Activity levels of tamoxifen metabolites at the estrogen receptor and the impact of genetic polymorphisms of phase I and II enzymes on their concentration levels in plasma

The therapeutic effect of tamoxifen depends on active metabolites, e.g., cytochrome P450 2D6 (CYP2D6) mediated formation of endoxifen. To test for additional relationships, 236 breast cancer patients were genotyped for CYP2D6, CYP2C9, CYP2B6, CYP2C19, CYP3A5, UGT1A4, UGT2B7, and UGT2B15; also, plasma concentrations of tamoxifen and 22 of its metabolites, including the (E)-, (Z)-, 3-, and 4'-hydroxymetabolites as well as their glucuronides, were quantified using liquid chromatography-tandem mass spectrometry (MS). The activity levels of the metabolites were measured using an estrogen response element reporter assay; the strongest estrogen receptor inhibition was found for (Z)-endoxifen and (Z)-4-hydroxytamoxifen (inhibitory concentration 50 (IC50) 3 and 7 nmol/l, respectively). CYP2D6 genotypes explained 39 and 9% of the variability of steady-state concentrations of (Z)-endoxifen and (Z)-4-hydroxytamoxifen, respectively. Among the poor metabolizers, 93% had (Z)-endoxifen levels below IC90 values, underscoring the role of CYP2D6 deficiency in compromised tamoxifen bioactivation. For other enzymes tested, carriers of reduced-function CYP2C9 (*2, *3) alleles had lower plasma concentrations of active metabolites (P < 0.004), pointing to the role of additional pathways.

[Arrhythmias in patients with surgically corrected tetralogy of Fallot]

The population of adults with surgically corrected tetralogy of Fallot (TOF) is increasing. Atrial and ventricular arrhythmias are prevalent, and therapeutical approaches including implantable cardioverter-defibrillators and radiofrequency catheter ablation need to be considered carefully for the prevention of hemodynamic deterioration and sudden cardiac death. Complex anatomy, myocardial hypertrophy, and broad channels of slow conduction may in part explain some challenges regarding risk stratification, and identification/modification of the arrhythmogenic substrate in these patients. The aim of this brief review is 2-fold: (1.) To present insights into characteristics of typical TOF related arrhythmias and (2.) to reflect therapeutical concepts targeting tachyarrhythmias in these patients by focusing on catheter ablation.

Preserved motor axonal membrane potential in mitochondrial disease

Mitochondrial disorders are characterised by protean neurological manifestations including peripheral neuropathy. The neuropathy is typically an axonal process, with a proposed mechanism being degradation of the membrane potential of the axon due to dysfunction of energy-dependent Na(+)/K(+) ATPase pump. To address this issue, we studied the excitability of motor axons in the median nerve in 16 individuals identified with gene testing or muscle biopsy. Twelve patients had clinical or nerve conduction abnormalities. Strength--duration time constant, threshold electrotonus, current--threshold relationship and recovery cycle were identical to control values. These findings imply that an alternative mechanism to a change in membrane potential is responsible for neuronal injury in these patients.

First Report of Malva vein clearing virus Naturally Occurring in Hollyhock in Germany

