[Myocardial metastasis of bronchial carcinoma. Disclosed by x-ray computed tomography].

One case of cardiac metastasis of epidermoid carcinoma discovered with CT during the preoperative assessment is reported. The authors stress that the discovery of cardiac metastases in vivo is relatively infrequent. They emphasize the role of imaging, which allows ruling out the operation in these cases.

Can portable chest x-ray examination accurately diagnose lung consolidation after major abdominal surgery? A comparison with computed tomography scan.

Purpose: To prospectively quantify the degree of accuracy of portable chest x-ray film examination in the detection of postoperative lung consolidations.

Study: Nineteen patients had a chest x-ray film and computed tomography (CT) scan the day before and 48 h following elective abdominal aortic replacement.

Results: The diagnosis of lung consolidations by x-ray film examination showed sensitivity of between 0.

[X-ray computed tomography of thoracic injuries. Apropos of 40 cases].

On chest radiographs, the precise assessment of thoracic injuries consecutive to blunt trauma is often compromised by the nonspecific appearance of many lesions. Furthermore, significant injuries are frequently overlooked. However, the management of the patients with chest trauma is still often based primarily upon clinical and radiographic findings and Computed Tomography (CT) is often performed secondarily on the basis of unexplained clinical signs or suspected radiographic abnormality.

Accuracy of in-vivo assessment of prostatic volume by MRI and transrectal ultrasonography.

More accurate noninvasive estimation of prostate size is important in therapeutic trials for benign prostatic hyperplasia. The accuracy of MRI and transrectal ultrasound (TRUS) in assessing prostate weight was evaluated in 48 patients who underwent radical prostatectomy for stage A or B cancer. The volume derived from the wet weight of the freshly excised specimen was used as a reference.

Castleman disease mimicking liver tumor: CT and MR features.

We report the CT and MR features of two localized abdominal forms of Castleman disease mimicking hypervascular liver tumors due to their unusual location in the porta hepatis and the portacaval space. The MR appearance of Castleman lymph nodes is emphasized, including their characteristics on dynamic turbo-fast low angle shot (FLASH) sequences after Gd-DOTA bolus injection. Our report suggests that the CT and MR features of Castleman lymph nodes in these locations cannot enable their differentiation from other hypervascular masses such as benign liver tumors.

[Clinical symptomatology and radiological aspects of primary cancers of the liver].

Hepatocellular carcinoma is a malignant tumor derived from hepatocytes. It is the most frequent of primary liver cancers. In 90% of the cases, it occurs in a cirrhotic liver and is now more and more detected by ultrasonographic screening of cirrhotic patients.

Fast magnetic resonance imaging in the evaluation of tumoral obstructions of the inferior vena cava.

A prospective study was conducted on 9 patients with suspected obstruction of the inferior vena cava on ultrasonography, dynamic computerized tomography and/or inferior venacavography during the course of a retroperitonal tumor to assess the value of magnetic resonance imaging with gradient echo sequences. The findings on gradient echo magnetic resonance imaging were compared with the other imaging modalities and surgical or necropsy results. Our results suggest that gradient echo magnetic resonance imaging is the most appropriate imaging modality to diagnose and delineate the extent of inferior vena caval obstruction.

Unusual complication of liver irradiation: acute thrombosis of a main hepatic vein: CT and MR imaging features.

The pathologic changes resulting from liver irradiation include congestion, fibrosis, and veno-occlusive disease. We report an unusual complication of radiation induced injury: acute thrombosis of a main hepatic vein within the radiation port. CT and MR features are described and the etiology of this unusual complication is discussed.

Asymptomatic renal-vein thrombosis in adult nephrotic syndrome ultrasonography and urinary fibrin-fibrinogen products: a prospective study.

Objectives: The diagnosis of renal vein thrombosis (RVT), a frequent complication of adult nephrotic syndrome (NS), is generally made by means of invasive methods, i.e. renal venography, venous time of renal arteriography and, more recently, computed tomography (CT).

Z-DNA as a probe for localized supercoiling in vivo.

Biological processes such as transcription are expected to generate local variations in DNA supercoiling. The existence of localized supercoiling was recently demonstrated in Escherichia coli by using the supercoil-driven B-to-Z transition as a superhelicity probe. This new methodology is described and its extension to other biological systems discussed.

Direct evidence for the effect of transcription on local DNA supercoiling in vivo.

The B-to-Z structural transition of varying lengths (74 to 14 base-pairs) of (CG) tracts has been used as a superhelicity probe to examine the local topological changes induced by transcription at defined genetic loci in vivo. The local-topology reporter sequences indicate that under steady-state transcription the region upstream from the promoter experiences an increase in negative supercoiling whereas the region downstream from the terminator displays a decrease in negative superhelicity. This result provides direct in vivo evidence for the notion that the translocation of an RNA polymerase elongation complex along the double-helical DNA generates positive supercoils in front of it and negative supercoils behind it.

Value of CT and sonography in the conservative management of acute splenoportal and superior mesenteric venous thrombosis.

Acute splenoportal and superior mesenteric venous thrombosis were diagnosed on sonography and computed tomography (CT) in six patients. Sonography demonstrated the presence of echoic material filling the involved vessels in all patients. Precontrast CT scans demonstrated an increased, intra luminal density of the clots in four patients with splenoportal thrombosis.

[Gradient echo sequences in the diagnosis of inferior vena cava thrombosis].

The capability for studying noninvasively vessels has been dramatically improved with the use of gradient echo sequences. Twenty-one patients presenting a suspected inferior vena cava obstruction on cavography underwent MR examination with axial, sagittal and coronal gradient echo images. Eighteen patients were also imaged with ultrasound and/or CT.

