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21.
Monika Burns Sureshkumar Muthupalani Zhongming Ge Timothy C. Wang Vasudevan Bakthavatchalu Catriona Cunningham Kathleen Ennis Michael Georgieff James G. Fox 《PloS one》2015,10(11)
Iron deficiency anemia (IDA) affects > 500 million people worldwide, and is linked to impaired cognitive development and function in children. Helicobacter pylori, a class 1 carcinogen, infects about half of the world’s population, thus creating a high likelihood of overlapping risk. This study determined the effect of H. pylori infection on iron homeostasis in INS-GAS mice. Two replicates of INS-GAS/FVB male mice (n = 9-12/group) were dosed with H. pylori (Hp) strain SS1 or sham dosed at 6–9 weeks of age, and were necropsied at 27–29 weeks of age. Hematologic and serum iron parameters were evaluated, as was gene expression in gastric and brain tissues. Serum ferritin was lower in Hp SS1-infected mice than uninfected mice (p < 0.0001). Infected mice had a lower red blood cell count (p<0.0001), hematocrit (p < 0.001), and hemoglobin concentration (p <0.0001) than uninfected mice. Relative expression of gastric hepcidin antimicrobial peptide (Hamp) was downregulated in mice infected with Hp SS1 compared to sham-dosed controls (p<0.001). Expression of bone morphogenic protein 4 (Bmp4), a growth factor upstream of hepcidin, was downregulated in gastric tissue of Hp SS1-infected mice (p<0.001). Hp SS1-infected mice had downregulated brain expression of tyrosine hydroxylase (Th) (p = 0.02). Expression of iron-responsive genes involved in myelination (myelin basic protein (Mbp) and proteolipid protein 2 (Plp2)) was downregulated in infected mice (p = 0.001 and p = 0.02). Expression of synaptic plasticity markers (brain derived neurotrophic factor 3 (Bdnf3), Psd95 (a membrane associated guanylate kinase), and insulin-like growth factor 1 (Igf1)) was also downregulated in Hp SS1-infected mice (p = 0.09, p = 0.04, p = 0.02 respectively). Infection of male INS-GAS mice with Hp SS1, without concurrent dietary iron deficiency, depleted serum ferritin, deregulated gastric and hepatic expression of iron regulatory genes, and altered iron-dependent neural processes. The use of Hp SS1-infected INS-GAS mice will be an appropriate animal model for further study of the effects of concurrent H. pylori infection and anemia on iron homeostasis and adult iron-dependent brain gene expression. 相似文献
22.
Tetrasaccharide cap present in lipophosphoglycan of the Leishmania donovani responsible for visceral Leishmaniaisis is synthesized as a fully protected propargyl glycoside. AuBr(3) mediated selective glycosylation of propargyl 1,2-orthoester in the presence of propargyl glycoside is employed as a key step to obtain propargyl containing oligomers. Further, propargyl tetrasaccharide is connected with a long chain hydrocarbon containing azidothiol functionality situated at two terminal ends via 'click' reaction. 相似文献
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Kay Schneitz Sureshkumar Balasubramanian Ursula Schiefthaler 《Trends in plant science》1998,3(12):468-472
The ovule is the site of megagametogenesis and fertilization and hence is of central importance to sexual reproduction in seed plants. In recent years, the ovule has become established as an excellent model system in which to study organogenesis. Progress has been made in several aspects of ovule development: the control of ovule identity, the mechanism of primordium outgrowth, early pattern formation and the regulation of integument morphogenesis. 相似文献
25.
A method has been developed to continuously measure the intracellular pH (pH(i)) of cells cultivated in a bioreactor in an on-line fashion over extend time periods. The methods is attractive in its simplicity and involves the use of a fluorescent pH(i) indicator 9-aminoacridine (9A A) which is a week base. An expression has been derived to calculate changes in pH(i) from measured 9AA-fluorescence changes. The indicator 9AA was found t be nontoxic to yeast cells at concentrations used to measure pH(i) (7 muM). The fluorescence of nicotinamide adenine dinucleotide (NADH) molecules did not interfere significantly with the measurement of 9AA-fluorescence. The pH(i) change in yeast cell following the addition of a proton ionophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) measured by 9AA compared favorably with that measured by the well-established pH(i), indicator (which is however unsuitable for on-line applications in a bioreactor) bis-carboxyethyl carboxy fluorescein (BCECF). The pH(i) of yeast under substrate starved conditions was 6.4 units. The responses of pH(i) of yeast cells to induced metabolic transitions were studied. Under aerobic condition, pH(i) increased by 0.12 unit following a 100-ppm glucose pulse addition and by 0.25 unit following a 300-ppm ethanol pulse addition. Under anaerobic condition, pH(i) increased by 0.1 unit following a 500-ppm glucose pulse addition. Comparison of pH(i) with other indicators of cellular metabolic state suggests that pH(i) is a cellular metabolic state indicator. (c) 1993 John Wiley & Sons, Inc. 相似文献
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Pyocyanin, a potential antimicrobial agent, was secreted by Xanthomonas campestris. Treatments with agents causing oxidative stress in the organism caused up to 4.4-fold increase in pyocyanin production.