Hollyhocks are popular garden plants and selected cultivars of Alcea rosea (family Malvaceae) are widespread in Germany. In spring 2009, dozens of A. rosea plants displaying strong vein clearing and veinal yellowing symptoms were found in private gardens in Hannover, Lower Saxony. Electron microscopic examinations of negatively stained adsorption preparations of five randomly selected samples of symptomatic plants or their offshoots revealed flexuous filamentous particles resembling those of potyviruses. Sap extracts also reacted strongly positive in an antigen coated plate (ACP)-ELISA with the broad-spectrum potyvirus antiserum AS-0573/I (DSMZ, Braunschweig, Germany). RNA extracts (RNeasy Kit, Qiagen, Valencia, CA) of the above mentioned leaf samples were used as templates in reverse transcription (RT)-PCR assays with potyvirus specific primers (2) that have been shown to amplify the 3' terminus of the genome of many potyvirus species. For extracts from symptomatic samples, this resulted in a consistent amplification of an ~1.6-kbp fragment, whereas no products were obtained from RNA extracts of asymptomatic plants. From one positive sample, the amplified fragment was cloned and one clone was partially sequenced. The nucleotide (nt) and amino acid sequences showed the highest identities (81 to 83% and 87 to 90%, respectively) to GenBank sequences FJ539084, FM212972, EU884405, and FJ561293 of the potyvirus Malva vein clearing virus (MVCM). On the basis of these identity values and according to the species demarcation criteria in the genus Potyvirus, the virus can be regarded as a German isolate of the recently sequenced MVCV (3,4). Direct sequencing of the 5'-end of the amplified RT-PCR fragment revealed sequences of only one potyvirus species. The virus isolate has been submitted to the DSMZ Plant Virus Collection (Braunschweig, Germany) under accession PV-0963 and the sequence obtained from the cloned cDNA is deposited in GenBank (GQ856544). In addition, sap from affected leaves was mechanically inoculated onto sets of herbaceous indicator plants (Chenopodium quinoa, C. foliosum, C. murale, C. amaranticolor, Datura stramonium, Nicotiana benthamiana, N. hesperis, Petunia hybrida, and Solanum lycopersicum) of which only C. quinoa plants became infected. Symptoms of weak chlorosis along and beside veins of inoculated leaves, but not systemic leaves, became visible 2 weeks postinoculation. Symptomatic leaves contained flexuous filamentous particles and ACP-ELISA and RT-PCR confirmed virus presence. The partially sequenced amplicon showed 99% nt identity to the sequence from the cloned cDNA. To our knowledge, this is the first report of a MVCV isolate naturally occurring in A. rosea and C. quinoa is the first host identified that does not belong to the plant family Malvaceae. In contrast, the MVCV isolate used in the host range study of Lunello et al. (4) did not infect A. rosea and C. quinoa, confirming previous host range descriptions by Brunt et al. (1). Since MVCV infections of hollyhocks seem to cause only leaf symptoms and do not noticeably affect growth or flowering of the plants, this will hopefully not impair the usability of this popular garden plant. References: (1) A. A. Brunt et al. Descriptions and Lists from the VIDE Database. Online publication. Version: 16th January, 1997. (2) J. Chen et al. Arch. Virol. 146:757, 2001. (3) A. Hein Phytopathol. Z. 28:205, 1957. (4) P. Lunello et al. Virus Res. 140:91, 2009.

First Report of Carrot red leaf virus and Carrot mottle virus, Causal Agents of Carrot Motley Dwarf, in Carrot in Mauritius

Carrot motley dwarf (CMD) affects carrot and other apiaceous plants by causing leaf yellowing or reddening as well as plant stunting and leads often to serious economic losses wherever these crops are grown (2). CMD has been reported from Australia, Europe, Japan, Israel, and North America and is known to result from a mixed infection by at least two viruses, the polerovirus, Carrot red leaf virus (CtRLV), and one of the umbraviruses, Carrot mottle virus (CMoV) or Carrot mottle mimic virus (CMoMV). The viruses are transmitted in a circulative persistent manner by aphid species (Cavariella spp.). In November of 2008, symptoms typical of CMD were observed in carrot (Daucus carota) and coriander (Coriandrum sativum) plantations in the region of Henrietta in the central part of Mauritius. Carrot cultivars affected were Victoria, Sigma, and Namdhari. Incidences of up to 50% were recorded in some fields. Symptoms were observed mainly on plants near the edges of fields and were initially attributed to physiological factors. However, following RNA extraction from affected carrot plants and reverse transcription (RT)-PCR, fragments of the expected sizes (CtRLV; 377 bp: CMoV; 549 bp) were obtained. For CtRLV, a pair of degenerate primers (S2/AS3 [1]) for poleroviruses, and for the above mentioned umbraviruses, a universal primer pair (UmbraCS: CTTTGGAGTACACAACAACTCC and UmbraCAS: GCA/GTCIAGICCIACACAA/GACTGG, I = Inosin; unpublished) was used. Direct sequencing of one PCR product for each virus (Eurofins MWG Operon GmbH, Martinsried, Germany) and comparison with sequences retrieved from GenBank resulted in nucleotide and amino acid sequence identities of 93 and 90% (coat protein) to the CtRLV strain UK-1 (Accession No. AY695933) and 86 and 96% (replicase) to the German CMoV isolate (Accession No. FJ188473), respectively. Carrot samples also tested CtRLV-positive in triple-antibody sandwich-ELISA using polyclonal IgGs to CtRLV for trapping and a mixture of two CtRLV-specific monoclonal antibodies (CtRLV-2-3A9 and CtRLV 3-4B9) as detecting antibodies (all from the stock of the Julius Kuehn Institute; H. J. Vetten, Braunschweig, Germany). The presence of CMoV was confirmed by sap transmission to Nicotiana benthamiana and N. occidentalis 'P1', which resulted in vein yellowing/etching symptoms. In addition, agarose gel electrophoresis of the dsRNA extract of a primary infected carrot sample revealed major dsRNAs of approximately 4.2 and 1.4 kbp, which represent the genomic and subgenomic RNAs of an umbravirus. Thus, sequence analysis, as well as serological and biological data, demonstrates that CMD-affected carrot plants from Mauritius were infected with CtRLV and CMoV isolates closely related to those from Europe. The sequences obtained in this study for CtRLV and CMoV have been deposited in GenBank under Accession Nos. FJ969849 and FJ969848, respectively. To our knowledge, this is the first report of CMD in Mauritius and the Indian Ocean Region. Future works comprise an island wide survey across carrot-growing regions to determine the incidence of the virus complex and the natural host range of the viruses in Mauritius. References: (1) A. D. Abraham et al. Plant Dis. 91:1059, 2007. (2) A. F. Murant. No 137 in: Descriptions of Plant Viruses. Assoc. Appl. Biol. Kew, England, 1974.

