bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of photosynthetic efficiency and water availability on tolerance of leaf removal inAmaranthus hybridus
Authors: GASSMANN AARON J. 
Published: September 2004

SummaryAlthough substantial genetic variation in photosynthetic rate exists within natural populations, it is unclear how such variation might affect the capacity of plants to tolerate herbivore damage.I tested if decreased efficiency of electron transport, caused by a mutation that confers resistance to the herbicide triazine, affected the ability ofAmaranthus hybridusto tolerate leaf removal, and if this genotypic effect interacted with water availability.Tolerance levels were compared with the root‐to‐shoot ratio and with compensatory photosynthesis, to investigate the mechanisms of tolerance.Triazine‐resistantA. hybriduswas found to have lower tolerance to herbivory suggesting that herbivores should drive selection for higher photosynthetic capacity.Although interactive effects between water availability and photosynthetic genotype were not detected, reduced water availability did cause an overall increase in the ability of plants to tolerate damage.Greater tolerance of plants under low water availability and of the TS genotype was associated positively with root‐to‐shoot ratios, but there was a negative association between greater tolerance under low water availability and compensatory photosynthesis.These results suggest that photosynthetic variation is more likely to alter tolerance indirectly though changes in resource allocation, and that direct associations between physiological variables and tolerance may be uncommon in natural systems.
Is tolerance to summer flooding correlated with distribution patterns in river floodplains? A comparative study of 20 terrestrial grassland species
Authors: Van Eck W. H. J. M. , Van De Steeg H. M. , Blom C. W. P. M. , De Kroon H. 
Published: September 2004

It is generally assumed that floods during the growing season have a strong impact on the distribution of grassland plant species in river floodplains but this proposition has never been tested. We examined the survival and growth responses of twenty species, originating from mid‐ and high‐level floodplain grasslands along the River Rhine in the Netherlands, to total submergence for a maximum of two months in an outdoor flooding experiment. Plant survival and biomass reduction with flooding duration was determined as well as biomass recovery after de‐submergence.Our results indicate that species survival is the most prominent factor correlated with species distribution in floodplain areas. Relatively flood tolerant species occurred mainly at low elevations along the floodplain while more flood sensitive species were restricted to high parts of the floodplain gradient. Biomass reduction rates during submergence were only marginally significantly correlated with species lower distribution boundaries along the flooding gradient. Biomass recovery rate was significantly correlated with species distribution patterns in the field only after 2 weeks of complete submergence, but not after 4 and 8 weeks. Our results suggest that the more flood tolerant species can have various ways to survive and recover from flooding, ranging from low rates of biomass loss and low recovery to relatively high rates of biomass loss and quick recovery.Our results are consistent with the notion that disturbance by floods during the growing season is an important determinant of species lower distribution boundaries in river floodplains. They also suggest that high survival under flooding may be achieved by different physiological mechanisms. Such mechanisms are discussed in this paper.
A secondary structural model of the 28S rRNA expansion segments D2 and D3 from rootworms and related leaf beetles (Coleoptera: Chrysomelidae; Galerucinae)
Authors: Gillespie J. , Cannone J. , Gutell R. , Cognato A. 
Published: September 2004

AbstractWe analysed the secondary structure of two expansion segments (D2, D3) of the 28S rRNA gene from 229 leaf beetles (Coleoptera: Chrysomelidae), the majority of which are in the subfamily Galerucinae. The sequences were compared in a multiple sequence alignment, with secondary structure inferred primarily from the compensatory base changes in the conserved helices of the rRNA molecules. This comparative approach yielded thirty helices comprised of base pairs with positional covariation. Based on these leaf beetle sequences, we report an annotated secondary structural model for the D2 and D3 expansion segments that will prove useful in assigning positional nucleotide homology for phylogeny reconstruction in these and closely related beetle taxa. This predicted structure, consisting of seven major compound helices, is mostly consistent with previously proposed models for the D2 and D3 expansion segments in insects. Despite a lack of conservation in the primary structure of these regions of insect 28S rRNA, the evolution of the secondary structure of these seven major motifs may be informative above the nucleotide level for higher‐order phylogeny reconstruction of major insect lineages.
Expression of a sterol carrier protein‐x gene in the Yellow fever mosquito, Aedes aegypti
Authors: Lan Q. , Wessely V. 
Published: September 2004

