Implication of Bemisia tabaci heat shock protein 70 in Begomovirus-whitefly interactions

The whitefly Bemisia tabaci (Gennadius) is a major cosmopolitan pest capable of feeding on hundreds of plant species and transmits several major plant viruses. The most important and widespread viruses vectored by B. tabaci are in the genus Begomovirus, an unusual group of plant viruses owing to their small, single-stranded DNA genome and geminate particle morphology. B. tabaci transmits begomoviruses in a persistent circulative nonpropagative manner. Evidence suggests that the whitefly vector encounters deleterious effects following Tomato yellow leaf curl virus (TYLCV) ingestion and retention. However, little is known about the molecular and cellular basis underlying these coevolved begomovirus-whitefly interactions. To elucidate these interactions, we undertook a study using B. tabaci microarrays to specifically describe the responses of the transcriptomes of whole insects and dissected midguts following TYLCV acquisition and retention. Microarray, real-time PCR, and Western blot analyses indicated that B. tabaci heat shock protein 70 (HSP70) specifically responded to the presence of the monopartite TYLCV and the bipartite Squash leaf curl virus. Immunocapture PCR, protein coimmunoprecipitation, and virus overlay protein binding assays showed in vitro interaction between TYLCV and HSP70. Fluorescence in situ hybridization and immunolocalization showed colocalization of TYLCV and the bipartite Watermelon chlorotic stunt virus virions and HSP70 within midgut epithelial cells. Finally, membrane feeding of whiteflies with anti-HSP70 antibodies and TYLCV virions showed an increase in TYLCV transmission, suggesting an inhibitory role for HSP70 in virus transmission, a role that might be related to protection against begomoviruses while translocating in the whitefly.

Automatic detection of atrial fibrillation in cardiac vibration signals

We present a study on the feasibility of the automatic detection of atrial fibrillation (AF) from cardiac vibration signals (ballistocardiograms/BCGs) recorded by unobtrusive bedmounted sensors. The proposed system is intended as a screening and monitoring tool in home-healthcare applications and not as a replacement for ECG-based methods used in clinical environments. Based on BCG data recorded in a study with 10 AF patients, we evaluate and rank seven popular machine learning algorithms (naive Bayes, linear and quadratic discriminant analysis, support vector machines, random forests as well as bagged and boosted trees) for their performance in separating 30 s long BCG epochs into one of three classes: sinus rhythm, atrial fibrillation, and artifact. For each algorithm, feature subsets of a set of statistical time-frequency-domain and time-domain features were selected based on the mutual information between features and class labels as well as first- and second-order interactions among features. The classifiers were evaluated on a set of 856 epochs by means of 10-fold cross-validation. The best algorithm (random forests) achieved a Matthews correlation coefficient, mean sensitivity, and mean specificity of 0.921, 0.938, and 0.982, respectively.

