排序方式: 共有166条查询结果,搜索用时 15 毫秒
111.
M. A. Aladag Y. Turkoz H. Parlakpinar H. Ozen M. Egri S. C. Unal 《Neurochemical research》2009,34(11):1935-1944
In the present study, we investigated the in vivo effects of melatonin on SAH-induced cerebral vasospasm and oxidative stress,
resulting from SAH in an experimental rat model. Twenty-eight rats (225–250 g) were divided into four groups equally: group
1; control, group 2; SAH, group 3; SAH plus placebo, and group 4; SAH plus melatonin. We used double haemorrhage method for
SAH groups. Beginning 6 h after SAH, 20 mg/kg melatonin or equal volume of 0.9% saline was administered intraperitoneally
twice daily for 5 days to groups 3 and 4, respectively. Melatonin or 0.9% saline injections were continued up to fifth day
after SAH and rats were sacrificed at the end of this period. Brain sections at the level of the pons were examined by light
microscopy. The lumen diameter and the vessel wall thickness of basilar artery were measured using a micrometer. The serum
levels of cerebral vasodilator nitric oxide (NO), the brain levels of an intrinsic antioxidant superoxide dismutase (SOD)
and a NO regulator arginase activities were measured. The brain levels of inducible nitric oxide (iNOS) and nitrotyrosine,
a nitrosative stress parameter immunohistochemiacally determined. In conclusion, melatonin administration ameliorated cerebral
vasospasm by increasing serum NO level and decreasing the brain the levels of arginase and oxidative stress. It is therefore
possible that increased brain arginase activity after SAH may also have a significant role in the pathogenesis of vasospasm
by limiting the availability of arginine for NO production. 相似文献
112.
Involvement of T-type voltage dependent Ca2+ channels (VDCCs) on morphine antinociception, in the development of tolerance and dependence to morphine, and naloxone-precipitated abstinence syndrome in morphine dependent mice was examined by using mibefradil, a T-type VDCCs blocker. Mice were rendered tolerant and dependent on morphine by subcutaneous (s.c.) implantation of a morphine pellet containing 75 mg of morphine base for 72 hr. The tail-flick test was used to assess the nociceptive threshold. Coadministration of acute mibefradil (10 mg/kg, i.p.) with morphine enhanced the antinociceptive effects of acute morphine. Repeated mibefradil administration (10 mg/kg, i.p., just before, 24 and 48 hr after morphine pellet implantation) completely blocked the development of tolerance to the antinociceptive effect of morphine and even by this effect reached supersensitivity to morphine. However, repeated mibefradil treatment did not alter the development of dependence to morphine assessed by the A(50) values of naloxone (s.c.) required to precipitate withdrawal jumping 72 hr after morphine pellet. But, acute mibefradil (10, 30, and 50 mg/kg, i.p.) dose dependently decreased the expression of morphine abstinence syndrome when given directly 30 min prior to naloxone (0,05 mg/kg, s.c.) 72 hr after morphine pellet. These results indicate a critical role of T-type VDCCs in morphine antinociception, the development of tolerance to the antinociceptive effects of morphine and in morphine abstinence syndrome. 相似文献
113.
Defining a minimal cell: essentiality of small ORFs and ncRNAs in a genome-reduced bacterium 下载免费PDF全文
Verónica Lloréns‐Rico Francis J O'Reilly Judith AH Wodke E Besray Unal Eva Yus Sira Martínez Robert J Nichols Tony Ferrar Ana Vivancos Arne Schmeisky Jörg Stülke Vera van Noort Anne‐Claude Gavin Peer Bork Luis Serrano 《Molecular systems biology》2015,11(1)
Identifying all essential genomic components is critical for the assembly of minimal artificial life. In the genome-reduced bacterium Mycoplasma pneumoniae, we found that small ORFs (smORFs; < 100 residues), accounting for 10% of all ORFs, are the most frequently essential genomic components (53%), followed by conventional ORFs (49%). Essentiality of smORFs may be explained by their function as members of protein and/or DNA/RNA complexes. In larger proteins, essentiality applied to individual domains and not entire proteins, a notion we could confirm by expression of truncated domains. The fraction of essential non-coding RNAs (ncRNAs) non-overlapping with essential genes is 5% higher than of non-transcribed regions (0.9%), pointing to the important functions of the former. We found that the minimal essential genome is comprised of 33% (269,410 bp) of the M. pneumoniae genome. Our data highlight an unexpected hidden layer of smORFs with essential functions, as well as non-coding regions, thus changing the focus when aiming to define the minimal essential genome. 相似文献
114.
115.
Cecener G Tunca B Egeli U Bekar A Tezcan G Erturk E Bayram N Tolunay S 《Cellular and molecular neurobiology》2012,32(2):237-244
Glioblastoma (GBM) is an aggressive and lethal cancer, accounting for the majority of primary brain tumors in adults. GBMs
are characterized by large and small alterations in genes that control cell growth, apoptosis, angiogenesis, and invasion.
Epigenetic alterations also affect the expression of cancer genes, either alone or in combination with genetic mechanisms.
