Biomedical subjects

K Voigt

Publications and source records attributed to K Voigt.

At least 19 recordsLinked to original sources

PubMed2001

Phylogeny and origin of 82 zygomycetes from all 54 genera of the Mucorales and Mortierellales based on combined analysis of actin and translation elongation factor EF-1alpha genes.

True fungi (Eumycota) are heterotrophic eukaryotic microorganisms encompassing ascomycetes, basidiomycetes, chytridiomycetes and zygomycetes. The natural systematics of the latter group, Zygomycota, are very poorly understood due to the lack of distinguishing morphological characters. We have determined sequences for the nuclear-encoded genes actin (act) from 82 zygomycetes representing all 54 currently recognized genera from the two zygomycetous orders Mucorales and Mortierellales. We also determined sequences for translation elongation factor EF-1alpha (tef) from 16 zygomycetes (total of 96,837 bp). Phylogenetic analysis in the context of available sequence data (total 2,062 nucleotide positions per species) revealed that current classification schemes for the mucoralean fungi are highly unnatural at the family and, to a large extent, at the genus level. The data clearly indicate a deep, ancient and distinct dichotomy of the orders Mucorales and Mortierellales, which are recognized only in some zygomycete systems. Yet at the same time the data show that two genera - Umbelopsis and Micromucor - previously placed within the Mortierellales on the basis of their weakly developed columella (a morphological structure of the sporangiophore well-developed within all Mucorales) are in fact members of the Mucorales. Phylogenetic analyses of the encoded amino acid sequences in the context of homologues from eukaryotes and archaebacterial outgroups indicate that the Eumycota studied here are a natural group but provide little or no support for the monophyly of either zygomycetes, ascomycetes or basidiomycetes. The data clearly indicate that a complete revision of zygomycete natural systematics is necessary.

Actins↗

PubMed2001

Strain typing of polish Leptosphaeria maculans isolates supports at the genomic level the multi-species concept of aggressive and non-aggressive strains.

47 Polish isolates of the blackleg fungus Leptosphaeria maculans (Phoma lingam) were compared with eight well-defined reference strains from Germany, France, Denmark, Australia and one Polish isolate of Phoma nigrificans. The isolates were tested (i) for growth characteristics, (ii) for their ability to form sirodesmins, (iii) for cellulolytic enzymes, and (iv) for pathotype-differentiating molecular markers generated by RAPD-PCR, PCR analysis with pathotype-specific primer pairs and PFGE. With two exceptions all Polish isolates do not form sirodesmins. grow rapidly without penetrating into the substrate and form in most cases yellow or brown pigments in Czapek-Dox liquid cultures. With respect to cellulase secretion and molecular fingerprinting Polish A strains (aggressive) fit into the general picture of the aggressive pathotype group, whereas the NA isolates (non-aggressive) display a higher degree of heterogeneity. This matches with inoculation tests on rape seedlings, which revealed a considerable number of isolates ranging in aggressivity between the conventional A and NA pathotype group. Molecular fingerprinting techniques unequivocally sorted intermediately aggressive isolates into the NA pathotype group. Isolate Ph Bial, which produces sirodesmin but groups within NA isolates according to molecular and physiological markers, may represent a novel third group besides A and NA strains with intermediate aggressivity (IA). We hybridized Southern blots of electrophoretically separated chromosomes with radioactively labelled PCR fragments used for differentiation between A and NA isolates. The specificity of diagnostic PCR amplicons is reflected at the genomic level. The A probe reveals a single hybridizing chromosome exclusively in A strains. The NA probe reveals several chromosomes and is specific for the NA pathotype group. Chromosomes from intermediately aggressive strains are equally well recognized by the NA probe as are Polish isolates with low aggressivity and give no signal with the A probe. Both diagnostic DNA sequences are highly specific for the pathotype group they were derived from. The lack of correspondence of both genetic elements between A and NA strains strongly supports the idea of ascribing the pathotype groups to different species. Whereas the A pathotype group is genetically homogeneous and congruent with the species Leptosphaeria maculans, the NA group needs to be revised taxonomically. NA isolates will presumably have to be split into several independent species.

Ascomycota↗

PubMed2000

Correlated and uncorrelated regions in heart-rate fluctuations during sleep.