First Report of Shallot virus X in Onion in Sudan

Onion (Alium cepa L.) is among the most important vegetable field crops in Sudan. During a disease survey in crops (cvs. Kamleen Yellow and Abu-freua) conducted in 2010, samples showing mild mottling symptoms were collected from Shambat Research Station Farm, Khartoum North, Sudan. A CF-11 cellulose chromatography dsRNA preparation (4) of a mixed onion leaf sample of five plants (20 g) resulted, apart from smaller dsRNAs up to 3 kbp, in a high molecular weight dsRNA of approximately 9 kbp. This dsRNA was used as a template for a random reverse transcriptase (RT)-PCR followed by cloning (4) and sequencing of two randomly selected clones by the ABI BigDye Terminator v3.1 Cycle Sequencing Kit. Comparison with sequences available at GenBank revealed high identities to Shallot virus X (ShVX). ShVX is the type member of the genus Allexivirus (Alphaflexiviridae). One sequence obtained showed 84% nt and 98% aa sequence identity (genome position 414 to 1,285 of Accession No. M97264) to the replicase, whereas the other sequence partially covered the ORF4 and coat protein (CP) coding region (7,127 to 7,998). This sequence showed 80% nt (entire sequence) and 80/89% aa sequence identity to the ORF4 encoded protein/coat protein of a Russian ShVX isolate, respectively. ShVX was first reported in shallot in Russia (2) and subsequently in the Netherlands, Germany, India (3), and New Zealand (1). To confirm the presence of ShVX in Sudan, 32 symptomatic leaf samples were collected in 2011 from different onion fields in Khartoum North, with a similar disease incidence compared to 2010. Thirty-one of these onion samples reacted positively in a double antibody sandwich-ELISA with a ShVX-specific antiserum (DSMZ AS-1042). Total RNA was extracted from five ShVX-ELISA positive onion samples using the RNeasy Plant Mini Kit (QIAGEN, Hilden, Germany) according to the manufacturer's protocol. Two primer pairs were also designed on the basis of sequences obtained in the random RT-PCR approach, targeting a 659-bp fragment of the coat protein region (ShVX-CPs 5'GTTGAATGTGGCGAGCGCAA3' and ShVX-CPas 5'AGTGCAGAAGCCTTCCACA3') or a 686-bp fragment of the replicase (ShVX-Rs 5'ATGTACTTCGGTACGGCATCA3' and ShVX-R-as 5'TAATCGAATGAGGTCGGCCA3'). Fragments of the expected sizes were obtained for all positive samples. One RT-PCR product of each primer pair was directly sequenced, showing high sequence identities to those previously obtained (>98%). The random RT-PCR sequences obtained in this study were submitted to GenBank (JQ751056 and JQ751057). On the basis of the nucleotide sequences obtained with the dsRNA template, ShVX specific RT-PCR, and ELISA, the presence of ShVX in Sudan was confirmed in two consecutive years. To our knowledge, this is the first report of ShVX in Sudan and Africa, indicating this virus is more widespread than previously reported. The presence of ShVX also suggests the presence of its only known vector, the mite Aceria tulipae. The virus may have been introduced to Sudan by infected onion sets. Even if the impact of ShVX on onion production has not been determined, its identification and the availability of a diagnostic antiserum may be helpful to select virus-free propagation material in order to achieve sustainable onion production in Sudan. References: (1) Z. Egusquiza et al. New Disease Reports 18:29, 2008. (2) K. V. Kanyuka et al. J. Gen. Virol. 73:2553, 1992. (3) S. Majumder et al. New Disease Reports 15:52, 2007. (4) W. Menzel et al. Arch. Virol. 154:1343, 2009.

Characterization and Distribution of a Potyvirus Associated with Passion Fruit Woodiness Disease in Uganda

This article describes the incidence and etiology of a viral disease of passion fruit in Uganda. Symptoms, including those characteristic of passion fruit woodiness disease (PWD), were observed on 32% of plants in producing areas. Electron microscopic observations of infected tissues revealed flexuous filaments of ca. 780 nm. Enzymelinked immunosorbent assays indicated a serological relationship with Cowpea aphid-borne mosaic virus (CABMV) and Passion fruit ringspot virus (PFRSV). In host range studies, only species in the families Solanaceae and Chenopodiaceae were susceptible, and neither Vigna unguiculata nor Phaseolus vulgaris became infected. Coat protein (CP) gene sequences of eight isolates exhibited features typical of potyviruses and were highly similar (88 to 100% identity). However, the sequences had limited sequence identity with CP genes of two of the three potyviruses reported to cause PWD: East Asian Passiflora virus and Passion fruit woodiness virus (PWV). Deduced amino acid sequences for the CP of isolates from Uganda had highest identity with Bean common mosaic necrosis virus (BCMNV) (72 to 79%, with evolutionary divergence values between 0.17 and 0.19) and CABMV (73 to 76%, with divergence values between 0.21 and 0.25). Based on these results and in accordance with International Committee for Taxonomy of Viruses criteria for species demarcation in the family Potyviridae, we conclude that a previously unreported virus causes viral diseases on passion fruit in Uganda. The name "Ugandan Passiflora virus" is proposed for this virus.

Analysis of the tomato mild mottle virus genome indicates that it is the most divergent member of the genus Ipomovirus (family Potyviridae)

The complete genome of a tomato mild mottle virus (ToMMV) isolate was analysed, and some biological features were characterized. The ssRNA genome of ToMMV from Ethiopia encompasses 9283 nucleotides (excluding the 3' poly(A) tail) and encodes a polyprotein of 3011 amino acids. Phylogenetic and pairwise comparisons with other members of the family Potyviridae revealed that ToMMV is the most divergent member of the genus Ipomovirus, with a genome organization similar to that of members of the species Sweet potato mild mottle virus, the type species of the genus. In contrast to earlier reports, ToMMV isolates from Yemen and Ethiopia were not transmitted by the aphid Myzus persicae, but they were transmitted very erratically by the whitefly Bemisia tabaci. A comparison of the 3'-proximal sequences of different isolates provided evidence for geographically associated genetic variation.

