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  • 2000-2004  (180)
  • MRI  (121)
  • Rat
  • Nuclear reactions
  • 1
    ISSN: 1432-2277
    Schlagwort(e): Key words Implantation model ; Aortic valves ; Valve dysfunction ; Rejection ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Structural failure of heart valve allografts may be related to technical factors or immunological reactions. To circumvent nonimmunological factors a new rat implantation model was developed to study whether alloreactivity results in histopathological changes and valve dysfunction. Syngeneic (WAG-WAG, DA-DA) and allogeneic (WAG-BN, WAG-DA) transplantation was carried out using this new technique, and the function of explanted valves was assessed 21 days later by retrograde comptence testing. Additionally, grafts were examined using standard histological and immunohistochemical techniques. There was no leakage during retrograde injection in nine of tem syngeneic and two of ten allogeneic grafts. Microscopically, syngeneic valves appeared normal without fibrosis or intimal thickening, although CD8+ lymphocytes and macrophages were found in necrotic myocardial rim and adventitia. In contrast, allogeneic valves were deformed and noncellular, with extensive infiltration of CD4+, CD8+ and CD68+ cells in adventitia and media. Absence of fibrosis and intimal thickening in syngeneic transplanted valves indicated circumvention of nonimmunological factors. Allogeneic valve transplantation induces cellular infiltration in the graft with subsequent graft failure.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1432-2277
    Schlagwort(e): Key words Hypoxia-reoxygenation ; JNK1/SAPK1 ; Rat ; Hepatocytes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Organ injury after ischemia and reperfusion (I/R) remains one of the most important limiting factors in liver surgery and transplantation. Oxygen-free radical (OFR) generation is considered a major cause of this damage. JNK1/SAPK1, a member of MAPK family, regulates cell adaptation to stressful conditions. The aim of this study was to determine if hypoxia-reoxygenation (H/R) can activate JNK1/SAPK1 and if OFR are involved in this activation. Primary cultured rat hepatocytes isolated from other liver cells and blood flow were submitted to warm and cold H/R phases mimicking surgical and transplant conditions. JNK1/SAPK1 was activated by both warm and cold H/R. Deferoxamine (1 mM), di-phenyleneiodonium (50 μM) and N-acetylcysteine (10 mM) significantly inhibited this kinase activation.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-2277
    Schlagwort(e): Key words Small bowel transplantation ; Split tolerance ; FK 506 ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Functional long-term allograft survival after experimental small bowel transplantation (SBT) is limited by chronic rejection. Initial application of high-dose FK 506 has been shown to induce stable long-term graft function. In order to examine whether this long-term function is associated with donor-specific tolerance, we analyzed the functional status of recipient T cells in vivo and in vitro. One-step orthotopic SBT was performed in the allogeneic Brown Norway (BN)-to-Lewis rat strain combination. FK 506 was given daily at a dose of 2 mg/kg from days 0–5 in the rejection model and from days 0–9 in the long-term functional model. Mean survival time in the rejection model was 98 ± 2.8 days. Histological examination of these small bowel allografts disclosed signs of chronic rejection. In contrast, all animals of the long-term functional model survived long term ( 〉 250 days) without clinical signs of chronic rejection. The latter model, furthermore, produced evidence of donor-specific tolerance. Whereas heterotopic Dark Agouti (DA) hearts were rejected regularly within 7 days, BN hearts survived indefinitely ( 〉 70 days). In vitro, mixed leukocyte reactivity of CD4 + T cells was similarly strong against donor (BN) antigens as against third-party (DA) antigens. The split tolerance revealed by our in vivo and in vitro results enabled acceptance of both the small bowel allograft without signs of chronic rejection and of donor-specific heart allografts.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-2307
    Schlagwort(e): Key words T-type calcium channel blockade ; Mibefradil ; Myocardial infarction ; Cardiac remodeling ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Fibrillar collagen accumulates within the interstitium and around coronary arteries following cardiac failure and is responsible for abnormal myocardial stiffness and reduced coronary performance associated with impaired cardiac function. The aim of the study was to determine the effects of long-term treatment with the T-type calcium channel antagonist mibefradil on myocardial remodeling and cardiac function after chronic myocardial infarction (MI). MI was induced by permanent ligation of the left coronary artery in male Wistar rats. Animals were assigned to sham-operated, placebo-treated or mibefradil-treated (10 mg/kg per day p.o.) MI groups. Treatment with mibefradil was started either 7 days before, 24 h after, or 7 days after ligation and continued for 6 weeks after MI. At this time point, mean arterial blood pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP) and cardiac contractility (dP/dtmax) were measured in conscious rats. Morphometric parameters were determined in picrosirius red-stained hearts: total heart weight (THW), interstitial and perivascular collagen volume fraction (ICVF, PCVF), myocardial infarct size (IS), vascular perimeter (VP), inner vascular diameter (IVD) and media thickness (MT). Six weeks after MI, MAP and dP/dtmax were decreased, and LVEDP was increased in placebo-treated animals. In mibefradil-treated animals whose treatment started 7 days before or 24 h after MI, MAP and dP/dtmax were higher, and LVEDP was lower than in placebo-treated controls. THW, ICVF, PCVF and MT were higher in placebo-treated animals. Mibefradil treatment resulted in higher ICVF and IS, higher VP and IVD (when started 7 days before MI) and lower PCVF and MT (when started 7 days before or 24 h after MI) than were observed in placebo-treated controls. Chronic treatment with mibefradil reduced interstitial and perivascular fibrosis and improved cardiac function in MI-induced heart failure in rats. Cardiac remodeling was best prevented when treatment was begun before the ischemic event.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-2307
    Schlagwort(e): Keywords 7 ; 12-dimethylbenz(a)anthracene ; Rat ; Submandibular gland ; Adenocarcinoma Myoepithelial cell
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  In an attempt to induce adenocarcinoma containing myoepithelial cells (MECs) in the rat submandibular gland, we injected 7,12-dimethylbenz(a)anthracene (DMBA) dissolved in acetone into the glands of rat pups at the age of 10 days. In both male and female pups, the glands, including their developing terminal secretory units, contained far greater numbers of cells positive for proliferating cell nuclear antigen (PCNA) than did adult glands. A single administration of 1% DMBA (0.05 ml/130 g b.w.) did not produce adenocarcinoma, but did induce occasional sarcomas, such as rhabdomyosarcoma and fibrosarcoma, in 2 months. Most glands regenerated with minimal scar formation. Microscopically, these glands were atypical in that they contained increased numbers of PCNA-positive cells, underdeveloped granular ducts, and striated ducts surrounded by MECs positive for alpha smooth muscle actin (αSMA). Though these features were also observed in the regenerated glands after acetone injection, the number of PCNA-positive cells was relatively high in the glands of DMBA-treated females, especially in the terminal secretory unit. The second DMBA injection at 10 weeks of age produced adenocarcinoma made up of αSMA-positive MECs and keratin 19-positive duct cells. Such MEC-associated adenocarcinoma was induced in the glands of more than half the female but not the male animals. Replacement of either of the double DMBA treatments with acetone, or DMBA treatment, single or double, of adult glands did not produce adenocarcinoma, but did produce sarcoma and squamous cell carcinoma. These results suggest that (1) at least two genetic mutations are necessary for induction of adenocarcinoma with MECs in the rat submandibular gland, (2) the mutation is efficiently introduced to pup glands whose terminal secretory units exhibit extreme proliferative activity, and (3) the second mutation is difficult to introduce in male glands, whose proliferative activity is relatively low, and/or transformed cells need some female hormone after the mutation to propagate.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-2161
    Schlagwort(e): Keywords Gaucher disease ; MRI ; Enzyme replacement therapy ; Liver ; Spleen ; Bone marrow
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Purpose. To determine whether T1-weighted magnetic resonance (MR) images can demonstrate response in the marrow of patients with type 1 Gaucher disease treated with enzyme replacement therapy (ERT) and to determine whether a relationship exists between liver and spleen volume reductions and visible marrow changes. Patients. Forty-two patients with type 1 Gaucher disease were evaluated on at least two occasions. Thirty-two patients received ERT. Of these patients, 15 had a baseline examination prior to the initiation of ERT. The remaining 10 patients did not receive ERT. Design. T1-weighted and gradient recalled echo (GRE) coronal images of the femurs and hips were obtained. Concurrently, liver and spleen volumes were determined using contiguous breath-hold axial gradient-echo images. T1-weighted images of the hips and femurs were evaluated to determine change or lack of change in the yellow marrow. Results. Of the 32 patients receiving ERT, 14 (44%) demonstrated increased signal on T1-weighted images suggesting an increase in the amount of yellow marrow. If only the 15 patients with a baseline examination were considered, the response rate to ERT was 67%. Using Student’s t-test a highly significant correlation (P〈0.005) was found between marrow response and reduction in liver and spleen volume. Conclusions. Marrow changes in patients receiving ERT can be detected by T1-weighted images. This response correlated with reductions in visceral volumes (P〈0.0005).
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 81-84 
    ISSN: 1432-2161
    Schlagwort(e): Key words Arthrography ; MRI ; Fluoroscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Purpose. To describe a technique for intra-articular injection in the MR suite after conventional fluoroscopic landmarking in order to streamline MR arthrography. Design and patients. This technique was performed on 33 consecutive patients referred for MR arthrography of the shoulder to evaluate the glenoid labrum and on 15 consecutive patients referred for MR arthrography of the hip to evaluate the acetabular labrum. The patients were landmarked in the fluoroscopy suite, followed by a conventional MR examination. The intra-articular injection was then performed on the MR table and the MR arthrographic sequences obtained. Results. One of the 48 injections was extra-articular, requiring a second injection. The other injections were performed without incident, and the average total procedure time for all injections was 10 min. Conclusions. This technique is a reliable method of streamlining intra-articular injections when performing conventional MR imaging prior to the MR arthrographic portion of the examination. It shortens the total MR examination time by eliminating a visit to the fluoroscopy suite in the middle of the MR study, and its use of a straight anterior approach for both the shoulder and hip joints should be familiar to most people who perform conventional arthrography.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 109-111 
    ISSN: 1432-2161
    Schlagwort(e): Key words Fat ; Elastofibroma ; Neck ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Elastofibromas are benign lesions of the chest wall. We describe the first reported case of elastofibroma in the neck. Imaging features as well as location of the lesion were atypical. On computed tomography and magnetic resonance imaging the lesion contained a marked preponderance of fat, because the lesion arose within fat.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 117-124 
    ISSN: 1432-2161
    Schlagwort(e): Key words Osteomalacia ; Metabolic disease ; Hemangiopericytoma ; Fibrohistiocytic tumors ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The clinical, imaging, metabolic, histologic and biochemical aspects of oncogenic osteomalacia are reviewed. The bone and soft tissue tumor and tumor-like lesions associated with this paraneoplastic syndrome are discussed. The radiologist’s role in the diagnosis and evaluation of this entity is presented.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 165-167 
    ISSN: 1432-2161
    Schlagwort(e): Key words Rheumatoid arthritis ; Geode ; Pathological fracture ; Humerus ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We describe the imaging features of a giant geode of the distal humerus in a patient with rheumatoid arthritis, which presented initially as a pathological fracture. The value of magnetic resonance imaging in establishing this diagnosis is emphasized.
    Materialart: Digitale Medien
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 162-164 
    ISSN: 1432-2161
    Schlagwort(e): Key words Retroisthmic cleft ; Stress fracture ; Laminar fracture ; Xray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The retroisthmic cleft is a rarely diagnosed defect in the lamina of the lumbar spine. It has always been considered a congenital anomaly. This is the first report we are aware of showing radiological changes in a retroisthmic cleft over a period of time. The follow-up of this patient over a period of 6 years, the radiological and scintigraphic appearances and a review of the literature suggests that the retroisthmic cleft is a stress fracture of the lamina.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 270-274 
    ISSN: 1432-2161
    Schlagwort(e): Key words Soft tissue neoplasm ; Metastasis ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To describe a series of patients with no known primary malignancy who presented with a solitary unsuspected soft tissue metastasis masquerading as a soft tissue sarcoma, and secondarily to describe the imaging appearance of these lesions. Design. Records of two academic hospitals with active orthopedic oncology services were reviewed for patients meeting the above criteria. Clinical charts were examined, and the imaging appearance of the soft tissue lesions retrospectively reviewed. Patients. Of 1421 patients examined for soft tissue lesions, 11 were found who met the above criteria. Results. Of the 11 patients whose initial presentation was a solitary soft tissue metastasis, eight were found to have a primary lung cancer, two were diagnosed with adenocarcinoma of unknown primary, and adenocarcinoma of the colon was discovered in the remaining patient. Conclusions. The clinical presentation of a solitary soft tissue metastasis without a known primary malignancy is a rare occurrence, with an incidence of approximately 0.8%. Lung cancer is the primary neoplasm in a high percentage of these cases.
    Materialart: Digitale Medien
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  • 13
    ISSN: 1432-2161
    Schlagwort(e): Key words Clear cell sarcoma ; Malignant melanoma of soft parts ; MRI ; Magnetic resonance ; Neoplasm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). Design and patients. MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study. Results. On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. Conclusions. Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 227-230 
    ISSN: 1432-2161
    Schlagwort(e): Key words Erdheim-Chester Disease ; Lipogranuloma ; MRI ; Muscle ; Rectus femoris
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report on a rare manifestation of Erdheim-Chester disease with intramuscular lipogranuloma. The patient was a 66-year-old man who noted a soft tissue mass in the right quadriceps femoris muscle. Radiographs revealed symmetrical osteosclerosis in the diametaphysis of both femora and tibiae. An open biopsy revealed a proliferation of lipid-laden histiocytes in the femoral bone marrow and the quadriceps femoris muscle. To our knowledge, this is the second case of Erdheim-Chester disease involving muscle.
    Materialart: Digitale Medien
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 235-238 
    ISSN: 1432-2161
    Schlagwort(e): Key words Femur echinococcosis ; MRI ; echinococcosis ; Hydatid cyst surgery ; Hydatid cyst ; anticestodal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Magnetic resonance (MR) findings of a rare case of osseous echinococcosis with involvement of the femur are described. Attention is drawn to the typical MR appearances and therapeutic management.
    Materialart: Digitale Medien
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 243-246 
    ISSN: 1432-2161
    Schlagwort(e): Key words Tibial deficiency ; Fibular deficiency ; Congenital hip dislocation ; Transverse limb deficiency ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report two similar, but unrelated, patients with congenital bilateral partial deficiencies of the tibia and fibula associated with intact feet. In both patients, the tibia and fibula were absent on initial radiographs, while the femur and the tarsal bones were well developed and there was bilateral teratologic dislocation of the hips. Ultrasound and magnetic resonance imaging (MRI) studies suggested the presence of cartilaginous remnants of the tibia and fibula. There were multidirectional instabilities in the knees and ankles. The clinical and radiological features of these cases are distinct from those of congenital longitudinal deficiency of the tibia, in which the fibula is always preserved, and from longitudinal deficiency of the fibula, in which the tibia is present and the foot is usually involved. We suggest that the bilateral partial deficiencies of the tibia and fibula associated with the intact foot and teratologic dislocation of the hips is a single-entity disorder, possibly categorized as an intercalary transverse deficiency of the lower limb.
