In vivo electrochemical demonstration of potassium-evoked monoamine release from rat cerebellum

In vivo electrochemical methods were employed to study the potassium (K⁺-evoked release of monoamines from the cerebellum of the chloral hydrate anesthetized rat. K⁺-evoked releases were elicited using micropipette-Nafion-coated graphite epoxy electrode arrays in the granule/Purkenje cell layer, molecular layer, and white matter. These recorded releases were generally found to be reversible, moderately dose-dependent, and reproducible. However, the temporal dynamics of the releases were different for the cell layer versus molecular layer records. Releases were infrequently observed in cerebellar white matter, an area which is relatively devoid of monoamine containing terminals. The signals recorded from the cell and molecular layers were significantly attenuated by pretreatment with nomifensine, a potent catecholamine reuptake blocker, significantly prolonged the K⁺-evoked signals observed in both the granule/Purkenje cell and molecular layers. These data, taken together with earlier reports on the electrophysiological responses to activation of cerebellar noradrenergic inputs, support the conjecture that in vivo electrochemical recording methods have the sensitivity and spatial resolution for studies of functional monoamine release from brain regions that have a diffuse or laminated monoamine innervation.     

The validity of a separate classification of cryptogenic localization related epilepsy amongst childhood epilepsies.

INTRODUCTION: One-third of children with epilepsy are classified as having a cryptogenic localization related epilepsy (CLRE). In cohort studies CLRE is often grouped together with either symptomatic localization related epilepsy (SLRE) or idiopathic generalized epilepsy (IGE). Therefore, this categorization is not specific enough and will not lead to prognostic or treatment information. We objectified the classification differences between these categories. METHODS: A total of 114 children admitted to our epilepsy centre underwent a standardized clinical analysis, which yielded age at onset, duration of the epilepsy, seizure frequency, seizure type, percentage of interictal epileptiform activity on EEG (IEA), type of treatment, and full scale IQ. These variables are regarded the characteristics of the epilepsy, and used in a discriminant function analysis. RESULTS: IEA was found to be the only variable to distinguish between groups of epilepsy. SLRE could easily be distinguished significantly from IGE and CLRE, while the latter two did not differ significantly. Discriminant function analysis combined the variables into two functions, applicable to classify the children. By applying this statistical analysis method, the groups clinically classified as SLRE and IGE were mostly classified as SLRE (71.4%) and IGE (57.9%). However, CLRE appeared difficult to classify (49.2%), and most children were classified as either SLRE (19%) or IGE (31.7%). CONCLUSION: The current opinion that CLRE is 'probably symptomatic' cannot be confirmed in all cases in this study. It is most likely that the current CLRE population consists of both children with eventually SLRE, as well as yet to be described syndromes to be classified as idiopathic epilepsies. We emphasize the need for separate studies regarding children with 'probably symptomatic' (cryptogenic) localization related epilepsy, as this will maximally help children, caretakers and treating physicians to achieve the best possible outcome.     

Einmal- versus wiederverwendbare Instrumente in der laparoskopischen Cholezystektomie — Kostenkalkulation und Nutzwertbestimmung

Zusammenfassung Grundlagen: Seit Einführung der laparoskopischen Cholezystektomie wird diskutiert, ob bei diesem Eingriff Einmal- oder wiederverwendbare Instrumente eingesetzt werden sollten. Argumenten der Wirtschaftlichkeit wurden Aspekte der Sicherheit und Hygiene entgegengestzt. Eine Beurteilung des Ger?teeinsatzes unter Berücksichtigung der Kosten als auch des Nutzwertes der Instrumente ist bis heute nicht erfolgt. Methodik: Es wurde ein Kostenvergleich von 3 Varianten des Instrumenteneinsatzes durchgeführt (1. wiederverwendbare Instrumente, 2. Einmalger?te, 3. kombinierte Anwendung). Der Wirtschaftlichkeitsrechnung wurde eine Nutzwertbestimmung der einzelnen Instrumente durch die Operateure entgegengestellt. Ergebnisse: Durch den Einsatz von wiederverwendbaren Instrumenten ist eine betr?chtlichen Kostenreduktion (5888 ATS bei ausschlie?licher Anwendung von wiederverwendbaren Ger?ten. 3945 ATS bei kombiniertem Einsatz) zu erreichen. Der Nutzenvergleich zeigte beim Clipsetzer und dem Port für die erste Insertion Vorteile für die Einmalinstrumente. Schlu?folgerungen: Aufgrund der Ergebnisse von Kostenkalkulation und Nutzwertbestimmung stellt der kombinierte Einsatz von wiederverwendbaren und Einmalinstrumenten derzeit die beste Alternative dar.