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The epitranscriptome has emerged as a new fundamental layer of control of gene expression. Nevertheless, the determination of the transcriptome-wide occupancy and function of RNA modifications remains challenging. Here we have developed Rho-seq, an integrated pipeline detecting a range of modifications through differential modification-dependent rhodamine labeling. Using Rho-seq, we confirm that the reduction of uridine to dihydrouridine (D) by the Dus reductase enzymes targets tRNAs in E. coli and fission yeast. We find that the D modification is also present on fission yeast mRNAs, particularly those encoding cytoskeleton-related proteins, which is supported by large-scale proteome analyses and ribosome profiling. We show that the α-tubulin encoding mRNA nda2 undergoes Dus3-dependent dihydrouridylation, which affects its translation. The absence of the modification on nda2 mRNA strongly impacts meiotic chromosome segregation, resulting in low gamete viability. Applying Rho-seq to human cells revealed that tubulin mRNA dihydrouridylation is evolutionarily conserved.

Mitotic spindle function depends on the precise regulation of microtubule dynamics and microtubule sliding. Throughout mitosis, both processes have to be orchestrated to establish and maintain spindle stability. We show that during anaphase B spindle elongation in Schizosaccharomyces pombe, the sliding motor Klp9 (kinesin-6) also promotes microtubule growth in vivo. In vitro, Klp9 can enhance and dampen microtubule growth, depending on the tubulin concentration. This indicates that the motor is able to promote and block tubulin subunit incorporation into the microtubule lattice in order to set a well-defined microtubule growth velocity. Moreover, Klp9 recruitment to spindle microtubules is dependent on its dephosphorylation mediated by XMAP215/Dis1, a microtubule polymerase, creating a link between the regulation of spindle length and spindle elongation velocity. Collectively, we unravel the mechanism of anaphase B, from Klp9 recruitment to the motors dual-function in regulating microtubule sliding and microtubule growth, allowing an inherent coordination of both processes.

Mitotic spindle function depends on the precise regulation of microtubule dynamics and microtubule sliding. Throughout mitosis, both processes have to be orchestrated to establish and maintain spindle stability. We show that during anaphase B spindle elongation inS. pombe, the sliding motor Klp9 (kinesin-6) also promotes microtubule growthin vivo. In vitro, Klp9 can enhance and dampen microtubule growth, depending on the tubulin concentration. This indicates that the motor is able to promote and block tubulin subunit incorporation into the microtubule lattice in order to set a well-defined microtubule growth velocity. Moreover, Klp9 recruitment to spindle microtubules is dependent on its dephosphorylation mediated by XMAP215/Dis1, a microtubule polymerase, to link the regulation of spindle length and spindle elongation velocity. Collectively, we unravel the mechanism of anaphase B, from Klp9 recruitment to the motors dual-function in regulating microtubule sliding and microtubule growth, allowing an inherent coordination of both processes.

The mitotic spindle robustly scales with cell size in a plethora of different organisms. During development and throughout evolution, the spindle adjusts to cell size in metazoans and yeast in order to ensure faithful chromosome separation. Spindle adjustment to cell size occurs by the scaling of spindle length, spindle shape and the velocity of spindle assembly and elongation. Different mechanisms, depending on spindle structure and organism, account for these scaling relationships. The limited availability of critical spindle components, protein gradients, sequestration of spindle components, or post-translational modification and differential expression levels have been implicated in the regulation of spindle length and the spindle assembly/elongation velocity in a cell size-dependent manner. In this review, we will discuss the phenomenon and mechanisms of spindle length, spindle shape and spindle elongation velocity scaling with cell size.

Epitranscriptomic has emerged as a fundamental control of gene expression. Nevertheless, the determination of the transcriptome-wide occupancy of RNA modifications remains challenging. We have developed Rho-seq, an integrated pipeline detecting a range of modifications through differential modification-dependent Rhodamine labeling. Using Rho-seq, we confirm that the reduction of uridine to dihydrouridine targets tRNAs in E. coli. Unexpectedly, we find that the D modification expands to mRNAs in fission yeast.The modified mRNAs are enriched for cytoskeleton-related encoding proteins. We show that the α-tubulin encoding mRNA nda2 undergoes dihydrouridylation, which affects its protein expression level. The absence of the modification onto the nda2 mRNA impacts meiosis by inducing a metaphase delay or by completely preventing the formation of spindles during meiosis I and meiosis II, resulting in low gamete viability. Collectively these data show that the codon-specific reduction of uridine within specific mRNA is required for proper meiotic chromosome segregation and gamete viability.

