Haematological and biochemical changes in dogs naturally infected with Angiostrongylus vasorum before and after treatment

Haematological and biochemical parameters were studied prospectively in 48 dogs naturally infected with Angiostrongylus vasorum in a primary care setting. Samples for analysis were obtained when treatment was started and 42days afterwards. Prior to treatment, 21% of affected dogs exhibited eosinophilia, whereas increased total white blood cell (WBC) counts and neutrophilia were observed in only 4.2%. WBC counts and concentrations of neutrophils, eosinophils and monocytes decreased significantly from days 0 to 42, indicating that, even in dogs without elevated absolute blood values, a low grade inflammatory response may be present in dogs with A. vasorum infection. Biochemical changes (especially an increase in serum globulins and a decrease in serum fructosamine) were in agreement with the findings of other studies. The results show that the diagnosis of canine angiostrongylosis should not be excluded based on unremarkable haematological and blood biochemical parameters. They also support our recent finding that a low serum fructosamine concentration may be associated with infection with A. vasorum.     

Influence of Acute and Fractionated X-Ray Doses on Shoot Production of in Vitro Derived Explants of Gerbera jamesonii H. Bolus

In vitro mutation induction experiments will become economically relevant only if the genetic variation can be highly increased by this procedure. For that purpose the utilization of as high X-ray doses as possible are considered an important prerequisite. It was the objective to investigate the effect of split versus acute X-ray doses on in vitro derived micro shoots of Gebera jamesonii used as references system for plant species that can be propagated in vitro by axillary shoots. Splitting of doses between 10 Gy and 50 Gy into 2 or 3 fractions separated by periods of 4th each for recovery led to considerably rising shoot production. The recovery from damage, represented by accumulating the number of shoots developed during 16 weeks at 4 subsequent dates pf cutoff post-treatment, by propagation profiles, and by calculation of the factor of recovery, resulted in the application of very high X-ray doses only usable by means of multiple dose fraction procedures.     

Resistance to tomato spotted wilt virus in transgenic tomato hybrids

Summary Tomato spotted wilt virus (TSWV) causes significant economic losses in the commercial culture of tomato (Lycopersicon esculentum Mill.). Culture practices and introgression of natural sources of resistance to TSWV have only been marginally effective in controlling the TSWV disease. Recently however, high levels of protection against TSWV have been obtained by transforming tobacco with a chimaeric gene cassette comprising the TSWV nucleoprotein gene. This report demonstrates the successful application of this newly-created TSWV resistance gene in cultivated tomato. Transformation of an inbred tomato line with the TSWV nucleoprotein gene cassette resulted in high levels of resistance to TSWV that were maintained in hybrids derived from the parental tomato line. Therefore, transformant lines carrying the synthetic TSWV resistance gene make suitable progenitors for TSWV resistance to be incorporated into the breeding programmes of tomato.     

Beziehungen zwischen Fahnenblattfläche,Photosyntheserate und Einzelährenertrag bei Sommerweizen

Zusammenfassung In dreijährigen Untersuchungen an einem Sortiment von über 100 Sommerweizensorten wurde in jedem Jahr eine Korrelation von r=0.5 zwischen Fläche der Fahnenblattspreite und Einzelährenertrag gefunden. Bei Sorten, die von der Regressionslinie am weitesten entfernt lagen, zeigte sich eine Häufung extremer Werte der Photosyntheserate. Formen mit kleinem Fahnenblatt und relativ hohem Einzelährenertrag wiesen besonders hohe Photosyntheseraten auf, solche mit großem Fahnenblatt und geringem Einzelährenertrag dagegen niedrige.Im Interesse der Erhöhung der Bestandesdichte ist die Selektion von Formen mit kleinen Blättern und hoher Photosyntheseleistung anzustreben.

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Relationships between flag leaf area, photosynthetic rate and grain yield per ear in spring wheat

Summary The coefficient of correlation between flag leaf area and grain yield per ear was r=0.5 in a collection of more than 100 varieties of spring wheat. This coefficient was the same in three successive years, despite of different climatic conditions. In varieties with the greatest distance from the regression line we found extreme values of flag leaf photosynthesis.Small flag leaves connected with high yield per ear exhibited high values of the photosynthetic rate and vice versa.Selection of varieties with relatively small leaves but high photosynthetic efficiency seems possible and useful with the view of a very high density of field crops.

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Small-molecule inhibition of TNF-alpha

We have identified a small-molecule inhibitor of tumor necrosis factor alpha (TNF-alpha) that promotes subunit disassembly of this trimeric cytokine family member. The compound inhibits TNF-alpha activity in biochemical and cell-based assays with median inhibitory concentrations of 22 and 4.6 micromolar, respectively. Formation of an intermediate complex between the compound and the intact trimer results in a 600-fold accelerated subunit dissociation rate that leads to trimer dissociation. A structure solved by x-ray crystallography reveals that a single compound molecule displaces a subunit of the trimer to form a complex with a dimer of TNF-alpha subunits.     

