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Biomedical subjects

F Deckert

Publications and source records attributed to F Deckert.

At least 19 recordsLinked to original sources
PubMed2006

[Radiation exposure with 3D rotational angiography of the skull].

PURPOSE: Determination and comparison of radiation exposure for examinations of the skull with unsubtracted 3D Rotational Angiography (3D RA) and 2D Digital Subtraction Angiography (2D DSA). MATERIALS AND METHODS: Measurements were carried out with a skull of an Alderson phantom for 3D RA and for 2D DSA in p. a. and lateral projections using an Innova 4100 angiography system with a digital flat panel detector from GE Healthcare. 45 thermoluminescent dosimeters TLD 100H from Harshaw were placed inside the phantom to measure organ doses. In addition the dose area product was recorded and the effective dose was calculated using the Monte Carlo program PCXMC. RESULTS: For a biplanar DSA run (lateral and p. a. projection), the organ doses were 4 to 5 times higher and the effective dose was 4 times higher than for a 3D RA even though the number of images for the two DSA runs was only half of that for 3D RA. CONCLUSION: The radiation exposure for unsubtracted 3D RA using a flat panel detector is significantly lower than for biplanar DSA. Using 3D RA in place of 2D DSA can reduce the radiation exposure of patients in neuroradiology procedures.

Angiography, Digital Subtraction↗
PubMed2005

Acute portal vein thrombosis after splenic embolization and splenectomy for autoimmune pancytopenia.

Postsplenectomy portal vein thrombosis for hematological diseases is uncommon in the pediatric population. The case summarized is, to our knowledge, the first manifestation of portal vein thrombosis in a child after preoperative splenic artery embolization and subsequent splenectomy for severe hypersplenism. We suggest that early routine diagnosis by Doppler ultrasonography and subcutaneous low molecular weight heparin therapy are useful steps for a successful outcome.

Adolescent↗
PubMed2002

[Port catheter fractures in 361 implanted port systems. Analysis of the causes--possible solutions--review of the literature].

INTRODUCTION: The use of a venous port-catheter-system is known as a relatively safe implant. Besides infections, the breakage of PIPS is the most common reason for explanation before term. The purpose of this study is to analyse port-related complications and to show ways of preventing them. METHOD: Between 1.1.1994 and 31.12.1999, 391 PIPS were implanted in the V. subclavia with the Seldinger technique at Surgical Clinic 1 of the University of Leipzig. Subsequently, 311 of them were followed up until 31.12.2000, with a mean observation time of 45 months. RESULTS: We registered 48 complications altogether (15.4% of 311), 21(6.7%) of which occurred immediately after implantation (up to 30 days postoperatively). These could be divided either into wound-healing disorders/pulmonary distress (4.5%, n = 14) or complications concerning the catheter systems (2.3%, n = 7). Long-term complications after 31 days were evident in 27 patients (8.7%), due either to infections (4.5%, n = 13) or catheter-associated problems (4.5%, n = 14). Catheter lesions occurred in nine cases (2.9% out of 311) at the point of entry into the musculus pectoralis, i.e., where the catheter had to change direction. Typically these were lengthways tears caused by the catheter. We observed one full breakage without dislocation, and two dislocated catheter fragments in the systemic circulation. We consider the change of direction to be responsible for wear on the silicon catheter. During implantation, extreme change of direction of the catheter should be avoided because this is where breakage happens. Catheter implantation by means of exposure of the vena basilica in the infraclavicular triangle is the method of choice.

Catheters, Indwelling↗
PubMed2000

Development and validation of an IL-6 immuno-receptor assay based on surface plasmon resonance.

Interleukin-6 (IL-6) is a pleiotropic cytokine which interacts with the specific IL-6 receptor at the surface of the T lymphocytes. A combined immuno- and receptor-assay has been developed and validated to characterize the biological activity of recombinant IL-6 (rIL-6). This assay is based on Surface Plasmon Resonance (SPR) technology. From each experiment two successive interactions were monitored: anti-IL-6 antibody/rIL-6 and rIL-6/IL-6 soluble Receptor (sIL-6R). Based on the first interaction an immuno-assay for rIL-6 was optimized and validated. Based on the second interaction a receptor-assay for rIL-6 biological activity was optimized and validated. The assays were validated by performing three different assays on three different days. The intra- and inter-day precisions (%CV) for the immuno-assay were respectively 0.9% and 1.7%. The overall recovery of the immuno-assay was 98.9 +/- 1.6. Intra- and inter-day precisions for the receptor-assay were respectively 1.1% and 1.4%. The overall recovery of the receptor-assay was 99.4% +/- 1.1. This immuno-receptor assay has allowed to compare the rIL-6 stability after storage at different temperatures. The results did not show significant difference between the three lower storage temperatures (-70, -20 and 5 degrees C). However, results obtained for the aliquot stored at 25 degrees C have shown a drastic denaturation of the rIL-6. These results illustrate the advantage of this method combining the evaluation of the immunological and biological integrity of the drug and high reproducibility and precision of the biosensor based technology.

