Molecular Methods

For rapid diagnosis, two nucleic acid amplification tests (NAA), the amplified M. tuberculosis direct test (MTD) (bioMerieux) and AMPLICOR (Roche) M. tuberculosis test, have been cleared by the Food and Drug Adminis tration (FDA) for direct use in smear-positive respiratory samples, whereas enhanced MTD (Genprobe, bioMerieux) is also approved for smear-negative respiratory cases. A number of molecular methods have been used to differentiate between M. tuberculosis and NTM and also for speciating NTM.

Nucleic acid sequence-based amplification assay, a MTD type of assay, has been used for the detection of M. avium, Mycobacterium paratuberculosis, and Mycobacterium intracellulare using a set of primers and probes[15] directly on sputum sample. Restriction enzyme analysis of the amplified segment of the gene encoding for the 650 kDa mol. wt. heat shock protein and polymerase chain reaction with single universal primer was used to identify MTB complex and species identification of NTM.[17] Bhattacharya et al.[18] have developed a multiplex PCR based on amplification of 165-, 365-, and 541-bp target fragments to distinguish between strains of MTB complex and NTM.

Hall et al.[19] evaluated the Microseq 500 system and could identify 98.3% of the ATCC strains and 90.1% of the clinical isolates to the species/group level. The 5' exonuclease fluorogenic PCR assay[20] had a 100% positive predictive value to detect mycobacteria in clinical samples. Smear-positive samples had a sensitivity of 90.3% as compared with smear-negative (49.2%). The INNO-LiPA Mycobacteria and GenoType Mycobakterien (Hain Diagnostica) are DNA strip assays and have identified 89.4% and 95.1% of mycobacterial isolates, respectively.[21]

A new technology involving high-density oligonucle-otide arrays or ''DNA chips'' can be used to examine large amount of DNA sequences. The nucleotide sequence diversity in 10 mycobacterial species from 121 mycobac-terial isolates was examined by Gingeras et al.[22] by analyzing the rpoB oligonucleotide array hybridization patterns. The use of this array allowed simultaneous detection of mutations that confer rifampicin resistance as well as species identification.

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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