Neuroblastoma with neuronal differentiation in the spinal cord in an Aberdeen Angus heifer calf

A 5-month-old, female, Aberdeen Angus heifer presented to the veterinary medical teaching hospital for evaluation of slowly progressive hindlimb ataxia. The calf was clinically normal until 4 months of age, following routine pregnancy and delivery. Neurologic examination revealed marked symmetric spastic hindlimb paraparesis. Thoracolumbar radiographs and cerebrospinal fluid (CSF) analysis were unremarkable. A presumptive diagnosis of T3-L3 myelopathy was made, and neurologic status remained static for 3 months with broad-spectrum antibiotic and nonsteroidal anti-inflammatory therapy. Additional diagnostic tests were refused, and a necropsy was performed following euthanasia. A moderately well delineated, reddish-tan, soft mass 18 mm in diameter replaced 80% of the fourth lumbar spinal cord segment. Histologic examination revealed two distinct features: undifferentiated, primitive, polygonal-to-round cells with typical morphologic characteristics of primitive neuroectoderm; and interspersed areas containing myelinated axons and cells with neuronal differentiation. Immunohistochemical examination confirmed the presence of primitive neuroepithelium and cells with neuronal differentiation.     

Measurement of hydraulic characteristics of porous media used to grow plants in microgravity

Understanding the effect of gravity on hydraulic properties of plant growth medium is essential for growing plants in space. The suitability of existing models to simulate hydraulic properties of porous medium is uncertain due to limited understanding of fundamental mechanisms controlling water and air transport in microgravity. The objective of this research was to characterize saturated and unsaturated hydraulic conductivity (K) of two particle-size distributions of baked ceramic aggregate using direct measurement techniques compatible with microgravity. Steady state (Method A) and instantaneous profile measurement (Method B) methods for K were used in a single experimental unit with horizontal flow through thin sections of porous medium providing an earth-based analog to microgravity. Comparison between methods was conducted using a crossover experimental design compatible with limited resources of space flight. Satiated (natural saturation) K ranged from 0.09 to 0.12 cm s-1 and 0.5 to >1 cm s-1 for 0.25- to 1- and 1- to 2-mm media, respectively. The K at the interaggregate/intraaggregate transition was approximately 10(-4) cm s-1 for both particle-size distributions. Significant differences in log(10)K due to method and porous medium were less than one order of magnitude and were attributed to variability in air entrapment. The van Genuchten/Mualem parametric models provided an adequate prediction of K of the interaggregate pore space, using residual water content for that pore space. The instantaneous profile method covers the range of water contents relevant to plant growth using fewer resources than Method A, all advantages for space flight where mass, volume, and astronaut time are limited.     

Suppressiveness of 18 composts against 7 pathosystems: Variability in pathogen response

Compost is often reported as a substrate that is able to suppress soilborne plant pathogens, but suppression varies according to the type of compost and pathosystem. Reports often deal with a single pathogen while in reality crops are attacked by multiple plant pathogens. The goal of the present study was to evaluate the disease suppression ability of a wide range of composts for a range of plant pathogens. This study was conducted by a consortium of researchers from several European countries. Composts originated from different countries and source materials including green and yard waste, straw, bark, biowaste and municipal sewage. Suppressiveness of compost-amended (20% vol./vol.) peat-based potting soil was determined against Verticillium dahliae on eggplant, Rhizoctonia solani on cauliflower, Phytophthora nicotianae on tomato, Phytophthora cinnamomi on lupin and Cylindrocladium spathiphylli on Spathiphyllum sp., and of compost-amended loamy soil (20% vol./vol.) against R. solani on Pinus sylvestris and Fusarium oxysporum f. sp. lini on flax. From the 120 bioassays involving 18 composts and 7 pathosystems, significant disease suppression was found in 54% of the cases while only 3% of the cases showed significant disease enhancement. Pathogens were affected differently by the composts. In general, prediction of disease suppression was better when parameters derived from the compost mixes were used rather than those derived from the pure composts. Regression analyses of disease suppression of the individual pathogens with parameters of compost-amended peat-based mixes revealed the following groupings: (1) competition-sensitive: F. oxysporum and R. solani/cauliflower; (2) rhizosphere-affected: V. dahliae; (3) pH-related: P. nicotianae; and (4) specific/unknown: R. solani/pine, P. cinnamomi and C. spathiphylli. It was concluded that application of compost has in general a positive or no effect on disease suppression, and only rarely a disease stimulating effect.     

Diapause induction in field populations of the codling moth,Cydia Pomonella,in Northern Israel

Diapause induction in field populations of the codling moth,Cydia pomonella L., was studied for three consecutive seasons (1984–86) in two commercial apple orchards in Upper Galilee. One orchard was located in the Hula Valley and the other in the high mountain region. The onset of diapause sometimes occurred during increasing day-length, before the summer solstice. This phenomenon represents a small proportion of the population which is probably genetically univoltine. The critical photoperiod which induces 50% diapause (= CPhP₅₀) varied up to 5 days within the valley region, up to 6 days within the mountain region, and up to 7 days between the two regions. The trend of this variation was consistent: the CPhP₅₀ of the valley poulation preceded that of the mountain on both ‘Jonathan’ and ‘Granny Smith’ apple varieties and, within each location, the CPhP₅₀ on the early-ripening ‘Jonathan’ preceded that of the late-ripening ‘Granny Smith’. The higher prediapause temperatures of the Hula Valley caused earlier diapause induction as compared with the lower temperatures of the mountain region. Immature fruits delayed diapause induction in comparison with mature ones.     

