Increased carbonylation of the lipid phosphatase PTEN contributes to Akt2 activation in a murine model of early alcohol-induced steatosis.

The production of reactive aldehydes such as 4-hydroxynonenal (4-HNE) is a key event in the pathogenesis of alcoholic liver disease (ALD), which ranges from simple steatosis to fibrosis. The lipid phosphatase PTEN plays a central role in the regulation of lipid metabolism in the liver. In this study, the effects of chronic ethanol feeding and carbonylation on the PTEN signaling pathway were examined in a 9-week mouse feeding model for ALD. Chronic ethanol consumption resulted in altered redox homeostasis as evidenced by decreased GSH, decreased Trx1, and increased GST activity. Both PTEN expression and PTEN phosphorylation were significantly increased in the livers of ethanol-fed mice. Carbonylation of PTEN increased significantly in the ethanol-fed mice compared to pair-fed control animals, corresponding to decreased PTEN 3-phosphatase activity. Concomitantly, increased expression of Akt2 along with increased Akt phosphorylation at residues Thr(308), Thr(450), and Ser(473) was observed resulting in increased Akt2 activity in the ethanol-fed animals. Akt2 activation corresponded to a decrease in cytosolic SREBP and ChREBP. Subsequent LC/MS/MS analysis of 4-HNE-modified recombinant human PTEN identified Michael addition adducts of 4-HNE on Cys(71), Cys(136), Lys(147), Lys(223), Cys(250), Lys(254), Lys(313), Lys(327), and Lys(344). Computational-based molecular modeling analysis of 4-HNE adducted to Cys(71) near the active site and Lys(327) in the C2 domain of PTEN suggested inhibition of enzyme catalysis via either stearic hindrance of the active-site pocket or prevention of C2 domain-dependent PTEN function. We hypothesize that 4-HNE-mediated PTEN inhibition contributes to the observed activation of Akt2, suggesting a possible novel mechanism of lipid accumulation in response to increased reactive aldehyde production during chronic ethanol administration in mice.

Advanced breast biopsy instrumentation device: percentages of lesion and surrounding tissue removed.

OBJECTIVE: This study reports the percentage of tissue in breast biopsy specimens from the lesion, and from the surrounding tissue, in 101 cases of Advanced Breast Biopsy Instrumentation (ABBI) biopsies. It also reports the status of the histologic margins for the malignant biopsies. MATERIALS AND METHODS: One hundred one consecutive ABBI biopsies were reviewed. The ABBI specimen radiographs were used to measure the area occupied by the entire specimen, the area excluding the lesion, and the area of the lesion alone. These areas, the length, and the width of all specimens were statistically analyzed using computer software. RESULTS: Of the 101 biopsies, histologic diagnosis was malignant in 27 and benign in 74. Of the 27 malignancies, four had negative margins and 23 had positive margins. Of the 23 with positive margins, eight were ductal carcinoma in situ (tumor within 0.5 mm or less of the surgical margin), and 15 were not ductal carcinoma in situ (tumor at the surgical margin). The average specimen length was 5.51 cm and the average width was 1.65 cm. The average percentage of lesion tissue was 9.9%. CONCLUSION: An average of 90.1% of tissue removed by ABBI biopsies was from surrounding tissue only. Uninvolved tissue is unfortunately included because of the cylindric geometry of the ABBI cannula. The ABBI biopsy has a high percentage (85.2%) of positive margins for malignant lesions and is poor excisional tool. For diagnostic biopsies, core needle biopsy is preferable because a smaller tissue volume is resected directly from the lesion site.

Internal mammary lymphadenopathy: imaging of a vital lymphatic pathway in breast cancer.

The prognostic significance of metastases to the internal mammary lymph nodes in patients with breast carcinoma has long been recognized. While ipsilateral dissection of axillary nodes remains a popular staging strategy for breast cancer, surgical sampling of the upper anterior intercostal spaces, a tedious procedure, has been largely abandoned. Diagnostic imaging of the parasternal lymphatic pathway is a useful and noninvasive alternative to surgical staging. This report reviews the pertinent regional anatomy and illustrates the criteria for diagnosing internal mammary lymphadenopathy by means of lateral chest radiography, computed tomography, high-resolution sonography, magnetic resonance imaging, and radionuclide lymphoscintigraphy.

Testes and scrotum: MR imaging at 1.5 T.

Magnetic resonance (MR) images of the scrotum were obtained at 1.5 T in 20 subjects, 13 patients with intrascrotal pathologic conditions and seven healthy subjects. Characteristic MR imaging signals obtained on T1- and T2-weighted images allowed differentiation of testis from epididymis and spermatic cord. Masses were differentiated from normal testicular parenchyma in all cases. Atrophic or ischemic testes had lower signal intensity than normal testes on T2-weighted images. Hematoma displayed a characteristic high intensity on both T1- and T2-weighted images. Intratesticular and extratesticular pathologic conditions were readily differentiated. These results suggest that MR imaging is useful in the diagnosis of scrotal and testicular abnormalities.

Mammographic microcalcifications: detection with xerography, screen-film, and digitized film display.

