bluuebunny/crossref_metadata_2025 huggingface dataset:
OS‐D‐like genes and their expression in aphids (Hemiptera: Aphididae)
Authors: Jacobs S. P. , Liggins A. P. , Zhou J.‐J. , Pickett J. A. , Jin X. , Field L. M.
Published: July 2005

It has been proposed that a family of small soluble binding proteins, variously named as chemosensory proteins, sensory appendage proteins, pherokines and OS‐D‐like proteins, are involved in insect chemoreception. These proteins are present in a wide range of insect species and have a characteristic four cysteine motif. We have cloned cDNAs and gene sequences encoding these proteins from a number of aphid species, the first report of such in the order Hemiptera and supporting the view that these genes predate the divergence of the Neoptera. In one aphid species, Megoura viciae, we have shown that the proteins are present primarily in adults with one protein being most abundant in antennae and legs. This supports the view that the proteins could be involved in chemoreception but our preliminary binding studies failed to detect binding to a range of compounds which are known to elicit an electrophysiological response by aphids.
Capillary feeding of specific dsRNA induces silencing of the isac gene in nymphal Ixodes scapularis ticks
Authors: Soares C. A. G. , Lima C. M. R. , Dolan M. C. , Piesman J. , Beard C. B. , Zeidner N. S.
Published: July 2005

Ixodes scapularis transmits several pathogens including Borrelia burgdorferi. Bioactive compounds in tick saliva support tick feeding and influence pathogen transmission to the mammalian host. These studies utilized oral delivery of dsRNA to silence an anticomplement gene (isac) in I. scapularis nymphs. Silencing of isac significantly reduced fed‐tick weight compared to delivery of control lacZ dsRNA, and immunoblots specific for FlaB protein indicated a reduction in spirochete load in isac‐silenced infected nymphs. SDS‐PAGE demonstrated that isac gene silencing affected expression of a number of salivary and non‐salivary gland proteins in ticks. Finally, multiple isac cDNA homologues were cloned, and these may represent a new gene family coexpressed during tick feeding. This work presents a novel oral delivery approach for specific gene silencing in I. scapularis nymphs and characterizes the effect of isac on blood‐feeding in an attempt to block transmission of B. burgdorferi.
Population structure and colonization history of the olive fly, Bactrocera oleae (Diptera, Tephritidae)
Authors: NARDI FRANCESCO , CARAPELLI ANTONIO , DALLAI ROMANO , RODERICK GEORGE K. , FRATI FRANCESCO
Published: July 2005

The olive fly, Bactrocera oleae, is the major pest of olives in most commercial olive‐growing regions worldwide. The species is abundant in the Mediterranean basin and has been introduced recently into California and Mexico, creating problems for quarantine protection and international trade. Here, we use nuclear microsatellite markers and mitochondrial sequences to examine the history of olive fly range expansion and colonization. Sampled populations span the current distribution of the olive fly worldwide, including South and Central Africa, Pakistan, Mediterranean Europe and Middle East, California, and Mexico. The Pakistani populations appear to be genetically well differentiated from the remaining populations, though rooting the origins of the species is problematic. Genetic similarity and assignment tests cluster the remaining populations into two genetic groups — Africa and a group including the Mediterranean basin and the American region. That Africa, and not the Mediterranean, is the origin of flies infesting cultivated olive is supported by the significantly greater genetic diversity at microsatellite loci in Africa relative to the Mediterranean area. The results also indicate that the recent invasion of olive flies in the American region most likely originated from the Mediterranean area.
Uptake of Bt endotoxins by nontarget herbivores and higher order arthropod predators: molecular evidence from a transgenic corn agroecosystem
Authors: HARWOOD JAMES D. , WALLIN WILLIAM G. , OBRYCKI JOHN J.
Published: July 2005

The planting of transgenic crops expressing Bacillus thuringiensis endotoxins is widespread throughout the world; the prolific increase in their application exposes nontarget organisms to toxins designed to control pests. To date, studies have focused upon the effects of Bt endotoxins on specific herbivores and detritivores, without consideration of their persistence within arthropod food webs. Here, we report the first quantitative field evaluation of levels of Bt endotoxin within nontarget herbivores and the uptake by higher order arthropods. Antibody‐based assays indicated significant quantities of detectable Cry1Ab endotoxin within nontarget herbivores which feed on transgenic corn (including the corn flea beetle, Chaetocnema pulicaria, Japanese beetle, Popillia japonica and southern corn rootworm, Diabrotica undecimpunctata howardi). Furthermore, arthropod predators (Coccinellidae, Araneae, and Nabidae) collected from these agroecosystems also contained significant quantities of Cry1Ab endotoxin indicating its movement into higher trophic levels. This uptake by predators is likely to have occurred by direct feeding on plant material (in predators which are facultatively phytophagous) or the consumption of arthropod prey which contained these proteins. These data indicate that long‐term exposure to insecticidal toxins occurs in the field. These levels of exposure should therefore be considered during future risk assessments of transgenic crops to nontarget herbivores and arthropod predators.
Enterobacteria‐mediated nitrogen fixation in natural populations of the fruit fly Ceratitis capitata
Authors: BEHAR A. , YUVAL B. , JURKEVITCH E.
Published: July 2005