The aim of the study was to explore the possible role of Trefoil Factor Family peptide 3 (TFF3) for skeletal repair. The expression of TFF3 was analyzed in human joint tissues as well as in a murine bone fracture model. Serum levels of TFF3 following a defined skeletal trauma in humans were determined by ELISA. The mRNA expression of TFF3 was analyzed under normoxia and hypoxia. Expression analysis after stimulation of human mesenchymal progenitor cells (MPCs) with TFF3 was performed by RT2 Profiler PCR Array. The effect of recombinant human (rh)TFF3 on MPCs was analysed by different migration and chemotaxis assays. The effect on cell motility was also visualized by fluorescence staining of F-Actin. TFF3 was absent in human articular cartilage, but strongly expressed in the subchondral bone and periosteum of adult joints. Strong TFF3 immunoreactivity was also detected in murine fracture callus. Serum levels of TFF3 were significantly increased after skeletal trauma in humans. Expression analysis demonstrated that rhTFF3 significantly decreased mRNA of ROCK1. Wound healing assays showed increased cell migration of MPCs by rhTFF3. The F-Actin cytoskeleton was markedly influenced by rhTFF3. Cell proliferation was not increased by rhTFF3. The data demonstrate elevated expression of TFF3 after skeletal trauma. The stimulatory effects on cell motility and migration of MPCs suggest a role of TFF3 in skeletal repair., publishedVersion

// Annika Hohn 1 , Katharina Kruger 1 , Margaretha A. Skowron 2 , Stefanie Bormann 1 , Lena Schumacher 1 , Wolfgang A. Schulz 2 , Michele J. Hoffmann 2 , Gunter Niegisch 2 , Gerhard Fritz 1 1 Institute of Toxicology, Medical Faculty, Heinrich Heine University Dusseldorf, 40225, Dusseldorf, Germany 2 Department of Urology, Medical Faculty, Heinrich Heine University Dusseldorf, 40225, Dusseldorf, Germany Correspondence to: Gerhard Fritz, email: fritz@uni-duesseldorf.de Keywords: cisplatin, urothelial carcinoma, DNA damage response, DNA repair, cisplatin resistance Received: October 07, 2015 Accepted: April 22, 2016 Published: May 12, 2016 ABSTRACT Cisplatin (CisPt) is frequently used in the therapy of urothelial carcinoma (UC). Its therapeutic efficacy is limited by inherent or acquired drug resistance. Here, we comparatively investigated the CisPt-induced response of two different parental urothelial carcinoma cell lines (RT-112, J-82) with that of respective drug resistant variants (RT-112 R , J-82 R ) obtained upon month-long CisPt selection. Parental RT-112 cells were ~2.5 fold more resistant to CisPt than J-82 cells and showed a different expression pattern of CisPt-related resistance factors. CisPt resistant RT-112 R and J-82 R variants revealed a 2–3-fold increased CisPt resistance as compared to their corresponding parental counterparts. Acquired CisPt resistance was accompanied by morphological alterations resembling epithelial mesenchymal transition (EMT). RT-112 R cells revealed lower apoptotic frequency and more pronounced G2/M arrest following CisPt exposure than RT-112 cells, whereas no differences in death induction were observed between J-82 and J-82 R cells. CisPt resistant J-82 R cells however were characterized by a reduced formation of CisPt-induced DNA damage and related DNA damage response (DDR) as compared to J-82 cells. Such difference was not observed between RT-112 R and RT-112 cells. J-82 R cells showed an enhanced sensitivity to pharmacological inhibition of checkpoint kinase 1 (Chk1) and, moreover, could be re-sensitized to CisPt upon Chk1 inhibition. Based on the data we suggest that mechanisms of acquired CisPt resistance of individual UC cells are substantially different, with apoptosis- and DDR-related mechanisms being of particular relevance. Moreover, the findings indicate that targeting of Chk1 might be useful to overcome acquired CisPt resistance of certain subtypes of UC.

Patients with HPV-positive head and neck squamous cell carcinoma (HNSCC) show better survival rates than those with HPV-negative HNSCC. While an enhanced radiosensitivity of HPV-positive tumors is clearly evident from single modality treatment, cisplatin is never administered as monotherapy and therefore its contribution to the enhanced cure rates of HPV-positive HNSCC is not known. Both cisplatin and radiotherapy can cause severe irreversible side effects and therefore various clinical studies are currently testing deintensified regimes for patients with HPV-positive HNSCC. One strategy is to omit cisplatin-based chemotherapy or replace it by less toxic treatments but the risk assessment of these approaches remains difficult. In this study we have compared the cytotoxic effects of cisplatin in a panel of HPV-positive and -negative HNSCC cell lines alone and when combined with radiation. While cisplatin-treated HPV-positive strains showed a slightly stronger inhibition of proliferation, there was no difference regarding colony formation. Cellular responses to the drug, namely cell cycle distribution, apoptosis and γH2AX-induction did not differ between the two entities but assessment of cisplatin-DNA-adducts suggests differences regarding the mechanisms that determine cisplatin sensitivity. Combining cisplatin with radiation, we generally observed an additive but only in a minority of strains from both entities a clear synergistic effect on colony formation. In summary, HPV-positive and -negative HNSCC cells were equally sensitive to cisplatin. Therefore replacing cisplatin may be feasible but the substituting agent should be of similar efficacy in order not to jeopardize the high cure rates for HPV-positive HNSCC.

