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91.
Macrophage tumoricidal activity relies, mainly, on the release of Tumor Necrosis
Factor alpha (TNFα) and/or on reactive oxygen or nitrogen intermediates. In
the present work, we investigated the cytotoxic activity of resident peritoneal
macrophages against L929 fibrosarcoma cell line in vitro and
in vivo. Resident macrophages lysed L929 cells in a mechanism
independent of TNFα and cell-to-cell contact. The cytotoxic activity was
largely dependent on nitric oxide (NO) release since treatment with L-NAME (NOS
inhibitor) inhibited L929 cells killing. Macrophages from mice with targeted deletion
of inducible NO synthase (iNOS) together with L929 cells produced less NO and
displayed lower, but still significant, tumoricidal activity. Notably, NO production
and tumor lysis were abolished in co-cultures with macrophages deficient in
Interferon Regulatory Factor, IRF-1. Importantly, the in vitro
findings were reproduced in vivo as IRF-1 deficient animals
inoculated i.p with L929 cells were extremely susceptible to tumor growth and their
macrophages did not produce NO, while WT mice killed L929 tumor cells and their
macrophages produced high levels of NO. Our results indicate that IRF-1 is a master
regulator of bi-directional interaction between macrophages and tumor cells. Overall,
IRF-1 was essential for NO production by co-cultures and macrophage tumoricidal
activity in vitro as well as for the control of tumor growth
in vivo. 相似文献
92.
Increased urine podocyte‐associated messenger RNAs in severe obesity are evidence of podocyte injury 下载免费PDF全文
93.
Magna C. Paiva Marcelo P. ávila Mariana P. Reis Patrícia S. Costa Regina M. D. Nardi Andréa M. A. Nascimento 《PloS one》2015,10(6)
Bacteria are assumed to efficiently remove organic pollutants from sewage in sewage treatment plants, where antibiotic-resistance genes can move between species via mobile genetic elements known as integrons. Nevertheless, few studies have addressed bacterial diversity and class 1 integron abundance in tropical sewage. Here, we describe the extant microbiota, using V6 tag sequencing, and quantify the class 1 integron-integrase gene (intI1) in raw sewage (RS) and activated sludge (AS). The analysis of 1,174,486 quality-filtered reads obtained from RS and AS samples revealed complex and distinct bacterial diversity in these samples. The RS sample, with 3,074 operational taxonomic units, exhibited the highest alpha-diversity indices. Among the 25 phyla, Proteobacteria, Bacteroidetes and Firmicutes represented 85% (AS) and 92% (RS) of all reads. Increased relative abundance of Micrococcales, Myxococcales, and Sphingobacteriales and reduced pathogen abundance were noted in AS. At the genus level, differences were observed for the dominant genera Simplicispira and Diaphorobacter (AS) as well as for Enhydrobacter (RS). The activated sludge process decreased (55%) the amount of bacteria harboring the intI1 gene in the RS sample. Altogether, our results emphasize the importance of biological treatment for diminishing pathogenic bacteria and those bearing the intI1 gene that arrive at a sewage treatment plant. 相似文献
94.
Vanessa Carregaro José M. Ribeiro Jesus G. Valenzuela Djalma L. Souza-Júnior Diego L. Costa Carlo J. F. Oliveira Laís A. Sacramento Manuela S. L. Nascimento Cristiane M. Milanezi Fernando Q. Cunha Jo?o S. Silva 《PLoS neglected tropical diseases》2015,9(4)
Background
Sand fly saliva plays a crucial role in establishing Leishmania infection. We identified adenosine (ADO) and adenosine monophosphate (AMP) as active pharmacologic compounds present in Phlebotomus papatasi saliva that inhibit dendritic cell (DC) functions through a PGE2/IL 10-dependent mechanism.Methodology/Principal Findings
Herein, we prepared a mixture of ADO and AMP in equimolar amounts similar to those present in the salivary-gland extract (SGE) form one pair of salivary glands of P. papatasi and co-injected it with Leishmania amazonensis or L. major into mouse ears. ADO+AMP mimicked exacerbative effects of P. papatasi saliva in leishmaniasis, increasing parasite burden and cutaneous lesions. Enzymatic catabolism of salivary nucleosides reversed the SGE-induced immunosuppressive effect associated with IL-10 enhancement. Immunosuppressive factors COX2 and IL-10 were upregulated and failed to enhance ear lesion and parasite burden in IL 10-/- infected mice. Furthermore, nucleosides increased regulatory T cell (Treg) marker expression on CD4+CD25- cells, suggesting induction of Tregs on effector T cells (T eff). Treg induction (iTreg) was associated with nucleoside-induced tolerogenic dendritic cells (tDCs) expressing higher levels of COX2 and IL-10. In vitro generation of Tregs was more efficient in DCs treated with nucleosides. Suppressive effects of nucleosides during cutaneous leishmaniasis were mediated through an A2AR-dependent mechanism. Using BALB/c mice deficient in A2A ADO receptor (A2AR–/–), we showed that co-inoculated mice controlled infection, displaying lower parasite numbers at infection sites and reduced iTreg generation.Conclusion/Significance
We have demonstrated that ADO and AMP in P. papatasi saliva mediate exacerbative effects of Leishmania infection by acting preferentially on DCs promoting a tolerogenic profile in DCs and by generating iTregs in inflammatory foci through an A2AR mechanism. 相似文献95.