Nitrogen, although abundant in the atmosphere, is paradoxically a limited resource for multicellular organisms. In the Animalia, biological nitrogen fixation has solely been demonstrated in termites. We found that all individuals of field‐collected Mediterranean fruit flies (Ceratitis capitata) harbour large diazotrophic enterobacterial populations that express dinitrogen reductase in the gut. Moreover, nitrogen fixation was demonstrated in isolated guts and in live flies and may significantly contribute to the fly's nitrogen intake. The presence of similar bacterial consortia in additional insect orders suggests that nitrogen fixation occurs in vast pools of terrestrial insects. On such a large scale, this phenomenon may have a considerable impact on the nitrogen cycle.
Impact of ice ages on circumpolar molecular diversity: insights from an ecological key species
Authors: ALSOS I. G. , ENGELSKJØN T. , GIELLY L. , TABERLET P. , BROCHMANN C.
Published: July 2005

We address the impact of the ice age cycles on intraspecific cpDNA diversity, for the first time on the full circumboreal‐circumarctic scale. The bird‐dispersed bog bilberry (or arctic blueberry, Vaccinium uliginosum) is a key component of northern ecosystems and is here used to assess diversity in previously glaciated vs. unglaciated areas and the importance of Beringia as a refugium and source for interglacial expansion. Eighteen chloroplast DNA haplotypes were observed in and among 122 populations, grouping into three main lineages which probably diverged before, and thus were affected more or less independently by, all major glaciations. The boreal ‘Amphi‐Atlantic lineage’ included one haplotype occurring throughout northern Europe and one occurring in eastern North America, suggesting expansion from at least two bottlenecked, glacial refugium populations. The boreal ‘Beringian lineage’ included seven haplotypes restricted to Beringia and the Pacific coast of USA. The ‘Arctic‐Alpine lineage’ included nine haplotypes, one of them fully circumpolar. This lineage was unexpectedly diverse, also in previously glaciated areas, suggesting that it thrived on the vast tundras during the ice ages and recolonized deglaciated terrain over long distances. Its largest area of persistence during glaciations was probably situated in the north, stretching from Beringia and far into Eurasia, and it probably also survived the last glaciation in southern mountain ranges. Although Beringia apparently was important for the initial divergence and expansion of V. uliginosum as well as for continuous survival of both the Beringian and Arctic‐Alpine lineages during all ice ages, this region played a minor role as a source for later interglacial expansions.
Population genetic structure in migratory sandhill cranes and the role of Pleistocene glaciations
Authors: JONES KENNETH L. , KRAPU GARY L. , BRANDT DAVID A. , ASHLEY MARY V.
Published: July 2005

Previous studies of migratory sandhill cranes (Grus canadensis) have made significant progress explaining evolution of this group at the species scale, but have been unsuccessful in explaining the geographically partitioned variation in morphology seen on the population scale. The objectives of this study were to assess the population structure and gene flow patterns among migratory sandhill cranes using microsatellite DNA genotypes and mitochondrial DNA haplotypes of a large sample of individuals across three populations. In particular, we were interested in evaluating the roles of Pleistocene glaciation events and postglaciation gene flow in shaping the present‐day population structure. Our results indicate substantial gene flow across regions of the Midcontinental population that are geographically adjacent, suggesting that gene flow for most of the region follows an isolation‐by‐distance model. Male‐mediated gene flow and strong female philopatry may explain the differing patterns of nuclear and mitochondrial variation. Taken in context with precise geographical information on breeding locations, the morphologic and microsatellite DNA variation shows a gradation from the Arctic‐nesting subspeciesG. c. canadensisto the nonArctic subspeciesG. c. tabida. Analogous to other Arctic‐nesting birds, it is probable that the population structure seen in Midcontinental sandhill cranes reflects the result of postglacial secondary contact. Our data suggest that subspecies of migratory sandhills experience significant gene flow and therefore do not represent distinct and independent genetic entities.
Strong spatial genetic structure in peripheral but not core populations of Sitka spruce [Picea sitchensis (Bong.) Carr.]
Authors: GAPARE WASHINGTON J. , AITKEN SALLY N.
Published: July 2005

We examined spatial genetic structure within eight populations of Sitka spruce classified as core or peripheral based on ecological niche, and continuous or disjunct based on species distribution. In each population, 200 trees were spatially mapped and genotyped for eight cDNA‐based sequence tagged site (STS) codominant markers. Spatial autocorrelation was assessed by estimating pij, the average co‐ancestry coefficient, between individuals within distance intervals. The distribution of alleles and genotypes within core populations was almost random, with nonsignificant co‐ancestry values among trees as close as 50 m in core populations. In contrast, the distribution of alleles and genotypes within peripheral populations revealed an aggregation of similar multilocus genotypes, with co‐ancestry values greater than 0.20 among trees up to 50 m apart and significant, positive values between trees up to 500 m. The relatively high density of reproductive adults in core populations may lead to highly overlapping seed shadows that limit development of spatial genetic structure. However, in peripheral populations with a lower density of adults, the distribution of alleles and genotypes was highly structured, likely due to offspring establishment near maternal trees and subsequent biparental inbreeding, as well as more recent population establishment at the leading edge of post‐Pleistocene range expansion. Conserving genetic diversity in peripheral populations may require larger reserves for in situ conservation than required in core populations. These data on spatial genetic structure can be used to provide guidance for sampling strategies for both ex situ conservation and research collections.
Clone identification and clonal structure of the European aspen (Populus tremula)
Authors: SUVANTO LEENA I. , LATVA‐KARJANMAA TARJA B.
Published: July 2005