Healthy sleep consists of several stages: deep sleep, light sleep, and rapid eye movement (REM) sleep. Here we show that these sleep stages can be characterized and distinguished by correlations of heart rates separated by n beats. Using the detrended fluctuation analysis (DFA) up to fourth order we find that long-range correlations reminiscent to the wake phase are present only in the REM phase. In the non-REM phases, the heart rates are uncorrelated above the typical breathing cycle time, pointing to a random regulation of the heartbeat during non-REM sleep.

Biometry↗

PubMed2000

Classification of acquired lesions of the corpus callosum with MRI.

MRI has facilitated diagnostic assessment of the corpus callosum. Diagnostic classification of solitary or multiple lesions of the corpus callosum has not attracted much attention, although signal abnormalities are not uncommon. Our aim was to identify characteristic imaging features of lesions frequently encountered in practice. We reviewed the case histories of 59 patients with lesions shown on MRI. The nature of the lesions was based on clinical features and/or long term follow-up (ischaemic 20, Virchow-Robin spaces 3, diffuse axonal injury 7, multiple sclerosis 11, hydrocephalus 5, acute disseminated encephalomyelitis 5, Marchiafava-Bignami disease 4, lymphoma 2, glioblastoma hamartoma each 1). The location in the sagittal plane, the relationship to the borders of the corpus callosum and midline and the size were documented. The 20 ischaemic lesions were asymmetrical but adjacent to the midline; the latter was involved in new or large lesions. Diffuse axonal injury commonly resulted in large lesions, which tended to be asymmetrical; the midline and borders of the corpus callosum were always involved. Lesions in MS were small, at the lower border of the corpus callosum next to the septum pellucidum, and crossed the midline asymmetrically. Acute disseminated encephalomyelitis and the other perivenous inflammatory diseases caused relatively large, asymmetrical lesions. Hydrocephalus resulted in lesions of the upper part of the corpus callosum, and mostly in its posterior two thirds; they were found in the midline. Lesions in Marchiafava-Bignami disease were large, often symmetrically in the midline in the splenium and did not reach the edge of the corpus callosum.

Adolescent↗

PubMed2000

Mechanisms of changes in lymphocyte numbers after psychological stress.

In the field of psychoneuroimmunology it has become obvious that the immune system is governed by multiple influences from the central nervous system. One approach to verify these interactions can be seen in stress research. While the phenomenon of stress-induced changes in immunological processes is widely accepted, more recent studies focus on possible moderators and mechanisms of these responses. Within this research strategy it became evident that catecholamine increases upon stress are of major importance for the frequently observed mild leukocytosis. The present study was conducted to investigate whether the often observed stress-induced increases in the number of peripheral lymphocyte subsets depends on the amount of epinephrine or norepinephrine release. Moreover, the question was addressed whether high or low catecholamine release is related to subjective ratings on discomfort. Using a "public speaking paradigm", we were able to replicate previous findings of high increases in the absolute number of CD8+ and CD56+ cells in peripheral blood. Moreover, when dividing subjects into high and low catecholamine responders, the amount of change was significantly larger in catecholamine responders irrespective of whether norepinephrine or epinephrine was used for grouping the subjects. However, high and low catecholamine responders did not differ with respect to subjective ratings on discomfort. The data are discussed with respect to underlying mechanisms in catecholamine-induced lymphocyte migration and possible reasons for the mismatch between objective and subjective indicators of stressor efficacy.

Adult↗

PubMed2000

A role for preirradiation PCV chemotherapy for oligodendroglial brain tumors.

Oligodendroglial tumors have been identified as a subgroup of glial neoplasms with a distinctly better response to chemotherapy and overall survival than purely astrocytic gliomas. Here we report our experience with adjuvant postirradiation and preirradiation chemotherapy using procarbazine, lomustine, and vincristine (PCV) in 27 patients with WHO grade II or III oligodendroglioma or oligoastrocytoma. The efficacy of chemotherapy was assessed according to the Macdonald response criteria (complete response, CR; partial response, PR; stable disease, SD; progressive disease, PD) and progression-free survival intervals by computed tomography or magnetic resonance imaging. First, we confirm that PCV salvage therapy for patients progressing after radiotherapy is highly effective (n = 11, 1 CR, 5 PR, 5 SD; median progression-free survival has not yet been reached, but is longer than 18 months). Second, 3 patients who received radiotherapy plus PCV as first-line therapy achieved CR and 2 achieved SD, and all 5 are progression-free with a median follow-up of 12 months. Third, given these encouraging results, 11 patients received postoperative preirradiation PCV chemotherapy and were given radiotherapy only upon progression. Preirradiation PCV chemotherapy was also effective (2 CR, 3 PR, 6 SD; median progression-free survival has not been yet reached, but is longer than 14 months). Patients with anaplastic oligoastrocytomas were as likely to respond to PCV chemotherapy, as were patients with anaplastic oligodendroglioma. Three patients who had previously responded to PCV were successfully treated with a second course of PCV upon recurrence. PCV chemotherapy was also effective in patients with leptomeningeal spread of oligodendrogliomas. A randomized prospective trial is required to compare the effectiveness and neurotoxicity of first-line PCV chemotherapy followed by radiotherapy to the traditional reverse sequence.

