PubMed Health⌕ Search

Biomedical subjects

A Wunderlich

Publications and source records attributed to A Wunderlich.

At least 19 recordsLinked to original sources
PubMed2006

Targeting the EGF/VEGF-R system by tyrosine-kinase inhibitors--a novel antiproliferative/antiangiogenic strategy in thyroid cancer.

AIM: In thyroid cancer (TC), endothelial growth factor (EGF) has been associated with dedifferentiation, tumor cell proliferation, and angiogenesis. Vascular endothelial growth factor (VEGF) has been documented to be the main stimulator of angiogenesis in the thyroid gland. Patients with undifferentiated thyroid cancer are in desperate need of new therapeutic strategies because common protocols of therapy usually fail. The aim of this study, therefore, was to evaluate two tyrosine-kinase inhibitors (TKI, ZD 1839 gefitinib and ZD 6474 vandetanib), directed against the EGF/VEGF receptor for possible antitumor therapy in thyroid cancer. METHODS: EGF/VEGF-R was documented in anaplastic (Hth74, C643), follicular (FTC133), and papillary (TPC1) thyroid cancer cell lines by Western blot analysis. The antiproliferative effect of two TKI (0.1-10 microM) on thyroid cancer cell lines in vitro was quantified by MTT assay, the antiangiogenic effect by assessing secretion of VEGF by enzyme-linked immunosorbent assay (R&D Systems). ZD 1839 is mainly directed against EGF-R and ZD 6474 against VEGF-R (AstraZeneca, UK), single applications and combinations of compounds were evaluated. RESULTS: EGF-R and VEGF-R as well as the phosphorylated receptor were documented in all of the cell lines. Administration of ZD1839 led to an up to 90% reduction of cell number in Hth74, 80% in C643, 50% in FTC133, and 90% in TPC1 (p < 0.05). ZD1839 induced a decrease of VEGF secretion between 30% in C643 and 90% in Hth74. Administration of ZD6474 led to an up to 95% reduction of cell number in Hth74, 85% in C643, 90% in FTC133, and 90% in TPC1 (p < 0.05). The ZD6474 induced decrease of VEGF secretion ranged between 20% (FTC133) and 60% (TPC1). Combinations of IC50 concentrations of TKI showed synergistic effects, resulting in additional inhibition of proliferation between 50 and 90% compared to single drug administration. CONCLUSION: The EGF/EGF-R system resembles a powerful VEGF-stimulating pathway in all histiotypes of TC and can be inhibited by TKI. TKI directed against EGF-R as well as VEGF-R inhibit tumor cell proliferation and VEGF secretion in vitro. Combinations of TKI are more effective than strategies using single agents. It is suggested that targeting EGF-R/VEGF-R-mediated pathways may have therapeutic potential in some undifferentiated thyroid cancers.

Carcinoma↗
PubMed2006

Antisense p53 decreases production of VEGF in follicular thyroid cancer cells.

Inactivating mutations of wild-type p53 (WTp53) tumor suppressor gene are common in anaplastic thyroid cancer (ATC) and are associated with poor prognosis. Mutated p53 (MTp53) has been implicated with angiogenesis. Therefore, the potential of MTp53 knockout by oligodeoxyribonucleotide phosphorothioates (ODNs) to affect VEGF production of undifferentiated thyroid cancer cells with a recessive MTp53 mutation was evaluated. Transient transfection with 20 bp ODNs complementary to portions of exon 10 of p53 and a negative control ODN (HIV-RT) were carried out in FTC-133 cells. In vitro secretion of VEGF protein was quantified by EIA and correlated to cell numbers, which was evaluated by in vitro MTT assay. Transfection of undifferentiated thyroid cancer cells with ODN reduced VEGF secretion of FTC-133 cells following transfection by 34% as compared to the negative control (cells transfected with ODN-HIV; p = 0.03). These results suggest that transient MTp53 knockout with ODNs complementary to p53 nucleotide sequences impair secretion of VEGF in the undifferentiated thyroid cancer cell line FTC-133.

