Lymphoproliferation und Antigenspezifität von Lymphozyten frisch manifestierter Typ I Diabetiker gegen die Proteine Bovines Serum Albumin und Beta-Casein sowie Insulin

Ziel dier Arbeit war der Nachweis T-Lymphozyten, die spezifisch auf in der Nahrung vorkommende bzw. körpereigene Antigene reagieren, sowie die Bildung antigenspezifischer T-Zelllinien.Es wurde dabei untersucht, ob Unterschiede in Lyphoproliferation und Antigenspezifität zwischen frisch manifestierten Typ I Diabetikern sowie gesunden Kontrollpersonen nachweisbar sind.Nach der Isolation von Lymphozyten aus dem peripher venösen Blut der Probanden erfolgte die Kultivierung der Zellen mit den verschiedenen Antigenen sowie Tetanol als Kontrolle. Es folgten 5-7 Stimulationen mit Interleukin-2, im Anschluß daran der Test auf antigenspezifische Proliferation. Dabei wurden die Zellen der generierten Linien erneut mit ihren jeweiligen Antigenen kultiviert, nach 56 h radioaktiv markiert und nach 72 h geerntet. Die intrazelluläre Radioaktivität wurde gemessen, und galt als ein Maß für die Proliferationsaktivität der Zellen. Weiterhin wurde ein Proliferationsindex gebildet als Maß für die antigenspezifische Proliferation.Beim Vergleich zwischen den Gruppen ergaben sich keine signifikannten Unterschiede. Typ I Diabetiker wiesen tendeziell die höhere Lymphoproliferatin auf.The aim of this study was T-lymphocytes, specific for cow´s milk antigens and insulin, and the generation of antigen specific T-cellines.Furhtermore was tried to give evidence for differences in lymphoproliferation and antigen specificity between newly diagnosed patients with type I diabetes and healthy controls.After isolation of lymphocytes from peripheral blood, they were cocultered with the investigated antigens BSA, Casein and insulin, tetanol was used as control; followed by 5-7 stimulations with interleukin-2.After this generation of T-cellines the test for antigen specific proliferation was assesed.The generated t-cells were cultured again with the specific antigen, marked with a radioactive amino acid, and harvested after 72 h. The incorporated radioactivity was the expression for lymphoproliferation. To determine antigen specific proliferation the proliferation index was developed.The results of the tested groups were compared. No significant differebces were found. Type I diabetic patinets seem to express higher activity of T-lymphocytes

π-Facial Selectivity in Diels-Alder Cycloadditions

Diels-Alder reactions between π-facially differentiated dienes and/or π-facially differentiated dienophiles frequently proceed with remark-able π-facial selectivity. Experimental and theoretical studies have been undertaken in an effort to gain insight into the fundamental origins of this phenomenon. Reactions of interest in this connection include thermal [4 + 2] cycloadditions between (i) various dienophiles and cage-annulated 1,3-cyclohexadienes (i.e. systems 1, 4, 6, and 9) and (ii) various dienes and cage-annulated dienophiles (i.e. systems 1a, 11a, and 14). The results of relevant molecular mechanics, semiempirical, and ab initio molecular orbital calculations generally are consistent with experiment

The fall and rise of corticomotor excitability with cancellation and reinitiation of prepared action

