bluuebunny/crossref_metadata_2025 huggingface dataset:
Recombination and gene duplication in the evolutionary diversification of P1 proteins in the family Potyviridae
Authors: Valli Adrian , López-Moya Juan José , García Juan Antonio
Published: February 2007

Genome structure and sequence are notably conserved between members of the familyPotyviridae. However, some genomic regions of these viruses, such as that encoding the P1 protein, show strikingly high variability. In this study, some partially conserved motifs were identified upstream of the quite well-conserved protease domain located near the P1 C terminus. The irregular distribution of these motifs suggests that the potyviral P1 proteins have undergone complex evolutionary diversification. Evidence was found of recombination events in the P1 N-terminal region, similar to those reported in potyviruses of the bean common mosaic virus subgroup, but also affecting other potyviruses. Moreover, intergeneric recombination events affecting potyviruses and ipomoviruses were also observed. Evidence that these recombination events could be linked to host adaptation is provided. Specific sequence features and differences in net charge help to classify the P1 proteins of members of the familyPotyviridaeinto two groups: those from potyviruses and rymoviruses and those from tritimoviruses. The ipomovirusCucumber vein yellowing virushas two P1 copies arranged in tandem, the most N-terminal one being of the potyvirus type and the other being of the tritimovirus type. These findings suggest that both recombination and gene duplication have contributed to P1 evolution and helped to facilitate successful adaptation of members of the familyPotyviridaeto a wide range of host species.
West Nile virus isolates from India: evidence for a distinct genetic lineage
Authors: Bondre Vijay P. , Jadi R. S. , Mishra A. C. , Yergolkar P. N. , Arankalle V. A.
Published: February 2007

The complete genomic sequence of one human isolate of West Nile virus (WNV) and the partial genomic sequences of 14 other strains from India isolated in the period 1955–1982 from different hosts and geographical areas were determined. Phylogenetic analyses based on complete and partial genomic sequences (921 nt of the C–prM–E region) revealed that WNV could be classified into five distinct groups that differed from each other by 20–25 % at the complete genome level and by 20–26 % using partial sequences. Of the Indian isolates, 13 formed a distinct genetic lineage, lineage 5, whereas two isolates, one from a human patient (1967) and another from a bat (1968), were related closely to lineage 1 strains. The complete genomic sequence of the Indian isolate, 804994, showed 20–22 % genetic divergence from the previously proposed lineage 1 and 2 strains and 24–25 % divergence from isolates of the newly proposed lineages 3 (Rabensburg isolate 97-103 of 1997) and 4 (Russian isolate LEIV-Krnd88-190 of 1998). Similarly, the partial genomic sequences of the Indian isolates showed 21–26 % divergence from lineage 1 and 2 strains and from the Rabensburg (97-103) and Russian (LEIV-Krnd88-190) isolates. Cross-neutralization using strain-specific polyclonal antibodies against lineage 1 strain Eg-101 and representative Indian strains suggests substantial antigenic variation. This study documents circulation of WNV strains typical to India for 27 years and the introduction of lineage 1 strains during 1967–1968. These results indicate strongly that WNV should be classified into five genetic lineages, with Indian viruses constituting the distinct genetic lineage 5.
A chimeric GB virus B encoding the hepatitis C virus hypervariable region 1 is infectious in vivo
Authors: Haqshenas G. , Dong X. , Netter H. , Torresi J. , Gowans E. J.
Published: February 2007

Two GB virus B (GBV-B) chimeric genomes, GBV-HVR and GBV-HVRh (with a hinge), containing the coding region of the immunodominant hypervariable region 1 (HVR1) of the E2 envelope protein of Hepatitis C virus (HCV) were constructed. Immunoblot analysis confirmed that HVR1 was anchored to the GBV-B E2 protein. To investigate the replication competence and in vivo stability of in vitro-generated chimeric RNA transcripts, two naïve marmosets were inoculated intrahepatically with the transcripts. The GBV-HVR chimeric genome was detectable for 2 weeks post-inoculation (p.i.), whereas GBV-HVRh reverted to wild type 1 week p.i. Sequencing analysis of the HVR1 and flanking regions from GBV-HVR RNA isolated from marmoset serum demonstrated that the HVR1 insert remained unaltered in the GBV-HVR chimera for 2 weeks. Inoculation of a naïve marmoset with serum collected at 1 week p.i. also resulted in viraemia and confirmed that the serum contained infectious particles. All animals cleared the infection by 3 weeks p.i. and remained negative for the remaining weeks. The chimera may prove useful for the in vivo examination of any HCV HVR1-based vaccine candidates.
Genomic analysis of diverse rubella virus genotypes
Authors: Zhou Yumei , Ushijima Hiroshi , Frey Teryl K.
Published: February 2007

