[Detection of liver lesions with gadolinium-enhanced VIBE sequence in comparison with SPIO-enhanced MRI]. / Detektion von Leberläsionen mit der Gadolinium-verstärkten VIBE-Sequenz im Vergleich zur SPIO-verstärkten MRT.

PURPOSE: Detection of malignant liver lesions with gadolinium-enhanced volumetric interpolated breath-hold examination (VIBE) in comparison with SPIO-enhanced MRT (four different SPIO-enhanced T2w sequences) and histological and imaging follow-up in non-cirrhotic livers at 1.5 T. PATIENTS AND METHODS: Twenty-two patients with suspected focal liver lesions prospectively underwent a gadolinium-enhanced 3D VIBE. Four T2w sequences (HASTE sequence, fast spin-echo-sequence with and without fat-saturation, FLASH 2D gradient echo-sequence) after administration of superparamagnetic iron oxide (SPIO) served as gold standard combined with histological work-up in 17 patients and histological and imaging follow-up in five patients. The image quality was evaluated and the detectability of intrahepatic lesions was rated by the alternative free-response receiver operating characteristic (AFROC) analysis. In addition, the contrast-to-noise ratio was compared. RESULTS: Altogether 49 malignant and 35 benign liver lesions were found. Concerning the image quality, VIBE turned out to be of slightly poorer image quality than the SPIO-enhanced examination with HASTE sequence (4.95 vs. 5.0). The fast spin-echo-sequence without fat-saturation demonstrated the highest contrast-to-noise ratio. All sequences showed a comparable certainty in detecting lesion (area under the curve 0.68-0.73) and identifying malignant liver lesions. CONCLUSION: Despite the small number of patients, VIBE seems to be a comparable, inexpensive and fast method in diagnosing malignant liver lesions.

Optical pattern recognition by use of a segmented semiconductor optical amplifier.

A technique for high-speed, all-optical pattern recognition based on cross correlation in a segmented semiconductor optical amplifier (SSOA) is presented. A counterpropagating pump-probe setup is used to perform cross correlation of the spatial gain-loss pattern in the SSOA with the optical data pattern (pump), and the result is read out with a counterpropagating probe. Cross correlation of 4-bit patterns at 85 Gbits/s is experimentally demonstrated. Simulations show reasonable agreement with experimental measurements and are used to address scalability to higher bit rates and longer data patterns.

Biosynthesis of phytochelatins in the fission yeast. Phytochelatin synthesis: a second role for the glutathione synthetase gene of Schizosaccharomyces pombe.

By complementation screening of a cadmium-sensitive Schizosaccharomyces pombe mutant deficient in phytochelatin synthesis, but with 44% of the wild-type glutathione content, we cloned a DNA fragment involved in phytochelatin synthesis. Sequence analysis revealed that it encodes the second enzyme involved in glutathione (GSH) biosynthesis, glutathione synthetase (GSH2) (E.C.6.3.2.3, Wang and Oliver, 1997). The mutant allele shows a single base-pair exchange at the 3' end of the reading frame leading to a single amino acid change from glycine to aspartate. This mutation leads to a significant reduction of phytochelatin synthesis, whereas glutathione synthesis is impaired to a far lesser extent. Complementation with the Arabidopsis thaliana GSH2 cDNA led to a partial restoration of phytochelatin synthesis. These data strongly suggest that the GSH2 gene encodes a bifunctional enzyme that is able to catalyse both the synthesis of GSH by adding glycine to the dipeptide (gammaGlu-Cys) and the synthesis of phytochelatins. The sequence has been submitted to EMBL, Accession No. Y08414.

Programmable high-bit-rate pattern generator with a segmented semiconductor optical amplifier.

We have demonstrated that spatial gain modulation in a segmented semiconductor optical amplifier can be converted to a temporal signal. A four-segment amplifier was used to generate digital return-to-zero patterns at 40 Gbits/s , and this technique should be readily scalable to more than 100 Gbits/s .

