Sysmex XT‐2000iV scattergram analysis in a cat with basophilia

A 13‐year‐old female Domestic Shorthair cat was presented to the Veterinary Teaching Hospital of the University of Milan for an interscapular mass suspected to be a mesenchymal malignant tumor. A preoperative CBC performed with Sysmex XT‐2000iV showed leukocytosis with neutrophilia and eosinophilia. The Sysmex WBC/DIFF scattergram showed an additional, well‐separated cluster of events between the neutrophil, eosinophil, and lymphocyte clusters. Blood smear evaluation revealed the presence of a significant number of basophils; thus, it was hypothesized that the additional cluster could represent the basophilic population. A second CBC, 24 days later, showed the same pattern on the WBC/DIFF scattergram in the absence of leukocytosis and neutrophilia. After surgical excision of the mass, a definitive diagnosis of feline injection site sarcoma was made. To the author's knowledge, there are no previous reports about the identification of feline basophils in the WBC/DIFF scattergram of Sysmex XT‐2000iV.     

Relationships of climate and cell features in stems and roots of black spruce and balsam fir

? The anatomical differences of mature black spruces and balsam firs were examined at stem and root level in order to characterize their wood properties at cellular level and link these differences to climate.

? Anatomical variability of these species was evaluated in relation to climate data gathered from 2001 to 2004 during the cell enlargement (CE) and wall thickening and lignification (WTL) phases. Lumen area, single cell wall thickness and total tracheid radial diameter were analyzed and regrouped into earlywood and latewood.

? Results from a principal component analysis (PCA) indicated that both first eigenvectors account for 82% and 90% of total variance for CE and WTL respectively. These component factors revealed that precipitation, humidity and number of days with precipitation significantly influence the lumen area (p = 0.0168) and radial cell diameter (p = 0.0222) in earlywood. Significant differences were registered between species and tree parts (stem and root) for the lumen area, radial cell diameter and cell wall thickness in both earlywood and latewood.

? In our study, black spruce exhibited smaller tracheid size in both stem and roots compared to balsam fir. Furthermore, the lower amount of tracheids produced during the growing season and higher proportion of latewood ensure a higher wood density of black spruce. The influence of temperature on earlywood formation is significant, whereas no influence was observed on latewood.

     

Bovine respiratory syncytial virus infection of bovine embryonic lung cultures: a kinetic study by the fluorescent antibody technique.

Development of fluorescence in bovine embryonic lung cells infected with bovine respiratory syncytial virus (BRSV) was studied by the fluorescent antibody (FA) test. Similar patterns of fluorescence were seen with the direct FA test, in which the immunoglobulin G fraction of antiserum to BRSV was conjugated with fluorescein isothiocyanate and used; and the indirect test, in which antiserum to the Long strain of respiratory syncytial virus and fluorescein isothiocyanate-conjugated anti-rabbit immunoglobulin G were used. In different trials, fluorescence was first detected between 16 and 18 hours after inoculation with BRSV. Fluorescence always was confined to the cytoplasm. Before 24 hours, fluorescence consisted of fine fibrils, usually parallel to the long axis of the cell, and cytoplasmic granules. After 24 hours, coincident with rounding of the cells, fluorescence slowly moved to the periphery of the cytoplasm. Under the growth conditions used, syncytia did not develop. By the FA test and as determined by the release of BRSV into the supernatant fluid, the minimal time for a single cycle of infection was between 24 and 26 hours.     

