Photochromic histone deacetylase inhibitors based on dithienylethenes and fulgimides.

Histone deacetylases (HDACs) play a crucial role in numerous biological processes and therefore are targeted in anticancer research and in the field of epigenetics. Dithienylethenes (DTEs) and fulgimides were functionalized with hydroxamic acids, which is a known moiety binding to zinc dependent HDACs, to gain photoswitchable HDAC inhibitors. The new DTE based inhibitors showed moderate photochromic properties in polar solvents and the inhibitory activity changes up to a factor of four. The photochromic performance of the prepared fulgimide inhibitors was very good, even in aqueous buffer. They achieved a maximum three-fold difference in inhibitory activity. Docking experiments using the crystal structures of the tested enzymes gave a rationale for the observed moderate differences in the activities of the inhibitors.

Synthesis, biological characterisation and structure activity relationships of aromatic bisamidines active against Plasmodium falciparum.

Malaria is one of the most significant tropical diseases and remains a major challenge due to the lack of a broadly effective vaccine and parasite resistance to current drugs. This means there is a need for new drug candidates with novel modes of action. Aromatic bisamidines, such as furamidine (DB75), were initially developed as anti-Trypanosoma agents however as clinical trials with furamidine highlighted potential side effects they were not pursued further in that setting. Despite apparent cytotoxicity liabilities the potency of furamidine against Plasmodium falciparum makes it a promising scaffold for the development of new anti-Plasmodium agents with improved selectivity. In this study a bisamidine compound series based on furamidine was synthesized by introducing modifications at the furan core structure and terminal amidine groups. The activity of the derived compounds was tested in vitro against drug sensitive and resistant P. falciparum lines and a human cell line (HEK293 cells) to generate anti-Plasmodium structure-activity relationships and to provide preliminary selectivity data.

Biomarkers in Obesity: Serum Myeloperoxidase and Traditional Cardiac Risk Parameters.

BACKGROUND: Chronic low-grade inflammation, combined with traditional cardiovascular risk factors, is common in obesity, providing systemic inflammation that is associated with increased cardiovascular risk. Studies have shown serum mieloperoxidase as a potential biomarker and its clinical applicability for evaluating cardiovascular risk. This study aimed to evaluate the MPO in obese individuals, with or without systemic inflammation and potential cardiovascular risk, as well as correlating MPO with some classic cardiovascular risk parameters. METHODS: Inflammatory and cardiovascular risk markers, as well as different biochemical and hematological laboratory parameters, were analyzed. The volunteers were divided into 3 groups according to the presence (hs-CRP>3 mg/L) or absence (hs-CRP<3 mg/L) of systemic inflammation and possible cardiovascular risk. RESULTS: MPO was significantly increased (p<0.05) in the obese individuals with systemic inflammation. A significant increase (p<0.05) in the following biochemical parameters: glucose, HbA1c, triglycerides, non-HDL, TG/HDL was observed, and a significant decrease (p<0.01) in HDL was observed. Significant increases in the counts of total leukocytes, neutrophils and monocytes (p<0.01), as well as elevated blood pressure (p<0.05), were observed in the group of obese individuals with systemic inflammation. Serum MPO levels were correlated with classic proinflammatory and cardiovascular risk parameters. CONCLUSIONS: High serum levels of MPO were observed in obese individuals with hs-CRP above 3 mg/L, which is a classic biomarker for inflammation and cardiovascular risk, suggesting the potential role of MPO in clinical applicability for cardiovascular disease in this population. However, considering that inflammation in obesity appears to manifest as a non-classical mechanism, further studies are necessary to elucidate the role of MPO in cardiovascular events in the population with obesity.

The Hippo pathway is controlled by Angiotensin II signaling and its reactivation induces apoptosis in podocytes.

