[Cystic echinococcosis and hepatocellular carcinoma--a coincidence? A case report]. / Zystische Echinokokkose und hepatozelluläres Karzinom--zufällige Koinzidenz? Ein Fallbericht.

INTRODUCTION: The coincidence of echinococcosis and hepatocellular carcinoma (HCC) is quite rare. We report the case of a 45-year-old man who was admitted to our hospital because of abdominal pain in the right upper quadrant and jaundice. Clinical features and diagnostics: There was no history of weight loss or fever. No abdominal mass was palpable. The laboratory reports showed increased transaminase levels. Ultrasonography revealed an inhomogenous, cystic lesion measuring 6 cm in diameter in the segments VI and VII. Serology for echinococcosis was negative, alpha-fetoprotein (AFP) was considerably increased. CT scan showed a solid mass of 3,7 cm in diameter adjacent to the cystic lesion. THERAPY AND COURSE: Anthelminthic therapy with albendazole caused a massive increase of cholestasis parameters and treatment had to be stopped. The simultaneous occurrence of serologically negative cystic echinococcosis and HCC was suspected and partial liver resection was performed. Histological examination confirmed both diagnoses and tumor resection in healthy tissue. 5 months after resection CT scan showed multicentric HCC affecting the whole liver. Palliative therapy with sorafenib was established. DISCUSSION: The coincidence of HCC and cystic echinococcosis in the non-cirrhotic liver of a young man is a rare event. Despite resection in healthy tissue multicentric HCC was diagnosed 5 months later. Only few cases of simultaneous occurrence of HCC and echinococcosis have been published so far. Some authors considered echinococcosis as a trigger for HCC. A causal link between both entities has not been demonstrated until now.

Wavelet versus JPEG (Joint Photographic Expert Group) and fractal compression. Impact on the detection of low-contrast details in computed radiographs.

RATIONALE AND OBJECTIVES: The aim of this study was to evaluate different lossy image compression algorithms in direct comparison. METHODS: Computed radiographs were reviewed after compression with Wavelet, Fractal, and Joint Photographic Expert Group (JPEG) algorithms. For receiver operating characteristic (ROC) analysis, 54 thoracic computed radiographs (31 showing pulmonary nodules) were compressed with a ratio of 1:60. Five images of a test-phantom were coded at 1:13. All images were reviewed on a PC. Uncompressed images were reviewed at a PC and at a radiologic workstation (with image processing). RESULTS: For thorax images, decrease of diagnostic accuracy was significant with Wavelets. Fractal performed worse than Wavelets. No ROC curve was observed for JPEG due to poor image quality. No diagnostic loss was noted comparing PC and Workstation review. For low-contrast details of the phantom, results of Wavelet compression were equal to uncompressed images. Fewer true positives and increased true negatives were noted with Wavelets though. Wavelets were superior to JPEG, and JPEG images were superior to Fractal. Workstation review was superior to PC review. CONCLUSIONS: Only Wavelets provided accurate review of low-contrast details at a compression of 1:13. Frequency filtering of Wavelets affects contrast even at a low compression ratio. JPEG performed better than Fractal at low and worse at high compression ratio.

[Comparative findings of digital thoracic images and digital images of statistical phantoms as film copy, a radiological work station and a PC]. / Vergleichende Befundung von digitalen Thoraxbildern und digitalen Aufnahmen eines statistischen Phantoms als Filmkopie, an einer radiologischen Workstation und an einem PC.

INTRODUCTION: An ROC analysis was carried out in order to determine the reliability of digital luminescence radiography review at a PC and this was compared with a radiological work station and with X-ray film on a viewing box. MATERIAL AND METHOD: 54 chest images obtained by digital luminescence radiography were selected, 31 of these contained small pulmonary nodules. In order to evaluate critical detail, five images of a phantom showing round foci were used. Five radiologists examined these, using a Siemens Magic View work station, a PC with proprietary software (ViewMed) and X-ray films on a viewing box. Image processing of the work station used the standard clinical application. ViewMed performs linear scaling of grey levels to 8 Bit. The results were examined statistically by means of a t-test. RESULTS: As far as the chest images were concerned there was no significant difference in the diagnostic value of these methods. There was, however, a highly significant loss of diagnostic information with respect to the round focus phantom when using the PC compared with the other methods. CONCLUSION: In the configuration in which it was used, the PC should not be relied on as a primary means of examination since critical details cannot always be seen. In routine use these play a subordinate role and there was no significant diagnostic loss where the chest images were concerned. We expect that by improvements in the frequency and contrast processing the PC accuracy will be considerably increased.

[How certain is teleradiological telediagnosis for the tomographic procedure?]. / Wie sicher ist die teleradiologische Ferndiagnose für Schnittbildverfahren?

