University of Alabama at Birmingham

About: University of Alabama at Birmingham is a education organization based out in Birmingham, Alabama, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 38523 authors who have published 86775 publications receiving 3930642 citations. The organization is also known as: UAB & The University of Alabama at Birmingham.

Influence of computer-aided detection on performance of screening mammography.

Abstract: BACKGROUND Computer-aided detection identifies suspicious findings on mammograms to assist radiologists. Since the Food and Drug Administration approved the technology in 1998, it has been disseminated into practice, but its effect on the accuracy of interpretation is unclear. METHODS We determined the association between the use of computer-aided detection at mammography facilities and the performance of screening mammography from 1998 through 2002 at 43 facilities in three states. We had complete data for 222,135 women (a total of 429,345 mammograms), including 2351 women who received a diagnosis of breast cancer within 1 year after screening. We calculated the specificity, sensitivity, and positive predictive value of screening mammography with and without computer-aided detection, as well as the rates of biopsy and breast-cancer detection and the overall accuracy, measured as the area under the receiver-operating-characteristic (ROC) curve. RESULTS Seven facilities (16%) implemented computer-aided detection during the study period. Diagnostic specificity decreased from 90.2% before implementation to 87.2% after implementation (P<0.001), the positive predictive value decreased from 4.1% to 3.2% (P=0.01), and the rate of biopsy increased by 19.7% (P<0.001). The increase in sensitivity from 80.4% before implementation of computer-aided detection to 84.0% after implementation was not significant (P=0.32). The change in the cancer-detection rate (including invasive breast cancers and ductal carcinomas in situ) was not significant (4.15 cases per 1000 screening mammograms before implementation and 4.20 cases after implementation, P=0.90). Analyses of data from all 43 facilities showed that the use of computer-aided detection was associated with significantly lower overall accuracy than was nonuse (area under the ROC curve, 0.871 vs. 0.919; P=0.005). CONCLUSIONS The use of computer-aided detection is associated with reduced accuracy of interpretation of screening mammograms. The increased rate of biopsy with the use of computer-aided detection is not clearly associated with improved detection of invasive breast cancer.

Tau phosphorylation in neuronal cell function and dysfunction

Abstract: Tau is a group of neuronal microtubule-associated proteins that are formed by alternative mRNA splicing and accumulate in neurofibrillary tangles in Alzheimer's disease (AD) brain. Tau plays a key role in regulating microtubule dynamics, axonal transport and neurite outgrowth, and all these functions of tau are modulated by site-specific phosphorylation. There is significant evidence that a disruption of normal phosphorylation events results in tau dysfunction in neurodegenerative diseases, such as AD, and is a contributing factor to the pathogenic processes. Indeed, the abnormal tau phosphorylation that occurs in neurodegenerative conditions not only results in a toxic loss of function (e.g. decreased microtubule binding) but probably also a toxic gain of function (e.g. increased tau-tau interactions). Although tau is phosphorylated in vitro by numerous protein kinases, how many of these actually phosphorylate tau in vivo is unclear. Identification of the protein kinases that phosphorylate tau in vivo in both physiological and pathological processes could provide potential therapeutic targets for the treatment of AD and other neurodegenerative diseases in which there is tau pathology.

Repeatability of published microarray gene expression analyses.

Abstract: Given the complexity of microarray-based gene expression studies, guidelines encourage transparent design and public data availability. Several journals require public data deposition and several public databases exist. However, not all data are publicly available, and even when available, it is unknown whether the published results are reproducible by independent scientists. Here we evaluated the replication of data analyses in 18 articles on microarray-based gene expression profiling published in Nature Genetics in 2005-2006. One table or figure from each article was independently evaluated by two teams of analysts. We reproduced two analyses in principle and six partially or with some discrepancies; ten could not be reproduced. The main reason for failure to reproduce was data unavailability, and discrepancies were mostly due to incomplete data annotation or specification of data processing and analysis. Repeatability of published microarray studies is apparently limited. More strict publication rules enforcing public data availability and explicit description of data processing and analysis should be considered.

Oral Azole Drugs as Systemic Antifungal Therapy

Abstract: The oral azole drugs--ketoconazole, fluconazole, and itraconazole--represent a major advance in systemic antifungal therapy. Among the three, fluconazole has the most attractive pharmacologic profile, including the capacity to produce high concentrations of active drug in cerebrospinal fluid and urine. Ketoconazole, the first oral azole to be introduced, is less well tolerated than either fluconazole or itraconazole and is associated with more clinically important toxic effects, including hepatitis and inhibition of steroid hormone synthesis. However, ketoconazole is less expensive than fluconazole and itraconazole--an especially important consideration for patients receiving long-term therapy. All three drugs are effective alternatives to amphotericin B and flucytosine as therapy for selected systemic mycoses. Ketoconazole and itraconazole are effective in patients with the chronic, indolent forms of the endemic mycoses, including blastomycosis, coccidioidomycosis, and histoplasmosis; itraconazole is also effective in patients with sporotrichosis. Fluconazole is useful in the common forms of fungal meningitis--namely, coccidioidal and cryptococcal meningitis. In addition, fluconazole is effective for selected patients with serious candida syndromes such as candidemia, and itraconazole is the most effective of the azoles for the treatment of aspergillosis.