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排序方式: 共有1215条查询结果,搜索用时 359 毫秒
91.
Zimmerman MC Lazartigues E Lang JA Sinnayah P Ahmad IM Spitz DR Davisson RL 《Circulation research》2002,91(11):1038-1045
Angiotensin II (Ang II) has profound effects in the central nervous system (CNS), including promotion of thirst, regulation of vasopressin secretion, and modulation of sympathetic outflow. Despite its importance in cardiovascular and volume homeostasis, angiotensinergic mechanisms are incompletely understood in the CNS. Recently, a novel signaling mechanism for Ang II involving reactive oxygen species (ROS) has been identified in a variety of peripheral tissues, but the involvement of ROS as second messengers in Ang II-mediated signaling in the CNS has not been reported. The hypothesis that superoxide is a key mediator of the actions of Ang II in the CNS was tested in mice using adenoviral vector-mediated expression of superoxide dismutase (AdSOD). Changes in blood pressure, heart rate, and drinking elicited by injection of Ang II in the CNS were abolished by prior treatment with AdSOD in the brain, whereas the cardiovascular responses to carbachol, another central vasopressor agent, were unaffected. In addition, Ang II stimulated superoxide generation in primary CNS cell cultures, and this was prevented by the Ang II receptor (Ang II type 1 subtype) antagonist losartan or AdSOD. These results identify a novel signaling mechanism mediating the actions of Ang II in the CNS. Dysregulation of this signaling cascade may be important in hypertension and heart failure triggered by Ang II acting in the CNS. 相似文献
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Duzkale H Jilani I Orsolic N Zingaro RA Golemovic M Giles FJ Kantarjian H Albitar M Freireich EJ Verstovsek S 《Cancer chemotherapy and pharmacology》2003,51(5):427-432
PURPOSE: Arsenic trioxide (As(2)O(3)), an inorganic arsenic compound, has recently been approved for the treatment of relapsed or refractory acute promyelocytic leukemia. However, systemic toxicity associated with As(2)O(3) treatment remains a problem. Inorganic arsenic is detoxified in vivo by methylation reactions into organic arsenic compounds that are less toxic. METHODS AND RESULTS: We investigated the antiproliferative and cytotoxic activity of dimethylarsinic acid (DMAA), an organic arsenic derivative and major metabolic by-product of As(2)O(3), against a panel of eight leukemia and multiple myeloma cell lines. As(2)O(3) was tested in comparison. In clonogenic assay, the average concentration of DMAA that suppressed cell colony growth by 50% was 0.5-1 m M, while for As(2)O(3) it was on average 1-2 microM. At those concentrations DMAA and As(2)O(3) had significantly less effect on colony growth of normal progenitor cells. Cytotoxic doses of DMAA and As(2)O(3) in 3-day trypan blue dye exclusion assay experiments were similar to doses effective in clonogenic assay. Assessment of apoptosis by annexin V assay revealed a high rate of apoptosis in all cell lines treated with DMAA and As(2)O(3), but significantly less effect on normal progenitor cells. DMAA, unlike As(2)O(3), had no effect on the maturation of leukemic cells. CONCLUSIONS: DMAA exerts differential antiproliferative and cytotoxic activity against leukemia and multiple myeloma cells, with no significant effect on normal progenitor cells. However, concentrations of DMAA needed to achieve such efficacy are up to 1000 times those of As(2)O(3). Evaluation of novel organic arsenic that would combine the high efficacy of As(2)O(3) and the low toxicity of DMAA is warranted. 相似文献
94.
Iman Abou-Gareeb Susan Lewallen Ken Bassett Paul Courtright 《Ophthalmic epidemiology》2013,20(1):39-56
BACKGROUND: Many individual surveys of blindness have reported slightly higher rates of blindness for women. In order to gain a continent-by-continent and global sense of the burden of blindness by sex we conducted a meta-analysis of published, population-based surveys of blindness. METHOD: Published reports were collected using a predetermined search protocol involving commercial electronic databases, hand-searching of references and direct contact with researchers. Studies were included that were population-based, included clinical examination and had a minimum sample size of 1000. The studies were critically appraised to determine methodological rigour. Data were analysed using the Cochrane Collaboration Review Manager. RESULTS: The overall odds ratio (age-adjusted) of blind women to men is 1.43 (95% CI 1.33–1.53), ranging from 1.39 (95% CI 1.20–1.61) in Africa, 1.41 (95% CI 1.29–1.54) in Asia, and 1.63 (95% CI 1.30–2.05) in industrialised countries. There was good homogeneity of findings from Africa, Asia, and the industrialised countries. Globally, women bear excess blindness compared to men. In these surveys, overall, women account for 64.5% of all blind people. The excess of blindness in women was marked among the elderly and not due only to differential life expectancy. CONCLUSION: The excess burden of blindness among women is likely due to a number of factors, which are different in industrialised countries compared to developing countries. Particular attention to gender differences in blindness is needed in the creation of targets for blindness reduction and in the development of interventions. 相似文献
95.