Invasion of the neurovascular bundle by prostate cancer: evaluation with MR imaging.

Preservation of the neurovascular bundle (NVB) and potency without compromising tumor control are current objectives of radical retropubic prostatectomy as treatment for prostate cancer, but preoperative determination of whether cancer has invaded the NVB can be difficult. The use of conventional body-coil magnetic resonance (MR) imaging to make this preoperative determination was evaluated in 50 patients with biopsy-proved cancer. All patients underwent radical retropubic prostatectomy after MR imaging.

Focal nodular hyperplasia of the liver: assessment with contrast-enhanced TurboFLASH MR imaging.

Twenty-two patients with 25 cases of focal nodular hyperplasia (FNH) proved with pathologic study were imaged with a TurboFLASH (fast low angle shot) sequence combined with bolus administration of gadolinium tetraazacyclododecanetetraacetic acid (DOTA), spin-echo (SE) T2-weighted sequences, and postcontrast T1-weighted sequences. FNH-liver signal-difference-to-noise ratios were quantified; the features of the central scar were qualitatively analyzed. On SE T2-weighted images, all FNHs were hyperintense; in two cases the central scar exhibited a high signal intensity associated with hypointense areas corresponding to fibrous tissue within the branches of the scar.

Interstrand cross-links are preferentially formed at the d(GC) sites in the reaction between cis-diamminedichloroplatinum (II) and DNA.

A DNA restriction fragment with convergent SP6 and T7 promoters has undergone reaction with cis-diamminedichloroplatinum(II) (cis-DDP) and was then used as a template for RNA synthesis in vitro. The T7 and SP6 RNA polymerases generate fragments of defined sizes. Analysis of the RNA fragments shows that the polymerases are mainly blocked at the level of the d(GG) and d(AG) sites and to a lesser extent at the level of the d(GC) sites.

Flanking AT-rich tracts cause a structural distortion in Z-DNA in plasmids.

The effect of neighboring AT-rich sequences on the right-handed B to left-handed Z transition was investigated in plasmids. The supercoil stabilized Z-DNA structure in (CG) tracts 36 and 40 base pairs (bp) in length revealed an unexpected conformational aberration at defined C residues proximal to one end (colL) when the inserts were bilaterally flanked by an 80% AT-rich segment (90 bp on one side and 331 bp on the other). The presence of the perturbed Z-conformation required (CG) stretches longer than 32 bp and bilateral flanking by the AT-rich tracts, since plasmids with the (CG) tracts unilaterally flanked had an orthodox Z-structure.

Normal age-related patterns of cellular and fatty bone marrow distribution in the axial skeleton: MR imaging study.

Knowledge of age-related distribution patterns of cellular and fatty marrow is critical to the interpretation of magnetic resonance (MR) imaging studies. To determine such patterns, the authors retrospectively evaluated 70 examinations each of the skull, cervical spine, thoracic spine, lumbar spine, pelvis, and proximal femur (420 examinations) in patients without known bone marrow abnormality who ranged in age from 6 months to older than 70 years. Two to four distinct patterns were identified in each anatomic area on spin-echo images obtained with a short repetition time and a short echo time.

Stabilization of Z DNA in vivo by localized supercoiling.

Biological processes such as transcription may generate domains of supercoiling on a circular DNA. The existence of these domains in Escherichia coli was investigated by the ability of different lengths of (CG) tracts, cloned upstream or downstream from the tetracycline resistance gene (tet) of pBR322, to adopt the Z structure in vivo. Segments as short as 12 base pairs adopt the Z form when cloned upstream from the tet gene (Eco RI site), whereas no Z DNA was detected when this sequence was cloned downstream (Sty I site), even with a 74-base pair (CG) tract that requires less supercoiling than shorter tracts for the B-Z transition.

Structure of the intrastrand cis-[Pt(NH3)2(d(GpCpG))] adduct in a dodecanucleotide duplex: II. A molecular mechanics modeling study.

Molecular mechanics modeling has been carried out for the intrastrand cis-[Pt(NH3)2(d(pGpCpG))] adduct in a dodecanucleotide duplex. In a first step, an analysis of the conformation of a platinated trinucleotide shows the tendency of the two chelating guanines to take respectively anti-syn or syn-anti positions and the role of phosphate-platinum amino group interactions. In a second step, duplex structures are examined.

Structure of the intrastrand cis-[Pt(NH3)2(d(GpCpG))] adduct in a dodecanucleotide duplex: I. A 1H and 31P n.m.r. study.

The structure of an intrastrand cis-[Pt(NH3)2(d(GpCpG))] adduct in a dodecanucleotide duplex has been investigated by using ultraviolet absorption, circular dichroism, 1H and 31P n.m.r.

Aging of the diaphragm: a CT study.

To determine the normal morphologic evolution of the diaphragm with aging and to correlate age-related changes with other indicators of physical condition--such as skeletal muscle status, obesity, presence of pulmonary emphysema, and presence of esophageal hiatus hernia--a systematic morphometric and morphologic evaluation of computed tomographic studies of 120 patients from the 3d to 8th decades of life was undertaken. Diaphragm muscle thickness did not change significantly with increasing age. Diaphragmatic defects and pseudotumors, nonexistent in the 3d and 4th decades, increased in number and severity to affect 56% of the patients in the 7th and 8th decades.

Reaction of nucleic acids with cis-diamminedichloroplatinum(II): interstrand cross-links.

In the reaction of cis-diamminedichloroplatinum(II) (cis-DDP) with double-helical (dC-dG)4.(dC-dG)4 or (dC-dG)5.(dC-dG)5, intrastrand and interstrand cross-links between two guanine residues are formed.