Based on the sequence of the E1 glycoprotein gene, two clades and ten genotypes ofRubella virushave been distinguished; however, genomic sequences have been determined for viruses in only two of these genotypes. In this report, genomic sequences for viruses in an additional six genotypes were determined. The genome was found to be well conserved. The viruses in all eight of these genotypes had the same number of nucleotides in each of the two open reading frames (ORFs) and the untranslated regions (UTRs) at the 5′ and 3′ ends of the genome. Only the UTR between the ORFs (the junction region) exhibited differences in length. Of the nucleotides in the genome, 78 % were invariant. The greatest observed distance between viruses in different genotypes was 8.74 % and the maximum calculated genetic distance was 14.78 substitutions in 100 sites. This degree of variability was similar among regions of the genome with two exceptions, both within the P150 non-structural protein gene: the N-terminal region that encodes the methyl/guanylyltransferase domain was less variable, whereas the hypervariable domain in the middle of the gene was more divergent. Comparative phylogenetic analysis of different regions of the genome was done, using sequences from 43 viruses of the non-structural protease (near the 5′ end of the genome), the junction region (the middle) and the E1 gene (the 3′ end). Phylogenetic segregation of sequences from these three genomic regions was similar with the exception of genotype 1B viruses, among which a recombinational event near the junction region was identified.
Full-length EBNA1 mRNA-transduced dendritic cells stimulate cytotoxic T lymphocytes recognizing a novel HLA-Cw*0303- and -Cw*0304-restricted epitope on EBNA1-expressing cells
Authors: Ito Yoshinori , Demachi-Okamura Ayako , Ohta Rieko , Akatsuka Yoshiki , Nishida Keiko , Tsujimura Kunio , Morishima Yasuo , Takahashi Toshitada , Kuzushima Kiyotaka
Published: February 2007

Epstein–Barr virus (EBV)-encoded nuclear antigen 1 (EBNA1) is an attractive target for immunotherapy against EBV-associated malignancies because it is expressed in all EBV-positive cells. Although CD8+ cytotoxic T-lymphocyte (CTL) epitope presentation is largely prevented by its glycine–alanine-repeat domain (GAr), the use of mRNA-transduced dendritic cells (DCs) would offer the advantage of priming EBNA1-specific CTLs. After stimulation with GAr-containing EBNA1-transduced monocyte-derived DCs, two EBNA1-specific CTL clones, B5 and C6, were isolated successfully from a healthy donor. These CTLs recognize peptides in the context of HLA-B*3501 and HLA-Cw*0303, respectively. A novel epitope, FVYGGSKTSL, was then identified, presented by both HLA-Cw*0303 and -Cw*0304, which are expressed by >35 % of Japanese, >20 % of Northern Han Chinese and >25 % of Caucasians. The mixed lymphocyte–peptide culture method revealed that FVYGGSKTSL-specific CTL-precursor frequencies in HLA-Cw*0303- or -Cw*0304-positive donors were between 1×10−5 and 1×10−4 CD8+ T cells. Moreover, both CTL clones inhibited growth of HLA-matched EBV-transformed B lymphocytes in vitro, and B5 CTLs produced a gamma interferon response to EBNA1-expressing gastric carcinoma cells in the context of HLA-Cw*0303. These data demonstrate that EBNA1 mRNA-transduced DCs may be useful tools for inducing EBNA1-specific CTLs that might be of clinical interest for CTL therapy of EBV-associated malignancies.
Development and evaluation of an efficient cell-culture system for Hepatitis E virus
Authors: Tanaka Toshinori , Takahashi Masaharu , Kusano Eiji , Okamoto Hiroaki
Published: February 2007

Using a faecal suspension with high load of Hepatitis E virus (HEV) (2.0×107 copies ml−1, genotype 3), we developed an efficient cell-culture system for HEV in a hepatocarcinoma cell line (PLC/PRF/5). HEV progeny released in the culture medium were passaged five times successively in PLC/PRF/5 cells. The initial day of appearance and load of HEV detectable in the culture supernatant after inoculation were dependent on the titre of seed virus in the inoculum. When 6.4×104 copies of HEV were inoculated on monolayers of PLC/PRF/5 cells in six-well microplates, HEV RNA was first detected in the culture medium on day 14 post-inoculation and increased to 9.1×105 copies ml−1 on day 60. When 8.6×105 copies of HEV were inoculated, HEV RNA was initially detected on day 12 and reached the highest titre of 8.6×107 copies ml−1 on day 60. HEV incubated at temperatures higher than 70 °C did not grow in PLC/PRF/5 cells, while HEV incubated at 56 °C for 30 min was infectious. Convalescent serum samples with IgM-class HEV antibodies obtained from patients infected with HEV of genotype 1, 3 or 4 neutralized the genotype 3 virus, indicating that HEV antibodies are broadly cross-reactive. Serum samples obtained from patients 8.7 or 24.0 years after the onset of HEV infection also prevented the propagation of HEV in PLC/PRF/5 cells, suggesting the presence of long-lasting HEV antibodies with neutralizing activity in individuals with past HEV infection.
Antibodies specific to the HA2 glycopolypeptide of influenza A virus haemagglutinin with fusion-inhibition activity contribute to the protection of mice against lethal infection
Authors: Gocník M. , Fislová T. , Sládková T. , Mucha V. , Kostolanský F. , Varečková E.
Published: February 2007

Four monoclonal antibodies (mAbs) recognizing distinct antigenic sites on the HA2 glycopolypeptide of influenza virus A/Dunedin/4/73 (H3N2) have been tested forin vivoprotection. When applied intravenously before infection, three of them increased the survival of BALB/c mice infected with 1 LD50homologous virus. The protection resulted simultaneously in 2 days earlier clearance of virus from the lungs. These three antibodies inhibited the fusion activity of virus in previousin vitroexperiments. One of them, specific to N-terminal aa 1–38 of the HA2 glycopolypeptide, was also tested for protection against the heterologous virus A/Mississippi/1/85 (H3N2). Protection similar to that against the homologous virus was observed. The fourth mAb, without fusion-inhibition activity, did not protect mice. It is concluded that antibodies specific to the antigenically conserved HA2 glycopolypeptide that exhibit fusion-inhibition activity can contribute to the protection of infected mice and mediate more effective recovery from infection.
Role of the mutant spectrum in adaptation and replication of West Nile virus
Authors: Ciota Alexander T. , Ngo Kiet A. , Lovelace Amy O. , Payne Anne F. , Zhou Yangsheng , Shi Pei-Yong , Kramer Laura D.
Published: February 2007