The Hippo pathway fulfills a crucial function in controlling the balance between proliferation, differentiation and apoptosis in cells. Recent studies showed that G protein-coupled receptors (GPCRs) serve as upstream regulators of Hippo signaling, that either activate or inactivate the Hippo pathway via the large tumor suppressor kinase (LATS) and its substrate, the co-transcription factor Yes-associated protein (YAP). In this study, we focused on the Angiotensin II type 1 receptor (AT1R), which belongs to the GPCR family and has an essential role in the control of blood pressure and water homeostasis. We found that Angiotensin II (Ang II) inactivates the pathway by decreasing the activity of LATS kinase; therefore, leading to an enhanced nuclear shuttling of unphosphorylated YAP in HEK293T cells. This shuttling of YAP is actin-dependent as disruption of the actin cytoskeleton inhibited dephosphorylation of LATS and YAP. Interestingly, in contrast to HEK293T cells, podocytes, which are a crucial component of the glomerular filtration barrier, display a predominant nuclear YAP localization in vivo and in vitro. Moreover, stimulation with Ang II did not alter Hippo pathway activity in podocytes, which show a deactivated pathway. Reactivation of the LATS kinase activity in podocytes resulted in an increased cytoplasmic YAP localization accompanied by a strong induction of apoptosis. Thus, our work indicates that the control of LATS activation and subsequent YAP localization is important for podocyte homeostasis and survival.

Reversible inhibition of calcineurin by the polyphenolic aldehyde gossypol.

The reversible inhibition of calcineurin (CaN), which is the only Ca(2+)/calmodulin-dependent protein Ser/Thr phosphatase, is thought to be a key functional event for most cyclosporin A (CsA)- and tacrolimus (FK506)-mediated biological effects. In addition to CaN inhibition, however, CsA and FK506 have multiple biochemical effects because of their action in a gain-of-function model that requires prior binding to immunophilic proteins. We screened a small molecule library for direct inhibitors of CaN using CaN-mediated dephosphorylation of (33)P-labeled 19-residue phosphopeptide substrate (RII phosphopeptide) as an assay and found the polyphenolic aldehyde gossypol to be a novel CaN inhibitor. Unlike CsA and FK506, gossypol does not require a matchmaker protein for reversible CaN inhibition with an IC(50) value of 15 microm. Gossypolone, a gossypol analog, showed improved inhibition of both RII phosphopeptide and p-nitrophenyl phosphate dephosphorylation with an IC(50) of 9 and 6 microm, respectively. In contrast, apogossypol hexaacetate was inactive. Gossypol acts noncompetitively, interfering with the binding site for the cyclophilin 18.CsA complex in CaN. In contrast to CsA and FK506, gossypol does not inactivate the peptidyl-prolyl-cis/trans-isomerase activity of immunophilins. Similar to CsA and FK506, T cell receptor signaling induced by phorbol 12-myristate 13-acetate/ionomycin is inhibited by gossypol in a dose-dependent manner, demonstrated by the inhibition of nuclear factor of activated T cell (NFAT) c1 translocation from the cytosol into the nucleus and suppression of NFAT-luciferase reporter gene activity.

[Detection of the cholinesterase inhibitor tacrine and its main metabolites]. / Nachweis des Cholinesterasehemmers Tacrin und seiner Hauptmetaboliten.

Tacrine, a cholinesterase inhibitor for symptomatic treatment of minor to moderate dementia, and its primary metabolites 1-hydroxy-tacrine and 4-hydroxy-tacrine were studied by means of thin-layer chromatography, UV spectroscopy and gas-chromatography/mass spectroscopy. The analytical data (corrected hRf values, UV spectra in solution as well as reflectance spectra, high-pressure liquid chromatography data, GC retention indices and EI mass spectra) including various derivatization methods are described.

Multiple homicides as a result of chloroform poisoning: case report and experimental study.

Two cases (involving five murder victims) of multiple homicide by inhalational chloroform intoxication are reported. In the discussion of the findings the valence of toxicological analyses is underlined with regard to the possibility of forcible external suffocation due to occlusion of the respiratory orifices by means of a chloroform-soaked soft covering. In addition storage experiments were performed at +4, +20 and -20 degrees C with cadaver blood mixed with chloroform. The optimal solution for avoiding volatile losses was stored in glass tubes with ground glass stoppers. In cases of unclear death in which involvement of volatile substances is suspected it is, therefore, advisable to preserve an additional blood sample at -20 degrees C in glass tubes that are only opened for the analysis of volatile substances.

Different utilization of neutral lipids by Malassezia furfur and Malassezia sympodialis.