Targeting of oncogene-driven replicative stress as therapeutic option for high-risk medullobastoma was assessed using a panel of medulloblastoma cells differing in their c-Myc expression [i.e. group SHH (c-Myc low) vs. group 3 (c-Myc high)]. High c-Myc levels were associated with hypersensitivity to pharmacological Chk1 and ATR inhibition but not to CDK inhibition nor to conventional (genotoxic) anticancer therapeutics. The enhanced sensitivity of group 3 medulloblastoma cells to Chk1 inhibitors likely results from enhanced damage to intracellular organelles, elevated replicative stress and DNA damage and activation of apoptosis/necrosis. Furthermore, Chk1 inhibition differentially affected c-Myc expression and functions. In c-Myc high cells, Chk1 blockage decreased c-Myc and p-GSK3α protein and increased p21 and GADD45A mRNA expression. By contrast, c-Myc low cells revealed increased p-GSK3β protein and CHOP and DUSP1 mRNA levels. Inhibition of Chk1 sensitized medulloblastoma cells to additional replication stress evoked by cisplatin independent of c-Myc. Importantly, Chk1 inhibition only caused minor toxicity in primary rat neurons in vitro. Collectively, targeting of ATR/Chk1 effectively triggers death in high-risk medulloblastoma, potentiates the anticancer efficacy of cisplatin and is well tolerated in non-cancerous neuronal cells.

Recent evidence from histology studies regarding random prostate biopsies hint toward a relationship between higher biopsy Gleason score and the development of metastatic castration resistant prostate cancer (mCRPC). However, prostate biopsy underestimates final pathology in about one-third of patients. We evaluated the final whole gland pathology from radical prostatectomy exclusively in order to assess the true risk of progressing to the mCRPC state for patients with confirmed Gleason ≤6 prostate cancer. Patients with confirmed mCRPC from our outpatient clinic were retrospectively evaluated with regard to whole gland pathology and the occurrence of Gleason 6 histology from 1995 to 2015. Conversely, patients with confirmed Gleason 6 pathology from our institutional database were followed up for the development of mCRPC from 2001 to 2015. Kaplan–Meier analysis and the log rank test were applied for survival analysis. The binomial test was used to evaluate occurrence rates of Gleason ≤6 pathologies in mCRPC patients. Out of 62 patients with mCRPC none had confirmed Gleason 6 pathology on whole gland histology of the prostate. Out of 86 patients with confirmed Gleason 6 pathology none developed an mCRPC over the follow-up period. The development of mCRPC in patients with true Gleason 6 pathology is very rare and could not be confirmed in our series. This finding may have important implications in future treatment planning.

The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury.

We investigated the ability of cats to discriminate differences between vowel-like spectra, assessed their discrimination ability over time, and compared spectral receptive fields in primary auditory cortex (AI) of trained and untrained cats. Animals were trained to discriminate changes in the spectral envelope of a broad-band harmonic complex in a 2-alternative forced choice procedure. The standard stimulus was an acoustic grating consisting of a harmonic complex with a sinusoidally modulated spectral envelope ("ripple spectrum"). The spacing of spectral peaks was conserved at 1, 2, or 2.66 peaks/octave. Animals were trained to detect differences in the frequency location of energy peaks, corresponding to changes in the spectral envelope phase. Average discrimination thresholds improved continuously during the course of the testing from phase-shifts of 96 degrees at the beginning to 44 degrees after 4-6 months of training with a 1 ripple/octave spectral envelope. Responses of AI single units and small groups of neurons to pure tones and ripple spectra were modified during perceptual discrimination training with vowel-like ripple stimuli. The transfer function for spectral envelope frequencies narrowed and the tuning for pure tones sharpened significantly in discriminant versus naïve animals. By contrast, control animals that used the ripple spectra only in a lateralization task showed broader ripple transfer functions and narrower pure-tone tuning than naïve animals.

