Treatment of vertebro-basilar aneurysms

Summary In continuation of investigations on classification and treatment of ICA-system aneurysms and on the classification of the vertebro-basilar-system aneurysms their treatment has been discussed. Based on this, classification has been improved and the preoperative topographic diagnosis and the choice of approach have been influenced. The operative management has been pioneered by C. G. Drake, who described the technique in detail on hand of his enormous experience with 469 aneurysms of the vertebro-basilar-system (13). The necessity of a normal aneurysm neurosurgeon treating such aneurysms requires certain modifications of indication, approach and dissection. In a personal statement based on 35 VB-aneurysms (6 per cent) the strategy of handling these aneurysms has been developed (45). Microsurgical technique is regarded absolutely necessary. Thetransoral transclival access to aneurysms of the lower clivus should be included in the approaches, similarly to the transsphenoidal operations. It facilitates the direct isolation in a very difficult region.Electrothermic dissection of the aneurysm diminishes the risk of rupture during the isolation of the sack and facilitates the isolation of the neck. The statistics of Drake provide full data for the prognosis of these aneurysms. It is to note that in the recent time the results reported from different centres became more and more similar. The embolization of large bulbous or spheric and giant aneurysms by inflatable balloon-technique possibly may replace some risky direct or indirect operations.

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Zusammenfassung In Fortsetzung unserer Untersuchungen über die mikrochirurgische Klassifikation und Behandlung der Aneurysmen des A. carotis interna-Systems, sowie die Klassifikation der Aneurysmen des Vertebro-Basilaris-Gebietes befaßt sich der Beitrag mit der Therapie letzterer. Die moderne Klassifikation und parallel dazu die präoperative angiographische Diagnostik haben die Wahl der Craniotomie und des direkten Zugangs zum Aneurysma unmittelbar beeinflußt. Die operative Behandlung ist im wesentlichen das Werk eines Mannes — Charles Drake — der die Technik anhamd seines großen Krankengutes von derzeit 469 Fällen im Detail beschrieben hat. Die Notwendigkeit für den normalen Aneurysma-Neurochirurgen, derartige Aneurysmen zu behandeln, erfordert nach meiner Überzeugung gewisse Modifikationen der Indikation, des Zuganges und der Präparation. In einer persönlichen Stellungnahme, die sich auf eine Erfahrung von 35 Aneurysmen des Vertebro-Basilaris-Gebietes stützt (6%), werden die Prinzipien des Vorgehens erläutert. Die mikrochirurgische Technik ist unerläßlich.Dertransorale transclivale Zugang sollte für bestimmte Aneurysmen der A. basilaris ebenso durchgeführt werden, wie der transsphenoidale Zugang für Hypophysenadenome selbstverständlich geworden ist. Er erleichtert die direkte Freilegung in dem sehr risikoreichen Gebiet von Brücke und Hirnnerven.Dieelektrothermische Dissektion verringert das Risiko der Ruptur während der Präparation und erleichtert die Isolierung des Aneurysmahalses.Drake's Statistik enthält alle Einzelheiten über die Prognose der verschiedenen Vertebro-Basilaris-Aneurysmen als Maßstab für das eigene Resultat. Erfahrungen der letzten Jahre aus verschiedenen Kliniken zeigen, daß die Ergebnisse sich mehr und mehr angleichen.DieEmbolisation großer bulböser und sphärischer Aneurysmen und der Riesenaneurysmen durch die Ballon-Technik erscheint geeignet, risikoreiche direkte oder indirekte Operationen zumindest teilweise zu ersetzen.

     

51. Schädel-Hirn-Verletzungen

Zusammenfassung Erfahrungen der Kriegschirurgie seit dem 1. Weltkrieg, vor allem im 2. Weltkrieg, in Deutschland durch W. Tönnis, in Korea, Vietnam und Libanon belegen die Notwendigkeit sofortiger definitiver Versorgung der penetrierenden Hirnverletzungen durch neurochirurgische Ärzte- und Schwestern-Gruppen. Die moderne Diagnostik. durch Computer-Tomographie mit Nachweis jeder Verletzungsform und Komplikation und Ausschluß von Fehlbeurteilungen und die heutige Neurochirurgie bieten noch bessere Voraussetzungen für eine optimale Versorgung. In die Ausbildung der Chirurgen mu die Neurotraumatologie vordringlich aufgenommen werden.     