Ultrastructural and biomolecular detection of Rickettsiales‐like organisms in tissues of rainbow trout with Red Mark Syndrome

Red mark syndrome (RMS) and US strawberry disease (US SD) are skin disorders affecting rainbow trout farmed in Europe and USA. The disease etiology has not yet been established. In spite of specific investigations, identifying Rickettsia‐like organism (RLO)‐ and Midichloria‐like organism (MLO)‐related DNA in affected individuals, these pathogens have never been observed. We performed histological, ultrastructural and biomolecular analysis on skin and spleen samples of trout with RMS. Examination by TEM revealed the presence of intracytoplasmic microorganisms resembling Rickettsiales within macrophages, fibroblasts and erythrocytes. The microorganisms were oval or short rod shaped (400–800 nm in length and 100–200 nm in width) and often showed a cell wall similar to Gram‐negative bacteria. PCR analysis for Rickettsiales supported these findings: 53% of affected trout were positive by both PCR and TEM The primers RiFCfw‐RiFCrev were used to anneal both the RLO 16S DNA sequence and the MLO 16S DNA sequence. For this reason, and in agreement with previous studies confirming the presence of Rickettsiales‐related DNA in trout with RMS, we assume that TEM detected microorganisms morphologically consistent with bacteria belonging to Rickettsiales order and could be considered as possible causative agents of RMS.     

Factors affecting the assay of bovine type I interferon on bovine embryonic lung cells

One preparation of interferon (IF) on 7-day-old bovine embryonic lung cultures free of bovine viral diarrhea virus had titers ranging from 20 to 10,240 in plaque-reduction tests, using bovine vesicular stomatitis virus. Factors believed to contribute to this variation were investigated. Although titers differed on different cell strains, different passages, and on cultures of different ages, variations between the two assays definitely could not be established as a function of these factors. However, IF titers on low passage cultures were usually lower than were titers on subsequent passages of the same cell strain. Calf serum in the diluent for IF reduced the titer one or two twofold dilutions. Over the range of 7 to 24 hours contact of IF with bovine embryonic lung cultures, and titer decreased steadily and was one twofold dilution less at 24 hours than it was at 7 hours. Latent viruses were not found in cultures by electron microscopy. Treatment of cultures with a noncytopathogenic strain of bovine viral diarrhea virus almost eliminated the effect of IF. Naturally occurring production of IF was not a major problem. While IF was on the cells, the pH of IF had a pronounced effect on the titer and may have been responsible for the vatiation observed with different passages, different cell strains, use of cultures of different ages, and use of calf serum in the diluent. Interferon at a low pH had a titer three or four twofold dilutions less than did the IF at a high pH.     

Haemorrhagic disease of lagomorphs: evidence for a calicivirus.

Studies on the aetiological agents of rabbit haemorrhagic disease (RHD) and European brown hare syndrome show that the viruses responsible for these infections can be placed in the family Caliciviridae. Established members of this group are vesicular exanthema virus (prototype), San Miguel sea lion virus and feline calcivirus. The human hepatitis E virus and the Norwalk agent may soon be included. The RHD virus genome consists of a positive stranded RNA molecule composed of 7437 nucleotides. A major subgenomic RNA of 2.2 kb, colinear with the 3' end of the genomic RNA, can also be recovered from infected liver tissue, and both RNAs are enclosed within viral capsids formed by a single major protein of approximately 60 kDa. Electron microscopic examination of organ suspensions from diseased animals shows two types of particle; 35-40 nm complete virions have the regularly arranged cup-shaped depressions typical of calcivirus morphology, and 23-25 nm smooth particles resulting from degradation of the outer surface structures of the complete virions.     

A simulation model for the development of brown rust epidemics in winter wheat

A model simulating the progress of Puccinia recondita severity, expressed as a percentage of rusted leaf area (both as average and its 95% confidence interval) on individual wheat leaves over the course of a growing season, with a time step of one day, was elaborated using laboratory and field data from literature. Data on the stages of each infection cycle (uredospore germination, penetration, latency, uredium eruption and infectiousness) were transformed into model parameters by curve fitting, Montecarlo stochastic procedures, corrections and empirical assumptions. Data on host growth, like the timing of all phenological stages, the dynamic of the green area of each leaf from appearance to complete senescence, and tillering were obtained from a specific sub-model. Model validation was performed on actual data not used in model building and representing a wide range of conditions (several winter wheat cultivars grown at eight locations in northern Italy between 1990 and 1994) by using subjective, non-parametric and parametric tests: it revealed a satisfactory agreement between the data simulated by the model and actual data.