bluuebunny/crossref_metadata_2025 huggingface dataset:
Larval competition alters susceptibility of adultAedesmosquitoes to dengue infection
Authors: Alto Barry W , Lounibos L. Philip , Mores Christopher N , Reiskind Michael H
Published: December 2007

Dengue, the most important human arboviral disease, is transmitted primarily byAedes aegyptiand, to a lesser extent, byAedes albopictus. The current distributions of these invasive species overlap and are affected by interspecific larval competition in their container habitats. Here we report that competition also enhances dengue infection and dissemination rates in one of these two vector species. We determined the effects of competition on adultA. aegyptiandA. albopictus, comparing their susceptibility to infection with a Southeast Asian strain of dengue-2 virus. High levels of intra- or interspecific competition among larvae enhanced the susceptibility ofA. albopictusto dengue virus infection and potential for transmission, as indicated by disseminated infections. Doubling the number of competing larvae (A. albopictusorA. aegypti), led to a significant (more than 60%) increase in the proportion ofA. albopictuswith disseminated dengue-2 infection. Competition-enhanced vector competence appears to result from a reduction in ‘barriers’ (morphological or physiological) to virus infection and dissemination and may contribute to the importance ofA. albopictusin dengue transmission. Similar results for other unrelated arboviruses suggest that larval competition, common in mosquitoes, should be considered in estimates of vector competence for pathogens that infect humans.
Diagnostic Testing in the Elderly: Imaging Is Great, But It's Not the Whole Story
Authors: Forman Daniel E.
Published: December 2007

Management of coronary artery disease (CAD) is a large and growing challenge for today's burgeoning population of older adults, especially because age is a key risk factor for CAD and because morbidity/mortality from CAD increases with age. Whereas many people look to cardiovascular imaging to enhance CAD management, it often remains difficult to interpret the clinical implications of positive imaging studies. Functional assessment, heart rate and rhythm dynamics, and prognostic scoring tools all provide insights that complement the data provided by high‐tech imaging options.
Atherosclerosis Monitoring in the Elderly Using Magnetic Resonance Imaging: Is the Extra Step Needed?
Authors: Gottlieb Ilan , Xavier Sérgio Salles , Lima João A.C.
Published: December 2007

Atherosclerotic disease represents an enormous burden in the elderly population, yet elderly patients are underrepresented in clinical trials and receive lower standard‐of‐care treatment compared with similar‐risk younger individuals. Magnetic resonance imaging (MRI) is a powerful noninvasive imaging technique that can target atherosclerotic lesions and help better understand the pathophysiologic process of this disease in the elderly. Cholesterol‐targeted interventions have improved the outcomes in patients with atherosclerotic disease, but clearly additional efforts are needed. Whether medical therapy can be effectively adjusted based on atherosclerosis progression revealed by MRI is still to be proven, but the technique certainly looks promising.
A Drosophila metallothionein promoter is inducible in mosquito cells
Authors: Kovach M. J. , Carlson J. O. , Beaty B. J.
Published: December 2007

Expression from a Drosophila metallothionein promoter (Mtn) was investigated in mosquito cells. Recombinant plasmids carrying a transcription unit comprised of the Escherichia coliβ‐galactosidase gene (lacZ) fused to the metallothionein promoter were stably introduced into Aedes albopictus C6/36 cells. A low copy transformant containing approximately 60 copies of plasmid per cell, and a high copy transformant (1–2 times 104 copies/cell) were characterized. The expression of β‐galactosidase from the metallothionein promoter could be induced and controlled in this heterologous system, even when the copy number of introduced plasmid was several thousand.
Codon usage patterns in chromosomal and retrotransposon genes of the mosquito Anopheles gambiae
Authors: Besansky N. J.
Published: December 2007

Codon usage was compiled for fourteen chromosomal genes and four retrotransposons from the mosquito Anopheles gambiae. Variation exists among chromosomal genes in the degree of bias. The genes showing the highest bias are probably most highly expressed. In these genes, the base composition at the third codon position is much richer in G + C than is the overall coding sequence. Thus, codon usage is biased toward G‐ or C‐ending codons. Codon usage in each retrotransposon is quite different, not only from chromosomal genes but also from the other retrotransposons. Codon usage comparisons among homologous genes from An. gambiae and two other Dipterans, the yellow fever mosquito Aedes aegypti and the fruitfly Drosophila melanogaster, show that while there are similarities, particularly between An. gambiae and D. melanogaster in the preference for G‐and C‐ending codons, each species has evolved a distinct pattern of codon usage.
TTAA serves as the target site for TFP3 lepidopteran transposon insertions in both nuclear polyhedrosis virus and Trichoplusia ni genomes
Authors: Wang Hwei‐gene Heidi , Fraser M. J.
Published: December 2007