AbstractThe sterol carrier protein‐x (SCP‐x), a peroxisomal thiolase/nonspecific lipid binding protein, was characterized in the yellow fever mosquito, Aedes aegypti. The Aedes aegypti SCP‐x (AeSCP‐x) has 83% and 75% similarities to Drosophila and mammalian SCP‐x, respectively. However, the AeSCP‐x gene did not produce multiple transcripts, which is characteristic of the vertebrate SCP‐x gene. Levels of AeSCP‐x transcription were higher in larvae and pupae. Gut tissue showed the highest level of AeSCP‐x mRNA in larvae. In adults, low levels of AeSCP‐x transcription were detected in both sexes. Polyclonal antibodies against the sterol carrier protein‐2 (SCP‐2) domain of AeSCP‐x detected two proteins of 62 kDa and 13 kDa. The results indicate that AeSCP‐x is proteolytically cleaved after translation to produce a smaller protein that contains only the SCP‐2 domain, which is similar to post‐translational modification of the vertebrate's SCP‐x to produce multiple products.
Identification of mutations conferring insecticide‐insensitive AChE in the cotton‐melon aphid, Aphis gossypii Glover
Authors: Andrews M. C. , Callaghan A. , Field L. M. , Williamson M. S. , Moores G. D. 
Published: September 2004

AbstractWe have identified two mutations in the ace1 gene of Aphis gossypii that are associated with insensitivity of acetylcholinesterase (AChE) to carbamate and organophosphate insecticides. The first of these, S431F (equivalent to F331 in Torpedo californica), is associated with insensitivity to the carbamate insecticide pirimicarb in a range of A. gossypii clones. The S431F mutation is also found in the peach‐potato aphid, Myzus persicae (Sulzer), and a rapid RFLP diagnostic allows the identification of individuals of both aphid species with a resistant genotype. This diagnostic further revealed the presence of S431 in several other pirimicarb‐susceptible aphid species. The serine at this position in the wild‐type enzyme has only been reported for aphids and provides a molecular explanation of why pirimicarb has a specific aphicidal action. A less specific insensitivity to a wide range of carbamates and organophosphates is associated with a second mutation, A302S (A201 in T. californica).
Emergency cricothyrotomy: a randomised crossover trial comparing the wire‐guided and catheter‐over‐needle techniques
Authors: Fikkers B. G. , Van Vugt S. , Van Der Hoeven J. G. , Van Den Hoogen F. J. A. , Marres H. A. M. 
Published: September 2004

SummaryIn a randomised crossover trial, we compared a wire‐guided cricothyrotomy technique (Minitrach) with a catheter‐over‐needle technique (Quicktrach). Performance time, ease of method, accuracy in placement and complication rate were compared. Ten anaesthesiology and 10 ENT residents performed cricothyrotomies with both techniques on prepared pig larynxes. The catheter‐over‐needle technique was faster than the wire‐guided (48 compared to 150 s, p < 0.001) and subjectively easier to perform (VAS‐score 2.1 vs. 5.6, p < 0.001). Correct positioning of the cannula could be achieved in 95% and 85%, respectively (NS). There was one complication in the catheter‐over‐needle group compared to five in the wire‐guided group. We conclude that the wire‐guided minitracheotomy kit is unsuitable for emergency cricothyrotomies performed by inexperienced practitioners. On the other hand, the catheter‐over‐needle technique appears to be quick, safe and reliable.
A homemade model for training in cricothyrotomy*
Authors: Varaday S. S. , Yentis S. M. , Clarke S. 
Published: September 2004

SummaryWe describe a simple, homemade model for teaching cricothyrotomy. It can easily be constructed from materials found in every anaesthetic room and is cheap, portable and usable several times before requiring replacement. We also describe evaluation of the model in a two‐part study. First, 20 anaesthetic trainees, both with and without prior experience of percutaneous cricothyrotomy/tracheotomy, cannulated the ‘trachea’ using two percutaneous airway sets (Ravussin jet ventilation catheter®[VBM] and Mini‐Trach II Seldinger®[Portex]), then scored the model for realism and usefulness for training. Next, 20 further trainees used the Mini‐Trach II Seldinger on both the homemade model and a commercially available cricothyrotomy/tracheotomy trainer (Pharmabotics), scoring both models as before. In the first part of the study, trainees found the homemade model a useful substitute for practice of percutaneous techniques and teaching. In the second part, both models were rated well, with similar scores. The homemade model is an easily assembled alternative to more expensive models. Both experienced and inexperienced trainees find practising on such models useful.
Ultrasound guidance for a lateral approach to the sciatic nerve in the popliteal fossa
Authors: McCartney C. J. L. , Brauner I. , Chan V. W. S. 
Published: September 2004

