Topology of megagauss magnetic fields and of heat-carrying electrons produced in a high-power laser-solid interaction

The intricate spatial and energy distribution of magnetic fields, self-generated during high power laser irradiation (at Iλ^{2}∼10^{13}-10^{14}  W.cm^{-2}.μm^{2}) of a solid target, and of the heat-carrying electron currents, is studied in inertial confinement fusion (ICF) relevant conditions. This is done by comparing proton radiography measurements of the fields to an improved magnetohydrodynamic description that fully takes into account the nonlocality of the heat transport. We show that, in these conditions, magnetic fields are rapidly advected radially along the target surface and compressed over long time scales into the dense parts of the target. As a consequence, the electrons are weakly magnetized in most parts of the plasma flow, and we observe a reemergence of nonlocality which is a crucial effect for a correct description of the energetics of ICF experiments.

Epizootic heamorragic disease

Epizootic haemorrhagic disease (EHD) is an infectious non-contagious viral disease transmitted by insects of the genus Culicoides which affects wild and domestic ruminants. The causative agent, the epizootic haemorrhagic disease virus (EHDV), belongs to the family Reoviridae, genus Orbivirus and shares many morphological and structural characteristics with the other members of the genus such as bluetongue, African horse sickness and equine encephalosis viruses. In recent years EHD outbreaks have been reported in countries bordering the European Union. They caused disease in cattle and severe repercussion on the livestock industry of the affected countries. In the light of recent European bluetongue epizootic these events pose an increasing threat to the European Union. This review includes the most recent information regarding the virus and the disease as well as tools for its diagnosis and control. It is our conviction that more attention should be drawn to both EHDV and the disease itself in order to fulfil all these gaps and not to be unprepared in case future possible incursions.

Evaluation of an in vitro sulphidoleukotriene release test for diagnosis of insect bite hypersensitivity in horses

REASONS FOR PERFORMING STUDY

Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis caused by bites of Culicoides and Simulium species, and improved means of diagnosis are required.

OBJECTIVES

The cellular antigen simulation test (CAST) with C. nubeculosus and S. vittatum extracts was assessed in a population of IBH-affected and healthy horses. Variations in test results over a one year period and possible cross-reactivity between different insect extracts was studied.

METHODS

A total of 314 mature horses were studied using the CAST. Influence of severity of clinical signs, gender and age were evaluated, and 32 horses were tested repeatedly over one year. The kappa reliability test was used to assess agreement of the test results with different insect extracts.

RESULTS

Horses with IBH had significantly higher sLT release than controls with C. nubeculosus and S. vittatum. The highest diagnostic sensitivity and specificity levels were attained when using adult C. nubeculosus extracts with the CAST (78% and 97%, respectively), suggesting that most horses with IBH are sensitised against Culicoides allergens. A proportion of IBH-affected horses was found to be sensitised to allergens of Simulium spp. in addition to those of C. nubeculosus. The CAST with C. nubeculosus had positive and negative predictive values > or = 80% for a true prevalence of IBH of 12-52%. In the follow-up study, the proportion of IBH-affected horses with a positive test result ranged from 90% in November to 68% in March. Severity of clinical signs or age did not influence test results significantly. However, IBH-affected males achieved significantly more positive test results than IBH-affected females.

CONCLUSIONS

The CAST with adult C. nubeculosus has high specificity and good sensitivity for diagnosis of IBH. Horses with IBH are mainly sensitised to Culicoides allergens, and some horses are additionally also sensitised to allergens in Simulium spp.

POTENTIAL RELEVANCE

The CAST is likely to be a useful test for diagnosis of IBH, even allowing the identification of IBH-affected but asymptomatic horses. This test may also help in further characterisation of allergens involved in this condition.

