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The L-type Ca2+ channel CaV1.2 controls gene expression, cardiac contraction, and neuronal activity. Calmodulin (CaM) governs CaV1.2 open probability (Po) and Ca2+-dependent inactivation (CDI) but the mechanisms remain unclear. Here, we present electrophysiological data that identify a half Ca2+-saturated CaM species (Ca2/CaM) with Ca2+ bound solely at the third and fourth EF-hands (EF3 and EF4) under resting Ca2+ concentrations (50-100nM) that constitutively preassociates with CaV1.2 to promote Po and CDI. We also present an NMR structure of a complex between the CaV1.2 IQ motif (residues 1644-1665) and Ca2/CaM12', a calmodulin mutant in which Ca2+ binding to EF1 and EF2 is completely disabled. We found that the CaM12' N-lobe does not interact with the IQ motif. The CaM12' C-lobe bound two Ca2+ ions and formed close contacts with IQ residues I1654 and Y1657. I1654A and Y1657D mutations impaired CaM binding, CDI, and Po, as did disabling Ca2+ binding to EF3 and EF4 in the CaM34 mutant when compared to WT CaM. Accordingly, a previously unappreciated Ca2/CaM species promotes CaV1.2 Po and CDI, identifying Ca2/CaM as an important mediator of Ca signaling.

Diabetic vasculopathy is a significant cause of morbidity and mortality in the diabetic population. Hyperglycemia, one of the central metabolic abnormalities in diabetes, has been associated with vascular dysfunction due to endothelial cell damage. However, studies also point toward vascular smooth muscle as a locus for hyperglycemia-induced vascular dysfunction. Emerging evidence implicates hyperglycemia-induced regulation of vascular L-type Ca

The L-type Ca

The L-type Ca2+ channel CaV1.2 controls gene expression, cardiac contraction, and neuronal activity. Calmodulin (CaM) governs CaV1.2 open probability (Po) and Ca2+-dependent inactivation (CDI) but the mechanisms remain unclear. We identified a half Ca2+-saturated CaM species (Ca2/CaM) with Ca2+ bound solely at the third and fourth EF-hands (EF3 and EF4) under resting Ca2+ concentrations (50-100 nM) that constitutively pre-associates with CaV1.2 to promote Po and CDI. We present an NMR structure of a complex between the CaV1.2 IQ motif (residues 1644-1665) and Ca2/CaM12’, a calmodulin mutant in which Ca2+ binding to EF1 and EF2 is completely disabled. The CaM12’ N-lobe does not interact with the IQ motif. The CaM12’ C-lobe bound two Ca2+ ions and formed close contacts with IQ residues I1654 and Y1657. I1654A and Y1657D mutations impaired CaM binding, CDI, and Po, as did disabling Ca2+ binding to EF3 and EF4 in the CaM34 mutant when compared to wildtype CaM. Accordingly, a previously unappreciated Ca2/CaM species promotes CaV1.2 Po and CDI identifying Ca2/CaM as an important mediator of Ca signaling.

Several Conus-derived venom peptides are promising lead compounds for the management of neuropathic pain, with α-conotoxins being of particular interest. Modification of the interlocked disulfide framework of α-conotoxin Vc1.1 has been achieved using on-resin alkyne metathesis. Although introduction of a metabolically stable alkyne motif significantly disrupts backbone topography, the structural modification generates a potent and selective GABAB receptor agonist that inhibits Cav2.2 channels and exhibits dose-dependent reversal of mechanical allodynia in a behavioral rat model of neuropathic pain. The findings herein support the hypothesis that analgesia can be achieved via activation of GABABRs expressed in dorsal root ganglion (DRG) sensory neurons.

A novel 4/8 subtype α-conotoxin, Vt1.27 (NCCMFHTCPIDYSRFNC-NH2), was identified from Conus vitulinus in the South China Sea by RACE methods. The peptide was synthesized and structurally characterized. Similar to other α-conotoxins that target neuronal nicotinic acetylcholine receptor (nAChR) subtypes, Vt1.27 inhibited the rat α3β2 nAChR subtype (IC50 = 1160 nM) and was inactive at voltage-gated sodium and potassium channels in rat sensory neurons. However, Vt1.27 inhibited high voltage-activated N-type (CaV2.2) calcium channels expressed in HEK293T cells with an IC50 of 398 nM. An alanine scan of the peptide showed that residues Phe5, Pro9, Ile10, and Ser13 contribute significantly to the inhibitory activity of Vt1.27. The molecular dockings indicate that Vt1.27 inhibits the transmembrane region of CaV2.2, which is different from that of ω-conotoxins. Furthermore, Vt1.27 exhibited potent anti-allodynic effect in rat partial sciatic nerve injury (PNL) and chronic constriction injury (CCI) pain models at 10 nmol/kg level with the intramuscular injection. The pain threshold elevation of Vt1.27 groups was higher than that of α-conotoxin Vc1.1 in CCI rat models. These findings expand our knowledge of targets of α-conotoxins and potentially provide a potent, anti-allodynic peptide for the treatment of neuropathic pain.