Prospective evaluation of comorbidity and psychosocial need in children and adolescents with anorectal malformation. Part one: paediatric surgical evaluation and treatment of defecating disorder

INTRODUCTION

Anorectal malformations represent a continuing challenge for the paediatric surgeon. Faecal and urinary incontinence can occur even with an excellent anatomic repair. We undertook a prospective evaluation of comorbidity and psychosocial needs in children and adolescents with anorectal malformation to test the hypothesis whether psychosocial workup in concert with an improved continence situation would lead to a better functional outcome in patients suffering from defecating disorders. Treatment of defecating disorder was based on differentiation between overflow pseudo-incontinence and true faecal incontinence.

MATERIALS AND METHODS

Patients who presented with soiling regardless of the type of anomaly were included in the study: 44 patients were investigated, 14 patients did not meet the criteria of the study, 30 patients aged 4-18 were evaluated. The surgical diagnostic program comprised a careful clinical history, physical examination, exact classification of the malformation, evaluation for associated defects, stool protocol.

RESULTS

Patients were grouped in two different management programs according to their continence situation. Patients with pseudo-incontinence were treated with enemas, diet, anal hygiene, behavioural therapy and physiotherapy. Patients with true faecal incontinence were included in a bowel management program: 28 patients were free of symptoms of soiling after 3 days of hospital treatment and remained free of symptoms 6 months and 1 year later at re-evaluation. Two patients did not follow the therapeutic regime and therefore did not show an improved condition concerning soiling in the long run.

CONCLUSION

Differentiating between overflow pseudo-incontinence and true faecal incontinence is the basis of an effective treatment of defecating disorders. All patients born with anorectal malformation can be kept clean of stool if they are subjected to an adequate treatment. A multidisciplinary approach is a valuable supplement to standard therapy.

Computer animation as a tool to study preferences in the cichlid Pelvicachromis taeniatus

Four choice experiments were conducted with both sexes of the cichlid Pelvicachromis taeniatus using computer-manipulated stimuli of digital images differing in movement, body shape or colouration. The results show that computer animations can be useful and flexible tools in studying preferences of a cichlid with complex and variable preferences for different visual cues.

Characterisation of lettuce virus X, a new potexvirus infecting lettuce in Iran

A virus with flexuous rod-shaped particle morphology was found in samples from lettuce during a survey of viruses infecting lettuce in Tehran province in Iran. This virus was subjected to a complete analysis of its biological and molecular features. The entire nucleotide sequence of the virus was determined, revealing a polyadenylated ssRNA genome consisting of 7,212 nucleotides [without poly (A) tail] and possessing an organization typical for potexviruses. Comparative genome analysis showed that the lettuce virus is closely related to Alstroemeria virus X, narcissus mosaic virus and asparagus virus 3. Based on particle morphology, physico-chemical properties and the complete genome sequence, this virus is a member of a new species in the genus Potexvirus, for which the name lettuce virus X (LeVX) is proposed. Biological assays using an infectious cDNA clone and a wild-type isolate of LeVX revealed that the virus, despite reaching high concentrations in all lettuce cultivars tested, does not cause symptoms in lettuce.

