Equine Multinodular Pulmonary Fibrosis and Lymphoma in a Horse Associated with Equine Herpesvirus-5

A 9-year-old mare presented with a 2-week history of partial anorexia, multiple swellings in the area of the throatlatch, and purulent nasal discharge. On initial presentation, the horse had submandibular and retropharyngeal lymphadenopathy, mild ventral edema, and weight loss. Thoracic radiographs revealed a pulmonary interstitial pattern. Necropsy revealed enlarged lymph nodes throughout the body. The lung parenchyma contained multiple random, well-circumscribed nodules, which, on cut section, were pale, tan colored, and very firm with a distinct line of demarcation from the surrounding normal parenchyma. The subendocardium of the left ventricle, left atrium, and, multifocally, the right ventricle contained white, gritty areas of mineralization. There was marked subintimal mineralization of the aorta and pulmonary artery. Histopathology of the lymph nodes revealed effacement of the parenchyma by a neoplasm composed of large numbers of small mature lymphocytes, fewer large lymphocytes, and scattered moderate numbers of histiocytes. Immunohistochemistry tests for CD3, CD79a, and CD20, confirmed the lymphoma was T-cell-rich B-cell lymphoma. The lungs contained marked interstitial fibrosis with alveolar histiocytosis. Polymerase chain reaction test results of lymph node and lungs were positive for equine herpesvirus-5 (EHV-5), a gammaherpesvirus. Gammaherpesvirus infection has been associated with lymphoma and pulmonary fibrosis in other species. This report describes the association between EHV-5 and both pulmonary fibrosis and lymphoma.     

INFLAMMATORY POLYP IN THE MIDDLE EAR WITH SECONDARY SUPPURATIVE MENINGOENCEPHALITIS IN A CAT

A 15-month-old male Maine Coon Cat presented with persistent auricular discharge and progressive head tilt, ataxia, and loss of blink on the right side. Using computed tomography a hyperattenuating, contrast-enhancing material within a thickened right tympanic bulla and contrast enhancement of the adjacent cerebellum were identified. Marked suppurative inflammation was identified on cerebrospinal fluid analysis with no growth on bacterial culture. Ventral bulla osteotomy was performed to remove a soft tissue mass, and an inflammatory polyp with chronic severe suppurative inflammation was confirmed using histology. Staphylococcus auricularis was grown on aerobic culture and Fusobacterium necrophorum and Peptostreptococcus anaerobius were grown on anaerobic culture. The cat was treated for 10 weeks with amoxicillin/clavulinic acid and metronidazole. Dramatic improvement in body weight, appetite, energy level, balance, and resolution of right-sided facial paralysis were noted, but the cat retained a head tilt.     

Assignment of the denso Dwarfing Gene to the Long Arm of Chromosome 3(3H) of Barley by Use of RFLP Markers

RFLP analysis of 105 doubled haploid lines from a cross between the barley varieties ‘Magnum’ and ‘Goldmarker’ located the denso dwarfing gene on the long arm of chromosome 3(3H), approximately 8 cM distal to the RFLP locus Xpsrl70. Lines with the denso gene showed a distinctive prostrate juvenile growth habit and tended to have later ear emergence times and lower plant grain weights, ear grain weights and 50 grain weights.     

Genotypic differences in polyembryo formation and somatic embryogenesis increment in wheat (Triticum aestivum L.), following 2,4-D treatment

Summary In the course of experiments performed to obtain haploid wheat plants in which 2,4-dichlorophenoxyacetic acid (2,4-D) was applied to developing spikes, it was found that three cultivars showed a different ability to produce polyembryos (Thatcher 20.19%, Chris 7.06%, Dollar 0%). This behaviour was related to their capacity to form somatic embryos. Diploid immature embryos cultured in vitro after 2,4-D treatment, gave a higher frequency of embryogenic callus in Thatcher and Chris than in Dollar. As the common factor in both experiments was the 2,4-D treatment we propose that the three cultivars showed a differential sensitivity to 2,4-D.     

Economic incentives reduce irrigation deliveries and drain water volume

This paper describes the application of an economic incentive program to achieve water quality objectives by motivating improvements in farm-level water management practices. The program includes farm-specific water allotments, tiered water pricing, and low-interest loans for purchasing irrigation equipment. The implementation of this program in a California water district has resulted in significant reductions in irrigation deliveries and drain water volume. Since the program was implemented, average irrigation depths have declined by 25% on cotton fields, 9% on tomatoes, 10% on cantaloupes, 30% on seed alfalfa, and 29% on grain fields. The average volume of drain water collected each year in subsurface drainage systems has declined from 4.8 million m³ during 1986 through 1989 to 2.6 million m³ during 1990 through 1993. These results confirm that economic incentives can be effective in generating improvements in water quality.     