Ca(2+) influx through the L-type Ca(2+) channel Cav1.2 triggers each heartbeat. The fight or flight response induces the release of the stress-response hormone norepinephrine to stimulate β adrenergic receptors, cAMP production, and protein kinase A activity to augment Ca(2+) influx through Cav1.2 and consequently cardiomyocyte contractility. Emerging evidence shows that Cav1.2 is regulated by different mechanisms in cardiomyocytes compared to neurons and vascular smooth muscle cells.

Ca2+ influx through the L-type Ca2+ channel Cav1.2 triggers each heartbeat. The fight-or-flight response induces the release of the stress response hormone norepinephrine to stimulate β-adrenergic receptors, cAMP production, and protein kinase A activity to augment Ca2+ influx through Cav1.2 and, consequently, cardiomyocyte contractility. Emerging evidence shows that Cav1.2 is regulated by different mechanisms in cardiomyocytes compared to neurons and vascular smooth muscle cells.

Drosophilaphotoreceptors respond to oscillating light of high frequency (∼100 Hz), while the detected maximal frequency is modulated by the light rearing conditions, thus enabling high sensitivity to light and high temporal resolution. However, the molecular basis for this adaptive process is unclear. Here, we report that dephosphorylation of the light-activated transient receptor potential (TRP) ion channel at S936 is a fast, graded, light-dependent, and Ca2+-dependent process that is partially modulated by the rhodopsin phosphatase retinal degeneration C (RDGC). Electroretinogram measurements of the frequency response to oscillating lightsin vivorevealed that dark-reared flies expressing wild-type TRP exhibited a detection limit of oscillating light at relatively low frequencies, which was shifted to higher frequencies upon light adaptation. Strikingly, preventing phosphorylation of the S936-TRP site by alanine substitution in transgenicDrosophila(trpS936A) abolished the difference in frequency response between dark-adapted and light-adapted flies, resulting in high-frequency response also in dark-adapted flies. In contrast, inserting a phosphomimetic mutation by substituting the S936-TRP site to aspartic acid (trpS936D) set the frequency response of light-adapted flies to low frequencies typical of dark-adapted flies. Light-adaptedrdgCmutant flies showed relatively high S936-TRP phosphorylation levels and light–dark phosphorylation dynamics. These findings suggest that RDGC is one but not the only phosphatase involved in pS936-TRP dephosphorylation. Together, this study indicates that TRP channel dephosphorylation is a regulatory process that affects the detection limit of oscillating light according to the light rearing condition, thus adjusting dynamic processing of visual information under varying light conditions.SIGNIFICANCE STATEMENTDrosophilaphotoreceptors exhibit high temporal resolution as manifested in frequency response to oscillating light of high frequency (≤∼100 Hz). Light rearing conditions modulate the maximal frequency detected by photoreceptors, thus enabling them to maintain high sensitivity to light and high temporal resolution. However, the precise mechanisms for this process are not fully understood. Here, we show by combination of biochemistry andin vivoelectrophysiology that transient receptor potential (TRP) channel dephosphorylation at a specific site is a fast, light-activated and Ca2+-dependent regulatory process. TRP dephosphorylation affects the detection limit of oscillating light according to the adaptation state of the photoreceptor cells by shifting the detection limit to higher frequencies upon light adaptation. This novel mechanism thus adjusts dynamic processing of visual information under varying light conditions.