SummaryDescriptions of the use of ultrasound for nerve location have focused on upper limb blocks. We present a case in which ultrasound imaging was used for a lateral approach to the sciatic nerve in the popliteal fossa. Ultrasound images taken proximal to the popliteal crease showed tibial and common peroneal nerves as round hyperechoic structures superficial and lateral to the tibial artery. Under direct ultrasound guidance, we placed a block needle close to the tibial nerve and confirmed its position with nerve stimulation. Injected local anaesthetic was seen on ultrasound as it spread around both tibial and common peroneal nerves.
Nucleotide diversity on the ovine Y chromosome
Authors: Meadows J. R. S. , Hawken R. J. , Kijas J. W. 
Published: September 2004

SummaryTo investigate the impact of male‐mediated introgression during the evolution of sheep breeds, a sequencing approach was used to identify single nucleotide polymorphisms (SNPs) from the male‐specific region of the ovine Y chromosome (MSY). A total of 4380 bp, which comprised nine fragments from five MSY genes was sequenced within a panel of 14 males from seven breeds. Sequence alignment identified a single segregating site, an A/G SNP located approximately 1685 bp upstream of the ovineSRYgene. The resulting estimation of nucleotide diversity (πY = 0.90 ± 0.50 × 10−4) falls towards the lower end of estimates from other species. This was compared with the nucleotide diversity estimated from the autosomal component of the genome. Sequence analysis of 2933 bp amplified from eight autosomal genes revealed a nucleotide diversity (πA = 2.15 ± 0.27 × 10−3) higher than previously reported for sheep. Following adjustment for the contrasting influence of effective population size and a male biased mutation rate, comparison revealed that approximately 10% of the expected nucleotide diversity is present on the ovine Y chromosome.
A melanocortin‐4 receptor (MC4R) polymorphism is associated with performance traits in divergently selected large white pig populations
Authors: Houston R. D. , Cameron N. D. , Rance K. A. 
Published: September 2004

Summary The melanocortin‐4 receptor (MC4R) has a vital role in the control of energy balance and the genetic basis of obesity. A polymorphism, which results in the replacement of aspartic acid with asparagine at position 298 of the porcine MC4R gene, within the seventh transmembrane domain, has previously been described. In the current study, allele frequencies for this Asp298Asn polymorphism were investigated in lines of Large White pigs which had been divergently selected for seven generations based on lean food conversion (LFC), lean growth with ad libitum feeding (LGA), lean growth with restricted feeding (LGS) and daily feed intake (DFI). The association of the Asp298Asn polymorphism with performance traits in these lines was assessed. The frequency of Asp298 was higher (P < 0.001) in the LFC high line (0.48) than the low line (0.00), while the frequency of Asn298 was higher (P < 0.01) in the LGA high line (0.22) than the low line (0.04). When analysed across all lines, the Asp298Asn polymorphism was significantly associated with ultrasonic backfat depth, average daily gain and daily feed intake (P < 0.05). Asp298 homozygous animals had mean values of 13.3 mm, 733 g and 1933 g for backfat, average daily gain and daily feed intake respectively, compared with 14.7 mm, 805 g and 2098 g for Asn298 homozygotes. Therefore, the data support a role for the MC4R Asp298Asn polymorphism in the genetic basis of economically important traits in Large White pigs.
Microarray analysis of human milk cells: persistent high expression of osteopontin during the lactation period
Authors: NAGATOMO T , OHGA S , TAKADA H , NOMURA A , HIKINO S , IMURA M , OHSHIMA K , HARA T 
Published: September 2004

