Diagnostic Tests

A definitive diagnosis of chlamydial genital infection can be established solely on the basis of laboratory testing. In the past, the standard laboratory test for C. trachomatis genital infections was isolation of the causative organisms in cell culture. By definition, this test is 100% specific but it lacks sensitivity when compared to the newer NAATs. Several commercial tests are currently available (Table 1), and new tests are being developed every year.[8-11] The Roche Amplicor and Cobas Amplicor CT/NG tests use polymerase chain reaction;[12] the Becton-Dickinson B-D-

ProbeTec test uses strand displacement amplification;1-13-1 and the GenProbe Aptima test uses transcription-mediated amplification. All three tests amplify the cryptic plasmid which is found in >99% of the clinical isolates.[14] Unfortunately, the Abbott LCx test, which employs the ligase chain reaction, is no longer commercially available. The NAATs are extremely sensitive and can be applied to noninvasive specimens such as first-catch urine and self-administered vaginal swabs. However, NAATS detect dead as well as living organisms and may give false-positive results, particularly in low-prevalence settings, and they are relatively expensive. Liquid Pap smear medium for CT/NG collection has also been used with acceptable results.[15] As with all testing, each laboratory must establish an ongoing quality-assurance program to validate the test results.[16] Two nonamplified nucleic acid probe tests are commercially available which can diagnose both C. trachomatis and Neisseria gonorrhoeae simultaneously, but cannot differentiate between the two, requiring additional tests for verification. The GenProbe PACE 2 test uses a DNA probe that is specific for the rRNA. The Digene Hybrid Capture II test uses an RNA probe that is specific for the DNA of C. trachomatis and targets both the genomic DNA and cryptic plasmid.[17] The commercial DNA probe tests, direct immunofluores-cence tests, and antigen-capture ELISA tests are all used in peripheral laboratories, but lack sensitivity when compared to NAATs. Serological tests are of little value in the diagnosis of C. trachomatis infections caused by serovars A-K except in the case of detection of specific IgM responses in babies presenting with neonatal pneumonia where high titers of antibody may be detected when using an indirect immunofluorescence test.

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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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