G protein-coupled receptors (GPCRs) transduce pleiotropic intracellular signals in mammalian cells. Here, we report neuronal excitability of β-blockers carvedilol and alprenolol at clinically relevant nanomolar concentrations. Carvedilol and alprenolol activate β2AR, which promote G protein signaling and cAMP/PKA activities without action of G protein receptor kinases (GRKs). The cAMP/PKA activities are restricted within the immediate vicinity of activated β2AR, leading to selectively enhance PKA-dependent phosphorylation and stimulation of endogenous L-type calcium channel (LTCC) but not AMPA receptor in rat hippocampal neurons. Moreover, we have engineered a mutant β2AR that lacks the catecholamine binding pocket. This mutant is preferentially activated by carvedilol but not the orthosteric agonist isoproterenol. Carvedilol activates the mutant β2AR in mouse hippocampal neurons augmenting LTCC activity through cAMP/PKA signaling. Together, our study identifies a mechanism by which β-blocker-dependent activation of GPCRs promotes spatially restricted cAMP/PKA signaling to selectively target membrane downstream effectors such as LTCC in neurons.

Ehrlich gesagt habe ich mich immer ein bisschen gewundert, wenn ich auf das Klischee gestosen bin, in Deutschland gebe es keine strategische Community, keine sicherheitspolitischen Think Tanks, keine ordentliche Debatte. Armes Deutschland! Viele einschlagige Wissenschaftler, Grosjournalisten und Ex-Militars redeten und reden gerne so. Sie konnen das auch auf Englisch sagen. Der angelsachsische Diskussionsraum gilt fur grosere Teile unserer Expertenschaft sowieso als Ideal schlechthin. Und wir haben ubrigens tatsachlich ziemlich viele Experten.

We here describe a novel α-conopeptide, Eu1.6 from Conus eburneus, which exhibits strong anti-nociceptive activity by an unexpected mechanism of action. Unlike other α-conopeptides that largely target nicotinic acetylcholine receptors (nAChRs), Eu1.6 displayed only weak inhibitory activity at the α3β4 and α7 nAChR subtypes and TTX-resistant sodium channels, and no activity at TTX-sensitive sodium channels in rat dorsal root ganglion (DRG) neurons, or opiate receptors, VR1, KCNQ1, L- and T-type calcium channels expressed in HEK293 cells. However, Eu1.6 inhibited high voltage-activated N-type calcium channel currents in isolated mouse DRG neurons which was independent of GABAB receptor activation. In HEK293 cells expressing CaV2.2 channels alone, Eu1.6 reversibly inhibited depolarization-activated Ba2+ currents in a voltage- and state-dependent manner. Inhibition of CaV2.2 by Eu1.6 was concentration-dependent (IC50 ~1 nM). Significantly, systemic administration of Eu1.6 at doses of 2.5–5.0 μg/kg exhibited potent analgesic activities in rat partial sciatic nerve injury and chronic constriction injury pain models. Furthermore, Eu1.6 had no significant side-effect on spontaneous locomotor activity, cardiac and respiratory function, and drug dependence in mice. These findings suggest α-conopeptide Eu1.6 is a potent analgesic for the treatment of neuropathic and chronic pain and opens a novel option for future analgesic drug design.

α-Conotoxin RgIA is both an antagonist of the α9α10 nicotinic acetylcholine receptor (nAChR) subtype and an inhibitor of high-voltage-activated N-type calcium channel currents. RgIA has therapeutic potential for the treatment of pain, but reduction of the disulfide bond framework under physiological conditions represents a potential liability for clinical applications. We synthesized four RgIA analogues that replaced native disulfide pairs with nonreducible dicarba bridges. Solution structures were determined by NMR, activity assessed against biological targets, and stability evaluated in human serum. [3,12]-Dicarba analogues retained inhibition of ACh-evoked currents at α9α10 nAChRs but not N-type calcium channel currents, whereas [2,8]-dicarba analogues displayed the opposite pattern of selectivity. The [2,8]-dicarba RgIA analogues were effective in HEK293 cells stably expressing human Cav2.2 channels and transfected with human GABAB receptors. The analogues also exhibited improved serum stability over the native peptide. These selectively acting dicarba analogues may represent mechanistic probes to explore analgesia-related biological receptors.

To directly address in vivo significance of the altered CaV1.2 channel property arising from alternative splicing, we generated CaV1.2 exon 33-specific knockout (exon 33−/−) mice. Here, we showed that the exclusion of alternative exon 33 altered CaV1.2 biophysical property, leading to greater ICa density. This increase in current density induced prolongation of ventricular cardiomyocyte action potential duration, and the cardiomyocytes exhibited increased early afterdepolarizations and autonomous action potentials—hallmarks of arrhythmias. In vivo, exon 33−/− mice had increased occurrences of premature ventricular contractions, tachycardia, and lengthened QT interval. As such, exclusion of exon 33 of the CaV1.2 channel is proarrhythmogenic. Although failing human hearts had greater inclusion of exon 33, it is unclear whether the inclusion is compensatory, neutral, or damaging.