West Nile virus (WNV) has successfully spread throughout the USA, Canada, Mexico, the Caribbean and parts of Central and South America since its 1999 introduction into North America. Despite infecting a broad range of both mosquito and avian species, the virus remains highly genetically conserved. This lack of evolutionary change over space and time is common with many arboviruses and is frequently attributed to the adaptive constraints resulting from the virus cycling between vertebrate hosts and invertebrate vectors. WNV, like most RNA viruses studied thus far, has been shown in nature to exist as a highly genetically diverse population of genotypes. Few studies have directly evaluated the role of these mutant spectra in viral fitness and adaptation. Using clonal analysis and reverse genetics experiments, this study evaluated genotype diversity and the importance of consensus change in producing the adaptive phenotype of WNV following sequential mosquito cell passage. The results indicated that increases in the replicative ability of WNV in mosquito cells correlate with increases in the size of the mutant spectrum, and that consensus change is not solely responsible for alterations in viral fitness and adaptation of WNV. These data provide evidence of the importance of quasispecies dynamics in the adaptation of a flavivirus to new and changing environments and hosts, with little evidence of significant genetic change.
Detection and characterization of infectious Hepatitis E virus from commercial pig livers sold in local grocery stores in the USA
Authors: Feagins A. R. , Opriessnig T. , Guenette D. K. , Halbur P. G. , Meng X.-J.
Published: February 2007

Hepatitis E virus (HEV) is a zoonotic pathogen of which pigs are reservoirs. To determine the presence of HEV RNA in commercial pig livers sold in local grocery stores in the USA, 127 packages of commercial pig liver were purchased and tested by a universal RT-PCR assay capable of detecting all four known HEV genotypes. Among the 127 livers tested, 14 were positive for HEV RNA. Sequence and phylogenetic analyses revealed that the 14 isolates all belonged to genotype 3. An animal study was subsequently conducted in pigs to determine whether the PCR-positive pig livers still contained infectious virus. The results showed that pigs inoculated with two of the three PCR-positive pig-liver homogenates became infected, as evidenced by the detection of faecal virus shedding, viraemia and seroconversion. The data demonstrated that commercial pig livers sold in grocery stores are contaminated by HEV and that the contaminating virus remains infectious, thus raising a public-health concern for food-borne HEV infection.
Sensitivity analysis, molecular systematics and natural history evolution of Scathophagidae (Diptera: Cyclorrhapha: Calyptratae)
Authors: Kutty Sujatha Narayanan , Bernasconi Marco Valerio , Šifner František , Meier Rudolf
Published: February 2007

The 60 000 described species of Cyclorrhapha are characterized by an unusual diversity in larval life‐history traits, which range from saprophagy over phytophagy to parasitism and predation. However, the direction of evolutionary change between the different modes remains unclear. Here, we use the Scathophagidae (Diptera) for reconstructing the direction of change in this relatively small family (≈ 250 spp.) whose larval habits mirror the diversity in natural history found in Cyclorrhapha. We subjected a molecular data set for 63 species (22 genera) and DNA sequences from seven genes (12S, 16S, Cytb, COI, 28S, Ef1‐alfa, Pol II) to an extensive sensitivity analysis and compare the performance of three different alignment strategies (manual, Clustal, POY). We find that the default Clustal alignment performs worst as judged by character incongruence, topological congruence and branch support. For this alignment, scoring indels as a fifth character state worsens character incongruence and topological congruence. However, manual alignment and direct optimization perform similarly well and yield near‐identical trees, although branch support is lower for the direct‐optimization trees. All three alignment techniques favor the upweighting of transversion. We furthermore confirm the independence of the concepts “node support” and “node stability” by documenting several cases of poorly supported nodes being very stable and cases of well supported nodes being unstable. We confirm the monophyly of the Scathophagidae, its two constituent subfamilies, and most genera. We demonstrate that phytophagy in the form of leaf mining is the ancestral larval feeding habit for Scathophagidae. From phytophagy, two shifts to saprophagy and one shift to predation has occurred while a second origin of predation is from a saprophagous ancestor.

© The Willi Hennig Society 2006.
Distinguishing between convergence and parallelism is central to comparative biology: a reply to Williams and Ebach
Authors: Desutter‐Grandcolas Laure , Legendre Frédéric , Grandcolas Philippe , Robillard Tony , Murienne Jérôme
Published: February 2007

The definitions of character similarity, homology, homoplasy, heterology, parallelism and convergence are clarified in the framework of current phylogenetic methodology. They are all associated with definite patterns of character change and can consequently be tested by phylogeny building. Their crucial significance in comparative biology is illustrated using demonstrative examples.