Receptors, Interleukin-6↗
PubMed2000

CT-guided intervention using a patient laser marker system.

To prove the usefulness of a simple laser marker system (LMS) in target definition as well as examination procedure for CT-guided interventions, 130 cases of diagnostic biopsies and lumbal sympathectomies were compared. In 75 cases LMS and in 55 cases a simple crossgrid was used. Taking advantage of the LMS, the parameters of intervention (cutaneous location, length, and angle) can be planned, exactly demonstrated, and it is possible to check the needle position during the whole procedure. Thus, the number of necessary control scans decreased to 30%, and corrections of needle location were reduced to approximately 30%. Moreover, the average target deviation of the needle decreased below 5 mm in 50% of cases, and the duration of interventional procedure was reduced considerably. It can be concluded that LMSs are recommended in CT-guided interventions for quality assurance, dose reduction, and improvement of handling. It will be especially advantageous in cases of small target volume, oblique needle path, and tilted gantry.

Biopsy, Needle↗
PubMed1999

Development and validation of an immunoreceptor assay for simulect based on surface plasmon resonance.

Simulect is a chimeric human/mouse antibody directed against interleukin-2 (IL-2) receptor. A combined immuno- and receptor assay has been developed and validated to characterize the production of Simulect batches. This assay is based on surface plasmon resonance (SPR) technology. In each experiment two successive interactions were monitored: the direct binding of Simulect to an anti-human IgG antibody, followed by the direct binding of IL-2-soluble receptor to the preformed anti-human IgG antibody/Simulect complex. Based on the first interaction a direct immunoassay for Simulect was optimized and validated. Based on the second interaction a direct receptor assay for Simulect biological activity was optimized and validated. The assays were validated by performing three independent assays on 3 different days. The intra- and interday variations of the immunoassay (expressed as % CV) were, respectively, 1.7 and 1.6%. The overall accuracy for the immunoassay was 98.5% +/- 1. The intra- and interday variations of the receptor assay (% CV) were, respectively, 1.6 and 3.7%. The overall accuracy of the receptor assay was 100% +/- 2. Four batches of Simulect were compared to a reference batch. The results did not show significant differences for the immunoreactivity. However, the results of the receptor assay showed accuracies which were apparently higher than 100%. This was explained by a slight degradation of the reference batch after few years of storage. These results demonstrate the advantage of this method combining evaluation of the immunological and biological integrity of the drug and a high reproducibility in accuracy and precision of the biosensor-based technology.

Animals↗
PubMed1998

[Effect of forced organ cooling on microperfusion of donor livers].

UNLABELLED: With regard to the factors of graft damage the role of rapid cooling during cold in situ perfusion should not be underestimated. The aim of this study was to analyse the effect of rapid cooling on microperfusion of rat livers in an in vitro model. MATERIAL AND METHODS: During harvest of 14 rat livers the organs' core temperature was monitored. Two groups were formed: (1) cold UW perfusion. (2) cold UW perfusion under additional graft cooling by iced water. Thereafter, isolated livers were perfused (4 degrees C. 1 h, 5 mmHg) monitoring the portocaval resistance, and liver enzyme release and pH levels in the perfusate. Finally, portal angiography of each liver was performed. RESULTS: Rapid in situ cooling resulted in a decrease of the plateau temperature of the organ by 6.5 degrees C (p < 0.01). The pH slope in the perfusate and the enzyme release were diminished obviously, but not significantly. On the other hand, the portocaval resistance was increased by more than 20% (p < 0.05). Portal angiographies assessed by a special score expressed a marked deterioration of microperfusion in peripheral and subcapsular regions. CONCLUSIONS: This study shows that rapid cooling results in worsened microperfusion of liver grafts. The effect of rapid cooling on function and histomorphology of transplanted livers should be analysed in further investigations.

Animals↗
PubMed1995

[Testing methods for the characterization of catheter balloons and lumina].

The present paper reports on the characterization of catheter balloons and lumina on the basis of such known parameters as residual volume, compliance, burst pressure and flow rate, with the aim of developing standards, test methods and testing equipment as well as standards. These are becoming ever more important with the coming into force of the EC directive on medical products [7] and the law governing medical products in Germany [13], which requires manufacturers to specify the properties of their products. Our testing concept is based on a commercially available machine that subjects materials to alternating extension and compression forces over the long-term, to which we added a special hydraulic module. Using the multimedia technology we achieved a real time superimposition of the volume-diameter curve on the balloon. The function of the testing device and method is demonstrated on dilatation catheters. Our initial results reveal compatibility with the requirements of the 1% accuracy class. Use of this methodology for comparative testing of catheters and quality evaluation is recommended.