Alternative splicing changes the CaV1.2 calcium channel electrophysiological property, but the in vivo significance of such altered channel function is lacking. Structure-function studies of heterologously expressed CaV1.2 channels could not recapitulate channel function in the native milieu of the cardiomyocyte. To address this gap in knowledge, we investigated the role of alternative exon 33 of the CaV1.2 calcium channel in heart function. Exclusion of exon 33 in CaV1.2 channels has been reported to shift the activation potential -10.4 mV to the hyperpolarized direction, and increased expression of CaV1.2Δ33 channels was observed in rat myocardial infarcted hearts. However, how a change in CaV1.2 channel electrophysiological property, due to alternative splicing, might affect cardiac function in vivo is unknown. To address these questions, we generated mCacna1c exon 33-/--null mice. These mice contained CaV1.2Δ33 channels with a gain-of-function that included conduction of larger currents that reflects a shift in voltage dependence and a modest increase in single-channel open probability. This altered channel property underscored the development of ventricular arrhythmia, which is reflected in significantly more deaths of exon 33-/- mice from β-adrenergic stimulation. In vivo telemetric recordings also confirmed increased frequencies in premature ventricular contractions, tachycardia, and lengthened QT interval. Taken together, the significant decrease or absence of exon 33-containing CaV1.2 channels is potentially proarrhythmic in the heart. Of clinical relevance, human ischemic and dilated cardiomyopathy hearts showed increased inclusion of exon 33. However, the possible role that inclusion of exon 33 in CaV1.2 channels may play in the pathogenesis of human heart failure remains unclear.

Drosophila photoreceptors respond to oscillating light of high frequency (∼100 Hz), while the detected maximal frequency is modulated by the light rearing conditions, thus enabling high sensitivity to light and high temporal resolution. However, the molecular basis for this adaptive process is unclear. Here, we report that dephosphorylation of the light-activated transient receptor potential (TRP) ion channel at S936 is a fast, graded, light-dependent, and Ca2+-dependent process that is partially modulated by the rhodopsin phosphatase retinal degeneration C (RDGC). Electroretinogram measurements of the frequency response to oscillating lights in vivo revealed that dark-reared flies expressing wild-type TRP exhibited a detection limit of oscillating light at relatively low frequencies, which was shifted to higher frequencies upon light adaptation. Strikingly, preventing phosphorylation of the S936-TRP site by alanine substitution in transgenic Drosophila (trpS936A) abolished the difference in frequency response between dark-adapted and light-adapted flies, resulting in high-frequency response also in dark-adapted flies. In contrast, inserting a phosphomimetic mutation by substituting the S936-TRP site to aspartic acid (trpS936D) set the frequency response of light-adapted flies to low frequencies typical of dark-adapted flies. Light-adapted rdgC mutant flies showed relatively high S936-TRP phosphorylation levels and light–dark phosphorylation dynamics. These findings suggest that RDGC is one but not the only phosphatase involved in pS936-TRP dephosphorylation. Together, this study indicates that TRP channel dephosphorylation is a regulatory process that affects the detection limit of oscillating light according to the light rearing condition, thus adjusting dynamic processing of visual information under varying light conditions.

Weil Demokratie sich nicht von selbst versteht, brauchen wir immer besondere Anstrengungen, um sicher sein zu konnen, dass sie von Dauer ist und nicht hohl wird oder eines Tages wieder mal kippt. Zahlen belegen: Viele Burger wissen zu wenig uber ihre eigenen Rechte und Moglichkeiten, uber Parteien, Parlamente und Regierungen und daruber, wie dort tatsachlich gearbeitet und entschieden wird. Schule, Medien, politische Bildung und Politikbetrieb tragen zu dem Bild bei, das wir vom Funktionieren unseres demokratischen Gemeinwesens haben. Dieses Bild wird allzu oft zum Zerrbild. Hans-Peter Bartels pladiert fur mehr und neue Anstrengungen in der „Demokratiepolitik“: in der Lehrerausbildung und in der Schule, in der politischen Bildung und im Politikbetrieb, in den Medien und in der Journalistenausbildung.