Spatial, temporal and subcellular localization of islet-brain 1 (IB1), a homologue of JIP-1, in mouse brain

Islet-brain 1 (IB1) was recently identified as a DNA-binding protein of the GLUT2 gene promoter. The mouse IB1 is the rat and human homologue of the Jun-interacting protein 1 (JIP-1) which has been recognized as a key player in the regulation of c-Jun amino-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathways. JIP-1 is involved in the control of apoptosis and may play a role in brain development and aging. Here, IB1 was studied in adult and developing mouse brain tissue by in situ hybridization, Northern and Western blot analysis at cellular and subcellular levels, as well as by immunocytochemistry in brain sections and cell cultures. IB1 expression was localized in the synaptic regions of the olfactory bulb, retina, cerebral and cerebellar cortex and hippocampus in the adult mouse brain. IB1 was also detected in a restricted number of axons, as in the mossy fibres from dentate gyrus in the hippocampus, and was found in soma, dendrites and axons of cerebellar Purkinje cells. After birth, IB1 expression peaks at postnatal day 15. IB1 was located in axonal and dendritic growth cones in primary telencephalon cells. By biochemical and subcellular fractionation of neuronal cells, IB1 was detected both in the cytosolic and membrane fractions. Taken together with previous data, the restricted neuronal expression of IB1 in developing and adult brain and its prominent localization in synapses suggest that the protein may be critical for cell signalling in developing and mature nerve terminals.     

Vascular endothelial growth factor and p53 expressions in liver and abdominal metastases from colon cancer.

OBJECTIVE: To determine the relationship between p53 overexpression and vascular endothelial growth factor (VEGF) upregulation in liver and abdominal metastases from colon cancer. The analysis in the two metastatic sites was carried out to evaluate the potential role of microenvironment in the molecular regulation of VEGF. METHODS: Bioptic specimens of liver and abdominal metastases from colon carcinomas were examined by immunohistochemistry for p53 and VEGF expressions. Consecutive cases with assessable tumor tissue were selected. RESULTS: The study population consisted of 24 cases having liver metastases and 34 cases having abdominal metastases. Abdominal metastases showed a higher number of VEGF-positive cases and a higher intensity of VEGF immunoreactivity than liver metastases did (p = 0.01). The combined analysis of p53 and VEGF showed a strong association between the two markers in the 24 liver metastases; 9 cases were VEGF positive/p53 positive and 15 cases were VEGF negative/p53 negative. This relationship was not found in the 34 abdominal metastases, which showed concordance between the two markers in 9 VEGF-positive/p53-positive cases only. CONCLUSIONS: Microenvironment factors like hypoxia may have a predominant role in inducing VEGF expression and they can override the molecular control of p53 on VEGF.     

CT-verified intracranial calcifications and contrast enhancement in acute disseminated encephalomyelitis: a case report

Acute disseminated encephalomyelitis (ADEM) is a demyelinating disease which follows viral infection or vaccination. We report the CT findings in a 13-year-old boy with ADEM after infection with Epstein-Barr virus. After 11 days, the patient developed intracranial calcifications in addition to demyelinating lesions. This is a rare finding in ADEM. Received: 1 August 1997 Accepted: 9 January 1998     

Neurons immunoreactive for vasoactive intestinal polypeptide in the rat primary somatosensory cortex: morphology and spatial relationship to barrel-related columns