The current evidence suggests that hypermethylation of promoter CpG islands is a common epigenetic event in a variety of human
cancers. A subset of GBMs is also characterized by a locus-specific and genome-wide decrease in DNA methylation. Epigenetic
alterations are important in the molecular pathology of GBM. However, there are very limited data about these epigenetic alterations
in GBM. Alterations in promoter methylations are important to understand because histone deacetylases are targets for drugs
that are in clinical trial for GBMs. The aim of the current study was to investigate whether the promoter hypermethylation
of putative tumor suppressor genes was involved in GBM. We examined the methylation status at the promoter regions of GATA6, MGMT, and FHIT using the methylation-specific polymerase chain reaction in 61 primary GBMs. Our results reveal that there is no promoter
hypermethylation of FHIT in the examined GBM tissue specimens. In contrast, the promoter hypermethylation of GATA6 and MGMT was detected in 42.8 and 11.11% of GBMs, respectively. The frequency of MGMT promoter hypermethylation was low in the group of patients we evaluated. In conclusion, our study demonstrates that promoter
hypermethylation of MGMT is a common event in GBMs, whereas GATA6 is epigenetically affected in GBMs. Furthermore, inactivation of FHIT by epigenetic mechanisms in GBM may not be associated with brain tumorigenesis. 相似文献
116.
117.
Birendra Singh Anna M. Blom Can Unal Bo Nilson Matthias Mörgelin Kristian Riesbeck 《Molecular microbiology》2010,75(6):1426-1444
The serum resistance of the common respiratory pathogen Moraxella catarrhalis is mainly dependent on ubiquitous surface proteins (Usp) A1 and A2 that interact with complement factor 3 (C3) and complement inhibitor C4b binding protein (C4BP) preventing the alternative and classical pathways of the complement system respectively. UspA2 also has the capacity to attract vitronectin that in turn binds C9 and hereby inhibits membrane attack complex (MAC) formation. We found UspA2 as a major vitronectin binding protein and hence the UspA2/vitronectin interaction was studied in detail. The affinity constant (KD) for vitronectin binding to UspA2 was 2.3 × 10?8 M, and the N‐terminal region encompassing residues UspA2 30–170 bound vitronectin with a KD of 7.9 × 10?8 M. Electron microscopy verified that the active binding domain (UspA230–177) was located at the head region of UspA2. Experiments with recombinantly expressed vitronectin also revealed that UspA230–177 bound to the C‐terminal region of vitronectin residues 312–396. Finally, when human serum was pre‐incubated with UspA2, bacteria showed significantly less serum resistance. Our study directly reveals the binding mode between the N‐terminal domain of UspA2 and the C‐terminal part of vitronectin and thus sheds light upon the mechanism of M. catarrhalis‐dependent serum resistance. 相似文献
118.
Hui Hui Wong Sze Hwee Seet Michael Maier Ayse Gurel Ricardo Moreno Traspas Cheryl Lee Shan Zhang Beril Talim Abigail Y.T. Loh Crystal Y. Chia Tze Shin Teoh Danielle Sng Jarred Rensvold Sule Unal Evgenia Shishkova Ece Cepni Fatima M. Nathan Fernanda L. Sirota Bruno Reversade 《American journal of human genetics》2021,108(7):1301-1317
119.
Helen Mason Azza Shoaibi Rula Ghandour Martin O'Flaherty Simon Capewell Rana Khatib Samer Jabr Belgin Unal Kaan S?zmen Chokri Arfa Wafa Aissi Habiba Ben Romdhane Fouad Fouad Radwan Al-Ali Abdullatif Husseini the MedCHAMPS project team 《PloS one》2014,9(1)
Background
Coronary Heart Disease (CHD) is rising in middle income countries. Population based strategies to reduce specific CHD risk factors have an important role to play in reducing overall CHD mortality. Reducing dietary salt consumption is a potentially cost-effective way to reduce CHD events. This paper presents an economic evaluation of population based salt reduction policies in Tunisia, Syria, Palestine and Turkey.Methods and Findings
Three policies to reduce dietary salt intake were evaluated: a health promotion campaign, labelling of food packaging and mandatory reformulation of salt content in processed food. These were evaluated separately and in combination. Estimates of the effectiveness of salt reduction on blood pressure were based on a literature review. The reduction in mortality was estimated using the IMPACT CHD model specific to that country. Cumulative population health effects were quantified as life years gained (LYG) over a 10 year time frame. The costs of each policy were estimated using evidence from comparable policies and expert opinion including public sector costs and costs to the food industry. Health care costs associated with CHDs were estimated using standardized unit costs. The total cost of implementing each policy was compared against the current baseline (no policy). All costs were calculated using 2010 PPP exchange rates. In all four countries most policies were cost saving compared with the baseline. The combination of all three policies (reducing salt consumption by 30%) resulted in estimated cost savings of $235,000,000 and 6455 LYG in Tunisia; $39,000,000 and 31674 LYG in Syria; $6,000,000 and 2682 LYG in Palestine and $1,3000,000,000 and 378439 LYG in Turkey.Conclusion
Decreasing dietary salt intake will reduce coronary heart disease deaths in the four countries. A comprehensive strategy of health education and food industry actions to label and reduce salt content would save both money and lives. 相似文献120.