Efficacy of alphacypermethrin applied to cattle and sheep against the biting midge Culicoides nubeculosus

The recent emergence of bluetongue virus (BTV) in northern Europe, has led to an urgent need to identify methods to control the Culicoides biting midges that transmit it. Here, an in vitro assay was used to assess the effects of the proprietary pyrethroid insecticide alphacypermethrin applied to cattle and sheep (Dysect Cattle Pour-On, Dysect Sheep Pour-On; Ford Dodge Animal Health) against the biting midge Culicoides nubeculosus (Meigen) (Diptera: Ceratopogonidae). Hair or wool was collected from the back, belly and legs of animals immediately prior to treatment and 7, 14, 21, 28 and 35 days after treatment, and also from untreated controls. In the laboratory assay groups of 10 adult females C. nubeculosus were exposed to 0.5 g of hair or wool for 3 min. In all cases, no mortality was observed in the pre-treatment sample or the untreated controls. In the post-treatment samples, for both cattle and sheep mortality was close to 100% 7 days after treatment. For cattle, treatment effect persisted for up to 21 days post-treatment, following which the mortality rate following exposure to hair samples declined. In contrast, for sheep, mortality levels declined more slowly, and approximately 50% mortality was still observed 35 days after treatment. There was no significant difference in the kill rate for wool collected from the back, belly or legs of either sheep or cattle. The results demonstrate the potential for pour-on insecticide treatment to offer a degree of mitigation to livestock against onward transmission from infected animals--and in particular demonstrate that sufficient compound is able to reach the lower legs to kill in contact midges. The practical issues associated with achieving adequate protection are discussed.

Home treatment in haemophilia: clinical, social and economic advantages

Twenty-eight severely affected haemophiliacs were observed for 3 months under treatment as hospital out-patients and for the subsequent 9 months while treating themselves at home. Delay in receiving treatment and financial costs were both clearly reduced by home treatment, the patients recovered from individual bleeds more quickly and reported a greater sense of personal freedom and independence. The amount of treatment required did not materially change and no untoward effects were noted; the use of analgesics tended to be less.

Modulatory effects of heparin and short-length oligosaccharides of heparin on the metastasis and growth of LMD MDA-MB 231 breast cancer cells in vivo

Expression of the chemokine receptor CXCR4 allows breast cancer cells to migrate towards specific metastatic target sites which constitutively express CXCL12. In this study, we determined whether this interaction could be disrupted using short-chain length heparin oligosaccharides. Radioligand competition binding assays were performed using a range of heparin oligosaccharides to compete with polymeric heparin or heparan sulphate binding to I(125) CXCL12. Heparin dodecasaccharides were found to be the minimal chain length required to efficiently bind CXCL12 (71% inhibition; P<0.001). These oligosaccharides also significantly inhibited CXCL12-induced migration of CXCR4-expressing LMD MDA-MB 231 breast cancer cells. In addition, heparin dodecasaccharides were found to have less anticoagulant activity than either a smaller quantity of polymeric heparin or a similar amount of the low molecular weight heparin pharmaceutical product, Tinzaparin. When given subcutaneously in a SCID mouse model of human breast cancer, heparin dodecasaccharides had no effect on the number of lung metastases, but did however inhibit (P<0.05) tumour growth (lesion area) compared to control groups. In contrast, polymeric heparin significantly inhibited both the number (P<0.001) and area of metastases, suggesting a differing mechanism for the action of polymeric and heparin-derived oligosaccharides in the inhibition of tumour growth and metastases.

Reduced tear production in three canine endocrinopathies

OBJECTIVES

Previous reports have suggested that hypothyroid and diabetic patients can be predisposed to keratoconjunctivitis sicca. This study aimed to measure tear production in dogs with diabetes, hypothyroidism and hyperadrenocorticism using the Schirmer tear test and to compare these results with Schirmer tear test values for a group of normal dogs.

METHODS

Schirmer tear tests were performed on 16 dogs with hyperadrenocorticism, 18 with diabetes and 12 with hypothyroidism together with 100 control dogs. Corneal sensitivity was also measured in 12 of the 18 diabetic dogs with a Cochet Bonnet aesthesiometer and compared with age- and breed-matched normal dogs.

