Membrane Properties of D-erythro-N-acyl Sphingomyelins and Their Corresponding Dihydro Species

AbstractWe have prepared acyl chain-defined D-erythro-sphingomyelins and D-erythro-dihydrosphingomyelins and compared their properties in monolayer and bilayer membranes. Surface pressure/molecular area isotherms of D-erythro-N-16:0-sphingomyelin (16:0-SM) and D-erythro-N-16:0-dihydrosphingomyelin (16:0-DHSM) show very similar packing properties, except that the expanded-to-condensed phase transition (crystallization) occurs at a lower surface pressure for 16:0-DHSM. The measured surface potential was generally about 100mV less for 16:0-DHSM monolayers compared to 16:0-SM monolayers. The condensed domains (crystals) that formed in 16:0-SM monolayers as a function of compression displayed star-shaped morphology when viewed under an epifluorescence microscope. 16:0-DHSM monolayers did not form similar crystals upon compression. 16:0-DHSM was degraded much faster by sphingomyelinase from Staphylococcus aureus than 16:0-SM (10-fold difference in enzyme activity needed for comparable hydrolytic rate). Cholesterol desorption from 16:0-DHSM to cyclodextrin was slightly slower (∼20%) than the rate measured from 16:0-SM monolayers (at 60mol % cholesterol). The bilayer melting temperature of 16:0-DHSM was 47.7°C (ΔH 8.3kcal/mol) whereas it was 41.2°C for 16:0-SM (ΔH 8.1kcal/mol). Cholesterol/16:0-DHSM bilayers (15mol % sterol) had more condensed domains than comparable 16:0-SM bilayers, as evidenced from the quenching resistance of DPH in DHSM membranes. We conclude that cholesterol interacts more favorably with 16:0-DHSM and that the membranes are more condensed than comparable 16:0-SM-containing membranes

The striatal dopamine transporter in first-episode, drug-naive schizophrenic patients: evaluation by the new SPECT-ligand[99mTc]TRODAT-1

Following the current hypothesis that acute schizophrenic psychotic illness is associated with a triatal ‘hyperdopaminergic state’, presynaptic integrity and dopamine transporter (DAT) density in first-episode, neuroleptic-naive schizophrenic patients was measured by single-photonemission- tomography (SPECT) and compared with that in healthy control subjects. A new SPECT-ligand for assessment of the striatal DAT, the Technetium-99m-labelled tropane TRODAT-1 ([99mTc]TRODAT-1), was used. Ten inpatients suffering from a first acute schizophrenic episode and 10 age- and sex-matched healthy control subjects underwent SPECT with [99mTc]TRODAT-1. On the day of SPECT, psychopathological ratings were performed with the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS) and Schedule for Assessment of Negative Symptoms (SANS). Patients had not previously received any neuroleptic or antidepressant medication. Mean specific TRODAT-1 binding in the striatum did not differ significantly between the patient and the age- and sex-matched control group (1.25 vs. 1.28). Variance was significantly higher in the patient group. The data obtained with the new ligand in first-episode, drug-naive schizophrenic patients are in line with the PET results from the group of Laakso et al. in a comparable patient sample. [99mTc]TRODAT-1 seems to be a valuable new SPECTligand in the evaluation of the presynaptic site of the striatal dopaminergic synapse in schizophrenia

One Screening Magnetic Resonance Imaging Sequence in Evaluation of Chondral and Meniscal Lesions of the Knee − A Pilot Study

This prospective study aimed to evaluate if chondral and meniscal lesions in symptomatic knees of osteoarthritis patients can be reliably identified using only one sagittal dual-echo MRI (Magnetic Resonance Imaging) sequence. MRI was performed on 13 patients after knee arthroscopy due to knee pain and clinically suspected osteoarthritis using a 1.5-Tesla scanner with knee coil and a sagittal dual-echo turbo spin-echo PD (Proton Density)- and T2-weighted sequence. The MRI and arthroscopic findings were then compared. Of 65 articular surfaces, 47 were damaged. For articular cartilage lesions, the overall sensitivity of MRI was 46.8%, specificity 72.2%, and diagnostic accuracy 53.9%, and for meniscal ruptures 81.2%, 66.7%, and 73.1%, respectively. The present study showed that the reliability of screening MRI of knees using only one sagittal dual-echo sequence does not suffice for diagnosis of chondral or meniscal lesions, and should therefore not replace routine knee MRI or diagnostic arthroscopy

The Finnish Think Tank Landscape : A Mixture of Consensualism and Adversity?

As a common feature of Nordic countries, the Finnish landscape of thinks tanks has been populated by large corporatist interest organisations and government-funded research organisations. In addition to this, since 2005, party-affiliated think tanks form a notable part of the picture. Recently, several small think tanks that are oriented towards specific themes, such as international relations, the environment and feminism, have been founded. This article examines Finnish developments in the field of think tanks with two objectives. First, it gives a general overview of the Finnish think tank landscape. Second, by using interview data and public mission statements of the most prominent think tanks, it explores how these organisations see their role in Finnish society. What is their relationship with media and the political machinery, and how does this relate to their position and activities as either consensual or adversarial actors? It is concluded that redeeming the place of think tanks in the Finnish polity is a continuing challenge, and resorting to adversarial tactics is not a favourable way to do so. This approach has mostly been attempted by neoliberal think tanks that, in the past, have also profited from corporatist structures to enhance their objectives.Peer reviewe

37^th plenary meeting report of the scientific, technical and economic committee for fisheries (PLEN-11-02)

The Scientific, Technical and Economic Committee for Fisheries hold its 37th plenary on 11-15 July 2011 in Copenhagen (Denmark). The terms of reference included both issues assessments of STECF Expert Working Group reports and additional requests submitted to the STECF by the Commission. Topics dealt with ranged from fisheries economics to management plan evaluation issues

The clinical relevance of PCL index on the reconstruction of anterior cruciate ligament with hamstring tendon autograft

The posterior cruciate ligament index (PCL index) has been reported as a diagnostic and prognostic marker for anterior cruciate ligament (ACL) reconstruction. The clinical relevance of PCL index on the reconstruction of ACL with hamstring tendon autograft has not been described in the literature. The objective of this study is to evaluate the importance of the PCL index as a marker of anatomic reconstruction and of functional improvement of patients undergoing ACL reconstruction with HT autograft. Twenty-four patients were submitted to ACL reconstruction with HT autograft. The PCL index was assessed by magnetic resonance imaging before and after surgery. The functional evaluation was performed through the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form© and Knee Society Knee Scoring System© (IKS). Patients presented a significant positive variation of the PCL index, IKDC and IKS scores. There is no significant correlation between PCL index variation and IKDC and IKS scores (p > 0.05). Unlike other studies reporting a relationship between the PCL index, control of rotational kinematics, and functional improvement in patients undergoing ACL reconstruction with bone-patellar tendon-bone autograft, this study does not demonstrate this association. There is evidence in this study to show that the PCL index may be used as an anatomic reconstructive marker of ACL but not to predict the clinical outcome in this type of reconstruction.(undefined