Ganglioneurocytoma of the Third Ventricle

We present a very rare case of an intracranial ganglioneurocytoma. This 57-year-old female patient noticed some concentration difficulties for about 5 months. Visual acuity was 80% on both sides. CT and MRI of her head demonstrated a 3 x 2.5 x 2.8 cm3 lesion within the third ventricle with inhomogenous enhancement of contrast medium. After a right pterional approach the tumor could be removed completely. Postoperatively there was a paresis of the oculomotor nerve on the right side and psychological changes. Histological examination revealed neuronal differentiation with neurocytes and small ganglionic cells and the tumor was graded as a ganglioneurocytoma (WHO grade II). Follow-up examination 6 months after the operation showed improvement of her third nerve paresis and of her neuropsychological deficits. MRI showed no recurrence.     

Early prediction of changes in weight during six weeks of treatment with antidepressants

Weight gain is a frequent and important side effect of psychotropic treatment. We sought to determine weight change predictors during treatment with antidepressant drugs. In 24 patients weight, plasma levels of leptin, tumor necrosis factor-alpha (TNF-alpha and soluble TNF receptors were determined longitudinally and a multiple linear regression analysis was used to predict weight change from baseline to the sixth week of treatment. Changes of weight during the first week of treatment, but no other parameter, strongly predicted weight change until endpoint (adjusted R2 = 0.68, F = 50.45, df = 1,23, p < 0.001). Very early changes in weight during treatment with psychotropic drugs might be a simple and clinically useful predictor of future weight development.     

Disturbance of cultured rat neuronal network activity depends on concentration and ratio of leucine and alpha-ketoisocaproate: implication for acute encephalopathy of maple syrup urine disease

Increased concentrations of leucine and its respective ketoacid alpha-ketoisocaproate (KIC) in plasma and cerebrospinal fluid are related to acute and reversible encephalopathy in patients with maple syrup urine disease. We studied electrophysiological properties of primary dissociated rat neurons at increased extracellular concentrations of leucine and KIC (1-10 mM). Spontaneous neuronal network activity was reversibly reduced or blocked by leucine as well as by KIC in a dose-dependent manner. Simultaneous incubation with both substances led to a minor inhibition compared to the effect of each substance alone. Neuronal resting potential, voltage dependent Na(+) (I(Na)) and K(+) (I(K)) currents, the GABA- and glycine-elicited membrane currents, and glutamate-induced intracellular Ca(2+) increase of single neurons, however, were unaffected by both substances. We conclude that acute neuronal network dysfunction in maple syrup urine disease is mainly based on an imbalance of the presynaptic glutamatergic/GABAergic neurotransmitter concentrations or their release.     

High-throughput genotyping by DHPLC of the dihydropyrimidine dehydrogenase gene implicated in (fluoro)pyrimidine catabolism

Dihydropyrimidine dehydrogenase (DPD) is the first and rate-limiting enzyme in the degradation of pyrimidines and pyrimidine base analogs including the anticancer drugs 5-fluorouracil (5-FU) and Xeloda. A decreased DPD enzyme activity has been described in cancer patients experiencing severe and life-threatening toxicity after 5-FU treatment and distinct sequence variants in the DPD gene (DPYD) have been associated with impaired enzyme function. The most prominent mutation in the DPD deficient patient group, a mutation in the splicing donor consensus sequence of intron 14, IVS14+1g>a, resulting in a truncated protein, has been observed in the Caucasian population at frequencies as high as 0.91%-0.94%. This underlines the need for a test system for DPYD mutations in patients undergoing chemotherapy with 5-FU or with Xeloda. To set up a fast and sensitive method to identify variant DPYD alleles, we analyzed 50 healthy individuals by denaturing high performance liquid chromatography (DHPLC). A primer set spanning the whole coding region and the exon-intron boundaries of DPYD was used. In addition, a cDNA-based assay was developed to rapidly identify the 165 base pair deletion in the corresponding RNA of IVS14+1g>a mutation carriers. The optimal mutation detection was elaborated for each of the PCR fragments. DHPLC analysis detected 5 different genetic alterations occurring in the coding region of the gene, as well as 10 intronic sequence variants, respectively. In conclusion, high-throughput screening for DPYD variants by DHPLC may be a reliable tool in the investigation of the molecular basis of DPD deficiency. Furthermore, it will help to identify patients at risk for toxic side effects upon chemotherapy using 5-FU and will facilitate individual treatment of patients.     