[Pleural drainage in acute thoracic trauma. Comparison of the radiologic image and computer tomography]. / Pleuradrainagen bei akuten Thoraxtraumen. Vergleich der Röntgenaufnahme im Liegen mit der Computertomographie.

PURPOSE: Estimation of chest tube placement in patients with thoracic trauma with regard to chest tube malposition in chest radiography in the supine position compared to additional computed tomography of the thorax. MATERIAL AND METHODS: Apart from compulsory chest radiography after one or multiple chest tube insertions, 31 severely injured patients with thoracic trauma underwent a CT scan of the thorax. These 31 patients with 40 chest tubes constituted the basis for the present analysis. RESULTS: In chest radiography in the supine position there were no chest tube malpositions (n = 40); In the CT scans 25 correct positions, 7 pseudo-malpositions, 6 intrafissural and 2 intrapulmonary malpositions were identified. Moreover 16 sufficient, 18 insufficient and 6 indifferent functions of the chest tubes were seen. CONCLUSION: In case of lasting clinical problems and questionable function of the chest tube, chest radiography should be supplemented by a CT scan of the thorax in order to estimate the position of the chest tube.

Ehlers-Danlos Syndrome Type VI (EDS VI): problems of diagnosis and management.

Ehlers-Danlos Syndrome Type VI (EDS VI) is a rare autosomal recessively inherited connective tissue disorder, which poses several problems of diagnosis and management. We report on a patient who developed severe kyphoscoliosis long before the diagnosis was reached. We conclude that early biochemical diagnosis and a timely operative procedure by extensive posterior instrumentation is the basis for successful management of this disorder.

Leukodystrophy incidence in Germany.

Through a survey of all departments of pediatrics, neurology and neuropathology in Germany, we calculated the incidence of all major forms of leukodystrophy. Only diagnoses based on specific biochemical tests in association with typical findings and/or neuroradiologically proven white matter involvement were accepted. In accordance with these strict criteria, 617 cases of leukodystrophy were found (incidence of all forms: app. 2.0/100,000). Minimal incidence was estimated at 0.8/100,000 for adrenoleukodystrophy/adrenomyeloneuropathy (ALD/AMN), 0.6/100,000 for metachromatic leukodystrophy (MLD), and 0.6/100,000 for Krabbe disease. Thus ALD/AMN is apparently underdiagnosed in Germany. A considerable proportion of leukodystrophies could not be classified in spite of adequate diagnostic procedures in experienced centers.

Hydrogen sulfide in parenteral amino-acid solutions.

We have previously reported appreciable concentrations of hydrogen sulfide (H2S) in paediatric amino-acid solutions, apparently formed from cysteine during the production process. Since manufacturers assured us of their aim to reduce the contents of the potentially toxic H2S in these solutions, we determined whether lower amounts have been achieved 2 years after our first report. Median H2S content of 13 paediatric amino-acid solutions was 22.8 microg/l (range: not detectable to > 280 microg/l which is comparable to the amounts previously found. Median H2S content of 8 special solutions for renal and hepatic disorders was 15.8 microg/l (range not detectable to > 280 microg/l). We conclude that manufacturers should make further efforts to reduce H2S amounts in parenteral amino-acid solutions.

Getting beyond "she said, he said".

Men and women grow up in different cultures and as a result learn different lessons about "appropriate" adult behaviors. But these lessons are invisible to us and that creates a variety of work-related problems. This article addresses the double blind and hidden expectations that nursing executives face as a member of the male-dominated administration team.

Quantization effects in digitally behaving circuit implementations of Kohonen networks.

Implementing a neural network on a digital or mixed analog and digital chip yields the quantization of the synaptic weights dynamics. This paper addresses this topic in the case of Kohonen's self-organizing maps. We first study qualitatively how the quantization affects the convergence and the properties, and deduce from this analysis the way to choose the parameters of the network (adaptation gain and neighborhood). We show that a spatially decreasing neighborhood function is far more preferable than the usually rectangular neighborhood function, because of the weight quantization. Based on these results, an analog nonlinear network, integrated in a standard CMOS technology, and implementing this spatially decreasing neighborhood function is then presented. It can be used in a mixed analog and digital circuit implementation.