© The Willi Hennig Society 2006.
Arterial oxygen saturation during induction of anaesthesia
Authors: THORPE C. M. , GAUNTLETT I. S.
Published: February 2007

Three groups of 10 ASA 1 patients were studied to determine the incidence of hypoxaemia (oxygen saturation ≤ 90%) using pulse oximetry during induction of ‘mask’ anaesthesia, and whether simple oxygenation techniques could prevent its occurrence. We also surveyed all anaesthetists in three major hospitals to ascertain their techniques for this method of anaesthesia. Anaesthesia was induced in all patients with thiopentone and maintained with nitrous oxide and isoflurane. The first group received 33% oxygen in nitrous oxide as carrier gases, a second group a few normal breaths of 100% oxygen during thiopentone administration followed by 33% oxygen in nitrous oxide, while a third group received 100% oxygen after loss of eyelash reflex until spontaneous breathing was established. No patient received positive pressure ventilation before spontaneous breathing was established. Six of the 10 patients in the first group became hypoxaemic compared to none in the second group, and three patients became hypoxaemic in the third group. Thirty‐seven percent of anaesthetists who responded to the survey either did not apply positive pressure ventilation before establishment of spontaneous breathing, or only did so if apnoea was prolonged. Only one anaesthetist fully pre‐oxygenated patients lungs. We conclude that to avoid the likely occurrence of hypoxaemia during induction of mask anaesthesia, a minimum of a few breaths pre‐oxygenation is necessary.
The effects of midazolam on cerebral blood flow and oxygen consumption Interaction with nitrous oxide in patients undergoing craniotomy for supratentorial cerebral tumours
Authors: KNUDSEN L. , COLD G. E. , HOLDGÅRD H. O. , And U. T. , JENSEN S.
Published: February 2007

Cerebral blood flow and the cerebral metabolic rate of oxygen were measured in 30‐patients during craniotomy for supratentorial cerebral tumours by a modification of the Kety‐Schmidt technique using Xenon 133 intravenously. Anaesthesia was induced with midazolam 0.3 mg/kg, fentanyl and pancuronium, and maintained with midazolam as a continuous infusion, fentanyl, pancuronium and nitrous oxide in oxygen or oxygen in air. The concentration of midazolam in the blood of 10 patients was about 300 ng/litre during two measurements; the patients’ lungs were ventilated with N2O in oxygen. The concentration of midazolam in the blood of another 10 patients was doubled to about 600 ng/litre during the second flow measurement; the patients’ lungs were ventilated with N2O/O2. The concentration of midazolam in the blood of the third group of 10 patients was doubled to 600 ng/litre during the second flow measurement; the patients’ lungs were ventilated with oxygen in air. No relationship was found between the dose of midazolam and cerebral blood flow or oxygen consumption. Nitrous oxide in combination with midazolam also had no effect on these variables.
Obstetric epidural analgesia with mixtures of bupivacaine, adrenaline and fentanyl
Authors: YAU G. , GREGORY M. A. , GIN T. , OH T. E.
Published: February 2007

We performed a double‐blind comparison of six solutions for epidural analgesia in 90 healthy Chinese women with uncomplicated pregnancies. Patients were randomly allocated to receive 10 ml bupivacaine 0.125% or 0.25% plain, bupivacaine 0.125% with adrenaline 1.25 μg/ml, bupivacaine 0.25% with adrenaline 2.5 μg/ml or the latter two solutions with added fentanyl 50 μg. Analgesia was unsatisfactory in 30% of the bupivacaine 0.125% groups without fentanyl. The addition of adrenaline, compared with bupivacaine 0.25% plain, gave faster onset and longer duration of analgesia (p < 0.05) which was similar to that found in both fentanyl groups. There were no differences in method of delivery or neonatal Apgar scores among groups. The least concentrated mixture that gave the best analgesia was the combination of bupivacaine 0.125% with adrenaline 1.25 μg/ml and fentanyl 50 μg.
A randomised double‐blind study of interpleural analgesia after cholecystectomy
Authors: LEE A. , BOON D. , BAGSHAW P. , KEMPTHORNE P.
Published: February 2007

Continuous interpleural analgesia provided by 4 hourly injections of 20 ml bupivacaine 0.5% with adrenaline 5 μg/ml was compared with placebo in a randomised, double‐blind study after cholecystectomy. All patients self‐administered intravenous morphine using a patient‐controlled analgesia device. There was a highly significant difference in mean morphine consumption between the groups (72mg as compared with 22 mg). Visual analogue pain scores tended to be lower in the bupivacaine group throughout and this was significant at 2 hours. Respiratory function measurements were not significantly different between the groups. The mean peak venous plasma bupivacaine concentration after the sixth dose was 3.03 μg/ml and no symptoms suggestive of local anaesthetic toxicity occurred. It is concluded that this regimen can provide effective and continuous analgesia after cholecystectomy and that combined administration of interpleural bupivacaine and systemic morphine is more effective than morphine alone in the immediate postoperative period. The doses of bupivacaine required for optimal use of the technique lead to significant total plasma bupivacaine concentrations within 24 hours.
Anaphylactic anaesthetic reactions. The value of paper radioallergosorbent tests for IgE antibodies to muscle relaxants and thiopentone
Authors: ASSEM E. S. K.
Published: February 2007

The three currently available paper radioallergosorbent tests (‘suxamethonium’, alcuronium and thiopentone) were evaluated. ‘Suxamethonium’ radioallergosorbent test (which employs choline conjugated to paper discs) proved to be reliable in the detection of allergy to neuromuscular blockers, which were confirmed as the most common cause of anaphylactic reaction during general anaesthesia. Thiopentone radioallergosorbent test may also be useful, and is recommended in conjunction with ‘suxamethonium’ radioallergosorbent test in the preliminary investigation of reactions. Patients with positive ‘suxamethonium’ radioallergosorbent test usually require further testing, including alcuronium radioallergosorbent test, skin testing with a wide range of drug concentrations or leucocyte histamine release test.
Aspiration pneumonia and the laryngeal mask airway
Authors: GRIFFIN R. M. , Hatcher I. S.
Published: February 2007

