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71.
Under strong light conditions, long-lived chlorophyll triplets (3Chls) are formed, which can sensitize singlet oxygen, a species harmful to the photosynthetic apparatus of plants. Plants have developed multiple photoprotective mechanisms to quench 3Chl and scavenge singlet oxygen in order to sustain the photosynthetic activities. The lumenal loop of light-harvesting chlorophyll a/b complex of photosystem II (LHCII) plays important roles in regulating the pigment conformation and energy dissipation. In this study, site-directed mutagenesis analysis was applied to investigate triplet–triplet energy transfer and quenching of 3Chl in LHCII. We mutated the amino acid at site 123 located in this region to Gly, Pro, Gln, Thr and Tyr, respectively, and recorded fluorescence excitation spectra, triplet-minus-singlet (TmS) spectra and kinetics of carotenoid triplet decay for wild type and all the mutants. A red-shift was evident in the TmS spectra of the mutants S123T and S123P, and all of the mutants except S123Y showed a decrease in the triplet energy transfer efficiency. We propose, on the basis of the available structural information, that these phenomena are related to the involvement, due to conformational changes in the lumenal region, of a long-wavelength lutein (Lut2) involved in quenching 3Chl. 相似文献
72.
Hasan Moradian Ali K. Esmailizadeh Saeed S. Sohrabi Ehsan Nasirifar Nahid Askari Mohammad Reza Mohammadabadi Amin Baghizadeh 《Molecular biology reports》2014,41(7):4455-4462
The purpose of this study was to identify genomic regions, quantitative trait loci (QTL), affecting carcass traits on chromosome 1 in an F2 population of Japanese quail. For this purpose, two white and wild strains of Japanese quail (16 birds) were crossed reciprocally and F1 generation (34 birds) was created. The F2 generation was produced by intercrossing of the F1 birds. Phenotypic data including carcass weight, internal organs and carcass parts were collected on F2 animals (422 birds). The total mapping population (472 birds) was genotyped for 8 microsatellite markers on chromosome 1. QTL analysis was performed with interval mapping method applying the line-cross model. Significant QTL were identified for breast weight at 0 (P < 0.01), 172 (P < 0.05) and 206 (P < 0.01), carcass weight at 91 (P < 0.05), carcass fatness at 0 (P < 0.01), pre-stomach weight at 206 (P < 0.01) and uropygial weight gland at 197 (P < 0.01) cM on chromosome 1. There was also evidence for imprinted QTL affecting breast weight (P < 0.01) on chromosome 1. The proportion of the F2 phenotypic variation explained by the significant additive, dominance and imprinted QTL effects ranged from 1.0 to 7.3 %, 1.2 to 3.3 % and 1.4 to 2.2 %, respectively. 相似文献
73.
Nahid Aboutaleb Hamid Kalalianmoghaddam Sanaz Eftekhari Ali Shahbazi Hadi Abbaspour Mehdi Khaksari 《International journal of peptide research and therapeutics》2014,20(2):127-132
Stroke is the third leading cause of death world-wide, affecting 15 million people annually. Diminished blood supply to the brain cells is the main cause of damage following stroke. When focal ischemia occurs, the core of brain tissue influenced by reduced blood supply undergoes necrotic cell death. The adipocytokine Apelin is a peptide that was isolated from a bovine stomach for the first time. This peptide and its receptor are abundantly expressed in the nervous and cardiovascular systems. According to previous studies, Apelin-13 protects cardiomyocytes from ischemic injury and apoptosis. In addition, this peptide has neuroprotective effect on hippocampal and cultured mouse cortical neurons against NMDA receptor-mediated excitotoxicity as well as cortical neurons from ischemic injury. The present study was conducted to determine whether Apelin-13 inhibits apoptosis in the ischemic penumbra in transient focal cerebral ischemia. Focal cerebral ischemia was induced in male Wistar rats by 60 min middle cerebral artery occlusion (MCAO) using a filament method, followed by 23-h reperfusion. Saline as a vehicle and Apelin-13 at doses of 50 and 100 μg were injected intracerebro-ventriculary (ICV) at the beginning of ischemia. Apoptosis and neurological dysfunction were assessed 24-h after MCAO. Our results indicated that administration of Apelin-13 at doses of 50 and 100 μg ICV markedly reduced apoptosis by decreasing positive TUNEL cells (P < 0.001). In addition, Apelin-13 at doses of 100 μg significantly change neurological dysfunction (P < 0.05). Our findings demonstrate that treatment by Apelin-13 exerts its protective effects in ischemic models via blocking programmed cell-death. We suggest that Apelin-13 might be a promising therapeutic target for stroke, although more researches are necessary to take into account the potential therapeutic effects of Apelin-13 in stroke patients. 相似文献
74.
