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排序方式: 共有257条查询结果,搜索用时 19 毫秒
51.
Anna Bylander Magdalena Nutu Rikard Wellander Mattias Goksör Håkan Billig DG Joakim Larsson 《Reproductive biology and endocrinology : RB&E》2010,8(1):48
Background
The physiological regulation of ciliary beat frequency (CBF) within the fallopian tube is important for controlling the transport of gametes and the fertilized ovum. Progesterone influences gamete transport in the fallopian tube of several mammalian species. In fallopian tubes isolated from cows, treatment with 20 micromolar progesterone caused a rapid reduction of the tubal CBF. The aims of this study were to establish methodology for studying fallopian tube CBF in the mouse, as it is an important model species, and to investigate if progesterone rapidly affects the CBF of mice at nM concentrations. 相似文献52.
Ustundag B Yilmaz E Dogan Y Akarsu S Canatan H Halifeoglu I Cikim G Aygun AD 《Mediators of inflammation》2005,2005(6):331-336
It has been well documented that human milk contains several immunomodulator components which are important during infant period when the newborn's immune system is still under development. In this study, we aim at examining levels of cytokines, zinc (Zn), and copper (Cu) in milk from mothers of premature and mature infants, and comparing changes during lactation periods consequently. Milk was collected from total of 40 mothers (group M: mothers of mature infants, n = 20; group PM: mothers of premature infants, n = 20) from four lactation stages: colostrum (0-7 days), transitional (7-14 days), mature milk (21 days), and mature milk (2nd month). Levels of cytokines (interleukin [IL]-lbeta, IL-2, IL-6, IL-8, tumor necrosis factor-alpha [TNF-alpha]) were determined by chemiluminesence method, whereas atomic absorption spectrophotometer was used for the determination of Zn and Cu levels. Cytokine levels were determined to be high in colostrum and transient milk from mothers of full-term infants, whereas their levels were reduced drastically in the 21st day and the 2nd month milk (P < .01, P < .001). Similar trends were observed in milk from mothers of premature infants, but cytokine levels were significantly lower in colostrum compared to colostrum from mothers of mature infants (P < .01). The differences in cytokine levels were continuous in transient milk (P < .05) and mature milk (21 days) (P < .05), whereas there was no statistically significant differences between milk from both groups of mothers in the 2nd month (P > .05). Zn levels in milk from mothers of premature infants were significantly lower compared to the ones from mothers of mature infants (P < .01) and these differences continued through the 2nd month. Although Cu levels were lower in milk from mothers of premature infants, there was no statistically significant difference except colostrum (P > .05). Our results clearly demonstrate that the level of immunomodulating agents such as cytokines and trace elements in milk from mothers of premature infants is less than the level of the same agents in milk from mothers of full-term infants. Although there are commercially available products for infant feeding, human milk is still the best natural nutrient for newborns. Therefore, when premature infants are breastfed, necessary precautions such as supplemantary diets must be considered for possible infections and risks related with immune system deficiency. 相似文献
53.