A case of aspiration pneumonia is reported after the use of a laryngeal mask airway in a young woman undergoing an elective cholecystectomy. The case illustrates the hazards of regurgitation with the laryngeal mask airway and the need for further evaluation when used with controlled mechanical ventilation.
Severe anaphylactoid reaction to hydroxyethyl starch
Authors: CULLEN M. J. , SINGER M.
Published: February 2007

A case is presented of a severe anaphylactoid reaction to hydroxyethyl starch solution that occurred peri‐operatively and required extended intensive management of the resultant bronchospasm and hypotension. Subsequent intradermal injection of hetastarch produced a delayed positive response, suggestive of a complement‐mediated mechanism.
Pregnancy associated with Gorlin's syndrome
Authors: YOSHIZUMI J. , VAUGHAN R. S. , JASANI B.
Published: February 2007

A pregnant woman with Gorlin's syndrome presented for the removal of malignant ovarian tumours. The main problem encountered by the anaesthetists was an unexpected increase in arterial blood pressure. This was most probably associated with surgical manipulation of the ovaries with an increase in prorenin/renin production.
Patients’ expectations of patient‐controlled analgesia
Authors: Kluger M. T. , Owen H.
Published: February 2007

Patient‐controlled analgesia is an increasingly popular method of postoperative pain relief. However, patients often worry about new therapies. Eighty ASA 1 and 2 patients aged 18–65 years were asked to list the advantages and disadvantages of using patient‐controlled analgesia. The most important advantage as perceived by patients was the reduced time spent by nurses in giving medication, but there was concern that direct personal contact would also be lessened. Preservation of self control, autonomy, rapid onset of analgesia, ability to titrate analgesia and lack of injections were seen as an advantage. Addiction and machine faults were seen as minimal problems. Preservation of patient‐nurse contact is of great importance to ensure success of postoperative analgesia.
Paraesthesia with lumbar epidural catheters.
Authors: Sarna M. C. , Smith I. , James J. M.
Published: February 2007

The epidural space was located in 32 obstetric patients using loss of resistance to air, while in a further 35 saline was used. The incidence of paraesthesia was 56% in the air group and 57% in the saline group. There was no significant difference between the groups in terms of other complications or in the quality of analgesia provided.
Effects of hypnotics on sleep and psychomotor performance A double‐blind randomised study of lormetazepam, midazolam and zopiclone
Authors: Rettig H. C. , de Haan P. , Zuurmond W. W. A. , Leeuwen L. v.
Published: February 2007

Lormetazepam, midazolam and zopiclone were compared as night medication in patients scheduled for elective surgery the next morning. Sixty patients divided at random into three groups, received double‐blind lormetazepam 1 mg, midazolam 15 mg or zopiclone 7.5 mg, by mouth at 2200 hours. The quality of sleep was assessed at 0700 hours from responses to a questionnaire, and psychomotor function by comparing paper and pencil (p‐deletion) and Maddox Wing tests with reference values from the day before. The three hypnotics were equally effective as sleep medication for time until onset of sleep, duration of sleep and condition upon awakening, whereas zopiclone provided significantly fewer (p < 0.05) spontaneous awakenings. The p‐deletion test did not differ in any of the three groups from the reference values. The ocular imbalance test in all three groups was significantly different (p < 0.01) from control. The lormetazepam group scored significantly better (p < 0.05) than the zopiclone group. No side effects were seen.
Evaluation of the BCR sequential extraction for trace elements in European reference volcanic soils
Authors: Hernández‐Moreno J. M. , Rodríguez‐González J. I. , Espino‐Mesa M.
Published: February 2007

Trace metal behaviour in volcanic ash soils displays distinctive features related to the soils’ large contents of metal‐binding phases and to the rapid release of trace metals from glasses and weatherable minerals. In this work, the BCR (Community Bureau of Reference) sequential extraction scheme (exchangeable + weak acid soluble, reducible, oxidizable, and non‐extractable metal fractions) was applied to selected COST‐622 European reference volcanic soils to determine partitioning of zinc and copper between various solid‐phase constituents, along with the major elements Al, Fe and Mn. The total extracted Al (ΣAl) was strongly correlated with acid ammonium oxalate extractable Al (Alo) (ΣAl = 0.985Alo+ 0.11, R2= 0.98), while the total extracted Fe clearly underestimated the amorphous fraction. Large values for the non‐extractable Al fraction were associated with the presence of gibbsite and phyllosilicates. Although the Zn and Cu contents of the soils were generally large, total amounts extracted (the potentially mobilizable fraction) were small, especially for Zn and for soils with crystalline secondary minerals. The fraction of the total Cu which was potentially mobilizable generally exceeded that of Zn. In the potentially mobilizable Cu the oxidizable fraction was generally dominant. Biocycling appears to play an important role in the surface enrichment of potentially mobilizable Zn and Mn. Although further methodological research seems necessary, the BCR sequential extraction appears to be a valuable tool for studies on metal dynamics in soils with andic properties.
Angiotensin converting enzyme inhibitor and angiotensin receptor blockade use in relation to outcomes in anticoagulated patients with atrial fibrillation
Authors: Lip G. Y. H. , Frison L. , Grind M. ,   on Behalf of the SPORTIF Investigators and the SPORTIF Executive Steering Committee
Published: February 2007

Background.  The renin‐angiotensin‐aldosterone‐system (RAAS) plays an important role in atrial fibrillation (AF). Evidence shows that blocking the RAAS with angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) has a definite role in preventing new onset AF and in maintaining sinus rhythm in recurrent AF. Our aim was to determine if ACEI/ARB treatment was associated with clinical outcomes [stroke/systemic embolic events (SEE), mortality] in a controlled, anticoagulated AF population.