First Report of Cucurbit chlorotic yellows virus Infecting Muskmelon and Cucumber in Sudan

In summer 2009, a survey for virus diseases in cucurbits was conducted in open fields and plastichouses in Khartoum State, the most important growing area for cucurbits in Sudan. Chlorosis and yellowing symptoms on middle and lower leaves were observed on many muskmelon (Cucumis melo L.) plants grown in open fields in the Assilat agricultural scheme and on approximately 80% of the cucumber (Cucumis sativus L.) plants grown in plastichouses in Khartoum North. Large populations of whiteflies (Bemisia tabaci L.) were present in both locations. Leaf symptoms that were observed were similar to those caused by Cucurbit chlorotic yellows virus (CCYV), a recently described new Crinivirus species infecting cucurbits in Japan (4), indicating presence of this virus previously only reported from Japan, Taiwan (2), and China (1). Samples from seven symptomatic muskmelon leaves were collected from individual plants grown in different open fields in Assilat and from a symptomatic cucumber plant grown in a plastichouse. Total RNA was extracted from these samples with the RNeasy Plant Mini Kit (QIAGEN, Hilden, Germany) to amplify putative CCYV sequences with primers (Crini-s2 5'-CATTCCTACCTGTTTAGCCA and Crini-as2 5'-TGCACTTATAATCTGCTGGTAC) designed from CCYV sequences available at GenBank. A 353-bp DNA fragment of the HSP70 gene was amplified by reverse transcription (RT)-PCR for all samples. Further analysis by direct sequencing of two PCR products showed 99 to 100% nt sequence identity to Asian CCYV isolates. Amplification of the coat protein sequence with the primer pair (CCYV-CPs 5'-ATGGAGAAGACTGACAATAAACAA and CCYV-CPas 5'-TTTACTACAACCTCCCGGTG) followed by cloning and sequencing yielded a 760-bp fragment having 99% nucleotide sequence identity to all Asian isolates. For confirmation, dsRNA preparations of symptomatic muskmelon tissue (collected in June 2010) were made, showing dsRNA patterns typical for criniviruses after separation on agarose gels. This dsRNA was used as template for random RT-PCR followed by sequencing of the cloned PCR products (3). Comparison with sequences available at GenBank revealed that cDNA sequences from dsRNA also were 99 to 100% identical to the CCYV genome sequence (AB523788.1). Whitefly transmission of the virus was confirmed by giving a population of B. tabaci an acquisition access period of 24 h and a further 24 h on muskmelon and cucumber seedlings. Symptoms were observed after 5 to 7 days, and the presence of CCYV was confirmed by RT-PCR. In conclusion, symptoms, RT-PCR, and dsRNA sequencing results confirm the presence and establishment of CCYV in cucurbit crops in Sudan. It is remarkable that the sequences obtained from the Sudanese samples show only negligible sequence differences from Asian isolates. Because of the large whitefly vector populations, the spread of CCYV to neighboring countries in Africa and potentially southern Europe, or wherever cucurbits are grown, can be expected. To our knowledge, this is the first report of CCYV in Sudan and outside Eastern Asia. The sequences obtained in this study have been submitted to GenBank under Accession Nos. JF807053 to JF807055. References: (1) Q. S. Gu et al. Plant Dis. 95:73, 2011. (2) L. H. Huang et al. Plant Dis. 94:1168, 2010. (3) W. Menzel et al. Arch. Virol. 154:1343, 2009. (4) M. Okuda et al. Phytopathology 100:560, 2010.

Sequencing of the Tamus red mosaic virus genome: further evidence that it is a distinct species of the genus Potexvirus

In 1993, a virus causing red mosaic and leaf distortion has been isolated from black bryony (Tamus communis) in Italy. Based on particle properties and serology, the virus was assigned to the genus Potexvirus and named Tamus red mosaic virus (TRMV), pending a genome sequence. The original Italian TRMV isolate was submitted to the DSMZ plant virus collection (PV-0397). To confirm the taxonomic status of the virus, the entire genome sequence was determined comprising 6,495 nucleotides excluding the poly(A)-tail. Five putative open reading frames (ORFs) in an arrangement typical for potexviruses were predicted. TRMV is closely related to but distinct from Clover yellow mosaic virus and Allium virus X. In addition to previous morphological and serological characterization, the results presented in this study further reinforce the classification of TRMV as a distinct virus species of the genus Potexvirus.