    Materialart: Digitale Medien
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 1-9 
    ISSN: 1432-2161
    Schlagwort(e): Key words Soft tissue masses ; Hemorrhage ; MRI ; Iron ; Contrast enhancement, MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Hematomas in the extremities can present clinically as a soft tissue mass. Hematomas can usually be distinguished from neoplasia on MR by the signal patterns of hemoglobin breakdown products, which are dependent on the chemical bonding and oxidation state of hemoglobin iron. Beginning with a discussion of relevant atomic electronic structure, this review will examine how oxyhemoglobin, deoxyhemoglobin, methemoglobin, and hemosiderin, the principal iron compounds occurring in the various stages of a hematoma, affect its appearance on MRI.
    Materialart: Digitale Medien
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 10-14 
    ISSN: 1432-2161
    Schlagwort(e): Key words Wrist ; MR arthrography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Purpose.In the wrist, to determine whether passive motion or active exercise yields a better indirect MR arthrographic effect following intravenous gadolinium administration. Design and patients. Twenty-six consecutive patients were studied by indirect wrist MR arthrography. In half active exercise and in half passive motion was performed. Four regions of interest were studied including the distal radioulnar joint, the radiocarpal joint, the midcarpal joint, and the triangular fibrocartilage. Ranges and means of signal intensity were calculated. Surgical follow-up was performed in 22 patients. Results. The joint fluid intensity was greatest in the distal radioulnar joint. Fluid signal intensity was greater and more consistent in the passive motion group although the results did not achieve statistical significance. Imaging accuracy appeared similar in the two groups and was excellent for the triangular fibrocartilage (100%) and scapholunate ligaments (96%). Conclusion. Active exercise and passive motion yield similar degrees of wrist arthrographic effect, but the effect of passive motion is somewhat more consistent. Preliminary data show good accuracy for internal derangements.
    Materialart: Digitale Medien
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  • 19
    ISSN: 1432-2161
    Schlagwort(e): Key words Gaucher disease ; Bone disease ; Extraosseous Gaucher disease ; Bone marrow imaging ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To investigate the frequency and morphology of extraosseous extension in patients with Gaucher disease type I. Design and patients. MRI examinations of the lower extremities were analyzed in 70 patients with Gaucher disease type I. Additionally, the thoracic spine and the midface were investigated on MRI in two patients. Results. Four cases are presented in which patients with Gaucher disease type I and severe skeletal involvement developed destruction or protrusion of the cortex with extraosseous extension into soft tissues. In one patient, Gaucher cell deposits destroyed the cortex of the mandible and extended into the masseter muscle. In the second patient, multiple paravertebral masses with localized destruction of the cortex were apparent in the thoracic spine. In the third and fourth patient, cortical destruction with extraosseous tissue extending into soft tissues was seen in the lower limbs. Conclusions. Extraosseous extension is a rare manifestation of Gaucher bone disease. While an increased risk of cancer, especially hematopoietic in origin, is known in patients with Gaucher disease, these extraosseous benign manifestations that may mimic malignant processes should be considered in the differential diagnosis of extraosseous extension into soft tissues. A narrow neck of tissue was apparent in all cases connecting bone and extraosseous extensions.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 40-44 
    ISSN: 1432-2161
    Schlagwort(e): Key words Subchondral insufficiency fracture ; Femoral head ; Medial femoral condyle ; Osteonecrosis ; MRI ; X-ray
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This case report documents the clinical, radiographic, and histologic findings in a 69-year-old obese man, who had subchondral insufficiency fracture both in the femoral head and medial femoral condyle. On plain radiographs, both lesions underwent subchondral collapse. Magnetic resonance images of the left hip showed a bone marrow edema pattern with associated low-intensity band on T1-weighted images, which was convex to the articular surface. The histopathologic findings in the hip and knee were characterized by the presence of a subchondral fracture with associated callus and granulation tissue along both sides of a fracture line. There was no evidence of antecedent osteonecrosis. To our knowledge, this is the first case report to describe the multiple occurrence of collapsed subchondral insufficiency fracture.
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 45-48 
    ISSN: 1432-2161
    Schlagwort(e): Key words Cystic fibrous dysplasia ; Giant cell tumor ; Femur ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report the case of a 43-year-old man who presented with an osteolytic and expansive lesion in the left distal femur mimicking a giant cell tumor. Magnetic resonance imaging (MRI) showed that most of the lesion was cystic, and histological examination revealed fibrous dysplasia with marked cystic degeneration. Radiographic findings of cystic fibrous dysplasia in the end of a long bone may be similar to those of a giant cell tumor, and a biopsy is essential for the final diagnosis.
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  • 22
    ISSN: 1432-2161
    Schlagwort(e): Key words Hemangiopericytoma ; Tibia ; MRI ; Angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The Magnetic Resonance Imaging (MRI) appearances of primary osseous hemangiopericytoma (HPC) have been rarely described. We report on a 46-year-old Chinese man with primary osseous HPC of the right tibia. The characteristic vascular distribution of this tumor, presenting with a ”spoke-wheel” appearance on MR images and with angiographic correlation, is described. Although not pathognomonic, this MR appearance may be an important finding in suggesting the diagnosis of osseous HPC.
    Materialart: Digitale Medien
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 555-562 
    ISSN: 1432-2161
    Schlagwort(e): Keywords Diffusion ; MRI ; Skeletal system ; Spine ; neoplasms
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This article reviews the principles of diffusion-weighted imaging (DWI) and recent results in DWI of the musculoskeletal system. The potential of DWI in the diagnosis of pathology of the musculoskeletal system is discussed. DWI is a relatively new MR imaging technique that has already been established in neuroradiology, especially in the early detection of brain ischemia. The random motion of water protons on a molecular basis can be measured with DWI. To date DWI of the abdomen and of the musculoskeletal system has only been employed in scientific studies, but first results indicate that it may also be beneficial in these fields. Different diffusion characteristics have been found in normal tissues such as muscle, fat and bone marrow. Also, pathologic entities such as neoplasms, post-therapeutic soft tissue changes and inflammatory processes can be differentiated. Normal muscle shows significantly higher diffusion values than subcutaneous fat and bone marrow, due to a higher mobility of water protons within muscle. Soft tissue tumors exhibit a significantly lower diffusion value compared with post-therapeutic soft tissue changes and inflammatory processes. Necrotic tumor tissue can be distinguished from viable tumor due to significantly higher diffusion of water protons within necrotic tissue.
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 597-600 
    ISSN: 1432-2161
    Schlagwort(e): Keywords Parosteal osteosarcoma ; Telangiectatic osteosarcoma ; Dedifferentiation ; Femur ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A unique case of parosteal osteosarcoma (POS) of the proximal femur, with areas of telangiectatic dedifferentiation, in a 28-year-old woman is reported. The patient had a 7-week history of pain and swelling in her right thigh. A biopsy diagnosis of POS was established. The patient was treated with two cycles of intra-arterial chemotherapy, followed by limb salvage surgery. Histological examination of the resected specimen showed POS with areas of dedifferentiation composed of high-grade telangiectatic osteosarcoma with associated secondary aneurysmal bone cyst change.
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 646-651 
    ISSN: 1432-2161
    Schlagwort(e): Keywords Ewing sarcoma ; Primitive neuroectodermal tumour ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective.To describe the clinical, radiological and MRI features of six atypical cases of histologically proven appendicular Ewing sarcoma/ primitive neuroectodermal tumour (PNET). Design. Retrospective review of case notes and available imaging was carried out. Patients. Six patients (4 male, 2 female; mean age 27years, range 19–44 years), presenting over a 77-month period, were identified from the Bone Tumour Register. All had unusual clinical and imaging features for Ewing sarcoma/PNET. Results and conclusions. Four tumours were centred on the distal femoral metaphysis, one in the proximal tibial metaphysis and one in the distal tibial metaphysis. Plain radiographs were available in four cases and showed minor cortical changes. MRI demonstrated a relatively small, eccentrically located intraosseous component with a large, eccentric extraosseous component. Extension into the epiphysis was seen in three cases and into the adjacent joint in two cases. Intraosseous ”skip” metastases were present in three cases. The clinical and imaging features were atypical for conventional intraosseous Ewing sarcoma/PNET and the exact site of origin (intraosseous, periosteal or soft-tissue) was unclear.
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 656-659 
    ISSN: 1432-2161
    Schlagwort(e): Keywords Osteoblastoma-like osteosarcoma ; Osteosarcoma ; Aggressive osteoblastoma ; Fibula ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report an osteoblastoma-like osteosarcoma in the right proximal fibula in a 22-year-old woman. Radiographs showed an irregular osteolytic lesion from the metaphysis to the epiphysis in the proximal fibula with partial destruction of cortical bone. Tissue from a biopsy indicated a typical osteoblastoma. Curettage and bone graft was performed. One year after the surgery, local recurrence occurred, and a wide excision was performed. Histological examination of the en-bloc surgical specimen revealed the tumor had permeated through the host bony trabeculae, although the nuclear atypia was not marked. Immunohistochemical expression of MIB-1 was detected in 9.0% of cells.
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 660-663 
    ISSN: 1432-2161
    Schlagwort(e): Keywords Acute lymphoblastic leukemia ; Chemotherapy ; Spine ; Tunneling Schmorl’s nodes ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We present a 70-year-old woman with pre-B acute lymphoblastic leukemia in whom serial imaging studies showed the development of multiple vertebral collapse, and communicating superior and inferior Schmorl’s nodes creating a longitudinal channel (”tunneling” Schmorl’s nodes) through the anterior aspect of T12 to L3 vertebral bodies of her osteoporotic thoracolumbar spine. This was observed after achieving complete remission of the disease and during maintenance therapy. The finding is felt to be secondary to iatrogenic exacerbation of osteoporosis.
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 664-667 
    ISSN: 1432-2161
    Schlagwort(e): Keywords Giant cell tumor ; Multiple mid-foot bones ; Reconstructive surgery ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report on a patient who had giant cell tumor involving multiple bones of the mid-foot. The tumor originated from the navicular bone, but also destroyed the cuboid, and all cuneiform bones. This unusual presentation of giant cell tumor presented a therapeutic challenge for the surgeons. The patient was treated with en bloc resection and the bony defect replaced with a massive iliac crest graft which united within 9 months and has remained stable for 7 years without local recurrence, and with excellent function of the foot.
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 717-720 
    ISSN: 1432-2161
    Schlagwort(e): Keywords Amyloidoma ; Bilateral ; Knee ; Popliteal fossa ; Claudication ; MRI ; MR angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The authors report a case of bilateral popliteal amyloidoma causing stenosis of the popliteal artery and vein. This patient had been treated with hemodialysis for 26 years. The diagnosis was made with MR angiography. A popliteal tumor of the right knee was resected surgically and the histologic examination showed deposition of amyloid. After resecting the popliteal tumor, the severe leg pain and intermittent claudication improved. This report suggests that popliteal amyloid tumors should be considered in a patient undergoing long-term hemodialysis who complains of leg pain and intermittent claudication.
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 721-725 
    ISSN: 1432-2161
    Schlagwort(e): Key words Chordoma ; Sarcomatoid chordoma ; Transitional feature ; Sacrum ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a case of chordoma containing a spindle cell sarcomatoid component with a gradual transition from conventional chordoma. Immunohistochemically, many tumor cells in both conventional chordoma and sarcomatoid components were positive for cytokeratins (AE1/AE3, CAM5.2) and epithelial membrane antigen as well as vimentin. This report provides a rare example of sarcomatoid chordoma. Familiarity with this type of bone tumor should help to avoid confusion with dedifferentiated chordoma and other spindle cell sarcomas or carcinomas.
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 97-100 
    ISSN: 1432-2161
    Schlagwort(e): Key words Transient osteoporosis ; Transient bone marrow edema ; Intra-articular regional migratory osteoporosis ; Knee ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a case of lntra-articular regional migratory osteoporosis of the knee in a 53-year-old man. The case demonstrates an unusual pattern of migration of the marrow edema within the knee joint. This phenomenon has received scant attention in the radiological literature.
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 171-175 
    ISSN: 1432-2161
    Schlagwort(e): Key words Desmoplastic fibroma ; Bone tumor ; Femur ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Desmoplastic fibroma of bone is a very rare benign tumor, which may be locally aggressive. In contrast to the well-documented radiological appearance, the literature on MR imaging features of this tumor is scarce. The MR imaging characteristics in our case are compared to those previously reported. Although there is a considerable overlap in the MR imaging features with other bone tumors, an interesting MR feature of desmoplastic fibroma is the presence of low to intermediate signal intensity foci on T2-weighted images, which radiographically does not correspond to calcifications. This feature may help narrow the differential diagnosis.
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 168-170 
    ISSN: 1432-2161
    Schlagwort(e): Key words Chondromyxoid fibroma ; Acromium ; Soft tissue extension ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chondromyxoid fibroma is an unusual, benign tumor of cartilaginous origin and represents less than 1% of all primary bone tumors. It usually involves the long bones around the knee joint or the flat bones of the pelvis or ribs. Soft tissue extension is also thought to be rare in these lesions. They are usually eccentrically located in the metaphyses of the long bones and centrally in the flat bones. The radiographic appearances are characteristically those of a single, lytic lesion with lobulated margins, septations, cortical expansion and a sclerotic rim. Histologically, they display a lobulated pattern with spindle-shaped cells lying within a myxoid matrix with areas of hyaline cartilage. The differential diagnosis includes giant cell tumor, chondroblastoma or enchondroma as well as chondrosarcoma. The rarity of these lesions may render the diagnosis difficult to make, especially when the lesion involves an unusual site such as the acromium.
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 224-226 
    ISSN: 1432-2161
    Schlagwort(e): Key words Intraosseous neurilemmoma (schwannoma) ; Primary bone neoplasm ; Metacarpal ; X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Intraosseous schwannoma (neurilemmoma) is an extremely rare, benign neoplasm, constituting less than 0.2% of primary bone tumors. It infrequently involves the bones of the hand. We present a case of intraosseous neurilemmoma of the metacarpal.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 231-234 
    ISSN: 1432-2161
    Schlagwort(e): Key words Hemangioma ; Ulna ; CT ; MRI ; X-ray
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  An 18-year-old woman presented with left elbow joint pain. Radiographs and computed tomographic scan showed a well-defined osteolytic lesion of the left ulna associated with a honeycomb appearance on the radiographs. Magnetic resonance images showed intermediate signal intensity on T1-weighted images and mixed intermediate and high signal intensities on T2-weighted images. Only the periphery of the lesion enhanced with intravenously injected gadolinium-diethylenetriamine pentaacetic acid. The lesion was curetted to avoid pathologic fracture, and a histologic diagnosis of cavernous hemangioma of bone was made. Hemangioma involving the ulna is rare, but should be included in the differential diagnosis of a radiographic osteolytic lesion with a honeycomb appearance.
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 293-297 
    ISSN: 1432-2161
    Schlagwort(e): Key words Angiomyolipoma (AML) ; Soft tissue ; Thigh ; MRI ; CT ; Angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A 41-year-old man presented with an asymptomatic mass in the right medial thigh. Magnetic resonance imaging (MRI) revealed a well-demarcated, 10-cm mass in the right adductor muscles. The margins of the mass exhibited high signal intensity and the rest showed low or iso signal intensity on T1-weighted MR images. However, the high signal intensity was decreased on T2-weighted images with fat suppression. The central part of the tumor was of inhomogeneous high signal intensity on T2-weighted images; after Gd-DTPA injection it enhanced inhomogeneously on T1-weighted images with fat suppression. On dynamic computed tomography (CT) in the arterial phase, there were strongly enhancing spotty areas in the tumor. At surgery, a yellow-whitish tumor was resected and a pathological diagnosis of angiomyolipoma (AML) in the thigh was made.