The European aspen (Populus tremula) is thought to reproduce mostly asexually. Thus aspen forms clones, in which several ramets belong to one genetically defined genet. We compared the clonal structure of aspen in old‐growth and managed forests in southern and northeastern Finland. Clones were identified using morphological characters and nine microsatellite loci originally developed for Populus tremuloides. There were more clones identified by microsatellites than morphotypes both in old‐growth and managed forest. The average size of the clones was only 2.3 ramets and most clones (70%) consisted of just one ramet. The size of the clones showed no difference between managed and old‐growth forests or between northeastern and southern Finland. The small size of the clones suggests that most of them are relatively young. Therefore, sexual reproduction may be more common than previously thought. There was an aggregated spatial genetic structure as measured by Moran's I (0–10 m) and by co‐ancestry (ρij, 0–20 m). Low level of co‐ancestry can be explained by relatively unrestricted gene flow, the important role of disturbance in reproduction, and/or local selection.
Genetic structure of the cyclic fossorial water vole (Arvicola terrestris): landscape and demographic influences
Authors: BERTHIER K. , GALAN M. , FOLTÊTE J. C. , CHARBONNEL N. , COSSON J. F.
Published: July 2005

Genetic structure can be strongly affected by landscape features and variation through time and space of demographic parameters such as population size and migration rate. The fossorial water vole (Arvicola terrestris) is a cyclic species characterized by large demographic fluctuations over short periods of time. The outbreaks do not occur everywhere at the same time but spread as a wave at a regional scale. This leads to a pattern of large areas (i.e. some hundreds of km2), each with different vole abundances, at any given time. Here, we describe the abundance and genetic structures in populations of the fossorial water vole. We use the data to try to understand how landscape and demographic features act to shape the genetic structure. The spatial variability of vole abundance was assessed from surface indices, collected in spring 2002 (April) in eastern central France. Genetic variability was analysed using eight microsatellite loci at 23 localities sampled between October 2001 and April 2002. We found some congruence between abundance and genetic structures. At a regional scale, the genetic disruptions were associated with both sharp relief and transition between an area of low abundance and another of high abundance. At a local scale, we observed a variation of the isolation‐by‐distance pattern according to the abundance level of vole populations. From these results we suggest that the dispersal pattern in cyclic rodent populations varies throughout the demographic cycle.
Within‐population spatial genetic structure, neighbourhood size and clonal subrange in the seagrass Cymodocea nodosa
Authors: ALBERTO FILIPE , GOUVEIA LICÍNIA , ARNAUD‐HAOND SOPHIE , PÉREZ‐LLORÉNS JOSÉ L. , DUARTE CARLOS M. , SERRÃO ESTER A.
Published: July 2005

The extent of clonality within populations strongly influences their spatial genetic structure (SGS), yet this is hardly ever thoroughly analysed. We employed spatial autocorrelation analysis to study effects of sexual and clonal reproduction on dispersal of the dioecious seagrass Cymodocea nodosa. Analyses were performed both at genet level (i.e. excluding clonal repeats) and at ramet level. Clonal structure was characterized by the clonal subrange, a spatial measure of the linear limits where clonality still affects SGS. We show that the clonal subrange is equivalent to the distance where the probability of clonal identity approaches zero. This combined approach was applied to two meadows with different levels of disturbance, Cadiz (stable) and Alfacs (disturbed). Genotypic richness, the proportion of the sample representing distinct genotypes, was moderate (0.38 Cadiz, 0.46 Alfacs) mostly due to dominance of a few clones. Expected heterozygosities were comparable to those found in other clonal plants. SGS analyses at the genet level revealed extremely restricted gene dispersal in Cadiz (Sp = 0.052, a statistic reflecting the decrease of pairwise kinship with distance), the strongest SGS found for seagrass species, comparable only to values for selfing herbaceous land plants. At Cadiz the clonal subrange extended across shorter distances (20–25 m) than in Alfacs (30–35 m). Comparisons of sexual and vegetative components of gene dispersal suggest that, as a dispersal vector within meadows, clonal spread is at least as important as sexual reproduction. The restricted dispersal and SGS pattern in both meadows indicates that the species follows a repeated seedling recruitment strategy.
F‐statistics of clonal diploids structured in numerous demes
Authors: DE MEEÛS THIERRY , BALLOUX FRANÇOIS
Published: July 2005

The expected apportionment of genetic diversity in diploid clonal organisms structured in numerous subpopulations is explored. Under the specific assumptions considered, corresponding, for instance, to clonal pathogens infecting a large number of hosts, the co‐ancestry between individuals within subpopulations is the only nontrivial quantity. Thus the population structure can be fully described either by FST or FIS, as FST = –FIS/(1 − FIS). We show that, for most of the parameter space considered, including simulations where equilibrium is not reached and/or where homoplasy is high, the number of effective migrants is most accurately estimated as Nm = –(1 + FIS)/4FIS. We further propose a criterion to test for the absence of cryptic sexual reproduction based on the F‐statistics FIS and FST, which is applied to three previously published empirical data sets.
Reconstitution of a human immune system in immunodeficient mice: models of human alloreaction in vivo
Authors: Thomsen M. , Yacoub‐Youssef H. , Marcheix B.
Published: July 2005