Binding characteristics and crossreactivity of insulin autoantibodies and insulin antibodies directed to three different insulin molecules

To evaluate ex vivo/in vitro the binding and dissociation characteristics and the level of crossreactivity of insulin antibodies and insulin autoantibodies directed to three different insulin molecules (human, bovine and porcine insulin). In this study sera from 17 diabetic patients were included, who were exclusively treated with s.c. human insulin, but presenting with severe insulin antibody mediated, immunological insulin resistance (i.e., insulin antibodies, IA). In addition, we included serum from one female patient, previously diagnosed with insulin autoimmune syndrome (no exposure to exogenous insulin treatment, i.e., insulin autoantibodies, IAA). Antibody concentrations and a binding/dissociation analysis was performed by using J(125)-labelled (position: A-14) human, porcine and bovine insulin according to the protocol described recently. In the patient with insulin autoimmune syndrome (IAA) we observed total crossreactivity between human, bovine and porcine insulin. By contrast, in the group of s.c. insulin treated diabetic patients with antibody-mediated insulin resistance (IA) we detected only partial crossreactivity. In these patients, there was a significantly higher level in the inital insulin binding (P < 0.05) directed to human insulin (median: 34%, IQR: 21.0-62.0), compared to porcine (median: 29.5%, IQR: 18.3-61.0) and bovine insulin (29%, IQR: 20.3-61.5), respectively. Here, we demonstrate different binding characteristics between IAA and IA, suggesting different epitope specificities. The observation of a significantly lower insulin binding to the "natural insulin analogs" (bovine and porcine insulin) compared to human insulin in the IA-group is in support of the concept that insulin analogs are eventually less immunogenic.

Analysis of nucleotide sequence of Iranian maize mosaic virus confirms its identity as a distinct nucleorhabdovirus

The nucleotide sequence of the Iranian maize mosaic rhabdovirus (IMMV) was obtained using a random-PCR method (rPCR) followed by PCR with specific primers. Analysis of the complete nucleotide sequence of the IMMV genes and intergenic regions comprising a total of 12,381 nucleotides (including the partial sequences of leader and trailer regions) revealed six open reading frames (ORF) on the viral complementary RNA (vcRNA). On the basis of its similarities to other rhabdovirus sequences, the IMMV genome consists of 3'-leader-N-P-3-M-G-L-5'-trailer. The intergenic regions contained a characteristic consensus sequence, 3'-AAUUCUUUUUGGGUUU/G-5'. The IMMV gene products showed a high similarity to those of maize mosaic virus and taro vein chlorosis virus and a more distant relationship to other rhabdoviruses. Together with the biological, serological and morphological features described earlier, our molecular data provide evidence that IMMV is a distinct member of the genus Nucleorhabdovirus in the family Rhabdoviridae.

Selective breeding for deficient sensorimotor gating is accompanied by increased perseveration in rats

Prepulse inhibition (PPI) of the acoustic startle response is a measure of sensorimotor gating that is deficient in some neuropsychiatric disorders, such as schizophrenia and Tourette's syndrome. Experimentally induced PPI deficits in rats are regarded as endophenotype to study the biological mechanisms and therapeutic strategies of these disorders. We have recently shown that selectively breeding rats for high and low PPI levels, respectively, leads to groups with different PPI performance that remains stable from the second generation on. We here tested whether the low PPI is accompanied by other behavioral deficits. Different spatial and operant learning paradigms were used to assess rats' learning and memory abilities as well as their behavioral flexibility. In the delayed alternation T-maze task the two groups did not differ in task acquisition and working memory. Rats with low PPI showed enhanced perseveration during switching between an egocentric and allocentric radial maze task. Enhanced perseveration was also found in an operant behavioral task, where different demands, i.e. a different number of lever presses for a pellet-reward, were assigned to and switched between two levers of a Skinner box. Rats with low PPI stayed longer at the ineffective lever before switching, thus being less able to adjust their behavior to changing reward values. Additionally, PPI low rats had a higher breakpoint value during a progressive ratio-schedule of reinforcement. Rats selectively bred for low PPI showed some cognitive deficits that are apparent in a number of psychiatric disorders with deficient information processing. Specifically in both, spatial and operant behavioral paradigms, PPI low rats are deteriorated in their ability to modulate behavior based upon new changing information. They may thus provide a non-pharmacological model that can be used to evaluate new therapeutic strategies ranging from pharmacological treatment to functional neurosurgery.

Fluorescence and binding properties of phenazine derivatives in complexes with polynucleotides of various base compositions and secondary structures

The interactions of two phenazine derivatives, one with a neutral chromophore (glycoside) and the other with a cationic one (quaternary salt), with various synthetic single- and double-stranded polynucleotides and natural DNA were studied by fluorescence techniques, conducting measurements of steady-state fluorescence intensity and polarization degree as well as fluorescence lifetime. These dyes show fluorescence quenching upon intercalation into the GC sequences of the double-stranded nucleic acids and an increase in fluorescence emission and lifetime upon incorporation into the AT and AU sequences. GC base pairs in continuous deoxynucleotide sequences were found to be preferred as binding sites for both phenazines, in contrast to AT base pairs. On the contrary, the continuous ribonucleotide GC sequence binds the phenazines more weakly than does the AU sequence. With regard to the interaction of the phenazines with single-stranded polynucleotides, a stacking interaction of the dye chromophores with the nucleic bases was observed. In that case the guanine residue quenches the cationic phenazine fluorescence, while the stacking interaction with the other bases results in an increase in the fluorescence quantum yield. Unlike the cationic dye, the fluorescence of the neutral phenazine was quenched by both purine bases.