Dynamics of the free-living stages of sheep intestinal parasites on pasture in the North Island of New Zealand. 1. Patterns of seasonal development

Abstract

AIM: To describe the seasonal pattern of development of third-stage infective larvae (L3) from eggs of Teladorsagia (=Ostertagia) circumcincta, Trichostrongylus colubriformis and Haemonchus contortus on pasture in the North Island of New Zealand.

METHODS: Sheep faeces containing known numbers of eggs of all three nematode species were deposited on, or buried in, pasture plots at three sites, viz coastal Manawatu, Upper Hutt Valley, and East Cape hill country. Development was measured by recovering L3 from faeces, herbage and soil 28–31 days after deposition on 13–18 occasions, between January 2005 and July 2006. Analysis of the number of larvae recovered used a mixed model including number of eggs deposited, weight of faeces recovered (an assumed indicator of earthworm activity), site, contamination date, and position of deposited faeces, i.e. on the surface or buried.

RESULTS: There was a significant effect of contamination date on development of all three species, with maximum numbers ofL3 developing between late spring (November) and early autumn (March), and minimum numbers in June and July. There were large differences between species, with H. contortus exhibiting a long period (April to October) where development was close to zero, whereas T. circumcincta developed to some extent all year round. Development of T. colubriformis was intermediate between the other two species.

Burying faeces containing nematode eggs increased the number of L3 recovered compared with surface deposition (p≤0.001), although there were a small number of exceptions involving only T. colubriformis. The weight of faeces recovered at harvest, which was assumed to be an indication of earthworm activity, was correlated with the number of L3 recovered for all species (p<0.001). In a separate analysis, earthworms were assumed tohave been active if <5 g faeces remained at harvest. Where this occurred, the number of L3 of T. colubriformis and T.circumcincta recovered was reduced by 56% and 58%, respectively (p<0.001).

CONCLUSIONS: A marked seasonal pattern of development was observed for all three species, with the most larvae developing in spring-early autumn and the least in winter. This seasonal pattern was most pronounced in H. contortus and least obvious in T. circumcincta. Burying faeces containing eggs generally resulted in more L3 being recovered, whilst the apparent activity of earthworms resulted in fewer larvae being recovered.     

Retrospective study of tetanus in 20 dogs: 1988-2004

The case records of 20 dogs that were treated for tetanus between 1988 and 2004 were reviewed. Young, large-breed dogs were most commonly affected. Twelve dogs had a likely source of infection identified. All dogs were treated with intravenous antibiotics and supportive care, such as muscle relaxants and sedation for muscle tremors and rigidity. Sixteen dogs received tetanus antitoxin. The mortality rate was 50%. Complete recovery in survivors required approximately 1 month.     

Discontinuous pore fluid distribution under microgravity--KC-135 flight investigations

Designing a reliable plant growth system for crop production in space requires the understanding of pore fluid distribution in porous media under microgravity. The objective of this experimental investigation, which was conducted aboard NASA KC-135 reduced gravity flight, is to study possible particle separation and the distribution of discontinuous wetting fluid in porous media under microgravity. KC-135 aircraft provided gravity conditions of 1, 1.8, and 10(-2) g. Glass beads of a known size distribution were used as porous media; and Hexadecane, a petroleum compound immiscible with and lighter than water, was used as wetting fluid at residual saturation. Nitrogen freezer was used to solidify the discontinuous Hexadecane ganglia in glass beads to preserve the ganglia size changes during different gravity conditions, so that the blob-size distributions (BSDs) could be measured after flight. It was concluded from this study that microgravity has little effect on the size distribution of pore fluid blobs corresponding to residual saturation of wetting fluids in porous media. The blobs showed no noticeable breakup or coalescence during microgravity. However, based on the increase in bulk volume of samples due to particle separation under microgravity, groups of particles, within which pore fluid blobs were encapsulated, appeared to have rearranged themselves under microgravity.     

MALIGNANT TRANSFORMATION OF SOLITARY SPINAL OSTEOCHONDROMA IN TWO MATURE DOGS

Canine osteochondroma is an uncommon bony tumor that arises in skeletally immature animals. Consequently, clinical signs typically occur in young dogs as a result of impingement of normal structures by the tumor. Radiographically, osteochondromas are benign in appearance. They are well circumscribed and cause no bony lysis nor periosteal proliferation. Osteochondromas may occur in two forms; solitary or multiple. Although histology and biologic behavior are identical, when in the multiple form the condition has been termed multiple cartilaginous exostoses. Malignant transformation of multiple cartilaginous exostoses has been reported in three mature dogs. We report two dogs with malignant transformation of solitary spinal osteochondromas. Both underwent transformation to osteosarcoma. Despite the benign radiographic appearance of osteochondromas and multiple cartilaginous exostoses, clinical signs should alert the clinician to the possibility of malignant transformation.