Contrast media: future aspects

In spite of the dramatic development in CT, there was no major breakthrough in the iodinated contrast media development. New agents based on hybrid between MRI and CT compounds may be a new innovative alternative. This new approach may also open new indications such as radiotherapy.     

Magnetic resonance imaging of atherosclerosis by targeting extracellular matrix deposition with Gadofluorine M

As previously reported, Gadofluorine M‐enhanced magnetic resonance imaging clearly demarcates atherosclerotic plaques from the normal vessel wall. To date, the underlying mechanism has remained unknown. Gadofluorine M is a gadolinium‐containing macrocyclic contrast agent containing hydrophilic and hydrophobic moieties. To elucidate the mechanism of accumulation, fluorescently labeled and radioactively labeled derivates of Gadofluorine M were used to determine affinity and specificity of Gadofluorine M binding to blood serum and plaque components in vitro and for the distribution within the plaque of WHHL rabbits in vivo. Gadofluorine M binds to serum albumin, leading to a breakdown of micelles after intravenous injection. The affinity of Gadofluorine M to serum albumin is k_D = 2 µmol/l. Gadofluorine then penetrates the atherosclerotic plaque while bound to albumin and then accumulates within the extracellular, fibrous parts of the plaque by binding to collagens, proteoglycans and tenascin, having the same affinity to these plaque constituents as to albumin. In contrast, weak binding was determined to LDL (k_D = 2 mmol/l) and even no binding to hyaluronic acid. The driving force of binding and accumulation is the hydrophobic moiety of the molecules interacting with hydrophobic plaque materials. Thus, Gadofluorine M accumulates within the fibrous plaque or in the fibrous cap of a plaque containing high amounts of extracellular matrix components, but not in the lipid‐rich areas. In combination with high‐resolution MRI, Gadofluorine M might enable the detection of thin‐cap fibroatheromas, also named the vulnerable plaque. Copyright © 2007 John Wiley & Sons, Ltd.     

Testing Skype as an interview method in epidemiologic research: response and feasibility

Introduction

Despite its popularity, Skype has not been tested as a tool for epidemiologic research. We examined its feasibility in Germany.

Methods

A population-based sample of young adults was randomly invited to a Skype (n?=?150) or a phone interview (n?=?150). Response and duration of interviews were analysed to evaluate the feasibility of Skype interviews.

Results

Response was low and, with 10 % (95 % CI 5–15 %), even worse among Skype candidates, compared to 22 % (15–28 %) in the phone group. A third of the Skype group asked for being interviewed by phone. Median duration was 34.0 minutes for Skype interviews and 37.0 minutes for phone interviews.

Conclusions

Skype is not yet a feasible tool for data collection in Germany.     

Biological effects of ionizing radiation on human blood compounds ex vivo

Purpose: Blood compounds are irradiated ex vivo to prevent transfusion-associated graft-versus-host-disease. Recently, ex vivo irradiation of re-transfused wound blood has been proposed to prevent metastatic spread in patients with malignant tumors, an issue requiring different dose concepts. To determine effects on blood cells we examined the impact of various doses of ionizing radiation. Methods: Full blood was irradiated with doses of 10–150 Gy. Potassium, LDH and hemoglobin levels were determined 2 h–96 h after irradiation. The lymphocyte proliferation after irradiation was measured by means of a lymphocyte-transformation assay. The impact of irradiation on mitogen-induced secretion of cytokines was determined by the ELISA technique, and P-selectin expression as an indicator of platelet activation was analyzed by flow-cytometry. Results: Potassium levels increase with aging and irradiation dose. Mitogenic capacity is reduced by over 90% with moderate doses of 10–20 Gy, but a residual proliferation is still detectable up to 50 Gy. No enhancement of extracellular cytokine levels is detectable, but the cytokine release is reduced by radiation. Neither induction of platelet activation nor abrogation of activation has been detected. Conclusions: Doses of 30–50 Gy abrogate lymphocyte proliferation almost completely. In this range we did not observe severe adverse effects on blood transfusions. Hemolysis might be enhanced when the samples are stored for a longer period after irradiation. Received: 18 January 2000 / Accepted: 6 April 2000     

The impact of patient and tumour baseline characteristics on the overall survival of patients with advanced hepatocellular carcinoma treated with sorafenib

BackgroundImpact of patient and tumour baseline characteristics on the overall survival is not well characterized in patients with advanced hepatocellular carcinoma (HCC) treated with sorafenib.Aims/methodsUnivariate/multivariate analyses were conducted to identify retrospectively the impact of baseline characteristics on the survival of 110 patients with advanced HCC treated with sorafenib.ResultsMedian survival of the whole cohort was 6.7 months, median survival in Child-Pugh A, B, C patients was 10.5, 6.1 and 3.0 months and median survival of patients with Barcelona Clinic Liver Cancer (BCLC) stage C/D was 6.8/2.6 months. Presence of ascites, presence of macrovascular invasion and BCLC stage D (mainly determined by Child-Pugh C status and Eastern Cooperative Oncology Group Performance Status > 2) remained independent prognostic factors for the survival on multivariate analysis. Particularly, the presence of macrovascular invasion significantly influenced survival both in patients with liver cirrhosis Child-Pugh A and Child-Pugh B.ConclusionWell maintained liver function and performance status are prerequisites for sorafenib treatment in patients with advanced HCC. Our findings do not support routine clinical use of sorafenib in Child-Pugh B patients. Evaluation of ascites and particularly macrovascular invasion might help to identify patients more likely to benefit from sorafenib treatment.     

Consequences of factor IX mutations in 26 families with haemophilia B

Haemophilia B is due to a variety of mutations within the factor IX gene. In the Seattle series, 26 additional unrelated families have had a mutation identified within the past 2 years. Of these, 11 were common recurrent point mutations identifiable by rapid restriction digest screening; eight of these probably represent founder mutations. 15 others were identified by sequencing amplified coding region fragments; eight are novel. Two each had frameshift and donor splice mutations and 11 had missense mutations. Five of these mutations associated with normal levels of circulating dysfunctional factor IX were computer modelled into coordinates for factor IXa.     

Clinical trial of iotrol for lumbar myelography

Iotrol, a new nonionic, water-soluble, hexiodinated dimeric contrast medium for myelography, was used in clinical trials in 29 patients. The purpose of the study was to acquire information on local and general tolerance, distribution and excretion, and image quality. Preliminary results show that iotrol is well suited for lumbar and thoracolumbar myelography. Side effects observed with the use of iotrol were fewer and less severe than those reported with metrizamide. Iotrol is cleared from the cerebrospinal fluid and excreted by glomerular filtration within the same time range as other water-soluble contrast media.