Nicole A. Kruh-Garcia Lisa M. Wolfe Lelia H. Chaisson William O. Worodria Payam Nahid Jeff S. Schorey J. Lucian Davis Karen M. Dobos 《PloS one》2014,9(7)
The identification of easily measured, accurate diagnostic biomarkers for active tuberculosis (TB) will have a significant impact on global TB control efforts. Because of the host and pathogen complexities involved in TB pathogenesis, identifying a single biomarker that is adequately sensitive and specific continues to be a major hurdle. Our previous studies in models of TB demonstrated that exosomes, such as those released from infected macrophages, contain mycobacterial products, including many Mtb proteins. In this report, we describe the development of targeted proteomics assays employing multiplexed multiple reaction monitoring mass spectrometry (MRM-MS) in order to allow us to follow those proteins previously identified by western blot or shotgun mass spectrometry, and enhance biomarker discovery to include detection of Mtb proteins in human serum exosomes. Targeted MRM-MS assays were applied to exosomes isolated from human serum samples obtained from culture-confirmed active TB patients to detect 76 peptides representing 33 unique Mtb proteins. Our studies revealed the first identification of bacteria-derived biomarker candidates of active TB in exosomes from human serum. Twenty of the 33 proteins targeted for detection were found in the exosomes of TB patients, and included multiple peptides from 8 proteins (Antigen 85B, Antigen 85C, Apa, BfrB, GlcB, HspX, KatG, and Mpt64). Interestingly, all of these proteins are known mycobacterial adhesins and/or proteins that contribute to the intracellular survival of Mtb. These proteins will be included as target analytes in future validation studies as they may serve as markers for persistent active and latent Mtb infection. In summary, this work is the first step in identifying a unique and specific panel of Mtb peptide biomarkers encapsulated in exosomes and reveals complex biomarker patterns across a spectrum of TB disease states. 相似文献
75.
Binnur Eroglu Donald E. Kimbler Junfeng Pang Justin Choi Demetrius Moskophidis Nathan Yanasak Krishnan M. Dhandapani Nahid F. Mivechi 《Journal of neurochemistry》2014,130(5):626-641
Traumatic brain injury (TBI) induces severe harm and disability in many accident victims and combat‐related activities. The heat‐shock proteins Hsp70/Hsp110 protect cells against death and ischemic damage. In this study, we used mice deficient in Hsp110 or Hsp70 to examine their potential requirement following TBI. Data indicate that loss of Hsp110 or Hsp70 increases brain injury and death of neurons. One of the mechanisms underlying the increased cell death observed in the absence of Hsp110 and Hsp70 following TBI is the increased expression of reactive oxygen species‐induced p53 target genes Pig1, Pig8, and Pig12. To examine whether drugs that increase the levels of Hsp70/Hsp110 can protect cells against TBI, we subjected mice to TBI and administered Celastrol or BGP‐15. In contrast to Hsp110‐ or Hsp70i‐deficient mice that were not protected following TBI and Celastrol treatment, there was a significant improvement of wild‐type mice following administration of these drugs during the first week following TBI. In addition, assessment of neurological injury shows significant improvement in contextual and cued fear conditioning tests and beam balance in wild‐type mice that were treated with Celastrol or BGP‐15 following TBI compared to TBI‐treated mice. These studies indicate a significant role of Hsp70/Hsp110 in neuronal survival following TBI and the beneficial effects of Hsp70/Hsp110 inducers toward reducing the pathological consequences of TBI.
76.
BackgroundWith the paucity of new drugs and HIV co-infection, vaccination remains an unmet research priority to combat visceral leishmaniasis (VL) requiring strong cellular immunity. Protein vaccination often suffers from low immunogenicity and poor generation of memory T cells for long-lasting protection. Cysteine proteases (CPs) are immunogenic proteins and key mediators of cellular functions in Leishmania. Here, we evaluated the vaccine efficacies of CPs against VL, using cationic liposomes with Toll like receptor agonists for stimulating host immunity against L. donovani in a hamster model.Conclusion/SignificanceThe present study is the first report of a comparative efficacy of leishmanial CPs and their cocktail using liposomal formulation with MPL-TDM against L. donovani. The level of protection attained has not been reported for any other subcutaneous single or polyprotein vaccination against VL. 相似文献
77.