Methods.  An ancillary retrospective cross‐sectional and longitudinal analysis of participants in the Stroke Prevention using an ORal Thrombin Inhibitor in AF (SPORTIF) III and V trials, in relation to use (or nonuse) of ACEI/ARBs.

Results.  Rates of stroke/SEEs, mortality or major bleeding were no different between users and nonusers in the whole cohort, or in relation to the presence/absence of hypertension, coronary artery disease and previous stroke/transient ischaemic attack, nor amongst those aged <75 years. Patients aged ≥75 years taking ACEIs or ARBs had lower mortality (HR 0.71, 95% CI 0.52–0.95), but no significant influence on other end‐points was noted. Diabetics and those with left ventricular dysfunction on ximelagatran had a higher odds ratio of abnormal liver enzyme levels. There was no apparent benefit of ACEIs or ARBs on other event rates.

Conclusions.  This analysis from two large randomized trials of anticoagulation has not demonstrated a significant benefit of ACEI or ARB use amongst AF patients, except amongst elderly subjects.
Lhx3, a LIM domain transcription factor, is regulated by Pou4f3 in the auditory but not in the vestibular system
Authors: Hertzano Ronna , Dror Amiel A. , Montcouquiol Mireille , Ahmed Zubair M. , Ellsworth Buffy , Camper Sally , Friedman Thomas B. , Kelley Matthew W. , Avraham Karen B.
Published: February 2007

A dominant mutation of the gene encoding the POU4F3 transcription factor underlies human non‐syndromic progressive hearing loss DFNA15. Using oligonucleotide microarrays to generate expression profiles of inner ears of Pou4f3ddl/ddl mutant and wild‐type mice, we have identified and validated Lhx3, a LIM domain transcription factor, as an in vivo target gene regulated by Pou4f3. Lhx3 is a hair cell‐specific gene expressed in all hair cells of the auditory and vestibular system as early as embryonic day 16. The level of Lhx3 mRNA is greatly reduced in the inner ears of embryonic Pou4f3 mutant mice. Our data also show that the expression of Lhx3 is regulated differently in auditory and vestibular hair cells. This is the first example of a hair cell‐specific gene expressed both in auditory and in vestibular hair cells, with differential regulation of expression in these two closely related systems.
A model for mammalian cochlear hair cell differentiation in vitro: effects of retinoic acid on cytoskeletal proteins and potassium conductances
Authors: Helyer R. , Cacciabue‐Rivolta D. , Davies D. , Rivolta M. N. , Kros C. J. , Holley M. C.
Published: February 2007

We have established a model for the in‐vitro differentiation of mouse cochlear hair cells and have used it to explore the influence of retinoic acid on proliferation, cytoskeletal proteins and voltage‐gated potassium conductances. The model is based on the conditionally immortal cell line University of Sheffield/ventral otocyst‐epithelial cell line clone 36 (US/VOT‐E36), derived from ventral otic epithelial cells of the mouse at embryonic day 10.5 and transfected with a reporter for myosin VIIa. Retinoic acid did not increase cell proliferation but led to up‐regulation of myosin VIIa and formation of prominent actin rings that gave rise to numerous large, linear actin bundles. Cells expressing myosin VIIa had larger potassium conductances and did not express the cyclin‐dependent kinase inhibitor p27kip1. US/VOT‐E36 endogenously expressed the voltage‐gated potassium channel α‐subunits Kv1.3 and Kv2.1, which we subsequently identified in embryonic and neonatal hair cells in both auditory and vestibular sensory epithelia in vivo. These subunits could underlie the embryonic and neonatal delayed‐rectifiers recorded in nascent hair cells in vivo. Kv2.1 was particularly prominent on the basolateral membrane of cochlear inner hair cells. Kv1.3 was distributed throughout all hair cells but tended to be localized to the cuticular plates. US/VOT‐E36 recapitulates a coherent pattern of cell differentiation under the influence of retinoic acid and will provide a convenient model for screening the effects of other extrinsic factors on the differentiation of cochlear epithelial cell types in vitro.
Neuronal differentiation of the early embryonic auditory hindbrain of the chicken in primary culture
Authors: Kuenzel Thomas , Mönig Benedikt , Wagner Hermann , Mey Jörg , Luksch Harald
Published: February 2007

Neurons in the auditory hindbrain pathway of the chicken are physiologically and morphologically highly specialized. It remains unclear to what extent independent differentiation vs. activity‐dependent mechanisms determines the development of this system. To address this question we established a primary culture system of the early auditory hindbrain neurons. Primary cultures of neurons from nucleus magnocellularis and nucleus laminaris were prepared from embryonic day 6.5 chicken. These cells developed in culture under serum‐free conditions for up to 15 days. Immunocytochemical staining and whole‐cell patch recordings were used to characterize the development of the neurons. A stable expression of the calcium‐binding protein calretinin, which serves as a characteristic marker of the auditory pathway, was found at all stages. A voltage‐gated potassium channel (Kv3.1b) with a specific function in the auditory system was also expressed after about 1 week in culture. Electrophysiological recordings showed a general maturation of the neuronal phenotype as reflected by an increase in the mean resting membrane potential, a decrease in the mean input resistance as well as a maturation of action potential parameters. Four groups of neurons that generate action potentials could be distinguished. One of these showed the phasic firing pattern of auditory brainstem neurons known from slice preparations. In older cultures we demonstrated functional synaptogenesis in vitro by recording postsynaptic activity elicited by extracellular stimulation and styryl dye loading of vesicles. Thus, isolated neurons from the auditory region of the avian brainstem differentiate to specific neuronal subtypes and autonomously develop synaptic connections in vitro.
Alteration of the cell adhesion molecule L1 expression in a specific subset of primary afferent neurons contributes to neuropathic pain
Authors: Yamanaka Hiroki , Obata Koichi , Kobayashi Kimiko , Dai Yi , Fukuoka Tetsuo , Noguchi Koichi
Published: February 2007