The management of oesophageal soft food bolus obstruction: a systematic review

INTRODUCTION

Oesophageal soft food bolus obstruction (OSFBO) is a surgical emergency. However, no national guidelines exist regarding its management. This paper systematically reviews the literature with respect to the management of OSFBO.

METHODS

Relevant studies included were identified from the the Cochrane Library, the National Center for Biotechnology Information and the US National Library of Medicine resources. A systematic review was performed on 8 November 2010.

RESULTS

This systematic review of the management of OSFBO shows no evidence that any medical intervention is more effective than a 'watch and wait' policy in enabling spontaneous disimpaction. Furthermore, the use of hyoscine butylbromide for OSFBO probably stems from a misquoted textbook. Surgical removal of an OSFBO is effective but not without potential risk. There is some evidence to support surgical intervention within 24 hours to prevent complications deriving from the initial obstruction.

CONCLUSIONS

There is a need for large double-blind, randomised, placebo controlled trials of drugs used in the medical management of OSFBO. Until the results from such trials are available, the treatment of OSFBO will remain based on inconsistent clinical judgement.

Influence of brain tumors on the MR spectra of healthy brain tissue

The neurochemical environment of nontumorous white matter tissue was investigated in 135 single voxel spectra of "healthy" white matter regions of 43 tumor patients and 129 spectra of 52 healthy subjects. Spectra were acquired with short TE and TR values. With the data of tumor patients, it was examined whether differences were caused by the tumor itself or aggressive tumor therapies as confounding factors. Comparing the spectra of both classes, an excellent differentiation was possible based on the metabolite peak of N-acetylaspartate (P ≈ 0) and myoinositol (P < 0.03). The area under curve of the receiver operating characteristic was calculated as 0.86 and 0.62, respectively. With linear discriminant analysis using combinations of integrals, a prediction was possible, whether a spectrum belonged to the patient or the healthy subject class with an overall accuracy above 80%. The confounding factors could be ruled out as source of the differences. The results show strong evidence for an influence of malignant growth on the biochemical environment of nontumorous white matter tissue. Because of the T(1) weighting, the measured differences between both classes were most likely concentration changes interfered by T(1) effects. The underlying processes will be subject of future studies.

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.

Analysis of cassava brown streak viruses reveals the presence of distinct virus species causing cassava brown streak disease in East Africa

Cassava brown streak virus (CBSV) isolates were analysed from symptomatic cassava collected between 1997 and 2008 in the major cultivation regions of East Africa. An analysis of complete RNA genomes of seven isolates from Kenya, Tanzania, Mozambique, Uganda and Malawi revealed a common genome structure, but the isolates clearly clustered in two distinct clades. The first comprised isolates from Kenya, Uganda, Malawi, north-western Tanzania and the CBSV described previously, and shared between 87 and 95% nucleotide sequence identity, whilst the second included isolates from coastal regions of Mozambique and Tanzania, which shared only 70% nucleotide sequence identities with isolates of the first clade. When the amino acid sequences of viral proteins were compared, identities as low as 47% (Ham1) and 59% (P1) between the two clades were found. An antiserum obtained against the capsid protein of a clade 1 isolate identified a 43 kDa protein in clade 1 isolates and a 45 kDa protein in clade 2 isolates. Several cassava cultivars were susceptible to isolates of clade 2 but resistant to those of clade 1. The differences observed both in biological behaviour and in genomic and protein sequences indicate that cassava brown streak disease in East Africa is caused by at least two distinct virus species. It is suggested that those of clade 1 retain the species name Cassava brown streak virus, whilst those of clade 2 be classified as Cassava brown streak Mozambique virus.

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.

