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61.
Ariel H. Méndez Fernando E. Novas Sankar Chatterjee 《Pal?ontologische Zeitschrift》2010,84(3):421-425
The Lameta Formation (Upper Cretaceous, Maastrichtian) of India has yielded abundant fossils of abelisaurid theropods, including
bones from the cranium, vertebral column, pectoral and pelvic girdles, and hindlimb. However, the forelimbs of Indian abelisaurids
remain unknown. Here we describe an abelisaurid humerus from exposure of the Lameta Formation near the village of Rahioli
in northwestern India. This new material exhibits derived traits that are distinctive of Abelisauridae, for example an articular
head that is hemispherical in proximal view, thus establishing the specimen as the first abelisaurid humerus from India. 相似文献
62.
Sankar Sridaran Shannon K McClintock Luke M Syphard Karen M Herman John W Barnwell Venkatachalam Udhayakumar 《Malaria journal》2010,9(1):1-22
Background
Mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) genes of Plasmodium falciparum are associated with resistance to anti-folate drugs, most notably sulphadoxine-pyrimethamine (SP). Molecular studies document the prevalence of these mutations in parasite populations across the African continent. However, there is no systematic review examining the collective epidemiological significance of these studies. This meta-analysis attempts to: 1) summarize genotype frequency data that are critical for molecular surveillance of anti-folate resistance and 2) identify the specific challenges facing the development of future molecular databases.Methods
This review consists of 220 studies published prior to 2009 that report the frequency of select dhfr and dhps mutations in 31 African countries. Maps were created to summarize the location and prevalence of the highly resistant dhfr triple mutant (N51I, C59R, S108N) genotype and dhps double mutant (A437G and K540E) genotype in Africa. A hierarchical mixed effects logistic regression was used to examine the influence of various factors on reported mutant genotype frequency. These factors include: year and location of study, age and clinical status of sampled population, and reporting conventions for mixed genotype data.Results
A database consisting of dhfr and dhps mutant genotype frequencies from all African studies that met selection criteria was created for this analysis. The map illustrates particularly high prevalence of both the dhfr triple and dhps double mutant genotypes along the Kenya-Tanzania border and Malawi. The regression model shows a statistically significant increase in the prevalence of both the dhfr triple and dhps double mutant genotypes in Africa.Conclusion
Increasing prevalence of the dhfr triple mutant and dhps double mutant genotypes in Africa are consistent with the loss of efficacy of SP for treatment of clinical malaria in most parts of this continent. Continued assessment of the effectiveness of SP for the treatment of clinical malaria and intermittent preventive treatment in pregnancy is needed. The creation of a centralized resistance data network, such as the one proposed by the WorldWide Antimalarial Resistance Network (WWARN), will become a valuable resource for planning timely actions to combat drug resistant malaria. 相似文献63.
DiMascio L Voermans C Uqoezwa M Duncan A Lu D Wu J Sankar U Reya T 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(6):3511-3520
The hemopoietic microenvironment consists of a diverse repertoire of cells capable of providing signals that influence hemopoietic stem cell function. Although the role of osteoblasts and vascular endothelial cells has recently been characterized, the function of the most abundant cell type in the bone marrow, the adipocyte, is less defined. Given the emergence of a growing number of adipokines, it is possible that these factors may also play a role in regulating hematopoiesis. Here, we investigated the role of adiponectin, a secreted molecule derived from adipocytes, in hemopoietic stem cell (HSC) function. We show that adiponectin is expressed by components of the HSC niche and its receptors AdipoR1 and AdipoR2 are expressed by HSCs. At a functional level, adiponectin influences HSCs by increasing their proliferation, while retaining the cells in a functionally immature state as determined by in vitro and in vivo assays. We also demonstrate that adiponectin signaling is required for optimal HSC proliferation both in vitro and in long term hemopoietic reconstitution in vivo. Finally we show that adiponectin stimulation activates p38 MAPK, and that inhibition of this pathway abrogates adiponectin's proliferative effect on HSCs. These studies collectively identify adiponectin as a novel regulator of HSC function and suggest that it acts through a p38 dependent pathway. 相似文献
64.
Chapoval SP Al-Garawi A Lora JM Strickland I Ma B Lee PJ Homer RJ Ghosh S Coyle AJ Elias JA 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(10):7030-7041
IL-13 is a major Th2 cytokine that is capable of inducing inflammation, excessive mucus production, airway hyperresponsiveness, alveolar remodeling, and fibrosis in the murine lung. Although IL-13 through its binding to IL-4Ralpha/IL-13Ralpha1 uses the canonical STAT6-signaling pathway to mediate these tissue responses, recent studies have demonstrated that other signaling pathways may also be involved. Previous studies from our laboratory demonstrated that IL-13 mediates its tissue effects by inducing a wide variety of downstream genes many of which are known to be regulated by NF-kappaB. As a result, we hypothesized that NF-kappaB activation plays a critical role in the pathogenesis of IL-13-induced tissue alterations. To test this hypothesis, we compared the effects of transgenic IL-13 in mice with normal and diminished levels of NF-kappaB activity. Three pharmacologic approaches were used to inhibit NF-kappaB including 1) PS1145, a small molecule inhibitor of IkappaBalpha kinase (IKK2), 2) antennapedia-linked NF-kappaB essential modulator-binding domain (NBD) peptide (wild-type NBD), and 3) an adenoviral construct expressing a dominant-negative version of IKK2. We also crossed IL-13-transgenic mice with mice with null mutations of p50 to generate mice that overproduced IL-13 in the presence and absence of this NF-kappaB component. These studies demonstrate that all these interventions reduced IL-13-induced tissue inflammation, fibrosis and alveolar remodeling. In addition, we show that both PS1145 and wild-type NBD inhibit lung inflammatory and structural cell apoptosis. PS1145 inhibits caspase activation and up-regulates inhibitor of apoptosis protein cellular-inhibitor of apoptosis protein 1 (c-IAP-1). Therefore, NF-kappaB is an attractive target for immunotherapy of IL-13-mediated diseases. 相似文献
65.
