Patterns of the UP-Down state in normal and epileptic mice

Goal of this manuscript is to investigate whether changes that exist in epileptic brain generating spontaneous seizures are reflected in the pattern of the UP-Down state (UDS) recorded from the neocortex and dentate gyrus. Experiments were carried out on naive and epileptic mice under urethane anesthesia. Local field potentials were recorded with chronically implanted microelectrodes and single unit activity was recorded with glass microelectrodes. Recorded neurons were labeled by neurobiotin and identified later as granular cells or interneurons in histological sections. The following major features differentiate the pattern of UDS in epilepsy from normal. (1) The duration of UP and Down phases is significantly longer. (2) Recovery of network excitability after termination of the UP phase is longer. (3) UP-spikes occur during the UP phase, which transiently interrupt the development of the normal electrographic pattern of UP phase. Our data provide evidence that UP-spikes result from gigantic EPSPs generated in response to afferent activity. UP-spikes in the neocortex and dentate gyrus occur in close temporal relationship indicating the existence of direct or indirect pathological functional connections between these areas. Changes in the duration of UP and Down phases as well increased time of recovery of excitability of epileptic brain after termination of UP phase suggest alterations in the homeostatic properties of neuronal network in epileptic brain. We suggest that the existence of UP-spikes in epileptic brain may be an additional electrographic pattern indicating epileptogenicity. Unraveling the neuronal substrates of UP-spikes may further improve our understanding of the mechanisms of epilepsy.

New fin-line devices for radiofrequency exposure of small biological samples in vitro allowing whole-cell patch clamp recordings

The development and analysis of three waveguides for the exposure of small biological in vitro samples to mobile communication signals at 900 MHz (GSM, Global System for Mobile Communications), 1.8 GHz (GSM), and 2 GHz (UMTS, Universal Mobile Telecommunications System) is presented. The waveguides were based on a fin-line concept and the chamber containing the samples bathed in extracellular solution was placed onto two fins with a slot in between, where the exposure field concentrates. Measures were taken to allow for patch clamp recordings during radiofrequency (RF) exposure. The necessary power for the achievement of the maximum desired specific absorption rate (SAR) of 20 W/kg (average over the mass of the solution) was approximately P(in)  = 50 mW, P(in)  = 19 mW, and P(in)  = 18 mW for the 900 MHz, 1800 MHz, and 2 GHz devices, respectively. At 20 W/kg, a slight RF-induced temperature elevation in the solution of no more than 0.3 °C was detected, while no thermal offsets due to the electromagnetic exposure could be detected at the lower SAR settings (2, 0.2, and 0.02 W/kg). A deviation of 10% from the intended solution volume yielded a calculated SAR deviation of 8% from the desired value. A maximum ±10% variation in the local SAR could occur when the position of the patch clamp electrode was altered within the area where the cells to be investigated were located.

Coupled-channel calculation of nonelastic cross sections using a density-functional structure model

A microscopic calculation of reaction cross sections for nucleon-nucleus scattering was performed by coupling the elastic channel to all particle-hole excitations in the target and one-nucleon pickup channels. The particle-hole states may be regarded as doorway states through which the flux flows to more complicated configurations, and subsequently to long-lived compound nucleus resonances. Target excitations for (40,48)Ca, 58Ni, 90Zr, and 144Sm were described in a random-phase framework using a Skyrme functional. Reaction cross sections obtained agreed very well with experimental data and predictions of a fitted optical potential. Couplings between inelastic states were found to be negligible, while the pickup channels contribute significantly. For the first time observed absorptions are completely accounted for by explicit channel coupling, for incident energies between 10 and 40 MeV.

Quality of life in localised malignant melanoma

BACKGROUND

The incidence of melanoma is still increasing in fair-skinned populations. At least 80% of patients have localised disease and expect a 5-year relative survival of >90%.

PATIENTS AND METHODS

In 2003-2004, disease-free patients with localised melanoma were recruited from the Munich Cancer Registry to answer quality-of-life (QoL) questionnaires 2 years after treatment.

RESULTS

A response rate of 72% was achieved from a total of 1085 distributed questionnaires. Hundred and seventeen questionnaires had to be excluded because of updated information about secondary tumour and progression events. Thus, questionnaires from 664 patients were evaluated. QoL scores in melanoma patients were essentially similar to those of a general population. Differences were detected between women and men concerning emotional and sexual functioning. Age and number of comorbidities were the strongest factors influencing most all aspects of QoL. Fifty percent of patients referred to deficits in communication with their doctors.

CONCLUSIONS

Patients who overcome melanoma do not necessarily have a reduced QoL. Strategies used by these melanoma patients resulted in similar levels of coping as previous studies in comparable general populations. Nevertheless, doctor-patient communication was correlated with emotional and social functioning and should be emphasised in treatment and care of melanoma patients.

Triple-Negative Breast Cancers Express Receptors for GnRH and Can Be Effectively Targeted by the Orally Active GnRH-Antagonist AEZS 115

IntroductionAEZS-115* is an orally active peptidomimetic antagonist of GnRH, which has been shown to block the pituitary GnRH receptor. In various tumors an autocrine growth promoting loop consisting of GnRH secreted by the malignant cells and tumoral GnRH receptors has been described. The current study investigates the expression of GnRH-receptors in tumor samples of triple-negative breast cancers and evaluates the anti-tumor activity of the GnRH antagonist AEZS 115 in in vitro models of triple negative breast cancers.Study design17 human samples of triple negative breast cancers were tested for GnRH-receptor expression by immunohistochemistry. Human triple negative breast cancer cell lines MDA-MB 468, HCC 1806 and HCC 1937 were analyzed for GnRH receptor expression by immunocytochemistry and western blot analysis. These cell lines were incubated with increasing concentrations of AEZS-115, peptidic GnRH-antagonist Cetrorelix and GnRH-agonist Triptorelin (1, 10, 100 µm) for 48 hours and the number of viable cells was determined by crystal violet staining as well as by ATP-dependent luminometric assay.ResultsPositive staining for GnRH-receptors was detected in all tumor samples (2 high, 12 moderate, 3 weak). Cell lines MDA MB 468, HCC 1806 and HCC 1937 expressed GnRH receptors as demonstrated by immunocytochemistry and western blot analysis. GnRH-antagonist AEZS 115 dose dependently inhibited growth of all three cell lines, while GnRH-agonist Triptorelin and peptidic GnRH antagonist Cetrorelix showed marginal growth inhibition. At 10 µm AEZS-115 inhibited cell growth by 40-60%, at 100 µm growth inhibition was 60-80%. These results obtained by crystal violet staining were confirmed by additional luminometric evaluation of the ATP content after treatment with the respective substances.ConclusionsThe orally active, peptdidomimetic GnRH antagonist AEZS-115 showed substantial anti-tumor activity in these cell lines, while GnRH-agonist Triptorelin and peptidic antagonist Cetrorelix showed only minor growth inhibition. Thus, in triple negative breast cancers the peptidomimetic antagonist AEZS-115 was more potent than the decapeptide Cetrorelix. This finding could be explained by atypical GnRH-receptors on tumor tissue to which the different GnRH-antagonists might bind with different affinity. Due to high receptor expression the GnRH receptor is a promising target in triple negative breast cancers. The good antitumor-activity makes AEZS-115 a promising candidate for in vivo studies in this tumor entity.*Aeterna Zentaris GmbH, Frankfurt/M, Germany.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6108.