Adenocarcinoma, Follicular↗
PubMed2006

Functional thyrotropin receptor attenuates malignant phenotype of follicular thyroid cancer cells.

Thyrotropin (TSH) is a thyroid-specific growth factor inducing differentiated function and growth of thyrocytes in vitro. In thyroid cancer, loss of TSH-receptor (TSHR) expression is a sign of de-differentiation and is believed to contribute to the malignant phenotype. The present studies aimed to determine the in vitro and in vivo effects of functioning TSHR in the follicular thyroid cancer cell line HTC, a subclone of FTC133 cells, lacking endogenous expression of TSHR, and HTCtshr+ cells transfected with human TSHR-cDNA. HTCtshr+ cells grew faster in vitro (doubling time 1.15 vs 1.56 d, p < 0.05) and TSH caused a dose-dependent growth response. Adhesion to and invasion through reconstituted basement membrane were reduced in HTCtshr+ cells, but when stimulated with TSH increased to levels comparable to naïve HTC cells. In vivo, tumor latency was 11 d for naïve HTC as compared to 21 d for HTCtshr+ xenografts. Smaller tumor volumes were registered for HTCtshr+ cells (250 +/- 217 vs 869 +/- 427 mm3, p < 0.05). Angiogenesis, as determined by vascular surface density (VSD) of experimental tumors, was enhanced in naïve HTC tumors (VSD 0.87 +/- 0.1 microm-1 vs 0.55 +/- 0.2 microm-1 in HTCtshr+, p < 0.05). VEGF secretion was more pronounced in naïve HTC cells stimulated with EGF, than in HTCtshr+ cells stimulated with either TSH or EGF. In conclusion, regained expression of functional TSHR in the follicular thyroid cancer cell line HTC alters in vitro features commonly associated with the malignant phenotype. Smaller tumors and reduced angiogenesis of xenotransplanted HTC cells with functioning TSHR suggest a less aggressive in vivo phenotype. The present data highlight the pivotal role of TSHR to affect transformed thyrocytes in vitro and in vivo. They also suggest a role for EGF as a modulator of angiogenesis in thyrocytes devoid of TSHR.

Adenocarcinoma, Follicular↗
PubMed2006

Internal radionuclide therapy: software for treatment planning using tomographic data.

AIM: Accurate dosimetry must be performed for each patient before therapy with unsealed radionuclides. Recently, the software tool ULMDOS was developed to facilitate planar dosimetric calculations and to support traceability and documentation as a prerequisite for good clinical practice. Here, the extended version of ULMDOS for processing of tomographic data is presented. METHODS: ULMDOS is developed in IDL 6.1 (Interactive Data Language) under Windows XP/2000. Serial tomographic data can be loaded in an ECAT7 or DICOM format, and presented as maximum intensity projection. The definition of volumes of interest is supported by various tools (e.g., freehand, isocontour, polygon), region growing, and cluster analysis. Residence times are calculated from fits of the time activity data to exponential functions. RESULTS, DISCUSSION: Quantitative 3-dimensional data allow performing a more individualized dosimetry, as problems due to organ overlay, insufficient attenuation and scatter correction in the planar approach can be avoided. For traceability, documentation, retrospective examination and later processing all data can be saved in binary or ASCII format. Dosimetric calculations can be conducted within a single environment, thus it spares the time-consuming transfer of data between different software tools.

Humans↗
PubMed2005

Brain tumour surgery in the vicinity of short-term memory representation--results of neuronavigation using fMRI images.