We have analysed TFP3 transposable elements from five independently isolated FP mutants of the Autographa californica nuclear polyhedrosis virus (AcMNPV). We also analysed genomic copies of TFP3 elements amplified from the DNAs of the Trichoplusia ni cell line (TN‐368) and T. ni larvae using the polymerase chain reaction (PCR). The sequences of all the newly isolated TFP3 elements closely resemble the previously described TFP3/1 element. Each of the transposons isolated from the virus mutants duplicated a TTAA tetranucleotide target site upon insertion into the viral genome. Four of these TFP3 elements transposed into three different ‘TTAA’ target sites within the 25 K gene (FP locus, map units 36–37 of AcMNPV). The fifth TFP3 element inserted at a ’TTAA’ site within the AcMNPV Hin dlll‐E fragment. One genomic TFP3 element, amplified from the TN‐368 cell line DNA by an inverse PCR method, duplicated a ‘TTAA’ tetranucleotide target site that is present only once in the homologous larval DNA sequence. These data suggest that mobilization of TFP3 into both viral and cellular sites is identical in specificity and mechanism.
Genetic transformation and phylogeny of bacterial symbionts from tsetse
Authors: Beard C. B. , O'Neill S. L. , Mason P. , Mandelco L. , Woese C. R. , Tesh R. B. , Richards F. F. , Aksoy S.
Published: December 2007

Two isolates of bacterial endosymbionts, GP01 and GM02, were established in cell free medium from haemolymph of the tsetse, Glossina pallidipes and G. morsitans. These microorganisms appear similar to rickettsia‐like organisms reported previously from various tsetse species. The 16s rRNA sequence analysis, however, placed them within the gamma subdivision of the Proteobacteria, phylogenetically distinct from most members of the Rickettsiaceae which align with the alpha subdivision. Distinct multiple endogenous plasmids are harboured by GP01 and GM02, suggesting that the two isolates are different. Restriction mapping analysis showed that one of the conserved plasmids is present in high copy number and is at least 80 kb in size. A heterologous plasmid pSUP204, which contains the broad host range oriV replication origin, was used to transfect bacterial cultures. The symbiont GM02 was transformed, and it expressed plasmid encoded resistance to the antibiotics ampicillin, tetracycline and chloramphenicol. Transformation of these symbionts may provide a novel means for expressing anti‐parasitic genes within tsetse populations.
A comparison of three methods for isolating RNA from mosquitoes
Authors: Noriega F. G. , Wells M. A.
Published: December 2007

The two most common protocols for RNA isolation, Chirgwin et al., 1979, and Chomczynski & Sacchi, 1987, were compared with a protocol using glass powder. The quality of the recovered RNA was tested using agarose gels and Northern hybridization. With the glass powder protocol, we consistently obtained intact RNA, whereas with the other protocols we often obtained degraded RNA. Using specific radioactive probes, we measured ribosomal RNA and trypsin mRNA recovered from fed adult Aedes aegypti females. Our protocol gave a 40‐ and a 3‐fold increase in recovery when compared with the Chirgwin and Chomczynski protocol, respectively. The method using glass powder is simple, fast, reproducible and gives a high yield of intact RNA.
An improved primer for PCR amplification of mitochondrial DNA in a variety of insect species
Authors: Roehrdanz R. L.
Published: December 2007

A PCR primer from the mitochondrial COi gene is described that enhances the amplification of the COI‐COJI region of insect mtDNA. When used in conjunction with a primer from the COII gene identified by R. Crozier, a 1600–1700 bp segment is amplified in nine species of insects representing the orders Lepidop‐tera, Diptera, Coleoptera and Hymenoptera.
Conservation of cyclodiene insecticide resistance‐associated mutations in insects
Authors: Thompson M. , Steichen J. C. , Ffrench‐Constant R. H.
Published: December 2007

Cyclodiene insecticide resistance has accounted for over 60% of reported cases of insecticide resistance. in Drosophila melanogaster resistance is associated with a single base pair substitution in the GABA receptor/chloride ion channel gene Rdl. This substitution predicts the replacement of an alanine with a serine in the second membrane spanning domain, the region thought to line the chloride ion channel pore. Here we report, via the use of degenerate primers in the polymerase chain reaction, that precisely the same substitution is present in three pests from three different insect orders: the house fiy (Diptera), red flour beetle (Coleoptera) and American cockroach (Dicty‐optera). This finding suggests that there are a limited number of mutations that can confer resistance to cyclodienes, putative channel blockers, while still maintaining adequate chloride ion channel function. The conservation of the resistance‐associated mutation between Drosophila and pest insects directly validates the approach of using this insect as a model system for isolating and studying resistance genes. The importance of single base pair substitutions in the evolution of pesticide resistance and in the design of molecular monitoring techniques is discussed.
Localization of ribosomal DNA in Rhagoletis pomonella (Diptera: Tephritidae) by in situ hybridization
Authors: Procunier W. S. , Smith J. J.
Published: December 2007

The ribosomal DNA (rDNA) of Rhagoletis pomonella was localized within both salivary gland polytene chromosomes and somatic cell mitotic chromosomes by in situ hybridization using the heterospecific Drosophila melanogaster rDNA clone, Dm238. In situ hybridization analysis of polytene nuclei showed that R pomonella rDNA is located in the nucleolus and adjacent granular network of chromosome 1. The site of origin of rDNA is within this isomorphic granular network. The preservation of nucleolar ultrastructure in some polytene chromosome preparations allowed light microscope localization of R. pomonella rDNA to the apparent periphery of fibrillar centres within fibrillar complexes. In somatic cell nuclei, DM238 hybridized to the nucleolus organizing region (NOR) located on chromosome 1 at the site of the secondary constriction. The frequency distribution of heteromorphisms for rDNA content, differential appearance of secondary constrictions, non‐pairing of the NOR and differences in homologue lengths suggests that the structural differentiation of this region in chromosome 1 is sex linked. This the first published description of the salivary gland polytene chromosomes from R. pomonella, and we include a tentative karyotype description, polytene chromosome maps and comments on their suitability for banding and molecular analysis.
Cloning and analysis of the locus for mosquito vitellogenic carboxypeptidase
Authors: Deitsch K. W. , Raikhel A. S.
Published: December 2007

