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排序方式: 共有278条查询结果,搜索用时 36 毫秒
81.
Elnakish MT Awad MM Hassona MD Alhaj MA Kulkarni A Citro LA Sayyid M Abouelnaga ZA El-Sayed O Kuppusamy P Moldovan L Khan M Hassanain HH 《American journal of physiology. Heart and circulatory physiology》2011,301(3):H868-H880
Rac1-GTPase activation plays a key role in the development and progression of cardiac remodeling. Therefore, we engineered a transgenic mouse model by overexpressing cDNA of a constitutively active form of Zea maize Rac gene (ZmRacD) specifically in the hearts of FVB/N mice. Echocardiography and MRI analyses showed cardiac hypertrophy in old transgenic mice, as evidenced by increased left ventricular (LV) mass and LV mass-to-body weight ratio, which are associated with relative ventricular chamber dilation and systolic dysfunction. LV hypertrophy in the hearts of old transgenic mice was further confirmed by an increased heart weight-to-body weight ratio and histopathology analysis. The cardiac remodeling in old transgenic mice was coupled with increased myocardial Rac-GTPase activity (372%) and ROS production (462%). There were also increases in α(1)-integrin (224%) and β(1)-integrin (240%) expression. This led to the activation of hypertrophic signaling pathways, e.g., ERK1/2 (295%) and JNK (223%). Pravastatin treatment led to inhibition of Rac-GTPase activity and integrin signaling. Interestingly, activation of ZmRacD expression with thyroxin led to cardiac dilation and systolic dysfunction in adult transgenic mice within 2 wk. In conclusion, this is the first study to show the conservation of Rho/Rac proteins between plant and animal kingdoms in vivo. Additionally, ZmRacD is a novel transgenic model that gradually develops a cardiac phenotype with aging. Furthermore, the shift from cardiac hypertrophy to dilated hearts via thyroxin treatment will provide us with an excellent system to study the temporal changes in cardiac signaling from adaptive to maladaptive hypertrophy and heart failure. 相似文献
82.
Lapointe JF Dunphy GB Giannoulis P Mandato CA Nardi JB Gharib OH Niven DF 《Journal of invertebrate pathology》2011,108(3):180-193
The innate non-self response systems of the deciduous tree pest, the forest tent caterpillar, Malacosoma disstria has been documented by us in terms of in vitro and in vivo reactions towards the Gram-positive nonpathogenic bacterium, Bacillus subtilis and Gram-negative pathogenic microbe, Xenorhabdus nematophila and their respective surface antigens, lipopoteichoic acids (LTA) and lipopolysaccharides (LPS). These studies, often conducted in whole and diluted hemolymph, preclude examination of plasma-free cellular (hemocyte) responses. Plasma-free hemocytes as primary cultures are difficult to obtain. The floating cell line Md66 and attached cell line Md108 from M. disstria hemocytes were examined as a model for plasma-free M. disstria hemocyte non-self responses. Herein, it was established that although both lines differed from each other and from the primary hemocyte cultures of M. disstria in growth parameters, cell composition and sizes both cell lines displayed granular cell-like (GL) cells and plasmatocyte-like (PL) cells according to morphological criteria and to some extent antigenic similarities based on labeling with anti-Chrysodeixis includens hemocyte monoclonal antibodies. Hemocyte-specific neuroglian-like protein was detected on cells of both cell lines and in the primary hemocyte cultures albeit with staining patterns differing according to culture and cell types, confluency levels and cell–cell adhesion. Both cell lines bound B. subtilis and X. nematophila, the reaction extent varying with the cell line and its cell types. LPS damaged both cell types in the two cell lines whereas LTA enhanced the adhesion of Md66 GL cells to flask surfaces followed by PL cell adhesion. PL cells of both lines, like the primary cultures, phagocytosed FITC-labeled B. subtilis; only Md108 GL cells phagocytosed B. subtilis. In either case phagocytosis was always less in frequency and intensity than the primary cultures. Proteins released from the cell lines differed in pattern and magnitude but contained bacterial binding proteins that enhanced differential bacterial adhesion to both cell types in both cell lines: the GL cells both cultures, and those of granular cells in primary cultures, were more involved than the primary plasmatocytes and PL cells. Only Md66 cells possessed lysozyme and both cell types of both lines contained phenoloxidase. Neither enzyme type was released during early phase reaction with the bacteria. LPS inhibited phenoloxidase activity. The similarities and differences between the lines and primary cultures make Md66 and Md108 useful for the systematic examination of plasma-free cellular non-self reactions. 相似文献
83.