Pyocyanin added in the extracellular space did not affect growth rate of X. campestris, but decreased maximum cell concentration and specific product formation. However, the growth of Escherichia coli, the indicator target organism, was affected by pyocyanin. There was also a significant increase in the intracellular reactive
oxygen species (ROS) concentration and antioxidant enzyme [catalase, superoxide dismutase (SOD)] concentrations, in the presence
of pyocyanin. The intracellular ROS concentrations in E. coli formed upon exposure to pyocyanin, which is an indicator of the toxicity, was dependent on the growth phase of the organism.
Studies with mutants of E. coli showed that intracellular ROS concentration was not significantly affected by the absence of the regulon OxyR, but, was significantly higher in cases when the regulon rpoS or the genes katG or katE were absent. Journal of Industrial Microbiology & Biotechnology (2000) 25, 266–272.
Received 08 May 2000/ Accepted in revised form 04 August 2000 相似文献
28.
Acute and chronic forms of inflammation are known to affect liver responses and susceptibility to disease and injury. Furthermore, intestinal microbiota has been shown critical in mediating inflammatory host responses in various animal models. Using C. rodentium, a known enteric bacterial pathogen, we examined liver responses to gastrointestinal infection at various stages of disease pathogenesis. For the first time, to our knowledge, we show distinct liver pathology associated with enteric infection with C. rodentium in C57BL/6 mice, characterized by increased inflammation and hepatitis index scores as well as prominent periportal hepatocellular coagulative necrosis indicative of thrombotic ischemic injury in a subset of animals during the early course of C. rodentium pathogenesis. Histologic changes in the liver correlated with serum elevation of liver transaminases, systemic and liver resident cytokines, as well as signal transduction changes prior to peak bacterial colonization and colonic disease. C. rodentium infection in C57BL/6 mice provides a potentially useful model to study acute liver injury and inflammatory stress under conditions of gastrointestinal infection analogous to enteropathogenic E. coli infection in humans. 相似文献
29.
J Jerobin RS Sureshkumar CH Anjali A Mukherjee N Chandrasekaran 《Carbohydrate polymers》2012,90(4):1750-1756
Azadirachtin a biological compound found in neem have medicinal and pesticidal properties. The present work reports on the encapsulation of neem oil nanoemulsion using sodium alginate (Na-Alg) by cross linking with glutaraldehyde. Starch and polyethylene glycol (PEG) were used as coating agents for smooth surface of beads. The SEM images showed beads exhibited nearly spherical shape. Swelling of the polymeric beads reduced with coating which in turn decreased the rate of release of Aza-A. Starch coated encapsulation of neem oil nanoemulsion was found to be effective when compared to PEG coated encapsulation of neem oil nanoemulsion. The release rate of neem Aza-A from the beads into an aqueous environment was analyzed by UV-visible spectrophotometer (214nm). The encapsulated neem oil nanoemulsion have the potential for controlled release of Aza-A. Neem oil nanoemulsion encapsulated beads coated with PEG was found to be toxic in lymphocyte cells. 相似文献
30.
Gopalakrishnan M Sureshkumar P Thanusu J Kanagarajan V 《Journal of enzyme inhibition and medicinal chemistry》2008,23(3):347-351
Compound 26 is more potent against Escherichia coli. and 24 is more active against Staphylococcus aureus, beta-Heamolytic streptococcus, Vibreo cholerae, Salmonella typhii, and Shigella flexneri than the standard drug ciprofloxacin. Moreover, of all the compounds tested, 26 is more effective against Aspergillus flavus and Mucor, than the standard drug fluconazole. 相似文献