Vitellogenic carboxypeptidase is a 53 kDa yolk protein produced by the fat body of the female mosquito, Aedes aegypti, in response to a blood meal. Its expression is sex‐, stage‐ and tissue‐specific and is identical to that of the major yoik protein, vitellogenin. The gene is intronless and two alleles have been cloned and sequenced, including more than 1.5 kb on both sides of the coding region. A capsite consensus recently identified as an arthropod initiator is present at the start site of transcription. Upstream of this capsite is a 16 bp imperfect palindrome repeated four times showing strong homology to defined hormone‐response elements. In addition, a region that closely resembles the fat body enhancer and double sex binding site from the Drosophila yolk protein genes and several potential fat body‐specific regulatory protein binding sites were found.
The internal transcribed spacers of ribosomal DNA in five members of the Anopheles gambiae species complex
Authors: Paskewitz S. M. , Wesson D. M. , Collins F. H.
Published: December 2007

The primary and secondary structure of the internal transcribed spacers of ribosomal DNA (ITS1 and ITS2) and their utility for phylogenetic analysis of closely related species were examined using the Anopheles gambiae complex as a model. Restriction mapping revealed an unusual architectural feature in the ITS1 of several members of an An. gambiae cryptic species complex. Multiple spacer lengths are prevalent in An. merus and An. melas and are due to variable numbers of a repeated 250 bp sequence. Secondary structure analysis indicated that the repeat forms a helix and loop that may be involved in rDNA processing. Intra‐and interspecific polymorphism within the species complex were further examined by DNA sequencing of forty‐eight ITS2 clones obtained by polymerase chain reaction from individuals of the five species. Interspecies variation in the approximately 426 bp ITS2 sequence ranged between 0.4% and 1.6%; intraspecies variation ranged from 0.07% in An. arabiensis to 0.43% in An. gambiae. lntraindividual variation ranged from 0% in four individuals to a high of 0.4% in one An. quadriannulatus specimen. None of the variants were shared between species. The low level of variation supports the hypothesis that species of the complex evolved recently.
Chromosomal mapping of two loci affecting filarial worm susceptibility in Aedes aegypti
Authors: Severson D. W. , Mori A. , Zhang Y. , Christensen B. M.
Published: December 2007

Two quantitative trait loci (QTL) affecting susceptibility of the mosquito Aedes aegypti to the filarial worm parasite Brugia malayi were identified using restriction fragment length polymorphism (RFLP) markers. The first locus, fsb[1,LF178], resides within a 10 cM interval on chromosome 1 and exhibits a recessive effect with respect to susceptibility. The second locus, fsb[2,LF98], resides within a 9 cM interval on chromosome 2 and exhibits an additive effect on susceptibility. Significant epistasis was detected between these loci, although the effect of fsb[2,LF98] was dependent on the genetic background of the mosquito strains. Suggestions for a standard QTL nomenclature are included.
Evolutionary origin of whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) inferred from 18S rDNA sequences
Authors: Campbell B. C. , Steffen‐Campbell J. D. , Gill R. J.
Published: December 2007

Phylogenetic analysis of 18S rDNA nucleotide sequences of hemipteran exemplars shows Sternorrhyncha (psyllids, whiteflies, aphids and scales) is monophyletic and forms a sister group to all other hemipterans (Euhemiptera). Whiteflies form a sister group to aphids and scales. Psyllids form a sister group to all other Sternorrhyncha. Primary structures of 18S rDNAs of all sternorrhynchans are exceptionally long (˜2200 to ˜2500 bp) due to internal expansions. These expansions are a synapomorphy of Sternorrhyncha; other hemipterans possess shorter 18S rDNAs (˜1900 to ˜1925 bp). The 18S rDNA of whiteflies is the longest recorded to date and has a base substitution rate of ˜3 times greater than Euhemiptera taxa examined. The relevance of these findings to the fossil record, feeding strategies, reproductive biologies, and geoclimatic distribution is discussed.
The peach‐potato aphid Myzus persicae and the tobacco aphid Myzus nicotianae have the same esterase‐based mechanisms of insecticide resistance
Authors: Field L. M. , Javed N. , Stribley M. F. , Devonshire A. L.
Published: December 2007

Biochemical and molecular studies have established that in the peach‐potato aphid, Myzus persicae, insecticide resistance is conferred by amplification of genes encoding the insecticide‐detoxifying esterases E4 or FE4. Here we report that two insecticide‐resistant clones of the closely related tobacco aphid Myzus nicotianae have elevated esterases indistinguishable from E4 and FE4 and amplified esterase DNA sequences, and flanking regions, with identical restriction maps to the M. persicae genes. Furthermore, the DNA sequences of c. 630 bp fragments of the E4 and FE4 genes of M. persicae are different from each other but identical to the fragment from corresponding M. nicotianae clones. The existence of apparently identical insecticide resistance genes in the two species can be best explained by the selection of the amplified genes in M. persicae, transfer to hybrids of M. persicae and M. nicotianae by sexual reproduction and subsequent spread through M. nicotianae populations.
Isolation of a trypsin‐like serine protease gene family from the sheep blowfly Lucilia cuprina
Authors: Casu R. E. , Jarmey J. M. , Elvin C. M. , Eisemann C. H.
Published: December 2007