OBJECTIVE: Functional information concerning the surrounding brain is mandatory for a good clinical outcome in brain tumour surgery. The value of fMRI to detect the motorcortex and Broca's area is widely accepted today. If an appropriate paradigm is used, short-term memory areas can be visualized as well. Obviously this information must be integrated into cranial neuronavigation for an appropriate intra-operative use. We report our first experiences with the direct integration of short-term memory fMRI into cranial neuronavigation. METHOD: From January 2001 to March 2002 14 patients were operated on for intracranial tumours with short-term memory fMRI imaging, using the "two-back-paradigm". Both pre- and postoperatively, the short-term memory of all patients was tested additionally by a standardized test battery including 16 different verbal and visuo-spatial items. RESULTS: In all 14 patients the general level of working memory capacity was preserved after surgery. The visuo-spatial performance was kept unchanged or deteriorated slightly, the alertness slightly worsened as well, but we found an improvement in verbal test items. CONCLUSION: The two-back paradigm is able to visualize verbal memory tasks in fMRI. For visuo-spatial items, a new paradigm has to be designed. In contrast to deep seated brain lesions, focal cortical impairments do not lead to obvious and serious memory deficits. Therefore, the aim of gross total tumour removal has to be balanced against the aim of preservation of short-term memory fields. Nevertheless, the knowledge of the localization of cortical short-term memory fields may combine both aims during navigated brain tumour surgery, thus preserving the patient with a better quality of life.

Adult↗
PubMed2005

[Measurement of noise protection in functional magnetic resonance imaging].

BACKGROUND: Functional magnetic resonance imaging (fMRI) can detect changes in oxygen saturation of the brain. Fast changing high gradient fields are necessary which produce high levels of noise. In studies of the auditory cortex, auditory stimuli have to be perceived and discriminated against the noise level of the activated tomograph. MATERIAL AND METHODS: The generated frequency bands and their intensities during fMRI with a Siemens Magnetom Vision, 1.5 T, EPI sequence were measured in the outer ear canal of a dummy head. Noise attenuation was evaluated with four different noise muffs (simple/inexpensive products, quality product, specialized fMRI muffs). RESULTS: Without protection, peak noise levels reached up to 111 dB(A) near 1000 Hz in the dummy ear canal. Major noise attenuation was only found at higher frequencies (4000 Hz by about 25 dB; 8000 Hz by about 35 dB) with the quality product and the specialized fMRI muffs. CONCLUSION: Only quality noise products can sufficiently protect patients from high sound pressure levels of tomograph noise. If in the future higher gradient fields are applied at faster slew rates, acoustic stimuli can safely be applied only in combination with increased hearing protection systems in order to minimize the risk of noise trauma.

Ear Protective Devices↗
PubMed2005

Differential pattern of integrin receptor expression in differentiated and anaplastic thyroid cancer cell lines.

Adhesion of tumor cells to the extracellular matrix (ECM) is a crucial step for the development of metastatic disease and is mediated by specific integrin receptor molecules (IRM). The pattern of metastatic spread differs substantially among the various histotypes of thyroid cancer (TC). However, IRM have only occasionally been characterized in TC until now. IRM expression was investigated in 10 differentiated (FTC133, 236, 238, HTC, HTC TSHr, XTC, PTC4.0/4.2, TPC1, Kat5) and two anaplastic TC cell lines (ATC, C643, Hth74), primary cultures of normal thyroid tissue (Thy1,3), and thyroid cancer specimens (TCS). Expression of 16 IRM (beta1-4, beta7, alpha1-6, alphaV, alphaIIb, alphaL, alphaM, alphaX) and of four IRM heterodimers (alpha2beta1, alpha5beta1, alphaVbeta3, alphaVbeta5), was analyzed by fluorescent-activated cell sorter (FACS) and immunohistochemical staining. Thyroid tumor cell adhesion to ECM proteins and their IRM expression in response to thyrotropin (TSH) was assessed. Follicular TC cell lines presented high levels of integrins alpha2, alpha3, alpha5, beta1, beta3 and low levels of alpha1, whereas papillary lines expressed a heterogenous pattern of IRM, dominated by alpha5 and beta1. ATC mainly displayed integrins alpha2, alpha3, alpha5, alpha6, beta1 and low levels of alpha1, alpha4 and alphaV. Integrin heterodimers correlated with monomer expression. Evaluation of TCS largely confirmed these results with few exceptions, namely alpha4, alpha6, and beta3. The ability of TC cell lines to adhere to purified ECM proteins correlated with IRM expression. TSH induced TC cell adhesion in a dose-dependent fashion, despite an unchanged array of IRM expression or level of a particular IRM. Thyroid carcinoma cell lines of different histogenetic background display profoundly different patterns of IRM expression that appear to correlate with tumor aggressiveness. In vitro adhesion to ECM proteins and IRM expression concur. Finally, TSH-stimulated adhesion of thyroid tumor cell lines to ECM may not be associated with altered IRM expression.