Adolescent↗

PubMed2000

The role of tumor necrosis factor (TNF) in the febrile and metabolic responses of rats to intraperitoneal injection of a high dose of lipopolysaccharide.

The role of tumor necrosis factor (TNF) in the febrile and metabolic responses of rats to intraperitoneal injection of a high dose of lipopolysaccharide Injection of a high dose of lipopolysaccharide (LPS) induces a septic-shock-like state, which can be accompanied by phases of hypothermia and phases of fever. In the present study we monitored body core temperature and locomotor activity, both by remote radiotelemetry, as well as changes in food intake, body mass and water intake for 3 days after an intraperitoneal (i.p.) injection of a high dose of LPS (5 mg/kg) along with sterile 0.9% saline or a neutralizing form of the soluble tumor necrosis factor (TNF) type 1 receptor (referred to as TNF-binding protein, TNF bp). Intraperitoneal injection of LPS rapidly induced high concentrations of TNF in the plasma and peritoneal lavage fluid. TNF was undetectable in the plasma and peritoneal lavage fluid of animals co-injected with LPS and TNF bp, implying neutralization of peripheral bioactive TNF. Administration of LPS induced hypothermia by about 1.5 degrees C, which lasted for 5 h after injection. During the light-time periods of days 2 and 3 after injection, the rats developed a robust fever. Treatment with TNF bp resulted in a faster recovery from the LPS-induced hypothermia so that the rats developed a pronounced fever on the day of injection. Locomotor activity during night-time periods was suppressed in LPS-treated animals. The LPS-induced depression of night-time activity was not antagonized by co-injection of TNF bp. On day 1 after the injection of LPS, food intake reduced to virtually zero, water intake fell to about 30% of the control value and body mass dropped by 25 g (about 10% of total body mass). With the exception of body mass, these variables recovered slowly during days 2 and 3 after LPS injection, but did not reach the control values. The LPS-induced decreases in food intake, body mass and water intake were significantly attenuated by the treatment with TNF bp. These results confirm that TNF contributes significantly to the rats' responses to intraperitoneal injection of a high dose of LPS. The fact that treatment with TNF bp accelerated and improved the rats' ability to develop a febrile response supports the view that the fever is beneficial, since all other metabolic responses measured in this study were normalized more effectively in those rats that developed a faster and more pronounced increase in body temperature.

Animals↗

PubMed2000

Reliable amplification of actin genes facilitates deep-level phylogeny.

The gene for actin as a highly conserved and functionally essential genetic element is developing into a major tool for phylogenetic analysis within a broad organismic range. We therefore propose a set of universally applicable primers that allow reliable amplification of actin genes. For primer construction the amino acid sequences of 57 actin genes comprising fungi, animals, plants and protists were analysed, aligned and used for the definition of six well-conserved regions which are suitable as priming sites in PCR amplification experiments. Ten primers were designed for specific in vitro amplification of actin gene fragments from a wide range of microorganisms. The corresponding gene fragments provide a strong basis to isolate nearly complete actin genes for further molecular characterization and for establishing phylogenies based on actin gene trees.

Absidia↗

PubMed2000

Comparative evaluation of chemical and environmental online and CD-ROM databases

In a constantly expanding world of chemical and environmental information sources, the need for their evaluation gains more and more importance. This paper presents a comparative evaluation of datasources of online databases and databases on CD-ROM (called CD-ROMs in this paper) in the field of environmental chemicals. The approach is based on research results gained in the years 1996/1997. The authors are aware that changes in the database industry may lead to different results. Before the actual evaluation process can be carried out, two major procedures are necessary, namely, the selection of sets of datasources and the definition of evaluation criteria. In order to perform the difficult task of an evaluation based on several criteria, a general order relation has to be introduced. Methods of partially ordered set theory are applied, and the results are visualized by the technique of Hasse diagrams. On the basis of these evaluation results, the datasources are grouped and then evaluated. It will be shown that there are groups of datasources with quite specific property profiles, and only two groups turn out to be relatively better than the others.