Various protease inhibitors active against both trypsin‐ and chymotrypsin‐like serine proteases were used to characterize gut proteases from Lucilia cuprina by in vitro feeding assays. Significant larval growth retardation was observed on feeding first‐instar larvae with trypsin inhibitors, particularly soybean trypsin inhibitor. Feeding of chymostatin, a specific chymotrypsin inhibitor, resulted in no significant growth retardation. This information suggests that trypsin‐like serine proteases are probably the major gut digestive enzymes. A DNA fragment obtained by PCR which coded for part of a putative trypsin gene from L. cuprina was used to isolate a four‐member multigene family of trypsins. The full nucleotide sequence of one of the genes and partial sequence from the other three genes were determined. Transcription of at least one of the genes has been confirmed. All four of the genes appear to have arisen by two separate gene duplication events.
Comparative linkage maps for the mosquitoes, Aedes albopictus and Ae. aegypti, based on common RFLP loci
Authors: Severson D. W. , Mori A. , Kassner V. A. , Christensen B. M.
Published: December 2007

Aedes albopictus and Aedes aegypti are members of the mosquito family Culicidae and share a haploid chromosome complement of three. Although a genetic linkage map based on restriction fragment length polymorphism (RFLP), markers exists for Ae. aegypti, the extent of synteny and linkage order conservation between the two species was unknown. A comparative linkage map for Ae. albopictus was constructed based mainly on cDNA clones from Ae. aegypti. Nearly all Ae. aegypti probes hybridized to Ae. albopictus DNA at high stringency. For eighteen RFLP markers tested, the linkage group and linear order appears to be identical for the two species. 78% of the loci tested exhibited significant deviations from the expected segregation ratio in at least one of the test crosses. An excess of heterozygote genotypes was recovered with most loci. This probably reflects the effects of lethal loci on survival of F2 progeny homozygous for the parental genotypes. These results demonstrate that comparative linkage maps based on common DNA markers provide a basis for rapidly developing linkage maps for various mosquito species, and the opportunity to examine the significance and function of orthologous quantitative trait loci associated with mosquito vector competence for disease transmission.
Molecular mechanisms involved in increased expression of a cytochrome P450 responsible for pyrethroid resistance in the housefly, Musca domestica
Authors: Tomita T. , Liu N. , Smith F. F. , Sridhar P. , Scott J. G.
Published: December 2007

Cytochrome P450Ipr is a developmentally regulated P450 responsible for monooxygenase‐mediated pyrethroid resistance in the LPR strain of housefly. CYP6D1, the gene coding for P450iIpr, has recently been sequenced. We investigated the molecular basis for CYP6D1‐mediated pyrethroid resistance by comparison of mRNA levels, gene sequences, and gene copy number between LPR and pyrethroid susceptible strains of housefly. CYP6D1 mRNA levels were elevated in the LPR strain to a similar level as P450Ipr protein, suggesting that over‐expression of this important P450 in the resistant strain is probably due to increased transcription. Southern blots of susceptible and LPR strain DNA suggest that gene amplification is probably not involved in the increased expression of CYP6D1 protein. Five alleles of CYP6D1 were discovered and their possible role in resistance is discussed.
Parthenogenesis‐inducing microorganisms in Aphytis (Hymenoptera: Aphelinidae)
Authors: Zchori‐Fein E. , Faktor O. , Zeidan M. , Gottlieb Y. , Czosnek H. , Rosen D.
Published: December 2007

Production of males in uniparental lines of two species in the parasitic wasp genus Aphytis was induced by rifampicin, and male sexual functioning was determined. Wolbachia‐specific 16S rDNA primers were used in a PCR in order to: (1) assess correlation between thelytokous reproduction and the presence of Wolbachia; (2) detect the loss of Wolbachia DNA in uniparental A. lingnanensis following antibiotic treatments, with or without the presence of a host; and (3) clone and sequence part of the Wolbachia 16S rDNA from the uniparental Aphytis species for phylogenetic studies. Males produced viable sperm that was transferred to the female spermatheca following mating. However, sperm failure to effect egg fertilization resulted in all‐male progeny. Wolbachia were found in the two uniparental (A. lingnanensis and A. diaspidis) but not in the two biparental (A. lingnanensis and A. melinus) Aphytis lines tested. They can be detected in wasps up to 7 days following antibiotic treatments, regardless of the presence of host. The 16S rDNA for the symbionts in the two Aphytis species is virtually identical, and is most closely related to the Wolbachia found in Muscidifurax uniraptor (Pteromalidae).
A single isoform of the Na+/K+‐ATPase α‐subunit in Diptera: evidence from characterization of the first extracellular domain
Authors: Emery A. M. , Ready P. D. , Billingsley P. F. , Djamgoz M. B. A.
Published: December 2007