Carcinoma↗
PubMed2004

Quasi-automatic 3D finite element model generation for individual single-rooted teeth and periodontal ligament.

The paper demonstrates how to generate an individual 3D volume model of a human single-rooted tooth using an automatic workflow. It can be implemented into finite element simulation. In several computational steps, computed tomography data of patients are used to obtain the global coordinates of the tooth's surface. First, the large number of geometric data is processed with several self-developed algorithms for a significant reduction. The most important task is to keep geometrical information of the real tooth. The second main part includes the creation of the volume model for tooth and periodontal ligament (PDL). This is realized with a continuous free form surface of the tooth based on the remaining points. Generating such irregular objects for numerical use in biomechanical research normally requires enormous manual effort and time. The finite element mesh of the tooth, consisting of hexahedral elements, is composed of different materials: dentin, PDL and surrounding alveolar bone. It is capable of simulating tooth movement in a finite element analysis and may give valuable information for a clinical approach without the restrictions of tetrahedral elements. The mesh generator of FE software ANSYS executed the mesh process for hexahedral elements successfully.

Algorithms↗
PubMed2003

[Brain abscesses in diffusion-weighted imaging (DWI)--comparison to cystic brain tumors].

PURPOSE: The clinical usefulness of diffusion-weighted imaging (DWI) was evaluated in patients with brain abscesses in comparison to patients with cystic brain tumors. MATERIAL AND METHODS: Five patients with surgically confirmed brain abscesses underwent beside a brain MRI examination with contrast media application diffusion weighted imaging. Apparent diffusion coefficients (rADC) in three orthogonal diffusion gradient were calculated. The same protocol was used to examine 5 patients with cystic brain tumors. RESULTS: Showing an rADC of 0.33 x 10(-3)/mm(2)/s abscesses have a highly restricted diffusion in comparison to cystic brain tumors with an rADC of 1,67 x 10(-3)/mm(2)/s. CONCLUSION: Diffusion weighted imaging is a usefull diagnostic tool in the work up of brain abscesses.

Adult↗
PubMed2003

Verbal storage in a premotor-parietal network: evidence from fMRI-guided magnetic stimulation.

Phonological rehearsal helps to keep selected information consciously in mind for further processing. This part of short-term storage takes place during the delay period of verbal working memory tasks and involves a frontoparietal network as functional magnetic resonance imaging (fMRI) studies have shown. The involved cortical areas can be further investigated by interfering with the local information processing using transcranial magnetic stimulation (TMS). On a single subject level, we identified predominantly left-sided premotor, prefrontal, and parietal areas active during the delay period of a verbal working memory task using event-related fMRI. In a pilot approach, TMS was neuronavigated to the individually active areas by using a stereotaxic device. Then, TMS was applied during the delay period of similar tasks as in fMRI. Error rates increased significantly upon stimulating left premotor cortex, but not upon parietal or prefrontal stimulation. The contribution of the premotor cortex to storage and rehearsal is discussed as an active top-down storage process within the frontoparietal network.

Adult↗
PubMed2003

Practicability and acute haematological toxicity of 2- and 3-weekly CHOP and CHOEP chemotherapy for aggressive non-Hodgkin's lymphoma: results from the NHL-B trial of the German High-Grade Non-Hodgkin's Lymphoma Study Group (DSHNHL).