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 346-348 
    ISSN: 1432-2161
    Schlagwort(e): Key words Amyloid tumor ; Tibia ; Periosteum ; Bilateral ; MRI ; Bilateral metachronous periosteal tibial amyloid tumors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Localized primary periosteal amyloid tumors are extremely rare. A case of bilateral tibial amyloid tumor is presented. A 62-year-old woman initially presented with a painful mass in the anterior aspect of the right leg. There was no evidence of underlying systemic disease, including chronic infection or malignancy. Based on the results of resistance with Congo red staining to treatment with potassium permanganate and positivity for kappa light chain, we classified this particular case as AL-type amyloidosis. The patient noticed a swelling in the opposite leg 2 years later. The second tumor was also an AL-type amyloidoma. Amyloid tumors are generally solitary. This is the first case of bilateral periosteal amyloid tumors of the AL-type occurring in the tibiae.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 387-391 
    ISSN: 1432-2161
    Schlagwort(e): Key words Trauma ; Hand ; Sonography ; Ultrasound ; Annular pulleys ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To evaluate the sonographic (US) appearance of digital annular pulley (DAP) tears in high-level rock climbers. Design and patients. We performed a retrospective analysis of the US examinations of 16 high-level rock climbers with clinical signs of DAP lesions. MRI and surgical evaluation were performed in five and three patients respectively. The normal US and MRI appearances of DAP were evaluated in 40 and three normal fingers respectively. Results. Nine of 16 patients presented a DAP tear. In eight subjects (seven with complete tears involving the fourth finger and one the fifth finger), US diagnosis was based on the indirect sign of volar bowstringing of the flexor tendons. Injured pulleys were not appreciated by US. Tears concerned the A2 and A3 in six patients and the A3 and A4 in two patients. A2 pulley thickening and hypoechogenicity compatible with a partial tear was demonstrated in one patient. MRI and surgical data correlated well with the US findings. Four patients had tenosynovitis of the flexor tendons but no evidence of pulley disruption. US examinations of three patients were normal. In the healthy subjects US demonstrated DAP in 16 of 40 digits. Conclusion. US can diagnose DAP tears and correlates with the MRI and surgical data. Because of its low cost and non-invasiveness we suggest US as the first imaging modality in the evaluation of injuries of the digital pulley.
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  • 39
    ISSN: 1432-2161
    Schlagwort(e): Key words Bones ; infection ; Bones ; radionuclide studies ; MRI ; comparative studies ; Bones ; MRI studies ; MRI ; extremities ; Bones ; immunoscintigraphy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. A retrospective study of the validity of combined bone scintigraphy (BS) and immunoscintigraphy (IS) using 99mTc-labelled murine antigranulocyte antibodies (MAB) and magnetic resonance imaging (MRI) in chronic post- traumatic osteomyelitis. Design and patients. The results of MRI and combined BS/IS of 19 lesions in 18 patients (13 men, 5 women; mean age 45 years, range 27–65 years) were independently evaluated by two radiologists and one nuclear medicine physician with regard to bone infection activity and extent. The patient group was a highly selective collection of clinical cases: the average number of operations conducted because of relapsing infection was eight (range 2–27), the average time interval between the last surgical intervention and the present study was 6.5 years (range 3 months to 39 years), and from the first operation was 14 years (range 1.5–42 years). Interobserver agreement on MRI was measured by kappa statistics. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for MRI and the nuclear medicine studies. Results. For MRI/nuclear medicine, a sensitivity of 100%/77%, a specificity of 60%/50%, an accuracy of 79%/61%, a PPV of 69%/58% and a NPV of 100%/71% were calculated. Four MR examinations were false positives because of postsurgical granulation tissue. A high degree of interobserver agreement was found on MRI (κ=0.88). A low-grade infection was missed on two scintigrams, while four were false positive because of ectopic haematopoietic bone marrow, and in one examination the anatomical distortion resulted in an inaccurate assignment of the uptake leading to false positive findings. Image analysis was frequently hindered by susceptibility artefacts due to residual abrasions of metallic implants after removal of orthopaedic devices (15/18 patients); this led to limited assessment in 17% (3/18 patients). Conclusion. Acute activity in a chronic osteomyelitis can be excluded with high probability if the MRI findings are negative. In the first postoperative year fibrovascular scar cannot be distinguished accurately from reactivated infection on MRI and scintigraphy may improve the accuracy of diagnosis. MRI is more sensitive in low-grade infection during the later course than combined BS/IS. Scintigraphic errors due to ectopic, peripheral, haematopoietic bone marrow can be corrected by MRI.
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 447-453 
    ISSN: 1432-2161
    Schlagwort(e): Key words Tuberculosis ; Sternum ; Clavicle ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To describe the imaging findings in sterno-clavicular tubercular involvement. Design and patients. Fifteen patients with pathologically proven tuberculosis of the sternum and clavicle were retrospectively evaluated. Routine radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were used in some or all of the patients. Clinical information and imaging features were evaluated in each case. Results. Eight patients had sterno-clavicular joint (SCJ) involvement, five had isolated sternal involvement and two had isolated clavicular involvement. Seven patients were evaluated with only CT, six with only MRI and two with both. There were eight male and seven female patients, varying in age between 16 and 78 years. Fever, swelling and pain were common presenting symptoms. Two patients were HIV positive. Radiographs were positive in only eight patients. Destruction and signal intensity (SI) changes of the sternum and clavicle, destruction of the cartilage, soft tissue changes representing granulation tissue/abscess, displacement of the adjacent structures (vessels, trachea, etc.) and inflammatory changes in the adjacent structures in the form of cellulitis and myositis were common imaging features. Conclusions. All imaging methods can provide complementary information regarding sterno-clavicular tubercular involvement that is helpful for determination of the therapy. MRI is useful in determining the extent of the lesion, particularly marrow involvement and soft tissue extent.
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 477-480 
    ISSN: 1432-2161
    Schlagwort(e): Key words Diabetes mellitus ; Muscle, infarction ; Short T1 ; Hemorrhage ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We describe a case of diabetic muscle infarction which had atypical features of hyperintensity of the affected muscle on T1-weighted images. Biopsy was performed which revealed diffuse extensive hemorrhage within the infarcted muscle. We believe increased signal intensity on T1-weighted images should suggest hemorrhage within the infarcted muscle.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 481-484 
    ISSN: 1432-2161
    Schlagwort(e): Key words Meniscal ossicles ; Ultrasound ; CT-arthrography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A case of meniscal ossicles occurring in the left knee of a 23-year-old woman is presented. Radiographs showed two calcified lesions at the posteromedial aspect of the knee which were interpreted as loose bodies. Sonography, computed tomography arthrography and magnetic resonance imaging showed the fragments within the posterior horn of the medial meniscus permitting a diagnosis of meniscal ossicles. These techniques can detect meniscal ossicles and exclude intra-articular loose bodies.
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  • 43
    ISSN: 1432-2161
    Schlagwort(e): Key words Metastatic bone tumor ; Knee ; Spontaneous osteonecrosis ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a case of a metastatic bone tumor that mimicked spontaneous osteonecrosis of the medial condyle of the femur on magnetic resonance imaging.
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  • 44
    ISSN: 1432-2161
    Schlagwort(e): Key words Chronic leg ulcers ; Squamous cell carcinoma ; Malignancy ; Snake bite ; X-rays ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chronic ulcers of the leg are common in Brazil, perhaps more common than in the developed world. We report a case of a chronic ulcer of the leg following extensive scarring due to a bite by a venomous snake, which eventually led to a squamous cell carcinoma.
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  • 45
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 354-357 
    ISSN: 1432-2161
    Schlagwort(e): Key words Intraosseous meningioma ; Microcystic meningioma ; Parietal bone ; X ray ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Extradural ectopic meningioma is a rare tumor. We report on an example of microcystic meningioma arising in the skull of an elderly woman. Radiological examination revealed a localized osteolytic lesion in the left parietal bone. At surgery, it was discovered that the tumor was located within the skull without any evidence of extraosseous extension. The light microscopic, immunohistochemical and ultrastructural features were consistent with a microcystic variant of meningioma. To our knowledge, this is the first case of an intraosseous microcystic meningioma, and we believe that this type of meningioma should be considered in the differential diagnoses of myxoid bone tumors of the calvarium.
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 417-420 
    ISSN: 1432-2161
    Schlagwort(e): Key words Arm ; Collagenous fibroma ; Desmoplastic fibroblastoma ; Short T2 ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A recently proposed addition to fibrous tumors in soft tissue was first described as desmoplastic fibroblastoma and later renamed collagenous fibroma. This tumor is clinically and morphologically distinct and benign. However, only a few series have been reported, and the clinicopathologic features are not widely recognized. We present two cases of collagenous fibroma of the arm. Both patients presented with an enlarging, well-circumscribed and mobile soft tissue mass. Magnetic resonance imaging showed areas of low signal intensity on both T1- and T2-weighted sequences. Needle aspiration cytology revealed nondiagnostic samples because of the low cellularity of the tumors. Each of the resected tumors was composed of low-cellular spindle- to stellate-shaped cells in a fibrous matrix with clear margination. After the marginal excisions, no recurrences were observed. Clinicians should be aware of this entity to prevent overtreatment, because imaging findings and cytologic features are similar to those of desmoid tumor.
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 425-438 
    ISSN: 1432-2161
    Schlagwort(e): Key words Muscles ; MRI ; Myositis ; Muscles ; Abscess ; Dermatomyositis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Inflammatory myopathies encompass a group of acquired muscle disorders caused by infectious agents (bacteria, viruses, fungi and parasitic agents) or autoimmune processes (polymyositis, dermatomyositis and other types). In suspected infection sonography, CT and MRI are all able to show edema and fluid collections in soft tissues and muscles; sonography and CT may help guidance of a needle aspiration to establish a correct diagnosis. By offering better tissue differentiation, MRI appears to be more efficient than sonography and CT in diagnosing and managing autoimmune myopathies. MRI is indeed very sensitive to the presence of water and edema, and appears to be a very good indicator for an early diagnosis of diseases. MRI may also help to evaluate the extent and number of lesions, to guide a biopsy in an area of active disease and finally to follow the evolution under therapy.
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  • 48
    ISSN: 1432-2161
    Schlagwort(e): Key words Chondrolipoma ; Liposarcoma ; Mesenchymoma ; Cartilage ; Metaplasia ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chondro-osseous differentiation of three benign or malignant fat tissue tumors – two chondrolipomas and a liposarcoma with cartilaginous metaplasia – was studied with magnetic resonance (MR) imaging and compared with their pathological findings. The results suggest that demarcation of cartilage tisssue can be clearly defined on MR imaging when the size of the cartilaginous area is large. Myxoid matrix, degenerative fat tissue and lipodystrophic change may decrease the delineation of the cartilage tissue.
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  • 49
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Gelenkknorpel ; MRT ; Arthrose ; Keywords Hyaline cartilage ; MRI ; Osteoarthritis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract MRI is the most accurate noninvasive technique available for assessment of normal articular cartilage and cartilage lesions. MRI cannot only provide morphologic information about the area of damage, but can also provide unique insight into the biochemical composition of the articular cartilage. New image processing techniques such as three-dimensional mapping of cartilage thickness will help to establish automated analysis of cartilage loss. Theses techniques are ideally suited for monitoring patients who undergo treatment with new chondroregenerative drugs.
    Notizen: Zusammenfassung Die MRT ist die beste verfügbare Untersuchungsmethode zur Darstellung des normalen und geschädigten Gelenkknorpels. Sie gibt nicht nur Aufschluss über die Morphologie des geschädigten Areals, sondern auch über die biochemische Zusammensetzung des Gelenkknorpels. Neue Bildverarbeitungstechniken wie die dreidimensionale Erfassung/Darstellung der Knorpeldicke werden bei der Entwicklung einer automatisierten Analyse des Knorpelverlustes helfen. Diese Techniken sind auch ideal zur Verlaufsbeobachtung von Patienten, die sich einer Behandlung mit knorpelregenerierenden Substanzen unterziehen.
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Der Radiologe 40 (2000), S. 469-472 
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Nutritialgefäßkanäle ; Os lunatum ; Lunatummalazie ; Ganglion ; Ulnaimpaktionssyndrom ; Key words Nutrient vessel canals ; Lunate bone ; MRI ; Kienböcks disease ; Ulna impaction syndrome ; Carpal ganglia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Purpose: To find and describe potential MRI criteria of nutrient vessel canals of carpal bones. Methods and Material: 16 wrists of 13 patients with pain and radiographic depiction of cystic changes within the lunate were examined. The MRI protocol included coronal and sagittal T1- and T2-weighted SE sequences (4 mm slices, 120 FOV, 256×256 matrix) as well as coronal STIR images. Final diagnosis was confirmed by surgery (n=5) and follow up. 10 cadaveric ossa lunata were studied to describe size, number, location and shape of nutrient vessel canals. Results: Ganglion cysts (n=6) showed characteristic signs. In ulnar impaction syndrome (n=1) small cystic lesions in the lunate were surrounded by a sclerotic rim and located near the proximal ulnar surface. In Kienböck’s disease (n=3) cystic components were irregular and surrounded by bone marrow edema. Nutrient vessel canals (n=7) imaged as 1 to 3 small cystic lesions within the palmar or dorsal subchondral region. Conclusion: MRI can aid in differential diagnosis of cystic carpal lesions. Nutrient vessel canals may not be mistaken for pathologic cystic lesions. Carpal ganglion cysts show distinct diagnostic pattern.
    Notizen: Zusammenfassung Fragestellung: Sind karpale Nutritialgefäßkanäle auf MRI Bildern sichtbar und welche differentialdiagnostischen Kriterien lassen sich finden. Material und Methode: In 16 Fällen lagen bei 13 Patienten röntgenologisch wenige mm bis 2 cm große zystische Läsionen im Os lunatum vor. Das MRT-Protokoll umfaßte koronare und sagittale T1- und T2-gewichtete SE-Sequenzen mit 4 mm Schichtdicke, 120 mm Meßfeld und 2562 Matrix sowie koronare STIR-Sequenzen. Die Diagnosesicherung erfolgte durch Operation in 5 Fällen sowie Verlaufskontrollen. 10 mazerierte Ossa lunata wurden auf Form, Lokalisation, Anzahl und Größe der Nutritialgefäßkanäle untersucht. Ergebnisse: Ganglien (n=6) wiesen typische Zeichen auf. Im Falle eines Ulnaimpaktionssyndroms bei Ulna-Nullvariante wurden mehrere kleine zystische Läsionen im Os lunatum gefunden, umgeben von einem Sklerosesaum. Bei 3 Fällen einer frühen Lunatummalazie waren unregelmäßige zystische Komponenten von einem diffusen Ödem umgeben. In 7 Fällen mit sehr kleinen zystischen Defekten waren diese subchondral, palmar und dorsal gelegen und entsprachen aufgrund des klinischen Verlaufs und der Lokalisation Nutritialgefäßkanälen. Schlußfolgerung: Nutritialgefäßkanäle dürfen nicht mit pathologischen zystischen Prozessen des Os lunatums verwechselt werden. Mittels MRT können zystische Läsionen im und am Os lunatum weiter spezifiziert werden. Handgelenksganglien weisen typische MR-Zeichen auf.