Pulverized bone specks and aluminum oxide specks were measured by hand into sizes ranging from 0.2 mm to 1.0 mm and then arranged in clusters. These clusters were superimposed on a human breast tissue phantom, and xeromammograms and screen-film mammograms of the clusters were made. The screen-film mammograms were digitized using a high-resolution laser scanner and then displayed on cathode ray tube (CRT) monitors. Six radiologists independently counted the microcalcifications on the xeromammograms, the screen-film mammograms, and the digitized-film mammograms. The xeromammograms were examined with a magnifying glass; the screen-film images were examined with a magnifying glass and by hot light; and the digitized-film images were examined by electronic magnification and image processing. The bone speck size that corresponded to a mean 50% detectability level for each technique was as follows: xeromammography, 0.550 mm; digitized film, 0.573 mm; and screen-film, 0.661 mm. We postulate that electronic magnification and image processing with edge enhancement can improve the capability of screen-film mammography to enhance the detection of microcalcifications.

[3-dimensional craniofacial computerized tomography]. / Tomografia computerizzata tridimensionale cranio-facciale.

Computed tomography allows today to reconstruct three-dimensional (3D) images from axial scans. The authors report their experience in cranio-facial pathology achieved in two Departments of Radiology (University of Trieste, Italy and University of Stanford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The applications in maxillo-facial traumas, cranio-facial malformations and head tumours are discussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demonstration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.

[Digital radiology. Clinical experience]. / Radiologia digitale. Esperienza clinica.

The authors report the experience achieved at the Stanford University (USA) with a digital radiography system which allows the digitization of the film and of the images collected with photostimulable phosphors. The phosphor is essentially an intensifying screen where a latent image is stored after exposure to X-rays and is extracted by a laser scanning. The images collected with the digitized film and with the phosphor (chest, breast, bone) have been analyzed. The digitized film offers potential diagnostic advantages over the conventional film, because of the contrast manipulation and many other processing options. The possibility to recover the information of overexposed films appears very attractive. The photostimulable phosphors allow to get good quality images, with a consistent reduction of dose and costs. These plates offer the possibility, in the next future, to replace the conventional screen-film systems.

Intratesticular adrenal rests diagnosed by ultrasound.

Adrenal rest tumors of the testes may occur in conditions associated with increased circulating adrenocorticotropic hormone (ACTH), including congenital adrenal hyperplasia (CAH) and Addison disease. Sonographically, these tumors appear as multiple round, hypoechoic nodules near the testicular hilus and are usually bilateral. They may undergo extensive fibrosis and become hyperechoic with acoustic shadowing. In the absence of excess ACTH or characteristic ultrasound findings, biopsy is recommended to exclude malignancy. Because malignant degeneration is very rare, close clinical and sonographic follow-up without biopsy is generally sufficient. Serial sonograms are useful to document stability or regression of tumor size during glucocorticoid replacement therapy.

Computed tomography of amiodarone pulmonary toxicity.

Amiodarone, an antiarrhythmic agent, is known to induce pulmonary toxicity in some patients. Previously described radiographic findings include alveolar and interstitial infiltrates. We report a patient who developed biapical infiltrates on chest X-ray film and demonstrated an unusual, symmetric appearance on CT. Correlative postmortem histologic findings are presented. Amiodarone-induced pulmonary toxicity should be considered in the differential diagnosis of pulmonary parenchymal infiltrates seen on CT of patients receiving this medication.

Digital processing of film radiographs.

Initial clinical experience with a system for the digitization, processing, and display of film radiographs is described. Film is digitized using a high-intensity laser scanner; the recorded image data may then be subjected to a wide variety of processing options, with display of processed images on television monitors. The possibilities of clinical applications to processing and display of chest radiographs and film mammograms are described. A comparison of conventional analog subtraction and digitized film subtraction angiography indicated equivalent diagnostic capability, with the advantage of flexible, interactive image processing with the digital technique. A specially designed, energy-selective cassette permits dual-energy imaging from two films effectively exposed to different x-ray energy spectra. Dual-energy imaging may be capable of the characterization of body materials, including lung nodules, and useful for eliminating obscuring radiographic shadows overlying regions of interest.

Intravenous cholangiography in the CT era.

With the availability of computed tomography (CT), ultrasonography (US), percutaneous transhepatic cholangiography (PTC), and endoscopic retrograde cholangiopancreatography (ERCP), the use of intravenous cholangiography (IVC) has waned. A retrospective study of 69 intravenous cholangiograms performed from 1979 through 1982 assessed the utility of intravenous cholangiography, as well as its effect on patient management, at an institution where CT was highly developed. In no case after normal findings on CT and/or ultrasound examination did IVC make a positive pathologic diagnosis. After abnormal results on CT and/or US examinations, in no case did IVC add to the diagnosis. Finally, after technically suboptimal results of CT and/or US examinations, IVC made only 1 positive pathologic diagnosis. Overall, IVC correctly demonstrated only 5 of 9 cases of common duct stones or strictures. Of the 26 cases with anatomical correlation there were a total of 7 false-positive and -negative IVC examinations. In this series, IVC was rarely useful in the diagnosis of biliary tract disease. Given the high inaccuracy rate of IVC in this study, its use for the exclusion of biliary tract disease is discouraged.