BACKGROUND: There is evidence that intensified variants of the classical 3-weekly CHOP-21 chemotherapy [cyclophosphamide (C), doxorubicin (H), vincristine (O), prednisone (P)] may improve treatment outcome in aggressive lymphoma. Three variants using either an addition of etoposide (CHOEP-21: 100 mg/m(2) on days 1-3), the shortening to 2-week intervals using recombinant human granulocyte colony-stimulating factor (rhG-CSF; CHOP-14) or both (CHOEP-14) are currently compared with CHOP-21 in the NHL-B trial of the German High-Grade Non-Hodgkin's Lymphoma Study Group (DSHNHL). To enable more extensive testing of these schemes we here characterise their practicability regarding schedule adherence, acute haematotoxicity and need for supportive treatment. PATIENTS AND METHODS: The trial included patients with normal lactate dehydrogenase (LDH) aged </=60 years (NHL-B1) and patients aged 61-75 years (NHL-B2). The data are taken from an interim analysis. Data from 959 patients (CHOP-21: 232; CHOP-14: 238; CHOEP-21: 244; CHOEP-14: 245) from 162 institutions with a total of 5331 therapy cycles were evaluated. RESULTS: The dose adherence in the NHL-B1 trial was excellent. The median relative dose (RD; i.e. actually given compared to planned dose) exceeds 98% for the myelosuppressive drugs in all four regimens. Only </=5% of patients received a relative dose <80% (RD <80). The median treatment duration could be shortened as scheduled for both CHOP-14 by 36 days and CHOEP-14 by 35 days. The dose adherence in the NHL-B2 trial was excellent for CHOP-21 and CHOP-14 for the myelosuppressive drugs (median RD >/=98%, RD <80 </=15%). Addition of etoposide, however, was accompanied by more dose erosion (median RD >/=97%, RD <80 </=17% for CHOEP-21 and </=27% for CHOEP-14). The median treatment duration could be shortened by 34 days with CHOP-14 compared with CHOP-21. Less treatment shortening was feasible for CHOEP-14 compared with CHOP-21 (median of 29 days). CHOP-14 and CHOP-21 were similar regarding toxicity profile, rate of infection, use of antibiotics, rate of transfusions and hospitalisation. CHOEP schemes were associated with a higher rate of infections, more transfusion requirements, more antibiotic use and longer hospitalisation than the CHOP schemes, particularly in patients aged >60 years. Haematopoietic recovery was age- and treatment-related. CONCLUSIONS: CHOP-14 with the addition of rhG-CSF is safe and practicable in a large multicentre setting in patients aged 18-75 years. Despite shorter treatment intervals it can be delivered at the same dose as the classical 3-weekly CHOP with a comparable toxicity profile. The addition of etoposide is feasible and safe for patients </=60 years old in both the CHOEP-21 and CHOEP-14 schemes. For patients >60 years of age the addition of etoposide is associated with marked dose erosion due to increased toxicity. In this age group CHOEP should be used with caution.

Acute Disease↗
PubMed2002

In vitro and in vivo angiogenesis in PC12 pheochromocytoma cells is mediated by vascular endothelial growth factor.

Angiogenesis, the formation of new blood vessels from existing vascular endothelium, is essential for tumor growth. Vascular endothelial growth factor (VEGF) is an endotheliumspecific mitogen and regulator of angiogenesis. Angiogenesis has been associated to the malignant phenotype of pheochromocytomas and is readily observed in experimental pheochromocytomas. Although VEGF gene expression has already been demonstrated in the rat PC12 cell line, the detailed mechanisms of action are not known. We have, therefore, studied angiogenesis in the rat PC12 pheochromocytoma cell line in vitro and in vivo. VEGF gene expression and accumulation of VEGF protein in cytoplasm and conditioned medium of PC12 cells was found. Conditioned medium from PC12 cells significantly increased proliferation of VEGF-dependent endothelial cells from human umbilical veins, and this effect reversed upon addition of a neutralizing anti-VEGF antibody. Dexamethasone and nerve growth factor (NGF) increased VEGF mRNA expression and accumulation of VEGF protein of PC12 subclones with established metastatic activity in vivo. PC12 cells xenotransplanted to nude mice had marked VEGF expression and induced host angiogenesis, confirmed by the presence of CD34-positive endothelial cells in the experimental PC12 tumors. When NGF-primed PC12 cells were immobilized in Matrigel supplemented with rising concentrations of the growth factor and xenotransplanted, increasing NGF resulted in tumors with smaller areas of necrosis and increased vital tumor volume. These results suggest that VEGF is a mediator of angiogenesis in the PC12 pheochromocytoma cell line, and that dexamethasone and NGF affect VEGF expression. Our data further suggest that NGF may contribute to angiogenesis in experimental pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed2001

Multimodal cranial neuronavigation: direct integration of functional magnetic resonance imaging and positron emission tomography data: technical note.

