Stereochemistry of phase-1 metabolites of mephedrone determines their effectiveness as releasers at the serotonin transporter

Mephedrone (4-methyl-N-methylcathinone) is a psychostimulant that promotes release of monoamines via the high affinity transporters for dopamine (DAT), norepinephrine (NET) and serotonin (SERT). Metabolic breakdown of mephedrone results in bioactive metabolites that act as substrate-type releasers at monoamine transporters and stereospecific metabolism of mephedrone has been reported. This study compared the effects of the enantiomers of the phase-1 metabolites nor-mephedrone, 4-hydroxytolyl-mephedrone (4-OH-mephedrone) and dihydro-mephedrone on (i) DAT, NET and SERT mediated substrate fluxes, (ii) determined their binding affinities towards a battery of monoamine receptors and (iii) examined the relative abundance of the enantiomers in human urine. Each of the enantiomers tested inhibited uptake mediated by DAT, NET and SERT. No marked differences were detected at DAT and NET. However, at SERT, the S-enantiomers of nor-mephedrone and 4-OH-mephedrone were several times more potent than the corresponding R-enantiomers. Moreover, the R-enantiomers were markedly less effective as releasers at SERT. S-nor-mephedrone displayed moderate affinities towards human alpha; 1A; , human 5-HT; 2A; and rat and mouse trace amine-associated receptor 1. These results demonstrate that stereochemistry dictates the pharmacodynamics of the phase-1 metabolites of mephedrone at SERT, but not at DAT and NET, which manifests in marked differences in their relative potencies, i.e. DAT/SERT ratios. Chiral analysis of urine samples demonstrated that nor-mephedrone predominantly exists as the S-enantiomer. Given the asymmetric abundance of the enantiomers in biological samples, these findings may add to our understanding of the subjective effects of administered mephedrone, which indicate pronounced effects on the serotonergic system

First escaping fast ion mesurements in ITER-like geometry using an activation probe

More research is needed to develop suitable diagnostics for measuring alpha particle confinement in ITER and techniques relevant for fusion reactor conditions need further development. Based on nuclear reactions, the activation probe is a novel concept first tested in JET. It may offer a more robust solution for performing alpha particle measurements in ITER. This paper describes the first escaping fast ion measurements performed at ASDEX Upgrade (AUG) tokamak using an activation probe. A detailed analysis, outside the scope of this contribution, will be published in a journal paper.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Placental growth factor-overexpressing myoblasts in treatment of ischemic heart failure

