A class of potent antimalarials and their specific accumulation in infected erythrocytes

During asexual development within erythrocytes, malaria parasites synthesize considerable amounts of membrane. This activity provides an attractive target for chemotherapy because it is absent from mature erythrocytes. We found that compounds that inhibit phosphatidylcholine biosynthesis de novo from choline were potent antimalarial drugs. The lead compound, G25, potently inhibited in vitro growth of the human malaria parasites Plasmodium falciparum and P. vivax and was 1000-fold less toxic to mammalian cell lines. A radioactive derivative specifically accumulated in infected erythrocytes to levels several hundredfold higher than in the surrounding medium, and very low dose G25 therapy completely cured monkeys infected with P. falciparum and P. cynomolgi.     

Respiration of three Belgian crops: Partitioning of total ecosystem respiration in its heterotrophic, above- and below-ground autotrophic components

An experimental system combining an eddy covariance system, a micrometeorological station and soil chambers placed in planted areas and in root exclusion zones was installed during three successive years in a production crop managed in a traditional way at the Lonzée experimental site (Belgium). Measurements were made successively on seed potato, winter wheat and sugar beet. The general objectives of the study were, first to evaluate the relative contributions to total ecosystem respiration (TER) of heterotrophic, above ground autotrophic and below ground autotrophic respiration over a succession of three agricultural crops (seed potato, winter wheat and sugar beet) cultivated on successive years at the same location and, secondly, to identify the driving variables of these contributions.Results showed that, during the observation periods, TER was dominated by autotrophic respiration (AR) (60-90%) and that AR was dominated by its above ground component (60-80%). HR was found to increase with temperature and to be independent of Gross Primary Production (GPP), whereas AR was driven by GPP and was mostly independent of temperature. The AR response to GPP was specific to the crop: not only AR intensity but also AR distribution between its above- (ARa) and below- (ARb) ground components were found to differ from one crop to another and, in the winter wheat, from one development stage to another. Generally, ARb contribution to AR was found larger when carbon allocation towards roots was more important.An uncertainty analysis was made and showed that the main sources of uncertainties on the estimates were the spatial variability for soil chamber measurements and uncertainties linked to the data gap filling method for eddy covariance measurements.     

Prospective medical evaluation of 7 dogs presented with fly biting

Fly biting describes a syndrome in which dogs appear to be watching something and then snapping at it. Medical work-up of fly biting in dogs has never been reported. The aims of this case series were to characterize fly biting and perform a complete medical evaluation of dogs displaying fly biting.     

Demographic characteristics of scrapie-affected holdings identified by active and passive surveillance schemes in Great Britain: 2002–2005

Several surveillance techniques have been used to quantify the prevalence of both classical and atypical scrapie in British sheep, namely the recording of clinical suspects (RC) and the testing of animals slaughtered at abattoir (AS) or reported as fallen stock (FS). Any estimate of prevalence based on a particular source is likely to have been affected by demographic differences in the populations sampled. In this study, the demographic characteristics of scrapie-affected holdings detected by each of the surveillance streams (RC, AS, FS) in Great Britain were compared. Analyses of all three streams indicated that the probability of an affected holding being detected by a particular stream differed by geographical area, the number of animals brought onto the holding, the type of scrapie identified (classical vs. atypical) and the year. More detailed analysis of AS and FS suggested that the annual and regional differences between these surveys could be explained by differences in sampling effort.     