Ozlem?Gursoy?CalanEmail author Pinar?Akan Aysenur?Cataler Cumhur?Dogan Semra?Kocturk 《Neurochemical research》2016,41(7):1700-1712
Increased amyloid beta (AB) peptide concentration is one of the initiating factors in the neurodegeneration process. It has been suggested that cholesterol induces the synthesis of AB peptide from amyloid precursor protein or facilitates the formation of amyloid plaque by lowering the aggregation threshold of the peptide. It is also shown that AB peptides may affect cholesterol metabolism and the synthesis of steroid hormones such as progesterone and estradiol. Pregnenolone (P) and pregnenolone sulfate (PS) are the major steroids produced from cholesterol in neural tissue. In toxicity conditions, the effect of AB peptides on P and PS levels has not yet been determined. Furthermore, it has not been clearly defined how changes in cellular P and PS levels affect neuronal cell survival. The aim of this study was to determine the effects of AB peptides on cellular changes in P and PS levels depending on the level of their main precursor, cholesterol. Cholesterol and toxic concentrations of AB fragments (AB 25–35, AB 1–40 and AB 1–42) were applied to PC-12 and SH-SY5Y cells. Changes in cellular cholesterol, P and PS levels were determined simultaneously in a dose—and time-dependent manner. The cell viability and cell death types were also evaluated. AB peptides affected both cell viability and P/PS levels. Steroid levels were altered depending on AB fragment type and the cholesterol content of the cells. Treatment with each of the AB fragments alone increased P levels by twofold. However, combined treatment with AB peptides and cholesterol increased P levels by approximately sixfold, while PS levels were increased only about 2.5 fold in both cell lines. P levels in the groups treated with AB 25–35 were higher than those in AB 1–40 and AB 1–42 groups. The cell viabilities were significantly low in the group treated by AB and cholesterol (9 mM). The effect of AB peptides on P levels might be a result of cellular self-defense. On the other hand, the rate of P increase might be playing a key role in the cell death mechanism of AB toxicity depending on cellular cholesterol levels. 相似文献
54.
In vivo and in vitro effects of a HIF-1alpha inhibitor, RX-0047 总被引:1,自引:0,他引:1
Dikmen ZG Gellert GC Dogan P Yoon H Lee YB Ahn CH Shay JW 《Journal of cellular biochemistry》2008,104(3):985-994
55.
Per Jemth Xin Mu ?ke Engstr?m Jakob Dogan 《The Journal of biological chemistry》2014,289(9):5528-5533
Intrinsically disordered proteins are very common in the eukaryotic proteome, and many of them are associated with diseases. Disordered proteins usually undergo a coupled binding and folding reaction and often interact with many different binding partners. Using double mutant cycles, we mapped the energy landscape of the binding interface for two interacting disordered domains and found it to be largely suboptimal in terms of interaction free energies, despite relatively high affinity. These data depict a frustrated energy landscape for interactions involving intrinsically disordered proteins, which is likely a result of their functional promiscuity. 相似文献
56.
The hand is not only one of the principal structures related to motor function but is also essential for tactile sensations. The genetic endowment of an individual plays an important role in the development and differentiation of the hands. Certain features of hands are known to be sexually dimorphic and body morphology may also affect hand morphology. The aim of this study was to evaluate the anthropometric aspects of the hand in terms of its overall morphology and shape in relation to sex. 相似文献
57.
Dogan N Erdem AF Gundogdu C Kursad H Kizilkaya M 《Canadian journal of physiology and pharmacology》2004,82(7):502-505
Analgesics are commonly injected intra-articularly for analgesia after arthroscopic surgery, especially of knee joints. The aim of this study was to research the effects of ketorolac and morphine on articular cartilage and synovial membrane. This study used rabbit right and left hind knee joints. The treatments, saline, morphine, or ketorolac, were administered intra-articularly 24 h after injection, and 5 joints from animals in each drug group were chosen randomly to form Group I and subgroups of Group I. The same procedures were applied after 48 h and 10 days of injection to form Groups II and III, respectively, and subgroups of these groups. Knee joints were excised and a blinded observer evaluated the histopathology according to inflammation of the articular cartilage, inflammatory cell infiltration, hypertrophy, and hyperplasia of the synovial membrane. No histopathological changes were found in the control groups. In the ketorolac and morphine groups, there were varying degrees of synovial membrane inflammatory cell infiltration and minimal, mild, or moderate synovial membrane cell hyperplasia or hypertrophy. Except for the ketorolac group at 24 h, both ketorolac and morphine groups showed more histopathological changes than controls (p < 0.05). Morphine and ketorolac both cause mild histopathological changes in rabbit knee joints, morphine causing more than ketorolac, but both of the drugs can be used intra-articularly with safety. 相似文献
58.
