Stereochemical analysis of 3,4-methylenedioxymethamphetamine and its main metabolites in human samples including the catechol-type metabolite (3,4-dihydroxymethamphetamine).

3,4-Methylenedioxymethamphetamine (MDMA; "ecstasy") is a designer drug commonly misused in large segments of young populations. MDMA is usually formulated in tablets of its racemate (1:1 mixture of its enantiomers) in doses ranging from 50 to 200 mg. MDMA has an enantioselective metabolism, the (S)-enantiomer being metabolized faster than the (R)-enantiomer. Different pharmacologic properties have been attributed to each enantiomer. The carbon responsible for MDMA chirality is preserved along its metabolic disposition. An analytical method has been developed to determine MDMA enantiomers and those from its major metabolites, 3,4-methylenedioxyamphetamine (MDA), 3,4-dihydroxymeth-amphetamine (HHMA), and 4-hydroxy-3-methoxymethamphet-amine (HMMA). It has been applied to the analysis of plasma and urine samples from healthy recreational users of MDMA who participated voluntarily in a clinical trial and received 100 mg (R,S)-MDMA. HCl orally. (R)/(S) ratios both in plasma (0-48 h) and urine (0-72 h) for MDMA and MDA were >1 and <1, respectively. Ratios corresponding to HHMA and HMMA, close to unity, deviate from theoretical expectations and are most likely explained by the ability of MDMA to autoinhibit its own metabolism. The short elimination half-life of (S)-MDMA (4.8 h) is consistent with the subjective effects and psychomotor performance reported in subjects exposed to MDMA, whereas the much longer half-life of the (R)-enantiomer (14.8 h) correlates with mood and cognitive effects experienced on the next days after MDMA use.     

Medial temporal MR spectroscopy is related to memory performance in normal adolescent subjects

In addition to the study of pathological conditions, magnetic resonance spectroscopy can provide useful information about brain-behavior relationships in normal subjects. Recently, there have been reports of correlations between N-acetylaspartate (NAA) values and cognitive functions in normal adults. We tested the possible specific relationship between the NAA/choline (Cho) ratio in the medial temporal lobe and memory performance in normal adolescents. The medial temporal NAA/Cho ratio was unrelated to age, gender and general intelligence but presented a clear correlation with several memory measures. In the regression analysis two memory variables (RAVLT learning and a face-name recognition task) explained 55.6% of NAA/Cho variance. We conclude that NAA values in the medial temporal lobe are related to memory abilities but not to global intelligence in normal adolescent subjects.     

Assessment of the potential irritation and photoirritation of novel amino acid-based surfactants by in vitro methods as alternative to the animal tests

The ultraviolet-A radiation damage effects on skin and eyes will be increased by phototoxic compounds which could be present in pharmaceutical or cosmetic formulations. Great efforts have been made in the last years to find surfactants to replace those with phototoxic potential in commercial use. Series of different in vitro models for phototoxicity, included to validated neutral red uptake (NRU) 3T3 phototoxicity assay are useful screening tools. The phototoxic effects of a novel family of glycerol amino acid-based surfactant compounds were examined via these assays. Human red blood cells and two immortalised cell lines, murine fibroblast cell line 3T3, and one human keratinocyte cell line, HaCaT, were the in vitro models employed to predict potential photoirritation. The phototoxic end-points assessed were hemolysis (human red blood cell test) and resazurin transformation to resorufin and NRU in cell culture methods. The results suggest that no phototoxic effects by any new amino acid derived-surfactants, could be identified.     

The European Cancer Anaemia Survey (ECAS): a large, multinational, prospective survey defining the prevalence, incidence, and treatment of anaemia in cancer patients

The European Cancer Anaemia Survey (ECAS) was conducted to prospectively evaluate the prevalence, incidence and treatment of anaemia (haemoglobin <12.0 g/dL) in European cancer patients, including the relationship of mild, moderate and severe anaemia to performance status. Patients were evaluated for up to 6 months. Data (N=15367) included demographics, tumour type, performance status, haemoglobin levels, cancer treatments and anaemia treatments. Prevalence of anaemia at enrollment was 39.3% (haemoglobin <10.0 g/dL, 10%), and 67.0% during the survey (haemoglobin <10.0 g/dL, 39.3%). Low haemoglobin levels correlated significantly with poor performance status. Incidence of anaemia was 53.7% (haemoglobin <10.0 g/dL, 15.2%). Anaemia was treated in 38.9% of patients (epoetin, 17.4%; transfusion, 14.9%; and iron, 6.5%). Mean haemoglobin to initiate anaemia treatment was 9.7 g/dL. Anaemia prevalence and incidence in cancer patients are high. Anaemia significantly correlates with poor performance status and many anaemic patients are not treated.     

Role of baseline human immunodeficiency virus genotype as a predictor of viral response to tenofovir in heavily pretreated patients

Human immunodeficiency virus (HIV)-infected patients (n = 153) failing antiretroviral therapy after exposure to compounds from all three drug families were monitored for 6 months after beginning a rescue intervention program including tenofovir (TDF). At 3 months, levels of HIV RNA in plasma dropped by a mean of 0.9 log(10) and the mean CD4 count increased by 52 cells/ micro l. At 6 months, HIV RNA levels had dropped by a mean of 1.06 log(10) and the mean CD4 count had increased by 49 cells/ micro l. Only five (3.7%) patients discontinued TDF use due to adverse events. In the multivariate analysis, the presence of M41L and/or L210W at baseline was the only viral determinant of a lower response to TDF.     

Autoreactive CD8 T cells in organ-specific autoimmunity: emerging targets for therapeutic intervention

The importance of CD8 T cells in the pathogenesis of organ-specific autoimmune diseases has not previously been well recognized. Recent evidence, however, indicates that autoreactive CD8 T cells can contribute substantially to tissue damage in both murine and human autoimmune disorders. As such, these T cells now become an attractive target for therapeutic intervention.     

External validation of a prognostic model for predicting survival of cirrhotic patients with refractory ascites

OBJECTIVE: Cirrhotic patients with refractory ascites (RA) have a poor prognosis, although individual survival varies greatly. A model that could predict survival for patients with RA would be helpful in planning treatment. Moreover, in cases of potential liver transplantation, a model of these characteristics would provide the bases for establishing priorities of organ allocation and the selection of patients for a living donor graft. Recently, we developed a model to predict survival of patients with RA. The aim of this study was to establish its generalizability for predicting the survival of patients with RA. METHODS: The model was validated by assessing its performance in an external cohort of patients with RA included in a multicenter, randomized, controlled trial that compared large-volume paracentesis and peritoneovenous shunt. The values for actual and model-predicted survival of three risk groups of patients, established according to the model, were compared graphically and by means of the one-sample log-rank test. RESULTS: The model provided a very good fit to the survival data of the three risk groups in the validation cohort. We also found good agreement between the survival predicted from the model and the observed survival when patients treated with peritoneovenous shunt and with paracentesis were considered separately. CONCLUSION: Our survival model can be used to predict the survival of patients with RA and may be a useful tool in clinical decision making, especially in deciding priority for liver transplantation.