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Objectives To compare image quality and diagnostic accuracy for the detection of liver lesions of virtual unenhanced (VU) images based on third-generation dual-source dual- energy computed tomography (DECT) compared to conventional unenhanced (CU) images. Methods Thirty patients underwent triphasic abdominal CT consisting of single-energy CU (120 kV, 147 ref.mAs) and dual-energy CT arterial and portal-venous phase acquisitions (100/Sn150 kV, 180/90 ref.mAs). VU images were generated from arterial (AVU) and portal venous (PVU) phases. CU, AVU and PVU datasets were reconstructed. Quantitative image quality analysis was performed and two abdominal radiologists independently analyzed all datasets to evaluate image quality and identify liver lesions. Radiation dose was recorded and potential radiation dose reduction was estimated. Results Image quality was rated diagnostic in 100% of the VU datasets. The mean subjective image quality of the CU datasets was higher than that of VU images (p < 0.0001). No significant difference was observed in the mean attenuation values of the liver parenchyma (p > 0.99) and hypoattenuating liver lesions (p ≥ 0.21) between CU, AVU and PVU. However, a significant reduction in the attenuation values of calcified lesions (p < 0.0001), metallic clips (p < 0.0001) and gallstones (p ≤ 0.047) was observed in the AVU and PVU images compared with CU images. A total of 122 liver lesions were found in 25 patients. VU images were more sensitive than CU images for detection of small hypoattenuating liver lesions (≤1 cm). However, CU images were more sensitive than VU for calcified liver lesions. The mean radiation dose reduction achievable by avoiding the unenhanced acquisition was 32.9% ± 1.1% (p < 0.01). Conclusions Third-generation DSCT VU images of the liver provide diagnostic image quality and improve small (≤1 cm) liver lesion detection; however calcified liver lesions can be missed due to complete subtraction.

Contains fulltext : 118685.pdf (publisher's version ) (Open Access), Facioscapulohumeral dystrophy (FSHD) is a progressive muscular dystrophy caused by decreased epigenetic repression of the D4Z4 macrosatellite repeats and ectopic expression of DUX4, a retrogene encoding a germline transcription factor encoded in each repeat. Unaffected individuals generally have more than 10 repeats arrayed in the subtelomeric region of chromosome 4, whereas the most common form of FSHD (FSHD1) is caused by a contraction of the array to fewer than 10 repeats, associated with decreased epigenetic repression and variegated expression of DUX4 in skeletal muscle. We have generated transgenic mice carrying D4Z4 arrays from an FSHD1 allele and from a control allele. These mice recapitulate important epigenetic and DUX4 expression attributes seen in patients and controls, respectively, including high DUX4 expression levels in the germline, (incomplete) epigenetic repression in somatic tissue, and FSHD-specific variegated DUX4 expression in sporadic muscle nuclei associated with D4Z4 chromatin relaxation. In addition we show that DUX4 is able to activate similar functional gene groups in mouse muscle cells as it does in human muscle cells. These transgenic mice therefore represent a valuable animal model for FSHD and will be a useful resource to study the molecular mechanisms underlying FSHD and to test new therapeutic intervention strategies.

Item does not contain fulltext, Facioscapulohumeral muscular dystrophy (FSHD) is a common form of muscular dystrophy in adults that is foremost characterized by progressive wasting of muscles in the upper body. FSHD is associated with contraction of D4Z4 macrosatellite repeats on chromosome 4q35, but this contraction is pathogenic only in certain "permissive" chromosomal backgrounds. Here, we show that FSHD patients carry specific single-nucleotide polymorphisms in the chromosomal region distal to the last D4Z4 repeat. This FSHD-predisposing configuration creates a canonical polyadenylation signal for transcripts derived from DUX4, a double homeobox gene of unknown function that straddles the last repeat unit and the adjacent sequence. Transfection studies revealed that DUX4 transcripts are efficiently polyadenylated and are more stable when expressed from permissive chromosomes. These findings suggest that FSHD arises through a toxic gain of function attributable to the stabilized distal DUX4 transcript.

The CIA has had an Inspector General (IG) since 1952. But it was only in 1989 that Congress enacted legislation creating an "independent" IG at CIA, appointed by the President with the advice and consent of the Senate. Before that, IGs were appointed by the Director of Central Intelligence (DCI)., Published in Studies in Intelligence, v44 n5 p15-21, Winter-Spring 2001.

In January 1975, I was offered a position as counsel on the staff of the Church Committee. I was 30, and Senator Sam Ervin, for whom I had worked since 1971, had retired and returned to North Carolina. While I had participated in Senator Ervins inquiry into the domestic activities of Army intelligence elements during the Vietnam era, the foreign intelligence apparatus of the United States, which I now confronted, was, quite literally, foreign to me, as it was to many of those joining the Church Committee staff. To make matters worse, I was given the task (along with a staff colleague, Peter Fenn) of trying to crack what was perceived to be the most secretive of US intelligence agencies, the National Security Agency (NSA). Unlike the CIA and FBI, which were the agencies principally in the Committees sights thanks to a number of sensational press accounts, there had been no press exposes about NSA. Our supervisor, in fact, seemed to take particular delight in pitting Pete and me against this mysterious Goliath. They call it No Such Agency, he said. Lets see what you boys can find out about it. It was the first time I had heard the agency referred to this way, and it was not long before I understood why., Published in Studies in Intelligence, v43 n3 p43-51, Winter 1999-2000.

The intelligence services of the United States, like their counterparts in most countries, exist principally to serve the needs of the executive authority. The US intelligence apparatus, however unlike that of most countries also makes a large part of its output available to the legislative authority. It has not always been so. Before the mid-1970s, Congress was given little intelligence, and access to it was limited. The Congressional investigations of US intelligence agencies in 1975-76 by the Church and Pike Committees fundamentally altered this situation. For the first time, voluminous amounts of intelligence information were shared with the investigating committees. When permanent oversight committees were later created in both Houses, the trend toward ever-increasing disclosure continued. Ground rules to govern intelligence sharing were agreed to shortly after the oversight committees began operations, but none were written down. Over time, these understandings often gave way in the continuing tussle between the overseers and the overseen. Twenty years later, the system still operates without formal rules of the road. Serious problems, however, have largely been avoided because intelligence agencies have sought to accommodate virtually all Congressional requests in some manner. Congress, in turn, has generally demonstrated a willingness to protect the intelligence it has been given. The two sides continue to muddle along from one episode to the next, accommodating where they can, bending where they must., Published in Studies in Intelligence, v41, n5 p47-69, Spring 1998.