Involvement of phosphatidylinositol 3-kinase-mediated up-regulation of I kappa B alpha in anti-inflammatory effect of gemfibrozil in microglia 总被引:1,自引:0,他引:1
Jana M Jana A Liu X Ghosh S Pahan K 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(6):4142-4152
The present study underlines the importance of PI3K in mediating the anti-inflammatory effect of gemfibrozil, a prescribed lipid-lowering drug for humans, in mouse microglia. Gemfibrozil inhibited LPS-induced expression of inducible NO synthase (iNOS) and proinflammatory cytokines in mouse BV-2 microglial cells and primary microglia. By overexpressing wild-type and dominant-negative constructs of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) in microglial cells and isolating primary microglia from PPAR-alpha-/- mice, we have demonstrated that gemfibrozil inhibits the activation of microglia independent of PPAR-alpha. Interestingly, gemfibrozil induced the activation of p85alpha-associated PI3K (p110beta but not p110alpha) and inhibition of that PI3K by either chemical inhibitors or dominant-negative mutants abrogated the inhibitory effect of gemfibrozil. Conversely, overexpression of the constitutively active mutant of p110 enhanced the inhibitory effect of gemfibrozil on LPS-induced expression of proinflammatory molecules. Similarly, gemfibrozil also inhibited fibrillar amyloid beta (Abeta)-, prion peptide (PrP)-, dsRNA (poly IC)-, HIV-1 Tat-, and 1-methyl-4-phenylpyridinium (MPP+)-, but not IFN-gamma-, induced microglial expression of iNOS. Inhibition of PI3K also abolished the inhibitory effect of gemfibrozil on Abeta-, PrP-, poly IC-, Tat-, and MPP+-induced microglial expression of iNOS. Involvement of NF-kappaB activation in LPS-, Abeta-, PrP-, poly IC-, Tat-, and MPP+-, but not IFN-gamma-, induced microglial expression of iNOS and stimulation of IkappaBalpha expression and inhibition of NF-kappaB activation by gemfibrozil via the PI3K pathway suggests that gemfibrozil inhibits the activation of NF-kappaB and the expression of proinflammatory molecules in microglia via PI3K-mediated up-regulation of IkappaBalpha. 相似文献
66.
67.
Wang L Surendran S Michals-Matalon K Bhatia G Tanskley S Koch R Grady J Tyring SK Stevens RC Guttler F Matalon R 《Genetic testing》2007,11(2):174-178
Tetrahydrobiopterin (BH4) is a co-factor that enhances the activity of other enzymes, and this co-factor level is found to be affected in phenylketonuria (PKU), an amino acid metabolism disorder. The present study was aimed at understanding the effect of BH4 on mutations in the regulatory domain of phenylalanine hydroxylase (PAH). Among 14 patients, 5 patients were classical PKU, 3 were atypical PKU, and 6 were mild PKU. All of these patients had at least one mutation in the regulatory domain. Patients were given 10 mg/kg BH4, and the response of blood phenylalanine (Phe) levels was monitored following treatment. The level of blood Phe decreased after BH4 treatment in all of the patients. These studies suggest that mutations in the regulatory domain also responded to BH4 even if the patient had classical PKU. 相似文献
68.
69.
Sibani Sankar GHATAK Md. Wasim REZA 《昆虫学报》2007,50(9):962-966
分别在2005年和2006年的5、6月份,在Kamalpur和Hunterpara茶园、孟加拉西部以及印度地区对一种昆虫致病真菌球孢白僵菌对油桐尺蛾Buzura (=Biston) suppressaria Guen.的生物效力进行了评估。以农场主常用的化学杀虫剂40% SP灭多虫和25% EC氯氰菊酯作为标准检测物。试验中球孢白僵菌浓度为1.50 g,2.00 g和2.5 g/lit. of water;灭多虫和氯氰菊酯浓度分别为0.75 mL,1.00 mL和1.50 mL,和0.50 mL,1.00 mL和1.50 mL/lit. of water。在喷洒2.5 g/lit. of water 球孢白僵菌3天后,Kamalpur和Hunterpara茶园中油桐尺蛾种群个体数分别降低了88.00%和84.00%。死的毛虫变成黑色,垂悬在叶片上。并且发现球孢白僵菌的杀虫活性与高剂量的灭多虫和氯氰菊酯的相当。 相似文献
70.
Urinary catheterization is a routine procedure in an intensive care unit (ICU) for monitoring the urine output of critically ill patients. The catheters which are most often used to help with urinary incontinence and retention also face problems like blockage, leakage and infection. These problems are due to proteins that adhere to the catheter surface and quickly build up on each other forming a protein layer. As the layers build up they can crystallize, providing the major source of blockage and leakage. Current strategies to avoid these problems include coating a catheter with silver alloy to reduce bacteria on the catheter surface. However, silver alloy coatings can lead to increased silver resistance for bacteria. Since silver is already used as an antibacterial agent in many places in a hospital, it is even more possible that resistance can develop. An alternative solution is presented involving coating latex, a common urinary catheter material with a micro layer (5-100 microns) of polyethylene glycol. This hydrogel is applied using an interfacial photopolymerization process with ethyl eosin as the photoinitiator. A 25 ppm concentration of ethyl eosin provided the strongest gel to surface adhesion and significantly lowered protein adhesion when compared to an uncoated latex substrate. 相似文献