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排序方式: 共有93条查询结果,搜索用时 15 毫秒
81.
Walton C Somboon P Harbach RE Zhang S Weerasinghe I O'Loughlin SM Phompida S Sochantha T Tun-Lin W Chen B Butlin RK 《Medical and veterinary entomology》2007,21(1):30-35
The Anopheles annularis group of subgenus Cellia Theobald (Diptera: Culicidae) includes five currently recognized species in southern Asia: An. annularis Van der Wulp, Anopheles nivipes (Theobald) and Anopheles philippinensis Ludlow, which are widespread in the region, Anopheles pallidus Theobald, which is known in Sri Lanka, India and Myanmar, and Anopheles schueffneri Stanton, which occurs in Java and Sumatra. Identification of the four mainland species based on morphology is problematic. In view of the fact that the three widespread species are variously involved in malaria transmission in different parts of the region, we developed a species-specific polymerase chain reaction assay based on rDNA internal transcribed spacer 2 (ITS2) sequences to facilitate entomological and epidemiological studies of the four species. The method proved to be reliable when tested over a wide geographical area. 相似文献
82.
Plasticity of photosynthetic heat tolerance in plants adapted to thermally contrasting biomes 总被引:1,自引:0,他引:1
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Lingling Zhu Keith J. Bloomfield Charles H. Hocart John J.G. Egerton Odhran S. O'Sullivan Aurore Penillard Lasantha K. Weerasinghe Owen K. Atkin 《Plant, cell & environment》2018,41(6):1251-1262
In many biomes, plants are subject to heatwaves, potentially causing irreversible damage to the photosynthetic apparatus. Field surveys have documented global, temperature‐dependent patterns in photosynthetic heat tolerance (P HT); however, it remains unclear if these patterns reflect acclimation in P HT or inherent differences among species adapted to contrasting habitats. To address these unknowns, we quantified seasonal variations in T crit (high temperature where minimal chlorophyll‐a fluorescence rises rapidly, reflecting disruption to photosystem II) in 62 species native to 6 sites from 5 thermally contrasting biomes across Australia. T crit and leaf fatty acid (FA) composition (important for membrane stability) were quantified in three temperature‐controlled glasshouses in 20 of those species. T crit was greatest at hot field sites and acclimated seasonally (summer > winter, increasing on average 0.34 °C per °C increase in growth temperature). The glasshouse study showed that T crit was inherently higher in species from warmer habitats (increasing 0.16 °C per °C increase in origin annual mean maximum temperature) and acclimated to increasing growth temperature (0.24 °C °C?1). Variations in T crit were positively correlated with the relative abundance of saturated FAs, with FAs accounting for 40% of T crit variation. These results highlight the importance of both plastic adjustments and inherent differences determining contemporary continent‐wide patterns in P HT. 相似文献
83.
Champica K. Bodinayake Ajith DeS Nagahawatte Vasantha Devasiri Niroshana J. Dahanayake Gaya B. Wijayaratne Nayani P. Weerasinghe Madureka Premamali Tianchen Sheng Bradley P. Nicholson Harshanie A. Ubeysekera Ruvini MP Kurukulasooriya Aruna D. de Silva Truls
stbye Christopher W. Woods L. Gayani Tillekeratne 《PLoS neglected tropical diseases》2022,16(5)
84.
Jeevaka P Weerasinghe Tao Dong Michael R Schertzberg Mark G Kirchhof Yuan Sun Herb E Schellhorn 《BMC microbiology》2006,6(1):14-12
Background
Arginine biosynthesis in Escherichia coli is elevated in response to nutrient limitation, stress or arginine restriction. Though control of the pathway in response to arginine limitation is largely modulated by the ArgR repressor, other factors may be involved in increased stationary phase and stress expression. 相似文献85.