Journal Article↗

PubMed2000

MEN1 at work.

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Humans↗

PubMed2000

MR imaging and (1)H spectroscopy of brain metabolites in hepatic encephalopathy: time-course of renormalization after liver transplantation.

PURPOSE: To evaluate changes in hydrogen 1 magnetic resonance (MR) spectroscopic findings in overt or subclinical hepatic encephalopathy (HE) after liver transplantation and to compare these changes with clinical outcomes and basal ganglia high signal intensity (BGH). MATERIALS AND METHODS: Twenty-two patients scheduled for liver transplantation and 17 healthy control subjects were examined with (1)H MR spectroscopy and standard nonenhanced MR imaging. Eight patients underwent complete MR imaging and (1)H spectroscopic examinations before liver transplantation and at 3-4-week, 12-28-week, and 10-12-month follow-up after liver transplantation. RESULTS: Before liver transplantation, typical (1)H spectroscopic changes-decreased myo-inositol (mI)/creatine (Cr) and choline (Cho)/Cr ratios and an elevated glutamine and glutamate (Glx)/Cr ratio-were found in 21 patients. Eighteen patients had BGH at T1-weighted imaging. Three to 7 months after liver transplantation, the mI/Cr and Glx/Cr ratios were within the normal range in five of eight and eight of eight patients, respectively, without any residual signs of subclinical or overt HE; however, at MR imaging, seven patients still had BGH. CONCLUSION: After successful liver transplantation, renormalization of HE-specific brain metabolite changes is detected at (1)H spectroscopy and precedes the disappearance of BGH. The neuropsychologic signs of subclinical or overt HE follow the changes seen at (1)H spectroscopy rather than those seen at MR imaging.

Adult↗

PubMed2000

The role of local induction of tumor necrosis factor by LPS within a subcutaneous air pouch in the development of a febrile response in guinea pigs.

In rats, fever can be induced by injection of bacterial lipopolysaccharide (LPS) into a subcutaneous air pouch. This febrile response is in part dependent on the local action of interleukin-1beta within the pouch. In the present study, we tried to find out if this model of fever induction can be applied in guinea pigs and if the local LPS-induced formation of tumor necrosis factor-alpha (TNF-alpha) participates in the development of the febrile response. A dose of 100 microg/kg LPS was injected into a subcutaneous air pouch along with solvent (0.9% saline), or 100 mg/kg pentoxifylline, or 1 mg/animal soluble 55-kD TNF receptor (referred to as TNF-binding protein, TNF bp). The mean LPS-induced concentration of TNF in the lavage of the air pouch (measured 60 min after injection) was 17,765 pg/ml in animals injected with LPS and solvent. This value was reduced to 7,631 pg/ml if pentoxifylline was injected along with LPS into the pouch. If LPS was injected along with TNF bp, no bioactive TNF was detected in the lavage of the air pouch. Simultaneously, TNF was measured in blood plasma. Circulating concentrations of TNF were about 5-8% of the values detected in the lavage of the air pouch (mean values: 1,366 pg/ml in response to LPS plus solvent; 377 pg/ml in response to LPS plus pentoxifylline; no circulating TNF at all in response to LPS plus TNF bp). These data indicated a small spill-over of TNF from the air pouch into the circulation. Neither the reduction of local TNF formation in the air pouch by pentoxifylline nor the complete neutralization of TNF within the pouch by TNF bp resulted in a significant attenuation of the febrile response induced by injection of LPS into the subcutaneous air pouch. If there were an activation of cutaneous nerves to induce fever by a local formation of cytokines within the air pouch, TNF would not represent a likely candidate to be responsible for such a neural stimulation.

Animals↗

PubMed2000

Stability of the disulfide bond in an avidin-biotin linked chimeric peptide during in vivo transcytosis through brain endothelial cells.