Sediments of the Elbe River have been extremely polluted by contaminants originating from previous large-scale hexachlorocyclohexane (HCH) production and the application of γ-HCH (lindane) in its catchment in the second half of the twentieth century. In order to gain knowledge on bioaccumulation processes at lower trophic levels, field investigations of HCHs in macroinvertebrates were carried out along the longitudinal profile of the Elbe and tributary. Among the sites studied, concentrations in macroinvertebrates ranged within five orders of magnitude (0.01–100 μg/kg). In general, lower values of HCH isomers were observed at all Czech sites (mostly

We investigated the biophysical mechanism of inhibition of recombinant T-type calcium channels Ca(V)3.1 and Ca(V)3.2 by nitrous oxide (N(2)O). To identify functionally important channel structures, chimeras with reciprocal exchange of the N-terminal domains I and II and C-terminal domains III and IV were examined. In whole-cell recordings N(2)O significantly inhibited Ca(V)3.2, and - less pronounced - Ca(V)3.1. A Ca(V)3.2-prevalent inhibition of peak currents was also detected in cell-attached multi-channel patches. In cell-attached patches containing < or = 3 channels N(2)O reduced average peak current of Ca(V)3.2 by decreasing open probability and open time duration. Effects on Ca(V)3.1 were smaller and mediated by a reduced fraction of sweeps containing channel activity. Without drug, single Ca(V)3.1 channels were significantly less active than Ca(V)3.2. Chimeras revealed that domains III and IV control basal gating properties. Domains I and II, in particular a histidine residue within Ca(V)3.2 (H191), are responsible for the subtype-prevalent N(2)O inhibition. Our study demonstrates the biophysical (open times, open probability) and structural (domains I and II) basis of action of N(2)O on Ca(V)3.2. Such a fingerprint of single channels can help identifying the molecular nature of native channels. This is exemplified by a characterization of single channels expressed in human hMTC cells as functional homologues of recombinant Ca(V)3.1.

Diclofenac, as one of the most popular antiphlogistics, is produced in great quantities. Nowadays this drug is ubiquitously present in the aquatic environment due to its resistance to biodegradation. Degradation by ultrasonic irradiation is a possibility to eliminate diclofenac from water without the addition of chemicals. The sonolysis of diclofenac in water was investigated at ultrasound frequencies of 24 kHz, 216 kHz, 617 kHz, and 850 kHz and in the presence of various catalysts (TiO 2 , SiO 2 , SnO 2 , and titanosilicate). The degradation of diclofenac by sonolysis of an aqueous solution at 617 kHz followed first-order kinetics. Catalysts, especially TiO 2 increased the rate of degradation. Within 30 min of irradiation, the relative concentration of diclofenac decreased from 100% to 16%. By HPLC and GC-MS methods, chlorinated anilines, phenols and carboxylic acid derivatives were detected as a result of the sonolysis. About 35% of organic chlorine was transformed into inorganic chloride. Most of the identified degradation products in the sonolysis of diclofenac were the same compounds that were detected during photo-oxidation experiments with this anti-inflammatory drug.

Objectives: Cardiac troponins T (cTnT) and I (cTnI) are the most sensitive biochemical parameters in the detection of myocardial damage. In neonates, in utero exposure to tocolytic therapy results in detectable values of cardiac troponins after delivery. Additionally, some preliminary results suggest that the upper reference limits for healthy newborns are higher than those for adults but definitive reference limits for newborns are not available. Our objective was to determine those limits. Design and methods: In this study we investigated the distribution of cTnT and cTnI in cord blood of 869 healthy newborns. cTnT was determined with the 3rd generation assay and cTnI with the Dade Behring assay on a Dimension RxL. For data analysis Student's t test and the Mann–Whitney U test were used. Results: Using the 99th percentile, the upper reference limit in healthy termed newborns was 0.097 μg/l for cTnT and 0.183 μg/l for cTnI. Compared to the adult values, the newborn upper limit was tripled for cTnT and doubled for cTnI. Statistically significant differences were found between males and females for cTnT and between natural childbirth and caesarean section for cTnI. Conclusion: Healthy-termed newborns have a higher upper reference limit for both cTnT and cTnI compared to adults. This circumstance must be taken into account when interpreting slightly “elevated” cTnT and cTnI values in newborns.

