[MRI-guided musculoskeletal biopsy]. / Möglichkeiten mit der MRT-gesteuerten Tumorbiopsie am Bewegungsapparat.

MRI-guided musculoskeletal biopsy has been mentioned to be a minimally invasive method to obtain specimens for diagnostic purposes in bone tumors. To evaluate the viability, to assess the accuracy, and to record possible complications of this method, clinical data of 19 MRI-guided biopsies were analyzed. Interventions were performed on 18 patients (1-78 years) as an outpatient procedure: 15 skeletal and 4 soft tissue biopsies were taken from the pelvis, upper limb,or lower limb. We used T1-weighted gradient echoes (GE) for locating the puncture site and T2-weighted turbo spin echoes (TSE) for visualization of needle position. In 14 of 18 MRI-guided biopsies, a definite histological diagnosis was obtained. According to the pathologist, the inadequate size of the specimen was the main reason for missing the diagnoses in four cases.Long intervention time and inappropriate biopsy tools proved to be the main disadvantages of MRI-guided biopsy, but technical improvement might solve these technical problems in future.A postbiopsy hematoma was the only complication observed. Once technically improved, MRI-guided biopsy could be a precise alternative routine method for musculoskeletal biopsies in future.

[Characteristic perfusion pattern of osseous giant cell tumor in dynamic contrast-enhanced MRI]. / Charakteristisches Perfusionsmuster des ossären Riesenzelltumors in der dynamischen kontrastverstärkten MRT.

PURPOSE: To describe the perfusion pattern of giant cell tumor (GCT) of bone with Gd-enhanced dynamic MR imaging. To compare time-intensity-curves in patients with local recurrence and postoperative alterations without recurrence. METHODS: Nine patients (5 women, 4 men) with GCT of bone underwent 19 dynamic MRI examinations. Mean age was 34 years (range 24-64 years). All diagnoses were proven by pathology. Dynamic contrast-enhanced MRI was performed at 1.0 T using T1-weighted gradient echo sequences. GCT was located in the distal radius (4x), tibia (3x), fibula (1x) and humeral head (1x). RESULTS: All giant cell tumors showed a uniform perfusion pattern with a steep slope and maximum intensity value followed by an early and rapid washout phase. The same pattern appeared in five local recurrences of GCT in four patients. In nine follow-up examinations without local recurrence dynamic MRI yielded in uncharacteristic perfusion patterns. CONCLUSION: These results demonstrate a uniform perfusion pattern of GCT of bone obtained by dynamic MRI. It is characterized by a steep slope followed by an early and rapid washout phase. This characteristic pattern can also be obtained in local recurrences. Dynamic contrast-enhanced MRI appears a helpful method for primary diagnosis of GCT of bone and detection of local recurrences after surgery.

[After-care of TIPSS patients. Comparison between color Doppler ultrasound and portography]. / Nachsorge bei TIPPS. Vergleich zwischen Farbdopplersonographie und Portographie.

PURPOSE: Comparison of color Doppler sonography and venous portography in patients with a transjugular intrahepatic portosystemic stent shunt (TIPSS). MATERIALS AND METHODS: In a prospective study 40 consecutive patients with TIPSS underwent venous portography and color Doppler sonography on the same day as follow-up. Shunt velocities were recorded within the TIPSS at the proximal (hepatic vein segment) and distal part (portal vein segment). RESULTS: In 28 patients with functioning TIPSS the mean shunt velocity ranged between 30 and 120 cm/s (median 60 cm/s) at the portal vein segment and between 60 and 155 cm/s (median 82 cm/s) at the hepatic vein segment. There was a significant increase of the mean shunt velocity in the hepatic vein segment (P < 0.001). In 12 patients with compromised TIPSS the mean shunt velocity was reduced to 26 +/- 7 cm/s at the portal venous end (P < 0.0001). CONCLUSION: Because of an accelerated shunt velocity in the hepatic vein segment a site-specific evaluation of both TIPSS endings is necessary with color Doppler sonography. In compromised TIPSS the shunt velocity is reduced at the portal venous end. Color Doppler sonography is a valid non-invasive means for follow-up of patients with TIPSS.

[Changes in liver perfusion caused by transjugular intrahepatic stent shunt (TIPSS)]. / Die Veränderungen der Leberperfusion durch den transjugulären intrahepatischen Stent-Shunt (TIPSS).