Plantibody-mediated inhibition of the Potato leafroll virus P1 protein reduces virus accumulation

The P1 protein of Potato leafroll virus (PLRV) is thought to play a major role in the replication cycle by promoting the maturation of the genome-linked virion protein VPg. To study the relevance of P1 and its autoproteolytic derivative P1-C25 in the viral life cycle, the V H and V L domains of monoclonal antibody mAbP1-1, raised against the C-terminus of P1, were used to develop a single chain variable fragment antibody scFvP1-1 for expression in plants. The transient expression of scFvP1-1 in tobacco (Nicotiana tabacum) strongly reduced virus accumulation, while transgenic potato (Solanum tuberosum) plants expressing scFvP1-1 showed high levels of resistance following PLRV inoculation by viruliferous aphids. This is the first report that conclusively demonstrates that a PLRV gene product is essential for the completion of the virus life cycle in vivo without genetic alteration of the viral genome. This is also the first time plantibody-mediated resistance has been demonstrated with a luteovirus.

Functional characterization and subcellular localization of the 16K cysteine-rich suppressor of gene silencing protein of tobacco rattle virus

The 16 kDa cysteine-rich protein (16K) of tobacco rattle virus (TRV) is known to partially suppress RNA silencing in Drosophila cells. In this study, we show that 16K suppresses RNA silencing in green fluorescent protein (GFP)-transgenic Nicotiana benthamiana plants using an Agrobacterium-mediated transient assay. 16K slightly reduced the accumulation of short interfering RNAs (siRNA) of GFP, suggesting that the protein may interfere with the initiation and/or maintenance of RNA silencing. Deletion of either the N- or C-terminal part of 16K indicated that the entire 16K open reading frame (ORF) is necessary for its silencing suppression function. Pentapeptide insertion scanning mutagenesis (PSM) revealed that only two short regions of 16K tolerated five extra amino acid insertions without considerable reduction in its silencing suppression function. The tolerant regions coincide with sequence variability between tobravirus cysteine-rich proteins, indicating a strong functional and/or structural conservation of TRV 16K. Confocal laser scanning microscopy of transiently expressed 16K fusions to red fluorescent protein (RFP) revealed a predominant cytoplasmic localization and, in addition, a nuclear localization. In contrast, fusions of RFP with the N-terminal region of 16K localized exclusively to the cytoplasm, whereas fusions between RFP and the C-terminal region of 16K displayed an exclusive nuclear localization. Further analysis of 16K-derived peptide fusions demonstrated that the 16K C-terminal region contained at least two functional bipartite nuclear localization signals which were independently capable of nuclear targeting.

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.

Landmark Hierarchies in Context

We are interested in the generation of distinguishing place or route descriptions for urban environments. Such descriptions require a hierarchical model of the discourse, the elements of the city. We postulate that cognitive hierarchies, as used in human communication, can be sufficiently reflected in machine-generated hierarchies. In this paper we (a) propose a computational model for the generation of a hierarchy of one of these elements of the city—landmarks—and (b) demonstrate that a set of filter rules applied on this hierarchy derives distinguishing route descriptions from spatial context.

Complete nucleotide sequence and experimental host range of Okra mosaic virus

Okra mosaic virus (OkMV) is a tymovirus infecting members of the family Malvaceae. Early infections in okra (Abelmoschus esculentus) lead to yield losses of 12-19.5%. Besides intensive biological characterizations of OkMV only minor molecular data were available. Therefore, we determined the complete nucleotide sequence of a Nigerian isolate of OkMV. The complete genomic RNA (gRNA) comprises 6,223 nt and its genome organization showed three major ORFs coding for a putative movement protein (MP) of M r 73.1 kDa, a large replication-associated protein (RP) of M r 202.4 kDa and a coat protein (CP) of M r 19.6 kDa. Prediction of secondary RNA structures showed three hairpin structures with internal loops in the 5'-untranslated region (UTR) and a 3'-terminal tRNA-like structure (TLS) which comprises the anticodon for valine, typical for a member of the genus Tymovirus. Phylogenetic comparisons based on the RP, MP and CP amino acid sequences showed the close relationship of OkMV not only to other completely sequenced tymoviruses like Kennedya yellow mosaic virus (KYMV), Turnip yellow mosaic virus (TYMV) and Erysimum latent virus (ErLV), but also to Calopogonium yellow vein virus (CalYVV), Clitoria yellow vein virus (CYVV) and Desmodium yellow mottle virus (DYMoV). This is the first report of a complete OkMV genome sequence from one of the various OkMV isolates originating from West Africa described so far. Additionally, the experimental host range of OkMV including several Nicotiana species was determined.

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.