An Echinococcus multilocularis coproantigen is a surface glycoprotein with unique O-gycosylation

A major surface constituent of Echinococcus multilocularis adult worms, referred to as EmA9 antigen, was immunoaffinity purified and identified as a high molecular weight glycoconjugate. Labelling studies using the monoclonal antibody MAbEmA9 indicated that this antigen undergoes a regulated expression during the development from the larval to the adult parasite. Chemical modification of carbohydrate by periodate oxidation resulted in a reduced reactivity with antigen specific antibodies. Non-reductive beta-elimination of the purified molecule indicated the presence of O-linked glycans attached to threonine residues. Carbohydrate compositional analyses indicated the presence of N- and O-glycans with the ratio of carbohydrate to protein being 1.5:1 (w/w). N- and O-linked glycans were released by hydrazinolysis and analysed as 2-aminobenzamide derivatised glycans by mass spectrometry together with HPLC and enzymatic sequencing. Novel linear O-linked saccharides with multiple beta-HexNAc extensions of reducing end Gal were identified. N-linked glycans were also detected with oligomannose and mono-, bi-, tri- and tetra-antennary type structures, most of which were found to be core-fucosylated. Taken together, the results indicate that the EmA9 antigen is a glycoprotein located at the outer surface of the adult E. multilocularis. The observation that the EmA9 antigen expression is developmentally regulated suggests an involvement of this glycoprotein in the establishment of the parasite in its canine hos

Efficacy of a combination of imidacloprid 10%/moxidectin 2.5% spot-on (Advocate® for dogs) in the prevention of canine spirocercosis (Spirocerca lupi)

The nematode Spirocerca lupi is a major canine parasite in warm regions of the world, classically causing parasitic nodules in the esophagus, aortic aneurysms, and spondylitis. This study evaluated the preventive efficacy of monthly treatment with imidacloprid 10%/moxidectin 2.5% spot-on (Advocate® for dogs) administered over a period of 9 months in young dogs naturally exposed to S. lupi on Réunion island. One hundred and twelve puppies, aged from 2.0 to 4.0 months and with a negative spirocerca fecal examination at inclusion, completed the study. They were randomly allocated to two groups. Group A puppies (n = 58) received nine spot-on treatments with Advocate® at the minimum dose of 2.5 mg moxidectin/kg bw at monthly intervals. Control group B puppies (n = 54) received no treatment for S. lupi. During the study, regular clinical and fecal examinations were performed, as was final upper gastrointestinal endoscopy. Endoscopy showed that 19 dogs from group B had spirocerca nodules, corresponding to a prevalence of 35.2% in dogs aged 12 to 14 months. In contrast, only one dog from group A had a nodule, corresponding to a preventive efficacy of 94.7% (p < 0.0001). None of the 378 fecal examinations were positive for spirocerca. This study confirms a high prevalence of canine spirocercosis on Réunion and shows that infestation occurs in very young puppies. Furthermore, it demonstrates that monthly spot-on administration of a combination of imidacloprid 10%/moxidectin 2.5% (Advocate® for dogs) in puppies starting at the age of 2 to 4 months achieves effective and safe prevention of canine spirocercosis

Scanning electron microscopy observations of the hedgehog stomach worm, Physaloptera clausa (Spirurida: Physalopteridae).

Background: Physaloptera clausa (Spirurida: Physalopteridae) nematodes parasitize the stomach of the European hedgehog (Erinaceus europaeus) and cause weight loss, anorexia and gastric lesions. The present study provides the first morphological description of adult P. clausa from the stomachs of infected hedgehogs, using scanning electron microscopy (SEM). Methods. From June to October 2011, 10 P. clausa from European hedgehogs were fixed, dried, coated and subjected to SEM examination. Results: Males and females (22-30 mm and 28-47 mm, respectively) were stout, with the cuticle reflecting over the lips to form a large cephalic collarette and showing fine transverse striations in both sexes. The mouth was characterized by two large, simple triangular lateral pseudolabia, each armed with external and internal teeth. Inside the buccal cavity, a circle of internal small teeth can be observed. Around the mouth, four sub-median cephalic papillae and two large amphids were also observed. The anterior end of both male and female bore an excretory pore on the ventral side and a pair of lateral ciliated cervical papillae. In the female worm, the vulva was located in the middle and the eggs were characterized by smooth surfaces. The posterior end of the female worm was stumpy with two large phasmids in proximity to its extremity. The posterior end of the male had large lateral alae, joined together anteriorly across the ventral surface, with subequal and dissimilar spicules, as well as four pairs of stalked pre-cloacal papillae, three pairs of post-cloacal papillae, and two phasmids. Three sessile papillae occured anteriorly and four posteriorly to the cloaca. Conclusions: The present SEM study provides the first in-depth morphological characterization of adult P. clausa, and highlights similarities and differences with P. bispiculata P. herthameyerae, Heliconema longissimum and Turgida turgida

Evaluation of the electrical properties of nickel silicide films for ULSI applications

NRC publication: Ye

Thickness dependence of the properties and thermal stability of PtSi films

The phase growth sequence, structural, electrical and optical properties and thermal stability of platinum silicide films were investigated as a function of silicide film thickness in the range 133-2506 ?. The platinum silicide films were formed by ex situ silicidation of Pt films sputter-deposited onto n--Si (100) substrates. Films of all thickness were polycrystalline but exhibited columnar growth morphology and strong orientation effects. The orientation, grain size, electrical resistivity, specular reflectance and thermal stability were observed to be strongly thickness dependent. The temperature at which the film properties degraded increased with film thickness. The degradation mechanism appeared to be Pt diffusion into Si accompanied by the disintegration of the PtSi layer and the formation of an additional Pt3Si phase.NRC publication: Ye

Bacteria as potential tumour fighter

Despite significant progress in the development of therapeutic drugs and treatments, deaths due to cancer still remains high. These therapies are also not specific to tumour regions, hence causing adverse effects to the patients. Bacteria had long been studied for its ability to multiple within tumour regions and also reducing tumour volumes. Salmonella had also been studied and shown to be able to attack cancerous cells. To ensure the bacteria therapy is safe for clinical trial purposes, the bacteria need to undergo the process of silencing and in vivo assessment. This study was carried out to assess the use of SPI knockout S. Typhimurium and S. Agona as a possible tumour reduction agent and to investigate the effect of the SPI knockout strains on the survival of mice with induced tumour. 3 x 106 CT26 cells suspended in PBS were inoculated subcutaneously on the thigh to induce solid tumour. The subjects were then treated with the four bacterial treatments via intraperitoneal and intratumoural route of administration. The changes in the sizes of the tumours were observed daily using a calipher. The subjects were then sacrificed and the organs were harvested for histopathological analysis. One-way ANOVA indicated that the treatments had significant effects at p < 0.05, on both the changes of the tumour volumes and also the survival periods of the subjects. Subjects treated with S. Agona showed better survival compared to subjects treated with S. Typhimurium. S. Agona is found to be a better candidate as a tumour reduction agent, compared to S. Typhimurium, since it showed longer survival period of subjects after treatment and yet, had similar capacity as a tumour reduction agent