    Materialart: Digitale Medien
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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Der Radiologe 40 (2000), S. 557-560 
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Plasmazell-Osteomyelitis ; Magnetresonanztomografie ; Wirbelsäule ; Key words Plasmacellular osteomyelitis ; MRI ; Spine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract The authors report the case of a young patient suffering from plasmacellular osteomyelitis of the thoracic spine, a unusual localisation of this type of chronic osteomyelitis. They discuss the role of imaging diagnostic modalities in this disease, focussing on MRI.
    Notizen: Zusammenfassung Wir berichten über den Fall einer jungen Patientin mit Plasmazell-Osteomyelitis an der Brustwirbelsäule als ungewöhnliche Lokalisation dieser chronischen Osteomyelitis-Form. Dabei wird die Rolle der bildgebenden Diagnostik, insbesondere der Magnetresonanztomografie diskutiert.
    Materialart: Digitale Medien
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    Der Radiologe 40 (2000), S. 1017-1029 
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Hirnabszess ; Zerebritis ; Metastatische Herdenzephalitis ; Endokarditis ; MRT ; Gd-DTPA ; Keywords Brain abscess ; Cerebritis ; Metastatic focal encephalitis ; Endocarditis ; MRI ; Gd-DTPA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract The hematogenous spread of bacteria, fungi and protozoa may also reach the brain vessels, which happens mostly through septic emboli. From such an embolus a metastatic focal encephalitis and later a septic-embolic brain abscess may arise. The most frequently underlying infections that may cause septic emboli are bacterial endocarditis as well as bacterial infections of artificial heart valve prostheses. Congenital heart malformations with a right-to-left shunt also play here a certain role. Basically, however, all septic conditions and bacteriemias may cause septic-embolic brain abscesses. They occur frequently as multiple lesions. MRI is superior to CT in depicting the different stages of evolution from focal encephalitis, through the hardly encapsulated early abscess, to the formation of a membrane and later a dense fibrous capsule. The medical treatment of a brain abscess requires properly performed CT or MRI follow-up examinations in order to realize early enough a possible growing of such a lesion.
    Notizen: Zusammenfassung Die hämatogene Ausbreitung von Bakterien, Pilzen oder Protozoen bis in die Hirngefäße erfolgt meist durch eine septische Embolie. Es entstehen eine metastatische Herdenzephalitis und im weiteren Verlauf daraus ein septisch-embolischer Hirnabszess. Die häufigste Grunderkrankung die zu septischen Embolien führt ist die bakterielle Endokarditis sowie die bakterielle Infektion von Herzklappenprothesen. Eine besondere Bedeutung kommt hier den angeborenen kardialen Fehlbildungen mit Rechts-Links-Shunt zu. Grundsätzlich können jedoch alle Bakteriämien zu septisch-embolischen Hirnabszessen führen. Septisch-embolische Hirnabszesse treten aufgrund ihres Entstehungsmechanismus häufig multipel auf. Die CT und besser noch die MRT erlauben die Darstellung aller Entwicklungsstadien von der Herdenzephalitis über den kaum abgegrenzten Abszess, die Membranbildung bis zur Entstehung einer dicken, die eitergefüllte Höhle allseits umgebenden Abszesskapsel. Die medikamentöse Therapie von Hirnabszessen erfordert Verlaufsuntersuchungen, um einer eventuellen Größenzunahme der Läsion(en) frühzeitig durch Umstellung der antibiotischen Medikation oder durch operative Abszessentfernung zu begegnen.
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  • 53
    Digitale Medien
    Digitale Medien
    Springer
    Der Radiologe 40 (2000), S. 18-27 
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter ; MRT ; Neugeborene ; Cerebrum ; Fetus ; Key words ; MRI ; Neonatal ; Brain ; Fetal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Magnetic resonance tomography (MRT) has become the most important method in the workup of infantile cerebral complications after primary sonography. Cerebral MR examination and image interpretation during the infantile period require extensive knowledge of morphological manifestations, their pathophysiological background, and frequency. The choice of imaging parameters and image interpretation is demonstrated in infarctions and hemorrhages of the mature and immature brain. A review of the main differential diagnoses is also given. The relevance of MR spectroscopy and fetal MRI is discussed.
    Notizen: Zusammenfassung Zur Abklärung zerebraler Veränderungen bei Neugeborenen hat sich die Magnetresonanztomographie (MRT) als wichtigste weiterführende Methode nach der Sonographie entwickelt. Die Durchführung und Auswertung der MR-Untersuchungen erfordern jedoch eine genaue Kenntnis der morphologischen Manifestationen, des pathophysiologischen Hintergrunds und der Häufigkeit bestimmter zerebraler Komplikationen in diesem Lebensalter. Resümee: Ausgehend von zerebrovaskulären Erkrankungen werden diese Fragen behandelt, wobei sowohl auf die Auswahl der adäquaten Untersuchungsparameter als auch auf die Bildinterpretation und die wichtigsten Differentialdiagnosen eingegangen wird. Die Bedeutung von MR-Spektroskopie und fetaler MRT wird diskutiert.
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  • 54
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Mammatumor ; MRT ; Markierung ; Biopsie ; Keywords Breast lesion ; MRI ; Localization ; Biopsy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Purpose. MRI-guided interventional maneuvers in the breast, when closed MRI scanners are employed are relatively complex and time consuming. The purpose of our investigations was to develop a special device for the localization and biopsy of breast lesions using an open low-field MRI Scanner (Magnetom Open, Siemens, Erlangen, Germany) permitting free access to the patient. Materials and Methods. Due to its particular material and construction characteristics, a newly developed device for localization and biopsy of breast lesions is appropriate to remain within the magnetic field during the examination without degrading image quality. We performed 125 tests in a phantom and 31 investigations in patients including 26 wire-localizations and 5 biopsies. Results. The interventional maneuvers in the phantom could be performed very precisely. In all 125 phantom studies, the needle (14G coaxial biopsy cannula, Bard) was positioned close to the simulated lesion. In 25 out of 26 patients the needle was positioned within a distance less than 5 mm from the lesion. When using the 14G coaxial biopsy cannula (Bard, Karlsruhe, Germany) the needle tip was found adjacent next to the lesion in all 12 cases (7 wire-localizations, 5 biopsies). Conclusions. Our results indicate that our device allows very precise preoperative localization of breast lesions within the Magnetom Open. Using MRI-compatible, large-core needles, biopsy under direct MRI control resulted in good results.
    Notizen: Zusammenfassung Zielsetzung. Am geschlossenen MRT-Gerät sind Interventionen an der Mamma relativ aufwendig und zeitintensiv. Ziel unserer Untersuchungen war es, eine Lokalisations- und Biopsieeinrichtung für das offene MRT-Gerät (Magnetom Open, Siemens) zu entwickeln und zu erproben, das Patienten und Methode. Es wurde eine Lokalisations- und Biopsieeinrichtung entwickelt, die aufgrund ihrer Bauart während der Intervention im Magnetfeld des MRT-Gerätes verbleiben kann und die Bildgebung nicht nachteilig beeinflusst. Um die Tauglichkeit dieses Gerätes zu überprüfen wurden 125 Untersuchungen am Phantom und 31 Patientenuntersuchungen (26 Drahtlokalisationen, 5 Biopsien) durchgeführt. Ergebnisse. Die Interventionen am Phantom konnten sehr genau gesteuert werden. In allen 125 Fällen lag die Interventionsnadel (14 G-Coaxial-Biopsiekanüle, Bard) direkt der Läsion an. Bei den Patientenuntersuchungen lag die Interventionsnadel in 25 von 26 Fällen weniger als 5 mm von der Läsion entfernt. Bei Verwendung der 14 G-Coaxial-Biopsie-Kannüle (Bard, Karlsruhe, Germany) lag die Interventionsnadel in allen 12 Fällen direkt der Läsion an (7 Drahtlokalisationen, 5 Hochgeschwindigkeitsbiopsien). Schlussfolgerung. Die Untersuchungen zeigen, dass mit der von uns entwickelten Zieleinrichtung sehr genaue präoperative Lokalisationen am Magnetom Open durchführbar sind. Durch die stabile Nadelführung sind bei Verwendung lumenstarker Materialien (14G) zudem exakte MRT-kontrollierte Biopsien möglich.
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  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Der Radiologe 40 (2000), S. 737-744 
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Lymphom ; MRI ; Keywords Lymphoma ; Bone neoplasms ; Diffusion coefficient ; ADC
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Purpose. Skeletal manifestation of Non-Hodgkin's lymphoma is rare in pediatric patients. Objective of the study was to determine imaging features, before and after treatment, and to correlate these features with clinical outcome. Methods. A retrospective analysis of 1246 patients from two therapy studies (NHL-BMF-90 and 95) was performed. Imaging studies of 63 patients with bone involvement of lymphoma were reevaluated. Results. Incidence of initial bone involvement in Non-Hodgkin's lymphoma was 6.8%. Distribution was best assessed by bone scan, MRI revealed larger areas of marrow involvement and detected additional lesions. Sites of prediliction were long bones of the lower extremities with epiphyseal involvement in 39%. Residual signal alterations in MRI after succussful therapy remained in 71%. Osteonecrosis after therapy was a common finding. Clinical outcome war not correlated to the presence of bone involvement. Conclusions. Since clinical outcome is not effected by bone involvement in childhood NHL, value of screening may be limited. Knowledge of imaging characteristics is mandatory for inital evaluation of primary osseous lymphomas and symptomatic lesions as well as for therapy controlls.
    Notizen: Zusammenfassung Fragestellung. Skelettale Manifestationen des Non-Hodgkin-Lymphoms sind selten. Ziel der Studie waren die Analyse charakteristischer Veränderungen in der Bildgebung vor und nach Therapie sowie die Korrelation mit dem Therapieerfolg. Methode. Die retrospektive Analyse von 2 Therapiestudien (NHL-BMF-90 und 95) schloss 1246 Patienten ein. Die bildgebenden Untersuchungen von 63 Patienten mit skelettalem Lymphombefall wurden reevaluiert. Ergebnisse. Die Inzidenz des initialen Skelettbefalls beim Non-Hodgkin-Lymphom lag bei 6,8%. Die Verteilung der Skelettherde wurde durch die Szintigraphie am sichersten erfasst, die MRT detektierte im Vergleich größere Markraumbeteiligungen sowie zusätzliche Herdbildungen im Skelett. Prädilektionsorte waren die langen Röhrenknochen der unteren Extremitäten mit epiphysärer Beteiligung in 39% der Fälle. Residuale Signalveränderungen im MRT verblieben trotz kompletter Remission in 71% der Fälle. Osteonekrosen nach Chemotherapie waren häufig. Die therapeutische Ergebnisse wurden durch das Vorhandensein eines Skelettbefalls nicht beeinflusst. Schlussfolgerungen. Aufgrund der Beobachtung, dass die Therapieergebnisse vom Nachweis eines Skelettbefalls nicht wesentlich beeinflusst werden, erscheint der Wert der Screeninguntersuchung begrenzt. Die Kenntnis des Erscheinungsbilds vom NHL in der Bildgebung ist aber für die Beurteilung der primär ossären Lymphome und symptomatischer Herdbildungen sowie in der Therapiekontrolle notwendig.
    Materialart: Digitale Medien
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  • 56
    ISSN: 1432-2277
    Schlagwort(e): Key words Small bowel transplantation ; Monoclonal antibody ; Rat ; Rejection ; Flow cytometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This study assessed the effect of an anti-rat CD4 monoclonal antibody (OX38) on heterotopic small bowel allograft rejection. Fully allogeneic small bowel transplants were performed in the PVG-to-DA-rat strain combination. Animals received either i) short course (days –1, 0 and 1) of 1 mg/kg per day OX38, ii) short course of 5 mg/kg per day or iii) extended course (days –2, –1, 0, 1, 2 and twice weekly thereafter) of 1 mg/kg per day. Both the high dose (13 days) and extended low-dose (12 days) courses prolonged graft survival compared to untreated control animals (7 days). The low-dose, short-course treatment had no effect. Similar regimens were given to animals that did not receive transplants and in which peripheral blood CD4+ cell counts fell to between 20 and 55 % of pretreatment levels and 20–30 % of binding sites were blocked. In summary, anti-CD4 monoclonal antibody therapy delayed rejection of rat small bowel allografts; however, long-term survival was not achieved.
    Materialart: Digitale Medien
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  • 57
    ISSN: 1432-198X
    Schlagwort(e): Key words Metabolic acidosis ; Growth ; Growth hormone ; Insulin-like growth factor-I ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Growth impairment induced by chronic metabolic acidosis is associated with an abnormal growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis. To examine the potentially beneficial effects of IGF-I on acidosis-induced growth impairment and the influence of GH and IGF-I treatment on the GH/IGF-I axis, three groups of acidotic young rats (untreated, AC, n=12; treated with recombinant human GH, GH, n=8; treated with recombinant human IGF-I, IGF-I, n=8) were studied, and compared with nonacidotic rats fed ad libitum (C, n=9)) or pair-fed with the AC group (PF, n=12). After 14 days of acidosis and 7 days of treatment, growth rate, hepatic abundance of 4.7-kilobase (kb) and 1.2-kb GH receptor transcripts and 7.5-kb and 1.8- to 0.8-kb IGF-I transcripts, serum GH-binding protein (GHBP), and IGF-I concentrations (mean±SEM) were analyzed. Significant decreases of 4.7-kb GH receptor [26±2 vs. 49±6 arbitrary densitometry units (ADU)] and 7.5 kb IGF-I (41±3 vs. 104±10 ADU) transcripts and low serum GHBP (25±1 vs. 32±1 ng/ml) and IGF-I (279±50 vs. 366±6 nmol/l) levels were found in the AC compared with the C rats. The majority of these alterations were also observed in PF rats. Compared with acidotic untreated rats, GH and IGF-I therapy produced no improvement in growth rate. GH treatment normalized the levels of IGF-I mRNA, aggravated the acidosis-related inhibition of the GH receptor gene, and did not modify the serum levels of GHBP and IGF-I. In contrast, IGF-I administration depressed the hepatic expression of all GH and IGF-I transcripts and normalized serum IGF-I concentrations. Our results confirm that sustained metabolic acidosis alters the GH/IGF-I axis, in part because of associated malnutrition, and induced growth retardation that is resistant to GH therapy. Our study also shows that administration of IGF-I does not accelerate the growth of acidotic rats, suggesting a peripheral mechanism, at the level of target tissues, is responsible for the resistance to the growth-promoting actions of GH and IGF-I.
    Materialart: Digitale Medien
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric nephrology 15 (2000), S. 188-191 
    ISSN: 1432-198X
    Schlagwort(e): Key words Apoptosis ; Ceramide ; Development ; Kidney ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Ceramide is emerging as an important hydrophobic sphingolipid involved in cell differentiation and apoptosis. Since apoptosis plays a significant role in cellular remodeling during renal morphogenesis, we measured ceramide content and apoptosis in the fetal (18 days gestation), neonatal (3, 7, and 14 days postnatal), and adult rat kidney. In addition, to determine whether developmental changes in ceramide content are tissue-specific, we compared renal ceramide content with that in lung and liver. Ceramide was measured by the diacylglycerol kinase assay, and apoptosis was determined by the TUNEL technique. Renal ceramide content fell over 100-fold from the fetus to the 7th postnatal day. Renal apoptosis paralleled ceramide content, with a greater than 300-fold decrease in apoptosis from fetal to adult life. Ceramide content of the lung and liver was significantly less than that of the kidney, and changed less with maturation. We conclude that maturational changes in ceramide content are tissue-specific, and that the high rate of apoptosis in the developing kidney may be related to the elevated ceramide content.