The cell adhesion molecule L1 (L1‐CAM) plays important functional roles in the developing and adult nervous systems. Here we show that peripheral nerve injury induced dynamic post‐transcriptional alteration of L1‐CAM in the rat dorsal root ganglia (DRGs) and spinal cord. Sciatic nerve transection (SCNT) changed the expression of L1‐CAM protein but not L1‐CAM mRNA. In DRGs, SCNT induced accumulation of the L1‐CAM into the surface of somata, which resulted in the formation of immunoreactive ring structures in a number of unmyelinated C‐fiber neurons. These neurons with L1‐CAM‐immunoreactive ring structures were heavily colocalized with phosphorylated p38 MAPK. Western blot analysis revealed the increase of full‐length L1‐CAM and decrease of fragments of L1‐CAM after SCNT in DRGs. Following SCNT, L1‐CAM‐immunoreactive profiles in the dorsal horn showed an increase mainly in pre‐synaptic areas of laminae I–II with a delayed onset and colocalized with growth‐associated protein 43. In contrast to DRGs, SCNT increased the proteolytic 80‐kDa fragment of L1‐CAM and decreased full‐length L1‐CAM in the spinal cord. The intrathecal injection of L1‐CAM antibody for the extracellular domain of L1‐CAM inhibited activation of p38 MAPK and emergence of ring structures of L1‐CAM immunoreactivity in injured DRG neurons. Moreover, inhibition of extracellular L1‐CAM binding by intrathecal administration of antibody suppressed the mechanical allodynia and thermal hyperalgesia induced by partial SCNT. Collectively, these data suggest that the modification of L1‐CAM in nociceptive pathways might be an important pathomechanism of neuropathic pain.
Neuropeptide Y suppresses absence seizures in a genetic rat model primarily through effects on Y2 receptors
Authors: Morris Margaret J. , Gannan Emma , Stroud Leanne M. , Beck‐Sickinger Annette G. , O'Brien Terence J.
Published: February 2007

Neuropeptide Y (NPY) potently suppresses absence seizures in a model of genetic generalized epilepsy, genetic absence epilepsy rats of Strasbourg (GAERS). Here we investigated the Y‐receptor subtype(s) on which NPY exerts this anti‐absence effect. A dual in vivo approach was used: the cumulative duration of seizures was quantified in adult male GAERS in 90‐min electroencephalogram recordings following intracerebroventricular (i.c.v.) injection of: (i) subtype‐selective agonists of Y1 ([Leu31Pro34]NPY, 2.5 nmol), Y2 (Ac[Leu28,31]NPY24–36, 3 nmol), Y5 receptors [hPP1−17,Ala31,Aib32]NPY, 4 nmol), NPY (3 nmol) or vehicle; and following (ii) i.c.v. injection of antagonists of Y1 (BIBP3226, 20 nmol), Y2 (BIIE0246, 20 nmol) and Y5 (NPY5RA972, 20 nmol) receptors or vehicle, followed by NPY (3 nmol). Injection of the Y1‐ and Y5‐selective agonists resulted in significantly less mean seizure suppression (37.4% and 53.9%, respectively) than NPY (83.2%; P < 0.05), while the Y2 agonist had similar effects to NPY (62.3% suppression, P = 0.57). Food intake was not increased following injection of the Y2 agonist, while significant increases in food intake were seen following NPY and the other Y‐subtype agonists. Compared with vehicle, NPY injection suppressed seizures following the Y1 and Y5 antagonists (45.3% and 80.1%, respectively, P < 0.05), but not following the Y2 antagonist (5.1% suppression, P = 0.46). We conclude that NPY Y2 receptors are more important than Y1 and Y5 receptors in mediating the effect of NPY to suppress absence seizures in a genetic rat model. Y2 receptor agonists may represent targets for novel drugs against genetic generalized epilepsies without resulting in appetite stimulation.
Plasticity of inhibitory synaptic network interactions in the lateral amygdala upon fear conditioning in mice
Authors: Szinyei Csaba , Narayanan Rajeevan T. , Pape Hans‐Christian
Published: February 2007

After fear conditioning, plastic changes of excitatory synaptic transmission occur in the amygdala. Fear‐related memory also involves the GABAergic system, although no influence on inhibitory synaptic transmission is known. In the present study we assessed the influence of Pavlovian fear conditioning on the plasticity of GABAergic synaptic interactions in the lateral amygdala (LA) in brain slices prepared from fear‐conditioned, pseudo‐trained and naïve adult mice. Theta‐burst tetanization of thalamic afferent inputs to the LA evoked an input‐specific potentiation of inhibitory postsynaptic responses in projection neurons; the cortical input was unaffected. Philanthotoxin (10 µm), an antagonist of Ca2+‐permeable AMPA receptors, disabled this plastic phenomenon. Surgical isolation of the LA, extracellular application of a GABAB receptor antagonist (CGP 55845A, 10 µm) or an NMDA receptor antagonist (APV, 50 µm), or intracellular application of BAPTA (10 mm), did not influence the plasticity. The plasticity also showed as a potentiation of monosynaptic excitatory responses in putative GABAergic interneurons. Pavlovian fear conditioning, but not pseudo‐conditioning, resulted in a significant reduction in this potentiation that was evident 24 h after training. Two weeks after training, the potentiation returned to control levels. In conclusion, a reduction in potentiation of inhibitory synaptic interactions occurs in the LA and may contribute to a shift in synaptic balance towards excitatory signal flow during the processes of fear‐memory acquisition or consolidation.
Spontaneous depolarization waves of multiple origins in the embryonic rat CNS
Authors: Momose‐Sato Yoko , Sato Katsushige , Kinoshita Masae
Published: February 2007