Mark L. Eberhard Gholamabbas Amin Ostovar Kote Chundu Dan Hobohm Iman Feiz-Erfan Blaine A. Mathison Henry S. Bishop Paul T. Cantey 《The American journal of tropical medicine and hygiene》2013,88(3):601-605
A 22-month-old girl presented with neck pain and stiffness and magnetic resonance imaging showed an extradural mass extending from C2 through the C4 level with moderate to severe compression of the cord. A left unilateral C2–C4 laminectomy was performed revealing an extradural rubbery tumor; a small biopsy was obtained. Examination of stained tissue revealed the presence of a parasitic worm that was identified as a gravid female Onchocerca lupi. A magnetic resonance imaging at 7 weeks follow-up showed a significantly decreased size of the enhancing lesion and the patient''s symptoms gradually resolved. This is the first report of zoonotic O. lupi in the United States. The parasite has been reported in dogs and cats in the western United States, and from people in four cases reported from Europe. A great deal more needs to be learned, including full host range and geographic distribution, before we fully understand O. lupi infections in animals and man. 相似文献
96.
Blastocystis hominis is a ubiquitous enteric protozoan whose pathogenic potential is still controversial. This study was carried out to clarify
the pathogenecity of B. hominis infection and to study the proper number of parasites for mice infection. A total of 15 albino mice were orally inoculated
with B. hominis and divided according to the inoculums, 102, 105, and 4 × 107
B. hominis forms/100 μl saline, into three groups consisting of five mice each, GI, GII GIII, respectively. In addition with group IV
(uninfected control) consisting of five mice. All mice were sacrificed 2 weeks post-infection. The results revealed that all
mice of GIII and two mice of GII got the infection while all mice of GI showed a completely negative result. Histopathological
examination of large intestine on highly infected group (GIII) showed that B. hominis infiltrated the lamina propria, the submucosa, and the muscle layers in the form of collection of vacuolar forms. This was
accompanied by active colitis with infiltration of mixed inflammatory cells. In conclusion, this study revealed that large
number of B. hominis is essential for oral infection of mice and that vacuolar forms of B. hominis can invade the lamina propria, the submucosa, and even the muscle layers. 相似文献
97.
Shaimaa Elshafie Iman Zaghloul Anne Marie Roberti 《International journal of clinical pharmacy》2018,40(4):758-763
The thalidomide disaster was the significant historical event that acted as a catalyst for pharmacovigilance activity. Following this event developed countries initiated drug monitoring systems that evolved and now extend their scope to broader drug-related safety issues; however, this was not the case in developing countries. Pharmacovigilance is still a relatively new concept with low priority in developing countries although various issues are raising concerns that magnify the need for systems to monitor post marketing drug safety in these countries. This article analyzes the barriers to introducing robust pharmacovigilance systems in developing countries. 相似文献
98.
Asghar Davood Ali reza Nematollahi Maryam Iman Abbas Shafiee 《Archives of pharmacal research》2009,32(4):481-487
1,4-Dihydropyridines have been recognized as calcium channel agonist. Three new analogues of Bay K8644 in which the ortho
trifluromethyl phenyl group at position 4 is replaced by the 4-(5)-Chloro-2-ethyl-5-(4)-imidazolyl substituent, were designed
and synthesized as calcium channel agonist. For this propose, the structures of designed compounds were drawn by HYPERCHEM
program. Conformations of the compounds were optimized through semi-empirical method followed by PM3 calculation. Then the
crystalin stucture of L-type calcium channel was obtained from the Protein Data Bank (PDB) server. Docking calculations were
carried out using Auto-Dock.4 program. The good interaction of our 1,4-DHP derivatives showed that they can be as possible
calcium channel agonist agents. Finally compounds were synthesized according to a modified Hantzsch condensation procedure. 相似文献
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100.