A comparison of transmission characteristics of Salmonella enterica serovar Enteritidis between pair-housed and group-housed laying hens

ABSTRACT: Human cases of bacterial gastro-enteritis are often caused by the consumption of eggs contaminated with Salmonella species, mainly Salmonella enterica serovar Enteriditis (Salmonella Enteritidis). To reduce human exposure, in several countries worldwide surveillance programmes are implemented to detect colonized layer flocks. The sampling schemes are based on the within-flock prevalence, and, as this changes over time, knowledge of the within-flock dynamics of Salmonella Enteritidis is required. Transmission of Salmonella Enteritidis has been quantified in pairs of layers, but the question is whether the dynamics in pairs is comparable to transmission in large groups, which are more representative for commercial layer flocks. The aim of this study was to compare results of transmission experiments between pairs and groups of laying hens. Experimental groups of either 2 or 200 hens were housed at similar densities, and 1 or 4 hens were inoculated with Salmonella Enteritidis, respectively. Excretion was monitored by regularly testing of fecal samples for the presence of Salmonella Enteritidis. Using mathematical modeling, the group experiments were simulated with transmission parameter estimates from the pairwise experiments. Transmission of the bacteria did not differ significantly between pairs or groups. This finding suggests that the transmission parameter estimates from small-scale experiments might be extrapolated to the field situation.     

Canine specific ELISA for coagulation factor VII

Canine coagulation factor VII (FVII) deficiency can be hereditary or acquired and may cause life threatening bleeding episodes if untreated. FVII procoagulant activity can be measured by FVII activity (FVII:C), but assays for measurement of canine specific FVII antigen (FVII:Ag) have not been available to date. In this study, a canine specific ELISA for measurement of FVII:Ag in plasma was developed and validated. The FVII:Ag ELISA correctly diagnosed homozygous and heterozygous hereditary FVII deficiency. Together with activity based assays, such as FVII:C, the FVII:Ag ELISA should be valuable in the diagnosis of hereditary canine FVII deficiency.     

Long unfolded linkers facilitate membrane protein import through the nuclear pore complex

Active nuclear import of soluble cargo involves transport factors that shuttle cargo through the nuclear pore complex (NPC) by binding to phenylalanine-glycine (FG) domains. How nuclear membrane proteins cross through the NPC to reach the inner membrane is presently unclear. We found that at least a 120-residue-long intrinsically disordered linker was required for the import of membrane proteins carrying a nuclear localization signal for the transport factor karyopherin-α. We propose an import mechanism for membrane proteins in which an unfolded linker slices through the NPC scaffold to enable binding between the transport factor and the FG domains in the center of the NPC.     

Assessment of the use of gross lesions at post-mortem to detect outbreaks of classical swine fever

The performance of pathological findings as a diagnostic tool for the detection of classical swine fever (CSF) outbreaks during the 1997/1998 CSF-epidemic in The Netherlands was evaluated by constructing and analysing receiver operating characteristic (ROC) curves. This was done at the individual pig level and at the submission level (a group of pigs from the same herd submitted together for post-mortem investigation). At post-mortem examination, the tonsils, spleen, ileo-caecal valve and renal pelvis were sampled, sent to the reference laboratory, and tested by means of a CSF-specific fluorescent antibody test in combination with a confirmatory test. This resulted in an infection status at the individual pig level. The infection status and pathological findings of 1072 individual pigs from a total of 230 infected herds were included in this analysis. We also included submissions of pigs from herds that were sent to post-mortem examination because of a clinically CSF-suspect situation but afterwards were concluded to be from non-infected herds. Infection status and pathological findings of 1224 individual pigs from a total of 241 non-infected herds were included in the analysis. Pneumonia, pleuritis, chronic bronchitis, pulmonary oedema, chronic gastric ulceration, dry faecal contents in the colon, conjunctivitis, haemorrhages in the renal pelvis, renal haemorrhages, splenic enlargement, haemorrhages in the urinary bladder, haemorrhagic and enlarged lymph nodes were the most frequently recorded pathological findings during a post-mortem examination of pigs submitted in a CSF-suspect clinical situation. However, some of these pathological findings (e.g. pneumonia, pleuritis) were almost evenly distributed in infected and in non-infected pigs, resulting in a high sensitivity combined with a low specificity. The area under the ROC curve of pathological findings at the individual pig level and at the submission level was 0.720 and 0.782, respectively, which was significantly (P<0.0001) larger than the area under the random ROC curve. It was concluded that, although gross pathology is a legitimate test, its quantitative contribution to the detection of CSF is limited.