PURPOSE: To define the value of teleradiographic studies, a comparison was carried out between digitised copies of CT examinations of the skull with the original images. Differences in image quality obtained from a digital scanner and a camera were quantified. MATERIAL AND METHOD: 56 CT examinations of the skull, 28 of which had discrete abnormalities, were chosen for ROC analysis. The original films were digitised with a Vidar VXR-12 scanner and Panasonic WV-160 and WV-BP 500 cameras. The images were evaluated by five radiologists after image transfer with Video Conference software to a personal computer. RESULTS: For the analysis of the films the area under the ROC curve was 0.91 +/- 0.04, for the digital scanner it was 0.85 +/- 0.04, for camera WV-BP 500 0.89 +/- 0.06 and for camera WE-160 0.87 +/- 0.09. Comparison with the film findings showed. a minimal p-value of 0.17 which indicated that there was no significant reduction in diagnostic value following digitization. CONCLUSION: The probable reason for the slight deterioration using the digital scanner was the reduction to 75 dpi compared with 134 dpi on the CT films. The cameras produce image noise comparable to CT with low window settings and reduced local resolution. We expect similar results for CT with soft tissue windows or for MRT of the skull. Conventional radiographs containing high local resolution, wide grey scale and low image noise would presumably make higher demands on methods of digitization.

Interaction of the yeast pleiotropic drug resistance genes PDR1 and PDR5.

The network of genes which mediates multiple drug resistance in yeast includes, among others, the PDR1 gene, which encodes a putative regulator of gene expression, and PDR5, a locus whose amplification leads to resistance. We demonstrate that disruption of PDR5 causes marked hypersensitivity not only to cycloheximide but also to sulphometuron methyl and the mitochondrial inhibitors chloramphenicol, lincomycin, erythromycin and antimycin. Genetic analysis of double mutants containing an insertion in PDR5 (pdr5:Tn5), which renders cells hypersensitive to cycloheximide, and a pdr1 mutation, which confers resistance to this inhibitor, indicates that the expression of resistance requires a functional PDR5 gene. The same interdependency is observed for chloramphenicol, but not for oligomycin, lincomycin, erythromycin or sulphometuron methyl. Northern analysis of PDR1 and PDR5 transcripts reveals that the 5.2 kbp PDR5 transcript is overexpressed in pdr1 (resistant) mutants, but underexpressed in a disruption of PDR1. These observations provide strong experimental support for our former proposal that the PDR5 gene is a target for regulation by the PDR1 gene product.

Repeated upper gastrointestinal hemorrhage caused by metachromatic leukodystrophy of the gall bladder.

A 27-year-old man with metachromatic leukodystrophy (MLD) of the adult type had developed repeated severe gastrointestinal (GI) bleeding. During endoscopic retrograde cholangiography (ERC), hemobilia was observed on two occasions. The definite diagnosis was obtained by a biopsy specimen taken from the lumen of the gall bladder during ERC, demonstrating large masses of metachromatic material inside the gall bladder. Upon cholecystectomy, papillomatosis of the gall bladder was found virtually obliterating the lumen of the gall bladder. A blood clot was observed at the angle of the cystic duct; histologic examination revealed diffuse hemorrhage into the stroma of the gall bladder. The patient is without upper GI hemorrhage since 3 years. In patients with MLD and upper GI bleeding, one should, therefore, be aware of the gall bladder as a possible source of hemorrhage.

Evidence for an involvement of NMDA and non-NMDA receptors in synaptic excitation of phrenic motoneurons in the rabbit.

The action of endogenous excitatory amino acids on phrenic motoneurons was studied in anesthetized, vagotomized, paralyzed and artificially ventilated rabbits. The NMDA receptor antagonists APV and ketamine, as well as the non-NMDA receptor antagonists GAMS and DNQX were administered by microinjection into the ventral horn of the spinal segments C3-C5. Injection of each antagonist resulted in a reversible reduction of the phrenic nerve activity. Results suggest an important function of endogenous excitatory amino acids in the excitation of phrenic motoneurons. NMDA as well as non-NMDA receptors are involved. The functional role of both receptor types in bulbospinal neurotransmission is discussed.

Heterologous expression of human 5-aminolevulinate dehydratase in Saccharomyces cerevisiae.

A cDNA coding for human 5-amino-levulinate dehydratase was placed in a yeast expression vector under the control of the GAL10 promoter. The resulting multicopy plasmid was then used to transform a yeast mutant which contains a defective hem2 gene coding for 5-aminolevulinate dehydratase. Expression of the human cDNA was shown in four ways: (1) restoration of normal growth on glycerol/galactose as primary carbon source, (2) decrease in intracellular 5-aminolevulinic acid concentration, (3) restoration of cytochrome biosynthesis and (4) direct, in situ assay of 5-aminolevulinic acid dehydratase. Curing transformed cells of plasmid restored the hem2 mutant phenotype. This heterologous system could be used to produce large quantities of human 5-aminolevulinic acid dehydratase for physical and biochemical studies.