RESULTS

Schirmer tear test values in dogs with hypothyroidism, hyperadrenocorticism and diabetes were 12.3+/-3.2, 14.0+/-4.0 and 12.3+/-5.3 mm/minutes, respectively. Schirmer tear test values were significantly lower than that for the control group (19.6+/-4.2 mm/minutes) in all dogs with an endocrinopathy. Only in two hypothyroid dogs and three diabetics, this was manifested as profound keratoconjunctivitis sicca with Schirmer tear test value lower than 5 mm/minutes. Diabetic dogs had significantly reduced corneal sensitivity compared with a matched set of control dogs.

CLINICAL SIGNIFICANCE

This study shows a significant reduction in tear production in animals with diabetes mellitus, hypothyroidism and hyperadrenocorticism. Further research is needed to elucidate the mechanisms by which this reduction in tear production occurs. Assessment of tear production should be undertaken in animals diagnosed with these endocrinopathies, as these animals may progress to clinical keratoconjunctivitis sicca.

Equine insect bite hypersensitivity: immunoblot analysis of IgE and IgG subclass responses to Culicoides nubeculosus salivary gland extract

Insect bite hypersensitivity (IBH) is an allergic dermatitis of horses caused by IgE-mediated reactions to bites of Culicoides and sometimes Simulium spp. The allergens causing IBH are probably salivary gland proteins from these insects, but they have not yet been identified. The aim of our study was to identify the number and molecular weight of salivary gland extract (SGE) proteins derived from Culicoides nubeculosus which are able to bind IgE antibodies (ab) from the sera of IBH-affected horses. Additionally, we sought to investigate the IgG subclass (IgGa, IgGb and IgGT) reactivity to these proteins. Individual IgE and IgG subclass responses to proteins of C. nubeculosus SGE were evaluated by immunoblot in 42 IBH-affected and 26 healthy horses belonging to different groups (Icelandic horses born in Iceland, Icelandic horses and horses from different breeds born in mainland Europe). Additionally, the specific antibody response was studied before exposure to bites of Culicoides spp. and over a period of 3 years in a cohort of 10 Icelandic horses born in Iceland and imported to Switzerland. Ten IgE-binding protein bands with approximate molecular weights of 75, 66, 52, 48, 47, 32, 22/21, 19, 15, 13/12 kDa were found in the SGE. Five of these bands bound IgE from 50% or more of the horse sera. Thirty-nine of the 42 IBH-affected horses but only 2 of the 26 healthy horses showed IgE-binding to the SGE (p<0.000001). Similarly, more IBH-affected than healthy horses had IgGa ab binding to the Culicoides SGE (19/22 and 9/22, respectively, p<0.01). Sera of IBH-affected horses contained IgE, IgGa and IgGT but not IgGb ab against significantly more protein bands than the sera of the healthy horses. The cohort of 10 Icelandic horses confirmed these results and showed that Culicoides SGE specific IgE correlates with onset of IBH. IBH-affected horses that were born in Iceland had IgGa and IgGT ab (p< or =0.01) as well as IgE ab (p=0.06) against a significantly higher number of SGE proteins than IBH-affected horses born in mainland Europe. The present study shows that Culicoides SGE contains at least 10 potential allergens for IBH and that IBH-affected horses show a large variety of IgE-binding patterns in immunoblots. These findings are important for the future development of a specific immunotherapy with recombinant salivary gland allergens.

Histiocytic sarcoma of the spleen in flat-coated retrievers with regenerative anaemia and hypoproteinaemia

Three flat-coated retrievers with a regenerative anaemia were examined. They were hypoproteinaemic suggesting that the anaemia might be due to blood loss, but it was not possible to identify a site of haemorrhage. All three had splenomegaly with splenic abnormalities apparent on ultrasonography. Ultimately all three animals were shown to have a histiocytic sarcoma involving the spleen and other tissues. A fourth flat-coated retriever with anaemia, hypoproteinaemia and an abdominal mass was also diagnosed with a histiocytic sarcoma of the spleen following splenectomy. It is postulated that the dogs' anaemia was due to erythrophagocytosis, either directly by neoplastic cells or by reactive macrophages.