Drug delivery of potential neuropharmaceuticals with poor intrinsic permeability through the blood-brain barrier (BBB), such as peptides, is facilitated by coupling to a vector that undergoes receptor-mediated transcytosis through the endothelial cells of brain microvessels. When cleavable disulfide linkers are used in the synthesis of such "chimeric peptides", it is crucial that the S-S-bridge is stable during transcytosis. Cleavage within endothelial cells could result in sequestration of the drug moiety instead of passage through the BBB. In the present study the metabolically stable opioid peptide [3 H]DALDA ([3 H]Tyr-DArg-Phe-Lys-NH2 ) was used as a model drug. It was monobiotinylated with the cleavable biotin reagent sulfosuccinimidyl 2-(biotinamido)ethyl-1,3'-dithiopropionate (NHS-SS-biotin) to obtain bio-[3 H]DALDA. The biotinylated peptide was then bound to a vector for brain delivery after intravenous injection in rats, a covalent conjugate of streptavidin and the transferrin receptor monoclonal antibody, OX26. Compared to peptide without vector, brain uptake of bio-[3 H]DALDA after was increased 18-fold to reach 0.12% of the injected dose per g tissue. Transcranial microdialysis was performed for 60 min after an intravenous bolus of chimeric peptide, followed by reverse phase HPLC of dialysate. Stability of the chimeric peptide during transport through the BBB into brain extracellular fluid was concluded from the absence of a peptide peak generated by disulfide cleavage.

Analgesics↗

PubMed2000

Role of hydrodynamic processes in the pathogenesis of peritumoral brain edema in meningiomas.

OBJECT: In a prospective study, 28 patients with 32 intracranial meningiomas were examined to determine the role of hydrodynamic interaction between tumor and surrounding brain tissue in the pathogenesis of peritumoral brain edema. METHODS: Gadolinium-diethylenetriamine pentaacetic acid (Gd-DPTA), an extracellular contrast agent used for routine clinical imaging, remains strictly extracellular without crossing an intact blood-brain barrier. Therefore, it is well suited for investigations of hydrodynamic extracellular mechanisms in the development of brain edema. Spin-echo T1-weighted magnetic resonance images were acquired before and after intravenous administration of 0.2 mmol/kg Gd-DPTA. Additional T1-weighted imaging was performed 0.6, 3.5, and 6.5 hours later. No significant Gd-DPTA diffused from tumor into peritumoral brain tissue in 12 meningiomas without surrounding brain edema. In contrast, in 17 of 20 meningiomas with surrounding edema, contrast agent in peritumoral brain tissue was detectable after 3.5 hours and 6.5 hours. In three of 20 meningiomas with minimum surrounding edema (<5 cm3), contrast agent effusion was absent. After 3.5 hours and 6.5 hours strong correlations of edema volume and the maximum distance of contrast spread from the tumor margin into adjacent brain parenchyma (r = 0.84 and r = 0.87, respectively, p < 0.0001) indicated faster effusion in larger areas of edema. CONCLUSIONS: The results of this study show that significant contrast agent effusion from the extracellular space of the tumor into the interstitium of the peritumoral brain tissue is only found in meningiomas with surrounding edema. This supports the hypothesis that hydrodynamic processes play an essential role in the pathogenesis of peritumoral brain edema in meningiomas.

Adult↗

PubMed2000

Heart rate variability during sleep stages in normals and in patients with sleep apnea.

Heart rate and heart rate variability are under the control of the autonomous nervous system. It can be assumed that during sleep internal influences dominate the autonomous nervous system. During the different sleep stages heart rate regulation differs in normal subjects. Obstructive sleep apnea is a disorder which has its origin in sleep and has strong modulating effects on the autonomous nervous system with prominent heart rate variations in consequence. In order to separate the influences of sleep stages and sleep apnea on heart rate variability we applied detrended fluctuation analysis in 12 healthy subjects and 20 patients with sleep apnea. We could show that the differences between sleep stages observed in healthy subjects were still present in subjects with sleep apnea despite their cyclical variation in heart rate. We conclude, that detrended fluctuation analysis is able to separate the influences of sleep stages and sleep apnea on heart rate variability.

Autonomic Nervous System↗

PubMed1999

Dose-dependent attenuation of lipopolysaccharide-fever by inhibitors of inducible nitric oxide-synthase in guinea pigs.