The first extracellular domain of the α‐subunit of the Na+/K+‐ATPase (sodium/potassium pump) is functionally important, affecting sensitivity of the enzyme to cardiac glycosides (e.g. ouabain) and being implicated in the transport of K+. This domain is also variable among mammalian isoforms of the α‐subunit. Using PCR, we have isolated from seven insect species with contrasting physiologies a DNA fragment containing this region, in order to help determine whether tissue‐specific expression might be associated with isoforms encoded by a gene family, as it is in mammals. A single sequence (with one ORF) characteristic of Na+/K+‐ATPase was obtained from genomic DNA of each species. Only the fragment from Manduca sexta contained an intron, but at a location different to that found in mammals. For all Diptera so far characterized, the species phylogeny is the same as the α‐subunit gene phylogeny (based on the sequences of the first extracellular domain and flanking transmembrane domains). The results strongly indicate a single, ouabain‐sensitive isoform of the α‐subunit of Na+/K+‐ATPase is present in Diptera.
PCR primers for the amplification of four insect mitochondrial gene fragments
Authors: Kambhampati S. , Smith P. T.
Published: December 2007

Insect mitochondrial genome (mtDNA) analysis is a powerful tool for the study of population genetics and phylogenetics. In the past few years primer sequences for the PCR amplification of various insect mtDNA genes have been published. The objectives of this study were (1) present new primer sequences for six insect mitochondrial genes and (2) test primers designed in our laboratory and some previously published primers on a wide range of insects to determine if amplification of the target fragment could be obtained. The primers for the amplification of the two ribosomal RNA gene (16S and 12S rRNA) fragments are universal for insects and related groups; the primers for NADH5 and NADH4 dehydrogenase gene fragments and cytochrome c oxidase I gene fragment are applicable broadly.
Isolation and characterization of a retroelement from B chromosome (PSR) in the parasitic wasp Nasonia vitripennis
Authors: McAllister B. F.
Published: December 2007

Molecular characterization of the paternal‐sex‐ratio (PSR) chromosome in Nasonia vitripennis (Hymenoptera: Pteromalidae) has led to the isolation of a dispersed repetitive element. The element is a LTR‐containing retrotransposon which has been named NATE (NAsonia Transposable Element). NATE has direct terminal repeats and has an internal amino acid sequence similar to reverse transcriptases of other retroelements. Phylogenetic analysis indicates NATE is a member of the Gypsy/Ty3 group of retrotransposons, and represents the first isolated from Hymenoptera. Five closely related copies of NATE were isolated from the PSR chromosome, but cross‐hybridizing elements were not detected on the autosomes of N. vitripennis. Strongly cross‐hybridizing elements were, however, detected in two other Nasonia species. This observed distribution of NATE is interesting, because the supernumerary PSR chromosome may be derived from the genome of a sibling species of N. vitripennis.
Molecular characterization of the Anopheles gambiae 2L telomeric region via an integrated transgene
Authors: Biessmann H. , Donath J. , Walter M. F.
Published: December 2007

A Drosophila P‐element derivative (pUChsneo) integrated into the telomeric region of the left arm of the second chromosome of Anopheles gambiae was used to clone the proximally flanking An. gambiae sequences. Molecular analyses revealed that the pUChsneo construct was partially duplicated and had integrated into a subterminal minisatellite. This satellite has a repeat unit of 820 bp and is located exclusively at the tip of 2L. No sequence similarity to subterminal minisatellites from other dipterans was detected, but some structural features such as tandem subrepeats are shared. The end of the chromosome was mapped with respect to restriction sites in pUChsneo at approximately generation 100 after the integration event. Considering inevitable terminal nucleotide loss due to incomplete DNA replication, we conclude that the chromosome end must have undergone a dramatic elongation process since it was mapped in generation 23.
Evolution of the mitochondrial DNA control region in the Anopheles gambiae complex
Authors: Caccone A. , Garcia B. A. , Powell J. R.
Published: December 2007

We have sequenced the AT‐rich control region of the mitochondrial DNA (mtDNA) of six species in the Afrotropical Anopheles gambiae complex and the closely related A. christyi. Contrary to expectations, the AT‐rich region in this group is evolving rather slowly, more slowly than the third position of mtDNA proteincoding genes. Despite being relatively conserved between species, we detected intraspecific and intra‐individual (heteroplasmy) variation in this region. Phylogenetically, we found we could place the rare endemic A. bwambae as a sister taxon to A. melas, the same evolutionary position as indicated by chromosomal inversions. The outgroup, A. christyi, gave evidence of the root of the tree. In comparing the molecular trees with that deduced by chromosomal inversions, they are completely congruent with the exception of the placement of A. arabiensis. The anomalous position of this species can be explained by introgression with A. gambiae. From the phylo‐genetic position, we could infer mtDNA gene flow from A. gambiae to A. arabiensis.
The polyubiquitin gene of the mosquito Anopheles gambiae: structure and expression
Authors: Beard C. B. , Cornel A. J. , Colllns F. H.
Published: December 2007