Abstract:  Rodents have been widely used for studies in transplantation immunology because of their short reproduction period and the relative ease of generating inbred mutant or transgenic strains. However, although many biological mechanisms are similar between rodents and humans, several features clearly distinguish the immune system in these species. Consequently, it is rarely possible to extrapolate observations from rodent models directly into clinical practice. In vitro studies with human cells are useful for elucidation of basic mechanisms, but in order to study complex biological phenomena, in vivo studies are indispensable. In later years, a number of interesting models have been described where immunodeficient mice have been reconstituted with human cells, so‐called humanized mice, in order to study human immune responses in vivo. This has opened a new field of experimental immunology that has been applied to areas such as cancer, autoimmunity, allergy, infections, and transplantation biology. In this review, we shall concentrate on the use of severe combined immunodeficient mice reconstituted with human immune or stem cells for studies of human alloreaction in vivo.
Novel MASP2 variants detected among North African and Sub‐Saharan individuals
Authors: Lozano F. , Suárez B. , Muñoz A. , Jensenius J.C. , Mensa J. , Vives J. , Horcajada J.‐P.
Published: July 2005

Abstract:  The lectin pathway of the complement system is activated when mannan‐binding lectin (MBL) in complex with MBL‐associated serine protease 2 (MASP‐2) binds to carbohydrate structures on microorganisms. Structural gene mutations and promoter polymorphisms in the MBL2 gene responsible for low‐MBL serum levels are present in all human populations and associate with increased risk of infection. Recently, investigations on Danes revealed the existence of a mutation on the MASP2 gene, which introduces an amino acid substitution in the CUB1 domain (Asp105Gly; numbering refers to the mature protein), and is associated with reduction in the level of MASP‐2 in serum. Here, we present the results of a sequence‐based typing analysis of the MBL2 and MASP2 gene polymorphisms in a group of 65 Africans (50 North Africans and 15 Sub‐Saharan) and of 104 Spaniards. The analysis identified three novel exon 3 MASP2 variants introducing amino acid substitutions at positions 84 (Arg→Gln), 103 (Arg→Cys) and 111 (Pro→Leu) in the CUB1 domain. None of these variants were identified in Spaniards. The Arg84Gln was detected in four of the 15 Sub‐Saharans. The Arg103Cys and Pro111Leu variants were detected only among North Africans (two and four individuals, respectively). The Asp105Gly variant was similarly represented among Spaniards and North Africans (three and two individuals, respectively), which appears to be a lower frequency than that reported for Danes (5.5%). As reported for MBL2, the marked geographic distribution of the new MASP2 variants may represent an evolutionary adaptation to different environments.
Identification of an HLA‐B*07 allele variant (B*0740) in the Chinese Han population
Authors: Wang C.Y. , Pan Q. , Xue M. , Miao K.R. , Fei X.M. , Zhou X.Y. , Zhao X. , KuKuruga D. , Osowski L. , Poore B. , Beattie R. , Shi W.X. , Zhang H.
Published: July 2005

Abstract:  A novel HLA‐B*07 allele, B*0740, has been identified by sequence‐based typing (SBT) in the Chinese Han population. This new allele is identical to B*0705 and B*0706 for exons 2, 3, and 4, except for a single nucleotide at position 605 of codon 202 in exon 3 (AAG→ATG) leading to an amino acid change from lysine to methionine. SBT was performed following allele separation using the Haploprep® method. The serological equivalence of B*0740 to the B7 antigen did not change.
Novel HLA‐A*31 allele, A*3111 identified by sequence‐based typing
Authors: Hwang S.‐H. , Oh H.‐B. , Hur S.‐S. , Lee M.‐N. , Hong S.‐A. , Kwon O.‐J.
Published: July 2005

Abstract:  In this report, we describe the identification of an HLA‐A*31 nucleotide sequence variant, a new HLA‐A*3111, in three members of a Korean family by using sequence‐based typing (SBT). The new allele was detected during routine HLA typing by high‐resolution SBT. Allele A*3111 showed one nucleotide difference with A*310102 at codon 165 (GTG→CTG) resulting in an amino acid change from valine to leucine (V165L). Serologic reactivity was shorter than normally expected.
Frequencies of HLA‐A, HLA‐B, HLA‐DR, and HLA‐DQ phenotypes in the United Arab Emirates population
Authors: Valluei V. , Mustafa M. , Santhosh A. , Middleton D. , Alvales M. , El Haj E. , Gumama O. , Abdel‐Waieth L.
Published: July 2005

Abstract:  The high degree of polymorphism of the human leukocyte antigen (HLA) system provides means for the study of diversity in different populations. The aim of this work is to study the HLA phenotype frequencies in the United Arab Emiratis in comparison with other geographically related Arabs, Iranians, and Asians, all living in the United Arab Emirates (UAE). Healthy blood donors and potential kidney or bone marrow donors were typed for HLA class I (n = 1880) and class II (n = 2022). Only one representative member of each family was included to avoid bias. UAE Emiratis, Arabs of Arabian Gulf Peninsula (AGP), Arabs of South Mediterranean (SMR), North African Arabs (NA), Iranians, and Asians. HLA typing was done by microlymphocytotoxicity method and/or low‐resolution polymerase chain reaction‐sequence‐specific primer techniques. As an individual antigen, HLA‐A2 had the highest frequency in all populations studied, however, the frequency of the broad antigen A19 surpassed A2 in all the groups except the AGP Arabs and Iranians. B5 was the predominant B antigen in all groups except the SMR and Asians. Amongst the class II broad antigens, DR2 was the most frequent antigen in UAE, AGP Arabs, Iranians, and Asians. The overall frequency of DQ1 was high in all groups except the SMR Arabs who had an almost equal distribution of DQ1 and DQ3. In conclusion, this study indicates that the most frequent antigens in the UAE population are HLA‐A19, HLA‐A2, HLA‐B5, and HLA‐DR2. It also sheds light on the similarities between the UAE Emiratis, AGP Arabs, Iranians, and Asians, specially the predominance of DR2 of the class II antigens.
The recombinant HLA‐B*5518 allele supports the evidence of conserved haplotype association of rare alleles
Authors: Lebedeva T.V. , Huang A. , Ohashi M. , Sibilia P. , Alosco S.M. , Kempenich J. , Yu N.
Published: July 2005