OBJECTIVE: This is the first report of the direct integration of functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) data into cranial neuronavigation. METHODS: In a patient with a left precentral oligodendroglioma (World Health Organization Grade III), the Zeiss MKM system (Carl Zeiss Co., Oberkochen, Germany) was used for navigation based on thin-slice, T1-weighted, contrast-enhanced magnetic resonance imaging (MRI) scans. fMRI and methionine PET data were integrated by landmark matching, with reference to skin fiducials. RESULTS: The inaccuracy of the image fusion between fMRI and T1-weighted MRI data was 1.7 mm, that between PET and T1-weighted MRI data was 4.3 mm, and that for the subsequent registration of the navigation was 1.2 mm. The correct fMRI localization of the precentral gyrus was intraoperatively verified by cortical somatosensory evoked potential (phase-reversal) monitoring. Although the tumor was not clearly defined in the MRI scans, [11C]methionine PET demonstrated a clear tumor border, enabling us to achieve gross total tumor removal without postoperative functional deficits. CONCLUSION: Functional neuronavigation permits observation and preservation of relevant brain areas. Other functional areas (such as short-term memory areas) that can be detected only by fMRI might also warrant future monitoring. The simultaneous integration of fMRI and PET data adds a new dimension to cranial neuronavigation, enabling the observation of tumors in relation to functional cortical areas (in our case, the motor strip).

Brain↗
PubMed2000

Functional cranial neuronavigation. Direct integration of fMRI and PET data.

OBJECTIVE: We report our first experiences with the direct integration of fMRI data into cranial neuronavigation. METHOD: For navigation we used the MKM system and thin-sliced T1 contrast enhanced images. As a first step 21 patients had fMRI for localization of the precentral gyrus, 2 patients for Broca area detection. By anatomical correlation, these functional data were indirectly compared to the intraoperative findings using cortical SSEP (n=20) or cortical stimulation (n=3). Encouraged by these preliminary results, we started the direct integration of fMRI into neuronavigation in June 1999, followed by PET in January 2000, enabling us to compare functional images with intraoperative findings directly. fMRI and PET data were integrated by landmark matching referring on skin fiducials. Meanwhile, fMRI data of 8 patients (6 motorcortex, 2 Broca) and PET images of 1 patient were directly integrated into neuronavigation. Six out of 8 patients had additional cortical monitoring, 2/8 were exclusively operated on by functional neuronavigation. RESULTS: Using indirect comparison between fMRI and intraoperative findings we observed a good correlation in every case for the motorcortex, but only in 1/2 for the speech area. In all 6 direct integrated fMRI cases, these findings corresponded well to the conventional ones. Both patients with sole functional navigation did not have any postoperative neurological deficit. The inaccuracy of the fMRI ifT1 matching was 2. 7 mm (sigma=0.9 mm) and 1.3 mm (sigma=0.4 mm) of the subsequent referenciation of the navigation. The tumor delinement shown by 11C-methionine PET could be proven by intraoperative biopsy outside its indicated tumor margin. The inaccuracy of the PET matching was 0. 8 mm. CONCLUSION: Functional neuronavigation enables to visualize and preserve relevant brain areas. Other functional areas like short-term memory, which solely can be detected by fMRI might also be monitored in the future. The integration of PET data expect to gain a better differentiation of tumor and edema.

Adult↗
PubMed1999

Expression of K13/v-FLIP gene of human herpesvirus 8 and apoptosis in Kaposi's sarcoma spindle cells.