Deokiee Chon Kenneth C Beck Brett A Simon Hidenori Shikata Osama I Saba Eric A Hoffman 《Journal of applied physiology》2007,102(4):1535-1544
Xenon computed tomography (Xe-CT) is used to estimate regional ventilation by measuring regional attenuation changes over multiple breaths while rebreathing a constant Xe concentration ([Xe]). Xe-CT has potential human applications, although anesthetic properties limit [Xe] to 相似文献
84.
Mohamed M.A. Amer Osama M. Salama Ferdinand Bohlmann Jürgen Ziesche 《Phytochemistry》1984,23(3):692-693
The roots of Urospermum picroides afforded urospermal A 15-O-β-d-glucoside. 相似文献
85.
H/ACA RNP complexes change uridines to pseudouridines in target non-coding RNAs in eukaryotes and archaea. H/ACA RNPs are comprised of a guide RNA and four essential proteins: Cbf5 (pseudouridine synthase), L7Ae, Gar1 and Nop10 in archaea. The guide RNA captures the target RNA via two antisense elements brought together to form a contiguous binding site within the pseudouridylation pocket (internal loop) of the guide RNA. Cbf5 and L7Ae interact independently with the guide RNA, and here we have examined the impacts of these proteins on the RNA in nucleotide protection assays. The results indicate that the interactions observed in a fully assembled H/ACA RNP are established in the sub-complexes, but also reveal a unique Cbf5–guide RNA interaction that is displaced by L7Ae. In addition, the results indicate that L7Ae binding at the kink (k)-turn of the guide RNA induces the formation of the upper stem, and thus also the pseudouridylation pocket. Our findings indicate that L7Ae is essential for formation of the substrate RNA binding site in the archaeal H/ACA RNP, and suggest that k-turn-binding proteins may remodel partner RNAs with important effects distant from the protein-binding site. 相似文献
86.
Molecular Biology Reports - Pediatric bronchial asthma signifies a frequent chronic inflammatory airway disorder influencing many children. Despite its irrefutable importance, its exact... 相似文献
87.
88.
Essam H. Ibrahim Mona Kilany Osama M.S. Mostafa Kamel H. Shaker Mohammed Alshehri Khalid M. Alsyaad Ali Alshehri Khalid Ali Khan Muhammad Qasim Nahla Kotb Abeer S. Alahmari Hamed A. Ghramh Saad M. Dajem 《Saudi Journal of Biological Sciences》2019,26(7):1716-1723
Natural products, including their purified materials, play a remarkable role in drug development. The Euphorbiaceae family, mainly Euphorbia tirucalli, is used in some traditional medicine, and has evidence that its latex comprises immunomodulatory properties and cytokine production. This study aimed to measure the in vivo production of chemokines (IL-1α, IL-1β, IL-12, and RANTES), TH1 cytokines (IFN-γ, TNF-α, GM-CSF, and IL-2) and TH2 cytokines (IL-4, IL-6, IL-10, and IL-13) in rats after treatments with ethanol latex extract of E. tirucalli. Vaccine treated and untreated rats were divided into seven groups to assess antimicrobial activities of the extracted components. After completion of the treatment schedule, blood was withdrawn and sera were collected. The results showed that the main component of the extract was a euphol compound. The extract showed antimicrobial activity and had the ability to modulate innate and adaptive immunity. Animals treated with extract for only 7 days before vaccination showed higher levels of antibody production. The extract showed antibacterial and antifungal activities. The extract could stimulate both adaptive and innate immunity. Pre-treatment with the extract increased immune responses in vaccinated animals, indicating the usefulness of the extract before immunization. 相似文献
89.