The polyubiquitin gene from the mosquito Anopheles gambiae has been cloned and sequenced, and its stucture is reported along with sequence analysis results. The gene consists of approximately seven tandem head‐to‐tail repeat units of the seventy‐six amino acid‐coding ubiquitin monomer. It is expressed constitutively in larvae, pupae and adults of An. gambiae, as well as in a cell line derived from this mosquito species. A probe made from a DNA fragment containing the coding region of the gene recognizes transcripts of approximately 3.6 kb and 4.4 kb in RNA isolated from all mosquito developmental stages and a unique transcript of approximately 3.0 kb in RNA from the cell line. Single monomeric units of the An. gambiae polyubiquitin gene shared from 75.9% to 85.5% identity at the DNA level with homologous sequences from other organisms ranging from yeast to man. A comparison of individual repeat units of the An. gambiae gene revealed that, in general, the 5′ ends of the individual monomers are more highly conserved than the 3 ends. The gene mapped by in situ hybridization on ovarian nurse cell polytene chromosomes to a primary site at division 12C on chromosome 2R and to a secondary site at division 9C on the same chromosome.
Sequence and secondary structure of the rDNA second internal transcribed spacer in the sibling species Culex pipiens L. and Cx. quinquefasciatus Say (Diptera: Culicidae)
Authors: Severini C. , Sllvestrlnl F. , Manclnl P. , Rosa G. La , Marlnucci M.
Published: December 2007

The primary and secondary structure of the second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA) of two members of the Cx. pipiens complex, Cx. pipiens and Cx. quinquefasciafus, were examined in order to better understand the relationships between these two sibling mosquito species. The length of the sequenced rDNA fragments was 512 bp (Cx. pipiens) and 513 bp (Cx. quinquefasciatus), including the ITS2 regions and flanking 5.8S‐28S coding regions. The ITS2 sequences of Cx. pipiens and Cx. quinquefasciatus were 297 and 298 bp in length respectively and showed a 97% identity. In fact, they had identical G + C content (58%) and the only differences observed are six mismatches (three transitionslthree transversions), six single‐base and one triple‐base deletions/insertions. The observed ITS2 secondary structures of Cx. pipiens and Cx. quinquefasciafus were very similar. Furthermore, the ITS2 sequences of specimens belonging to three populations of Cx. pipiens from Italy and four populations of Cx. quinquefasciatus (three from Africa and one from North America) were enalysed in order to detect the presence of potential species‐specific diagnostic restriction sites.
Molecular identification of a Wolbachia endosymbiont in a Tetranychus urticae strain (Acari: Tetranychidae)
Authors: Tsagkarakou A. , Gulllemaud T. , Rousset F. , NavaJas M.
Published: December 2007

Wolbachia, a maternally lnherlted bacierium, is Involved In alterations of arthropod sexuality. Reproductive incompatlbllities are often observed in mites, but the existence of this microorganism In their cytoplasm has not yet been demonstrated. We Identified the presence of Wolbachia In a strain of the spider mite Tetranychus urticae based on the ampllflcatlon and sequencing of part of the 16S rDNA and ftsZ genes. In order to establish the phylogenetlc relationships between Wolbachia found In T. urticae and In other arthropods, we aligned the resulting sequences with already published ones. For both 16s and ftsZ genes the Wolbachia carried by T. urticae clustered together with Wolbachia found in other arthropods.
Phylogenetic relationship among termite families based on DNA sequence of mitochondrial 16S ribosomal RNA gene
Authors: Kambhampati S. , Kjer K. M. , Thorne B. L.
Published: December 2007

Termites (Order isoptera: Class Insecta), are comprised of a complex assemblage of species, with considerable variation in life history, morphology, social behaviour, caste development and ecology. At present, isoptera is divided into seven families, fourteen subfamilies, ∼ 270 genera and over 2000 species. Phylogenetic hypotheses currently available for termite families and genera are based on a limited number of morphological characters and lack rigorous cladistic analysis. In this paper we report on phylogenetic relationships among ten termite genera of five families based on a DNA sequence analysis of a portion of the mitochondrial 16S rRNA gene. Parsimony and distance analysis of DNA sequences supported the existing hypothesis that Mastotermitidae is the basal lineage among extant termites. Kalotermitidae was not found to be a sister taxon of Mastotermitidae as existing hypotheses suggest, but was most closely related to Rhinotermitidae and Termitidae. Representatives of Termopsidae were more basal relative to those of Kaiotermitidae. The utility of 16S rRNA nucieotide sequence analysis for inferring phylogenetic relationships among termite families, subfamilies and genera is discussed.
Multiple alleles encoding a virus‐like particle protein in the ichneumonid endoparasitoid Venturia canescens
Authors: Hellers M. , Beck M. , Theopoid U. , Kamei M. , Schmidt O.
Published: December 2007

Hymenopteran endoparasitoids produce nuclear secretions from ovarian glands, which are deposited into the host insect together with the egg, protecting the developing parasitoid against the host's defence reactions. In the ichneumonid Venturia canescens, virus‐like particies (VLPs), are attached to the egg surface and provide passive protection against encapsulation by the host. One of the four major particle proteins (p40) is expressed not only in the calyx gland but also in tissues that are not involved in particle production. The p40 coding DNA from V. canescens was cloned and sequenced. Within the coding DNA a tandem repeat sequence, coding for a putative proteolytic cleavage site of the PEST type, is rearranged in a significant portion of the wasp population. A corresponding polymorphism was also detected in the protein. The amino‐terminal region of the deduced protein contains a putative type II transmembrane domain. The carboxy‐terminal region shows similarity to the phosphoiipid hydroxyperoxide giutathione peroxidase (PHGPX) of vertebrates. A peroxidase function of the p40, although not ruled out, Is unlikely due to the absence of a reactive centre which is typical for many vertebrate peroxidases. The overall conservation of the hydropathic region is discussed in the context of the formation of the viral envelope and its possible function In the Immune protection.
Structure of the Bombyx sorbitol dehydrogenase gene: a possible alternative use of the promoter
Authors: Niimi T. , Yamaahlta O. , Yaginuma T.
Published: December 2007