BACKGROUND: Human herpesvirus 8 (HHV8) infection is associated with all forms of Kaposi's sarcoma (KS). The HHV8 genome locus ORFK13-72-73 (ORF = open reading frame) encodes proteins that may be important in HHV8-mediated pathogenesis, i.e., the latency-associated nuclear antigen (encoded by ORF73), viral-cyc-D (v-cyc-D), a viral homologue of cellular cyclin D (encoded by ORF72), and viral-FLIP (v-FLIP), a homologue of the cellular FLICE (Fas-associated death domain-like interleukin 1 beta-converting enzyme) inhibitory protein (encoded by ORFK13; is an inhibitor of apoptosis [programmed cell death]). Through differential splicing events, this locus expresses individual RNA transcripts that encode all three proteins (tricistronic transcripts) or just two of them (v-FLIP and v-cyc-D; bicistronic transcripts). We examined expression of these transcripts in KS tissues. METHODS: We collected tissues from patients with KS of different stages. By use of an optimized in situ hybridization procedure, we examined different ORFK13-72-73 locus transcripts in HHV8-infected cells in skin lesions and in one adjacent lymph node. Apoptosis in KS lesions was determined by use of an in situ assay. RESULTS AND CONCLUSIONS: Our results indicate the following: 1) Transcripts from the ORFK13-72-73 locus appear to be spliced differentially in latently infected KS cells in skin lesions and in HHV8-infected cells in lymph nodes; specifically, ORFK13-ORF72 bicistronic transcripts were expressed abundantly in KS cells, whereas ORFK13-ORF72-ORF73 tricistronic transcripts were detected only in lymph node cells. 2) Sequences encoding the antiapoptotic protein v-FLIP are expressed at very low levels in early KS lesions, but expression increases dramatically in late-stage lesions. 3) The increase in expression of v-FLIP-encoding transcripts is associated with a reduction in apoptosis in KS lesions. IMPLICATIONS: These data suggest that functional v-FLIP is produced in vivo and that antiapoptotic mechanisms may be involved in the rapid growth of KS lesions, where only a few cells undergoing mitosis are generally observed.

Antigens, Viral↗
PubMed1998

[Temperature stress for patients in routine magnetic resonance examinations].

PURPOSE: To determine energy exposure and temperature changes in routine magnetic resonance imaging practice. MATERIALS AND METHODS: Body core and skin temperatures were compared in 155 persons (143 patients, 12 volunteers) undergoing routine magnetic resonance examinations with a 1.5 T field-strength magnetic resonance tomography unit using a fluoroptic temperature measurement system. RESULTS: Average applied energy was 0.3 W/kg for whole body and 1.92 W/kg for spatially localized SAR. The maximum whole-body SAR was 1.43 W/kg spatially localized. Body core temperatures differed from those of the control group by a median 0.1 degree C and only a few patients (16.8%) exceeded the limit (+/- 0.5%) at which regulatory mechanisms set in. All patients remained within the normal physiological circadian temperature range (+/- 1 degree C). Skin temperature rose a median 0.49 degree C, with a maximal increase of 5.31 degrees C, which may be considered to be within the limits of physiological temperature change. CONCLUSIONS: Clinically relevant warming of the body is unlikely in routine magnetic resonance imaging practice.

Adolescent↗
PubMed1998

Virtual cystoscopy based on helical CT scan datasets: perspectives and limitations.

The purpose of the study was to simulate cystoscopy based on three-dimensional helical CT scan datasets in real-time in patients with tumours of the urinary bladder. A helical CT scan with double detector technology was carried out pre-operatively in 11 patients with histologically confirmed carcinoma of the urinary bladder and one patient with chronic cystitis. A non-enhanced scan was first performed, followed by an examination in the early phase of contrast medium enhancement. Further images were acquired after adequate filling of the bladder with contrast medium, approximately 30 min after injection. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and histopathological findings. All tumours of the urinary bladder identified at fibreoptic cystoscopy were shown on virtual cystoscopy. The best reconstruction results were obtained from data acquired 30 min after injection of contrast medium. The ureteric orifices were not visualized at virtual cystoscopy. These data lead us to conclude that, at present, virtual cystoscopy has not reached the quality of fibreoptic examination and remains restricted to use in specific cases, for example patients with urethral strictures.

Aged↗