N.-phrenicus-Stimulation bei biventrikulären Schrittmachern

BACKGROUND

Phrenic nerve stimulation (PNS) complicates the positioning of the left ventricle lead. We present a step-by-step approach to correct PNS during implantation, as established in our daily routine.

METHODS

The incidence of PNS, its successful correction, and long-term results (median 27 months) were analyzed retrospectively in 266 lead positions.

RESULTS

Phrenic nerve stimulation occurred in 13.9% of the lead positions. Multivariate analysis (P<0.02) showed that PNS only depended on the place of stimulation (coronary sinus side branch). Lead type, CRT indication, and patient's sex had no significant correlation. Following the step-by-step approach presented here, PNS was corrected satisfactorily in all cases.

CONCLUSIONS

Approach in case of PNS: 1. push or pull the lead within the same vein, 2. change to a different vein, 3. maintain position in case of a safe distance between the phrenic nerve and the pacing threshold, 4. change the lead type to achieve stable anchorage at adequate positions, 5. use a device featuring electronic repositioning.

Regulation of vesicular monoamine and glutamate transporters by vesicle-associated trimeric G proteins: new jobs for long-known signal transduction molecules

Neurotransmitters of neurons and neuroendocrine cells are concentrated first in the cytosol and then in either small synaptic vesicles ofpresynaptic terminals or in secretory vesicles by the activity of specific transporters of the plasma and the vesicular membrane, respectively. In the central nervous system the postsynaptic response depends--amongst other parameters-on the amount of neurotransmitter stored in a given vesicle. Neurotransmitter packets (quanta) vary over a wide range which may be also due to a regulation of vesicular neurotransmitter filling. Vesicular filling is regulated by the availability of transmitter molecules in the cytoplasm, the amount of transporter molecules and an electrochemical proton-mediated gradient over the vesicular membrane. In addition, it is modulated by vesicle-associated heterotrimeric G proteins, Galphao2 and Galphaq. Galphao2 and Galphaq regulate vesicular monoamine transporter (VMAT) activities in brain and platelets, respectively. Galphao2 also regulates vesicular glutamate transporter (VGLUT) activity by changing its chloride dependence. It appears that the vesicular content activates the G protein, suggesting a signal transduction from the luminal site which might be mediated by a vesicular G protein-coupled receptor or as an alternative possibility by the transporter itself. Thus, G proteins control transmitter storage and thereby probablylink the regulation of the vesicular content to intracellular signal cascades.

The use of biolistic inoculation of cassava mosaic begomoviruses in screening cassava for resistance to cassava mosaic disease

Inoculation of cassava with infectious clones of cassava mosaic geminiviruses (Geminiviridae: Begomovirus) and total DNA extracts from plants infected with well-characterised viruses was evaluated using the Bio-Rad Helios Gene Gun System. Total DNA extracts from infected plants and cloned viruses were produced for coating gold particles and bombardment onto new cassava genotypes, 96/1089A, 96/1039, 96/0160, 96/0304 and three local landraces TME 117, TME 3 and TME 4. Cloned DNA of a Kenyan isolate of the recombinant variant of East African cassava mosaic virus (EACMV-UG2-[Ka]), was only infectious to TME 117 (7/10 plants), 3 weeks post-inoculation with mild infection symptoms in the newly developing leaves. Biolistic inoculation with a chimeric pseudorecombinant virus between DNA A and B components from EACMV-[Ke-Kilifi] and EACMV-UG2-[Ka], respectively, was infectious to TME 117, 96/1039 and 96/0304 and developed very severe and persistent symptoms. TME 3 and TME 4 also developed symptoms, 12 days post-inoculation (d.p.i.). Total DNA extracts of ACMV and EACMV-[Ke-Kilifi] resulted in serious infections with symptoms already evident, 10d.p.i. In general, biolistic inoculation trials with total DNA extracts resulted in a higher number of infected plants expressing symptoms at a much earlier stage (10-12d.p.i.) compared with trials inoculated with virus clones.