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排序方式: 共有491条查询结果,搜索用时 31 毫秒
101.
Kang Wang Shuling You Hesheng Hu Xiaolu Li Jie Yin Yugen Shi Lei Qi Pingjiang Li Yuepeng Zhao Suhua Yan 《Journal of cellular and molecular medicine》2022,26(10):2959
Sympathetic activation after myocardial infarction (MI) leads to ventricular arrhythmias (VAs), which can result in sudden cardiac death (SCD). The toll‐like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor‐kappa B (NF‐kB) axis within the hypothalamic paraventricular nucleus (PVN), a cardiac‐neural sympathetic nerve centre, plays an important role in causing VAs. An MI rat model and a PVN‐TLR4 knockdown model were constructed. The levels of protein were detected by Western blotting and immunofluorescence, and localizations were visualized by multiple immunofluorescence staining. Central and peripheral sympathetic activation was visualized by immunohistochemistry for c‐fos protein, renal sympathetic nerve activity (RSNA) measurement, heart rate variability (HRV) analysis and norepinephrine (NE) level detection in serum and myocardial tissue measured by ELISA. The arrhythmia scores were measured by programmed electrical stimulation (PES), and cardiac function was detected by the pressure–volume loop (P‐V loop). The levels of TLR4 and MyD88 and the nuclear translocation of NF‐kB within the PVN were increased after MI, while sympathetic activation and arrhythmia scores were increased and cardiac function was decreased. However, inhibition of TLR4 significantly reversed these conditions. PVN‐mediated sympathetic activation via the TLR4/MyD88/NF‐kB axis ultimately leads to the development of VAs after MI. 相似文献
102.
Jessica R. Murray Monika E. Stanciauskas Tejas S. Aralere Margaret S. Saha 《Journal of visualized experiments : JoVE》2014,(88)
The zebra finch (Taeniopygiaguttata) has become an increasingly important model organism in many areas of research including toxicology1,2, behavior3, and memory and learning4,5,6. As the only songbird with a sequenced genome, the zebra finch has great potential for use in developmental studies; however, the early stages of zebra finch development have not been well studied. Lack of research in zebra finch development can be attributed to the difficulty of dissecting the small egg and embryo. The following dissection method minimizes embryonic tissue damage, which allows for investigation of morphology and gene expression at all stages of embryonic development. This permits both bright field and fluorescence quality imaging of embryos, use in molecular procedures such as in situ hybridization (ISH), cell proliferation assays, and RNA extraction for quantitative assays such as quantitative real-time PCR (qtRT-PCR). This technique allows investigators to study early stages of development that were previously difficult to access. 相似文献
103.
Patterns of increment width and strontium: calcium ratios in otoliths of juvenile rock blackfish, Girella elevata (M.) 总被引:1,自引:0,他引:1
Otoliths of juvenile Girella elevata (M.) were examined to obtain information about the environmental conditions experienced during early life. Patterns of increment deposition and elemental ratios in otoliths were compared in wild fish. A tetracycline experiment indicated that increments were deposited daily in juveniles. Although different patterns in the spacing of increments were found among juveniles collected at different locations and times, the widest increments were always found in the first 40 increments. Strontium: calcium (Sr: Ca) ratios increased with age in the otoliths of most wild G. elevata .
The patterns of increment width and Sr: Ca ratios were not related and, therefore, were probably not under the same relative control by environmental or physiological factors. Although the number of increments can be used to age juvenile G. elevata , the utility of increment widths and Sr: Ca ratios as environmental predictors in this species is questionable without experimental validation. 相似文献
The patterns of increment width and Sr: Ca ratios were not related and, therefore, were probably not under the same relative control by environmental or physiological factors. Although the number of increments can be used to age juvenile G. elevata , the utility of increment widths and Sr: Ca ratios as environmental predictors in this species is questionable without experimental validation. 相似文献
104.