Einleitung. Die Prävalenz von Herzinsuffizienz nach Myokardinfarkt ist in industrialisierten Ländern steigend und die Herztransplantation stellt die letztmögliche Therapieform für Patienten in fortgeschrittenen Stadien (NYHA III-IV) dar. Aufgrund begrenzter Verfügbarkeit von Spenderorganen, sind Entwicklung und Einsatz alternativer Therapieansätze notwendig. So konnte in verschiedenen experimentellen Studien gezeigt werden, dass die Transplantation autologer Myoblasten in das ischämische Myokard die Herzfunktion verbessert, ventrikuläres Remodeling verringert und Gefäßneubildung steigert. Mit modifizierten, einen Wachstumsfaktor überexprimierenden Myoblasten können diese Ergebnisse weiter verbessert werden. Placental growth factor (PlGF), ein "Vascular Endothelial Growth Factor" Homolog induziert Angiogenese und beeinflußt Monozyten, glatte Muskelzellen und Endothelzellen, die alle in Arteriogenese involviert sind. Ziel dieser Arbeit war es, den Einfluss von PlGF überexprimierenden Myoblasten auf Herzfunktion, Myoblastenüberleben, Gefäßneubildung und ventrikuläres Remodeling in einem chronisch ischämischen Herzinsuffizienzmodell an der Ratte zu untersuchen. Materialien und Methoden. Sprague Dawley Ratten, die drei Wochen nach Induktion eines Myokardinfarktes eine ischämische Herzinsuffizienz entwickelten, erhielten intrakardiale Injektionen von Ringerlösung (Kontrolle), autologen Myoblasten (MB) oder PlGF überexprimierenden autologen Myoblasten (MB-PlGF). Die Herzfunktion wurde mittels Echokardiographie bis zum Tag 86 erfasst. Gefäßneubildung, Myoblastenüberleben und ventrikuläres Remodeling wurden mit histologischen und fluoreszierenden Methoden erhoben. Mittels RT-PCR und Western Blotting wurde mRNA und Proteinexpression im Gewebe gemessen. Resultate. In der MB-PlGF Gruppe verbesserte sich die linksventrikuläre Herzfunktion kontinuierlich und war am Tag 86 signifikant besser als in der Kontroll- und MB Gruppe. Sowohl Gefäßneubildung als auch das Überleben der transplantierten Myoblasten konnte in der MB-PlGF Gruppe signifikant gesteigert werden. Weiters reduzieren PlGF überexprimierende Myoblasten das ventrikuläre Remodeling, indem das Ausmaß der Fibrosierung verringert und die linksventrikuläre Infarktwanddicke erhöht werden. Schlussfolgerung. Intramyokardiale Injektion von PlGF überexprimierenden Myoblasten verbessert die Herzfunktion, reduziert ventrikuläres Remodeling, induziert Gefäßneubildung und erhöht das Überleben der Myoblasten in einem chronischen Herzinsuffizienzmodell an der Ratte.Introduction. In industrialized countries the prevalence of heart failure resulting from myocardial infarction is growing in incidence. Despite optimized treatment options, heart transplantation remains the only accepted treatment for end-stage patients with NYHA stage III-IV classified heart failure. Due to organ shortage, alternatives such as transplantation of autologous myoblasts have received tremendous interest. In various experimental studies it has been demonstrated that transplantation of autologous skeletal myoblasts improves cardiac function, decreases adverse cardiac remodeling and induces angiogenesis in the failing heart. These results are further significantly improved by creating modified, growth factor overexpressing myoblasts. Placental growth factor (PlGF), a vascular endothelial growth factor homologue, induces angiogenesis and influences cells involved in arteriogenesis: monocytes, smooth muscle cells and endothelial cells. Whether myoblasts engineered to overexpress PlGF improve cardiac function, enhance myoblast survival, induce angiogenesis or ameliorate adverse cardiac remodeling in an experimental rat model of chronic ischemic heart failure, is unknown. The aim of this doctoral thesis was to address this issue. Materials and Methods. Sprague Dawley rats developed heart failure three weeks after myocardial infarction and received intramyocardial injections of Ringer's solution (control), autologous unmodified myoblasts (MB) or MB transfected with a PlGF (MB-PlGF) expression plasmid. Cardiac function was assessed by echocardiography over time up to 86 days following engraftment. Immunocytochemistry and fluorescence imaging were used to investigate vessel formation, grafted myoblast survival, infarct wall thickness and infarct size. Quantitative real time RT-PCR and Western blotting were performed to measure tissue mRNA and protein expression. Results. In the MB-PlGF group left ventricular function improved over time and was significantly enhanced on day 86 compared to control and MB groups. Vascular density and myoblast survival were enhanced in rats treated with MB-PlGF. Further, MB-PlGF attenuated adverse ventricular remodeling by reducing mean fraction of fibrotic scar tissue and increasing left ventricular wall thickness. Conclusions. Intramyocardial injections of MB-PlGF improve cardiac function, attenuate adverse cardiac remodeling, induce angiogenesis and enhance the survival of grafted myoblasts.submitted by Matthias GmeinerAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheWien, Med. Univ., Diss., 2011OeBB(VLID)171544

Bowel perforation after ventriculoperitoneal-shunt placement: case report and review of the literature

Bowel perforation by a peritoneal catheter (BPPC) is a serious complication after ventriculoperitoneal shunting, with high mortality and morbidity rates. This patient presented with scalp ulceration over the shunt valve at the retromastoid region 26 years after shunt placement. During revision, the catheter distal to the valve was divided in the clavicular region. As there was no cerebrospinal fluid drainage, we decided to remove the ventricular catheter and valve. The ulceration was debrided and primarily closed. Distal to the clavicle, the disconnected peritoneal catheter was encased in a fibrous, calcified tunnel. To avoid piecemeal resection with multiple incisions, the catheter was not retrieved. Two years later, the patient presented with an abscess and pus draining from the clavicular wound. Cultures were positive for enteric bacteria. BPPC with retrograde spread of infection was suspected, and abdominal computed tomography confirmed perforation. We removed the disconnected catheter, but the perforation site could not be detected during laparotomy. The patient was treated with intravenous antibiotics and recovered without complications. To minimize complications, abandoned catheters should be avoided. Otherwise, patients unnecessarily have a life-long risk of developing abdominal complications. In patients with abandoned catheters and severe abdominal symptoms, BPPC is an important differential diagnosis

Persistent plasminogen activator inhibitor 1 gene expression in cardiac transplant recipients with idiopathic dilated cardiomyopathy