78.
Elaine K. Lau Nahid Tayebi Loring J. Ingraham Suzanne L. Winfield V. Koprivica Deborah L. Stone Ari Zimran Edward I. Ginns E. Sidransky 《Human genetics》1999,104(4):293-300
Gaucher disease, an inherited glycolipid storage disorder, is caused by a deficiency of the catabolic enzyme glucocerebrosidase
(EC 3.2.1.45). The gene for human glucocerebrosidase is located on chromosome 1q21 and has a highly homologous pseudogene
situated 16 kb downstream. We report two novel polymorphic sequences in the glucocerebrosidase gene region: the first consists
of a variable number of dinucleotide (CT) repeats located 3.2 kb upstream from the glucocerebrosidase gene, and the second
is a tetranucleotide (AAAT) repeat found between the glucocerebrosidase gene and its pseudogene, 9.8 kb downstream from the
functional gene. These polymorphic sequences, along with a previously reported PvuII polymorphism in intron 6 of the glucocerebrosidase gene, were analyzed in patients with Gaucher disease (n=106) and in two normal control populations, one of Ashkenazi Jewish ancestry (n=72) and the second comprising non-Jewish individuals (n=46). In these samples, strong linkage disequilibrium was found between mutations N370S, c.84–85insG, and R463C and specific
haplotypes; no significant linkage disequilibrium was found when examining haplotypes of patients with the L444P mutation.
Studies of these polymorphic sites in several instances also led to the recognition of genotyping errors and the identification
of unusual recombinant alleles. These new polymorphic sites provide additional tools for mutational screening and founder
effect studies of Gaucher disease.
Received: 5 December 1998 / Accepted: 14 January 1999 相似文献
79.
Razi Dmi'el David Tel-Tzur 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1985,155(3):395-402
Summary Body temperature (T
b), oxygen consumption
, thermal conductance (C) and evaporative water loss (EWL) were measured at various air temperatures (T
a) in two starlings which evolved in the tropics: a migratory species from a temperate climate,Sturnus vulgaris, and a resident, desert species,Onychognathus tristrami (Aves, Passeriformes, Sturnidae).AtT
a's of 4–35°C both birds hadT
b of 40.6°C. At 44°C,T
b ofSturnus was 45.8°C and that ofOnychognathus 43.3°C.T
a of 44°C was tolerated only byOnychognathus. The thermoneutral zone (TNZ) ofSturnus was in theT
a range of 29.5°C–36.5°C, that ofOnychognathus 21.5–36.5°C.
ofSturnus within its TNZ (BMR) was 2.37 ml O2 g–1 h–1, which is close to the expected BMR; that ofOnychognathus, 1.67 ml O2 g–1 h–1, is only 74% of the expected. AtT
a'sNZ,C ofSturnus was twice as high as that ofOnychognathus and 1.68 times the expected value, whereasC ofOnychognathus was only 94% of the expected. At highT
a'sOnychognathus had higherC thanSturnus. At either low or highT
a's EWL ofSturnus was greater than ofOnychognathus.The responses shown bySturnus are typical of a tropical bird living in a moderate environment. This indicates that neither in USSR where it spends the summer, nor in Israel where it spends the winter, is this starling exposed to extreme temperatures.Onychognathus is better adapted not only to high but also to the low temperatures prevailing in mountainous regions of the desert.Symbols and abbreviations
BMR
basal metabolic rate
-
C
thermal conductance
-
EWL
evaporative water loss
-
HE
evaporative heat loss
-
HP
heat production
-
TNZ
thermoneutral zone 相似文献
80.
Young Chan Kim Cesar Lopez-Camacho Joanne E. Nettleship Nahid Rahman Michelle L. Hill Laura Silva-Reyes Georgina Ortiz-Martinez Gloria Figueroa-Aguilar María Antonieta Mar Héctor Vivanco-Cid Christine S. Rollier Nicole Zitzmann Martha Eva Viveros-Sandoval Raymond J. Owens Arturo Reyes-Sandoval 《Virology journal》2018,15(1):193