Ana Luiza A. Siebra Larissa R. Oliveira Anita O.B.P.B. Martins David C. Siebra Rosimeire S. Albuquerque Izabel Cristina Santiago Lemos Gyllyandeson A. Delmondes Saulo R. Tintino Fernando G. Figueredo Jose Galberto M. da Costa Henrique D.M. Coutinho Irwin R.A. Menezes Cicero F.B. Felipe Marta R. Kerntopf 《Saudi Journal of Biological Sciences》2018,25(1):37-43
The development of new drugs from plants is an interesting alternative approach to overcoming microbial resistance. Passiflora cincinnata shows resistance to diseases and pests and a higher concentration of chemical components that may be useful in the pharmaceutical industry. We investigated the potential antimicrobial and antibiotic-modifying activity of hydroalcoholic extracts of leaves, stems, bark, pulp and seeds of P. cincinnata. The extracts were prepared by homogenization of material in 50% ethanol. Minimum inhibitory concentration (MIC) was determined by the broth dilution method, and the bacterial strains tested were Staphylococcus aureus and Escherichia coli. Antibiotic-modifying activity was evaluated against the strains S. aureus 03 and E. coli 08, using a subinhibitory concentration of extract. The antibiotics tested were: amikacin, gentamicin, ampicillin, potassium benzylpenicillin and oxacillin. The extracts did not show antimicrobial activity of clinical relevance, where the MIC was equal to or greater than 1024 μg/mL. S. aureus showed 13 events, while E. coli showed only 4 events. Among these events, 14 involved synergistic activity, potentiating the effect of the antibiotics, and only 3 events demonstrated antagonistic activity toward ampicillin. Hydroalcoholic extracts are potential antimicrobial agents when combined with conventional drugs little utilized in in vivo treatment. 相似文献
105.
106.
Khaddouj Benmoussa Johan Garaude Rebeca Acín-Pérez 《Journal of molecular biology》2018,430(21):3906-3921
Metabolic reprogramming of cells from the innate immune system is one of the most noteworthy topics in immunological research nowadays. Upon infection or tissue damage, innate immune cells, such as macrophages, mobilize various immune and metabolic signals to mount a response best suited to eradicate the threat. Current data indicate that both the immune and metabolic responses are closely interconnected. On account of its peculiar position in regulating both of these processes, the mitochondrion has emerged as a critical organelle that orchestrates the coordinated metabolic and immune adaptations in macrophages. Significant effort is now underway to understand how metabolic features of differentiated macrophages regulate their immune specificities with the eventual goal to manipulate cellular metabolism to control immunity. In this review, we highlight some of the recent work that place cellular and mitochondrial metabolism in a central position in the macrophage differentiation program. 相似文献
107.
Effect of transmembrane Ca2+ gradient on the coupling of β-adrenergic receptors and adenylyl cyclase
In order to investigate the effect of transmembrane Ca2+ gradient on Gs mediated coupling of -AR and adenylyl cyclase, -AR from duck erythrocytes and Gs and adenylyl cyclase from bovine brain cortices were co-reconstituted into asolectin liposomes with different transmembrane Ca2+ gradient. These proteoliposomes were proven to be impermeable to water-soluble substances. The results obtained indicate that a physiological transmembrane Ca2– gradient (1000-fold) is essential for higher stimulation of adenylyl cyclase by hormone-activated -AR via coupling to Gs and can be further enhanced by the decrease of such Ca2+ gradient within certain range (100 fold) following Ca2+ influx into cells during signal transduction. Fluorescence polarization of DPH revealed that transmembrane Ca2+ gradient modulates adenylyl cyclase and its stimulation by hormones through mediating a change in lipid fluidity. Correspondent conformational changes of -AR were also detected from the fluorescence spectra and quenching of Acrylodan-labelled -AR in those proteoliposomes. It is suggested that a proper transmembrane Ca2+ gradient is essential for the optimal fluidity of the phospholipid bilayer in the proteoliposomes, which favors the formation of a suitable conformation of the reconstituted -AR and thus promotes the stimulation of adenylyl cyclase activities by hormone-activated -AR via Gs.Abbreviations ATP
adenosine triphosphate
- -AR
-adrenergic receptors
- AC
adenylyl cyclase
- DHA
dihydroalprenolol
- DPH
diphenylhexatriene
- [Ca2+]i
Ca2+ concentration inside proteoliposomes
- [Ca2+]o
Ca2+ concentration outside proteoliposomes
- cAMP
cyclic adenosine monophosphate
- DTT
Dithiothreitol
- FS
fluorescein sulfonate
- Gs
Stimulatory GTP-binding protein
- GTP
guanosine triphosphate
- GTPS
guanosine 5-O-(3-thiotriphosphate)
- kDa
kilodalton
- SDS
sodium dodecyl sulfate
- Tris
N-tris(hydroxymethyl)aminomethane 相似文献
108.