Entwassertes Manganchlorid und -bromid reagiert mit 2,3-Dicyanonaphthalin in Ethylenglycol zu grunem, schwerloslichen Halogeno-2,3-naphthalocyaninatomangan(III), [Mn(X)nc2–] (X = Cl, Br). Die magnetischen Momente (μeff £ 5,3 μB, 300 K) bestatigen einen elektronischen high-spin-d4-Grundzustand fur penta-koordiniertes MnIII. In den elektronischen Absorptionsspektren beobachtet man (in cm–1) den B- (∼ 11200), Q- (20000–28000), N- (∼ 35000) und L-Bereich (39600). Weitere Banden bei 5300/7200 und 16200/17600 cm–1 werden spinerlaubten Trip-Quintett-Ubergangen (TQ1 und TQ2) zugeordnet. Die (Mn–X)-Valenzschwingung liegt bei 283 cm–1 (X = Cl) und 223 cm–1 (X = Br); ihre Intensitat wird bei Koinzidenz der Anregungsfrequenz der Resonanz-Raman-Spektren mit dem TQ2-Ubergang selektiv verstarkt. Die spektroskopischen Eigenschaften werden mit denen der analogen MnIII-Phthalocyaninate verglichen. Trip-Multiplet Transitions and Resonance Raman Spectra of Halo-2,3-naphthalocyaninato(2–)manganese(III) and Comparison with Halophthalocyaninato(2–)manganese(III) Dehydrated manganese chloride and bromide reacts with 2,3-dicyanonaphthalene in ethylene glycol yielding green, scarcely soluble halo-2,3-naphthalocyaninato(2–)manganese(III), [Mn(X)nc2–] (X = Cl, Br). The magnetic moment (μeff £ 5.3 μB at 300 K) confirms the electronic high-spin d4 ground-state of penta-coordinated MnIII. The electronic absorption spectra show (in cm–1) the typical B (∼ 11200), Q (20000–28000), N (34600) and L region (39600). Additional bands at 5300/7200 cm–1 and 16200/17600 cm–1 are attributed to spin-allowed trip-quintet transitions (TQ1, TQ2). The Mn–X stretching vibration is at 283 cm–1 (X = Cl) and 223 cm–1 (X = Br), respectively; its intensity is selectively enhanced by coincidence of the excitation frequency of the resonance Raman spectra with TQ2. The spectroscopic properties are compared to those of the structurally related MnIII phthalocyaninates.

Parteien-, Politik- und Politikerverachtung gehoren in Deutschland (wie in vielen anderen etablierten Demokratien) zum guten Ton. Auf Dauer aber kann ein demokratisches Gemeinwesen nur ein begrenztes Mas dieser Haltung ertragen.

Since the efficacy of oseltamivir carboxylate (OC) as the active metabolite of Tamiflu has been demonstrated against influenza viruses and even against the avian influenza virus (H5N1), millions of Tamiflu treatment courses are stockpiled worldwide. This was done not at least to follow the recommendations of the World Health Organization (WHO) to cope with a viral influenza pandemic. Concentrations up to 26-32 microg l(-1) OC in river catchment areas in the United States and in the United Kingdom had been predicted recently for a pandemic case, assuming an apparent persistence of the Tamiflu metabolite. Such concentrations may involve the risk of generation of antiviral resistance. But there is still a lack of data concerning the stability of OC in a surface water environment. Under this aspect these predictions have to be validated with concrete facts about the environmental fate of OC. In this article we summarized the results of three different daylight exposure experiments with OC in different waters under sterile and non-sterile conditions simulating shallow water processes at the latitude of approximately 52 degrees N. Using a river water solution containing 50 microg l(-1) OC under non-sterile conditions a half-life time of 17.8 days was observed. Direct photolysis plays no or only a negligible role for the decomposition of OC. Degradation of OC seems to occur as a combination of microbial metabolism and indirect photolysis.

The occurrence of pharmaceuticals in the environment is an emerging issue. Several studies observed that the non-steroidal anti-inflammatory drug diclofenac is ubiquitously present in most of the surveyed surface waters, worldwide. Phototransformation of diclofenac was reported from laboratory assays as well as in natural water systems, raising the question of possible adverse effects of the phototransformation products of diclofenac to aquatic organisms. In this study the phytotoxicity of diclofenac exposed to natural sunlight was evaluated using synchronized cultures of the unicellular chlorophyte Scenedesmus vacuolatus. Diclofenac dissolved in ultra-pure water at 50 mg L(-1) was exposed to natural midsummer sunlight for a maximum of 145 h. Twice a day subsamples were taken for chromatography and parallel phytotoxicity assessment. Inhibition of algal reproduction of the initial diclofenac solution was in the mg L(-1) range indicating no specific toxicity of diclofenac towards S. vacuolatus. Fast degradation of diclofenac was observed with half lives between 3.3 and 6.4 h during the first and the third day of exposure, respectively. Phytotoxicity increased after 3.5 h of exposure of diclofenac to sunlight and showed a maximum of sixfold enhanced toxicity after 53 h of exposure to sunlight. Several phototransformation products were found during the experiment. The time courses of the relative concentration of three transformation products significantly correlated with enhanced phytotoxicity during the experiment. This indicates a high toxicity potential of phototransformation products of diclofenac at concentration levels that may come close to environmental concentrations of residual diclofenac after degradation. We conclude that toxicity assessment of phototransformation products should be included in the risk assessment of pharmaceuticals in the environment.

