural (n = 32) and urban (n = 50) companion animal shelters across Canada, and compared the wholesale cost of commercially available anthelmintics to identify cost-effective methods of managing parasites within shelters. Almost all shelters employed nematocides (98% to 99%), but cestocides and ectoparasiticides were used less frequently. Shelters identified cost as an important consideration in choosing to perform fecal diagnostic testing and administer anthelmintics, and this motivated many shelters to selectively perform testing (66%) or never to test (32%), and to use drugs extralabel (80%).     

Environmental DNA as a non‐invasive sampling tool to detect the spawning distribution of European anadromous shads (Alosa spp.)

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