Pascal Reboul Pascal George Delphine Miquel Pierre Louisot Pierre Broquet 《Glycoconjugate journal》1996,13(1):69-79
When treated with retinoic acidin vivo, C6 glioma cells show an enhancement of CMP-Neu5Ac:Gal 1–3 GalNAc-R -2,3 sialyltransferase activity. A 300kDa glycoprotein was detected by lectin affinoblotting in retinoic acid-treated C6 cells which stained weakly or not at all in control cells. Comparative studies with different lectins demonstrated that this glycoprotein contains 2,3 Neu5Ac Gal-GalNAc O-glycan moieties. Cultures in the presence of an inhibitor of O-glycan synthesis (N-acetylgalactosaminide -O-benzyl) demonstrated that enhancement of staining of the 300 kDa glycoprotein was not due to the increase of the 2,3 sialyltransferase but to thede novo synthesis of the polypeptide chain of this glycoprotein.Abbreviations RA
retinoic acid
- Neu5Ac
N-acetylneuraminic acid
- CMP-Neu5Ac
cytidine 5 monophosphosialate
- 2,3 ST
CMP-Neu5Ac:Gal 1–3 GalNAc-R -2,3 sialyltransferase
- GalNAc-O-benzyl
N-acetylgalactosaminide -O-benzyl
- Gal1-3GalNAc-O-benzyl
Galactosyl 1-3N-acetylgalactosaminide -O-benzyl
- TBS
Tris-HCl buffer 50mm pH 7.5 containing NaCl 0.15m and Tween 20 0.05%
- B1 buffer
TBS containing MgCl2 1mm, MnCl2 1mm and CaCl2 1mm 相似文献
109.
Viji Vidyadharan E. Sreeja Saritha K. Jose Cyriac Joseph N. V. Unnikrishnan P. R. Biju 《Luminescence》2016,31(1):202-209
The spectroscopic and photoluminescence characteristics of trivalent dysprosium (Dy3+)‐doped Sr0.5Ca0.5TiO3 phosphor materials synthesized via solid‐state reaction method were studied. The X‐ray diffraction profile confirmed the orthorhombic perovskite structure of the prepared samples. Judd–Ofelt analysis was carried out to obtain the intensity parameters and predicted radiative properties of Sr0.5Ca0.5TiO3:2wt%Dy3+. The photoluminescence spectrum of Dy3+‐doped Sr0.5Ca0.5TiO3 showed three emission peaks at 481, 574 and 638 nm corresponding to 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H11/2 transitions respectively. The variation of luminescence intensity with different excitation wavelengths and Dy3+ concentrations is discussed. The decay profiles of 4F9/2 excited levels of Dy3+ ions show bi‐exponential behaviour and also a decrease in average lifetime with increase in Dy3+ concentration. Yellow to blue luminescence intensity ratio, CIE chromaticity co‐ordinates and correlated color temperature were also calculated for different concentrations of Dy3+‐doped Sr0.5Ca0.5TiO3 phosphor at different λex. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
110.
The wheat durable,multipathogen resistance gene Lr34 confers partial blast resistance in rice 下载免费PDF全文
Simon G. Krattinger Justine Sucher Liselotte L. Selter Harsh Chauhan Bo Zhou Mingzhi Tang Narayana M. Upadhyaya Delphine Mieulet Emmanuel Guiderdoni Denise Weidenbach Ulrich Schaffrath Evans S. Lagudah Beat Keller 《Plant biotechnology journal》2016,14(5):1261-1268
The wheat gene Lr34 confers durable and partial field resistance against the obligate biotrophic, pathogenic rust fungi and powdery mildew in adult wheat plants. The resistant Lr34 allele evolved after wheat domestication through two gain‐of‐function mutations in an ATP‐binding cassette transporter gene. An Lr34‐like fungal disease resistance with a similar broad‐spectrum specificity and durability has not been described in other cereals. Here, we transformed the resistant Lr34 allele into the japonica rice cultivar Nipponbare. Transgenic rice plants expressing Lr34 showed increased resistance against multiple isolates of the hemibiotrophic pathogen Magnaporthe oryzae, the causal agent of rice blast disease. Host cell invasion during the biotrophic growth phase of rice blast was delayed in Lr34‐expressing rice plants, resulting in smaller necrotic lesions on leaves. Lines with Lr34 also developed a typical, senescence‐based leaf tip necrosis (LTN) phenotype. Development of LTN during early seedling growth had a negative impact on formation of axillary shoots and spikelets in some transgenic lines. One transgenic line developed LTN only at adult plant stage which was correlated with lower Lr34 expression levels at seedling stage. This line showed normal tiller formation and more importantly, disease resistance in this particular line was not compromised. Interestingly, Lr34 in rice is effective against a hemibiotrophic pathogen with a lifestyle and infection strategy that is different from obligate biotrophic rusts and mildew fungi. Lr34 might therefore be used as a source in rice breeding to improve broad‐spectrum disease resistance against the most devastating fungal disease of rice. 相似文献