Vasoactive intestinal polypeptide (VIP) in neocortex affects neuronal excitability as well as cortical blood flow and metabolism. Interneurons immunoreactive for VIP (VIP-IR neurons) are characterized by their predominantly bipolar appearance and the radial orientation of their main dendrites. In order to determine whether the morphology of VIP-IR neurons is related to the functional organization of the cortex into vertical columns, we combined both immunostaining of neurons containing VIP and cytochrome oxidase histochemistry for visualizing barrels, morphological layer IV correlates of functional columns, in the primary somatosensory (barrel) cortex of rats. VIP-IR neurons were localized in supragranular (48%), granular (16%), and infragranular layers (36%) as well as in the white matter. In the granular layer, a clear trend that more neurons were located in interbarrel septa rather than in barrels could be observed, resulting in a neuronal density which was about one-third higher in the septal area. VIP-IR neurons from the different cortical layers were three-dimensionally reconstructed from serial sections by using a computer microscope system. The neurons were mostly bipolar. Striking morphological differences in both axonal and dendritic trees were found between neurons whose cell bodies were located in supragranular, granular, and the upper part of infragranular layers, and those whose cell bodies were located in the area below. The former had dendrites which often reached layer I, where they bifurcated several times, and axonal trees which were particularly oriented vertically, with a tangential extent smaller than the width of barrels. Therefore, these neurons were mostly confined to either a barrel- or septum-related column. By contrast, the dendrites of neurons of the latter group did not reach the granular layer. Furthermore, these neurons had axons with sometimes very long horizontal collaterals, which often spanned two, in one case three, barrel columns. It is proposed that the differential morphology of neurons with different locations as stated above parallels to some extent the divergence of input streaming into the corresponding layer-defined areas. As a possible consequence of this, VIP-IR neurons may be capable of adapting the excitability and metabolism of cortical compartments either in a spatially limited or more extensive way.     

mGluR5 antagonist MPEP reduces ethanol-seeking and relapse behavior.

The glutamatergic system plays an important role in mediating neurobehavioral effects of ethanol. Metabotropic glutamate receptors subtype 5 (mGluR5) are modulators of glutamatergic neurotransmission and are abundant in brain regions known to be involved in ethanol self-administration. Here, we studied the effects of 2-methyl-6-(phenylethynyl)-pyridine (MPEP), a highly potent, noncompetitive mGlu5 receptor antagonist, on voluntary ethanol consumption and relapse behavior. For this purpose, we used two models for the measurement of relapse behavior: (i) reinstatement of ethanol-seeking behavior by drug-associated cues and (ii) the alcohol deprivation effect in long-term ethanol-consuming rats. In the first set of experiments, rats were trained to lever press for ethanol in the presence of a distinct set of cues. After extinction, the animals were exposed to the respective cues that initiated reinstatement of responding. A response-contingent ethanol prime further enhanced responding compared to the conditioned cues alone. Under these conditions, MPEP (0, 1, 3, and 10 mg/kg) attenuated ethanol seeking significantly and in a dose-related manner. However, at the highest dose, MPEP also decreased the number of inactive lever responses. In the second set of experiments, rats with 1 year of ethanol experience and repeated deprivation phases were used. A subchronic treatment with MPEP (twice daily; 0, 3, and 10 mg/kg) resulted in a significant and dose-dependent reduction of the alcohol deprivation effect (ADE). Although the same MPEP treatment regimen decreased baseline drinking, this effect was not as pronounced as on the ADE. These results show in two commonly used models of relapse to ethanol that pharmacological targeting of mGlu5 receptors may be a promising approach for the treatment of alcoholism.     

Metabolism of 8-prenylnaringenin, a potent phytoestrogen from hops (Humulus lupulus), by human liver microsomes.

The female flowers of hops are used throughout the world as a flavoring agent for beer. Recently, there has been increasing interest in the potential estrogenic properties of hop extracts. Among the possible estrogenic compounds in hops, 8-prenylnaringenin is perhaps most significant due to its high in vitro potency exceeding that of other known phytoestrogens. Since data regarding the pharmacokinetic properties of this compound are lacking, we investigated the in vitro metabolism of 8-prenylnaringenin by human liver microsomes. A total of 12 metabolites were identified, and biotransformation occurred on the prenyl group and the flavanone skeleton. The major site of oxidation was on the terminal methyl groups, and of the two possible isomers, the transisomer was more abundant. The double bond on the prenyl group was also oxidized to an epoxide that was opened by intramolecular reaction with the neighboring hydroxyl group. On the flavanone skeleton, the major site of oxidation was at 3'position on the B ring. Other metabolites included oxidation at carbon-3 as well as desaturation of the C ring to produce 8-prenylapigenin. An unusual hydroxy quinone product formed by ipso hydroxylation of the B ring of 8-prenylnaringenin was also detected. This product was probably an intermediate for the B ring cleavage product, 8-prenylchromone.