SUMMARYTo continue the search for immunological roles of breast milk, cDNA microarray analysis on cytokines and growth factors was performed for human milk cells. Among the 240 cytokine-related genes, osteopontin (OPN) gene ranked top of the expression. Real-time PCR revealed that the OPN mRNA levels in colostrum cells were approximately 100 times higher than those in PHA-stimulated peripheral blood mononuclear cells (PBMNCs), and 10 000 times higher than those in PB CD14+ cells. The median levels of OPN mRNA in early milk or mature milk cells were more than three times higher than those in colostrum cells. Western blot analysis of human milk showed appreciable expression of full-length and short form proteins of OPN. The concentrations of full-length OPN in early milk or mature milk whey continued to be higher than those in colostrum whey and plasma as assessed by ELISA. The early milk (3–7 days postpartum) contained the highest concentrations of OPN protein, while the late mature milk cells (1 years postpartum) had the highest expression of OPN mRNA of all the lactating periods. The results of immunohistochemical and immunocytochemical staining indicated that OPN-producing epithelial cells and macrophages are found in actively lactating mammary glands. These results suggest that the persistently and extraordinarily high expression of OPN in human milk cells plays a potential role in the immunological development of breast-fed infants.
Anti-myeloperoxidase antibodies in sera from patients with propylthiouracil-induced vasculitis might recognize restricted epitopes on myeloperoxidase molecule
Authors: YE H , ZHAO M-H , GAO Y , GUO X-H , WANG H-Y 
Published: September 2004

SUMMARY
Myeloperoxidase (MPO) is one of the major target antigens of antineutrophil cytoplasmic antibodies (ANCA) in primary systemic vasculitis. It is known that propylthiouracil (PTU) could induce MPO–ANCA-positive vasculitis. The production of anti-MPO antibodies in patients with PTU-induced vasculitis may be different from that in patients with primary microscopic polyangiitis (MPA). One possible reason for this may be differences in epitope recognition. The aim of this study is to compare the epitopes of antibodies to MPO in sera from patients with PTU-induced vasculitis (n = 10) and MPA (n = 10). The sera were collected and used to inhibit monoclonal antibodies against human MPO (3D8 and 6B9) and affinity purified, horseradish peroxidase conjugated human anti-MPO antibodies (Pab1-HRP, Pab2-HRP) in a competitive inhibition enzyme-linked immunosorbent assay (ELISA) system using soluble human MPO as solid phase ligand. The Pab1-HRP and Pab2-HRP were affinity purified from plasma exchanges of a patient with PTU-induced vasculitis and a patient with MPA, respectively. The inhibition rates were evaluated and compared between the PTU and primary MPA groups. In the PTU group all 10 sera could inhibit 3D8: the average inhibition rate was 44.7% ± 5.0%; 9/10 sera could inhibit 6B9: the average inhibition rate was 35.6% ± 6.0%. However, in the MPA group all 10 sera could inhibit 3D8 and 6B9; the average inhibition rates were 68.4% ± 16.1% (P &lt; 0.01) and 62.2% ± 17.2% (P &lt; 0.01), respectively. Sera in both the PTU and MPA groups could inhibit Pab1-HRP and the inhibition rates were 81.4% ± 9.4%versus 86.6% ± 17.2% (P &gt; 0.05). However, the average inhibition rate for Pab2-HRP in the MPA group was significantly higher than that in the PTU group (76.3% ± 7.8%versus 58.9% ± 15.5%, P &lt; 0.01). We conclude that anti-MPO antibodies from patients with PTU-induced vasculitis and from patients with primary MPA could recognize more than one epitope on the native MPO molecule. Although the epitopes overlapped between the two groups, the epitopes of anti-MPO antibodies from patients with PTU-induced vasculitis might be more restricted.
Multiple loci are linked with anti-red blood cell antibody production in NZB mice−comparison with other phenotypes implies complex modes of action
Authors: LEE N J , RIGBY R J , GILL H , BOYLE J J , FOSSATI-JIMACK L , MORLEY B J , VYSE T J 
Published: September 2004

SUMMARYThe New Zealand Black (NZB) mouse strain is a model of autoimmune haemolytic anaemia (AHA) and systemic lupus erythematosus (SLE), characterized by the production of anti-red blood cell (RBC) antibodies and anti-nuclear antibodies (ANA), respectively. A linkage analysis was carried out in an (NZB × BALB/c) F2 cross in order to identify loci involved in the production of both anti-RBC IgM and IgG antibodies. These regions of linkage were compared with linkage data to ANA from the same cohort and other linkage analyses involving New Zealand mice. Four previously described NZB loci linked to anti-RBC antibodies were confirmed, and eight novel loci linked to this trait were also mapped: five of which were of NZB origin, and three derived from the non-autoimmune BALB/c background. A comparison between loci linked with anti-RBC antibodies and ANA demonstrated many that co-localize, suggesting the presence of genes that result in the general breaking of tolerance to self-antigen. Furthermore, the observation that some loci were associated only with the anti-RBC response suggests an antigen specific mechanism in addition to a general breaking of tolerance. A locus linked with anti-RBC antibodies and ANA on distal chromosome 7 in this cohort is orthologous to one on the q arm of human chromosome 11, a region linked to AHA and ANA in human SLE.
Up-regulation of IL-18 and predominance of a Th1 immune response is a hallmark of lupus nephritis
Authors: CALVANI N , RICHARDS H B , TUCCI M , PANNARALE G , SILVESTRIS F 
Published: September 2004