Rescue-Thrombektomie nach Stentimplantation in einem degenerierten aortokoronaren Venenbypass

Zusammenfassung Hintergrund: Die kathetervermittelte Therapie degenerierter aortokoronarer Venenbypässe ist häufig mit einer periinterventionellen Embolisation von Thromben, Plaqueartikeln und atherosklerotischem Debris verbunden. Fallbeschreibung: Ein 66-jähriger männlicher Patient mit operativer Myokardrevaskularisation 1995 wurde aufgrund eines akuten koronaren Ischämiesyndroms in unsere Abteilung stationär eingewiesen. Unter einer antiischämischen Kombinationstherapie konnte eine klinische Stabilisierung erzielt werden. In einer elektiven Koronarangiographie stellten sich zwei kritische Stenosen im Venengraft zum Ramus interventricularis anterior (RIVA) als klinisch führende Läsionen heraus. Nach einer 24-stündigen Vorbehandlung mit einem Glykoprotein-IIb/IIIa-Inhibitor wurden im Bereich der distalen Stenose ein Stentgraft (Jostent™, Jomed) und im Bereich der proximalen Stenose ein Magic Wallstent™ (Boston Scientific) implantiert. Nach einer Hochdruckdilatation im Magic Wallstent™ verblieb keinerlei residuelle Stenose. Im weiteren Verlauf klagte der Patient über heftige Stenokardien, die mit ausgeprägten ST-Hebungen über den linkspräkordialen Ableitungen einhergingen. Angiographisch war der RIVA nach der koronaren Bypassanastomose okkludiert. Nach Einführen eines X-Sizer™-Absaugsystems (EndiCOR Medical, Inc.) in den Venengraft und das proximale Drittel der Vorderwandarterie konnte nach mehrfacher Aspiration eine komplette Reperfusion des RIVA wiederhergestellt werden. Die maximale CK-Aktivität betrug postinterventionell 127 U/l. In einer Kontrollkoronarangiographie nach 7 Tagen war der RIVA weiterhin perfundiert. Schlussfolgerung: Das X-Sizer™-Absaugsystem erscheint als eine erfolgversprechende Therapieoption zur perkutanen transluminalen Thrombektomie bei stattgehabter Makroembolisation mit No-Reflow-Phänomen bei Katheterinterventionen in degenerierten Venenbypässen. Abstract Background: Distal showering of atherosclerotic debris or thrombus is a feared event during percutaneous angioplasty of degenerated vein grafts. Case Report: We report on a 66-year-old male patient with a history of coronary artery disease who was admitted into hospital with an acute coronary syndrome. He had had coronary artery bypass graft surgery in 1995. His chest pain resolved under treatment with aspirin, heparin, betablocker, and nitrate. A diagnostic angiogram demonstrated two critical stenoses of the left anterior descending graft. After a continuous infusion of tirofiban administered for 24 h prior to elective angioplasty, a JR 4SH 6 F guiding catheter (Cordis) was positioned. The lesions were crossed with a 0.014" Galeo F™ wire (Biotronik). A 4 mm 2 16 mm stent graft (Jostent™, Jomed) was deployed in the distal stenosis and a 4,5 mm 2 32 mm self-expandable stent (Magic Wallstent™, Boston Scientific) in the proximal stenosis. Thereafter, the patient suffered from chest pain, and the ECG showed ST elevation from V1 to V5. Angiography revealed total occlusion of the left anterior descending artery. An X-Sizer™ catheter (EndiCOR Medical, Inc.) was introduced and advanced through the vein graft with slow back-and-forth movements. After several aspirations, blood flow was significantly improved. A modest CK elevation (127 U/l) indicated a rather small loss of myocardial tissue. Conclusion: Percutaneous revascularization of narrowed aortocoronary saphenous vein grafts is associated with increased risk of distal embolization and "no flow". The X-Sizer™ catheter system is compatible with commercially available guiding catheters, and capable of retrieving thrombotic debris after macroembolization from degenerated saphenous vein grafts including the native coronary artery.     

The TNF-α System: Functional Aspects in Depression, Narcolepsy and Psychopharmacology

Changes of the tumor necrosis factor-alpha (TNF-α) system have been shown to be involved in the development of psychiatric disorders and are additionally associated with changes in body weight as well as endocrine and metabolic changes in psychiatric patients.     

A 3D fiber model of the human brainstem

A new neuroanatomic approach to evaluate the fiber orientation in gross histological sections of the human brain was developed. Serial sections of a human brainstem were used to derive fiber orientation maps by analysis of polarized light sequences of these sections. Fiber inclination maps visualize angles of inclination, and fiber direction maps show angles of direction. These angles define vectors which can be visualized as RGB-colors. The serial sections were aligned to each other using the minimized Euclidian distance as fit criterion. In the 3D data set of the human brainstem the major fiber tracts were segmented, and three-dimensional models of these fiber tracts were generated. The presented results demonstrate that two kinds of fiber atlases are feasible: a fiber orientation atlas representing a vector in each voxel, which shows the nerve fiber orientation, and a volume-based atlas representing the major fiber tracts. These models can be used for the evaluation of diffusion tensor data as well as for neurosurgical planning.     

Änderungen im O2-Verbrauch (Grundumsatz) bei nicht ausreichender Versorgung mit Vitamin C

Zusammenfassung Beim Meerschweinchen führt selbst eine Zufuhr von etwas mehr als 10 mg Vitamin C pro Tag (einerlei ob in natürlicher oder synthetischer Form) noch zur Unfähigkeit, den O₂-Verbrauch (Grundumsatz) konstant halten zu können. Eine ernährungsphysiologisch als ausreichend oder gar als optimal zu bezeichende Vitamin C-Zuhr muß demnach wesentlich höher sein als die Skorbutschutzdosis und zwar um so viel, daß auch diese als latente Hypovitaminosen zu bezeichnenden Störungen der Stoffwechselregulation vermieden werden.