In recent years, the genus Malassezia has been expanded based on molecular data; in addition to M. furfur and M. pachydermatis, five new species (M. sympodialis, M. globosa, M. obtusa, M. restricta, M. slooffiae) have been described. Apart from their lipid dependence, little is known about the metabolism and nutritional requirements of these new species. Defined inocula of Malassezia reference strains were cultured on selective agar for pathogenic fungi which was overlaid with olive oil. Samples of the olive oil overlay were taken at regular intervals and the lipid fractions were analysed by high performance thin layer chromatography. Depending on the time of incubation and the number of cells, M. sympodialis and the other recently described species produced a significant increase in free fatty acids. In addition, a band of an apolar substance was identified as a mixture of fatty acid ethyl esters. While showing growth, strains of M. furfur produced only small amounts of ethyl esters and free fatty acids. The growth kinetics of M. furfur and M. sympodialis were also different: for M. sympodialis, a clear lag phase was observed, possibly indicating the necessity of extracellular hydrolysis of the triglycerides. The significance of the synthesis of ethyl esters could not be clarified. For routine differentiation, this metabolic difference is only of limited usefulness because slight contamination of M. furfur strains with other lipophilic Malassezia species may lead to misinterpretation due to the high metabolic activity. These metabolic differences might be important in the pathogenesis of Malassezia infections.

[Analytical confirmation of error in false positive amphetamine immunoassays and results]. / Fehlerhafte Bestätigungsanalytik bei falsch-positiven Amphetamin-Immunoassays und ihre Auswirkungen.

Numerous urine samples were found to be positive when using a new amphetamine immunoassay (AxSYM). Confirmation analysis was carried out in a second laboratory at "reasonable prices" using a simple TLC-method with non specific ninhydrine detection and resulted in many "positive" confirmation findings. The GC/MS analysis clearly indicated the absence of amphetamine derivatives regularly encountered in forensic toxicology. The false-positive immunochemical findings may probably be caused by endogenous substances.

[Experiences with congener analysis of beverages without congeners]. / Erfahrungen mit Begleitstoffanalysen bei Getränken (Nachtrunk) ohne Begleitstoffe.

Many alcoholic beverages contain no forensically relevant concentrations of congeners. Despite this fact they can be subject of a congener analysis. Another applicability of congener analyses are cases in connection with a differentiation between the short- or longterm ingestion of beverages containing 1-propanol and iso-butanol as congeners (e.g. beer or wine).

[Critical questions regarding standard deviation as a precision parameter of blood alcohol determination]. / Kritische Fragen zur Standardabweichung als Präzisionsparameter der Blutalkoholbestimmung.

The relative absolute standard deviation, which was introduced for the control of the precision of blood alcohol-determinations by the BGH reveals, that according to technical rules the admissible standard deviation in the range of higher blood alcohol concentrations is exceeded despite the fact, that the width of the variation is still in the acceptable range. The standard deviation of 0.05% should therefore only be applied to the blood alcohol range up to 1.5%. As an alternative the coefficient of variation can be chosen for the precision control.

[An improved screening program for 160 pesticides]. / Ein optimiertes Screeningprogramm für 170 Pestizide.

A screening system for 170 pesticides is reported. The following analytical methods are used: TLC (corrected Rf-value), GLC (retention index) and UV-spectroscopy. Also quantitative aspects are mentioned when modern TLC-scanners are applied.

A TLC screening program for 170 commonly used pesticides using the corrected Rf value (Rf(c) value).

This article reports TLC data (corrected Rf values; Rf(c) values) of 170 commonly used pesticides which are regularly encountered in toxicological analysis. Silica gel was used as the stationary phase and three binary systems were chosen as solvents.

[Screening and detection of quazepam and its metabolites]. / Screening und Nachweis von Quazepam und seinen Metaboliten.

The paper describes a sensitive screening procedure for 7-chloro-5-(2-fluorophenyl)-1,3-dihydro-1-(2,2,2-trifluoroethyl)-2H-1,4- benzodiazepine-2-thione (quazepam, Oniria, Quazium) and its major metabolites.

[Screening of the new benzodiazepine derivative, pinazepan, and its major metabolites]. / Screening des neuen Benzodiazepin-Derivates Pinazepam und seiner Hauptmetaboliten.

The paper describes a sensitive method for the detection of 7-chloro-2,3-dihydro-5-phenyl-1-(2-propinyl)-1H-1,4-benzodiazepine -2-one (pinazepam, Domar) and its major metabolites.