The aim of this study was to investigate the effects of monomethyltin trichloride (MMT) and dimethyltin dichloride (DMT) on various neuronal ion channels heterologously expressed in Xenopus oocytes and on synaptic transmission in hippocampal slices of young (14-21 days old) and adult (2-4 months old) rats. The Xenopus oocyte expression system was chosen to allow direct assessment of the effects of MMT and DMT both on glutamate receptors sensitive to AMPA and NMDA and on various voltage-operated potassium and sodium channels. Hippocampal slices were used to analyze the effects of MMT and DMT on synaptic potentials generated by the important excitatory Schaffer collateral-CA1 synapse. In general, MMT and DMT were found to have no effect either on voltage-operated sodium and potassium channels or on the metabotropic glutamate receptor but they did differentially affect the functions of ionotropic glutamate receptors and glutamatergic synaptic transmission. MMT (100 microM) significantly reduced NMDA-mediated ion currents by up to 32%, but had no effect on ion currents through AMPA receptors. In slices of adult rats, MMT had no effect on the amplitudes of evoked fEPSPs and brought about a 35% reduction in the LTP amplitudes. In contrast, in slices of young rats MMT evoked a reversible 30% increase in the amplitudes of fEPSPs but had no effect on LTP induction. DMT (100 microM) reduced ion currents through NMDA-receptor ion channels by up to 29% and those through AMPA-receptor ion channels by up to 7%. In hippocampal slices 100 microM DMT reduced the amplitudes of fEPSPs (adults: 50%; young rats: 70%) and LTP (adults: 40%; young rats: 55%). Neither of the organotins affected the paired-pulse facilitation at this synapse, indicating that the organotins exert their effects at the postsynaptic site. The action of MMT and DMT may contribute to the organotin-induced impairment of behavior patterns in connection with learning and memory.

Organotin compounds such as trimethyltin chloride (TMT) are among the most toxic of the organometallics. As their main target for toxicity is the central nervous system, the aim of the present study was to investigate the effects of TMT on receptor channels involved in various processes of synaptic transmission. The Xenopus oocyte expression system was chosen for direct assessment of TMT effects on voltage-operated potassium channels and glutamatergic and GABAergic receptors, and hippocampal slices from rat brain for analyzing TMT effects on identified synaptic sites. TMT was found to be ineffective, at 100 μmol l−1, against several potassium- and sodium-operated ion channel functions as well as the metabotropic glutamate receptor. The functions of the ionotropic glutamate and the GABAA receptor channels were inhibited by TMT in micromolar concentrations. Thus, at a maximum concentration of 100 μmol l−1, around 20–30% of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid and GABAA receptor-mediated ion currents and 35% of the N-methyl-D-aspartate receptor-mediated ion currents were blocked. In the hippocampal slice model, the inhibitory effects of TMT were much stronger than expected from the results on the ion channels. Bath application of TMT significantly reduced the amplitudes of evoked excitatory postsynaptic field potentials in a concentration-dependent and nonreversible manner. Induction of long-term potentiation, recorded from the CA1 dendritic region, was inhibited by TMT and failed completely at a concentration of 10 μmol l−1. In general, TMT affects the excitatory and inhibitory synaptic processes in a receptor specific manner and is able to disturb the activity within a neuronal network. Keywords: Xenopus oocyte, hippocampal slice, membrane currents, glutamate receptors, GABA receptors, potassium channels, organotin, trimethyltin Introduction Contamination of the environment with organometallic compounds is a result of their widespread use, for example, as preservatives, biocides and antifouling paints, or by their natural formation via biomethylation of inorganic substrates (Thayer, 1995; Appel et al., 2000; Craig et al., 2003). Many of the organometallic compounds found in the environment are known to be highly toxic and especially neurotoxic (Craig et al., 2003), thus representing a considerable environmental health hazard. This is especially true of organotin compounds such as trimethyltin chloride (TMT), which is among the most toxic of the organometallics (Snoeij et al., 1987; Cima et al., 2003). Due to their high toxicity, TMT compounds are no longer produced on an industrial scale. Nevertheless, they are detected for example in water and in waste deposit gas (Feldmann et al., 1994). It is suggested that environmental methylated tin species are mostly formed by biomethylation (Cima et al., 2003). The main target of TMT toxicity is the central nervous system (CNS). Symptoms like decreased hearing, restlessness, psychomotor agitation, ataxia, confusion, disorientation, disturbances of short-term memory, amnesia, as well as partial or generalized seizures are reported after accidental intoxications (Besser et al., 1987; Saary & House, 2002). TMT is known from animal experiments to accumulate in the CNS, resulting in pathological damage characterized by neuronal destruction, predominantly in the hippocampus and the cerebral cortex (Aschner & Aschner, 1992). Neurobehavioral alterations and impaired learning and performance are the result of TMT exposure of rats and are attributed to neuronal cell death (Reiter & Ruppert, 1984; Stanton et al., 1991; Moser, 1996). Despite these findings, the mechanisms involved in TMT-induced neuronal damage and in the neurotoxic symptoms observed are still not completely understood. Although neuronal cell death has, up to now, been the explanation for all observed effects, functional changes in the elemental processes of reception, conduction and transmission of bioelectrical signals might also contribute to TMT neurotoxicity and in particular to the impairment of learning and memory. The aim of the present study was to investigate the effects of TMT on receptor channels involved in a variety of processes of synaptic transmission. For this purpose, we chose the Xenopus oocyte expression system for direct assessment of TMT effects on voltage- and ligand-operated ion channels, and hippocampal slices from rat brain for analyzing TMT effects on transmission at identified synaptic sites. The experiments were focused on glutamate receptors of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) type and on GABA receptors of the GABAA type. Potassium channels were also studied, since the clinical signs of poisoning with metalloid compounds or metal ions include an increase of excitation, which would be in line with a blockade of potassium currents.