ObjectivesPlasminogen activator inhibitor 1 is the primary regulator of urokinase plasminogen activator and tissue plasminogen activator. Plasminogen activator inhibitor 1 is essential in the control of the thrombotic/fibrinolytic balance and is a marker of endothelial cell injury. Idiopathic dilated cardiomyopathy is reportedly associated with endothelial cell dysfunction. Whether endothelial cell damage plays a role in patients with dilated cardiomyopathy after cardiac transplantation remains unknown.MethodsIn this study explanted hearts of cardiac transplant recipients with ischemic cardiomyopathy and dilated cardiomyopathy, as well as control myocardial tissue, were investigated for expression of urokinase plasminogen activator, tissue plasminogen activator, urokinase plasminogen activator receptor, and plasminogen activator inhibitor 1 and 2. Furthermore, plasminogen activator inhibitor 1 expression was examined in endomyocardial biopsy specimens and sera of patients with ischemic cardiomyopathy and those with dilated cardiomyopathy during the first posttransplantation year. The effect of the patient's serum on endothelial cells was assessed in vitro to examine the role of circulating endothelial cell damage–related factors.ResultsPlasminogen activator inhibitor 1 expression was upregulated in ischemic cardiomyopathy and dilated cardiomyopathy myocardial tissue versus that seen in control tissue. After transplantation, plasminogen activator inhibitor 1 expression returned to control levels in patients with ischemic cardiomyopathy. In patients with dilated cardiomyopathy, plasminogen activator inhibitor 1 expression increased at 24 weeks after transplantation in both biopsy specimens and sera versus that seen in control tissue. Sera of patients with dilated cardiomyopathy, but not that of patients with ischemic cardiomyopathy, inhibited vascular endothelial growth factor A–induced proliferation of endothelial cells, although downstream target gene activation of early growth response factor 1 and NGFI-A binding protein 2 was not affected.ConclusionsThese data suggest for the first time that the endothelial cell damage–related process recurs in patients with dilated cardiomyopathy after transplantation, which, independently of vascular endothelial growth factor, is associated with increased plasminogen activator inhibitor 1 expression, and that this pathology might play a role in allograft remodeling in patients with dilated cardiomyopathy

Abdominal Pseudocysts and Peritoneal Catheter Revisions: Surgical Long-Term Results in Pediatric Hydrocephalus

Objective: An abdominal pseudocyst (APC) is a distal catheter site-specific failure in patients treated with ventriculoperitoneal shunts. Few studies with more than 10 patients have been reported. The aim of this study was to analyze causes of peritoneal catheter revisions with special emphasis on revisions because of an APC. Methods: Pediatric patients with first shunt operation between 1982 and 1992 were included, and time, cause, and modality of peritoneal catheter revision were determined retrospectively. Results: One hundred thirty-eight patients were treated for hydrocephalus, and 112 patients received a peritoneal catheter during the follow-up. An APC was diagnosed in 14 (12.5%) patients, and 28 revisions were needed for its treatment. The rate of shunt infection in patients with APC was 50%, but bacterial examination of the pseudofluid culture revealed infection in only 3 patients. Age at first surgical procedure, type of first surgical procedure, and etiology of hydrocephalus were not associated with APC diagnosis. APC recurred in 4 patients. These patients had a catheter repositioning directly into the peritoneum as first surgical treatment. No recurrences were observed in patients with shunt externalization or replacement of the peritoneal catheter. Conclusions: An APC is a major long-term complication after ventriculoperitoneal shunt treatment. Although a sterile inflammatory response cannot be excluded completely, our results favor the hypothesis of low-level shunt infection. In both cases, the surgical consequences are the same. An infected APC should be treated as a shunt infection. Uninfected patients can be treated with shunt externalization and replacement of only the peritoneal catheter

Long-term mortality rates in pediatric hydrocephalus—a retrospective single-center study

Purpose: Very long-term follow-up and outcome are rare for pediatric patients with hydrocephalus and shunt operations. The aim of this study was to determine the long-term mortality rates in these patients. Methods: Pediatric patients with first shunt operation between 1982 and 1992 were included. For each patient, time and cause of death were determined. Further, patients with first operation from 1982 to 1987 were compared to those first operated from 1988 to 1992. Results: One-hundred thirty-seven patients were included. Etiologies of hydrocephalus were intraventricular hemorrhage (31.4 %), meningomyelocele (25.5 %), postinfectious (11.7 %), congenital (10.2 %), posterior fossa cyst (8.8 %), aqueductal stenosis (8 %), and others (4.4 %). Overall, 53 patients (38.7 %) died. The percentage of patients surviving 1, 2, 10, and 20 years after first operation were 82.6, 73.6, 69.4, and 65.3 %, respectively. In 23 patients, the cause of death was related to shunt treatment: shunt infection was diagnosed in 18 and acute shunt dysfunction in 5 patients. Mortality was considerably higher for patients with their first operation in time period 1982–1987 compared to time period 1988–1992 (51 versus 25 %). The reduction of mortality was mainly due to an increased survival after shunt infection. Eighty-seven patients survived more than 20 years after initial shunt operation. Of those long-term survivors, three (3.4 %) patients died 22–24 years after first operation. Conclusion: Mortality in hydrocephalic pediatric patients is high especially in the first postoperative years but is even significant in adult patients with pediatric hydrocephalus. As deaths occur even after 20 years, routine follow-up of long-term survivors remains necessary