Radiation dose reduction in the neonatal intensive care unit. Comparison of three gadolinium oxysulfide screen-film combinations.

Infant radiation exposure in the neonatal intensive care unit was quantitated by thermoluminescent dosimetry in 513 mobile unit roentgen examinations of the chest and abdomen. Three combinations of gadolinium oxysulfide intensifying screens and radiographic films were compared. The skin entrance dose in millirads at the mid-chest, mid-abdomen and symphysis pubis levels was measured. Radiation dose reductions of 52% and 68% were achieved using the intermediate and fast combinations relative to the near par speed standard combination. Comparison of the relative line pair resolution of the three combinations under clinical conditions was done and subjective comparison of image detail and image mottle was made by two radiologists. The standard and intermediate speed combinations were considered very acceptable for general neonatal diagnostic interpretation but the fastest combination was not considered acceptable for general purposes. Because of the decreased radiation dose, the intermediate speed combination is now used for all routine neonatal radiography at our institution. The near par speed combination is now used only occasionally for "high-detail" examinations. The fastest combination has a limited role for frequently repeated, less critical studies, such as tube or catheter placement or routine follow-up examinations.

Computed tomography of fatal hepatic rupture due to peliosis hepatis.

Hepatic rupture with subcapsular hematoma and hemoperitoneum is shown by CT in a patient with peliosis hepatis. Peliosis hepatis is pathologically characterized by blood-filled cystic spaces in the liver associated with the administration of anabolic androgenic steroids or oral contraceptive agents, particularly those with large components of estrogen. We report a fatal case in a patient receiving diethylstilbestrol for 3 years. In patients receiving these medications, peliosis hepatis should be considered in the differential diagnosis of low attenuation areas in the liver by CT. These patients are subject to increased risk of spontaneous hepatic rupture.

Differentiation of complicated cholecystitis from gallbladder carcinoma by computed tomography.

Differentiation between complicated cholecystitis and advanced gallbladder carcinoma can be difficult when clinical findings are confusing. Computed tomographic (CT) scans were reviewed from 22 patients with a surgical diagnosis of complicated cholecystitis (11 cases) or advanced gallbladder carcinoma (11 cases). The presence of a curvilinear low-attenuation "halo" around the gallbladder wall was specific for complicated cholecystitis. Findings indicative of gallbladder carcinoma included a focal soft-tissue mass, biliary obstruction at the level of the porta hepatis, and direct hepatic invasion or metastases. Other findings, such as diffuse wall thickening, streaky soft-tissue densities in the pericholecystic fat, and thickening of the hepatoduodenal ligament, could be seen in both entities and, therefore, were less useful in differentiating these two disease processes. Knowledge of these differential CT findings may result in a more accurate preoperative diagnosis.

CT of benign soft-tissue masses of the extremities.

The computed tomographic (CT) scans and medical records of 35 patients with proven benign soft-tissue masses of the extremities were reviewed to assess the contribution of CT in the evaluation of such masses. CT demonstrated the mass in all 35 cases and was able to provide a specific diagnosis in 28 (80%); 25 prospectively, three retrospectively. Correct diagnoses made using CT included hematomas (five), synovial cysts (seven), myositis ossificans (six), fatty tumors (four), aneurysms (three), pseudoaneurysms (two), schwannoma (one), and abscess (one). The CT appearance of a hematoma depends on its age. Synovial cysts are near-water-density masses, often associated with a small joint effusion. Myositis ossificans can be differentiated from parosteal osteosarcoma by virtue of its characteristic zonal ossification. Lipomas are recognized on noncontrast scans by the characteristic low attenuation of fat, while aneurysms and pseudoaneurysms are best diagnosed on postcontrast scans. In seven cases (20%) a specific diagnosis could not be made on the basis of the CT scan. However, in these cases CT delineated the extent of the mass and demonstrated its relation to surrounding structures; this anatomic information was helpful in planning surgical excision or percutaneous biopsy. The authors conclude that CT is a valuable noninvasive imaging method for the evaluation of soft-tissue masses of the extremities.

The diagnostic significance of posttraumatic sphenoid sinus effusions: correlation with head computed tomography.

In review of 1544 patients with both head computed tomography (CT) examinations and skull radiographs, 150 patients were found to have a history of acute head trauma. Twenty-nine of these patients had sphenoid sinus effusions. Ninety-three percent (27/29) of those cases had abnormal CT examinations, as compared with 48% (58/121) of cases without sphenoid effusions. Of the patients with sphenoid effusions, 31% (9/29) had intracerebral hematomas, 24% (7/29) had extracerebral hematomas, 13% (4/29) had pneumocephalus, and 13% (4/29) had cerebral edema. We conclude that the presence of posttraumatic sphenoid sinus effusion on the skull radiograph is a sensitive sign for intracranial damage and serves as an emergent indication for head CT.