A fluid stream induced by a concentration clamp system evokes in Xenopus oocytes a deformation of the membrane which results in transient chloride currents of high amplitude (stream-evoked inward current, I i,st ) during calcium-activated chloride current oscillations. The involvement of cytoskeleton elements and of components of the phospholipase C-dependent signaling pathway on the generation of the I i,st were investigated. Incubation of the oocytes with cytoskeleton-disrupting agents exerted no effects on generation of the I i,st , suggesting that the mechanotransduction is not mediated by these structures. The fluid stream induced an elevation of the submembraneous calcium concentration, as measured by an increase of Fluo-4-mediated fluorescence after the stimulus. Lowering the intracellular calcium concentration by injection of calcium chelators or depleting inositol 1,4,5-triphosphate (InsP 3 )-sensitive calcium stores by blockers of the calcium pumps suppressed the generation of the I i,st in most cases. Furthermore, the phospholipase C inhibitor U73122 reversibly blocked the I i,st . The results suggest that the fluid stream leads to a membrane stretch which modulates directly or indirectly the activity of a membrane-bound phospholipase C. The phospholipase C transiently elevates the InsP 3 concentration, in turn releasing calcium from InsP 3 -sensitive internal calcium stores, thus evoking an enhanced calcium-sensitive chloride current.

Background Platinum compounds are potent anticancer drugs but also evoke considerable normal tissue damage. Here, we elucidate the molecular mechanisms contributing to the nephrotoxic effects of cisplatin. Methods We comparatively investigated the stress responses of rat kidney tubular (NRK-52E) and glomerular cells (RGE) following treatment with cisplatin (CisPt), oxaliplatin (OxaliPt) and carboplatin (CarboPt). To this end, cell viability, apoptosis, cell cycle progression, DNA damage response (DDR) and repair of DNA adducts were investigated. Results CisPt reduced the viability of tubular NRK-52E and glomerular RGE cells most efficiently. Cytotoxicity evoked by CarboPt occurred with a delay, which might be related to a retarded formation of Pt-(GpG) intrastrand crosslinks. RGE cells were more sensitive towards all platinum compounds than NRK-52E cells. Platinum drugs efficiently induced caspase-mediated apoptosis in tubular cells, while RGE cells favored G2/M arrest when treated with equitoxic platinum doses. Mitotic index of NKR-52E and RGE cells was worst affected by OxaliPt. Activation of the DDR was strikingly agent- and cell type-specific. Most comprehensive and substantial stimulation of DDR mechanisms was provoked by CisPt. Repair of Pt-(GpG) intrastrand crosslinks was best in RGE, which was reflected by high mRNA expression of nucleotide excision repair (NER) factors. Conclusions There are substantial differences regarding the cause of sensitivity and mechanisms of DDR between tubular and glomerular cells following platinum injury. CisPt is the most potent stimulator of the DDR. We hypothesize that specific DNA adducts and thereby forcefully activated pro-toxic DDR mechanisms contribute to the exceptionally high acute nephrotoxicity of CisPt.