Diclofenac can be detected in surface water of many rivers with human impacts worldwide. The observed decrease of the diclofenac concentration in waters and the formation of its photochemical transformation products under the impact of natural irradiation during one to 16 days are explained in this article. In semi-natural laboratory tests and in a field experiment it could be shown, that sunlight stimulates the decomposition of diclofenac in surface waters. During one day intensive solar radiation in middle European summer diclofenac decomposes in the surface layer of the water (0 to 5 cm) up to 83%, determined in laboratory exposition experiments. After two weeks in a field experiment, the diclofenac was not detectable anymore in the water surface layer (limit of quantification: 5 ng/L). At a water depth of 50 cm, within two weeks 96% of the initial concentration was degraded, while in 100 cm depth 2/3 of the initial diclofenac concentration remained. With the decomposition, stable and meta-stable photolysis products were formed and observed by UV detection. Beyond that the chemical structure of these products were determined. Three transformation products, that were not described in the literature so far, were identified and quantified with GC-MS.

Purpose: Previously, we reported the results of a Phase III, placebo-controlled trial in 2,297 randomized participants with moderately severe actinic keratoses wherein 25,000 IU/day vitamin A caused a 32% risk reduction in squamous cell skin cancers. We hypothesized that dose escalation of vitamin A to 50,000 or 75,000 IU/day would be both safe and more efficacious in skin cancer chemoprevention. Experimental Design: One hundred and twenty-nine participants with severely sun-damaged skin on their lateral forearms were randomized to receive placebo or 25,000, 50,000, or 75,000 IU/day vitamin A for 12 months. The primary study end points were the clinical and laboratory safety of vitamin A, and the secondary end points included quantitative, karyometric image analysis and assessment of retinoid and rexinoid receptors in sun-damaged skin. Results: There were no significant differences in expected clinical and laboratory toxicities between the groups of participants randomized to placebo, 25,000 IU/day, 50,000 IU/day, and 75,000 IU/day. Karyometric features were computed from the basal cell layer of skin biopsies, and a total of 22,600 nuclei from 113 participants were examined, showing statistically significant, dose-response effects for vitamin A at the 25,000 and 50,000 IU/day doses. These karyometric changes correlated with increases in retinoic acid receptor α, retinoic acid receptor β, and retinoid X receptor α at the 50,000 IU/day vitamin A dose. Conclusions: The vitamin A doses of 50,000 and 75,000 IU/day for 1 year proved safe and equally more efficacious than the 25,000 IU/day dose and can be recommended for future skin cancer chemoprevention studies.

To use karyometric analysis methods to compare actinic keratoses (AKs) to squamous cell carcinomas (SCCs) to determine if SCCs showed a logical progression beyond that seen in AKs and to explore variability within and between lesion types to better understand distinctions between the 2.Biopsies from 31 subjects with AKs were obtained from upper inner arm skin, forearm skin and AK lesions. Biopsies from 23 different subjects in a related subproject provided SCC biopsies for comparison.Karyometric measures of nuclear abnormality and sun damage were derived. Mean actinic damage levels progressed logically from inner arm to sun-exposed skin, to AK, to SCC. Considerable heterogeneity existed at the case level. Unsupervised learning methods revealed 2 distinct clusters of progressed lesions with different nuclear signatures, reflecting differing levels of actinic damage. Number of AKs and SCCs and invasiveness and differentiation of SCCs were distributed across both clusters in roughly equivalent proportions.Karyometric methods, shown previously to be capable of sensitively detecting subtle nuclear changes, revealed the possibility of 2 progression pathways, each containing AKs and SCCs. This finding may have prognostic implications.