In an Initial effort to understand the molecular mechanism of how low temperature induces sorbitol dehydrogenase gene expression in diapause eggs of the silkworm, the sorbitol dehydrogenase gene was isolafed from a Bombyx genomic library using a cDNA encoding the Bombyx homologue of mammalian sorbitol dehydrogenase as a probe. The gene extended for about 10 kb, consisting of eight exons and seven introns. Four TATA motifs were found In the 5′ upstream region of the gene, without CCAAT. AATTAA, instead of AATAAA, was localized in the upstream region of the polyadenylation site. Although a single copy of this gene was present per haploid genome, 1.2 kb and 1.1 kb transcripts were found from yolk cells in diapause eggs and from larval fat‐body cells, respectively. The two major transcription initiation sites corresponding to both transcripts were localized at 355 and 226 base pairs upstream from the translation start she, indicating an alternative use of promoter. The 5′‐upstream region of the gene contained a consensus sequence, TGA(A/T)AA(A/GIT), that has been found in insect genes expressed mainly in larval and pupal fat bodies. It also contained three kinds of sequences similar to cis‐elements recognized by members of the steroid receptor superfamily, such as chicken ovalbumin upstream promoter transcription factor (COUP‐TF)/Drosophila Seven up (SVP), Drosophila hormone receptor 39 (DHR39) and Bombyx fushi tarazu transcriptional factor 1 (BmFTZ‐F1).
Mitochondrial COI sequences in mites: evidence for variations in base composition
Authors: Navajas M. , Fournier D. , Lagnel J. , Gutlerrez J. , Boursot P.
Published: December 2007

Studies of mitochondrial DNA sequences in a variety of animals have shown important differences between phyla, including differences in the genetic codes used, and varying constraints on base composition. In that respect, little is known of mites, an important and diversified group. We sequenced a portion (340 nt) of the cytochrome oxidase subunit I (COI) encoding gene in twenty species of phytophagous mites belonging to nine genera of the two families Tetranychidae and Tenuipalpidae. The mitochondrial genetic code used in mites appeared to be the same as in insects. As is generally also the case in insects, the mite sequences were very rich in A + T (75% on average), especially at the third codon position (94%). However, important variations of base composition were observed among mite species, one of them showing as little as 69% A + T. Variations of base composition occur mostly through synonymous transitions, and do not have detectable effects on polypeptide evolution in this group.
An action research investigation into the feasibility of experienced registered sick children's nurses (RSCNs) becoming children's emergency nurse practitioners (ENPs)
Authors: JONES SUE
Published: December 2007

Emergency nurse practitioners (ENPs) formally developed in accident and emergency (A & E) departments as a direct response to waiting times for the walking wounded, the need to reduce junior doctors hours and changes in nursing practice.

ENPs existed informally for many years in minor injuries units and specialist ophthalmic departments.

This study aimed to examine whether or not the role of ENP could be applied to the specialist service of a paediatric casualty department.

The results showed that 3% of patients could be seen and treated to conclusion by a children's ENP, and some patients could have their care accelerated by a children's ENP.

The introduction of children's ENPs would have an impact on waiting times, junior doctors work‐load and the quality of patient care.
Eating despite severe difficulties: assessment of poststroke eating
Authors: JACOBSSON CATRINE , AXELSSON KARIN , WENNGREN BRITT‐INGER , NORBERG ASTRID
Published: December 2007

A programme for the assessment and nursing diagnoses of eating difficulties among stroke patients was tested. The patients' experiences regarding eating were expressed in interviews and dialogues. Eating was observed during both a test meal and regular meals.

The assessments included the prerequisites for eating as well as oral, pharyngeal and oesophageal functions.

General and specific nursing diagnoses as well as life consequences (handicap) were established, based on assessment of disabilities and impairments, and interviewing the patients and their families, respectively. The general nursing diagnoses were formulated on admission after the test meal and these were reformulated to form specific nursing diagnoses after assessments of the functions.

The programme presented proved to be useful in clinical practice. It is emphasized that many assessments must be co‐ordinated for each individual.
Clinical practice development and research activities in four district health authorities
Authors: KITSON ALISON , CURRIE LYNNE
Published: December 2007

This review is based on findings from a postal survey undertaken between March and September 1993 to elicit information from nurses in four district health authorities regarding development and research activity in which they were involved.

The objectives of the review were to obtain baseline information on the extent, variety and scope of work being carried out, to provide staff with a mechanism for networking good practice and to identify any areas of replication.

A snowball sampling technique was used to obtain information from nursing personnel. A total of 141 responses were received out of which 4% (n= 5) reported no activity. Response rates varied between organizations and specialist groups but were similar in terms of the number of small‐scale clinical practice developments undertaken without identified support or supervision.

Fifty‐five per cent (n= 75) of the reported developments related to the organization and management of services while 11% (n= 15) focused on consumer‐related issues. Few studies identified dissemination strategies and there was generally a lack of clarity over expected benefits of the study in terms of measurable outcomes to the organization, nursing staff or patients. Funding for clinical practice development and research in nursing was found to be very sparse; the reasons for this were not identified.