Abstract:  Allelic polymorphism of the major histocompatibility complex arises mostly from gene recombination. Intralocus gene recombination usually involves short fragments of DNA leading most commonly to single‐nucleotide substitutions and rarely involves large fragments. Here, we report a new recombinant human leukocyte antigen (HLA)‐B*5518 allele that has arisen via recombination of a large fragment of DNA spanning more than 70 nucleotides. During routine HLA typing of potential volunteer donors for the National Marrow Donor Program®, a new HLA‐B allele was identified in two donors from Guam. The allele, B*5518, appears to be a product of recombination between B*5502 and B*40. Exons 1, 3, and 4 of the new allele belong to B*5502, whereas part of exon 2 belongs to one of B*40 alleles. Introns 1 and 2 appear to belong to B*55, suggesting that the recombination event may have occurred within the homologous parts of exon 2.
Novel HLA‐A*11 allele, A*1120, identified by sequence‐based typing
Authors: Kwon O.‐J. , Hwang S.‐H. , Heo Y.‐S. , Hur S.‐S. , Lee M.‐N. , Oh H.‐B.
Published: July 2005

Abstract:  In this report, we describe the identification of a human leucocyte antigen‐A*11 (HLA‐A*11) nucleotide sequence variant, a new HLA‐A*1120 by using sequence‐based typing (SBT). The new allele was detected during routine HLA typing by high‐resolution SBT. Allele A*1120 showed one nucleotide difference with A*110101 at codon 152 (GCG→GAG) resulting in an amino acid change from alanine to glutamate. Residue 152 is located on α2‐helix of HLA class I molecule and involved in peptide binding by constructing E pocket of peptide‐binding groove, implying that the change of the residue 152 would affect the binding affinity of peptides to A*1120 allele.
Characterization and application of two novel monoclonal antibodies against 2IgB7‐H3: expression analysis of 2IgB7‐H3 on dendritic cells and tumor cells
Authors: Zhang G.‐B. , Zhou H. , Chen Y.‐J. , Ge Y. , Xie F. , Shi Q. , Ma H.‐B. , Fei M. , Zhang X.‐G.
Published: July 2005

Abstract:  2IgB7‐H3 has recently been identified as a new member of the B7 family. Its expression at the protein level remains largely unknown due to the lack of the specific monoclonal antibody (mAb). To characterize the expression of 2IgB7‐H3, we newly generated two mouse antihuman 2IgB7‐H3 mAbs (4H7 and 21D4). We found the constitutive expression of 2IgB7‐H3 on a series of tumor cell lines. Furthermore, the expression was examined on monocyte‐derived dendritic cells (Mo‐DCs) and DCs from CD34+ hematopoietic progenitor cells (HPC) by means of mAb staining. The results showed that 2IgB7‐H3 was expressed on Mo‐DCs at a high and stable level during differentiation in vitro. With the maturation of DCs from CD34+ HPCs, the expression of the molecule was upregulated. However, the 2IgB7‐H3 was not expressed on fresh isolated T and B lymphocytes, monocytes, or CD34+ HPCs. These results suggested that 2IgB7‐H3 may be a valuable surface antigen for the detection of DCs.
Toll‐like receptor 3 gene polymorphisms in South African Blacks with type 1 diabetes
Authors: Pirie F.J. , Pegoraro R. , Motala A.A. , Rauff S. , Rom L. , Govender T. , Esterhuizen T.M.
Published: July 2005

Abstract:  Type 1 diabetes is the consequence of exposure of genetically susceptible individuals to specific environmental precipitants. The innate immune system provides the initial response to exogenous antigen and links with the adaptive immune system. The aim of this study was to assess the role of polymorphisms occurring in the cytoplasmic region of toll‐like receptor (TLR) 3 gene and immediate 5′ sequence, in subjects of Zulu descent with type 1 diabetes in KwaZulu‐Natal, South Africa. Seventy‐nine subjects with type 1 diabetes and 74 healthy normal glucose tolerant gender‐matched control subjects were studied. Parts of exon 4 and exon 3/intron 3 of the TLR3 gene were studied by polymerase chain reaction, direct sequencing and restriction enzyme digestion with Bts 1. Of the nine polymorphisms studied, a significant association with type 1 diabetes was found for the major allele in the 2593 C/T polymorphism and for the minor alleles in the 2642 C/A and 2690 A/G polymorphisms, which were found to be in complete linkage disequilibrium. Correction of the P‐values for the number of alleles studied, however, rendered the results no longer significant. These results suggest that polymorphisms in the TLR3 gene, which is part of the innate immune system, may be associated with type 1 diabetes in this population.
Involvement of arabinogalactan proteins in protonemata development from cultured cells of Marchantia polymorpha
Authors: Shibaya Taeko , Kaneko Yasuko , Sugawara Yasutake
Published: July 2005

