[MR aortofemorography versus DSA: prospective evaluation]. / Aortofémorographie par résonance magnétique nucléaire versus artériographie conventionnelle: évaluation prospective.

PURPOSE: To determine how far MRA of lower limbs obviates the need for pre-therapeutic DSA. MATERIALS AND METHOD: Three-step 3-D gadolinium enhanced aortofemorography with a moving bed was prospectively compared to DSA in 49 consecutive patients (40 males, 9 females; age range 38-80 years; mean age 64 years). According to Leriche and Fontaine's clinical gradation of lower limb ischemia, 5 patients were graded I, 37 graded II, 4 graded III, and 3 graded IV. Two observers graded stenoses for DSA and three for MRA. Cohen's kappa statistics were used to evaluate interobserver variability using MRA, as well as to compare MRA to DSA. In addition, sensitivity, specificity, positive and negative predictive values of MRA for the assessment of stenosis superior to 80% were calculated by using DSA as a gold standard, respectively for arterial trunks above and below the level of the knees. RESULTS: Overall accuracy of MRA was 92%. Comparison of DSA and MRA yielded a kappa value of 0.87 (0.95 for arterial trunks located above the level of the knees and 0.75 below). Interobserver agreement was very good. Sensitivity, specificity, positive and negative predictive values of MRA for the diagnosis of > 80% stenosis were respectively 98, 98, 85 and 99% above the level of the knees and 87, 91, 77 and 96% below the knees. CONCLUSION: MRA can be considered as valuable technique for the evaluation of peripheral arterial obstructive disease, especially for stenosis located above the level of the knees.

User tests with the multi-mode compression architecture.

The Multi-Mode Compression (MMC) architecture is a new system for better speech understanding, listening comfort and user acceptance. This study reports on the user tests that have been performed to verify the benefits of the concept and the quality of the fitting process for the individual hearing impaired. The study concentrates on the 4-channel version of a new series of digital instruments with this MMC architecture.

A randomized controlled study comparing the endocrine effects of pulsatile intravenous gonadotropin-releasing hormone after gonadotropin-releasing hormone agonist pretreatment versus clomiphene citrate in patients with polycystic ovary syndrome.

OBJECTIVE: To compare the endocrine changes in the follicular phase in infertile patients with polycystic ovary syndrome (PCOS) treated with either pulsatile IV GnRH after GnRH-agonist (GnRH-a) down-regulation or clomiphene citrate (CC). DESIGN: Subgroup analysis within a randomized, controlled, multicenter study. SETTING: Women referred to the Infertility Clinic, Catharina Hospital Eindhoven, The Netherlands. PATIENT(S): Twenty-eight infertile patients with PCOS. INTERVENTIONs): Patients were randomly assigned to pulsatile IV GnRH (10-20 microgram/90 min) after GnRH-a down-regulation or CC (50-150 mg; cycle days 3-7). Patients were monitored on alternate days with ovarian sonography and serum concentrations of E(2), LH, and FSH. Serum P and sonography confirmed ovulation. MAIN OUTCOME MEASURE(S): Serum concentrations of E(2), LH, and FSH were assessed before treatment was started and after each ovarian sonography. RESULT(S): In ovulatory cycles, no statistically significant differences were observed during the follicular phase comparing serum concentrations of E(2), LH, and FSH between the treatments. However, a significant increase in LH occurred in the GnRH group. CONCLUSION(S): No significant endocrine differences were observed between GnRH and CC treatment. However, there was a significant increase in the serum LH concentration during the follicular phase in the GnRH group. Increments of LH in the GnRH group may be due to recovery of endogenous LH secretion.

Relevant radiological anatomy of the pig as a training model in interventional radiology.

The use of swine for teaching purposes in medicine and surgery has largely increased in recent years. Detailed knowledge of the porcine anatomy and physiology is a prerequisite for proper use of pigs as a teaching or an experimental model in interventional radiology. A systematic study of the radiological anatomy was undertaken in more than 100 female pigs aged 6-8 weeks. All studies were performed under general anesthesia in a single session. Animals were sacrificed at the end of the study. Selective angiographies were systematically obtained in all anatomical territories. In other animals CT and MRI examinations were performed and were correlated to anatomical sections and acrylic casts of the vascular structures. Endoscopical examinations of the upper gastrointestinal tract, including retrograde opacification of the biliary and pancreatic ducts, were added in selected animals. The main angiographic aspects of the brain, head and neck, thorax, abdomen, and pelvis were recorded. Similarities and differences in comparison with human anatomy are stressed. Potential applications in interventional radiology are indicated.

Basal Mg(2+)-dependent ATPase activity of rat liver microsomes is not influenced by ambient free Ca2+.

The potent inhibitor of Ca2+, Mg(2+)-ATPase activity, thapsigargin, has been used to investigate the effect of ambient free Ca2+ on basal Mg(2+)-dependent ATPase activity in rat liver microsomes. Thapsigargin non-competitively inhibited both Ca(2+)-stimulated ATP-dependent Ca2+ uptake and Ca(2+)-stimulated Mg(2+)-dependent ATPase activity. At a concentration of 1 microM, thapsigargin completely inhibited the Ca(2+)-pump activity, without affecting Mg(2+)-dependent ATPase activity measured in the absence of Ca2+. Increasing the ambient free Ca2+ concentration did not alter the basal Mg(2+)-dependent ATPase activity. The data presented indicate that ATPase activity measured in the absence of Ca2+ is a reliable measure for the basal Mg(2+)-dependent ATPase activity and that, consequently, the Ca(2+)-stimulated Mg(2+)-dependent ATPase activity can indeed be defined as the difference between the ATPase activity measured in the presence and the absence of Ca2+.

Rapid bioassay of human interferon by direct enzyme immunoassay of encephalomyocarditis virus in HEp-2 cell monolayers after a single cycle of infection.

Multiplication of encephalomyocarditis virus (EMCV) in human HEp-2 cells, and its suppression by interferon (IFN), was demonstrated by direct enzyme immunoassay (EIA) in cell culture. EMCV was detected in glutaraldehyde fixed HEp-2 cell monolayers, in wells of 96-well plates, with a horse radish peroxidase (HRPO) labelled EMCV specific monoclonal antibody. Multiplication of EMCV (multiplicity of infection: 50) was indicated by a steep rise of absorbance values measured against infected monolayers starting as early as 5 h after infection and reaching relatively high values at 6 and 7 h. The rise in absorbance values did not occur after preincubation of the HEp-2 cells with either Newcastle disease virus-induced IFN, recombinant gamma IFN or recombinant alfa-2a IFN. Absorbance values were inversely dependent on the amount of IFN used. Therefore the EIA was suitable for rapid titration of IFN. The titres of recombinant gamma and alfa-2a IFN determined with EIA proved to be similar to those given by the manufacturers. The described bioassay of human IFN is objective, rapid and easy to perform and suitable for large scale experiments.