Response of healthy dogs to infusions of human serum albumin

OBJECTIVE: To evaluate the clinical and immunologic response in healthy dogs to infusions of human serum albumin (HSA). ANIMALS: 9 healthy purpose-bred mixed-breed dogs. PROCEDURES: Each dog was administered a 25% HSA solution once or twice. Various physical examination and laboratory variables were serially evaluated. Antibody against HSA was assayed before and after infusion by use of an ELISA. Intradermal testing was also conducted. A repeated-measures ANOVA or Friedman repeated-measures ANOVA on ranks was used to compare results for the variables. RESULTS: Adverse clinical reactions were observed after the first or second infusion in 3 dogs. Anaphylactoid reactions were observed in 1 of 9 dogs during the first infusion and in 2 of 2 dogs administered a second infusion. Two dogs developed severe edema and urticaria 6 or 7 days after an initial infusion. All dogs developed anti-HSA antibodies. Positive responses for ID tests were observed in 8 of 9 dogs. Short-term increases were detected in blood protein, total bilirubin, and calcium concentrations after HSA infusion. Serum cholesterol concentrations and platelet counts decreased after HSA infusion. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of HSA resulted in profound reactions in 2 of 9 dogs administered a single infusion and in 2 of 2 dogs administered a second infusion. This indicates that there is risk of life-threatening adverse reactions to HSA infusion in healthy dogs.     

Lumbo-sacral epidural anaesthesia as a complement to dissociative anaesthesia during scrotal herniorrhaphy of livestock pigs in the field

Background

In Sweden, scrotal or inguinal herniorrhaphy of livestock pigs in the field has traditionally been an important part of the surgical skills training of veterinary students. Few substances meet the legal requirements for field anaesthesia of production animals in the European Union but a protocol based on azaperone-detomidine-butorphanol-ketamine does. Unfortunately the anaesthesia is characterised by unpredictable duration and depth and of abrupt awakenings which is not acceptable from an animal welfare perspective and impedes surgical training. Lumbo-sacral epidural analgesia is proven to provide sufficient analgesia to allow abdominal surgery, but there are few reports on the field use of this loco-regional technique. The study aim was to evaluate whether lumbo-sacral anaesthesia can be safely and successfully used in the field by a veterinary student and whether the combination of dissociative and lumbo-sacral epidural anaesthesia improves analgesia and anaesthesia to guarantee animal welfare during herniorrhaphy in livestock pigs, enabling surgical skills training.

Results

Pigs in the control-group (placebo) responded significantly stronger to surgery, with five out of 11 requiring additional doses of detomidine and ketamine. There were no significant differences between groups in respiratory rate, heart rate, blood pressure, SpO₂ or blood gases. SpO₂ levels <94 % were recorded in several pigs in both groups. No post-injection complications were reported at follow-up.

Conclusions

The results from this study showed that lumbo-sacral epidural anaesthesia with lidocaine could successfully be administered during dissociative anaesthesia of livestock pigs by a veterinary student and without reported post-injection complications. It improved analgesia and anaesthesia during herniorrhaphy of sufficient duration to enable surgical skills training. The risks and consequences of hypoxaemia and hypoventilation should be considered.     

Distribution of CCR3 mRNA expression in horse tissues

CCL11 (also known as eotaxin) is a very potent and selective mediator of eosinophil migration which exerts its effects through its receptor, CCR3. In this study we report the cloning of an equine CCR3 cDNA sequence and investigation of the localization of CCR3 mRNA expression in horse tissues. Equine CCR3 displayed high levels of sequence identity with CCR3 sequences in other species. RT-PCR analysis revealed the expression of CCR3 in colon, lung and spleen of normal horses. In situ hybridisation experiments indicated that expression of CCR3 mRNA in colon was predominantly in eosinophils and to a lesser extent in mast cells, whereas CCR3 was seen mainly in lymphocytes of the lung and spleen. In view of the role of CCR3 in the recruitment of cells into sites of allergic inflammation, equine-specific CCR3 sequence data and information on tissue localization will be of potential benefit in the development of CCR3-targeted anti-inflammatory therapies in the horse.     

What veterinary practitioners should know about scrapie

Scrapie is the longest known and most widely spread of the transmissible spongiform encephalopathies and remains the model for much of the research regarding these diseases. Because scrapie is a reportable disease and the subject of an active eradication program in the United States, veterinary practitioners should have a basic understanding of the disease.