During development, correlated neuronal activity plays an important role in the establishment of the central nervous system (CNS). We have previously reported that a widely propagating correlated neuronal activity, termed the depolarization wave, is evoked by various sensory inputs. A remarkable feature of the depolarization wave is that it spreads broadly through the brain and spinal cord. In the present study, we examined whether the depolarization wave occurs spontaneously in the embryonic rat CNS and, if so, where it originates. In E15–16 rat embryos, spontaneous optically‐revealed signals appeared in association with the rhythmic discharges of cranial motoneurons and propagated widely with similar characteristics to the evoked depolarization wave. At E15, the spontaneous wave mostly originated in the cervical to upper lumbar cords. At E16, the wave was predominantly generated in the lumbosacral cord although a wave associated with the second oscillatory burst was initiated in the rostral cord. At E16, a few waves also originated in the rostral ventrolateral medulla and the dorsomedial pons. When the influence of the caudal cord was removed by transecting the spinal cord, the contribution of the medulla and pons became more significant. These results show that the depolarization wave can be triggered by the spontaneous activity of multiple neuronal populations which are distributed widely from the pons to the lumbosacral cord, although the spinal cord usually plays a predominant role. This network possibly works as a self‐distributing system that maintains the incidence and complicated patterns of the correlated activity in the developing CNS.
Developmental changes in cell–extracellular matrix interactions limit proliferation in the mammalian inner ear
Authors: Davies Dawn , Magnus Christopher , Corwin Jeffrey T.
Published: February 2007

Hair cell losses can produce severe hearing and balance deficits in mammals and nonmammals alike, but nonmammals recover after epithelial supporting cells divide and give rise to replacement hair cells. Here, we describe cellular changes that appear to underlie the permanence of hair cell deficits in mammalian vestibular organs. In sensory epithelia isolated from the utricles of embryonic day 18 (E18) mice, supporting cells readily spread and proliferated, but spreading and proliferation were infrequent in supporting cells from postnatal day 6 (P6) mice. Cellular spreading and proliferation were dependent on α6 integrin, which disappeared from lateral cell membranes by P6 and colocalized with β4 integrin near the basement membrane at both ages. In the many well‐spread, proliferating E18 supporting cells, β4 was localized at cell borders, but it was localized to hemidesmosome‐like structures in the columnar, nondividing supporting cells that were prevalent in P6 cultures. We treated cultures with phorbol myristate acetate (PMA) to activate protein kinase C (PKC) in an initial test of the possibility that maturational changes in supporting cell cytoskeletons or their anchorage might restrict the proliferation of these progenitor cells in the developing mammalian inner ear. That treatment triggered the disassembly of the hemidesmosome‐like β4 structures and resulted in significantly increased cellular spreading and S‐phase entry in the P6 epithelia. The results suggest that maturational changes in cytoskeletal organization and anchorage restrict proliferation of mammalian supporting cells whose counterparts are the progenitors of replacement hair cells in nonmammals, thereby leaving mammals vulnerable to persistent sensory deficits caused by hair cell loss.
Preliminary sex differences in human cortical BOLD fMRI activity during the preparation of increasingly complex visually guided movements
Authors: Gorbet Diana J. , Sergio Lauren E.
Published: February 2007

In the past it has often been assumed that the cortical networks for visually guided movement are the same for males and females. Here we use functional magnetic resonance imaging (fMRI) to show significant sex‐related differences in human brain activity during visual‐to‐motor transformation tasks. Although the behavioural performance of the male and female groups did not differ, sex‐related differences in levels of blood oxygen level‐dependent fMRI activity are apparent in several cortical areas that have previously been demonstrated to be important for visually guided movements. These areas include the primary sensorimotor, dorsal premotor, superior parietal and lateral sulcus regions. Furthermore, the data indicate that the nature of these sex differences depends on the spatial mapping between a visual cue and the motor response that it guides.
Differential neurogenesis in the adult rat dentate gyrus: an identifiable zone that consistently lacks neurogenesis
Authors: Melvin Neal R. , Spanswick Simon C. , Lehmann Hugo , Sutherland Robert J.
Published: February 2007

The dentate gyrus continues to produce new neurons in adult rodents. The possibility of differential regulation of neurogenesis within regions of the dentate gyrus is largely unexplored, despite several other aspects of this phenomenon being well characterized in a large number of studies. In this report, we describe an area located at the anterior pole of the dentate gyrus that consistently lacks neurogenesis. This neurogenically quiescent zone invariably lacks expression of the neuroblast marker doublecortin (DCX), bromodeoxyuridine and Ki‐67, though DCX expression can be elicited in response to a combined paradigm of environmental enrichment and wheel running. We propose that this region may provide a valuable model system to discern the factors that regulate the process of neurogenesis.