Arabinogalactan proteins (AGPs) are abundant plant cell‐surface proteoglycans widely distributed in plant species. Crossed electrophoresis patterns of AGPs isolated from cultured cells before and after protonemata development differed, indicating that AGPs are involved in protonemata differentiation and development. Moreover, the addition of β‐glucosyl Yariv reagent (βglcY), which binds specifically to AGPs, inhibits protonemata differentiation in cells of the liverwort Marchantia polymorpha L. cultured in protonemata‐inducing medium. Transmission electron microscopic examination revealed that βglcY caused conspicuous disorder at the cell surface and the accumulation of abnormal structures between the plasma membrane and the cell wall. These results suggest that AGPs/βglcY complexes caused disturbances at the cell surface and inhibited cell‐wall synthesis required for protonemata differentiation. Our results indicate that AGPs play a significant role in cell‐wall synthesis during the protonemata‐differentiation process of M. polymorpha.
Evaluation of a new centrifuge technique for rapid generation of xylem vulnerability curves
Authors: Cochard Hervé , Damour Gaëlle , Bodet Christian , Tharwat Ibrahim , Poirier Magalie , Améglio Thierry
Published: July 2005

A new technique for generating xylem cavitation and vulnerability curves was evaluated. The centrifugal force was used to lower the negative pressure in a xylem segment and to induce a positive pressure difference between sample's ends. This enabled the determination of sample hydraulic conductance during centrifugation and, hence, its variation with decreasing xylem pressures. The centrifuge technique was compared with standard methods on a large number of species including conifers, diffuse‐porous and ring‐porous woody angiosperms. A very good agreement was found for coniferous and diffuse‐porous species. However, the technique was not appropriate for ring‐porous species, probably because many vessels were cut open in the centrifuged xylem segments. The main advantage of this technique is its rapidity, the vulnerability curve of a xylem segment being constructed typically in less than half an hour. This will greatly facilitate the study of xylem cavitation in ecological or genetic researches.
Induction of xylem sap methylglycine by a drought and rewatering treatment and its inhibitory effects on the growth and development of plant organs
Authors: Oda Atsushi , Shimizu Madoka , Kuroha Takeshi , Satoh Shinobu
Published: July 2005

In higher plants, the xylem vessels functionally connect the roots with the above‐ground organs. The xylem sap transports various organic compounds, such as proteins and amino acids. We examined drought and rewatering‐inducible changes in the amino acid composition of root xylem sap collected from Cucurbita maxima roots. The major free amino acids in C. maxima root xylem sap were methylglycine (MeGly; sarcosine) and glutamine (Gln), but MeGly was not detected in the xylem sap of cucumber. MeGly is an intermediate compound in the metabolism of trimethylglycine (TMG; betaine), but its physiological effects in plants are unknown. Drought and rewatering treatment resulted in an increase in the concentration of MeGly in root xylem sap to 2.5 mM. After flowering, the MeGly concentration in the xylem sap dropped significantly, whereas the concentration of Gln decreased only after fruit ripening. One milli molar MeGly inhibited the formation of adventitious roots and their elongation in C. maxima, but glycine, dimethylglycine, or TMG had no effect. Similar effects and the inhibition of stem elongation were observed in shoot cuttings of cucumber and Phaseolus angularis. These observations seem to imply a possible involvement of xylem sap MeGly in the physiological responses of C. maxima plants to drought stress.
Regulation of the uptake and distribution of Na+ in shoots of rice (Oryza sativa) variety Pokkali: role of Ca2+ in salt tolerance response
Authors: Anil Veena S. , Krishnamurthy Pannaga , Kuruvilla Sam , Sucharitha K. , Thomas George , Mathew M. K.
Published: July 2005

Soil salinity is a major factor affecting crop productivity worldwide. This study explores mechanisms that contribute to salt tolerance in rice (Oryza sativa L.). Hydroponically grown, 2‐week‐old salt tolerant and sensitive indica rice varieties, Pokkali and Jaya, respectively, were exposed to a 48‐h stress period with NaCl (0–250 mM). When exposed to 200 mM NaCl, micromolar levels of external Ca2+ elevated survival of both varieties. The Ca2+ levels required were lower for Pokkali than for Jaya, but resulted in significantly higher survival. Estimates of Na+ and K+ in root and shoot compartments were made by flame photometry, while X‐ray microanalysis was used to localize Na+ in the extracellular matrix of the shoot. Transpirational bypass flow was estimated using the apoplastic tracer, 8‐hydroxypyrene‐1,3,6‐trisulphonic acid, trisodium salt. Our data demonstrate a Ca2+‐dependent reduction in Na+ transport to shoots, which correlated with a decline in bypass flow and of Na+ in the transpirational stream. In addition, the Na+ that enters the shoot is partitioned among several distinct compartments. Survival is inversely correlated with Na+ levels in the shoot apoplastic fluid, which surrounds the cell and influences cytosolic composition. Pokkali maintained lower Na+ in its apoplast compared with the salt sensitive Jaya at the same total shoot Na+. Na+ in the apoplast appears to be regulated by sequestration into intracellular compartments. This sink supplements the primary response of reducing Na+ influx into the shoot and effectively buffers the apoplastic fluid in Pokkali. All of these mechanisms are operational in Jaya as well but are deployed less effectively.
Investigation of the biosynthesis of 3‐deoxyanthocyanins in Sinningia cardinalis
Authors: Winefield Chris S. , Lewis David H. , Swinny Ewald E. , Zhang Huaibi , Arathoon H. Steve , Fischer Thilo C. , Halbwirth Heidrun , Stich Karl , Gosch Christian , Forkmann Gert , Davies Kevin M.
Published: July 2005