96.
97.
Jose MG Vilar 《BMC systems biology》2010,4(1):152
Background
Cellular responses to death-promoting stimuli typically proceed through a differentiated multistage process, involving a lag phase, extensive death, and potential adaptation. Deregulation of this chain of events is at the root of many diseases. Improper adaptation is particularly important because it allows cell sub-populations to survive even in the continuous presence of death conditions, which results, among others, in the eventual failure of many targeted anticancer therapies. 相似文献98.
Silva Ide G Moura Ado N Dantas EW Bittencourt-Oliveira Mdo C 《Revista de biología tropical》2010,58(4):1421-1436
Natural lake systems represent important reservoirs for residential water supply, fish production, recreational activities and enjoyment of their natural beauty. Nevertheless, human impacts may affect their health status resulting in degradation and loss of biodiversity. The aim of the present study was to obtain data on the health status of a natural lake located in an indigenous reservation in the Brazilian Amazon, using the phytoplankton community changes along the rainy (June) and dry (November) seasons of 2006. We collected water (temperature, pH, Secchi depth and conductivity) and phytoplankton samples from the subsurface, middle of the water column, and approximately 30 cm above the bottom, over 24-hour sampling periods, from a central station in the lake. Samples taken from biotic and abiotic variables were correlated using canonical correspondence analysis (CCA). Results showed that the lake exhibited high temperatures in both seasons, and showed thermal stratification only during the rainy season. Dissolved oxygen exhibited a clinograde pattern in the rainy season and high oxygen in the hypolimnion in the dry season. In the rainy season, the water near the bottom was acidic, turbid and had a greater concentration of phosphorus. Dissolved oxygen, conductivity, pH, nitrite, total phosphorus and total dissolved phosphorus exhibited diel variations in the rainy season, whereas water temperature, dissolved oxygen, total nitrogen and total dissolved phosphorus exhibited significant differences between hours of the day in the dry season. The phytoplankton was represented by 39 taxa, and Chlorophyta showed the greatest species richness, totaling 25 taxa. Among Chlorophyta, desmids were the most diverse, accounting 52%. Bacillariophyta (nine species) was the second most diverse group. Cyanophyta was represented by three species, including Merismopedia tenuissima, the most abundant taxon. Despite the occurrence of taxa that indicate organic pollution, their biomass and frequency indicate that the system is not currently threatened. Lake Caracaran? is an oligotrophic system, with low algal density and isolated blooming episodes due to its shallow depth. 相似文献
99.
Edleide L. da Silva Cenira M. de Carvalho Ruth R. do Nascimento Adriana L. Mendonça Carlos E. da Silva Gláucia B. Gonçalves Maria do Rosário T. de Freitas & Antônio E. G. Sant'Ana 《Ethology : formerly Zeitschrift fur Tierpsychologie》2006,112(10):971-976
The Annona fruit borer, Cerconota anonella, causes significant damage to the fruits of Annona squamosa (custard apple) and A. muricata (soursop). The methods currently available for the control of this pest are costly and new techniques, possibly involving the use of pheromones for trapping or disrupting the mating cycle of the insect are required. In order to provide the basic information required for the development of new control systems, the reproductive behaviour of the moth was observed under laboratory conditions. The calling and courtship behaviours exhibited by virgin females and males of C. anonella commenced at the eighth hour of the scotophase and continued for a 3.5‐h period. Males were attracted by conspecific females as young as 1 d old, and showed a courtship behaviour composed of three steps: antennation, wing fanning and short flights. Mating mainly occurred when both males and females were between 2 and 5 d old, but maximum activity was observed on the third day after emergence. Receptive females elevated their wings, showing their abdomens where the abdominal hairpencils were already exposed. As part of the courtship repertoire and immediately prior to copula, males performed pronounced sideways movements of their abdomens, a behaviour that appears to be exclusive to C. anonella. 相似文献
100.
Marreiro DN do Perpetuo Socorro C Martins M de Sousa SS Ibiapina V Torres S Pires LV do Nascimento Nogueira N Lima JM do Monte SJ 《Biological trace element research》2007,120(1-3):42-50
The objective of this study was to assess urinary excretion of zinc and evaluation parameters of metabolic control in type
2 diabetic patients. Thirty-one type 2 diabetic patients, of both genders, with 5.8 ± 5.6 years average time of the disease,
age range 20–60 years, were selected. Evaluation of the nutritional status was performed using anthropometric measurements.
To evaluate food consumption, the 3-day alimentary log method was used, and its analysis was performed using a software. Determination
of urinary zinc was by atomic absorption spectrophotometry. From the obtained results, it was concluded that 51.6% of the
patients were overweight. The mean of found waist circumference was 100.4 and 92.2 cm for men and women, respectively. Blood
glucose and glycated hemoglobin values were higher than reference values, and plasma albumin concentration was adequate. The
median of found urinary zinc excretion was 474.9 μg/24 h, within normal standards (300–600 μg/day). Regarding diet composition,
calorie and protein concentration were above recommendation, while mean zinc concentration was adequate. This data allow the
conclusion that the evaluated patients presented adequate urinary zinc excretion in comparison with reference values. 相似文献