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排序方式: 共有873条查询结果,搜索用时 703 毫秒
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Koki Tokunaga Yoichiro Takami Kumiko Mera Chika Nishida Yozo Yoshimine Mayumi Fukumoto Manei Oku Atsushi Sogabe Tsuyoshi Nosaki Akihiro Moriuchi Makoto Oketani Akio Ido Hirohito Tsubouchi 《Biochemical and biophysical research communications》2010,399(2):144-149
The mechanisms underlying the pathogenesis of immunoglobulin A (IgA) nephropathy (IgAN) are not well understood. In this study, we examined gene expression profiles in kidneys obtained from mice with high serum IgA levels (HIGA mice), which exhibit features of human IgAN. Female inbred HIGA, established from the ddY line, were used in these experiments. Serum IgA levels, renal IgA deposition, mesangial proliferation, and glomerulosclerosis were increased in 32-week-old HIGA mice in comparison to ddY animals. By microarray analysis, five genes were observed to be increased by more than 2.5-fold in 32-week-old HIGA in comparison to 16-week-old HIGA; these same five genes were decreased more than 2.5-fold in 32-week-old ddY in comparison to 16-week-old ddY mice. Of these five genes, insulin-like growth factor (IGF) binding protein (IGFBP)-1 exhibited differential expression between these mouse lines, as confirmed by quantitative RT-PCR. In addition, serum IGFBP-1 levels were significantly higher in patients with IgAN than in healthy controls. In patients with IgAN, these levels correlated with measures of renal function, such as estimated glomerular filtration rate (eGFR), but not with sex, age, serum IgA, C3 levels, or IGF-1 levels. Pathologically, serum IGFBP-1 levels were significantly associated with the severity of renal injury, as assessed by mesangial cell proliferation and interstitial fibrosis. These results suggest that increased IGFBP-1 levels are associated with the severity of renal pathology in patients with IgAN. 相似文献
205.
This article traces a critical change in the professional therapy of posttraumatic stress disorder (PTSD): from treatment
of a disorder borne by individuals to treatment of an anticipated disorder to be prevented by fortifying the entire population.
A community resilience program in the city of Sderot in southern Israel, which has been subjected to Qassam rockets by its
Palestinian neighbors across the border, serves as our case study. Drawing on an ethnographic study of this new therapeutic
program, we analyze how the social body that the professionals attempt to immunize against trauma was treated. In particular,
we follow the various practices used to expand the clinical. We found that the population was split into several groups on
a continuum between the clinical and the preclinical, each receiving different treatment. Moreover, the social body managed
according to this new form of PTSD was articulated through ethnic and geopolitical power relations between professionals from
the country’s center and professionals from its periphery, and between the professionals and the city’s residents. Finally,
we discuss how this Israeli case compares with other national sites of the growing globalization of PTSD, like Bali, Haiti
and Ethiopia, which anthropologists have been exploring in recent years. 相似文献
206.
The filamentous cyanobacterium Microcoleus vaginatus, a major primary producer in desert biological sand crusts, is exposed to frequent hydration (by early morning dew) followed by desiccation during potentially damaging excess light conditions. Nevertheless, its photosynthetic machinery is hardly affected by high light, unlike “model” organisms whereby light-induced oxidative stress leads to photoinactivation of the oxygen-evolving photosystem II (PSII). Field experiments showed a dramatic decline in the fluorescence yield with rising light intensity in both drying and artificially maintained wet plots. Laboratory experiments showed that, contrary to “model” organisms, photosynthesis persists in Microcoleus sp. even at light intensities 2–3 times higher than required to saturate oxygen evolution. This is despite an extensive loss (85–90%) of variable fluorescence and thermoluminescence, representing radiative PSII charge recombination that promotes the generation of damaging singlet oxygen. Light induced loss of variable fluorescence is not inhibited by the electron transfer inhibitors 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), 2,5-dibromo-3-methyl-6-isopropylbenzoquinone (DBMIB), nor the uncoupler carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), thus indicating that reduction of plastoquinone or O2, or lumen acidification essential for non-photochemical quenching (NPQ) are not involved. The rate of QA
− re-oxidation in the presence of DCMU is enhanced with time and intensity of illumination. The difference in temperatures required for maximal thermoluminescence emissions from S2/QA
− (Q band, 22°C) and S2,3/QB
− (B band, 25°C) charge recombinations is considerably smaller in Microcoleus as compared to “model” photosynthetic organisms, thus indicating a significant alteration of the S2/QA
− redox potential. We propose that enhancement of non-radiative charge recombination with rising light intensity may reduce harmful radiative recombination events thereby lowering 1O2 generation and oxidative photodamage under excess illumination. This effective photo-protective mechanism was apparently lost during the evolution from the ancestor cyanobacteria to the higher plant chloroplast. 相似文献
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Prospecting in a solitary breeder: chick production elicits territorial intrusions in common loons 总被引:2,自引:0,他引:2
Piper Walter H.; Walcott Charles; Mager John N. III; Perala Margaret; Tischler Keren B.; Harrington Erin; Turcotte Amy J.; Schwabenlander Marc; Banfield Nathan 《Behavioral ecology》2006,17(6):881-888
In many species, young animals learn about various breedingpatches in one year and use what they have learned to settlein a promising patch the next. Common loons (Gavia immer) seemgood candidates for such prospecting as prebreeders and displacedbreeders intrude frequently into breeding territories defendedby monogamous pairs yet engage in no extrapair copulations.We tested 3 hypotheses for prospecting in loons. The permanentattributes hypothesis gained little support as we found no consistentdifferences in quality between territories and no physical orbiotic trait that predicted reproductive success in a territory.We found some support for the conspecific attraction hypothesisas intruders were attracted to conspecifics in a lake in theshort term; however, intrusions were not more frequent in territoriesthat had experienced regular use by a pair the previous yearthan in territories that had previously been vacant. Instead,the increase in intrusion rate after a year of chick productionsupported the habitat-copying hypothesis, which states thatfloaters use the presence of chicks as a cue to target territoriesfor future attempts at territorial takeover. Despite this systemof prospecting, founding of new territories was common. Onestriking finding was the tendency of territorial breeders toconceal chicks from flying intruders, perhaps to avoid futureterritorial takeover. 相似文献
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Persister cells and tolerance to antimicrobials 总被引:26,自引:0,他引:26
Bacterial populations produce persister cells that neither grow nor die in the presence of microbicidal antibiotics. Persisters are largely responsible for high levels of biofilm tolerance to antimicrobials, but virtually nothing was known about their biology. Tolerance of Escherichia coli to ampicillin and ofloxacin was tested at different growth stages to gain insight into the nature of persisters. The number of persisters did not change in lag or early exponential phase, and increased dramatically in mid-exponential phase. Similar dynamics were observed with Pseudomonas aeruginosa (ofloxacin) and Staphylococcus aureus (ciprofloxacin and penicillin). This shows that production of persisters depends on growth stage. Maintaining a culture of E. coli at early exponential phase by reinoculation eliminated persisters. This suggests that persisters are not at a particular stage in the cell cycle, neither are they defective cells nor cells created in response to antibiotics. Our data indicate that persisters are specialized survivor cells. 相似文献