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Neuroradiology 42 (2000), S. 290-295 
    ISSN: 1432-1920
    Schlagwort(e): Key words Blake's pouch cyst ; Dandy-Walker complex ; Dandy-Walker malformation ; Posterior fossa malformation ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Abnormal cerebrospinal fluid (CSF) collections within the posterior fossa are defined by the Dandy-Walker complex (DWC) and by arachnoid cysts (AC). The DWC includes the Dandy-Walker malformation (DWM), the Dandy-Walker variant (DWV) and the mega-cisterna magna (MCM). In addition, Tortori-Donati et al. added persistent Blake's pouch cyst (BPC) as an independent entity within the DWC. BPC represents a posterior ballooning of the superior medullary velum into the cisterna magna. All of these malformations are overlapping developmental anomalies characterized by varying degrees of malformation of the medullary vela, the cerebellar vermis and hemispheres, the fourth ventricle choroid plexus, the posterior fossa subarachnoid cisterns and the enveloping meningeal structures. We present two cases of persistent BPC detected in two adult women without history of gestational or subsequent growth problems. They underwent neuroradiological investigation because of headache and because of recurrent episodes of loss of consciousness, respectively. The MRI findings included tetraventricular hydrocephalus, wide communication of the fourth ventricle and the cystic posterior fossa (i. e. BPC), inferior posterior fossa mass effect with or without hypoplasia of both the cerebellar vermis and the medial aspects of the cerebellar hemispheres, and absence of communication between fourth ventricle and the basal subarachnoid space in the midline posteriorly. Persistent BPC is defined by a failure of embryonic assimilation of the area membranacea anterior within the tela choroidea associated with imperforation of the foramen of Magendie. Typically this condition becomes symptomatic early in life. In the current cases the normal function of the laterally positioned foramina of Luschka probably helped to maintain some CSF flow between intraventricular and subarachnoid spaces, with the establishment of a precarious equilibrium characterized by a compensatory enlargement of the cerebral ventricular system (i. e. hydrocephalus).
    Materialart: Digitale Medien
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  • 60
    ISSN: 1432-1262
    Schlagwort(e): Keywords Fecal incontinence ; Constipation ; MRI ; Ultrasound
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This study assessed the value of common surface coil mag-netic resonance imaging (MRI) in patients with evacuatory disorders including fecal incontinence and constipation. These findings were then compared with those from other standard physiological examinations and/or surgical findings. From July 1996 to June 1997, 14 consecutive patients underwent surface coil MRI for evaluation of either fecal incontinence (n=5) or constipation (n=9). In patients with incontinence we compared the findings from endoanal ultrasound (EAUS), anal MRI, and surgery regarding morphopathological findings of the internal and external anal sphincter components. In constipated patients the findings of videoprography and dynamic pelvic MRI were compared regarding the presence of rectocele, rectoanal intussusception, and sigmoidocele as well as the measurements of anorectal angle and perineal descent. The five incontinent patients were all women, with a median age of 67 years (range 43–77). EAUS revealed an anterior sphincter defect in two patients, a posterior defect in one, and normal anal sphincter images in two. Surgical findings confirmed an anterior external anal sphincter scar in two patients, an internal anal sphincter defect in one, and an anatomically normal anal sphincter in two. In one patient, although anal MRI showed posterior external anal sphincter defect, EAUS and surgery revealed normal external anal sphincter appearance. The accuracy rate between EAUS and anal MRI was only 20%, that between surgery and anal MRI 40%, and that between surgery and EAUS 80%. Thus EAUS was more accurate than anal MRI in incontinent patients. The nine constipated patients were all women, with a mean age of 59 years (range 40–78). Videoproctography revealed an anterior rectocele in six patients, rectoanal intussusception in three, and sigmoidocele in five; no abnormalities were identified in two patients. On dynamic pelvic MRI anterior rectocele was seen in three patients and sigmoidocele in two, and five studies were interpreted as normal. One of the patients underwent sigmoidectomy for sigmoidocele, and five patients were treated by biofeedback. Thus the accuracy rate of dynamic pelvic MRI against videoproctography was 60% for anterior rectocele, 40% for sigmoidocele, and zero for rectoanal intussusception. In conclusion, neither MRI for the evaluation of patients with fecal incontinence nor for the evaluation of patients with constipation added any significant information that would warrant its continued use in these patient groups. Perhaps the more widespread availability of an endoanal coil will alter this conclusion; however, at the present time we cannot routinely endorse the expense, time, or inconvenience of these MRI investigations in patients with these diagnoses. Larger prospective comparative studies are required prior to endorsing the technique.
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 126 (2000), S. 27-32 
    ISSN: 1432-1335
    Schlagwort(e): Key words Heart irradiation ; Plasma enzyme levels ; Myocardial enzyme levels ; Rat ; AbbreviationsCK creatine kinase ; LDH lactate de-hydrogenase ; AST aspartate aminotransferase ; ALT alanine aminotransferase ; α-HBDHα-hydroxybutyrate dehydrogenase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Plasma levels of myocardial enzymes present after local heart irradiation were studied in a rat model. The purpose was to investigate whether, within days after irradiation, these enzyme levels change to such an extent that they may be helpful in assessing the severity of cardiac damage after radiotherapy. Therefore, activities of creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and α-hydroxybutyrate dehydrogenase (α-HBDH) were determined in the plasma and left ventricular myocardium of rats following local heart irradiation with a single dose of 20 Gy. A dose of 20 Gy is known to cause irreversible cardiac damage and to reduce survival times of the animals. Cardiac enzyme assays were performed directly after and twice daily for up to 2 weeks after radiation. Plasma CK, LDH, AST and α-HBDH levels were increased between 2 h and 24 h after irradiation. Plasma ALT levels remained unchanged. Myocardial enzyme levels, measured between 24 h and 16 days after radiation, did not differ between irradiated and control animals, although acute (first 12 h) reductions were observed in the irradiated group. The elevated enzyme levels in plasma appeared to correlate with the acutely reduced myocardial enzyme levels. Although irradiation with a dose of 20 Gy induced acute rises of cardiac enzyme levels in plasma, it is doubtful that fractionated radiation, as applied clinically for treatment of solid tumors, will induce plasma enzyme elevations that are large enough to indicate the extent of cardiac damage occurring acutely or chronically.
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Child's nervous system 16 (2000), S. 731-734 
    ISSN: 1433-0350
    Schlagwort(e): Keywords Children ; Brain ; Tumour ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The author reviews the progress made during the last 25 years in noninvasive diagnosis of brain tumours in children. MRI has replaced all other modalities available at that time. The diagnosis is still based on a precise anatomical analysis of the lesion rather than on other specific findings. New techniques, such as spectroscopy and diffusion, may help to characterise further brain tumours in children preoperatively.
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Child's nervous system 16 (2000), S. 451-456 
    ISSN: 1433-0350
    Schlagwort(e): Keywords Intracranial pressure ; CSF dynamics ; Infusion test ; Rat ; H-Tx rat ; Outflow resistance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Although the hydrocephalic H-Tx rat is a widely used model, data on the cerebrospinal fluid (CSF) dynamics in hydrocephalic rats are rare or – as the pressure volume index (PVI) – not available. We used hydrocephalic and nonhydrocephalic H-Tx rats, a stock with a high percentage of inherited hydrocephalus, for the evaluation of such data. In addition, a new, simple mathematical algorithm (”dynamic infusion test”), which has not formerly been used in animal experiments, was used as a pathophysiological model of CSF dynamics. Compared with classical methods for evaluation of these data, the dynamic infusion test gives a deeper insight into the relation between ICP and CSF dynamics. It was found that the resistance to outflow (ROF) in hydrocephalic rats was at least twice that in nonhydrocephalic rats. The PVI measured was similar in hydrocephalic and nonhydrocephalic animals, but clearly higher than the values reported in the literature. This may be attributable to the fact that the classically used bolus test, in contrast to the ”dynamic infusion test”, is representative only for the CSF compartment which is directly exposed to the bolus application.
    Materialart: Digitale Medien
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Der Nervenarzt 71 (2000), S. 411-415 
    ISSN: 1433-0407
    Schlagwort(e): Schlüsselwörter Kufs ; Neuronale Zeroidlipofuszinose ; Demenz ; PET ; MRT ; Key words Kufs disease ; Neuronal ceroid lipofuscinosis ; Dementia ; PET ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary The case of a 35-year-old man with progressive dementia from the age of 17 is presented. Clinical examination showed mild extrapyramidal and cerebellar signs and rare myoclonus. Neuropsychological evaluation disclosed severe cognitive deficits. Magnetic resonance imaging (MRI) revealed moderate generalized atrophy with abnormal iron deposition in the basal ganglia. Positron emission tomography (PET) with 18-fluorodeoxyglucose (18-FDG) demonstrated clear temporoparietal hypermetabolism. The clinical symptoms and course are typical for the rare adult type of neuronal ceroid lipofusconoses (Kufs' disease). The diagnosis is supported by the electron microscope detection of an abnormal accumulation of lipid vacuoles and lipofuscin in the eccrine sweat glands and the rectal ganglia cells.
    Notizen: Zusammenfassung Berichtet wird der Fall eines 35-jährigen Patienten mit langsam progredienter Demenz seit dem 18. Lebensjahr. Zum Zeitpunkt der Untersuchung fielen klinisch eine leichtgradige extrapyramidale und zerebelläre Symptomatik sowie seltene Myoklonien auf, während die neuropsychologische Testung ausgeprägte kognitive Defizite ergab. Die kraniale Magnetresonanztomographie zeigte eine mäßige globale Atrophie und eine abnorme Eisenablagerung in den Basalganglien. In der Positronenemissionstomographie mit 18-FDG war ein deutlicher temporoparietaler Hypometabolismus erkennbar. Klinik und Verlauf sind typisch für die seltene adulte Variante der neuronalen Zeroidlipofuszinosen (Kufs-Typ). Diese Diagnose wird gestützt durch den elektronenmiroskopischen Nachweis abnormer Akkumulationen von Fettvakuolen und Lipofuszinablagerungen in den ekkrinen Schweißdrüsen der Haut und in den rektalen Ganglienzellen.
    Materialart: Digitale Medien
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Arthroskopie 13 (2000), S. 132-137 
    ISSN: 1434-3924
    Schlagwort(e): Schlüsselwörter Qualitätssicherung ; Knorpeldefekte ; MRT ; Scores ; Keywords Quality control ; Cartilage repair ; MRI ; Clinical scores
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Most procedures currently in use for the treatment of full thickness cartilage defects lack solid data as a proof of quality. Various techniques for quality control are advisable. Meticulous documentation of adverse events and treatment failures is crucial. Patient self-assessment and clinical scores are often biased but focussed on the basis of medical efforts: the well-being of the patient. Second-look arthroscopies produce fewer facts for quality control than expected but enable therapeutical intervention. Magnetic resonance imaging will be essential for cartilage assessment in the future. To date, the evaluation of tissue quality is experimental. Histology and immunohistochemistry are widely accepted as precise tools to characterize cartilaginous tissue. Ethical reasons prohibit daily use. Quality control following the repair of cartilage defects is complicated, expensive, and of variable outcome, but dangerous if neglected. Multiple insignificant results can lead to a sharp image of the postoperative condition and may enable quality control of treatment and surgery.
    Notizen: Die meisten Verfahren zur Behandlung von Gelenkknorpeldefekten werden angewendet, ohne dass ihre Qualität zweifelsfrei nachgewiesen ist. Verschiedene Möglichkeiten der Qualitätssicherung können derzeit mit vertretbarem Aufwand routinemäßig eingesetzt werden. Die Beurteilung der Sicherheit einer Behandlung hinsichtlich Komplikationen und Therapieversagern ist von eminenter Bedeutung. Patientenfragebögen und klinische Scores sind subjektiv, orientieren sich aber am eigentlichen Ziel einer Therapie: der Wiederherstellung des Wohlbefindens des Patienten. Noch in den Anfängen, aber mit hervorragenden Perspektiven für die Zukunft steht die Magnetresonanztomographie. Knorpelqualität und -aktivität können heute noch nicht beurteilt werden. Die Kontrollarthroskopie nach der Behandlung von Gelenkknorpeldefekten liefert weniger harte Daten für die Qualitätssicherung als erwünscht, ermöglicht aber therapeutische Maßnahmen. Histologische Untersuchungen stehen im Ruf der unbestechlichen Präzision. Dem breiten Einsatz stehen jedoch fehlende Standards und berechtigte ethische Bedenken entgegen. Qualitätssicherung nach der operativen Behandlung von Gelenkknorpeldefekten ist schwierig, teuer und häufig ungenau – keine Qualitätssicherung ist oft gefährlich. Aus vielen, isoliert gesehen ungenauen Befunden werden die Bewertung eines Zustands immer sicherer und die Beurteilung der Qualität einer Behandlung möglich.
    Materialart: Digitale Medien
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  • 66
    ISSN: 1434-3940
    Schlagwort(e): Schlüsselwörter Kiefergelenk-MRT ; Diskusdislokation ; Kiefergelenkhistologie ; Keywords Temporomandibular joint (TMJ) ; MRI ; Anterior disk dislocation ; TMJ histology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Problem. Anterior dislocation of the articular disk of the temporomandibular joint (TMJ) found by MRI tomography often presents a problem. It may persist in MRI despite improvement of articular symptoms and even be found in healthy persons free of any symptoms. Can this be explained by the similarity in structure of the anterior connective tissue of the disk and capsule and their pathological changes? Is a second coronal plane required for MRI investigation? Material and methods. The preauricular regions of 72 patients of the TMJ clinic were examined by oblique-sagittal and oblique-coronal MRI. A Siemens-Vision MRI was used. It was also possible to prepare 10 articular disks of the TMJ with anterior capsular tissue as well as 20 complete TMJs of adults from autopsy material. Sagittal, transversal, and horizontal serial sections were examined histologically. Results. In 49 of the 72 cases examined, an anterior dislocation without reduction found in the sagittal MRI was not confirmed in the oblique-coronal MRI. In the sagittal MRI it was possible to differentiate three, in the coronal MRI six typical forms of magnetic resonance signals, which are represented in figures. They are compared with anatomical and histological connective tissue findings adjacent to the TMJ. The structural similarity of the disk and anterior capsular tissue of the TMJ is demonstrated. The close connection of the disk and connective tissue surrounding the TMJ makes differentiation of MRI findings difficult especially following regressive and adaptive reactions. Conclusions. In MRI, anterior capsular tissue is able to simulate dislocation of the disk. Pathological tissue reactions may alter the MRI signal and lead to the wrong diagnosis of dislocation of the disk. Diagnosis of an anterior disk dislocation cannot be established solely on the basis of oblique-sagittal MRI findings.