Different doses of aminoguanidine or S-methylisothiourea, both predominantly inhibitors of the inducible form of nitric oxide (NO)-synthase, were injected into the arterial circulation of guinea pigs alone or along with 10 microg/kg bacterial lipopolysaccharide. Doses of 10 mg/kg, 50 mg/kg or 250 mg/kg aminoguanidine per se had no influence on abdominal temperature of guinea pigs. Only the highest dose of aminoguanidine (250 mg/kg) completely suppressed the first phase of the biphasic febrile response to lipopolysaccharide-injections. Lipopolysaccharide-fever was not modulated by administration of 10 mg/kg or 50 mg/kg aminoguanidine, when compared to fever in response to injections of lipopolysaccharide along with solvent. Doses of 10 mg/kg or 50 mg/kg S-methylisothiourea did not alter abdominal temperature while a dose of 250 mg/kg S-methylisothiourea had a lethal effect in guinea pigs. The febrile response to lipopolysaccharide was unimpaired by administration of 10 mg/kg S-methylisothiourea, while a dose of 50 mg/kg again attenuated fever predominantly by a suppression of the first fever phase. None of the applied doses of aminoguanidine or S-methylisothiourea resulted in a significant attenuation of the lipopolysaccharide-induced circulating cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6. The drugs themselves, without lipopolysaccharide-injections, did not enhance or reduce circulating levels of the investigated cytokines. The results indicate that endogenous NO may participate in the induction of lipopolysaccharide-fever and that fever suppression by systemic administration of NO-synthase inhibitors occurs independently from the lipopolysaccharide-induced circulating cytokines.

Animals↗

PubMed1999

Echo planar perfusion imaging with high spatial and temporal resolution: methodology and clinical aspects.

The purpose of the present study was to analyse specific advantages of calculated parameter images and their limitations using an optimized echo-planar imaging (EPI) technique with high spatial and temporal resolution. Dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) was performed in 12 patients with cerebrovascular disease and in 13 patients with brain tumours. For MR imaging of cerebral perfusion an EPI sequence was developed which provides a temporal resolution of 0.68 s for three slices with a 128 x 128 image matrix. To evaluate DSC-MRI, the following parameter images were calculated pixelwise: (1) Maximum signal reduction (MSR); (2) maximum signal difference (delta SR); (3) time-to-peak (Tp); and (4) integral of signal-intensity-time curve until Tp (SInt). The MSR maps were superior in the detection of acute infarctions and delta SR maps in the delineation of vasogenic brain oedema. The time-to-peak (Tp) maps seemed to be highly sensitive in the detection of poststenotic malperfused brain areas (sensitivity 90%). Hyperperfused areas of brain tumours were detectable down to a diameter of 1 cm with high sensitivity (> 90%). Distinct clinical and neuroradiological conditions revealed different suitabilities for the parameter images. The time-to-peak (Tp) maps may be an important advantage in the detection of post-stenotic "areas at risk", due to an improved temporal resolution using an EPI technique. With regard to spatial resolution, a matrix size of 128 x 128 is sufficient for all clinical conditions. According to our results, a further increase in matrix size would not improve the spatial resolution in DSC-MRI, since the degree of the vascularization of lesions and the susceptibility effect itself seem to be the limiting factors.

Adult↗

PubMed1999

[The significance of morphological changes in the brain-tumor border area for the pathogenesis of brain edema in meningiomas: magnetic resonance tomographic and intraoperative studies].

PURPOSE: The aim of the study was to verify a possible correlation between macroscopic changes of the brain-tumor interface (BTI) and the development of a peritumoral brain edema in meningiomas. METHODS: 27 meningiomas were investigated in this prospective study using an optimized inversion-recovery (IR) sequence. After i.v. administration of 0.2 mmol Gd-DTPA/kg axial and coronary images were acquired (slice thickness = 2 mm). The distances of signal altered cortex and obliterations of the subarachnoid space (SAS) were measured at the BTI and related to the pial tumor circumference (cortical-index and SAS-index). Intraoperatively the BTI was divided into the following categories: 0: SAS not obliterated, 1: SAS partially obliterated, 2: direct contact between tumor and white matter, 3: tumor infiltration into brain. RESULTS: Edema-associated meningiomas showed a significantly (p = 0.0001) increased SAS-index (0.47 vs. 0.07) and cortical index (0.45 vs. 0.0) compared to cases without edema. Intraoperatively 95% of meningiomas with brain edema showed SAS-obliterations, compared to 50% of cases without an edema. CONCLUSIONS: Arachnoid adhesions at the BTI with obliteration of the SAS seem to play an essential role in the induction of brain edema in meningiomas.

Adult↗