The GeneXpert MTB/RIF assay was evaluated with microscopically negative and positive pulmonary and extrapulmonary specimens from patients with substantial clinical indications for tuberculosis. For the pulmonary samples, the sensitivity, specificity, and positive and negative predictive values were 90.6%, 94.3%, 93.5%, and 91.7%, and for the extrapulmonary samples, they were 100%, 91.6%, 50%, and 100%, respectively. For microscopically negative specimens, the respective values were 86.3%, 93%, 79%, and 95.6%. The assay correctly detected rifampin resistance in all but one specimen, which harbored a mixed population. The GeneXpert assay was highly effective for tuberculosis diagnosis and identification of rifampin-resistant strains in smear-negative samples.Tuberculosis (TB) remains a major public health problem, accounting for more than 9.4 million incident cases and 1.3 million deaths every year, worldwide (10). The emergence and spread of multidrug (MDR) and extensively (XDR) drug-resistant Mycobacterium tuberculosis complex (MTBC) strains poses significant challenges to disease control (11). In order to overcome conventional methods' low sensitivity and diagnostic delays, nucleic acid amplification (NAA) tests have been introduced. The NAA tests' sensitivities are high for specimens that are acid-fast bacillus (AFB) microscopy positive but lower for AFB-negative specimens (3). The identification of mutations associated with drug resistance depends on additional NAA tests, whose application on clinical samples is indicated only for AFB-positive specimens.The recently introduced Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA) detects the presence of MTBC DNA and its susceptibility to rifampin (RMP) in a single reaction (4,8). Monoresistance to RMP is rare; however, Ͼ90% of RMPresistant isolates also exhibit resistance to isoniazid (INH). Therefore, the detection of RMP resistance may serve as a surrogate marker for MDR M. tuberculosis (9). The assay is based on a heminested real-time PCR (RT-PCR) that targets the rpoB gene hot spot region. Any deviation from the wildtype sequence resulting in a delay in the appearance of the signal exceeding a predetermined ⌬C T value (Ͼ3.5), between the earliest and latest cycle threshold (C T ) values, is reported as RIF resistant. The test is carried out within 2 h in a disposable cartridge. The only manual step is the mixing of a bactericidal buffer with the sample prior to addition to the cartridge. This preamplification step reduces the viability of MTBC organisms, making the assay suitable for use near patients in settings with limited biocontainment facilities (1).A prospective study was conducted between September 2009 and May 2010 at the National Reference Laboratory for Mycobacteria (NRLM), Athens, Greece, in order to assess the performance of the Xpert MTB/RIF assay in AFB-negative respiratory and nonrespiratory specimens in a routine hospital laboratory setting. Specimens were selected from patients with strong clinical indications for TB. A small number of AFBpositiv...

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The oncofetal CRD-BP/IMP1 RNA binding protein regulates posttranscriptionally a handful of RNA transcripts, implicated in cell adhesion and invadopodia formation and was recently identified as a target of the b-catenin/Tcf transcription factor that is constitutively activated in colorectal carcinomas (CRCs). The expression of CRD-BP/IMP1 was studied in normal adult intestines and CRCs. In normal mucosa, CRD-BP/IMP1 immunoreactivity was observed in few scattered cells located predominantly at or near the bottom of the crypts, whereas in CRCs the protein was detectable in tumor cells of 50% of the specimens analyzed. CRD-BP/ IMP1 mRNA expression was measured by qRT-PCR in 78 CRCs. Thirty-two (41%) of the specimens were negative or had negligible expression, whereas the remaining forty-six (59%) expressed a wide range of CRD-BP/IMP1 mRNA levels. CRD-BP/IMP1 mRNA expression correlated with that of the putative stem/progenitor cell marker Musashi-1 mRNA (p 5 0. 035). CRD-BP/IMP1 positive tumors metastasized and/or recurred more frequently (p 5 0.001) and its expression defined a group of patients with shorter survival (p 5 0.014). Furthermore, in a multivariate analysis CRD-BP/IMP1 expression was found to be an independent predictor of survival (p 5 0.015). For stage I & II patients, the differences in metastasis/recurrence and survival rates remained significant (p 5 0.001 and 0.033, respectively). These findings indicate that CRD-BP/IMP1 positive tumors exhibit early disease dissemination and unfavorable prognosis. ' 2007 Wiley-Liss, Inc.

The coding region determinant binding protein (CRD-BP) was isolated by virtue of its high affinity to the c-myc mRNA coding region stability determinant and shown to shield this message from nucleolytic attack, prolonging its half -life. CRD-BP is normally expressed during fetal life but is also activated de novo in tumors. Considering that aberrant CRD-BP expression may represent an additional mechanism interfering with c-myc regulation, we screened 118 primary breast carcinomas for CRD-BP expression, 60 of which had also been analyzed by comparative genomic hybridization (CGH). Copy number gains encompassing 8q24, the chromosome band that contains the c-myc locus, were detected in 48.3% (29/60) of tumors, whereas gains involving band 17q21, which contains the CRD-BP locus, were observed in 18.3% (11/60) of tumors. CRD-BP expression was detected in 58.5% (69/118) of tumors, implying mechanisms of activation alternative to gene amplification. Altogether, some 75% of the tumors had alterations pertaining to c-myc since they either harbored 8q24 gains and/or expressed CRD-BP. Significant associations were detected between CRD-BP expression and the absence of estrogen receptors (p ‫؍‬ 0.005) and between the presence of 8q24 gains and an increased number of genomic changes as measured by CGH (p ‫؍‬ 0.0017). Tumors were divided into 4 groups according to CRD-BP expression and 8q24 gains. The odds for tumors having both characteristics to be classified as poorly differentiated (grade III vs. grade I and II) were 19.6 times the corresponding odds for tumors neither expressing CRD-BP nor harboring 8q24 gains. For tumors either harboring 8q24 gains only or expressing CRD-BP alone, the corresponding odds were 6.4 and 3, respectively.