In the present study, the immunophenotype of basal cell carcinoma was analysed in comparison with human vellus hair follicular keratinocytes. We also established the lectin binding profile of basal cell carcinoma and human vellus hair follicles (VHF), using several lectins with different sugar specificities. Our findings showed an almost identical immunohistochemical profile for basal cell carcinoma and the suprabulbar region of the outer root sheath of VHF, whereas other follicular compartments such as the bulbar, the isthmus or the supraseboglandular regions did not correlate. In particular, homogeneous and constant expression of the basal differentiation markers CK 5 and CK 14 were found in both specimen, with no expression of the simple epithelium type keratin CK 8 and the suprabasal differentiation markers CK 1 and CK 10. CK 19 showed variable expression in basal cell carcinoma, with constant expression in the outer root sheath and the follicular bulge regions, but was always absent in interfollicular epidermal keratinocytes. In addition, the lectin binding profiles of basal cell carcinoma and the outer root sheath in the suprabulbar region of human VHF were comparable, with the presence of binding sites for PNA, Con A and WGA. These findings provide evidence for a histochemical relationship between basal cell carcinoma and the follicular epithelium of VHF which is closer than that with the epidermis, and suggest its possible origin from or possibly its differentiation pattern towards the cells of the outer root sheath and/or the follicular bulge region of the VHF.

A 76-year-old female patient developed severe manifestations of a kaposi-like acroangiodermatitis (so-called Mali's disease) due to chronic venous insufficiency of the lower extremities. The patient presented with large areas of confluent, violaceous or brown-black papules on both lower legs. Histologically, proliferation of thick-walled capillaries was seen in the upper dermis consisting of fully differentiated endothelial cells, as shown by immunohistochemistry. In contrast to true Kaposi's sarcoma, human-herpes-virus-8 DNA could not be detected by polymerase-chain-reaction in this condition. We review the diagnostic criteria used to distinguish between acroangiodermatitis, also called pseudo-Kaposi's sarcoma, and the true Kaposi's sarcoma.

Die perforierenden Dermatosen bilden eine heterogene Gruppe von Erkrankungen, die durch transepidermale Eliminationsphanomene gekennzeichnet sind. Abzugrenzen sind die primar perforierenden Dermatosen von solchen perforierenden Dermatosen, bei denen Perforation oder Elimination sekundar und als seltenes Teilsymptom bei bestehenden Dermatosen anderer Provenienz auftreten konnen. Zu den primar perforierenden Dermatosen zahlen dabei als Prototypen die Hyperkeratosis follicularis et parafollicularis in cutem penetrans (M. Kyrle), die Elastosis perforans serpiginosa und die perforierende Follikulitis. Die erworbene reaktiv perforierende Dermatose (syn. erworbene reaktiv perforierende Kollagenose) stellt zusammen mit der hereditaren, reaktiv perforierenden Kollagenose eine weitere Variante der primar perforierenden Dermatosen dar. Wir stellen hier eine 84jahrige und eine 96jahrige Patientin mit einer erworbenen reaktiv perforierenden Dermatose vor. Bei beiden Patientinnen lagen eine diabetogene und eine hyperurikamische Stoffwechsellage vor. Eine Therapie mit Allopurinol (100 mg/d) fuhrte bereits nach kurzer Dauer (1 bis 2 Wochen) zu einer weitgehenden Abheilung der disseminierten Lasionen. Uber einen Nachbeobachtungszeitraum von jeweils 6 Monaten befanden sich beide Patientinnen in Vollremission. Diese Beobachtungen belegen erneut die Existenz und Massivitat der Erkrankung und zeigen, das Allopurinol neben der bekannten urikostatischen Wirkung moglicherweise in der Haut immunologische oder differenzierungsmodulierende Effekte vermittelt.

Nephrotoxicity is the major dose-limiting adverse effect of cisplatin (CisPt) and results from CisPt-induced damage of tubular cells. Nephroprotective strategies are preferential to improve supportive care in cancer. We investigated a subset of purified substances originating from various plants or from marine sponges as to their potency to protect rat renal tubular cells (NRK-52E) against the cytotoxic and genotoxic effects of cisplatin. Cotreatment with a substance pool containing five purified substances originating from marine sponges increased the viability of NRK-52E cells following cisplatin treatment. Cytoprotection was accompanied by a reduced level of DNA damage as indicated by a lower amount of S139 phosphorylated histone H2AX (γH2AX) 24 h after treatment. Cytoprotection and genoprotection by the sponge substance pool did not comprise the anthracycline derivative doxorubicin. The spongean alkaloid aaptamine was identified as major bioactive compound that mediates cisplatin resistance. Aeroplysinin-1 was less cytoprotective than aaptamine. Notably, aaptamine preferentially conferred resistance to cisplatin, but not to oxaliplatin. Cytoprotection by aaptamine was also observed in rat glomerular endothelial cells, but not in RT-112 bladder cancer cells. Protection by aaptamine does not rest on a reduced formation of DNA damage caused by cisplatin treatment. Aaptamine and aeroplysinin-1 affected cisplatin-stimulated DDR as reflected on the level of S15-phosphorlyated p53 and S345-phosphorylated checkpoint kinase-1. Summarizing, the spongean alkaloid aaptamine alleviates cisplatin-induced damage in tubular and glomerular rat kidney cells. Therefore, we hypothesize that aaptamine might be useful to widen the therapeutic window of a cisplatin-based therapeutic regimen.