Overall the review confirmed statements from other sources (DoH, 1993a,b) that nursing development and research tends to be small scale and unsupported with nursing staff trying hard to implement research findings or be innovative in their practice without the necessary expertise and support. Such findings have implications for the current drive to implement research into practice.
The supervision of Project 2000 students in the clinical setting: issues and implications for practitioners
Authors: TWINN SHEILA , DAVIES SUSAN
Published: December 2007

The aim of this 2‐year study funded by the English National Board for Nursing, Midwifery and Health Visiting was to examine the relationship between teaching, support, supervision and role modelling in student clinical learning within the context of Project 2000 courses.

The research, using a two‐stage case‐study design, employing predominantly qualitative methods of data collection, investigated the perceptions of students, tutors and practitioners of their experiences of these processes in the clinical setting.

This paper focuses on the findings obtained from the practitioner data, highlighting not only the significant role played by practitioners in facilitating student learning, but also the implications for practitioners in undertaking this role.

The preparation required for supervising clinical learning, the integration of theory and practice and the organization of patient care have been identified as particularly important to the development of effective clinical learning environments.
Introducing primary nursing: nurses' opinions
Authors: WEBB CHRISTINE , PONTIN DAVID
Published: December 2007

This article reports on one aspect of a research project carried out to monitor and evaluate the introduction of primary nursing on four demonstration wards in one health authority.

Nursing staff working on the wards were interviewed to identify how the changes were affecting them and their work.

Stress questionnaires were also completed by a sample of nurses on the wards.

Responsibility and communication — key concepts emerging from the data — are discussed and related to the literature on primary nursing.
A study of the efficacy of dressings in preventing infections of continuous ambulatory peritoneal dialysis catheter exit sites
Authors: NAYLOR MARGARET , ROE BRENDA
Published: December 2007

This paper describes a preliminary investigation into the efficacy of dressings in preventing catheter exit site infections in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). It has been carried out in the form of a pilot study.

The background to the study is described and the literature is reviewed. This revealed that it is an important field of research.

Exit site infections are the main cause of morbidity and treatment failure in CAPD patients.

The rationale for carrying the study out, the findings and the implications for further study are reported and discussed.

There is little guidance in current literature for clinicians on the prevention of catheter exit site infection. Patients are difficult to recruit to research studies. Practising nurses need training and careful management as data collectors.
A review of educational issues in resuscitation training
Authors: COOPER SIMON , LIBBY JUDY
Published: December 2007

This paper considers a number of concerns about resuscitation training.

Poor retention of skills and the factors which affect understanding and memory, as well as the need for a positive attitude towards resuscitation, are discussed.

Some specific points are made on how these, as well as the trainer's ability to teach resuscitation, can be improved.
The use of a ward‐based educational teaching package to enhance nurses' compliance with infection control procedures
Authors: GOULD DINAH , CHAMBERLAIN ANGELA
Published: December 2007

Obtaining study leave is becoming difficult for clinical nurses in the current economic climate, but the need to develop new clinical skills and to maintain existing good practice remains of prime importance to patient care and will become mandatory with the advent of post‐registration education and practice (PREP) in the UK.

The ward is widely acknowledged as the best venue for learning clinical skills by nurse educationalists and for many nurses is the preferred learning environment.

The feasibility of using a ward‐based teaching package to enhance nurses' compliance with key infection control precautions (hand decontamination, the use of gloves and the safe handling and disposal of sharp instruments) was tested in a quasi‐experimental research study conducted on matched surgical wards in a teaching hospital, controlling for variables likely to influence performance (knowledge, availability of resources to perform infection control, previous opportunity to develop infection control expertise and nursing workload). Nurses on two wards received the intervention (experimental group). The remaining wards, which received no intervention, operated as controls.

The ward‐based sessions consisted of a carefully planned sequence of theory and practical demonstration delivered to qualified nurses in the clinical environment at convenient times selected by the ward managers. Performance of infection control precautions was audited before the intervention and 3 months afterwards.

The sessions were well evaluated and the clinical environment was considered suitable for teaching by the nurses, but heavy and unpredictable workload prevented the teaching programme from being implemented as planned. The analysis of covariance failed to detect any changes in performance between nurses in the control and experimental groups.

The implications of the study findings are discussed to help develop creative new ways of strengthening ward‐based educational programmes.
The quality and management of written information presented to women undergoing hysterectomy
Authors: SCRIVEN ANGELA , TUCKER CHRISTINE
Published: December 2007

A study of a random sample of hospitals in England that provide information leaflets for women undergoing hysterectomy indicates a large variation in quality.

In general, the findings reveal that written information for patients is given a relatively low priority.

Production and dissemination of information for hysterectomy patients is somewhat ad hoc.

It is not clear that any evaluation of the leaflets has been conducted to prove the efficacy of the available literature.

While the majority of leaflets include information deemed essential by past hysterectomy patients, the presentation of the recovery process often implies no control for the patient, and conceives normality with a narrow perspective about what healthy behaviour means for women. The provision of a specific timetable for resumption of housework duties in 65% of the leaflets is a case in point.

On the basis of the results of the survey, recommendations are made concerning the improvement of the standard of patient information leaflets.