PURPOSE: to demonstrate and document TIPSS-induced changes of the perfusion pattern of the liver with special reference to several rheologic, morphologic, functional and biochemical parameters. Our analysis was based on a study in 100 consecutive cases. PATIENTS AND METHODS: Evaluation and assessment of the following parameters before and within a 30-day post TIPSS period: portosystemic gradient; morphologic delineation of the portal circulation; invasive scintigraphic determination of the portal perfusion fraction (PPF) and the total liver perfusion (GLP); transcatheter intraarterial flow change measurement; serum levels of albumin and bilirubin; assessment of hepatic encephalopathy by appropriate testing; assessment of recurrent variceal bleeding RESULTS: by TIPSS variceal filling was widely reduced; as assessed morphologically and rheologically portal liver perfusion was significantly reduced. However, there was immediate onset of compensated liver perfusion by increased arterial inflow. Total liver perfusion was not significantly altered. In TIPSS portal decompression was readily achieved with reduction of the portosystemic gradient from an average of 24 mmHg to 10.5 mmHg. In our series we could not demonstrate an increased incidence of hepatic encephalopathy during the 30-day post TIPSS period. Bilirubin levels were significantly increased after TIPSS from 2.45 to 2.61 mg/dl (p = 0.0067), while albumin levels were not altered. Early mortality was 4% and early re-bleeding rate 3%, respectively. CONCLUSION: the concept of TIPSS represents an individually calibrated H-shunt. The significant reduction of post TIPSS portal perfusion appears to be compensated by increased arterial inflow. This is reflected by invasive flow measurement results and by the clinical results. Letality of TIPSS is low.

Immunocytochemical localization of nicotinic acetylcholine receptors in the terminal abdominal ganglion of the cockroach (Periplaneta americana).

A polyclonal, monospecific antiserum raised against a nicotinic acetylcholine receptor protein affinity-purified from insect nervous tissue, was employed to demonstrate the localization of antigenic sites in the neuropile of the terminal (sixth) abdominal ganglion of the cockroach Periplaneta americana. In agreement with previously published autoradiographic mapping of specific [125I]alpha-bungarotoxin binding sites, specific areas of the central neuropile of this ganglion were densely stained, but not the cercal afferent axons. No staining was detected corresponding to the dense, peripheral, partly non-specific binding of alpha-bungarotoxin seen in autoradiographs of the same tissue. Certain peripherally located neuronal cell bodies, including the cell body of giant interneuron 2, contained intracellularly located antigenic sites.

Immunocytochemical localization of glutamate decarboxylase in the mesothoracic ganglion of Locusta migratoria.

Glutamate decarboxylase immunoreactivity has been located in the thoracic ganglia of the locust, Locusta migratoria, using an antiserum raised from rat brain. At the light microscopic level clusters of nerve cell somata as well as nerve fibres were positively labelled by the antiserum. Electron microscopy showed that glutamic acid decarboxylase was localized in numerous synaptic terminals.

Monoclonal antibodies against the high affinity choline transport system.

Monoclonal antibodies have been isolated that specifically block the high affinity, Na(+)-dependent transport of choline in insect synaptosomes and synaptosomal ghosts. Antibodies were derived after immunization of mice with synaptosomal membranes from locust. Antibody VIB6F5, an IgG isotype, significantly inhibited the high affinity translocation of choline, the effect exhibited saturation at increased antibody concentrations. Antibodies recognized a 80 kDa antigen identified by Western blot analysis of synaptosomal membranes. In immunocytochemical approaches VIB6F5 specifically stained distinct areas in the neuropil of head and thoracic ganglia.

[Nosocomial infection of hospitalised patients with chemotherapy-resistant strains of Klebsiella pneumoniae (author's transl)]. / Durchseuchung von Patienten eines Krankenhauses mit chemotherapieresistenten Stämmen von Klebsiella pneumoniae.

In a 500-bed general hospital the incidence of highly resistant strains of Klebsiella pneumonia was examined. About 20% of examined patients in the surgical and medical departments were carriers. Spread of the organism was via the hands of personnel and patients as well as various objects. The use of broad-spectrum antibiotics, especially ampicillin and cefalotin is thought to be the chief cause of the high incidence of Klebsiella emergence. About 90% of carriers had previously received antibiotics.