Herbal smoking blends, available on the German market were analyzed and several known synthetic cannabinoids were identified (JWH-122 and JWH-018). In addition, we isolated a new active ingredient by silica gel column chromatography and elucidated the structure by nuclear magnetic resonance (NMR) methods. The compound was identified as JWH-307, a synthetic cannabinoid of the phenyl-pyrrole subclass with known in vitro binding affinities for cannabinoid receptors. To date, this is the first appearance of this subclass of cannabimimetics in such products. JWH-307 has been further characterized by gas chromatography accurate mass spectrometry (GC-HRMS), electrospray tandem mass spectrometry (ESI-MS/MS), ultraviolet (UV) and infrared (IR) spectroscopy. JWH-018 was among the first compounds banned by many countries world-wide including Germany. The identification of JWH-018 was striking, since this is the first report where JWH-018 recurred on the German market thus violating existing laws. A generic method was established to quantify synthetic cannabinoids in herbal smoking blends. Quantification was achieved using an isotopically labeled standard (JWH-018-D(3)). JWH-018 was found at a level of 150 mg/g while JWH-122 and JWH-307 occurred as a mixture at a total level of 232 mg/g.

Schnitzler’s syndrome (SS) is characterized by the association of generalized chronic urticaria, osteocondensation and monoclonal IgM gammopathy. Nonsteroidal anti-inflammatory drugs and systemic steroids are the most promising treatments. In our patient, they were ineffective. By contrast, during the follow-up period of 18 months, interferon α2b therapy (IFN-α) relieved the patient from its urticarial lesions and bone pain. IFN-α was tried to be stopped twice: each time, relapse of urticaria was noticed and, each time, the cutaneous lesions disappeared after IFN-α had been reintroduced. Furthermore, our observation supports the idea of the interleukin (IL)-1-mediated pathogenesis of SS as IFN-α induces high levels of IL-1 receptor antagonists. IFN-α could be an alternative treatment in disabling SS resisting other drugs.

Using a 2-alternative-forced-choice-procedure on a jumping stand, four adult cats were trained to make simple depth discriminations. They were tested binocularly and monocularly before and after bilateral lesions of different parts of the lateral suprasylvian cortex. Our results give support to a functional segregation between the lateral suprasylvian visual areas (LSA) and area 7. Lesion of any of these areas impairs the ability to use binocular depth cues. However, lesion of LSA more severely impairs the ability to use monocular depth cues whereas binocular ones can still be used. After lesion of area 7, binocular depth cues can no longer be used. Additional undercutting of areas 17/18/19 leads to a performance similar to that of area 17/18 lesioned cats.

Pentavalent and trivalent organoarsenic compounds belong to the major metabolites of inorganic arsenicals detected in humans. Recently, the question was raised whether the organic arsenicals represent metabolites of a detoxification process or methylated species with deleterious biological effects. In this study, the effects of trivalent arsenite (AsO(3) (3-); iA(III)), the pentavalent organoarsenic compounds monomethylarsonic acid (CH(3)AsO(OH)(2); MMA(V)) and dimethylarsinic acid ((CH(3))(2)AsO(OH); DMA(V)) and the trivalent compounds monomethylarsonous acid (CH(3)As(OH)(2), MMA(III)) and dimethylarsinous acid ((CH(3))(2)As(OH); DMA(III)) were tested on glutamate receptors and on voltage-operated potassium and sodium channels heterologously expressed in Xenopus oocytes. Membrane currents of ion channels were measured by conventional two-electrode voltage-clamp techniques. The effects of arsenite were tested in concentrations of 1-1,000 micromol/l and the organic arsenical compounds were tested in concentrations of 0.1-100 micromol/l. We found no significant effects on voltage-operated ion channels; however, the arsenicals exert different effects on glutamate receptors. While MMA(V) and MMA(III) significantly enhanced ion currents through N-methyl-D: -aspartate (NMDA) receptor ion channels with threshold concentrations10 micromol/l, DMA(V) and DMA(III) significantly reduced NMDA-receptor mediated responses with threshold concentrations0.1 micromol/l; iA(III) had no effects on glutamate receptors of the NMDA type. MMA(III) and DMA(V) significantly reduced ion currents through alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-receptor ion channels with threshold concentrations10 micromol/l (MMA(III)) and1 micromol/l (DMA(V)). MMA(V) and iA(III) had no significant effects on glutamate receptors of the AMPA type. The effects of MMA(V), MMA(III), DMA(V) and DMA(III )on glutamate receptors point to a neurotoxic potential of these substances.