The sudden cancellation of a motor action, known as response inhibition (RI), is fundamental to human motor behavior. The behavioral selectivity of RI can be studied by cueing cancellation of only a subset of a planned response, which markedly delays the remaining executed components. The present study examined neurophysiological mechanisms that may contribute to these delays. In two experiments, human participants received single- and paired-pulse transcranial magnetic stimulation while performing a bimanual anticipatory response task. Participants performed most trials bimanually (Go trials) and were sometimes cued to cancel the response with one hand while responding with the other (Partial trials). Motor evoked potentials were recorded from left first dorsal interosseous (FDI) as a measure of corticomotor excitability (CME) during Go and Partial trials. CME was temporally modulated during Partial trials in a manner that reflected anticipation, suppression, and subsequent initiation of a reprogrammed response. There was an initial increase in CME, followed by suppression 175 ms after the stop signal, even though the left hand was not cued to stop. A second increase in excitability occurred prior to the (delayed) response. We propose an activation threshold model to account for nonselective RI. To investigate the inhibitory component of our model, we investigated short-latency intracortical inhibition (sICI), but results indicated that sICI cannot fully explain the observed temporal modulation of CME. These neurophysiological and behavioural results indicate that the default mode for reactive partial cancellation is suppression of a unitary response, followed by response reinitiation with an inevitable time delay. </jats:p

Exploiting Carbonyl Groups to Control Intermolecular Rhodium-Catalyzed Alkene and Alkyne Hydroacylation

Readily available β-carbonyl-substituted aldehydes are shown to be exceptional substrates for Rh-catalyzed intermolecular alkene and alkyne hydroacylation reactions. By using cationic rhodium catalysts incorporating bisphosphine ligands, efficient and selective reactions are achieved for β-amido, β-ester, and β-keto aldehyde substrates, providing a range of synthetically useful 1,3-dicarbonyl products in excellent yields. A correspondingly broad selection of alkenes and alkynes can be employed. For alkyne substrates, the use of a catalyst incorporating the Ampaphos ligand triggers a regioselectivity switch, allowing both linear and branched isomers to be prepared with high selectivity in an efficient manner. Structural data, confirming aldehyde chelation, and a proposed mechanism are provided

Hot plasma in the magnetotail lobes shows characteristics consistent with closed field lines trapped in the lobes

We examine the magnetotail using data from the Hot Ion Analyzer on Cluster 1 during 2001–2009. We develop and utilise an algorithm in order to identify times during which Cluster 1 is in the magnetotail lobe but observes plasma which is hotter than our expectations of the lobe. We analyze the prevailing Interplanetary Magnetic Field (IMF) Bz conditions for our algorithm and a reference algorithm (with no particle energy criteria) and find that the periods we select are, on average, ~2 nT more towards northward IMF. Examining the temperature in the magnetotail for our periods shows that the morphology of the average temperature is consistent with the Milan et al. (2005) model of magnetotail structure during Northward IMF, in which closed field lines are prevented from convecting to the dayside, causing them and the plasma trapped on them to protrude into the magnetotail lobes. We also find evidence that ~0.5% of our identified periods may be driven by direct entry into the magnetosphere from the solar wind

Dopamine Gene Profiling to Predict Impulse Control and Effects of Dopamine Agonist Ropinirole

Dopamine agonists can impair inhibitory control and cause impulse control disorders for those with Parkinson disease (PD), although mechanistically this is not well understood. In this study, we hypothesized that the extent of such drug effects on impulse control is related to specific dopamine gene polymorphisms. This double-blind, placebo-controlled study aimed to examine the effect of single doses of 0.5 and 1.0 mg of the dopamine agonist ropinirole on impulse control in healthy adults of typical age for PD onset. Impulse control was measured by stop signal RT on a response inhibition task and by an index of impulsive decision-making on the Balloon Analogue Risk Task. A dopamine genetic risk score quantified basal dopamine neurotransmission from the influence of five genes: catechol-O-methyltransferase, dopamine transporter, and those encoding receptors D1, D2, and D3. With placebo, impulse control was better for the high versus low genetic risk score groups. Ropinirole modulated impulse control in a manner dependent on genetic risk score. For the lower score group, both doses improved response inhibition (decreased stop signal RT) whereas the lower dose reduced impulsiveness in decision-making. Conversely, the higher score group showed a trend for worsened response inhibition on the lower dose whereas both doses increased impulsiveness in decision-making. The implications of the present findings are that genotyping can be used to predict impulse control and whether it will improve or worsen with the administration of dopamine agonists