SUMMARYThere is evidence that nephritis is dominated by a Th1 immune response in systemic lupus erythematosus. Since IL-18 promotes polarization of the immune response toward Th1, we investigated the role of this cytokine in lupus nephritis (LN). A total of 133 lupus patients and 44 healthy subjects were enrolled. Demographic and clinical characteristics with renal biopsy data were recorded. IL-18 along with IFN-γ and IL-4, two prototypical of Th1 and Th2 cytokines, were measured in serum by ELISA. Peripheral blood lymphocytes were analysed by flow cytometry for IFN-γ and IL-4. IL-18 expression was determined by immunohistochemistry in 13 renal biopsy specimens from patients with LN and 2 controls. Serum IL-18 was higher in lupus patients than in controls. Levels of IL-18 correlated with urinary microalbumin and were increased in patients with LN when compared to those without LN. IL-18 expression was also increased within the glomeruli of nephritic patients and was primarily detected within the mesangial matrix and in infiltrating mononuclear cells. Measurement of IFN-γ and IL-4 in either sera or peripheral blood lymphocytes showed high IFN-γ along with low IL-4 expression in LN patients compared to patients without nephritis. A positive correlation between serum IL-18 and IFN-γ levels was found. IL-18 may play a prominent role in the pathogenesis of LN by promoting a cytokine imbalance towards a Th1 immune response. Measurement of IL-18 may be helpful for the early identification of lupus patients with LN and may help gauge the response to treatment in patients with active LN undergoing treatment.
Persistent HIV-1 replication does not explain low levels of T-cell interferon-γmRNA and elevated serum NO2–/NO3– in patients with stable CD4 T-cell responses to HAART
Authors: LEE S , ALMEIDA C-A , FRENCH M A H , PRICE P 
Published: September 2004

SUMMARYHIV-1 infected patients adherent to HAART and displaying stable increases in CD4 T-cell counts differ in their control of HIV replication and one might expect this to reflect depressed immune function. The importance of virological control in functional immune reconstitution was investigated in HIV-1 infected patients who maintained high or undetectable plasma HIV RNA levels over 2–4 years on HAART (discordant and complete responders, respectively). Immunocompetance and immune activation were assessed directly ex vivo and after a short period of culture, as HIV replication in cultures from viraemic patients may artificially depress responses. Expression of cytokine (interferon-γ, interleukin-5) and chemokine receptor (CCR5, CRTH2) mRNA were determined and soluble CD30 and NO2–/NO3– were measured in sera. Unstimulated cells from all patients had low levels of IFNγ mRNA relative to uninfected controls. Discordant responders had more IFNγ, IL-5 and CCR5 mRNA in mitogen-stimulated PBMC than complete responders, where the difference could be attributed to CD8-T-cells. Serum NO2–/NO3– levels were significantly higher in all patients than controls, with no difference between complete and discordant responders. Serum CD30 levels were significantly higher in discordant responders. These data indicate a persistent immune deficit in immune reconstituted patients irrespective of HIV viral load and associate persistent viral replication with lymphocyte activation, probably involving CD8 T-cells.
Human endogenous retroviruses: transposable elements with potential?
Authors: NELSON P N , HOOLEY P , RODEN D , DAVARI EJTEHADI H , RYLANCE P , WARREN P , MARTIN J , MURRAY P G 
Published: September 2004

SUMMARYHuman endogenous retroviruses (HERVs) are a significant component of a wider family of retroelements that constitute part of the human genome. These viruses, perhaps representative of previous exogenous retroviral infection, have been integrated and passed through successive generations within the germ line. The retention of HERVs and isolated elements, such as long-terminal repeats, could have the potential to harm. In this review we describe HERVs within the context of the family of known transposable elements and survey these viruses in terms of superantigens and molecular mimics. It is entirely possible that these mechanisms provide the potential for undesired immune responses.