Breakdown points of t-type regression estimators 总被引:5,自引:0,他引:5
59.
Minh Thu Nguyen Beatrice Kraft Wenqi Yu Dogan Doruk Demicrioglu Tobias Hertlein Marc Burian Mathias Schmaler Klaus Boller Isabelle Bekeredjian-Ding Knut Ohlsen Birgit Schittek Friedrich G?tz 《PLoS pathogens》2015,11(6)
All Staphylococcus aureus genomes contain a genomic island, which is termed νSaα and characterized by two clusters of tandem repeat sequences, i.e. the exotoxin (set) and ''lipoprotein-like'' genes (lpl). Based on their structural similarities the νSaα islands have been classified as type I to IV. The genomes of highly pathogenic and particularly epidemic S. aureus strains (USA300, N315, Mu50, NCTC8325, Newman, COL, JH1 or JH9) belonging to the clonal complexes CC5 and CC8 bear a type I νSaα island. Since the contribution of the lpl gene cluster encoded in the νSaα island to virulence is unclear to date, we deleted the entire lpl gene cluster in S. aureus USA300. The results showed that the mutant was deficient in the stimulation of pro-inflammatory cytokines in human monocytes, macrophages and keratinocytes. Purified lipoprotein Lpl1 was further shown to elicit a TLR2-dependent response. Furthermore, heterologous expression of the USA300 lpl cluster in other S. aureus strains enhanced their immune stimulatory activity. Most importantly, the lpl cluster contributed to invasion of S. aureus into human keratinocytes and mouse skin and the non-invasive S. carnosus expressing the lpl gene cluster became invasive. Additionally, in a murine kidney abscess model the bacterial burden in the kidneys was higher in wild type than in mutant mice. In this infection model the lpl cluster, thus, contributes to virulence. The present report is one of the first studies addressing the role of the νSaα encoded lpl gene cluster in staphylococcal virulence. The finding that the lpl gene cluster contributes to internalization into non-professional antigen presenting cells such as keratinocytes highlights the lpl as a new cell surface component that triggers host cell invasion by S. aureus. Increased invasion in murine skin and an increased bacterial burden in a murine kidney abscess model suggest that the lpl gene cluster serves as an important virulence factor. 相似文献
60.
Carbone M Ly BH Dodson RF Pagano I Morris PT Dogan UA Gazdar AF Pass HI Yang H 《Journal of cellular physiology》2012,227(1):44-58
Malignant mesothelioma (MM) is a neoplasm arising from mesothelial cells lining the pleural, peritoneal, and pericardial cavities. Over 20 million people in the US are at risk of developing MM due to asbestos exposure. MM mortality rates are estimated to increase by 5–10% per year in most industrialized countries until about 2020. The incidence of MM in men has continued to rise during the past 50 years, while the incidence in women appears largely unchanged. It is estimated that about 50–80% of pleural MM in men and 20–30% in women developed in individuals whose history indicates asbestos exposure(s) above that expected from most background settings. While rare for women, about 30% of peritoneal mesothelioma in men has been associated with exposure to asbestos. Erionite is a potent carcinogenic mineral fiber capable of causing both pleural and peritoneal MM. Since erionite is considerably less widespread than asbestos, the number of MM cases associated with erionite exposure is smaller. Asbestos induces DNA alterations mostly by inducing mesothelial cells and reactive macrophages to secrete mutagenic oxygen and nitrogen species. In addition, asbestos carcinogenesis is linked to the chronic inflammatory process caused by the deposition of a sufficient number of asbestos fibers and the consequent release of pro‐inflammatory molecules, especially HMGB‐1, the master switch that starts the inflammatory process, and TNF‐alpha by macrophages and mesothelial cells. Genetic predisposition, radiation exposure and viral infection are co‐factors that can alone or together with asbestos and erionite cause MM. J. Cell. Physiol. 227: 44–58, 2012. © 2011 Wiley Periodicals, Inc. 相似文献