Effects of antiepileptic drugs in electrophysiological tests

Methods of the study of antiepileptic drugs activity by means of analysis of their effects on bioelectrical ictal phenomena in the animal brain are described. The paper deals especially with EEG signal processing methods. Application of various nonparametric models (e.g. interval-amplitude scatter plots, power spectra analysis) as well as parametric models (e.g. autoregressive model, segmentation analysis) is discussed. A discriminative approach to some of these methods (especially to autoregressive model) is also presented. Special attention is stressed on the value of these methods for the study of anticonvulsant drugs activity.     

Cardiotoxicity of adrenochrome in isolated rabbit hearts assessed by epicardial NADH fluorescence

Noradrenaline in a micromolar concentration has recently been shown to contribute to ischemic tissue injury by direct cardiotoxic effects independent of functional alterations. Oxygen free radicals, generated during the auto-oxidation of catecholamines, are important mediators of catecholamine cardiotoxicity. However, the role of the oxidative products (aminochromes) is still unclear. We examined the effects of adrenochrome on functional parameters and on regional myocardial ischemia (MI) in isolated electrically-driven rabbit hearts with depleted catecholamine stores (reserpine 7.0 mg/kg i.p. 16 – 24 h before preparation, Langendorff, constant pressure: 70 cm H₂O, Tyrode solution, Ca⁺⁺ 1.8 mmol/l, 37°C). Repetitive MI, separated by a reperfusion period of 50 min, was induced by coronary artery branch ligature, and MI was quantitated from epicardial NADH fluorescence photography. Adrenochrome-treatment (10^– 6 M or 10^– 4 M) was started after a reperfusion period of 20 min. The left ventricular pressure (LVP) was significantly enhanced by adrenochrome (p <0.05), but it fell thereafter to below its initial value in hearts treated with adrenochrome 10^– 4 M. The global coronary flow (CF) was not affected by adrenochrome 10^– 6 M (P >0.05), but it was significantly decreased by adrenochrome 10^– 4 M (P <0.05). The relative CF (= CF/LVP × heart-rate) was numerically decreased by adrenochrome 10^– 6 M (p >0.05) and more markedly by adrenochrome 10^– 4 M (p <0.05). Whereas epicardial NADH fluorescence was similar after repetitive coronary artery occlusions in controls and in hearts treated with adrenochrome 10^– 6 M (p >0.05), it was significantly enhanced by adrenochrome 10^– 4 M (p <0.05). In isolated rabbit hearts, adrenochrome possesses deleterious effects on MI only at a very high concentration but not in a micromolar concentration. Therefore, it seems that aminochromes may be less cardiotoxic than catecholamines. Received: 28 February 1994 / Accepted: 2 May 1994     

Phase II trial of sunitinib as adjuvant therapy after stereotactic radiosurgery in patients with 1–3 newly diagnosed brain metastases

Journal of Neuro-Oncology - Patients with 1–3 brain metastases (BM) often receive sterotactic radiosurgery (SRS) without whole brain radiotherapy (WBRT). SRS without WBRT carries a high rate...     

Differenzialdiagnostik der schwer einstellbaren Hypertonie

Patients with uncontrollable hypertension are characterized by an increased cardiovascular risk. In contrast to well-controlled essential hypertension where there is rarely a single underlying cause, in patients where hypertension is difficult to control a secondary cause can often be found. Frequently, sleep apnea, primary hyperaldosteronism and renal forms of hypertension including renoparenchymal disease and renal artery stenosis can be found. Rare forms are Cushing??s syndrome, pheochromocytoma, hyperthyroidism or hypothyroidism and coarctation of the aorta. Careful preselection of patients using simple clinical tests needs to be carried out as this increases the chances of finding an underlying cause. Broad screening of all hypertensive patients is certainly not effective. When a secondary form is highly suspected or identified, referral to a specialized center is recommended. Besides secondary causes of hypertension, drug interactions, e.g. non-steroidal anti-inflammatory drugs (NSAID), low adherence, suboptimal therapy and lifestyle issues play a major role and need to be addressed in order to get the blood pressure under control. Renal denervation and baroreceptor stimulation are new and very promising options when patients are refractory but both invasive procedures should only be performed in specialized hypertension centers.     

B lymphoblastoid cell lines with normal and defective O-glycosylation established from an individual with blood group Tn

Individuals with the Tn blood group contain terminal serine/threonine- linked N-acetylgalactosamine residues in their blood cells. This is due to lack of UDP-D-galactose: D-N-acetyl galactosamine beta-D-galactosyl transferase from part of their red cells and probably from their leukocytes. We have established B lymphoblastoid cell lines from such an individual by in vitro infection of his lymphocytes with Epstein- Barr virus. The original line contained a mixture of cells reactive and nonreactive with Helix pomatia lectin (Hp). These cells were subcloned after staining with fluorescent Hp by a fluorescence-activated cell sorter (FACS) into homogeneous, phenotypically stable lines of Hp- positive (Hp+) and Hp-negative (Hp-) cells. The molecular differences between the membrane glycoproteins were characterized by carbohydrate- specific surface labeling techniques, Hp affinity chromatography, polyacrylamide slab gel electrophoresis and glycopeptide/oligosaccharide analysis. The major O-glycosidic membrane glycoprotein (GP105) was retained on Hp-Sepharose columns only from Hp+ cells, whereas the common leukocyte antigen (GP160-200) was partially retained on Hp columns from both lines. These proteins were isolated by immune precipitation with monoclonal antibodies and characterized. The results show that the GP105 glycoprotein from Hp+ cells contains terminal N-acetylgalactosamine residues but also more complex oligosaccharides. The common leukocyte antigen showed different electrophoretic mobilities in Hp+ and Hp- cells. UDP-galactose D-N- acetyl galactosamine beta-galactosyl transferase was almost absent in the Hp+ cells. These cell lines are useful for studies on the functional role and regulation of the biosynthesis of O-glycosidic carbohydrates.     

Kriterien der Deutschen Gesellschaft für Kardiologie, Deutschen Hochdruckliga e.V. DHL®/Deutschen Gesellschaft für Hypertonie und Prävention und der Deutschen Gesellschaft für Nephrologie zur Zertifizierung von „Renale-Denervations-Zentren (RDZ)“

This position paper from the Deutsche Gesellschaft für Kardiologie – Herz- und Kreislaufforschung e.V., the Deutsche Gesellschaft für Nephrologie e.V. and the Deutsche Hochdruckliga summarizes the criteria for certification of renal denervation centers. In addition to personnel and facility requirements, proper patient selection as well as pre- and post-procedural follow-up examinations are discussed. The certification of renal denervation centers ought to help physicians, patients, and health care providers/insurance companies to identify appropriate sites for the implementation of catheter-based renal denervation.     

Strahlenwirkungen

Ohne Zusammenfassung