Clinical pathology of Australian bluetongue virus serotype 16 infection in Merino sheep

SUMMARY Viraemic blood from an ox naturally infected with Australian bluetongue (BLU) virus serotype 16 was passaged twice in sheep. Twelve 2- to 4-years-old Merino ewes, negative in a bluetongue agar gel Immunodiffusion test, were Inoculated with viraemic blood from the second sheep passage. They were examined for 18 days and compared with a control group. Significant changes in haematological measurements, namely packed cell volume, total white cell count and lymphocyte count, and in plasma enzyme concentrations, namely aspartate transaminase and creatine kinase, occurred in the infected sheep. All Infected sheep became sick. The antibody response, and clinical and necropsy findings were consistent with other reports of mild to moderate disease with Australian BLU serotypes.     

Hierarchical structure in polymeric materials

The diversity of monomers available for synthesis of high polymers makes it possible to prepare a wide variety of long-chain macromolecular compounds. It is instructive to consider a hierarchical organization of structure in polymers at four successive levels--the molecular, nano-, micro-, and macrolevels--and to examine how interactions at and between these various levels of structure have important and often quite specific influences. Examples are drawn from semicrystalline polymers with flexible chains, liquid-crystalline polymers composed of rigid macromolecules, and amorphous polymers. Structural hierarchies in biocomposite systems are also discussed, particularly in soft connective tissues such as tendon and intervertebral disk.     

PCR detection ofclavibacter michiganensis subsp.sepedonicus- infected tuber samples in a plate capture assay

The speed and sensitivity of PCR-based assays allow shorter turnaround times for the detection of pathogens for which culture and serological methods are difficult or unavailable. PCR was performed with primer sets Cms50 and Cms72, designed previously by Millset al. (1997) through subtractive hybridization to detectClavibacter michiganensis subspeciessepedonicus (Cms). In bacterial suspensions, fewer than three cells/10 ul reaction were detected after PCR amplicons were hybridized with specific DIG-labeled DNA probes in an enzyme-linked oligonucleosorbent assay (ELOSA). In naturally infected tuber samples representing three cultivars of potato, the diagnostic sensitivity of PCR/ ELOSA was 96%, while the specificity exceeded 99%. PCR/ELOSA detectedCms in infected tuber samples with equal sensitivity regardless of colony morphology, potato cultivar, or primer sets.