Hypercalcaemia associated with granulomatous lymphadenitis and elevated 1,25 dihydroxyvitamin D concentration in a dog

A seven-year-old Labrador was presented with weight loss and mild generalised lymphadenopathy. Histopathology of an excised lymph node by the referring veterinarian demonstrated granulomatous lymphadenitis. At the time of referral, fine-needle aspirates of the lymph nodes confirmed the presence of ongoing granulomatous inflammation. Further investigations revealed marked hypercalcaemia, a low parathyroid hormone concentration, a parathyroid hormone related protein concentration within the reference range, and an elevated serum concentration of 1,25 dihydroxyvitamin D. An underlying cause of the granulomatous lymphadenitis could not be identified. The clinical signs, hypercalcaemia and elevated serum concentrations of 1,25 dihydroxyvitamin D resolved following prednisolone treatment. In contrast to dogs, hypercalcaemia occurred secondarily to granulomatous disease and elevated 1,25 dihydroxyvitamin D concentrations is a well-recognised condition in human beings. To the authors' knowledge, this is the first case report to describe elevated serum calcium and 1,25 dihydroxyvitamin D concentrations in a dog with histologically confirmed granulomatous disease.

Expression of the major core structural protein (VP7) of bluetongue virus, by a recombinant capripox virus, provides partial protection of sheep against a virulent heterotypic bluetongue virus challenge

A recombinant capripox virus was constructed containing a cDNA copy of genome segment 7 of bluetongue virus (BTV) serotype 1 from South Africa (BTV 1SA), which expressed high levels of the major BTV core protein VP7 in infected lamb testis (LT) cells. Sheep vaccinated with this recombinant virus developed antibodies to VP7 (detected by ELISA) but no neutralizing antibodies to either the homologous or heterologous BTV serotype, prior to challenge (BTV 1 or BTV 3, respectively). Following challenge with a virulent heterotypic strain of BTV (BTV3 SA), all of the animals developed clinical signs of disease, indicating that they were infected and that the challenge virus did replicate. While all of the control animals died, six of the eight animals that were vaccinated with the recombinant capripox virus expressing VP7 recovered fully. This is the first report of a significant level of cross serotype protection against the lethal effects of a challenge with virulent BTV, produced by vaccination with a single BTV core protein, which did not generate a neutralizing antibody response.

Contamination of genetically engineered CHO-cells by epizootic haemorrhagic disease virus (EHDV)

The characterization of a contaminating virus which was detected in genetically-engineered Chinese hamster ovary (CHO) cells during the production of biologicals is described in the present paper. Under electron microscopy, the contaminating virus had a morphology resembling that of an orbivirus. The relationship was confirmed by nucleic acid analysis which showed a RNA segment pattern characteristic of orbiviruses. With an immunoperoxidase staining of monolayer cells and through sero-neutralization tests the virus was identified as being identical to Epizootic Haemorrhagic Disease Virus (EHDV), isolate 318 (untyped) from Bahrain. Potential sources of the contaminating virus and feasible procedures to avoid adventitous virus infections in cell cultures are discussed.

The anthelmintic effects of a new compound "E" (Friedheim) on Onchocerca gutturosa in the cow--a possible tertiary screening system for drug action against O. volvulus in man

Three cows were treated with different levels of compound "E" which is known to have strong filaricidal activity. In all three animals the number of microfilariae of Onchocerca gutturosa declined after treatment. At autopsy most of the adult worms found were dead and in those still living embryogenesis appeared to have ceased. It is concluded that, despite the disadvantages, this system represents a possible way of assessing onchocercicidal activity before undertaking human trials.