The effects of trivalent arsenite were tested at the Schaffer collateral-CA1 synapse of adult (2-4 month) and young (14-21 days) rats. Exposure of 100micromol/l arsenite led to a slight and reversible reduction of the amplitudes of evoked excitatory postsynaptic field potentials in adult and young rats, while exposure of 0.1 and 1micromol/l arsenite had no effects. The long-term potentiation (LTP) was significantly inhibited by arsenite in adult but not in young rats. Exposure of 0.1, 1 and 100micromol/l arsenite to slices of adult rats before and during the LTP stimulus led to a significant reduction in the potentiated amplitudes amounting to a maximum of 50% of the control values. In young animals, however, exposure of 1micromol/l arsenite showed no effect on the LTP potentiated amplitudes, while exposure of 100micromol/l arsenite led initially to a significant reduction in the amplitudes, compared to the control level, which was completely reversible 20min after washout. Exposure of 100micromol/l arsenite did not affect the paired-pulse facilitation, indicating that arsenite does not exert its effects by influencing presynaptic transmitter release mechanisms.

Organometal(loid)s from anthropogenic or geogenic sources represent an important group of environmentally hazardous substances. The use of a variety of compounds such as preservatives, antifouling paints and biocides, as well as the biomethylation of inorganic substrates leads to widespread contamination of water, air, sediments etc. (e.g. Thayer 1995; Appel et al. 2000).

We obtained visual response latencies and response durations following visual stimulation of neurones recorded in the lateral geniculate nucleus (LGN), areas 17, 18, 19, the posteromedial lateral suprasylvian sulcus (PMLS), and area 7 of the cat. We found an increasing lengthening of the mean response latencies, consistent with the view of a progressive advance of processing from stage to stage. However, we also observed a substantial and increasing scatter in these latencies. Moreover, response durations vastly supersede this gradual increase in latencies. Taken together, these results suggest that most of the neurones within different stages of a hierarchically organized sensory pathway are simultaneously active when stimulated. Implications of a time-based processing scheme for models of information processing in highly interconnected, multi-layered systems are discussed.

The contribution of the lateral suprasylvian cortex to pattern recognition was studied by behavioural detection experiments in combination with bilateral lesions of different parts of the lateral suprasylvian areas (LSA) and area 7 in seven cats. In a two-alternatives forced choice task the cats had to discriminate simple outline patterns which were additively superimposed on a structured visual background made up of broadband Gaussian noise. For various stimulus conditions (moving or stationary patterns and/or background) the detection probability (PD) of the cats was measured as a function of the signal-to-noise ratio (S/N). Each cat was tested before and after the lesion. Four different types of lesion could be distinguished depending on their extent: (1) lesion of parts of the (LSA); (2) lesion of parts of the LSA with undercutting of areas 17, 18 and 19; (3) lesion of area 7; (4) lesion of area 7 and parts of the LSA. 1. We found that a large bilateral lesion of the LSA led to significant deficits in all test situations which were dependent on the existence of relative velocity of moving patterns against a structured background. The ability of the cats to discriminate simple outline patterns which were kept stationary was not reduced. On the contrary, when they were tested with stationary and moving patterns on unfocused (empty) backgrounds, we found, to our great surprise, that the performance of the lesioned cats was significantly improved compared with intact animals. As these lesioned cats had no deficits with moving patterns on a uniformly grey background, we conclude that the deficits with the moving patterns must have been caused by interactions between patterns and background, and not by movement of a pattern per se. 2. As soon as the lesion of the LSA was extended by a bilateral undercutting of areas 17, 18 and 19 we found very severe deficits in all test situations, regardless of whether the patterns were moving or kept stationary, or whether they were superimposed on a background or not. The most substantial deficits occurred when the patterns were moving on a stationary background. In these situations the cats were no longer able to reach the 84% correct criterion. Again, the cats were able to reach criterion with moving patterns on a uniformly grey background indicating that this deficit is probably caused by the interaction of patterns and background and not by motion of the patterns per se.(ABSTRACT TRUNCATED AT 400 WORDS)

Since the work of Hartline in 1938 the concept of receptive fields (RFs) as one of the basic elements for information processing has been the guiding principle in the investigation of sensory systems. Although we perceive the visual world as a unitary whole, the neuronal machinery consists of elements that can analyse only small portions of the visual field. Knowing structure, organization and properties of RFs is indispensable for understanding their contribution for signal processing and, more generally, for brain function.