3‐Deoxyanthocyanins provide bright orange‐red colours to flowers of some members of the Gesneriaceae, including sinningia (Sinningia cardinalis). We examined 3‐deoxyanthocyanin biosynthesis in sinningia, in particular, the expression of key flavonoid biosynthetic genes and the activities of the encoded proteins. Two abundant 3‐deoxyanthocyanins, luteolinidin 5‐O‐glucoside and apigeninidin 5‐O‐glucoside, three flavone glycosides, luteolin 7‐O‐glucoside, luteolin 7‐O‐glucuronide and apigenin 7‐O‐glucuronide, and the cinnamic acid verbascoside were identified in sinningia petal tissue. Small amounts of a 3‐hydroxyanthocyanin were also detected in a limited region of the petal. cDNA clones for three flavonoid enzymes, flavanone 3‐hydroxylase (F3H), dihydroflavonol 4‐reductase/flavanone 4‐reductase (DFR/FNR) and anthocyanidin synthase (ANS), were isolated from a sinningia cDNA library made from petal RNA and used to measure transcript abundance during petal development. Only very low levels of F3H transcript were detected, while DFR/FNR transcript was highly abundant. ANS transcript levels were intermediate between these two. The F3H cDNA was shown to encode a functional F3H protein by complementation of the phenotype of an Antirrhinum majus F3H mutant. The recombinant DFR/FNR had activity against both flavanone and dihydroflavonol substrates to a comparable extent. The results suggest a mechanism of 3‐deoxyflavonoid biosynthesis in sinningia similar to that reported for Zea mays, in which lack of F3H activity allows action of the DFR/FNR on flavanone substrates and production of flavan‐4‐ols. These are then likely converted to 3‐deoxyanthocyanins through the action of the ANS and subsequent glucosylation.
Nicotine‐free and salt‐tolerant tobacco plants obtained by grafting to salinity‐resistant rootstocks of tomato
Authors: Ruiz Juan M. , Blasco Begoña , Rivero Rosa M. , Romero Luis
Published: July 2005

In this work we present the first study of the behaviour of tobacco plants, under saline conditions, grafted to salinity‐resistant rootstocks of tomato cultivars. To test the viability and efficiency of this grafting technique in tobacco plants subjected to salinity, we analyse the production of foliar biomass and different quality parameters in this crop. With this aim, Nicotiana tabacum cv. Sevilla (scion) was grafted to two cultivars of Lycopersicum esculentum (rootstocks): cv. Jaguar (Sevilla/Jaguar) and cv. Brillante (Sevilla/Brillante). Furthermore, as controls, tobacco plants of cv. Sevilla were used grafted to themselves (Sevilla/Sevilla) and non‐grafted plants of cv. Sevilla. Plants were grafted by needle graft following the procedure described by Rivero RM, Ruiz JM, Romero L (2002) Role of grafting in horticultural plants, pp 229–254. In the present work, we demonstrate that the graft of tobacco scions with tomato rootstocks is an effective agricultural approach to improve production and quality in tobacco leaves under conditions of saline stress. Our results show that the rootstock of the cv. Brillante best induced salt resistance in tobacco cv. Sevilla, registering the lowest foliar concentrations of Na+ and Cl–, the lowest lipid peroxidation and the highest proline and sugar concentrations. Overall, this is reflected in better biomass production of the aerial part of the plant. Finally, it is noteworthy that grafting in tobacco plants to tomato rootstocks essentially eliminates foliar nicotine levels (reduced to 1%). These results are of great importance, as this technique implies a rapid, efficient and natural alternative in increasing tobacco‐leaf quality and thus reducing harmful effects of this alkaloid on the health of smokers.
Physiological responses to drought and shade in two contrasting Picea asperata populations
Authors: Duan Baoli , Lu Yanwei , Yin Chunying , Junttila Olavi , Li Chunyang
Published: July 2005

The responses of photosynthetic gas exchange, chlorophyll fluorescence, activities of antioxidant enzymes and lipid membrane peroxidation of two contrasting Picea asperata Mast. populations to 30% of full sunlight (shade) and full sunlight (sun) were investigated under well‐watered and drought conditions. Two contrasting populations were from the wet and dry climate regions in China, respectively. For both populations tested, drought resulted in lower needle relative water content (RWC), CO2 assimilation rate (A), stomatal conductance (gs) and effective PSII quantum yield (Y), and higher non‐photochemical quenching (qN), superoxide dismutase (SOD), ascorbate peroxidase (APX) activities as well as malondialdehyde (MDA) levels and electrolyte leakage in sun plants, whereas these changes were not significant in shade plants. For the wet climate population, shade plants showed higher chlorophyll contents (Chla, Chlb and Chla + b) than sun plants under both well‐watered and drought conditions. Our study results implied that shade, applied together with drought, ameliorated the detrimental effects of drought. On the other hand, compared with the wet climate population, the dry climate population was more tolerant to drought in the sun treatment, as indicated by less decreases in A and mass‐based leaf nitrogen content (Nmass), more responsive stomata, greater capacity for non‐radiative dissipation of excitation energy as heat (analysed by qN), and higher level of antioxidant enzyme activities as well as lower MDA content and electrolyte leakage. These results demonstrated that the different physiological strategies were employed by the P. asperata populations from contrasting climate regions when the plants were exposed to drought and shade.
Interception of potential adverse drug events in long‐term psychiatric care units
Authors: SAWAMURA KANAE , ITO HIROTO , YAMAZUMI SYUN , KURITA HIROSHI
Published: July 2005