    Notizen: Zusammenfassung Fragestellung. Der Befund anteriore Diskusdislokation im sagittalen MRT beinhaltet 2 ungeklärte Probleme. Trotz Rückbildung einer Gelenksymptomatik können anteriore Diskusdislokationen im MRT unverändert bestehen, sie wurden sogar bei gesunden Probanden beschrieben. Ist die Ursache in der feingeweblichen Ähnlichkeit der anterioren Diskus- und Kapselbindegewebe und in deren pathologischen Strukturänderungen zu suchen? Kann auf die Befundung in der 2. koronalen Ebene verzichtet werden? Material und Methode. Die präartikulären Regionen im schräg-sagittalen und im schräg-koronalen MRT von 72 Patienten aus der Kiefergelenkspezialsprechstunde wurden befundet. Die Untersuchungen erfolgten mit dem Siemens-Vision-MRT. Bei unselektierten Sektionen konnten 10 Disci articulares mit dem anterioren Kapselgewebe sowie 20 Kiefergelenkpräparate Erwachsener präpariert werden. Sagittale, transversale und horizontale Serienschnitte wurden histologisch untersucht. Ergebnisse. Bei 49 von 72 ausgewählten Fällen gab es für eine anteriore Diskusdislokation ohne Reduktion im sagittalen MRT keine Bestätigung im schräg-koronalen MRT. Es konnten in den sagittalen MRT 3, in den koronalen MRT 6 sich wiederholende Signalformen differenziert werden. Sie sind skizziert. Ihre Zuordnung zu gelenkumgebenden Bindegeweben erfolgte mittels Vergleich dieser Signalformen mit den anatomischen und histologischen Kiefergelenkpräparaten. Die feingewebliche Ähnlichkeit des Discus articularis mit dem anterioren Kapselbindegewebe wird aufgezeigt. Seine enge Verbindung mit den gelenkumgebenden Bindegeweben erschwert die Differenzierung im MRT insbesondere beim Vorliegen regressiver und adaptiver Reaktionen. Schlussfolgerung. Das anteriore Kapselgewebe kann eine Diskusdislokation im MRT vortäuschen. Pathologische Gewebereaktionen ändern das MRT-Signal und tragen dazu bei, falsch-positive Befunde zur Diskusdislokation entstehen zu lassen. Schräg-sagittale MRT sind für die Diagnosefindung „anteriore Diskusdislokation mit und ohne Reposition“ nicht ausreichend.
    Materialart: Digitale Medien
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  • 67
    ISSN: 1432-0843
    Schlagwort(e): Key words 7-Hydroxymethotrexate ; Methotrexate ; Maximum tolerated dose ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Purpose: After more than 50 years of methotrexate (MTX) treatment of acute lymphoblastic leukaemia (ALL), it is currently believed that as long as dose escalations are followed by adequate leucovorin rescue guided by monitoring MTX serum concentrations, hydration and urinary alkalinization, high-dose MTX (HD-MTX) can be tolerated without life-threatening toxicity. However, our recent experimental animal studies of the major metabolite of MTX, 7-OH-MTX, indicate that this concept may have some limitations. Animals with levels of 7-OH-MTX of 1 mM, which is below the levels routinely found in patients on HD-MTX, demonstrate intolerable toxicity and some animals die within 8 h. Electron microscopy indicates that endothelial cell and platelet functions are perturbed. Since animal data are lacking, and interspecies differences not known, we wanted to investigate the maximum tolerated doses of MTX and 7-OH-MTX in a rat model of short-term effects. The maximum tolerated dose was chosen instead of LD50 for reasons of animal welfare. Methods: We infused MTX and 7-OH-MTX into anaesthetized male Wistar rats and monitored the animals for 8 h. The drugs were given as a bolus plus continuous infusion. The dose-finding ranges were 1.8–11.3 g/kg MTX and 0.1–1.2 g/kg 7-OH-MTX. Results: The maximum tolerated dose was between 3 and 5 g/kg for MTX and lower than 0.1 g/kg for 7-OH-MTX. The mean serum concentrations of MTX and 7-OH-MTX in animals that did not survive the 8-h period were 21.9 and 1.6 mM, respectively. The animals that received the highest MTX or 7-OH-MTX doses and concentrations died after sudden reductions in heart rate and blood pressure. Conclusions: We demonstrated a lower maximum tolerated dose of 7-OH-MTX than of MTX in rats after 8 h. The 7-OH-MTX concentrations were in the therapeutic range after HD-MTX. If the rat/human interspecies differences are not large, our data may indicate that HD-MTX regimens should not be further dose intensified, due not so much to the effects of MTX as to those of 7-OH-MTX.
    Materialart: Digitale Medien
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    European spine journal 9 (2000), S. 426-429 
    ISSN: 1432-0932
    Schlagwort(e): Key words Osteoid osteoma ; MRI ; Inflammatory reaction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report a case of 14-year-old male patient with osteoid osteoma of the cervical spine. Magnetic resonance imaging (MRI) revealed a large dumbbell-shaped paravertebral tumor in the region of the exiting left C6 nerve. A computed tomographic (CT) scan after myelography showed a much smaller bony defect in the medial aspect of the left C6 pedicle with central calcification and extensive bone sclerosis around the defect, typical of osteoid osteoma. The diagnosis was confirmed postoperatively. The resected specimen exhibited extensive vascularization of the osteoid tissue. The case is presented because MRI did not allow a specific diagnosis of osteoid osteoma, and suggested the tumor was larger than in reality it was, by also depicting the reactive inflammation around the tumor as if it were part of the tumor.
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    European journal of orthopaedic surgery & traumatology 10 (2000), S. 203-205 
    ISSN: 1432-1068
    Schlagwort(e): Cervical spondylotic myelopathy ; Syringomyelia ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of syringomyelia associated with cervical spondylotic myelopathy is presented. A decompressive cervical laminectomy was performed. The patient improved gradually after operation. It is concluded that the choice of surgical treatment in cases with syringomyelia associated with cervical spondylotic myelopathy requires a careful neurological and radiological examination based on the findings of magnetic resonance imaging (MRI) and cine-MRI.
    Materialart: Digitale Medien
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  • 70
    ISSN: 1432-0738
    Schlagwort(e): Key wordsα2u-Globulin ; Diethylstilbestrol ; Endocrine disrupter ; Rat ; Screening
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract α2u-Globulin (AUG) is a major rat urinary protein, which has a molecular weight of 16 kDa (kidney type) or 19 kDa (native type). The biosynthesis of this protein is under multi-hormonal regulation. In this study, we investigated changes in serum AUG level and their association with changes in the reproductive organs of male rats after the administration of the estrogenic chemical, diethylstilbestrol (DES) at doses ranging from 0.01 mg/kg per day to 100 mg/kg per day by gavage for 14 days. Our aim was to establish basic data for the development of a new screening method for endocrine disrupting chemicals based on serum AUG levels. DES treatment decreased the weight of testes in a dose-dependent manner; and was accompanied by atrophic histopathological changes in testes. Testis weights were significantly decreased by the group given 1 mg/kg per day DES; however, histopathological abnormalities were found in the group given 0.1 mg/kg per day DES. In four of five animals in the group given 1 mg/kg per day there was no significant decrease in testis weight and only a slight or moderate degeneration of the pachytene spermatocytes. Despite these findings, serum AUG levels in this group decreased markedly, while the serum AUG level markedly decreased even in the animals with no histopathological change in the 1 mg/kg per day or 0.1 mg/kg per day groups with no histopathological change also showed decreased serum AUG level. These results suggest that the serum AUG level may be a sensitive parameter for detecting the activity of estrogenic chemicals in intact male rats. Although a uterotropic assay has been proposed for immature female or ovariectomized female rats and is currently undergoing validation studies internationally, there is no screening method for estrogenic chemicals in intact male animals. More data on AUG changes by treatment with other estrogenic chemicals are needed in order to determine the sensitivity and specificity of this response to estrogens. Nonetheless, an AUG-based screening test for estrogenic chemicals may be useful owing to its applicability to conventional toxicity studies and an apparently higher sensitivity of this parameter compared to organ weight change or histology of testis in intact male rats and applicability to conventional toxicity studies.
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  • 71
    ISSN: 1432-0738
    Schlagwort(e): Key words Flutamide ; Androgen antagonist ; Rat ; Enhanced OECD Test Guideline 407 ; Endocrine disrupters
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In association with the international validation project to establish a test protocol for the `Enhanced OECD Test Guideline 407', we performed a preliminary 28-day, repeated-dose toxicity study of flutamide, a non-steroidal androgen antagonist, and assessed the sensitivity of a list of parameters for detecting endocrine-related effects of endocrine-disrupting chemicals (EDCs). Seven-week-old CD(SD)IGS rats were divided into four groups, each consisting of 10 males and 10 females, and administered flutamide once daily by oral gavage at doses of 0 (control), 0.25, 1 and 4 mg/kg body weight/day. Male rats were killed 1 day after the 28th administration. Female rats were killed on the day they entered the diestrus stage in the estrous cycle following the last treatment. Male rats receiving flutamide at dose levels of 1 and 4 mg/kg showed lobular atrophy of the mammary gland and a decrease in epididymal weight. In addition, 4 mg/kg flutamide-treated males exhibited raised serum testosterone and estradiol levels and decreased weight of the accessory sex glands. In females, a slight prolongation of the estrous cycle was also observed in the 4 mg/kg flutamide-treated group. No dose-related changes could be detected by haematology, serum biochemistry and sperm analysis. Thus, among the parameters tested in the present experimental system, the weight of endocrine-linked organs and their histopathological assessment, serum hormone levels, and estrous cycle stage allowed the detection of endocrine-related effects of flutamide.
    Materialart: Digitale Medien
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Archives of gynecology and obstetrics 264 (2000), S. 42-44 
    ISSN: 1432-0711
    Schlagwort(e): Key words Thecoma ; Ascites ; CA125 ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report a 34-year-old woman with an ovarian thecoma and ascites who exhibited high serum levels of CA125. Measuring serum tumor markers and imaging are two important diagnostic tools for malignant ovarian tumors. In the present case, a preoperative diagnosis of benign ovarian tumor could not be made due to the elevation of CA125 (895 U/ml) and nonspecific MRI findings.
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  • 73
    ISSN: 1432-0932
    Schlagwort(e): Key words Chronic low back pain ; Erector spinae muscle ; MRI ; Muscle biopsy ; Fibre type ; distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Many studies have documented an association between chronic low back pain (LBP) and deficits in back muscle strength and endurance. The sub-optimal performance is believed to be the result of alterations in the size and structure of the muscle, although the long-standing issue of whether the observed changes precede or are a consequence of the pain remains unresolved. If consequent to the problem, and predominantly related to disuse of the muscles, then it may be expected that a relationship between muscle structure and symptom duration would exist. Lumbar paraspinal muscle samples were obtained from 59 chronic LBP patients using the percutaneous biopsy technique. The samples were subject to routine histochemical analysis for the examination of muscle fibre type characteristics and cytochemical architectural changes. In 55 of the patients, the gross cross-sectional areas of magnetic resonance images of the trunk muscles were also measured. Multivariate analysis showed that symptom duration was the strongest predictor of the individual proportions of the fast-fatigable type IIX fibres; with age and gender included in the model, nearly 30% of the variance in fibre type distribution could be accounted for. Duration of pain had no influence on fibre size. Gross muscle cross-sectional area correlated directly with lean body mass and inversely with age, but showed no relationship with symptom duration. Pathological changes in the internal fibre structure were more frequently encountered in older patients, and were independent of symptom duration. The results suggest that, over the long term, fibre type transformations rather than alterations in fibre size are the predominant changes to be found in the muscles of chronic LBP patients. The direction of change supports the results of many previous studies that have demonstrated corresponding differences in the fatigability of the muscles. There is a strong case for the early implementation of active measures to attempt to offset the development of these changes in back pain patients.
    Materialart: Digitale Medien
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  • 74
    ISSN: 1432-119X
    Schlagwort(e): Endothelin-A receptor ; Endothelin-B receptor ; Rat ; Pulmonary fibrosis ; Immunohistochemistry ; Quantitative PCR
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: AbstractPulmonary fibrosis is characterized by excessive extracellular matrix deposition with concomitant loss of gas exchange units, and endothelin-1 (ET-1) has been implicated in its pathogenesis. Increased levels of ET-1 from tissues and bronchoalveolar lavage have been reported in patients with pulmonary fibrosis and in animal models after intratracheal bleomycin. We characterized the cellular distribution of alveolar ET receptors by immunohistochemistry in bleomycin-induced pulmonary fibrosis in the rat and determined the regulation by bleomycin of ET receptor mRNA expression in isolated alveolar macrophages and rat lung fibroblasts. We found significant increases in the numbers of fibroblasts and macrophages at day 7 compared to day 28 and control animals. ETB receptor immunoreactivity was observed on fibroblasts and invading monocytes. Isolated fibroblasts expressed both ETA and ETB receptor mRNA, and ETA receptor mRNA was upregulated by bleomycin. Isolated resident alveolar macrophages expressed neither ETA nor ETB receptor mRNA which were also not induced by bleomycin. We conclude that, while ETB receptor stimulation of fibroblasts and monocytes recruited during bleomycin-induced lung injury exerts antagonistic effects on fibroblast collagen synthesis, the observed increase in the number of fibroblasts in vivo and upregulation of fibroblast ETA receptor mRNA by bleomycin in vitro point to a predominance of the profibrotic effects of ET receptor engagement.
    Materialart: Digitale Medien
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 1832-1835 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Platyspondyly ; MRI ; Progressive pseudorheumatoid dysplasia ; Bone ; Osteochondrodysplasia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. A rare case of progressive pseudorheumatoid dysplasia (PPD) in a 9-year-old girl is presented. Clinically, chronic painless swollen joints, accompanied by progressive motion restriction and progressive walking difficulties, were found. Radiologically, there was enlargement of the epimetaphyseal portions of the large joints, metacarpal heads, and phalanges, and generalized platyspondyly with irregular delineation of the endplates of the vertebral bodies. The radioclinical features at the peripheral joints were originally misdiagnosed as juvenile rheumatoid arthritis (JRA), and the structural spinal abnormalities were neglected and interpreted as Scheuermann's disease. However, the absence of active inflammatory parameters argues against JRA, whereas the low age of onset of the irregularities at the vertebral endplates is an argument against the diagnosis of Scheuermann's disease. The combination of the dysplastic abnormalities of the spine, with platyspondyly and Scheuermann-like lesions at an unusually low age of onset, and radiological features mimicking JRA of the peripheral joints, is the clue to the diagnosis of this rare autosomal-recessive disease. This case is the first to document the MRI features of PPD of the spine.
    Materialart: Digitale Medien
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  • 76
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 780-782 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Uterus ; Endometrial stromal sarcoma ; Uterine myometrium ; Uterine leiomyoma ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Two cases of uterine endometrial stromal sarcoma whose main mass was located in uterine myometrium are reported. They mimicked uterine leiomyoma with cystic degeneration or uterine leiomyosarcoma. Endometrial stromal sarcoma should be suggested in the differential diagnosis of mass lesion in uterine myometrium.