Catheterization↗
PubMed1993

[Gestosis, thrombophilia and pulmonary embolism in a primipara with twin pregnancy].

This is a case report on a course of gemini-pregnancy complicated by gestosis, recurrent submassive pulmonary embolism and discordant growth of the hypotrophic twins. It is concluded from this report that: 1. the AT-III-deficiency in gestosis can be caused by loss and consumption; 2. due to decrease below a critical AT-III-level the coagulation-fibrinolysis system tends to decompensate, reflected in a disseminated intravascular coagulation and/or a pulmonary embolism. The tendency consists particularly in immobilisation and stasis; 3. the daily determination of AT III, better of TAT-complex and D-dimer, the daily clinical examination regarding signs of thrombosis and in cases of heparinization the measurement of PTT several times daily, are necessary to avoid or recognise disorders, of the coagulation-fibrinolysis-system at an early stage. 4. The increased consumption in coagulation systems can be avoided by AT-III substitution and correct heparinisation. 5. In cases of risk of pulmonary embolisation in pregnancy a cava filter should be temporarily implanted. The filter must be changed every 3 days, if it is required for a longer period. 6. In high-risk pregnancy the check for factors of thrombophilia is a basic diagnostic procedure.

Adult↗
PubMed1991

[The correlation of duplex sonography and intra-arterial DSA in degenerative vascular diseases in the supra-aortic region].

In 46 patients the common and internal carotid artery were examined by duplex sonography and intraarterial DSA in a prospective study. A correlation of 80% was found in diagnosis and degree of the pathological changes. Small lesions of the vessels are more exactly demonstrated by duplex sonography. In subtotal stenosis duplex sonography is inferior to angiography.

Adult↗
PubMed1983

[Organ-preserving therapy of splenic injuries in childhood--radiologic and immunologic follow-up studies].

Care of traumatized spleen has undergone an interesting change. In view of the fact that children without spleen are exposed to an increased infection risk, attempts are now directed at preserving the organ. The author's own patients included 9 children whose spleen had been traumatized at an age between 5 4/12 and 11 7/12 years. 4 children were given conservative treatment under intensive care, whereas surgery of the traumatized spleen was performed five times. 7 children were followed up. The changed morphological structure and the immunological situation were factors of particular interest. Depending upon the degree of severity of the injury to the spleen, scars remain in the parenchyma which are of different extension and which are associated with corresponding storage defects. The humoral and cell-promoted immunity is maintained.

Age Factors↗
PubMed1981

[Electro-thrombosis -- an alternative to embolisation using particles (author's transl)].

The use of a suitable direct current applied to a vessel wall by an electrode results in the formation of a thrombus. Firm contact between the intravascular anode and the endothelium is necessary to obtain a strictly localised thrombus. The use of a direct current of 10 to 30 mA. for a period of 15 minutes results in the certain thrombotic occlusion of an artery of 5 mm. diameter. The method is an effective alternative to vascular embolisation used as a preoperative or palliative procedure. Animal experiments and our own clinical experience are described and discussed.

Aged↗
PubMed1980

[Personal experiences in the diagnosis and treatment of primary hyperparathyroidism].

It is reported on an interdisciplinary team consisting of internists, radiologists and urologists which treated twelve patients with suspicion of primary hyperparathyroidism. The diagnostics is performed in form of a three-step progamme. A great importance is still ascribed to hypercalcaemia and therefore it serves as leading symptom. By means of the selective determination of parathormones no clear side classification could be achieved. In ten patients the operation could successfully be finished with the exstirpation of one or more adenomas of the parathyroid glands. A special importance deserves the intensive postoperative control with regular determinations of serum calcium in order to encounter in time a hypocalcaemia with tetanies by applications of calcium. It is referred to the necessity to search for an adenoma of the parathyroid gland at the slightest suspicion of the presence of a primary hyperparathyroidism.

Adenoma↗
PubMed1980

[Hypertension in angiodysplasia and carcinoma of the kidney].

A case of renal carcinoma is described, the only leading symptom of which was the hypertension. On account of a contralaterally appearing hypernephroma, which was removed by means of a partial resection of the kidney, at first on the side of the diagnosed angiodysplasia a spiral embolisation took place, which, however, did not lead to the decrease of the hypertension. The nephrectomy, which was carried out after the control angiography of the embolised kidney, resulted in a large sac of venous aneurysm as well as in a hypernephrotic renal carcinoma. The questions of the affection with a bilateral renal tumour, of the generalized growth of the tumour as well as of the angiodysplasia as a second independent disease were discussed.

Adenocarcinoma↗