Diagnosis

This can be by visualization of the virus by electron microscopy, detection of antigens, detection of genome by RT-PCR, or detection of specific antibody. Electron microscopy is how the viruses were first detected; however, the sensitivity of the test is low. Feces must contain at least 106 virus particles per milliliter. The virus is small and detection requires an experienced electron microscopist. Finally, the quantity of virus excreted drops rapidly below detectable levels after onset of disease. Antigen detection has used immune adherence hemagglutination, radioimmunoassay, and enzyme immu-noassay (EIA) formats.[1] Enzyme immunoassays for antigen detection are now available commercially. However, they are neither highly specific nor sensitive at detecting all genogroups of noroviruses.[21- There are no commercially available antigen capture EIAs for sapovi-ruses. Genome detection by reverse transcription poly-merase chain reaction (RT-PCR) is the most sensitive and specific method available for detection of human

caliciviruses.[1,22,23- However, selection of the correct primers is of major importance. Even relatively well-conserved regions of the genome such as the helicase or polymerase regions have nucleotide identities as low as 36% between genera and genotypes.[1] However, broadly reactive primer sets targeting the RNA polymerase of circulating noro- and sapoviruses have been designed which perform well[22- but may cross-react with the poly-merase of other viruses.[24] It may therefore be necessary to screen for the two genera separately. A highly sensitive broadly based quantitative RT-PCR has recently been

Table 2 Examples of primers used for the detection of human calicivirus from feces

Primer

Norwalk-like viruses[25] JV12 SM31 Ni E3

(A nested RT-PCR) Sapporo-like viruses[26] Sapp 36 Sapp 35 Both NLV and SLV[22] P289 P290

Sense

Sequence

5'ATA CCA CTA TGA TGC AGA TTA 3' 5'CGA TTT CAT CAT CAC CAT A 3' 5' GAA TTC CAT CGC CCA CTG GCT 3' 5' ATC TCA TCA TCA CCA TA-3'

5'-GTT CGT GTT GGC ATT AAC A-3' 5'-GCA GTG GGT TTG AGA CCA AAG-3'

5'-TGA CAA TGT AAT CAT CAC CAT A-3' 5'-GAT TAC TCC AAG TGG GAC TCC AC-3'

Amplicon size

333 bp 114 bp

470 bp

devised for noroviruses.[23] Some primer sets used to detect the human caliciviruses are shown in Table 2. It is likely that new primer sets will be required as our understanding of the range and variability of human caliciviruses expands. Antibody detection is used only for epidemiological purposes and numerous different antigens are needed.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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