Sensitization to common ragweed in Southern Bavaria: clinical and geographical risk factors in atopic patients

Background: Sensitization to common ragweed (Ambrosia artemisiifolia) is associated with a variety of risk factors, which are incompletely defined. Our aim was to evaluate the association of a variety of clinical, geographical and demographical variables with ragweed sensitization and also to determine its frequency in southern Bavaria. Methods: In this cross-sectional multicentre study, we enrolled 977 patients with a documented or suspected atopic disease or food allergy. Data were collected on aeroallergen sensitization, age, sex, type and history of allergic disease, place of residence and potential local ragweed exposure. For this last variable, county ragweed cover was taken as a surrogate variable. Relative rates were calculated with multiple additive logistic regression models. Randomly selected patients with ragweed sensitization had a conjunctival provocation test. Results: According to skin prick tests, 190 patients (19.5%) were sensitized to ragweed. The frequency of this finding increased significantly with a rising number of additional sensitizations. Other less important predictors for a ragweed sensitization were male gender, mugwort sensitization, food allergy and a maximum of complaints in September or October. County of residence, extent of local ragweed cover or type of residential area were without relevance. Of 48 sensitized patients, 26 (54.2%) had a positive conjunctival provocation test. Discussion: Patients with multiple sensitizations may be more readily sensitized to a new aeroallergen. Local geographic or environmental conditions are presumably of minor importance for becoming sensitized to ragweed. The frequency of ragweed allergy among sensitized patients might be high

Adult Outcome in Shunted Pediatric Hydrocephalus: Long-Term Functional, Social, and Neurocognitive Results

Objective: Very long-term outcomes are rarely reported for patients with shunted pediatric hydrocephalus. This study aimed to determine the functional, social, and neurocognitive outcomes of such patients after transition to adulthood. Methods: Adult patients with pediatric hydrocephalus who underwent their first shunt operation between 1982 and 1992 were included. Functional, social, educational, working aspects, and verbal intelligence were evaluated. In patients with average or above average verbal intelligence, detailed neuropsychological testing was performed and memory, executive functioning, selective attention, and concentration were assessed. Results: Overall, 137 patients underwent primary surgery because of pediatric hydrocephalus, 53 (38.7%) of whom died during the follow-up period. Of the 84 long-term survivors, 65 (77.4%) agreed to participate and were included for further analysis. Forty-five patients (69.2%) had completed secondary school, but only 34 (52.3%) were integrated in the open labor market. Although the verbal intelligence of 31 patients (47.7%) was within the normal range, 19 (29.2%) had a severe mental handicap. Shunt infections (P = 0.0025), epilepsy (P < 0.0001), and the number of shunt operations (P = 0.0082) were associated with reduced verbal intelligence. Most patients with average or above average verbal intelligence had deficits in detailed neuropsychological testing. In 23 patients, detailed neuropsychological testing was performed. Conclusions: The overall long-term outcome of patients with shunted pediatric hydrocephalus is poor. These results highlight the importance of lifelong routine controls to avoid later complications. Further, repeated neuropsychological examinations might be important to understand the patient's special needs to optimize professional support

Development of a Fluorescent Ligand for the Intracellular Allosteric Binding Site of the Neurotensin Receptor 1

The membrane protein family of G protein-coupled receptors (GPCRs) represents a major class of drug targets. Over the last years, the presence of additional intracellular binding sites besides the canonical orthosteric binding pocket has been demonstrated for an increasing number of GPCRs. Allosteric modulators harnessing these pockets may represent valuable alternatives when targeting the orthosteric pocket is not successful for drug development. Starting from SBI-553, a recently discovered intracellular allosteric modulator for neurotensin receptor subtype 1 (NTSR1), we developed the fluorescent molecular probe 14. Compound 14 binds to NTSR1 with an affinity of 0.68 μM in the presence of the agonist NT(8–13). NanoBRET-based ligand binding assays with 14 were established to derive the affinity and structure–activity relationships for allosteric NTSR1 modulators in a direct and nonisotopic manner, thereby facilitating the search for and optimization of novel allosteric NTSR1 ligands. As a consequence of cooperativity between the ligands binding to the allosteric and orthosteric pocket, compound 14 can also be used to investigate orthosteric NTSR1 agonists and antagonists. Moreover, employing 14 as a probe in a drug library screening, we identified novel chemotypes as binders for the intracellular allosteric SBI-553 binding pocket of NTSR1 with single-digit micromolar affinity. These hits may serve as interesting starting points for the development of novel intracellular allosteric ligands for NTSR1 as a highly interesting yet unexploited drug target in the fields of pain and addiction disorder therapy