S Maruyama M Minagawa T Shimizu H Oya S Yamamoto N Musha W Abo A Weerasinghe K Hatakeyama T Abo 《Cellular immunology》1999,194(1):28-35
Glucocorticoids, steroid hormones, are widely used as an anti-inflammatory drug. However, clinicians have sometimes encountered adverse drug reactions such as ulcers and tissue damage. In this study, we investigated how such adverse reactions of glucocorticoids are evoked, using an experimental mice model. When hydrocortisone (0.5 or 1.0 mg/day/mouse) was administered daily for 2 weeks, severe leukocytopenia was induced in all immune system organs. However, granulocytes (Gr-1(+)Mac-1(+)) were increased in number in the bone marrow and peripheral blood. This seemed to be due to an elevated level of myelopoiesis in the bone marrow. As well as increasing in number, granulocytes were functionally activated as estimated by the Ca2+ influx and superoxide production. The proportion of primordial T cells (CD3(int)IL-2Rbeta+) in the thymus and the number of primordial T cells in the bone marrow also increased. Mice administered hydrocortisone became susceptible to stress. Thus, these mice showed gastric ulcers when they were exposed to restraint stress for 12 h. These results suggest that activated granulocytes and primordial T cells might provide a mechanism involved in steroid ulcers and tissue damage, possibly through the superoxide production of granulocytes and the autoreactivity of primordial T cells. 相似文献
86.
Molecular evolution of olfactomedin 总被引:2,自引:0,他引:2
Olfactomedin is a secreted polymeric glycoprotein of unknown function,
originally discovered at the mucociliary surface of the amphibian olfactory
neuroepithelium and subsequently found throughout the mammalian brain. As a
first step toward elucidating the function of olfactomedin, its
phylogenetic history was examined to identify conserved structural motifs.
Such conserved motifs may have functional significance and provide targets
for future mutagenesis studies aimed at establishing the function of this
protein. Previous studies revealed 33% amino acid sequence identity between
rat and frog olfactomedins in their carboxyl terminal segments. Further
analysis, however, reveals more extensive homologies throughout the
molecule. Despite significant sequence divergence, cysteines essential for
homopolymer formation such as the CXC motif near the amino terminus are
conserved, as is the characteristic glycosylation pattern, suggesting that
these posttranslational modifications are essential for function.
Furthermore, evolutionary analysis of a region of 53 amino acids of fish,
frog, rat, mouse, and human olfactomedins indicates that an ancestral
olfactomedin gene arose before the evolution of terrestrial vertebrates and
evolved independently in teleost, amphibian, and mammalian lineages.
Indeed, a distant olfactomedin homolog was identified in Caenorhabditis
elegans. Although the amino acid sequence of this invertebrate protein is
longer and highly divergent compared with its vertebrate homologs, the
protein from C. elegans shows remarkable similarities in terms of conserved
motifs and posttranslational modification sites. Six universally conserved
motifs were identified, and five of these are clustered in the carboxyl
terminal half of the protein. Sequence comparisons indicate that evolution
of the N-terminal half of the molecule involved extensive insertions and
deletions; the C-terminal segment evolved mostly through point mutations,
at least during vertebrate evolution. The widespread occurrence of
olfactomedin among vertebrates and invertebrates underscores the notion
that this protein has a function of universal importance. Furthermore,
extensive modification of its N-terminal half and the acquisition of a
C-terminal SDEL endoplasmic-reticulum- targeting sequence may have enabled
olfactomedin to adopt new functions in the mammalian central nervous
system.
相似文献
87.
88.
AAM Coelho-Castelo AP Trombone RS Rosada RR Santos Jr VLD Bonato A Sartori CL Silva 《Genetic vaccines and therapy》2006,4(1):1-10
In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system. 相似文献
89.
JOACHIM RYCHLY HAGEN POMMERENKE FRIEDA DÜRR ERIK SCHREIBER BARBARA NEBE 《Cell biology international》1998,22(1):7-12
Confocal laser scanning microscopy represents a suitable technique to study the localization of cellular components in three dimension. The authors used this technique to analyse cellular events related to mechanical stimulation of integrin receptors on the cell surface. By performing optical sections the distribution of integrin receptors on the apical surface of an osteoblastic cell was determined. Concerning intracellular compartimentalization of signal transduction events, it was demonstrated that mechanical stimulation of integrins induced their linkage to the cytoskeleton. Cytoskeletally associated proteins like vinculin and talin accumulated in the vicinity of the site where the mechanical stress was applied to integrins on the cell surface. Optical sections revealed that clustering of these proteins proceeded to the base of the cell with gradually decreasing extent. In summary, it was demonstrated that the local distribution of cellular components is an important factor in mechanically induced signal transduction. 相似文献