Abstract  The interception of medication errors is required for patient safety. The aim of the present study was to clarify factors associated with the interception of potential adverse drug events in long‐term psychiatric care units. A survey was conducted of medication‐related errors in 132 Japanese long‐term psychiatric care units for 2 months using an incident reporting system. The relationship was analyzed between the reported potential adverse drug events and the characteristics of the units and the staff, as well as those of the patients involved. A multivariate logistic regression analysis was performed with environmental, organizational, and human factors as independent variables to predict the interception of potential adverse drug events. Of the 221 reported incidents, 55 (24.9%) were intercepted before reaching patients. The following patient groups were significantly associated with the failure to intercept potential adverse drug events: patients receiving a relatively large number of tablets, patients with relatively frequent admissions, and patients exposed to a relatively high patient–staff ratio in the evening. In contrast, patients with a diagnosis of schizophrenia were significantly associated with an increased possibility of interception. To intercept more potential adverse drug events, simpler prescriptions are crucial. To improve the current situation, organizational efforts, such as increasing staff in the evening, and educating the staff about medications, will be required, as well as improvements in the medications themselves.
Pharmacoeconomic evaluation of schizophrenia in Taiwan: Model comparison of long‐acting risperidone versus olanzapine versus depot haloperidol based on estimated costs
Authors: YANG YEN KUANG , TARN YENG HUI , WANG TING YING , LIU CHIA‐YIH , LAIO YI‐CHENG , CHOU YUAN‐HWA , LEE SHIN‐MIN , CHEN CHUN‐CHIH
Published: July 2005

Abstract  Antipsychotics are the keystone in schizophrenia treatment. Although the benefits of the new generation of antipsychotics has been demonstrated over the last decade, the issues of patient compliance and higher purchasing price of atypical antipsychotics remain unresolved. Risperidone is the only atypical antipsychotic agent with long‐acting formulation. Long‐acting risperidone is a water‐based injection and it has been associated with a low level of pain. The aim of the present study was to test whether an improvement in compliance with the use of a long‐acting risperidone, compared with olanzapine and depot haloperidol, can increase the effectiveness and the cost‐effectiveness indexes. An economic comparison model with decision tree, rather than a prospective design with real clinical drug trial, was applied. The unit cost for each medical procedure was obtained from the claimed‐database of the Bureau of National Health Insurance in Taiwan. An executive committee simulated the incidence of extrapyramidal side‐effects and proposed a therapeutic model for each strategy based on a literature review. The probabilities of treatment response of different agents and those of different mental health states were estimated by the executive committee and 10 senior psychiatrists who were randomly selected. Sensitivity analysis was performed for drug cost‐effectiveness and compliance improvement for using long‐acting risperidone. The results showed that long‐acting risperidone is more cost‐effective than either olanzapine or depot haloperidol for treating schizophrenia patients whose conditions are stable and whose illness duration ranges from 1 to 5 years. The comparison model with the Kaplan–Meier decision tree may serve as an alternative to prospectively designed studies for cost‐effectiveness of atypical antipsychotics.
Prevalence of insomnia and its relationship to menopausal status in middle‐aged Korean women
Authors: SHIN CHOL , LEE SANGYEOL , LEE TAEWOOK , SHIN KYUNGRIM , YI HYERYEON , KIMM KUCHAN , CHO NAMHAN
Published: July 2005

Abstract  Although the prevalence of insomnia and the association of insomnia with menopause have been well reported, not much work has been conducted in population‐based research on insomnia and menopause in Korea. The purpose of the present report was to determine overall and different prevalence of insomnia by menopausal status, and the relationship between insomnia and menopause in a population‐based sample of middle‐aged Korean women. A total of 96.1% of 2497 randomly selected middle‐aged Korean women participated. Insomnia was defined as occurring three times a week or more in the previous month. Subjects were categorized into three groups: premenopaues, perimenopause, and postmenopause. The overall prevalence of insomnia in middle‐aged Korean women was 14.3%. The most common symptom of insomnia was difficulty maintaining sleep (9.7%), followed by difficulty initiating sleep (7.9%), and early morning awakening (7.5%). Multiple logistic regression analysis revealed that menopause was independently associated with insomnia after adjusting for confounding factors such as age, income, and depression. Perimenopause was significantly associated with a dramatic increase in the risk of insomnia, but there was no significant association for postmenopause. The major finding is that insomnia is significantly associated with the menopausal transition. The prevalence of insomnia increases significantly by the transition from premenopause to perimenopause, but not to postmenopause. A further prospective study is needed to investigate the influence of menopause on insomnia.