Das allgemeine Ziel wissenschaftlicher Arbeit ist in Natur- wie Sozialwissenschaften das gleiche; herausgeschalt aus seinen philosophischen Verkrustungen, besteht es darin, zu entdecken, wie und warum wahrgenommene Ereignisse miteinander zusammenhangen. (ED, 24) Zusammenhange dort aufzudecken, wo sie vorher nicht bekannt waren, ist eine Zentralaufgabe wissenschaftlicher Untersuchungen. (WiS, 177) Die Wissenschaftler des 20. Jahrhunderts suchen Fortschritte zu machen uber den jeweils existierenden Stand des Wissens in ihrem Fach hinaus. (ED, 64)

Man kann von der Einstellung eines Menschen nicht in einem absoluten Sinne sagen, sie sei distanziert oder engagiert, oder wenn man lieber will: sie sei „rational“ oder „irrational“, „objektiv“ oder „subjektiv“. (ED, 9) Die Moglichkeit eines jeden geordneten Gruppenlebens beruht auf dem Zusammenspiel zwischen engagierenden und distanzierenden Impulsen im menschlichen Denken und Handeln, die sich gegenseitig in Schach halten. (ED, 10) Durch den Gebrauch dieser Begriffe verweist man also auf wechselnde Balancen zwischen Typen von Verhaltens- und Erlebensimpulsen, die in den Beziehungen von Menschen zu Menschen, zu nicht-menschlichen Objekten und zu sich selbst (was immer ihre sonstigen Funktionen sein mogen) mehr zum Engagement oder mehr zur Distanzierung hindrangen. (ED, 10)

Es bedarf eines Prozesmodells, einer symbolischen Darstellung des Nacheinanders als Ausgangspunkt fur die Suche nach der Antwort auf die Frage, wie und warum das Universum und alle Teilgestalten, die es bilden, so und nicht anders geworden sind. (Fragment I, 192)

Menschen sind keine fensterlosen Monaden, keine vereinzelten „Subjekte“, denen die ganze Welt, also auch alle anderen Menschen, als „Ausenwelt “ gegenubersteht und deren „Innenwelt “ wie durch eine unsichtbare Mauer von dieser „Ausenwelt“, also auch von anderen Menschen, abgetrennt ist. (Einsamkeit, 81)* Der „homo clausus“ ist ein Phantasiebild.

Die neue transklassische Logik kann ansetzen bei der unausgeschopften „Tiefendimension“ der zweiwertigen Logik, die sich an der kenogrammatischen Basis des Aussagenkalkuls als ein strukturelles Fragment erweist; sie kann vom nicht auflosbaren Reflexionsrest der iterierten Negation als ausgeschlossenem Dritten begrundet werden; sie kann bei der exklusiven Annahme eines Rangverhaltnisses von Objekt und Subjekt beginnen oder die Frage nach logischen Aussagen uber zukunftige Ereignisse an den Anfang stellen. Die neue Gunther-Logik kann aber auch von der Ontologie, der Lehre vom Wesen des Seins, ausgehen, indem sie die Evidenz einer Pluralitat sich selbst erlebender Subjekte betont, die mit keiner der beiden klassischen Seinskomponenten, Objekt-uberhaupt oder Subjekt-uberhaupt, identisch sein wollen.

In ihrer klassischen Gestalt, die auf Aristoteles (384–322 v.Chr.) zuruckgeht und die uber mehr als zweitausend Jahre bestimmt hat, was als rational gelten durfte und was nicht, grundet die Logik auf drei elementaren Satzen: auf dem Satz der Identitat von Denken und Sein (Lehre vom Begriff), dem Satz vom verbotenen Widerspruch (Urteilslehre) und dem Satz vom ausgeschlossenen Dritten (Lehre Vom Schlus). Ein viertes Axiom, der Satz vom zureichenden Grunde (Methodenlehre), behauptet, das durch die ersten drei Axiome — Identitat, Widerspruchsfreiheit und Drittenausschlus — die Allgemeinheit des theoretischen Bewustseins zureichend, endgultig und transzendental begrundet sei; ein allgemeineres und wahreres Denken als jenes, das die klassische Logik definiert, ist nach ihren eigenen Gesetzen nicht denkbar.

Soweit wir wissen, sind Menschen insofern einzigartig, sagt Elias, als sie aufgrund der grosen Zahl ihrer Integrationsstufen eine „Selbststeuerungsapparatur“ besitzen, „die an Variabilitat die aller anderen Naturgebilde ubertrifft.“ (Fragment I, 205) Sie sind weit mehr als die Summe der Atome, aus denen sie bestehen, in ihrem Verhalten nicht von diesen gesteuert und nicht reduzierbar auf sie. „Die Zellen, die miteinander einen Menschen bilden, sterben, wenn der Mensch stirbt; die Atome, die einen Menschen bilden, verandern sich kaum.“ (Fragment II, 260f.)