Mohamed T. El-Saadony Osama S. F. Khalil Ali Osman Mashaeal S. Alshilawi Ayman E. Taha Salama M. Aboelenin Mustafa Shukry Ahmed M. Saad 《Saudi Journal of Biological Sciences》2021,28(8):4581-4591
This study aimed to prolong the raw buffalo milk handling and cold storage period by controlling the microbes, enhancing sensory properties and their functionality after supplementing bioactive peptides. The additions included hen and duck egg white protein isolates (HPI and DPI), pepper seed protein (PSP), and pepsin-kidney bean protein hydrolysate (PKH). Five milk treatments were prepared and evaluated as non-supplemented milk (M- Control), hen egg white protein isolate-supplemented milk (M-HPI), duck egg white protein isolate-supplemented milk (M-DPI), pepper seeds protein-supplemented milk (M-PSP), and kidney bean hydrolysate-supplemented milk (M-PKH). Pyrogallol, protocatechuic, catechin, benzoic and caffeine were the main phenolic compounds, Apignin-6-arabinose, naringin, hesperidin, naringenin, kaempferol 3–2-p-comaroyl were the dominant flavonoids in milk samples based on HPLC profile. During 30 days of cold storage, the antioxidant potential of peptides-supplemented milk samples was significantly decreased (p ≤ 0.05) as decrement of phenolic compounds and flavonoids; the pH was nearly stable, the titratable acidity and total soluble solids (TTS) were (p ≤ 0.05) raised. PSP and PKH were inhibited (p ≤ 0.05) the decay of sugars in M-PSP, and M-PKH by reducing 45% of bacterial load as compared to other milk samples. PSP was significantly (p ≤ 0.05) scavenged 87% of DPPḢ compared to other peptides. Besides, PSP followed by PKH reduced considerably (p ≤ 0.05) the growth of tested bacteria, molds, and yeasts. The PSP has significantly increased the whiteness of M-PSP as compared to other milk samples. M-PSP had the highest score in color, taste, and flavor, followed by M-PKH. 相似文献
90.
Saleh A. Al-Quraishy Saad M. Bin Dajem Osama M. Mostafa Essam H. Ibrahim Ahmed Al-Qahtani 《Saudi Journal of Biological Sciences》2014,21(1):65-70
Schistosoma mansoni is mediated through the intermediate host Biomphalaria arabica which lives in Saudi Arabia. Molecular characterization and identification of this intermediate host are important for epidemiological studies of schistosomiasis. The present work aimed to determine the molecular variations among the populations of B. arabica found in Southern part of Saudi Arabia, and to develop species-specific primers for identification of these snails as a first step in the development of multiplex PCR for simultaneously identifying the snails and diagnosing its infections in a single step. Five populations of Saudi B. arabica snails were collected from freshwater bodies. Three populations were collected from Asser and two populations were collected from AL-Baha. Genomic DNA was extracted from snails and was amplified using five different RAPD–PCR primers. The banding patterns of amplified materials by primers P1 and P5 were identical in all populations. However, the rest primers displayed intra-specific differences among populations with variable degrees. Largest sizes of RAPD–PCR products were cloned into TA cloning vector as a preparatory step for DNA sequence analysis. After sequencing, similarity searches of obtained DNA sequences revealed that there are no similar sequences submitted to genebank data bases and its associated banks. The results obtained will be helpful in the development of simultaneous identification of B. arabica snails and diagnosis of S. mansoni infection within it in a single step by an implementation of multiplex PCR. 相似文献