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  • 77
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 832-840 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Osteochondroma ; Complications ; Chondrosarcoma ; Bone tumors ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Osteochondromas can be complicated by mechanical irritation, compression or injury of adjacent structures, fracture, malignant transformation, and postoperative recurrence. Magnetic resonance imaging represents the most valuable imaging modality in symptomatic cases, because it can demonstrate typical features of associated soft tissue pathology, which can be differentiated from malignant transformation. Reactive bursae formation presents as an overlying fluid collection with peripheral contrast enhancement. Dislocation, deformation, and signal alterations of adjacent soft tissue structures can be observed in different impingement syndromes caused by osteochondromas. Magnetic resonance imaging provides excellent demonstration of arterial and venous compromise and represents the method of choice in cases with compression of spinal cord, nerve roots, or peripheral nerves, depicting changes in size, position, and signal intensity of the affected neural structures. Malignant transformation as the most worrisome complication occurs in approximately 1 % of solitary and 5–25 % of multiple osteochondromas. Magnetic resonance imaging is the most accurate method in measuring cartilage cap thickness, which represents an important criterion for differentiation of osteochondromas and exostotic (low-grade) chondrosarcomas. Cartilage cap thickness exceeding 2 cm in adults and 3 cm in children should raise the suspicion for malignant transformation. Finally, MR imaging can detect postoperative recurrence by depiction of a recurrent mass presenting typical morphological features of a cartilage-forming lesion.
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  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 130 (2000), S. 100-104 
    ISSN: 1432-1106
    Schlagwort(e): Key words NF-κB ; p65 ; Hippocampal neurons ; Glia ; Astrocytes ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  NF-κB is found in many neuronal cell types in different states of activity. This study aimed to define which conditions induce constitutive NF-κB activity in cultured hippocampal neurons using activity-specific antibody staining. In co-culture with astroglia, hippocampal neurons were devoid of activated NF-κB. In these co-cultures, NF-κB could not be activated via kainate or glutamate. In contrast, separating neurons from the glial compartment resulted in a time-dependent increase of activated neuronal NF-κB. In this line, activation of NF-κB by kainate or glutamate is very effective in freshly separated cultures, but inhibited when the cultures are reassembled after stimulation. These findings suggests that a neuronal-glial interaction may regulate gene expression via NF-κB.
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  • 79
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 1691-1696 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Herniography ; MRI ; Hernia ; Groin pain
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The aims of the present study were to assess if MRI gives the same diagnostic information as herniography concerning the presence of hernias and reveals other causes of groin pain. The prospective study enrolled 20 patients referred for herniography, 6 women and 14 men, mean age 48 years. After herniography the patients underwent MRI using T1-weighted, fat-suppressed inversion recovery (STIR), and magnetic resonance cholangiopancreaticography (MRCP) pulse sequences. No contrast medium was administered at MRI. Herniography revealed 11 hernias and MRI depicted 8 of these. Magnetic resonance imaging depicted well the anatomy in the groins. In 3 patients where hernias were not revealed, MRI revealed inflammatory changes in the symphysis region as a possible cause of groin pain. The primary diagnostic tool for diagnosing hernias is herniography. If the herniogram is normal, MRI may reveal other causes of groin pain and may also better visualize related structures in the groin.
    Materialart: Digitale Medien
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  • 80
    ISSN: 1432-1084
    Schlagwort(e): Key words: Lumbar spine ; Ganglion cyst ; Posterior longitudinal ligament ; Radiculopathy ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. A 35-year-old man with a long history of left L5 radicular pain was found to have an intraspinal cystic lesion causing radicular compression. Magnetic resonance imaging demonstrated a round lesion situated in the anterior epidural space, with uniform high signal intensity on T2-weighted sequences characteristic of a cystic lesion. During surgery a liquid-containing cyst originating from the posterior longitudinal ligament was punctured and resected. The histologic aspect was that of a ganglion cyst without synovial layers. The radiologic differential diagnoses are discussed.
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 786-801 
    ISSN: 1432-1084
    Schlagwort(e): Key words: CT ; MRI ; Colon ; Colonography ; Virtual colonoscopy ; Colorectal polyp ; Screening
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. With the introduction of multidetector technology in CT and the moveable table with integrated coil modules in MRI, the concept of multiorgan screening has become realistic. CT colonography and MR colonography are new radiologic techniques that promise to be highly sensitive colorectal screening examinations. This article reviews the current status and research directions in CT colonography and MR colonography, and compares these methods.
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 855-858 
    ISSN: 1432-1084
    Schlagwort(e): Key words:18FDG-PET ; Osteomyelitis ; Antigranulocyte antibody scintigraphy ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The purpose of this report is to discuss FDG-PET as a potentially new imaging tool in the diagnosis of infections of osteosynthetic material. We present a patient with a poly-trauma who developed a chronic osteomyelitis and ostitis after repeated osteosynthesis in a fibular transplant to the left femur. Work up included MRI, antigranulocyte antibody scintigraphy and positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG). Infection of the fibular transplant was demonstrated clearly by PET but not by the other methods. Positron emission tomography may become an important indication in the diagnosis and follow-up of bone infection.
    Materialart: Digitale Medien
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  • 83
    ISSN: 1432-1084
    Schlagwort(e): Key words: Brain ; MRI ; Neoplasms ; Diffusion image ; Echo-planar MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. We assess diffusion-weighted MR images in the differential diagnosis of intracranial brain tumors and tumor-like conditions. Heavily diffusion-weighted (b = 1100 or 1200 s/mm2) axial images were obtained with single-shot echo-planar technique in 93 patients with pathologically confirmed various intracranial tumors and tumor-like conditions with diffusion gradient perpendicular to the images. We compared signal intensity of the lesions with those of gray and white matter, and cerebrospinal fluid (CSF). In 29 cases (31.1 %) the lesions were isointense to gray and/or white matter. However, 5 cases (5.4 %) showed extremely increased signal intensity: two epidermoid cysts; two chordomas; and one brain abscess. The entire portion of a tumor was markedly hyperintense in 10 cases (10.8 %): four malignant lymphomas; four medulloblastomas; one germinoma; and one pineoblastoma. A CSF-like hypointense signal was seen in many cystic tumors, and cystic or necrotic portions of tumors. A neurosarcoid granulation was the only solid lesion showing characteristically a hypointense signal like CSF. The combination of markedly hyperintense and hypointense signals was seen generally in hemorrhagic tumors. Diffusion-weighted echo-planar MR imaging is useful in the differential diagnosis of brain tumors and tumor-like conditions, and suggests specific histological diagnosis in some cases.
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  • 84
    ISSN: 1432-1084
    Schlagwort(e): Key words: Ovarian cancer ; Lesion characterization ; Recurrence ; PET ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The aim of this study was to compare prospectively the accuracy of whole-body positron emission tomography (PET), CT and MRI in diagnosing primary and recurrent ovarian cancer. Nineteen patients (age range 23–76 years) were recruited with suspicious ovarian lesions at presentation (n = 8) or follow-up for recurrence (n = 11). All patients were scheduled for laparotomy and histological confirmation. Whole-body PET with FDG, contrast-enhanced spiral CT of the abdomen, including the pelvis, and MRI of the entire abdomen were performed. Each imaging study was evaluated separately. Imaging findings were correlated with histopathological diagnosis. The sensitivity, specificity and accuracy for lesion characterization in patients with suspicious ovarian lesions (n = 7) were, respectively: 100, 67 and 86 % for PET; 100, 67 and 86 % for CT; and 100, 100 and 100 % for MRI. For the diagnosis of recurrent disease (n = 10), PET had a sensitivity of 100 %, specificity of 50 % and accuracy of 90 %. The PET technique was the only technique which correctly identified a single transverse colon metastasis. Results for CT were 40, 50 and 43 %, and for MRI 86, 100 and 89 %, respectively. No statistically significant difference was seen. Neither FDG PET nor CT nor MRI can replace surgery in the detection of microscopic peritoneal disease. No statistically significant difference was observed for the investigated imaging modalities with regard to lesion characterization or detection of recurrent disease; thus, the methods are permissible alternatives. The PET technique, however, has the drawback of less accurate spatial assignment of small lesions compared with CT and MRI.
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  • 85
    ISSN: 1432-1084
    Schlagwort(e): Key words: Eye injuries ; CT ; MRI ; Eye foreign body
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Detection and characterization of intraorbital foreign bodies (IFB) is fundamental in acute trauma setting, preventing inflammatory sequelae or complications related to IFB movements when a MRI study is planned. Papers concerning plain film and CT sensibility in IFB detection show controversial results. For this reason we investigated plain film, CT and MRI sensibility in the evaluation of IFB. For an in vitro model, specimens of dry and fresh wood, glass, iron, plastic and graphite were immersed in animal lard and in a 0.9 % sodium chloride plus 3.5 g/dl human serum albumin solution. Specimens of different size and nature where also implanted into enucleated pig eyes. Air bubbles were introduced also. Plain film, CT and MRI investigation were performed. Plain films underestimated intraocular IFB as plastic, fresh or dry wooden IFB were not demonstrated. The CT study was always able to depict and differentiate IFB according to the attenuation values. Severe artefacts prevented demonstration of iron, glass and graphite IFB on MRI, whereas plastic or wooden IFB were always detected. Despite radiographs have been suggested as a prerequisite for MR imaging, because our results showed plain film to underestimate radiolucent IFB, we suggest CT as the modality of choice when IFB has to be ruled out.
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 1242-1244 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Muscle anomalies ; Median nerve compression ; Wrist ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Muscle anomalies around the wrist, in particular the palmaris longus muscle, may cause effort-related median nerve compression. A search of the medical records at our university hospital between 1994 and 1999 revealed four patients with an effort-related median nerve compression due to a reversed palmaris longus muscle. Magnetic resonance imaging was used in the patient work-up and showed an anomalous muscle in each case that had been missed initially. All four patients were free of pain after simple excision of the anomalous muscle. Awareness of muscle anomalies at the wrist on MR imaging is essential in evaluating patients with nerve compressions at the wrist. The purpose of this article is to heighten this awareness in radiologists.
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 10 (2000), S. 1310-1314 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Thorax ; Mediastinum ; Lymphangioma ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Adult mediastinal lymphangiomas are rare lesions the diagnosis of which is difficult based on imaging studies. A retrospective study of CT, MR, and pathologic findings of mediastinal lymphangioma was performed in order to correlate pathological and imaging findings. Nine cases of adult lymphangiomas were identified in the records of our institution over a 12-year period. The CT, MR, and pathologic findings were reviewed. Lesions were classified pathologically as unilocular, cavernous, and intermediate types. Pathologic examination identified six cases of unilocular lesion, two cases of cavernous type, and one intermediate type. The CT features (n = 9) included a smoothly marginated non-enhancing mass of water attenuation (n = 7), a non-enhancing mass of soft tissue attenuation (n = 1), and an enhancing multiseptated mass (n = 1). Lesions were located in the anterior mediastinum (n = 2), right paratracheal (n = 4), subcarinal (n = 1), aortopulmonic window (n = 1) areas, and below the left hilum extending into the posterior mediastinum (n = 1). The MR features (n = 3) were characterized by an enhancing multicystic and multiseptated appearance, evocative of a cavernous type in two cases. The CT appearance of mediastinal thoracic lymphangioma is variable depending on the pathologic type. The most common unilocular type is a non-enhancing thin-walled mass on CT. A less frequent cavernous type can be suggested based on a multiseptated and loculated mass on CT and/or MR examination.
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 100 (2000), S. 75-81 
    ISSN: 1432-0533
    Schlagwort(e): Key words Fas ; Fas ligand ; Rat ; Spinal cord ; Trauma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This immunohistochemical study evaluated Fas and Fas ligand (FasL) in the rat nervous system and their changes in the spinal cord subjected to compression. Normal spinal cord showed a low level of Fas and FasL immunoreactivity in the white matter except in the corticospinal tracts. Fas and FasL immunoreactivity seemed to be located in axons and their myelin sheaths. Other regions of the nervous system did not show immunoreactivity to Fas and FasL. Moderate and severe compression injury of the spinal cord resulted in a reduction of Fas and FasL immunoreactivity in the white matter of injured T8–9 segments at 4 h and a complete loss at 1 day after trauma. This was seen even in the remaining white matter. In contrast, increased immunoreactivity to Fas and FasL was present in the cranial T7, caudal T10 (moderate injury) and T12 (severe injury) segments at day 4 with most intense staining were seen at day 9 after trauma. Increased Fas and FasL immunoreactivity may have pathophysiological implications for the development of secondary injuries after trauma to the spinal cord. Fas-FasL interactions may for instance be involved in apoptosis of oligodendrocytes which occurs as a delayed phenomenon after trauma to the spinal cord. The integrity of myelin sheaths may in this way be jeopardized by apoptosis of oligodendrocytes.
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  • 89
    ISSN: 1432-0533
    Schlagwort(e): Key words Hypothermia ; Immunohistochemistry ; Microtubule-associated protein 2 (MAP2) ; Rat ; Spinal cord injury
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Systemic hypothermia has been shown to exert neuroprotective effects in experimental ischemic CNS models caused by vascular occlusions. The present study addresses the question as to whether systemic hypothermia has similar neuroprotective qualities following severe spinal cord compression trauma using microtubule-associated protein 2 (MAP2) immunohistochemistry combined with the avidin-biotin-peroxidase complex method as marker to identify neuronal and dendritic lesions. Fifteen rats were randomized into three equally sized groups. One group sustained thoracic laminectomy, the others severe spinal cord compression trauma of the T8-9 segment. The control group contained laminectomized animals submitted to a hypothermic procedure in which the esophageal temperature was reduced from 38 °C to 30 °C. The two trauma groups were either submitted to the same hypothermic procedure or kept normothermic during the corresponding time. All animals were sacrificed 24 h following the surgical procedure. The MAP2 immunostaining in the normothermic trauma group indicated marked reductions in MAP2 antigen in the cranial and caudal peri-injury zones (T7 and T10, respectively). This reduction was much less pronounced in the hypothermic trauma group. In fact, the MAP2 antigen was present in almost equally sized areas in both the hypothermic groups independent of previous laminectomy alone or the addition of trauma. Our study thus indicates that hypothermia has a neuroprotective effect on dendrites of rat spinal cords subjected to compression trauma.
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  • 90
    ISSN: 1279-8517
    Schlagwort(e): Anterior cruciate ligament ; Kinematics ; Knee ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The aim of this study is to suggest an anatomic study of the modifications of the length of the anterior cruciate ligament (ACL) and its bundles during flexion with the aid of a 3D computerized model of the knee in a living subject. The method of evaluation suggested is a 3D computerized reconstruction based on MRI sections, reproducing the movement of flexion of the knee from 0 to 75°. Twenty-one sections were made for each of the 13 positions of flexion. The reconstruction of Delaunay and the realignment of each position provided a 3D model which allowed monitoring of a bony point during the movement. By knowing the relative displacement of the ligamentous attachments it was possible to define the biometry of the ligament by calculating the length of the bundles of the ACL in each position and to demonstrate the variations in length during the movement. The mean length of the ligament was 3.4 mm. The anteromedial bundle was longer by 30% compared with the other two bundles. During flexion the anteromedial bundle was not much modified (this feature seems to provide a reference position for a ligamentoplasty), the posterolateral bundle became taut after 30°, and the intermediate bundle relaxed from the beginning of movement. Based on the data from the literature, this method allows an anatomic approach to the ACL, bundle by bundle, during flexion movement.
