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Showing papers by "Ulrich Bogdahn published in 1991"


Journal ArticleDOI
TL;DR: In this article, the authors used transcranial color-coded real-time sonography to diagnose spontaneous subarachnoid hemorrhage using a 2.25-MHz transducer.
Abstract: Thirty-six patients with acute spontaneous subarachnoid hemorrhage (26 caused by rupture of an aneurysm) were examined by transcranial color-coded real-time sonography by using a 2.25-MHz ultrasound transducer. In 20 of these 26 patients (76%), the aneurysm could be identified by a characteristic abnormal blood flow pattern within the aneurysm in coronal and axial scanning planes by transcranial color-coded real-time sonography. Blood within the basal cisterns, on top of the tentorium, and within the ventricles and parenchyma was sonographically detected by increased echodensity in 75%. In addition, cerebrospinal fluid circulation disturbances and cerebral vasospasm were detected in two-dimensional B-mode images in 85% and 100%, respectively. In Doppler mode, intravascular blood flow velocity could be quantified. We conclude that transcranial color-coded real-time sonography, a new, noninvasive method for diagnosis and follow-up of patients with subarachnoid hemorrhage, allows detection of the primary vascular lesion and monitoring of complications.

63 citations


Journal ArticleDOI
TL;DR: Real‐time ultrasound findings in partially and completely denervated muscles of 30 patients with focal neurpathy and various other disorders of the second motor neuron are presented, showing in vivo correlation of muscle morphology with muscle function.
Abstract: Presented are real-time ultrasound findings in partially and completely denervated muscles of 30 patients with focal neuropathy and various other disorders of the second motor neuron. Sonographic scans of affected muscles are analyzed in conjunction with unaffected muscles of the same individual, under identical examination conditions. Initial pathological ultrasound changes could be detected as soon as 2 weeks after an acute neurogenic lesion. In denervation, the echodensity of the muscle was high and the normal intramuscular pattern was decomposed. Findings were more intense in severe and longstanding denervation. Ultrasound-indicated pathology correlated highly (chi-square: P less than 0.001) with pathological spontaneous activity detected by electromyography. Focal and systemic neuropathies showed no differences in ultrasound pathology. Six cases with central motor palsy had normal sonograms. Poor spatial resolution of real-time ultrasonography--as compared with CT and MRI--is compensated by its bedside availability, frequent repeatability without patient risk and discomfort, and its in vivo correlation of muscle morphology with muscle function.

55 citations


Journal ArticleDOI
TL;DR: It is concluded that drug combination chemotherapy effects at the cellular level may be extremely heterogeneous.
Abstract: Combination chemotherapy is widely employed in clinical oncology; however, there is no generally accepted model to evaluate individual tumour susceptibility to a given drug combination protocol. We therefore investigated the drug interaction of ifosfamide (4-hydroxyperoxy-ifosfamide) and ACNU in a recently developed in vitro model of paired sequential combination chemotherapy in primary and metastatic malignant brain tumours. A long-term standard [6,3-3H]-thymidine-incorporation assay, employing a liquid scintillation counting protocol, was selected to assess the drug sensitivity of human tumours. In vitro drug exposures were derived from correlating in vivo-(systemic and CNS) and in vitro-pharmacokinetic drug parameters. In combination experiments tumour cells were treated sequentially by two drugs in both sequences: drug exposures were calculated for 2 h with a 1-h drug-free interval in between. "Cut-off" concentrations (maximum in vitro exposure doses) were calculated as 1.74 microM (for primary CNS tumours: 0.58 microM) for ifosfamide and 5.4 microM (for primary CNS tumours: 1.33 microM) for ACNU. Dose/response relations were derived from isotope incorporation rates after cells had grown for approximately five population doubling times. Combination isoboles were plotted after drug doses had been transformed into "equieffective doses", enabling comparison of drug combination effects. In all three glioblastomas (with CNS exposure dose) an additive or supra-additive effect could be observed in either sequence (in one tumour a biphasic additive isobole was found for both sequences). Out of three bronchial carcinomas (small-cell type, brain metastases) in two non-identical sequences a supra-additive effect was observed in two tumours, with antagonistic effects in the third tumour. In all three malignant melanomas and in one renal carcinoma antagonistic effects were observed, whereas in a second renal carcinoma supra-additive effects were demonstrated for both sequences. We conclude that drug combination chemotherapy effects at the cellular level may be extremely heterogeneous.

1 citations


Book ChapterDOI
01 Jan 1991
TL;DR: In der klinischen Neuroonkologie wird derzeit wie in der ubrigen Onkologies eine kombinierte Chemotherapie angestrebt, sodas wir uns darum bemuhten, ein in vitro-Modell zur Vorhersage der Substanzinteraktion einer kombi-nierten ChemotherAPie zu entwickeln.
Abstract: Das von Nowell (1) eingefuhrte Tumorstammzellmodell und der von Hamburger und Salmon (2) entwickelte Tumorstammzellassay fuhrten zu einer Vielzahl pratherapeutischer in vitro-Ansatze, die das klinische Ansprechen von Tumoren auf die Chemotherapie abschatzen wollten. Fur maligne Gliome existieren eine Reihe von Verfahren (u. a. R/3.), die einesehr gute (Correlation der pradiktiven Testergebnisse mit den tatsachlichen klinischen Verlaufen chemotherapierter Tumorpatienten erlauben. In der klinischen Neuroonkologie wird derzeit wie in der ubrigen Onkologie eine kombinierte Chemotherapie angestrebt, sodas wir uns darum bemuhten, ein in vitro-Modell zur Vorhersage der Substanzinteraktion einer kombi-nierten Chemotherapie zu entwickeln. Es gait hierbei das von Loewe und Muischnik (4) entwickelte Modell der Kombinationsisobolen auf die in vitro- Chemotherapie anzuwenden und gleichzeitig die in vivo und in vitro pharmakokinetischen Daten der verwandten Substanzen einzusetzen.