Recombinant BRICHOS chaperone domains delivered to mouse brain parenchyma by focused ultrasound and microbubbles are internalized by hippocampal and cortical neurons.

The BRICHOS domain is found in human precursor proteins associated with cancer, dementia (Bri2) and amyloid lung disease (proSP-C). Recombinant human (rh) proSP-C and Bri2 BRICHOS domains delay amyloid-ß peptide (Aß) fibril formation and reduce associated toxicity in vitro and their overexpression reduces Aß neurotoxicity in animal models of Alzheimer's disease. After intravenous administration in wild-type mice, rh Bri2, but not proSP-C, BRICHOS was detected in the brain parenchyma, suggesting that Bri2 BRICHOS selectively bypasses the blood-brain barrier (BBB). Here, our objective was to increase the brain delivery of rh proSP-C (trimer of 18 kDa subunits) and Bri2 BRICHOS (monomer to oligomer of 15 kDa subunits) using focused ultrasound combined with intravenous microbubbles (FUS + MB), which enables targeted and transient opening of the BBB. FUS + MB was targeted to one hemisphere of wild type mice and BBB opening in the hippocampal region was confirmed by magnetic resonance imaging. Two hours after FUS + MB brain histology showed no signs of tissue damage and immunohistochemistry showed abundant delivery to the brain parenchyma in 13 out of 16 cases given 10 mg/kg of proSP-C or Bri2 BRICHOS domains. The Bri2, but not proSP-C BRICHOS domain was detected also in the non-targeted hemisphere. ProSP-C and Bri2 BRICHOS domains were taken up by a subset of neurons in the hippocampus and cortex, and were detected to a minor extent in early endosomes. These results indicate that rh Bri2, but not proSP-C, BRICHOS, can be efficiently delivered into the mouse brain parenchyma and that both BRICHOS domains can be internalized by cell-specific mechanisms.

Impact of magnetic resonance urography on preoperative diagnostic workup in children affected by hydronephrosis: should IVU be replaced?

PURPOSE: The aim of this study was to determine the role of magnetic resonance urography (MRU) in preoperative diagnostic workup of children with hydronephrosis in a prospective clinical study with comparison of MRU, standard diagnostic investigations, and intraoperative findings. METHODS: Thirty-one children with hydronephrosis secondary to different causes underwent ultrasound scan (US), intravenous urography (IVU), micturation cysto-urethrography (MCU), isotope nephrography (ING) and MRU. For MRU the authors performed sagittal and coronal halve-Fourier SSFSE scans in a 1.5 Tesla MR system. T1- and T2-weighted sequences were used in axial orientation to improve morphologic information. In 24 patients, preoperative data were compared with intraoperative findings. RESULTS: Comparison of the different imaging modalities proved MRU to be able to provide more detailed information about the correct localization of stenoses along the urinary tract and the morphology of renal parenchyma. MRU showed the highest concordance of all imaging modalities with intraoperative findings. CONCLUSION: As a reliable investigation, MRU has the potentials to replace IVU in preoperative diagnostic workup of hydronephrosis in childhood.

[Intestinal tuberculosis: Easier overlooked than diagnosed]. / Darmtuberkulose: leichter zu übersehen als zu sichern.

Intestinal tuberculosis: Easier overlooked than diagnosed. The medical history of two Asian immigrants suffering from intestinal tuberculosis demonstrates the difficulties in finding the correct diagnosis. Intestinal tuberculosis resembles Crohn's disease with regard to clinical symptoms, macroscopic and microscopic intestinal findings. Sonographic, radiologic, endoscopic, and histological examinations facilitate distinguishing both entities. Diagnosis of intestinal tuberculosis is made by identification of the causative microorganism in tissue specimens. As this may be difficult and time-consuming, a therapeutic trial with anti-tuberculous agents may be warranted.

Evaluation of right ventricular performance with a right ventricular ejection fraction thermodilution catheter and MRI in patients with pulmonary hypertension.