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Surgical and radiologic anatomy 22 (2000), S. 5-11 
    ISSN: 1279-8517
    Schlagwort(e): Larynx ; MRI ; Histology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The larynx is an organ with a complex anatomic structure. MRI allows the performance of sections in the three planes of space, so that this study of the soft parts of the larynx yields results superior to those of other imaging techniques. Together with laryngoscopy, MRI is most often used in assessing the extension of malignant laryngeal tumors. This assessment is fundamental in choosing the indications for surgery, but the published reports of MRI of the larynx are sometimes discordant. The visualization of certain important anatomic structures such as the conus elasticus is uncertain. Our aim was to study the MRI radio-anatomy of the larynx based on correlations between MRI and histologic sections. Eight anatomic specimens were studied four in the transverse plane, two in the sagittal plane, and two in the frontal plane. The MRI and histologic sections made at the same levels were compared. These comparisons allowed a description of the sectional radio-anatomy of the larynx and an assessment of the reliability and limitations of MRI. All the major anatomic structures could be identified. It was possible to demonstrate the conus elasticus. We were able to visualize the vocal process of the arytenoid cartilage, which has not to our knowledge been previously described in the literature.
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  • 92
    ISSN: 1432-2277
    Schlagwort(e): Key words Kidney transplantation ; Rat ; Chronic rejection ; Cytomegalovirus ; Adhesion molecules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Previous studies have demonstrated that both cytomegalovirus (CMV) infection and prolonged cold ischemia of the allograft (CI) are associated with chronic rejection of renal transplants. The purpose of this study is to investigate the effect of CMV infection, of CI and of the combination of both, on the progression of chronic rejection, and to obtain a more detailed insight in their effects on the expression of adhesion molecules. Therefore, a rat transplantation model was used. Lewis recipients of renal allografts (with and without CI) from MHC-incompatible Brown Norway rats were inoculated with rat CMV or left uninfected. CMV infection alone resulted in an increased influx of CD4+ cells and macrophages early after infection, and in an increase in glomerular sclerosis and intima proliferation. CI caused an increase in infiltrating NK cells and an effect on intimal proliferation, glomerular sclerosis, and tubular atrophy. When CMV infection and CI were combined, an additive effect could be measured. This was however not the case for the function of the kidney. The creatinin showed a synergistic effect of the two influencing factors. Due to the CMV infection, an increase in CD49 d cells was detected. CI resulted in an increase in CD18 cells and an increase in the expression of CD62P on vessels, and CD54 and CD44 on tubules. When CMV infection and CI were combined, all the effects caused by CMV and CI alone were present in an additional way.¶The results of the present study suggest that special attention should be paid to the recipient of an ischemically injured graft when either the donor or the recipient is CMV-infected. The patterns seen in histology, the infiltration of leukocytes and the expression of adhesion molecules, suggest that CI and CMV infection both have an effect on rejection, but act by different mechanisms.
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 538-542 
    ISSN: 1432-2161
    Schlagwort(e): Key words Ancient neurilemmoma ; Pelvis ; Ultrasound ; CT ; MRI ; Venous obstruction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A 43-year-old man with a large ancient schwannoma of the pelvis, presenting with varicose veins, is reported. Ancient schwannoma (neurilemmoma) is a benign tumour of nerve sheath origin characterised histologically by features of severe degeneration and which rarely can grow to a large size. Malignant transformation, though reported, is extremely rare.
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 29 (2000), S. 543-547 
    ISSN: 1432-2161
    Schlagwort(e): Key words Neurofibromatosis ; Segmental plexiform neurofibromatosis ; Schwannomatosis ; Malignant peripheral nerve sheath tumor ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Segmental neurofibromatosis is a rare disease characterized by neurofibromas with or without café au lait spots localized to one segment of the body. The majority of reported cases have had cutaneous neurofibromas, and patients with deep involvement have rarely been described. We report on two patients with deep-seated segmental plexiform neurofibromatosis and review the literature. All reviewed cases including the present two had no café au lait spots, axillary freckling, Lisch nodules, family history or malignant progression of disease. Differential diagnoses from neuro-fibromatosis 1 (von Recklinghausen disease) and malignant peripheral nerve sheath tumor are important for genetic counseling and avoiding overtreatment.
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  • 95
    ISSN: 1432-2072
    Schlagwort(e): Keywords Novelty ; Context ; Environment ; Stress ; 6-OHDA ; Rotational behavior ; Striatum ; Nucleus accumbens shell ; Caudate ; Amphetamine ; Dopamine ; Glutamate ; Aspartate ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: We have previously shown that environmental novelty enhances the behavioral activating effects of amphetamine and amphetamine-induced expression of the immediate early gene c-fos in the striatal complex, particularly in the most caudal portion of the caudate. In contrast, we found no effect of novelty on the ability of amphetamine to induce dopamine (DA) overflow in the rostral caudate or in the core of the nucleus accumbens. Objectives: The twofold aim of the present study was to determine the effect of environmental novelty on (1) amphetamine-induced DA overflow in the shell of the nucleus accumbens and in the caudal portions of the caudate, and (2) glutamate and aspartate overflow in the caudal portions of the caudate. Methods: Two groups of rats with a unilateral 6-hydroxydopamine lesion of the mesostriatal dopaminergic system received amphetamine (0.5 mg/kg, i.v.) in physically identical cages. For one group, the cages were also the home environment, whereas, for the other group, they were a completely novel environment. In vivo microdialysis was used to estimate DA, glutamate, and aspartate concentrations. Results: Environmental novelty enhanced amphetamine-induced rotational behavior (experiments 1–3) but did not alter amphetamine-induced DA overflow in either the shell of the nucleus accumbens (experiment 1) or the caudate (experiment 2). In addition, the ability of environmental novelty to enhance amphetamine-induced behavioral activation was not associated with changes in glutamate or aspartate efflux in the caudate (experiment 3). Conclusions: The present data indicate that the psychomotor activating effects of amphetamine can be modulated by environmental context independent of its primary neuropharmacological actions in the striatal complex.
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 151 (2000), S. 219-225 
    ISSN: 1432-2072
    Schlagwort(e): Keywords Amphetamine ; Wheel running ; Behavioral sensitization ; Pharmacological sensitization ; Novelty ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: This study explored whether repeated injections of amphetamine (AMP), which increase general locomotion, also increase acute wheel running, a highly structured, rewarding, motor behavior not correlated with other locomotor activities. Objectives: The experiments determine how 1–5 mg/kg d-AMP affects wheel running and see if, over repeated injections, the AMP effects show context specific sensitization. Methods: In experiment 1, 2 mg/kg AMP or saline (SAL) was injected on days 1, 3, 6, 8, and 10 to male Sprague-Dawley rats with either limited or no wheel experience. 20 min after the injection animals were tested in an open field for 5 min and then in a running wheel for 1 h. Rats were injected with SAL or AMP on the days following testing. On days 13 and 15, animals were tested for conditioning (following SAL) and sensitization (following AMP). In experiment 2, the effects on wheel running of repeated 1, 2, or 5 mg/kg AMP were tested. Results: In experiment 1, AMP (2 mg/kg) elevated open field ambulation but suppressed wheel running. Limited wheel experience potentiated the AMP-induced suppression. At test, the suppression of running was found to be context specific. In experiment 2, 1 mg/kg did not affect running, while 2 and 5 mg/kg resulted in dose-dependent running suppression. Acquisition and test AMP dose both influenced the running suppression at test; context had a marginal influence. Conclusions: The degree of running suppression induced by repeated AMP is determined by both psychological (the injection context) and pharmacological (the acquisition dose) factors. This AMP-induced running suppression is consistent with the sensitization of stereotyped behavior.
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  • 97
    ISSN: 1432-2072
    Schlagwort(e): Key words Nicotine ; Drug discrimination ; Self-administration ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: The cellular effects of nicotine underlying its addictive liability are thought to be mediated by neuronal nicotinic receptors (nACHRs) in the central nervous system. It is believed that densely expressed β2-containing nACHRs in the central nervous system are responsible for these actions, but few data are available that can directly assess subtype mediation of nicotine’s acute subjective and reinforcing effects. Objective: The present study compared the effects of the competitive nACHR antagonist erysodine and the noncompetitive antagonist mecamylamine in rats trained to discriminate or self-administer nicotine. Methods: Adult male rats were trained to disciminate 0.4-mg/kg injections of nicotine from vehicle in a two-lever procedure of food-maintained behavior, or to self-administer 0.03-mg/kg injections of nicotine under fixed-ratio 5 or progressive-ratio schedules of reinforcement. Additional rats were trained under a food-maintained procedure of lever pressing. Results: Erysodine (0.3–10 mg/kg) and mecamylamine (0.1–1.0 mg/kg) blocked nicotine discrimination, although only erysodine produced the rightward shift that would be predicted of a competitive antagonist. Erysodine (0.32–32 mg/kg) and mecamylamine (0.32–3.2 mg/kg) also selectively reduced nicotine self-administration on a fixed-ratio schedule and lowered break points on a progressive-ratio schedule. Conclusions: Based on the known affinity of erysodine for α4β2 nACHRs and its selectivity relative to α7 and α1β1γδ receptors, the present data support a critical role of β2-containing nACHR constructs in the discriminative and reinforcing actions of nicotine.
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 148 (2000), S. 224-233 
    ISSN: 1432-2072
    Schlagwort(e): Key words Drug discrimination ; Olanzapine ; Clozapine ; Chlorpromazine ; Haloperidol ; Thioridazine ; Raclopride ; Risperidone ; Scopolamine ; Ritanserin ; Atypical antipsychotic ; Neuroleptic ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Analysis of the preclinical behavioral effects of atypical antipsychotic agents will provide a better understanding of how they differ from typical antipsychotics and aid in the development of future atypical antipsychotic drugs. Objectives: The present study was designed to provide information about the discriminative stimulus properties of the atypical antipsychotic olanzapine. Methods: Rats were trained to discriminate the atypical antipsychotic olanzapine (either 0.5 mg/kg OLZ or 0.25 mg/kg OLZ, i.p.) from vehicle in a two- lever drug discrimination procedure. The atypical antipsychotic clozapine fully substituted for olanzapine in both the 0.5-mg/kg OLZ group (99.3% drug lever responding [DLR]) and the 0.25-mg/kg OLZ group (99.9% DLR). The typical antipsychotic chlorpromazine also substituted for olanzapine in both the 0.5-mg/kg OLZ group (87.5% DLR) and in the 0.25-mg/kg OLZ group (98.9% DLR); whereas, haloperidol displayed partial substitution for olanzapine in the 0.5-mg/kg OLZ group (56.1% DLR) and in the 0.25-mg/kg OLZ group (76.4% DLR). The 5.0-mg/kg dose of thioridazine produced olanzapine-appropriate responding in the 0.5-mg/kg OLZ group (99.6% DLR), but only partial substitution was seen with the 0.25-mg/kg OLZ training dose (64.0% DLR). The atypical antipsychotics raclopride (53.9% DLR) and risperidone (60.1% DLR) displayed only partial substitution in the 0.5-mg/kg OLZ group. Both the muscarinic cholinergic antagonist scopolamine (90.0% DLR) and the 5-HT2A/2C serotonergic antagonist ritanserin (86.0% DLR) fully substituted for olanzapine in the 0.5-mg/kg OLZ group. Conclusions: In contrast to previous discrimination studies with clozapine-trained rats, the typical antipsychotic agents chlorpromazine and thioridazine and the serotonin antagonist ritanserin substituted for olanzapine. These results demonstrate that there are differences in the mechanisms underlying the discriminative stimulus properties of clozapine and olanzapine. Specifically, olanzapine’s discriminative stimulus properties appear to be meditated in part by both cholinergic and serotonergic mechanisms.
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 148 (2000), S. 243-250 
    ISSN: 1432-2072
    Schlagwort(e): Key words Attention ; Scopolamine ; Mecamylamine ; Oxotremorine ; Physostigmine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: This study tried to determine the relative roles of muscarinic and nicotinic cholinergic receptors in attentional processing. Methods: The effects of cholinoceptor agonists and antagonists, and of an anticholinesterase, were studied on performance of rats in a five-choice serial reaction time task. Results: Scopolamine (0.1 mg/kg) and mecamylamine (5.0 mg/kg) produced deficits in accuracy and reaction time, respectively. This may suggest a differential role for the two types of cholinoceptors in information processing. Combinations of sub-threshold doses of scopolamine (0.01–0.03 mg/kg) and mecamylamine (0.5–1.6 mg/kg), which alone did not affect accuracy or reaction time, did not produce significant deficits in attention. However, the pattern of effects after combined treatment suggested that the differential deficits seen with these drugs alone remained. The anticholinesterase physostigmine (0.1 mg/kg) and the non- selective muscarinic agonist oxotremorine (0.03 mg/kg) induced severe behavioural disruption at doses that appeared to be relatively well tolerated in previous studies; this precluded the derivation of accuracy and response time data at these doses. At lower doses, neither physostigmine (0.05 mg/kg) nor oxotremorine (0.003 mg/kg) significantly affected any performance measure; this may reflect the ability of both drugs to indirectly or directly activate presynaptic muscarinic receptors that inhibit acetylcholine release, respectively. Conclusions: Both muscarinic and nicotinic cholinoceptors may be important in attention but they may serve different roles in information processing; this hypothesis could be tested using tasks that place different emphasis on different stages of information processing.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 100
    ISSN: 1432-2072
    Schlagwort(e): Key words ACTH ; Corticosterone ; GABA ; Noradrenaline ; Adrenaline ; Stress ; Rat ; Diazepam
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Gabolysat PC60 is a fish protein hydrolysate with anxiolytic properties commonly used as a nutritional supplement. Objective: The diazepam-like effects of PC60 on stress responsiveness of the rat pituitary-adrenal system and on sympathoadrenal activity were studied. Methods: The activity of the pituitary-adrenal axis, measured by plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone (B) of the sympathoadrenal complex, measured by circulating levels of noradrenaline (NA) and adrenaline (A), and the gamma aminobutyric acid (GABA) content in the hippocampus and the hypothalamus were investigated in male rats which received daily, by an intragastric feeding tube, for 5 days running either diazepam (1 mg/kg) or PC60 (300 or 1200 mg/kg). Controls received only solvent (carboxymethylcellulose 1%). Six hours after the last force-feeding, the rats were subjected to 3 min ether inhalation or 30 min restraint and killed by decapitation 30 min after ether stress or at the end of restraint. Results: Baseline plasma levels of ACTH, B, NA and A were not affected by either diazepam or PC60. Both ether- and restraint-induced release of ACTH, but not B, were similarly and drastically reduced by diazepam and PC60 (1200 mg/kg). Both diazepam and PC60 (1200 mg/kg) deleted restraint-induced NA and A increases. Both treatments also reduced the ether-induced rise of A. Basal levels of GABA were significantly increased in both the hippocampus and the hypothalamus in PC60-treated rats and only in the hippocampus in diazepam-treated ones. In controls, ether inhalation as well as restraint increased GABA content of these two brain structures. In contrast, such stress procedures performed in PC60-treated rats reduced GABA content slightly in the hippocampus but significantly in the hypothalamus. In diazepam-treated rats, GABA content of the hypothalamus was unaffected by stresses but that of the hippocampus was slightly decreased. Conclusions: Present data suggest diazepam-like effects of PC60 on stress responsiveness of the rat pituitary adrenal axis and the sympathoadrenal activity as well as GABA content of the hippocampus and the hypothalamus under resting and stress conditions. These effects of PC60 agree with anxiolytic properties of this nutritional supplement, previously reported in both rats and humans.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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