Diversity and distribution of Victoria Land biota

Understanding the relationship between soil biodiversity and ecosystem functioning is critical to predicting and monitoring the effects of ecosystem changes on important soil processes. However, most of Earth's soils are too biologically diverse to identify each species present and determine their functional role in food webs. The soil ecosystems of Victoria Land (VL) Antarctica are functionally and biotically simple, and serve as in situ models for determining the relationship between biodiversity and ecosystem processes. For a few VL taxa (microarthropods, nematodes, algae, mosses and lichens), species diversity has been intensively assessed in highly localized habitats, but little is known of how community assemblages vary across broader spatial scales, or across latitudinal and environmental gradients. The composition of tardigrade, rotifer, protist, fungal and prokaryote communities is emerging. The latter groups are the least studied, but potentially the most diverse. Endemism is highest for microarthropods and nematodes, less so for tardigrades and rotifers, and apparently low for mosses, lichens, protists, fungi and prokaryotes. Much of what is known about VL diversity and distribution occurs in an evolutionary and ecological vacuum; links between taxa and functional role in ecosystems are poorly known and future studies must utilize phylogenetic information to infer patterns of community assembly, speciation, extinction, population processes and biogeography. However, a comprehensive compilation of all the species that participate in soil ecosystem processes, and their distribution across regional and landscape scales is immediately achievable in VL with the resources, tools, and expertise currently available. We suggest that the soil ecosystems of VL should play a major role in exploring the relationship between biodiversity and ecosystem functioning, and in monitoring the effects of environmental change on soil processes in real time and space.     

Necrotizing Enterocolitis in Horses: A Retrospective Study

The clinical and clinicopathologic characteristics of fatal necrotizing enterocolitis were examined in 16 horses (age 4 months to 12 years). At initial presentation, 8 of 16 horses were pyrexic (median temperature, 38.4°C; range, 33.8 to 40.6°C); all 16 were tachycardic (median heart rate, 93 bpm, range, 66 to 138 bpm); 13 of 16 were tachypneic (median heart rate, 36 bpm, range, 16 to 80 bpm), dehydrated, and had discolored mucous membranes. All horses that were pyrexic were also tachycardic and tachypneic. PCV was high (>45%) in 14 horses. Six horses were leukopenic (<5,000 cells/μL); 12 were neutropenic (<2,300 cells/μL), and 14 had >100 band neutrophils/μL. Twelve horses were acidemic (pH 7.37; range, 6.88 to 7.33) and the venous bicarbonate concentration was low (<23 mEq/L) in 14 horses. Median anion gap in 16 horses was 31.5 mEq/L (>15 mEq/L in 15 horses). Eleven of 16 horses were hyponatremic (<137 mEq/L), 1 horse was hypernatremic (> 143 mEq/L), 3 were hypoka-(emic (<3.2 mEq/L), 6 were hyperkalemic (>4.5 mEq/L), and 14 were hypochloremic (<98 mEq/L). Serum creatinine concentrations were high (>1.4 mg/dL) in 15 horses. Abdominal fluid was examined in 12 horses: 4 had total protein concentrations 2.5 g/dL and 6 had nucleated cell counts >5,000/μL and <10,000/μL; none had >10,000/μL. Eight of 12 samples revealed a nondegenerate neutrophilia (>50%). Abdominal fluid collected from 4 horses immediately before death was normal in 2 horses and indicative of suppurative inflammation in 2. All 8 horses tested had low or nonexistent serum immunofluorescent antibody titers to Ehrlichia risticii. Four of 16 horses had Salmonella spp isolated from feces or tissues. All 16 horses either died (5 of 16; 31%) or were euthanized because of a grave prognosis. Median time to death was 45.5 hours (range, 7 to 113 hours) from the time of admission. Death was preceded by severe abdominal pain in 14 horses. Fatal necrotizing enterocolitis of horses is characterized by a brief course, profound dehydration, electrolyte derangements, acid-base abnormalities, and terminally, severe abdominal pain. Abdominal fluid analysis was frequently not indicative of the severity of disease. J Vet Intern Med 1996;10:265–270. Copyright©1996 by the American College of Veterinary Internal Medicine.     

Antigenic comparison of Lelystad virus and swine infertility and respiratory syndrome (SIRS) virus.

This study reports the antigenic relatedness of isolates of Lelystad virus collected in the Netherlands, Germany, and the United States. The binding of antibodies directed against these isolates was tested in a set of field sera collected during outbreaks of porcine epidemic abortion and respiratory syndrome in Europe and outbreaks of swine infertility and respiratory syndrome (SIRS) in North America. Two sets of sera from pigs experimentally infected with Lelystad virus or SIRS virus were also tested. Although all 7 isolates reacted with anti-Lelystad virus sera, antigenic variation was considerable. The 4 European isolates resembled each other closely, but differed from the American isolates, and the 3 American isolates differed antigenically from each other. To reliably diagnose Lelystad virus infection, a common antigen must first be identified.