STUDY OBJECTIVES: We sought to compare catheter studies using a right ventricular ejection fraction (REF) catheter together with echocardiography and MRI in patients with pulmonary hypertension. PATIENTS AND METHODS: We compared hemodynamic findings, echocardiography, and MRI studies in 16 patients with pulmonary hypertension. Six healthy volunteers served as control subjects for the MRI studies. RESULTS: MRI imaging provided accurate assessment of cardiac output in all but two patients. As compared with MRI, the REF catheter constantly underestimated the REF and overestimated right ventricular volumes in patients with pulmonary hypertension. REF, end-systolic and end-diastolic right ventricular volumes, and right ventricular muscle mass, as determined by MRI, were almost identical in patients with preserved cardiac function and those with low-output failure. The only factor that was different in both groups was the severity of tricuspid regurgitation. CONCLUSION: Right ventricular dimensions and muscle mass do not differ in patients with pulmonary hypertension who have low cardiac output and those who do not. According to our results, the major determinant of cardiac output in these patients appears to be the severity of tricuspid regurgitation. The REF catheter provides invalid data on right ventricular dimensions in patients with pulmonary hypertension.

Percutaneous superselective coil-embolization of intrarenal arteriovenous fistulas. Case reports.

PURPOSE: To evaluate the role of percutaneous transcatheter coil-occlusion in the management of uncontrollable postoperative hematuria due to iatrogenic arteriovenous (AV) fistulas. MATERIAL AND METHODS: In 2 patients, AV fistulas were occluded with percutaneous catheter-guided superselective coil embolization. RESULTS: In both cases, occlusion of the AV fistulas was successful. Only small parts (less than 10%) of the parenchyma had to be sacrificed. No hypertension occurred. CONCLUSION: Percutaneous coil embolization is a useful alternative to surgery in cases of postoperative AV fistulas. Hematuria can be effectively controlled without resulting hypertension.

Detection of simulated chest lesions: comparison of a conventional screen-film combination, an asymmetric screen-film system, and storage phosphor radiography.

PURPOSE: To compare a high-contrast asymmetric screen-film system with a conventional screen-film combination and storage phosphor radiographs for detection of simulated chest lesions. MATERIALS AND METHODS: To test the diagnostic performance of these three systems, the authors used three types of simulated lesions that were superimposed over the chests of 10 patients and an anthropomorphic phantom. In the patient and phantom study, a total of 1,350 observations by each of the eight radiologists were analyzed by means of receiver operating characteristics. RESULTS: In the patient study, mediastinal nodules were better visualized with high-contrast asymmetric screen-film and storage phosphor radiographs compared with the conventional screen-film system. For visualization of pulmonary nodules, the high-contrast asymmetric screen-film system was best. Micronodules were poorly visualized on high-contrast asymmetric screen-film and storage phosphor radiographs, but only in the phantom study. CONCLUSION: The high-contrast asymmetric screen-film system combines the advantages of conventional screen-film radiographs with improved visualization of the mediastinum.

[The x-ray clinical picture and evaluation criteria of implantable cardioverter-defibrillator systems]. / Röntgenologische Erscheinungsbilder und Beurteilungskriterien von implantierbaren Kardioverter-Defibrillatorsystemen.

Since the first implantation of an automatic cardioverter defibrillator (ICD) in February 1980, the therapy of ventricular tachyarrhythmia has been changed drastically. The original therapy with antiarrhythmic agents has been increasingly replaced by the implantation of the ICD. The radiologist should be aware of the different types of ICDs and their normal appearance, because thorax radiography is often used during regular routine follow-up of the ICD system. The different types of ICDs, their normal radiological appearances, the indications and the implantation technique are discussed in the present study. The radiologist has to interpret the radiographs with respect to the electrodes, the device and changes in heart configuration. Major migration of electrodes is visible, but the detection of little changes in configuration is only possible with the help of serial radiographs. If extraperitoneal placement of the device is suspected, an ultrasound examination should be obtained. An important complication for the radiologist is a possible deactivation of some devices by electromagnetic interference.