Differences in the composition of the gut microbial community have been associated with diseases such as obesity, Crohn's disease, ulcerative colitis and colorectal cancer (CRC). We used 454 titanium pyrosequencing of the V1-V2 region of the 16S rRNA gene to characterize adherent bacterial communities in mucosal biopsy samples from 33 subjects with adenomas and 38 subjects without adenomas (controls). Biopsy samples from subjects with adenomas had greater numbers of bacteria from 87 taxa than controls; only 5 taxa were more abundant in control samples. The magnitude of the differences in the distal gut microbiota between patients with adenomas and controls was more pronounced than that of any other clinical parameters including obesity, diet or family history of CRC. This suggests that sequence analysis of the microbiota could be used to identify patients at risk for developing adenomas.
We report the results of pyrosequencing of DNA collected from the activated sludge basin of a wastewater treatment plant in Charlotte, NC. Using the 454-FLX technology, we generated 378,601 sequences with an average read length of 250.4 bp. Running the 454 assembly algorithm over our sequences yielded very poor assembly, with only 0.3% of our sequences participating in assembly of significant contigs. Of the 117 contigs greater than 500 bp long that were assembled, the most common annotations were to transposases and hypothetical proteins. Comparing our sequences to known microbial genomes showed nonspecific recruitment, indicating that previously described taxa are only distantly related to the most abundant microbes in this treatment plant. A comparison of proteins generated by translating our sequence set to translations of other sequenced microbiomes shows a distinct metabolic profile for activated sludge with high counts for genes involved in metabolism of aromatic compounds and low counts for genes involved in photosynthesis. Taken together, these data document the substantial levels of microbial diversity within activated sludge and further establish the great utility of pyrosequencing for investigating diversity in complex ecosystems.Although largely invisible in the urban landscape when they are functioning well, wastewater treatment plants are integral to the municipal obligation to protect public health, aquatic ecosystems, and the quality of life. At the heart of wastewater treatment plants is a process whereby a dense microbial consortium is employed to remove organic and nutrient contaminants. The microbes used to treat wastewater are a crucial tool in environmental protection. The current use of molecular techniques that do not require the isolation and cultivation of microorganisms (1, 33), including 16S rRNA analysis (6,13,20) and fluorescent in situ hybridization (8), have greatly expanded our understanding of wastewater microbial communities. Researchers have identified many bacteria of importance to wastewater treatment, including the bacteria involved in biological phosphorus removal (5, 16, 29), nitrifiers (8, 19, 25), denitrifiers (3, 12, 17), and methanogens (18, 36). Molecular techniques have also improved our understanding of fundamental processes such as nitrification and denitrification, as well as plant upsets, such as foaming (9, 24), which can decrease treatment efficiency.In this paper, we apply recently developed pyrosequencing technology to probe the molecular diversity of the aerobic basin of a wastewater treatment plant in Charlotte, NC. In line with other studies of complex microbial communities (28, 32), we observed astounding levels of diversity. We found that substantial regions of the genomes of the most prevalent microbes in the wastewater treatment plant are poorly described by existing sequence databases. Our results demonstrate that despite recent technological advances that allow identification of microorganisms, the microbial population of wastewater treatment plan...
Acute pulmonary embolism (PE) is the third leading cause of cardiovascular death in the United States. Moderate to severe PE can cause pulmonary arterial hypertension (PH) with resultant right ventricular (RV) heart damage. The mechanisms leading to RV failure after PE are not well defined, although it is becoming clear that PH-induced inflammatory responses are involved. We previously demonstrated profound neutrophil-mediated inflammation and RV dysfunction during PE that was associated with increased expression of several chemokine genes. However, a complete assessment of transcriptional changes in RVs during PE is still lacking. We have now used DNA microarrays to assess the alterations in gene expression in RV tissue during acute PE/PH in rats. Key results were confirmed with real-time RT-PCR. Nine CC-chemokine genes (CCL-2, -3, -4, -6, -7, -9, -17, -20, -27), five CXC-chemokine genes (CXCL-1, -2, -9, -10, -16), and the receptors CCR1 and CXCR4 were upregulated after 18 h of moderate PE, while one C-chemokine (XCL-1) and one CXC-chemokine (CXCL-12) were downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated increased expression of many inflammatory genes. There was also a major shift in the expression of components of metabolic pathways, including downregulation of fatty acid transporters and oxidative enzymes, a change in glucose transporters, and upregulation of stretch-sensing and hypoxia-inducible transcription factors. This pattern suggests an extensive shift in cardiac physiology favoring the expression of the "fetal gene program."
BackgroundExperimental models of pulmonary embolism (PE) that produce pulmonary hypertension (PH) employ many different methods of inducing acute pulmonary occlusion. Many of these models induce PE with intravenous injection of exogenous impervious objects that may not completely reproduce the physiological properties of autologous thromboembolism. Current literature lacks a simple, well-described rat model of autlogous PE. Objective: Test if moderate-severity autologous PE in Sprague-Dawley (SD) and Copenhagen (Cop) rats can produce persistent PH.Methodsblood was withdrawn from the jugular vein, treated with thrombin-Ca++ and re-injected following pretreatment with tranexamic acid. Hemodynamic values, clot weights and biochemical measurements were performed at 1 and 5 days.ResultsInfusion of clot significantly increased the right ventricular peak systolic pressure to 45-55 mm Hg, followed by normalization within 24 hours in SD rats, and within 5 days in COP rats. Clot lysis was 95% (24 hours) and 97% (5 days) in SD rats and was significantly lower in COP rats (70%, 24 hours; 87% 5 days). Plasma D-dimer was elevated in surgical sham animals and was further increased 8 hours after pulmonary embolism. Neither strain showed a significant increase in bronchoalveolar chemotactic activity, myeloperoxidase activity, leukocyte infiltration, or chemokine accumulation, indicating that there was no significant pulmonary inflammation.ConclusionsBoth SD and COP rats exhibited near complete fibrinolysis of autologous clot PE within 5 days. Neither strain developed persistent PH. Experimental models of PE designed to induce sustained PH and a robust inflammatory response appear to require significant, persistent pulmonary vascular occlusion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.