Incidence of neuronal ceroid-lipofuscinoses in West Germany: variation of a method for studying autosomal recessive disorders.

The incidence of neuronal ceroid-lipofuscinoses (NCL) in West Germany was determined using a novel method which is applicable to other autosomal recessively inherited diseases. Questionnaires were sent to all pediatric departments (answer rate 189/276, 68%), schools for the blind (39/46, 85%), and neuropathological institutes (15/22, 68%). Diagnoses were accepted only when based on firm clinical and/or electron microscopic criteria; 207 such identified patients were sorted according to year of birth. Plotting the cumulative number of new cases per year against the year of birth resulted in a slightly S-shaped curve. Before the year 1962, the curve is relatively flat, probably due to inefficient case registration. Between 1968 and 1977, the slope of the curve is constant--a steep, nearly straight line. Thereafter the curve flattens out again, likely due to inefficient registration of young, still undiagnosed patients. We interpret the central segment of the curve, which is continuously straight over a period of 10 years and corresponds to 92 patients, as a period in which efficient registration of new cases occurred. The number of live births being 7,211,543 during the same period, the NCL incidence is calculated to be 1.28 per 100,000 live births (0.71 for juvenile NCL and 0.46 for late infantile NCL).

Influence of azithromycin and other macrolides on the intracellular killing of Staphylococcus aureus by human polymorphonuclear leucocytes of healthy donors and a patient with Chédiak-Higashi syndrome.

A mixture of human blood phagocytes from healthy donors and opsonized staphylococci was incubated in vitro for 30 min. After that time all the bacteria were phagocytosed. The test tubes were further incubated for 2, 4 and 24 h with or without addition of a macrolide (erythromycin, azithromycin, clarithromycin, roxithromycin) and the effect of these drugs on the survival of intracellular staphylococci (Staphylococcus aureus ATCC 25923) was measured. The minimal effective concentration of the antibiotic which killed 80-90% of the bacteria after a 4-hour incubation was 0.1 mg/l for erythromycin, azithromycin and clarithromycin and 1.2 mg/l for roxithromycin. The percentage of surviving bacteria after 2 and 4 h incubation was not significantly different between these macrolides at the minimal effective concentration. Increasing the concentration of each antibiotic above the minimal effective concentration did not alter the killing rate of intracellular staphylococci. The bacterial activity of polymorphonuclear leucocytes (PMNL) from a patient with Chédiak-Higashi syndrome was less in comparison to PMNL from healthy donors, but was improved in vitro by the addition of erythromycin or azithromycin.

Congenital blindness with ocular developmental anomalies, including retinal dysplasia, in Doberman Pinscher dogs.

Hereditary, congenital blindness was studied in 15 Doberman Pinscher pups. The eyes were smaller than normal, and there was complete absence of the anterior chamber, aphakia, retinal detachment, and dysplasia as well as an irregular swelling and partial depigmentation of the retinal pigment epithelial cells. It was concluded that the condition was inherited as a recessive, autosomal trait.

Behaviour analysis and treatment of essential hypertensives.

Various relaxation techniques have the potential to bring about promising blood pressure (BP) reductions in essential hypertension; but the treatment gains often fail to be sustained over a prolonged period of time. Until now, behavioural treatment approaches have not included efforts to increase patient awareness of situations that provoke BP elevations. In our study, numerous BP measurements were therefore taken In various situations by approximately 120 essential hypertensives. These measures were used to acquaint the patients with their own BP variability, to help them understand psychologically induced BP-variations, and to encourage them to cope with their hyper-reactivity in general and in response to specific stressful situations. Forty-eight patients were given the opportunity to learn to relax and to cope with stressful life situations. They showed promising BP reductions after treatment and at follow-up one year later. But our diagnostic findings using these methods indicate that essential hypertensives are anything but a homogeneous group. A variety of treatment approaches may therefore be required.